PMAnalyzer: a new web interface for bacterial growth curve analysis.
Cuevas, Daniel A; Edwards, Robert A
2017-06-15
Bacterial growth curves are essential representations for characterizing bacteria metabolism within a variety of media compositions. Using high-throughput, spectrophotometers capable of processing tens of 96-well plates, quantitative phenotypic information can be easily integrated into the current data structures that describe a bacterial organism. The PMAnalyzer pipeline performs a growth curve analysis to parameterize the unique features occurring within microtiter wells containing specific growth media sources. We have expanded the pipeline capabilities and provide a user-friendly, online implementation of this automated pipeline. PMAnalyzer version 2.0 provides fast automatic growth curve parameter analysis, growth identification and high resolution figures of sample-replicate growth curves and several statistical analyses. PMAnalyzer v2.0 can be found at https://edwards.sdsu.edu/pmanalyzer/ . Source code for the pipeline can be found on GitHub at https://github.com/dacuevas/PMAnalyzer . Source code for the online implementation can be found on GitHub at https://github.com/dacuevas/PMAnalyzerWeb . dcuevas08@gmail.com. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press.
Developmental trajectories of adolescent popularity: a growth curve modelling analysis.
Cillessen, Antonius H N; Borch, Casey
2006-12-01
Growth curve modelling was used to examine developmental trajectories of sociometric and perceived popularity across eight years in adolescence, and the effects of gender, overt aggression, and relational aggression on these trajectories. Participants were 303 initially popular students (167 girls, 136 boys) for whom sociometric data were available in Grades 5-12. The popularity and aggression constructs were stable but non-overlapping developmental dimensions. Growth curve models were run with SAS MIXED in the framework of the multilevel model for change [Singer, J. D., & Willett, J. B. (2003). Applied longitudinal data analysis. Oxford, UK: Oxford University Press]. Sociometric popularity showed a linear change trajectory; perceived popularity showed nonlinear change. Overt aggression predicted low sociometric popularity but an increase in perceived popularity in the second half of the study. Relational aggression predicted a decrease in sociometric popularity, especially for girls, and continued high-perceived popularity for both genders. The effect of relational aggression on perceived popularity was the strongest around the transition from middle to high school. The importance of growth curve models for understanding adolescent social development was discussed, as well as specific issues and challenges of growth curve analyses with sociometric data.
Growth Curve Analysis and Change-Points Detection in Extremes
Meng, Rui
2016-05-15
The thesis consists of two coherent projects. The first project presents the results of evaluating salinity tolerance in barley using growth curve analysis where different growth trajectories are observed within barley families. The study of salinity tolerance in plants is crucial to understanding plant growth and productivity. Because fully-automated smarthouses with conveyor systems allow non-destructive and high-throughput phenotyping of large number of plants, it is now possible to apply advanced statistical tools to analyze daily measurements and to study salinity tolerance. To compare different growth patterns of barley variates, we use functional data analysis techniques to analyze the daily projected shoot areas. In particular, we apply the curve registration method to align all the curves from the same barley family in order to summarize the family-wise features. We also illustrate how to use statistical modeling to account for spatial variation in microclimate in smarthouses and for temporal variation across runs, which is crucial for identifying traits of the barley variates. In our analysis, we show that the concentrations of sodium and potassium in leaves are negatively correlated, and their interactions are associated with the degree of salinity tolerance. The second project studies change-points detection methods in extremes when multiple time series data are available. Motived by the scientific question of whether the chances to experience extreme weather are different in different seasons of a year, we develop a change-points detection model to study changes in extremes or in the tail of a distribution. Most of existing models identify seasons from multiple yearly time series assuming a season or a change-point location remains exactly the same across years. In this work, we propose a random effect model that allows the change-point to vary from year to year, following a given distribution. Both parametric and nonparametric methods are developed
Mediation Analysis in a Latent Growth Curve Modeling Framework
von Soest, Tilmann; Hagtvet, Knut A.
2011-01-01
This article presents several longitudinal mediation models in the framework of latent growth curve modeling and provides a detailed account of how such models can be constructed. Logical and statistical challenges that might arise when such analyses are conducted are also discussed. Specifically, we discuss how the initial status (intercept) and…
Parent involvement and science achievement: A latent growth curve analysis
Johnson, Ursula Yvette
This study examined science achievement growth across elementary and middle school and parent school involvement using the Early Childhood Longitudinal Study - Kindergarten Class of 1998--1999 (ECLS-K). The ECLS-K is a nationally representative kindergarten cohort of students from public and private schools who attended full-day or half-day kindergarten class in 1998--1999. The present study's sample (N = 8,070) was based on students that had a sampling weight available from the public-use data file. Students were assessed in science achievement at third, fifth, and eighth grades and parents of the students were surveyed at the same time points. Analyses using latent growth curve modeling with time invariant and varying covariates in an SEM framework revealed a positive relationship between science achievement and parent involvement at eighth grade. Furthermore, there were gender and racial/ethnic differences in parents' school involvement as a predictor of science achievement. Findings indicated that students with lower initial science achievement scores had a faster rate of growth across time. The achievement gap between low and high achievers in earth, space and life sciences lessened from elementary to middle school. Parents' involvement with school usually tapers off after elementary school, but due to parent school involvement being a significant predictor of eighth grade science achievement, later school involvement may need to be supported and better implemented in secondary schooling.
Curve-of-growth analysis of M-type giants. beta. and. beta. Peg
Energy Technology Data Exchange (ETDEWEB)
Hanni, L.; Kipper, M.
1975-01-01
The curve-of-growth analysis is carried out with high-dispersion spectrograms of the region lambda lambda 5050--6150 for two M-type stars ..beta.. And (MOIII) and ..beta.. Peg (M2II-III) by using the newest oscillator strengths available. It has been found that the form of our empirical curve of growth is consistent with that of the theoretical curve by Wrubel. By making use of the data derived from the curve-of-growth analyses, atmospheric parameters such as THETA/sub ex/, rho/sub e/, ..nu../sub t/ and the abundances of the elements have been determined.
Growth Curve Analysis and Change-Points Detection in Extremes
Meng, Rui
2016-01-01
of salinity tolerance in plants is crucial to understanding plant growth and productivity. Because fully-automated smarthouses with conveyor systems allow non-destructive and high-throughput phenotyping of large number of plants, it is now possible to apply
International Nuclear Information System (INIS)
Saboori, Behnaz; Sulaiman, Jamalludin; Mohd, Saidatulakmal
2012-01-01
This paper attempts to establish a long-run as well as causal relationship between economic growth and carbon dioxide (CO 2 ) emissions for Malaysia. Using data for the years from 1980 to 2009, the Environmental Kuznets Curve (EKC) hypothesis was tested utilizing the Auto Regressive Distributed Lag (ARDL) methodology. The empirical results suggest the existence of a long-run relationship between per capita CO 2 emissions and real per capita Gross Domestic Product (GDP) when the CO 2 emissions level is the dependent variable. We found an inverted-U shape relationship between CO 2 emissions and GDP in both short and long-run, thus supporting the EKC hypothesis. The Granger Causality test based on the Vector Error Correction Model (VECM) presents an absence of causality between CO 2 emissions and economic growth in the short-run while demonstrating uni-directional causality from economic growth to CO 2 emissions in the long-run. - Highlights: ► We tested the dynamic relationship between economic growth and CO 2 emissions. ► The Environmental Kuznets Curve hypothesis was tested using bounds testing approach. ► The empirical analysis confirms the existence of EKC for Malaysia. ► Causality results in an absence of causality between CO 2 and income in the short-run. ► There is uni-directional causality from income to CO 2 emissions in the long-run.
Johnson, Ursula Y.; Hull, Darrell M.
2014-01-01
The authors examined science achievement growth at Grades 3, 5, and 8 and parent school involvement at the same time points using the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999. Data were analyzed using cross-classified multilevel latent growth curve modeling with time invariant and varying covariates. School-based…
Growth curves for Laron syndrome.
Laron, Z; Lilos, P; Klinger, B
1993-01-01
Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls co...
Energy Technology Data Exchange (ETDEWEB)
Fodha, Mouez [Paris School of Economics and CES, University Paris 1 Pantheon-Sorbonne, Maison des Sciences Economiques, 106-112 Bd de l' Hopital, 75647 Paris (France); Zaghdoud, Oussama [CES, University Paris 1 Pantheon-Sorbonne and Department of Economics, High School of Economic and Commercial Sciences of Tunis, 4 Rue Abou Zakaria El Hafsi, 1089 Montfleury (Tunisia)
2010-02-15
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to 1200 (constant 2000 prices) or to 3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one of unidirectional causality with income causing environmental changes and not vice versa, both in the short-run and long-run. This implies that an emission reduction policies and more investment in pollution abatement expense will not hurt economic growth. It could be a feasible policy tool for Tunisia to achieve its sustainable growth in the long-run. (author)
Energy Technology Data Exchange (ETDEWEB)
Fodha, Mouez, E-mail: fodha@univ-paris1.f [Paris School of Economics and CES, University Paris 1 Pantheon-Sorbonne, Maison des Sciences Economiques, 106-112 Bd de l' Hopital, 75647 Paris (France); Zaghdoud, Oussama [CES, University Paris 1 Pantheon-Sorbonne and Department of Economics, High School of Economic and Commercial Sciences of Tunis, 4 Rue Abou Zakaria El Hafsi, 1089 Montfleury (Tunisia)
2010-02-15
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO{sub 2}) and sulfur dioxide (SO{sub 2}) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO{sub 2} emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO{sub 2} emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one of unidirectional causality with income causing environmental changes and not vice versa, both in the short-run and long-run. This implies that an emission reduction policies and more investment in pollution abatement expense will not hurt economic growth. It could be a feasible policy tool for Tunisia to achieve its sustainable growth in the long-run.
International Nuclear Information System (INIS)
Fodha, Mouez; Zaghdoud, Oussama
2010-01-01
This paper investigates the relationship between economic growth and pollutant emissions for a small and open developing country, Tunisia, during the period 1961-2004. The investigation is made on the basis of the environmental Kuznets curve hypothesis, using time series data and cointegration analysis. Carbon dioxide (CO 2 ) and sulfur dioxide (SO 2 ) are used as the environmental indicators, and GDP as the economic indicator. Our results show that there is a long-run cointegrating relationship between the per capita emissions of two pollutants and the per capita GDP. An inverted U relationship between SO 2 emissions and GDP has been found, with income turning point approximately equals to $1200 (constant 2000 prices) or to $3700 (in PPP, constant 2000 prices). However, a monotonically increasing relationship with GDP is found more appropriate for CO 2 emissions. Furthermore, the causality results show that the relationship between income and pollution in Tunisia is one of unidirectional causality with income causing environmental changes and not vice versa, both in the short-run and long-run. This implies that an emission reduction policies and more investment in pollution abatement expense will not hurt economic growth. It could be a feasible policy tool for Tunisia to achieve its sustainable growth in the long-run.
Curve-of-growth analysis of a red giant in the globular cluster M13
International Nuclear Information System (INIS)
Griffin, R.
1979-01-01
A coude spectrogram of a red giant (L973) in the globular cluster M13 is analysed, with respect to α Boo, by the differential curve-of-growth technique. The overall metal abundance is found to be approximately one-tenth of that of α Boo, or one-fortieth that of the Sun. (author)
On the analysis of Canadian Holstein dairy cow lactation curves using standard growth functions
López, S.; France, J.; Odongo, N.E.; McBride, R.A.; Kebreab, E.; Alzahal, O.; McBride, B.W.; Dijkstra, J.
2015-01-01
Six classical growth functions (monomolecular, Schumacher, Gompertz, logistic, Richards, and Morgan) were fitted to individual and average (by parity) cumulative milk production curves of Canadian Holstein dairy cows. The data analyzed consisted of approximately 91,000 daily milk yield records
On the analysis of Canadian Holstein dairy cow lactation curves using standard growth functions.
López, S; France, J; Odongo, N E; McBride, R A; Kebreab, E; AlZahal, O; McBride, B W; Dijkstra, J
2015-04-01
Six classical growth functions (monomolecular, Schumacher, Gompertz, logistic, Richards, and Morgan) were fitted to individual and average (by parity) cumulative milk production curves of Canadian Holstein dairy cows. The data analyzed consisted of approximately 91,000 daily milk yield records corresponding to 122 first, 99 second, and 92 third parity individual lactation curves. The functions were fitted using nonlinear regression procedures, and their performance was assessed using goodness-of-fit statistics (coefficient of determination, residual mean squares, Akaike information criterion, and the correlation and concordance coefficients between observed and adjusted milk yields at several days in milk). Overall, all the growth functions evaluated showed an acceptable fit to the cumulative milk production curves, with the Richards equation ranking first (smallest Akaike information criterion) followed by the Morgan equation. Differences among the functions in their goodness-of-fit were enlarged when fitted to average curves by parity, where the sigmoidal functions with a variable point of inflection (Richards and Morgan) outperformed the other 4 equations. All the functions provided satisfactory predictions of milk yield (calculated from the first derivative of the functions) at different lactation stages, from early to late lactation. The Richards and Morgan equations provided the most accurate estimates of peak yield and total milk production per 305-d lactation, whereas the least accurate estimates were obtained with the logistic equation. In conclusion, classical growth functions (especially sigmoidal functions with a variable point of inflection) proved to be feasible alternatives to fit cumulative milk production curves of dairy cows, resulting in suitable statistical performance and accurate estimates of lactation traits. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Growth curves for Laron syndrome.
Laron, Z; Lilos, P; Klinger, B
1993-01-01
Growth curves for children with Laron syndrome were constructed on the basis of repeated measurements made throughout infancy, childhood, and puberty in 24 (10 boys, 14 girls) of the 41 patients with this syndrome investigated in our clinic. Growth retardation was already noted at birth, the birth length ranging from 42 to 46 cm in the 12/20 available measurements. The postnatal growth curves deviated sharply from the normal from infancy on. Both sexes showed no clear pubertal spurt. Girls completed their growth between the age of 16-19 years to a final mean (SD) height of 119 (8.5) cm whereas the boys continued growing beyond the age of 20 years, achieving a final height of 124 (8.5) cm. At all ages the upper to lower body segment ratio was more than 2 SD above the normal mean. These growth curves constitute a model not only for primary, hereditary insulin-like growth factor-I (IGF-I) deficiency (Laron syndrome) but also for untreated secondary IGF-I deficiencies such as growth hormone gene deletion and idiopathic congenital isolated growth hormone deficiency. They should also be useful in the follow up of children with Laron syndrome treated with biosynthetic recombinant IGF-I. PMID:8333769
Quantitative analysis by laser-induced breakdown spectroscopy based on generalized curves of growth
Energy Technology Data Exchange (ETDEWEB)
Aragón, C., E-mail: carlos.aragon@unavarra.es; Aguilera, J.A.
2015-08-01
A method for quantitative elemental analysis by laser-induced breakdown spectroscopy (LIBS) is proposed. The method (Cσ-LIBS) is based on Cσ graphs, generalized curves of growth which allow including several lines of various elements at different concentrations. A so-called homogeneous double (HD) model of the laser-induced plasma is used, defined by an integration over a single-region of the radiative transfer equation, combined with a separated treatment for neutral atoms (z = 0) and singly-charged ions (z = 1) in Cσ graphs and characteristic parameters. The procedure includes a criterion, based on a model limit, for eliminating data which, due to a high line intensity or concentration, are not well described by the HD model. An initial procedure provides a set of parameters (βA){sup z}, (ηNl){sup z}, T{sup z} and N{sub e}{sup z} (z = 0, 1) which characterize the plasma and the LIBS system. After characterization, two different analytical procedures, resulting in relative and absolute concentrations, may be applied. To test the method, fused glass samples prepared from certified slags and pure compounds are analyzed. We determine concentrations of Ca, Mn, Mg, V, Ti, Si and Al relative to Fe in three samples prepared from slags, and absolute concentrations of Fe, Ca and Mn in three samples prepared from Fe{sub 2}O{sub 3}, CaCO{sub 3} and Mn{sub 2}O{sub 3}. The accuracy obtained is 3.2% on the average for relative concentrations and 9.2% for absolute concentrations. - Highlights: • Method for quantitative analysis by LIBS, based on Csigma graphs • Conventional calibration is replaced with characterization of the LIBS system. • All elements are determined from measurement of one or two Csigma graphs. • The method is tested with fused glass disks prepared from slags and pure compounds. • Accurate results for relative (3.2%) and absolute concentrations (9.2%)
Choi, Hye Jeong; Miller-Day, Michelle; Shin, YoungJu; Hecht, Michael L.; Pettigrew, Jonathan; Krieger, Janice L.; Lee, JeongKyu; Graham, John W.
2017-01-01
This current study identifies distinct parent prevention communication profiles and examines whether youth with different parental communication profiles have varying substance use trajectories over time. Eleven schools in two rural school districts in the Midwestern United States were selected, and 784 students were surveyed at three time points from the beginning of 7th grade to the end of 8th grade. A series of latent profile analyses were performed to identify discrete profiles/subgroups of substance-specific prevention communication (SSPC). The results revealed a 4-profile model of SSPC: Active-Open, Passive-Open, Active-Silent, and Passive-Silent. A growth curve model revealed different rates of lifetime substance use depending on the youth’s SSPC profile. These findings have implications for parenting interventions and tailoring messages for parents to fit specific SSPC profiles. PMID:29056872
Economic growth and environmental pollution in Myanmar: an analysis of environmental Kuznets curve.
Aung, Thiri Shwesin; Saboori, Behnaz; Rasoulinezhad, Ehsan
2017-09-01
This empirical study examines the short- and long-run relationship between GDP as an economic growth indicator and CO 2 emissions as an environmental pollution indicator in Myanmar by using annual time series data over the period of 1970-2014. It also carefully considered other proxies, such as trade openness, financial openness and urbanization, and structural breaks in the country. The fundamental objective of this study is to test the validity of environmental Kuznets curve (EKC) in the context of Myanmar. The dynamic estimates of the long- and short-term relationship among greenhouse gases (CO 2 , CH 4 , N 2 O), GDP, trade intensity, financial openness, and urbanization growth are built through an autoregressive distributed lag (ARDL) model. The empirical findings indicate that there is positive short- and long-run relationship between CO 2 and GDP and thus, no evidence of EKC hypothesis is found for CO 2 in Myanmar. Nevertheless, the existence of the EKC is observed for CH 4 and N 2 O. On the other hand, trade and financial openness have inverse relationship with CO 2 emissions. These results demonstrate that trade liberalization and financial openness will improve the environment quality in Myanmar in the long run.
Incorporating Measurement Non-Equivalence in a Cross-Study Latent Growth Curve Analysis.
Flora, David B; Curran, Patrick J; Hussong, Andrea M; Edwards, Michael C
2008-10-01
A large literature emphasizes the importance of testing for measurement equivalence in scales that may be used as observed variables in structural equation modeling applications. When the same construct is measured across more than one developmental period, as in a longitudinal study, it can be especially critical to establish measurement equivalence, or invariance, across the developmental periods. Similarly, when data from more than one study are combined into a single analysis, it is again important to assess measurement equivalence across the data sources. Yet, how to incorporate non-equivalence when it is discovered is not well described for applied researchers. Here, we present an item response theory approach that can be used to create scale scores from measures while explicitly accounting for non-equivalence. We demonstrate these methods in the context of a latent curve analysis in which data from two separate studies are combined to create a single longitudinal model spanning several developmental periods.
Residual Structures in Latent Growth Curve Modeling
Grimm, Kevin J.; Widaman, Keith F.
2010-01-01
Several alternatives are available for specifying the residual structure in latent growth curve modeling. Two specifications involve uncorrelated residuals and represent the most commonly used residual structures. The first, building on repeated measures analysis of variance and common specifications in multilevel models, forces residual variances…
Growth curve models and statistical diagnostics
Pan, Jian-Xin
2002-01-01
Growth-curve models are generalized multivariate analysis-of-variance models. These models are especially useful for investigating growth problems on short times in economics, biology, medical research, and epidemiology. This book systematically introduces the theory of the GCM with particular emphasis on their multivariate statistical diagnostics, which are based mainly on recent developments made by the authors and their collaborators. The authors provide complete proofs of theorems as well as practical data sets and MATLAB code.
Directory of Open Access Journals (Sweden)
Sutawanir Darwis
2012-05-01
Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.
Growth Curves for Girls with Turner Syndrome
Directory of Open Access Journals (Sweden)
Fabio Bertapelli
2014-01-01
Full Text Available The objective of this study was to review the growth curves for Turner syndrome, evaluate the methodological and statistical quality, and suggest potential growth curves for clinical practice guidelines. The search was carried out in the databases Medline and Embase. Of 1006 references identified, 15 were included. Studies constructed curves for weight, height, weight/height, body mass index, head circumference, height velocity, leg length, and sitting height. The sample ranged between 47 and 1,565 (total = 6,273 girls aged 0 to 24 y, born between 1950 and 2006. The number of measures ranged from 580 to 9,011 (total = 28,915. Most studies showed strengths such as sample size, exclusion of the use of growth hormone and androgen, and analysis of confounding variables. However, the growth curves were restricted to height, lack of information about selection bias, limited distributional properties, and smoothing aspects. In conclusion, we observe the need to construct an international growth reference for girls with Turner syndrome, in order to provide support for clinical practice guidelines.
Rayleigh-Taylor instability under curved substrates: An optimal transient growth analysis
Balestra, Gioele; Brun, P.-T.; Gallaire, François
2016-12-01
We investigate the stability of thin viscous films coated on the inside of a horizontal cylindrical substrate. In such a case, gravity acts both as a stabilizing force through the progressive drainage of the film and as a destabilizing force prone to form droplets via the Rayleigh-Taylor instability. The drainage solution, derived from lubrication equations, is found asymptotically stable with respect to infinitesimally small perturbations, although in reality, droplets often form. To resolve this paradox, we perform an optimal transient growth analysis for the first-order perturbations of the liquid's interface, generalizing the results of Trinh et al. [Phys. Fluids 26, 051704 (2014), 10.1063/1.4876476]. We find that the system displays a linear transient growth potential that gives rise to two different scenarios depending on the value of the Bond number (prescribing the relative importance of gravity and surface tension forces). At low Bond numbers, the optimal perturbation of the interface does not generate droplets. In contrast, for higher Bond numbers, perturbations on the upper hemicircle yield gains large enough to potentially form droplets. The gain increases exponentially with the Bond number. In particular, depending on the amplitude of the initial perturbation, we find a critical Bond number above which the short-time linear growth is sufficient to trigger the nonlinear effects required to form dripping droplets. We conclude that the transition to droplets detaching from the substrate is noise and perturbation dependent.
Mandys, Frantisek; Dolan, Conor V.; Molenaar, Peter C. M.
1994-01-01
Studied the conditions under which the quasi-Markov simplex model fits a linear growth curve covariance structure and determined when the model is rejected. Presents a quasi-Markov simplex model with structured means and gives an example. (SLD)
Growth curves for twins in Slovenia.
Bricelj, Katja; Blickstein, Isaac; Bržan-Šimenc, Gabrijela; Janša, Vid; Lučovnik, Miha; Verdenik, Ivan; Trojner-Bregar, Andreja; Tul, Nataša
2017-02-01
Abnormalities of fetal growth are more common in twins. We introduce the growth curves for monitoring fetal growth in twin pregnancies in Slovenia. Slovenian National Perinatal Information System for the period between 2002 and 2010 was used to calculate birth weight percentiles for all live born twins for each week from 22nd to 40th week. The calculated percentiles of birth weight for all live-born twins in Slovenia served as the basis for drawing 'growth' curves. The calculated growth curves for twins will help accurately diagnose small or large twin fetuses for their gestational age in the native central European population.
