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Sample records for two-stage epidemiological study

  1. A two-stage epidemiological study of eating disorders and muscle dysmorphia in male university students in Buenos Aires.

    Science.gov (United States)

    Compte, Emilio J; Sepulveda, Ana R; Torrente, Fernando

    2015-12-01

    Studies using traditional screening instruments tend to report a lower prevalence of eating disorders (EDs) in men than is observed in women. It is therefore unclear whether such instruments are valid for the assessment of ED in males. Lack of a formal diagnostic definition of muscle dysmorphia syndrome (MD) makes it difficult to identify men at risk. The study aimed to assess the prevalence of ED and MD in male university students of Buenos Aires. A cross-sectional, two-stage, representative survey was of 472 male students from six different schools in Buenos Aires, mostly aged between 18 and 28 years. The first stage involved administration of self-report questionnaires (Eating Attitude Test-26; scores ≥15 indicate "at risk" status). In Stage 2 students at risk of developing EDs were evaluated with a clinical interview, the Eating Disorder Examination (EDE; 12th edition). Two control students were interviewed for every at risk student. The prevalence of EDs among university male students was 1.9% (n = 9). All participants with an ED presented with illness classified as eating disorder not otherwise specified (EDNOS). Using the Drive for Muscularity Scale (DMS) with a 52-point threshold we identified possible MD in 6.99% (n = 33) of the sample. The prevalence of ED detected in this study is comparable with previous findings in male populations, and below that observed in female populations. However, the prevalence of possible cases of MD resembles the total rate of EDs in women. Characteristics associated with EDs and MD in men are also discussed. © 2015 Wiley Periodicals, Inc.

  2. 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.

  3. Epidemiological Study of Heart Failure in China

    Directory of Open Access Journals (Sweden)

    Yang Guo

    2015-10-01

    Full Text Available Heart failure (HF is a complex clinical syndrome that results from any structural or functional impairment of ventricular filling or ejection of blood. HF is one of the most important and severe end stages of many cardiovascular diseases. Epidemiological studies of HF have focused mainly on the prevalence, incidence, mortality, fatality, and distribution and temporal trends of these indicators among different populations. This review highlights important epidemiological studies of HF in China.

  4. 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

  5. Optics of two-stage photovoltaic concentrators with dielectric second stages

    Science.gov (United States)

    Ning, Xiaohui; O'Gallagher, Joseph; Winston, Roland

    1987-04-01

    Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

  6. Optics of two-stage photovoltaic concentrators with dielectric second stages.

    Science.gov (United States)

    Ning, X; O'Gallagher, J; Winston, R

    1987-04-01

    Two-stage photovoltaic concentrators with Fresnel lenses as primaries and dielectric totally internally reflecting nonimaging concentrators as secondaries are discussed. The general design principles of such two-stage systems are given. Their optical properties are studied and analyzed in detail using computer ray trace procedures. It is found that the two-stage concentrator offers not only a higher concentration or increased acceptance angle, but also a more uniform flux distribution on the photovoltaic cell than the point focusing Fresnel lens alone. Experimental measurements with a two-stage prototype module are presented and compared to the analytical predictions.

  7. Epidemiologic study of end stage renal disease and related risk factors in patients under hemodialysis in Lorestan province

    Directory of Open Access Journals (Sweden)

    babak Hadian

    2015-01-01

    Full Text Available Background: Prevalence of End Stage Renal Disease (ESRD is increasing in the world. Because of clinical importance of ESRD and absence of significant data, we studied the epidemiology of end stage renal failure in patients under hemodialysis in Lorestan province. Material and methods: This descriptive cross sectional study was carried out between January 2012 and January 2013 in dialysis centers of Lorestan university of medical sciences .Subject were selected by census method and data galhered using a questionnaire. At the end, collected data were analyzed by SPSS software, descriptive statistics and Chi-square test. Results: All the patients under hemodialysis were 318 cases, 182 out of them (57.2% and 136(42.8% were male and female respectively. The mean age of the subjects was 53.2± 16.4 years. The cause of renal failure in 38.1% of the patients were hypertension, diabetes (19.2% and unknown factors (27.4%. As well as 5.97% of the patients infected by HCV, HBV or HIV . A significant statistical difference was observed between causes of chronic renal failure and different ages of the subjects (p=0.002. Conclusion: Augmentation of screening programs and especially, early referral of high risk subjects to nephrologists is recommended for prevention of end stage renal disease.

  8. Composite likelihood and two-stage estimation in family studies

    DEFF Research Database (Denmark)

    Andersen, Elisabeth Anne Wreford

    2004-01-01

    In this paper register based family studies provide the motivation for linking a two-stage estimation procedure in copula models for multivariate failure time data with a composite likelihood approach. The asymptotic properties of the estimators in both parametric and semi-parametric models are d...

  9. Experimental and numerical studies on two-stage combustion of biomass

    Energy Technology Data Exchange (ETDEWEB)

    Houshfar, Eshan

    2012-07-01

    In this thesis, two-stage combustion of biomass was experimentally/numerically investigated in a multifuel reactor. The following emissions issues have been the main focus of the work: 1- NOx and N2O 2- Unburnt species (CO and CxHy) 3- Corrosion related emissions.The study had a focus on two-stage combustion in order to reduce pollutant emissions (primarily NOx emissions). It is well known that pollutant emissions are very dependent on the process conditions such as temperature, reactant concentrations and residence times. On the other hand, emissions are also dependent on the fuel properties (moisture content, volatiles, alkali content, etc.). A detailed study of the important parameters with suitable biomass fuels in order to optimize the various process conditions was performed. Different experimental studies were carried out on biomass fuels in order to study the effect of fuel properties and combustion parameters on pollutant emissions. Process conditions typical for biomass combustion processes were studied. Advanced experimental equipment was used in these studies. The experiments showed the effects of staged air combustion, compared to non-staged combustion, on the emission levels clearly. A NOx reduction of up to 85% was reached with staged air combustion using demolition wood as fuel. An optimum primary excess air ratio of 0.8-0.95 was found as a minimizing parameter for the NOx emissions for staged air combustion. Air staging had, however, a negative effect on N2O emissions. Even though the trends showed a very small reduction in the NOx level as temperature increased for non-staged combustion, the effect of temperature was not significant for NOx and CxHy, neither in staged air combustion or non-staged combustion, while it had a great influence on the N2O and CO emissions, with decreasing levels with increasing temperature. Furthermore, flue gas recirculation (FGR) was used in combination with staged combustion to obtain an enhanced NOx reduction. The

  10. Empirical study of classification process for two-stage turbo air classifier in series

    Science.gov (United States)

    Yu, Yuan; Liu, Jiaxiang; Li, Gang

    2013-05-01

    The suitable process parameters for a two-stage turbo air classifier are important for obtaining the ultrafine powder that has a narrow particle-size distribution, however little has been published internationally on the classification process for the two-stage turbo air classifier in series. The influence of the process parameters of a two-stage turbo air classifier in series on classification performance is empirically studied by using aluminum oxide powders as the experimental material. The experimental results show the following: 1) When the rotor cage rotary speed of the first-stage classifier is increased from 2 300 r/min to 2 500 r/min with a constant rotor cage rotary speed of the second-stage classifier, classification precision is increased from 0.64 to 0.67. However, in this case, the final ultrafine powder yield is decreased from 79% to 74%, which means the classification precision and the final ultrafine powder yield can be regulated through adjusting the rotor cage rotary speed of the first-stage classifier. 2) When the rotor cage rotary speed of the second-stage classifier is increased from 2 500 r/min to 3 100 r/min with a constant rotor cage rotary speed of the first-stage classifier, the cut size is decreased from 13.16 μm to 8.76 μm, which means the cut size of the ultrafine powder can be regulated through adjusting the rotor cage rotary speed of the second-stage classifier. 3) When the feeding speed is increased from 35 kg/h to 50 kg/h, the "fish-hook" effect is strengthened, which makes the ultrafine powder yield decrease. 4) To weaken the "fish-hook" effect, the equalization of the two-stage wind speeds or the combination of a high first-stage wind speed with a low second-stage wind speed should be selected. This empirical study provides a criterion of process parameter configurations for a two-stage or multi-stage classifier in series, which offers a theoretical basis for practical production.

  11. Two-stage anaerobic digestion of cheese whey

    Energy Technology Data Exchange (ETDEWEB)

    Lo, K V; Liao, P H

    1986-01-01

    A two-stage digestion of cheese whey was studied using two anaerobic rotating biological contact reactors. The second-stage reactor receiving partially treated effluent from the first-stage reactor could be operated at a hydraulic retention time of one day. The results indicated that two-stage digestion is a feasible alternative for treating whey. 6 references.

  12. Combining evidence from multiple electronic health care databases: performances of one-stage and two-stage meta-analysis in matched case-control studies.

    Science.gov (United States)

    La Gamba, Fabiola; Corrao, Giovanni; Romio, Silvana; Sturkenboom, Miriam; Trifirò, Gianluca; Schink, Tania; de Ridder, Maria

    2017-10-01

    Clustering of patients in databases is usually ignored in one-stage meta-analysis of multi-database studies using matched case-control data. The aim of this study was to compare bias and efficiency of such a one-stage meta-analysis with a two-stage meta-analysis. First, we compared the approaches by generating matched case-control data under 5 simulated scenarios, built by varying: (1) the exposure-outcome association; (2) its variability among databases; (3) the confounding strength of one covariate on this association; (4) its variability; and (5) the (heterogeneous) confounding strength of two covariates. Second, we made the same comparison using empirical data from the ARITMO project, a multiple database study investigating the risk of ventricular arrhythmia following the use of medications with arrhythmogenic potential. In our study, we specifically investigated the effect of current use of promethazine. Bias increased for one-stage meta-analysis with increasing (1) between-database variance of exposure effect and (2) heterogeneous confounding generated by two covariates. The efficiency of one-stage meta-analysis was slightly lower than that of two-stage meta-analysis for the majority of investigated scenarios. Based on ARITMO data, there were no evident differences between one-stage (OR = 1.50, CI = [1.08; 2.08]) and two-stage (OR = 1.55, CI = [1.12; 2.16]) approaches. When the effect of interest is heterogeneous, a one-stage meta-analysis ignoring clustering gives biased estimates. Two-stage meta-analysis generates estimates at least as accurate and precise as one-stage meta-analysis. However, in a study using small databases and rare exposures and/or outcomes, a correct one-stage meta-analysis becomes essential. Copyright © 2017 John Wiley & Sons, Ltd.

  13. Bias due to two-stage residual-outcome regression analysis in genetic association studies.

    Science.gov (United States)

    Demissie, Serkalem; Cupples, L Adrienne

    2011-11-01

    Association studies of risk factors and complex diseases require careful assessment of potential confounding factors. Two-stage regression analysis, sometimes referred to as residual- or adjusted-outcome analysis, has been increasingly used in association studies of single nucleotide polymorphisms (SNPs) and quantitative traits. In this analysis, first, a residual-outcome is calculated from a regression of the outcome variable on covariates and then the relationship between the adjusted-outcome and the SNP is evaluated by a simple linear regression of the adjusted-outcome on the SNP. In this article, we examine the performance of this two-stage analysis as compared with multiple linear regression (MLR) analysis. Our findings show that when a SNP and a covariate are correlated, the two-stage approach results in biased genotypic effect and loss of power. Bias is always toward the null and increases with the squared-correlation between the SNP and the covariate (). For example, for , 0.1, and 0.5, two-stage analysis results in, respectively, 0, 10, and 50% attenuation in the SNP effect. As expected, MLR was always unbiased. Since individual SNPs often show little or no correlation with covariates, a two-stage analysis is expected to perform as well as MLR in many genetic studies; however, it produces considerably different results from MLR and may lead to incorrect conclusions when independent variables are highly correlated. While a useful alternative to MLR under , the two -stage approach has serious limitations. Its use as a simple substitute for MLR should be avoided. © 2011 Wiley Periodicals, Inc.

  14. Two-stage revision of septic knee prosthesis with articulating knee spacers yields better infection eradication rate than one-stage or two-stage revision with static spacers.

    Science.gov (United States)

    Romanò, C L; Gala, L; Logoluso, N; Romanò, D; Drago, L

    2012-12-01

    The best method for treating chronic periprosthetic knee infection remains controversial. Randomized, comparative studies on treatment modalities are lacking. This systematic review of the literature compares the infection eradication rate after two-stage versus one-stage revision and static versus articulating spacers in two-stage procedures. We reviewed full-text papers and those with an abstract in English published from 1966 through 2011 that reported the success rate of infection eradication after one-stage or two-stage revision with two different types of spacers. In all, 6 original articles reporting the results after one-stage knee exchange arthoplasty (n = 204) and 38 papers reporting on two-stage revision (n = 1,421) were reviewed. The average success rate in the eradication of infection was 89.8% after a two-stage revision and 81.9% after a one-stage procedure at a mean follow-up of 44.7 and 40.7 months, respectively. The average infection eradication rate after a two-stage procedure was slightly, although significantly, higher when an articulating spacer rather than a static spacer was used (91.2 versus 87%). The methodological limitations of this study and the heterogeneous material in the studies reviewed notwithstanding, this systematic review shows that, on average, a two-stage procedure is associated with a higher rate of eradication of infection than one-stage revision for septic knee prosthesis and that articulating spacers are associated with a lower recurrence of infection than static spacers at a comparable mean duration of follow-up. IV.

  15. SUCCESS FACTORS IN GROWING SMBs: A STUDY OF TWO INDUSTRIES AT TWO STAGES OF DEVELOPMENT

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    Tor Jarl Trondsen

    2002-01-01

    Full Text Available The study attempts to identify factors for growing SMBs. An evolutionary phase approach has been used. The study also aims to find out if there are common and different denominators for newer and older firms that can affect their profitability. The study selects a sampling frame that isolates two groups of firms in two industries at two stages of development. A variety of organizational and structural data was collected and analyzed. Amongst the conclusions that may be drawn from the study are that it is not easy to find a common definition of success, it is important to stratify SMBs when studying them, an evolutionary stage approach helps to compare firms with roughly the same external and internal dynamics and each industry has its own set of success variables.The study has identified three success variables for older firms that reflect contemporary strategic thinking such as crafting a good strategy and changing it only incrementally, building core competencies and outsourcing the rest, and keeping up with innovation and honing competitive skills.

  16. Two stages of economic development

    OpenAIRE

    Gong, Gang

    2016-01-01

    This study suggests that the development process of a less-developed country can be divided into two stages, which demonstrate significantly different properties in areas such as structural endowments, production modes, income distribution, and the forces that drive economic growth. The two stages of economic development have been indicated in the growth theory of macroeconomics and in the various "turning point" theories in development economics, including Lewis's dual economy theory, Kuznet...

  17. 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

  18. Meta-analysis of Gaussian individual patient data: Two-stage or not two-stage?

    Science.gov (United States)

    Morris, Tim P; Fisher, David J; Kenward, Michael G; Carpenter, James R

    2018-04-30

    Quantitative evidence synthesis through meta-analysis is central to evidence-based medicine. For well-documented reasons, the meta-analysis of individual patient data is held in higher regard than aggregate data. With access to individual patient data, the analysis is not restricted to a "two-stage" approach (combining estimates and standard errors) but can estimate parameters of interest by fitting a single model to all of the data, a so-called "one-stage" analysis. There has been debate about the merits of one- and two-stage analysis. Arguments for one-stage analysis have typically noted that a wider range of models can be fitted and overall estimates may be more precise. The two-stage side has emphasised that the models that can be fitted in two stages are sufficient to answer the relevant questions, with less scope for mistakes because there are fewer modelling choices to be made in the two-stage approach. For Gaussian data, we consider the statistical arguments for flexibility and precision in small-sample settings. Regarding flexibility, several of the models that can be fitted only in one stage may not be of serious interest to most meta-analysis practitioners. Regarding precision, we consider fixed- and random-effects meta-analysis and see that, for a model making certain assumptions, the number of stages used to fit this model is irrelevant; the precision will be approximately equal. Meta-analysts should choose modelling assumptions carefully. Sometimes relevant models can only be fitted in one stage. Otherwise, meta-analysts are free to use whichever procedure is most convenient to fit the identified model. © 2018 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

  19. The household contact study design for genetic epidemiological studies of infectious diseases

    Directory of Open Access Journals (Sweden)

    Catherine eStein

    2013-04-01

    Full Text Available Most genetic epidemiological study designs fall into one of two categories: family-based and population-based (case-control. However, recent advances in statistical genetics call for study designs that combine these two approaches. We describe the household contact study design as we have applied it in our several years of study of the epidemiology of tuberculosis. Though we highlight its applicability for genetic epidemiological studies of infectious diseases, there are many facets of this design that are appealing for modern genetic studies, including the simultaneous enrollment of related and unrelated individuals, closely and distantly related individuals, collection of extensive epidemiologic and phenotypic data, and evaluation of effects of shared environment and gene by environment interaction. These study design characteristics are particularly appealing for current sequencing studies.

  20. Profile of an epidemiological study of urinary schistosomiasis in two ...

    African Journals Online (AJOL)

    Aim: This study was conducted in an attempt to establish the prevalence of urinary schistosomiasis in relation to epidemiological factors among children in Buruku and Katsina-Ala local government areas, Benue, Nigeria. Materials and Methods: Urine filtration technique using polycarbonate membrane filters was employed ...

  1. 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.

  2. 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.

  3. Evaluation of epidemiological studies

    International Nuclear Information System (INIS)

    Breckow, J.

    1995-01-01

    The publication is intended for readers with a professional background in radiation protection who are not experts in the field of epidemiology. The potentials and the limits of epidemiology are shown and concepts and terminology of radioepidemilogic studies as well as epidemiology in general are explained, in order to provide the necessary basis for understanding or performing evaluations of epidemiologic studies. (orig./VHE) [de

  4. Profile of an epidemiological study of urinary schistosomiasis in two ...

    African Journals Online (AJOL)

    McRoy

    schistosomiasis in relation to epidemiological factors among children in Buruku ... [5]. Praziquantel has been adopted as the drug of choice for control strategy by the .... are low literacy, presence of infested water bodies .... rate of 38.2% found in the 8-12 years in this study ... maturity and abundance of the snail vectors.

  5. One-stage and two-stage penile buccal mucosa urethroplasty

    Directory of Open Access Journals (Sweden)

    G. Barbagli

    2016-03-01

    Full Text Available The paper provides the reader with the detailed description of current techniques of one-stage and two-stage penile buccal mucosa urethroplasty. The paper provides the reader with the preoperative patient evaluation paying attention to the use of diagnostic tools. The one-stage penile urethroplasty using buccal mucosa graft with the application of glue is preliminary showed and discussed. Two-stage penile urethroplasty is then reported. A detailed description of first-stage urethroplasty according Johanson technique is reported. A second-stage urethroplasty using buccal mucosa graft and glue is presented. Finally postoperative course and follow-up are addressed.

  6. One-stage versus two-stage exchange arthroplasty for infected total knee arthroplasty: a systematic review.

    Science.gov (United States)

    Nagra, Navraj S; Hamilton, Thomas W; Ganatra, Sameer; Murray, David W; Pandit, Hemant

    2016-10-01

    Infection complicating total knee arthroplasty (TKA) has serious implications. Traditionally the debate on whether one- or two-stage exchange arthroplasty is the optimum management of infected TKA has favoured two-stage procedures; however, a paradigm shift in opinion is emerging. This study aimed to establish whether current evidence supports one-stage revision for managing infected TKA based on reinfection rates and functional outcomes post-surgery. MEDLINE/PubMed and CENTRAL databases were reviewed for studies that compared one- and two-stage exchange arthroplasty TKA in more than ten patients with a minimum 2-year follow-up. From an initial sample of 796, five cohort studies with a total of 231 patients (46 single-stage/185 two-stage; median patient age 66 years, range 61-71 years) met inclusion criteria. Overall, there were no significant differences in risk of reinfection following one- or two-stage exchange arthroplasty (OR -0.06, 95 % confidence interval -0.13, 0.01). Subgroup analysis revealed that in studies published since 2000, one-stage procedures have a significantly lower reinfection rate. One study investigated functional outcomes and reported that one-stage surgery was associated with superior functional outcomes. Scarcity of data, inconsistent study designs, surgical technique and antibiotic regime disparities limit recommendations that can be made. Recent studies suggest one-stage exchange arthroplasty may provide superior outcomes, including lower reinfection rates and superior function, in select patients. Clinically, for some patients, one-stage exchange arthroplasty may represent optimum treatment; however, patient selection criteria and key components of surgical and post-operative anti-microbial management remain to be defined. III.

  7. Two-stage implant systems.

    Science.gov (United States)

    Fritz, M E

    1999-06-01

    Since the advent of osseointegration approximately 20 years ago, there has been a great deal of scientific data developed on two-stage integrated implant systems. Although these implants were originally designed primarily for fixed prostheses in the mandibular arch, they have been used in partially dentate patients, in patients needing overdentures, and in single-tooth restorations. In addition, this implant system has been placed in extraction sites, in bone-grafted areas, and in maxillary sinus elevations. Often, the documentation of these procedures has lagged. In addition, most of the reports use survival criteria to describe results, often providing overly optimistic data. It can be said that the literature describes a true adhesion of the epithelium to the implant similar to adhesion to teeth, that two-stage implants appear to have direct contact somewhere between 50% and 70% of the implant surface, that the microbial flora of the two-stage implant system closely resembles that of the natural tooth, and that the microbiology of periodontitis appears to be closely related to peri-implantitis. In evaluations of the data from implant placement in all of the above-noted situations by means of meta-analysis, it appears that there is a strong case that two-stage dental implants are successful, usually showing a confidence interval of over 90%. It also appears that the mandibular implants are more successful than maxillary implants. Studies also show that overdenture therapy is valid, and that single-tooth implants and implants placed in partially dentate mouths have a success rate that is quite good, although not quite as high as in the fully edentulous dentition. It would also appear that the potential causes of failure in the two-stage dental implant systems are peri-implantitis, placement of implants in poor-quality bone, and improper loading of implants. There are now data addressing modifications of the implant surface to alter the percentage of

  8. Single-stage-to-orbit versus two-stage-two-orbit: A cost perspective

    Science.gov (United States)

    Hamaker, Joseph W.

    1996-03-01

    This paper considers the possible life-cycle costs of single-stage-to-orbit (SSTO) and two-stage-to-orbit (TSTO) reusable launch vehicles (RLV's). The analysis parametrically addresses the issue such that the preferred economic choice comes down to the relative complexity of the TSTO compared to the SSTO. The analysis defines the boundary complexity conditions at which the two configurations have equal life-cycle costs, and finally, makes a case for the economic preference of SSTO over TSTO.

  9. Mental health problems in Austrian adolescents: a nationwide, two-stage epidemiological study applying DSM-5 criteria.

    Science.gov (United States)

    Wagner, Gudrun; Zeiler, Michael; Waldherr, Karin; Philipp, Julia; Truttmann, Stefanie; Dür, Wolfgang; Treasure, Janet L; Karwautz, Andreas F K

    2017-12-01

    This is a nationwide epidemiological study using DSM-5 criteria to assess the prevalence of mental disorders in a large sample of Austrian adolescents between 10 and 18 years including hard-to-reach samples. A sample of 3615 adolescents from four cohorts (school grades 5, 7, 9, 11; age range 10-18 years) was recruited from 261 schools, samples of unemployed adolescents (n = 39) and adolescents from mental health institutions (n = 137) were added. The Youth Self-Report and SCOFF were used to screen for mental health problems. In a second phase, the Childrens' Diagnostic Interview for Mental Disorders was used to make point and lifetime psychiatric diagnoses. Mental health service use was also assessed. Point prevalence and lifetime prevalence rates for at least one psychiatric disorder were 23.9% and 35.8%. The highest lifetime prevalence rates were found for anxiety disorders (15.6%), neurodevelopmental disorders (9.3%; ADHD 5.2%) and depressive disorders (6.2%). Forty-seven percent of adolescents with a lifetime psychiatric disorder had a second diagnosis. Internalising disorders were more prevalent in girls, while neurodevelopmental disorders and disruptive, impulse control and conduct disorders were more prevalent in boys. Of those with a lifetime psychiatric disorder, 47.5% had contacted mental health services. Of the residual 52.5% who had not contacted mental health services, 18.1% expressed an interest in treatment. DSM-5 mental health disorders are highly prevalent among Austrian adolescents. Over 50% had or were interested in accessing treatment. Early access to effective interventions for these problems is needed to reduce burden due to mental health disorders.

  10. On bi-criteria two-stage transportation problem: a case study

    Directory of Open Access Journals (Sweden)

    Ahmad MURAD

    2010-01-01

    Full Text Available The study of the optimum distribution of goods between sources and destinations is one of the important topics in projects economics. This importance comes as a result of minimizing the transportation cost, deterioration, time, etc. The classical transportation problem constitutes one of the major areas of application for linear programming. The aim of this problem is to obtain the optimum distribution of goods from different sources to different destinations which minimizes the total transportation cost. From the practical point of view, the transportation problems may differ from the classical form. It may contain one or more objective function, one or more stage to transport, one or more type of commodity with one or more means of transport. The aim of this paper is to construct an optimization model for transportation problem for one of mill-stones companies. The model is formulated as a bi-criteria two-stage transportation problem with a special structure depending on the capacities of suppliers, warehouses and requirements of the destinations. A solution algorithm is introduced to solve this class of bi-criteria two-stage transportation problem to obtain the set of non-dominated extreme points and the efficient solutions accompanied with each one that enables the decision maker to choose the best one. The solution algorithm mainly based on the fruitful application of the methods for treating transportation problems, theory of duality of linear programming and the methods of solving bi-criteria linear programming problems.

  11. Comparisons of single-stage and two-stage approaches to genomic selection.

    Science.gov (United States)

    Schulz-Streeck, Torben; Ogutu, Joseph O; Piepho, Hans-Peter

    2013-01-01

    Genomic selection (GS) is a method for predicting breeding values of plants or animals using many molecular markers that is commonly implemented in two stages. In plant breeding the first stage usually involves computation of adjusted means for genotypes which are then used to predict genomic breeding values in the second stage. We compared two classical stage-wise approaches, which either ignore or approximate correlations among the means by a diagonal matrix, and a new method, to a single-stage analysis for GS using ridge regression best linear unbiased prediction (RR-BLUP). The new stage-wise method rotates (orthogonalizes) the adjusted means from the first stage before submitting them to the second stage. This makes the errors approximately independently and identically normally distributed, which is a prerequisite for many procedures that are potentially useful for GS such as machine learning methods (e.g. boosting) and regularized regression methods (e.g. lasso). This is illustrated in this paper using componentwise boosting. The componentwise boosting method minimizes squared error loss using least squares and iteratively and automatically selects markers that are most predictive of genomic breeding values. Results are compared with those of RR-BLUP using fivefold cross-validation. The new stage-wise approach with rotated means was slightly more similar to the single-stage analysis than the classical two-stage approaches based on non-rotated means for two unbalanced datasets. This suggests that rotation is a worthwhile pre-processing step in GS for the two-stage approaches for unbalanced datasets. Moreover, the predictive accuracy of stage-wise RR-BLUP was higher (5.0-6.1%) than that of componentwise boosting.

  12. Two-stage free electron laser research

    Science.gov (United States)

    Segall, S. B.

    1984-10-01

    KMS Fusion, Inc. began studying the feasibility of two-stage free electron lasers for the Office of Naval Research in June, 1980. At that time, the two-stage FEL was only a concept that had been proposed by Luis Elias. The range of parameters over which such a laser could be successfully operated, attainable power output, and constraints on laser operation were not known. The primary reason for supporting this research at that time was that it had the potential for producing short-wavelength radiation using a relatively low voltage electron beam. One advantage of a low-voltage two-stage FEL would be that shielding requirements would be greatly reduced compared with single-stage short-wavelength FEL's. If the electron energy were kept below about 10 MeV, X-rays, generated by electrons striking the beam line wall, would not excite neutron resonance in atomic nuclei. These resonances cause the emission of neutrons with subsequent induced radioactivity. Therefore, above about 10 MeV, a meter or more of concrete shielding is required for the system, whereas below 10 MeV, a few millimeters of lead would be adequate.

  13. Design considerations for single-stage and two-stage pneumatic pellet injectors

    International Nuclear Information System (INIS)

    Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

    1988-09-01

    Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs

  14. Two-Stage Series-Resonant Inverter

    Science.gov (United States)

    Stuart, Thomas A.

    1994-01-01

    Two-stage inverter includes variable-frequency, voltage-regulating first stage and fixed-frequency second stage. Lightweight circuit provides regulated power and is invulnerable to output short circuits. Does not require large capacitor across ac bus, like parallel resonant designs. Particularly suitable for use in ac-power-distribution system of aircraft.

  15. Frequency analysis of a two-stage planetary gearbox using two different methodologies

    Science.gov (United States)

    Feki, Nabih; Karray, Maha; Khabou, Mohamed Tawfik; Chaari, Fakher; Haddar, Mohamed

    2017-12-01

    This paper is focused on the characterization of the frequency content of vibration signals issued from a two-stage planetary gearbox. To achieve this goal, two different methodologies are adopted: the lumped-parameter modeling approach and the phenomenological modeling approach. The two methodologies aim to describe the complex vibrations generated by a two-stage planetary gearbox. The phenomenological model describes directly the vibrations as measured by a sensor fixed outside the fixed ring gear with respect to an inertial reference frame, while results from a lumped-parameter model are referenced with respect to a rotating frame and then transferred into an inertial reference frame. Two different case studies of the two-stage planetary gear are adopted to describe the vibration and the corresponding spectra using both models. Each case presents a specific geometry and a specific spectral structure.

  16. A Two-Stage Penalized Logistic Regression Approach to Case-Control Genome-Wide Association Studies

    Directory of Open Access Journals (Sweden)

    Jingyuan Zhao

    2012-01-01

    Full Text Available We propose a two-stage penalized logistic regression approach to case-control genome-wide association studies. This approach consists of a screening stage and a selection stage. In the screening stage, main-effect and interaction-effect features are screened by using L1-penalized logistic like-lihoods. In the selection stage, the retained features are ranked by the logistic likelihood with the smoothly clipped absolute deviation (SCAD penalty (Fan and Li, 2001 and Jeffrey’s Prior penalty (Firth, 1993, a sequence of nested candidate models are formed, and the models are assessed by a family of extended Bayesian information criteria (J. Chen and Z. Chen, 2008. The proposed approach is applied to the analysis of the prostate cancer data of the Cancer Genetic Markers of Susceptibility (CGEMS project in the National Cancer Institute, USA. Simulation studies are carried out to compare the approach with the pair-wise multiple testing approach (Marchini et al. 2005 and the LASSO-patternsearch algorithm (Shi et al. 2007.

  17. On the robustness of two-stage estimators

    KAUST Repository

    Zhelonkin, Mikhail

    2012-04-01

    The aim of this note is to provide a general framework for the analysis of the robustness properties of a broad class of two-stage models. We derive the influence function, the change-of-variance function, and the asymptotic variance of a general two-stage M-estimator, and provide their interpretations. We illustrate our results in the case of the two-stage maximum likelihood estimator and the two-stage least squares estimator. © 2011.

  18. Sensitivity Analysis in Two-Stage DEA

    Directory of Open Access Journals (Sweden)

    Athena Forghani

    2015-07-01

    Full Text Available Data envelopment analysis (DEA is a method for measuring the efficiency of peer decision making units (DMUs which uses a set of inputs to produce a set of outputs. In some cases, DMUs have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. One important issue in two-stage DEA is the sensitivity of the results of an analysis to perturbations in the data. The current paper looks into combined model for two-stage DEA and applies the sensitivity analysis to DMUs on the entire frontier. In fact, necessary and sufficient conditions for preserving a DMU's efficiency classiffication are developed when various data changes are applied to all DMUs.

  19. Sensitivity Analysis in Two-Stage DEA

    Directory of Open Access Journals (Sweden)

    Athena Forghani

    2015-12-01

    Full Text Available Data envelopment analysis (DEA is a method for measuring the efficiency of peer decision making units (DMUs which uses a set of inputs to produce a set of outputs. In some cases, DMUs have a two-stage structure, in which the first stage utilizes inputs to produce outputs used as the inputs of the second stage to produce final outputs. One important issue in two-stage DEA is the sensitivity of the results of an analysis to perturbations in the data. The current paper looks into combined model for two-stage DEA and applies the sensitivity analysis to DMUs on the entire frontier. In fact, necessary and sufficient conditions for preserving a DMU's efficiency classiffication are developed when various data changes are applied to all DMUs.

  20. Evaluating the Validity of a Two-stage Sample in a Birth Cohort Established from Administrative Databases.

    Science.gov (United States)

    El-Zein, Mariam; Conus, Florence; Benedetti, Andrea; Parent, Marie-Elise; Rousseau, Marie-Claude

    2016-01-01

    When using administrative databases for epidemiologic research, a subsample of subjects can be interviewed, eliciting information on undocumented confounders. This article presents a thorough investigation of the validity of a two-stage sample encompassing an assessment of nonparticipation and quantification of the extent of bias. Established through record linkage of administrative databases, the Québec Birth Cohort on Immunity and Health (n = 81,496) aims to study the association between Bacillus Calmette-Guérin vaccination and asthma. Among 76,623 subjects classified in four Bacillus Calmette-Guérin-asthma strata, a two-stage sampling strategy with a balanced design was used to randomly select individuals for interviews. We compared stratum-specific sociodemographic characteristics and healthcare utilization of stage 2 participants (n = 1,643) with those of eligible nonparticipants (n = 74,980) and nonrespondents (n = 3,157). We used logistic regression to determine whether participation varied across strata according to these characteristics. The effect of nonparticipation was described by the relative odds ratio (ROR = ORparticipants/ORsource population) for the association between sociodemographic characteristics and asthma. Parental age at childbirth, area of residence, family income, and healthcare utilization were comparable between groups. Participants were slightly more likely to be women and have a mother born in Québec. Participation did not vary across strata by sex, parental birthplace, or material and social deprivation. Estimates were not biased by nonparticipation; most RORs were below one and bias never exceeded 20%. Our analyses evaluate and provide a detailed demonstration of the validity of a two-stage sample for researchers assembling similar research infrastructures.

  1. Two stage-type railgun accelerator

    International Nuclear Information System (INIS)

    Ogino, Mutsuo; Azuma, Kingo.

    1995-01-01

    The present invention provides a two stage-type railgun accelerator capable of spiking a flying body (ice pellet) formed by solidifying a gaseous hydrogen isotope as a fuel to a thermonuclear reactor at a higher speed into a central portion of plasmas. Namely, the two stage-type railgun accelerator accelerates the flying body spiked from a initial stage accelerator to a portion between rails by Lorentz force generated when electric current is supplied to the two rails by way of a plasma armature. In this case, two sets of solenoids are disposed for compressing the plasma armature in the longitudinal direction of the rails. The first and the second sets of solenoid coils are previously supplied with electric current. After passing of the flying body, the armature formed into plasmas by a gas laser disposed at the back of the flying body is compressed in the longitudinal direction of the rails by a magnetic force of the first and the second sets of solenoid coils to increase the plasma density. A current density is also increased simultaneously. Then, the first solenoid coil current is turned OFF to accelerate the flying body in two stages by the compressed plasma armature. (I.S.)

  2. Analysis of the epidemiological profile, staging and survival of patients diagnosed with gastric cancer at the Hospital San Juan de Dios during 2004

    International Nuclear Information System (INIS)

    Moreira Vasquez, Christian

    2012-01-01

    The gastric cancer has been the second most common cause of death associated with cancer mortality worldwide; Costa Rica ranks second worldwide. The detection and treatment of this disease in early stages have been vital to reduce mortality so elevated that has been presented. A review of the literature on the subject is performed: epidemiology, risk factors, diagnostic methods, staging and therapeutic options. Survival at 5 years and epidemiological profile are analyzed with gastric cancer patients diagnosed at the Hospital San Juan de Dios during the year 2004 [es

  3. 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)

  4. Changes in clinical presentation and staging of lung cancer over two decades.

    Science.gov (United States)

    Leiro-Fernández, Virginia; Mouronte-Roibás, Cecilia; Ramos-Hernández, Cristina; Botana-Rial, Maribel; González-Piñeiro, Ana; García-Rodríguez, Esmeralda; Represas-Represas, Cristina; Fernández-Villar, Alberto

    2014-10-01

    Important clinical and epidemiological changes have been observed in lung cancer (LC) in our healthcare area compared to the previous decade. In the last 10 years, specific LC care circuits have been implemented and the active search for cases has been stepped up. The aim of this study was to analyze the progress of these changes over the last 20 years. This is a retrospective study comparing clinical and epidemiological changes between 2 historical cohorts of LC patients (1992-1994 [group 1, 164 patients] and 2004-2006 [group 2, 250 patients]) and a current group from the period 2011-2012 (group 3, 209 patients) Two hundred and nine (209) LC patients were included in group 3 (2011-2012 period). After comparing groups 3 and 2, a non-significant rise in smoking was observed in women (59% vs 41%, p=.25), while the prevalence of adenocarcinoma was unchanged (45% vs 44%, p=.9). The main changes observed were the increase in cases with previous malignancies (23% vs 16%, p=.04), the rise in patients with no associated LC symptoms (33% vs 16%, p<.001), and an increased number of localized NSCLC (non-small cell LC) diagnoses (42% vs 24% in series 2, p<.001 and 14.2% in series 1, p<.001). The number of LC patients diagnosed in localized stages has increased significantly. Furthermore, the number of patients with no symptoms associated with LC and with a history of previous malignancy were significantly increased. Copyright © 2013 SEPAR. Published by Elsevier Espana. All rights reserved.

  5. Comparison of Oone-Stage Free Gracilis Muscle Flap With Two-Stage Method in Chronic Facial Palsy

    Directory of Open Access Journals (Sweden)

    J Ghaffari

    2007-08-01

    Full Text Available Background:Rehabilitation of facial paralysis is one of the greatest challenges faced by reconstructive surgeons today. The traditional method for treatment of patients with facial palsy is the two-stage free gracilis flap which has a long latency period of between the two stages of surgery.Methods: In this paper, we prospectively compared the results of the one-stage gracilis flap method with the two -stage technique.Results:Out of 41 patients with facial palsy refered to Hazrat-e-Fatemeh Hospital 31 were selected from whom 22 underwent two- stage and 9 one-stage method treatment. The two groups were identical according to age,sex,intensity of illness, duration, and chronicity of illness. Mean duration of follow up was 37 months. There was no significant relation between the two groups regarding the symmetry of face in repose, smiling, whistling and nasolabial folds. Frequency of complications was equal in both groups. The postoperative surgeons and patients' satisfaction were equal in both groups. There was no significant difference between the mean excursion of muscle flap in one-stage (9.8 mm and two-stage groups (8.9 mm. The ratio of contraction of the affected side compared to the normal side was similar in both groups. The mean time of the initial contraction of the muscle flap in the one-stage group (5.5 months had a significant difference (P=0.001 with the two-stage one (6.5 months.The study revealed a highly significant difference (P=0.0001 between the mean waiting period from the first operation to the beginning of muscle contraction in one-stage(5.5 monthsand two-stage groups(17.1 months.Conclusion:It seems that the results and complication of the two methods are the same,but the one-stage method requires less time for facial reanimation,and is costeffective because it saves time and decreases hospitalization costs.

  6. Experimental studies of two-stage centrifugal dust concentrator

    Science.gov (United States)

    Vechkanova, M. V.; Fadin, Yu M.; Ovsyannikov, Yu G.

    2018-03-01

    The article presents data of experimental results of two-stage centrifugal dust concentrator, describes its design, and shows the development of a method of engineering calculation and laboratory investigations. For the experiments, the authors used quartz, ceramic dust and slag. Experimental dispersion analysis of dust particles was obtained by sedimentation method. To build a mathematical model of the process, dust collection was built using central composite rotatable design of the four factorial experiment. A sequence of experiments was conducted in accordance with the table of random numbers. Conclusion were made.

  7. Two-Stage Fuzzy Portfolio Selection Problem with Transaction Costs

    Directory of Open Access Journals (Sweden)

    Yanju Chen

    2015-01-01

    Full Text Available This paper studies a two-period portfolio selection problem. The problem is formulated as a two-stage fuzzy portfolio selection model with transaction costs, in which the future returns of risky security are characterized by possibility distributions. The objective of the proposed model is to achieve the maximum utility in terms of the expected value and variance of the final wealth. Given the first-stage decision vector and a realization of fuzzy return, the optimal value expression of the second-stage programming problem is derived. As a result, the proposed two-stage model is equivalent to a single-stage model, and the analytical optimal solution of the two-stage model is obtained, which helps us to discuss the properties of the optimal solution. Finally, some numerical experiments are performed to demonstrate the new modeling idea and the effectiveness. The computational results provided by the proposed model show that the more risk-averse investor will invest more wealth in the risk-free security. They also show that the optimal invested amount in risky security increases as the risk-free return decreases and the optimal utility increases as the risk-free return increases, whereas the optimal utility increases as the transaction costs decrease. In most instances the utilities provided by the proposed two-stage model are larger than those provided by the single-stage model.

  8. One-stage or two-stage revision surgery for prosthetic hip joint infection--the INFORM trial: a study protocol for a randomised controlled trial.

    Science.gov (United States)

    Strange, Simon; Whitehouse, Michael R; Beswick, Andrew D; Board, Tim; Burston, Amanda; Burston, Ben; Carroll, Fran E; Dieppe, Paul; Garfield, Kirsty; Gooberman-Hill, Rachael; Jones, Stephen; Kunutsor, Setor; Lane, Athene; Lenguerrand, Erik; MacGowan, Alasdair; Moore, Andrew; Noble, Sian; Simon, Joanne; Stockley, Ian; Taylor, Adrian H; Toms, Andrew; Webb, Jason; Whittaker, John-Paul; Wilson, Matthew; Wylde, Vikki; Blom, Ashley W

    2016-02-17

    Periprosthetic joint infection (PJI) affects approximately 1% of patients following total hip replacement (THR) and often results in severe physical and emotional suffering. Current surgical treatment options are debridement, antibiotics and implant retention; revision THR; excision of the joint and amputation. Revision surgery can be done as either a one-stage or two-stage operation. Both types of surgery are well-established practice in the NHS and result in similar rates of re-infection, but little is known about the impact of these treatments from the patient's perspective. The main aim of this randomised controlled trial is to determine whether there is a difference in patient-reported outcome measures 18 months after randomisation for one-stage or two-stage revision surgery. INFORM (INFection ORthopaedic Management) is an open, two-arm, multi-centre, randomised, superiority trial. We aim to randomise 148 patients with eligible PJI of the hip from approximately seven secondary care NHS orthopaedic units from across England and Wales. Patients will be randomised via a web-based system to receive either a one-stage revision or a two-stage revision THR. Blinding is not possible due to the nature of the intervention. All patients will be followed up for 18 months. The primary outcome is the WOMAC Index, which assesses hip pain, function and stiffness, collected by questionnaire at 18 months. Secondary outcomes include the following: cost-effectiveness, complications, re-infection rates, objective hip function assessment and quality of life. A nested qualitative study will explore patients' and surgeons' experiences, including their views about trial participation and randomisation. INFORM is the first ever randomised trial to compare two widely accepted surgical interventions for the treatment of PJI: one-stage and two-stage revision THR. The results of the trial will benefit patients in the future as the main focus is on patient-reported outcomes: pain, function

  9. Comparison of single-stage and temperature-phased two-stage anaerobic digestion of oily food waste

    International Nuclear Information System (INIS)

    Wu, Li-Jie; Kobayashi, Takuro; Li, Yu-You; Xu, Kai-Qin

    2015-01-01

    Highlights: • A single-stage and two two-stage anaerobic systems were synchronously operated. • Similar methane production 0.44 L/g VS_a_d_d_e_d from oily food waste was achieved. • The first stage of the two-stage process became inefficient due to serious pH drop. • Recycle favored the hythan production in the two-stage digestion. • The conversion of unsaturated fatty acids was enhanced by recycle introduction. - Abstract: Anaerobic digestion is an effective technology to recover energy from oily food waste. A single-stage system and temperature-phased two-stage systems with and without recycle for anaerobic digestion of oily food waste were constructed to compare the operation performances. The synchronous operation indicated the similar ability to produce methane in the three systems, with a methane yield of 0.44 L/g VS_a_d_d_e_d. The pH drop to less than 4.0 in the first stage of two-stage system without recycle resulted in poor hydrolysis, and methane or hydrogen was not produced in this stage. Alkalinity supplement from the second stage of two-stage system with recycle improved pH in the first stage to 5.4. Consequently, 35.3% of the particulate COD in the influent was reduced in the first stage of two-stage system with recycle according to a COD mass balance, and hydrogen was produced with a percentage of 31.7%, accordingly. Similar solids and organic matter were removed in the single-stage system and two-stage system without recycle. More lipid degradation and the conversion of long-chain fatty acids were achieved in the single-stage system. Recycling was proved to be effective in promoting the conversion of unsaturated long-chain fatty acids into saturated fatty acids in the two-stage system.

  10. Experimental study on an innovative multifunction heat pipe type heat recovery two-stage sorption refrigeration system

    International Nuclear Information System (INIS)

    Li, T.X.; Wang, R.Z.; Wang, L.W.; Lu, Z.S.

    2008-01-01

    An innovative multifunction heat pipe type sorption refrigeration system is designed, in which a two-stage sorption thermodynamic cycle based on two heat recovery processes was employed to reduce the driving heat source temperature, and the composite sorbent of CaCl 2 and activated carbon was used to improve the mass and heat transfer performances. For this test unit, the heating, cooling and heat recovery processes between two reactive beds are performed by multifunction heat pipes. The aim of this paper is to investigate the cycled characteristics of two-stage sorption refrigeration system with heat recovery processes. The two sub-cycles of a two-stage cycle have different sorption platforms though the adsorption and desorption temperatures are equivalent. The experimental results showed that the pressure evolutions of two beds are nearly equivalent during the first stage, and desorption pressure during the second stage is large higher than that in the first stage while the desorption temperatures are same during the two operation stages. In comparison with conventional two-stage cycle, the two-stage cycle with heat recovery processes can reduce the heating load for desorber and cooling load for adsorber, the coefficient of performance (COP) has been improved more than 23% when both cycles have the same regeneration temperature of 103 deg. C and the cooling water temperature of 30 deg. C. The advanced two-stage cycle provides an effective method for application of sorption refrigeration technology under the condition of low-grade temperature heat source or utilization of renewable energy

  11. The cyclops and the mermaid: an epidemiological study of two types of rare malformation.

    Science.gov (United States)

    Källén, B; Castilla, E E; Lancaster, P A; Mutchinick, O; Knudsen, L B; Martínez-Frías, M L; Mastroiacovo, P; Robert, E

    1992-01-01

    Infants with cyclopia or sirenomelia are born at an approximate rate of 1 in 100,000 births. Eight malformation monitoring systems around the world jointly studied the epidemiology of these rare malformations: 102 infants with cyclopia, 96 with sirenomelia, and one with both conditions were identified among nearly 10.1 million births. Maternal age is somewhat increased for cyclopia, indicating the likely inclusion of some chromosomally abnormal infants which were not identified. About half of the infants are stillborn. There is a female excess among infants with cyclopia. Excess twinning occurred for cyclopia and possibly also for sirenomelia. An analysis of associated malformations indicates the similarity between the two conditions, which is in agreement with recent embryological analysis. Images PMID:1552541

  12. Two-Stage Centrifugal Fan

    Science.gov (United States)

    Converse, David

    2011-01-01

    Fan designs are often constrained by envelope, rotational speed, weight, and power. Aerodynamic performance and motor electrical performance are heavily influenced by rotational speed. The fan used in this work is at a practical limit for rotational speed due to motor performance characteristics, and there is no more space available in the packaging for a larger fan. The pressure rise requirements keep growing. The way to ordinarily accommodate a higher DP is to spin faster or grow the fan rotor diameter. The invention is to put two radially oriented stages on a single disk. Flow enters the first stage from the center; energy is imparted to the flow in the first stage blades, the flow is redirected some amount opposite to the direction of rotation in the fixed stators, and more energy is imparted to the flow in the second- stage blades. Without increasing either rotational speed or disk diameter, it is believed that as much as 50 percent more DP can be achieved with this design than with an ordinary, single-stage centrifugal design. This invention is useful primarily for fans having relatively low flow rates with relatively high pressure rise requirements.

  13. Methodological aspects of epidemiological studies on groups of workers and members of the public

    International Nuclear Information System (INIS)

    Inskip, H.; Davies, J.

    1987-01-01

    Two reports have been prepared for the Nuclear Energy Agency which discuss epidemiological studies of two types of groups exposed to radiation, namely those exposed in the course of their work and those exposed non-occupationally. In each report the various epidemiological methods used in assessing the relationship between the exposure and subsequent morbidity or mortality have been described. This paper aims to draw on the material in the two reports to provide some guidelines for interpreting and assessing the value of any particular epidemiological study. Many such studies have been discussed in the two reports, and it is not within the scope of this paper to examine specific examples

  14. [Scientific, practical and educational aspects of clinical epidemiology].

    Science.gov (United States)

    Briko, N I

    2012-01-01

    This article defines clinical epidemiology and describes its goal and objectives. The author claims that clinical epidemiology is a section of epidemiology which underlies the development of evidence-based standards for diagnostics, treatment and prevention and helps to select the appropriate algorithm for each clinical case. The study provides a comprehensive overview of the relationship between clinical epidemiology and evidence-based medicine. Epidemiological research is shown to be methodological basis of clinical epidemiology and evidence-based medicine with randomized controlled trials being the "gold standard" for obtaining reliable data. The key stages in the history of clinical epidemiology are discussed and further development of clinical epidemiology and the integration of courses on clinical epidemiology in education is outlined for progress in medical research and health care practice.

  15. A survey of variable selection methods in two Chinese epidemiology journals

    Directory of Open Access Journals (Sweden)

    Lynn Henry S

    2010-09-01

    Full Text Available Abstract Background Although much has been written on developing better procedures for variable selection, there is little research on how it is practiced in actual studies. This review surveys the variable selection methods reported in two high-ranking Chinese epidemiology journals. Methods Articles published in 2004, 2006, and 2008 in the Chinese Journal of Epidemiology and the Chinese Journal of Preventive Medicine were reviewed. Five categories of methods were identified whereby variables were selected using: A - bivariate analyses; B - multivariable analysis; e.g. stepwise or individual significance testing of model coefficients; C - first bivariate analyses, followed by multivariable analysis; D - bivariate analyses or multivariable analysis; and E - other criteria like prior knowledge or personal judgment. Results Among the 287 articles that reported using variable selection methods, 6%, 26%, 30%, 21%, and 17% were in categories A through E, respectively. One hundred sixty-three studies selected variables using bivariate analyses, 80% (130/163 via multiple significance testing at the 5% alpha-level. Of the 219 multivariable analyses, 97 (44% used stepwise procedures, 89 (41% tested individual regression coefficients, but 33 (15% did not mention how variables were selected. Sixty percent (58/97 of the stepwise routines also did not specify the algorithm and/or significance levels. Conclusions The variable selection methods reported in the two journals were limited in variety, and details were often missing. Many studies still relied on problematic techniques like stepwise procedures and/or multiple testing of bivariate associations at the 0.05 alpha-level. These deficiencies should be rectified to safeguard the scientific validity of articles published in Chinese epidemiology journals.

  16. Recruitment and Participation of Recreational Runners in a Large Epidemiological and Genetic Research Study: Retrospective Data Analysis.

    Science.gov (United States)

    Manzanero, Silvia; Kozlovskaia, Maria; Vlahovich, Nicole; Hughes, David C

    2018-05-23

    With the increasing capacity for remote collection of both data and samples for medical research, a thorough assessment is needed to determine the association of population characteristics and recruitment methodologies with response rates. The aim of this research was to assess population representativeness in a two-stage study of health and injury in recreational runners, which consisted of an epidemiological arm and genetic analysis. The cost and success of various classical and internet-based methods were analyzed, and demographic representativeness was assessed for recruitment to the epidemiological survey, reported willingness to participate in the genetic arm of the study, actual participation, sample return, and approval for biobank storage. A total of 4965 valid responses were received, of which 1664 were deemed eligible for genetic analysis. Younger age showed a negative association with initial recruitment rate, expressed willingness to participate in genetic analysis, and actual participation. Additionally, female sex was associated with higher initial recruitment rates, and ethnic origin impacted willingness to participate in the genetic analysis (all P<.001). The sharp decline in retention through the different stages of the study in young respondents suggests the necessity to develop specific recruitment and retention strategies when investigating a young, physically active population. ©Silvia Manzanero, Maria Kozlovskaia, Nicole Vlahovich, David C Hughes. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 23.05.2018.

  17. Clinical and epidemiological profile of patients diagnosed with neurocysticercosis at two hospitals in Chiclayo, Peru

    Directory of Open Access Journals (Sweden)

    Giuseppe Rojas-Panta

    2017-01-01

    Full Text Available Objective: To describe the clinical and epidemiological profile of patients diagnosed with neurocysticercosis at two hospitals in Chiclayo, Peru. Materials and methods: A descriptive, cross-sectional and retrospective study was performed at the Almanzor Aguinaga Asenjo Hospital and Lambayeque Regional Hospital. Ninety-six (96 medical records of patients attended in 2014 with a diagnosis of neurocysticercosis were reviewed. Results: The mean age of the patients was 42.8 ± 18.8 years old, 52.1% were female, 26% came from Chiclayo and 54.2% received care for the first time. The most common symptom leading to medical consultation was headache. All patients underwent a diagnostic imaging method. The location of the parasite was mostly in the brain and the calcified stage was the most common one. The most widely used treatments were anticonvulsants and pain relievers. Conclusions: Neurocysticercosis mainly affects the economically active population, is more common in women and the most common clinical manifestation is headache

  18. Exercise and limitations in physical activity levels among new dialysis patients in the United States: an epidemiologic study.

    LENUS (Irish Health Repository)

    Stack, Austin G

    2008-12-01

    Epidemiologic studies of physical activity among patients with end-stage renal disease (ESRD) are lacking. The aim of this study was to describe the patterns of physical activity among new dialysis patients in the United States.

  19. Managing uncertainty - a qualitative study of surgeons' decision-making for one-stage and two-stage revision surgery for prosthetic hip joint infection.

    Science.gov (United States)

    Moore, Andrew J; Blom, Ashley W; Whitehouse, Michael R; Gooberman-Hill, Rachael

    2017-04-12

    Approximately 88,000 primary hip replacements are performed in England and Wales each year. Around 1% go on to develop deep prosthetic joint infection. Between one-stage and two-stage revision arthroplasty best treatment options remain unclear. Our aims were to characterise consultant orthopaedic surgeons' decisions about performing either one-stage or two-stage revision surgery for patients with deep prosthetic infection (PJI) after hip arthroplasty, and to identify whether a randomised trial comparing one-stage with two-stage revision would be feasible. Semi-structured interviews were conducted with 12 consultant surgeons who perform revision surgery for PJI after hip arthroplasty at 5 high-volume National Health Service (NHS) orthopaedic departments in England and Wales. Surgeons were interviewed before the development of a multicentre randomised controlled trial. Data were analysed using a thematic approach. There is no single standardised surgical intervention for the treatment of PJI. Surgeons balance multiple factors when choosing a surgical strategy which include multiple patient-related factors, their own knowledge and expertise, available infrastructure and the infecting organism. Surgeons questioned whether it was appropriate that the two-stage revision remained the best treatment, and some surgeons' willingness to consider more one-stage revisions had increased over recent years and were influenced by growing evidence showing equivalence between surgical techniques, and local observations of successful one-stage revisions. Custom-made articulating spacers was a practice that enabled uncertainty to be managed in the absence of definitive evidence about the superiority of one surgical technique over the other. Surgeons highlighted the need for research evidence to inform practice and thought that a randomised trial to compare treatments was needed. Most surgeons thought that patients who they treated would be eligible for trial participation in instances

  20. Comparing toxicologic and epidemiologic studies: methylene chloride--a case study.

    Science.gov (United States)

    Stayner, L T; Bailer, A J

    1993-12-01

    Exposure to methylene chloride induces lung and liver cancers in mice. The mouse bioassay data have been used as the basis for several cancer risk assessments. The results from epidemiologic studies of workers exposed to methylene chloride have been mixed with respect to demonstrating an increased cancer risk. The results from a negative epidemiologic study of Kodak workers have been used by two groups of investigators to test the predictions from the EPA risk assessment models. These two groups used very different approaches to this problem, which resulted in opposite conclusions regarding the consistency between the animal model predictions and the Kodak study results. The results from the Kodak study are used to test the predictions from OSHA's multistage models of liver and lung cancer risk. Confidence intervals for the standardized mortality ratios (SMRs) from the Kodak study are compared with the predicted confidence intervals derived from OSHA's risk assessment models. Adjustments for the "healthy worker effect," differences in length of follow-up, and dosimetry between animals and humans were incorporated into these comparisons. Based on these comparisons, we conclude that the negative results from the Kodak study are not inconsistent with the predictions from OSHA's risk assessment model.

  1. 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.

  2. Does the recent evolution of Canadian mortality agree with the epidemiologic transition theory?

    Directory of Open Access Journals (Sweden)

    Robert Choinière

    2008-06-01

    Full Text Available After studying the epidemiologic transition's situation in Canada, it is determined that the delimitation of temporal stages within the epidemiologic transition as put forward by Omran (1971, 1998, Olshansky and Ault (1986, Rogers and Hackenberg (1987 and Olshansky et al. (1998 does not suit the Canadian evolution. Many of the researchers' postulates on the epidemiologic transition were not confirmed, which leads us to assert that, since 1958, the epidemiologic transition is best described as an evolution process rather than specific stages confined within time limits.

  3. The influence of magnetic field strength in ionization stage on ion transport between two stages of a double stage Hall thruster

    International Nuclear Information System (INIS)

    Yu Daren; Song Maojiang; Li Hong; Liu Hui; Han Ke

    2012-01-01

    It is futile for a double stage Hall thruster to design a special ionization stage if the ionized ions cannot enter the acceleration stage. Based on this viewpoint, the ion transport under different magnetic field strengths in the ionization stage is investigated, and the physical mechanisms affecting the ion transport are analyzed in this paper. With a combined experimental and particle-in-cell simulation study, it is found that the ion transport between two stages is chiefly affected by the potential well, the potential barrier, and the potential drop at the bottom of potential well. With the increase of magnetic field strength in the ionization stage, there is larger plasma density caused by larger potential well. Furthermore, the potential barrier near the intermediate electrode declines first and then rises up while the potential drop at the bottom of potential well rises up first and then declines as the magnetic field strength increases in the ionization stage. Consequently, both the ion current entering the acceleration stage and the total ion current ejected from the thruster rise up first and then decline as the magnetic field strength increases in the ionization stage. Therefore, there is an optimal magnetic field strength in the ionization stage to guide the ion transport between two stages.

  4. 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.

  5. The experimental study of a two-stage photovoltaic thermal system based on solar trough concentration

    International Nuclear Information System (INIS)

    Tan, Lijun; Ji, Xu; Li, Ming; Leng, Congbin; Luo, Xi; Li, Haili

    2014-01-01

    Highlights: • A two-stage photovoltaic thermal system based on solar trough concentration. • Maximum cell efficiency of 5.21% with the mirror opening width of 57 cm. • With single cycle, maximum temperatures rise in the heating stage is 12.06 °C. • With 30 min multiple cycles, working medium temperature 62.8 °C, increased 28.7 °C. - Abstract: A two-stage photovoltaic thermal system based on solar trough concentration is proposed, in which the metal cavity heating stage is added on the basis of the PV/T stage, and thermal energy with higher temperature is output while electric energy is output. With the 1.8 m 2 mirror PV/T system, the characteristic parameters of the space solar cell under non-concentrating solar radiation and concentrating solar radiation are respectively tested experimentally, and the solar cell output characteristics at different opening widths of concentrating mirror of the PV/T stage under condensation are also tested experimentally. When the mirror opening width was 57 cm, the solar cell efficiency reached maximum value of 5.21%. The experimental platform of the two-stage photovoltaic thermal system was established, with a 1.8 m 2 mirror PV/T stage and a 15 m 2 mirror heating stage, or a 1.8 m 2 mirror PV/T stage and a 30 m 2 mirror heating stage. The results showed that with single cycle, the long metal cavity heating stage would bring lower thermal efficiency, but temperature rise of the working medium is higher, up to 12.06 °C with only single cycle. With 30 min closed multiple cycles, the temperature of the working medium in the water tank was 62.8 °C, with an increase of 28.7 °C, and thermal energy with higher temperature could be output

  6. A stage is a stage is a stage: a direct comparison of two scoring systems.

    Science.gov (United States)

    Dawson, Theo L

    2003-09-01

    L. Kohlberg (1969) argued that his moral stages captured a developmental sequence specific to the moral domain. To explore that contention, the author compared stage assignments obtained with the Standard Issue Scoring System (A. Colby & L. Kohlberg, 1987a, 1987b) and those obtained with a generalized content-independent stage-scoring system called the Hierarchical Complexity Scoring System (T. L. Dawson, 2002a), on 637 moral judgment interviews (participants' ages ranged from 5 to 86 years). The correlation between stage scores produced with the 2 systems was .88. Although standard issue scoring and hierarchical complexity scoring often awarded different scores up to Kohlberg's Moral Stage 2/3, from his Moral Stage 3 onward, scores awarded with the two systems predominantly agreed. The author explores the implications for developmental research.

  7. Two-Stage Fuzzy Portfolio Selection Problem with Transaction Costs

    OpenAIRE

    Chen, Yanju; Wang, Ye

    2015-01-01

    This paper studies a two-period portfolio selection problem. The problem is formulated as a two-stage fuzzy portfolio selection model with transaction costs, in which the future returns of risky security are characterized by possibility distributions. The objective of the proposed model is to achieve the maximum utility in terms of the expected value and variance of the final wealth. Given the first-stage decision vector and a realization of fuzzy return, the optimal value expression of the s...

  8. Update on Merkel Cell Carcinoma: Epidemiology, Etiopathogenesis, Clinical Features, Diagnosis, and Staging.

    Science.gov (United States)

    Llombart, B; Requena, C; Cruz, J

    2017-03-01

    Merkel cell carcinoma (MCC) is a rare, highly aggressive tumor, and local or regional disease recurrence is common, as is metastasis. MCC usually develops in sun-exposed skin in patients of advanced age. Its incidence has risen 4-fold in recent decades as the population has aged and immunohistochemical techniques have led to more diagnoses. The pathogenesis of MCC remains unclear but UV radiation, immunosuppression, and the presence of Merkel cell polyomavirus in the tumor genome seem to play key roles. This review seeks to update our understanding of the epidemiology, etiology, pathogenesis, and clinical features of MCC. We also review histologic and immunohistochemical features required for diagnosis. MCC staging is discussed, given its great importance in establishing a prognosis for these patients. Copyright © 2016 AEDV. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Two-stage thermal/nonthermal waste treatment process

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Anderson, G.K.; Coogan, J.J.; Kang, M.; Tennant, R.A.; Wantuck, P.J.

    1993-01-01

    An innovative waste treatment technology is being developed in Los Alamos to address the destruction of hazardous organic wastes. The technology described in this report uses two stages: a packed bed reactor (PBR) in the first stage to volatilize and/or combust liquid organics and a silent discharge plasma (SDP) reactor to remove entrained hazardous compounds in the off-gas to even lower levels. We have constructed pre-pilot-scale PBR-SDP apparatus and tested the two stages separately and in combined modes. These tests are described in the report

  10. Statistical inference for extended or shortened phase II studies based on Simon's two-stage designs.

    Science.gov (United States)

    Zhao, Junjun; Yu, Menggang; Feng, Xi-Ping

    2015-06-07

    Simon's two-stage designs are popular choices for conducting phase II clinical trials, especially in the oncology trials to reduce the number of patients placed on ineffective experimental therapies. Recently Koyama and Chen (2008) discussed how to conduct proper inference for such studies because they found that inference procedures used with Simon's designs almost always ignore the actual sampling plan used. In particular, they proposed an inference method for studies when the actual second stage sample sizes differ from planned ones. We consider an alternative inference method based on likelihood ratio. In particular, we order permissible sample paths under Simon's two-stage designs using their corresponding conditional likelihood. In this way, we can calculate p-values using the common definition: the probability of obtaining a test statistic value at least as extreme as that observed under the null hypothesis. In addition to providing inference for a couple of scenarios where Koyama and Chen's method can be difficult to apply, the resulting estimate based on our method appears to have certain advantage in terms of inference properties in many numerical simulations. It generally led to smaller biases and narrower confidence intervals while maintaining similar coverages. We also illustrated the two methods in a real data setting. Inference procedures used with Simon's designs almost always ignore the actual sampling plan. Reported P-values, point estimates and confidence intervals for the response rate are not usually adjusted for the design's adaptiveness. Proper statistical inference procedures should be used.