Nonlinear Growth Curves in Developmental Research
Grimm, Kevin J.; Ram, Nilam; Hamagami, Fumiaki
2011-01-01
Developmentalists are often interested in understanding change processes, and growth models are the most common analytic tool for examining such processes. Nonlinear growth curves are especially valuable to developmentalists because the defining characteristics of the growth process such as initial levels, rates of change during growth spurts, and…
International Nuclear Information System (INIS)
Imre, K.
1995-07-01
In this project, we parameterize the shape and magnitude of the temperature and density profiles on JET and the temperature profiles on TFTR. The key control variables for the profiles were tabulated and the response functions were estimated. A sophisticated statistical analysis code was developed to fit the plasma profiles. Our analysis indicate that the JET density shape depends primarily on bar n/B t for Ohmic heating, bar n for L-mode and I p for H-mode. The temperature profiles for JET are mainly determined by q 95 for the case of Ohmic heating, and by B t and P/bar n for the L-mode. For the H-mode the shape depends on the type of auxiliary heating, Z eff , N bar n, q 95 , and P
Kuppan Gokulan; Katherine Williams; Sangeeta Khare
2017-01-01
Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1) the presence of silver resistance genes in tested bacteria; or 2) lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]). This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysi...
Directory of Open Access Journals (Sweden)
Kuppan Gokulan
2017-04-01
Full Text Available Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1 the presence of silver resistance genes in tested bacteria; or 2 lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]. This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysis and an assessment of the minimum inhibitory concentration of silver ions for Salmonella.
Gokulan, Kuppan; Williams, Katherine; Khare, Sangeeta
2017-04-01
Limited antibacterial activity of silver ions leached from silver-impregnated food contact materials could be due to: 1) the presence of silver resistance genes in tested bacteria ; or 2) lack of susceptibility to silver ion-mediated killing in the bacterial strain (K. Williams, L. Valencia, K. Gokulan, R. Trbojevich, S. Khare, 2016 [1]). This study contains data to address the specificity of silver resistance genes in Salmonella Typhimurium during the real time PCR using melting curve analysis and an assessment of the minimum inhibitory concentration of silver ions for Salmonella .
Surface growth kinematics via local curve evolution
Moulton, Derek E.
2012-11-18
A mathematical framework is developed to model the kinematics of surface growth for objects that can be generated by evolving a curve in space, such as seashells and horns. Growth is dictated by a growth velocity vector field defined at every point on a generating curve. A local orthonormal basis is attached to each point of the generating curve and the velocity field is given in terms of the local coordinate directions, leading to a fully local and elegant mathematical structure. Several examples of increasing complexity are provided, and we demonstrate how biologically relevant structures such as logarithmic shells and horns emerge as analytical solutions of the kinematics equations with a small number of parameters that can be linked to the underlying growth process. Direct access to cell tracks and local orientation enables for connections to be made to the underlying growth process. © 2012 Springer-Verlag Berlin Heidelberg.
On the solar curve of growth of titanium
International Nuclear Information System (INIS)
Foy, R.
1975-01-01
Our purpose in the present work is to investigate whether or not the splitting of the solar curve of growth found in the case of iron applies to other elements. We show that, contrary to the solar curve of growth for iron, that for titanium is not split in its damping part; this result emphasizes that reference curves of growth have to be used very carefully in detailed analysis of stellar atmospheres. We confirm that the microturbulent velocity is very low in the solar photosphere, namely within the limits: 0.5 [de
Nonlinear Growth Curves in Developmental Research
Grimm, Kevin J.; Ram, Nilam; Hamagami, Fumiaki
2011-01-01
Developmentalists are often interested in understanding change processes and growth models are the most common analytic tool for examining such processes. Nonlinear growth curves are especially valuable to developmentalists because the defining characteristics of the growth process such as initial levels, rates of change during growth spurts, and asymptotic levels can be estimated. A variety of growth models are described beginning with the linear growth model and moving to nonlinear models of varying complexity. A detailed discussion of nonlinear models is provided, highlighting the added insights into complex developmental processes associated with their use. A collection of growth models are fit to repeated measures of height from participants of the Berkeley Growth and Guidance Studies from early childhood through adulthood. PMID:21824131
Byrne, Catherine E; Wonderlich, Joseph A; Curby, Timothy; Fischer, Sarah; Lock, James; Le Grange, Daniel
2018-04-25
This study explored the relation between eating-related obsessionality and weight restoration utilizing bivariate latent basis growth curve modelling. Eating-related obsessionality is a moderator of treatment outcome for adolescents with anorexia nervosa (AN). This study examined the degree to which the rate of change in eating-related obsessionality was associated with the rate of change in weight over time in family-based treatment (FBT) and individual therapy for AN. Data were drawn from a 2-site randomized controlled trial that compared FBT and adolescent focused therapy for AN. Bivariate latent basis growth curves were used to examine the differences of the relations between trajectories of body weight and symptoms associated with eating and weight obsessionality. In the FBT group, the slope of eating-related obsessionality scores and the slope of weight were significantly (negatively) correlated. This finding indicates that a decrease in overall eating-relating obsessionality is significantly associated with an increase in weight for individuals who received FBT. However, there was no relation between change in obsessionality scores and change in weight in the adolescent focused therapy group. Results suggest that FBT has a specific impact on both weight gain and obsessive compulsive behaviour that is distinct from individual therapy. Copyright © 2018 John Wiley & Sons, Ltd and Eating Disorders Association.
Extended analysis of cooling curves
International Nuclear Information System (INIS)
Djurdjevic, M.B.; Kierkus, W.T.; Liliac, R.E.; Sokolowski, J.H.
2002-01-01
Thermal Analysis (TA) is the measurement of changes in a physical property of a material that is heated through a phase transformation temperature range. The temperature changes in the material are recorded as a function of the heating or cooling time in such a manner that allows for the detection of phase transformations. In order to increase accuracy, characteristic points on the cooling curve have been identified using the first derivative curve plotted versus time. In this paper, an alternative approach to the analysis of the cooling curve has been proposed. The first derivative curve has been plotted versus temperature and all characteristic points have been identified with the same accuracy achieved using the traditional method. The new cooling curve analysis also enables the Dendrite Coherency Point (DCP) to be detected using only one thermocouple. (author)
Growth in Adolescent Self-Regulation and Impact on Sexual Risk-Taking: A Curve-of-Factors Analysis.
Crandall, AliceAnn; Magnusson, Brianna M; Novilla, M Lelinneth B
2018-04-01
Adolescent self-regulation is increasingly seen as an important predictor of sexual risk-taking behaviors, but little is understood about how changes in self-regulation affect later sexual risk-taking. Family financial stress may affect the development of self-regulation and later engagement in sexual risk-taking. We examined whether family financial stress influences self-regulation in early adolescence (age 13) and growth in self-regulation throughout adolescence (from age 13-17 years). We then assessed the effects of family financial stress, baseline self-regulation, and the development of self-regulation on adolescent sexual risk-taking behaviors at age 18 years. Using a curve-of-factors model, we examined these relationships in a 6-year longitudinal study of 470 adolescents (52% female) and their parents from a large northwestern city in the United States. Results indicated that family financial stress was negatively associated with baseline self-regulation but not with growth in self-regulation throughout adolescence. Both baseline self-regulation and growth in self-regulation were predictive of decreased likelihood of engaging in sexual risk-taking. Family financial stress was not predictive of later sexual risk-taking. Intervening to support the development of self-regulation in adolescence may be especially protective against later sexual risk-taking.
Vergara-Lopez, Chrystal; Chaudoir, Stephenie; Bublitz, Margaret; O'Reilly Treter, Maggie; Stroud, Laura
2016-11-01
We examined the association between two dimensions of maternal parenting style (care and overprotection) and cortisol response to an acute laboratory-induced stressor in healthy youth. Forty-three participants completed the Parental Bonding Instrument and an adapted version of the Trier Social Stress Test-Child (TSST-C). Nine cortisol samples were collected to investigate heterogeneity in different phases of youth's stress response. Multiphase growth-curve modeling was utilized to create latent factors corresponding to individual differences in cortisol during baseline, reactivity, and recovery to the TSST-C. Youth report of maternal overprotection was associated with lower baseline cortisol levels, and a slower cortisol decline during recovery, controlling for maternal care, puberty, and gender. No additive or interactive effects involving maternal care emerged. These findings suggest that maternal overprotection may exert a unique and important influence on youth's stress response.
Frison, Eline; Eggermont, Steven
2016-10-01
Despite increasing evidence that specific types of Facebook use (i.e., active private, active public, and passive Facebook use) are differently related to adolescents' well-being, little is known how these types function over the course of adolescence and whether gender and Facebook motives may predict the initial level and changes in these types over time. To address these gaps, Flemish adolescents (ages 12-19) were questioned at three different time points, with six months in between (NTime1 = 1866). Latent growth curve models revealed that active private Facebook use increased over the course of adolescence, whereas public Facebook use decreased. Passive Facebook use, however, remained stable. In addition, gender and Facebook motives were related to initial levels of specific types of Facebook use, and predictive of dynamic change in specific types of Facebook use over time. The discussion focuses on the understanding and implications of these findings. Copyright © 2016. Published by Elsevier Ltd.
Modeling error distributions of growth curve models through Bayesian methods.
Zhang, Zhiyong
2016-06-01
Growth curve models are widely used in social and behavioral sciences. However, typical growth curve models often assume that the errors are normally distributed although non-normal data may be even more common than normal data. In order to avoid possible statistical inference problems in blindly assuming normality, a general Bayesian framework is proposed to flexibly model normal and non-normal data through the explicit specification of the error distributions. A simulation study shows when the distribution of the error is correctly specified, one can avoid the loss in the efficiency of standard error estimates. A real example on the analysis of mathematical ability growth data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 is used to show the application of the proposed methods. Instructions and code on how to conduct growth curve analysis with both normal and non-normal error distributions using the the MCMC procedure of SAS are provided.
Du, Jingjing; Liu, Chendong; Wu, Xiaoqian; Pu, Qiang; Fu, Yuhua; Tang, Qianzi; Liu, Yuanrui; Li, Qiang; Yang, Runlin; Li, Xuewei; Tang, Guoqing; Jiang, Yanzhi; Li, Mingzhou; Zhang, Shunhua; Zhu, Li
2015-01-01
Animal growth curves can provide essential information for animal breeders to optimize feeding and management strategies. However, the genetic mechanism underlying the phenotypic differentiation between the inflection point and asymptotic stages of the growth curve is not well characterized. Here, we employed Liangshan pigs in stages of growth at the inflection point (under inflection point: UIP) and the two asymptotic stages (before the inflection point: BIP, after the inflection point: AIP) as models to survey global gene expression in the longissimus dorsi muscle using digital gene expression (DGE) tag profiling. We found Liangshan pigs reached maximum growth rate (UIP) at 163.6 days of age and a weight of 134.6 kg. The DGE libraries generated 117 million reads of 5.89 gigabases in length. 21,331, 20,996 and 20,139 expressed transcripts were identified BIP, UIP and AIP, respectively. Among them, we identified 757 differentially expressed genes (DEGs) between BIP and UIP, and 271 DEGs between AIP and UIP. An enrichment analysis of DEGs proved the immune system was strengthened in the AIP stage. Energy metabolism rate, global transcriptional activity and bone development intensity were highest UIP. Meat from Liangshan pigs had the highest intramuscular fat content and most favorable fatty acid composition in the AIP. Three hundred eighty (27.70%) specific expression genes were highly enriched in QTL regions for growth and meat quality traits. This study completed a comprehensive analysis of diverse genetic mechanisms underlying the inflection point and asymptotic stages of growth. Our findings will serve as an important resource in the understanding of animal growth and development in indigenous pig breeds. PMID:26292092
Predicting Change in Postpartum Depression: An Individual Growth Curve Approach.
Buchanan, Trey
Recently, methodologists interested in examining problems associated with measuring change have suggested that developmental researchers should focus upon assessing change at both intra-individual and inter-individual levels. This study used an application of individual growth curve analysis to the problem of maternal postpartum depression.…
Gutiierrez, Gabriel; Vanderwood, Mike L.
2013-01-01
The literacy growth of 260 second-grade English learners (ELs) with varying degrees of English language proficiency (e.g., Beginning, Early Intermediate, Intermediate, Early Advanced and Advanced English language proficiency) was assessed with English literacy skill assessments. Dynamic Indicators of Basic Early Literacy Skills measures were…
Schwarz, L.K.; Runge, M.C.
2009-01-01
Age estimation of individuals is often an integral part of species management research, and a number of ageestimation techniques are commonly employed. Often, the error in these techniques is not quantified or accounted for in other analyses, particularly in growth curve models used to describe physiological responses to environment and human impacts. Also, noninvasive, quick, and inexpensive methods to estimate age are needed. This research aims to provide two Bayesian methods to (i) incorporate age uncertainty into an age-length Schnute growth model and (ii) produce a method from the growth model to estimate age from length. The methods are then employed for Florida manatee (Trichechus manatus) carcasses. After quantifying the uncertainty in the aging technique (counts of ear bone growth layers), we fit age-length data to the Schnute growth model separately by sex and season. Independent prior information about population age structure and the results of the Schnute model are then combined to estimate age from length. Results describing the age-length relationship agree with our understanding of manatee biology. The new methods allow us to estimate age, with quantified uncertainty, for 98% of collected carcasses: 36% from ear bones, 62% from length.
ECONOMIC GROWTH AND AIR POLLUTION IN THECZECHREPUBLIC: DECOUPLING CURVES
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Petr Šauer
2012-07-01
Full Text Available The decoupling curve, together with the Environmental Kuznets Curve, has beenrecognized as one of the important indicators showing relations betweeneconomic growth and environmental degradation/pollution. Many boththeoreticaland empirical studies have been published on it. Our paper brings models whichinvestigate relations between the economic growth per capita and selectedindicators of air pollution in theCzechRepublic. The analysis tried to go beforethe year 1990, despite the difficulties when dealing with different macroeconomicindicators published during the socialist period and those introduced after thetransition to a market economy. The results might be somehow surprising forthose dealing only with data generated after the year 1990: it is possible todiscover the turning points for some of the airborne pollutants already in the1980s.
Senn, Theresa E.; Scott-Sheldon, Lori A. J.; Vanable, Peter A.; Carey, Michael P.
2011-01-01
Background The Information-Motivation-Behavioral Skills (IMB) model often guides sexual risk reduction programs even though no studies have examined covariation in the theory’s constructs in a dynamic fashion with longitudinal data. Purpose Using new developments in latent growth modeling, we explore how changes in information, motivation, and behavioral skills over 9 months relate to changes in condom use among STD clinic patients. Methods Participants (N = 1281, 50% female, 66% African American) completed measures of IMB constructs at three time points. We used parallel process latent growth modeling to examine associations among intercepts and slopes of IMB constructs. Results Initial levels of motivation, behavioral skills, and condom use were all positively associated, with behavioral skills partially mediating associations between motivation and condom use. Changes over time in behavioral skills positively related to changes in condom use. Conclusions Results support the key role of behavioral skills in sexual risk reduction, suggesting these skills should be targeted in HIV prevention interventions. PMID:21638196
Growth curve of buffalo grazing on a grass pasture
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Teresa Cristina Alves
2015-09-01
Full Text Available ABSTRACTThe objective of this study was to evaluate the performance of 17 buffaloes (Mediterranean, from birth to slaughter age (720 days with monthly measures of weight, thoracic perimeter, body length, and height at withers. At the end of experimental period, the animals were separated into two different groups for statistical analysis according to slaughter weight: light body weight (LBW, mean 517 kg and heavy body weight (HBW, mean 568 kg. Buffalo growth occurs in the same way up to weaning age, and after that, two distinct groups grow in different forms in the same conditions of management and feeding. Body weight can be estimated according to age, thoracic perimeter, height, and length, showing high correlations. Buffaloes show growth in a sigmoid-curve model.
Modelling growth curves of Nigerian indigenous normal feather ...
African Journals Online (AJOL)
This study was conducted to predict the growth curve parameters using Bayesian Gompertz and logistic models and also to compare the two growth function in describing the body weight changes across age in Nigerian indigenous normal feather chicken. Each chick was wing-tagged at day old and body weights were ...
Interactions of cosmic rays in the atmosphere: growth curves revisited
Energy Technology Data Exchange (ETDEWEB)
Obermeier, A.; Boyle, P.; Müller, D. [Enrico Fermi Institute, University of Chicago, Chicago, IL 60637 (United States); Hörandel, J., E-mail: a.obermeier@astro.ru.nl [Radboud Universiteit Nijmegen, 6525-HP Nijmegen (Netherlands)
2013-12-01
Measurements of cosmic-ray abundances on balloons are affected by interactions in the residual atmosphere above the balloon. Corrections for such interactions are particularly important for observations of rare secondary particles such as boron, antiprotons, and positrons. These corrections either can be calculated if the relevant cross sections in the atmosphere are known or may be empirically determined by extrapolation of the 'growth curves', i.e., the individual particle intensities as functions of atmospheric depth. The growth-curve technique is particularly attractive for long-duration balloon flights where the periodic daily altitude variations permit rather precise determinations of the corresponding particle intensity variations. We determine growth curves for nuclei from boron (Z = 5) to iron (Z = 26) using data from the 2006 Arctic balloon flight of the TRACER detector for cosmic-ray nuclei, and we compare the growth curves with predictions from published cross section values. In general, good agreement is observed. We then study the boron/carbon abundance ratio and derive a simple and energy-independent correction term for this ratio. We emphasize that the growth-curve technique can be developed further to provide highly accurate tests of published interaction cross section values.
Liu, Xiao-Hui; Wang, Wei-Liang; Lu, Shao-Yong; Wang, Yu-Fan; Ren, Zongming
2016-08-01
In Zaozhuang, economic development affects the discharge amount of industrial wastewater, chemical oxygen demand (COD), and ammonia nitrogen (NH3-N). To reveal the trend of water environmental quality related to the economy in Zaozhuang, this paper simulated the relationships between industrial wastewater discharge, COD, NH3-N load, and gross domestic product (GDP) per capita for Zaozhuang (2002-2012) using environmental Kuznets curve (EKC) models. The results showed that the added value of industrial GDP, the per capita GDP, and wastewater emission had average annual growth rates of 16.62, 16.19, and 17.89 %, respectively, from 2002 to 2012, while COD and NH3-N emission in 2012, compared with 2002, showed average annual decreases of 10.70 and 31.12 %, respectively. The export of EKC models revealed that industrial wastewater discharge had a typical inverted-U-shaped relationship with per capita GDP. However, both COD and NH3-N showed the binding curve of the left side of the "U" curve and left side U-shaped curve. The economy in Zaozhuang had been at the "fast-growing" stage, with low environmental pollution according to the industrial pollution level. In recent years, Zaozhuang has abated these heavy-pollution industries emphatically, so pollutants have been greatly reduced. Thus, Zaozhuang industrial wastewater treatment has been quite effective, with water quality improved significantly. The EKC models provided scientific evidence for estimating industrial wastewater discharge, COD, and NH3-N load as well as their changeable trends for Zaozhuang from an economic perspective.
Growth curve registration for evaluating salinity tolerance in barley
Meng, Rui
2017-03-23
Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.
Growth curve registration for evaluating salinity tolerance in barley
Meng, Rui; Saade, Stephanie; Kurtek, Sebastian; Berger, Bettina; Brien, Chris; Pillen, Klaus; Tester, Mark A.; Sun, Ying
2017-01-01
Background: Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results: We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions: Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.
Growth Curve Models and Applications : Indian Statistical Institute
2017-01-01
Growth curve models in longitudinal studies are widely used to model population size, body height, biomass, fungal growth, and other variables in the biological sciences, but these statistical methods for modeling growth curves and analyzing longitudinal data also extend to general statistics, economics, public health, demographics, epidemiology, SQC, sociology, nano-biotechnology, fluid mechanics, and other applied areas. There is no one-size-fits-all approach to growth measurement. The selected papers in this volume build on presentations from the GCM workshop held at the Indian Statistical Institute, Giridih, on March 28-29, 2016. They represent recent trends in GCM research on different subject areas, both theoretical and applied. This book includes tools and possibilities for further work through new techniques and modification of existing ones. The volume includes original studies, theoretical findings and case studies from a wide range of app lied work, and these contributions have been externally r...
Economic growth and energy regulation in the environmental Kuznets curve.
Lorente, Daniel Balsalobre; Álvarez-Herranz, Agustín
2016-08-01
This study establishes the existence of a pattern of behavior, between economic growth and environmental degradation, consistent with the environmental Kuznets curve (EKC) hypothesis for 17 Organization for Economic Cooperation and Development (OECD) countries between 1990 and 2012. Based on this EKC pattern, it shows that energy regulation measures help reduce per capita greenhouse gas (GHG) emissions. To validate this hypothesis, we also add the explanatory variables: renewable energy promotion, energy innovation processes, and the suppression effect of income level on the contribution of renewable energy sources to total energy consumption. It aims to be a tool for decision-making regarding energy policy. This paper provides a two-stage econometric analysis of instrumental variables with the aim of correcting the existence of endogeneity in the variable GDP per capita, verifying that the instrumental variables used in this research are appropriate for our aim. To this end, it first makes a methodological contribution before incorporating additional variables associated with environmental air pollution into the EKC hypothesis and showing how they positively affect the explanation of the correction in the GHG emission levels. This study concludes that air pollution will not disappear on its own as economic growth increases. Therefore, it is necessary to promote energy regulation measures to reduce environmental pollution.
Genomic growth curves of an outbred pig population
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Fabyano Fonseca e Silva
2013-01-01
Full Text Available In the current post-genomic era, the genetic basis of pig growth can be understood by assessing SNP marker effects and genomic breeding values (GEBV based on estimates of these growth curve parameters as phenotypes. Although various statistical methods, such as random regression (RR-BLUP and Bayesian LASSO (BL, have been applied to genomic selection (GS, none of these has yet been used in a growth curve approach. In this work, we compared the accuracies of RR-BLUP and BL using empirical weight-age data from an outbred F2 (Brazilian Piau X commercial population. The phenotypes were determined by parameter estimates using a nonlinear logistic regression model and the halothane gene was considered as a marker for evaluating the assumptions of the GS methods in relation to the genetic variation explained by each locus. BL yielded more accurate values for all of the phenotypes evaluated and was used to estimate SNP effects and GEBV vectors. The latter allowed the construction of genomic growth curves, which showed substantial genetic discrimination among animals in the final growth phase. The SNP effect estimates allowed identification of the most relevant markers for each phenotype, the positions of which were coincident with reported QTL regions for growth traits.
Estimation of growth curve parameters in Konya Merino sheep ...
African Journals Online (AJOL)
The objective of this study was to determine the fitness of Quadratic, Cubic, Gompertz and Logistic functions to the growth curves of Konya Merino lambs obtained by using monthly records of live weight from birth to 480 days of age. The models were evaluated according to determination coefficient (R2), mean square ...
Sensitivity of Fit Indices to Misspecification in Growth Curve Models
Wu, Wei; West, Stephen G.