  11. Radiation epidemiology: Past and present

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.

    1997-01-01

    Major advancements in radiation epidemiology have occurred during the last several years in studies of atomic bomb survivors, patients given medical radiation, and radiation workers, including underground miners. Risks associated with the Chernobyl accident, indoor radon and childhood exposure to I-131 have yet to be elucidated. Situations in the former Soviet Union around Chelyabinsk, a nuclear installation in the southern Urals, and in the Altai, which received radioactive fallout from weapons testing at Semipalatinsk, Kazakhstan, have the potential to provide information on the effects of chronic radiation exposure. Since Roentgen's discovery of x-rays just 100 years ago, a tremendous amount of knowledge has been accumulated about human health effects following irradiation. The 1994 UNSCEAR report contains the latest compilation and synthesis of radiation epidemiology. This overview will cover epidemiology from a radiation perspective. The different types of study methodologies will be described, followed by a kaleidoscope coverage of past and present studies; ending with some remaining questions in radiation epidemiology. This should set the stage for future chapters, and stimulate thinking about implications of the new data on radiation cancer risks

  12. Retrospective study of epidemiological, clinicopathological and ...

    African Journals Online (AJOL)

    Retrospective study of epidemiological, clinicopathological and biological profils of 62 colorectal cancers cases in Jijel provence (Algeria) ... Our results were often compatible with the available literature and may provide reliable and relevant data on this disease. Key words: Colorectal cancer; Epidemiology; Therapy; ...

  13. Treatment of corn ethanol distillery wastewater using two-stage anaerobic digestion.

    Science.gov (United States)

    Ráduly, B; Gyenge, L; Szilveszter, Sz; Kedves, A; Crognale, S

    In this study the mesophilic two-stage anaerobic digestion (AD) of corn bioethanol distillery wastewater is investigated in laboratory-scale reactors. Two-stage AD technology separates the different sub-processes of the AD in two distinct reactors, enabling the use of optimal conditions for the different microbial consortia involved in the different process phases, and thus allowing for higher applicable organic loading rates (OLRs), shorter hydraulic retention times (HRTs) and better conversion rates of the organic matter, as well as higher methane content of the produced biogas. In our experiments the reactors have been operated in semi-continuous phase-separated mode. A specific methane production of 1,092 mL/(L·d) has been reached at an OLR of 6.5 g TCOD/(L·d) (TCOD: total chemical oxygen demand) and a total HRT of 21 days (5.7 days in the first-stage, and 15.3 days in the second-stage reactor). Nonetheless the methane concentration in the second-stage reactor was very high (78.9%); the two-stage AD outperformed the reference single-stage AD (conducted at the same reactor loading rate and retention time) by only a small margin in terms of volumetric methane production rate. This makes questionable whether the higher methane content of the biogas counterbalances the added complexity of the two-stage digestion.

  14. The French Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort study.

    Science.gov (United States)

    Stengel, Bénédicte; Combe, Christian; Jacquelinet, Christian; Briançon, Serge; Fouque, Denis; Laville, Maurice; Frimat, Luc; Pascal, Christophe; Herpe, Yves-Edouard; Deleuze, Jean-François; Schanstra, Joost; Pisoni, Ron L; Robinson, Bruce M; Massy, Ziad A

    2014-08-01

    While much has been learned about the epidemiology and treatment of end-stage renal disease (ESRD) in the last 30 years, chronic kidney disease (CKD) before the end-stage has been less investigated. Not enough is known about factors associated with CKD progression and complications, as well as its transition to ESRD. We designed the CKD-renal epidemiology and information network (REIN) cohort to provide a research platform to address these key questions and to assess clinical practices and costs in patients with moderate or advanced CKD. A total of 46 clinic sites and 4 renal care networks participate in the cohort. A stratified selection of clinic sites yields a sample that represents a diversity of settings, e.g. geographic region, and public versus for-profit and non-for-profit private clinics. In each site, 60-90 patients with CKD are enrolled at a routine clinic visit during a 12-month enrolment phase: 3600 total, including 1800 with Stage 3 and 1800 with Stage 4 CKD. Follow-up will continue for 5 years, including after initiation of renal replacement therapy. Data will be collected from medical records at inclusion and at yearly intervals, as well as from self-administered patient questionnaires and provider-level questionnaires. Patients will also be interviewed at baseline, and at 1, 3 and 5 years. Healthcare costs will also be determined. Blood and urine samples will be collected and stored for future studies on all patients at enrolment and at study end, and at 1 and 3 years in a subsample of 1200. The CKD-REIN cohort will serve to improve our understanding of the biological, clinical and healthcare system determinants associated with CKD progression and adverse outcomes as well as of international variations in collaboration with the CKD Outcome and Practice Pattern Study (CKDopps). It will foster CKD epidemiology and outcomes research and provide evidence to improve the health and quality of life of patients with CKD and the performances of the

  15. Epidemiological studies on syncope

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth

    2013-01-01

    of the patients play an essential role. In epidemiology these factors have major impact on the outcome of the patients. Until recently, even the definition of syncope differed from one study to another which has made literature reviews difficult. Traditionally the data on epidemiology of syncope has been taken...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate......, prevalence and cardiovascular factors associated with the risk of syncope, 4) the prognosis in healthy individuals discharged after syncope, and 5) the prognosis of patients after syncope and evaluation of the CHADS2 score as a tool for short- and long-term risk prediction. The first studies of the present...

  16. Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

    International Nuclear Information System (INIS)

    Ariunbaatar, Javkhlan; Scotto Di Perta, Ester; Panico, Antonio; Frunzo, Luigi; Esposito, Giovanni; Lens, Piet N.L.; Pirozzi, Francesco

    2015-01-01

    Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC 50 of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid

  17. Staging of gastric adenocarcinoma using two-phase spiral CT: correlation with pathologic staging

    International Nuclear Information System (INIS)

    Seo, Tae Seok; Lee, Dong Ho; Ko, Young Tae; Lim, Joo Won

    1998-01-01

    To correlate the preoperative staging of gastric adenocarcinoma using two-phase spiral CT with pathologic staging. One hundred and eighty patients with gastric cancers confirmed during surgery underwent two-phase spiral CT, and were evaluated retrospectively. CT scans were obtained in the prone position after ingestion of water. Scans were performed 35 and 80 seconds after the start of infusion of 120mL of non-ionic contrast material with the speed of 3mL/sec. Five mm collimation, 7mm/sec table feed and 5mm reconstruction interval were used. T-and N-stage were determined using spiral CT images, without knowledge of the pathologic results. Pathologic staging was later compared with CT staging. Pathologic T-stage was T1 in 70 cases(38.9%), T2 in 33(18.3%), T3 in 73(40.6%), and T4 in 4(2.2%). Type-I or IIa elevated lesions accouted for 10 of 70 T1 cases(14.3%) and flat or depressed lesions(type IIb, IIc, or III) for 60(85.7%). Pathologic N-stage was NO in 85 cases(47.2%), N1 in 42(23.3%), N2 in 31(17.2%), and N3 in 22(12,2%). The detection rate of early gastric cancer using two-phase spiral CT was 100.0%(10 of 10 cases) among elevated lesions and 78.3%(47 of 60 cases) among flat or depressed lesions. With regard to T-stage, there was good correlation between CT image and pathology in 86 of 180 cases(47.8%). Overstaging occurred in 23.3%(42 of 180 cases) and understaging in 28.9%(52 of 180 cases). With regard to N-stage, good correlation between CT image and pathology was noted in 94 of 180 cases(52.2%). The rate of understaging(31.7%, 57 of 180 cases) was higher than that of overstaging(16.1%, 29 of 180 cases)(p<0.001). The detection rate of early gastric cancer using two-phase spiral CT was 81.4%, and there was no significant difference in detectability between elevated and depressed lesions. Two-phase spiral CT for determing the T-and N-stage of gastric cancer was not effective;it was accurate in abont 50% of cases understaging tended to occur.=20

  18. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts.

    Science.gov (United States)

    Chien, Chia-Chang; Huang, Shu-Fen; Lung, For-Wey

    2009-01-27

    The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts. We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST) and the Wechsler Adult Intelligence Scale-Revised (WAIS-R) assessments. Logistic regression analysis showed the conceptual level responses (CLR) index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84). We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%. The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future.

  19. A two-stage genome-wide association study of sporadic amyotrophic lateral sclerosis.

    Science.gov (United States)

    Chiò, Adriano; Schymick, Jennifer C; Restagno, Gabriella; Scholz, Sonja W; Lombardo, Federica; Lai, Shiao-Lin; Mora, Gabriele; Fung, Hon-Chung; Britton, Angela; Arepalli, Sampath; Gibbs, J Raphael; Nalls, Michael; Berger, Stephen; Kwee, Lydia Coulter; Oddone, Eugene Z; Ding, Jinhui; Crews, Cynthia; Rafferty, Ian; Washecka, Nicole; Hernandez, Dena; Ferrucci, Luigi; Bandinelli, Stefania; Guralnik, Jack; Macciardi, Fabio; Torri, Federica; Lupoli, Sara; Chanock, Stephen J; Thomas, Gilles; Hunter, David J; Gieger, Christian; Wichmann, H Erich; Calvo, Andrea; Mutani, Roberto; Battistini, Stefania; Giannini, Fabio; Caponnetto, Claudia; Mancardi, Giovanni Luigi; La Bella, Vincenzo; Valentino, Francesca; Monsurrò, Maria Rosaria; Tedeschi, Gioacchino; Marinou, Kalliopi; Sabatelli, Mario; Conte, Amelia; Mandrioli, Jessica; Sola, Patrizia; Salvi, Fabrizio; Bartolomei, Ilaria; Siciliano, Gabriele; Carlesi, Cecilia; Orrell, Richard W; Talbot, Kevin; Simmons, Zachary; Connor, James; Pioro, Erik P; Dunkley, Travis; Stephan, Dietrich A; Kasperaviciute, Dalia; Fisher, Elizabeth M; Jabonka, Sibylle; Sendtner, Michael; Beck, Marcus; Bruijn, Lucie; Rothstein, Jeffrey; Schmidt, Silke; Singleton, Andrew; Hardy, John; Traynor, Bryan J

    2009-04-15

    The cause of sporadic amyotrophic lateral sclerosis (ALS) is largely unknown, but genetic factors are thought to play a significant role in determining susceptibility to motor neuron degeneration. To identify genetic variants altering risk of ALS, we undertook a two-stage genome-wide association study (GWAS): we followed our initial GWAS of 545 066 SNPs in 553 individuals with ALS and 2338 controls by testing the 7600 most associated SNPs from the first stage in three independent cohorts consisting of 2160 cases and 3008 controls. None of the SNPs selected for replication exceeded the Bonferroni threshold for significance. The two most significantly associated SNPs, rs2708909 and rs2708851 [odds ratio (OR) = 1.17 and 1.18, and P-values = 6.98 x 10(-7) and 1.16 x 10(-6)], were located on chromosome 7p13.3 within a 175 kb linkage disequilibrium block containing the SUNC1, HUS1 and C7orf57 genes. These associations did not achieve genome-wide significance in the original cohort and failed to replicate in an additional independent cohort of 989 US cases and 327 controls (OR = 1.18 and 1.19, P-values = 0.08 and 0.06, respectively). Thus, we chose to cautiously interpret our data as hypothesis-generating requiring additional confirmation, especially as all previously reported loci for ALS have failed to replicate successfully. Indeed, the three loci (FGGY, ITPR2 and DPP6) identified in previous GWAS of sporadic ALS were not significantly associated with disease in our study. Our findings suggest that ALS is more genetically and clinically heterogeneous than previously recognized. Genotype data from our study have been made available online to facilitate such future endeavors.

  20. Automatic sleep stage classification using two facial electrodes.

    Science.gov (United States)

    Virkkala, Jussi; Velin, Riitta; Himanen, Sari-Leena; Värri, Alpo; Müller, Kiti; Hasan, Joel

    2008-01-01

    Standard sleep stage classification is based on visual analysis of central EEG, EOG and EMG signals. Automatic analysis with a reduced number of sensors has been studied as an easy alternative to the standard. In this study, a single-channel electro-oculography (EOG) algorithm was developed for separation of wakefulness, SREM, light sleep (S1, S2) and slow wave sleep (S3, S4). The algorithm was developed and tested with 296 subjects. Additional validation was performed on 16 subjects using a low weight single-channel Alive Monitor. In the validation study, subjects attached the disposable EOG electrodes themselves at home. In separating the four stages total agreement (and Cohen's Kappa) in the training data set was 74% (0.59), in the testing data set 73% (0.59) and in the validation data set 74% (0.59). Self-applicable electro-oculography with only two facial electrodes was found to provide reasonable sleep stage information.

  1. Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients.

    Science.gov (United States)

    Fink, Bernd; Schlumberger, Michael; Oremek, Damian

    2017-08-01

    patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database. Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation. This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored. Level IV, therapeutic study.

  2. Teaching basic life support with an automated external defibrillator using the two-stage or the four-stage teaching technique.

    Science.gov (United States)

    Bjørnshave, Katrine; Krogh, Lise Q; Hansen, Svend B; Nebsbjerg, Mette A; Thim, Troels; Løfgren, Bo

    2018-02-01

    Laypersons often hesitate to perform basic life support (BLS) and use an automated external defibrillator (AED) because of self-perceived lack of knowledge and skills. Training may reduce the barrier to intervene. Reduced training time and costs may allow training of more laypersons. The aim of this study was to compare BLS/AED skills' acquisition and self-evaluated BLS/AED skills after instructor-led training with a two-stage versus a four-stage teaching technique. Laypersons were randomized to either two-stage or four-stage teaching technique courses. Immediately after training, the participants were tested in a simulated cardiac arrest scenario to assess their BLS/AED skills. Skills were assessed using the European Resuscitation Council BLS/AED assessment form. The primary endpoint was passing the test (17 of 17 skills adequately performed). A prespecified noninferiority margin of 20% was used. The two-stage teaching technique (n=72, pass rate 57%) was noninferior to the four-stage technique (n=70, pass rate 59%), with a difference in pass rates of -2%; 95% confidence interval: -18 to 15%. Neither were there significant differences between the two-stage and four-stage groups in the chest compression rate (114±12 vs. 115±14/min), chest compression depth (47±9 vs. 48±9 mm) and number of sufficient rescue breaths between compression cycles (1.7±0.5 vs. 1.6±0.7). In both groups, all participants believed that their training had improved their skills. Teaching laypersons BLS/AED using the two-stage teaching technique was noninferior to the four-stage teaching technique, although the pass rate was -2% (95% confidence interval: -18 to 15%) lower with the two-stage teaching technique.

  3. Epidemiology of Acute Gastroenteritis Outbreaks Caused by Human Calicivirus (Norovirus and Sapovirus in Catalonia: A Two Year Prospective Study, 2010-2011.

    Directory of Open Access Journals (Sweden)

    Nuria Torner

    Full Text Available The epidemiology of cases of acute gastroenteritis (AGE of viral etiology is a relevant public health issue. Due to underreporting, the study of outbreaks is an accepted approach to investigate their epidemiology. The objective of this study was to investigate the epidemiological characteristics of AGE outbreaks due to norovirus (NoV and sapovirus (SV in Catalonia.Prospective study of AGE outbreaks of possible viral etiology notified during two years in Catalonia. NoV and SV were detected by real time reverse transcription polymerase (RT-PCR.A total of 101 outbreaks were registered affecting a total of 2756 persons and 12 hospitalizations (hospitalization rate: 0.8x1,000,000 persons-year; 49.5% of outbreaks were foodborne, 45.5% person to person and 5% waterborne. The distribution of outbreaks according to the setting showed a predominance of catering services (39.6%, nursing homes and long term care facilities (26.8% and schools (11.9%. The median number of cases per outbreak was 17 (range 2-191. The total Incidence rate (IR was 18.3 per 100,000 persons-years (95%CI: 17.6-19.0. The highest IR was in persons aged ≥65 years (43.6x100,000 (95% CI: 41.0-46.2 (p<0.001. A total of 1065 samples were analyzed with a positivity rate of 60.8%. 98% of positive samples were NoV (GII 56.3%; GI 4.2%; GII+GI 4.2%; non- typable 33.0%. SV was identified in two person-to-person transmission outbreaks in children.These results confirm the relevance of viral AGE outbreaks, both foodborne and person-to-person, especially in institutionalized persons. SV should be taken into account when investigating viral AGE outbreaks.

  4. Epidemiology of Acute Gastroenteritis Outbreaks Caused by Human Calicivirus (Norovirus and Sapovirus) in Catalonia: A Two Year Prospective Study, 2010-2011

    Science.gov (United States)

    Martinez, Ana; Moreno, Antonio; Camps, Neus

    2016-01-01

    Background The epidemiology of cases of acute gastroenteritis (AGE) of viral etiology is a relevant public health issue. Due to underreporting, the study of outbreaks is an accepted approach to investigate their epidemiology. The objective of this study was to investigate the epidemiological characteristics of AGE outbreaks due to norovirus (NoV) and sapovirus (SV) in Catalonia. Material and Methods Prospective study of AGE outbreaks of possible viral etiology notified during two years in Catalonia. NoV and SV were detected by real time reverse transcription polymerase (RT-PCR). Results A total of 101 outbreaks were registered affecting a total of 2756 persons and 12 hospitalizations (hospitalization rate: 0.8x1,000,000 persons-year); 49.5% of outbreaks were foodborne, 45.5% person to person and 5% waterborne. The distribution of outbreaks according to the setting showed a predominance of catering services (39.6%), nursing homes and long term care facilities (26.8%) and schools (11.9%). The median number of cases per outbreak was 17 (range 2–191). The total Incidence rate (IR) was 18.3 per 100,000 persons-years (95%CI: 17.6–19.0). The highest IR was in persons aged ≥65 years (43.6x100,000 (95% CI: 41.0–46.2)) (p<0.001). A total of 1065 samples were analyzed with a positivity rate of 60.8%. 98% of positive samples were NoV (GII 56.3%; GI 4.2%; GII+GI 4.2%; non- typable 33.0%). SV was identified in two person-to-person transmission outbreaks in children. Conclusions These results confirm the relevance of viral AGE outbreaks, both foodborne and person-to-person, especially in institutionalized persons. SV should be taken into account when investigating viral AGE outbreaks. PMID:27120472

  5. Wide-bandwidth bilateral control using two-stage actuator system

    International Nuclear Information System (INIS)

    Kokuryu, Saori; Izutsu, Masaki; Kamamichi, Norihiro; Ishikawa, Jun

    2015-01-01

    This paper proposes a two-stage actuator system that consists of a coarse actuator driven by a ball screw with an AC motor (the first stage) and a fine actuator driven by a voice coil motor (the second stage). The proposed two-stage actuator system is applied to make a wide-bandwidth bilateral control system without needing expensive high-performance actuators. In the proposed system, the first stage has a wide moving range with a narrow control bandwidth, and the second stage has a narrow moving range with a wide control bandwidth. By consolidating these two inexpensive actuators with different control bandwidths in a complementary manner, a wide bandwidth bilateral control system can be constructed based on a mechanical impedance control. To show the validity of the proposed method, a prototype of the two-stage actuator system has been developed and basic performance was evaluated by experiment. The experimental results showed that a light mechanical impedance with a mass of 10 g and a damping coefficient of 2.5 N/(m/s) that is an important factor to establish good transparency in bilateral control has been successfully achieved and also showed that a better force and position responses between a master and slave is achieved by using the proposed two-stage actuator system compared with a narrow bandwidth case using a single ball screw system. (author)

  6. 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.

  7. Two-stage precipitation of neptunium (IV) oxalate

    International Nuclear Information System (INIS)

    Luerkens, D.W.

    1983-07-01

    Neptunium (IV) oxalate was precipitated using a two-stage precipitation system. A series of precipitation experiments was used to identify the significant process variables affecting precipitate characteristics. Process variables tested were input concentrations, solubility conditions in the first stage precipitator, precipitation temperatures, and residence time in the first stage precipitator. A procedure has been demonstrated that produces neptunium (IV) oxalate particles that filter well and readily calcine to the oxide

  8. Effects of Two-stage Heat Treatment on Delayed Coke and Study of Their Surface Texture Characteristics

    Science.gov (United States)

    Im, Ui-Su; Kim, Jiyoung; Lee, Seon Ho; Lee, Byung-Rok; Peck, Dong-Hyun; Jung, Doo-Hwan

    2017-12-01

    In the present study, surface texture features and chemical properties of two types of cokes, made from coal tar by either 1-stage heat treatment or 2-stage heat treatment, were researched. The relationship between surface texture characteristics and the chemical properties was identified through molecular weight distribution, insolubility of coal tar, weight loss with temperature increase, coking yield, and polarized light microscope analysis. Rapidly cleared anisotropy texture in cokes was observed in accordance with the coking temperature rise. Quinoline insolubility and toluene insolubility of coal tar increased with a corresponding increases in coking temperature. In particular, the cokes produced by the 2-stage heat treatment (2S-C) showed surface structure of needle cokes at a temperature approximately 50°C lower than the 1-stage heat treatment (1S-C). Additionally, the coking yield of 2S-C increased by approximately 14% in comparison with 1S-C.

  9. Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

    Energy Technology Data Exchange (ETDEWEB)

    Ariunbaatar, Javkhlan, E-mail: jaka@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Scotto Di Perta, Ester [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy); Panico, Antonio [Telematic University PEGASO, Piazza Trieste e Trento, 48, 80132 Naples (Italy); Frunzo, Luigi [Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, Via Claudio, 21, 80125 Naples (Italy); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); Lens, Piet N.L. [UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Pirozzi, Francesco [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy)

    2015-04-15

    Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC{sub 50} of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid.

  10. Study on the Control Algorithm of Two-Stage DC-DC Converter for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Changhao Piao

    2014-01-01

    Full Text Available The fast response, high efficiency, and good reliability are very important characteristics to electric vehicles (EVs dc/dc converters. Two-stage dc-dc converter is a kind of dc-dc topologies that can offer those characteristics to EVs. Presently, nonlinear control is an active area of research in the field of the control algorithm of dc-dc converters. However, very few papers research on two-stage converter for EVs. In this paper, a fixed switching frequency sliding mode (FSFSM controller and double-integral sliding mode (DISM controller for two-stage dc-dc converter are proposed. And a conventional linear control (lag is chosen as the comparison. The performances of the proposed FSFSM controller are compared with those obtained by the lag controller. In consequence, the satisfactory simulation and experiment results show that the FSFSM controller is capable of offering good large-signal operations with fast dynamical responses to the converter. At last, some other simulation results are presented to prove that the DISM controller is a promising method for the converter to eliminate the steady-state error.

  11. 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.

  12. Epidemiological, clinical and sleep laboratory evaluations of insomnia

    Science.gov (United States)

    Bixler, E. O.; Kales, A.; Kales, J. D.

    1975-01-01

    Epidemiological studies have contributed to the understanding of the total scope of the insomnia problem, both in terms of the incidence of sleep difficulties, and the extent and frequency of hypnotic drug use. Clinical studies - at the Sleep Research and Treatment Center - have been used to evaluate the medical, psychological, pharmacological and situational factors contributing to insomnia, and to evaluate the psychotherapy and chemotherapy best suited to treatment of insomnia. The sleep laboratory studies were of two types: (1) the study of sleep induction, sleep maintenance, and sleep stages, and (2) the use of hypnotic drugs, emphasizing their effectiveness in inducing and maintaining sleep, and the duration of this effectiveness.

  13. Condensate from a two-stage gasifier

    DEFF Research Database (Denmark)

    Bentzen, Jens Dall; Henriksen, Ulrik Birk; Hindsgaul, Claus

    2000-01-01

    Condensate, produced when gas from downdraft biomass gasifier is cooled, contains organic compounds that inhibit nitrifiers. Treatment with activated carbon removes most of the organics and makes the condensate far less inhibitory. The condensate from an optimised two-stage gasifier is so clean...... that the organic compounds and the inhibition effect are very low even before treatment with activated carbon. The moderate inhibition effect relates to a high content of ammonia in the condensate. The nitrifiers become tolerant to the condensate after a few weeks of exposure. The level of organic compounds...... and the level of inhibition are so low that condensate from the optimised two-stage gasifier can be led to the public sewer....

  14. Methodological exploratory study applied to occupational epidemiology

    Energy Technology Data Exchange (ETDEWEB)

    Carneiro, Janete C.G. Gaburo; Vasques, MOnica Heloisa B.; Fontinele, Ricardo S.; Sordi, Gian Maria A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: janetegc@ipen.br

    2007-07-01

    The utilization of epidemiologic methods and techniques has been object of practical experimentation and theoretical-methodological reflection in health planning and programming process. Occupational Epidemiology is the study of the causes and prevention of diseases and injuries from exposition and risks in the work environment. In this context, there is no intention to deplete such a complex theme but to deal with basic concepts of Occupational Epidemiology, presenting the main characteristics of the analysis methods used in epidemiology, as investigate the possible determinants of exposition (chemical, physical and biological agents). For this study, the social-demographic profile of the IPEN-CNEN/SP work force was used. The knowledge of this reference population composition is based on sex, age, educational level, marital status and different occupations, aiming to know the relation between the health aggravating factors and these variables. The methodology used refers to a non-experimental research based on a theoretical methodological practice. The work performed has an exploratory character, aiming a later survey of indicators in the health area in order to analyze possible correlations related to epidemiologic issues. (author)

  15. Methodological exploratory study applied to occupational epidemiology

    International Nuclear Information System (INIS)

    Carneiro, Janete C.G. Gaburo; Vasques, MOnica Heloisa B.; Fontinele, Ricardo S.; Sordi, Gian Maria A.

    2007-01-01

    The utilization of epidemiologic methods and techniques has been object of practical experimentation and theoretical-methodological reflection in health planning and programming process. Occupational Epidemiology is the study of the causes and prevention of diseases and injuries from exposition and risks in the work environment. In this context, there is no intention to deplete such a complex theme but to deal with basic concepts of Occupational Epidemiology, presenting the main characteristics of the analysis methods used in epidemiology, as investigate the possible determinants of exposition (chemical, physical and biological agents). For this study, the social-demographic profile of the IPEN-CNEN/SP work force was used. The knowledge of this reference population composition is based on sex, age, educational level, marital status and different occupations, aiming to know the relation between the health aggravating factors and these variables. The methodology used refers to a non-experimental research based on a theoretical methodological practice. The work performed has an exploratory character, aiming a later survey of indicators in the health area in order to analyze possible correlations related to epidemiologic issues. (author)

  16. Evidence of two-stage melting of Wigner solids

    Science.gov (United States)

    Knighton, Talbot; Wu, Zhe; Huang, Jian; Serafin, Alessandro; Xia, J. S.; Pfeiffer, L. N.; West, K. W.

    2018-02-01

    Ultralow carrier concentrations of two-dimensional holes down to p =1 ×109cm-2 are realized. Remarkable insulating states are found below a critical density of pc=4 ×109cm-2 or rs≈40 . Sensitive dc V-I measurement as a function of temperature and electric field reveals a two-stage phase transition supporting the melting of a Wigner solid as a two-stage first-order transition.

  17. Two-stage liquefaction of a Spanish subbituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, M.T.; Fernandez, I.; Benito, A.M.; Cebolla, V.; Miranda, J.L.; Oelert, H.H. (Instituto de Carboquimica, Zaragoza (Spain))

    1993-05-01

    A Spanish subbituminous coal has been processed in two-stage liquefaction in a non-integrated process. The first-stage coal liquefaction has been carried out in a continuous pilot plant in Germany at Clausthal Technical University at 400[degree]C, 20 MPa hydrogen pressure and anthracene oil as solvent. The second-stage coal liquefaction has been performed in continuous operation in a hydroprocessing unit at the Instituto de Carboquimica at 450[degree]C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al[sub 2]O[sub 3]) and HT-500E (Ni-Mo/Al[sub 2]O[sub 3]). The total conversion for the first-stage coal liquefaction was 75.41 wt% (coal d.a.f.), being 3.79 wt% gases, 2.58 wt% primary condensate and 69.04 wt% heavy liquids. The heteroatoms removal for the second-stage liquefaction was 97-99 wt% of S, 85-87 wt% of N and 93-100 wt% of O. The hydroprocessed liquids have about 70% of compounds with boiling point below 350[degree]C, and meet the sulphur and nitrogen specifications for refinery feedstocks. Liquids from two-stage coal liquefaction have been distilled, and the naphtha, kerosene and diesel fractions obtained have been characterized. 39 refs., 3 figs., 8 tabs.

  18. One-stage and two-stage penile buccal mucosa urethroplasty

    African Journals Online (AJOL)

    G. Barbagli

    2015-12-02

    Dec 2, 2015 ... there also seems to be a trend of decreasing urethritis and an increase of instrumentation and catheter related strictures in these countries as well [4–6]. The repair of penile urethral strictures may require one- or two- stage urethroplasty [7–10]. Certainly, sexual function can be placed at risk by any surgery ...

  19. Optimization of Two-Stage Peltier Modules: Structure and Exergetic Efficiency

    Directory of Open Access Journals (Sweden)

    Cesar Ramirez-Lopez

    2012-08-01

    Full Text Available In this paper we undertake the theoretical analysis of a two-stage semiconductor thermoelectric module (TEM which contains an arbitrary and different number of thermocouples, n1 and n2, in each stage (pyramid-styled TEM. The analysis is based on a dimensionless entropy balance set of equations. We study the effects of n1 and n2, the flowing electric currents through each stage, the applied temperatures and the thermoelectric properties of the semiconductor materials on the exergetic efficiency. Our main result implies that the electric currents flowing in each stage must necessarily be different with a ratio about 4.3 if the best thermal performance and the highest temperature difference possible between the cold and hot side of the device are pursued. This fact had not been pointed out before for pyramid-styled two stage TEM. The ratio n1/n2 should be about 8.

  20. Improved survival of baby boomer women with early-stage uterine cancer: A Surveillance, Epidemiology and End Results (SEER) Study.

    Science.gov (United States)

    Elshaikh, Mohamed A; Ruterbusch, Julie; Cote, Michele L; Cattaneo, Richard; Munkarah, Adnan R

    2013-11-01

    To study the prognostic impact of baby boomer (BB) generation on survival end-points of patients with early-stage endometrial carcinoma (EC). Data were obtained from the SEER registry between 1988-2009. Inclusion criteria included women who underwent hysterectomy for stage I-II EC. Patients were divided into two birth cohorts: BB (women born between 1946 and 1964) and pre-boomers (PB) (born between 1926 and 1945). A total of 30,956 patients were analyzed. Considering that women in the PB group were older than those of the BB generation, the statistical analysis was limited to women 50-59 years of age at the time of diagnosis (n=11,473). Baby boomers had a significantly higher percentage of endometrioid histology (pgeneration compared to the PB generation (p=0.0003) with a trend for improved uterine cancer-specific survival (p=0.0752). On multivariate analysis, birth cohort (BB vs. PB) was not a significant predictor of survival end-points. Factors predictive of survival included: tumor grade, FIGO stage, African-American race, and increased number of dissected LN. Our study suggests that the survival of BB women between 50-60 years of age is better compared to women in the PB generation. As more BB patients are diagnosed with EC, further research is warranted.

  1. Two-Stage Variable Sample-Rate Conversion System

    Science.gov (United States)

    Tkacenko, Andre

    2009-01-01

    A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

  2. Issues in epidemiological studies of radiofrequency workers

    International Nuclear Information System (INIS)

    Hocking, B.

    1985-01-01

    The paper reviews some of the issues in a proposed epidemiological study of radiofrequency workers. First a few other epidemiological studies are discussed to illustrate some of the common problems such as inadequate definition of effects and/or exposure. Then technical problems in determining dosage and responses as well as study design are reviewed, and finally the administrative aspects of ethics, industrial relations and costs are considered

  3. Improved Survival With Radiation Therapy in Stage I-II Primary Mediastinal B Cell Lymphoma: A Surveillance, Epidemiology, and End Results Database Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Matthew W., E-mail: matthew.jackson@ucdenver.edu [Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado (United States); Rusthoven, Chad G.; Jones, Bernard L. [Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado (United States); Kamdar, Manali [Department of Medical Oncology, University of Colorado Cancer Center, Aurora, Colorado (United States); Rabinovitch, Rachel [Department of Radiation Oncology, University of Colorado Cancer Center, Aurora, Colorado (United States)

    2016-01-01

    Background: Primary mediastinal B cell lymphoma (PMBCL) is an uncommon lymphoma for which trials are few with small patient numbers. The role of radiation therapy (RT) after standard immunochemotherapy for early-stage disease has never been studied prospectively. We used the Surveillance, Epidemiology, and End Results (SEER) database to evaluate PMBCL and the impact of RT on outcomes. Methods and Materials: We queried the SEER database for patients with stage I-II PMBCL diagnosed from 2001 to 2011. Retrievable data included age, gender, race (white/nonwhite), stage, extranodal disease, year of diagnosis, and use of RT as a component of definitive therapy. Kaplan-Meier overall survival (OS) estimates, univariate (UVA) log-rank and multivariate (MVA) Cox proportional hazards regression analyses were performed. Results: Two hundred fifty patients with stage I-II disease were identified, with a median follow-up time of 39 months (range, 3-125 months). The median age was 36 years (range, 18-89 years); 61% were female; 76% were white; 45% had stage I disease, 60% had extranodal disease, and 55% were given RT. The 5-year OS for the entire cohort was 86%. On UVA, OS was improved with RT (hazard ratio [HR] 0.446, P=.029) and decreased in association with nonwhite race (HR 2.70, P=.006). The 5-year OS was 79% (no RT) and 90% (RT). On MVA, white race and RT remained significantly associated with improved OS (P=.007 and .018, respectively). The use of RT decreased over time: 61% for the 67 patients whose disease was diagnosed from 2001 to 2005 and 53% in the 138 patients treated from 2006 to 2010. Conclusion: This retrospective population-based analysis is the largest PMBCL dataset to date and demonstrates a significant survival benefit associated with RT. Nearly half of patients treated in the United States do not receive RT, and its use appears to be declining. In the absence of phase 3 data, the use of RT should be strongly considered for its survival benefit in early-stage

  4. The study on a gas-coupled two-stage stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Zhu, X. S.; Pan, C. Z.; Guo, J.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A two-stage gas-coupled Stirling-type pulse tube cryocooler (SPTC) driven by a linear dual-opposed compressor has been designed, manufactured and tested. Both of the stages adopted coaxial structure for compactness. The effect of a cold double-inlet at the second stage on the cooling performance was investigated. The test results show that the cold double-inlet will help to achieve a lower cooling temperature, but it is not conducive to achieving a higher cooling capacity. At present, without the cold double-inlet, the second stage has achieved a no-load temperature of 11.28 K and a cooling capacity of 620 mW/20 K with an input electric power of 450 W. With the cold double-inlet, the no-load temperature is lowered to 9.4 K, but the cooling capacity is reduced to 400 mW/20 K. The structure of the developed cryocooler and the influences of charge pressure, operating frequency and hot end temperature will also be introduced in this paper.

  5. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts

    Directory of Open Access Journals (Sweden)

    Chia-Chang Chien

    2009-01-01

    Full Text Available Chia-Chang Chien1, Shu-Fen Huang1,2,3,4, For-Wey Lung1,2,3,41Department of Psychiatry, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan; 2Graduate Institute of Behavioral Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Department of Psychiatry, National Defense Medical Center, Taipei, Taiwan; 4Calo Psychiatric Center, Pingtung County, TaiwanObjective: The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of military conscripts.Methods: We collected 99 conscripted soldiers whose educational levels were senior high school level or lower to be the participants. Every participant was required to take the Wisconsin Card Sorting Test (WCST and the Wechsler Adult Intelligence Scale-Revised (WAIS-R assessments.Results: Logistic regression analysis showed the conceptual level responses (CLR index of the WCST was the most significant index for determining intellectual disability (ID; FIQ ≤ 84. We used the receiver operating characteristic curve to determine the optimum cut-off point of CLR. The optimum one cut-off point of CLR was 66; the two cut-off points were 49 and 66. Comparing the two-stage window screening with the two-stage positive screening, the area under the curve and the positive predictive value increased. Moreover, the cost of the two-stage window screening decreased by 59%.Conclusion: The two-stage window screening is more accurate and economical than the two-stage positive screening. Our results provide an example for the use of two-stage screening and the possibility of the WCST to replace WAIS-R in large-scale screenings for ID in the future.Keywords: intellectual disability, intelligence screening, two-stage positive screening, Wisconsin Card Sorting Test, Wechsler Adult Intelligence Scale-Revised

  6. Epidemiological, clinical and developmental aspects of chronic ...

    African Journals Online (AJOL)

    Introduction: Our objective in this study was to describe both the epidemiological and clinical aspects and the difficulties of management of childhood CKD stages 3-5 in Senegal in order to express recommendations. Materials and Methods: This was a retrospective study from January 2005 to December 2013 in the ...

  7. High performance work systems and employee well-being: a two stage study of a rural Australian hospital.

    Science.gov (United States)

    Young, Suzanne; Bartram, Timothy; Stanton, Pauline; Leggat, Sandra G

    2010-01-01

    This paper aims to explore the attitudes of managers and employees to high performance work practices (HPWS) in a medium sized rural Australian hospital. The study consists of two stages. Stage one involved a qualitative investigation consisting of interviews and focus group sessions with senior, middle and line management at the hospital. Bowen and Ostroffs framework was used to examine how strategic HRM was understood, interpreted and operationalised across the management hierarchy. Stage one investigates the views of managers concerning the implementation of strategic HRM/HPWS. Stage two consisted of a questionnaire administered to all hospital employees. The mediation effects of social identification on the relationship between high performance work systems and affective commitment and job satisfaction are examined. The purpose of stage two was to investigate the views and effects of SHRM/HPWS on employees. It should be noted that HPWS and strategic HRM are used inter-changeably in this paper. At the management level the importance of distinctiveness, consistency and consensus in the interpretation of strategic HRM/HPWS practices across the organization was discovered. Findings indicate that social identification mediates the relationship between HPWS and affective commitment and also mediates the relationship between HPWS and job satisfaction. High performance work systems may play a crucial role facilitating social identification at the unit level. Such practices and management support is likely to provide benefits in terms of high performing committed employees. The paper argues that team leaders and managers play a key role in building social identification within the team and that organizations need to understand this role and provide recognition, reward, education and support to their middle and lower managers.

  8. Study of two-stage turbine characteristic and its influence on turbo-compound engine performance

    International Nuclear Information System (INIS)

    Zhao, Rongchao; Zhuge, Weilin; Zhang, Yangjun; Yang, Mingyang; Martinez-Botas, Ricardo; Yin, Yong

    2015-01-01

    Highlights: • An analytical model was built to study the interactions between two turbines in series. • The impacts of HP VGT and LP VGT on turbo-compound engine performance were investigated. • The fuel reductions obtained by HP VGT at 1900 rpm and 1000 rpm are 3.08% and 7.83% respectively. • The optimum value of AR ranged from 2.0 to 2.5 as the turbo-compound engine speed decreases. - Abstract: Turbo-compounding is an effective way to recover waste heat from engine exhaust and reduce fuel consumption for internal combustion engine (ICE). The characteristics of two-stage turbine, including turbocharger turbine and power turbine, have significant effects on the overall performance of turbo-compound engine. This paper investigates the interaction between two turbines in a turbo-compound engine and its impact on the engine performance. Firstly an analytical model is built to investigate the effects of turbine equivalent flow area on the two-stage turbine characteristics, including swallowing capacity and load split. Next both simulation and experimental method are carried out to study the effects of high pressure variable geometry turbine (HP VGT), low pressure variable geometry turbine (LP VGT) and combined VGT on the engine overall performance. The results show that the engine performance is more sensitive to HP VGT compared with LP VGT at all the operation conditions, which is caused by the larger influences of HP VGT on the total expansion ratio and engine air–fuel ratio. Using the HP VGT method, the fuel reductions of the turbo-compound engine at 1900 rpm and 1000 rpm are 3.08% and 7.83% respectively, in comparison with the baseline engine. The corresponding optimum values of AR are 2.0 and 2.5

  9. [Study on supply and demand relation based on two stages division of market of Chinese materia medica].

    Science.gov (United States)

    Yang, Guang; Guo, Lan-Ping; Wang, Nuo; Zeng, Yan; Huang, Lu-Qi

    2014-01-01

    The complex production processes and long industrial chain in traditional Chinese medicine (TCM) market result in difficulty in Chinese market microstructure research. Based on the defining the logical relationships among different concepts. This paper divides TCM market into two stages as Chinese materia medica resource market and traditional Chinese Patent Medicines market. Under this foundation, we investigated the supply capacity, approaching rules and motivation system of suppliers in TCM market, analyzed the demand situation in the perspective of demand side, and evaluated the purchasing power in terms of population profile, income, and insurance. Furthermore we also analyzed the price formation mechanism in two stages of TCM market. We hope this study can make a positive and promotion effect on TCM market related research.

  10. Studies on quantitative physiology of Trichoderma reesei with two-stage continuous culture for cellulase production

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, D; Andreotti, R; Mandels, M; Gallo, B; Reese, E T

    1979-11-01

    By employing a two-stage continuous-culture system, some of the more important physiological parameters involved in cellulase biosynthesis have been evaluated with an ultimate objective of designing an optimally controlled cellulase process. The two-stage continuous-culture system was run for a period of 1350 hr with Trichoderma reesei strain MCG-77. The temperature and pH were controlled at 32/sup 0/C and pH 4.5 for the first stage (growth) and 28/sup 0/C and pH 3.5 for the second stage (enzyme production). Lactose was the only carbon source for both stages. The ratio of specific uptake rate of carbon to that of nitrogen, Q(C)/Q(N), that supported good cell growth ranged from 11 to 15, and the ratio for maximum specific enzyme productivity ranged from 5 to 13. The maintenance coefficients determined for oxygen, M/sub 0/, and for carbon source, M/sub c/, are 0.85 mmol O/sub 2//g biomass/hr and 0.14 mmol hexose/g biomass/hr, respectively. The yield constants determined are: Y/sub X/O/ = 32.3 g biomass/mol O/sub 2/, Y/sub X/C/ = 1.1 g biomass/g C or Y/sub X/C/ = 0.44 g biomass/g hexose, Y/sub X/N/ = 12.5 g biomass/g nitrogen for the cell growth stage, and Y/sub X/N/ = 16.6 g biomass/g nitrogen for the enzyme production stage. Enzyme was produced only in the second stage. Volumetric and specific enzyme productivities obtained were 90 IU/liter/hrand 8 IU/g biomass/hr, respectively. The maximum specific enzyme productivity observed was 14.8 IU/g biomass/hr. The optimal dilution rate in the second stage that corresponded to the maximum enzyme productivity was 0.026 approx. 0.028 hr/sup -1/, and the specific growth rate in the second stage that supported maximum specific enzyme productivity was equal to or slightly less than zero.

  11. What is desirable and feasible in dose reconstruction for application in epidemiological studies?

    International Nuclear Information System (INIS)

    Bouville, A.; Beebe, G.W.; Anspaugh, L.

    1996-02-01

    Epidemiological studies of populations are of two general forms, monitoring or formal, and serve several possible purposes. Monitoring studies inform members of potentially affected population groups of the nature and magnitude of the risks that might have been imposed on them. Formal epidemiological studies can increase scientific knowledge about the quantitative risk that attends exposure. Risks of human health due to radiation exposure are most appropriately estimated by means of formal epidemiological studies. Dosimetric data are essential for any epidemiological study, but the detail and accuracy needed depend on the purposes to be served. If the need is for a monitoring study, then general information about doses will suffice. However, a formal study that is expected to contribute to scientific information about quantitative radiation risk requires careful individual dose estimation. This paper is devoted to the discussion of dosimetric data needed for formal epidemiological studies of populations exposed as a result of nuclear power operations. The recommendations made by the National Research Council have largely been followed. The examples used in this paper are relevant to the Chernobyl accident, which caused a large number of people to be exposed at relatively high doses and provided an opportunity for formal epidemiological studies to be initiated. The studies that are singled out are those of thyroid cancer among children who resided in Belarus and in Ukraine at the time of the accident, and those of leukemia among workers involved in the mitigation of the accident and in clean-up operations

  12. Two-stage case-control association study of dopamine-related genes and migraine

    Directory of Open Access Journals (Sweden)

    Pardo Julio

    2009-09-01

    Full Text Available Abstract Background We previously reported risk haplotypes for two genes related with serotonin and dopamine metabolism: MAOA in migraine without aura and DDC in migraine with aura. Herein we investigate the contribution to migraine susceptibility of eight additional genes involved in dopamine neurotransmission. Methods We performed a two-stage case-control association study of 50 tag single nucleotide polymorphisms (SNPs, selected according to genetic coverage parameters. The first analysis consisted of 263 patients and 274 controls and the replication study was composed by 259 cases and 287 controls. All cases were diagnosed according to ICHD-II criteria, were Spanish Caucasian, and were sex-matched with control subjects. Results Single-marker analysis of the first population identified nominal associations of five genes with migraine. After applying a false discovery rate correction of 10%, the differences remained significant only for DRD2 (rs2283265 and TH (rs2070762. Multiple-marker analysis identified a five-marker T-C-G-C-G (rs12363125-rs2283265-rs2242592-rs1554929-rs2234689 risk haplotype in DRD2 and a two-marker A-C (rs6356-rs2070762 risk haplotype in TH that remained significant after correction by permutations. These results, however, were not replicated in the second independent cohort. Conclusion The present study does not support the involvement of the DRD1, DRD2, DRD3, DRD5, DBH, COMT, SLC6A3 and TH genes in the genetic predisposition to migraine in the Spanish population.

  13. One-stage exchange with antibacterial hydrogel coated implants provides similar results to two-stage revision, without the coating, for the treatment of peri-prosthetic infection.

    Science.gov (United States)

    Capuano, Nicola; Logoluso, Nicola; Gallazzi, Enrico; Drago, Lorenzo; Romanò, Carlo Luca

    2018-03-16

    Aim of this study was to verify the hypothesis that a one-stage exchange procedure, performed with an antibiotic-loaded, fast-resorbable hydrogel coating, provides similar infection recurrence rate than a two-stage procedure without the coating, in patients affected by peri-prosthetic joint infection (PJI). In this two-center case-control, study, 22 patients, treated with a one-stage procedure, using implants coated with an antibiotic-loaded hydrogel [defensive antibacterial coating (DAC)], were compared with 22 retrospective matched controls, treated with a two-stage revision procedure, without the coating. At a mean follow-up of 29.3 ± 5.0 months, two patients (9.1%) in the DAC group showed an infection recurrence, compared to three patients (13.6%) in the two-stage group. Clinical scores were similar between groups, while average hospital stay and antibiotic treatment duration were significantly reduced after one-stage, compared to two-stage (18.9 ± 2.9 versus 35.8 ± 3.4 and 23.5 ± 3.3 versus 53.7 ± 5.6 days, respectively). Although in a relatively limited series of patients, our data shows similar infection recurrence rate after one-stage exchange with DAC-coated implants, compared to two-stage revision without coating, with reduced overall hospitalization time and antibiotic treatment duration. These findings warrant further studies in the possible applications of antibacterial coating technologies to treat implant-related infections. III.

  14. Cocoa Polyphenols: Evidence from Epidemiological Studies.

    Science.gov (United States)

    Matsumoto, Chisa

    2018-01-01

    Accumulating evidence suggests potential preventive effects of chocolate/cocoa on the risk of cardio vascular disease (CVD). However, cocoa products also contain high levels of sugar and fat, which increase CVD risk factors. Even, the identity of the substance in chocolate/cocoa that has a favorable effect on CVD and CVD risk factors remains unclear, growing evidence from experimental studies suggests that cocoa polyphenols might be a major contributor to cardiovascular-protective effects. However, epidemiological studies, which are necessary to evaluate an association between the risk of CVD and cocoa polyphenol, remain sparse. We will discuss recent evidence regarding the association between cocoa polyphenol consumption and the risks of CVD and its risk factors by reviewing recent epidemiological studies. We shall also provide some guidance for patient counseling and will discuss the public health implications for recommending cocoa polyphenol consumption to prevent CVD. Epidemiological studies evaluating the association between cocoa polyphenol itself and the risk of CVD are sparse. However, evidence from limited epidemiological studies suggests that cocoa polyphenol consumption may lower the risk of CVD. Given the potential adverse effects of the consumption of cocoa products with high fat and sugar and the fact that the most appropriate dose of cocoa polyphenol for cardio-protective effects has not yet been established, health care providers should remain cautious about recommending cocoa/cocoa polyphenol consumption to their patients to reduce the risk of CVD, taking the characteristics of individual patients into careful consideration. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. Review of epidemiological studies of human populations exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Rao, B.S.

    2002-01-01

    Epidemiological studies undertaken in many radiation exposed cohorts have played an important role in the quantification of radiation risk. Follow up of nearly 100,000 A-bomb survivors by the Radiation Effects Research Foundation (RERF), constitutes the most comprehensive human epidemiological study. The study population covered both sexes, different age groups and dose ranges from a few mSv to 2-3 Sv. Among nearly 90,000 cohorts, as on 1990, 54% are alive. Among these, 35,000 are those exposed as children at the age<20 years. Nearly 20 % of the mortalities (8,040) were due to cancer. It was estimated from the analysis of these data that among the cancers observed in LSS cohorts, 425±45 cases (335 solid cancers+90 leukaemias) were attributable to radiation exposure. Assuming a value of two for DDREF, ICRP 60, 1991 estimated a cancer risk of 5% per Sv for low dose and low dose rate exposure conditions. There have been a number of efforts to study the human populations exposed to low level radiations. Epidemiological studies on nuclear workers from USA, UK and Canada constituting 95,673 workers spanning 2,124,526 person years was reported by Cardis et al. (1995). Total number of deaths were 15,825, of which 3,976 were cancer mortalities. The excess relative risk for all cancers excluding leukaemia is -0.07 per Sv (-0.4- +0.3) and for leukaemia (excluding CLL) is 2.18 (0.1-5.7). Epidemiological studies in high background radiation areas (HBRA) of Yangjiang, China and coastal Kerala showed no detectable increase in the incidence of cancers or of any genetic disorders. Epidemiological studies in human populations exposed to elevated background radiation for several generations did not show any increase in the genetic disorders. Recent information on the background incidence of monogenic disorders in human populations and the recoverability factor of induced genetic changes suggests a risk much lower than the earlier ICRP estimates. Many other epidemiological studies of

  16. Epidemiological studies of radiation workers in nuclear facilities

    International Nuclear Information System (INIS)

    Iwai, Satoshi; Semba, Tsuyoshi; Ishida, Kenji; Takagi, Syunji; Igari, Takafumi

    2017-01-01

    Regarding workers at nuclear facilities, this paper described INWORKS epidemiological research published in 2015, cooperative cohort epidemiological research of IARC 15 countries 10 years before that (15-country study), and the flow of radiation epidemiological research in the period from 15-country study to INWORKS. INWORKS is a retrospective cohort study to investigate the correlation between mortality due to solid cancer, blood cancer, and cardiovascular diseases in workers in three countries of France / the U.K. / the U.S. and low dose exposure through long-term photon external exposure. It obtained the data showing the statistical significance of increased cancer death rate. However, from the subjects of the analysis, no significant evaluation was made on neutron exposure and internal exposure. Statistically significant cancer mortality was confirmed in 15-country study at low dose, low dose rate, and prolonged exposure, but significant cancer mortality rate could not be confirmed excluding Canadian data, which had problems in dose evaluation. In the epidemiological studies of cancer mortality rates of radiation workers in nuclear power industries performed in France / the U.K. / the U.S. in the period ranging from 15-country study to INWORKS, significant difference was not recognized between cancer death rate and excessive relative risk (ERR) compared with LSS epidemiological research studies that handled acute exposure. Several tasks are still remaining. (A.O.)

  17. Methodologic assessment of radiation epidemiology studies

    International Nuclear Information System (INIS)

    Beebe, G.W.

    1983-01-01

    Epidemiologic studies of the late effects of ionizing radiation have utilized the entire spectrum of situations in which man has been exposed. These studies have provided insights into the dependence of human effects upon not only dose to target tissues but also other dimensions of exposure, host characteristics, and time following exposure. Over the past three decades studies have progressed from the mere identification of effects to their measurement. Because investigators of human effects have no control over the exposure situation, validity must be sought in the consistency of findings among independent studies and with accepted biologic principles. Because exposure may be confounded with factors that are hidden from view, bias may enter into any study of human exposure. Avoidance of bias and attainment of sufficient power to detect relationships that are real are methodologic challenges. Many methodologic issues, e.g., those associated with the definition and measurement of specific end-points, or with the selection of appropriate controls, permeate epidemiologic work in all fields. Others, especially those concerned with the measurement of exposure, the patterning of events in time after exposure, and the prediction of events beyond the scope of existing observations give radiation epidemiology its distinctive character

  18. 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…

  19. ADHD in the Arab World: A Review of Epidemiologic Studies

    Science.gov (United States)

    Farah, Lynn G.; Fayyad, John A.; Eapen, Valsamma; Cassir,Youmna; Salamoun, Mariana M.; Tabet, Caroline C.; Mneimneh, Zeina N.; Karam, Elie G.

    2009-01-01

    Objective: Epidemiological studies on psychiatric disorders are quite rare in the Arab World. This article reviews epidemiological studies on ADHD in all the Arab countries. Method: All epidemiological studies on ADHD conducted from 1966 through th present were reviewed. Samples were drawn from the general community, primary care clinical…

  20. Hybrid biogas upgrading in a two-stage thermophilic reactor

    DEFF Research Database (Denmark)

    Corbellini, Viola; Kougias, Panagiotis; Treu, Laura

    2018-01-01

    The aim of this study is to propose a hybrid biogas upgrading configuration composed of two-stage thermophilic reactors. Hydrogen is directly injected in the first stage reactor. The output gas from the first reactor (in-situ biogas upgrade) is subsequently transferred to a second upflow reactor...... (ex-situ upgrade), in which enriched hydrogenotrophic culture is responsible for the hydrogenation of carbon dioxide to methane. The overall objective of the work was to perform an initial methane enrichment in the in-situ reactor, avoiding deterioration of the process due to elevated pH levels......, and subsequently, to complete the biogas upgrading process in the ex-situ chamber. The methane content in the first stage reactor reached on average 87% and the corresponding value in the second stage was 91%, with a maximum of 95%. A remarkable accumulation of volatile fatty acids was observed in the first...

  1. An adaptive two-stage dose-response design method for establishing proof of concept.

    Science.gov (United States)

    Franchetti, Yoko; Anderson, Stewart J; Sampson, Allan R

    2013-01-01

    We propose an adaptive two-stage dose-response design where a prespecified adaptation rule is used to add and/or drop treatment arms between the stages. We extend the multiple comparison procedures-modeling (MCP-Mod) approach into a two-stage design. In each stage, we use the same set of candidate dose-response models and test for a dose-response relationship or proof of concept (PoC) via model-associated statistics. The stage-wise test results are then combined to establish "global" PoC using a conditional error function. Our simulation studies showed good and more robust power in our design method compared to conventional and fixed designs.

  2. Evaluation of the AJCC 8th Edition Staging System for Pathologically Versus Clinically Staged Intrahepatic Cholangiocarcinoma (iCCA): a Time to Revisit a Dogma? A Surveillance, Epidemiology, and End Results (SEER) Analysis.

    Science.gov (United States)

    Kamarajah, Sivesh K

    2018-03-07

    Recently, the AJCC has released its 8th edition changes to the staging system for intrahepatic cholangiocarcinoma (iCCA). This study sought to validate the proposed changes to the 8th edition of AJCC system for T and N classification of iCCA using a population-based data set. Using the Surveillance, Epidemiology, and End Results (SEER) database (1998-2013), patients undergoing resection or non-surgical management for non-metastatic iCCA were identified. Overall survival was estimated using the Kaplan-Meier method and compared using log-rank tests. Concordance indices (c-indices) calculated from Cox proportional hazards models were calculated to evaluate discriminatory power. The study included 2630 patients resected (37%) or non-surgically managed (63%) for iCCA. Nodal staging was performed in 56%, of whom 31% had positive nodes. For all patients with iCCA, the median 5-year survival by AJCC T classification for T1a, T1b, T2, T3, and T4 was 32, 21, 14, 10, and 10 months, respectively (p < 0.001). The concordance index for the staging system was 0.57 for all patients, 0.62 for those who underwent resection, and 0.54 for patients who did not undergo resection. In summary, the new AJCC 8th edition staging system is comparable to the 7th edition and valid in stratifying patients with iCCA. However, the performance of the staging system is better in patients undergoing surgical resection than those undergoing non-surgical management. These findings further highlight the need for improved accuracy of radiological imaging in clinically staging patients to guide prognosis.

  3. [Comparison research on two-stage sequencing batch MBR and one-stage MBR].

    Science.gov (United States)

    Yuan, Xin-Yan; Shen, Heng-Gen; Sun, Lei; Wang, Lin; Li, Shi-Feng

    2011-01-01

    Aiming at resolving problems in MBR operation, like low nitrogen and phosphorous removal efficiency, severe membrane fouling and etc, comparison research on two-stage sequencing batch MBR (TSBMBR) and one-stage aerobic MBR has been done in this paper. The results indicated that TSBMBR owned advantages of SBR in removing nitrogen and phosphorous, which could make up the deficiency of traditional one-stage aerobic MBR in nitrogen and phosphorous removal. During steady operation period, effluent average NH4(+) -N, TN and TP concentration is 2.83, 12.20, 0.42 mg/L, which could reach domestic scenic environment use. From membrane fouling control point of view, TSBMBR has lower SMP in supernatant, specific trans-membrane flux deduction rate, membrane fouling resistant than one-stage aerobic MBR. The sedimentation and gel layer resistant of TSBMBR was only 6.5% and 33.12% of one-stage aerobic MBR. Besides high efficiency in removing nitrogen and phosphorous, TSBMBR could effectively reduce sedimentation and gel layer pollution on membrane surface. Comparing with one-stage MBR, TSBMBR could operate with higher trans-membrane flux, lower membrane fouling rate and better pollutants removal effects.

  4. 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)

  5. Two-stage exchange knee arthroplasty: does resistance of the infecting organism influence the outcome?

    Science.gov (United States)

    Kurd, Mark F; Ghanem, Elie; Steinbrecher, Jill; Parvizi, Javad

    2010-08-01

    Periprosthetic joint infection after TKA is a challenging complication. Two-stage exchange arthroplasty is the accepted standard of care, but reported failure rates are increasing. It has been suggested this is due to the increased prevalence of methicillin-resistant infections. We asked the following questions: (1) What is the reinfection rate after two-stage exchange arthroplasty? (2) Which risk factors predict failure? (3) Which variables are associated with acquiring a resistant organism periprosthetic joint infection? This was a case-control study of 102 patients with infected TKA who underwent a two-stage exchange arthroplasty. Ninety-six patients were followed for a minimum of 2 years (mean, 34.5 months; range, 24-90.1 months). Cases were defined as failures of two-stage exchange arthroplasty. Two-stage exchange arthroplasty was successful in controlling the infection in 70 patients (73%). Patients who failed two-stage exchange arthroplasty were 3.37 times more likely to have been originally infected with a methicillin-resistant organism. Older age, higher body mass index, and history of thyroid disease were predisposing factors to infection with a methicillin-resistant organism. Innovative interventions are needed to improve the effectiveness of two-stage exchange arthroplasty for TKA infection with a methicillin-resistant organism as current treatment protocols may not be adequate for control of these virulent pathogens. Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

  6. Two-staged management for all types of congenital pouch colon

    Directory of Open Access Journals (Sweden)

    Rajendra K Ghritlaharey

    2013-01-01

    Full Text Available Background: The aim of this study was to review our experience with two-staged management for all types of congenital pouch colon (CPC. Patients and Methods: This retrospective study included CPC cases that were managed with two-staged procedures in the Department of Paediatric Surgery, over a period of 12 years from 1 January 2000 to 31 December 2011. Results: CPC comprised of 13.71% (97 of 707 of all anorectal malformations (ARM and 28.19% (97 of 344 of high ARM. Eleven CPC cases (all males were managed with two-staged procedures. Distribution of cases (Narsimha Rao et al.′s classification into types I, II, III, and IV were 1, 2, 6, and 2, respectively. Initial operative procedures performed were window colostomy (n = 6, colostomy proximal to pouch (n = 4, and ligation of colovesical fistula and end colostomy (n = 1. As definitive procedures, pouch excision with abdomino-perineal pull through (APPT of colon in eight, and pouch excision with APPT of ileum in three were performed. The mean age at the time of definitive procedures was 15.6 months (ranges from 3 to 53 months and the mean weight was 7.5 kg (ranges from 4 to 11 kg. Good fecal continence was observed in six and fair in two cases in follow-up periods, while three of our cases lost to follow up. There was no mortality following definitive procedures amongst above 11 cases. Conclusions: Two-staged procedures for all types of CPC can also be performed safely with good results. The most important fact that the definitive procedure is being done without protective stoma and therefore, it avoids stoma closure, stoma-related complications, related cost of stoma closure and hospital stay.

  7. Two-stage revision surgery with preformed spacers and cementless implants for septic hip arthritis: a prospective, non-randomized cohort study

    Directory of Open Access Journals (Sweden)

    Logoluso Nicola

    2011-05-01

    Full Text Available Abstract Background Outcome data on two-stage revision surgery for deep infection after septic hip arthritis are limited and inconsistent. This study presents the medium-term results of a new, standardized two-stage arthroplasty with preformed hip spacers and cementless implants in a consecutive series of adult patients with septic arthritis of the hip treated according to a same protocol. Methods Nineteen patients (20 hips were enrolled in this prospective, non-randomized cohort study between 2000 and 2008. The first stage comprised femoral head resection, debridement, and insertion of a preformed, commercially available, antibiotic-loaded cement hip spacer. After eradication of infection, a cementless total hip arthroplasty was implanted in the second stage. Patients were assessed for infection recurrence, pain (visual analog scale [VAS] and hip joint function (Harris Hip score. Results The mean time between first diagnosis of infection and revision surgery was 5.8 ± 9.0 months; the average duration of follow up was 56.6 (range, 24 - 104 months; all 20 hips were successfully converted to prosthesis an average 22 ± 5.1 weeks after spacer implantation. Reinfection after total hip joint replacement occurred in 1 patient. The mean VAS pain score improved from 48 (range, 35 - 84 pre-operatively to 18 (range, 0 - 38 prior to spacer removal and to 8 (range, 0 - 15 at the last follow-up assessment after prosthesis implantation. The average Harris Hip score improved from 27.5 before surgery to 61.8 between the two stages to 92.3 at the final follow-up assessment. Conclusions Satisfactory outcomes can be obtained with two-stage revision hip arthroplasty using preformed spacers and cementless implants for prosthetic hip joint infections of various etiologies.

  8. Epidemiological study around La Hague

    International Nuclear Information System (INIS)

    1999-01-01

    The North Cotentin is in France, the area where have been led until now, the biggest number of epidemiology studies on the effects of ionizing radiations on man, in order to assess the leukemia incidences and other cancer pathologies around nuclear facilities. The North Cotentin concentrates four nuclear installations.The objective of this file is to take stock of the situation in this field. In 1995 and 1998 have been published two sections of an epidemiology study about the incidence of leukemia in North Cotentin (J.F. Viel study for the period 1978-1992, Spira study for 1993-1997). The study of the Professor Spira does not bring to the fore a significant excess of leukemia for the period 1978-1997. The report of the professor Spira advocates several complementary epidemiology studies to precise or complete the data and lighten the causes of leukemia in North Cotentin. The studies of J.F.Viel shows that it does not exist a significant excess of cases in the studied area (25 cases for 22.8 expected cases, so a non significant difference) but notices an aggregate at the limit to be significant in the Beaumont-Hague canton (4 cases for 1.4 expected cases). J.F.Viel puts forward a relationship between the risk increase (of leukemia incidence) and some individual characteristics linked to the way of life of the studied persons: the North Cotentin beaches frequenting by the mothers or the children at least one time by month, the consumption of fish or shellfish having a local origin at least one time by week. This study suggests that it is the radioactivity, on the beaches on in fishes and shellfish that would be at the origin of the additional noticed leukemia. The authorities asked at the beginning of 1997, a scientific commission directed by the Professor Souleau to propose a new epidemiology study on the leukemia risk around La Hague. The report concludes that the leukemia incidence in the North Cotentin is in accordance with the expected incidence (25 observed

  9. Performance study of a heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system

    International Nuclear Information System (INIS)

    Zhang, Ning; Yin, Shao-You; Zhang, Li-Zhi

    2016-01-01

    Graphical abstract: A heat pump driven, hollow fiber membrane-based two-stage liquid desiccant air dehumidification system. - Highlights: • A two-stage hollow fiber membrane based air dehumidification is proposed. • It is heat pump driven liquid desiccant system. • Performance is improved 20% upon single stage system. • The optimal first to second stage dehumidification area ratio is 1.4. - Abstract: A novel compression heat pump driven and hollow fiber membrane-based two-stage liquid desiccant air dehumidification system is presented. The liquid desiccant droplets are prevented from crossing over into the process air by the semi-permeable membranes. The isoenthalpic processes are changed to quasi-isothermal processes by the two-stage dehumidification processes. The system is set up and a model is proposed for simulation. Heat and mass capacities in the system, including the membrane modules, the condenser, the evaporator and the heat exchangers are modeled in detail. The model is also validated experimentally. Compared with a single-stage dehumidification system, the two-stage system has a lower solution concentration exiting from the dehumidifier and a lower condensing temperature. Thus, a better thermodynamic system performance is realized and the COP can be increased by about 20% under the typical hot and humid conditions in Southern China. The allocations of heat and mass transfer areas in the system are also investigated. It is found that the optimal regeneration to dehumidification area ratio is 1.33. The optimal first to second stage dehumidification area ratio is 1.4; and the optimal first to second stage regeneration area ratio is 1.286.

  10. Two-stage implant placement technique for the management of irradiated jaws: An animal study.

    Science.gov (United States)

    Aboushelib, Moustafa N; Arnaout, Mohamed A; Elsafi, Mohamed H; Kassem, Youssef M

    2017-10-01

    Radiotherapy results in diminished bone remodeling capacity and an elevated risk of osteoradionecrosis, which can negatively influence the survival rate of dental implants. Patients receiving radiotherapy are advised not to receive dental implants during or soon after completing their radiotherapy. The purpose of this animal study was to investigate a 2-stage implant placement technique designed to diminish applied trauma on irradiated bone. Two groups of white New Zealand rabbits received radiotherapy in ascending doses (2, 4, 8 Gy), while a nonirradiated group served as control. Three weeks after completion of the last radiotherapy session, one of the irradiated groups and the control group received titanium dental implants bilaterally in the femur head. For the second irradiated group, an osteotomy was performed, and the surgical wound was left to heal for 2 weeks before implant placement. All animals were sacrificed 4 weeks after implant placement, and histomorphometric analysis was used to study bone-implant contact (n=14, α=.05). Statistical analysis revealed significantly higher (F=159, P<.001) bone-implant contact in the 2-stage (40.2 ±1.9) implant placement technique than in the immediately placed implants (21.2 ±2.3) in irradiated bone. Both of the groups had a significantly lower bone-to-implant contact ratio than the non-irradiated control (64.2 ±3.8). Within the limitations of this animal study, the 2-stage implant placement technique could be used to reduce trauma in irradiated bone and to improve wound healing around dental implants. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  11. Validity of Center for Epidemiologic Studies Depression (CES-D scale in a sample of Iraq and Afghanistan Veterans

    Directory of Open Access Journals (Sweden)

    Ana R Quiñones

    2016-04-01

    Full Text Available Objectives: Optimal depression screening necessitates measurement tools that are valid across varied populations and in the presence of comorbidities. Methods: This study assessed the test properties of two versions of the Center for Epidemiologic Studies Depression scale against psychiatric diagnoses established by the Mini International Neuropsychiatric Interview among a clinical sample of US Veterans deployed during Operations Enduring Freedom, Iraqi Freedom, and New Dawn. Participants (N = 359 recruited from two Department of Veterans Affairs hospitals completed a clinical interview, structured diagnostic interview, and self-reported measures. Results: Based on diagnostic interview and the Diagnostic and Statistical Manual of Mental Disorders 4th Edition criteria, 29.5% of the sample met diagnostic criteria for major depressive disorder and 26.5% met diagnostic criteria for post-traumatic stress disorder. Both Center for Epidemiologic Studies Depression-20 and Center for Epidemiologic Studies Depression-10 scales performed well and almost identically against the Mini International Neuropsychiatric Interview-major depressive disorder in identifying Veterans with major depressive disorder (Center for Epidemiologic Studies Depression-20 area under the Receiver Operating Characteristic curve 91%; Center for Epidemiologic Studies Depression-10 area under the ROC curve 90%. Overall, higher cut points for the Center for Epidemiologic Studies Depression scales performed better in correctly identifying true positives and true negatives for major depressive disorder (Center for Epidemiologic Studies Depression-20 cut point 18+ sensitivity 92% specificity 72%; Center for Epidemiologic Studies Depression-10 cut point 10+ sensitivity 92% specificity 69%. Conclusions: The specificity of the Center for Epidemiologic Studies Depression scales was poor among Veterans with co-occurring post-traumatic stress disorder (13% and 16%. Veterans with post

  12. Polymorphisms in CARS are associated with gastric cancer risk: a two-stage case-control study in the Chinese population.

    Science.gov (United States)

    Tian, Tian; Xiao, Ling; Du, Jiangbo; Zhu, Xun; Gu, Yayun; Qin, Na; Yan, Caiwang; Liu, Li; Ma, Hongxia; Jiang, Yue; Chen, Jiaping; Yu, Hao; Dai, Juncheng

    2017-11-01

    The cysteinyl transfer RNA synthetase gene (CARS) is located on chromosome band 11p15.5, which is an important tumor-suppressor gene region. Mutations in CARS have been identified in many kinds of cancers; however, evidence for a relationship between genetic variants in CARS and gastric cancer at the population level is still lacking. Thus, we explored the association of variants in CARS with gastric cancer using a two-stage case-control strategy in Chinese. We undertook a two-stage case-control study to investigate the association between polymorphisms in CARS and risk of gastric cancer with use of an Illumina Infinium ® BeadChip and an ABI 7900 system. Four single nucleotide polymorphisms (SNPs) were significantly associated with gastric cancer risk in both the discovery stage and the validation stage after adjustment for age and sex. In addition, the combined results of the two stages showed these SNPs were related to gastric cancer risk (P false discovery rate  ≤ 0.001 for rs384,490, rs729662, rs2071101, and rs7394702). In silico analyses revealed that rs384490 and rs7394702 could affect transcription factor response elements or DNA methylation of CARS, and rs729662 was associated with the prognosis of gastric cancer. Additionally, expression quantitative trait loci analysis showed rs384490 and rs729662 might alter expression of CARS-related genes. The potential functional SNPs in CARS might influence the biological functions of CARS or CARS-related genes and ultimately modify the occurrence and development of gastric cancer in Chinese. Further large-scale population-based studies or biological functional assays are warranted to validate our findings.

  13. Outbreaks of paralytic poliomyelitis during 1996-2012: the changing epidemiology of a disease in the final stages of eradication.

    Science.gov (United States)

    Mach, Ondrej; Tangermann, Rudolf H; Wassilak, Steve G; Singh, Simarjit; Sutter, Roland W

    2014-11-01

    Despite substantial progress toward eradication of poliomyelitis, the risk of poliomyelitis outbreaks resulting from virus importations into polio-free areas persists. We reviewed the changing epidemiology of outbreaks in the final stages of the eradication initiative. Available literature on outbreaks of poliomyelitis caused by wild polioviruses between 1996 and 2012 was reviewed. During this period, there were 22 outbreaks involving 39 countries. Outbreaks ranged in size from 1 to 1335 cases. These outbreaks caused 4571 cases, representing 21% of all cases reported during this period. Five outbreaks involved multiple countries. In 76% of outbreaks (16/21) with a known age distribution, cases concentrated among children aged poliomyelitis had not occurred for many years. The changing epidemiology, with cases and higher case-fatality ratios among adults, increased the severity of these outbreaks. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  14. Epidemiology of Clostridium difficile infection in two tertiary-care hospitals in Perth, Western Australia: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    N.F. Foster

    2014-05-01

    Full Text Available The epidemiology of Clostridium difficile infection (CDI has changed over time and between countries. It is therefore essential to monitor the characteristics of patients at risk of infection and the circulating strains to recognize local and global trends, and improve patient management. From December 2011 to May 2012 we conducted a prospective, observational epidemiological study of patients with laboratory-confirmed CDI at two tertiary teaching hospitals in Perth, Western Australia to determine CDI incidence and risk factors in an Australian setting. The incidence of CDI varied from 5.2 to 8.1 cases/10 000 occupied bed days (OBDs at one hospital and from 3.9 to 16.3/10 000 OBDs at the second hospital. In total, 80 patients with laboratory-confirmed CDI met eligibility criteria and consented to be in the study. More than half (53.8% had hospital-onset disease, 28.8% had community-onset and healthcare facility-associated disease and 7.5% were community-associated infections according to the definitions used. Severe CDI was observed in 40.0% of these cases but the 30-day mortality rate for all cases was only 2.5%. Besides a shorter length of stay among cases of community-onset CDI, no characteristics were identified that were significantly associated with community-onset or severe CDI. From 70 isolates, 34 different ribotypes were identified. The predominant ribotypes were 014 (24.3%, 020 (5.7%, 056 (5.7% and 070 (5.7%. Whereas this study suggests that the characteristics of CDI cases in Australia are not markedly different from those in other developed countries, the increase in CDI rate observed emphasizes the importance of surveillance.

  15. Hodgkin's disease part 1: pathology, staging, and management of early stage disease

    International Nuclear Information System (INIS)

    Mauch, Peter; Yahalom, Joachim

    1995-01-01

    Over the past 25 years there have been dramatic improvements in our understanding of the epidemiology, biology, natural history, and treatment of Hodgkins disease. Hodgkin's disease is one of the few cancers where both chemotherapy and radiation therapy have provided dramatic improvements in cure of this once uniformly fatal disease. Part 1 of the refresher course on Hodgkin's disease will include a review of: 1) New Findings in epidemiology, immunohistochemistry and molecular biology of the Reed-Sternberg cell including association with Epstein-Barr virus; 2) Review of pathology including discussions of NS 1 vs NS2, and nodular LP subclassifications; 3) Recommendations for staging including the role of staging laparotomy in Hodgkin's disease; 4) Standard techniques for commonly used radiation therapy fields for Hodgkin's disease and 5) Treatment of early stage Hodgkin's disease including an overview on recent and current clinical trials

  16. Epidemiology of injuries in elite taekwondo athletes: two Olympic periods cross-sectional retrospective study

    Science.gov (United States)

    Altarriba-Bartes, Albert; Drobnic, Franchek; Til, Lluís; Malliaropoulos, Nikolaos; Montoro, José Bruno; Irurtia, Alfredo

    2014-01-01

    Objective Taekwondo injuries differ according to the characteristics of the athletes and the competition. This analytical cross-sectional retrospective cohort study aimed to describe reported taekwondo injuries and to determine the prevalence, characteristics and possible risk factors for injuries sustained by athletes of the Spanish national team. In addition, we compared each identified risk factor—age, weight category, annual quarter, injury timing and competition difficulty level—with its relation to injury location and type. Settings Injury occurrences in taekwondo athletes of the Spanish national team during two Olympic periods at the High Performance Centre in Barcelona were analysed. Participants 48 taekwondo athletes (22 male, 26 female; age range 15–31 years) were studied; 1678 injury episodes occurred. Inclusion criteria were: (1) having trained with the national taekwondo group for a minimum of one sports season; (2) being a member of the Spanish national team. Results Independently of sex or Olympic period, the anatomical sites with most injury episodes were knee (21.3%), foot (17.0%), ankle (12.2%), thigh (11.4%) and lower leg (8.8%). Contusions (29.3%) and cartilage (17.6%) and joint (15.7%) injuries were the prevalent types of injury. Chronological age, weight category and annual quarter can be considered risk factors for sustaining injuries in male and female elite taekwondists according to their location and type (p≤0.001). Conclusions This study provides epidemiological information that will help to inform future injury surveillance studies and the development of prevention strategies and recommendations to reduce the number of injuries in taekwondo competition. PMID:24531455

  17. Using whole genome sequencing to study American foulbrood epidemiology in honeybees.

    Directory of Open Access Journals (Sweden)

    Joakim Ågren

    Full Text Available American foulbrood (AFB, caused by Paenibacillus larvae, is a devastating disease in honeybees. In most countries, the disease is controlled through compulsory burning of symptomatic colonies causing major economic losses in apiculture. The pathogen is endemic to honeybees world-wide and is readily transmitted via the movement of hive equipment or bees. Molecular epidemiology of AFB currently largely relies on placing isolates in one of four ERIC-genotypes. However, a more powerful alternative is multi-locus sequence typing (MLST using whole-genome sequencing (WGS, which allows for high-resolution studies of disease outbreaks. To evaluate WGS as a tool for AFB-epidemiology, we applied core genome MLST (cgMLST on isolates from a recent outbreak of AFB in Sweden. The high resolution of the cgMLST allowed different bacterial clones involved in the disease outbreak to be identified and to trace the source of infection. The source was found to be a beekeeper who had sold bees to two other beekeepers, proving the epidemiological link between them. No such conclusion could have been made using conventional MLST or ERIC-typing. This is the first time that WGS has been used to study the epidemiology of AFB. The results show that the technique is very powerful for high-resolution tracing of AFB-outbreaks.

  18. Single-stage versus two-stage anaerobic fluidized bed bioreactors in treating municipal wastewater: Performance, foulant characteristics, and microbial community.

    Science.gov (United States)

    Wu, Bing; Li, Yifei; Lim, Weikang; Lee, Shi Lin; Guo, Qiming; Fane, Anthony G; Liu, Yu

    2017-03-01

    This study examined the receptive performance, membrane foulant characteristics, and microbial community in the single-stage and two-stage anaerobic fluidized membrane bioreactor (AFMBR) treating settled raw municipal wastewater with the aims to explore fouling mechanisms and microbial community structure in both systems. Both AFMBRs exhibited comparable organic removal efficiency and membrane performances. In the single-stage AFMBR, less soluble organic substances were removed through biosorption by GAC and biodegradation than those in the two-stage AFMBR. Compared to the two-stage AFMBR, the formation of cake layer was the main cause of the observed membrane fouling in the single-stage AFMBR at the same employed flux. The accumulation rate of the biopolymers was linearly correlated with the membrane fouling rate. In the chemical-cleaned foulants, humic acid-like substances and silicon were identified as the predominant organic and inorganic fouants respectively. As such, the fluidized GAC particles might not be effective in removing these substances from the membrane surfaces. High-throughout pyrosequencing analysis further revealed that beta-Proteobacteria were predominant members in both AFMBRs, which contributed to the development of biofilms on the fluidized GAC and membrane surfaces. However, it was also noted that the abundance of the identified dominant in the membrane surface-associated biofilm seemed to be related to the permeate flux and reactor configuration. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Compressed gas combined single- and two-stage light-gas gun

    Science.gov (United States)

    Lamberson, L. E.; Boettcher, P. A.

    2018-02-01

    With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation materials for space exploration, this paper presents a unique two-stage light-gas gun capable of replicating hypervelocity impacts. While a limited number of these types of facilities exist, they typically are extremely large and can be costly and dangerous to operate. The design presented in this paper is novel in two distinct ways. First, it does not use a form of combustion in the first stage. The projectile is accelerated from a pressure differential using air and inert gases (or purely inert gases), firing a projectile in a nominal range of 1-4 km/s. Second, the design is modular in that the first stage sits on a track sled and can be pulled back and used in itself to study lower speed impacts without any further modifications, with the first stage piston as the impactor. The modularity of the instrument allows the ability to investigate three orders of magnitude of impact velocities or between 101 and 103 m/s in a single, relatively small, cost effective instrument.

  20. Final Report on Two-Stage Fast Spectrum Fuel Cycle Options

    International Nuclear Information System (INIS)

    Yang, Won Sik; Lin, C. S.; Hader, J. S.; Park, T. K.; Deng, P.; Yang, G.; Jung, Y. S.; Kim, T. K.; Stauff, N. E.

    2016-01-01

    This report presents the performance characteristics of two ''two-stage'' fast spectrum fuel cycle options proposed to enhance uranium resource utilization and to reduce nuclear waste generation. One is a two-stage fast spectrum fuel cycle option of continuous recycle of plutonium (Pu) in a fast reactor (FR) and subsequent burning of minor actinides (MAs) in an accelerator-driven system (ADS). The first stage is a sodium-cooled FR fuel cycle starting with low-enriched uranium (LEU) fuel; at the equilibrium cycle, the FR is operated using the recovered Pu and natural uranium without supporting LEU. Pu and uranium (U) are co-extracted from the discharged fuel and recycled in the first stage, and the recovered MAs are sent to the second stage. The second stage is a sodium-cooled ADS in which MAs are burned in an inert matrix fuel form. The discharged fuel of ADS is reprocessed, and all the recovered heavy metals (HMs) are recycled into the ADS. The other is a two-stage FR/ADS fuel cycle option with MA targets loaded in the FR. The recovered MAs are not directly sent to ADS, but partially incinerated in the FR in order to reduce the amount of MAs to be sent to the ADS. This is a heterogeneous recycling option of transuranic (TRU) elements

  1. Two-stage electrolysis to enrich tritium in environmental water

    International Nuclear Information System (INIS)

    Shima, Nagayoshi; Muranaka, Takeshi

    2007-01-01

    We present a two-stage electrolyzing procedure to enrich tritium in environmental waters. Tritium is first enriched rapidly through a commercially-available electrolyser with a large 50A current, and then through a newly-designed electrolyser that avoids the memory effect, with a 6A current. Tritium recovery factor obtained by such a two-stage electrolysis was greater than that obtained when using the commercially-available device solely. Water samples collected in 2006 in lakes and along the Pacific coast of Aomori prefecture, Japan, were electrolyzed using the two-stage method. Tritium concentrations in these samples ranged from 0.2 to 0.9 Bq/L and were half or less, that in samples collected at the same sites in 1992. (author)

  2. Two-stage nonrecursive filter/decimator

    International Nuclear Information System (INIS)

    Yoder, J.R.; Richard, B.D.

    1980-08-01

    A two-stage digital filter/decimator has been designed and implemented to reduce the sampling rate associated with the long-term computer storage of certain digital waveforms. This report describes the design selection and implementation process and serves as documentation for the system actually installed. A filter design with finite-impulse response (nonrecursive) was chosen for implementation via direct convolution. A newly-developed system-test statistic validates the system under different computer-operating environments

  3. [Eco-epidemiology: towards epidemiology of complexity].

    Science.gov (United States)

    Bizouarn, Philippe

    2016-05-01

    In order to solve public health problems posed by the epidemiology of risk factors centered on the individual and neglecting the causal processes linking the risk factors with the health outcomes, Mervyn Susser proposed a multilevel epidemiology called eco-epidemiology, addressing the interdependence of individuals and their connection with molecular, individual, societal, environmental levels of organization participating in the causal disease processes. The aim of this epidemiology is to integrate more than a level of organization in design, analysis and interpretation of health problems. After presenting the main criticisms of risk-factor epidemiology focused on the individual, we will try to show how eco-epidemiology and its development could help to understand the need for a broader and integrative epidemiology, in which studies designed to identify risk factors would be balanced by studies designed to answer other questions equally vital to public health. © 2016 médecine/sciences – Inserm.

  4. 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 ...

  5. Epidemiological studies of general population groups exposed to low-level radiation

    International Nuclear Information System (INIS)

    Davies, J.M.; Inskip, H.

    1986-01-01

    The exposure of man to radiation and the resulting risk of carcinogenesis continue to be of concern to the public. In this context, there is often a tendency to carry out epidemiological studies concerning the induction of cancer in radiation workers and members of the public which are not supported by a statistically valid data base or whose result are misinterpreted or misused. To assist national authorities in evaluating radiological risks, the Nuclear Energy Agency has sponsored a critical review of the methodologies for, and the limitations of, these epidemiological studies, and of the precautions to be adopted in interpreting their results. Prepared by two consultants, Dr. Joan M. Davies and Dr. Hazel Inskip, the review focuses on the problems encountered when carrying out epidemiological studies on groups of the general population exposed to radiation, and using their results for radiological protection purposes. The primary objective is to provide background material for national authorities who have responsibilities in the field of radiological protection, as well as to other persons interested in this subject. It is published under the responsibility of the Secretary General of the OECD, and does not necessarily reflect the views of Member Governments

  6. Rapid Two-stage Versus One-stage Surgical Repair of Interrupted Aortic Arch with Ventricular Septal Defect in Neonates

    Directory of Open Access Journals (Sweden)

    Meng-Lin Lee

    2008-11-01

    Conclusion: The outcome of rapid two-stage repair is comparable to that of one-stage repair. Rapid two-stage repair has the advantages of significantly shorter cardiopulmonary bypass duration and AXC time, and avoids deep hypothermic circulatory arrest. LVOTO remains an unresolved issue, and postoperative aortic arch restenosis can be dilated effectively by percutaneous balloon angioplasty.

  7. Assessing efficiency and effectiveness of Malaysian Islamic banks: A two stage DEA analysis

    Science.gov (United States)

    Kamarudin, Norbaizura; Ismail, Wan Rosmanira; Mohd, Muhammad Azri

    2014-06-01

    Islamic banks in Malaysia are indispensable players in the financial industry with the growing needs for syariah compliance system. In the banking industry, most recent studies concerned only on operational efficiency. However rarely on the operational effectiveness. Since the production process of banking industry can be described as a two-stage process, two-stage Data Envelopment Analysis (DEA) can be applied to measure the bank performance. This study was designed to measure the overall performance in terms of efficiency and effectiveness of Islamic banks in Malaysia using Two-Stage DEA approach. This paper presents analysis of a DEA model which split the efficiency and effectiveness in order to evaluate the performance of ten selected Islamic Banks in Malaysia for the financial year period ended 2011. The analysis shows average efficient score is more than average effectiveness score thus we can say that Malaysian Islamic banks were more efficient rather than effective. Furthermore, none of the bank exhibit best practice in both stages as we can say that a bank with better efficiency does not always mean having better effectiveness at the same time.

  8. Relative Efficiencies of a Three-Stage Versus a Two-Stage Sample Design For a New NLS Cohort Study. 22U-884-38.

    Science.gov (United States)

    Folsom, R. E.; Weber, J. H.

    Two sampling designs were compared for the planned 1978 national longitudinal survey of high school seniors with respect to statistical efficiency and cost. The 1972 survey used a stratified two-stage sample of high schools and seniors within schools. In order to minimize interviewer travel costs, an alternate sampling design was proposed,…

  9. The global stability of a delayed predator-prey system with two stage-structure

    International Nuclear Information System (INIS)

    Wang Fengyan; Pang Guoping

    2009-01-01

    Based on the classical delayed stage-structured model and Lotka-Volterra predator-prey model, we introduce and study a delayed predator-prey system, where prey and predator have two stages, an immature stage and a mature stage. The time delays are the time lengths between the immature's birth and maturity of prey and predator species. Results on global asymptotic stability of nonnegative equilibria of the delay system are given, which generalize and suggest that good continuity exists between the predator-prey system and its corresponding stage-structured system.

  10. Two-stage hepatectomy: who will not jump over the second hurdle?

    Science.gov (United States)

    Turrini, O; Ewald, J; Viret, F; Sarran, A; Goncalves, A; Delpero, J-R

    2012-03-01

    Two-stage hepatectomy uses compensatory liver regeneration after a first noncurative hepatectomy to enable a second curative resection in patients with bilobar colorectal liver metastasis (CLM). To determine the predictive factors of failure of two-stage hepatectomy. Between 2000 and 2010, 48 patients with irresectable CLM were eligible for two-stage hepatectomy. The planned strategy was a) cleaning of the left hepatic lobe (first hepatectomy), b) right portal vein embolisation and c) right hepatectomy (second hepatectomy). Six patients had occult CLM (n = 5) or extra-hepatic disease (n = 1), which was discovered during the first hepatectomy. Thus, 42 patients completed the first hepatectomy and underwent portal vein embolisation in order to receive the second hepatectomy. Eight patients did not undergo a second hepatectomy due to disease progression. Upon univariate analysis, two factors were identified that precluded patients from having the second hepatectomy: the combined resection of a primary tumour during the first hepatectomy (p = 0.01) and administration of chemotherapy between the two hepatectomies (p = 0.03). An independent association with impairment to perform the two-stage strategy was demonstrated by multivariate analysis for only the combined resection of the primary colorectal cancer during the first hepatectomy (p = 0.04). Due to the small number of patients and the absence of equivalent conclusions in other studies, we cannot recommend performance of an isolated colorectal resection prior to chemotherapy. However, resection of an asymptomatic primary tumour before chemotherapy should not be considered as an outdated procedure. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Final Report on Two-Stage Fast Spectrum Fuel Cycle Options

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Won Sik [Purdue Univ., West Lafayette, IN (United States); Lin, C. S. [Purdue Univ., West Lafayette, IN (United States); Hader, J. S. [Purdue Univ., West Lafayette, IN (United States); Park, T. K. [Purdue Univ., West Lafayette, IN (United States); Deng, P. [Purdue Univ., West Lafayette, IN (United States); Yang, G. [Purdue Univ., West Lafayette, IN (United States); Jung, Y. S. [Purdue Univ., West Lafayette, IN (United States); Kim, T. K. [Argonne National Lab. (ANL), Argonne, IL (United States); Stauff, N. E. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-30

    This report presents the performance characteristics of twotwo-stage” fast spectrum fuel cycle options proposed to enhance uranium resource utilization and to reduce nuclear waste generation. One is a two-stage fast spectrum fuel cycle option of continuous recycle of plutonium (Pu) in a fast reactor (FR) and subsequent burning of minor actinides (MAs) in an accelerator-driven system (ADS). The first stage is a sodium-cooled FR fuel cycle starting with low-enriched uranium (LEU) fuel; at the equilibrium cycle, the FR is operated using the recovered Pu and natural uranium without supporting LEU. Pu and uranium (U) are co-extracted from the discharged fuel and recycled in the first stage, and the recovered MAs are sent to the second stage. The second stage is a sodium-cooled ADS in which MAs are burned in an inert matrix fuel form. The discharged fuel of ADS is reprocessed, and all the recovered heavy metals (HMs) are recycled into the ADS. The other is a two-stage FR/ADS fuel cycle option with MA targets loaded in the FR. The recovered MAs are not directly sent to ADS, but partially incinerated in the FR in order to reduce the amount of MAs to be sent to the ADS. This is a heterogeneous recycling option of transuranic (TRU) elements

  12. Population-Based Study of the Epidemiology of Herpes Zoster in Korea

    OpenAIRE

    Kim, You Jeong; Lee, Chang Nam; Lim, Chi-Yeon; Jeon, Woo Seok; Park, Young Min

    2014-01-01

    General epidemiological data regarding herpes zoster (HZ) are necessary for treatment and prevention of this disease. In addition, epidemiological data can play an important role in evaluating the efficacy and impact of vaccination. Though several epidemiological studies of HZ in Korea have been conducted, they usually depend on hospital-based data and may not be representative of HZ characteristics all over Korea. The purpose of this study was to evaluate the incidence and other epidemiologi...

  13. Runway Operations Planning: A Two-Stage Heuristic Algorithm

    Science.gov (United States)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, can also be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. This paper introduces a two stage heuristic algorithm for solving the Runway Operations Planning (ROP) problem. In the first stage, sequences of departure class slots and runway crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the departure class slots are populated with specific flights from the pool of available aircraft, by solving an integer program with a Branch & Bound algorithm implementation. Preliminary results from this implementation of the two-stage algorithm on real-world traffic data are presented.

  14. Influence of radiation exposure on our society and epidemiological study

    International Nuclear Information System (INIS)

    Yoshimoto, Yasuhiko

    1997-01-01

    A brief epidemiological review of risk assessment of radiation was discussed with respect to two periods; before and after the establishment of the United Nations Scientific Committee on the Effects of Atomic Radiation. Selected topics were the studies of atomic bomb survivors and people living in the contaminated areas due to Chernobyl nuclear power plant accident. An ethical view to ensure that potential social benefits of epidemiology are maximized was emphasized as well as a scientific view. On the other hand it should be recognized that there are the limitations of epidemiological studies on the basis of the observations on man in which the animal-experimental setting generally cannot be controlled over. Informing people about the professional confidence and caution of radiation exposure is needed to resolve social concern associated with low dose, low dose rate of radiation. Also there are guidelines for the investigation of clusters of adverse health events. In the future an appropriate strategy for decontamination might be expected to unusual radiation exposure as a consequence of a nuclear power plant accident. Justification for the implementations can be determined only through the assessment of the effects both on the environment and health of humans after the accident. (author)

  15. The Two-Word Stage: Motivated by Linguistic or Cognitive Constraints?

    Science.gov (United States)

    Berk, Stephanie; Lillo-Martin, Diane

    2012-01-01

    Child development researchers often discuss a "two-word" stage during language acquisition. However, there is still debate over whether the existence of this stage reflects primarily cognitive or linguistic constraints. Analyses of longitudinal data from two Deaf children, Mei and Cal, not exposed to an accessible first language (American Sign…

  16. 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.

  17. A two-stage heating scheme for heat assisted magnetic recording

    Science.gov (United States)

    Xiong, Shaomin; Kim, Jeongmin; Wang, Yuan; Zhang, Xiang; Bogy, David

    2014-05-01

    Heat Assisted Magnetic Recording (HAMR) has been proposed to extend the storage areal density beyond 1 Tb/in.2 for the next generation magnetic storage. A near field transducer (NFT) is widely used in HAMR systems to locally heat the magnetic disk during the writing process. However, much of the laser power is absorbed around the NFT, which causes overheating of the NFT and reduces its reliability. In this work, a two-stage heating scheme is proposed to reduce the thermal load by separating the NFT heating process into two individual heating stages from an optical waveguide and a NFT, respectively. As the first stage, the optical waveguide is placed in front of the NFT and delivers part of laser energy directly onto the disk surface to heat it up to a peak temperature somewhat lower than the Curie temperature of the magnetic material. Then, the NFT works as the second heating stage to heat a smaller area inside the waveguide heated area further to reach the Curie point. The energy applied to the NFT in the second heating stage is reduced compared with a typical single stage NFT heating system. With this reduced thermal load to the NFT by the two-stage heating scheme, the lifetime of the NFT can be extended orders longer under the cyclic load condition.

  18. Efficacy of single-stage and two-stage Fowler–Stephens laparoscopic orchidopexy in the treatment of intraabdominal high testis

    Directory of Open Access Journals (Sweden)

    Chang-Yuan Wang

    2017-11-01

    Conclusion: In the case of testis with good collateral circulation, single-stage F-S laparoscopic orchidopexy had the same safety and efficacy as the two-stage F-S procedure. Surgical options should be based on comprehensive consideration of intraoperative testicular location, testicular ischemia test, and collateral circumstances surrounding the testes. Under the appropriate conditions, we propose single-stage F-S laparoscopic orchidopexy be preferred. It may be appropriate to avoid unnecessary application of the two-stage procedure that has a higher cost and causes more pain for patients.

  19. Perceptions of molecular epidemiology studies of HIV among stakeholders

    Directory of Open Access Journals (Sweden)

    Cynthia Schairer

    2017-12-01

    Full Text Available Background: Advances in viral sequence analysis make it possible to track the spread of infectious pathogens, such as HIV, within a population. When used to study HIV, these analyses (i.e., molecular epidemiology potentially allow inference of the identity of individual research subjects. Current privacy standards are likely insufficient for this type of public health research. To address this challenge, it will be important to understand how stakeholders feel about the benefits and risks of such research. Design and Methods: To better understand perceived benefits and risks of these research methods, in-depth qualitative interviews were conducted with HIV-infected individuals, individuals at high-risk for contracting HIV, and professionals in HIV care and prevention. To gather additional perspectives, attendees to a public lecture on molecular epidemiology were asked to complete an informal questionnaire. Results: Among those interviewed and polled, there was near unanimous support for using molecular epidemiology to study HIV. Questionnaires showed strong agreement about benefits of molecular epidemiology, but diverse attitudes regarding risks. Interviewees acknowledged several risks, including privacy breaches and provocation of anti-gay sentiment. The interviews also demonstrated a possibility that misunderstandings about molecular epidemiology may affect how risks and benefits are evaluated. Conclusions: While nearly all study participants agree that the benefits of HIV molecular epidemiology outweigh the risks, concerns about privacy must be addressed to ensure continued trust in research institutions and willingness to participate in research.

  20. Two-Stage Regularized Linear Discriminant Analysis for 2-D Data.

    Science.gov (United States)

    Zhao, Jianhua; Shi, Lei; Zhu, Ji

    2015-08-01

    Fisher linear discriminant analysis (LDA) involves within-class and between-class covariance matrices. For 2-D data such as images, regularized LDA (RLDA) can improve LDA due to the regularized eigenvalues of the estimated within-class matrix. However, it fails to consider the eigenvectors and the estimated between-class matrix. To improve these two matrices simultaneously, we propose in this paper a new two-stage method for 2-D data, namely a bidirectional LDA (BLDA) in the first stage and the RLDA in the second stage, where both BLDA and RLDA are based on the Fisher criterion that tackles correlation. BLDA performs the LDA under special separable covariance constraints that incorporate the row and column correlations inherent in 2-D data. The main novelty is that we propose a simple but effective statistical test to determine the subspace dimensionality in the first stage. As a result, the first stage reduces the dimensionality substantially while keeping the significant discriminant information in the data. This enables the second stage to perform RLDA in a much lower dimensional subspace, and thus improves the two estimated matrices simultaneously. Experiments on a number of 2-D synthetic and real-world data sets show that BLDA+RLDA outperforms several closely related competitors.

  1. Two-stage precipitation of plutonium trifluoride

    International Nuclear Information System (INIS)

    Luerkens, D.W.

    1984-04-01

    Plutonium trifluoride was precipitated using a two-stage precipitation system. A series of precipitation experiments identified the significant process variables affecting precipitate characteristics. A mathematical precipitation model was developed which was based on the formation of plutonium fluoride complexes. The precipitation model relates all process variables, in a single equation, to a single parameter that can be used to control particle characteristics

  2. Epidemiology of chronic kidney disease in children

    NARCIS (Netherlands)

    Harambat, Jérôme; van Stralen, Karlijn J.; Kim, Jon Jin; Tizard, E. Jane

    2012-01-01

    In the past 30 years there have been major improvements in the care of children with chronic kidney disease (CKD). However, most of the available epidemiological data stem from end-stage renal disease (ESRD) registries and information on the earlier stages of pediatric CKD is still limited. The

  3. Biomarkers in Czech workers exposed to 1,3-butadiene: a transitional epidemiologic study

    NARCIS (Netherlands)

    Albertini, Richard J.; Srám, Radim J.; Vacek, Pamela M.; Lynch, Jeremiah; Nicklas, Janice A.; van Sittert, Nico J.; Boogaard, Peter J.; Henderson, Rogene F.; Swenberg, James A.; Tates, Ad D.; Ward, Jonathan B.; Wright, Michael; Ammenheuser, Marinel M.; Binkova, Blanka; Blackwell, Walter; de Zwart, Franz A.; Krako, Dean; Krone, Jennifer; Megens, Hendricus; Musilová, Petra; Rajská, Gabriela; Ranasinghe, Asoka; Rosenblatt, Judah I.; Rössner, Pavel; Rubes, Jiri; Sullivan, Linda; Upton, Patricia; Zwinderman, Ailko H.

    2003-01-01

    A multiinstitutional, transitional epidemiologic study was conducted with a worker population in the Czech Republic to evaluate the utility of a continuum of non-disease biological responses as biomarkers of exposure to 1,3-butadiene (BD)* in an industrial setting. The study site included two BD

  4. 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.

  5. Considerations Regarding Age at Surgery and Fistula Incidence Using One- and Two-stage Closure for Cleft Palate

    Directory of Open Access Journals (Sweden)

    Simona Stoicescu

    2013-12-01

    Full Text Available Introduction: Although cleft lip and palate (CLP is one of the most common congenital malformations, occurring in 1 in 700 live births, there is still no generally accepted treatment protocol. Numerous surgical techniques have been described for cleft palate repair; these techniques can be divided into one-stage (one operation cleft palate repair and two-stage cleft palate closure. The aim of this study is to present our cleft palate team experience in using the two-stage cleft palate closure and the clinical outcomes in terms of oronasal fistula rate. Material and methods: A retrospective analysis was performed on medical records of 80 patients who underwent palate repair over a five-year period, from 2008 to 2012. All cleft palate patients were incorporated. Information on patient’s gender, cleft type, age at repair, one- or two-stage cleft palate repair were collected and analyzed. Results: Fifty-three (66% and twenty-seven (34% patients underwent two-stage and one-stage repair, respectively. According to Veau classification, more than 60% of them were Veau III and IV, associating cleft lip to cleft palate. Fistula occurred in 34% of the two-stage repairs versus 7% of one-stage repairs, with an overall incidence of 24%. Conclusions: Our study has shown that a two-stage cleft palate closure has a higher rate of fistula formation when compared with the one-stage repair. Two-stage repair is the protocol of choice in wide complete cleft lip and palate cases, while one-stage procedure is a good option for cleft palate alone, or some specific cleft lip and palate cases (narrow cleft palate, older age at surgery

  6. A New Concept of Two-Stage Multi-Element Resonant-/Cyclo-Converter for Two-Phase IM/SM Motor

    Directory of Open Access Journals (Sweden)

    Mahmud Ali Rzig Abdalmula

    2013-01-01

    Full Text Available The paper deals with a new concept of power electronic two-phase system with two-stage DC/AC/AC converter and two-phase IM/PMSM motor. The proposed system consisting of two-stage converter comprises: input resonant boost converter with AC output, two-phase half-bridge cyclo-converter commutated by HF AC input voltage, and induction or synchronous motor. Such a system with AC interlink, as a whole unit, has better properties as a 3-phase reference VSI inverter: higher efficiency due to soft switching of both converter stages, higher switching frequency, smaller dimensions and weight with lesser number of power semiconductor switches and better price. In comparison with currently used conventional system configurations the proposed system features a good efficiency of electronic converters and also has a good torque overloading of two-phase AC induction or synchronous motors. Design of two-stage multi-element resonant converter and results of simulation experiments are presented in the paper.

  7. One- and two-stage surgical revision of peri-prosthetic joint infection of the hip: a pooled individual participant data analysis of 44 cohort studies.

    Science.gov (United States)

    Kunutsor, Setor K; Whitehouse, Michael R; Blom, Ashley W; Board, Tim; Kay, Peter; Wroblewski, B Mike; Zeller, Valérie; Chen, Szu-Yuan; Hsieh, Pang-Hsin; Masri, Bassam A; Herman, Amir; Jenny, Jean-Yves; Schwarzkopf, Ran; Whittaker, John-Paul; Burston, Ben; Huang, Ronald; Restrepo, Camilo; Parvizi, Javad; Rudelli, Sergio; Honda, Emerson; Uip, David E; Bori, Guillem; Muñoz-Mahamud, Ernesto; Darley, Elizabeth; Ribera, Alba; Cañas, Elena; Cabo, Javier; Cordero-Ampuero, José; Redó, Maria Luisa Sorlí; Strange, Simon; Lenguerrand, Erik; Gooberman-Hill, Rachael; Webb, Jason; MacGowan, Alasdair; Dieppe, Paul; Wilson, Matthew; Beswick, Andrew D

    2018-04-05

    One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip.

  8. Evaluating damping elements for two-stage suspension vehicles

    Directory of Open Access Journals (Sweden)

    Ronald M. Martinod R.

    2012-01-01

    Full Text Available The technical state of the damping elements for a vehicle having two-stage suspension was evaluated by using numerical models based on the multi-body system theory; a set of virtual tests used the eigenproblem mathematical method. A test was developed based on experimental modal analysis (EMA applied to a physical system as the basis for validating the numerical models. The study focused on evaluating vehicle dynamics to determine the influence of the dampers’ technical state in each suspension state.

  9. Study of shallow junction formation by boron-containing cluster ion implantation of silicon and two-stage annealing

    Science.gov (United States)

    Lu, Xin-Ming

    Shallow junction formation made by low energy ion implantation and rapid thermal annealing is facing a major challenge for ULSI (ultra large scale integration) as the line width decreases down to the sub micrometer region. The issues include low beam current, the channeling effect in low energy ion implantation and TED (transient enhanced diffusion) during annealing after ion implantation. In this work, boron containing small cluster ions, such as GeB, SiB and SiB2, was generated by using the SNICS (source of negative ion by cesium sputtering) ion source to implant into Si substrates to form shallow junctions. The use of boron containing cluster ions effectively reduces the boron energy while keeping the energy of the cluster ion beam at a high level. At the same time, it reduces the channeling effect due to amorphization by co-implanted heavy atoms like Ge and Si. Cluster ions have been used to produce 0.65--2keV boron for low energy ion implantation. Two stage annealing, which is a combination of low temperature (550°C) preannealing and high temperature annealing (1000°C), was carried out to anneal the Si sample implanted by GeB, SiBn clusters. The key concept of two-step annealing, that is, the separation of crystal regrowth, point defects removal with dopant activation from dopant diffusion, is discussed in detail. The advantages of the two stage annealing include better lattice structure, better dopant activation and retarded boron diffusion. The junction depth of the two stage annealed GeB sample was only half that of the one-step annealed sample, indicating that TED was suppressed by two stage annealing. Junction depths as small as 30 nm have been achieved by two stage annealing of sample implanted with 5 x 10-4/cm2 of 5 keV GeB at 1000°C for 1 second. The samples were evaluated by SIMS (secondary ion mass spectrometry) profiling, TEM (transmission electron microscopy) and RBS (Rutherford Backscattering Spectrometry)/channeling. Cluster ion implantation

  10. On the robustness of two-stage estimators

    KAUST Repository

    Zhelonkin, Mikhail; Genton, Marc G.; Ronchetti, Elvezio

    2012-01-01

    The aim of this note is to provide a general framework for the analysis of the robustness properties of a broad class of two-stage models. We derive the influence function, the change-of-variance function, and the asymptotic variance of a general

  11. Ionizing radiation biomarkers for potential use in epidemiological studies

    International Nuclear Information System (INIS)

    Pernot, Eileen; Cardis, Elisabeth; Hall, Janet; Baatout, Sarah; El Saghire, Houssein; Mohammed Abderrafi Benotmane; Roel Quintens; Blanchardon, Eric; Bouffler, Simon; Gomolka, Maria; Guertler, Anne; Kreuzer, Michaela; Harms-Ringdahl, Mats; Jeggo, Penny; Laurier, Dominique; Lindholm, Carita; Mkacher, Radhia; Sabatier, Laure; Tapio, Soile; De Vathaire, Florent

    2012-01-01

    Ionizing radiation is a known human carcinogen that can induce a variety of biological effects depending on the physical nature, duration, doses and dose-rates of exposure. However, the magnitude of health risks at low doses and dose-rates (below 100 mSv and/or 0.1 mSv min -1 ) remains controversial due to a lack of direct human evidence. It is anticipated that significant insights will emerge from the integration of epidemiological and biological research, made possible by molecular epidemiology studies incorporating biomarkers and bioassays. A number of these have been used to investigate exposure, effects and susceptibility to ionizing radiation, albeit often at higher doses and dose rates, with each reflecting time-limited cellular or physiological alterations. This review summarises the multidisciplinary work undertaken in the framework of the European project DoReMi (Low Dose Research towards Multidisciplinary Integration) to identify the most appropriate biomarkers for use in population studies. In addition to logistical and ethical considerations for conducting large-scale epidemiological studies, we discuss the relevance of their use for assessing the effects of low dose ionizing radiation exposure at the cellular and physiological level. We also propose a temporal classification of biomarkers that may be relevant for molecular epidemiology studies which need to take into account the time elapsed since exposure. Finally, the integration of biology with epidemiology requires careful planning and enhanced discussions between the epidemiology, biology and dosimetry communities in order to determine the most important questions to be addressed in light of pragmatic considerations including the appropriate population to be investigated (occupationally, environmentally or medically exposed), and study design. The consideration of the logistics of biological sample collection, processing and storing and the choice of biomarker or bioassay, as well as awareness of

  12. Epidemiological characterization of oral cancer. Study Protocol.

    Directory of Open Access Journals (Sweden)

    Alejandra Fernández

    2015-04-01

    Full Text Available Oral cancer is a disease of high impact globally. It ranks as the sixth more frequent one among all types of cancer. In spite of being a widely known pathology and easy access to the diagnosis, the lack of epidemiological data reported in the last 10 years in Chile called attention to. At the global level, the World Health Organization (WHO has developed a project called “GLOBOCAN” in order to collect epidemiological data of the global cancer, between its data, highlights the high incidence and high rate of mortality in the male sex, parameter that shows tendency to replicate in both America and Chile. In consequence to these data, a narrative review of the literature concerning the epidemiological profile of the different forms of oral cancer in the past 15 years was done. The diagnosis of oral cancer crosses transversely the Dental Science, forcing us to establish triads of work between oral and maxillofacial surgeons, pathologists and dentists of the various specialties, so as to allow a timely research, appropriate biopsies and histopathological studies finishes with the purpose of, on the one hand, obtain timely and accurate diagnostics, in addition, maintaining the epidemiological indicators.

  13. EVALUATION OF A TWO-STAGE PASSIVE TREATMENT APPROACH FOR MINING INFLUENCE WATERS

    Science.gov (United States)

    A two-stage passive treatment approach was assessed at bench-scale using two Colorado Mining Influenced Waters (MIWs). The first-stage was a limestone drain with the purpose of removing iron and aluminum and mitigating the potential effects of mineral acidity. The second stage w...

  14. Snowboard traumatology: an epidemiological study.

    Science.gov (United States)

    Pigozzi, F; Santori, N; Di Salvo, V; Parisi, A; Di-Luigi, L

    1997-06-01

    In the past 10 years, snowboarding has become a popular winter sport among young people, and the number of accidents has increased proportionately. The incidence of traumas from snowboarding is shown to be 4 to 6 for every 1000 medical examinations, which is similar to that of downhill skiing. However, other important statistical differences exist between the two sports. This study of 106 snowboarding-related injury cases analyzes the epidemiology of these injuries in Italy. Results found that 45.1% of injuries are located in the upper limbs and that significant advantages are obtained with the introduction of guards to protect the upper limbs during descent. Serious ligament injuries to the knee are more rare in snowboarding than in downhill skiing. In both sports, injuries are more common with rigid boots, which lead to a higher incidence of injury to the upper limbs. Finally, a high percentage of injury to beginners was found in this study. Training courses for those who are considering taking up the sport of snowboarding could significantly lower their risk of trauma.

  15. Transport fuels from two-stage coal liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Benito, A.; Cebolla, V.; Fernandez, I.; Martinez, M.T.; Miranda, J.L.; Oelert, H.; Prado, J.G. (Instituto de Carboquimica CSIC, Zaragoza (Spain))

    1994-03-01

    Four Spanish lignites and their vitrinite concentrates were evaluated for coal liquefaction. Correlationships between the content of vitrinite and conversion in direct liquefaction were observed for the lignites but not for the vitrinite concentrates. The most reactive of the four coals was processed in two-stage liquefaction at a higher scale. First-stage coal liquefaction was carried out in a continuous unit at Clausthal University at a temperature of 400[degree]C at 20 MPa hydrogen pressure and with anthracene oil as a solvent. The coal conversion obtained was 75.41% being 3.79% gases, 2.58% primary condensate and 69.04% heavy liquids. A hydroprocessing unit was built at the Instituto de Carboquimica for the second-stage coal liquefaction. Whole and deasphalted liquids from the first-stage liquefaction were processed at 450[degree]C and 10 MPa hydrogen pressure, with two commercial catalysts: Harshaw HT-400E (Co-Mo/Al[sub 2]O[sub 3]) and HT-500E (Ni-Mo/Al[sub 2]O[sub 3]). The effects of liquid hourly space velocity (LHSV), temperature, gas/liquid ratio and catalyst on the heteroatom liquids, and levels of 5 ppm of nitrogen and 52 ppm of sulphur were reached at 450[degree]C, 10 MPa hydrogen pressure, 0.08 kg H[sub 2]/kg feedstock and with Harshaw HT-500E catalyst. The liquids obtained were hydroprocessed again at 420[degree]C, 10 MPa hydrogen pressure and 0.06 kg H[sub 2]/kg feedstock to hydrogenate the aromatic structures. In these conditions, the aromaticity was reduced considerably, and 39% of naphthas and 35% of kerosene fractions were obtained. 18 refs., 4 figs., 4 tabs.

  16. 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 ...

  17. 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

  18. Comparison of two school-based programmes for health behaviour change: the Belo Horizonte Heart Study randomized trial.

    Science.gov (United States)

    Ribeiro, Robespierre Q C; Alves, Luciana

    2014-06-01

    To assess the efficacy of two school-based programmes to promote students' willingness to engage in lifestyle changes related to eating habits and physical activity behaviours. Elementary school-based health promotion intervention, designed as a multicomponent experimental study, based on a behavioural epidemiological model. Nine intervention and eight comparative public and private elementary schools. The goal was to determine the impact on the longitudinally assessed outcomes of two programmes that addressed healthy nutrition and active living in a cohort of 2038 children. The evaluations used pre-intervention and follow-up student surveys that were based on the Transtheoretical Model of the stages of behaviour change. In the intervention group, there were significant (P motivated teachers. The comparison group did not show significant differences between the pre- and post-intervention times for any of the stages of behaviour. The intervention programme encouraged the students to make healthy lifestyle choices related to eating habits and physical activity behaviours.

  19. The response rate in postal epidemiological studies in the context of national cultural behaviour

    DEFF Research Database (Denmark)

    Angelova, Radostina A.; Naydenov, Kiril; Hägerhed-Engman, Linda

    2012-01-01

    The purpose of this study was to analyse the effect of national cultural differences on the response rate, obtained in questionnaire based epidemiological studies on allergy and asthma, performed in Sweden (DBH) and Bulgaria (ALLHOME). The two studies used one and the same methodology, but the ob...

  20. Two technicians apply insulation to S-II second stage

    Science.gov (United States)

    1964-01-01

    Two technicians apply insulation to the outer surface of the S-II second stage booster for the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

  1. Measurement of Radiofrequency Radiation Exposure in Epidemiological Studies (invited paper)

    International Nuclear Information System (INIS)

    Swerdlow, A.J.

    1999-01-01

    The measurement of radiofrequency (RF) exposure is important to the quality of epidemiological studies of the possible association of RF exposure with disease. The extent and type of exposure measurement in past epidemiological studies of RF, and the features of measurement that would be desirable for better studies in the future are summarised. Measurement characteristics that are discussed include quantification of radiation frequency and of intensity and timing of exposures, measurement (or good estimation) of exposures for individuals rather than only for groups, quality of measurement, and measurement of RF exposures experienced outside the study setting. Integration of exposure measurement into the design of epidemiological studies is needed for better assessments of possible RF effects. (author)

  2. Statistical significance of epidemiological data. Seminar: Evaluation of epidemiological studies

    International Nuclear Information System (INIS)

    Weber, K.H.

    1993-01-01

    In stochastic damages, the numbers of events, e.g. the persons who are affected by or have died of cancer, and thus the relative frequencies (incidence or mortality) are binomially distributed random variables. Their statistical fluctuations can be characterized by confidence intervals. For epidemiologic questions, especially for the analysis of stochastic damages in the low dose range, the following issues are interesting: - Is a sample (a group of persons) with a definite observed damage frequency part of the whole population? - Is an observed frequency difference between two groups of persons random or statistically significant? - Is an observed increase or decrease of the frequencies with increasing dose random or statistically significant and how large is the regression coefficient (= risk coefficient) in this case? These problems can be solved by sttistical tests. So-called distribution-free tests and tests which are not bound to the supposition of normal distribution are of particular interest, such as: - χ 2 -independence test (test in contingency tables); - Fisher-Yates-test; - trend test according to Cochran; - rank correlation test given by Spearman. These tests are explained in terms of selected epidemiologic data, e.g. of leukaemia clusters, of the cancer mortality of the Japanese A-bomb survivors especially in the low dose range as well as on the sample of the cancer mortality in the high background area in Yangjiang (China). (orig.) [de

  3. Two stage study of wound microorganisms affecting burns and plastic surgery inpatients.

    Science.gov (United States)

    Miranda, Benjamin H; Ali, Syed N; Jeffery, Steven L A; Thomas, Sunil S

    2008-01-01

    This study was designed to identify wound microorganisms and the reasons for differing prevalence between the wards, burns unit and intensive care unit (ICU) in a regional centre for burns and plastic surgery. Antibiotic sensitivities of the 10 most prevalent microorganisms cultured from inpatient wound swabs were also investigated. Inpatient wound swab data were collected retrospectively using notes and departmental database information between January and June 2007. Data were analyzed using chi-squared tests and P-values. Eight hundred five positive wound swabs from 204 swab positive inpatients were analyzed. Stage 1 of this study demonstrated 917 positive swab episodes and 30 varieties of organism. The five most prevalent organisms cultured were Staphylococcus (23.9%), Acinetobacter (21.2%), Methicillin Resistant Staphylococcus aureus (MRSA) (20.8%), Pseudomonas (9.7%) and Enterococcus (5.2%). Stage 2 revealed that Acinetobacter baumanni (ABAU) was significantly more prevalent in military over civilian inpatients (P < .001) and that military inpatients had a significantly greater proportion of ABAU over civilian inpatients within the first 24 hours after admission (P < .001). ABAU episodes were significantly higher on the ICU over the burns unit and on the wards (P < .001). MRSA was significantly more prevalent in military inpatients (P < .001); however, no significant difference was observed within the first 24 hours after admission (P = .440). MRSA was more prevalent on the ICU over the burns unit (P = .023). Pseudomonas aeruginosa (PAER) was significantly more prevalent in military inpatients over civilian inpatients (P < .001), and on the ICU over the burns unit and wards (P = .018). Stage 1 generated a comprehensive, up to date cross section of bacterial flora, with corresponding percentage antibiotic sensitivities, in a regional burns and plastic surgery centre. This will give clinicians a snapshot of organisms affecting inpatient wounds in advance of

  4. Influence of capacity- and time-constrained intermediate storage in two-stage food production systems

    DEFF Research Database (Denmark)

    Akkerman, Renzo; van Donk, Dirk Pieter; Gaalman, Gerard

    2007-01-01

    In food processing, two-stage production systems with a batch processor in the first stage and packaging lines in the second stage are common and mostly separated by capacity- and time-constrained intermediate storage. This combination of constraints is common in practice, but the literature hardly...... of systems like this. Contrary to the common sense in operations management, the LPT rule is able to maximize the total production volume per day. Furthermore, we show that adding one tank has considerable effects. Finally, we conclude that the optimal setup frequency for batches in the first stage...... pays any attention to this. In this paper, we show how various capacity and time constraints influence the performance of a specific two-stage system. We study the effects of several basic scheduling and sequencing rules in the presence of these constraints in order to learn the characteristics...

  5. Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP project: study design and methods for pooling results of genetic epidemiological studies

    Directory of Open Access Journals (Sweden)

    Raimondi Sara

    2012-08-01

    Full Text Available Abstract Background For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods Based on our experience with the study design of the Melanocortin-1 receptor (MC1R gene, SKin cancer and Phenotypic characteristics (M-SKIP project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields.

  6. Melanocortin-1 receptor, skin cancer and phenotypic characteristics (M-SKIP) project: study design and methods for pooling results of genetic epidemiological studies

    Science.gov (United States)

    2012-01-01

    Background For complex diseases like cancer, pooled-analysis of individual data represents a powerful tool to investigate the joint contribution of genetic, phenotypic and environmental factors to the development of a disease. Pooled-analysis of epidemiological studies has many advantages over meta-analysis, and preliminary results may be obtained faster and with lower costs than with prospective consortia. Design and methods Based on our experience with the study design of the Melanocortin-1 receptor (MC1R) gene, SKin cancer and Phenotypic characteristics (M-SKIP) project, we describe the most important steps in planning and conducting a pooled-analysis of genetic epidemiological studies. We then present the statistical analysis plan that we are going to apply, giving particular attention to methods of analysis recently proposed to account for between-study heterogeneity and to explore the joint contribution of genetic, phenotypic and environmental factors in the development of a disease. Within the M-SKIP project, data on 10,959 skin cancer cases and 14,785 controls from 31 international investigators were checked for quality and recoded for standardization. We first proposed to fit the aggregated data with random-effects logistic regression models. However, for the M-SKIP project, a two-stage analysis will be preferred to overcome the problem regarding the availability of different study covariates. The joint contribution of MC1R variants and phenotypic characteristics to skin cancer development will be studied via logic regression modeling. Discussion Methodological guidelines to correctly design and conduct pooled-analyses are needed to facilitate application of such methods, thus providing a better summary of the actual findings on specific fields. PMID:22862891

  7. Is the continuous two-stage anaerobic digestion process well suited for all substrates?

    Science.gov (United States)

    Lindner, Jonas; Zielonka, Simon; Oechsner, Hans; Lemmer, Andreas

    2016-01-01

    Two-stage anaerobic digestion systems are often considered to be advantageous compared to one-stage processes. Although process conditions and fermenter setups are well examined, overall substrate degradation in these systems is controversially discussed. Therefore, the aim of this study was to investigate how substrates with different fibre and sugar contents (hay/straw, maize silage, sugar beet) influence the degradation rate and methane production. Intermediates and gas compositions, as well as methane yields and VS-degradation degrees were recorded. The sugar beet substrate lead to a higher pH-value drop 5.67 in the acidification reactor, which resulted in a six time higher hydrogen production in comparison to the hay/straw substrate (pH-value drop 5.34). As the achieved yields in the two-stage system showed a difference of 70.6% for the hay/straw substrate, and only 7.8% for the sugar beet substrate. Therefore two-stage systems seem to be only recommendable for digesting sugar rich substrates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Dynamic Modeling and Control Studies of a Two-Stage Bubbling Fluidized Bed Adsorber-Reactor for Solid-Sorbent CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Modekurti, Srinivasarao; Bhattacharyya, Debangsu; Zitney, Stephen E.

    2013-07-31

    A one-dimensional, non-isothermal, pressure-driven dynamic model has been developed for a two-stage bubbling fluidized bed (BFB) adsorber-reactor for solid-sorbent carbon dioxide (CO{sub 2}) capture using Aspen Custom Modeler® (ACM). The BFB model for the flow of gas through a continuous phase of downward moving solids considers three regions: emulsion, bubble, and cloud-wake. Both the upper and lower reactor stages are of overflow-type configuration, i.e., the solids leave from the top of each stage. In addition, dynamic models have been developed for the downcomer that transfers solids between the stages and the exit hopper that removes solids from the bottom of the bed. The models of all auxiliary equipment such as valves and gas distributor have been integrated with the main model of the two-stage adsorber reactor. Using the developed dynamic model, the transient responses of various process variables such as CO{sub 2} capture rate and flue gas outlet temperatures have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the incoming flue gas from pulverized coal-fired power plants. In control studies, the performance of a proportional-integral-derivative (PID) controller, feedback-augmented feedforward controller, and linear model predictive controller (LMPC) are evaluated for maintaining the overall CO{sub 2} capture rate at a desired level in the face of typical disturbances.

  9. Investigation of Power Losses of Two-Stage Two-Phase Converter with Two-Phase Motor

    Directory of Open Access Journals (Sweden)

    Michal Prazenica

    2011-01-01

    Full Text Available The paper deals with determination of losses of two-stage power electronic system with two-phase variable orthogonal output. The simulation is focused on the investigation of losses in the converter during one period in steady-state operation. Modeling and simulation of two matrix converters with R-L load is shown in the paper. The simulation results confirm a very good time-waveform of the phase current and the system seems to be suitable for low-cost application in automotive/aerospace industries and in application with high frequency voltage sources.

  10. Some aspects of cancer epidemiology

    International Nuclear Information System (INIS)

    Lilienfeld, A.M.

    1982-01-01

    Epidemiolgic studies have strongly suggested that a vast majority (80-90%) of cancers are caused by radiation, chemical and biologic agents; the remainder result from endogenous or genetic factors. Biologically, cancer is most probably the end result of a complex multistage process and therefore may be due to a sequence of exposures to different agents at each of these stages. This emphasizes the need to stress the study of interactions in epidemiologic studies to a greater extent than has been done thus far. Examples of the importance of interactions in several types of cancer are presented

  11. Epidemiologic studies of cancer in populations near nuclear facilities

    International Nuclear Information System (INIS)

    Shleien, B.; Ruttenber, A.J.; Sage, M.

    1991-01-01

    The authors reviewed over 40 epidemiologic studies around nuclear power stations, fuel reprocessing plants, and weapons production facilities and testing sites in the United Kingdom, the United States, France, and Canada. They examined these studies for their potential to support a cause and effect relationship between cancer risk and radiation exposure. The extent to which an epidemiologic study supports a causal relation between radiation exposure and increased cancer risk can be evaluated using a set of criteria that have become known as Hill's postulates. In their review, epidemiologic studies yielded results that were biologically plausible and were supported by experimental data, but in almost all of the studies the methodologies were not adequate for evaluating causality. In the majority of cases, the methodologies did not permit examination of dose-response associations, making it impossible to support or refute causal relations. They suggest that investigators consider these issues when designing studies and employ dose reconstruction methodology to estimate radiation doses for specific individuals and population groups.86 references

  12. Neurocysticercosis an epidemiological survey in two small rural communities

    Directory of Open Access Journals (Sweden)

    Walter O. Arruda

    1990-12-01

    Full Text Available The authors describe the epidemiological findings related to human taeniasis and cysticercosis, and swine cysticercosis in two small rural communities, Postinho (P and Tigre (T, of South Brazil. The prevalence of epilepsy was 2.04% (P and 2.25% (T. The prevalence of neurocysticercosis was 0.47% (P and 0.93% (T, and prevalence of swine cysticercosis was 12.8% (P and 27.8% (T. Taenia sp. infestation wis detected in 4.3% (P and 4.6% (T of stool examinations. The hyperendemic human taeniasis and cysticercosis and swine cysticercosis seems to be related to poor hygienic habits of the population, and the free access to human excreta by the pigs.

  13. Sample size reassessment for a two-stage design controlling the false discovery rate.

    Science.gov (United States)

    Zehetmayer, Sonja; Graf, Alexandra C; Posch, Martin

    2015-11-01

    Sample size calculations for gene expression microarray and NGS-RNA-Seq experiments are challenging because the overall power depends on unknown quantities as the proportion of true null hypotheses and the distribution of the effect sizes under the alternative. We propose a two-stage design with an adaptive interim analysis where these quantities are estimated from the interim data. The second stage sample size is chosen based on these estimates to achieve a specific overall power. The proposed procedure controls the power in all considered scenarios except for very low first stage sample sizes. The false discovery rate (FDR) is controlled despite of the data dependent choice of sample size. The two-stage design can be a useful tool to determine the sample size of high-dimensional studies if in the planning phase there is high uncertainty regarding the expected effect sizes and variability.

  14. Comparison of two-stage thermophilic (68 degrees C/55 degrees C) anaerobic digestion with one-stage thermophilic (55 degrees C) digestion of cattle manure

    DEFF Research Database (Denmark)

    Nielsen, H.B.; Mladenovska, Zuzana; Westermann, Peter

    2004-01-01

    A two-stage 68degreesC/55degreesC anaerobic degradation process for treatment of cattle manure was studied. In batch experiments, an increase of the specific methane yield, ranging from 24% to 56%, was obtained when cattle manure and its fractions (fibers and liquid) were pretreated at 68degrees......, was compared with a conventional single-stage reactor running at 55degreesC with 15-days HRT. When an organic loading of 3 g volatile solids (VS) per liter per day was applied, the two-stage setup had a 6% to 8% higher specific methane yield and a 9% more effective VS-removal than the conventional single......-stage reactor. The 68degreesC reactor generated 7% to 9% of the total amount of methane of the two-stage system and maintained a volatile fatty acids (VFA) concentration of 4.0 to 4.4 g acetate per liter. Population size and activity of aceticlastic methanogens, syntrophic bacteria, and hydrolytic...