2010-01-01
This study investigated the sensitivity of fit indices to model misspecification in within-individual covariance structure, between-individual covariance structure, and marginal mean structure in growth curve models. Five commonly used fit indices were examined, including the likelihood ratio test statistic, root mean square error of…
Short communication Estimation of growth curve parameters in ...
African Journals Online (AJOL)
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The shape of growth curves has been reported to vary according to the species of .... a,b,c The means within columns with different superscripts are significantly .... J. Anim. Sci. 84, 2642-2654. The South African Journal of Animal Science is ...
ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro
2013-01-01
Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods. PMID:24834004
Howarter, Alisha D; Bennett, Kymberley K; Barber, Carolyn E; Gessner, Stacia N; Clark, Jillian M R
2014-01-01
Cardiac rehabilitation is often recommended after experiencing a cardiac event and has been shown to significantly improve health outcomes among patients. Several psychosocial variables have been linked with cardiac rehabilitation program success, including exercise self-efficacy. However, little is known about temporal patterns in patients' exercise self-efficacy after program completion. This study examined changes in exercise self-efficacy among 133 cardiac rehabilitation patients and whether symptoms of depression impacted the rate of change in exercise self-efficacy. Participants completed questionnaires at the beginning and end of cardiac rehabilitation and at 6-month intervals for 2 years. Growth curve analyses showed that exercise self-efficacy levels were highest at the beginning of cardiac rehabilitation, significantly declined 6 months after cardiac rehabilitation, and leveled off over the next 18 months. Results also showed that baseline depressive symptoms interacted with time: Compared with participants with fewer symptoms, participants high in depressive symptoms began cardiac rehabilitation with lower levels of exercise self-efficacy and evidenced significant declines 6 months after cardiac rehabilitation. At no time were they equal to their counterparts in exercise self-efficacy, and their means were lower 2 years after cardiac rehabilitation than before cardiac rehabilitation. Our findings imply that patients show unrealistic optimism surrounding the ease of initiating and maintaining an exercise program and that integrating efficacy-building activities into cardiac rehabilitation, especially for patients who show signs of distress, is advisable.
Environmental Kuznets curve and growth source in Iran
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Asghari Maryam
2012-01-01
Full Text Available Recent empirical research has examined the relationship between certain indicators of environmental degradation and income, concluding that in some cases an inverted U-shaped relationship, which has been called an environmental Kuznets curve (EKC, exists between these variables. The source of growth explanation is important for two reasons. First, it demonstrates how the pollution consequences of growth depend on the source of growth. Therefore, the analogy drawn by some in the environmental community between the damaging effects of economic development and those of liberalized trade is, at best, incomplete. Second, the source of growth explanation demonstrates that a strong policy response to income gains is not necessary for pollution to fall with growth. The aim of this paper investigates the role of differences source of growth in environmental quality of Iran. The results show the two growth resources in Iran cause, in the early stages, CO2 emission decreases until turning point but beyond this level of income per capita, economic growth leads to environmental degradation. I find a U relationship between environmental degradation (CO2 emission and economic growth in Iran.
ECONOMIC GROWTH, TRADE AND ENVIRONMENTAL ISSUES: TESTING ENVIRONMENTAL KUZNETS CURVE
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Dedi Budiman Hakim
2013-04-01
Full Text Available ASEAN experiences a dynamic economic growth due to its liberalised markets. However concerns arise related to environmental issues resulting from the economic activities. It reflects tradeoffs between economic growth driven by trade and foreign direct investment (FDI, and environment. To investigate such a relation the Environmental Kuznets Curve was applied by regressing amount of carbon emission with gross domestic product (GDP, quadratic GDP, trade openness and FDI. The result reveals that amount of carbon emission is linearly and positively correlated with GDP per capita. It is predicted that as ASEAN economies grow, carbon emission increases. Trade openness is also found to contribute to carbon emission. Keywords: Kuznets curve, carbon emission, gross domestic product, trade, foreign direct investment JEL classification number: F15, F18
Incorporating experience curves in appliance standards analysis
International Nuclear Information System (INIS)
Desroches, Louis-Benoit; Garbesi, Karina; Kantner, Colleen; Van Buskirk, Robert; Yang, Hung-Chia
2013-01-01
There exists considerable evidence that manufacturing costs and consumer prices of residential appliances have decreased in real terms over the last several decades. This phenomenon is generally attributable to manufacturing efficiency gained with cumulative experience producing a certain good, and is modeled by an empirical experience curve. The technical analyses conducted in support of U.S. energy conservation standards for residential appliances and commercial equipment have, until recently, assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. This assumption does not reflect real market price dynamics. Using price data from the Bureau of Labor Statistics, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These experience curves were incorporated into recent energy conservation standards analyses for these products. Including experience curves increases the national consumer net present value of potential standard levels. In some cases a potential standard level exhibits a net benefit when considering experience, whereas without experience it exhibits a net cost. These results highlight the importance of modeling more representative market prices. - Highlights: ► Past appliance standards analyses have assumed constant equipment prices. ► There is considerable evidence of consistent real price declines. ► We incorporate experience curves for several large appliances into the analysis. ► The revised analyses demonstrate larger net present values of potential standards. ► The results imply that past standards analyses may have undervalued benefits.
Predicting Madura cattle growth curve using non-linear model
Widyas, N.; Prastowo, S.; Widi, T. S. M.; Baliarti, E.
2018-03-01
Madura cattle is Indonesian native. It is a composite breed that has undergone hundreds of years of selection and domestication to reach nowadays remarkable uniformity. Crossbreeding has reached the isle of Madura and the Madrasin, a cross between Madura cows and Limousine semen emerged. This paper aimed to compare the growth curve between Madrasin and one type of pure Madura cows, the common Madura cattle (Madura) using non-linear models. Madura cattles are kept traditionally thus reliable records are hardly available. Data were collected from small holder farmers in Madura. Cows from different age classes (5years) were observed, and body measurements (chest girth, body length and wither height) were taken. In total 63 Madura and 120 Madrasin records obtained. Linear model was built with cattle sub-populations and age as explanatory variables. Body weights were estimated based on the chest girth. Growth curves were built using logistic regression. Results showed that within the same age, Madrasin has significantly larger body compared to Madura (plogistic models fit better for Madura and Madrasin cattle data; with the estimated MSE for these models were 39.09 and 759.28 with prediction accuracy of 99 and 92% for Madura and Madrasin, respectively. Prediction of growth curve using logistic regression model performed well in both types of Madura cattle. However, attempts to administer accurate data on Madura cattle are necessary to better characterize and study these cattle.
Numerical analysis of thermoluminescence glow curves
International Nuclear Information System (INIS)
Gomez Ros, J. M.; Delgado, A.
1989-01-01
This report presents a method for the numerical analysis of complex thermoluminescence glow curves resolving the individual glow peak components. The method employs first order kinetics analytical expressions and is based In a Marquart-Levenberg minimization procedure. A simplified version of this method for thermoluminescence dosimetry (TLD) is also described and specifically developed to operate whit Lithium Fluoride TLD-100. (Author). 36 refs
Light Curve Analysis of SAO23229
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Ho-Il Kim
1993-06-01
Full Text Available We have made UBV light curves of a newly discovered eclipsing binary, SAO23229 at Sobaeksan Astronomy Observatory. We determined a minimum light time of HJD2448636.1170+/-0.0005 that is 3 minutes later than predicted time, and founda peculiar light variation at phase 0.75 that may not be secondary eclipse. Orbital period of SAO23229 would be 4.2 days rather than 2.1 days. Our analysis of the light curves shows that SAO23229 has a detached configuration consisting of two almost identical F type main sequence stars.
Maulana, Ridwan; Opdenakker, Marie-Christine; Stroet, Kim; Bosker, Roel
2013-09-01
Research consistently shows that the learning environment plays an important role for early adolescents' learning and outcomes and suggests that good teacher-student relationships can serve as a protective factor for maintaining young adolescents' interest and active engagement in learning. However, less is known about the dynamic nature of teacher-student relationships and how they link with academic motivation development. Furthermore, little is known about the nature and the effects of teacher-student relationships in a cross-national context. The present study investigated changes in two components of teacher-student relationships (teachers' involvement vs. rejection) and examined links with students' academic motivation during the first grade of secondary school. Ten Dutch and ten Indonesian teachers (65 % female) from 24 classes were videoed 12 times across the school year, and four videos for each class were selected randomly and coded on teachers' involvement versus rejection. A total of 713 students (52 % girls) completed four-wave measures of their academic motivation after each video observation. Multilevel growth curve modeling revealed that the teacher's involvement changed in a curvilinear way and decreased across the first year of secondary education, while changes in the teacher's rejection did not follow a linear time function. Academic motivation changed in an undesirable way: controlled motivation increased, while autonomous motivation decreased over time. Teachers' involvement had a unique contribution in preventing high levels of controlled motivation in both countries. Findings suggest that teacher-student relationships (teachers' involvement) play an essential role in early adolescents' motivation regardless of the nations and should be a priority for schools.
Distortion-product otoacoustic emission growth curves in neonates
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Tania Alves Barbosa
2014-12-01
Full Text Available Background: The recording of otoacoustic emissions (OAE enabled us to prove that the cochlea is able not only to receive sounds but also to produce acoustic energy. Through the use of distortion-product otoacoustic emission measurements, the growth of the response was seen according to the intensity of the sound stimulus presented (growth curve. Objective: to determine the thresholds for the emergence of distortion-product otoacoustic emissions (DPOAE on frequencies of 2000 and 4000 Hz with a stimulus varying from 20 to 65dB SPL, and to establish the slope values obtained in the growth curves. Methods: 39 neonates aged 5 to 28 days without risk indicators of hearing loss were studied. The DPOAE growth curves were obtained on the frequencies from 2000 Hz and 4000 Hz with a level of intensity ranging from 20 to 65dB SPL divided into two paradigms (20 to 40dB SPL and 40-65dB SPL. Results: there was a statistically significant difference in the thresholds for the emergence of DPOAE depending on the criteria used. The thresholds were on average higher at 4000 Hz than 2000 Hz and the slope was higher on average at 2000 Hz than 4000 Hz, although not statistically significant in either case. Conclusion: the thresholds were on average 30dB SPL at 2000Hz and 35dB SPL at 4000Hz. The slope values varied between 3 and 4 on average, reaching 15 in some cases.
Incorporating Experience Curves in Appliance Standards Analysis
Energy Technology Data Exchange (ETDEWEB)
Garbesi, Karina; Chan, Peter; Greenblatt, Jeffery; Kantner, Colleen; Lekov, Alex; Meyers, Stephen; Rosenquist, Gregory; Buskirk, Robert Van; Yang, Hung-Chia; Desroches, Louis-Benoit
2011-10-31
The technical analyses in support of U.S. energy conservation standards for residential appliances and commercial equipment have typically assumed that manufacturing costs and retail prices remain constant during the projected 30-year analysis period. There is, however, considerable evidence that this assumption does not reflect real market prices. Costs and prices generally fall in relation to cumulative production, a phenomenon known as experience and modeled by a fairly robust empirical experience curve. Using price data from the Bureau of Labor Statistics, and shipment data obtained as part of the standards analysis process, we present U.S. experience curves for room air conditioners, clothes dryers, central air conditioners, furnaces, and refrigerators and freezers. These allow us to develop more representative appliance price projections than the assumption-based approach of constant prices. These experience curves were incorporated into recent energy conservation standards for these products. The impact on the national modeling can be significant, often increasing the net present value of potential standard levels in the analysis. In some cases a previously cost-negative potential standard level demonstrates a benefit when incorporating experience. These results imply that past energy conservation standards analyses may have undervalued the economic benefits of potential standard levels.
Analysis of characteristic performance curves in radiodiagnosis by an observer
International Nuclear Information System (INIS)
Kossovoj, A.L.
1988-01-01
Methods and ways of construction of performance characteristic curves (PX-curves) in roentgenology, their qualitative and quantitative estimation are described. Estimation of PX curves application for analysis of scintigraphic and sonographic images is presented
Academia-industry collaboration feeds exponential growth curve
Jones Bey Hassaun, A
2004-01-01
The use of silicon strip detectors in high-energy particle tracking is discussed. The functional strength of silicon for high-energy particle physics as well as astrophysics lies in the ability to detect passage of charged particles with micron-scale spatial resolution. In addition to vertex detection, silicon strip detectors also provide full tracking detection to include momentum determination of particles in the magnetic field. Even if silicon detectors for basic science applications do not continue to grow larger, exponential growth of the technology for terrestrial commercial applications is likely to follow a healthy growth curve, as researchers continue to adapt silicon detector technology for low- dose medical x-ray imaging. (Edited abstract)
Analysis of threshold curves for superconducting interferometers
International Nuclear Information System (INIS)
Peterson, R.L.; Hamilton, C.A.
1979-01-01
Threshold curves for multijunction superconducting interferometers have been calculated previously, showing general agreement with observed features, especially in symmetric cases. We here add some more details to the analysis, paying particular attention to the effects of asymmetries in coupling, inductance, or critical currents. Feed-loop inductance and flux quantization in the feed loop can be important. A changing lobe pattern over many periods, asymmetries within a period, shifting patterns between runs spanning a warm-up, and sudden changes in pattern because of noise in the environment are all quantitatively explainable on the basis of this model. By use of a single ''calibration curve'', the inductance for symmetric two- or three-junction interferometers can be obtained immediately
Ego, A; Prunet, C; Blondel, B; Kaminski, M; Goffinet, F; Zeitlin, J
2016-02-01
Our aim is to compare the new French EPOPé intrauterine growth curves, developed to address the guidelines 2013 of the French College of Obstetricians and Gynecologists, with reference curves currently used in France, and to evaluate the consequences of their adjustment for fetal sex and maternal characteristics. Eight intrauterine and birthweight curves, used in France were compared to the EPOPé curves using data from the French Perinatal Survey 2010. The influence of adjustment on the rate of SGA births and the characteristics of these births was analysed. Due to their birthweight values and distribution, the selected intrauterine curves are less suitable for births in France than the new curves. Birthweight curves led to low rates of SGA births from 4.3 to 8.5% compared to 10.0% with the EPOPé curves. The adjustment for maternal and fetal characteristics avoids the over-representation of girls among SGA births, and reclassifies 4% of births. Among births reclassified as SGA, the frequency of medical and obstetrical risk factors for growth restriction, smoking (≥10 cigarettes/day), and neonatal transfer is higher than among non-SGA births (P<0.01). The EPOPé curves are more suitable for French births than currently used curves, and their adjustment improves the identification of mothers and babies at risk of growth restriction and poor perinatal outcomes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Theoretical foundations for environmental Kuznets curve analysis
Lantz, Van
This thesis provides a dynamic theory for analyzing the paths of aggregate output and pollution in a country over time. An infinite horizon, competitive growth-pollution model is explored in order to determine the role that economic scale, production techniques, and pollution regulations play in explaining the inverted U-shaped relationship between output and some forms of pollution (otherwise known as the Environmental Kuznets Curve, or EKC). Results indicate that the output-pollution relationship may follow a strictly increasing, strictly decreasing (but bounded), inverted U-shaped, or some combination of curves. While the 'scale' effect may cause output and pollution to exhibit a monotonic relationship, 'technique' and 'regulation' effects may ultimately cause a de-linking of these two variables. Pollution-minimizing energy regulation policies are also investigated within this framework. It is found that the EKC may be 'flattened' or even eliminated moving from a poorly-regulated economy to one that minimizes pollution. The model is calibrated to the US economy for output (gross national product, GNP) and two pollutants (sulfur dioxide, SO2, and carbon dioxide, CO2) over the period 1900 to 1990. Results indicate that the model replicates the observations quite well. The predominance of 'scale' effects cause aggregate SO2 and CO2 levels to increase with GNP in the early stages of development. Then, in the case of SO 2, 'technique' and 'regulation' effects may be the cause of falling SO2 levels with continued economic growth (establishing the EKC). CO2 continues to monotonically increase as output levels increase over time. The positive relationship may be due to the lack of regulations on this pollutant. If stricter regulation policies were instituted in the two case studies, an improved allocation of resources may result. While GNP may be 2.596 to 20% lower than what has been realized in the US economy (depending on the pollution variable analyzed), individual
International Nuclear Information System (INIS)
Huang Weiming; Lee, Grace W.M.; Wu Chihcheng
2008-01-01
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not possess evidence that supports the EKC hypothesis for GHG emissions. The results from this study also indicated that the 38 industrialized countries are unable to meet their targets under the Kyoto Protocol within the specified time period, which are probably caused by the econometric method's inability to predict accurately the extents and development of innovative technologies and Clean Development Mechanism (CDM) projects. If the international community truly wants to reduce the GHG emissions, the effectiveness of the existing international framework for emissions reduction needs to be reconsidered seriously, and the global cooperation mechanism also needs to be greatly enhanced
Empirical Analysis on The Existence of The Phillips Curve
Directory of Open Access Journals (Sweden)
Shaari Mohd Shahidan
2018-01-01
Full Text Available The Phillips curve shows the trade-off relationship between the inflation and unemployment rates. A rise in inflation due to the high economic growth, more jobs are available and therefore unemployment will fall. However, the existence of the Phillips curve in high-income countries has not been much discussed. Countries with high income should have low unemployment rate, suggesting a high inflation. However, some high-income countries, the United States in 1970s for example, could not avert stagflation whereby high unemployment rate and inflation occurred in the same time. This situation is contrary to the Phillips curve. Therefore, this study aims to investigate the existence of the Phillips curve in high-income countries for the period 1990-2014 using the panel data analysis. The most interesting finding of this study is the existence of a bidirectional relationship between unemployment rate and inflation rate in both long and short runs. Therefore, the governments should choose to stabilize inflation rate or reduce unemployment rate
Growth curve of buffalo grazing on a grass pasture
Teresa Cristina Alves; Raul Franzolin
2015-01-01
ABSTRACTThe objective of this study was to evaluate the performance of 17 buffaloes (Mediterranean), from birth to slaughter age (720 days) with monthly measures of weight, thoracic perimeter, body length, and height at withers. At the end of experimental period, the animals were separated into two different groups for statistical analysis according to slaughter weight: light body weight (LBW, mean 517 kg) and heavy body weight (HBW, mean 568 kg). Buffalo growth occurs in the same way up to w...
Integrated healthcare networks' performance: a growth curve modeling approach.
Wan, Thomas T H; Wang, Bill B L
2003-05-01
This study examines the effects of integration on the performance ratings of the top 100 integrated healthcare networks (IHNs) in the United States. A strategic-contingency theory is used to identify the relationship of IHNs' performance to their structural and operational characteristics and integration strategies. To create a database for the panel study, the top 100 IHNs selected by the SMG Marketing Group in 1998 were followed up in 1999 and 2000. The data were merged with the Dorenfest data on information system integration. A growth curve model was developed and validated by the Mplus statistical program. Factors influencing the top 100 IHNs' performance in 1998 and their subsequent rankings in the consecutive years were analyzed. IHNs' initial performance scores were positively influenced by network size, number of affiliated physicians and profit margin, and were negatively associated with average length of stay and technical efficiency. The continuing high performance, judged by maintaining higher performance scores, tended to be enhanced by the use of more managerial or executive decision-support systems. Future studies should include time-varying operational indicators to serve as predictors of network performance.
Directory of Open Access Journals (Sweden)
Fabyano Fonseca e Silva
Full Text Available ABSTRACT: Genome association analyses have been successful in identifying quantitative trait loci (QTLs for pig body weights measured at a single age. However, when considering the whole weight trajectories over time in the context of genome association analyses, it is important to look at the markers that affect growth curve parameters. The easiest way to consider them is via the two-step method, in which the growth curve parameters and marker effects are estimated separately, thereby resulting in a reduction of the statistical power and the precision of estimates. One efficient solution is to adopt nonlinear mixed models (NMM, which enables a joint modeling of the individual growth curves and marker effects. Our aim was to propose a genome association analysis for growth curves in pigs based on NMM as well as to compare it with the traditional two-step method. In addition, we also aimed to identify the nearest candidate genes related to significant SNP (single nucleotide polymorphism markers. The NMM presented a higher number of significant SNPs for adult weight (A and maturity rate (K, and provided a direct way to test SNP significance simultaneously for both the A and K parameters. Furthermore, all significant SNPs from the two-step method were also reported in the NMM analysis. The ontology of the three candidate genes (SH3BGRL2, MAPK14, and MYL9 derived from significant SNPs (simultaneously affecting A and K allows us to make inferences with regards to their contribution to the pig growth process in the population studied.
The Biasing Effects of Unmodeled ARMA Time Series Processes on Latent Growth Curve Model Estimates
Sivo, Stephen; Fan, Xitao; Witta, Lea
2005-01-01
The purpose of this study was to evaluate the robustness of estimated growth curve models when there is stationary autocorrelation among manifest variable errors. The results suggest that when, in practice, growth curve models are fitted to longitudinal data, alternative rival hypotheses to consider would include growth models that also specify…
Growth curves in Down syndrome with congenital heart disease
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Caroline D’Azevedo Sica
Full Text Available SUMMARY Introduction: To assess dietary habits, nutritional status and food frequency in children and adolescents with Down syndrome (DS and congenital heart disease (CHD. Additionally, we attempted to compare body mass index (BMI classifications according to the World Health Organization (WHO curves and curves developed for individuals with DS. Method: Cross-sectional study including individuals with DS and CHD treated at a referral center for cardiology, aged 2 to 18 years. Weight, height, BMI, total energy and food frequency were measured. Nutritional status was assessed using BMI for age and gender, using curves for evaluation of patients with DS and those set by the WHO. Results: 68 subjects with DS and CHD were evaluated. Atrioventricular septal defect (AVSD was the most common heart disease (52.9%. There were differences in BMI classification between the curves proposed for patients with DS and those proposed by the WHO. There was an association between consumption of vitamin E and polyunsaturated fatty acids. Conclusion: Results showed that individuals with DS are mostly considered normal weight for age, when evaluated using specific curves for DS. Reviews on specific curves for DS would be the recommended practice for health professionals so as to avoid precipitated diagnosis of overweight and/or obesity in this population.
Directory of Open Access Journals (Sweden)
P. C. Muth
2017-11-01
Full Text Available The effects of the increase of body weight of contemporary broilers during growth on functional meat quality and color characteristics of the chicken breast muscle are controversially debated. Therefore, male chickens (n = 264 of a fast-growing commercial broiler (Ross 308 and two slow-growing experimental meat-type chicken lines were compared at equal age and at similar body weight in order to investigate the effect of growth rate on selected functional breast meat traits and meat color. Additionally, the breast meat characteristics of birds with different growth profiles were compared within lines. When the body weight of commercial broilers reached about 40 to 60 % of their growth potential, they exhibited particularly high ultimate pH values compared with slow-growing lines. The ability of the meat of fast-growing broilers to retain water during cooking was impaired (5 to 16 percentage points increased cooking loss compared to slow-growing lines, which, in contrast to pH, was only marginally affected by body weight and/or age at slaughter. No unfavorable correlations of breast meat quality traits with the growth profile, represented by growth curve parameters derived from the Gompertz–Laird equation, were detected within any of the investigated chicken lines. It is noteworthy that the associations of ultimate pH and cooking loss with maximum growth speed indicate a non-linear relationship. Thus, some of the functional characteristics of breast meat of the fast-growing broiler resembled the white-striping defect described for poultry meat, but the hypothesis that selection on increased growth rates is detrimental for meat quality per se could not be confirmed. In fact, an elevated growth potential in particular, i.e., body weight at maturity, could have some beneficial effects for the water-holding capacity of breast meat, regardless of the genotypic growth rate.
Lu, Yi
2016-01-01
To model students' math growth trajectory, three conventional growth curve models and three growth mixture models are applied to the Early Childhood Longitudinal Study Kindergarten-Fifth grade (ECLS K-5) dataset in this study. The results of conventional growth curve model show gender differences on math IRT scores. When holding socio-economic…
A Multilevel Latent Growth Curve Approach to Predicting Student Proficiency
Choi, Kilchan; Goldschmidt, Pete
2012-01-01
Value-added models and growth-based accountability aim to evaluate school's performance based on student growth in learning. The current focus is on linking the results from value-added models to the ones from growth-based accountability systems including Adequate Yearly Progress decisions mandated by No Child Left Behind. We present a new…
Energy Technology Data Exchange (ETDEWEB)
Huang, Wei Ming; Lee, Grace W.M. [Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Road, Taipei 106 (China); Wu, Chih Cheng [Energy and Air Pollution Control Section, New Materials R and D Department, China Steel Corporation, 1, Chung-Kang Road, Siaogang District, Kaohsiung 81233 (China)
2008-01-15
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not possess evidence that supports the EKC hypothesis for GHG emissions. The results from this study also indicated that the 38 industrialized countries are unable to meet their targets under the Kyoto Protocol within the specified time period, which are probably caused by the econometric method's inability to predict accurately the extents and development of innovative technologies and Clean Development Mechanism (CDM) projects. If the international community truly wants to reduce the GHG emissions, the effectiveness of the existing international framework for emissions reduction needs to be reconsidered seriously, and the global cooperation mechanism also needs to be greatly enhanced. (author)
Energy Technology Data Exchange (ETDEWEB)
Huang Weiming [Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Road, Taipei 106, Taiwan (China); Lee, Grace W.M. [Graduate Institute of Environmental Engineering, National Taiwan University, 71, Chou-Shan Road, Taipei 106, Taiwan (China)], E-mail: gracelee@ntu.edu.tw; Wu Chihcheng [Energy and Air Pollution Control Section, New Materials R and D Department, China Steel Corporation, 1, Chung-Kang Road, Siaogang District, Kaohsiung 81233, Taiwan (China)
2008-01-15
The Kyoto Protocol attempts through political negotiations to guide participating industrialized countries' greenhouse gas (GHG) emissions from a positive growing trend, to reach a peak point (or turning point), and then be reduced to a negative growth. That means the relationship between decreasing GHG emissions and economic growth may be described by an inverted-U curve (or called a bell-shaped curve), which is consistent with the concept of the Environmental Kuznets Curve (EKC) hypothesis. This research observed that the economic development and GHG emissions in Economies in Transition (EITs) exhibit a hockey-stick curve trend (or called quasi-L-shape curve), that also generates a lot of 'hot air' which is significant to the implementation of the Kyoto Protocol. In addition, through the analysis of single-country time series data and GDP data, this research demonstrated that statistical data for most of the Annex II countries do not possess evidence that supports the EKC hypothesis for GHG emissions. The results from this study also indicated that the 38 industrialized countries are unable to meet their targets under the Kyoto Protocol within the specified time period, which are probably caused by the econometric method's inability to predict accurately the extents and development of innovative technologies and Clean Development Mechanism (CDM) projects. If the international community truly wants to reduce the GHG emissions, the effectiveness of the existing international framework for emissions reduction needs to be reconsidered seriously, and the global cooperation mechanism also needs to be greatly enhanced.
An introduction to latent variable growth curve modeling concepts, issues, and application
Duncan, Terry E; Strycker, Lisa A
2013-01-01
This book provides a comprehensive introduction to latent variable growth curve modeling (LGM) for analyzing repeated measures. It presents the statistical basis for LGM and its various methodological extensions, including a number of practical examples of its use. It is designed to take advantage of the reader's familiarity with analysis of variance and structural equation modeling (SEM) in introducing LGM techniques. Sample data, syntax, input and output, are provided for EQS, Amos, LISREL, and Mplus on the book's CD. Throughout the book, the authors present a variety of LGM techniques that are useful for many different research designs, and numerous figures provide helpful diagrams of the examples.Updated throughout, the second edition features three new chapters-growth modeling with ordered categorical variables, growth mixture modeling, and pooled interrupted time series LGM approaches. Following a new organization, the book now covers the development of the LGM, followed by chapters on multiple-group is...
Prospects for PV: a learning curve analysis
International Nuclear Information System (INIS)
Zwaan, Bob van der; Rabi, A.
2003-01-01
This article gives an overview of the current state-of-the-art of photovoltaic electricity technology, and addresses its potential for cost reductions over the first few decades of the 21st century. Current PV production cost ranges are presented, both in terms of capacity installation and electricity generation, of single crystalline silicon, multi-crystalline silicon, amorphous silicon and other thin film technologies. Possible decreases of these costs are assessed, as expected according to the learning-curve methodology. We also estimate how much PV could gain if external costs (due to environmental and health damage) of energy were internalised, for example by an energy tax. Our conclusions are that, (1) mainly due its high costs, PV electricity is unlikely to play a major role in global energy supply and carbon emissions abatement before 2020, (2) extrapolating learning curves observed in the past, one can expect its costs to decrease significantly over the coming years, so that a considerable PV electricity share world-wide could materialise after 2020, (3) niche-market applications, e.g. using stand-alone systems in remote areas, are crucial for continuing 'the ride along the learning curve', (4) damage costs of conventional (fossil) power sources are considerable, and their internalisation would improve the competitiveness of PV, although probably not enough to close the current cost gap. (author)
Comparison of wind turbines based on power curve analysis
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-02-01
In the study measured power curves for 46 wind turbines were analyzed with the purpose to establish the basis for a consistent comparison of the efficiency of the wind turbines. Emphasis is on wind turbines above 500 kW rated power, with power curves measured after 1994 according to international recommendations. The available power curves fulfilling these requirements were smoothened according to a procedure developed for the purpose in such a way that the smoothened power curves are equally representative as the measured curves. The resulting smoothened power curves are presented in a standardized format for the subsequent processing. Using wind turbine data from the power curve documentation the analysis results in curves for specific energy production (kWh/M{sup 2}/yr) versus specific rotor load (kW/M{sup 2}) for a range of mean wind speeds. On this basis generalized curves for specific annual energy production versus specific rotor load are established for a number of generalized wind turbine concepts. The 46 smoothened standardized power curves presented in the report, the procedure developed to establish them, and the results of the analysis based on them aim at providers of measured power curves as well as users of them including manufacturers, advisors and decision makers. (au)
Economic growth and emissions reconsidering the empirical basis of environmental Kuznets curves
International Nuclear Information System (INIS)
De Bruyn, S.M.; Van den Bergh, J.C.J.M.; Opschoor, J.B.
1998-01-01
Recent empirical research indicates that certain types of emissions follow an inverted-U or environmental Kuznets curve (EKC) as income grows. This regularity has been interpreted as a possible de-linking of economic growth and patterns of certain pollutants for developed economies. In this paper the empirical basis of this result is investigated, by considering some statistical particularities of the various EKC studies performed. It is argued that the inverted-U relationship between income and emissions estimated from panel data need not hold for specific individual countries over time. Based on insights from 'intensity-of-use' analysis in resource economics an alternative growth model is specified and estimated for three types of emissions (CO 2 , NO x and SO 2 ) in four countries (Netherlands, UK, USA and Western Germany). It is found that the time patterns of these emissions correlate positively with economic growth and that emission reductions may have been achieved as a result of structural and technological changes in the economy. 'Sustainable growth' is defined as the rate of economic growth that does not lead to growth in emissions. Its rate is calculated for each type of emission and country, based on estimated parameter values. The resulting indicators reflect a balance between the positive influence of growth and negative influence of structural change and technological progress on emission levels
Proposal of fatigue crack growth rate curve in air for nickel-base alloys used in BWR
International Nuclear Information System (INIS)
Ogawa, Takuya; Itatani, Masao; Nagase, Hiroshi; Aoike, Satoru; Yoneda, Hideki
2013-01-01
When the defects are detected in the nuclear components in Japan, structural integrity assessment should be performed for the technical judgment on continuous service based on the Rules on Fitness-for-Service for Nuclear Power Plants of the Japan Society of Mechanical Engineers Code (JSME FFS Code). Fatigue crack growth analysis is required when the cyclic loading would be applied for the components. Recently, fatigue crack growth rate curve in air environment for Nickel-base alloys weld metal used in BWR was proposed by the authors and it was adopted as a code case of JSME FFS Code to evaluate the embedded flaw. In this study, fatigue crack growth behavior for heat-affected zone (HAZ) of Nickel-base alloys in air was investigated. And a unified fatigue crack growth rate curve in air for HAZ and weld metal of Nickel-base alloys used in BWR was evaluated. As a result, it was found that the curve for weld metal could be applied as a curve for both HAZ and weld metal since moderately conservative assessment of fatigue crack growth rate of HAZ is possible by the curve for weld metal in the Paris region. And the threshold value of stress intensity far range (ΔK th ) is determined to 3.0 MPa√m based on the fatigue crack growth rate of HAZ. (author)
International Nuclear Information System (INIS)
Garces, F.; Vidania, R. de
1984-01-01
In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C 6 00. (Author)
Curve progression and spinal growth in brace treated idiopathic scoliosis
Tonseth, KA; Veldhuizen, AG; Cool, JC; van Horn, [No Value
The risk of progression of idiopathic scoliosis is correlated primarily to factors that predict potential remaining skeletal growth. The aim of the current study was to evaluate spinal growth, measured as the length of the scoliotic spine on serial longitudinal radiographs, and its relationship to
Precision-Recall-Gain Curves:PR Analysis Done Right
Flach, Peter; Kull, Meelis
2015-01-01
Precision-Recall analysis abounds in applications of binary classification where true negatives do not add value and hence should not affect assessment of the classifier's performance. Perhaps inspired by the many advantages of receiver operating characteristic (ROC) curves and the area under such curves for accuracy-based performance assessment, many researchers have taken to report Precision-Recall (PR) curves and associated areas as performance metric. We demonstrate in this paper that thi...
Error estimation in plant growth analysis
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Andrzej Gregorczyk
2014-01-01
Full Text Available The scheme is presented for calculation of errors of dry matter values which occur during approximation of data with growth curves, determined by the analytical method (logistic function and by the numerical method (Richards function. Further formulae are shown, which describe absolute errors of growth characteristics: Growth rate (GR, Relative growth rate (RGR, Unit leaf rate (ULR and Leaf area ratio (LAR. Calculation examples concerning the growth course of oats and maize plants are given. The critical analysis of the estimation of obtained results has been done. The purposefulness of joint application of statistical methods and error calculus in plant growth analysis has been ascertained.
International Nuclear Information System (INIS)
Eda, Isematsu; Kitahara, Tadashi; Takashima, Sachio; Takeshita, Kenzo
1982-01-01
Macrocephaly was defined as a head measuring larger than 98th percentile. We have evaluated CT findings and head growth curves in 25 infants with large heads. Ten (40%) of 25 infants with large heads were normal developmentally and neurologically. Five (20%) of those were mentally retarded. The other 10 infants (40%) included hydrocephalus (4 cases), malformation syndrome (3 cases), brain tumor (1 case), metabolic disorder (1 case) and degenerative disorder (1 case). Their head growth curves were typed as (I), (II) and (III): Type (I) (excessive head growth curve to 2 SDs above normal); Type (II) (head growth curve gradually approached to 2 SDs above normal); Type (III) (head growth curve parallel to 2 SDs above normal). Ten of macrocephaly with normal psychomotor development were studied clinically and radiologically in details. They were all male. CT pictures of those showed normal or various abnormal findings: ventricular dilatations, wide frontal and temporal subdural spaces, wide interhemispheric fissures, wide cerebral sulci, and large sylvian fissures. CT findings in 2 of those, which because normal after repeated CT examinations, resembled benign subdural collection. CT findings in one of those were external hydrocephalus. Head growth curves were obtained from 8 of those. Six cases revealed type (II) and two cases did type (III). The remaining 2 cases could not be followed up. We consider that CT findings of infants showed macrocephaly with normal psychomotor development reveals normal or various abnormal (ventricular dilatations, benign subdural collection, external hydrocephalus) and their head growth curves are not at least excessive. Infants with mental retardation showed similar CT findings and head growth curves as those with normal psychomotor development. It was difficult to distinguish normal from mentally retarded infants by either CT findings or head growth curves. (author)
ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro
2014-01-01
ABSTRACT We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods. PMID:25013356
Directory of Open Access Journals (Sweden)
Peng Bin
2016-06-01
Full Text Available Given the shrinking proportion of agriculture output and the growing mobility of the labor force in China, how agricultural labor productivity develops has become an increasingly attractive topic for researchers and policy makers. This study aims to depict the development trajectory of agricultural labor productivity in China after its WTO entry. Based on a balanced panel data containing 287 Chinese prefectures from 2000 to 2013, this study applies the Latent Growth Curve Model (LGCM and finds that the agricultural labor productivity follows a piecewise growth path with two breaking points in the years of 2004 and 2009. This may stem from some exogenous stimulus, such as supporting policies launched in the breaking years. Further statistical analysis shows an expanding gap of agricultural labor productivity among different Chinese prefectures.
Directory of Open Access Journals (Sweden)
Azizah Sarkowi
2015-12-01
Full Text Available Practicum is an important component in teacher education programs. This study identify the improvement in the quality of pre-service teachers for three phases practicum. Multi-point prospective panel study has been conducted on a 541 pre-service teachers at the Institute of Teacher Education. Teacher’s quality is measured based on the achievement of program learning outcomes. Based on matching last six digit identification card number for three studies series, 337 questionnaires were analyzed using a latent growth curve model using AMOS 18.0. Latent Analysis shows that the model achieve goodness of fit. There is a linear trend of improvement in the performance of the three phases of the practicum. This increase varies between individuals and the rate of growth depends on the level of achievement at practicum phase I. Studies indicate that the increase in the practicum period of teacher education policy should be continued.
Two-peaked dose curves for irradiated pollen growth
International Nuclear Information System (INIS)
Andrejchenko, S.V.; Grodzinskij, D.M.
1992-01-01
The effect of γ-radiation on growth activity of bicellular pollen of hybrid petunia has been investigated. Irradiation of pollen with doses of 5 to 70 Gy increases the pollen tube growth in an artificial culture medium. As the radiation dose increases the germination ability of pollen gradually decreases and the mean pollen tube length shortens, which is accompanied by the suppression of the generative cell division into spermia and inhibition of the unscheduled incorporation of labelled thymidine into DNA. With radiation doses of 1200 to 1700 Gy some pollen tubes grow intensively. It is suggested that the phenomenon observed lays the basis for the gametic transformation
Farrell, Albert D.; Sullivan, Terri N.
2004-01-01
Two studies used latent growth-curve analysis to examine the relation between witnessing violence and changes in problem behaviors (drug use, aggression, and delinquency) and attitudes during early adolescence. In Study 1, six waves of data covering 6th to 8th grades were collected from 731 students in urban schools serving mostly African-American…
Investigation of Mediational Processes Using Parallel Process Latent Growth Curve Modeling
Cheong, JeeWon; MacKinnon, David P.; Khoo, Siek Toon
2010-01-01
This study investigated a method to evaluate mediational processes using latent growth curve modeling. The mediator and the outcome measured across multiple time points were viewed as 2 separate parallel processes. The mediational process was defined as the independent variable influencing the growth of the mediator, which, in turn, affected the growth of the outcome. To illustrate modeling procedures, empirical data from a longitudinal drug prevention program, Adolescents Training and Learning to Avoid Steroids, were used. The program effects on the growth of the mediator and the growth of the outcome were examined first in a 2-group structural equation model. The mediational process was then modeled and tested in a parallel process latent growth curve model by relating the prevention program condition, the growth rate factor of the mediator, and the growth rate factor of the outcome. PMID:20157639
Simultaneity modeling analysis of the environmental Kuznets curve hypothesis
International Nuclear Information System (INIS)
Ben Youssef, Adel; Hammoudeh, Shawkat; Omri, Anis
2016-01-01
The environmental Kuznets curve (EKC) hypothesis has been recognized in the environmental economics literature since the 1990's. Various statistical tests have been used on time series, cross section and panel data related to single and groups of countries to validate this hypothesis. In the literature, the validation has always been conducted by using a single equation. However, since both the environment and income variables are endogenous, the estimation of a single equation model when simultaneity exists produces inconsistent and biased estimates. Therefore, we formulate simultaneous two-equation models to investigate the EKC hypothesis for fifty-six countries, using annual panel data from 1990 to 2012, with the end year is determined by data availability for the panel. To make the panel data analysis more homogeneous, we investigate this issue for a three income-based panels (namely, high-, middle-, and low-income panels) given several explanatory variables. Our results indicate that there exists a bidirectional causality between economic growth and pollution emissions in the overall panels. We also find that the relationship is nonlinear and has an inverted U-shape for all the considered panels. Policy implications are provided. - Highlights: • We have given a new look for the validity of the EKC hypothesis. • We formulate two-simultaneous equation models to validate this hypothesis for fifty-six countries. • We find a bidirectional causality between economic growth and pollution emissions. • We also discover an inverted U-shaped between environmental degradation and economic growth. • This relationship varies at different stages of economic development.
Body temperatures in dinosaurs: what can growth curves tell us?
Directory of Open Access Journals (Sweden)
Eva Maria Griebeler
Full Text Available To estimate the body temperature (BT of seven dinosaurs Gillooly, Alleen, and Charnov (2006 used an equation that predicts BT from the body mass and maximum growth rate (MGR with the latter preserved in ontogenetic growth trajectories (BT-equation. The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006. I first studied whether BTs derived from the BT-equation of today's crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006 did. In particular, I estimated BT of Archaeopteryx (from two MGRs, ornithischians (two, theropods (three, prosauropods (three, and sauropods (nine. For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal's core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006 I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately
Body temperatures in dinosaurs: what can growth curves tell us?
Griebeler, Eva Maria
2013-01-01
To estimate the body temperature (BT) of seven dinosaurs Gillooly, Alleen, and Charnov (2006) used an equation that predicts BT from the body mass and maximum growth rate (MGR) with the latter preserved in ontogenetic growth trajectories (BT-equation). The results of these authors evidence inertial homeothermy in Dinosauria and suggest that, due to overheating, the maximum body size in Dinosauria was ultimately limited by BT. In this paper, I revisit this hypothesis of Gillooly, Alleen, and Charnov (2006). I first studied whether BTs derived from the BT-equation of today's crocodiles, birds and mammals are consistent with core temperatures of animals. Second, I applied the BT-equation to a larger number of dinosaurs than Gillooly, Alleen, and Charnov (2006) did. In particular, I estimated BT of Archaeopteryx (from two MGRs), ornithischians (two), theropods (three), prosauropods (three), and sauropods (nine). For extant species, the BT value estimated from the BT-equation was a poor estimate of an animal's core temperature. For birds, BT was always strongly overestimated and for crocodiles underestimated; for mammals the accuracy of BT was moderate. I argue that taxon-specific differences in the scaling of MGR (intercept and exponent of the regression line, log-log-transformed) and in the parameterization of the Arrhenius model both used in the BT-equation as well as ecological and evolutionary adaptations of species cause these inaccuracies. Irrespective of the found inaccuracy of BTs estimated from the BT-equation and contrary to the results of Gillooly, Alleen, and Charnov (2006) I found no increase in BT with increasing body mass across all dinosaurs (Sauropodomorpha, Sauropoda) studied. This observation questions that, due to overheating, the maximum size in Dinosauria was ultimately limited by BT. However, the general high inaccuracy of dinosaurian BTs derived from the BT-equation makes a reliable test of whether body size in dinosaurs was ultimately limited
Energy Technology Data Exchange (ETDEWEB)
Roca Jusmet, J.; Padilla Rosa, E.
2004-07-01
From the beginning of the 90s the analysis of the relationships between economic growth and environmental pressures has been influenced by the Environmental Kuznets Curve hypothesis or inverted-U shaped relationship between environmental pressure and per capita income. Following this hypothesis, once achieved certain income level, more economic growth is followed by environmental quality improvement. In this paper, we analyse and discuss the theories that support this hypothesis as well as the empirical evidence on this subject. Further on we analyse the relationship between per capita income and the main environmental pollutants for the case does not support the hypothesis. The empirical evidence shows that economic growth, by itself, does not entail a pollution reduction. (Author) 35 refs.
An analysis on the environmental Kuznets curve of Chengdu
Gao, Zijian; Peng, Yue; Zhao, Yue
2017-12-01
In this paper based on the environmental and economic data of Chengdu from 2005 to 2014, the measurement models were established to analyze 3 kinds of environmental flow indicators and 4 kinds of environmental stock indicators to obtain their EKC evolution trajectories and characters. The results show that the relationship curve between the discharge of SO2 from industry and the GDP per capita is a positive U shape, just as the curve between discharge of COD from industry and the GDP per person. The relationship curve between the dust discharge from industry and the GDP per capita is an inverted N shape. In the central of the urban the relationship curve between the concentration of SO2 in the air and the GDP per person is a positive U shape. The relationship curves between the concentration of NO2 in the air and the GDP per person, between the concentration of the particulate matters and the GDP per person, and between the concentration of the fallen dusts and the GDP per person are fluctuating. So the EKC curves of the 7 kinds of environmental indicators are not accord with inverted U shape feature. In the development of this urban the environmental problems can’t be resolved only by economic growth. The discharge of industrial pollutants should be controlled to improve the atmospheric environmental quality and reduce the environmental risks.
Growth Curve and Structural Equation Modeling : Topics from the Indian Statistical Institute
2015-01-01
This book describes some recent trends in GCM research on different subject areas, both theoretical and applied. This includes tools and possibilities for further work through new techniques and modification of existing ones. A growth curve is an empirical model of the evolution of a quantity over time. Growth curves in longitudinal studies are used in disciplines including biology, statistics, population studies, economics, biological sciences, sociology, nano-biotechnology, and fluid mechanics. The volume includes original studies, theoretical findings and case studies from a wide range of applied work. This volume builds on presentations from a GCM workshop held at the Indian Statistical Institute, Giridih, January 18-19, 2014. This book follows the volume Advances in Growth Curve Models, published by Springer in 2013. The results have meaningful application in health care, prediction of crop yield, child nutrition, poverty measurements, estimation of growth rate, and other research areas.
Spencer, Phoebe R; Sanders, Katherine A; Judge, Debra S
2018-02-01
Population-specific growth references are important in understanding local growth variation, especially in developing countries where child growth is poor and the need for effective health interventions is high. In this article, we use mixed longitudinal data to calculate the first growth curves for rural East Timorese children to identify where, during development, deviation from the international standards occurs. Over an eight-year period, 1,245 children from two ecologically distinct rural areas of Timor-Leste were measured a total of 4,904 times. We compared growth to the World Health Organization (WHO) standards using z-scores, and modeled height and weight velocity using the SuperImposition by Translation And Rotation (SITAR) method. Using the Generalized Additive Model for Location, Scale and Shape (GAMLSS) method, we created the first growth curves for rural Timorese children for height, weight and body mass index (BMI). Relative to the WHO standards, children show early-life growth faltering, and stunting throughout childhood and adolescence. The median height and weight for this population tracks below the WHO fifth centile. Males have poorer growth than females in both z-BMI (p = .001) and z-height-for-age (p = .018) and, unlike females, continue to grow into adulthood. This is the most comprehensive investigation to date of rural Timorese children's growth, and the growth curves created may potentially be used to identify future secular trends in growth as the country develops. We show significant deviation from the international standard that becomes most pronounced at adolescence, similar to the growth of other Asian populations. Males and females show different growth responses to challenging conditions in this population. © 2017 Wiley Periodicals, Inc.