  15. Determinants of the incidence of childhood asthma: a two-stage case-control study.

    Science.gov (United States)

    Martel, Marie-Josée; Rey, Evelyne; Malo, Jean-Luc; Perreault, Sylvie; Beauchesne, Marie-France; Forget, Amélie; Blais, Lucie

    2009-01-15

    Extensive literature exists on potential risk factors for childhood asthma. To the authors' knowledge, no investigators have yet attempted to disentangle the effects of those determinants within a single study setting. The authors aimed to evaluate the independent effects of 47 potential determinants (from the prenatal, perinatal, and childhood periods) of asthma development in children within the first 10 years of life. From a Canadian birth cohort of 26,265 children (1990-2002), a 2-stage case-control study was conducted. In the first stage, 20 controls per case were selected from 3 administrative databases. In the second stage, selected mothers were mailed questionnaires for assessment of additional determinants. Increased risks of childhood asthma were found for > or =1 previous diagnosis of bronchopulmonary disease and atopic dermatitis in the child, oxygen administration after birth, prescription of antibiotics within the first 6 months of life, male gender, asthma during pregnancy, use of antibiotics during pregnancy, maternal receipt of social aid, paternal asthma, and asthma in siblings. Protective effects included use of intranasal corticosteroids during pregnancy, having a wood-burning fireplace, having pets in the home prior to the index date, breastfeeding, and day-care attendance. This study allowed the authors to identify, within a single setting, the most influential determinants of childhood asthma among 47 predictors assessed for the prenatal, perinatal, and childhood periods.

  16. Device for two-stage cementing of casing

    Energy Technology Data Exchange (ETDEWEB)

    Kudimov, D A; Goncharevskiy, Ye N; Luneva, L G; Shchelochkov, S N; Shil' nikova, L N; Tereshchenko, V G; Vasiliev, V A; Volkova, V V; Zhdokov, K I

    1981-01-01

    A device is claimed for two-stage cementing of casing. It consists of a body with lateral plugging vents, upper and lower movable sleeves, a check valve with axial channels that's situated in the lower sleeve, and a displacement limiting device for the lower sleeve. To improve the cementing process of the casing by preventing overflow of cementing fluids from the annular space into the first stage casing, the limiter is equipped with a spring rod that is capable of covering the axial channels of the check valve while it's in an operating mode. In addition, the rod in the upper part is equipped with a reinforced area under the axial channels of the check valve.

  17. Research Methods in Healthcare Epidemiology: Survey and Qualitative Research.

    Science.gov (United States)

    Safdar, Nasia; Abbo, Lilian M; Knobloch, Mary Jo; Seo, Susan K

    2016-11-01

    Surveys are one of the most frequently employed study designs in healthcare epidemiology research. Generally easier to undertake and less costly than many other study designs, surveys can be invaluable to gain insights into opinions and practices in large samples and may be descriptive and/or be used to test associations. In this context, qualitative research methods may complement this study design either at the survey development phase and/or at the interpretation/extension of results stage. This methods article focuses on key considerations for designing and deploying surveys in healthcare epidemiology and antibiotic stewardship, including identification of whether or not de novo survey development is necessary, ways to optimally lay out and display a survey, denominator measurement, discussion of biases to keep in mind particularly in research using surveys, and the role of qualitative research methods to complement surveys. We review examples of surveys in healthcare epidemiology and antimicrobial stewardship and review the pros and cons of methods used. A checklist is provided to help aid design and deployment of surveys in healthcare epidemiology and antimicrobial stewardship. Infect Control Hosp Epidemiol 2016;1-6.

  18. Two-stage categorization in brand extension evaluation: electrophysiological time course evidence.

    Directory of Open Access Journals (Sweden)

    Qingguo Ma

    Full Text Available A brand name can be considered a mental category. Similarity-based categorization theory has been used to explain how consumers judge a new product as a member of a known brand, a process called brand extension evaluation. This study was an event-related potential study conducted in two experiments. The study found a two-stage categorization process reflected by the P2 and N400 components in brand extension evaluation. In experiment 1, a prime-probe paradigm was presented in a pair consisting of a brand name and a product name in three conditions, i.e., in-category extension, similar-category extension, and out-of-category extension. Although the task was unrelated to brand extension evaluation, P2 distinguished out-of-category extensions from similar-category and in-category ones, and N400 distinguished similar-category extensions from in-category ones. In experiment 2, a prime-probe paradigm with a related task was used, in which product names included subcategory and major-category product names. The N400 elicited by subcategory products was more significantly negative than that elicited by major-category products, with no salient difference in P2. We speculated that P2 could reflect the early low-level and similarity-based processing in the first stage, whereas N400 could reflect the late analytic and category-based processing in the second stage.

  19. A Novel Two-Stage Dynamic Spectrum Sharing Scheme in Cognitive Radio Networks

    Institute of Scientific and Technical Information of China (English)

    Guodong Zhang; Wei Heng; Tian Liang; Chao Meng; Jinming Hu

    2016-01-01

    In order to enhance the efficiency of spectrum utilization and reduce communication overhead in spectrum sharing process,we propose a two-stage dynamic spectrum sharing scheme in which cooperative and noncooperative modes are analyzed in both stages.In particular,the existence and the uniqueness of Nash Equilibrium (NE) strategies for noncooperative mode are proved.In addition,a distributed iterative algorithm is proposed to obtain the optimal solutions of the scheme.Simulation studies are carried out to show the performance comparison between two modes as well as the system revenue improvement of the proposed scheme compared with a conventional scheme without a virtual price control factor.

  20. Outcomes of sentinel lymph node dissection alone vs. axillary lymph node dissection in early stage invasive lobular carcinoma: a retrospective study of the surveillance, epidemiology and end results (SEER database.

    Directory of Open Access Journals (Sweden)

    Jun Wang

    Full Text Available The American College of Surgeons Oncology Group (ACOSOG Z0011 trial demonstrated no difference in local-regional recurrence (LRR, disease-specific survival (DSS or overall survival (OS for sentinel lymph node dissection (SLND and completion axillary lymph node dissection (ALND among patients undergoing breast-conserving therapy for clinical T1-T2, N0 breast cancer with 1 or 2 positive SLNs. However, Only 7% of study participants had invasive lobular carcinoma (ILC. Because ILC has a different pattern of metastases, frequently presenting as small foci requiring immunohistochemistry for detection, the applicability of ACOSOG Z0011 trial data to ILC patients is unclear.We identified all ILC patients in the Surveillance, Epidemiology, and End Results (SEER database (1998-2009 who met the ACOSOG Z0011 eligibility criteria. Patients were evaluated on the basis of the extent of axillary surgery (SLND alone or ALND, and the clinical outcomes of these 2 groups were compared.1269 patients (393 SLND and 876 ALND were identified from the SEER database. At a median follow-up time of 71 months, there were no differences in OS or disease-specific survival between the two groups.SLND alone may result in outcomes comparable to those achieved with ALND for patients with early-stage ILC who meet the ACOSOG Z0011 eligibility criteria.

  1. Two stage treatment of dairy effluent using immobilized Chlorella pyrenoidosa

    Science.gov (United States)

    2013-01-01

    Background Dairy effluents contains high organic load and unscrupulous discharge of these effluents into aquatic bodies is a matter of serious concern besides deteriorating their water quality. Whilst physico-chemical treatment is the common mode of treatment, immobilized microalgae can be potentially employed to treat high organic content which offer numerous benefits along with waste water treatment. Methods A novel low cost two stage treatment was employed for the complete treatment of dairy effluent. The first stage consists of treating the diary effluent in a photobioreactor (1 L) using immobilized Chlorella pyrenoidosa while the second stage involves a two column sand bed filtration technique. Results Whilst NH4+-N was completely removed, a 98% removal of PO43--P was achieved within 96 h of two stage purification processes. The filtrate was tested for toxicity and no mortality was observed in the zebra fish which was used as a model at the end of 96 h bioassay. Moreover, a significant decrease in biological oxygen demand and chemical oxygen demand was achieved by this novel method. Also the biomass separated was tested as a biofertilizer to the rice seeds and a 30% increase in terms of length of root and shoot was observed after the addition of biomass to the rice plants. Conclusions We conclude that the two stage treatment of dairy effluent is highly effective in removal of BOD and COD besides nutrients like nitrates and phosphates. The treatment also helps in discharging treated waste water safely into the receiving water bodies since it is non toxic for aquatic life. Further, the algal biomass separated after first stage of treatment was highly capable of increasing the growth of rice plants because of nitrogen fixation ability of the green alga and offers a great potential as a biofertilizer. PMID:24355316

  2. Performance of an iterative two-stage bayesian technique for population pharmacokinetic analysis of rich data sets

    NARCIS (Netherlands)

    Proost, Johannes H.; Eleveld, Douglas J.

    2006-01-01

    Purpose. To test the suitability of an Iterative Two-Stage Bayesian (ITSB) technique for population pharmacokinetic analysis of rich data sets, and to compare ITSB with Standard Two-Stage (STS) analysis and nonlinear Mixed Effect Modeling (MEM). Materials and Methods. Data from a clinical study with

  3. Repetitive, small-bore two-stage light gas gun

    International Nuclear Information System (INIS)

    Combs, S.K.; Foust, C.R.; Fehling, D.T.; Gouge, M.J.; Milora, S.L.

    1991-01-01

    A repetitive two-stage light gas gun for high-speed pellet injection has been developed at Oak Ridge National Laboratory. In general, applications of the two-stage light gas gun have been limited to only single shots, with a finite time (at least minutes) needed for recovery and preparation for the next shot. The new device overcomes problems associated with repetitive operation, including rapidly evacuating the propellant gases, reloading the gun breech with a new projectile, returning the piston to its initial position, and refilling the first- and second-stage gas volumes to the appropriate pressure levels. In addition, some components are subjected to and must survive severe operating conditions, which include rapid cycling to high pressures and temperatures (up to thousands of bars and thousands of kelvins) and significant mechanical shocks. Small plastic projectiles (4-mm nominal size) and helium gas have been used in the prototype device, which was equipped with a 1-m-long pump tube and a 1-m-long gun barrel, to demonstrate repetitive operation (up to 1 Hz) at relatively high pellet velocities (up to 3000 m/s). The equipment is described, and experimental results are presented. 124 refs., 6 figs., 5 tabs

  4. Two-Stage Liver Transplantation with Temporary Porto-Middle Hepatic Vein Shunt

    Directory of Open Access Journals (Sweden)

    Giovanni Varotti

    2010-01-01

    Full Text Available Two-stage liver transplantation (LT has been reported for cases of fulminant liver failure that can lead to toxic hepatic syndrome, or massive hemorrhages resulting in uncontrollable bleeding. Technically, the first stage of the procedure consists of a total hepatectomy with preservation of the recipient's inferior vena cava (IVC, followed by the creation of a temporary end-to-side porto-caval shunt (TPCS. The second stage consists of removing the TPCS and implanting a liver graft when one becomes available. We report a case of a two-stage total hepatectomy and LT in which a temporary end-to-end anastomosis between the portal vein and the middle hepatic vein (TPMHV was performed as an alternative to the classic end-to-end TPCS. The creation of a TPMHV proved technically feasible and showed some advantages compared to the standard TPCS. In cases in which a two-stage LT with side-to-side caval reconstruction is utilized, TPMHV can be considered as a safe and effective alternative to standard TPCS.

  5. Two-stage perceptual learning to break visual crowding.

    Science.gov (United States)

    Zhu, Ziyun; Fan, Zhenzhi; Fang, Fang

    2016-01-01

    When a target is presented with nearby flankers in the peripheral visual field, it becomes harder to identify, which is referred to as crowding. Crowding sets a fundamental limit of object recognition in peripheral vision, preventing us from fully appreciating cluttered visual scenes. We trained adult human subjects on a crowded orientation discrimination task and investigated whether crowding could be completely eliminated by training. We discovered a two-stage learning process with this training task. In the early stage, when the target and flankers were separated beyond a certain distance, subjects acquired a relatively general ability to break crowding, as evidenced by the fact that the breaking of crowding could transfer to another crowded orientation, even a crowded motion stimulus, although the transfer to the opposite visual hemi-field was weak. In the late stage, like many classical perceptual learning effects, subjects' performance gradually improved and showed specificity to the trained orientation. We also found that, when the target and flankers were spaced too finely, training could only reduce, rather than completely eliminate, the crowding effect. This two-stage learning process illustrates a learning strategy for our brain to deal with the notoriously difficult problem of identifying peripheral objects in clutter. The brain first learned to solve the "easy and general" part of the problem (i.e., improving the processing resolution and segmenting the target and flankers) and then tackle the "difficult and specific" part (i.e., refining the representation of the target).

  6. Epidemiological studies on syncope--a register based approach

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth

    2013-01-01

    of the patients play an essential role. In epidemiology these factors have major impact on the outcome of the patients. Until recently, even the definition of syncope, differed from one study to another which has made literature reviews difficult. Traditionally the data on epidemiology of syncope has been taken......: 1) the use, validity and accuracy of the ICD-10 diagnosis of syncope R55.9 in the National Patient Registry for the use of this diagnosis in the epidemiology of syncope, 2) diagnostics used and etiology of a random selection of patients who had a discharge diagnosis of R55.9, 3) the incidence...... thesis demonstrated that the ICD-10 discharge diagnosis could reliably identify a cohort of patients admitted for syncope and that the discharge code carried a high number of unexplained cases despite use of numerous tests. The last studies showed that syncope is a common cause for hospital contact...

  7. An Epidemiological Study of Accidents in a Construction Industry: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Malakouti J.

    2013-01-01

    Full Text Available Background and Objectives: Despite science and technology development and their application in various industries, accidents continue to occur in many workplaces. This study was designed and carried out with the aim of epidemiological survey of accident among workers of a tunneling industry.Methods: This study was conducted on 144 out of a total of 440 employees of a tunneling project who were at risk of occupational accidents. 48 workers with a history of occupational accident over the past two years were selected as case group and 96 workers of the same project were selected as control group. The data were collected through a designed checklist and analyzed using logistic regression, chi-square and independent t tests.Results: A significant association was observed between accident rate and different age groups (p<0.05. There was a significant relationship (p=0.016 in the case of sport activities between case and control groups, and significant relationships were observed between two groups regarding education (p=0.057 and smoking (p=0.06, but there was no significant relationships between accident occurrence with marital status, residence in workplace, job related education, job experience, chronic diseases and obesity.Conclusion: The results of this study clarify the necessity of the use of epidemiological data in preventive and control measures in workplaces. Therefore, Developing programs for determination of physical and mental capacity of workers are essential to employ them in jobs commensurate with their abilities, especially in older workers.

  8. Poikiloderma of Civatte: a clinical and epidemiological study.

    Science.gov (United States)

    Katoulis, A C; Stavrianeas, N G; Georgala, S; Bozi, E; Kalogeromitros, D; Koumantaki, E; Katsambas, A D

    2005-07-01

    Although a common dermatosis, idiopathic poikiloderma of the face and neck has not been studied in depth for decades. To reassess the clinical and epidemiological characteristics of poikiloderma of Civatte (PC). Fifty consecutive patients with PC. Evaluation included history taking and physical examination. Epidemiological and clinical parameters were recorded and analysed. The literature from 1923 until today, was reviewed thoroughly. The frequency of PC among dermatologic patients was estimated to be 1.4%. There were 34 females (68%) and 16 males in the present study. The mean age at diagnosis was 47.8 years for females and 61.7 years for males. The majority (88%) had skin phototype II or III. Among females, 26 were at their peri-menopausal stage, including three cases of iatrogenic menopause. Four patients reported that other blood-related family members also had PC. The v and the sides of the neck and the upper chest were most often affected in a symmetric distribution. The face (preauricular and parotid region) was involved in 19 patients (38%). The erythemato-telangiectatic clinical type predominated (58%), followed by the mixed (22%) and the pigmented type (20%). Almost half of the patients (46%) were symptomatic (itching, burning and 'flushing'). The mean duration from onset to diagnosis was 6.2 years according to the patients' report. The course was usually slowly progressive (82%) and irreversible. PC shows characteristic features, supporting the theory that it represents a distinct entity. It is rather common in Greece. Although menopausal women predominated in our cohort, men were not uncommonly affected and were diagnosed at an older age. Based on the predominating clinical feature, PC can be classified into three clinical forms. Symmetry and sparing of the anatomically shaded areas of the neck are highly characteristic for PC. Face involvement was not as common and as severe as it had been considered in the past. Recognition of clinical type is

  9. EOG and EMG: two important switches in automatic sleep stage classification.

    Science.gov (United States)

    Estrada, E; Nazeran, H; Barragan, J; Burk, J R; Lucas, E A; Behbehani, K

    2006-01-01

    Sleep is a natural periodic state of rest for the body, in which the eyes are usually closed and consciousness is completely or partially lost. In this investigation we used the EOG and EMG signals acquired from 10 patients undergoing overnight polysomnography with their sleep stages determined by expert sleep specialists based on RK rules. Differentiation between Stage 1, Awake and REM stages challenged a well trained neural network classifier to distinguish between classes when only EEG-derived signal features were used. To meet this challenge and improve the classification rate, extra features extracted from EOG and EMG signals were fed to the classifier. In this study, two simple feature extraction algorithms were applied to EOG and EMG signals. The statistics of the results were calculated and displayed in an easy to visualize fashion to observe tendencies for each sleep stage. Inclusion of these features show a great promise to improve the classification rate towards the target rate of 100%

  10. Research on Two-channel Interleaved Two-stage Paralleled Buck DC-DC Converter for Plasma Cutting Power Supply

    DEFF Research Database (Denmark)

    Yang, Xi-jun; Qu, Hao; Yao, Chen

    2014-01-01

    As for high power plasma power supply, due to high efficiency and flexibility, multi-channel interleaved multi-stage paralleled Buck DC-DC Converter becomes the first choice. In the paper, two-channel interleaved two- stage paralleled Buck DC-DC Converter powered by three-phase AC power supply...

  11. Production of endo-pectate lyase by two stage cultivation of Erwinia carotovora

    Energy Technology Data Exchange (ETDEWEB)

    Fukuoka, Satoshi; Kobayashi, Yoshiaki

    1987-02-26

    The productivity of endo-pectate lyase from Erwinia carotovora GIR 1044 was found to be greatly improved by two stage cultivation: in the first stage the bacterium was grown with an inducing carbon source, e.g., pectin, and in the second stage it was cultivated with glycerol, xylose, or fructose with the addition of monosodium L-glutamate as nitrogen source. In the two stage cultivation using pectin or glycerol as the carbon source the enzyme activity reached 400 units/ml, almost 3 times as much as that of one stage cultivation in a 10 liter fermentor. Using two stage cultivation in the 200 liter fermentor improved enzyme productivity over that in the 10 liter fermentor, with 500 units/ml of activity. Compared with the cultivation in Erlenmeyer flasks, fermentor cultivation improved enzyme productivity. The optimum cultivating conditions were agitation of 480 rpm with aeration of 0.5 vvm at 28 /sup 0/C. (4 figs, 4 tabs, 14 refs)

  12. Two-stage pervaporation process for effective in situ removal acetone-butanol-ethanol from fermentation broth.

    Science.gov (United States)

    Cai, Di; Hu, Song; Miao, Qi; Chen, Changjing; Chen, Huidong; Zhang, Changwei; Li, Ping; Qin, Peiyong; Tan, Tianwei

    2017-01-01

    Two-stage pervaporation for ABE recovery from fermentation broth was studied to reduce the energy cost. The permeate after the first stage in situ pervaporation system was further used as the feedstock in the second stage of pervaporation unit using the same PDMS/PVDF membrane. A total 782.5g/L of ABE (304.56g/L of acetone, 451.98g/L of butanol and 25.97g/L of ethanol) was achieved in the second stage permeate, while the overall acetone, butanol and ethanol separation factors were: 70.7-89.73, 70.48-84.74 and 9.05-13.58, respectively. Furthermore, the theoretical evaporation energy requirement for ABE separation in the consolidate fermentation, which containing two-stage pervaporation and the following distillation process, was estimated less than ∼13.2MJ/kg-butanol. The required evaporation energy was only 36.7% of the energy content of butanol. The novel two-stage pervaporation process was effective in increasing ABE production and reducing energy consumption of the solvents separation system. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Current practice of epidemiology in Africa: highlights of the 3rd conference of the African epidemiological association and 1st conference of the Cameroon society of epidemiology, Yaoundé, Cameroon, 2014.

    Science.gov (United States)

    Nkwescheu, Armand Seraphin; Fokam, Joseph; Tchendjou, Patrice; Nji, Akindeh; Ngouakam, Hermann; Andre, Bita Fouda; Joelle, Sobngwi; Uzochukwu, Benjamin; Akinroye, Kingsley; Mbacham, Wilfred; Colizzi, Vittorio; Leke, Rose; Victora, Cesar

    2015-01-01

    As the study of disease occurrence and health indicators in human populations, Epidemiology is a dynamic field that evolves with time and geographical context. In order to update African health workers on current epidemiological practices and to draw awareness of early career epidemiologists on concepts and opportunities in the field, the 3(rd) African Epidemiology Association and the 1st Cameroon Society of Epidemiology Conference was organized in June 2-6, 2014 at the Yaoundé Mont Febe Hotel, in Cameroon. Under the theme«Practice of Epidemiology in Africa: Stakes, Challenges and Perspectives», the conference attracted close to five hundred guest and participants from all continents. The two main programs were the pre-conference course for capacity building of African Early Career epidemiologists, and the conference itself, providing a forum for scientific exchanges on recent epidemiological concepts, encouraging the use of epidemiological methods in studying large disease burden and neglected tropical diseases; and highlighting existing opportunities.

  14. Hypospadias repair: Byar's two stage operation revisited.

    Science.gov (United States)

    Arshad, A R

    2005-06-01

    Hypospadias is a congenital deformity characterised by an abnormally located urethral opening, that could occur anywhere proximal to its normal location on the ventral surface of glans penis to the perineum. Many operations had been described for the management of this deformity. One hundred and fifteen patients with hypospadias were treated at the Department of Plastic Surgery, Hospital Kuala Lumpur, Malaysia between September 1987 and December 2002, of which 100 had Byar's procedure performed on them. The age of the patients ranged from neonates to 26 years old. Sixty-seven patients had penoscrotal (58%), 20 had proximal penile (18%), 13 had distal penile (11%) and 15 had subcoronal hypospadias (13%). Operations performed were Byar's two-staged (100), Bracka's two-staged (11), flip-flap (2) and MAGPI operation (2). The most common complication encountered following hypospadias surgery was urethral fistula at a rate of 18%. There is a higher incidence of proximal hypospadias in the Malaysian community. Byar's procedure is a very versatile technique and can be used for all types of hypospadias. Fistula rate is 18% in this series.

  15. Comparison of two techniques used for the recovery of third-stage strongylid nematode larvae from herbage.

    Science.gov (United States)

    Krecek, R C; Maingi, N

    2004-07-14

    A laboratory trial to determine the efficacy of two methods in recovering known numbers of third-stage (L3) strongylid nematode larvae from herbage was carried out. Herbage samples consisting almost entirely of star grass (Cynodon aethiopicus) that had no L3 nematode parasitic larvae were collected at Onderstepoort, South Africa. Two hundred grams samples were placed in fibreglass fly gauze bags and seeded with third-stage strongylid nematode larvae at 11 different levels of herbage infectivity ranging from 50 to 8000 L3/kg. Eight replicates were prepared for each of the 11 levels of herbage infectivity. Four of these were processed using a modified automatic Speed Queen heavy-duty washing machine at a regular normal cycle, followed by isolation of larvae through centrifugation-flotation in saturated sugar solution. Larvae in the other four samples were recovered after soaking the herbage in water overnight and the larvae isolated with the Baermann technique of the washing. There was a strong correlation between the number of larvae recovered using both methods and the number of larvae in the seeded samples, indicating that the two methods give a good indication of changes in the numbers of larvae on pasture if applied in epidemiological studies. The washing machine method recovered higher numbers of larvae than the soaking and Baermann method at all levels of pasture seeding, probably because the machine washed the samples more thoroughly and a sugar centrifugation-flotation step was used. Larval suspensions obtained using the washing machine method were therefore cleaner and thus easier to examine under the microscope. In contrast, the soaking and Baermann method may be more suitable in field-work, especially in places where resources and equipment are scarce, as it is less costly in equipment and less labour intensive. Neither method recovered all the larvae from the seeded samples. The recovery rates for the washing machine method ranged from 18 to 41% while

  16. Effectiveness of medicines authentication technology to detect counterfeit, recalled and expired medicines: a two-stage quantitative secondary care study

    Science.gov (United States)

    Naughton, Bernard; Roberts, Lindsey; Dopson, Sue; Chapman, Stephen; Brindley, David

    2016-01-01

    Objectives To identify the authentication and detection rate of serialised medicines using medicines authentication technology. Design and intervention 4192 serialised medicines were entered into a hospital dispensary over two separate 8-week stages in 2015. Medicines were authenticated using secure external database cross-checking, triggered by the scanning of a two-dimensional data matrix with a unit specific 12-digit serial code. 4% of medicines included were preprogrammed with a message to identify the product as either expired, pack recalled, product recalled or counterfeit. Setting A site within a large UK National Health Service teaching hospital trust. Participants Accredited checking staff, pharmacists and dispensers in a pharmacy department. Primary outcome measures Authentication and detection rate of counterfeit expired and recalled medicines. Results The operational detection rate of counterfeit, recalled and expired medicines scanned as a combined group was 81.4% (stage 1 (S1)) and 87% (stage 2 (S2)). The technology's technical detection rate (TDR) was 100%; however, not all medicines were scanned and of those that were scanned not all that generated a warning message were quarantined. Owing to an operational authentication rate (OAR) of 66.3% (over both stages), only 31.8% of counterfeit medicines, 58% of recalled drugs and 64% of expired medicines were detected as a proportion of those entered into the study. Response times (RTs) of 152 ms (S1) and 165 ms (S2) were recorded, meeting the falsified medicines directive-mandated 300 ms limit. Conclusions TDRs and RTs were not a limiting factor in this study. The suboptimal OAR poses significant quality and safety issues with this detection approach. Authentication at the checking stage, however, demonstrated higher OARs. There is a need for further qualitative research to establish the reasons for less than absolute authentication and detection rates in the hospital environment to improve this

  17. Epidemiological and morphological studies of double-chambered right ventricle in dogs.

    Science.gov (United States)

    Fukushima, Ryuji; Tanaka, Ryou; Suzuki, Shuji; Hamabe, Rina; Machida, Noboru; Nakao, Shu; Saida, Yuto; Takashima, Kazuaki; Matsumoto, Hirotaka; Koyama, Hidekazu; Hirose, Hisashi; Yamane, Yoshihisa

    2011-10-01

    The double-chambered right ventricle (DCRV) is a rare congenital cardiac disease in dogs, and its detailed epidemiological and morphological features are not clearly understood. By investigating the profile, clinical signs, and characteristics of examination findings of eleven dogs with DCRV by means of a retrospective study, we attempted to clarify the epidemiology and morphology of the condition. The study group consisted of nine males and two females. Breeds included Pug (n=3), Miniature Dachshund (n=1), French Bull-dog (n=1), Shiba (n=1), and Retrievers (n=5). The attachment site of the anomalous muscular bundle was continuous with the cardiac apex in nine dogs, and it was attached to the right ventricle free wall in the other two dogs. In dogs with DCRV, at least one of the following conditions was present concurrently: congenital or acquired tricuspid valve regurgitation (TR), ventricular septal defect, and atrial septal defect. Also, the pressure difference between the two chambers increased over time, and progressive right-sided heart failure was observed. In summary, DCRV occurs in small breeds of dog as well as in large breeds of dog and it may be more prevalent in males. The existence of two types of DCRV in dogs was established. Dog with DCRVs will have a high incidence of concurrent cardiac abnormalities. Concurrent TR may be either congenital or acquired. DCRV is a congenital disorder, but the clinical condition progresses as the dog develops.

  18. Epidemiological studies of cognitive impairment and dementia across Eastern and Middle European countries (epidemiology of dementia in Eastern and Middle European Countries).

    Science.gov (United States)

    Kiejna, A; Frydecka, D; Adamowski, T; Bickel, H; Reynish, E; Prince, M; Caracciolo, B; Fratiglioni, L; Georges, J

    2011-02-01

    To determine the availability and the consistency of prevalence findings of epidemiological studies on cognitive impairment and dementia conducted in Eastern and Middle Europe. We adopted a stepwise multimethod study approach consisting of iterative literature searches for epidemiological articles published between 1990 and 2006 and subsequent data analyses of published material, reanalyses of existing accessible epidemiological data sets and expert inquiries in Eastern and Middle European countries. Systematic computer-assisted searches used the keywords: "dementia", "Alzheimer", "cognitive impairment", "incidence", "prevalence", "epidemiology" in combination with the name of the relevant countries or "Europe" in English and Polish language. We supplemented the literature search with a review of the references in the articles that were identified during the initial search. We were able to find few regional and country-specific epidemiological studies of various kinds (population-based, cohort, cross-sectional studies) and conducted on different restricted population groups of patients (from neurological units, out-patients units, residential homes). No studies were identified from most of the countries taken under consideration and the ones we found were characterized by an immense diversity with a considerable degree of clinical and methodological variations. The few studies that there are suggest prevalence rates of dementia in Eastern Europe similar to those in Western Europe. There is strong need for epidemiological studies in Eastern and Middle Europe, as well as for greater coordination and standardization of methods to improve the quality and comparability of epidemiological data to determine the prevalences' rates of dementia in all the EU countries. Copyright © 2010 John Wiley & Sons, Ltd.

  19. A two-stage method for inverse medium scattering

    KAUST Repository

    Ito, Kazufumi; Jin, Bangti; Zou, Jun

    2013-01-01

    We present a novel numerical method to the time-harmonic inverse medium scattering problem of recovering the refractive index from noisy near-field scattered data. The approach consists of two stages, one pruning step of detecting the scatterer

  20. Application of two-stage biofilter system for the removal of odorous compounds.

    Science.gov (United States)

    Jeong, Gwi-Taek; Park, Don-Hee; Lee, Gwang-Yeon; Cha, Jin-Myeong

    2006-01-01

    Biofiltration is a biological process which is considered to be one of the more successful examples of biotechnological applications to environmental engineering, and is most commonly used in the removal of odoriferous compounds. In this study, we have attempted to assess the efficiency with which both single and complex odoriferous compounds could be removed, using one- or two-stage biofiltration systems. The tested single odor gases, limonene, alpha-pinene, and iso-butyl alcohol, were separately evaluated in the biofilters. Both limonene and alpha-pinene were removed by 90% or more EC (elimination capacity), 364 g/m3/h and 321 g/m3/h, respectively, at an input concentration of 50 ppm and a retention time of 30 s. The iso-butyl alcohol was maintained with an effective removal yield of more than 90% (EC 375 g/m3/h) at an input concentration of 100 ppm. The complex gas removal scheme was applied with a 200 ppm inlet concentration of ethanol, 70 ppm of acetaldehyde, and 70 ppm of toluene with residence time of 45 s in a one- or two-stage biofiltration system. The removal yield of toluene was determined to be lower than that of the other gases in the one-stage biofilter. Otherwise, the complex gases were sufficiently eliminated by the two-stage biofiltration system.

  1. FIRST DIRECT EVIDENCE OF TWO STAGES IN FREE RECALL

    Directory of Open Access Journals (Sweden)

    Eugen Tarnow

    2015-12-01

    Full Text Available I find that exactly two stages can be seen directly in sequential free recall distributions. These distributions show that the first three recalls come from the emptying of working memory, recalls 6 and above come from a second stage and the 4th and 5th recalls are mixtures of the two.A discontinuity, a rounded step function, is shown to exist in the fitted linear slope of the recall distributions as the recall shifts from the emptying of working memory (positive slope to the second stage (negative slope. The discontinuity leads to a first estimate of the capacity of working memory at 4-4.5 items. The total recall is shown to be a linear combination of the content of working memory and items recalled in the second stage with 3.0-3.9 items coming from working memory, a second estimate of the capacity of working memory. A third, separate upper limit on the capacity of working memory is found (3.06 items, corresponding to the requirement that the content of working memory cannot exceed the total recall, item by item. This third limit is presumably the best limit on the average capacity of unchunked working memory.The second stage of recall is shown to be reactivation: The average times to retrieve additional items in free recall obey a linear relationship as a function of the recall probability which mimics recognition and cued recall, both mechanisms using reactivation (Tarnow, 2008.

  2. Maxillofacial growth and speech outcome after one-stage or two-stage palatoplasty in unilateral cleft lip and palate. A systematic review.

    Science.gov (United States)

    Reddy, Rajgopal R; Gosla Reddy, Srinivas; Vaidhyanathan, Anitha; Bergé, Stefaan J; Kuijpers-Jagtman, Anne Marie

    2017-06-01

    The number of surgical procedures to repair a cleft palate may play a role in the outcome for maxillofacial growth and speech. The aim of this systematic review was to investigate the relationship between the number of surgical procedures performed to repair the cleft palate and maxillofacial growth, speech and fistula formation in non-syndromic patients with unilateral cleft lip and palate. An electronic search was performed in PubMed/old MEDLINE, the Cochrane Library, EMBASE, Scopus and CINAHL databases for publications between 1960 and December 2015. Publications before 1950-journals of plastic and maxillofacial surgery-were hand searched. Additional hand searches were performed on studies mentioned in the reference lists of relevant articles. Search terms included unilateral, cleft lip and/or palate and palatoplasty. Two reviewers assessed eligibility for inclusion, extracted data, applied quality indicators and graded level of evidence. Twenty-six studies met the inclusion criteria. All were retrospective and non-randomized comparisons of one- and two-stage palatoplasty. The methodological quality of most of the studies was graded moderate to low. The outcomes concerned the comparison of one- and two-stage palatoplasty with respect to growth of the mandible, maxilla and cranial base, and speech and fistula formation. Due to the lack of high-quality studies there is no conclusive evidence of a relationship between one- or two-stage palatoplasty and facial growth, speech and fistula formation in patients with unilateral cleft lip and palate. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  3. Two-stage bargaining with coverage extension in a dual labour market

    DEFF Research Database (Denmark)

    Roberts, Mark A.; Stæhr, Karsten; Tranæs, Torben

    2000-01-01

    This paper studies coverage extension in a simple general equilibrium model with a dual labour market. The union sector is characterized by two-stage bargaining whereas the firms set wages in the non-union sector. In this model firms and unions of the union sector have a commonality of interest...

  4. Spawning strategies and transport of early stages of the two Cape ...

    African Journals Online (AJOL)

    Seasonal and short-term variability of environmental parameters influence the spawning strategies of fish species. In this study, the spawning strategies and the transport of early stages of the two Cape hake species off South Africa were investigated. Distribution of eggs and larvae of Merluccius paradoxus and M. capensis ...

  5. A cause and effect two-stage BSC-DEA method for measuring the relative efficiency of organizations

    Directory of Open Access Journals (Sweden)

    Seyed Esmaeel Najafi

    2011-01-01

    Full Text Available This paper presents an integration of balanced score card (BSE with two-stage data envelopment analysis (DEA. The proposed model of this paper uses different financial and non-financial perspectives to evaluate the performance of decision making units in different BSC stages. At each stage, a two-stage DEA method is implemented to measure the relative efficiency of decision making units and the results are monitored using the cause and effect relationships. An empirical study for a banking sector is also performed using the method developed in this paper and the results are briefly analyzed.

  6. Modal intersection types, two-level languages, and staged synthesis

    DEFF Research Database (Denmark)

    Henglein, Fritz; Rehof, Jakob

    2016-01-01

    -linguistic framework for staged program synthesis, where metaprograms are automatically synthesized which, when executed, generate code in a target language. We survey the basic theory of staged synthesis and illustrate by example how a two-level language theory specialized from λ∩ ⎕ can be used to understand......A typed λ-calculus, λ∩ ⎕, is introduced, combining intersection types and modal types. We develop the metatheory of λ∩ ⎕, with particular emphasis on the theory of subtyping and distributivity of the modal and intersection type operators. We describe how a stratification of λ∩ ⎕ leads to a multi...... the process of staged synthesis....

  7. The Epidemiology of Delirium: Challenges and Opportunities for Population Studies

    Science.gov (United States)

    Davis, Daniel H.J.; Kreisel, Stefan H.; Muniz Terrera, Graciela; Hall, Andrew J.; Morandi, Alessandro; Boustani, Malaz; Neufeld, Karin J.; Lee, Hochang Benjamin; MacLullich, Alasdair M.J.; Brayne, Carol

    2013-01-01

    Delirium is a serious and common acute neuropsychiatric syndrome that is associated with short- and long-term adverse health outcomes. However, relatively little delirium research has been conducted in unselected populations. Epidemiologic research in such populations has the potential to resolve several questions of clinical significance in delirium. Part 1 of this article explores the importance of population selection, case-ascertainment, attrition, and confounding. Part 2 examines a specific question in delirium epidemiology: What is the relationship between delirium and trajectories of cognitive decline? This section assesses previous work through two systematic reviews and proposes a design for investigating delirium in the context of longitudinal cohort studies. Such a design requires robust links between community and hospital settings. Practical considerations for case-ascertainment in the hospital, as well as the necessary quality control of these programs, are outlined. We argue that attention to these factors is important if delirium research is to benefit fully from a population perspective. PMID:23907068

  8. Two-stage, high power X-band amplifier experiment

    International Nuclear Information System (INIS)

    Kuang, E.; Davis, T.J.; Ivers, J.D.; Kerslick, G.S.; Nation, J.A.; Schaechter, L.

    1993-01-01

    At output powers in excess of 100 MW the authors have noted the development of sidebands in many TWT structures. To address this problem an experiment using a narrow bandwidth, two-stage TWT is in progress. The TWT amplifier consists of a dielectric (e = 5) slow-wave structure, a 30 dB sever section and a 8.8-9.0 GHz passband periodic, metallic structure. The electron beam used in this experiment is a 950 kV, 1 kA, 50 ns pencil beam propagating along an applied axial field of 9 kG. The dielectric first stage has a maximum gain of 30 dB measured at 8.87 GHz, with output powers of up to 50 MW in the TM 01 mode. In these experiments the dielectric amplifier output power is about 3-5 MW and the output power of the complete two-stage device is ∼160 MW at the input frequency. The sidebands detected in earlier experiments have been eliminated. The authors also report measurements of the energy spread of the electron beam resulting from the amplification process. These experimental results are compared with MAGIC code simulations and analytic work they have carried out on such devices

  9. Experimental study on two-stage compression refrigeration/heat pump system with dual-cylinder rolling piston compressor

    International Nuclear Information System (INIS)

    Shuxue, Xu; Guoyuan, Ma

    2014-01-01

    A thermodynamically analytical model on the two-stage compression refrigeration/heat pump system with vapor injection was derived. The optimal volume ratio of the high-pressure cylinder to the low-pressure one has been discussed under both cooling and heating conditions. Based on the above research, the prototype was developed and its experimental setup established. A comprehensive experiments for the prototype have been conducted, and the results show that, compared with the single-stage compression heat pump system, the cooling capacity and cooling COP can increase 5%–15% and 10–12%, respectively. Also, the heating capacity with the evaporating temperature ranging from 0.3 to 3 °C is 92–95% of that under the rate condition with the evaporating temperature of 7 °C, and 58% when the evaporation temperature is between −28 °C and −24 °C. -- Highlights: • The volume ratio of the compressor is between 0.65 and 0.78 and the relative vapor injection mass ranges from 15% to 20%. • The cooling capacity and COP of the two-stage compression system can improve 5%–15% and 10%–12%. • The heating capacity can also be improved under low temperature condition

  10. Anti-kindling induced by two-stage coordinated reset stimulation with weak onset intensity

    Directory of Open Access Journals (Sweden)

    Magteld eZeitler

    2016-05-01

    Full Text Available Abnormal neuronal synchrony plays an important role in a number of brain diseases. To specifically counteract abnormal neuronal synchrony by desynchronization, Coordinated Reset (CR stimulation, a spatiotemporally patterned stimulation technique, was designed with computational means. In neuronal networks with spike timing–dependent plasticity CR stimulation causes a decrease of synaptic weights and finally anti-kindling, i.e. unlearning of abnormally strong synaptic connectivity and abnormal neuronal synchrony. Long-lasting desynchronizing aftereffects of CR stimulation have been verified in pre-clinical and clinical proof of concept studies. In general, for different neuromodulation approaches, both invasive and non-invasive, it is desirable to enable effective stimulation at reduced stimulation intensities, thereby avoiding side effects. For the first time, we here present a two-stage CR stimulation protocol, where two qualitatively different types of CR stimulation are delivered one after another, and the first stage comes at a particularly weak stimulation intensity. Numerical simulations show that a two-stage CR stimulation can induce the same degree of anti-kindling as a single-stage CR stimulation with intermediate stimulation intensity. This stimulation approach might be clinically beneficial in patients suffering from brain diseases characterized by abnormal neuronal synchrony where a first treatment stage should be performed at particularly weak stimulation intensities in order to avoid side effects. This might, e.g., be relevant in the context of acoustic CR stimulation in tinnitus patients with hyperacusis or in the case of electrical deep brain CR stimulation with sub-optimally positioned leads or side effects caused by stimulation of the target itself. We discuss how to apply our method in first in man and proof of concept studies.

  11. Noncausal two-stage image filtration at presence of observations with anomalous errors

    OpenAIRE

    S. V. Vishnevyy; S. Ya. Zhuk; A. N. Pavliuchenkova

    2013-01-01

    Introduction. It is necessary to develop adaptive algorithms, which allow to detect such regions and to apply filter with respective parameters for suppression of anomalous noises for the purposes of image filtration, which consist of regions with anomalous errors. Development of adaptive algorithm for non-causal two-stage images filtration at pres-ence of observations with anomalous errors. The adaptive algorithm for noncausal two-stage filtration is developed. On the first stage the adaptiv...

  12. CFD simulations of compressed air two stage rotary Wankel expander – Parametric analysis

    International Nuclear Information System (INIS)

    Sadiq, Ghada A.; Tozer, Gavin; Al-Dadah, Raya; Mahmoud, Saad

    2017-01-01

    Highlights: • CFD ANSYS-Fluent 3D simulation of Wankel expander is developed. • Single and two-stage expander’s performance is compared. • Inlet and outlet ports shape and configurations are investigated. • Isentropic efficiency of two stage Wankel expander of 91% is achieved. - Abstract: A small scale volumetric Wankel expander is a powerful device for small-scale power generation in compressed air energy storage (CAES) systems and Organic Rankine cycles powered by different heat sources such as, biomass, low temperature geothermal, solar and waste heat leading to significant reduction in CO_2 emissions. Wankel expanders outperform other types of expander due to their ability to produce two power pulses per revolution per chamber additional to higher compactness, lower noise and vibration and lower cost. In this paper, a computational fluid dynamics (CFD) model was developed using ANSYS 16.2 to simulate the flow dynamics for a single and two stage Wankel expanders and to investigate the effect of port configurations, including size and spacing, on the expander’s power output and isentropic efficiency. Also, single-stage and two-stage expanders were analysed with different operating conditions. Single-stage 3D CFD results were compared to published work showing close agreement. The CFD modelling was used to investigate the performance of the rotary device using air as an ideal gas with various port diameters ranging from 15 mm to 50 mm; port spacing varying from 28 mm to 66 mm; different Wankel expander sizes (r = 48, e = 6.6, b = 32) mm and (r = 58, e = 8, b = 40) mm both as single-stage and as two-stage expanders with different configurations and various operating conditions. Results showed that the best Wankel expander design for a single-stage was (r = 48, e = 6.6, b = 32) mm, with the port diameters 20 mm and port spacing equal to 50 mm. Moreover, combining two Wankel expanders horizontally, with a larger one at front, produced 8.52 kW compared

  13. RISK CONCEPT AND RISK ASSESSMENT IN EPIDEMIOLOGIC STUDIES

    Directory of Open Access Journals (Sweden)

    Gamze CAN

    2006-10-01

    Full Text Available Basic aim of an epidemiological study is to quantify the association between the exposure and the outcome of interest. To achieve this, the incidence of disease in a group of individuals exposed to the putative risk factors must be compared with the incidence in a group of persons not exposed. This comparison can be summarized by calculating either the ratio of the measures of disease occurrence for the two groups, which indicates the likelihood of developing the disease in the exposed individuals relative to those unexposed, or the difference between the two, which provides information about the absolute effect of the exposure in those exposed compared with those unexposed. Some terms about relative risk were explained and examine with samples in this article. [TAF Prev Med Bull 2006; 5(5.000: 374-381

  14. IDGenerator: unique identifier generator for epidemiologic or clinical studies

    Directory of Open Access Journals (Sweden)

    Matthias Olden

    2016-09-01

    Full Text Available Abstract Background Creating study identifiers and assigning them to study participants is an important feature in epidemiologic studies, ensuring the consistency and privacy of the study data. The numbering system for identifiers needs to be random within certain number constraints, to carry extensions coding for organizational information, or to contain multiple layers of numbers per participant to diversify data access. Available software can generate globally-unique identifiers, but identifier-creating tools meeting the special needs of epidemiological studies are lacking. We have thus set out to develop a software program to generate IDs for epidemiological or clinical studies. Results Our software IDGenerator creates unique identifiers that not only carry a random identifier for a study participant, but also support the creation of structured IDs, where organizational information is coded into the ID directly. This may include study center (for multicenter-studies, study track (for studies with diversified study programs, or study visit (baseline, follow-up, regularly repeated visits. Our software can be used to add a check digit to the ID to minimize data entry errors. It facilitates the generation of IDs in batches and the creation of layered IDs (personal data ID, study data ID, temporary ID, external data ID to ensure a high standard of data privacy. The software is supported by a user-friendly graphic interface that enables the generation of IDs in both standard text and barcode 128B format. Conclusion Our software IDGenerator can create identifiers meeting the specific needs for epidemiologic or clinical studies to facilitate study organization and data privacy. IDGenerator is freeware under the GNU General Public License version 3; a Windows port and the source code can be downloaded at the Open Science Framework website: https://osf.io/urs2g/ .

  15. Evaluation of the effect of one stage versus two stage full mouth disinfection on C-reactive protein and leucocyte count in patients with chronic periodontitis.

    Science.gov (United States)

    Pabolu, Chandra Mohan; Mutthineni, Ramesh Babu; Chintala, Srikanth; Naheeda; Mutthineni, Navya

    2013-07-01

    Conventional non-surgical periodontal therapy is carried out in quadrant basis with 1-2 week interval. This time lag may result in re-infection of instrumented pocket and may impair healing. Therefore, a new approach to full-mouth non-surgical therapy to be completed within two consecutive days with full-mouth disinfection has been suggested. In periodontitis, leukocyte counts and levels of C-reactive protein (CRP) are likely to be slightly elevated, indicating the presence of infection or inflammation. The aim of this study is to compare the efficacy of one stage and two stage non-surgical therapy on clinical parameters along with CRP levels and total white blood cell (TWBC) count. A total of 20 patients were selected and were divided into two groups. Group 1 received one stage full mouth dis-infection and Group 2 received two stages FMD. Plaque index, sulcus bleeding index, probing depth, clinical attachment loss, serum CRP and TWBC count were evaluated for both the groups at baseline and at 1 month post-treatment. The results were analyzed using the Student t-test. Both treatment modalities lead to a significant improvement of the clinical and hematological parameters; however comparison between the two groups showed no significant difference after 1 month. The therapeutic intervention may have a systemic effect on blood count in periodontitis patients. Though one stage FMD had limited benefits over two stages FMD, the therapy can be accomplished in a shorter duration.

  16. Acute HIV infection (AHI) in a specialized clinical setting: case-finding, description of virological, epidemiological and clinical characteristics.

    Science.gov (United States)

    Ammassari, Adriana; Abbate, Isabella; Orchi, Nicoletta; Pinnetti, Carmela; Rozera, Gabriella; Libertone, Raffaella; Pierro, Paola; Martini, Federico; Puro, Vincenzo; Girardi, Enrico; Antinori, Andrea; Capobianchi, Maria Rosaria

    2014-01-01

    Diagnosis of HIV infection during early stages is mandatory to catch up with the challenge of limiting HIV viral replication and reservoirs formation, as well as decreasing HIV transmissions by immediate cART initiation. Aims were to describe (a) virological characteristics of AHI identified, (b) epidemiological and clinical factors associated with being diagnosed with AHI. Cross-sectional, retrospective study. All individuals diagnosed with AHI according to Fiebig's staging between Jan 2013 and Mar 2014 at the INMI "L. Spallanzani" were included. Serum samples reactive to a fourth generation HIV-1/2 assay (Architect HIV Ag/Ab Combo, Abbott) were retested with another fourth generation assay (VIDAS DUO HIV Ultra, Biomérieux) and underwent confirmation with HIV-1 WB (New Lav I Bio-Rad) and/or with Geenius confirmatory assay (Bio-Rad). WHO criteria (two env products reactivity) were used to establish positivity of confirmatory assays. In case of clinically suspected AHI, HIV-1 RNA (Real time, Abbott) and p24 assay (VIDAS HIV P24 Bio-Rad) were also performed. Avidity test was carried out, on confirmed positive samples lacking p31 reactivity, to discriminate between recent (true Fiebig V phase) and late infections; to avoid possible misclassifications, clinical data were also used. Demographic, epidemiological, clinical and laboratory data are routinely, and anonymously recorded in the SENDIH and SIREA studies. During the study period, we observed 483 newly HIV diagnosed individuals, of whom 40 were identified as AHI (8.3%). Fiebig classification showed: 7 stage II/III, 13 stage IV, 20 stage V. Demographic, epidemiological, and clinical characteristics of patients are shown in the Table. Overall, the study population had a median S/Co ratio at fourth generation EIA (Architect) of 49.50 (IQR, 23.54-98.05): values were significantly lower in Fiebig II-IV than in Fiebig V (38.68 [IQR, 20.08-54.84] vs 75.72 [IQR, 42.66-249.80], p=0.01). Overall, median HIV-1 RNA was 5

  17. [Bibliometric analysis of scientific articles on epidemiological study of burns in China].

    Science.gov (United States)

    Cheng, W F; Shen, Z A; Zhao, D X; Li, D W; Shang, Y R

    2017-04-20

    Objective: To analyze the current status of epidemiological study of burns in China, and to explore the related strategies. Methods: Retrospective or cross-sectional scientific articles in Chinese or English on epidemiological study of burns in China published from January 2005 to December 2015 were systemically retrieved from 4 databases. The databases include PubMed, Embase, China Biology Medicine disc, and Chinese Journals Full - text Database . From the results retrieved, data with regard to publication year, journal distribution, number of institutions participated in the study, affiliation of the first author and its location, and admission time span and age of patients in all the scientific articles were collected. Furthermore, the definition of age range and the grouping method of age of pediatric patients in English articles on epidemiological study of pediatric burns of China were recorded. Data were processed with descriptive statistical analysis. Results: A total of 256 scientific articles conforming to the study criteria were retrieved, among which 214 (83.59%) articles were in Chinese, and 42 (16.41%) articles were in English; 242 (94.53%) articles were retrospective studies, and 14 (5.47%) articles were cross-sectional studies. During the 11 years, the number of the relevant articles was fluctuant on the whole. The scientific articles were published in 130 journals, with 42 English articles in source journals for SCIENCE CITATION INDEX EXPANDED - JOURNAL LIST, accounting for 16.41%, and 116 Chinese articles in Source Journal for Chinese Scientific and Technical Papers, accounting for 45.31%. Totally 215 (83.98%) articles were single-center studies, and 29 (11.33%) articles were multicenter studies which were conducted by three or more centers. The number of affiliations of the first author of articles was 161 in total. The top 10 institutions regarding the article publishing number published 58 articles, accounting for 22.66%. Scientific articles on

  18. Geographic variations in epidemiology of two autoimmune bullous diseases: pemphigus and bullous pemphigoid.

    Science.gov (United States)

    Alpsoy, Erkan; Akman-Karakas, Ayse; Uzun, Soner

    2015-05-01

    Autoimmune bullous diseases are rare, organ-specific, a group of blistering disease of skin and mucous membranes. Recent studies suggest that the frequency of the autoimmune bullous diseases has been increasing. Pemphigus vulgaris and bullous pemphigoid are the most frequently reported autoimmune bullous diseases. High incidence of autoimmune bullous diseases in some ethnic groups such as pemphigus in Ashkenazi Jewish, or in some regions such as pemphigus foliaceus in Brazil has been shown to be related to genetic and environmental factors, respectively. Pemphigus has been reported more frequently in the female gender. Although it is most frequently diagnosed between the ages 50 and 60 in European countries, in the remaining countries in the world, it is seen between the ages of 30 and 50. Bullous pemphigoid is generally seen above 70 years of age. Although overall incidence is slightly higher in females, after the age of 80 years it is more frequent in males. Both pemphigus vulgaris and bullous pemphigoid has a chronic course with recurrences. Mortality risk of the patients with bullous pemphigoid was found at least 2 times higher and the mortality risk of the patients with pemphigus was found approximately 3 times higher than that of the general population. In this review, the results obtained from the epidemiological studies were analyzed according to geographic regions, and especially epidemiologic features of two prevalent autoimmune bullous diseases, pemphigus and bullous pemphigoid have been discussed.

  19. The RTD measurement of two stage anaerobic digester using radiotracer in WWTP

    International Nuclear Information System (INIS)

    Jin-Seop, Kim; Jong-Bum, Kim; Sung-Hee, Jung

    2006-01-01

    The aims of this study are to assess the existence and location of the stagnant zone by estimating the MRT (mean residence time) on the two stage anaerobic digester, with the results to be used as informative clue for its better operation

  20. A two-stage meta-analysis identifies several new loci for Parkinson's disease.

    NARCIS (Netherlands)

    Plagnol, V.; Nalls, M.A.; Bras, J.M.; Hernandez, D.; Sharma, M.; Sheerin, U.M.; Saad, M.; Simon-Sanchez, J.; Schulte, C.; Lesage, S.; Sveinbjornsdottir, S.; Amouyel, P.; Arepalli, S.; Band, G.; Barker, R.A.; Bellinguez, C.; Ben-Shlomo, Y.; Berendse, H.W.; Berg, D; Bhatia, K.P.; Bie, R.M. de; Biffi, A.; Bloem, B.R.; Bochdanovits, Z.; Bonin, M.; Brockmann, K.; Brooks, J.; Burn, D.J.; Charlesworth, G.; Chen, H.; Chinnery, P.F.; Chong, S.; Clarke, C.E.; Cookson, M.R.; Cooper, J.M.; Corvol, J.C.; Counsell, J.; Damier, P.; Dartigues, J.F.; Deloukas, P.; Deuschl, G.; Dexter, D.T.; Dijk, K.D. van; Dillman, A.; Durif, F.; Durr, A.; Edkins, S.; Evans, J.R.; Foltynie, T.; Freeman, C.; Gao, J.; Gardner, M.; Gibbs, J.R.; Goate, A.; Gray, E.; Guerreiro, R.; Gustafsson, O.; Harris, C.; Hellenthal, G.; Hilten, J.J. van; Hofman, A.; Hollenbeck, A.; Holton, J.L.; Hu, M.; Huang, X.; Huber, H; Hudson, G.; Hunt, S.E.; Huttenlocher, J.; Illig, T.; Jonsson, P.V.; Langford, C.; Lees, A.J.; Lichtner, P.; Limousin, P.; Lopez, G.; McNeill, A.; Moorby, C.; Moore, M.; Morris, H.A.; Morrison, K.E.; Mudanohwo, E.; O'Sullivan, S.S; Pearson, J.; Pearson, R.; Perlmutter, J.; Petursson, H.; Pirinen, M.; Polnak, P.; Post, B.; Potter, S.C.; Ravina, B.; Revesz, T.; Riess, O.; Rivadeneira, F.; Rizzu, P.; Ryten, M.; Sawcer, S.J.; Schapira, A.; Scheffer, H.; Shaw, K.; Shoulson, I.; Sidransky, E.; Silva, R. de; Smith, C.; Spencer, C.C.; Stefansson, H.; Steinberg, S.; Stockton, J.D.; Strange, A.; Su, Z.; Talbot, K.; Tanner, C.M.; Tashakkori-Ghanbaria, A.; Tison, F.; Trabzuni, D.; Traynor, B.J.; Uitterlinden, A.G.; Vandrovcova, J.; Velseboer, D.; Vidailhet, M.; Vukcevic, D.; Walker, R.; Warrenburg, B.P.C. van de; Weale, M.E.; Wickremaratchi, M.; Williams, N.; Williams-Gray, C.H.; Winder-Rhodes, S.; Stefansson, K.; Martinez, M.; Donnelly, P.; Singleton, A.B.; Hardy, J.; Heutink, P.; Brice, A.; Gasser, T.; Wood, N.W.

    2011-01-01

    A previous genome-wide association (GWA) meta-analysis of 12,386 PD cases and 21,026 controls conducted by the International Parkinson's Disease Genomics Consortium (IPDGC) discovered or confirmed 11 Parkinson's disease (PD) loci. This first analysis of the two-stage IPDGC study

  1. Multi stage electrodialysis for separation of two metal ion species

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, K.; Sakurai, H.; Nii, S.; Sugiura, K. [Nagoya Univ., Nagoya (Japan)

    1995-04-20

    In this article, separation of two metal ions by electrodialysis with a cation exchange membrane has been investigated. In other words, separation of potassium ion and sodium ion has been investigated by using batch dialysis with and without an electric field and continuous electrodialysis with a four-stage dialyzer. As a result, the difference in the permselectivity between the dialysis with and without an electric field has not been appreciable for the system of potassium and sodium ions with the cation exchange membrane. Concerning the continuous electrodialysis, the concentration ratio between potassium and sodium ions in the outlet solution from the recovery side of the dialyzer has increased with the reflux flow rate and the number of stages. In case when the reflux flow rate has been zero, the concentration ratio with the four-stage dialyzer has become 1.5 which is almost the same as with that with a two-stage dialyzer consisting of a simple membrane. When the reflux flow ratio has been 0.7, the concentration ratio has reached 3.6. 20 refs., 8 figs.

  2. Satellite remote sensing in epidemiological studies.

    Science.gov (United States)

    Sorek-Hamer, Meytar; Just, Allan C; Kloog, Itai

    2016-04-01

    Particulate matter air pollution is a ubiquitous exposure linked with multiple adverse health outcomes for children and across the life course. The recent development of satellite-based remote-sensing models for air pollution enables the quantification of these risks and addresses many limitations of previous air pollution research strategies. We review the recent literature on the applications of satellite remote sensing in air quality research, with a focus on their use in epidemiological studies. Aerosol optical depth (AOD) is a focus of this review and a significant number of studies show that ground-level particulate matter can be estimated from columnar AOD. Satellite measurements have been found to be an important source of data for particulate matter model-based exposure estimates, and recently have been used in health studies to increase the spatial breadth and temporal resolution of these estimates. It is suggested that satellite-based models improve our understanding of the spatial characteristics of air quality. Although the adoption of satellite-based measures of air quality in health studies is in its infancy, it is rapidly growing. Nevertheless, further investigation is still needed in order to have a better understanding of the AOD contribution to these prediction models in order to use them with higher accuracy in epidemiological studies.

  3. Gas pollutants removal in a single- and two-stage ejector-venturi scrubber.

    Science.gov (United States)

    Gamisans, Xavier; Sarrà, Montserrrat; Lafuente, F Javier

    2002-03-29

    The absorption of SO(2) and NH(3) from the flue gas into NaOH and H(2)SO(4) solutions, respectively has been studied using an industrial scale ejector-venturi scrubber. A statistical methodology is presented to characterise the performance of the scrubber by varying several factors such as gas pollutant concentration, air flowrate and absorbing solution flowrate. Some types of venturi tube constructions were assessed, including the use of a two-stage venturi tube. The results showed a strong influence of the liquid scrubbing flowrate on pollutant removal efficiency. The initial pollutant concentration and the gas flowrate had a slight influence. The use of a two-stage venturi tube considerably improved the absorption efficiency, although it increased energy consumption. The results of this study will be applicable to the optimal design of venturi-based absorbers for gaseous pollution control or chemical reactors.

  4. Worldwide Report, Epidemiology

    Science.gov (United States)

    1985-11-22

    caused by ingesting eggs of the pork tapeworm, Taenia solium . It has been described as the most com- mon parasitic disease of the central nervous...rather difficult to detect in stool specimens and at this stage it is impossible to distinguish between T. solium and T. saginata eggs either by...Knowledge and Perspectives, pp. 25-38. Academic Press, New York. 12. Pawlowskz S. (1982). Epidemiology and prevention of Taenia saginata infec- tion. In

  5. Epidemiologic studies based on the Chernobyl accident

    International Nuclear Information System (INIS)

    Beebe, G.

    1996-01-01

    There are great opportunities in the post-Chernobyl experience for significant epidemiologic research, perhaps even more in the area of disaster research than in the area of the human health effects of ionizing radiation. But the potential opportunity for learning the effects of radioiodine on the thyroid is very great and has aroused widespread national and international investigative interest. The opportunities for significant epidemiologic research are, however, severely limited currently by the worsening economic situation in Belarus and Ukraine, where the greatest exposure occurred, and by the lack of personnel trained in appropriate methods of study, the lack of modern equipment, the lack of supplies, the poor communication facilities, and the difficulties of accurate dose estimation. the disadvantages may or may not outweigh the obvious advantages of large numbers, the extensive direct thyroidal measurements made shortly after the accident in 1986, the magnitude of the releases of radioiodine, and the retention of the former Soviet system of universal medical care. Both the European Commission (EC) and the World Health Organization (WHO) have been working actively to strengthen the infrastructure of Russia, Belarus, and Ukraine. New scientific knowledge has yet to emerge from the extensive epidemiologic work but information of considerable public health significance has begun to accumulate. The bulk of the thyroid cancer has been shown to be valid by international pathology review; both EC and WHO representatives have declared the increase in thyroid cancer among children to have been caused in large part by Chernobyl. No increase in leukemia has been seen in the general population. The WHO pilot studies have shown no evidence of an increase in psychologic or neurologic complications among those exposed in utero. Ongoing epidemiologic work can be described by review of the inventory that the WHO has begun to maintain and publish. 20 refs., 7 tabs

  6. Epidemiologic studies of pilots and aircrew.

    Science.gov (United States)

    Boice, J D; Blettner, M; Auvinen, A

    2000-11-01

    During flight, pilots and cabin crew are exposed to increased levels of cosmic radiation which consists primarily of neutrons and gamma rays. Neutron dosimetry is not straightforward, but typical annual effective doses are estimated to range between two and five mSv. Higher dose rates are experienced at the highest altitudes and in the polar regions. Mean doses have been increasing over time as longer flights at higher altitudes have become more frequent. Because there are so few populations exposed to neutrons, studies of airline personnel are of particular interest. However, because the cumulative radiation exposure is so low, statistical power is a major concern. Further, finding an appropriate comparison group is problematic due to selection into these occupations and a number of biases are possible. For example, increased rates of breast cancer among flight attendants have been attributed to reproductive factors such as nulliparity and increased rates of melanoma among pilots have been attributed to excessive sun exposure during leisure time activities. Epidemiologic studies conducted over the last 20 y provide little consistent evidence linking cancer with radiation exposures from air travel.