Seismic Fragility Curves of Industrial Buildings by Using Nonlinear Analysis
Directory of Open Access Journals (Sweden)
Mohamed Nazri Fadzli
2017-01-01
Full Text Available This study presents the steel fragility curves and performance curves of industrial buildings of different geometries. The fragility curves were obtained for different building geometries, and the performance curves were developed based on lateral load, which is affected by the geometry of the building. Three records of far-field ground motion were used for incremental dynamic analysis (IDA, and the design lateral loads for pushover analysis (POA. All designs were based on British Standard (BS 5950; however, Eurocode 8 was preferred for seismic consideration in the analysis because BS 5950 does not specify any seismic provision. The five levels of performance stated by FEMA-273, namely, operational phase, immediate occupancy, damage control, life safety, and collapse prevention (CP were used as main guidelines for evaluating structural performance. For POA, Model 2 had highest base shear, followed by Model 1 and Model 3, even though Model 2 has a smaller structure compared with Model 3. Meanwhile, the fragility curves showed that the probability of reaching or exceeding the CP level of Model 2 is the highest, followed by that of Models 1 and 3.
Supplementary Material for: Growth curve registration for evaluating salinity tolerance in barley
Meng, Rui
2017-01-01
Abstract Background Smarthouses capable of non-destructive, high-throughput plant phenotyping collect large amounts of data that can be used to understand plant growth and productivity in extreme environments. The challenge is to apply the statistical tool that best analyzes the data to study plant traits, such as salinity tolerance, or plant-growth-related traits. Results We derive family-wise salinity sensitivity (FSS) growth curves and use registration techniques to summarize growth patterns of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we derive corrected values for family-wise salinity tolerance, which are strongly negatively correlated with Na but not significantly with K, indicating that Na content is an important factor affecting salinity tolerance in these families, at least for plants of this age and grown in these conditions. Conclusions Our family-wise methodology is suitable for analyzing the growth curves of a large number of plants from multiple families. The corrected curves accurately account for the spatial and temporal variations among plants that are inherent to high-throughput experiments.
Symphysis-fundal height curve in the diagnosis of fetal growth deviations
Directory of Open Access Journals (Sweden)
Djacyr Magna Cabral Freire
2010-12-01
Full Text Available OBJECTIVE: To validate a new symphysis-fundal curve for screening fetal growth deviations and to compare its performance with the standard curve adopted by the Brazilian Ministry of Health. METHODS: Observational study including a total of 753 low-risk pregnant women with gestational age above 27 weeks between March to October 2006 in the city of João Pessoa, Northeastern Brazil. Symphisys-fundal was measured using a standard technique recommended by the Brazilian Ministry of Health. Estimated fetal weight assessed through ultrasound using the Brazilian fetal weight chart for gestational age was the gold standard. A subsample of 122 women with neonatal weight measurements was taken up to seven days after estimated fetal weight measurements and symphisys-fundal classification was compared with Lubchenco growth reference curve as gold standard. Sensitivity, specificity, positive and negative predictive values were calculated. The McNemar χ2 test was used for comparing sensitivity of both symphisys-fundal curves studied. RESULTS: The sensitivity of the new curve for detecting small for gestational age fetuses was 51.6% while that of the Brazilian Ministry of Health reference curve was significantly lower (12.5%. In the subsample using neonatal weight as gold standard, the sensitivity of the new reference curve was 85.7% while that of the Brazilian Ministry of Health was 42.9% for detecting small for gestational age. CONCLUSIONS: The diagnostic performance of the new curve for detecting small for gestational age fetuses was significantly higher than that of the Brazilian Ministry of Health reference curve.
Wood, Phillip Karl; Jackson, Kristina M
2013-08-01
Researchers studying longitudinal relationships among multiple problem behaviors sometimes characterize autoregressive relationships across constructs as indicating "protective" or "launch" factors or as "developmental snares." These terms are used to indicate that initial or intermediary states of one problem behavior subsequently inhibit or promote some other problem behavior. Such models are contrasted with models of "general deviance" over time in which all problem behaviors are viewed as indicators of a common linear trajectory. When fit of the "general deviance" model is poor and fit of one or more autoregressive models is good, this is taken as support for the inhibitory or enhancing effect of one construct on another. In this paper, we argue that researchers consider competing models of growth before comparing deviance and time-bound models. Specifically, we propose use of the free curve slope intercept (FCSI) growth model (Meredith & Tisak, 1990) as a general model to typify change in a construct over time. The FCSI model includes, as nested special cases, several statistical models often used for prospective data, such as linear slope intercept models, repeated measures multivariate analysis of variance, various one-factor models, and hierarchical linear models. When considering models involving multiple constructs, we argue the construct of "general deviance" can be expressed as a single-trait multimethod model, permitting a characterization of the deviance construct over time without requiring restrictive assumptions about the form of growth over time. As an example, prospective assessments of problem behaviors from the Dunedin Multidisciplinary Health and Development Study (Silva & Stanton, 1996) are considered and contrasted with earlier analyses of Hussong, Curran, Moffitt, and Caspi (2008), which supported launch and snare hypotheses. For antisocial behavior, the FCSI model fit better than other models, including the linear chronometric growth curve
Photometric Observation and Light Curve Analysis of Binary System ...
Indian Academy of Sciences (India)
2016-01-27
Jan 27, 2016 ... Photometric Observation and Light Curve Analysis of Binary System ER-Orionis ... February to April 2008 with the 51 cm telescope of Biruni Observatory of Shiraz University in U, B and V filters (Johnson system) and an RCA 4509 photomultiplier. ... Articles are also visible in Web of Science immediately.
Directory of Open Access Journals (Sweden)
Michael D. Coovert
2017-08-01
Full Text Available Trust plays a central role in the effectiveness of work groups and teams. This is the case for both face-to-face and virtual teams. Yet little is known about the development of trust in virtual teams. We examined cognitive and affective trust and their relationship to team effectiveness as reflected through satisfaction with one’s team and task performance. Latent growth curve analysis reveals both trust types start at a significant level with individual differences in that initial level. Cognitive trust follows a linear growth pattern while affective trust is overall non-linear, but becomes linear once established. Latent change score models are utilized to examine change in trust and also its relationship with satisfaction with the team and team performance. In examining only change in trust and its relationship to satisfaction there appears to be a straightforward influence of trust on satisfaction and satisfaction on trust. However, when incorporated into a bivariate coupling latent change model the dynamics of the relationship are revealed. A similar pattern holds for trust and task performance; however, in the bivariate coupling change model a more parsimonious representation is preferred.
Analysis of power curves of Danish and foreign wind turbines
International Nuclear Information System (INIS)
Petersen, H.
1995-12-01
This report describes an analysis of power curves for a number of wind turbines, 30 Danish and 17 foreign - European - wind turbines. The investigation is limited to wind turbines of 150 kW capacity and greater, and to wind turbines for which a power curve is available. The power curves are transformed into a common, uniform presentation in order to facilitate the succeeding treatment, which primarily is the calculation of the production of electrical energy yielded per year. From the known data of the wind turbine, equipped generator power and rotor area and the area swept by the blades, the specific electrical production is calculated in three terms: yield per square meter of rotor area, yield per kW generator power and yield per square meter and per kilowatt generator power. Based on these findings a number of comparisons are established, such as comparisons of conceptual designs and technical- economical evaluations. (au)
Use of universal functional optimisation for TL glow curve analysis
International Nuclear Information System (INIS)
Pernicka, F.; Linh, H.Q.
1996-01-01
The effective use of any TL instrument requires an efficient software package to be able to fulfil different tasks required by research and practical applications. One of the standard features of the package used at the NPI Prague is the application of the interactive modular system Universal Functional Optimisation (UFO) for glow curve deconvolution. The whole system has been tested on standard glow curves using different models of the TL process (a single peak described by the Podgorsak approximation, first order kinetics and/or general order kinetics). Calculated values of basic TL parameters (E and s) show a good agreement with the results obtained by other authors. The main advantage of the system is in its modularity that enables flexible changes in the TL model and mathematical procedures of the glow curve analysis. (author)
Colombian reference growth curves for height, weight, body mass index and head circumference.
Durán, Paola; Merker, Andrea; Briceño, Germán; Colón, Eugenia; Line, Dionne; Abad, Verónica; Del Toro, Kenny; Chahín, Silvia; Matallana, Audrey Mary; Lema, Adriana; Llano, Mauricio; Céspedes, Jaime; Hagenäs, Lars
2016-03-01
Published Growth studies from Latin America are limited to growth references from Argentina and Venezuela. The aim of this study was to construct reference growth curves for height, weight, body mass index (BMI) and head circumference of Colombian children in a format that is useful for following the growth of the individual child and as a tool for public health. Prospective measurements from 27 209 Colombian children from middle and upper socio-economic level families were processed using the generalised additive models for location, scale and shape (GAMLSS). Descriptive statistics for length and height, weight, BMI and head circumference for age are given as raw and smoothed values. Final height was 172.3 cm for boys and 159.4 cm for girls. Weight at 18 years of age was 64.0 kg for boys and 54 kg for girls. Growth curves are presented in a ± 3 SD format using logarithmic axes. The constructed reference growth curves are a start for following secular trends in Colombia and are also in the presented layout an optimal clinical tool for health care. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Martinovic, B.; van Tubergen, F.; Maas, I.
2015-01-01
Interethnic ties are considered important for the cohesion in society. Previous research has studied the determinants of interethnic ties with cross-sectional data or lagged panel designs. This study improves on prior research by applying multilevel growth curve modelling techniques with lagged
Martinovic, Borja|info:eu-repo/dai/nl/304822752; van Tubergen, Frank|info:eu-repo/dai/nl/271429534; Maas, Ineke|info:eu-repo/dai/nl/075229390
2015-01-01
Interethnic ties are considered important for the cohesion in society. Previous research has studied the determinants of interethnic ties with cross-sectional data or lagged panel designs. This study improves on prior research by applying multilevel growth curve modelling techniques with lagged
Using Growth Curves To Determine the Timing of the Booster Sessions.
Hennessy, Michael; Bolan, Gail A.; Hoxworth, Tamara; Iatesta, Michael; Rhodes, Fen; Zenilman, Jonathan M.
1999-01-01
Demonstrates an application of a method for using growth curves to determine the timing of booster sessions to reinforce the cognitive messages or behavior changes of interventions. Uses data from a multisite randomized experiment that compared three counseling and testing methods for preventing sexual disease transmission. Presents…
Candidate genes and growth curves for adiposity in African- and European-American youth
Podolsky, R. H.; Barbeau, P.; Kang, H-S; Zhu, H.; Treiber, F. A.; Snieder, H.
2007-01-01
Objective: Obesity is associated with multiple health problems and often originates in childhood. This study investigated the association of genes with the development of general and central obesity from childhood into adulthood. Design: Individual growth curves for measures of general adiposity
From Experiment to Theory: What Can We Learn from Growth Curves?
Kareva, Irina; Karev, Georgy
2018-01-01
Finding an appropriate functional form to describe population growth based on key properties of a described system allows making justified predictions about future population development. This information can be of vital importance in all areas of research, ranging from cell growth to global demography. Here, we use this connection between theory and observation to pose the following question: what can we infer about intrinsic properties of a population (i.e., degree of heterogeneity, or dependence on external resources) based on which growth function best fits its growth dynamics? We investigate several nonstandard classes of multi-phase growth curves that capture different stages of population growth; these models include hyperbolic-exponential, exponential-linear, exponential-linear-saturation growth patterns. The constructed models account explicitly for the process of natural selection within inhomogeneous populations. Based on the underlying hypotheses for each of the models, we identify whether the population that it best fits by a particular curve is more likely to be homogeneous or heterogeneous, grow in a density-dependent or frequency-dependent manner, and whether it depends on external resources during any or all stages of its development. We apply these predictions to cancer cell growth and demographic data obtained from the literature. Our theory, if confirmed, can provide an additional biomarker and a predictive tool to complement experimental research.
[Reference curves for assessing the physical growth of male Wistar rats].
Cossio-Bolaños, Marco; Gómez Campos, Rossana; Vargas Vitoria, Rodrigo; Hochmuller Fogaça, Rosalvo Tadeu; de Arruda, Miguel
2013-11-01
Wistar rats are one of the most popular strains routinely used for research in the laboratory to serve as an important research tool, so it requires strict control of variables such as age, sex and body weight, and Thus to extrapolate the results to the human model. To develop reference curves for assessing the physical growth of male Wistar rats according to chronological age and somatic maturation from a non-invasive. The subjects studied were 731 male Wistar rats transversely. We assessed age, body weight and body surface. LMS method was used to construct percentile curves based on weight and somatic maturation. The proposed physical growth curves are used to track the physical growth and nutritional status diagnosis of male Wistar rats. Budgets by cutting points are: P3, P10, P25, P50, P75, P90 and P97. The results suggest that scientists from different areas can use such references, in order to extrapolate somatic growth phases of the laboratory rat and the human model is a non-invasive alternative to assess growth and nutritional status. Copyright AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.
The Kepler Light Curves of AGN: A Detailed Analysis
Smith, Krista Lynne; Mushotzky, Richard F.; Boyd, Patricia T.; Malkan, Matt; Howell, Steve B.; Gelino, Dawn M.
2018-04-01
We present a comprehensive analysis of 21 light curves of Type 1 active galactic nuclei (AGN) from the Kepler spacecraft. First, we describe the necessity and development of a customized pipeline for treating Kepler data of stochastically variable sources like AGN. We then present the light curves, power spectral density functions (PSDs), and flux histograms. The light curves display an astonishing variety of behaviors, many of which would not be detected in ground-based studies, including switching between distinct flux levels. Six objects exhibit PSD flattening at characteristic timescales that roughly correlate with black hole mass. These timescales are consistent with orbital timescales or free-fall accretion timescales. We check for correlations of variability and high-frequency PSD slope with accretion rate, black hole mass, redshift, and luminosity. We find that bolometric luminosity is anticorrelated with both variability and steepness of the PSD slope. We do not find evidence of the linear rms–flux relationships or lognormal flux distributions found in X-ray AGN light curves, indicating that reprocessing is not a significant contributor to optical variability at the 0.1%–10% level.
Orellana, Jesem D Y; Santos, Ricardo V; Coimbra, Carlos E A; Leite, Maurício S
2009-01-01
To perform a comparative analysis of anthropometric data from Suruí, Xavánte and Wari' indigenous children under 60 months of age using the NCHS/1977 and the WHO/2005 growth curves. Anthropometric measurements followed standard procedures and the data obtained were converted into z scores using the Epi-Info (Version 3.4) and WHO-Anthro (Version Beta) softwares. The indices height/age (H/A), weight/age (W/A) and weight/height (W/H) were descriptors of nutritional status for all children under 60 months of age, as well as the body mass index (BMI) for children 24-59 months old. The frequencies of Suruí children Wari' 61.7 and 68.3%. The frequencies of Suruí children Wari' 51.7 and 45.0%. None of the Suruí children were Wari' 1.7 and 0.0%. The frequencies of Suruí children > 2 z scores for W/H were 3.9 (NCHS/1977) and 3.9% (WHO/2005); Xavánte 0.0 and 0.8%; Wari' 0.0 and 0.0%. The frequency of Suruí children aged 24-59 months > 2 z scores for BMI was 5.4% (WHO/2005); Xavánte 9.5%; and Wari' 0.0%. Our findings revealed important differences in the results from nutritional assessment, according to the set of growth curves used; however, the use of both growth curves revealed a high prevalence of malnutrition. Therefore, future studies with indigenous populations should present their results using two sets of growth curves to allow consistent comparison.
Che, T D; Wang, C D; Jin, L; Wei, M; Wu, K; Zhang, Y H; Zhang, H M; Li, D S
2015-03-27
Giant panda cubs have a low survival rate during the newborn and early growth stages. However, the growth and developmental parameters of giant panda cubs during the early lactation stage (from birth to 6 months) are not well known. We examined the growth and development of giant panda cubs by the Chapman growth curve model and estimated the heritability of the maximum growth rate at the early lactation stage. We found that 83 giant panda cubs reached their maximum growth rate at approximately 75-120 days after birth. The body weight of cubs at 75 days was 4285.99 g. Furthermore, we estimated that the heritability of the maximum growth rate was moderate (h(2) = 0.38). Our study describes the growth and development of giant panda cubs at the early lactation stage and provides valuable growth benchmarks. We anticipate that our results will be a starting point for more detailed research on increasing the survival rate of giant panda cubs. Feeding programs for giant panda cubs need further improvement.
Borghi, E.; Onis, M. de; Garza, C.; Broeck, J. van den; Frongillo, E.A.; Grummer-Strawn, L.; Buuren, S. van; Pan, H.; Molinari, L.; Martorell, R.; Onyango, A.W.; Martines, J.C.; Pinol, A.; Siyam, A.; Victoria, C.G.; Bhan, M.K.; Araújo, C.L.; Lartey, A.; Owusu, W.B.; Bhandari, N.; Norum, K.R.; Bjoerneboe, G.-E.Aa.; Mohamed, A.J.; Dewey, K.G.; Belbase, K.; Chumlea, C.; Cole, T.; Shrimpton, R.; Albernaz, E.; Tomasi, E.; Cássia Fossati da Silveira, R. de; Nader, G.; Sagoe-Moses, I.; Gomez, V.; Sagoe-Moses, C.; Taneja, S.; Rongsen, T.; Chetia, J.; Sharma, P.; Bahl, R.; Baerug, A.; Tufte, E.; Alasfoor, D.; Prakash, N.S.; Mabry, R.M.; Al Rajab, H.J.; Helmi, S.A.; Nommsen-Rivers, L.A.; Cohen, R.J.; Heinig, M.J.
2006-01-01
The World Health Organization (WHO), in collaboration with a number of research institutions worldwide, is developing new child growth standards. As part of a broad consultative process for selecting the best statistical methods, WHO convened a group of statisticians and child growth experts to
Stress analysis in curved composites due to thermal loading
Polk, Jared Cornelius
Many structures in aircraft, cars, trucks, ships, machines, tools, bridges, and buildings, consist of curved sections. These sections vary from straight line segments that have curvature at either one or both ends, segments with compound curvatures, segments with two mutually perpendicular curvatures or Gaussian curvatures, and segments with a simple curvature. With the advancements made in multi-purpose composites over the past 60 years, composites slowly but steadily have been appearing in these various vehicles, compound structures, and buildings. These composite sections provide added benefits over isotropic, polymeric, and ceramic materials by generally having a higher specific strength, higher specific stiffnesses, longer fatigue life, lower density, possibilities in reduction of life cycle and/or acquisition cost, and greater adaptability to intended function of structure via material composition and geometry. To be able to design and manufacture a safe composite laminate or structure, it is imperative that the stress distributions, their causes, and effects are thoroughly understood in order to successfully accomplish mission objectives and manufacture a safe and reliable composite. The objective of the thesis work is to expand upon the knowledge of simply curved composite structures by exploring and ascertaining all pertinent parameters, phenomenon, and trends in stress variations in curved laminates due to thermal loading. The simply curved composites consist of composites with one radius of curvature throughout the span of the specimen about only one axis. Analytical beam theory, classical lamination theory, and finite element analysis were used to ascertain stress variations in a flat, isotropic beam. An analytical method was developed to ascertain the stress variations in an isotropic, simply curved beam under thermal loading that is under both free-free and fixed-fixed constraint conditions. This is the first such solution to Author's best knowledge
Using the Yield Curve in Forecasting Output Growth and In‡flation
DEFF Research Database (Denmark)
Hillebrand, Eric Tobias; Huang, Huiyu; Lee, Tae-Hwy
Following Diebold and Li (2006), we use the Nelson-Siegel (NS, 1987) yield curve factors. However the NS yield curve factors are not supervised for a specifi…c forecast target in the sense that the same factors are used for forecasting different variables, e.g., output growth or infl‡ation. We...... analytically and numerically how supervision works. For both CF and CI schemes, principal components (PC) may be used in place of the NS factors. In out-of-sample forecasting of U.S. monthly output growth and infl‡ation, we fi…nd that supervised CF-factor models (CF-NS, CF-PC) are substantially better than...
Evaluation of water beef buffalo from birth to two years using different growth curves
Directory of Open Access Journals (Sweden)
W.R. Lamberson
2010-02-01
Full Text Available The buffalo is a domestic animal species of growing world-wide importance. Research to improve genetic improvement programs is important to maintain the productivity of buffalo. The objective this research was to evaluate the growth of Brazilian buffalo to two years of age with different growth curves. Growth curves consolidate the information contained in the weight-age data into three or four biologically meaningful parameters. The data included 31,452 weights at birth and 120, 205, 365, 550 and 730 days of buffalo (n = 5,178 raised on pasture without supplementation. Logistic, Gompertz, quadratic logarithmic, and linear hyperbolic curves (designated L, G, QL, and LH, respectively were fitted to the data by using proc NLIN of SAS (SAS Institute, Inc., Cary, NC, USA. The parameters estimates for L [WT= A * (((1 + exp (-k * AGE**-m] were A = 865.1 ± 5.42; k= 0.0028 ± 0.00002; M= 3.808 ± 0.007; R2 = 0.95. For G [WT= A * exp (-b * exp (-k * age] the parameters estimates were A= 967.6 ± 7.23; k = 0.00217 ± 0.000015; b = -2.8152 ± 0.00532. For QL [WT= A + b*age + k*(age*age + m*log (age] parameters estimates were A= 37.41 ± 0.48; k= 0.00019 ± 6.4E-6; b= 0.539 ± 0.006; m= 2.32 ± 0.23; R2=0.96. For LH [WT= A + b*AGE + k*(1/AGE] the parameters estimates were A= 23.15 ± 0.44; k=15.16 ± 0.66; b= 0.707 ± 0.001; R2= 0.96. Each of these curves fit these data equally well and could be used for characterizing growth to two years in beef buffalo.
Self-Regulation and Recall: Growth Curve Modeling of Intervention Outcomes for Older Adults
West, Robin L.; Hastings, Erin C.
2011-01-01
Memory training has often been supported as a potential means to improve performance for older adults. Less often studied are the characteristics of trainees that benefit most from training. Using a self-regulatory perspective, the current project examined a latent growth curve model to predict training-related gains for middle-aged and older adult trainees from individual differences (e.g., education), information processing skills (strategy use) and self-regulatory factors such as self-effi...
SERIAL ULTRASOUND TO ESTIMATE FETAL GROWTH CURVES IN SOUTHERN TAMANDUA (TAMANDUA TETRADACTYLA).