  7. Runway Operations Planning: A Two-Stage Solution Methodology

    Science.gov (United States)

    Anagnostakis, Ioannis; Clarke, John-Paul

    2003-01-01

    The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. Thus, Runway Operations Planning (ROP) is a critical component of airport operations planning in general and surface operations planning in particular. From the perspective of departures, ROP solutions are aircraft departure schedules developed by optimally allocating runway time for departures given the time required for arrivals and crossings. In addition to the obvious objective of maximizing throughput, other objectives, such as guaranteeing fairness and minimizing environmental impact, may be incorporated into the ROP solution subject to constraints introduced by Air Traffic Control (ATC) procedures. Generating optimal runway operations plans was approached in with a 'one-stage' optimization routine that considered all the desired objectives and constraints, and the characteristics of each aircraft (weight class, destination, Air Traffic Control (ATC) constraints) at the same time. Since, however, at any given point in time, there is less uncertainty in the predicted demand for departure resources in terms of weight class than in terms of specific aircraft, the ROP problem can be parsed into two stages. In the context of the Departure Planner (OP) research project, this paper introduces Runway Operations Planning (ROP) as part of the wider Surface Operations Optimization (SOO) and describes a proposed 'two stage' heuristic algorithm for solving the Runway Operations Planning (ROP) problem. Focus is specifically given on including runway crossings in the planning process of runway operations. In the first stage, sequences of departure class slots and runwy crossings slots are generated and ranked based on departure runway throughput under stochastic conditions. In the second stage, the

  8. Fleet Planning Decision-Making: Two-Stage Optimization with Slot Purchase

    Directory of Open Access Journals (Sweden)

    Lay Eng Teoh

    2016-01-01

    Full Text Available Essentially, strategic fleet planning is vital for airlines to yield a higher profit margin while providing a desired service frequency to meet stochastic demand. In contrast to most studies that did not consider slot purchase which would affect the service frequency determination of airlines, this paper proposes a novel approach to solve the fleet planning problem subject to various operational constraints. A two-stage fleet planning model is formulated in which the first stage selects the individual operating route that requires slot purchase for network expansions while the second stage, in the form of probabilistic dynamic programming model, determines the quantity and type of aircraft (with the corresponding service frequency to meet the demand profitably. By analyzing an illustrative case study (with 38 international routes, the results show that the incorporation of slot purchase in fleet planning is beneficial to airlines in achieving economic and social sustainability. The developed model is practically viable for airlines not only to provide a better service quality (via a higher service frequency to meet more demand but also to obtain a higher revenue and profit margin, by making an optimal slot purchase and fleet planning decision throughout the long-term planning horizon.

  9. Two-stage combustion for reducing pollutant emissions from gas turbine combustors

    Science.gov (United States)

    Clayton, R. M.; Lewis, D. H.

    1981-01-01

    Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

  10. One-stage (Warsaw) and two-stage (Oslo) repair of unilateral cleft lip and palate: Craniofacial outcomes.

    Science.gov (United States)

    Fudalej, Piotr Stanislaw; Wegrodzka, Ewa; Semb, Gunvor; Hortis-Dzierzbicka, Maria

    2015-09-01

    The aim of this study was to compare facial development in subjects with complete unilateral cleft lip and palate (CUCLP) treated with two different surgical protocols. Lateral cephalometric radiographs of 61 patients (42 boys, 19 girls; mean age, 10.9 years; SD, 1) treated consecutively in Warsaw with one-stage repair and 61 age-matched and sex-matched patients treated in Oslo with two-stage surgery were selected to evaluate craniofacial morphology. On each radiograph 13 angular and two ratio variables were measured in order to describe hard and soft tissues of the facial region. The analysis showed that differences between the groups were limited to hard tissues – the maxillary prominence in subjects from the Warsaw group was decreased by almost 4° in comparison with the Oslo group (sella-nasion-A-point (SNA) = 75.3° and 79.1°, respectively) and maxillo-mandibular morphology was less favorable in the Warsaw group than the Oslo group (ANB angle = 0.8° and 2.8°, respectively). The soft tissue contour was comparable in both groups. In conclusion, inter-group differences suggest a more favorable outcome in the Oslo group. However, the distinctiveness of facial morphology in background populations (ie, in Poles and Norwegians) could have contributed to the observed results. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  11. Two-stage single-volume exchange transfusion in severe hemolytic disease of the newborn.

    Science.gov (United States)

    Abbas, Wael; Attia, Nayera I; Hassanein, Sahar M A

    2012-07-01

    Evaluation of two-stage single-volume exchange transfusion (TSSV-ET) in decreasing the post-exchange rebound increase in serum bilirubin level, with subsequent reduction of the need for repeated exchange transfusions. The study included 104 neonates with hyperbilirubinemia needing exchange transfusion. They were randomly enrolled into two equal groups, each group comprised 52 neonates. TSSV-ET was performed for the 52 neonates and the traditional single-stage double-volume exchange transfusion (SSDV-ET) was performed to 52 neonates. TSSV-ET significantly lowered rebound serum bilirubin level (12.7 ± 1.1 mg/dL), compared to SSDV-ET (17.3 ± 1.7 mg/dL), p < 0.001. Need for repeated exchange transfusions was significantly lower in TSSV-ET group (13.5%), compared to 32.7% in SSDV-ET group, p < 0.05. No significant difference was found between the two groups as regards the morbidity (11.5% and 9.6%, respectively) and the mortality (1.9% for both groups). Two-stage single-volume exchange transfusion proved to be more effective in reducing rebound serum bilirubin level post-exchange and in decreasing the need for repeated exchange transfusions.

  12. TWO-STAGE HEAT PUMPS FOR ENERGY SAVING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    A. E. Denysova

    2017-09-01

    Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources have essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two stages heat pump installation operating as heat source at ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of groundwater energy. Calculated are the values of electric energy consumption by the compressors’ drive, and the heat supply system transformation coefficient µ for a low-potential source of heat from ground waters allowing to estimate high efficiency of two stages heat pump installations.

  13. Development and testing of a two stage granular filter to improve collection efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Rangan, R.S.; Prakash, S.G.; Chakravarti, S.; Rao, S.R.

    1999-07-01

    A circulating bed granular filter (CBGF) with a single filtration stage was tested with a PFB combustor in the Coal Research Facility of BHEL R and D in Hyderabad during the years 1993--95. Filter outlet dust loading varied between 20--50 mg/Nm{sup 3} for an inlet dust loading of 5--8 gms/Nm{sup 3}. The results were reported in Fluidized Bed Combustion-Volume 2, ASME 1995. Though the outlet consists of predominantly fine particulates below 2 microns, it is still beyond present day gas turbine specifications for particulate concentration. In order to enhance the collection efficiency, a two-stage granular filtration concept was evolved, wherein the filter depth is divided between two stages, accommodated in two separate vertically mounted units. The design also incorporates BHEL's scale-up concept of multiple parallel stages. The two-stage concept minimizes reentrainment of captured dust by providing clean granules in the upper stage, from where gases finally exit the filter. The design ensures that dusty gases come in contact with granules having a higher dust concentration at the bottom of the two-stage unit, where most of the cleaning is completed. A second filtration stage of cleaned granules is provided in the top unit (where the granules are returned to the system after dedusting) minimizing reentrainment. Tests were conducted to determine the optimum granule to dust ratio (G/D ratio) which decides the granule circulation rate required for the desired collection efficiency. The data brings out the importance of pre-separation and the limitation on inlet dust loading for any continuous system of granular filtration. Collection efficiencies obtained were much higher (outlet dust being 3--9 mg/Nm{sub 3}) than in the single stage filter tested earlier for similar dust loading at the inlet. The results indicate that two-stage granular filtration has a high potential for HTHT application with fewer risks as compared to other systems under development.

  14. Nuclear accidents and epidemiology

    International Nuclear Information System (INIS)

    1987-01-01

    A consultation on epidemiology related to the Chernobyl accident was held in Copenhagen in May 1987 as a basis for concerted action. This was followed by a joint IAEA/WHO workshop in Vienna, which reviewed appropriate methodologies for possible long-term effects of radiation following nuclear accidents. The reports of these two meetings are included in this volume, and cover the subjects: 1) Epidemiology related to the Chernobyl nuclear accident. 2) Appropriate methodologies for studying possible long-term effects of radiation on individuals exposed in a nuclear accident. Figs and tabs

  15. CLINICO-EPIDEMIOLOGICAL PROFILE OF ORAL CANCER: A HOSPITAL BASED STUDY

    Directory of Open Access Journals (Sweden)

    Kapil H Agrawal

    2012-07-01

    Full Text Available Background: India is heading towards various types of non-communicable diseases, which are also known as modern epidemics. Among these modern epidemics cancer is among the ten commonest cause of mortality in developing countries including India. Oral cancer is a major problem in India and accounts for 50-70% of all the cancers diagnosed. Ninety percent (90% of oral cancers in South East Asia including India are linked to tobacco chewing and tobacco smoking. Research question: What is the profile of Oral cancer (Oral cavity cases reported in the hospital? Objective: To study the clinico-epidemiological profile associated with Oral cancer cases. Methods: Study Design: Hospital based, Cross -sectional study. Settings: Shri Siddhivinayak Ganapati Cancer Hospital, Miraj, Maharashtra. Participants and Sample size: As it is a time bound study sample size comprised of all the confirmed cases of oral cancer reported in the hospital during the study period. The study was carried out from 1st March 2005 to 28th February 2006. Study variables included demographic factors, socioeconomic factors, enquiries regarding modifiable risk factors such as tobacco usage, alcohol consumption, site involved (within oral cavity, staging, histopathological examination, treatment modality used. Data entry and statistical analysis was done using Microsoft excel. Data presented in form of percentages and proportions. Results: Out of the total 160 cases, majority of the subjects were above 40 years age. 36 (22% of subjects were young adults (below 40 years age. 125 (78% subjects were male. Most of the subjects belonged to upper lower and lower middle socio-economic scale according to modified Kuppuswamy classification. It was observed that 139 (87% cases consumed tobacco in all forms. Out of these, ninety cases consumed tobacco in chewable form. Tobacco was chewed mainly in the form of gutka. Only ten (10 female subjects chewed tobacco. No female subjects smoked. The most

  16. Evaluation Study for Secondary Stage EFL Textbook: EFL Teachers' Perspectives

    Science.gov (United States)

    Al Harbi, Abdullah Abdul Muhsen

    2017-01-01

    This study aimed at evaluating EFL textbook for secondary stage in Saudi Public schools. Participants consisted of (100) male teachers and (73) female teachers teaching secondary stage students in two cities: Madinah and Dowadmi. The tool of the study designed to cover five dimensions: layout and design, the objectives of the textbook, teaching…

  17. 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.

  18. A comprehensive study of task coalescing for selecting parallelism granularity in a two-stage bidiagonal reduction

    KAUST Repository

    Haidar, Azzam

    2012-05-01

    We present new high performance numerical kernels combined with advanced optimization techniques that significantly increase the performance of parallel bidiagonal reduction. Our approach is based on developing efficient fine-grained computational tasks as well as reducing overheads associated with their high-level scheduling during the so-called bulge chasing procedure that is an essential phase of a scalable bidiagonalization procedure. In essence, we coalesce multiple tasks in a way that reduces the time needed to switch execution context between the scheduler and useful computational tasks. At the same time, we maintain the crucial information about the tasks and their data dependencies between the coalescing groups. This is the necessary condition to preserve numerical correctness of the computation. We show our annihilation strategy based on multiple applications of single orthogonal reflectors. Despite non-trivial characteristics in computational complexity and memory access patterns, our optimization approach smoothly applies to the annihilation scenario. The coalescing positively influences another equally important aspect of the bulge chasing stage: the memory reuse. For the tasks within the coalescing groups, the data is retained in high levels of the cache hierarchy and, as a consequence, operations that are normally memory-bound increase their ratio of computation to off-chip communication and become compute-bound which renders them amenable to efficient execution on multicore architectures. The performance for the new two-stage bidiagonal reduction is staggering. Our implementation results in up to 50-fold and 12-fold improvement (∼130 Gflop/s) compared to the equivalent routines from LAPACK V3.2 and Intel MKL V10.3, respectively, on an eight socket hexa-core AMD Opteron multicore shared-memory system with a matrix size of 24000 x 24000. Last but not least, we provide a comprehensive study on the impact of the coalescing group size in terms of cache

  19. Study on a high capacity two-stage free piston Stirling cryocooler working around 30 K

    Science.gov (United States)

    Wang, Xiaotao; Zhu, Jian; Chen, Shuai; Dai, Wei; Li, Ke; Pang, Xiaomin; Yu, Guoyao; Luo, Ercang

    2016-12-01

    This paper presents a two-stage high-capacity free-piston Stirling cryocooler driven by a linear compressor to meet the requirement of the high temperature superconductor (HTS) motor applications. The cryocooler system comprises a single piston linear compressor, a two-stage free piston Stirling cryocooler and a passive oscillator. A single stepped displacer configuration was adopted. A numerical model based on the thermoacoustic theory was used to optimize the system operating and structure parameters. Distributions of pressure wave, phase differences between the pressure wave and the volume flow rate and different energy flows are presented for a better understanding of the system. Some characterizing experimental results are presented. Thus far, the cryocooler has reached a lowest cold-head temperature of 27.6 K and achieved a cooling power of 78 W at 40 K with an input electric power of 3.2 kW, which indicates a relative Carnot efficiency of 14.8%. When the cold-head temperature increased to 77 K, the cooling power reached 284 W with a relative Carnot efficiency of 25.9%. The influences of different parameters such as mean pressure, input electric power and cold-head temperature are also investigated.

  20. Development of Explosive Ripper with Two-Stage Combustion

    Science.gov (United States)

    1974-10-01

    inch pipe duct work, the width of this duct proved to be detrimental in marginally rippable material; the duct, instead of the penetrator tip, was...marginally rippable rock. ID. Operating Requirements 2. Fuel The two-stage combustion device is designed to operate using S A 42. the same diesel

  1. Occupational reproductive epidemiology: Pt. 1

    International Nuclear Information System (INIS)

    Roman, Eve; Doyle, Pat

    1993-01-01

    The authors review the current state of knowledge about possible adverse effects of hazardous paternal workplace exposures on human reproduction is scant. The methodology for studying possible association between occupational exposures and adverse reproductive events is not well developed. More detailed laboratory and epidemiological research is clearly required, and better collaboration between these two disciplines is needed. Associations suggested in the course of epidemiological research need to be tested in the laboratory, and vice versa. (author)

  2. A Two-Stage Meta-Analysis Identifies Several New Loci for Parkinson's Disease

    NARCIS (Netherlands)

    Plagnol, Vincent; Nalls, Michael A.; Bras, Jose M.; Hernandez, Dena G.; Sharma, Manu; Sheerin, Una-Marie; Saad, Mohamad; Simon-Sanchez, Javier; Schulte, Claudia; Lesage, Suzanne; Sveinbjornsdottir, Sigurlaug; Amouyel, Philippe; Arepalli, Sampath; Band, Gavin; Barker, Roger A.; Bellinguez, Celine; Ben-Shlomo, Yoav; Berendse, Henk W.; Berg, Daniela; Bhatia, Kailash; de Bie, Rob M. A.; Biffi, Alessandro; Bloem, Bas; Bochdanovits, Zoltan; Bonin, Michael; Brockmann, Kathrin; Brooks, Janet; Burn, David J.; Charlesworth, Gavin; Chen, Honglei; Chinnery, Patrick F.; Chong, Sean; Clarke, Carl E.; Cookson, Mark R.; Cooper, J. Mark; Corvol, Jean Christophe; Counsell, Carl; Damier, Philippe; Dartigues, Jean-Francois; Deloukas, Panos; Deuschl, Guenther; Dexter, David T.; van Dijk, Karin D.; Dillman, Allissa; Durif, Frank; Duerr, Alexandra; Edkins, Sarah; Evans, Jonathan R.; Foltynie, Thomas; Freeman, Colin; Gao, Jianjun; Gardner, Michelle; Gibbs, J. Raphael; Goate, Alison; Gray, Emma; Guerreiro, Rita; Gustafsson, Omar; Harris, Clare; Hellenthal, Garrett; van Hilten, Jacobus J.; Hofman, Albert; Hollenbeck, Albert; Holton, Janice; Hu, Michele; Huang, Xuemei; Huber, Heiko; Hudson, Gavin; Hunt, Sarah E.; Huttenlocher, Johanna; Illig, Thomas; Jonsson, Palmi V.; Langford, Cordelia; Lees, Andrew; Lichtner, Peter; Limousin, Patricia; Lopez, Grisel; Lorenz, Delia; McNeill, Alisdair; Moorby, Catriona; Moore, Matthew; Morris, Huw; Morrison, Karen E.; Mudanohwo, Ese; O'Sullivan, Sean S.; Pearson, Justin; Pearson, Richard; Perlmutter, Joel S.; Petursson, Hjoervar; Pirinen, Matti; Pollak, Pierre; Post, Bart; Potter, Simon; Ravina, Bernard; Revesz, Tamas; Riess, Olaf; Rivadeneira, Fernando; Rizzu, Patrizia; Ryten, Mina; Sawcer, Stephen; Schapira, Anthony; Scheffer, Hans; Shaw, Karen; Shoulson, Ira; Sidransky, Ellen; de Silva, Rohan; Smith, Colin; Spencer, Chris C. A.; Stefansson, Hreinn; Steinberg, Stacy; Stockton, Joanna D.; Strange, Amy; Su, Zhan; Talbot, Kevin; Tanner, Carlie M.; Tashakkori-Ghanbaria, Avazeh; Tison, Francois; Trabzuni, Daniah; Traynor, Bryan J.; Uitterlinden, Andre G.; Vandrovcova, Jana; Velseboer, Daan; Vidailhet, Marie; Vukcevic, Damjan; Walker, Robert; van de Warrenburg, Bart; Weale, Michael E.; Wickremaratchi, Mirdhu; Williams, Nigel; Williams-Gray, Caroline H.; Winder-Rhodes, Sophie; Stefansson, Kari; Martinez, Maria; Donnelly, Peter; Singleton, Andrew B.; Hardy, John; Heutink, Peter; Brice, Alexis; Gasser, Thomas; Wood, Nicholas W.

    2011-01-01

    A previous genome-wide association (GWA) meta-analysis of 12,386 PD cases and 21,026 controls conducted by the International Parkinson's Disease Genomics Consortium (IPDGC) discovered or confirmed 11 Parkinson's disease (PD) loci. This first analysis of the two-stage IPDGC study focused on the set

  3. Spatial statistics of magnetic field in two-dimensional chaotic flow in the resistive growth stage

    Energy Technology Data Exchange (ETDEWEB)

    Kolokolov, I.V., E-mail: igor.kolokolov@gmail.com [Landau Institute for Theoretical Physics RAS, 119334, Kosygina 2, Moscow (Russian Federation); NRU Higher School of Economics, 101000, Myasnitskaya 20, Moscow (Russian Federation)

    2017-03-18

    The correlation tensors of magnetic field in a two-dimensional chaotic flow of conducting fluid are studied. It is shown that there is a stage of resistive evolution where the field correlators grow exponentially with time. The two- and four-point field correlation tensors are computed explicitly in this stage in the framework of Batchelor–Kraichnan–Kazantsev model. They demonstrate strong temporal intermittency of the field fluctuations and high level of non-Gaussianity in spatial field distribution.

  4. Kinetics analysis of two-stage austenitization in supermartensitic stainless steel

    DEFF Research Database (Denmark)

    Nießen, Frank; Villa, Matteo; Hald, John

    2017-01-01

    The martensite-to-austenite transformation in X4CrNiMo16-5-1 supermartensitic stainless steel was followed in-situ during isochronal heating at 2, 6 and 18 K min−1 applying energy-dispersive synchrotron X-ray diffraction at the BESSY II facility. Austenitization occurred in two stages, separated...... that the austenitization kinetics is governed by Ni-diffusion and that slow transformation kinetics separating the two stages is caused by soft impingement in the martensite phase. Increasing the lath width in the kinetics model had a similar effect on the austenitization kinetics as increasing the heating-rate....

  5. Epidemiological Studies to Support the Development of Next Generation Influenza Vaccines.

    Science.gov (United States)

    Petrie, Joshua G; Gordon, Aubree

    2018-03-26

    The National Institute of Allergy and Infectious Diseases recently published a strategic plan for the development of a universal influenza vaccine. This plan focuses on improving understanding of influenza infection, the development of influenza immunity, and rational design of new vaccines. Epidemiological studies such as prospective, longitudinal cohort studies are essential to the completion of these objectives. In this review, we discuss the contributions of epidemiological studies to our current knowledge of vaccines and correlates of immunity, and how they can contribute to the development and evaluation of the next generation of influenza vaccines. These studies have been critical in monitoring the effectiveness of current influenza vaccines, identifying issues such as low vaccine effectiveness, reduced effectiveness among those who receive repeated vaccination, and issues related to egg adaptation during the manufacturing process. Epidemiological studies have also identified population-level correlates of protection that can inform the design and development of next generation influenza vaccines. Going forward, there is an enduring need for epidemiological studies to continue advancing knowledge of correlates of protection and the development of immunity, to evaluate and monitor the effectiveness of next generation influenza vaccines, and to inform recommendations for their use.

  6. Two-stage soil infiltration treatment system for treating ammonium wastewaters of low COD/TN ratios.

    Science.gov (United States)

    Lei, Zhongfang; Wu, Ting; Zhang, Yi; Liu, Xiang; Wan, Chunli; Lee, Duu-Jong; Tay, Joo-Hwa

    2013-01-01

    Soil infiltration treatment (SIT) is ineffective to treat ammonium wastewaters of total nitrogen (TN) > 100 mg l(-1). This study applied a novel two-stage SIT process for effective TN removal from wastewaters of TN>100 mg l(-1) and of chemical oxygen demand (COD)/TN ratio of 3.2-8.6. The wastewater was first fed into the soil column (stage 1) at hydraulic loading rate (HLR) of 0.06 m(3) m(-2) d(-1) for COD removal and total phosphorus (TP) immobilization. Then the effluent from stage 1 was fed individually into four soil columns (stage 2) at 0.02 m(3) m(-2) d(-1) of HLR with different proportions of raw wastewater as additional carbon source. Over the one-year field test, balanced nitrification and denitrification in the two-stage SIT revealed excellent TN removal (>90%) from the tested wastewaters. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Two-stage laparoscopic approaches for high anorectal malformation: transumbilical colostomy and anorectoplasty.

    Science.gov (United States)

    Yang, Li; Tang, Shao-Tao; Li, Shuai; Aubdoollah, T H; Cao, Guo-Qing; Lei, Hai-Yan; Wang, Xin-Xing

    2014-11-01

    Trans-umbilical colostomy (TUC) has been previously created in patients with Hirschsprung's disease and intermediate anorectal malformation (ARM), but not in patients with high-ARM. The purposes of this study were to assess the feasibility, safety, complications and cosmetic results of TUC in a divided fashion, and subsequently stoma closure and laparoscopic assisted anorectoplasty (LAARP) were simultaneously completed by using the colostomy site for a laparoscopic port in high-ARM patients. Twenty male patients with high-ARMs were chosen for this two-stage procedure. The first-stage consisted of creating the TUC in double-barreled fashion colostomy with a high chimney at the umbilicus, and the loop was divided at the same time, in such a way that the two diverting ends were located at the umbilical incision with the distal end half closed and slightly higher than proximal end. In the second-stage, 3 to 7 months later, the stoma was closed through a peristomal skin incision followed by end-to-end anastomosis and simultaneously LAARP was performed by placing a laparoscopic port at the umbilicus, which was previously the colonostomy site. Umbilical wound closure was performed in a semi-opened fashion to create a deep umbilicus. TUC and LAARP were successfully performed in 20 patients. Four cases with bladder neck fistulas and 16 cases with prostatic urethra fistulas were found. Postoperative complications were rectal mucosal prolapsed in three cases, anal stricture in two cases and wound dehiscence in one case. Neither umbilical ring narrowing, parastomal hernia nor obstructive symptoms was observed. Neither umbilical nor perineal wound infection was observed. Stoma care was easily carried-out by attaching stoma bag. Healing of umbilical wounds after the second-stage was excellent. Early functional stooling outcome were satisfactory. The umbilicus may be an alternative stoma site for double-barreled colostomy in high-ARM patients. The two-stage laparoscopic

  8. High-speed double-disc TMP [thermomechanical pulp] from northern and southern softwoods: One or two refining stages

    Energy Technology Data Exchange (ETDEWEB)

    Sabourin, M.J. (Andritz Sprout-Bauer, Inc., Springfield, OH (United States)); Cort, J.B.; Musselman, R.L. (Andritz Sprout-Bauer, Inc., Muncy, PA (United States))

    1994-01-01

    Pilot-plant studies were carried out to evaluate one- and two-stage high-speed refining processes for production of thermomechanical pulp (TMP) at minimal energy consumption. Both northern (black spruce/balsam fir) and southern (lobolly pine) wood species were tested. Preliminary results indicate both one- and two-stage high-speed refining are suitable for the production of TMP from spruce and fir. Single-stage, high-speed refining of spruce/fir resulted in over 25% energy savings compared to conventional TMP production. The resulting TMP had improved optical and shive content properties, with slightly reduced pulp strength and long fiber content. Two stages of refining were necessary to optimize pulp quality from the lobolly pine furnish. A 15% energy reduction was obtained when comparing high-speed and conventional TMP pulping of lobolly pine at similar operating conditions. The high-speed pine TMP had comparable bonding strength, shive content, and lower tear than conventional two-stage lobolly pine TMP. 14 refs., 11 figs., 6 tabs.

  9. Epidemiological studies on postpartum thyroid dysfunction and thyroid cancer in Southeastern Netherlands

    NARCIS (Netherlands)

    J.L.P. Kuijpens (Hans)

    1998-01-01

    textabstractThe studies described in this thesis concentrate OIl epidemiological and pathogenetic aspects of postpartum thyroid dysfunction (PPTD) and related topics, and on epidemiological and treatment aspects of thyroid cancer. The studies were petfonned in the southeastern part of the

  10. 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

  11. Cryptic relatedness in epidemiologic collections accessed for genetic association studies: experiences from the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study and the National Health and Nutrition Examination Surveys (NHANES).

    Science.gov (United States)

    Malinowski, Jennifer; Goodloe, Robert; Brown-Gentry, Kristin; Crawford, Dana C

    2015-01-01

    Epidemiologic collections have been a major resource for genotype-phenotype studies of complex disease given their large sample size, racial/ethnic diversity, and breadth and depth of phenotypes, traits, and exposures. A major disadvantage of these collections is they often survey households and communities without collecting extensive pedigree data. Failure to account for substantial relatedness can lead to inflated estimates and spurious associations. To examine the extent of cryptic relatedness in an epidemiologic collection, we as the Epidemiologic Architecture for Genes Linked to Environment (EAGLE) study accessed the National Health and Nutrition Examination Surveys (NHANES) linked to DNA samples ("Genetic NHANES") from NHANES III and NHANES 1999-2002. NHANES are population-based cross-sectional surveys conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention. Genome-wide genetic data is not yet available in NHANES, and current data use agreements prohibit the generation of GWAS-level data in NHANES samples due issues in maintaining confidentiality among other ethical concerns. To date, only hundreds of single nucleotide polymorphisms (SNPs) genotyped in a variety of candidate genes are available for analysis in NHANES. We performed identity-by-descent (IBD) estimates in three self-identified subpopulations of Genetic NHANES (non-Hispanic white, non- Hispanic black, and Mexican American) using PLINK software to identify potential familial relationships from presumed unrelated subjects. We then compared the PLINKidentified relationships to those identified by an alternative method implemented in Kinship-based INference for Genome-wide association studies (KING). Overall, both methods identified familial relationships in NHANES III and NHANES 1999-2002 for all three subpopulations, but little concordance was observed between the two methods due in major part to the limited SNP data available in Genetic NHANES

  12. Epidemiological studies of employees of the United Kingdom Atomic Energy Authority

    International Nuclear Information System (INIS)

    Fraser, P.; Beral, V.; Booth, M.; Inskip, H.; Carpenter, L.

    1987-01-01

    The Epidemiological Monitoring Unit at the London School of Hygiene and Tropical Medicine is carrying out several epidemiological studies of employees of the United Kingdom Atomic Energy Authority (UKAEA) in which mortality is being investigated in relation to radiation exposure. This paper summarises the results obtained so far and describes briefly studies currently in progress. (author)

  13. Epidemiological Study of Greek University Students' Mental Health

    Science.gov (United States)

    Kounenou, Kalliope; Koutra, Aikaterini; Katsiadrami, Aristea; Diacogiannis, Georgios

    2011-01-01

    In the present study, 805 Greek students participated by filling in self-report questionnaires studying depression (Center for Epidemiological Studies Depression Scale), general health status (General Health Questionnaire), general psychopathology (Symptom Checklist-90-R), and personal demographic features. Some of the more prevalent findings…

  14. Measuring taste impairment in epidemiologic studies: the Beaver Dam Offspring Study.

    Science.gov (United States)

    Cruickshanks, K J; Schubert, C R; Snyder, D J; Bartoshuk, L M; Huang, G H; Klein, B E K; Klein, R; Nieto, F J; Pankow, J S; Tweed, T S; Krantz, E M; Moy, G S

    2009-07-01

    Taste or gustatory function may play an important role in determining diet and nutritional status and therefore indirectly impact health. Yet there have been few attempts to study the spectrum of taste function and dysfunction in human populations. Epidemiologic studies are needed to understand the impact of taste function and dysfunction on public health, to identify modifiable risk factors, and to develop and test strategies to prevent clinically significant dysfunction. However, measuring taste function in epidemiologic studies is challenging and requires repeatable, efficient methods that can measure change over time. Insights gained from translating laboratory-based methods to a population-based study, the Beaver Dam Offspring Study (BOSS) will be shared. In this study, a generalized labeled magnitude scale (gLMS) method was used to measure taste intensity of filter paper disks saturated with salt, sucrose, citric acid, quinine, or 6-n-propylthiouracil, and a gLMS measure of taste preferences was administered. In addition, a portable, inexpensive camera system to capture digital images of fungiform papillae and a masked grading system to measure the density of fungiform papillae were developed. Adult children of participants in the population-based Epidemiology of Hearing Loss Study in Beaver Dam, Wisconsin, are eligible for this ongoing study. The parents were residents of Beaver Dam and 43-84 years of age in 1987-1988; offspring ranged in age from 21-84 years in 2005-2008. Methods will be described in detail and preliminary results about the distributions of taste function in the BOSS cohort will be presented.

  15. A two-stage preventive maintenance optimization model incorporating two-dimensional extended warranty

    International Nuclear Information System (INIS)

    Su, Chun; Wang, Xiaolin

    2016-01-01

    In practice, customers can decide whether to buy an extended warranty or not, at the time of item sale or at the end of the basic warranty. In this paper, by taking into account the moments of customers purchasing two-dimensional extended warranty, the optimization of imperfect preventive maintenance for repairable items is investigated from the manufacturer's perspective. A two-dimensional preventive maintenance strategy is proposed, under which the item is preventively maintained according to a specified age interval or usage interval, whichever occurs first. It is highlighted that when the extended warranty is purchased upon the expiration of the basic warranty, the manufacturer faces a two-stage preventive maintenance optimization problem. Moreover, in the second stage, the possibility of reducing the servicing cost over the extended warranty period is explored by classifying customers on the basis of their usage rates and then providing them with customized preventive maintenance programs. Numerical examples show that offering customized preventive maintenance programs can reduce the manufacturer's warranty cost, while a larger saving in warranty cost comes from encouraging customers to buy the extended warranty at the time of item sale. - Highlights: • A two-dimensional PM strategy is investigated. • Imperfect PM strategy is optimized by considering both two-dimensional BW and EW. • Customers are categorized based on their usage rates throughout the BW period. • Servicing cost of the EW is reduced by offering customized PM programs. • Customers buying the EW at the time of sale is preferred for the manufacturer.

  16. Review of epidemiologic studies at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Voelz, G.L.; Wilkinson, G.S.; Acquavella, J.F.; Reyes, M.; McInroy, J.F.

    1982-01-01

    Epidemiologic studies at Los Alamos are directed toward understanding potential health risks associated with activities pertaining to national energy and defense needs. Currently this research focuses on evaluating the effects of plutonium exposure in man. The major programs consist of (1) epidemiologic studies of the incidence of disease and mortality among plutonium and other workers at six Department of Energy (DOE) contractor facilities (Los Alamos, Rocky Flats, Mound, Savannah River, Hanford, and Oak Ridge), and (2) measurement of plutonium and other radionuclides in human tissues. Currently, investigations of mortality for Pantex workers and the surrounding general population are also being conducted for DOE in support of an Environment Impact Statement. This paper places emphasis on the activities of the national epidemiologic study of plutonium workers. The purpose of the plutonium workers study is to: (1) investigate whether adverse health effects are associated with exposures to plutonium, (2) explore whether adverse health effects are associated with exposure to transuranic elements, other radioisotopes, and hazardous substances that are found in nuclear facilities making routine use of plutonium, and (3) to describe in detail the nature of such health effects should they be discovered

  17. Two-stage agglomeration of fine-grained herbal nettle waste

    Science.gov (United States)

    Obidziński, Sławomir; Joka, Magdalena; Fijoł, Olga

    2017-10-01

    This paper compares the densification work necessary for the pressure agglomeration of fine-grained dusty nettle waste, with the densification work involved in two-stage agglomeration of the same material. In the first stage, the material was pre-densified through coating with a binder material in the form of a 5% potato starch solution, and then subjected to pressure agglomeration. A number of tests were conducted to determine the effect of the moisture content in the nettle waste (15, 18 and 21%), as well as the process temperature (50, 70, 90°C) on the values of densification work and the density of the obtained pellets. For pre-densified pellets from a mixture of nettle waste and a starch solution, the conducted tests determined the effect of pellet particle size (1, 2, and 3 mm) and the process temperature (50, 70, 90°C) on the same values. On the basis of the tests, we concluded that the introduction of a binder material and the use of two-stage agglomeration in nettle waste densification resulted in increased densification work (as compared to the densification of nettle waste alone) and increased pellet density.

  18. Comparative sport injury epidemiological study on a Spanish sample of 25 different sports

    OpenAIRE

    Pujals, Constanza; Rubio, Víctor J.; Márquez, María Oliva; Sánchez, Ivan; Ruiz Barquín, Roberto

    2016-01-01

    Reconocimiento-Compartir igual Sport injury is a widely extended morbidity condition. However, epidemiological studies are far from giving a convergent outlook. Moreover, there is a lack of studies comparing relative risks of different groups of sports. The present paper is aimed to carry out a descriptive epidemiological study of sport injuries of athletes from 25 sport modalities in order to identify risk factors as well as to compare epidemiological characteristics according to the ...

  19. Evaluation of a modified two-stage inferior alveolar nerve block technique: A preliminary investigation

    Directory of Open Access Journals (Sweden)

    Ashwin Rao

    2017-01-01

    Full Text Available Introduction: The two-stage technique of inferior alveolar nerve block (IANB administration does not address the pain associated with “needle insertion” and “local anesthetic solution deposition” in the “first stage” of the injection. This study evaluated a “modified two stage technique” to the reaction of children during “needle insertion” and “local anesthetic solution deposition” during the “first stage” and compared it to the “first phase” of the IANB administered with the standard one-stage technique. Materials and Methods: This was a parallel, single-blinded comparative study. A total of 34 children (between 6 and 10 years of age were randomly divided into two groups to receive an IANB either through the modified two-stage technique (MTST (Group A; 15 children or the standard one-stage technique (SOST (Group B; 19 children. The evaluation was done using the Face Legs Activity Cry Consolability (FLACC; which is an objective scale based on the expressions of the child scale. The obtained data was analyzed using Fishers Exact test with the P value set at <0.05 as level of significance. Results: 73.7% of children in Group B indicated moderate pain during the “first phase” of SOST and no children indicated such in the “first stage” of group A. Group A had 33.3% children who scored “0” indicating relaxed/comfortable children compared to 0% in Group B. In Group A, 66.7% of children scored between 1–3 indicating mild discomfort compared to 26.3% in group B. The difference in the scores between the two groups in each category (relaxed/comfortable, mild discomfort, moderate pain was highly significant (P < 0.001. Conclusion: Reaction of children in Group A during “needle insertion” and “local anesthetic solution deposition” in the “first stage” of MTST was significantly lower than that of Group B during the “first phase” of the SOST.

  20. Crohn's disease in Japan: diagnostic criteria and epidemiology.

    Science.gov (United States)

    Yao, T; Matsui, T; Hiwatashi, N

    2000-10-01

    New diagnostic criteria for Crohn's disease and a review of Japanese epidemiologic studies are presented. New diagnostic criteria for Crohn's disease were established by the Research Committee of Inflammatory Bowel Disease, set up by the Japanese Ministry of Health and Welfare. For a definite diagnosis one of the following three conditions is required: 1) longitudinal ulcer or luminal deformity induced by longitudinal ulcer or cobblestone pattern, 2) intestinal small aphthous ulcerations arranged in a longitudinal fashion for at least three months plus noncaseating granulomas, and 3) multiple small aphthous ulcerations in both the upper and lower digestive tract not necessarily with longitudinal arrangement, for at least three months, plus noncaseating granulomas. Moreover, ulcerative colitis, ischemic enterocolitis, and acute infectious enterocolitis should be excluded. Data from the Japanese Ministry of Health and Welfare, in addition to data collected from two study groups, these being the two largest studies in Japan, are reviewed with regard to epidemiology. The number of patients with Crohn's disease has increased remarkably. The prevalence and the annual incidence of patients with Crohn's disease in Japan were estimated to be approximately 2.9 and 0.6 per 10(5) population in 1986, respectively, and 13.5 and 1.2 per 10(5) population in 1998. Characteristic features of Crohn's disease in Japan are that the male-female ratio exceeds 2, and that there is no second peak of incidence in the age group of 55 to 65 years. Clinically, Crohn's disease with only multiple small aphthous ulcerations, which is the earliest stage of the disease that is diagnosable, was found in 5 percent of patients.

  1. Computerized micrographics in processing hard-copy records for an epidemiologic study

    International Nuclear Information System (INIS)

    Robie, D.M.; Fry, S.A.

    1983-01-01

    The availability of computers with increasing capabilities has made feasibile epidemiologic studies involving large populations such as those utilized to evaluate the health effects of occupational exposure to radiation. However, the storage and retrieval of data from the large numbers of hard-copy personnel, health physics, employment medical, historical or anecdotal documents that are the bases of such studies pose major logistics problems to investigators. The potential value of such records to epidemiologic studies depends, not only on their accuracy and completeness, but also on ease of accessibility. To address the latter problem, we are using a stand-alone user-oriented electronic filing system that records, stores, and secures hard-copy documents micrographically. This system is controlled by a computer that provides retrieval of a document image and printed copy (if desired) in less than 30 seconds from a maximum of eight fields. One thousand documents are randomly filmed and indexed on computer storage diskettes in two hours. Manual sorting and filing of the same number of documents takes over a day. At present two thousand documents can be recorded on each microfilm roll and 85,000 documents indexed on each diskette. Simultaneous searching for documents can be done using up to ten terminals while indexing is being done at the main terminal. The micrographics system provides the space-saving and security advantages of microfilm with the speed of computerized data retrieval

  2. A simple two stage optimization algorithm for constrained power economic dispatch

    International Nuclear Information System (INIS)

    Huang, G.; Song, K.

    1994-01-01

    A simple two stage optimization algorithm is proposed and investigated for fast computation of constrained power economic dispatch control problems. The method is a simple demonstration of the hierarchical aggregation-disaggregation (HAD) concept. The algorithm first solves an aggregated problem to obtain an initial solution. This aggregated problem turns out to be classical economic dispatch formulation, and it can be solved in 1% of overall computation time. In the second stage, linear programming method finds optimal solution which satisfies power balance constraints, generation and transmission inequality constraints and security constraints. Implementation of the algorithm for IEEE systems and EPRI Scenario systems shows that the two stage method obtains average speedup ratio 10.64 as compared to classical LP-based method

  3. Optimisation of Refrigeration System with Two-Stage and Intercooler Using Fuzzy Logic and Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Bayram Kılıç

    2017-04-01

    Full Text Available Two-stage compression operation prevents excessive compressor outlet pressure and temperature and this operation provides more efficient working condition in low-temperature refrigeration applications. Vapor compression refrigeration system with two-stage and intercooler is very good solution for low-temperature refrigeration applications. In this study, refrigeration system with two-stage and intercooler were optimized using fuzzy logic and genetic algorithm. The necessary thermodynamic characteristics for optimization were estimated with Fuzzy Logic and liquid phase enthalpy, vapour phase enthalpy, liquid phase entropy, vapour phase entropy values were compared with actual values. As a result, optimum working condition of system was estimated by the Genetic Algorithm as -6.0449 oC for evaporator temperature, 25.0115 oC for condenser temperature and 5.9666 for COP. Morever, irreversibility values of the refrigeration system are calculated.

  4. Genetic variants at 1p11.2 and breast cancer risk: a two-stage study in Chinese women.

    Directory of Open Access Journals (Sweden)

    Yue Jiang

    Full Text Available BACKGROUND: Genome-wide association studies (GWAS have identified several breast cancer susceptibility loci, and one genetic variant, rs11249433, at 1p11.2 was reported to be associated with breast cancer in European populations. To explore the genetic variants in this region associated with breast cancer in Chinese women, we conducted a two-stage fine-mapping study with a total of 1792 breast cancer cases and 1867 controls. METHODOLOGY/PRINCIPAL FINDINGS: Seven single nucleotide polymorphisms (SNPs including rs11249433 in a 277 kb region at 1p11.2 were selected and genotyping was performed by using TaqMan® OpenArray™ Genotyping System for stage 1 samples (878 cases and 900 controls. In stage 2 (914 cases and 967 controls, three SNPs (rs2580520, rs4844616 and rs11249433 were further selected and genotyped for validation. The results showed that one SNP (rs2580520 located at a predicted enhancer region of SRGAP2 was consistently associated with a significantly increased risk of breast cancer in a recessive genetic model [Odds Ratio (OR  =  1.66, 95% confidence interval (CI  =  1.16-2.36 for stage 2 samples; OR  =  1.51, 95% CI  =  1.16-1.97 for combined samples, respectively]. However, no significant association was observed between rs11249433 and breast cancer risk in this Chinese population (dominant genetic model in combined samples: OR  =  1.20, 95% CI  =  0.92-1.57. CONCLUSIONS/SIGNIFICANCE: Genotypes of rs2580520 at 1p11.2 suggest that Chinese women may have different breast cancer susceptibility loci, which may contribute to the development of breast cancer in this population.

  5. Human risk relationships derived from epidemiology and laboratory studies

    International Nuclear Information System (INIS)

    Cuddihy, R.G.; Boecker, B.B.; Hahn, F.F.; McClellan, R.O.

    1983-01-01

    Proven techniques are needed for incorporating the results of laboratory toxicology studies into human risk assessments. Two sample calculations of lung cancer risk factors for inhaled radioactive particles and diesel engine exhaust are given here to illustrate a toxicology information matrix approach. This approach combines the results of epidemiology and laboratory animal studies of the substance or agent of principal concern, along with similar information on other surrogate substances. Beyond the estimates of lung cancer risk factors derived by using this approach, an additional advantage is gained by having estimates of uncertainty that can be obtained by incorporating all available toxicology information into the analysis. This approach is recommended for both risk assessment and in designing follow-on toxicology studies to improve preliminary assessments for new potentially harmful agents entering our environment

  6. The social patterning of risk factors for noncommunicable diseases in five countries: evidence from the modeling the epidemiologic transition study (METS

    Directory of Open Access Journals (Sweden)

    Silvia Stringhini

    2016-09-01

    Full Text Available Abstract Background Associations between socioeconomic status (SES and risk factors for noncommunicable diseases (NCD-RFs may differ in populations at different stages of the epidemiological transition. We assessed the social patterning of NCD-RFs in a study including populations with different levels of socioeconomic development. Methods Data on SES, smoking, physical activity, body mass index, blood pressure, cholesterol and glucose were available from the Modeling the Epidemiologic Transition Study (METS, with about 500 participants aged 25–45 in each of five sites (Ghana, South Africa, Jamaica, Seychelles, United States. Results The prevalence of NCD-RFs differed between these populations from five countries (e.g., lower prevalence of smoking, obesity and hypertension in rural Ghana and by sex (e.g., higher prevalence of smoking and physical activity in men and of obesity in women in most populations. Smoking and physical activity were associated with low SES in most populations. The associations of SES with obesity, hypertension, cholesterol and elevated blood glucose differed by population, sex, and SES indicator. For example, the prevalence of elevated blood glucose tended to be associated with low education, but not with wealth, in Seychelles and USA. The association of SES with obesity and cholesterol was direct in some populations but inverse in others. Conclusions In conclusion, the distribution of NCD-RFs was socially patterned in these populations at different stages of the epidemiological transition, but associations between SES and NCD-RFs differed substantially according to risk factor, population, sex, and SES indicator. These findings emphasize the need to assess and integrate the social patterning of NCD-RFs in NCD prevention and control programs in LMICs.

  7. Two stages and three components of the postural preparation to action.

    Science.gov (United States)

    Krishnan, Vennila; Aruin, Alexander S; Latash, Mark L

    2011-07-01

    Previous studies of postural preparation to action/perturbation have primarily focused on anticipatory postural adjustments (APAs), the changes in muscle activation levels resulting in the production of net forces and moments of force. We hypothesized that postural preparation to action consists of two stages: (1) Early postural adjustments (EPAs), seen a few hundred ms prior to an expected external perturbation and (2) APAs seen about 100 ms prior to the perturbation. We also hypothesized that each stage consists of three components, anticipatory synergy adjustments seen as changes in covariation of the magnitudes of commands to muscle groups (M-modes), changes in averaged across trials levels of muscle activation, and mechanical effects such as shifts of the center of pressure. Nine healthy participants were subjected to external perturbations created by a swinging pendulum while standing in a semi-squatting posture. Electrical activity of twelve trunk and leg muscles and displacements of the center of pressure were recorded and analyzed. Principal component analysis was used to identify four M-modes within the space of muscle activations using indices of integrated muscle activation. This analysis was performed twice, over two phases, 400-700 ms prior to the perturbation and over 200 ms just prior to the perturbation. Similar robust results were obtained using the data from both phases. An index of a multi-M-mode synergy stabilizing the center of pressure displacement was computed using the framework of the uncontrolled manifold hypothesis. The results showed high synergy indices during quiet stance. Each of the two stages started with a drop in the synergy index followed by a change in the averaged across trials activation levels in postural muscles. There was a very long electromechanical delay during the early postural adjustments and a much shorter delay during the APAs. Overall, the results support our main hypothesis on the two stages and three components

  8. The dynamics of patients' life quality indices under the conditions of two-stage knee joint replacement

    Directory of Open Access Journals (Sweden)

    Shpinyak S.P.

    2017-09-01

    Full Text Available  The aim: to analyze the changes in the life quality indices of the patients with deep periprosthetic joint infection of the knee under the two-stage surgical treatment. Material and Methods. 57 patients who underwent two-stage revision-ary treatment in Research Institute of Traumatology, Orthopedics and Neurosurgery were interviewed with life quality questionnaire Short Form Medical Outcomes Study (SF 36 v.1. Interview results were compared with standardized population indices of SF-36 scales for males and females. Results. In all groups regardless of sex there was a general tendency for an increase in physical and psychological health component up to mean population values after the first stage of surgery and further growth after the second stage. Rehabilitation potential of psychomotor health was higher in women than in men. The ability to handle stress was lower in direct ratio with the patients' age. Conclusion. Two-stage reendoprosthetic treatment with articulating antimicrobial spacer implantation having high grade of fixation is an effective treatment method for deep periprosthetic infection which increases physical health and improves social functioning of patients.

  9. Consistency of external dosimetry in epidemiologic studies of nuclear workers

    International Nuclear Information System (INIS)

    Fix, J.J.; Gilbert, E.S.

    1992-01-01

    Efforts are underway to pool data from epidemiologic studies of nuclear workers to obtain more precise estimates of radiation risk than would be possible from any single study. The International Agency for Research on Cancer (IARC) is coordinating combined analyses of data from studies in the United States, Canada, and the United Kingdom. In the U.S., the Department of Energy (DOE) has established the Comprehensive Epidemiologic Data Resource (CEDR) to provide investigators an opportunity to analyze data from several DOE laboratories. IARC investigators, in collaboration with those conducting the individual studies, have developed a dosimetry protocol for the international combined analyses. (author)

  10. Consistency of external dosimetry in epidemiologic studies of nuclear workers

    International Nuclear Information System (INIS)

    Fix, J.J.; Gilbert, E.S.

    1992-05-01

    Efforts are underway to pool data from epidemiologic studies of nuclear workers to obtain more precise estimates of radiation risk than would be possible from any single study. The International Agency for Research on Cancer (IARC) is coordinating combined analyses of data from studies in the United States, Canada, and the United Kingdom. In the US, the Department of Energy (DOE) has established the Comprehensive Epidemiologic Data Resource (CEDR) to provide investigators an opportunity to analyze data from several DOE laboratories. IARC investigators, in collaboration with those conducting the individual studies, have developed a dosimetry protocol for the international combined analyses

  11. Kinetics of two-stage fermentation process for the production of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Nath, Kaushik [Department of Chemical Engineering, G.H. Patel College of Engineering and Technology, Vallabh Vidyanagar 388 120, Gujarat (India); Muthukumar, Manoj; Kumar, Anish; Das, Debabrata [Fermentation Technology Laboratory, Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India)

    2008-02-15

    Two-stage process described in the present work is a combination of dark and photofermentation in a sequential batch mode. In the first stage glucose is fermented to acetate, CO{sub 2} and H{sub 2} in an anaerobic dark fermentation by Enterobacter cloacae DM11. This is followed by a successive second stage where acetate is converted to H{sub 2} and CO{sub 2} in a photobioreactor by photosynthetic bacteria, Rhodobacter sphaeroides O.U. 001. The yield of hydrogen in the first stage was about 3.31molH{sub 2}(molglucose){sup -1} (approximately 82% of theoretical) and that in the second stage was about 1.5-1.72molH{sub 2}(molaceticacid){sup -1} (approximately 37-43% of theoretical). The overall yield of hydrogen in two-stage process considering glucose as preliminary substrate was found to be higher compared to a single stage process. Monod model, with incorporation of substrate inhibition term, has been used to determine the growth kinetic parameters for the first stage. The values of maximum specific growth rate ({mu} {sub max}) and K{sub s} (saturation constant) were 0.398h{sup -1} and 5.509gl{sup -1}, respectively, using glucose as substrate. The experimental substrate and biomass concentration profiles have good resemblance with those obtained by kinetic model predictions. A model based on logistic equation has been developed to describe the growth of R. sphaeroides O.U 001 in the second stage. Modified Gompertz equation was applied to estimate the hydrogen production potential, rate and lag phase time in a batch process for various initial concentration of glucose, based on the cumulative hydrogen production curves. Both the curve fitting and statistical analysis showed that the equation was suitable to describe the progress of cumulative hydrogen production. (author)

  12. Two-stage energy storage equalization system for lithium-ion battery pack

    Science.gov (United States)

    Chen, W.; Yang, Z. X.; Dong, G. Q.; Li, Y. B.; He, Q. Y.

    2017-11-01

    How to raise the efficiency of energy storage and maximize storage capacity is a core problem in current energy storage management. For that, two-stage energy storage equalization system which contains two-stage equalization topology and control strategy based on a symmetric multi-winding transformer and DC-DC (direct current-direct current) converter is proposed with bidirectional active equalization theory, in order to realize the objectives of consistent lithium-ion battery packs voltages and cells voltages inside packs by using a method of the Range. Modeling analysis demonstrates that the voltage dispersion of lithium-ion battery packs and cells inside packs can be kept within 2 percent during charging and discharging. Equalization time was 0.5 ms, which shortened equalization time of 33.3 percent compared with DC-DC converter. Therefore, the proposed two-stage lithium-ion battery equalization system can achieve maximum storage capacity between lithium-ion battery packs and cells inside packs, meanwhile efficiency of energy storage is significantly improved.

  13. Two-Stage Power Factor Corrected Power Supplies: The Low Component-Stress Approach

    DEFF Research Database (Denmark)

    Petersen, Lars; Andersen, Michael Andreas E.

    2002-01-01

    The discussion concerning the use of single-stage contra two-stage PFC solutions has been going on for the last decade and it continues. The purpose of this paper is to direct the focus back on how the power is processed and not so much as to the number of stages or the amount of power processed...

  14. On the prior probabilities for two-stage Bayesian estimates

    International Nuclear Information System (INIS)

    Kohut, P.

    1992-01-01

    The method of Bayesian inference is reexamined for its applicability and for the required underlying assumptions in obtaining and using prior probability estimates. Two different approaches are suggested to determine the first-stage priors in the two-stage Bayesian analysis which avoid certain assumptions required for other techniques. In the first scheme, the prior is obtained through a true frequency based distribution generated at selected intervals utilizing actual sampling of the failure rate distributions. The population variability distribution is generated as the weighed average of the frequency distributions. The second method is based on a non-parametric Bayesian approach using the Maximum Entropy Principle. Specific features such as integral properties or selected parameters of prior distributions may be obtained with minimal assumptions. It is indicated how various quantiles may also be generated with a least square technique

  15. Reporting of Human Genome Epidemiology (HuGE association studies: An empirical assessment

    Directory of Open Access Journals (Sweden)

    Gwinn Marta

    2008-05-01

    Full Text Available Abstract Background Several thousand human genome epidemiology association studies are published every year investigating the relationship between common genetic variants and diverse phenotypes. Transparent reporting of study methods and results allows readers to better assess the validity of study findings. Here, we document reporting practices of human genome epidemiology studies. Methods Articles were randomly selected from a continuously updated database of human genome epidemiology association studies to be representative of genetic epidemiology literature. The main analysis evaluated 315 articles published in 2001–2003. For a comparative update, we evaluated 28 more recent articles published in 2006, focusing on issues that were poorly reported in 2001–2003. Results During both time periods, most studies comprised relatively small study populations and examined one or more genetic variants within a single gene. Articles were inconsistent in reporting the data needed to assess selection bias and the methods used to minimize misclassification (of the genotype, outcome, and environmental exposure or to identify population stratification. Statistical power, the use of unrelated study participants, and the use of replicate samples were reported more often in articles published during 2006 when compared with the earlier sample. Conclusion We conclude that many items needed to assess error and bias in human genome epidemiology association studies are not consistently reported. Although some improvements were seen over time, reporting guidelines and online supplemental material may help enhance the transparency of this literature.

  16. Hydrogen and methane production from household solid waste in the two-stage fermentation process

    DEFF Research Database (Denmark)

    Lui, D.; Liu, D.; Zeng, Raymond Jianxiong

    2006-01-01

    A two-stage process combined hydrogen and methane production from household solid waste was demonstrated working successfully. The yield of 43 mL H-2/g volatile solid (VS) added was generated in the first hydrogen production stage and the methane production in the second stage was 500 mL CH4/g VS...... added. This figure was 21% higher than the methane yield from the one-stage process, which was run as control. Sparging of the hydrogen reactor with methane gas resulted in doubling of the hydrogen production. PH was observed as a key factor affecting fermentation pathway in hydrogen production stage....... Furthermore, this study also provided direct evidence in the dynamic fermentation process that, hydrogen production increase was reflected by acetate to butyrate ratio increase in liquid phase. (c) 2006 Elsevier Ltd. All rights reserved....

  17. Doses for post-Chernobyl epidemiological studies: are they reliable?

    Science.gov (United States)

    Drozdovitch, Vladimir; Chumak, Vadim; Kesminiene, Ausrele; Ostroumova, Evgenia; Bouville, André

    2016-09-01

    On 26 April 2016, thirty years will have elapsed since the occurrence of the Chernobyl accident, which has so far been the most severe in the history of the nuclear reactor industry. Numerous epidemiological studies were conducted to evaluate the possible health consequences of the accident. Since the credibility of the association between the radiation exposure and health outcome is highly dependent on the adequacy of the dosimetric quantities used in these studies, this paper makes an effort to overview the methods used to estimate individual doses and the associated uncertainties in the main analytical epidemiological studies (i.e. cohort or case-control) related to the Chernobyl accident. Based on the thorough analysis and comparison with other radiation studies, the authors conclude that individual doses for the Chernobyl analytical epidemiological studies have been calculated with a relatively high degree of reliability and well-characterized uncertainties, and that they compare favorably with many other non-Chernobyl studies. The major strengths of the Chernobyl studies are: (1) they are grounded on a large number of measurements, either performed on humans or made in the environment; and (2) extensive effort has been invested to evaluate the uncertainties associated with the dose estimates. Nevertheless, gaps in the methodology are identified and suggestions for the possible improvement of the current dose estimates are made.

  18. Development of a low-temperature two-stage fluidized bed incinerator for controlling heavy-metal emission in flue gases

    International Nuclear Information System (INIS)

    Peng, Tzu-Huan; Lin, Chiou-Liang; Wey, Ming-Yen

    2014-01-01

    This study develops a low-temperature two-stage fluidized bed system for treating municipal solid waste. This new system can decrease the emission of heavy metals, has low construction costs, and can save energy owing to its lower operating temperature. To confirm the treatment efficiency of this system, the combustion efficiency and heavy-metal emission were determined. An artificial waste containing heavy metals (chromium, lead, and cadmium) was used in this study. The tested parameters included first-stage temperature and system gas velocity. Results obtained using a thermogravimetric analyzer with a differential scanning calorimeter indicated that the first-stage temperature should be controlled to at least 400 °C. Although, a large amount of carbon monoxide was emitted after the first stage, it was efficiently consumed in the second. Loss of the ignition values of ash residues were between 0.005% and 0.166%, and they exhibited a negative correlation with temperature and gas velocity. Furthermore, the emission concentration of heavy metals in the two-stage system was lower than that of the traditional one-stage fluidized bed system. The heavy-metal emissions can be decreased by between 16% and 82% using the low-temperature operating process, silica sand adsorption, and the filtration of the secondary stage. -- Graphical abstract: Heavy-metal emission concentrations in flue gases under different temperatures and gas velocities (dashed line: average of the heavy-metal emission in flue gases in the one-stage fluidized-bed incinerator). Highlights: • Low temperature two-stage system is developed to control heavy metal. • The different first-stage temperatures affect the combustion efficiency. • Surplus CO was destroyed efficiently by the secondary fluidized bed combustor. • Metal emission in two-stage system is lower than in the traditional system. • Temperature, bed adsorption, and filtration are the main control mechanisms

  19. Robust Frequency-Domain Constrained Feedback Design via a Two-Stage Heuristic Approach.

    Science.gov (United States)

    Li, Xianwei; Gao, Huijun

    2015-10-01

    Based on a two-stage heuristic method, this paper is concerned with the design of robust feedback controllers with restricted frequency-domain specifications (RFDSs) for uncertain linear discrete-time systems. Polytopic uncertainties are assumed to enter all the system matrices, while RFDSs are motivated by the fact that practical design specifications are often described in restricted finite frequency ranges. Dilated multipliers are first introduced to relax the generalized Kalman-Yakubovich-Popov lemma for output feedback controller synthesis and robust performance analysis. Then a two-stage approach to output feedback controller synthesis is proposed: at the first stage, a robust full-information (FI) controller is designed, which is used to construct a required output feedback controller at the second stage. To improve the solvability of the synthesis method, heuristic iterative algorithms are further formulated for exploring the feedback gain and optimizing the initial FI controller at the individual stage. The effectiveness of the proposed design method is finally demonstrated by the application to active control of suspension systems.

  20. Epidemiological studies of groups with occupational exposure to radiation

    International Nuclear Information System (INIS)

    Davies, J.M.

    1985-01-01

    The exposure of man to radiation and the resulting risk of carcinogenesis continues to be of concern to the public. In this context, there is often a tendency to carry out epidemiological studies concerning the induction of cancer in radiation workers and members of the public which are not supported by a statistically valid data base or whose results are misinterpreted or misused. To assist national authorities in evaluating radiological risks, the Nuclear Energy Agency has sponsored a critical review of the methodologies for, and the limitations of, these epidemiological studies, and of the precautions to be adopted in interpreting their results. Prepared by a consultant, Dr. Joan M. Davies, the review focuses on the problems encountered when carrying out epidemiological studies on groups of workers occupationally exposed to radiations, and using their results for radiological protection purposes. It is published under the responsibility of the Secretary General of the OECD, and does not necessarily reflect the views of Member Governments. The primary objective is to provide background material to be used by national authorities that have responsibilities in the field of radiological protection as well as by other persons interested in this subject

  1. Recommendations for epidemiological studies on COPD

    DEFF Research Database (Denmark)

    Bakke, P S; Rönmark, E; Eagan, T

    2011-01-01

    of the disease and definitions of the risk factors. Few community studies have examined phenotypes of COPD and included other ways of characterising the disease beyond that of spirometry. The objective of the present Task Force report is to present recommendations for the performance of general population...... for planning and performing an epidemiological study on COPD. The main message of the paper is that thorough planning is worth half the study. It is crucial to stick to standardised methods and good quality control during sampling. We recommend collecting biological markers, depending on the specific...

  2. Two-stage atlas subset selection in multi-atlas based image segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Tingting, E-mail: tingtingzhao@mednet.ucla.edu; Ruan, Dan, E-mail: druan@mednet.ucla.edu [The Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States)

    2015-06-15

    Purpose: Fast growing access to large databases and cloud stored data presents a unique opportunity for multi-atlas based image segmentation and also presents challenges in heterogeneous atlas quality and computation burden. This work aims to develop a novel two-stage method tailored to the special needs in the face of large atlas collection with varied quality, so that high-accuracy segmentation can be achieved with low computational cost. Methods: An atlas subset selection scheme is proposed to substitute a significant portion of the computationally expensive full-fledged registration in the conventional scheme with a low-cost alternative. More specifically, the authors introduce a two-stage atlas subset selection method. In the first stage, an augmented subset is obtained based on a low-cost registration configuration and a preliminary relevance metric; in the second stage, the subset is further narrowed down to a fusion set of desired size, based on full-fledged registration and a refined relevance metric. An inference model is developed to characterize the relationship between the preliminary and refined relevance metrics, and a proper augmented subset size is derived to ensure that the desired atlases survive the preliminary selection with high probability. Results: The performance of the proposed scheme has been assessed with cross validation based on two clinical datasets consisting of manually segmented prostate and brain magnetic resonance images, respectively. The proposed scheme demonstrates comparable end-to-end segmentation performance as the conventional single-stage selection method, but with significant computation reduction. Compared with the alternative computation reduction method, their scheme improves the mean and medium Dice similarity coefficient value from (0.74, 0.78) to (0.83, 0.85) and from (0.82, 0.84) to (0.95, 0.95) for prostate and corpus callosum segmentation, respectively, with statistical significance. Conclusions: The authors

  3. Two-stage atlas subset selection in multi-atlas based image segmentation.

    Science.gov (United States)

    Zhao, Tingting; Ruan, Dan

    2015-06-01

    Fast growing access to large databases and cloud stored data presents a unique opportunity for multi-atlas based image segmentation and also presents challenges in heterogeneous atlas quality and computation burden. This work aims to develop a novel two-stage method tailored to the special needs in the face of large atlas collection with varied quality, so that high-accuracy segmentation can be achieved with low computational cost. An atlas subset selection scheme is proposed to substitute a significant portion of the computationally expensive full-fledged registration in the conventional scheme with a low-cost alternative. More specifically, the authors introduce a two-stage atlas subset selection method. In the first stage, an augmented subset is obtained based on a low-cost registration configuration and a preliminary relevance metric; in the second stage, the subset is further narrowed down to a fusion set of desired size, based on full-fledged registration and a refined relevance metric. An inference model is developed to characterize the relationship between the preliminary and refined relevance metrics, and a proper augmented subset size is derived to ensure that the desired atlases survive the preliminary selection with high probability. The performance of the proposed scheme has been assessed with cross validation based on two clinical datasets consisting of manually segmented prostate and brain magnetic resonance images, respectively. The proposed scheme demonstrates comparable end-to-end segmentation performance as the conventional single-stage selection method, but with significant computation reduction. Compared with the alternative computation reduction method, their scheme improves the mean and medium Dice similarity coefficient value from (0.74, 0.78) to (0.83, 0.85) and from (0.82, 0.84) to (0.95, 0.95) for prostate and corpus callosum segmentation, respectively, with statistical significance. The authors have developed a novel two-stage atlas

  4. Two-stage atlas subset selection in multi-atlas based image segmentation

    International Nuclear Information System (INIS)

    Zhao, Tingting; Ruan, Dan

    2015-01-01

    Purpose: Fast growing access to large databases and cloud stored data presents a unique opportunity for multi-atlas based image segmentation and also presents challenges in heterogeneous atlas quality and computation burden. This work aims to develop a novel two-stage method tailored to the special needs in the face of large atlas collection with varied quality, so that high-accuracy segmentation can be achieved with low computational cost. Methods: An atlas subset selection scheme is proposed to substitute a significant portion of the computationally expensive full-fledged registration in the conventional scheme with a low-cost alternative. More specifically, the authors introduce a two-stage atlas subset selection method. In the first stage, an augmented subset is obtained based on a low-cost registration configuration and a preliminary relevance metric; in the second stage, the subset is further narrowed down to a fusion set of desired size, based on full-fledged registration and a refined relevance metric. An inference model is developed to characterize the relationship between the preliminary and refined relevance metrics, and a proper augmented subset size is derived to ensure that the desired atlases survive the preliminary selection with high probability. Results: The performance of the proposed scheme has been assessed with cross validation based on two clinical datasets consisting of manually segmented prostate and brain magnetic resonance images, respectively. The proposed scheme demonstrates comparable end-to-end segmentation performance as the conventional single-stage selection method, but with significant computation reduction. Compared with the alternative computation reduction method, their scheme improves the mean and medium Dice similarity coefficient value from (0.74, 0.78) to (0.83, 0.85) and from (0.82, 0.84) to (0.95, 0.95) for prostate and corpus callosum segmentation, respectively, with statistical significance. Conclusions: The authors

  5. A systematic review of epidemiologic studies assessing condom use and risk of syphilis.

    Science.gov (United States)

    Koss, Catherine A; Dunne, Eileen F; Warner, Lee

    2009-07-01

    Although systematic reviews of epidemiologic studies have been conducted for condom use and the risk of several sexually transmitted diseases, there have been no such reviews for condom use and syphilis. A systematic literature review of epidemiologic studies published from 1972 to 2008 was conducted to evaluate study methods and measures of association reported for condom use and risk of syphilis. All 12 included studies had significant methodologic limitations. Nine (75%) studies were cross-sectional. Although 11 (92%) studies assessed consistent condom use, no studies assessed correct use or condom use problems, nor did any document exposure to a partner infected with syphilis. Ten studies had insufficient information to distinguish prevalent from incident infections. Two studies that assessed both incident infection and consistent condom use suggested a reduced risk of syphilis with consistent condom use; 1 study was statistically significant. Significant methodologic limitations exist for all reviewed studies of syphilis and condom use. Among the 2 most rigorously designed studies, both suggested a reduced risk of syphilis with consistent condom use. Additional studies incorporating rigorous methods are needed to further assess the effect of condom use on risk of syphilis.