Thompson, Rachel; Wolf, Tiffany M; Robertson, Heather; Colburn, Margarita Woc; Moreno, Alexis; Moresco, Anneke; Napier, Anne Elise; Nofs, Sally A
2017-06-01
From 2012 to 2015, 16 pregnancies were monitored by ultrasonography in nine tamanduas ( Tamandua tetradactyla ) housed in three zoological facilities. Sonographic measurements were recorded to establish fetal growth curves using thoracic and skull landmarks described for giant anteaters ( Myrmecophaga tridactyla ). All pregnancies resulted in the uncomplicated delivery of healthy offspring, thus gestational development was considered normal. These data may be used as a reference for normal fetal development with potential for estimating parturition date in the absence of breeding data.
Is cancer a pure growth curve or does it follow a kinetics of dynamical structural transformation?
González, Maraelys Morales; Joa, Javier Antonio González; Cabrales, Luis Enrique Bergues; Pupo, Ana Elisa Bergues; Schneider, Baruch; Kondakci, Suleyman; Ciria, Héctor Manuel Camué; Reyes, Juan Bory; Jarque, Manuel Verdecia; Mateus, Miguel Angel O'Farril; González, Tamara Rubio; Brooks, Soraida Candida Acosta; Cáceres, José Luis Hernández; González, Gustavo Victoriano Sierra
2017-03-07
Unperturbed tumor growth kinetics is one of the more studied cancer topics; however, it is poorly understood. Mathematical modeling is a useful tool to elucidate new mechanisms involved in tumor growth kinetics, which can be relevant to understand cancer genesis and select the most suitable treatment. The classical Kolmogorov-Johnson-Mehl-Avrami as well as the modified Kolmogorov-Johnson-Mehl-Avrami models to describe unperturbed fibrosarcoma Sa-37 tumor growth are used and compared with the Gompertz modified and Logistic models. Viable tumor cells (1×10 5 ) are inoculated to 28 BALB/c male mice. Modified Gompertz, Logistic, Kolmogorov-Johnson-Mehl-Avrami classical and modified Kolmogorov-Johnson-Mehl-Avrami models fit well to the experimental data and agree with one another. A jump in the time behaviors of the instantaneous slopes of classical and modified Kolmogorov-Johnson-Mehl-Avrami models and high values of these instantaneous slopes at very early stages of tumor growth kinetics are observed. The modified Kolmogorov-Johnson-Mehl-Avrami equation can be used to describe unperturbed fibrosarcoma Sa-37 tumor growth. It reveals that diffusion-controlled nucleation/growth and impingement mechanisms are involved in tumor growth kinetics. On the other hand, tumor development kinetics reveals dynamical structural transformations rather than a pure growth curve. Tumor fractal property prevails during entire TGK.
A Bayesian hierarchical model for demand curve analysis.
Ho, Yen-Yi; Nhu Vo, Tien; Chu, Haitao; Luo, Xianghua; Le, Chap T
2018-07-01
Drug self-administration experiments are a frequently used approach to assessing the abuse liability and reinforcing property of a compound. It has been used to assess the abuse liabilities of various substances such as psychomotor stimulants and hallucinogens, food, nicotine, and alcohol. The demand curve generated from a self-administration study describes how demand of a drug or non-drug reinforcer varies as a function of price. With the approval of the 2009 Family Smoking Prevention and Tobacco Control Act, demand curve analysis provides crucial evidence to inform the US Food and Drug Administration's policy on tobacco regulation, because it produces several important quantitative measurements to assess the reinforcing strength of nicotine. The conventional approach popularly used to analyze the demand curve data is individual-specific non-linear least square regression. The non-linear least square approach sets out to minimize the residual sum of squares for each subject in the dataset; however, this one-subject-at-a-time approach does not allow for the estimation of between- and within-subject variability in a unified model framework. In this paper, we review the existing approaches to analyze the demand curve data, non-linear least square regression, and the mixed effects regression and propose a new Bayesian hierarchical model. We conduct simulation analyses to compare the performance of these three approaches and illustrate the proposed approaches in a case study of nicotine self-administration in rats. We present simulation results and discuss the benefits of using the proposed approaches.
Statistical analysis of the W Cyg light curve
International Nuclear Information System (INIS)
Klyus, I.A.
1983-01-01
A statistical analysis of the light curve of W Cygni has been carried out. The process of brightness variations brightness of the star is shown to be a stationary stochastic one. The hypothesis of stationarity of the process was checked at the significance level of α=0.05. Oscillations of the brightness with average durations of 131 and 250 days have been found. It is proved that oscillations are narrow-band noise, i.e. cycles. Peaks on the power spectrum corresponding to these cycles exceed 99% confidence interval. It has been stated that the oscillations are independent
A new approach to the analysis of Mira light curves
International Nuclear Information System (INIS)
Mennessier, M.O.; Barthes, D.; Mattei, J.A.
1990-01-01
Two different but complementary methods for predicting Mira luminosities are presented. One method is derived from a Fourier analysis, it requires performing deconvolution, and its results are not certain due to the inherent instability of deconvolution problems. The other method is a learning method utilizing artificial intelligence techniques where a light curve is presented as an ordered sequence of pseudocycles, and rules are learned by linking the characteristics of several consecutive pseudocycles to one characteristic of the future cycle. It is observed that agreement between these methods is obtainable when it is possible to eliminate similar false frequencies from the preliminary power spectrum and to improve the degree of confidence in the rules
McNeish, Daniel; Dumas, Denis
2017-01-01
Recent methodological work has highlighted the promise of nonlinear growth models for addressing substantive questions in the behavioral sciences. In this article, we outline a second-order nonlinear growth model in order to measure a critical notion in development and education: potential. Here, potential is conceptualized as having three components-ability, capacity, and availability-where ability is the amount of skill a student is estimated to have at a given timepoint, capacity is the maximum amount of ability a student is predicted to be able to develop asymptotically, and availability is the difference between capacity and ability at any particular timepoint. We argue that single timepoint measures are typically insufficient for discerning information about potential, and we therefore describe a general framework that incorporates a growth model into the measurement model to capture these three components. Then, we provide an illustrative example using the public-use Early Childhood Longitudinal Study-Kindergarten data set using a Michaelis-Menten growth function (reparameterized from its common application in biochemistry) to demonstrate our proposed model as applied to measuring potential within an educational context. The advantage of this approach compared to currently utilized methods is discussed as are future directions and limitations.
Scintiscanning of arthritis and analysis of build-up curves
International Nuclear Information System (INIS)
Yamagishi, Tsuneo; Omori, Shigeo; Miyawaki, Haruo; Maniwa, Masato; Yoshizaki, Kenichi
1975-01-01
In the present study 40 knee joints with rheumatoid arthritis, 23 knee joints with osteoarthrosis deformans, 3 knee joints with non-synovitis, one knee joint with pyogenic arthritis and 4 normal knee joints were scanned. By analysis of build-up curves obtained immediately after the intravenous injection of sup(99m)Tc-pertechnetate, the rate of accumulation of radioactivity (t 1/2) in the affected joints was simultaneously estimated in order to compare them with clinical findings. 1. Scintiscanning of arthritis, rheumatoid arthritis, osteoarthrosis deformans of the knee joint, non-specific synovitis, and pyogenic arthritis of the knee joint, yielded a positive scan for all of the joint diseases. 2. In the scintigram of healthy knee joints, there are no areas of RI accumulation or right to left difference. 3. In some instances abnormal uptake of RI was seen on scintigrams of arthritis even after normal clinical and laboratory findings had been achieved with therapy. 4. sup(99m)Tc-pertechnetate, a radionuclide with a short half-life, allows repeated scans and provides a useful radiologic means of evaluating therapeutic course and effectiveness. 5. Analysis of build-up curves revealed that the rate of accumulation of RI was faster in rheumatoid arthritis than in osteoarthrosis deformans. (auth.)
Analysis of velocity planning interpolation algorithm based on NURBS curve
Zhang, Wanjun; Gao, Shanping; Cheng, Xiyan; Zhang, Feng
2017-04-01
To reduce interpolation time and Max interpolation error in NURBS (Non-Uniform Rational B-Spline) inter-polation caused by planning Velocity. This paper proposed a velocity planning interpolation algorithm based on NURBS curve. Firstly, the second-order Taylor expansion is applied on the numerator in NURBS curve representation with parameter curve. Then, velocity planning interpolation algorithm can meet with NURBS curve interpolation. Finally, simulation results show that the proposed NURBS curve interpolator meet the high-speed and high-accuracy interpolation requirements of CNC systems. The interpolation of NURBS curve should be finished.
Directory of Open Access Journals (Sweden)
Paula Beatriz Araujo
2004-03-01
Full Text Available The terrestrial isopod Atlantoscia floridana (van Name, 1940 occurs from the U.S.A. (Florida to Brazil and Argentina. In the southernmost Brazilian State, Rio Grande do Sul, the species is recorded in many localities, in urban and in non-urban areas. The growth curve of Atlantoscia floridana based on field data is presented. The specimens were sampled from April, 2000 to October, 2001 at the Reserva Biológica do Lami (RBL, Rio Grande do Sul. Captured individuals were sexed and had their cephalothorax width measured, with the data analyzed with von Bertalanffy's model. The growth curves for males and females are described, respectively, by the equations: Wt = 1.303 [1 - e-0.00941 (t + 50.37] and Wt = 1.682 [1 - e-0.00575 (t + 59.13]. The curves showed differential growth between sexes, where females reach a higher Wµ with a slower growth rate. Based on the growth curves it was also possible to estimate life expectancy for males and females.O isópodo terrestre Atlantoscia floridana (van Name, 1940 ocorre desde os Estados Unidos (Flórida até o Brasil e Argentina. No Rio Grande do Sul a espécie é registrada em muitas localidades, em áreas urbanas e não-urbanas. Este trabalho apresenta a curva de crescimento de Atlantoscia floridana, baseada em dados de campo. Os espécimes foram amostrados desde abril, 2000 a outubro, 2001 na Reserva Biológica do Lami (RBL, Rio Grande do Sul. Os indivíduos capturados foram sexados e tiveram o cefalotórax medido. Os dados foram analisados utilizando-se o modelo de von Bertalanffy. A curva de crescimento para machos e fêmeas são descritas, respectivamente, pelas equações Wt = 1.303 [1 - e-0.00941 (t + 50.37] e Wt = 1.682 [1 - e -0.00575 (t + 59.13]. As curvas mostraram crescimento diferencial entre os sexos, onde as fêmeas atingem o maior Wµ com uma taxa de crescimento menor. Com base nas curvas de crescimento também foi possível estimar a expectativa de vida para machos e fêmeas.
Fourier analysis of the light curves of eclipsing variables, XXIV
International Nuclear Information System (INIS)
Edalati, M.T.
1978-01-01
The aim of the present paper will be to evaluate numerically Jacobian and other functions which have been discussed in more detail in a previous paper of this series, and also choose the most convenient moments to obtain a good determination for the unknown eclipse parameters a and c 0 . More than 12 different pairs of g-functions for real values of m have been investigated numerically and diagrammatically. The behaviour of g-functions depends but very little on different combination of the moments, and related diagrams are approximately the same as g 2 and g 4 . The behaviour of the vanishing Jacobian, arising from different pairs of g-functions for real values of m>= 0 . Accordingly, the author obtains the optimum combination of the moments (i.e., A 6 , A 7 , A 8 and A 9 ) in g-functions g 7 and g 8 . It has been noted that the behaviour of the g-functions which depend on the combinations of the higher order moments (i.e., m>= 5) have been ruled out, because the proportional error of the moments Asub(2m) increases with increasing values of real m. The automated method has been tested successfully on the light curve of RT Per. Finally, a comparison is given of the elements of RT Per arising from two different pairs of g-functions, i.e. g 2 , g 4 and g 7 , g 8 for the light curves analysis. (Auth.)
Electromagnetic and structural interaction analysis of curved shell structures
International Nuclear Information System (INIS)
Horie, T.; Niho, T.
1993-01-01
This paper describes a finite element formulation of the eddy current and structure coupled problem for curved shell structures. Coupling terms produced by curved geometry as well as flat plate geometry were obtained. Both matrix equations for eddy current and structure were solved simultaneously using coupling sub-matrices. TEAM Workshop bench mark problem 16 was solved to verify the formulation and the computer code. Agreement with experimental results was very good for such plate problem. A coupled problem for cylindrical shell structure was also analyzed. Influence of each coupling term was examined. The next topic is the eigenvalues of the coupled equations. Although the coupled matrix equations are not symmetric, symmetry was obtained by introducing a symmetrizing variable. The eigenvalues of the coupled matrix equations are different from those obtained from the uncoupled equations because of the influence of the coupling sub-matrix components. Some parameters obtained by the eigenvalue analysis have characteristics of parameters which indicate the intensity of electromagnetic structural coupling effect. (author)
Analysis of interacting quantum field theory in curved spacetime
International Nuclear Information System (INIS)
Birrell, N.D.; Taylor, J.G.
1980-01-01
A detailed analysis of interacting quantized fields propagating in a curved background spacetime is given. Reduction formulas for S-matrix elements in terms of vacuum Green's functions are derived, special attention being paid to the possibility that the ''in'' and ''out'' vacuum states may not be equivalent. Green's functions equations are obtained and a diagrammatic representation for them given, allowing a formal, diagrammatic renormalization to be effected. Coordinate space techniques for showing renormalizability are developed in Minkowski space, for lambdaphi 3 /sub() 4,6/ field theories. The extension of these techniques to curved spacetimes is considered. It is shown that the possibility of field theories becoming nonrenormalizable there cannot be ruled out, although, allowing certain modifications to the theory, phi 3 /sub( 4 ) is proven renormalizable in a large class of spacetimes. Finally particle production from the vacuum by the gravitational field is discussed with particular reference to Schwarzschild spacetime. We shed some light on the nonlocalizability of the production process and on the definition of the S matrix for such processes
International Nuclear Information System (INIS)
Salas C, P.; Estrada G, R.; Gonzalez M, P.R.; Mendoza A, D.
2003-01-01
In this work, we present a mathematical analysis of the behavior of the thermoluminescent curve (Tl) induced by gamma radiation in samples made of zirconium oxide doped with different amounts of graphite. In accordance with the results gamma radiation induces a Tl curve with two maximum of emission localized in the temperatures at 139 and 250 C, the area under the curve is increasing as a function of the time of exposition to the radiation. The analysis of curve deconvolution, in accordance with the theory which indicates that this behavior must be obey a Boltzmann distribution, we found that each one of them has a different growth velocity as the time of exposition increase. In the same way, we observed that after the irradiation was suspended each one of the maximum decrease with different velocity. The behaviour observed in the samples is very interesting because the zirconium oxide has attracted the interest of many research groups, this material has demonstrated to have many applications in thermoluminescent dosimetry and it can be used in the quantification of radiation. (Author)
The Environmental Kuznets Curve. An empirical analysis for OECD countries
Energy Technology Data Exchange (ETDEWEB)
Georgiev, E.
2008-09-15
This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is rather an empirical artefact than a regularity.
The Environmental Kuznets Curve. An empirical analysis for OECD countries
International Nuclear Information System (INIS)
Georgiev, E.
2008-09-01
This paper tests the Environmental Kuznets Curve hypothesis for four local (SOx, NOx, CO, VOC) and two global (CO2, GHG) air pollutants. Using a new panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not hold for all gases. A meaningful Environmental Kuznets Curve exists only for CO, VOC and NOx, where for CO2 the curve is monotonically increasing. For GHG there is indication of an inverted U-shaped relationship between income and pollution, but still most countries are on the increasing path of the curve and hence the future development of the curve is uncertain. For SOx it was found that emissions follow an U-shaped curve. Based on the empirical results, the paper concludes that the Environmental Kuznets Curve does not hold for all gases, it is rather an empirical artefact than a regularity.
Stoel, R.D.; Peetsma, T.T.D.; Roeleveld, J.
2001-01-01
Latent growth curve (LGC) analysis of longitudinal data for pupils' school investment, self confidence and language ability is presented. A multivariate model is tested that relates the three developmental processes to each other and to intelligence. All processes show significant differences
Learning curve analysis of mitral valve repair using telemanipulative technology.
Charland, Patrick J; Robbins, Tom; Rodriguez, Evilio; Nifong, Wiley L; Chitwood, Randolph W
2011-08-01
To determine if the time required to perform mitral valve repairs using telemanipulation technology decreases with experience and how that decrease is influenced by patient and procedure variables. A single-center retrospective review was conducted using perioperative and outcomes data collected contemporaneously on 458 mitral valve repair surgeries using telemanipulative technology. A regression model was constructed to assess learning with this technology and predict total robot time using multiple predictive variables. Statistical analysis was used to determine if models were significantly useful, to rule out correlation between predictor variables, and to identify terms that did not contribute to the prediction of total robot time. We found a statistically significant learning curve (P learning percentage∗ derived from total robot times† for the first 458 recorded cases of mitral valve repair using telemanipulative technology is 95% (R(2) = .40). More than one third of the variability in total robot time can be explained through our model using the following variables: type of repair (chordal procedures, ablations, and leaflet resections), band size, use of clips alone in band implantation, and the presence of a fellow at bedside (P Learning in mitral valve repair surgery using telemanipulative technology occurs at the East Carolina Heart Institute according to a logarithmic curve, with a learning percentage of 95%. From our regression output, we can make an approximate prediction of total robot time using an additive model. These metrics can be used by programs for benchmarking to manage the implementation of this new technology, as well as for capacity planning, scheduling, and capital budget analysis. Copyright © 2011 The American Association for Thoracic Surgery. All rights reserved.
DEFF Research Database (Denmark)
Brünner, N; Spang-Thomsen, M; Vindeløv, L
1985-01-01
fraction of polyploid cells. The results suggest that estradiol induces a dose-dependent cell killing effect in the T61 human breast carcinoma. The correlation between the treatment-induced growth delay and the effect on the cell cycle distribution indicates that the changes in the cell cycle...
Nonlinear models for fitting growth curves of Nellore cows reared in the Amazon Biome
Directory of Open Access Journals (Sweden)
Kedma Nayra da Silva Marinho
2013-09-01
Full Text Available Growth curves of Nellore cows were estimated by comparing six nonlinear models: Brody, Logistic, two alternatives by Gompertz, Richards and Von Bertalanffy. The models were fitted to weight-age data, from birth to 750 days of age of 29,221 cows, born between 1976 and 2006 in the Brazilian states of Acre, Amapá, Amazonas, Pará, Rondônia, Roraima and Tocantins. The models were fitted by the Gauss-Newton method. The goodness of fit of the models was evaluated by using mean square error, adjusted coefficient of determination, prediction error and mean absolute error. Biological interpretation of parameters was accomplished by plotting estimated weights versus the observed weight means, instantaneous growth rate, absolute maturity rate, relative instantaneous growth rate, inflection point and magnitude of the parameters A (asymptotic weight and K (maturing rate. The Brody and Von Bertalanffy models fitted the weight-age data but the other models did not. The average weight (A and growth rate (K were: 384.6±1.63 kg and 0.0022±0.00002 (Brody and 313.40±0.70 kg and 0.0045±0.00002 (Von Bertalanffy. The Brody model provides better goodness of fit than the Von Bertalanffy model.
Mayer, M; Schmitt, K; Kapelari, K; Frisch, H; Köstl, G; Voigt, M
2010-01-01
Little is known about spontaneous growth of growth hormone (GH)-deficient children during infancy and childhood. Retrospectively, we calculated disease-specific pretreatment percentiles for height, weight, BMI and growth velocity of 113 GH-deficient boys and 41 GH-deficient girls from birth until 7 years of age, by mean and standard deviation. Infants with idiopathic GH deficiency (GHD) grow in disease-specific percentile channels. There is a significant difference in length and weight from birth onward compared to regional reference (pgrowth velocity, despite a wide variance in the first years, so height deficit became more evident with increasing age. GHD is a congenital disease no matter when height deficit becomes clinically evident, because GH-deficient children grow in disease-specific percentile channels with a highly significantly reduced length and weight, which demonstrates that GH is essential for adequate growth in infancy and early childhood. Copyright (c) 2010 S. Karger AG, Basel.
Directory of Open Access Journals (Sweden)
Tong Di Hua
2016-01-01
Full Text Available KR crack growth resistance curve can be used to predict crack propagation behavior, estimate the crack component bearing capacity after the crack, so KR curve research occupies very important position in the fracture mechanics. Based on crack growth resistance KR test curve of 2060 - T8E30 lithium aluminum alloy under the same thickness for different width, studies have shown that under the same thickness, the influence of the width on the resistance curve of crack propagation can be neglected. Empirical equation of resistance curve of crack extension of the smaller width specimen is given. Extending the fitting equation to that of larger width, it can be found that it is highly coincided with the experimental results.
ESTIMATING TORSION OF DIGITAL CURVES USING 3D IMAGE ANALYSIS
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Christoph Blankenburg
2016-04-01
Full Text Available Curvature and torsion of three-dimensional curves are important quantities in fields like material science or biomedical engineering. Torsion has an exact definition in the continuous domain. However, in the discrete case most of the existing torsion evaluation methods lead to inaccurate values, especially for low resolution data. In this contribution we use the discrete points of space curves to determine the Fourier series coefficients which allow for representing the underlying continuous curve with Cesàro’s mean. This representation of the curve suits for the estimation of curvature and torsion values with their classical continuous definition. In comparison with the literature, one major advantage of this approach is that no a priori knowledge about the shape of the cyclic curve parts approximating the discrete curves is required. Synthetic data, i.e. curves with known curvature and torsion, are used to quantify the inherent algorithm accuracy for torsion and curvature estimation. The algorithm is also tested on tomographic data of fiber structures and open foams, where discrete curves are extracted from the pore spaces.
Analysis and Design of Stimulus Response Curves of E. coli
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Andreas Kremling
2012-11-01
Full Text Available Metabolism and signalling are tightly coupled in bacteria. Combining several theoretical approaches, a core model is presented that describes transcriptional and allosteric control of glycolysis in Escherichia coli. Experimental data based on microarrays, signalling components and extracellular metabolites are used to estimate kinetic parameters. A newly designed strain was used that adjusts the incoming glucose flux into the system and allows a kinetic analysis. Based on the results, prediction for intracelluar metabolite concentrations over a broad range of the growth rate could be performed and compared with data from literature.