  6. Impact of radiobiological considerations on epidemiological inferences of age-dependent radiosensitivity

    International Nuclear Information System (INIS)

    Crawford-Brown, D.J.

    1983-01-01

    Current epidemiological studies of the age-dependent risk of radiogenic carcinomas are based on populations still in the early stages of cancer expression. The result is a set of logical uncertainties concerning the manner in which inferences may be drawn from the existing data. These uncertainties may be formalized and examined through the application of various radiobiological principles developed from more fundamental experimental data. Chief amongst these considerations are the time course of tumor expression, the role of relative and absolute risk models, the distribution of effects between initiation and promotion, the age-dependent fraction of time a critical cell remains in radiosensitive stages and the combinatorics of the critical cellular subpopulations. Each of these and the combinatorics of the critical cellular subpopulations. Each of these principles are examined in light of their impact on the structuring of epidemiologic data and the drawing of inferences concerning age-dependent radiogenic risk. The data on atomic bomb survivors are employed as a relevant example

  7. How to make epidemiological training infectious.

    Directory of Open Access Journals (Sweden)

    Steve E Bellan

    Full Text Available Modern infectious disease epidemiology builds on two independently developed fields: classical epidemiology and dynamical epidemiology. Over the past decade, integration of the two fields has increased in research practice, but training options within the fields remain distinct with few opportunities for integration in the classroom. The annual Clinic on the Meaningful Modeling of Epidemiological Data (MMED at the African Institute for Mathematical Sciences has begun to address this gap. MMED offers participants exposure to a broad range of concepts and techniques from both epidemiological traditions. During MMED 2010 we developed a pedagogical approach that bridges the traditional distinction between classical and dynamical epidemiology and can be used at multiple educational levels, from high school to graduate level courses. The approach is hands-on, consisting of a real-time simulation of a stochastic outbreak in course participants, including realistic data reporting, followed by a variety of mathematical and statistical analyses, stemming from both epidemiological traditions. During the exercise, dynamical epidemiologists developed empirical skills such as study design and learned concepts of bias while classical epidemiologists were trained in systems thinking and began to understand epidemics as dynamic nonlinear processes. We believe this type of integrated educational tool will prove extremely valuable in the training of future infectious disease epidemiologists. We also believe that such interdisciplinary training will be critical for local capacity building in analytical epidemiology as Africa continues to produce new cohorts of well-trained mathematicians, statisticians, and scientists. And because the lessons draw on skills and concepts from many fields in biology--from pathogen biology, evolutionary dynamics of host--pathogen interactions, and the ecology of infectious disease to bioinformatics, computational biology, and

  8. Distribution of extracellular potassium and electrophysiologic changes during two-stage coronary ligation in the isolated, perfused canine heart

    NARCIS (Netherlands)

    Coronel, R.; Fiolet, J. W.; Wilms-Schopman, J. G.; Opthof, T.; Schaapherder, A. F.; Janse, M. J.

    1989-01-01

    We studied the relation between [K+]o and the electrophysiologic changes during a "Harris two-stage ligation," which is an occlusion of a coronary artery, preceded by a 30-minute period of 50% reduction of flow through the artery. This two-stage ligation has been reported to be antiarrhythmic. Local

  9. A preventive maintenance policy based on dependent two-stage deterioration and external shocks

    International Nuclear Information System (INIS)

    Yang, Li; Ma, Xiaobing; Peng, Rui; Zhai, Qingqing; Zhao, Yu

    2017-01-01

    This paper proposes a preventive maintenance policy for a single-unit system whose failure has two competing and dependent causes, i.e., internal deterioration and sudden shocks. The internal failure process is divided into two stages, i.e. normal and defective. Shocks arrive according to a non-homogeneous Poisson process (NHPP), leading to the failure of the system immediately. The occurrence rate of a shock is affected by the state of the system. Both an age-based replacement and finite number of periodic inspections are schemed simultaneously to deal with the competing failures. The objective of this study is to determine the optimal preventive replacement interval, inspection interval and number of inspections such that the expected cost per unit time is minimized. A case study on oil pipeline maintenance is presented to illustrate the maintenance policy. - Highlights: • A maintenance model based on two-stage deterioration and sudden shocks is developed. • The impact of internal system state on external shock process is studied. • A new preventive maintenance strategy combining age-based replacements and periodic inspections is proposed. • Postponed replacement of a defective system is provided by restricting the number of inspections.

  10. Low dose epidemiology

    International Nuclear Information System (INIS)

    Tirmarche, M.; Hubert, P.

    1992-01-01

    Actually, epidemiological studies have to establish if the assessment of cancer risk can be verified at low chronic radiation doses. The population surveillance must be very long, the side effects and cancers of such radiation appearing much later. In France, this epidemiological study on nuclear workers have been decided recently. Before describing the experiment and french projects in epidemiology of nuclear workers, the authors present the main english and american studies

  11. One-Stage and Two-Stage Schemes of High Performance Synchronous PWM with Smooth Pulses-Ratio Changing

    DEFF Research Database (Denmark)

    Oleschuk, V.; Blaabjerg, Frede

    2002-01-01

    This paper presents detailed description of one-stage and two-stage schemes of a novel method of synchronous, pulsewidth modulation (PWM) for voltage source inverters for ac drive application. The proposed control functions provide accurate realization of different versions of voltage space vector...... modulation with synchronization of the voltage waveform of the inverter and with smooth pulse-ratio changing. Voltage spectra do not contain even harmonic and sub-harmonics (combined harmonics) during the whole control range including the zone of overmodulation. Examples of determination of the basic control...

  12. Two-stage image denoising considering interscale and intrascale dependencies

    Science.gov (United States)

    Shahdoosti, Hamid Reza

    2017-11-01

    A solution to the problem of reducing the noise of grayscale images is presented. To consider the intrascale and interscale dependencies, this study makes use of a model. It is shown that the dependency between a wavelet coefficient and its predecessors can be modeled by the first-order Markov chain, which means that the parent conveys all of the information necessary for efficient estimation. Using this fact, the proposed method employs the Kalman filter in the wavelet domain for image denoising. The proposed method has two stages. The first stage employs a simple denoising algorithm to provide the noise-free image, by which the parameters of the model such as state transition matrix, variance of the process noise, the observation model, and the covariance of the observation noise are estimated. In the second stage, the Kalman filter is applied to the wavelet coefficients of the noisy image to estimate the noise-free coefficients. In fact, the Kalman filter is used to estimate the coefficients of high-frequency subbands from the coefficients of coarser scales and noisy observations of neighboring coefficients. In this way, both the interscale and intrascale dependencies are taken into account. Results are presented and discussed on a set of standard 8-bit grayscale images. The experimental results demonstrate that the proposed method achieves performances competitive with the state-of-the-art denoising methods in terms of both peak-signal-to-noise ratio and subjective visual quality.

  13. Epidemiological studies of thyroid cancer in the CIS

    Energy Technology Data Exchange (ETDEWEB)

    Beebe, G W [National Cancer Institute, Bethesda, Maryland (United States)

    1996-07-01

    Despite the great international interest in Chernobyl and the need for quantitative risk information on the carcinogenic effectiveness of the radio iodines, there has been relatively little epidemiological research on thyroid cancer following the Chernobyl accident. The reasons for this are many, diverse, and difficult to eliminate, although some progress is being made. Among them are the natural priority of public health concerns, a weak infrastructure for conducting studies in chronic disease epidemiology, and the difficulty of assigning thyroid dose estimates to individuals for study. In spite of the difficulties a number of significant studies have been begun or are planned, and several valuable reports have appeared. From the descriptive studies it is now known that the latent period for thyroid cancer in children exposed to radio iodines is not 5 to 10, but probably three years, that the magnitude of the increase in thyroid cancer among children is beyond anything previously experienced or expected, and that there is a strong correlation between thyroid cancer and environmental radiocesium contamination levels in the Gomel region of Belarus, and between thyroid cancer and average regional levels of I{sup 131} dose to the thyroid in Ukraine. However, even today, there is very little hard scientific information on the relation of thyroid cancer in children and their exposure to the radio iodines in the fallout from the Chernobyl accident. This is information that only well-designed scientific epidemiological studies, based on firm dose estimates, could be expected to provide. With that purpose in mind, the US has planned with Belarus and Ukraine long-term cohort studies of many thousands of subjects with thyroid activity measurements.

  14. Epidemiological studies of thyroid cancer in the CIS

    International Nuclear Information System (INIS)

    Beebe, G.W.

    1996-01-01

    Despite the great international interest in Chernobyl and the need for quantitative risk information on the carcinogenic effectiveness of the radio iodines, there has been relatively little epidemiological research on thyroid cancer following the Chernobyl accident. The reasons for this are many, diverse, and difficult to eliminate, although some progress is being made. Among them are the natural priority of public health concerns, a weak infrastructure for conducting studies in chronic disease epidemiology, and the difficulty of assigning thyroid dose estimates to individuals for study. In spite of the difficulties a number of significant studies have been begun or are planned, and several valuable reports have appeared. From the descriptive studies it is now known that the latent period for thyroid cancer in children exposed to radio iodines is not 5 to 10, but probably three years, that the magnitude of the increase in thyroid cancer among children is beyond anything previously experienced or expected, and that there is a strong correlation between thyroid cancer and environmental radiocesium contamination levels in the Gomel region of Belarus, and between thyroid cancer and average regional levels of I 131 dose to the thyroid in Ukraine. However, even today, there is very little hard scientific information on the relation of thyroid cancer in children and their exposure to the radio iodines in the fallout from the Chernobyl accident. This is information that only well-designed scientific epidemiological studies, based on firm dose estimates, could be expected to provide. With that purpose in mind, the US has planned with Belarus and Ukraine long-term cohort studies of many thousands of subjects with thyroid activity measurements

  15. Two-year follow-up study on neurodevelopmental outcomes after term intrapartum asphyxia using age and stages questionnaire.

    Science.gov (United States)

    Keihani-Doust, Zarrin; Saeedi, Maryam; Esmaeilni, Tahere; Habibi, Massoud; Nazari, Seyed Saeed Hashemi

    2013-12-01

    Birth asphyxia is one of the multiple causes of neonatal encephalopathy. The objective of this study was to evaluate neurodevelopmental outcomes of newborn term infants with definitive asphyxia. Thirty infants met study criteria for asphyxia. The 5-year incidence of asphyxia was estimated to be 5.5 in 1000. According to the Age and Stage Questionnaire, 10.5% of 6-month-old infants, 14.3% of 12- and 18-month-old infants, and 5.3% of 24-month-old infants had neurodevelopmental delay in gross motor function in the absence of cerebral palsy. In 7.3% of 18-month-old infants, neurodevelopmental delay in problem-solving ability was observed. Higher values of Apgar score and bicarbonate levels were associated with higher Age and Stage Questionnaire total score. Delivery type, maternal age, gravidity of mother, and existence of mother disease during pregnancy were also associated with lower Age and Stage Questionnaire total score in different stages of life.

  16. Illumination uniformity issue explored via two-stage solar concentrator system based on Fresnel lens and compound flat concentrator

    International Nuclear Information System (INIS)

    Yeh, Naichia

    2016-01-01

    This paper illustrates details about the solar radiation distribution on the target of a two-stage solar concentrator that combines the Fresnel lens (FL) and the compound flat concentrator (CFC). The paper starts with a review of some FL development milestones such as the two-stage systems and the comparisons of flat vs. curved lenses in addition to the most noteworthy FL-based solar energy application, concentration photovoltaic (CPV). Through the review of the FL based CPV and two-stage concentrators, this study leads to the development of an algorithm to explore the spectrum distribution insight on the receiver of a two-stage (FL plus CFC) solar concentration system. It established the potential for using a correctly positioned 2nd stage reflector of right dimension to selectively redirect the desired spectrum on the target area so as to enhance the concentration flux intensity and uniformity at the same time. The study also helped to chart out the approximate locations of certain spectrum segments on the FL's target area, which is useful for exploring the spectrum control mechanism via the Fresnel lenses. - Highlights: • Map out the approximate locations of spectrum segments on FL's focal area. • Use the 2nd stage reflector to selectively reflect the desired spectrum on target. • Explore the spectrum distribution insight on FL solar concentrators' target area.

  17. Experimental Results of the First Two Stages of an Advanced Transonic Core Compressor Under Isolated and Multi-Stage Conditions

    Science.gov (United States)

    Prahst, Patricia S.; Kulkarni, Sameer; Sohn, Ki H.

    2015-01-01

    NASA's Environmentally Responsible Aviation (ERA) Program calls for investigation of the technology barriers associated with improved fuel efficiency of large gas turbine engines. Under ERA the task for a High Pressure Ratio Core Technology program calls for a higher overall pressure ratio of 60 to 70. This mean that the HPC would have to almost double in pressure ratio and keep its high level of efficiency. The challenge is how to match the corrected mass flow rate of the front two supersonic high reaction and high corrected tip speed stages with a total pressure ratio of 3.5. NASA and GE teamed to address this challenge by using the initial geometry of an advanced GE compressor design to meet the requirements of the first 2 stages of the very high pressure ratio core compressor. The rig was configured to run as a 2 stage machine, with Strut and IGV, Rotor 1 and Stator 1 run as independent tests which were then followed by adding the second stage. The goal is to fully understand the stage performances under isolated and multi-stage conditions and fully understand any differences and provide a detailed aerodynamic data set for CFD validation. Full use was made of steady and unsteady measurement methods to isolate fluid dynamics loss source mechanisms due to interaction and endwalls. The paper will present the description of the compressor test article, its predicted performance and operability, and the experimental results for both the single stage and two stage configurations. We focus the detailed measurements on 97 and 100 of design speed at 3 vane setting angles.

  18. Transcriptome analysis of Sacha Inchi (Plukenetia volubilis L. seeds at two developmental stages

    Directory of Open Access Journals (Sweden)

    Wang Xiaojuan

    2012-12-01

    Full Text Available Abstract Background Sacha Inchi (Plukenetia volubilis L., Euphorbiaceae is a potential oilseed crop because the seeds of this plant are rich in unsaturated fatty acids (FAs. In particular, the fatty acid composition of its seed oil differs markedly in containing large quantities of α-linolenic acid (18C:3, a kind of ω-3 FAs. However, little is known about the molecular mechanisms responsible for biosynthesis of unsaturated fatty acids in the developing seeds of this species. Transcriptome data are needed to better understand these mechanisms. Results In this study, de novo transcriptome assembly and gene expression analysis were performed using Illumina sequencing technology. A total of 52.6 million 90-bp paired-end reads were generated from two libraries constructed at the initial stage and fast oil accumulation stage of seed development. These reads were assembled into 70,392 unigenes; 22,179 unigenes showed a 2-fold or greater expression difference between the two libraries. Using this data we identified unigenes that may be involved in de novo FA and triacylglycerol biosynthesis. In particular, a number of unigenes encoding desaturase for formation of unsaturated fatty acids with high expression levels in the fast oil accumulation stage compared with the initial stage of seed development were identified. Conclusions This study provides the first comprehensive dataset characterizing Sacha Inchi gene expression at the transcriptional level. These data provide the foundation for further studies on molecular mechanisms underlying oil accumulation and PUFA biosynthesis in Sacha Inchi seeds. Our analyses facilitate understanding of the molecular mechanisms responsible for the high unsaturated fatty acids (especially α-linolenic acid accumulation in Sacha Inchi seeds.

  19. Multiple Genes Related to Muscle Identified through a Joint Analysis of a Two-stage Genome-wide Association Study for Racing Performance of 1,156 Thoroughbreds

    Directory of Open Access Journals (Sweden)

    Dong-Hyun Shin

    2015-06-01

    Full Text Available Thoroughbred, a relatively recent horse breed, is best known for its use in horse racing. Although myostatin (MSTN variants have been reported to be highly associated with horse racing performance, the trait is more likely to be polygenic in nature. The purpose of this study was to identify genetic variants strongly associated with racing performance by using estimated breeding value (EBV for race time as a phenotype. We conducted a two-stage genome-wide association study to search for genetic variants associated with the EBV. In the first stage of genome-wide association study, a relatively large number of markers (~54,000 single-nucleotide polymorphisms, SNPs were evaluated in a small number of samples (240 horses. In the second stage, a relatively small number of markers identified to have large effects (170 SNPs were evaluated in a much larger number of samples (1,156 horses. We also validated the SNPs related to MSTN known to have large effects on racing performance and found significant associations in the stage two analysis, but not in stage one. We identified 28 significant SNPs related to 17 genes. Among these, six genes have a function related to myogenesis and five genes are involved in muscle maintenance. To our knowledge, these genes are newly reported for the genetic association with racing performance of Thoroughbreds. It complements a recent horse genome-wide association studies of racing performance that identified other SNPs and genes as the most significant variants. These results will help to expand our knowledge of the polygenic nature of racing performance in Thoroughbreds.

  20. 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.

  1. Multicollinearity in Regression Analyses Conducted in Epidemiologic Studies.

    Science.gov (United States)

    Vatcheva, Kristina P; Lee, MinJae; McCormick, Joseph B; Rahbar, Mohammad H

    2016-04-01

    The adverse impact of ignoring multicollinearity on findings and data interpretation in regression analysis is very well documented in the statistical literature. The failure to identify and report multicollinearity could result in misleading interpretations of the results. A review of epidemiological literature in PubMed from January 2004 to December 2013, illustrated the need for a greater attention to identifying and minimizing the effect of multicollinearity in analysis of data from epidemiologic studies. We used simulated datasets and real life data from the Cameron County Hispanic Cohort to demonstrate the adverse effects of multicollinearity in the regression analysis and encourage researchers to consider the diagnostic for multicollinearity as one of the steps in regression analysis.

  2. 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.

  3. Prevalence of diabetes mellitus and diabetic retinopathy in Filipino vs Caucasian Americans: a retrospective cross-sectional epidemiologic study of two convenience samples.

    Science.gov (United States)

    Sáles, Christopher S; Lee, Roland Y; Agadzi, Anthony K; Hee, Michael R; Singh, Kuldev; Lin, Shan C

    2012-01-01

    To compare the prevalence of diabetic retinopathy in Filipino and Caucasian Americans in two clinic populations. Retrospective cross-sectional epidemiologic study of two convenience samples. Five hundred twelve Filipino and 600 Caucasian patients aged 40 years or older examined by two community-based comprehensive ophthalmology clinics during a one-year period. The prevalence of self-reported type 2 diabetes mellitus among Filipino (F) and Caucasian Americans (C) was 40.6% and 24.8%, respectively (PFilipino; 149 Caucasian), there was a statistically insignificant higher prevalence of diabetic retinopathy among Filipino diabetics compared to Caucasians (F vs C: all forms of diabetic retinopathy, 24.5% vs 16.8%, P=.08; non-proliferative retinopathy, 17.3% vs 12.8%, P=.24; proliferative retinopathy, 7.2% vs. 4.0%, P=.21). In multivariate analyses of the diabetic subpopulation, Filipino ethnicity was not a significant predictor of diabetic retinopathy. Filipino Americans may have a higher prevalence of type 2 diabetes mellitus and diabetic retinopathy than Caucasian Americans. Among those with type 2 diabetes, however, Filipino Americans were not found to be more likely to show manifestations of diabetic retinopathy than Caucasian Americans.

  4. Update of epidemiologic studies of plutonium-workers

    International Nuclear Information System (INIS)

    Voelz, G.L.; Wilkinson, G.S.; Acquavella, J.F.; Tietjen, G.L.; Brackbill, R.M.; Reyes, M.; Wiggs, L.D.

    1981-01-01

    Retrospective and prospective epidemiologic studies are being conducted as part of a national survey of plutonium workers at four Department of Energy facilities (Los Alamos, NM; Rocky Flats, CO; Mound Laboratory, OH; and Savannah River, SC). A preliminary analysis of mortality was done for all white males who have worked at the Rocky Flats Plant during the period 1952 to 1979. The 452 observed deaths were significantly fewer than the 831 expected for all causes. The 107 deaths due to all malignant neoplasms were also significantly fewer than the 167 expected from these diseases. Expected deaths were derived from age and calendar-specific death rates for US white males. Deaths reported for benign and unspecified neoplasms numbered eight versus an expected two, a significant elevation. These tumors, all intracranial, are the subject of a case-control study to be reported later. Subdividing the cohort on the basis of plutonium exposures and external radiation exposures results in similar overall findings. The benign and unspecified neoplasms, however, were not significantly high in the plutonium-exposed group

  5. Comparison of two-stage thermophilic (68 degrees C/55 degrees C) anaerobic digestion with one-stage thermophilic (55 degrees C) digestion of cattle manure.

    Science.gov (United States)

    Nielsen, H B; Mladenovska, Z; Westermann, P; Ahring, B K

    2004-05-05

    A two-stage 68 degrees C/55 degrees C anaerobic degradation process for treatment of cattle manure was studied. In batch experiments, an increase of the specific methane yield, ranging from 24% to 56%, was obtained when cattle manure and its fractions (fibers and liquid) were pretreated at 68 degrees C for periods of 36, 108, and 168 h, and subsequently digested at 55 degrees C. In a lab-scale experiment, the performance of a two-stage reactor system, consisting of a digester operating at 68 degrees C with a hydraulic retention time (HRT) of 3 days, connected to a 55 degrees C reactor with 12-day HRT, was compared with a conventional single-stage reactor running at 55 degrees C with 15-days HRT. When an organic loading of 3 g volatile solids (VS) per liter per day was applied, the two-stage setup had a 6% to 8% higher specific methane yield and a 9% more effective VS-removal than the conventional single-stage reactor. The 68 degrees C reactor generated 7% to 9% of the total amount of methane of the two-stage system and maintained a volatile fatty acids (VFA) concentration of 4.0 to 4.4 g acetate per liter. Population size and activity of aceticlastic methanogens, syntrophic bacteria, and hydrolytic/fermentative bacteria were significantly lower in the 68 degrees C reactor than in the 55 degrees C reactors. The density levels of methanogens utilizing H2/CO2 or formate were, however, in the same range for all reactors, although the degradation of these substrates was significantly lower in the 68 degrees C reactor than in the 55 degrees C reactors. Temporal temperature gradient electrophoresis profiles (TTGE) of the 68 degrees C reactor demonstrated a stable bacterial community along with a less divergent community of archaeal species. Copyright 2004 Wiley Periodicals, Inc.

  6. The Two-stage Constrained Equal Awards and Losses Rules for Multi-Issue Allocation Situation

    NARCIS (Netherlands)

    Lorenzo-Freire, S.; Casas-Mendez, B.; Hendrickx, R.L.P.

    2005-01-01

    This paper considers two-stage solutions for multi-issue allocation situations.Characterisations are provided for the two-stage constrained equal awards and constrained equal losses rules, based on the properties of composition and path independence.

  7. Faith Moves Mountains-Mountains Move Faith: Two Opposite Epidemiological Forces in Research on Religion and Health.

    Science.gov (United States)

    Hvidt, N C; Hvidtjørn, D; Christensen, K; Nielsen, J B; Søndergaard, J

    2017-02-01

    Research suggests opposite epidemiological forces in religion and health: (1). Faith seems to move mountains in the sense that religion is associated with positive health outcomes. (2). Mountains of bad health seem to move faith. We reflected on these forces in a population of 3000 young Danish twins in which all religiosity measures were associated with severe disease. We believe the reason for this novel finding is that the sample presents as a particularly secular population-based study and that the second epidemiological force has gained the upper hand in this sample. We suggest that all cross-sectional research on religion and health should be interpreted in light of such opposite epidemiological forces potentially diluting each other.

  8. Design and construction of a two-stage centrifugal pump | Nordiana ...

    African Journals Online (AJOL)

    Centrifugal pumps are widely used in moving liquids from one location to another in homes, offices and industries. Due to the ever increasing demand for centrifugal pumps it became necessary to design and construction of a two-stage centrifugal pump. The pump consisted of an electric motor, a shaft, two rotating impellers ...

  9. A Two-stage Improvement Method for Robot Based 3D Surface Scanning

    Science.gov (United States)

    He, F. B.; Liang, Y. D.; Wang, R. F.; Lin, Y. S.

    2018-03-01

    As known that the surface of unknown object was difficult to measure or recognize precisely, hence the 3D laser scanning technology was introduced and used properly in surface reconstruction. Usually, the surface scanning speed was slower and the scanning quality would be better, while the speed was faster and the quality would be worse. In this case, the paper presented a new two-stage scanning method in order to pursuit the quality of surface scanning in a faster speed. The first stage was rough scanning to get general point cloud data of object’s surface, and then the second stage was specific scanning to repair missing regions which were determined by chord length discrete method. Meanwhile, a system containing a robotic manipulator and a handy scanner was also developed to implement the two-stage scanning method, and relevant paths were planned according to minimum enclosing ball and regional coverage theories.

  10. Development and study of a 3.2-mm-diameter, 1.2-m-long two-stage plasma-arc-driven railgun for hypervelocity hydrogen pellet injection

    International Nuclear Information System (INIS)

    Zhang, D.; Kim, K.

    1988-12-01

    A detailed description of a prototype, fuseless, plasma-arc-driven, two-stage railgun system with a 1.2-m-long railgun barrel and a 3.2-mm-diameter circular bore is presented, along with the preliminary results indicating its capabilities and limitations. A hydrogen pellet generator, which has a straight-tube configuration and which is also operated as a gas gun, is employed as the first stage of the two-stage acceleration system. The design details of this preacceleration system and the results illustrating its performance are first presented. The second-stage accelerator which acts as a booster accelerator, is a fuseless plasma-arc-driven railgun, and constitutes the core of the entire two-stage acceleration scheme. Details of its design, ancillary systems, operation, and performance are described next in this report. The experimental data included herein represent only the preliminary data, and the system modifications that led to the improvements are described in the accompanying two other progress reports that precede this. 19 refs

  11. [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.

  12. A high-power two stage traveling-wave tube amplifier

    International Nuclear Information System (INIS)

    Shiffler, D.; Nation, J.A.; Schachter, L.; Ivers, J.D.; Kerslick, G.S.

    1991-01-01

    Results are presented on the development of a two stage high-efficiency, high-power 8.76-GHz traveling-wave tube amplifier. The work presented augments previously reported data on a single stage amplifier and presents new data on the operational characteristics of two identical amplifiers operated in series and separated from each other by a sever. Peak powers of 410 MW have been obtained over the complete pulse duration of the device, with a conversion efficiency from the electron beam to microwave energy of 45%. In all operating conditions the severed amplifier showed a ''sideband''-like structure in the frequency spectrum of the microwave radiation. A similar structure was apparent at output powers in excess of 70 MW in the single stage device. The frequencies of the ''sidebands'' are not symmetric with respect to the center frequency. The maximum, single frequency, average output power was 210 MW corresponding to an amplifier efficiency of 24%. Simulation data is also presented that indicates that the short amplifiers used in this work exhibit significant differences in behavior from conventional low-power amplifiers. These include finite length effects on the gain characteristics, which may account for the observed narrow bandwidth of the amplifiers and for the appearance of the sidebands. It is also found that the bunching length for the beam may be a significant fraction of the total amplifier length

  13. Biogas production of Chicken Manure by Two-stage fermentation process

    Science.gov (United States)

    Liu, Xin Yuan; Wang, Jing Jing; Nie, Jia Min; Wu, Nan; Yang, Fang; Yang, Ren Jie

    2018-06-01

    This paper performs a batch experiment for pre-acidification treatment and methane production from chicken manure by the two-stage anaerobic fermentation process. Results shows that the acetate was the main component in volatile fatty acids produced at the end of pre-acidification stage, accounting for 68% of the total amount. The daily biogas production experienced three peak period in methane production stage, and the methane content reached 60% in the second period and then slowly reduced to 44.5% in the third period. The cumulative methane production was fitted by modified Gompertz equation, and the kinetic parameters of the methane production potential, the maximum methane production rate and lag phase time were 345.2 ml, 0.948 ml/h and 343.5 h, respectively. The methane yield of 183 ml-CH4/g-VSremoved during the methane production stage and VS removal efficiency of 52.7% for the whole fermentation process were achieved.

  14. Epidemiological studies on radiation workers in Korea

    International Nuclear Information System (INIS)

    Soo Yong Choi; Hai Won Chung

    2007-01-01

    Complete text of publication follows. Objectives: The aim of this study is to analyze the occupational exposure for external radiation and to evaluate radiation effects on Korean radiation workers. Methods: The National Dose Registry contains radiation exposure records for all monitored radiation workers since its creation in 1983. We are carrying out epidemiological survey for radiation workers. The items of information included personal identification, employment and dose data. The frequencies of various types of chromosome aberrations in radiation workers were compared with controls. The data were analyzed according to year, sex, age, duration of occupation, exposure dose, etc. using SPSS statistical package(version 15.0). The goodness-of-fit test for Poisson assumption and dispersion test for detecting heterogeneity for Poisson distribution were done with chromosomal aberrations among study subjects. Results: The total number of workers registered from 1983 to 2005 was 61,610. The number of workers steadily increased and the accumulated dose somewhat increased. The collective annual dose of radiation workers was 345.823 man Sv and the mean annual dose was 1.34mSv. The frequencies of chromosome aberrations in 102 workers were compared with those in 42 controls. The frequencies of all types of chromosome aberrations in the exposed subjects were higher than those in the control group. Poisson regression analysis showed that there was significant association of chromosome aberrations with radiation dose, duration of work, age and alcohol intake. We started to survey radiation workers in order to evaluate radiation effects, collected epidemiological data for 9,157 workers at present and analyzed their lifetime radiation exposure doses. Follow-up is carrying out using the Korean Mortality Data, Cancer Registry and individual investigation. Among study patients, 11 of 38 deaths were identified with cancer. Conclusions: The data on occupational doses shows that

  15. Implications of inaccurate clinical nodal staging in pancreatic adenocarcinoma.

    Science.gov (United States)

    Swords, Douglas S; Firpo, Matthew A; Johnson, Kirsten M; Boucher, Kenneth M; Scaife, Courtney L; Mulvihill, Sean J

    2017-07-01

    Many patients with stage I-II pancreatic adenocarcinoma do not undergo resection. We hypothesized that (1) clinical staging underestimates nodal involvement, causing stage IIB to have a greater percent of resected patients and (2) this stage-shift causes discrepancies in observed survival. The Surveillance, Epidemiology, and End Results (SEER) research database was used to evaluate cause-specific survival in patients with pancreatic adenocarcinoma from 2004-2012. Survival was compared using the log-rank test. Single-center data on 105 patients who underwent resection of pancreatic adenocarcinoma without neoadjuvant treatment were used to compare clinical and pathologic nodal staging. In SEER data, medium-term survival in stage IIB was superior to IB and IIA, with median cause-specific survival of 14, 9, and 11 months, respectively (P < .001). Seventy-two percent of stage IIB patients underwent resection vs 28% in IB and 36% in IIA (P < .001). In our institutional data, 12.4% of patients had clinical evidence of nodal involvement vs 69.5% by pathologic staging (P < .001). Among clinical stage IA-IIA patients, 71.6% had nodal involvement by pathologic staging. Both SEER and institutional data support substantial underestimation of nodal involvement by clinical staging. This finding has implications in decisions regarding neoadjuvant therapy and analysis of outcomes in the absence of pathologic staging. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Two-stage high frequency pulse tube refrigerator with base temperature below 10 K

    Science.gov (United States)

    Chen, Liubiao; Wu, Xianlin; Liu, Sixue; Zhu, Xiaoshuang; Pan, Changzhao; Guo, Jia; Zhou, Yuan; Wang, Junjie

    2017-12-01

    This paper introduces our recent experimental results of pulse tube refrigerator driven by linear compressor. The working frequency is 23-30 Hz, which is much higher than the G-M type cooler (the developed cryocooler will be called high frequency pulse tube refrigerator in this paper). To achieve a temperature below 10 K, two types of two-stage configuration, gas coupled and thermal coupled, have been designed, built and tested. At present, both types can achieve a no-load temperature below 10 K by using only one compressor. As to gas-coupled HPTR, the second stage can achieve a cooling power of 16 mW/10K when the first stage applied a 400 mW heat load at 60 K with a total input power of 400 W. As to thermal-coupled HPTR, the designed cooling power of the first stage is 10W/80K, and then the temperature of the second stage can get a temperature below 10 K with a total input power of 300 W. In the current preliminary experiment, liquid nitrogen is used to replace the first coaxial configuration as the precooling stage, and a no-load temperature 9.6 K can be achieved with a stainless steel mesh regenerator. Using Er3Ni sphere with a diameter about 50-60 micron, the simulation results show it is possible to achieve a temperature below 8 K. The configuration, the phase shifters and the regenerative materials of the developed two types of two-stage high frequency pulse tube refrigerator will be discussed, and some typical experimental results and considerations for achieving a better performance will also be presented in this paper.

  17. Randomised study on single stage laparo-endoscopic rendezvous (intra-operative ERCP) procedure versus two stage approach (Pre-operative ERCP followed by laparoscopic cholecystectomy) for the management of cholelithiasis with choledocholithiasis.

    Science.gov (United States)

    Sahoo, Manash Ranjan; Kumar, Anil T; Patnaik, Aashish

    2014-07-01

    The 'Rendezvous' technique consists of laparoscopic cholecystectomy (LC) standards with intra-operative cholangiography followed by endoscopic sphincterotomy. The sphincterotome is driven across the papilla through a guidewire inserted by the transcystic route. In this study, we intended to compare the two methods in a prospective randomised trial. From 2005 to 2012, we enrolled 83 patients with a diagnosis of cholecysto-choledocolithiasis. They were randomised into two groups. In 'group-A',41 patients were treated with two stages management, first by pre-operative endoscopic retrograde cholangiopancreatography (ERCP) and common bile duct (CBD) clearance and second by LC. In 'group-B', 42 patients were treated with LC and intra-operative cholangiography; and when diagnosis of choledocholithiasis was confirmed, patients had undergone one stage management of by Laparo-endoscopic Rendezvous technique. In arm-A and arm-B groups, complete CBD clearance was achieved in 29 and 38 patients, respectively. Failure of the treatment in arm-A was 29% and in arm-B was 9.5%. In arm-A, selective CBD cannulation was achieved in 33 cases (80.5%) and in arm-B in 39 cases (93%). In arm-Agroup, post-ERCP hyperamylasia was presented in nine patients (22%) and severe pancreatitis in five patients (12%) versus none of the patients (0%) in arm-B group, respectively. Mean post-operative hospital stay in arm-A and arm-B groups are 10.9 and 6.8 days, respectively. One stage laparo-endoscopic rendezvous approach increases selective cannulation of CBD, reduces post-ERCP pancreatitis, reduces days of hospital stay, increases patient's compliance and prevents unnecessary intervention to CBD.

  18. Epidemiological and spatial analysis of scorpion stings in two regions of Morocco: Marrakesh-Tensift-Al Haouz and Souss-Massa-Draa

    OpenAIRE

    Moulay Abdelmonaim El Hidan; Oulaid Touloun; Rhizlane El Oufir; Ali Boumezzough

    2016-01-01

    Objective: To describe and compare the epidemiological features of scorpionism during six years (2005–2010) in two regions of Morocco: Marrakesh-Tensift-Al Haouz and Souss-MassaDraa. Methods: Clinical and epidemiological data were obtained from medical records of the Moroccan Poison Control Center during 2005–2010. The data comprised demographics, sting characteristics and clinical severity classes. Digital maps were produced for envenomation and death incidence with the distri...

  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. Effekt of a two-stage nursing assesment and intervention - a randomized intervention study

    DEFF Research Database (Denmark)

    Rosted, Elizabeth Emilie; Poulsen, Ingrid; Hendriksen, Carsten

    % of geriatric patients have complex and often unresolved caring needs. The objective was to examine the effect of a two-stage nursing assessment and intervention to address the patients uncompensated problems given just after discharge from ED and one and six months after. Method: We conducted a prospective...... nursing assessment comprising a checklist of 10 physical, mental, medical and social items. The focus was on unresolved problems which require medical intervention, new or different home care services, or comprehensive geriatric assessment. Following this the nurses made relevant referrals...... to the geriatric outpatient clinic, community health centre, primary physician or arrangements with next-of-kin. Findings: Primary endpoints will be presented as unplanned readmission to ED; admission to nursing home; and death. Secondary endpoints will be presented as physical function; depressive symptoms...

  1. Two-stage Catalytic Reduction of NOx with Hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Umit S. Ozkan; Erik M. Holmgreen; Matthew M. Yung; Jonathan Halter; Joel Hiltner

    2005-12-21

    A two-stage system for the catalytic reduction of NO from lean-burn natural gas reciprocating engine exhaust is investigated. Each of the two stages uses a distinct catalyst. The first stage is oxidation of NO to NO{sub 2} and the second stage is reduction of NO{sub 2} to N{sub 2} with a hydrocarbon. The central idea is that since NO{sub 2} is a more easily reduced species than NO, it should be better able to compete with oxygen for the combustion reaction of hydrocarbon, which is a challenge in lean conditions. Early work focused on demonstrating that the N{sub 2} yield obtained when NO{sub 2} was reduced was greater than when NO was reduced. NO{sub 2} reduction catalysts were designed and silver supported on alumina (Ag/Al{sub 2}O{sub 3}) was found to be quite active, able to achieve 95% N{sub 2} yield in 10% O{sub 2} using propane as the reducing agent. The design of a catalyst for NO oxidation was also investigated, and a Co/TiO{sub 2} catalyst prepared by sol-gel was shown to have high activity for the reaction, able to reach equilibrium conversion of 80% at 300 C at GHSV of 50,000h{sup -1}. After it was shown that NO{sub 2} could be more easily reduced to N{sub 2} than NO, the focus shifted on developing a catalyst that could use methane as the reducing agent. The Ag/Al{sub 2}O{sub 3} catalyst was tested and found to be inactive for NOx reduction with methane. Through iterative catalyst design, a palladium-based catalyst on a sulfated-zirconia support (Pd/SZ) was synthesized and shown to be able to selectively reduce NO{sub 2} in lean conditions using methane. Development of catalysts for the oxidation reaction also continued and higher activity, as well as stability in 10% water, was observed on a Co/ZrO{sub 2} catalyst, which reached equilibrium conversion of 94% at 250 C at the same GHSV. The Co/ZrO{sub 2} catalyst was also found to be extremely active for oxidation of CO, ethane, and propane, which could potential eliminate the need for any separate

  2. Enhancement of bioenergy production from organic wastes by two-stage anaerobic hydrogen and methane production process

    DEFF Research Database (Denmark)

    Luo, Gang; Xie, Li; Zhou, Qi

    2011-01-01

    The present study investigated a two-stage anaerobic hydrogen and methane process for increasing bioenergy production from organic wastes. A two-stage process with hydraulic retention time (HRT) 3d for hydrogen reactor and 12d for methane reactor, obtained 11% higher energy compared to a single......:12 to 1:14, 6.7%, more energy could be obtained. Microbial community analysis indicated that the dominant bacterial species were different in the hydrogen reactors (Thermoanaerobacterium thermosaccharolyticum-like species) and methane reactors (Clostridium thermocellum-like species). The changes...

  3. Epidemiological studies in mucus hypersecretion

    DEFF Research Database (Denmark)

    Vestbo, Jørgen

    2002-01-01

    Respiratory mucus in epidemiology has mainly been studied using standardized questionnaires including questions on cough and phlegm. In chronic obstructive pulmonary disease (COPD) much controversy exists regarding the importance of mucus hypersecretion. From being the key element in the 'British...... hypothesis' it was reduced to being an innocent disorder in the 1980s but is now again recognized as a potential risk factor for an accelerated loss of lung function. Whereas early studies in mainly occupational cohorts showed no effect of chronic mucus hypersecretion on decline in lung function......, such an effect has been shown in subsequent studies on general population samples. Chronic mucus hypersecretion also increases risk of hospital admission which may be due to an increased risk of lower respiratory tract infection. In severe COPD this may explain the increased mortality associated...

  4. [Bad habits and dysgnathia: epidemiological study].

    Science.gov (United States)

    Cordasco, G; Lo Giudice, G; Dolci, E; Romeo, U; Lafronte, G

    1989-01-01

    The authors refer about an epidemiological survey in 651 children in the school-age. The aim of study is to investigate about the frequency of the bad habits and the pathogenetic relations between these and the development of the dento-maxillo-facial deformities. They point out an incidence of these bad habits in the 35,48% with a predominance of mouth breathers (45,45%). After they discuss the necessity of an early detection of anomalous neuromuscular attitudes.

  5. Two-stage double-effect ammonia/lithium nitrate absorption cycle

    International Nuclear Information System (INIS)

    Ventas, R.; Lecuona, A.; Vereda, C.; Legrand, M.

    2016-01-01

    Highlights: • A two stage double effect cycle with NH3-LiNO3 is proposed. • The cycle operates at lower pressures than conventional. • Adiabatic absorber offers better performance than the diabatic version. • Evaporator external inlet temperatures higher than −10 °C avoids crystallization. • Maximum COP is 1.25 for driving water inlet temperature of 100 C. - Abstract: The two-stage configuration of a double-effect absorption cycle using ammonia/lithium nitrate as working fluid is studied by means of a thermodynamic model. The maximum pressure of this cycle configuration is the same as the single-effect cycle, up to 15.8 bars, being an advantage over the double-effect conventional configuration with three pressure levels that exhibits much higher maximum pressure. The performance of the cycle and the limitation imposed by crystallization of the working fluid is determined for both adiabatic and diabatic absorber cycles. Both cycles offer similar COP; however the adiabatic variant shows a larger margin against crystallization. This cycle can produce cold for external inlet evaporator temperatures down to −10 °C, but for this limit the crystallization could happen at high inlet generator temperatures. The maximum COP can be 1.25 for an external inlet generator temperature of 100 °C. This cycle shows a better COP than a typical double effect cycle with in-parallel configuration for the range of the moderate temperatures under study and using the same working fluid. Comparisons with double effect cycles using H_2O/LiBr and NH_3/H_2O as working fluids are also offered, highlighting the present configurations advantages regarding COP, evaporation and condensation temperatures as well as crystallization.

  6. Simultaneous versus sequential pharmacokinetic-pharmacodynamic population analysis using an iterative two-stage Bayesian technique

    NARCIS (Netherlands)

    Proost, Johannes H.; Schiere, Sjouke; Eleveld, Douglas J.; Wierda, J. Mark K. H.

    A method for simultaneous pharmacokinetic-pharmacodynamic (PK-PD) population analysis using an Iterative Two-Stage Bayesian (ITSB) algorithm was developed. The method was evaluated using clinical data and Monte Carlo simulations. Data from a clinical study with rocuronium in nine anesthetized

  7. Biomarkers in molecular epidemiology study of oral squamous cell carcinoma in the era of precision medicine

    Directory of Open Access Journals (Sweden)

    Qing-Hao Zhu

    2017-01-01

    Full Text Available Oral cancer, which occurs in the mouth, lips, and tongue, is a multifactorial disease whose etiology involves environment, genetic, and epigenetic factors. Tobacco use and alcohol consumption are regarded as the primary risk factors for oral squamous cell carcinoma (OSCC, and betel use, other chemicals, radiation, environmental, and genetics are reported as relevant risk factors for oral carcinogenesis. The human papillomavirus infection is an independent risk factor. Traditional epidemiology studies have revealed that environmental carcinogens are risk factors for OSCC. Molecular epidemiology studies have revealed that the susceptibility to OSCC is influenced by both environmental and genetic risk factors. However, the details and mechanisms of risk factors involved in OSCC are unclear. Advanced methods and techniques used in human genome studies provide great opportunities for researchers to explore and identify (a the details of such risk factors and (b genetic susceptibility involved in OSCC. Human genome epidemiology is a new branch of epidemiology, which leads the epidemiology study from the molecular epidemiology era into the era of genome-wide association study. In the era of precision medicine, molecular epidemiology studies should focus on biomarkers for cancer genomics and their potential utility in clinical practice. Here, we briefly reviewed several molecular epidemiology studies of OSCC, focusing on biomarkers as valuable utility in risk assessment, clinical screening, diagnosis, and prognosis prediction of OSCC in the era of precision medicine.

  8. Implementation and reporting of causal mediation analysis in 2015: a systematic review in epidemiological studies.

    Science.gov (United States)

    Liu, Shao-Hsien; Ulbricht, Christine M; Chrysanthopoulou, Stavroula A; Lapane, Kate L

    2016-07-20

    Causal mediation analysis is often used to understand the impact of variables along the causal pathway of an occurrence relation. How well studies apply and report the elements of causal mediation analysis remains unknown. We systematically reviewed epidemiological studies published in 2015 that employed causal mediation analysis to estimate direct and indirect effects of observed associations between an exposure on an outcome. We identified potential epidemiological studies through conducting a citation search within Web of Science and a keyword search within PubMed. Two reviewers independently screened studies for eligibility. For eligible studies, one reviewer performed data extraction, and a senior epidemiologist confirmed the extracted information. Empirical application and methodological details of the technique were extracted and summarized. Thirteen studies were eligible for data extraction. While the majority of studies reported and identified the effects of measures, most studies lacked sufficient details on the extent to which identifiability assumptions were satisfied. Although most studies addressed issues of unmeasured confounders either from empirical approaches or sensitivity analyses, the majority did not examine the potential bias arising from the measurement error of the mediator. Some studies allowed for exposure-mediator interaction and only a few presented results from models both with and without interactions. Power calculations were scarce. Reporting of causal mediation analysis is varied and suboptimal. Given that the application of causal mediation analysis will likely continue to increase, developing standards of reporting of causal mediation analysis in epidemiological research would be prudent.

  9. Novel rare missense variations and risk of autism spectrum disorder: whole-exome sequencing in two families with affected siblings and a two-stage follow-up study in a Japanese population.

    Directory of Open Access Journals (Sweden)

    Jun Egawa

    Full Text Available Rare inherited variations in multiplex families with autism spectrum disorder (ASD are suggested to play a major role in the genetic etiology of ASD. To further investigate the role of rare inherited variations, we performed whole-exome sequencing (WES in two families, each with three affected siblings. We also performed a two-stage follow-up case-control study in a Japanese population. WES of the six affected siblings identified six novel rare missense variations. Among these variations, CLN8 R24H was inherited in one family by three affected siblings from an affected father and thus co-segregated with ASD. In the first stage of the follow-up study, we genotyped the six novel rare missense variations identified by WES in 241 patients and 667 controls (the Niigata sample. Only CLN8 R24H had higher mutant allele frequencies in patients (1/482 compared with controls (1/1334. In the second stage, this variation was further genotyped, yet was not detected in a sample of 309 patients and 350 controls (the Nagoya sample. In the combined Niigata and Nagoya samples, there was no significant association (odds ratio = 1.8, 95% confidence interval = 0.1-29.6. These results suggest that CLN8 R24H plays a role in the genetic etiology of ASD, at least in a subset of ASD patients.

  10. Confidence interval estimation of the difference between two sensitivities to the early disease stage.

    Science.gov (United States)

    Dong, Tuochuan; Kang, Le; Hutson, Alan; Xiong, Chengjie; Tian, Lili

    2014-03-01

    Although most of the statistical methods for diagnostic studies focus on disease processes with binary disease status, many diseases can be naturally classified into three ordinal diagnostic categories, that is normal, early stage, and fully diseased. For such diseases, the volume under the ROC surface (VUS) is the most commonly used index of diagnostic accuracy. Because the early disease stage is most likely the optimal time window for therapeutic intervention, the sensitivity to the early diseased stage has been suggested as another diagnostic measure. For the purpose of comparing the diagnostic abilities on early disease detection between two markers, it is of interest to estimate the confidence interval of the difference between sensitivities to the early diseased stage. In this paper, we present both parametric and non-parametric methods for this purpose. An extensive simulation study is carried out for a variety of settings for the purpose of evaluating and comparing the performance of the proposed methods. A real example of Alzheimer's disease (AD) is analyzed using the proposed approaches. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 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

  12. International epidemiological studies on HIV, HCV and STI

    NARCIS (Netherlands)

    van der Helm, J.J.

    2014-01-01

    This thesis comprises international epidemiological studies on HIV, Hepatitis C (HCV) and sexually transmitted infections (STI) and the evaluation of STI diagnostic tests with the ultimate goal to decrease spread and disease burden of these infections. The main conclusions are: 1. Without the use of

  13. Optimizing malarial epidemiological studies in areas of low transmission

    DEFF Research Database (Denmark)

    Amerasinghe, Priyanie H; Alifrangis, Michael; van der Hoek, Wim

    2005-01-01

    risk factor in this area was the location of houses relative to confirmed vector breeding sites. At the peak of the transmission season, the results pointed in the same direction, irrespective of the diagnostic method used. However, the importance of distance from the breeding site......Malaria risk factor studies have traditionally used microscopy readings of blood slides as the measure of malaria infection in humans, although alternatives are available. There is the need for an assessment of how the use of these alternative diagnostic approaches will influence the efficiency...... and significance of epidemiological studies. In an area of Sri Lanka with known risk factors for malaria, two cross-sectional surveys were done at the start and at the peak of transmission season. Microscopy was compared with enzyme-linked immunosorbent assays (ELISA) and polymerase chain reaction (PCR). The major...

  14. Epidemiology of infertility: a population-based study in Babol, Iran.

    Science.gov (United States)

    Esmaeilzadeh, Seddigheh; Delavar, Mouloud Agajani; Zeinalzadeh, Mahtab; Mir, Mohammad-Reza Aghajani

    2012-01-01

    The aim of researchers in the present study was to determine the prevalence of infertility and self-reported cause of infertility in Babol, Iran and then identify the factors associated with infertility. A retrospective epidemiologic study was conducted of characteristics of urban and rural women related to infertility. A total of 1,140 women aged 20-45 years were selected using cluster sampling. Of these 1,140 women, 59 (5.2%) (CI 4.2, 6.2) were voluntarily childless. Of the remaining 1,081 women, 913 (84.5%) (CI 82.5, 86.5) reported no difficulties in having children, and the remaining 168 (15.5%) (CI 13.5, 17.5) experienced difficulty conceiving at some stage in their lives. The prevalence of ever having primary infertility was 4.3% (CI 2.3, 6.3). The most frequently self-reported causes of infertility in this study were ovulation problems (39.2%). Infertile women were significantly more likely to have a higher age at marriage (p = 0.001), lower education (p = 0.006), higher body mass index (p = 0.0001), long-term health problems (p = 0.0001), a partner who smoked (p = 0.029), and past history of tubal or ectopic pregnancy (p = 0.002). These risk factors may help inform reproductive health clinics and primary healthcare centers about factors associated with infertility.

  15. Influence of Cu(NO32 initiation additive in two-stage mode conditions of coal pyrolytic decomposition

    Directory of Open Access Journals (Sweden)

    Larionov Kirill

    2017-01-01

    Full Text Available Two-stage process (pyrolysis and oxidation of brown coal sample with Cu(NO32 additive pyrolytic decomposition was studied. Additive was introduced by using capillary wetness impregnation method with 5% mass concentration. Sample reactivity was studied by thermogravimetric analysis with staged gaseous medium supply (argon and air at heating rate 10 °C/min and intermediate isothermal soaking. The initiative additive introduction was found to significantly reduce volatile release temperature and accelerate thermal decomposition of sample. Mass-spectral analysis results reveal that significant difference in process characteristics is connected to volatile matter release stage which is initiated by nitrous oxide produced during copper nitrate decomposition.

  16. Adjuvant therapy in stage I and stage II epithelial ovarian cancer. Results of two prospective randomized trials

    International Nuclear Information System (INIS)

    Young, R.C.; Walton, L.A.; Ellenberg, S.S.; Homesley, H.D.; Wilbanks, G.D.; Decker, D.G.; Miller, A.; Park, R.; Major, F. Jr.

    1990-01-01

    About a third of patients with ovarian cancer present with localized disease; despite surgical resection, up to half the tumors recur. Since it has not been established whether adjuvant treatment can benefit such patients, we conducted two prospective, randomized national cooperative trials of adjuvant therapy in patients with localized ovarian carcinoma. All patients underwent surgical resection plus comprehensive staging and, 18 months later, surgical re-exploration. In the first trial, 81 patients with well-differentiated or moderately well differentiated cancers confined to the ovaries (Stages Iai and Ibi) were assigned to receive either no chemotherapy or melphalan (0.2 mg per kilogram of body weight per day for five days, repeated every four to six weeks for up to 12 cycles). After a median follow-up of more than six years, there were no significant differences between the patients given no chemotherapy and those treated with melphalan with respect to either five-year disease-free survival or overall survival. In the second trial, 141 patients with poorly differentiated Stage I tumors or with cancer outside the ovaries but limited to the pelvis (Stage II) were randomly assigned to treatment with either melphalan (in the same regimen as above) or a single intraperitoneal dose of 32P (15 mCi) at the time of surgery. In this trial (median follow-up, greater than 6 years) the outcomes for the two treatment groups were similar with respect to five-year disease-free survival (80 percent in both groups) and overall survival (81 percent with melphalan vs. 78 percent with 32P; P = 0.48). We conclude that in patients with localized ovarian cancer, comprehensive staging at the time of surgical resection can serve to identify those patients (as defined by the first trial) who can be followed without adjuvant chemotherapy

  17. Combined effects of channel curvature and rotor configuration on the performance of two-stage viscous micropumps

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Jin [Yeungnam University, Gyeongsan (Korea, Republic of)

    2017-06-15

    The combined effects of channel curvature and rotor configuration on the performance of two-stage viscous micropumps were studied numerically. The Navier-Stokes equations were simulated to investigate the performance of two-stage micropumps. The performance of two-stage micropumps was studied in terms of the dimensionless mass flow rate and dimensionless driving power. Four different rotor configurations were designed by changing placement of two rotors inside a microchannel: Two aligned and two staggered configurations. The aligned rotor configuration of type 1 is to place the two rotors along the convex wall, while type 2 is to place them along the concave wall. Numerical results show that the rotor configuration plays a significant role in the performance of two-stage micropumps. The chan-nel curvature acts in a different way according to the rotor configuration. The mass flow rate of aligned rotor configuration of type 1 is greatly improved by the channel curvature, while it diminishes the mass flow rate of type 2. The maximum mass flow rate for the aligned rotor configuration of type 1 is obtained when the two rotors are placed at the junction of the circular and straight sections of the channel. The performance of staggered configurations is negligibly affected by the channel curvature. This characteristics is found due to rotation direction of the rotors. As the two rotors rotate in the opposite direction for the staggered configurations, the flow characteristics in the circular section is little affected by the channel curvature. The circumferential distance between the two rotors can be optimized in terms of the mass flow rate. The optimal value of the circumferential distance is about L = 1.4 for the staggered rotor configurations, and it is almost independent of the channel curvature. As the channel height increases, the circumferential distance becomes less significant for the staggered rotor configurations while it becomes significant for the aligned

  18. A review of methods used for studying the molecular epidemiology of Brachyspira hyodysenteriae.

    Science.gov (United States)

    Zeeh, Friederike; Nathues, Heiko; Frey, Joachim; Muellner, Petra; Fellström, Claes

    2017-08-01

    Brachyspira (B.) spp. are intestinal spirochaetes isolated from pigs, other mammals, birds and humans. In pigs, seven Brachyspira spp. have been described, i.e. B. hyodysenteriae, B. pilosicoli, B. intermedia, B. murdochii, B. innocens, B. suanatina and B. hampsonii. Brachyspira hyodysenteriae is especially relevant in pigs as it causes swine dysentery and hence considerable economic losses to the pig industry. Furthermore, reduced susceptibility of B. hyodysenteriae to antimicrobials is of increasing concern. The epidemiology of B. hyodysenteriae infections is only partially understood, but different methods for detection, identification and typing have supported recent improvements in knowledge and understanding. In the last years, molecular methods have been increasingly used. Molecular epidemiology links molecular biology with epidemiology, offering unique opportunities to advance the study of diseases. This review is based on papers published in the field of epidemiology and molecular epidemiology of B. hyodysenteriae in pigs. Electronic databases were screened for potentially relevant papers using title and abstract and finally, Barcellos et al. papers were systemically selected and assessed. The review summarises briefly the current knowledge on B. hyodysenteriae epidemiology and elaborates on molecular typing techniques available. Results of the studies are compared and gaps in the knowledge are addressed. Finally, potential areas for future research are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Hospital Morbidity Database for Epidemiological Studies on Churg-Strauss Syndrome.

    Science.gov (United States)

    Kanecki, Krzysztof; Nitsch-Osuch, Aneta; Gorynski, Paweł; Tarka, Patryk; Tyszko, Piotr

    2017-01-01

    Churg-Strauss syndrome or more accurately eosinophilic granulomatosis with polyangiitis (EGPA) is a small-vessel necrotizing vasculitis with a characteristic late-onset allergic rhinitis and asthma. The use of hospital morbidity database is an important element of the epidemiological analysis of this rare disease. The present study was undertaken to assess the incidence of EGPA and factors related to its epidemiology in Poland; the first analysis of the kind in Poland, enabling a comparison in the European context. This is a retrospective, population-based study using hospital discharge records with EGPA diagnosis, collected for a National Institute of Public Health survey covering the period from 2008 to 2013. The group consisted of 344 patients (206 females and 138 males) with the first-time hospitalization for EGPA. The major findings are that the annual incidence of EGPA in Poland was 1.5 per million (95% confidence intervals: 1.2-1.8), with the point prevalence of 8.8 per million at the end of 2013. A greater incidence of EGPA was observed in the regions with urban predominance. We conclude that discharge records may be a useful element of epidemiological studies on EGPA.

  20. Feasibility of future epidemiological studies on possible health effects of mobile phone base stations.

    Science.gov (United States)

    Neubauer, Georg; Feychting, Maria; Hamnerius, Yngve; Kheifets, Leeka; Kuster, Niels; Ruiz, Ignacio; Schüz, Joachim; Uberbacher, Richard; Wiart, Joe; Röösli, Martin

    2007-04-01

    The increasing deployment of mobile communication base stations led to an increasing demand for epidemiological studies on possible health effects of radio frequency emissions. The methodological challenges of such studies have been critically evaluated by a panel of scientists in the fields of radiofrequency engineering/dosimetry and epidemiology. Strengths and weaknesses of previous studies have been identified. Dosimetric concepts and crucial aspects in exposure assessment were evaluated in terms of epidemiological studies on different types of outcomes. We conclude that in principle base station epidemiological studies are feasible. However, the exposure contributions from all relevant radio frequency sources have to be taken into account. The applied exposure assessment method should be piloted and validated. Short to medium term effects on physiology or health related quality of life are best investigated by cohort studies. For long term effects, groups with a potential for high exposure need to first be identified; for immediate effect, human laboratory studies are the preferred approach. (c) 2006 Wiley-Liss, Inc.

  1. SERUM ELECTROLYTES AND ENZYMES IN ENDOMETRITIC NILI-RAVI BUFF ALOES OF TWO AGE GROUPS AND AT TWO STAGES OF LACTATION

    Directory of Open Access Journals (Sweden)

    A. Sarwar, R. U. Shahid, S. Masood, R. Kausar and S. G. Sha

    2002-04-01

    Full Text Available Serum concentrations of tour electrol~1es including sodium (Na, potassium (K, calcium (Ca and Chloride ( Cl and activities of two enzymes i.e. aspartate transaminase ( AST and alanine transaminase (ALT were compared amongst 80 pregnant Nili-Ravi buffaloes in a 23 factorial experiment: between endometritic and health~ lots of two age groups and at two stages of lactation. The analysis of variance revealed that: endometritic buffaloes showing muco-purulent vaginal discharge exhibited raise in ALT, AST and Cl, while decline in Ca. Milking stage affected two parameters namely, serum Cl and AL T. Both Cl and ALT were found to be decreased up to 11 months of lactation. Age groups remained inert on all of the parameters studied. This data indicates that electrolytes and enzymes clearly deviate from their normal levels in endometritic buffaloes which may in turn affect reproductive performance negatively. Thus maintenance of optimal uterine health and balanced nutrition, particularly with reference to blood constituents are critical for better reproductive performance in animals of this species.

  2. Study of the International Epidemiology of Androgenetic Alopecia in Young Caucasian Men Using Photographs From the Internet.

    Science.gov (United States)

    Avital, Yaniv Shalom; Morvay, Marta; Gaaland, Magdolna; Kemény, Lajos

    2015-01-01

    The epidemiological evaluation of androgenetic alopecia (AGA) is based mainly on direct observation and questionnaires. The international epidemiology and environmental risk factors of AGA in young Caucasian men remain unknown. To use photographs and data from the Internet to evaluate severe AGA and generate greater understanding of the international epidemiology of the disorder in young Caucasian men. A population-based cross-sectional study design was used. The sample included 26,340 Caucasian men aged 30 to 40 years who had uploaded profiles to two dating websites. Their photographs were evaluated for AGA and graded as follows: severe AGA (Norwood type VI-VII), non-severe AGA, and unknown. Epidemiological data were collected from the sites. Logistic regression was used to analyze the effect of risk factors on the prevalence of severe AGA. The overall success rate for identifying severe AGA by indirect evaluation of Internet photographs was 94%. The prevalence of severe AGA was 15.33% overall and varied significantly by geographical region. The risk of having severe AGA was increased by 1.092 for every year of age between 30 and 40 years. Severe AGA was more prevalent in subjects with higher body mass index. Photographs from the Internet can be used to evaluate severe AGA in epidemiological studies. The prevalence of severe AGA in young Caucasian men increases with age and varies by geographical region. Body mass index is an environmental risk factor for severe AGA.

  3. Study of the international epidemiology of androgenetic alopecia in young caucasian men using photographs from the internet

    Directory of Open Access Journals (Sweden)

    Yaniv Shalom Avital

    2015-01-01

    Full Text Available Background: The epidemiological evaluation of androgenetic alopecia (AGA is based mainly on direct observation and questionnaires. The international epidemiology and environmental risk factors of AGA in young Caucasian men remain unknown. Aim: To use photographs and data from the Internet to evaluate severe AGA and generate greater understanding of the international epidemiology of the disorder in young Caucasian men. Materials and Methods: A population-based cross-sectional study design was used. The sample included 26,340 Caucasian men aged 30 to 40 years who had uploaded profiles to two dating websites. Their photographs were evaluated for AGA and graded as follows: severe AGA (Norwood type VI-VII, non-severe AGA, and unknown. Epidemiological data were collected from the sites. Logistic regression was used to analyze the effect of risk factors on the prevalence of severe AGA. Results : The overall success rate for identifying severe AGA by indirect evaluation of Internet photographs was 94%. The prevalence of severe AGA was 15.33% overall and varied significantly by geographical region. The risk of having severe AGA was increased by 1.092 for every year of age between 30 and 40 years. Severe AGA was more prevalent in subjects with higher body mass index. Conclusions: Photographs from the Internet can be used to evaluate severe AGA in epidemiological studies. The prevalence of severe AGA in young Caucasian men increases with age and varies by geographical region. Body mass index is an environmental risk factor for severe AGA.

  4. A novel flow sensor based on resonant sensing with two-stage microleverage mechanism

    Science.gov (United States)

    Yang, B.; Guo, X.; Wang, Q. H.; Lu, C. F.; Hu, D.

    2018-04-01

    The design, simulation, fabrication, and experiments of a novel flow sensor based on resonant sensing with a two-stage microleverage mechanism are presented in this paper. Different from the conventional detection methods for flow sensors, two differential resonators are adopted to implement air flow rate transformation through two-stage leverage magnification. The proposed flow sensor has a high sensitivity since the adopted two-stage microleverage mechanism possesses a higher amplification factor than a single-stage microleverage mechanism. The modal distribution and geometric dimension of the two-stage leverage mechanism and hair are analyzed and optimized by Ansys simulation. A digital closed-loop driving technique with a phase frequency detector-based coordinate rotation digital computer algorithm is implemented for the detection and locking of resonance frequency. The sensor fabricated by the standard deep dry silicon on a glass process has a device dimension of 5100 μm (length) × 5100 μm (width) × 100 μm (height) with a hair diameter of 1000 μm. The preliminary experimental results demonstrate that the maximal mechanical sensitivity of the flow sensor is approximately 7.41 Hz/(m/s)2 at a resonant frequency of 22 kHz for the hair height of 9 mm and increases by 2.42 times as hair height extends from 3 mm to 9 mm. Simultaneously, a detection-limit of 3.23 mm/s air flow amplitude at 60 Hz is confirmed. The proposed flow sensor has great application prospects in the micro-autonomous system and technology, self-stabilizing micro-air vehicles, and environmental monitoring.

  5. Energy production from agricultural residues: High methane yields in pilot-scale two-stage anaerobic digestion

    International Nuclear Information System (INIS)

    Parawira, W.; Read, J.S.; Mattiasson, B.; Bjoernsson, L.

    2008-01-01

    There is a large, unutilised energy potential in agricultural waste fractions. In this pilot-scale study, the efficiency of a simple two-stage anaerobic digestion process was investigated for stabilisation and biomethanation of solid potato waste and sugar beet leaves, both separately and in co-digestion. A good phase separation between hydrolysis/acidification and methanogenesis was achieved, as indicated by the high carbon dioxide production, high volatile fatty acid concentration and low pH in the acidogenic reactors. Digestion of the individual substrates gave gross energy yields of 2.1-3.4 kWh/kg VS in the form of methane. Co-digestion, however, gave up to 60% higher methane yield, indicating that co-digestion resulted in improved methane production due to the positive synergism established in the digestion liquor. The integrity of the methane filters (MFs) was maintained throughout the period of operation, producing biogas with 60-78% methane content. A stable effluent pH showed that the methanogenic reactors had good ability to withstand the variations in load and volatile fatty acid concentrations that occurred in the two-stage process. The results of this pilot-scale study show that the two-stage anaerobic digestion system is suitable for effective conversion of semi-solid agricultural residues as potato waste and sugar beet leaves

  6. Randomised study on single stage laparo-endoscopic rendezvous (intra-operative ERCP procedure versus two stage approach (Pre-operative ERCP followed by laparoscopic cholecystectomy for the management of cholelithiasis with choledocholithiasis

    Directory of Open Access Journals (Sweden)

    Manash Ranjan Sahoo

    2014-01-01

    Full Text Available Introduction : The ′Rendezvous′ technique consists of laparoscopic cholecystectomy (LC standards with intra-operative cholangiography followed by endoscopic sphincterotomy. The sphincterotome is driven across the papilla through a guidewire inserted by the transcystic route. In this study, we intended to compare the two methods in a prospective randomised trial. Materials And Methods: From 2005 to 2012, we enrolled 83 patients with a diagnosis of cholecysto-choledocolithiasis. They were randomised into two groups. In ′group-A′,41 patients were treated with two stages management, first by pre-operative endoscopic retrograde cholangiopancreatography (ERCP and common bile duct (CBD clearance and second by LC. In ′group-B′, 42 patients were treated with LC and intra-operative cholangiography; and when diagnosis of choledocholithiasis was confirmed, patients had undergone one stage management of by Laparo-endoscopic Rendezvous technique. Results: In arm-A and arm-B groups, complete CBD clearance was achieved in 29 and 38 patients, respectively. Failure of the treatment in arm-A was 29% and in arm-B was 9.5%. In arm-A, selective CBD cannulation was achieved in 33 cases (80.5% and in arm-B in 39 cases (93%. In arm-Agroup, post-ERCP hyperamylasia was presented in nine patients (22% and severe pancreatitis in five patients (12% versus none of the patients (0% in arm-B group, respectively. Mean post-operative hospital stay in arm-A and arm-B groups are 10.9 and 6.8 days, respectively. Conclusion: One stage laparo-endoscopic rendezvous approach increases selective cannulation of CBD, reduces post-ERCP pancreatitis, reduces days of hospital stay, increases patient′s compliance and prevents unnecessary intervention to CBD.

  7. Target tracking system based on preliminary and precise two-stage compound cameras

    Science.gov (United States)

    Shen, Yiyan; Hu, Ruolan; She, Jun; Luo, Yiming; Zhou, Jie

    2018-02-01

    Early detection of goals and high-precision of target tracking is two important performance indicators which need to be balanced in actual target search tracking system. This paper proposed a target tracking system with preliminary and precise two - stage compound. This system using a large field of view to achieve the target search. After the target was searched and confirmed, switch into a small field of view for two field of view target tracking. In this system, an appropriate filed switching strategy is the key to achieve tracking. At the same time, two groups PID parameters are add into the system to reduce tracking error. This combination way with preliminary and precise two-stage compound can extend the scope of the target and improve the target tracking accuracy and this method has practical value.

  8. Divergent methylation pattern in adult stage between two forms of Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Yang, Si-Xia; Guo, Chao; Zhao, Xiu-Ting; Sun, Jing-Tao; Hong, Xiao-Yue

    2017-02-19

    The two-spotted spider mite, Tetranychus urticae Koch has two forms: green form and red form. Understanding the molecular basis of how these two forms established without divergent genetic background is an intriguing area. As a well-known epigenetic process, DNA methylation has particularly important roles in gene regulation and developmental variation across diverse organisms that do not alter genetic background. Here, to investigate whether DNA methylation could be associated with different phenotypic consequences in the two forms of T. urticae, we surveyed the genome-wide cytosine methylation status and expression level of DNA methyltransferase 3 (Tudnmt3) throughout their entire life cycle. Methylation-sensitive amplification polymorphism (MSAP) analyses of 585 loci revealed variable methylation patterns in the different developmental stages. In particular, principal coordinates analysis (PCoA) indicates a significant epigenetic differentiation between female adults of the two forms. The gene expression of Tudnmt3 was detected in all examined developmental stages, which was significantly different in the adult stage of the two forms. Together, our results reveal the epigenetic distance between the two forms of T. urticae, suggesting that DNA methylation might be implicated in different developmental demands, and contribute to different phenotypes in the adult stage of these two forms. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  9. A Study of a Two Stage Maximum Power Point Tracking Control of a Photovoltaic System under Partially Shaded Insolation Conditions

    Science.gov (United States)

    Kobayashi, Kenji; Takano, Ichiro; Sawada, Yoshio

    A photovoltaic array shows relatively low output power density, and has a greatly drooping Current-Voltage (I-V) characteristic. Therefore, Maximum Power Point Tracking (MPPT) control is used to maximize the output power of the array. Many papers have been reported in relation to MPPT. However, the Current-Power (I-P) curve sometimes shows multi-local maximum points mode under non-uniform insolation conditions. The operating point of the PV system tends to converge to a local maximum output point which is not the real maximal output point on the I-P curve. Some papers have been also reported, trying to avoid this difficulty. However most of those control systems become rather complicated. Then, the two stage MPPT control method is proposed in this paper to realize a relatively simple control system which can track the real maximum power point even under non-uniform insolation conditions. The feasibility of this control concept is confirmed for steady insolation as well as for rapidly changing insolation by simulation study using software PSIM and LabVIEW. In addition, simulated experiment confirms fundament al operation of the two stage MPPT control.

  10. A two-stage optimal planning and design method for combined cooling, heat and power microgrid system

    International Nuclear Information System (INIS)

    Guo, Li; Liu, Wenjian; Cai, Jiejin; Hong, Bowen; Wang, Chengshan

    2013-01-01

    Highlights: • A two-stage optimal method is presented for CCHP microgrid system. • Economic and environmental performance are considered as assessment indicators. • Application case demonstrates its good economic and environmental performance. - Abstract: In this paper, a two-stage optimal planning and design method for combined cooling, heat and power (CCHP) microgrid system was presented. The optimal objective was to simultaneously minimize the total net present cost and carbon dioxide emission in life circle. On the first stage, multi-objective genetic algorithm based on non-dominated sorting genetic algorithm-II (NSGA-II) was applied to solve the optimal design problem including the optimization of equipment type and capacity. On the second stage, mixed-integer linear programming (MILP) algorithm was used to solve the optimal dispatch problem. The approach was applied to a typical CCHP microgrid system in a hospital as a case study, and the effectiveness of the proposed method was verified

  11. Hydrodeoxygenation of oils from cellulose in single and two-stage hydropyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, J.D.; Snape, C.E. [Strathclyde Univ., Glasgow (United Kingdom); Luengo, C.A. [Universidade Estadual de Campinas, SP (Brazil). Dept. de Fisica Aplicada

    1996-09-01

    To investigate the removal of oxygen (hydrodeoxygenation) during the hydropyrolysis of cellulose, single and two-stage experiments on pure cellulose have been carried out using hydrogen pressures up to 10 MPa and temperatures over the range 300-520{sup o}C. Carbon, oxygen and aromaticity balances have been determined from the product yields and compositions. For the two-stage tests, the primary oils were passed through a bed of commercial Ni/Mo {gamma}-alumina-supported catalyst (Criterion 424, presulphided) at 400{sup o}C. Raising the hydrogen pressure from atmospheric to 10 MPa increased the carbon conversion by 10 mole % which was roughly equally divided between the oil and hydrocarbon gases. The oxygen content of the primary oil was reduced by over 10% to below 20% w/w. The addition of a dispersed iron sulphide catalyst further increased the oil yield at 10 MPa and reduces the oxygen content of the oil by a further 10%. The effect of hydrogen pressure on oil yields was most pronounced at low flow rates where it is beneficial in helping to overcome diffusional resistances. Unlike the dispersed iron sulphide in the first stage, the use of the Ni-Mo catalyst in the second stage reduced both the oxygen content and aromaticity of the oils. (Author)

  12. Two-Stage Enzymatic Preparation of Eicosapentaenoic Acid (EPA) And Docosahexaenoic Acid (DHA) Enriched Fish Oil Triacylglycerols.

    Science.gov (United States)

    Zhang, Zhen; Liu, Fang; Ma, Xiang; Huang, Huihua; Wang, Yong

    2018-01-10

    Fish oil products in the form of triacylglycerols generally have relatively low contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and so it is of potential research and industrial interest to enrich the related contents in commercial products. Thereby an economical and efficient two-stage preparation of EPA and DHA enriched fish oil triacylglycerols is proposed in this study. The first stage was the partial hydrolysis of fish oil by only 0.2 wt.‰ AY "Amano" 400SD which led to increases of EPA and DHA contents in acylglycerols from 19.30 and 13.09 wt % to 25.95 and 22.06 wt %, respectively. Subsequently, products of the first stage were subjected to transesterification with EPA and DHA enriched fatty acid ethyl esters (EDEE) as the second stage to afford EPA and DHA enriched fish oil triacylglycerols by using as low as 2 wt % Novozyme 435. EDEEs prepared from fish oil ethyl ester, and recycled DHA and EPA, respectively, were applied in this stage. Final products prepared with two different sources of EDEEs were composed of 97.62 and 95.92 wt % of triacylglycerols, respectively, with EPA and DHA contents of 28.20 and 21.41 wt % for the former and 25.61 and 17.40 wt % for the latter. Results not only demonstrate this two-stage process's capability and industrial value for enriching EPA and DHA in fish oil products, but also offer new opportunities for the development of fortified fish oil products.

  13. 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.

  14. A review of epidemiological studies concerning leukaemia and lymphoma among young people and the genetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1994-01-01

    The review seeks to identify consistent patterns of results between 30 epidemiological studies of low dose parental exposure to radiation and leukaemia etc. in their offspring. Eight of the studies show significant increases in leukaemia but most are unreliable because they have flawed methodologies and several analyse the same basic data. Two studies free from major criticism do show an association with parental irradiation but both contain data from Seascale and are not independent. Two well conducted studies based on other areas (Canada and Scotland) are claimed by their authors to have sufficient statistical power to test the Seascale findings and do not confirm an association with paternal irradiation. It is concluded that there is little reliable evidence from epidemiological studies for a causal association between pre-conception, paternal or maternal, irradiation and an increase in the frequency of leukaemia or malignancies among offspring. (author)

  15. The hybrid two stage anticlockwise cycle for ecological energy conversion

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The anticlockwise cycle is commonly used for refrigeration, air conditioning and heat pumps applications. The application of refrigerant in the compression cycle is within the temperature limits of the triple point and the critical point. New refrigerants such as 1234yf or 1234ze have many disadvantages, therefore natural refrigerants application is favourable. The carbon dioxide and water can be applied only in the hybrid two stages cycle. The possibilities of this solutions are shown for refrigerating applications, as well some experimental results of the adsorption-compression double stages cycle, powered with solar collectors are shown. As a high temperature cycle the adsorption system is applied. The low temperature cycle is the compression stage with carbon dioxide as a working fluid. This allows to achieve relatively high COP for low temperature cycle and for the whole system.

  16. Two-Stage Part-Based Pedestrian Detection

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Prioletti, Antonio; Trivedi, Mohan M.

    2012-01-01

    Detecting pedestrians is still a challenging task for automotive vision system due the extreme variability of targets, lighting conditions, occlusions, and high speed vehicle motion. A lot of research has been focused on this problem in the last 10 years and detectors based on classifiers has...... gained a special place among the different approaches presented. This work presents a state-of-the-art pedestrian detection system based on a two stages classifier. Candidates are extracted with a Haar cascade classifier trained with the DaimlerDB dataset and then validated through part-based HOG...... of several metrics, such as detection rate, false positives per hour, and frame rate. The novelty of this system rely in the combination of HOG part-based approach, tracking based on specific optimized feature and porting on a real prototype....

  17. Anaerobic digestion of citrus waste using two-stage membrane bioreactor

    Science.gov (United States)

    Millati, Ria; Lukitawesa; Dwi Permanasari, Ervina; Wulan Sari, Kartika; Nur Cahyanto, Muhammad; Niklasson, Claes; Taherzadeh, Mohammad J.

    2018-03-01

    Anaerobic digestion is a promising method to treat citrus waste. However, the presence of limonene in citrus waste inhibits anaerobic digestion process. Limonene is an antimicrobial compound and could inhibit methane forming bacteria that takes a longer time to recover than the injured acid forming bacteria. Hence, volatile fatty acids will be accumulated and methane production will be decreased. One way to solve this problem is by conducting anaerobic digestion process into two stages. The first step is aimed for hydrolysis, acidogenesis, and acetogenesis reactions and the second stage is aimed for methanogenesis reaction. The separation of the system would further allow each stage in their optimum conditions making the process more stable. In this research, anaerobic digestion was carried out in batch operations using 120 ml-glass bottle bioreactors in 2 stages. The first stage was performed in free-cells bioreactor, whereas the second stage was performed in both bioreactor of free cells and membrane bioreactor. In the first stage, the reactor was set into ‘anaerobic’ and ‘semi-aerobic’ conditions to examine the effect of oxygen on facultative anaerobic bacteria in acid production. In the second stage, the protection of membrane towards the cells against limonene was tested. For the first stage, the basal medium was prepared with 1.5 g VS of inoculum and 4.5 g VS of citrus waste. The digestion process was carried out at 55°C for four days. For the second stage, the membrane bioreactor was prepared with 3 g of cells that were encased and sealed in a 3×6 cm2 polyvinylidene fluoride membrane. The medium contained 40 ml basal medium and 10 ml liquid from the first stage. The bioreactors were incubated at 55°C for 2 days under anaerobic condition. The results from the first stage showed that the maximum total sugar under ‘anaerobic’ and ‘semi-aerobic’ conditions was 294.3 g/l and 244.7 g/l, respectively. The corresponding values for total volatile

  18. Evaluation of the 8th AJCC staging system for pathologically versus clinically staged pancreatic adenocarcinoma: A time to revisit a dogma?

    Science.gov (United States)

    Abdel-Rahman, Omar

    2018-02-01

    The 8th edition of the American Joint Committee on Cancer (AJCC) staging system for pancreatic exocrine adenocarcinoma has been released. The current study seeks to assess the 7th and 8th editions among patients registered within the surveillance, epidemiology and end results (SEER) database. SEER database (2010-2013) has been accessed through SEER*Stat program and AJCC 8th edition stages were reconstructed utilizing the collaborative stage descriptions. Kaplan-Meier analysis of overall survival and pancreatic cancer-specific survival analyses (according to both 7th and 8th editions and according to whether pathological or clinical staging were conducted) has been performed. Multivariate analysis of factors affecting pancreatic cancer-specific survival was also conducted through a Cox proportional hazard model. A total of 18  948 patients with pancreatic adenocarcinoma were identified in the period from 2010-2013. Pancreatic cancer-specific survival among pathologically staged patients and according to the 8th edition showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between stage IA and stage IB (P = 0.307) and the comparison between stage IB and stage IIA (P = 0.116). Moreover, P value for stage IA vs IIA was 0.014; while pancreatic cancer-specific survival according to the 7th edition among pathologically staged patients showed significant differences for all pair wise comparisons among different stages (P < 0.0001) except for the comparison between IA and IB (P = 0.072), the comparison between stage IIA and stage IIB (P = 0.065), the comparison between stage IIA and stage III (P = 0.059) and the comparison between IIB and III (P = 0.595). Among clinically staged patients (i.e. those who did not undergo initial radical surgery), the prognostic performance of both 7th and 8th stages for both overall survival and pancreatic cancer-specific survival was

  19. Engineering analysis of the two-stage trifluoride precipitation process

    International Nuclear Information System (INIS)

    Luerkens, D.w.W.

    1984-06-01

    An engineering analysis of two-stage trifluoride precipitation processes is developed. Precipitation kinetics are modeled using consecutive reactions to represent fluoride complexation. Material balances across the precipitators are used to model the time dependent concentration profiles of the main chemical species. The results of the engineering analysis are correlated with previous experimental work on plutonium trifluoride and cerium trifluoride

  20. Recent developments of a two-stage light gas gun for pellet injection

    International Nuclear Information System (INIS)

    Reggiori, A.

    1984-01-01

    A report is given on a two-stage pneumatic gun operated with ambient air as first stage driver which has been built and tested. Cylindrical polyethylene pellets of 1 mm diameter and 1 mm length have been launched at velocities up to 1800 m/s, with divergence angles of the pellet trajectory less than 1 0 . It is possible to optimize the pressure pulse for pellets of different masses, simply changing the mass of the piston and/or the initial pressures in the second stage. (author)

  1. Complete mitochondrial genomes and nuclear ribosomal RNA operons of two species of Diplostomum (Platyhelminthes: Trematoda): a molecular resource for taxonomy and molecular epidemiology of important fish pathogens.

    Science.gov (United States)

    Brabec, Jan; Kostadinova, Aneta; Scholz, Tomáš; Littlewood, D Timothy J

    2015-06-19

    large-scale molecular epidemiology and disease ecology studies based on the most accessible life-cycle stages of eye flukes.

  2. Two-stage acid saccharification of fractionated Gelidium amansii minimizing the sugar decomposition.

    Science.gov (United States)

    Jeong, Tae Su; Kim, Young Soo; Oh, Kyeong Keun

    2011-11-01

    Two-stage acid hydrolysis was conducted on easy reacting cellulose and resistant reacting cellulose of fractionated Gelidium amansii (f-GA). Acid hydrolysis of f-GA was performed at between 170 and 200 °C for a period of 0-5 min, and an acid concentration of 2-5% (w/v, H2SO4) to determine the optimal conditions for acid hydrolysis. In the first stage of the acid hydrolysis, an optimum glucose yield of 33.7% was obtained at a reaction temperature of 190 °C, an acid concentration of 3.0%, and a reaction time of 3 min. In the second stage, a glucose yield of 34.2%, on the basis the amount of residual cellulose from the f-GA, was obtained at a temperature of 190 °C, a sulfuric acid concentration of 4.0%, and a reaction time 3.7 min. Finally, 68.58% of the cellulose derived from f-GA was converted into glucose through two-stage acid saccharification under aforementioned conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Epidemiologic studies of glyphosate and cancer: a review.

    Science.gov (United States)

    Mink, Pamela J; Mandel, Jack S; Sceurman, Bonnielin K; Lundin, Jessica I

    2012-08-01

    The United States Environmental Protection Agency and other regulatory agencies around the world have registered glyphosate as a broad-spectrum herbicide for use on multiple food and non-food use crops. Glyphosate is widely considered by regulatory authorities and scientific bodies to have no carcinogenic potential, based primarily on results of carcinogenicity studies of rats and mice. To examine potential cancer risks in humans, we reviewed the epidemiologic literature to evaluate whether exposure to glyphosate is associated causally with cancer risk in humans. We also reviewed relevant methodological and biomonitoring studies of glyphosate. Seven cohort studies and fourteen case-control studies examined the association between glyphosate and one or more cancer outcomes. Our review found no consistent pattern of positive associations indicating a causal relationship between total cancer (in adults or children) or any site-specific cancer and exposure to glyphosate. Data from biomonitoring studies underscore the importance of exposure assessment in epidemiologic studies, and indicate that studies should incorporate not only duration and frequency of pesticide use, but also type of pesticide formulation. Because generic exposure assessments likely lead to exposure misclassification, it is recommended that exposure algorithms be validated with biomonitoring data. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Two-stage nuclear refrigeration with enhanced nuclear moments

    International Nuclear Information System (INIS)

    Hunik, R.

    1979-01-01

    Experiments are described in which an enhanced nuclear system is used as a precoolant for a nuclear demagnetisation stage. The results show the promising advantages of such a system in those circumstances for which a large cooling power is required at extremely low temperatures. A theoretical review of nuclear enhancement at the microscopic level and its macroscopic thermodynamical consequences is given. The experimental equipment for the implementation of the nuclear enhanced refrigeration method is described and the experiments on two-stage nuclear demagnetisation are discussed. With the nuclear enhanced system PrCu 6 the author could precool a nuclear stage of indium in a magnetic field of 6 T down to temperatures below 10 mK; this resulted in temperature below 1 mK after demagnetisation of the indium. It is demonstrated that the interaction energy between the nuclear moments in an enhanced nuclear system can exceed the nuclear dipolar interaction. Several experiments are described on pulsed nuclear magnetic resonance, as utilised for thermometry purposes. It is shown that platinum NMR-thermometry gives very satisfactory results around 1 mK. The results of experiments on nuclear orientation of radioactive nuclei, e.g. the brute force polarisation of 95 NbPt and 60 CoCu, are presented, some of which are of major importance for the thermometry in the milli-Kelvin region. (Auth.)

  5. Toxicity of crude oil to early life stages of two fish species

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, L.M.; Hodson, P.V. [Queen' s Univ., Kingston, ON (Canada). Dept. of Biology; Brown, R.S. [Queen' s Univ., Kingston, ON (Canada). Dept. of Chemistry; King, T.; Lee, K. [Department of Fisheries and Oceans, Dartmouth, NS (Canada). Bedford Inst. of Oceanography

    2004-07-01

    Fish exposed to crude oil in their early life stages exhibit signs of dioxin-like toxicity which is linked to the presence of alkyl-substituted polycyclic aromatic hydrocarbons (PAHs). Exposure is characterized by the presence of blue-sac disease which manifests itself in edema, hemorrhaging, deformities and induction of CYP1A enzymes. In this study, the extent of CYP1A induction and BSD was compared in the early life stages of rainbow trout and Japanese medaka following exposure to two crude oils (Scotian Shelf and Alaskan North Slope Crude). Embryos were exposed to a broad range of concentrations of chemically enhanced water fractions of both oils which have unique PAH composition and chemical characteristics. It was assumed that Alaskan North Slope Crude would be more toxic than Scotian Shelf because it has a higher PAH concentration. The occurrence and severity of BSD was characterized along with the extent of PAH exposure. Preliminary results confirm that PAH exposure is greater for Alaskan North Slope Crude and that the responses of the two fish species were highly correlated.

  6. Epidemiology of ovarian cancers in Zaria, Northern Nigeria: a 10-year study

    Directory of Open Access Journals (Sweden)

    Zayyan MS

    2017-11-01

    Full Text Available Marliyya Sanusi Zayyan,1 Saad Aliyu Ahmed,2 Adekunle O Oguntayo,1 Abimbola O Kolawole,1 Tajudeen Ayodeji Olasinde3 1Gynaecological Oncology Unit, 2Department of Histopathology, 3Department of Radiation Oncology, Ahmadu Bello University, Zaria, Nigeria Background: Globally, the absence of a premalignant stage of ovarian cancer and a reliable screening tool make early diagnosis difficult. Locally, poverty, ignorance, and lack of organized cancer services make prognosis poor. We describe the epidemiological features of ovarian cancer seen at Ahmadu Bello University Teaching Hospital Zaria, Northern Nigeria, a tertiary referral center, over a 10-year period in this challenging setting. Methods: All cases of histologically diagnosed ovarian cancer between January 1, 2004 and December 31, 2013 were included in the study. Case notes were retrieved to collect clinical data including age, parity, clinical stage of disease at presentation, and known associated factors. Results were analyzed using Epi info™. Results: A total of 78 patients were included in the study. About 4–13 cases were seen every year with a tendency to increasing incidence. The patients were aged 8–80 years with mean of 37 years. Sixty-two (79.5% patients were premenopausal while postmenopausal women accounted for only seven cases or 9.0%. There were 17 cases (22.3% of aggressive cancers in patients aged ≤20 years. A majority of the patients, 65 (83.3%, were parous with only nine (11.5% patients being nulliparous. Serous cyst adenocarcinoma accounted for 32 (41% cases. Granulosa cell tumor was the second commonest with 18 cases (23.1%. The mean age of occurrence of serous cyst adenocarcinoma was 31 years and for epithelial ovarian cancers in general it was 33.5 years. Endometrioid adenocarcinoma was rare with only one case in 10 years. Factors like age, parity, and premenopausal status did not appear to be protective to the occurrence of malignant ovarian tumor in this group

  7. Exposure to uranium and cancer risk: a review of epidemiological studies

    International Nuclear Information System (INIS)

    Tirmarche, M.; Baysson, H.; Telle-Lamberton, M.

    2004-01-01

    Objective: At the end of 2000, certain diseases including leukemia were reported among soldiers who participated in the Balkan and in the Gulf wars. Depleted uranium used during these conflicts was considered as a possible cause. Its radiotoxicity is close to that of natural uranium. This paper reviews the epidemiological knowledge of uranium, the means of exposure and the associated risk of cancer. Methods: The only available epidemiological data concerns nuclear workers exposed to uranium. A review of the international literature is proposed by distinguishing between uranium miners and other workers of the nuclear industry. French studies are described in details. Results: In ionizing radiation epidemiology, contamination by uranium is often cited as a risk factor, but the dose-effect relationship is rarely studied. Retrospective assessment of individual exposure is generally insufficient. Moreover, it is difficult to distinguish between uranium radiotoxicity, its chemical toxicity and the radiotoxicity of its progeny. A causal relation between lung cancer and radon exposure, a gas derived from the decay of uranium, has been demonstrated in epidemiological studies of miners. Among other nuclear workers exposed to uranium, there is a mortality deficit from all causes (healthy worker effect). No cancer site appears systematically in excess compared to the national population; very few studies describe a dose-response relationship. Conclusion: Only studies with a precise reconstruction of doses and sufficient numbers of workers will allow a better assessment of risks associated with uranium exposure at levels encountered in industry or during conflicts using depleted uranium weapons. (author)

  8. CEDR: Comprehensive Epidemiologic Data Resource

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Department of Energy (DOE) and its predecessor agencies have a long history of epidemiologic research programs. The main focus of these programs has been the Health and Mortality Study of the DOE work force. This epidemiologic study began in 1964 with a feasibility study of workers at the Hanford facility. Studies of other populations exposed to radiation have also been supported, including the classic epidemiologic study of radium dial painters and studies of atomic bomb survivors. From a scientific perspective, these epidemiologic research program have been productive, highly credible, and formed the bases for many radiological protection standards. Recently, there has been concern that, although research results were available, the data on which these results were based were not easily obtained by interested investigators outside DOE. Therefore, as part of an effort to integrate and broaden access to its epidemiologic information, the DOE has developed the Comprehensive Epidemiologic Data Resource (CEDR) Program. Included in this effort is the development of a computer information system for accessing the collection of CEDR data and its related descriptive information. The epidemiologic data currently available through the CEDAR Program consist of analytic data sets, working data sets, and their associated documentation files. In general, data sets are the result of epidemiologic studies that have been conducted on various groups of workers at different DOE facilities during the past 30 years.

  9. Epidemiological studies on glyphosate - No new findings for the European risk assessment

    OpenAIRE

    German Federal Institute for Risk Assessment

    2016-01-01

    The assessment of epidemiological studies on the health effects of glyphosate is currently being discussed in the media. In this context, BfR evaluated a so-called expert opinion on epidemiological studies prepared by non-government organisations and concludes that no new findings are being reported for the joint European assessment of the active substance glyphosate. The accusations brought forth in the so-called expert opinion of scientific deception by the assessment authorities are c...

  10. Participatory epidemiology: the contribution of participatory research to epidemiology

    Directory of Open Access Journals (Sweden)

    Mario Bach

    2017-02-01

    Full Text Available Abstract Background Epidemiology has contributed in many ways to identifying various risk factors for disease and to promoting population health. However, there is a continuing debate about the ability of epidemiology not only to describe, but also to provide results which can be better translated into public health practice. It has been proposed that participatory research approaches be applied to epidemiology as a way to bridge this gap between description and action. A systematic account of what constitutes participatory epidemiology practice has, however, been lacking. Methods A scoping review was carried out focused on the question of what constitutes participatory approaches to epidemiology for the purpose of demonstrating their potential for advancing epidemiologic research. Relevant databases were searched, including both the published and non-published (grey literature. The 102 identified sources were analyzed in terms of comparing common epidemiologic approaches to participatory counterparts regarding central aspects of the research process. Exemplary studies applying participatory approaches were examined more closely. Results A highly diverse, interdisciplinary body of literature was synthesized, resulting in a framework comprised of seven aspects of the research process: research goal, research question, population, context, data synthesis, research management, and dissemination of findings. The framework specifies how participatory approaches not only differ from, but also how they can enhance common approaches in epidemiology. Finally, recommendations for the further development of participatory approaches are given. These include: enhancing data collection, data analysis, and data validation; advancing capacity building for research at the local level; and developing data synthesis. Conclusion The proposed framework provides a basis for systematically developing the emergent science of participatory epidemiology.

  11. SU-E-J-128: Two-Stage Atlas Selection in Multi-Atlas-Based Image Segmentation

    International Nuclear Information System (INIS)

    Zhao, T; Ruan, D

    2015-01-01

    Purpose: In the new era of big data, multi-atlas-based image segmentation is challenged by heterogeneous atlas quality and high computation burden from extensive atlas collection, demanding efficient identification of the most relevant atlases. This study aims to develop a two-stage atlas selection scheme to achieve computational economy with performance guarantee. Methods: We develop a low-cost fusion set selection scheme by introducing a preliminary selection to trim full atlas collection into an augmented subset, alleviating the need for extensive full-fledged registrations. More specifically, fusion set selection is performed in two successive steps: preliminary selection and refinement. An augmented subset is first roughly selected from the whole atlas collection with a simple registration scheme and the corresponding preliminary relevance metric; the augmented subset is further refined into the desired fusion set size, using full-fledged registration and the associated relevance metric. The main novelty of this work is the introduction of an inference model to relate the preliminary and refined relevance metrics, based on which the augmented subset size is rigorously derived to ensure the desired atlases survive the preliminary selection with high probability. Results: The performance and complexity of the proposed two-stage atlas selection method were assessed using a collection of 30 prostate MR images. It achieved comparable segmentation accuracy as the conventional one-stage method with full-fledged registration, but significantly reduced computation time to 1/3 (from 30.82 to 11.04 min per segmentation). Compared with alternative one-stage cost-saving approach, the proposed scheme yielded superior performance with mean and medium DSC of (0.83, 0.85) compared to (0.74, 0.78). Conclusion: This work has developed a model-guided two-stage atlas selection scheme to achieve significant cost reduction while guaranteeing high segmentation accuracy. The benefit

  12. 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.

  13. Two-Stage Load Shedding for Secondary Control in Hierarchical Operation of Islanded Microgrids

    DEFF Research Database (Denmark)

    Zhou, Quan; Li, Zhiyi; Wu, Qiuwei

    2018-01-01

    A two-stage load shedding scheme is presented to cope with the severe power deficit caused by microgrid islanding. Coordinated with the fast response of inverter-based distributed energy resources (DERs), load shedding at each stage and the resulting power flow redistribution are estimated....... The first stage of load shedding will cease rapid frequency decline in which the measured frequency deviation is employed to guide the load shedding level and process. Once a new steady-state is reached, the second stage is activated, which performs load shedding according to the priorities of loads...

  14. Two-stage gas-phase bioreactor for the combined removal of hydrogen sulphide, methanol and alpha-pinene.

    Science.gov (United States)

    Rene, Eldon R; Jin, Yaomin; Veiga, María C; Kennes, Christian

    2009-11-01

    Biological treatment systems have emerged as cost-effective and eco-friendly techniques for treating waste gases from process industries at moderately high gas flow rates and low pollutant concentrations. In this study, we have assessed the performance of a two-stage bioreactor, namely a biotrickling filter packed with pall rings (BTF, 1st stage) and a perlite + pall ring mixed biofilter (BF, 2nd stage) operated in series, for handling a complex mixture of hydrogen sulphide (H2S), methanol (CH3OH) and alpha-pinene (C10H16). It has been reported that the presence of H2S can reduce the biofiltration efficiency of volatile organic compounds (VOCs) when both are present in the gas mixture. Hydrogen sulphide and methanol were removed in the first stage BTF, previously inoculated with H2S-adapted populations and a culture containing Candida boidinii, an acid-tolerant yeast, whereas, in the second stage, alpha-pinene was removed predominantly by the fungus Ophiostoma stenoceras. Experiments were conducted in five different phases, corresponding to inlet loading rates varying between 2.1 and 93.5 g m(-3) h(-1) for H2S, 55.3 and 1260.2 g m(-3) h(-1) for methanol, and 2.8 and 161.1 g m(-3) h(-1) for alpha-pinene. Empty bed residence times were varied between 83.4 and 10 s in the first stage and 146.4 and 17.6 s in the second stage. The BTF, working at a pH as low as 2.7 as a result of H2S degradation, removed most of the H2S and methanol but only very little alpha-pinene. On the other hand, the BF, at a pH around 6.0, removed the rest of the H2S, the non-degraded methanol and most of the alpha-pinene vapours. Attempts were originally made to remove the three pollutants in a single acidophilic bioreactor, but the Ophiostoma strain was hardly active at pH elimination capacities (ECs) reached by the two-stage bioreactor for individual pollutants were 894.4 g m(-3) h(-1) for methanol, 45.1 g m(-3) h(-1) for H2S and 138.1 g m(-3) h(-1) for alpha-pinene. The results from this

  15. A Concept of Two-Stage-To-Orbit Reusable Launch Vehicle

    Science.gov (United States)

    Yang, Yong; Wang, Xiaojun; Tang, Yihua

    2002-01-01

    Reusable Launch Vehicle (RLV) has a capability of delivering a wide rang of payload to earth orbit with greater reliability, lower cost, more flexibility and operability than any of today's launch vehicles. It is the goal of future space transportation systems. Past experience on single stage to orbit (SSTO) RLVs, such as NASA's NASP project, which aims at developing an rocket-based combined-cycle (RBCC) airplane and X-33, which aims at developing a rocket RLV, indicates that SSTO RLV can not be realized in the next few years based on the state-of-the-art technologies. This paper presents a concept of all rocket two-stage-to-orbit (TSTO) reusable launch vehicle. The TSTO RLV comprises an orbiter and a booster stage. The orbiter is mounted on the top of the booster stage. The TSTO RLV takes off vertically. At the altitude about 50km the booster stage is separated from the orbiter, returns and lands by parachutes and airbags, or lands horizontally by means of its own propulsion system. The orbiter continues its ascent flight and delivers the payload into LEO orbit. After completing orbit mission, the orbiter will reenter into the atmosphere, automatically fly to the ground base and finally horizontally land on the runway. TSTO RLV has less technology difficulties and risk than SSTO, and maybe the practical approach to the RLV in the near future.

  16. Study on the effect of mutated bacillus megaterium in two-stage fermentation of vitamin C

    International Nuclear Information System (INIS)

    Lv Shujuan; Wang Jun; Yao Jianming; Yu Zengliang

    2003-01-01

    Bacillus megaterium as a companion strain in two-stage fermentation of vitamin C could secrete some active substances to spur growth of Gluconobacter oxydans to produce 2-KLG. In the fermenting system where Gluconobacter oxydans was combined with GB82-a mutated strain of B. megaterium by ion implantation, the amount of 2-KLG harvested was larger than that produced by the original B. megaterium BP52 being substituted for GB82. In this paper, authors studied the effect of the active substances secreted by GB82 to enhance the capability of Gluconobacter oxydans to produce 2-KLG. The supernate of GB82 sampled at different cultivation times all had much more activity to spur Gluconobacter oxydans to yield 2-KLG than that of the original B. megaterium, which might be due to the genetic changes in the active components caused by ion implantation. Furthermore, the active substances of GB82's supernate would lose a part of its activity in extreme environments, which is typical of some proteins

  17. Epidemiology of MRSA: the North/South study of MRSA in Ireland 1999.

    LENUS (Irish Health Repository)

    McDonald, P

    2003-06-01

    The North\\/South Study of methicillin-resistant Staphylococcus aureus (MRSA) in Ireland, 1999, includes a joint review of the epidemiology of MRSA across both jurisdictions on the island of Ireland. Data were gathered on all MRSA cases identified in laboratories in Northern Ireland (the North) and in the Republic of Ireland (the South) over a two-week period. The prevalence rate per 100000 population was 11.4 in the North and 14.0 in the South, with a marked variation across geographical regions. MRSA cases were located throughout hospitals and the community, were slightly more common in males than females, and occurred in all age groups, especially in the elderly. The majority of cases were inpatients in acute hospitals and were distributed across all types of wards. Most cases were colonized with MRSA but 5% of cases in the North and 10% in the South had invasive infection. Invasive infection was associated with intravascular lines and invasive procedures\\/surgery. Continuous surveillance is recommended to monitor the epidemiology of MRSA and the effectiveness of control measures.

  18. Theoretical and experimental investigations on the cooling capacity distributions at the stages in the thermally-coupled two-stage Stirling-type pulse tube cryocooler without external precooling

    Science.gov (United States)

    Tan, Jun; Dang, Haizheng

    2017-03-01

    The two-stage Stirling-type pulse tube cryocooler (SPTC) has advantages in simultaneously providing the cooling powers at two different temperatures, and the capacity in distributing these cooling capacities between the stages is significant to its practical applications. In this paper, a theoretical model of the thermally-coupled two-stage SPTC without external precooling is established based on the electric circuit analogy with considering real gas effects, and the simulations of both the cooling performances and PV power distribution between stages are conducted. The results indicate that the PV power is inversely proportional to the acoustic impedance of each stage, and the cooling capacity distribution is determined by the cold finger cooling efficiency and the PV power into each stage together. The design methods of the cold fingers to achieve both the desired PV power and the cooling capacity distribution between the stages are summarized. The two-stage SPTC is developed and tested based on the above theoretical investigations, and the experimental results show that it can simultaneously achieve 0.69 W at 30 K and 3.1 W at 85 K with an electric input power of 330 W and a reject temperature of 300 K. The consistency between the simulated and the experimental results is observed and the theoretical investigations are experimentally verified.

  19. The impact of medicinal drugs on traffic safety: a systematic review of epidemiological studies.

    Science.gov (United States)

    Orriols, Ludivine; Salmi, Louis-Rachid; Philip, Pierre; Moore, Nicholas; Delorme, Bernard; Castot, Anne; Lagarde, Emmanuel

    2009-08-01

    To evaluate the quality of epidemiological research into effects of medicinal drugs on traffic safety and the current knowledge in this area. The bibliographic search was done in Medline electronic database using the keywords: ((accident* or crash*) and traffic and drug*) leading to 1141 references. Additional references were retrieved from the Safetylit website and the reference lists of selected studies. Original articles published in English or French, between 1 April 1979 and 31 July 2008, were considered for inclusion. We excluded descriptive studies, studies limited to alcohol or illicit drug involvement and investigations of injuries other than from traffic crashes. Studies based on laboratory tests, driving simulators or on-the-road driving tests were also excluded. Eligible studies had to evaluate the causal relationship between the use of medicinal drugs and the risk of traffic crashes. Study quality was assessed by two independent experts, according to a grid adapted from the strengthening the reporting of observational studies in epidemiology (STROBE) statement. Twenty two studies of variable methodological quality were included. Definition of drug exposure varied across studies and depended on the data sources. Potential confounding due to the interaction between the effects of the medicinal drug and disease-related symptoms was often not controlled. The risk of motor-vehicle crashes related to benzodiazepines has been amply studied and demonstrated. Results for other medicinal drugs remain controversial. There is a need for large studies, investigating the role of individual substances in the risk of road traffic crashes. Copyright 2009 John Wiley & Sons, Ltd.

  20. Lingual mucosal graft two-stage Bracka technique for redo hypospadias repair

    Directory of Open Access Journals (Sweden)

    Ahmed Sakr

    2017-09-01

    Conclusion: Lingual mucosa is a reliable and versatile graft material in the armamentarium of two-stage Bracka hypospadias repair with the merits of easy harvesting and minor donor-site complications.

  1. Survey Definitions of Gout for Epidemiologic Studies: Comparison With Crystal Identification as the Gold Standard

    NARCIS (Netherlands)

    Dalbeth, N.; Schumacher, H.R.; Fransen, J.; Neogi, T.; Jansen, T.L; Brown, M.; Louthrenoo, W.; Vazquez-Mellado, J.; Eliseev, M.; McCarthy, G.; Stamp, L.K.; Perez-Ruiz, F.; Sivera, F.; Ea, H.K.; Gerritsen, M.; Scire, C.A.; Cavagna, L.; Lin, C.; Chou, Y.Y.; Tausche, A.K.; Rocha Castelar-Pinheiro, G. da; Janssen, M; Chen, J.H.; Cimmino, M.A.; Uhlig, T.; Taylor, W.J.

    2016-01-01

    OBJECTIVE: To identify the best-performing survey definition of gout from items commonly available in epidemiologic studies. METHODS: Survey definitions of gout were identified from 34 epidemiologic studies contributing to the Global Urate Genetics Consortium (GUGC) genome-wide association study.

  2. 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.

  3. Epidemiologic Study of One Million U.S. Radiation Workers and Veterans

    Energy Technology Data Exchange (ETDEWEB)

    Boice, John D. [National Council on Radiation Protection and Measurements, Bethesda, MD (United States)

    2017-12-14

    The single most important question in radiation epidemiology is determining the level of health risks associated with radiation exposures that occur gradually over time. The study of one million early U.S. radiation workers and veterans has been designed to provide information on risk following chronic exposures by focusing on occupational groups with differing radiation exposure patterns, including intakes of radionuclides. The cost-efficient study builds on the investments made and foundations laid by investigators and government agencies over the past 30-40 years, which have established early worker cohorts that can now provide answers to questions on the lifetime human health risks associated with low-level radiation exposures. Within the overall goal of the epidemiologic study of one million U.S. radiation workers and veterans, this project had a total of nine specific aims which included studies of six populations for multiple endpoints including cancer overall mortality, leukemia and non-cancer mortality. The six populations included: Mound, Ohio, workers exposed to polonium, tritium and plutonium; nuclear power plant workers within the Landauer dosimetry and Nuclear Regulatory Commission data files; industrial radiographers; Mallinckrodt uranium workers; uranium workers who linked with the US Renal Data System; and nuclear weapons test participants. Over 400,000 workers and atomic veterans are included in these populations, with vital status being determined and analyses of all causes of death undertaken. A critical, integral component of the studies has been comprehensive evaluations of dosimetry involving, in many cases, complex dose reconstructions, and assessments of uncertainties. The work has also involved development of state-of-the art statistical approaches and modeling. All nine aims were accomplished successfully, resulting in publication of two NCRP documents, 13 literature papers, numerous Boice Reports in Health Physics News and many

  4. The Netherlands Epidemiology of Obesity (NEO) study: study design and data collection

    NARCIS (Netherlands)

    de Mutsert, R.; den Heijer, M.; Rabelink, T.J.; Smit, J.W.A.; Romijn, J.A.; Jukema, J.W.; de Roos, A.; Cobbaert, C.M.; Kloppenburg, M.; Le Cessie, S.; Middeldorp, S.; Rosendaal, F.R.

    2013-01-01

    Obesity is a well-established risk factor for many chronic diseases. Incomplete insight exists in the causal pathways responsible for obesity-related disorders and consequently, in the identification of obese individuals at risk of these disorders. The Netherlands Epidemiology of Obesity (NEO) study

  5. Two-stage heterotrophic and phototrophic culture strategy for algal biomass and lipid production.

    Science.gov (United States)

    Zheng, Yubin; Chi, Zhanyou; Lucker, Ben; Chen, Shulin

    2012-01-01

    A two-stage heterotrophic and phototrophic culture strategy for algal biomass and lipid production was studied, wherein high density heterotrophic cultures of Chlorellasorokiniana serve as seed for subsequent phototrophic growth. The data showed growth rate, cell density and productivity of heterotrophic C.sorokiniana were 3.0, 3.3 and 7.4 times higher than phototrophic counterpart, respectively. Hetero- and phototrophic algal seeds had similar biomass/lipid production and fatty acid profile when inoculated into phototrophic culture system. To expand the application, food waste and wastewater were tested as feedstock for heterotrophic growth, and supported cell growth successfully. These results demonstrated the advantages of using heterotrophic algae cells as seeds for open algae culture system. Additionally, high inoculation rate of heterotrophic algal seed can be utilized as an effective method for contamination control. This two-stage heterotrophic phototrophic process is promising to provide a more efficient way for large scale production of algal biomass and biofuels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Adaptation of Chain Event Graphs for use with Case-Control Studies in Epidemiology.

    Science.gov (United States)

    Keeble, Claire; Thwaites, Peter Adam; Barber, Stuart; Law, Graham Richard; Baxter, Paul David

    2017-09-26

    Case-control studies are used in epidemiology to try to uncover the causes of diseases, but are a retrospective study design known to suffer from non-participation and recall bias, which may explain their decreased popularity in recent years. Traditional analyses report usually only the odds ratio for given exposures and the binary disease status. Chain event graphs are a graphical representation of a statistical model derived from event trees which have been developed in artificial intelligence and statistics, and only recently introduced to the epidemiology literature. They are a modern Bayesian technique which enable prior knowledge to be incorporated into the data analysis using the agglomerative hierarchical clustering algorithm, used to form a suitable chain event graph. Additionally, they can account for missing data and be used to explore missingness mechanisms. Here we adapt the chain event graph framework to suit scenarios often encountered in case-control studies, to strengthen this study design which is time and financially efficient. We demonstrate eight adaptations to the graphs, which consist of two suitable for full case-control study analysis, four which can be used in interim analyses to explore biases, and two which aim to improve the ease and accuracy of analyses. The adaptations are illustrated with complete, reproducible, fully-interpreted examples, including the event tree and chain event graph. Chain event graphs are used here for the first time to summarise non-participation, data collection techniques, data reliability, and disease severity in case-control studies. We demonstrate how these features of a case-control study can be incorporated into the analysis to provide further insight, which can help to identify potential biases and lead to more accurate study results.

  7. Assessing the first wave of epidemiological studies of nanomaterial workers

    Energy Technology Data Exchange (ETDEWEB)

    Liou, Saou-Hsing, E-mail: shliou@nhri.org.tw [National Health Research Institutes, National Institute of Environmental Health Sciences (China); Tsai, Candace S. J. [Colorado State University, Department of Environmental and Radiological Health Science (United States); Pelclova, Daniela [Charles University in Prague, Department of Occupational Medicine, First Faculty of Medicine (Czech Republic); Schubauer-Berigan, Mary K.; Schulte, Paul A. [National Institute for Occupational Safety and Health (United States)

    2015-10-15

    The results of early animal studies of engineered nanomaterials (ENMs) and air pollution epidemiology suggest that it is important to assess the health of ENM workers. Initial epidemiological studies of workers’ exposure to ENMs (<100 nm) are reviewed and characterized for their study designs, findings, and limitations. Of the 15 studies, 11 were cross-sectional, 4 were longitudinal (1 was both cross-sectional and longitudinal in design), and 1 was a descriptive pilot study. Generally, the studies used biologic markers as the dependent variables. All 11 cross-sectional studies showed a positive relationship between various biomarkers and ENM exposures. Three of the four longitudinal studies showed a negative relationship; the fourth showed positive findings after a 1-year follow-up. Each study considered exposure to ENMs as the independent variable. Exposure was assessed by mass concentration in 10 studies and by particle count in six studies. Six of them assessed both mass and particle concentrations. Some of the studies had limited exposure data because of inadequate exposure assessment. Generally, exposure levels were not very high in comparison to those in human inhalation chamber studies, but there were some exceptions. Most studies involved a small sample size, from 2 to 258 exposed workers. These studies represent the first wave of epidemiological studies of ENM workers. They are limited by small numbers of participants, inconsistent (and in some cases inadequate) exposure assessments, generally low exposures, and short intervals between exposure and effect. Still, these studies are a foundation for future work; they provide insight into where ENM workers are experiencing potentially adverse effects that might be related to ENM exposures.

  8. Assessing the first wave of epidemiological studies of nanomaterial workers

    International Nuclear Information System (INIS)

    Liou, Saou-Hsing; Tsai, Candace S. J.; Pelclova, Daniela; Schubauer-Berigan, Mary K.; Schulte, Paul A.

    2015-01-01

    The results of early animal studies of engineered nanomaterials (ENMs) and air pollution epidemiology suggest that it is important to assess the health of ENM workers. Initial epidemiological studies of workers’ exposure to ENMs (<100 nm) are reviewed and characterized for their study designs, findings, and limitations. Of the 15 studies, 11 were cross-sectional, 4 were longitudinal (1 was both cross-sectional and longitudinal in design), and 1 was a descriptive pilot study. Generally, the studies used biologic markers as the dependent variables. All 11 cross-sectional studies showed a positive relationship between various biomarkers and ENM exposures. Three of the four longitudinal studies showed a negative relationship; the fourth showed positive findings after a 1-year follow-up. Each study considered exposure to ENMs as the independent variable. Exposure was assessed by mass concentration in 10 studies and by particle count in six studies. Six of them assessed both mass and particle concentrations. Some of the studies had limited exposure data because of inadequate exposure assessment. Generally, exposure levels were not very high in comparison to those in human inhalation chamber studies, but there were some exceptions. Most studies involved a small sample size, from 2 to 258 exposed workers. These studies represent the first wave of epidemiological studies of ENM workers. They are limited by small numbers of participants, inconsistent (and in some cases inadequate) exposure assessments, generally low exposures, and short intervals between exposure and effect. Still, these studies are a foundation for future work; they provide insight into where ENM workers are experiencing potentially adverse effects that might be related to ENM exposures

  9. Recommendations for epidemiological studies on COPD

    DEFF Research Database (Denmark)

    Bakke, P S; Rönmark, E; Eagan, T

    2011-01-01

    of the disease and definitions of the risk factors. Few community studies have examined phenotypes of COPD and included other ways of characterising the disease beyond that of spirometry. The objective of the present Task Force report is to present recommendations for the performance of general population...... for planning and performing an epidemiological study on COPD. The main message of the paper is that thorough planning is worth half the study. It is crucial to stick to standardised methods and good quality control during sampling. We recommend collecting biological markers, depending on the specific......The prevalence of chronic obstructive pulmonary disease (COPD) has been extensively studied, especially in Western Europe and North America. Few of these data are directly comparable because of differences between the surveys regarding composition of study populations, diagnostic criteria...

  10. Measuring factor IX activity of nonacog beta pegol with commercially available one-stage clotting and chromogenic assay kits: a two-center study.

    Science.gov (United States)

    Bowyer, A E; Hillarp, A; Ezban, M; Persson, P; Kitchen, S

    2016-07-01

    Essentials Validated assays are required to precisely measure factor IX (FIX) activity in FIX products. N9-GP and two other FIX products were assessed in various coagulation assay systems at two sites. Large variations in FIX activity measurements were observed for N9-GP using some assays. One-stage and chromogenic assays accurately measuring FIX activity for N9-GP were identified. Background Measurement of factor IX activity (FIX:C) with activated partial thromboplastin time-based one-stage clotting assays is associated with a large degree of interlaboratory variation in samples containing glycoPEGylated recombinant FIX (rFIX), i.e. nonacog beta pegol (N9-GP). Validation and qualification of specific assays and conditions are necessary for the accurate assessment of FIX:C in samples containing N9-GP. Objectives To assess the accuracy of various one-stage clotting and chromogenic assays for measuring FIX:C in samples containing N9-GP as compared with samples containing rFIX or plasma-derived FIX (pdFIX) across two laboratory sites. Methods FIX:C, in severe hemophilia B plasma spiked with a range of concentrations (from very low, i.e. 0.03 IU mL(-1) , to high, i.e. 0.90 IU mL(-1) ) of N9-GP, rFIX (BeneFIX), and pdFIX (Mononine), was determined at two laboratory sites with 10 commercially available one-stage clotting assays and two chromogenic FIX:C assays. Assays were performed with a plasma calibrator and different analyzers. Results A high degree of variation in FIX:C measurement was observed for one-stage clotting assays for N9-GP as compared with rFIX or pdFIX. Acceptable N9-GP recovery was observed in the low-concentration to high-concentration samples tested with one-stage clotting assays using SynthAFax or DG Synth, or with chromogenic FIX:C assays. Similar patterns of FIX:C measurement were observed at both laboratory sites, with minor differences probably being attributable to the use of different analyzers. Conclusions These results suggest that, of the

  11. Investigation on a two-stage solar liquid-desiccant (LiBr) dehumidification system assisted by CaCl2 solution

    International Nuclear Information System (INIS)

    Xiong, Z.Q.; Dai, Y.J.; Wang, R.Z.

    2009-01-01

    A two-stage solar powered liquid-desiccant dehumidification system, for which two kinds of desiccant solution (lithium chloride and calcium bromide) are fed to the two dehumidification stages separately, has been studied. In the studied system air moisture (latent) load is separately removed by a pre-dehumidifier using cheap calcium chloride (CaCl 2 ) and a main dehumidifier using stable lithium bromide (LiBr). Side-effect of mixing heat rejected during dehumidification process is considerably alleviated by an indirect evaporative cooling unit added between the two dehumidification stages. The feasibility of high-desiccant concentration difference achieved by reusing desiccant solution to dehumidify air and regenerating desiccant repeatedly is analyzed. By increasing desiccant concentration difference, desiccant storage capacity is effectively explored. It is found that the pre-dehumidification effect of CaCl 2 solution is significant in high ambient humidity condition. Also seen is that the desiccant investment can be decreased by 53%, though the cost of equipments is somewhat increased, and the Tcop and COP of the proposed system can reach 0.97 and 2.13, respectively

  12. The big data potential of epidemiological studies for criminology and forensics.

    Science.gov (United States)

    DeLisi, Matt

    2018-07-01

    Big data, the analysis of original datasets with large samples ranging from ∼30,000 to one million participants to mine unexplored data, has been under-utilized in criminology. However, there have been recent calls for greater synthesis between epidemiology and criminology and a small number of scholars have utilized epidemiological studies that were designed to measure alcohol and substance use to harvest behavioral and psychiatric measures that relate to the study of crime. These studies have been helpful in producing knowledge about the most serious, violent, and chronic offenders, but applications to more pathological forensic populations is lagging. Unfortunately, big data relating to crime and justice are restricted and limited to criminal justice purposes and not easily available to the research community. Thus, the study of criminal and forensic populations is limited in terms of data volume, velocity, and variety. Additional forays into epidemiology, increased use of available online judicial and correctional data, and unknown new frontiers are needed to bring criminology up to speed in the big data arena. Copyright © 2016 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  13. Two-stage solar concentrators based on parabolic troughs: asymmetric versus symmetric designs.

    Science.gov (United States)

    Schmitz, Max; Cooper, Thomas; Ambrosetti, Gianluca; Steinfeld, Aldo

    2015-11-20

    While nonimaging concentrators can approach the thermodynamic limit of concentration, they generally suffer from poor compactness when designed for small acceptance angles, e.g., to capture direct solar irradiation. Symmetric two-stage systems utilizing an image-forming primary parabolic concentrator in tandem with a nonimaging secondary concentrator partially overcome this compactness problem, but their achievable concentration ratio is ultimately limited by the central obstruction caused by the secondary. Significant improvements can be realized by two-stage systems having asymmetric cross-sections, particularly for 2D line-focus trough designs. We therefore present a detailed analysis of two-stage line-focus asymmetric concentrators for flat receiver geometries and compare them to their symmetric counterparts. Exemplary designs are examined in terms of the key optical performance metrics, namely, geometric concentration ratio, acceptance angle, concentration-acceptance product, aspect ratio, active area fraction, and average number of reflections. Notably, we show that asymmetric designs can achieve significantly higher overall concentrations and are always more compact than symmetric systems designed for the same concentration ratio. Using this analysis as a basis, we develop novel asymmetric designs, including two-wing and nested configurations, which surpass the optical performance of two-mirror aplanats and are comparable with the best reported 2D simultaneous multiple surface designs for both hollow and dielectric-filled secondaries.

  14. [Epidemiological transition in Latin America: a comparison of four countries].

    Science.gov (United States)

    Albala, C; Vio, F; Yáñez, M

    1997-06-01

    In the last decade, Latin America has experienced important transformations in its health conditions, due to demographic changes and a rapid urbanization process. To analyze socioeconomic, demographic and epidemiological changes in Chile, Guatemala, Mexico and Uruguay and relate them to the different stages in the demographic and epidemiological transition of these countries. Data was obtained from official information of local and international organizations such as Pan-American Health Organization, United Nations, Latin American Center for Demography (CELADE) and World Bank. Guatemala is in a pre-transition stage with a high proportion of communicable diseases as causes of death (61%) as compared with Mexico (22%), Chile (13%) and Uruguay (7%). Mexico is in a prolonged transition situation and Chile is close to Uruguay in a post-transitional stage. Despite decreasing rates of mortality, the proportion of deaths represented by chronic diseases and injuries has increased to over 30% in all countries, except Uruguay. Adjusted mortality rates for cardiovascular diseases are lower in Latin American countries, as compared to Canada. However, excepting Guatemala, there are differences in the pattern of cardiovascular disease, with a higher mortality due to cerebrovascular and a lower mortality due to coronary artery diseases. An increment in non communicable diseases is expected for the next decades in Latin America. Analysis of demographic and epidemiological transition is crucial to define health policies and to adequate health systems to the new situations.

  15. Eliminating Survivor Bias in Two-stage Instrumental Variable Estimators.

    Science.gov (United States)

    Vansteelandt, Stijn; Walter, Stefan; Tchetgen Tchetgen, Eric

    2018-07-01

    Mendelian randomization studies commonly focus on elderly populations. This makes the instrumental variables analysis of such studies sensitive to survivor bias, a type of selection bias. A particular concern is that the instrumental variable conditions, even when valid for the source population, may be violated for the selective population of individuals who survive the onset of the study. This is potentially very damaging because Mendelian randomization studies are known to be sensitive to bias due to even minor violations of the instrumental variable conditions. Interestingly, the instrumental variable conditions continue to hold within certain risk sets of individuals who are still alive at a given age when the instrument and unmeasured confounders exert additive effects on the exposure, and moreover, the exposure and unmeasured confounders exert additive effects on the hazard of death. In this article, we will exploit this property to derive a two-stage instrumental variable estimator for the effect of exposure on mortality, which is insulated against the above described selection bias under these additivity assumptions.

  16. Improvement of two-stage GM refrigerator performance using a hybrid regenerator

    International Nuclear Information System (INIS)

    Ke, G.; Makuuchi, H.; Hashimoto, T.; Onishi, A.; Li, R.; Satoh, T.; Kanazawa, Y.

    1994-01-01

    To improve the performance of two-stage GM refrigerators, a hybrid regenerator with magnetic materials of Er 3 Ni and ErNi 0.9 Co 0.1 was used in the 2nd stage regenerator because of its large heat exchange capacity. The largest refrigeration capacity achieved with the hybrid regenerator was 0.95W at helium liquefied temperature of 4.2K. This capacity is 15.9% greater than the 0.82W refrigerator with only Er 3 Ni as the 2nd regenerator material. Use of the hybrid regenerator not only increases the refrigeration capacity at 4.2K, but also allows the 4K GM refrigerator to be used with large 1st stage refrigeration capacity, thus making it more practical

  17. NxStage dialysis system-associated thrombocytopenia: a report of two cases.

    Science.gov (United States)

    Sekkarie, Mohamed; Waldron, Michelle; Reynolds, Texas

    2016-01-01

    Thrombocytopenia in hemodialysis patients has recently been reported to be commonly caused by electron-beam sterilization of dialysis filters. We report the occurrence of thrombocytopenia in the first two patients of a newly established home hemodialysis program. The 2 patients switched from conventional hemodialysis using polysulfone electron-beam sterilized dialyzers to a NxStage system, which uses gamma sterilized polyehersulfone dialyzers incorporated into a drop-in cartridge. The thrombocytopenia resolved after return to conventional dialysis in both patients and recurred upon rechallenge in the patient who opted to retry NxStage. This is the first report of thrombocytopenia with the NxStage system according to the authors’ knowledge. Dialysis-associated thrombocytopenia pathophysiology and clinical significance are not well understood and warrant additional investigations.

  18. Application of the CALUX bioassay for epidemiological study. Analyses of Belgian human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wouwe, N. van; Debacker, N.; Sasse, A. [Scientific Institute of Public Health, Brussels (BE)] (and others)

    2004-09-15

    The CALUX bioassay is a promising screening method for the detection of dioxin-like compounds. The observed good sensitivity, low number of false negative results as well as the good correlations with the GC-HRMS TEQ-values in case of feed and food analyses allow this method to climb in the first assessment methods' scale. The low amount of sample needed in addition to those latest advantages suggest that the CALUX bioassay could be a good screening method for epidemiological studies. The Belgian epidemiological study concerning the possible effect of the dioxin incident on the body burden of the Belgian population was an opportunity to test this method in comparison to the gold reference one: the GC-HRMS. The first part of this abstract presents epidemiological parameters (sensibility, specificity,) of the CALUX bioassay using CALUX TEQ-values as estimators of the TEQ-values of the 17 PCDD/Fs. The second part examines epidemiological determinants observed for CALUX and GCHRMS TEQ-values.

  19. Epidemiological study of recent death risk of Nagasaki A-bomb survivors exposed at close range

    International Nuclear Information System (INIS)

    Ishii, Keiichiro; Mine, Mariko; Okumura, Yutaka.