Directory of Open Access Journals (Sweden)
Vinay K Gupta
2016-06-01
Full Text Available Objective: The aim of the study is to assess the trend in mean BMI z-score among private schools’ students from their anthropometric records when there were missing values in the outcome. Methodology: The anthropometric measurements of student from class 1 to 12 were taken from the records of two private schools in Delhi, India from 2005 to 2010. These records comprise of an unbalanced longitudinal data that is not all the students had measurements recorded at each year. The trend in mean BMI z-score was estimated through growth curve model. Prior to that, missing values of BMI z-score were imputed through multiple imputation using the same model. A complete case analysis was also performed after excluding missing values to compare the results with those obtained from analysis of multiply imputed data. Results: The mean BMI z-score among school student significantly decreased over time in imputed data (β= -0.2030, se=0.0889, p=0.0232 after adjusting age, gender, class and school. Complete case analysis also shows a decrease in mean BMI z-score though it was not statistically significant (β= -0.2861, se=0.0987, p=0.065. Conclusions: The estimates obtained from multiple imputation analysis were better than those of complete data after excluding missing values in terms of lower standard errors. We showed that anthropometric measurements from schools records can be used to monitor the weight status of children and adolescents and multiple imputation using growth curve model can be useful while analyzing such data
Growth curves and their implications in hand-fed Monk parrots (Myiopsitta monachus
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Petzinger C
2015-10-01
Full Text Available Christina Petzinger,1,2 J Jill Heatley,3 John E Bauer1,2 1Comparative Animal Nutrition Research Laboratory, Department of Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, 2Intercollegiate Faculty of Nutrition, Texas A&M University, 3Zoological Medicine Service, Department of Small Animal Medicine and Surgery, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA Abstract: Monk parrots (Myiopsitta monachus were hand-fed over two chick seasons spanning of 2010 to 2011. Information from the growth curve of chicks hand-fed in 2010 was used to develop a feeding protocol for the 2011 season (Protocol-2011. This protocol addressed the problems of delayed followed by excessive growth experienced by parrots hand fed in 2010. Monk parrots that were hand-fed in 2011 following the new protocol experienced delayed growth after 20 days of age. However, some Monk parrots were fed in excess of Protocol-2011 and did not experience a major delay in growth. The energy requirement equations used to construct Protocol-2011 were low when compared to adult Monk parrot maintenance energy requirements. The data suggest that growing birds do not require approximately twice their adult maintenance energy requirements, as is the case for growing dogs. Additionally, there appear to be fluctuations in energy needs as Monk parrots grow. A major increase in energy needs occurred between days 18 and 23 posthatching, which corresponds to feather development and growth in Monk parrot chicks. Thus, multiple equations estimating energy requirements, rather than just one equation, are likely needed from hatching to fledging in order to ensure adequate energy is provided to chicks. More research on the energy requirements of growing Monk parrots, especially around the time of fledging and weaning, is needed to improve hand-fed methods and potentially the adult health of hand-fed birds. Keywords
International Nuclear Information System (INIS)
Saboori, Behnaz; Sulaiman, Jamalludin
2013-01-01
This paper tests for the short and long-run relationship between economic growth, carbon dioxide (CO 2 ) emissions and energy consumption, using the Environmental Kuznets Curve (EKC) by employing both the aggregated and disaggregated energy consumption data in Malaysia for the period 1980–2009. The Autoregressive Distributed Lag (ARDL) methodology and Johansen–Juselius maximum likelihood approach were used to test the cointegration relationship; and the Granger causality test, based on the vector error correction model (VECM), to test for causality. The study does not support an inverted U-shaped relationship (EKC) when aggregated energy consumption data was used. When data was disaggregated based on different energy sources such as oil, coal, gas and electricity, the study does show evidences of the EKC hypothesis. The long-run Granger causality test shows that there is bi-directional causality between economic growth and CO 2 emissions, with coal, gas, electricity and oil consumption. This suggests that decreasing energy consumption such as coal, gas, electricity and oil appears to be an effective way to control CO 2 emissions but simultaneously will hinder economic growth. Thus suitable policies related to the efficient consumption of energy resources and consumption of renewable sources are required. - Highlights: • We investigated the EKC hypothesis by using Malaysian energy aggregated and disaggregated data. • It was found that the EKC is not supported, using the aggregated data (energy consumption). • However using disaggregated energy data (oil, coal and electricity) there is evidence of EKC. • Causality shows no causal relationship between economic growth and energy consumption in the short-run. • Economic growth Granger causes energy consumption and energy consumption causes CO 2 emissions in long-run
Directory of Open Access Journals (Sweden)
Alun Gu
2017-07-01
Full Text Available Global inequity and the unbalance of water resources has been a critical issue for many years; and the Chinese per capita water resources are only 1/4 of the global average. Meanwhile, as the Chinese economy is growing rapidly, the demand of Chinese industrial water use is also increasing. In this case, it is important to balance the relationship between economic growth and industrial water use. In this study, a reduction model is established for the northeastern, northern coastal, eastern coastal, southern coastal, middle Yellow River, middle Yangtze River, southwestern, and northwestern regions to verify the environmental Kuznets curve (EKC for their respective industrial water use and provide theoretical support for decision making from an economic perspective. It adopts the per capita industrial water use and GDP of the eight economic zones from 2002 to 2014. The unit root test and co-integration test were adopted to analyze the stationarity of the data, and the triple reduction model was used for the fitting of variables. The relationship between per capita industrial water use and GDP showed an inverted U-shaped curve from 2002 to 2014 for China, as well as for the eastern coastal and middle Yangtze River regions, with the coordinates of the turning points being (9.8749, 4.6735, (10.3098, 5.4783, and (9.8184, 5.0622, respectively. The per capita GDP at the turning point of the inverted U-shaped curve is 18,000–30,000 Yuan (at constant prices from 2000. This study provides important thoughts and lessons for collaborative research into the relationship between industrial water consumption and economic development. The central government should focus on the central and western regions when creating policies for water resource management and technological development to improve their industrial water use efficiency.
Magneto-electro-elastic buckling analysis of nonlocal curved nanobeams
Ebrahimi, Farzad; Reza Barati, Mohammad
2016-09-01
In this work, a size-dependent curved beam model is developed to take into account the effects of nonlocal stresses on the buckling behavior of curved magneto-electro-elastic FG nanobeams for the first time. The governing differential equations are derived based on the principle of virtual work and Euler-Bernoulli beam theory. The power-law function is employed to describe the spatially graded magneto-electro-elastic properties. By extending the radius of the curved nanobeam to infinity, the results of straight nonlocal FG beams can be rendered. The effects of magnetic potential, electric voltage, opening angle, nonlocal parameter, power-law index and slenderness ratio on buckling loads of curved MEE-FG nanobeams are studied.
Directory of Open Access Journals (Sweden)
Mazur Anna
2015-03-01
Full Text Available This research empirically explores the relation between carbon dioxide emission and economic growth during the period 1992-2010, using panel data on the European Union countries. Both fixed and random effect models are employed to test the Environmental Kuznets Curve (EKC relationship between CO2 emissions and GDP per capita. While no U-shaped EKC was confirmed empirically for all 28 current EU member states, the graphical analysis demonstrates a justified turning point for CO2 emissions as GDP per capita reaches the level of 23,000 USD. Furthermore, there is a firm empirical ground for the EKC hypothesis based on data from 16 older, relatively high-income EU states. Thus, though not empirically confirmed, there is ample data verifying the existence of the EKC in EU economies.
Economic growth, trade and energy. Implications for the environmental Kuznets curve
International Nuclear Information System (INIS)
Suri, Vivek; Chapman, Duane
1998-01-01
The environmental Kuznets curve (EKC) hypothesis asserts that pollution follows an inverted-U path with respect to economic growth. The EKC has been explained in terms of structural changes in the composition of economic output and increased environmental regulation at higher income levels. While some authors have incorporated the impact of trade policy orientation on the EKC, the impact of the actual movement between countries of goods that embody pollution has not been considered. This paper attempts to econometrically quantify the effect using pooled cross-country and time-series data. The EKC hypothesis is examined with respect to commercial energy consumption, the source of many serious environmental problems. It was found that while both industrializing and industrialized countries have added to their energy requirements by exporting manufactured goods, the growth has been substantially higher in the former. At the same time, industrialized countries have been able to reduce their energy requirements by importing manufactured goods. Exports of manufactured goods by industrialized countries has thus been an important factor in generating the upward sloping portion of the EKC and imports by industrialized countries have contributed to the downward slope
Analysis of growth characteristics in short-term divergently selected ...
African Journals Online (AJOL)
weeks of age body weight in divergent lines of Japanese quail. Growth curves for both sexes within each selection group resembled the general sigmoid shape of a typical growth curve. Gompertz model curves and the observed growth curves were ...
Establishment of Uropygial Gland Growth Curves for White, Three-Way Crossed Mule Ducklings
Directory of Open Access Journals (Sweden)
YH Chen
2015-06-01
Full Text Available Growth curves for the uropygial gland (UG of white, 3-way crossed mule ducklings were established using the Gompertz function. In total, 144 ducklings were fed in 12 floor pens with 12 birds in each pen. Each pen contained an equal number of animals of each sex. Feed and water were supplied ad libitumthroughout the entire experimental period. The weekly change in UG weight was recorded in males and females from hatch to 8 weeks of age. The weight and length of the UG, the width of the lobus glandulae uropygialis, the length and width of the pluma of the circulus uropygialis, and the index of the papilla uropygialis were measured once a week in individual ducklings in one pen. The average UG weight gain observed in white, 3-way crossed drakes was significantly higher than that of ducks of 21-56 days of age (P< 0.05. The UG length was 1.64-2.23 times the width of the left or right lobe, and the development of the UG was delayed from 3-4 weeks of age. The morphology of the UG changed from elliptical to elongated-elliptical with age. The right and left lobus glandulae uropygialis were symmetrical. The Gompertz growth functions of the UG in drakes and ducks were W=5.49e-e-0.675(t-1.955 and W=4.76e-e-0.685(t-1.936, respectively, where t represents age in weeks. These equations indicated that the maximum growth rate for drakes occurred at 14.1 days of age and for ducks at 13.6 days of age.
Automatic generation and analysis of solar cell IV curves
Kraft, Steven M.; Jones, Jason C.
2014-06-03
A photovoltaic system includes multiple strings of solar panels and a device presenting a DC load to the strings of solar panels. Output currents of the strings of solar panels may be sensed and provided to a computer that generates current-voltage (IV) curves of the strings of solar panels. Output voltages of the string of solar panels may be sensed at the string or at the device presenting the DC load. The DC load may be varied. Output currents of the strings of solar panels responsive to the variation of the DC load are sensed to generate IV curves of the strings of solar panels. IV curves may be compared and analyzed to evaluate performance of and detect problems with a string of solar panels.
Phase Curve Analysis of Super-Earth 55 Cancri e
Angelo, Isabel; Hu, Renyu
2018-01-01
One of the primary questions when characterizing Earth-sized and super-Earth-sized exoplanets is whether they have a substantial atmosphere like Earth and Venus, or a bare-rock surface that may come with a tenuous atmosphere like Mercury. Phase curves of the planets in thermal emission provide clues to this question, because a substantial atmosphere would transport heat more efficiently than a bare-rock surface. Analyzing phase curve photometric data around secondary eclipse has previously been used to study energy transport in the atmospheres of hot Jupiters. Here we use phase curve, Spitzer time-series photometry to study the thermal emission properties of the super-Earth exoplanet 55 Cancri e. We utilize a previously developed semi-analytical framework to fit a physical model to infrared photometric data of host star 55 Cancri from the Spitzer telescope IRAC 2 band at 4.5 μm. The model uses various parameters of planetary properties including Bond albedo, heat redistribution efficiency (i.e., the ratio between the radiative timescale and advective timescale of the photosphere), and atmospheric greenhouse factor. The phase curve of 55 Cancri e is dominated by thermal emission with an eastward-shifted hot spot located on the planet surface. We determine the heat redistribution efficiency to be ≈1.47, which implies that the advective timescale is on the same order as the radiative timescale. This requirement from the phase curve cannot be met by the bare-rock planet scenario, because heat transport by currents of molten lava would be too slow. The phase curve thus favors the scenario with a substantial atmosphere. Our constraints on the heat redistribution efficiency translate to a photosphere pressure of ~1.4 bar. The Spitzer IRAC 2 band is thus a window into the deep atmosphere of the planet 55 Cancri e.
Payande, Abolfazl; Tabesh, Hamed; Shakeri, Mohammad Taghi; Saki, Azadeh; Safarian, Mohammad
2013-01-14
Growth charts are widely used to assess children's growth status and can provide a trajectory of growth during early important months of life. The objectives of this study are going to construct growth charts and normal values of weight-for-age for children aged 0 to 5 years using a powerful and applicable methodology. The results compare with the World Health Organization (WHO) references and semi-parametric LMS method of Cole and Green. A total of 70737 apparently healthy boys and girls aged 0 to 5 years were recruited in July 2004 for 20 days from those attending community clinics for routine health checks as a part of a national survey. Anthropometric measurements were done by trained health staff using WHO methodology. The nonparametric quantile regression method obtained by local constant kernel estimation of conditional quantiles curves using for estimation of curves and normal values. The weight-for-age growth curves for boys and girls aged from 0 to 5 years were derived utilizing a population of children living in the northeast of Iran. The results were similar to the ones obtained by the semi-parametric LMS method in the same data. Among all age groups from 0 to 5 years, the median values of children's weight living in the northeast of Iran were lower than the corresponding values in WHO reference data. The weight curves of boys were higher than those of girls in all age groups. The differences between growth patterns of children living in the northeast of Iran versus international ones necessitate using local and regional growth charts. International normal values may not properly recognize the populations at risk for growth problems in Iranian children. Quantile regression (QR) as a flexible method which doesn't require restricted assumptions, proposed for estimation reference curves and normal values.
Quantitation and gompertzian analysis of tumor growth
DEFF Research Database (Denmark)
Rygaard, K; Spang-Thomsen, M
1998-01-01
to transform the experimental data into useful growth curves. A transformed Gompertz function is used as the basis for calculating relevant parameters pertaining to tumor growth and response to therapy. The calculations are facilitated by use of a computer program which performs the necessary calculations...... and presents the growth data in graphic form....
Semiparametric analysis to estimate the deal effect curve
Heerde, Harald J. van; Leeflang, Peter S.H.; Wittink, Dick R.
1999-01-01
The marketing literature suggests several phenomena that may contribute to the shape of the relationship between sales and price discounts. These phenomena can produce severe nonlinearities and interactions in the curves, and we argue that those are best captured with a flexible approach. Since a
Semiparametric analysis to estimate the deal effect curve
Van Heerde, HJ; Leeflang, PSH; Wittink, DR
The marketing literature suggests several phenomena that may contribute to the nature of the relationship between sales and price discounts. These phenomena can produce complex nonlinearities and interactions in the deal effect curve that are best captured with a flexible approach. Because a fully
The GO Cygni system: photoelectric observations and light curves analysis
International Nuclear Information System (INIS)
Rovithis, P.; Rovithis-Livaniou, H.; Niarchos, P.G.
1990-01-01
Photoelectric observations, in B and V, of the system GO Cygni obtained during 1985 at the Kryonerion Astronomical Station of the National Observatory of Greece are given. The corresponding light curves (typical β Lyrae) are analysed using Frequency Domain techniques. New photoelectric and absolute elements for the system are given, and its period was found to continue its increasing
An algorithm for unified analysis on the thermoluminescence glow curve
International Nuclear Information System (INIS)
Chung, K.S.; Park, C.Y.; Lee, J.I.; Kim, J.L.
2014-01-01
An algorithm was developed to integrally handle excitation by radiation, relaxation and luminescence by thermal or optical stimulation in thermoluminescence (TL) and optically stimulated luminescence (OSL) processes. This algorithm reflects the mutual interaction between traps through a conduction band. Electrons and holes are created by radiation in the beginning, and these electrons move to the trap through the conduction band. These holes move to the recombination center through a valence band. The ratio of the electrons allocated to each trap differs with the recombination probability and these values also relevant to the process of luminescence. Accordingly, the glow curve can be interpreted by taking the rate of electron–hole pairs created by ionizing radiation as a unique initial condition. This method differs from the conventional method of interpreting the measured glow curve with the initial electron concentration allocated to each trap at the end of irradiation. A program using the Visual Studio's C# subsystem was made to realize such a developed algorithm. To verify this algorithm it was applied to LiF:Mg,Cu,Si. The TL glow curve was deconvoluted with a model of five traps, one deep trap and one recombination center (RC). - Highlights: • TL glow curve deconvolution employing interacting model. • Simulation both irradiation and TL readout stages for various dose level. • Application in the identification TL kinetics of LiF:Mg,Cu,Si TLD
Photometric Observation and Light Curve Analysis of Binary System ...
Indian Academy of Sciences (India)
Abstract. Photometric observations of the over-contact binary ER ORI were performed during November 2007 and February to April 2008 with the 51cm telescope of Biruni Observatory of Shiraz University in U, B and V filters (Johnson system) and an RCA 4509 photomultiplier. We used these data to obtain the light curves ...
UNSUPERVISED TRANSIENT LIGHT CURVE ANALYSIS VIA HIERARCHICAL BAYESIAN INFERENCE
Energy Technology Data Exchange (ETDEWEB)
Sanders, N. E.; Soderberg, A. M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Betancourt, M., E-mail: nsanders@cfa.harvard.edu [Department of Statistics, University of Warwick, Coventry CV4 7AL (United Kingdom)
2015-02-10
Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometric observations of 76 SNe, corresponding to a joint posterior distribution with 9176 parameters under our model. Our hierarchical model fits provide improved constraints on light curve parameters relevant to the physical properties of their progenitor stars relative to modeling individual light curves alone. Moreover, we directly evaluate the probability for occurrence rates of unseen light curve characteristics from the model hyperparameters, addressing observational biases in survey methodology. We view this modeling framework as an unsupervised machine learning technique with the ability to maximize scientific returns from data to be collected by future wide field transient searches like LSST.
UNSUPERVISED TRANSIENT LIGHT CURVE ANALYSIS VIA HIERARCHICAL BAYESIAN INFERENCE
International Nuclear Information System (INIS)
Sanders, N. E.; Soderberg, A. M.; Betancourt, M.
2015-01-01
Historically, light curve studies of supernovae (SNe) and other transient classes have focused on individual objects with copious and high signal-to-noise observations. In the nascent era of wide field transient searches, objects with detailed observations are decreasing as a fraction of the overall known SN population, and this strategy sacrifices the majority of the information contained in the data about the underlying population of transients. A population level modeling approach, simultaneously fitting all available observations of objects in a transient sub-class of interest, fully mines the data to infer the properties of the population and avoids certain systematic biases. We present a novel hierarchical Bayesian statistical model for population level modeling of transient light curves, and discuss its implementation using an efficient Hamiltonian Monte Carlo technique. As a test case, we apply this model to the Type IIP SN sample from the Pan-STARRS1 Medium Deep Survey, consisting of 18,837 photometric observations of 76 SNe, corresponding to a joint posterior distribution with 9176 parameters under our model. Our hierarchical model fits provide improved constraints on light curve parameters relevant to the physical properties of their progenitor stars relative to modeling individual light curves alone. Moreover, we directly evaluate the probability for occurrence rates of unseen light curve characteristics from the model hyperparameters, addressing observational biases in survey methodology. We view this modeling framework as an unsupervised machine learning technique with the ability to maximize scientific returns from data to be collected by future wide field transient searches like LSST
Self-regulation and recall: growth curve modeling of intervention outcomes for older adults.
West, Robin L; Hastings, Erin C
2011-12-01
Memory training has often been supported as a potential means to improve performance for older adults. Less often studied are the characteristics of trainees that benefit most from training. Using a self-regulatory perspective, the current project examined a latent growth curve model to predict training-related gains for middle-aged and older adult trainees from individual differences (e.g., education), information processing skills (strategy use) and self-regulatory factors such as self-efficacy, control, and active engagement in training. For name recall, a model including strategy usage and strategy change as predictors of memory gain, along with self-efficacy and self-efficacy change, showed comparable fit to a more parsimonious model including only self-efficacy variables as predictors. The best fit to the text recall data was a model focusing on self-efficacy change as the main predictor of memory change, and that model showed significantly better fit than a model also including strategy usage variables as predictors. In these models, overall performance was significantly predicted by age and memory self-efficacy, and subsequent training-related gains in performance were best predicted directly by change in self-efficacy (text recall), or indirectly through the impact of active engagement and self-efficacy on gains (name recall). These results underscore the benefits of targeting self-regulatory factors in intervention programs designed to improve memory skills.
Millan Núñez-Cortés, Jesús; Alvarez Rodriguez, Ysmael; Alvarez Novés, Granada; Recarte Garcia-Andrade, Carlos; Alvarez-Sala Walther, Luis
2014-01-01
HMG-CoA-Reductase inhibitors, also known as statins, are currently the most powerful cholesterol-lowering drugs available on the market. Clinical trials and experimental evidence suggest that statins have heavy anti-atherosclerotic effects. These are in part consequence of lipid lowering but also result from pleiotropic actions of the drugs. These so-called pleiotropic properties affect various aspects of cell function, inflammation, coagulation, and vasomotor activity. These effects are mediated either indirectly through LDL-c reduction or via a direct effect on cellular functions. Although many of the pleiotropic properties of statins may be a class effect, some may be unique to certain agents and account for differences in their pharmacological activity. So, although statins typically have similar effects on LDL-c levels, differences in chemical structure and pharmacokinetic profile can lead to variations in pleiotropic effects. In this paper we analize the in vitro effects of different statins over different cell lines from cells implicated in atherosclerotic process: endothelial cells, fibroblasts, and vascular muscular cells. In relation with our results we can proof that the effects of different dosis of different statins provides singular effects over growth curves of different cellular lines, a despite of a class-dependent effects. So, pleiotropic effects and its reversibility with mevalonate are different according with the molecule and the dosis. Copyright © 2013 Elsevier España, S.L. y SEA. All rights reserved.
Thermodynamic Activity-Based Progress Curve Analysis in Enzyme Kinetics.
Pleiss, Jürgen
2018-03-01
Macrokinetic Michaelis-Menten models based on thermodynamic activity provide insights into enzyme kinetics because they separate substrate-enzyme from substrate-solvent interactions. Kinetic parameters are estimated from experimental progress curves of enzyme-catalyzed reactions. Three pitfalls are discussed: deviations between thermodynamic and concentration-based models, product effects on the substrate activity coefficient, and product inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.
The learning curve: implications of a quantitative analysis.
Gallistel, Charles R; Fairhurst, Stephen; Balsam, Peter
2004-09-07
The negatively accelerated, gradually increasing learning curve is an artifact of group averaging in several commonly used basic learning paradigms (pigeon autoshaping, delay- and trace-eye-blink conditioning in the rabbit and rat, autoshaped hopper entry in the rat, plus maze performance in the rat, and water maze performance in the mouse). The learning curves for individual subjects show an abrupt, often step-like increase from the untrained level of responding to the level seen in the well trained subject. The rise is at least as abrupt as that commonly seen in psychometric functions in stimulus detection experiments. It may indicate that the appearance of conditioned behavior is mediated by an evidence-based decision process, as in stimulus detection experiments. If the appearance of conditioned behavior is taken instead to reflect the increase in an underlying associative strength, then a negligible portion of the function relating associative strength to amount of experience is behaviorally visible. Consequently, rate of learning cannot be estimated from the group-average curve; the best measure is latency to the onset of responding, determined for each subject individually.
Fourier analysis of the light curves of eclipsing variables. XV
International Nuclear Information System (INIS)
Demircan, O.
1978-01-01
A new general expression for the theoretical moments Asub(2m) of the light curves of eclipsing systems has been presented in the form of infinite series expansion. In this expansion, the terms have been given as the product of two different polynomials which satisfy certain three-term recursion formulae, and the coefficients diminish rapidly with increasing number of terms. Thus, the numerical values of the theoretical moments Asub(2m) can be generated recursively up to four significant figures for any given set of eclipse elements. This can be utilized to solve the eclipse elements in two ways: (i) with an indirect method, (ii) with a direct method as minimization to the observational moments Asub(2m) (area fitting). The procedures for obtaining the elements of any eclipsing system consisting of spherical stars have been automated by making use of the new expression for the moments Asub(2m) of the light curves. The theoretical functions f 0 , f 2 , f 4 , f 6 , g 2 and g 4 which are the functions of a and c 0 , have been used to solve the eclipse elements from the observed photometric data. The closed-form expressions for the functions f 2 , f 4 and f 6 have also been derived in terms of Kopal's I-integrals. The automated methods for obtaining the eclipse elements from one minimum alone have been tested on the light curves of YZ (21) Cassiopeiae under the spherical model assumptions. The results of these applications are given. (Auth.)