    1992-01-01

    To elucidate the hormetic effect on health of human exposed with very low-dose ionizing radiation, we preliminary investigate the epidemiological study of Nagasaki A-bomb survivors. The major results are as follows; (1) Nagasaki A-bomb survivors exposed with 2-18 cGy are investigated, and the epidemiological data-base of Nagasaki A-bomb survivors are updated by these new data. (2) An applicability of the expanded new data-base to epidemiological analysis is investigated. Based on this investigation, the theme of epidemiological study to elucidate the hormetic effect on human health are discussed. (3) Effects of A-bomb dose on risk of total death cause, cancer death and non-cancer death are analysed by epidemiological method. The relative frequency of non-cancer death cause on male survivors exposed with 50-99 cGy is decreased relative to unexposed controls. (author)

  20. A Two-Stage Fuzzy Logic Control Method of Traffic Signal Based on Traffic Urgency Degree

    OpenAIRE

    Yan Ge

    2014-01-01

    City intersection traffic signal control is an important method to improve the efficiency of road network and alleviate traffic congestion. This paper researches traffic signal fuzzy control method on a single intersection. A two-stage traffic signal control method based on traffic urgency degree is proposed according to two-stage fuzzy inference on single intersection. At the first stage, calculate traffic urgency degree for all red phases using traffic urgency evaluation module and select t...

  1. Possible two-stage 87Sr evolution in the Stockdale Rhyolite

    International Nuclear Information System (INIS)

    Compston, W.; McDougall, I.; Wyborn, D.

    1982-01-01

    The Rb-Sr total-rock data for the Stockdale Rhyolite, of significance for the Palaeozoic time scale, are more scattered about a single-stage isochron than expected from experimental error. Two-stage 87 Sr evolution for several of the samples is explored to explain this, as an alternative to variation in the initial 87 Sr/ 86 Sr which is customarily used in single-stage dating models. The deletion of certain samples having very high Rb/Sr removes most of the excess scatter and leads to an estimate of 430 +- 7 m.y. for the age of extrusion. There is a younger alignment of Rb-Sr data within each sampling site at 412 +- 7 m.y. We suggest that the Stockdale Rhyolite is at least 430 m.y. old, that its original range in Rb/Sr was smaller than now observed, and that it experienced a net loss in Sr during later hydrothermal alteration at ca. 412 m.y. (orig.)

  2. Phase I (or phase II) dose-ranging clinical trials: proposal of a two-stage Bayesian design.

    Science.gov (United States)

    Zohar, Sarah; Chevret, Sylvie

    2003-02-01

    We propose a new design for phase I (or phase II) dose-ranging clinical trials aiming at determining a dose of an experimental treatment to satisfy safety (respectively efficacy) requirements, at treating a sufficiently large number of patients to estimate the toxicity (respectively failure) probability of the dose level with a given reliability, and at stopping the trial early if it is likely that no dose is safe (respectively efficacious). A two-stage design was derived from the Continual Reassessment Method (CRM), with implementation of Bayesian criteria to generate stopping rules. A simulation study was conducted to compare the operating characteristics of the proposed two-stage design to those reached by the traditional CRM. Finally, two applications to real data sets are provided.

  3. Profesi Epidemiologi

    Directory of Open Access Journals (Sweden)

    Buchari Lapau

    2011-01-01

    Full Text Available Makalah ini pertama kali menjelaskan perlu adanya profesi kesehatan masyarakat dalam rangka pembangunan kesehatan. Lalu dijelaskan apa profesi itu dan standar keberadaan profesi, atas dasar mana dapat ditetapkan bahwa pelayanan epidemiologi merupakan salah satu profesi. Dalam rangka pembinaan profesi kesehatan masyarakat, IAKMI dan APTKMI telah membentuk Majelis Kolegium Kesehatan Masyarakat Indonesia (MKKMI yang terdiri atas 8 kolegium antara lain Kolegium Epidemiologi, yang telah menyusun Standar Profesi Epidemiologi yang terdiri atas beberapa standar. Masing-masing standar dijelaskan mulai dari kurikulum, standar pelayanan epidmiologi, profil epidemiolog kesehatan, peran epidemiolog kesehatan, fungsi epidemiolog kesehatan, standar kompetensi epidemiologi, dan standar pendidikan profesi epidemiologi.

  4. The Biomonitoring, Environmental Epidemiology, and Short-Lived Chemicals (BEES-C) Instrument for Assessing Study Quality

    Science.gov (United States)

    Environmental epidemiology studies can be an effective means to assess impacts on human health from exposure to environmental stressors. Exposure scenarios are often extremely complex and proper assessment is critical for interpreting epidemiological study results. Biomarkers are...

  5. Thermodynamics analysis of a modified dual-evaporator CO2 transcritical refrigeration cycle with two-stage ejector

    International Nuclear Information System (INIS)

    Bai, Tao; Yan, Gang; Yu, Jianlin

    2015-01-01

    In this paper, a modified dual-evaporator CO 2 transcritical refrigeration cycle with two-stage ejector (MDRC) is proposed. In MDRC, the two-stage ejector are employed to recover the expansion work from cycle throttling processes and enhance the system performance and obtain dual-temperature refrigeration simultaneously. The effects of some key parameters on the thermodynamic performance of the modified cycle are theoretically investigated based on energetic and exergetic analyses. The simulation results for the modified cycle show that two-stage ejector exhibits more effective system performance improvement than the single ejector in CO 2 dual-temperature refrigeration cycle, and the improvements of the maximum system COP (coefficient of performance) and system exergy efficiency could reach 37.61% and 31.9% over those of the conventional dual-evaporator cycle under the given operating conditions. The exergetic analysis for each component at optimum discharge pressure indicates that the gas cooler, compressor, two-stage ejector and expansion valves contribute main portion to the total system exergy destruction, and the exergy destruction caused by the two-stage ejector could amount to 16.91% of the exergy input. The performance characteristics of the proposed cycle show its promise in dual-evaporator refrigeration system. - Highlights: • Two-stage ejector is used in dual-evaporator CO 2 transcritical refrigeration cycle. • Energetic and exergetic methods are carried out to analyze the system performance. • The modified cycle could obtain dual-temperature refrigeration simultaneously. • Two-stage ejector could effectively improve system COP and exergy efficiency

  6. Significance of epidemiological studies for estimating the genetic radiation hazards of man

    International Nuclear Information System (INIS)

    Stephan, G.

    1982-01-01

    Following a brief presentation of the fundamentals of epidemiological studies, the problems associated with such studies are discussed. Epidemiological investigations on survivors of the atomic bomb explosions in Hiroshima and Nagasaki and also on the population of Kerala, a state in south west India with a high natural radiation load, are then discussed. Consideration was given to the question whether the Down-Syndrom is a valid indicator for proving a causal relationship between radiation dose and genetic effects. (MG) [de

  7. Design and construction of the X-2 two-stage free piston driven expansion tube

    Science.gov (United States)

    Doolan, Con

    1995-01-01

    This report outlines the design and construction of the X-2 two-stage free piston driven expansion tube. The project has completed its construction phase and the facility has been installed in the new impulsive research laboratory where commissioning is about to take place. The X-2 uses a unique, two-stage driver design which allows a more compact and lower overall cost free piston compressor. The new facility has been constructed in order to examine the performance envelope of the two-stage driver and how well it couple to sub-orbital and super-orbital expansion tubes. Data obtained from these experiments will be used for the design of a much larger facility, X-3, utilizing the same free piston driver concept.

  8. Using external and internal locking plates in a two-stage protocol for treatment of segmental tibial fractures.

    Science.gov (United States)

    Ma, Ching-Hou; Tu, Yuan-Kun; Yeh, Jih-Hsi; Yang, Shih-Chieh; Wu, Chin-Hsien

    2011-09-01

    The tibial segmental fractures usually follow high-energy trauma and are often associated with many complications. We designed a two-stage protocol for these complex injuries. The aim of this study was to assess the outcome of tibial segmental fractures treated according to this protocol. A prospective series of 25 consecutive segmental tibial fractures were treated using a two-stage procedure. In the first stage, a low-profile locking plate was applied as an external fixator to temporarily immobilize the fractures after anatomic reduction had been achieved followed by soft-tissue reconstruction. The second stage involved definitive internal fixation with a locking plate using a minimally invasive percutaneous plate osteosynthesis technique. The median follow-up was 32 months (range, 20-44 months). All fractures achieved union. The median time for the proximal fracture union was 23 weeks (range, 12-30 weeks) and that for distal fracture union was 27 weeks (range, 12-46 weeks; p = 0.08). Functional results were excellent in 21 patients and good in 4 patients. There were three cases of delayed union of distal fracture. Valgus malunion >5 degrees occurred in two patients, and length discrepancy >1 cm was observed in two patients. Pin tract infection occurred in three patients. Use of the two-stage procedure for treatment of segmental tibial fractures is recommended. Surgeons can achieve good reduction with stable temporary fixation, soft-tissue reconstruction, ease of subsequent definitive fixation, and high union rates. Our patients obtained excellent knee and ankle joint motion, good functional outcomes, and a comfortable clinical course.

  9. [A sero-epidemiological study of hepatitis E among general population in Shandong Province of China in 2014].

    Science.gov (United States)

    Yan, B Y; Zhang, L; Lyu, J J; Feng, Y; Liu, J Y; Wu, W L; Song, L Z; Xu, A Q

    2017-07-06

    Objective: To analyze the sero-epidemiological characteristics of hepatitis E virus (HEV) in Shandong province, and thereby to provide evidence for the policy-making of hepatitis E prevention and control. Methods: The inhabitants aged between 1-59 years old were randomly selected to participate in the study by two-stage stratified random sampling method from 12 counties in Shandong province in October, 2014. Firstly two townships were selected from each county by probability proportional to size sampling (PPS) method. A total of 5 229 participants aged 1-59 years old were selected by stratified random sampling method. All the participants finished a questionnaire survey and a venous blood sample (3-5 ml) was collected from each to test anti-HEV IgG by enzyme-linked assay (ELISA). The weighted prevalence of anti-HEV IgG with different demographic characteristics was estimated. The variance of the positive rate of anti-HEV IgG was calculated by Taylor series linearization method, as well as its 95 %CI . A statistical test was conducted to compare the rate of its 95 %CI , and the results in the present study were compared with those in sero-survey in 2006. Results: A total of 5 229 subjects entered the final analysis in 2014. The overall weighed prevalence of anti-HEV IgG was 9.19% (95 %CI: 6.18%-12.20%) among natural population in Shandong province, decreased by 19.88% in comparison with that in 2006 sero-survey (11.47%, 95 %CI: 8.92%-14.02%). The prevalence increased with age increasing (χ(2trend)=288.11, Ppopulations (13.76%, 95 %CI: 10.15%-17.38%; 21.11%, 95 %CI: 12.67%-29.55%; 17.81%, 95 %CI: 7.63%-28.00%; 21.08%, 95 %CI: 0.03%-42.12%) in 2006 survey. Conclusion: The prevalence of anti-HEV IgG has decreased in Shandong province in the recent years, but the epidemiological characteristics found no obvious changes. HEV susceptibility in natural population was generally high. Hepatitis E vaccines were recommended to be used in HEV high-risk population in the

  10. Epidemiological studies on the relation between diet and COPD

    NARCIS (Netherlands)

    Tabak, C.

    2000-01-01

    Chronic Obstructive Pulmonary Disease (COPD) is an important cause of morbidity and mortality around the world. In the early 1990's several dietary factors were suggested to protect against COPD, based on proposed biological mechanisms and a small number of epidemiological studies.

  11. A deformation-based morphometry study of patients with early-stage Parkinson's disease

    DEFF Research Database (Denmark)

    Borghammer, P; Østergaard, Karen; Cumming, P

    2010-01-01

    BACKGROUND AND PURPOSE: Previous volumetric magnetic resonance imaging (MRI) studies of Parkinson's disease (PD) utilized primarily voxel-based morphometry (VBM), and investigated mostly patients with moderate- to late-stage disease. We now use deformation-based morphometry (DBM), a method...... purported to be more sensitive than VBM, to test for atrophy in patients with early-stage PD. METHODS: T1-weighted MRI images from 24 early-stage PD patients and 26 age-matched normal control subjects were compared using DBM. Two separate studies were conducted, where two minimally-biased nonlinear...... intensity-average were created; one for all subjects and another for just the PD patients. The DBM technique creates an average population-based MRI-average in an iterative hierarchical fashion. The nonlinear transformations estimated to match each subject to the MRI-average were then analysed. RESULTS...

  12. Exergy analysis of vapor compression refrigeration cycle with two-stage and intercooler

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Bayram [Mehmet Akif Ersoy University, Bucak Emin Guelmez Vocational School, Bucak, Burdur (Turkey)

    2012-07-15

    In this study, exergy analyses of vapor compression refrigeration cycle with two-stage and intercooler using refrigerants R507, R407c, R404a were carried out. The necessary thermodynamic values for analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total irreversibility rate of the system in the different operating conditions for these refrigerants were investigated. The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were compared. (orig.)

  13. Maximally efficient two-stage screening: Determining intellectual disability in Taiwanese military conscripts

    OpenAIRE

    Chien, Chia-Chang; Huang, Shu-Fen; Lung, For-Wey

    2009-01-01

    Chia-Chang Chien1, Shu-Fen Huang1,2,3,4, For-Wey Lung1,2,3,41Department of Psychiatry, Kaohsiung Armed Forces General Hospital, Kaohsiung, Taiwan; 2Graduate Institute of Behavioral Sciences, Kaohsiung Medical University, Kaohsiung, Taiwan; 3Department of Psychiatry, National Defense Medical Center, Taipei, Taiwan; 4Calo Psychiatric Center, Pingtung County, TaiwanObjective: The purpose of this study was to apply a two-stage screening method for the large-scale intelligence screening of militar...

  14. Epidemiologic Studies in Child and Adolescent Psychiatry: A Review of Methodology

    Directory of Open Access Journals (Sweden)

    Onur Burak Dursun

    2010-01-01

    Full Text Available Childhood psychiatric disorders are estimated to influence about 9 to 21% of relevant age group and interest in this disorders are increasing all over the world. The growing need to child and adolescent mental health leads the task of establishing proposals and policies in this field to become a priority for governments. The first step of such proposals should be determination of prevalence of child and adolescent mental disorders in that country. However, several major methodological problems make it hard to provide accurate prevalence estimates from epidemiological studies. Most common problems are within the fields of sampling, case definition, case ascertainment and data analyses. Such issues increases the costs of studies and hinder to reach large sample sizes. To minimize these problems, investigators have to be careful on choosing the appropriate methodology and diagnostic tools in their studies. Although there are many interviews and questionnaires for screening and diagnosing in child and adolescent psychiatry, only a few of them are suitable for epidemiological research. In parallel with the improvement in all fields of child and adolescent mental health in our country, some of the major screening and diagnosing tools used in prevalence studies in literature have already been translated and validated in Turkish. Most important of this tools for screening purposes are Child Behavior Checklist and Strengths and Difficulties Questionnaire and for diagnosing purposes are Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version and Development and Well-Being Assessment. The aims of this article are to review the methodological problems of epidemiologic studies in child and adolescent psychiatry and to briefly discuss suitable diagnostic tools for extended sampled epidemiologic studies in our country.

  15. Two-stage process analysis using the process-based performance measurement framework and business process simulation

    NARCIS (Netherlands)

    Han, K.H.; Kang, J.G.; Song, M.S.

    2009-01-01

    Many enterprises have recently been pursuing process innovation or improvement to attain their performance goals. To align a business process with enterprise performances, this study proposes a two-stage process analysis for process (re)design that combines the process-based performance measurement

  16. A biologic approach to environmental assessment and epidemiology

    National Research Council Canada - National Science Library

    Smith, Thomas J; Kriebel, David

    2010-01-01

    .... The two key fields of study on this issue, environmental epidemiology and exposure assessment, are still given separate names because of their separate historical roots and scientific traditions...

  17. Two stage approach to dynamic soil structure interaction

    International Nuclear Information System (INIS)

    Nelson, I.

    1981-01-01

    A two stage approach is used to reduce the effective size of soil island required to solve dynamic soil structure interaction problems. The ficticious boundaries of the conventional soil island are chosen sufficiently far from the structure so that the presence of the structure causes only a slight perturbation on the soil response near the boundaries. While the resulting finite element model of the soil structure system can be solved, it requires a formidable computational effort. Currently, a two stage approach is used to reduce this effort. The combined soil structure system has many frequencies and wavelengths. For a stiff structure, the lowest frequencies are those associated with the motion of the structure as a rigid body. In the soil, these modes have the longest wavelengths and attenuate most slowly. The higher frequency deformational modes of the structure have shorter wavelengths and their effect attenuates more rapidly with distance from the structure. The difference in soil response between a computation with a refined structural model, and one with a crude model, tends towards zero a very short distance from the structure. In the current work, the 'crude model' is a rigid structure with the same geometry and inertial properties as the refined model. Preliminary calculations indicated that a rigid structure would be a good low frequency approximation to the actual structure, provided the structure was much stiffer than the native soil. (orig./RW)

  18. Effects of earthworm casts and zeolite on the two-stage composting of green waste

    International Nuclear Information System (INIS)

    Zhang, Lu; Sun, Xiangyang

    2015-01-01

    Highlights: • Earthworm casts (EWCs) and clinoptilolite (CL) were used in green waste composting. • Addition of EWCs + CL improved physico-chemical and microbiological properties. • Addition of EWCs + CL extended the duration of thermophilic periods during composting. • Addition of EWCs + CL enhanced humification, cellulose degradation, and nutrients. • Combined addition of 0.30% EWCs + 25% CL reduced composting time to 21 days. - Abstract: Because it helps protect the environment and encourages economic development, composting has become a viable method for organic waste disposal. The objective of this study was to investigate the effects of earthworm casts (EWCs) (at 0.0%, 0.30%, and 0.60%) and zeolite (clinoptilolite, CL) (at 0%, 15%, and 25%) on the two-stage composting of green waste. The combination of EWCs and CL improved the conditions of the composting process and the quality of the compost products in terms of the thermophilic phase, humification, nitrification, microbial numbers and enzyme activities, the degradation of cellulose and hemicellulose, and physico-chemical characteristics and nutrient contents of final composts. The compost matured in only 21 days with the optimized two-stage composting method rather than in the 90–270 days required for traditional composting. The optimal two-stage composting and the best quality compost were obtained with 0.30% EWCs and 25% CL

  19. Effects of earthworm casts and zeolite on the two-stage composting of green waste

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lu, E-mail: zhanglu1211@gmail.com; Sun, Xiangyang, E-mail: xysunbjfu@gmail.com

    2015-05-15

    Highlights: • Earthworm casts (EWCs) and clinoptilolite (CL) were used in green waste composting. • Addition of EWCs + CL improved physico-chemical and microbiological properties. • Addition of EWCs + CL extended the duration of thermophilic periods during composting. • Addition of EWCs + CL enhanced humification, cellulose degradation, and nutrients. • Combined addition of 0.30% EWCs + 25% CL reduced composting time to 21 days. - Abstract: Because it helps protect the environment and encourages economic development, composting has become a viable method for organic waste disposal. The objective of this study was to investigate the effects of earthworm casts (EWCs) (at 0.0%, 0.30%, and 0.60%) and zeolite (clinoptilolite, CL) (at 0%, 15%, and 25%) on the two-stage composting of green waste. The combination of EWCs and CL improved the conditions of the composting process and the quality of the compost products in terms of the thermophilic phase, humification, nitrification, microbial numbers and enzyme activities, the degradation of cellulose and hemicellulose, and physico-chemical characteristics and nutrient contents of final composts. The compost matured in only 21 days with the optimized two-stage composting method rather than in the 90–270 days required for traditional composting. The optimal two-stage composting and the best quality compost were obtained with 0.30% EWCs and 25% CL.

  20. Basic concepts of epidemiology

    International Nuclear Information System (INIS)

    Savitz, D.A.

    1984-01-01

    Epidemiology can be defined simply as the science of the distribution and determinants of disease in human populations. As a descriptive tool, epidemiology can aid health care service providers, for example, in allocation of resources. In its analytic capacity, the epidemiologic approach can help identify determinants of disease through the study of human populations. Epidemiology is primarily an observational rather than experimental methodology, with corresponding strengths and limitations. Relative to other approaches for assessing disease etiology and impacts of potential health hazards, epidemiology has a rather unique role that is complementary to, but independent of, both basic biologic sciences and clinical medicine. Experimental biologic sciences such as toxicology and physiology provide critical information on biologic mechanisms of disease required for causal inference. Clinical medicine often serves as the warning system that provides etiologic clues to be pursued through systematic investigation. The advantage of the epidemiologic approach is its reliance on human field experience, that is, the real world. While laboratory experimentation is uniquely well suited to defining potential hazards, it can neither determine whether human populations have actually been affected nor quantify that effect. Building all the complexities of human behavior and external factors into a laboratory study or mathematical model is impossible. By studying the world as it exists, epidemiology examines the integrated, summarized product of the myriad factors influencing health

  1. Epidemiology of gingivitis in schoolchildren in Bucharest, Romania: a cross-sectional study.

    Science.gov (United States)

    Funieru, C; Klinger, A; Băicuș, C; Funieru, E; Dumitriu, H T; Dumitriu, A

    2017-04-01

    Gingivitis is the most prevalent oral disease in children, being strongly associated to social gradients. Many studies have reported different results concerning the extent and intra-oral distribution of gingivitis in children. The aim of this study was to investigate the epidemiologic parameters and socio-related risk factors of gingivitis in the 10-17-year-old Bucharest schoolchildren population and to analyze its intra-oral distribution. Cross-sectional data were obtained from 1595 schoolchildren, social condition being assigned using a simple questionnaire. Classes of students were used as clusters in a single-stage cluster sampling method. An intra-oral exam was performed for all the children included in this study. Silness and Löe scores, prevalence and the extent of gingivitis were calculated. The gingival scores showed a mild inflammation and the prevalence of gingivitis was 91%. Boys had a higher gingival (0.19 vs. 0.18; p gingival conditions (p Gingivitis was more severe on the upper teeth, with the maximum score being reached at the right upper lateral incisor (0.63 on distal surface). Gingival condition in Bucharest schoolchildren population was associated to social gradients. School dental services are also another factor that seems to be related with gingivitis. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. A two-stage flow-based intrusion detection model for next-generation networks.

    Science.gov (United States)

    Umer, Muhammad Fahad; Sher, Muhammad; Bi, Yaxin

    2018-01-01

    The next-generation network provides state-of-the-art access-independent services over converged mobile and fixed networks. Security in the converged network environment is a major challenge. Traditional packet and protocol-based intrusion detection techniques cannot be used in next-generation networks due to slow throughput, low accuracy and their inability to inspect encrypted payload. An alternative solution for protection of next-generation networks is to use network flow records for detection of malicious activity in the network traffic. The network flow records are independent of access networks and user applications. In this paper, we propose a two-stage flow-based intrusion detection system for next-generation networks. The first stage uses an enhanced unsupervised one-class support vector machine which separates malicious flows from normal network traffic. The second stage uses a self-organizing map which automatically groups malicious flows into different alert clusters. We validated the proposed approach on two flow-based datasets and obtained promising results.

  3. An epidemiological study of physical activity patterns and weight ...

    African Journals Online (AJOL)

    Physical activity during pregnancy has been investigated for its potential benefits which includes weight control. Physical activity patterns of pregnant women in Tshwane, South Africa, were investigated using the EPIC–Norfolk Physical Activity Questionnaire (EPAQ-2) in an epidemiological cross-sectional study. Differences ...

  4. Influence of various chlorine additives on the partitioning of heavy metals during low-temperature two-stage fluidized bed incineration.

    Science.gov (United States)

    Peng, Tzu-Huan; Lin, Chiou-Liang

    2014-12-15

    In this study, a pilot-scale low-temperature two-stage fluidized bed incinerator was evaluated for the control of heavy metal emissions using various chlorine (Cl) additives. Artificial waste containing heavy metals was selected to simulate municipal solid waste (MSW). Operating parameters considered included the first-stage combustion temperature, gas velocity, and different kinds of Cl additives. Results showed that the low-temperature two-stage fluidized bed reactor can be an effective system for the treatment of MSW because of its low NO(x), CO, HCl, and heavy metal emissions. The NO(x) and HCl emissions could be decreased by 42% and 70%, respectively. Further, the results showed that heavy metal emissions were reduced by bed material adsorption and filtration in the second stage. Regarding the Cl addition, although the Cl addition would reduce the metal capture in the first-stage sand bed, but those emitted metals could be effectively captured by the filtration of second stage. No matter choose what kind of additive, metal emissions in the low-temperature two-stage system are still lower than in a traditional high-temperature one-stage system. The results also showed that metal emissions depend not only on the combustion temperature but also on the physicochemical properties of the different metal species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Opposed piston linear compressor driven two-stage Stirling Cryocooler for cooling of IR sensors in space application

    Science.gov (United States)

    Bhojwani, Virendra; Inamdar, Asif; Lele, Mandar; Tendolkar, Mandar; Atrey, Milind; Bapat, Shridhar; Narayankhedkar, Kisan

    2017-04-01

    A two-stage Stirling Cryocooler has been developed and tested for cooling IR sensors in space application. The concept uses an opposed piston linear compressor to drive the two-stage Stirling expander. The configuration used a moving coil linear motor for the compressor as well as for the expander unit. Electrical phase difference of 80 degrees was maintained between the voltage waveforms supplied to the compressor motor and expander motor. The piston and displacer surface were coated with Rulon an anti-friction material to ensure oil less operation of the unit. The present article discusses analysis results, features of the cryocooler and experimental tests conducted on the developed unit. The two-stages of Cryo-cylinder and the expander units were manufactured from a single piece to ensure precise alignment between the two-stages. Flexure bearings were used to suspend the piston and displacer about its mean position. The objective of the work was to develop a two-stage Stirling cryocooler with 2 W at 120 K and 0.5 W at 60 K cooling capacity for the two-stages and input power of less than 120 W. The Cryocooler achieved a minimum temperature of 40.7 K at stage 2.

  6. Epidemiology applied to health physics

    International Nuclear Information System (INIS)

    1983-01-01

    The technical program of the mid-year meeting of the Health Physics Society, entitled Epidemiology Applied to Health physics, was developed to meet three objectives: (1) give health physicists a deeper understanding of the basics of epidemiological methods and their use in developing standards, regulations, and criteria and in risk assessment; (2) present current reports on recently completed or on-going epidemiology studies; and (3) encourage greater interaction between the health physics and epidemiology disciplines. Included are studies relating methods in epidemiology to radiation protection standards, risk assessment from exposure to bone-seekers, from occupational exposures in mines, mills and nuclear facilities, and from radioactivity in building materials

  7. Two Stage Fuzzy Methodology to Evaluate the Credit Risks of Investment Projects

    OpenAIRE

    O. Badagadze; G. Sirbiladze; I. Khutsishvili

    2014-01-01

    The work proposes a decision support methodology for the credit risk minimization in selection of investment projects. The methodology provides two stages of projects’ evaluation. Preliminary selection of projects with minor credit risks is made using the Expertons Method. The second stage makes ranking of chosen projects using the Possibilistic Discrimination Analysis Method. The latter is a new modification of a well-known Method of Fuzzy Discrimination Analysis.

  8. Long-term particulate matter exposure and mortality: a review of European epidemiological studies

    Directory of Open Access Journals (Sweden)

    Boffetta Paolo

    2009-12-01

    Full Text Available Abstract Background Several studies considered the relation between long-term exposure to particulate matter (PM and total mortality, as well as mortality from cardiovascular and respiratory diseases. Our aim was to provide a comprehensive review of European epidemiological studies on the issue. Methods We searched the Medline database for epidemiological studies on air pollution and health outcomes published between January 2002 and December 2007. We also examined the reference lists of individual papers and reviews. Two independent reviewers classified the studies according to type of air pollutant, duration of exposure and health outcome considered. Among European investigations that examined long-term PM exposure we found 4 cohort studies (considering total and cardiopulmonary mortality, 1 case-control study (considering mortality from myocardial infarction, and 4 ecologic studies (2 studies considering total and cardiopulmonary mortality and 2 studies focused on cardiovascular mortality. Results Measurement indicators of PM exposure used in European studies, including PM10, PM2.5, total suspended particulate and black smoke, were heterogeneous. This notwithstanding, in all analytic studies total mortality was directly associated with long-term exposure to PM. The excesses in mortality were mainly due to cardiovascular and respiratory causes. Three out of 4 ecologic studies found significant direct associations between PM indexes and mortality. Conclusion European studies on long-term exposure to PM indicate a direct association with mortality, particularly from cardiovascular and respiratory diseases.

  9. Two stage heterotrophy/photoinduction culture of Scenedesmus incrassatulus: potential for lutein production.

    Science.gov (United States)

    Flórez-Miranda, Liliana; Cañizares-Villanueva, Rosa Olivia; Melchy-Antonio, Orlando; Martínez-Jerónimo, Fernando; Flores-Ortíz, Cesar Mateo

    2017-11-20

    A biomass production process including two stages, heterotrophy/photoinduction (TSHP), was developed to improve biomass and lutein production by the green microalgae Scenedesmus incrassatulus. To determine the effects of different nitrogen sources (yeast extract and urea) and temperature in the heterotrophic stage, experiments using shake flask cultures with glucose as the carbon source were carried out. The highest biomass productivity and specific pigment concentrations were reached using urea+vitamins (U+V) at 30°C. The first stage of the TSHP process was done in a 6L bioreactor, and the inductions in a 3L airlift photobioreactor. At the end of the heterotrophic stage, S. incrassatulus achieved the maximal biomass concentration, increasing from 7.22gL -1 to 17.98gL -1 with an increase in initial glucose concentration from 10.6gL -1 to 30.3gL -1 . However, the higher initial glucose concentration resulted in a lower specific growth rate (μ) and lower cell yield (Y x/s ), possibly due to substrate inhibition. After 24h of photoinduction, lutein content in S. incrassatulus biomass was 7 times higher than that obtained at the end of heterotrophic cultivation, and the lutein productivity was 1.6 times higher compared with autotrophic culture of this microalga. Hence, the two-stage heterotrophy/photoinduction culture is an effective strategy for high cell density and lutein production in S. incrassatulus. Copyright © 2017. Published by Elsevier B.V.

  10. Epidemiologic studies of underground miners: New information from an old source

    International Nuclear Information System (INIS)

    Samet, J.

    1997-01-01

    Over 100 years have passed since Harting and Hesse first described an unusual pattern of thoracic malignancy in the underground metal miners of Schneeberg. It is now known that these miners had primary cancer of the lung, caused by exposure to radon progeny released into the air of the mines from the ore. The early case series of Harting and Hesse, based on the Schneeberg miners, and of Pirchan and Sikl, based on the Joachamisthal mines, have been followed by epidemiologic studies of more formal design of uranium and other underground miners exposed to radon throughout the world. These studies have confirmed the causal association of radon and its progeny with lung cancer and provided quantification of the risk of lung cancer in relation to exposure to radon progeny. These studies have also provided insights concerning the effect of radon progeny on smokers and on nonsmokers. The findings of the epidemiologic studies have provided a clear imperative for reducing exposures of miners to radon progeny. Consequently, exposures of underground uranium miners to radon progeny have been lowered substantially over the last 50 years in countries reporting exposures of underground miners. The epidemiologic studies have also documented the substantial burden of radon-caused lung cancers among miners of uranium and other ores. While the causal link of radon with lung cancer in underground miners is now established and unquestioned, the risk of radon in indoor air remains a highly controversial issue. During the last few decades, there has been increasing recognition that radon is ubiquitous in indoor environments, in some instances at concentrations as high as measured in underground mines. As a foundation for risk management, the epidemiologic evidence from underground miners has been the primary basis for estimating the risk of indoor radon

  11. A two-stage method for inverse medium scattering

    KAUST Repository

    Ito, Kazufumi

    2013-03-01

    We present a novel numerical method to the time-harmonic inverse medium scattering problem of recovering the refractive index from noisy near-field scattered data. The approach consists of two stages, one pruning step of detecting the scatterer support, and one resolution enhancing step with nonsmooth mixed regularization. The first step is strictly direct and of sampling type, and it faithfully detects the scatterer support. The second step is an innovative application of nonsmooth mixed regularization, and it accurately resolves the scatterer size as well as intensities. The nonsmooth model can be efficiently solved by a semi-smooth Newton-type method. Numerical results for two- and three-dimensional examples indicate that the new approach is accurate, computationally efficient, and robust with respect to data noise. © 2012 Elsevier Inc.

  12. A two-stage metal valorisation process from electric arc furnace dust (EAFD

    Directory of Open Access Journals (Sweden)

    H. Issa

    2016-04-01

    Full Text Available This paper demonstrates possibility of separate zinc and lead recovery from coal composite pellets, composed of EAFD with other synergetic iron-bearing wastes and by-products (mill scale, pyrite-cinder, magnetite concentrate, through a two-stage process. The results show that in the first, low temp erature stage performed in electro-resistant furnace, removal of lead is enabled due to presence of chlorides in the system. In the second stage, performed at higher temperatures in Direct Current (DC plasma furnace, valorisation of zinc is conducted. Using this process, several final products were obtained, including a higher purity zinc oxide, which, by its properties, corresponds washed Waelz oxide.

  13. Indoor radon epidemiological study

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, E; Tomasek, L; Mueller, T [National Radiation Protection Institute, Prague (Czech Republic); Placek, V [Inst. for Expertises and Emergencies, Pribram-Kamenna (Czech Republic); Matzner, J; Heribanova, A [State Office for Nuclear Safety, Prague (Czech Republic)

    1996-12-31

    The study is a long-term prospective cohort study of lung cancer and possibility other causes of death. The study population includes inhabitants of the area, who had resided there for at three years and at least one of these between 1.1.1960 and 21.12.1989. A total of 11865 inhabitants satisfied these criteria. The cumulative exposure of each respondent is being assessed on the basis of measurements in dwellings, time spent there and estimation of previous exposure levels by a model accounting for constructional changes in buildings. One year lasting measurements of radon daughter products by integral dosimeters (Kodak film LR 115) were performed in practically all dwellings of the specified area. Radon measurements in houses in term of equilibrium concentration are compared with the results of a pilot study in Petrovice in 1990-91 which gave the stimulus for the epidemiological study. The distribution of death causes and ratio of observed (O) to expected (E) cases among collected death cases in the cohort, generally, somewhat lower ratios than one reflect the non-industrial character of the region, with the exception of lung cancer in man. The differences in the O/E ratios for lung cancer among the separate communities indicate that even in the situation of generally lower mortality, the dependence of lung cancer mortality on radon.

  14. A Two-stage DC-DC Converter for the Fuel Cell-Supercapacitor Hybrid System

    DEFF Research Database (Denmark)

    Zhang, Zhe; Thomsen, Ole Cornelius; Andersen, Michael A. E.

    2009-01-01

    A wide input range multi-stage converter is proposed with the fuel cells and supercapacitors as a hybrid system. The front-end two-phase boost converter is used to optimize the output power and to reduce the current ripple of fuel cells. The supercapacitor power module is connected by push...... and designed. A 1kW prototype controlled by TMS320F2808 DSP is built in the lab. Simulation and experimental results confirm the feasibility of the proposed two stage dc-dc converter system.......-pull-forward half bridge (PPFHB) converter with coupled inductors in the second stage to handle the slow transient response of the fuel cells and realize the bidirectional power flow control. Moreover, this cascaded structure simplifies the power management. The control strategy for the whole system is analyzed...

  15. Two colonisation stages generate two different patterns of genetic diversity within native and invasive ranges of Ulex europaeus.

    Science.gov (United States)

    Hornoy, B; Atlan, A; Roussel, V; Buckley, Y M; Tarayre, M

    2013-11-01

    Genetic diversity and the way a species is introduced influence the capacity of populations of invasive species to persist in, and adapt to, their new environment. The diversity of introduced populations affects their evolutionary potential, which is particularly important for species that have invaded a wide range of habitats and climates, such as European gorse, Ulex europaeus. This species originated in the Iberian peninsula and colonised Europe in the Neolithic; over the course of the past two centuries it was introduced to, and has become invasive in, other continents. We characterised neutral genetic diversity and its structure in the native range and in invaded regions. By coupling these results with historical data, we have identified the way in which gorse populations were introduced and the consequences of introduction history on genetic diversity. Our study is based on the genotyping of individuals from 18 populations at six microsatellite loci. As U. europaeus is an allohexaploid species, we used recently developed tools that take into account genotypic ambiguity. Our results show that genetic diversity in gorse is very high and mainly contained within populations. We confirm that colonisation occurred in two stages. During the first stage, gorse spread out naturally from Spain towards northern Europe, losing some genetic diversity. During the second stage, gorse was introduced by humans into different regions of the world, from northern Europe. These introductions resulted in the loss of rare alleles but did not significantly reduce genetic diversity and thus the evolutionary potential of this invasive species.

  16. Comorbidities and the Risk of Late-Stage Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Steven T. Fleming

    2006-01-01

    Full Text Available The degree to which comorbidities affect the diagnosis of prostate cancer is not clear. The purpose of this study was to determine how comorbidities affect the stage at which prostate cancer is diagnosed in elderly white and black men. We obtained data from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute merged with Medicare claims data. For each patient, we estimated associations between stage of disease at diagnosis and each of the 27 comorbidities. The sample included 2,489 black and 2,587 white men with staged prostate cancer. Coronary artery disease, benign hypertension, and dyslipidemia reduced the odds of late-stage prostate cancer. A prior diagnosis of peripheral vascular disease, severe renal disease, or substance abuse increased the odds of being diagnosed with late-stage disease. The study shows some effect modification by race, particularly among white men with substance abuse, cardiac conduction disorders, and other neurologic conditions. The strongest predictors of late-stage prostate cancer diagnosis for both white and black men were age at diagnosis of at least 80 years and lack of PSA screening. Comorbidities do affect stage at diagnosis, although in different ways. Four hypotheses are discussed to explain these findings.

  17. Experimental Study of Thermal Field Evolution in the Short-Impending Stage Before Earthquakes

    Science.gov (United States)

    Ren, Yaqiong; Ma, Jin; Liu, Peixun; Chen, Shunyun

    2017-08-01

    Phenomena at critical points are vital for identifying the short-impending stage prior to earthquakes. The peak stress is a critical point when stress is converted from predominantly accumulation to predominantly release. We call the duration between the peak stress and instability "the meta-instability stage", which refers to the short-impending stage of earthquakes. The meta-instability stage consists of a steady releasing quasi-static stage and an accelerated releasing quasi-dynamic stage. The turning point of the above two stages is the remaining critical point. To identify the two critical points in the field, it is necessary to study the characteristic phenomena of various physical fields in the meta-instability stage in the laboratory, and the strain and displacement variations were studied. Considering that stress and relative displacement can be detected by thermal variations and peculiarities in the full-field observations, we employed a cooled thermal infrared imaging system to record thermal variations in the meta-instability stage of stick slip events generated along a simulated, precut planer strike slip fault in a granodiorite block on a horizontally bilateral servo-controlled press machine. The experimental results demonstrate the following: (1) a large area of decreasing temperatures in wall rocks and increasing temperatures in sporadic sections of the fault indicate entrance into the meta-instability stage. (2) The rapid expansion of regions of increasing temperatures on the fault and the enhancement of temperature increase amplitude correspond to the turning point from the quasi-static stage to the quasi-dynamic stage. Our results reveal thermal indicators for the critical points prior to earthquakes that provide clues for identifying the short-impending stage of earthquakes.

  18. Fate of dissolved organic nitrogen in two stage trickling filter process.

    Science.gov (United States)

    Simsek, Halis; Kasi, Murthy; Wadhawan, Tanush; Bye, Christopher; Blonigen, Mark; Khan, Eakalak

    2012-10-15

    Dissolved organic nitrogen (DON) represents a significant portion of nitrogen in the final effluent of wastewater treatment plants (WWTPs). Biodegradable portion of DON (BDON) can support algal growth and/or consume dissolved oxygen in the receiving waters. The fate of DON and BDON has not been studied for trickling filter WWTPs. DON and BDON data were collected along the treatment train of a WWTP with a two-stage trickling filter process. DON concentrations in the influent and effluent were 27% and 14% of total dissolved nitrogen (TDN). The plant removed about 62% and 72% of the influent DON and BDON mainly by the trickling filters. The final effluent BDON values averaged 1.8 mg/L. BDON was found to be between 51% and 69% of the DON in raw wastewater and after various treatment units. The fate of DON and BDON through the two-stage trickling filter treatment plant was modeled. The BioWin v3.1 model was successfully applied to simulate ammonia, nitrite, nitrate, TDN, DON and BDON concentrations along the treatment train. The maximum growth rates for ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria, and AOB half saturation constant influenced ammonia and nitrate output results. Hydrolysis and ammonification rates influenced all of the nitrogen species in the model output, including BDON. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. The NHLBI Retrovirus Epidemiology Donor Studies (REDS and REDS-II): Twenty years of research to advance blood product safety and availability

    Science.gov (United States)

    Kleinman, Steven; King, Melissa R; Busch, Michael P; Murphy, Edward L; Glynn, Simone A.

    2012-01-01

    The Retrovirus Epidemiology Donor Study (REDS), conducted from 1989–2001, and the Retrovirus Epidemiology Donor Study-II (REDS-II), conducted from 2004–2012, were National Heart Lung and Blood Institute (NHLBI) funded multicenter programs focused on improving blood safety and availability in the United States. REDS-II also included international study sites in Brazil and China. The three major research domains of REDS/REDS-II have been infectious disease risk evaluation, blood donation availability, and blood donor characterization. Both programs have made significant contributions to transfusion medicine research methodology by the use of mathematical modeling, large-scale donor surveys, innovative methods of repository sample storage, and establishing an infrastructure that responded to potential emerging blood safety threats such as XMRV. Blood safety studies have included protocols evaluating epidemiologic and/or laboratory aspects of HIV, HTLV I/II, HCV, HBV, WNV, CMV, HHV-8, B19V, malaria, CJD, influenza, and T. cruzi infections. Other analyses have characterized: blood donor demographics, motivations to donate, factors influencing donor return, behavioral risk factors, donors’ perception of the blood donation screening process, and aspects of donor deferral. In REDS-II, two large-scale blood donor protocols examined iron deficiency in donors and the prevalence of leukocyte antibodies. This review describes the major study results from over 150 peer-reviewed articles published by these two REDS programs. In 2011, a new seven year program, the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III), was launched. REDS-III expands beyond donor-based research to include studies of blood transfusion recipients in the hospital setting, and adds a third country, South Africa, to the international program. PMID:22633182

  20. Los Alamos National Laboratory: A guide to records series supporting epidemiologic studies conducted for the Department of Energy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    The purpose of this guide is to describe each series of records that pertains to the epidemiologic studies conducted by the Epidemiology Section of the Occupational Medicine Group (ESH-2) at the Department of Energy`s (DOE) Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico. The records described in this guide relate to occupational studies performed by the Epidemiology Section, including those pertaining to workers at LANL, Mound Plant, Oak Ridge Reservation, Pantex Plant, Rocky Flats Plant, and Savannah River Site. Also included are descriptions of other health-related records generated or collected by the Epidemiology Section and a small set of records collected by the Industrial Hygiene and Safety Group. This guide is not designed to describe the universe of records generated by LANL which may be used for epidemiologic studies of the LANL work force. History Associates Incorporated (HAI) prepared this guide as part of its work as the support services contractor for DOE`s Epidemiologic Records Inventory Project. This introduction briefly describes the Epidemiologic Records Inventory Project, HAI`s role in the project, the history of LANL the history and functions of LANL`s Health Division and Epidemiology Section, and the various epidemiologic studies performed by the Epidemiology Section. It provides information on the methodology that HAI used to inventory and describe records housed in the offices of the LANL Epidemiology Section in Technical Area 59 and at the LANL Records Center. Other topics include the methodology used to produce the guide, the arrangement of the detailed record series descriptions, and information concerning access to records repositories.

  1. Labor Union Effects on Innovation and Commercialization Productivity: An Integrated Propensity Score Matching and Two-Stage Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Dongphil Chun

    2015-04-01

    Full Text Available Research and development (R&D is a critical factor in sustaining a firm’s competitive advantage. Accurate measurement of R&D productivity and investigation of its influencing factors are of value for R&D productivity improvements. This study is divided into two sections. The first section outlines the innovation and commercialization stages of firm-level R&D activities. This section analyzes the productivity of each stage using a propensity score matching (PSM and two-stage data envelopment analysis (DEA integrated model to solve the selection bias problem. Second, this study conducts a comparative analysis among subgroups categorized as labor unionized or non-labor unionized on productivity at each stage. We used Korea Innovation Survey (KIS data for analysis using a sample of 400 Korean manufacturers. The key findings of this study include: (1 firm innovation and commercialization productivity are balanced and show relatively low innovation productivity; and (2 labor unions have a positive effect on commercialization productivity. Moreover, labor unions are an influential factor in determining manufacturing firms’ commercialization productivity.

  2. The second molecular epidemiological study of HIV infection in Mongolia between 2010 and 2016.

    Directory of Open Access Journals (Sweden)

    Davaalkham Jagdagsuren

    Full Text Available Our previous 2005-2009 molecular epidemiological study in Mongolia identified a hot spot of HIV-1 transmission in men who have sex with men (MSM. To control the infection, we collaborated with NGOs to promote safer sex and HIV testing since mid-2010. In this study, we carried out the second molecular epidemiological survey between 2010 and 2016 to determine the status of HIV-1 infection in Mongolia.The study included 143 new cases of HIV-1 infection. Viral RNA was extracted from stocked plasma samples and sequenced for the pol and the env regions using the Sanger method. Near-full length sequencing using MiSeq was performed in 3 patients who were suspected to be infected with recombinant HIV-1. Phylogenetic analysis was performed using the neighbor-joining method and Bayesian Markov chain Monte Carlo method.MSM was the main transmission route in the previous and current studies. However, heterosexual route showed a significant increase in recent years. Phylogenetic analysis documented three taxa; Mongolian B, Korean B, and CRF51_01B, though the former two were also observed in the previous study. CRF51_01B, which originated from Singapore and Malaysia, was confirmed by near-full length sequencing. Although these strains were mainly detected in MSM, they were also found in increasing numbers of heterosexual males and females. Bayesian phylogenetic analysis estimated transmission of CRF51_01B into Mongolia around early 2000s. An extended Bayesian skyline plot showed a rapid increase in the effective population size of Mongolian B cluster around 2004 and that of CRF51_01B cluster around 2011.HIV-1 infection might expand to the general population in Mongolia. Our study documented a new cluster of HIV-1 transmission, enhancing our understanding of the epidemiological status of HIV-1 in Mongolia.

  3. The second molecular epidemiological study of HIV infection in Mongolia between 2010 and 2016.

    Science.gov (United States)

    Jagdagsuren, Davaalkham; Hayashida, Tsunefusa; Takano, Misao; Gombo, Erdenetuya; Zayasaikhan, Setsen; Kanayama, Naomi; Tsuchiya, Kiyoto; Oka, Shinichi

    2017-01-01

    Our previous 2005-2009 molecular epidemiological study in Mongolia identified a hot spot of HIV-1 transmission in men who have sex with men (MSM). To control the infection, we collaborated with NGOs to promote safer sex and HIV testing since mid-2010. In this study, we carried out the second molecular epidemiological survey between 2010 and 2016 to determine the status of HIV-1 infection in Mongolia. The study included 143 new cases of HIV-1 infection. Viral RNA was extracted from stocked plasma samples and sequenced for the pol and the env regions using the Sanger method. Near-full length sequencing using MiSeq was performed in 3 patients who were suspected to be infected with recombinant HIV-1. Phylogenetic analysis was performed using the neighbor-joining method and Bayesian Markov chain Monte Carlo method. MSM was the main transmission route in the previous and current studies. However, heterosexual route showed a significant increase in recent years. Phylogenetic analysis documented three taxa; Mongolian B, Korean B, and CRF51_01B, though the former two were also observed in the previous study. CRF51_01B, which originated from Singapore and Malaysia, was confirmed by near-full length sequencing. Although these strains were mainly detected in MSM, they were also found in increasing numbers of heterosexual males and females. Bayesian phylogenetic analysis estimated transmission of CRF51_01B into Mongolia around early 2000s. An extended Bayesian skyline plot showed a rapid increase in the effective population size of Mongolian B cluster around 2004 and that of CRF51_01B cluster around 2011. HIV-1 infection might expand to the general population in Mongolia. Our study documented a new cluster of HIV-1 transmission, enhancing our understanding of the epidemiological status of HIV-1 in Mongolia.

  4. Advancing early detection of autism spectrum disorder by applying an integrated two-stage screening approach

    NARCIS (Netherlands)

    Oosterling, Iris J.; Wensing, Michel; Swinkels, Sophie H.; van der Gaag, Rutger Jan; Visser, Janne C.; Woudenberg, Tim; Minderaa, Ruud; Steenhuis, Mark-Peter; Buitelaar, Jan K.

    Background: Few field trials exist on the impact of implementing guidelines for the early detection of autism spectrum disorders (ASD). The aims of the present study were to develop and evaluate a clinically relevant integrated early detection programme based on the two-stage screening approach of

  5. Two-Stage Robust Security-Constrained Unit Commitment with Optimizable Interval of Uncertain Wind Power Output

    Directory of Open Access Journals (Sweden)

    Dayan Sun

    2017-01-01

    Full Text Available Because wind power spillage is barely considered, the existing robust unit commitment cannot accurately analyze the impacts of wind power accommodation on on/off schedules and spinning reserve requirements of conventional generators and cannot consider the network security limits. In this regard, a novel double-level robust security-constrained unit commitment formulation with optimizable interval of uncertain wind power output is firstly proposed in this paper to obtain allowable interval solutions for wind power generation and provide the optimal schedules for conventional generators to cope with the uncertainty in wind power generation. The proposed double-level model is difficult to be solved because of the invalid dual transform in solution process caused by the coupling relation between the discrete and continuous variables. Therefore, a two-stage iterative solution method based on Benders Decomposition is also presented. The proposed double-level model is transformed into a single-level and two-stage robust interval unit commitment model by eliminating the coupling relation, and then this two-stage model can be solved by Benders Decomposition iteratively. Simulation studies on a modified IEEE 26-generator reliability test system connected to a wind farm are conducted to verify the effectiveness and advantages of the proposed model and solution method.

  6. The epidemiology of hospitalized influenza in children, a two year population-based study in the People's Republic of China

    Science.gov (United States)

    2010-01-01

    Background The epidemiology and disease burden of annual influenza in children in mainland People's Republic of China have not been reported in detail. To understand the incidence and epidemiology of laboratory-proven influenza hospitalization in children in China, a review of available laboratory and hospital admission data was undertaken. Methods We conducted a retrospective population-based study in Suzhou and the surrounding area of Jiangsu province, China for hospitalized cases of respiratory illness at Suzhou Children's Hospital. Cases of pneumonia or respiratory illness were identified from hospital computer data bases. Routine virological testing by fluorescent monoclonal antibody assay of all hospitalized children identified influenza and other viruses. We calculated incidence rates using census population denominators. Results Of 7,789 specimens obtained during 2007 and 2008, 85 were positive for influenza A and 25 for influenza B. There were 282 specimens with parainfluenza virus and 1392 with RSV. Influenza occurred throughout the year, with peaks in the winter, and in August/September. Overall estimated annual incidence of laboratory-proven influenza hospitalization was 23-27/100,000 children 0-4 years old, and 60/100,000 in infants 0-6 months, with an average hospitalization of 9 days. Conclusions Influenza disease in young children in this part of China is a relatively common cause of hospitalization, and occurs throughout the year. The use of influenza vaccine in Chinese children has the potential to reduce the effect of influenza in the children, as well as in their communities. Studies are needed to further assess the burden of influenza, and to develop and refine effective strategies of immunization of young children in China. PMID:20353557

  7. [The Madrid autonomous community epidemiological bulletin. A survey on its dissemination and opinion thereof on among primary care physicians for the year 2000].

    Science.gov (United States)

    Fernández Rodríguez, Silvia; Zorrilla Torras, Belén; Ramírez Fernández, Rosa; Alvarez Castillo, M Carmen; López-Gay Lucio, Dulce; Ibáñez Martín, Cosuelo; Bueno Vallejos, Rafael

    2002-01-01

    The Autonomous Community of Madrid Epidemiological Bulletin is the main communications link between epidemiological monitoring system and health care professionals. The purpose of this study is that of ascertaining the dissemination and opinion of this Autonomous Community of Madrid Epidemiological Bulletin among primary care physicians for the purpose of adapting this publication to its readers' interests. A telephone survey among primary care physicians in the Autonomous Community of Madrid, asking how often they read the Bulletin, the interest and usefulness of the information included in it. The sample size was estimated at 346 physicians. A two-stage sampling process was carried out-by cluster sampling in the first stage, randomly selecting 125 health care centers and 2.7 physicians per center, 17% being primary care team coordinators. A comparison is made of the results among physicians and coordinators by means of the Chi-square and Fisher's Exact Test method, with Epi-Info v.6. A total of 305 surveys were conducted (245 physicians and 60 coordinators). There was an awareness of the existence of the Autonomous Community of Madrid Epidemiological Bulletin on the part of 91.5% (CI 95%: 88.1-94.8), and 27.2% (CI 95%: 21.9-32.5) were familiar with more than 50% of the last issues published. A total of 92.4% (CI 95%: 89.4-95.8) considered the Bulletin to be interesting or highly interesting, grading its usefulness an average of 3.5 on a maximum scale of 5. Of the permanent sections, the most highly-valued was Epidemic Outbreaks, those reports related to meningococcal infection, tuberculosis and HIV/AIDS being the most highly-valued. The Autonomous Community of Madrid Epidemiological Bulletin is a publication which, although not widely-known by the primary care physicians in the Community, is well-valued when it is read, thus being a useful feedback tool within the Epidemiological Monitoring System.

  8. Smoking, epidemiology and e-cigarettes

    Directory of Open Access Journals (Sweden)

    Raschke RA

    2013-07-01

    Full Text Available No abstract available. Article truncated at 150 words. “The true face of smoking is disease, death and horror - not the glamour and sophistication the pushers in the tobacco industry try to portray.” - David Byrne In our fellows’ conference we recently reviewed the evolution of the science of clinical epidemiology as it relates to the association of smoking and lung cancer and the concurrent history of tobacco marketing in the United States. This story begins in 1950, when Richard Doll and Austin Bradford Hill published their landmark case control study demonstrating the association between smoking and lung cancer (1. This study was performed with methodological standards that have rarely been matched in the 63 years since. Exhaustive analysis of possible confounders, a multi-stage evaluation of study blinding, determination of dose-effect, and the use of multiple analyses to establish consistency are among many examples of superb attention to detail exercised by Doll and Hill in this study. The …

  9. Two-stage anatomical repair of “simple” transposition of great arteries in neonates with extracardiac perinatal complications

    Directory of Open Access Journals (Sweden)

    O. Yu. Kornoukhov

    2017-07-01

    Full Text Available Aim. This study was designed to analyse the results of two-stage arterial switch operation (ASO of “simple” transposition of great arteries in patients with infection, neurological problems or necrotizing enterocolitis, which preclude neonatal surgery. Methods. Transthoracic echocardiography data and outcomes of surgery were investigated in 19 patients (study group; #1 after two-stage ASO and 67 patients (control group; #2 after a single-stage ASO. Age of patients at the first stage was 27 (8–55 days and at the second stage 172 (92–256 days. Patients in group 2 were 7 (2–53 days old. All of them were followed up for 21 (4–49 months (group 1 and 40 (7–79 months (group 2 after arterial switch operation. Results. There was no operative mortality at both stages in group 1. The duration of ventilation, length of intensive care unit and hospital stay after surgery were considerably lower in group 1. Actuarial sur-vival and freedom from reoperation at 4 years in group 1 accounted for 100%, while in the con-trol group those indicators at 6 years ran to 98.5% and 94%, respectively. The only difference detected by echocardiography was the aortic valve hinge points Z-score (3.9±1.44 vs 3.1±1.27; p=0.025 and sinuses of Valsalva (3.8±1.41 vs 2.8±1.19; p=0.03, which were higher in the 1st group. There was no aortic regurgitation >1 grade in both groups. Conclusion. Two-stage repair of “simple” transposition of great arteries, when it’s necessary to delay arterial switch operation on the clinical grounds, can be performed with excellent clinical outcomes. The tendency of group 1 patients to have a larger neo-aortic root does not appear to bear any clinical significance in mid-term follow-up.Received 21 December 2016. Accepted 8 May 2017.Funding: The study had no sponsorship.Conflict of interest: The authors declare no conflict of interest. Author contributions Study concept and design: Kornoukhov O.Yu., Ilyin V.N.Data collection and

  10. 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.

  11. The evaluation of the Center for Epidemiologic Studies Depression (CES-D) scale : Depressed and Positive Affect in cancer patients and healthy reference subjects

    NARCIS (Netherlands)

    Schroevers, MJ; Sanderman, R; van Sonderen, E; Ranchor, AV

    2000-01-01

    This study examined the reliability and validity of a two-factor structure of the Center for Epidemiologic Studies Depression (CES-D) scale. The study was conducted in a large group of cancer patients (n = 475) and a matched reference group (n = 255). Both groups filled in a questionnaire at two

  12. Cancer precursors epidemiology, detection, and prevention

    CERN Document Server

    Rohan, Thomas

    2002-01-01

    Dramatic advances in our understanding of cancer causation have come from epidemiologic and laboratory research, particularly over the past two decades. These developments have included a broadening interest in the critical events that take place during the early stages of the dynamic multistep process leading to - vasive cancer. Increasingly, cancer epidemiologists are pursuing research into the origins and natural history of premalignant lesions, including intermediate or surrogate endpoints, a trend - celerated by the development of molecular technologies that are revolutionizing our understanding of the transformation of normal to malignant cells. There seems little doubt that this emerging knowledge will provide further insights not only into carcinogenic processes, but also into more sensitive methods of early detection and more effective means of prevention. In this book, Drs. Franco and Rohan have succeeded in prep- ing a comprehensive, timely, and critical review of the substantial progress that has ...

  13. Pesticide Exposure and Neurodevelopmental Outcomes: Review of the Epidemiologic and Animal Studies

    Science.gov (United States)

    Burns, Carol J.; McIntosh, Laura J.; Mink, Pamela J.; Jurek, Anne M.; Li, Abby A.

    2013-01-01

    Assessment of whether pesticide exposure is associated with neurodevelopmental outcomes in children can best be addressed with a systematic review of both the human and animal peer-reviewed literature. This review analyzed epidemiologic studies testing the hypothesis that exposure to pesticides during pregnancy and/or early childhood is associated with neurodevelopmental outcomes in children. Studies that directly queried pesticide exposure (e.g., via questionnaire or interview) or measured pesticide or metabolite levels in biological specimens from study participants (e.g., blood, urine, etc.) or their immediate environment (e.g., personal air monitoring, home dust samples, etc.) were eligible for inclusion. Consistency, strength of association, and dose response were key elements of the framework utilized for evaluating epidemiologic studies. As a whole, the epidemiologic studies did not strongly implicate any particular pesticide as being causally related to adverse neurodevelopmental outcomes in infants and children. A few associations were unique for a health outcome and specific pesticide, and alternative hypotheses could not be ruled out. Our survey of the in vivo peer-reviewed published mammalian literature focused on effects of the specific active ingredient of pesticides on functional neurodevelopmental endpoints (i.e., behavior, neuropharmacology and neuropathology). In most cases, effects were noted at dose levels within the same order of magnitude or higher compared to the point of departure used for chronic risk assessments in the United States. Thus, although the published animal studies may have characterized potential neurodevelopmental outcomes using endpoints not required by guideline studies, the effects were generally observed at or above effect levels measured in repeated-dose toxicology studies submitted to the U.S. Environmental Protection Agency (EPA). Suggestions for improved exposure assessment in epidemiology studies and more effective

  14. Epidemiology of small intestinal atresia in Europe: a register-based study.

    LENUS (Irish Health Repository)

    Best, Kate E

    2012-09-01

    The epidemiology of congenital small intestinal atresia (SIA) has not been well studied. This study describes the presence of additional anomalies, pregnancy outcomes, total prevalence and association with maternal age in SIA cases in Europe.

  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. Health state of population in vicinity of the Mochovce nuclear power plant. Epidemiologic study

    International Nuclear Information System (INIS)

    Celko, M.; Durov, M.; Letkovicova, M.; Holy, R.; Sedliak, D.; Zrubec, M.; Kristufek, P.; Machata, M.; Prikazsky, V.; Rehak, R.; Stehlikova, B.; Vladar, M.

    1999-01-01

    Results of epidemiologic study of health state of population in vicinity of the Mochovce nuclear power plant (Slovak Republic) are presented. This report is reported under the headings: (1) Introduction; (2) Basic information about Mochovce NPP; (3) Assessment of population exposition by environmental factors; (4) Basic conceptions and principles of epidemiologic study; (5) Demography and health state of population; (6) Characterisation of databases and data; (7) Description of demographic and health indicators; (8) Calculation of demographic and health indicators in vicinity of the Mochovce NPP and in control areas; (9) Calculated indicators; (10) Statistical methods and evaluation of calculated indicators; (11) Summary and conclusions; (12) References; Appendixes: Literature review of similar epidemiologic studies; Quantities and units in radiation protection; Definitions of indicators calculation - specification of method

  17. The Ages and Stages Questionnaire and Neurodevelopmental Impairment in Two-Year-Old Preterm-Born Children

    NARCIS (Netherlands)

    Kerstjens, Jorien M.; Nijhuis, Ard; Hulzebos, Christian V.; van Imhoff, Deirdre E.; van Wassenaer-Leemhuis, Aleid G.; van Haastert, Ingrid C.; Lopriore, Enrico; Katgert, Titia; Swarte, Renate M.; van Lingen, Richard A.; Mulder, Twan L.; Laarman, Celeste R.; Steiner, Katerina; Dijk, Peter H.

    2015-01-01

    Objective To test the ability of the Ages and Stages Questionnaire, Third Edition (ASQ3) to help identify or exclude neurodevelopmental impairment (NDI) in very preterm-born children at the corrected age of two. Methods We studied the test results of 224 children, born at <32 postmenstrual weeks,

  18. Methodologic frontiers in environmental epidemiology.

    OpenAIRE

    Rothman, K J

    1993-01-01

    Environmental epidemiology comprises the epidemiologic study of those environmental factors that are outside the immediate control of the individual. Exposures of interest to environmental epidemiologists include air pollution, water pollution, occupational exposure to physical and chemical agents, as well as psychosocial elements of environmental concern. The main methodologic problem in environmental epidemiology is exposure assessment, a problem that extends through all of epidemiologic re...

  19. Two-stage heterotopic urethroplasty with usage of groin flap. Case report

    Directory of Open Access Journals (Sweden)

    R. T. Adamyan

    2014-11-01

    Full Text Available The article is devoted to the issues of struggle with problems of the urogenital region, arising as a consequence iatrogeny, with the help of plastic surgery. The article provides the case report, which deals with a two-step treatment of the patient with complete loss of the part of the urethra and bladder neck due to iatrogeny. The first stage of surgical treatment is the development of the artificial urethra formation by the rotation groin flap with the axis blood supply. The second stage is connection private urethra with artificial, with a heterotopic location of the lower urinary tract.

  20. The influence of marital status on the stage at diagnosis, treatment, and survival of adult patients with gastric cancer: a population-based study

    OpenAIRE

    Zhang, Jieyun; Gan, Lu; Wu, Zhenhua; Yan, Shican; Liu, Xiyu; Guo, Weijian

    2016-01-01

    Background & Aims Marital status was reported as a prognostic factor in many cancers. However, its role in gastric cancer (GC) hasn't been thoroughly explored. In this study, we aimed to investigate the effect of marital status on survival, stage, treatment, and survival in subgroups. Methods We used the Surveillance, Epidemiology and End Results (SEER) database and identified 16910 GC patients. These patients were categorized into married (58.44%) and unmarred (41.56%) groups. Pearson chi-sq...

  1. Two-Stage Fan I: Aerodynamic and Mechanical Design

    Science.gov (United States)

    Messenger, H. E.; Kennedy, E. E.

    1972-01-01

    A two-stage, highly-loaded fan was designed to deliver an overall pressure ratio of 2.8 with an adiabatic efficiency of 83.9 percent. At the first