Paleomagnetic analysis of curved thrust belts reproduced by physical models
Costa, Elisabetta; Speranza, Fabio
2003-12-01
This paper presents a new methodology for studying the evolution of curved mountain belts by means of paleomagnetic analyses performed on analogue models. Eleven models were designed aimed at reproducing various tectonic settings in thin-skinned tectonics. Our models analyze in particular those features reported in the literature as possible causes for peculiar rotational patterns in the outermost as well as in the more internal fronts. In all the models the sedimentary cover was reproduced by frictional low-cohesion materials (sand and glass micro-beads), which detached either on frictional or on viscous layers. These latter were reproduced in the models by silicone. The sand forming the models has been previously mixed with magnetite-dominated powder. Before deformation, the models were magnetized by means of two permanent magnets generating within each model a quasi-linear magnetic field of intensity variable between 20 and 100 mT. After deformation, the models were cut into closely spaced vertical sections and sampled by means of 1×1-cm Plexiglas cylinders at several locations along curved fronts. Care was taken to collect paleomagnetic samples only within virtually undeformed thrust sheets, avoiding zones affected by pervasive shear. Afterwards, the natural remanent magnetization of these samples was measured, and alternating field demagnetization was used to isolate the principal components. The characteristic components of magnetization isolated were used to estimate the vertical-axis rotations occurring during model deformation. We find that indenters pushing into deforming belts from behind form non-rotational curved outer fronts. The more internal fronts show oroclinal-type rotations of a smaller magnitude than that expected for a perfect orocline. Lateral symmetrical obstacles in the foreland colliding with forward propagating belts produce non-rotational outer curved fronts as well, whereas in between and inside the obstacles a perfect orocline forms
Existence of a common growth curve for silt-sized quartz OSL of loess from different continents
International Nuclear Information System (INIS)
Lai Zhongping; Brueckner, Helmut; Zoeller, Ludwig; Fuelling, Alexander
2007-01-01
Recent publications revealed different opinions regarding the existence of a common growth curve (CGC) for OSL of quartz. In the current study, 18 loess samples were collected from four continents (Asia, America, Africa, and Europe) in order to further examine this issue. Except the three samples from Chile in South America, 15 samples display similar dose-response curves up to a regeneration dose of 200 Gy using the SAR protocol, suggesting the existence of a global CGC for loess from different continents. For samples with equivalent doses (D e ) from ∼10 to ∼170Gy, the D e s determined by the CGC are in good agreement with the D e s by the SAR protocol. The Chilean samples posses a growth curve that differs from the CGC, showing much lower saturation doses. We suggest that it may be due to contamination with heavy minerals
The Effect of Divergent Selection on 4-wk BW on the Shape of Growth Curve in Japanese Quail
Directory of Open Access Journals (Sweden)
H Beyki
2011-12-01
Full Text Available The current study was conducted to investigate the effect of short-term divergent selection on the shape growth curve in different lines of Japanese quail. The Quail lines utilized in this study were two divergently selected for high (HW and low (LW 4-wk body weight during 7 generation and also a control line (C. The Richard function parameters were used to describe growth curves of different lines. The weight at hatch was approximately similar among lines (8.08 g, 7.55 g and 8.76 g for HW, LW and C line respectively. The results of current study indicated that the selected lines (HW & LW were immediately diverged from the C line after hatch. Sexes within each line had no difference in average growth rate, age and body weight at inflection point and adult body weight. However significant differences were found in the growth curve parameters among lines. The results of current study indicated that short term divergent selection for 4-wk BW in Japanese quail can change the growth pattern and the carcass compartments of the selected birds. Therefore to avoid undesirable side effects due to selection in Japanese quails it is recommended to consider the growth pattern changes of the selected birds in the breeding programs
Mozos, de los J.; Garcia Ruiz, A.I.; Hartog, den L.A.; Villamide, M.J.
2017-01-01
The aim of this work has been to assess the effect of diet density [control (CON) or 15% diluted (DIL)] and growth curve [recommended by the genetic line (RBW) or 15% heavier (HBW)] and their interaction on BW uniformity, feeding motivation, behavior, and body composition of broiler breeder pullets.
Robert O. Curtis; Nancy M. Diaz; Gary W. Clendenen
1990-01-01
Height growth and site index curves were constructed from stem analyses of mature western white pine (Pinus monticola Dougl. ex D. Don) growing in high-elevation forests of the Cascade Range in the Mount Hood and Gifford Pinchot National Forests of Oregon and Washington, respectively. Alternate systems using reference ages for site index of 50 and...
Directory of Open Access Journals (Sweden)
Prabuddha Manjula
2018-01-01
Full Text Available Objective This study estimated the genetic parameters for body weight gain and growth curve parameter traits in Korean native chicken (KNC. Methods A total of 585 F1 chickens were used along with 88 of their F0 birds. Body weights were measured every 2 weeks from hatching to 20 weeks of age to measure weight gain at 2-week intervals. For each individual, a logistic growth curve model was fitted to the longitudinal growth dataset to obtain three growth curve parameters (α, asymptotic final body weight; β, inflection point; and γ, constant scale that was proportional to the overall growth rate. Genetic parameters were estimated based on the linear-mixed model using a restricted maximum likelihood method. Results Heritability estimates of body weight gain traits were low to high (0.057 to 0.458. Heritability estimates for α, β, and γ were 0.211±0.08, 0.249±0.09, and 0.095±0.06, respectively. Both genetic and phenotypic correlations between weight gain traits ranged from −0.527 to 0.993. Genetic and phenotypic correlation between the growth curve parameters and weight gain traits ranged from −0.968 to 0.987. Conclusion Based on the results of this study population, we suggest that the KNC could be used for selective breeding between 6 and 8 weeks of age to enhance the overall genetic improvement of growth traits. After validation of these results in independent studies, these findings will be useful for further optimization of breeding programs for KNC.
Environment Kuznets curve for CO{sub 2} emissions. A cointegration analysis for China
Energy Technology Data Exchange (ETDEWEB)
Jalil, Abdul [Centre for Economic Development Research, Wuhan University, Wuhan 437002 (China); Mahmud, Syed F. [Department of Economics, Bilkent University, Ankara 06800 (Turkey)
2009-12-15
This study examines the long-run relationship between carbon emissions and energy consumption, income and foreign trade in the case of China by employing time series data of 1975-2005. In particular the study aims at testing whether environmental Kuznets curve (EKC) relationship between CO{sub 2} emissions and per capita real GDP holds in the long run or not. Auto regressive distributed lag (ARDL) methodology is employed for empirical analysis. A quadratic relationship between income and CO{sub 2} emission has been found for the sample period, supporting EKC relationship. The results of Granger causality tests indicate one way causality runs through economic growth to CO{sub 2} emissions. The results of this study also indicate that the carbon emissions are mainly determined by income and energy consumption in the long run. Trade has a positive but statistically insignificant impact on CO{sub 2} emissions. (author)
Environment Kuznets curve for CO{sub 2} emissions: A cointegration analysis for China
Energy Technology Data Exchange (ETDEWEB)
Jalil, Abdul, E-mail: jalil.hanif@gmail.co [Centre for Economic Development Research, Wuhan University, Wuhan 437002 (China); Mahmud, Syed F., E-mail: syed@bilkent.edu.t [Department of Economics, Bilkent University, Ankara 06800 (Turkey)
2009-12-15
This study examines the long-run relationship between carbon emissions and energy consumption, income and foreign trade in the case of China by employing time series data of 1975-2005. In particular the study aims at testing whether environmental Kuznets curve (EKC) relationship between CO{sub 2} emissions and per capita real GDP holds in the long run or not. Auto regressive distributed lag (ARDL) methodology is employed for empirical analysis. A quadratic relationship between income and CO{sub 2} emission has been found for the sample period, supporting EKC relationship. The results of Granger causality tests indicate one way causality runs through economic growth to CO{sub 2} emissions. The results of this study also indicate that the carbon emissions are mainly determined by income and energy consumption in the long run. Trade has a positive but statistically insignificant impact on CO{sub 2} emissions.
Environment Kuznets curve for CO2 emissions: A cointegration analysis for China
International Nuclear Information System (INIS)
Jalil, Abdul; Mahmud, Syed F.
2009-01-01
This study examines the long-run relationship between carbon emissions and energy consumption, income and foreign trade in the case of China by employing time series data of 1975-2005. In particular the study aims at testing whether environmental Kuznets curve (EKC) relationship between CO 2 emissions and per capita real GDP holds in the long run or not. Auto regressive distributed lag (ARDL) methodology is employed for empirical analysis. A quadratic relationship between income and CO 2 emission has been found for the sample period, supporting EKC relationship. The results of Granger causality tests indicate one way causality runs through economic growth to CO 2 emissions. The results of this study also indicate that the carbon emissions are mainly determined by income and energy consumption in the long run. Trade has a positive but statistically insignificant impact on CO 2 emissions.
Ruddock, Scott; Caeyenberghs, Karen; Piek, Jan; Sugden, David; Hyde, Christian; Morris, Sue; Rigoli, Daniela; Steenbergen, Bert; Wilson, Peter
2016-11-01
Previous research indicates that children with Developmental Coordination Disorder (DCD) show deficits performing online corrections, an issue exacerbated by adding inhibitory constraints; however, cross-sectional data suggests that these deficits may reduce with age. Using a longitudinal design, the aim of the study presented here was to model the coupling that occurs between inhibitory systems and (predictive) online control in typically developing children (TDC) and in those with Developmental Coordination Disorder (DCD) over an extended period of time, using a framework of interactive specialization. We predicted that TDC would show a non-linear growth pattern, consistent with re-organisation in the coupling during the middle childhood period, while DCD would display a developmental lag. A group of 196 children (111 girls and 85 boys) aged between 6 and 12years participated in the study. Children were classified as DCD according to research criteria. Using a cohort sequential design, both TDC and DCD groups were divided into age cohorts. Predictive (online) control was defined operationally by performance on a Double-Jump Reaching Task (DJRT), which was assessed at 6-month intervals over two years (5 time points in total). Inhibitory control was examined using an anti-jump condition of the DJRT paradigm whereby children were instructed to touch a target location in the hemispace opposite a cued location. For the TDC group, model comparison using growth curve analysis revealed that a quadratic trend was the most appropriate fit with evidence of rapid improvement in anti-reach performance up until middle childhood (around 8-9years of age), followed by a more gradual rate of improvement into late childhood and early adolescence. This pattern was evident on both chronometric and kinematic measures. In contrast, for children with DCD, a linear function provided the best to fit on the key metrics, with a slower rate of improvement than controls. We conclude that
The environmental Kuznets curve and sustainability: A panel data analysis
International Nuclear Information System (INIS)
Farhani, Sahbi; Mrizak, Sana; Chaibi, Anissa; Rault, Christophe
2014-01-01
In recent years, sustainability has represented one of the most important policy goals explored in the environmental Kuznets curve (EKC) literature. But related hypotheses, performance measures and results continue to present a challenge. The present paper contributes to this ongoing literature by studying two different EKC specifications for 10 Middle East and North African (MENA) countries over the period 1990–2010 using panel data methods. For the first specification, namely EKC, we show that there is an inverted U-shape relationship between environmental degradation and income; while for the second specification, namely modified EKC (MEKC), we show that there is an inverted U-shape relationship between sustainability and human development (HD). The relationships are shaped by other factors such as energy, trade, manufacture added value and the role of law. More interestingly, findings from the estimation show that EKC hypothesis, HD and sustainability are crucial to build effective environmental policies. - Highlights: • Environmental Kuznets curve (EKC) and modified EKC models are examined for 10 MENA countries. • We attempt to include energy, trade, human development and sustainability in our approach. • The inverted U-shape relationship is verified for two models. • Human development positively affects the pollution and sustainability level
Maulana, Ridwan; Opdenakker, Marie-Christine; Bosker, Roel
2014-09-01
Research has shown that the teacher-student interpersonal relationship (TSIR) is important for student motivation. Although TSIR has received a growing interest, there are only few studies that focus on changes and links between TSIR and student academic motivation in a longitudinal fashion in non-Western contexts. This study investigated changes in TSIR and links with academic motivation as perceived by first-grade secondary school students in Indonesia. TSIR was studied from the perspective of interpersonal behaviour in terms of Influence and Proximity. Students' academic motivation was studied from the perspective of self-determination theory. A total of 504 first-grade secondary school students of 16 mathematics and English classes participated in the study. Surveys were administered in five waves throughout the school year. Multilevel growth curve modelling was applied. Contrary to the (limited) general research findings from Western contexts, we found that the quality of TSIR (student perceptions) increased over time. The increase was slightly more pronounced for Proximity than for Influence. In accordance with the findings for the Western countries, the level of students' controlled motivation increased, while that of autonomous motivation decreased over time. However, the negative change in autonomous motivation was less pronounced. As in Western countries, TSIR was longitudinally linked with academic motivation, in particular, with autonomous motivation. Evidence is found that TSIR can change in a favourable way, and this positively affects student motivation. Future research could benefit from unravelling the influences of cultures on changes in TSIR in broader contexts. © 2013 The British Psychological Society.
Ntoumanis, N; Stenling, A; Thøgersen-Ntoumani, C; Vlachopoulos, S; Lindwall, M; Gucciardi, D F; Tsakonitis, C
2018-02-01
Past work linking exercise identity and exercise motivation has been cross-sectional. This is the first study to model the relations between different types of exercise identity and exercise motivation longitudinally. Understanding the dynamic associations between these sets of variables has implications for theory development and applied research. This was a longitudinal survey study. Participants were 180 exercisers (79 men, 101 women) from Greece, who were recruited from fitness centers and were asked to complete questionnaires assessing exercise identity (exercise beliefs and role-identity) and exercise motivation (intrinsic, identified, introjected, external motivation, and amotivation) three times within a 6 month period. Multilevel growth curve modeling examined the role of motivational regulations as within- and between-level predictors of exercise identity, and a model in which exercise identity predicted exercise motivation at the within- and between-person levels. Results showed that within-person changes in intrinsic motivation, introjected, and identified regulations were positively and reciprocally related to within-person changes in exercise beliefs; intrinsic motivation was also a positive predictor of within-person changes in role-identity but not vice versa. Between-person differences in the means of predictor variables were predictive of initial levels and average rates of change in the outcome variables. The findings show support to the proposition that a strong exercise identity (particularly exercise beliefs) can foster motivation for behaviors that reinforce this identity. We also demonstrate that such relations can be reciprocal overtime and can depend on the type of motivation in question as well as between-person differences in absolute levels of these variables. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
International Nuclear Information System (INIS)
Kim, Dong Wook; Chang, Hyun Joon
2012-01-01
Increasing awareness on environmental damage and climate change has induced many nations to engage in green growth. South Korea, as one of the largest consumers of energy, is no exception and has shown its determination to pursue green growth in the future. In order to do so, South Korea plans to substitute fossil fuel with alternative sources in electricity generation. However, the key constraint to green growth is the high cost faced by renewable electricity generation. Fortunately, nuclear energy can serve as an economic alternative to fossil fuel. To achieve CO 2 emission reduction and faster economic growth, it is wise to analyze prospects of alternatives using experience curve framework. The results and industry background are consistent for nuclear technology, and the results suggest that nuclear should serve as the main substitute. Consideration of policy risk inherent in renewable also strengthens the argument. Renewable technologies, on the other hand, showed overstated learning capacity that is partially inconsistent with technological background. Nevertheless, the renewable (photovoltaic and fuel cell) should help nuclear marginally in substituting fossil fuel in South Korea's Electricity Generation. - Highlights: ► Progress ratios of renewable energy show great prospect. ► The policy risk is inherent in renewable and may overestimate its prospect. ► Nuclear sources are economic and less affected by policy risk. ► Fuel cell and photovoltaic should help nuclear marginally in green growth.
Establishment and validation of a dose-effect curve for γ-rays by cytogenetic analysis
International Nuclear Information System (INIS)
Barquinero, Joan F.; Caballin, Maria Rosa; Barrios, Leonardo; Ribas, Montserrat; Miro, Rosa; Egozcue, Josep
1995-01-01
A dose-effect curve obtained by analysis of dicentric chromosomes after irradiation of peripheral blood samples, from one donor, at 11 different doses of γ-rays is presented. For the elaboration of this curve, more than 18,000 first division metaphases have been analyzed. The results fit very well to the linear-quadratic model. To validate the curve, samples from six individuals (three controls and three occupationally exposed persons) were irradiated at 2 Gy. The results obtained, when compared with the curve, showed that in all cases the 95% confidence interval included the 2 Gy dose, with estimated dose ranges from 1.82 to 2.19 Gy
Fourier techniques for an analysis of eclipsing binary light curves. Pt. 6b
International Nuclear Information System (INIS)
Demircan, O.
1980-01-01
This is a continuation of a previous paper which appeared in this journal (Demircan, 1980b) and aims at ascertaining some other relations between the integral transforms of the light curves of eclipsing binary systems. The appropriate use of these relations should facilitate the numerical computations for an analysis of eclipsing binary light curves by different Fourier techniques. (orig.)
p-y-ẏ curves for dynamic analysis of offshore wind turbine monopile foundations
DEFF Research Database (Denmark)
Bayat, Mehdi; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo
2016-01-01
Highlights •A two-dimensional analysis of a monopile segment moving horizontally through saturated soil is analyzed. •A p−y−ẏ curve accounting for the rate of pile motion is proposed as an alternative to static p−y curves. •The stiffness and damping properties related to soil structure interaction...
Supplementary Material for: Growth curve registration for evaluating salinity tolerance in barley
Meng, Rui; Saade, Stephanie; Kurtek, Sebastian; Berger, Bettina; Brien, Chris; Pillen, Klaus; Tester, Mark A.; Sun, Ying
2017-01-01
of HEB-25 barley families and the commercial variety, Navigator. We account for the spatial variation in smarthouse microclimates and in temporal variation across phenotyping runs using a functional ANOVA model to derive corrected FSS curves. From FSS, we
Income inequality and economic growth¡ª¡ªthe Kuznets curve revisited
YIN Heng; GONG Liutang; ZOU Heng-fu
2006-01-01
In a neoclassical growth framework with a typical political-economy mechanism, this paper reexamines the relationship between the income inequality and economic growth by introducing government spending into the production function and the utility function. It demonstrates that Kuznets famous inverted-U shape relationship between inequality and economic growth will hold the growth rate will be first increasing with the income inequality before the growth rate decreases with inequality.
Curvas de crescimento na produção animal Growth curves in animal production
Directory of Open Access Journals (Sweden)
Alfredo Ribeiro de Freitas
2005-06-01
Full Text Available Foram discutidas as propriedades de sete modelos não-lineares, considerando-se o ajuste de curvas de crescimento na produção animal. Os modelos utilizados: Brody, Richards, Von Bertalanffy e duas alternativas de Gompertz e de Logístico foram ajustados, pelo método de Gauss Newton por meio do procedimento NLIN do SAS, a dados peso-idade de oito espécies: camarão-d'água-doce, rã-pimenta, coelho, frango, ovino, caprino, suíno e bovino. Considerando-se os critérios como: convergência ou não, coeficiente de determinação e interpretabilidade biológica dos parâmetros, concluiu-se que: a o modelo Logístico y= A/(1 + e-ktm estimou o peso em todas as espécies animais, enquanto o de Von Bertalanffy apenas não foi adequado para camarão; b os dois modelos Gompertz foram adequados para camarão, rã, frango, suíno e bovino; c em cada espécie, pelo menos dois dos sete modelos mostraram-se adequados para estimar o crescimento corporal das espécies animais estudadas, pois os coeficientes de determinação foram superiores a 92,0%.The properties of seven nonlinear models were discussed concerning its applications in the fitting of growth curves in animal production. The models used: Brody, Richards, Von Bertalanffy and two alternatives of Gompertz and Logistic models, were fitted by Gauss Newton method to weight-age data from eight animal species: freshwater prawn Macrobrachium rosenbergi, pepper frog, rabbit, poultry, sheep, goat, swine and cattle. Considering results of the fitted models such as convergence or not, coefficient of determination and biological interpretation of parameters, it was concluded that: a the Logisticmethod y = A/(1 + e-ktm estimated body weight in all species, while the Von Bertalanffy model was not adequate only for freshwater prawn Macrobrachium rosenbergi; b both Gompertz models were adequate for freshwater prawn Macrobrachium rosenbergi, pepper frog, poultry, swine and cattle; c for each specie, at least two
Directory of Open Access Journals (Sweden)
Xavier João B
2011-06-01
Full Text Available Abstract Background Online spectrophotometric measurements allow monitoring dynamic biological processes with high-time resolution. Contrastingly, numerous other methods require laborious treatment of samples and can only be carried out offline. Integrating both types of measurement would allow analyzing biological processes more comprehensively. A typical example of this problem is acquiring quantitative data on rhamnolipid secretion by the opportunistic pathogen Pseudomonas aeruginosa. P. aeruginosa cell growth can be measured by optical density (OD600 and gene expression can be measured using reporter fusions with a fluorescent protein, allowing high time resolution monitoring. However, measuring the secreted rhamnolipid biosurfactants requires laborious sample processing, which makes this an offline measurement. Results Here, we propose a method to integrate growth curve data with endpoint measurements of secreted metabolites that is inspired by a model of exponential cell growth. If serial diluting an inoculum gives reproducible time series shifted in time, then time series of endpoint measurements can be reconstructed using calculated time shifts between dilutions. We illustrate the method using measured rhamnolipid secretion by P. aeruginosa as endpoint measurements and we integrate these measurements with high-resolution growth curves measured by OD600 and expression of rhamnolipid synthesis genes monitored using a reporter fusion. Two-fold serial dilution allowed integrating rhamnolipid measurements at a ~0.4 h-1 frequency with high-time resolved data measured at a 6 h-1 frequency. We show how this simple method can be used in combination with mutants lacking specific genes in the rhamnolipid synthesis or quorum sensing regulation to acquire rich dynamic data on P. aeruginosa virulence regulation. Additionally, the linear relation between the ratio of inocula and the time-shift between curves produces high-precision measurements of
Prediction of Accurate Mixed Mode Fatigue Crack Growth Curves using the Paris' Law
Sajith, S.; Krishna Murthy, K. S. R.; Robi, P. S.
2017-12-01
Accurate information regarding crack growth times and structural strength as a function of the crack size is mandatory in damage tolerance analysis. Various equivalent stress intensity factor (SIF) models are available for prediction of mixed mode fatigue life using the Paris' law. In the present investigation these models have been compared to assess their efficacy in prediction of the life close to the experimental findings as there are no guidelines/suggestions available on selection of these models for accurate and/or conservative predictions of fatigue life. Within the limitations of availability of experimental data and currently available numerical simulation techniques, the results of present study attempts to outline models that would provide accurate and conservative life predictions.
Study on elastic-plastic deformation analysis using a cyclic stress-strain curve
International Nuclear Information System (INIS)
Igari, Toshihide; Setoguchi, Katsuya; Yamauchi, Masafumi
1983-01-01
This paper presents the results of the elastic-plastic deformation analysis using a cyclic stress-strain curve with an intention to apply this method for predicting the low-cycle fatigue life. Uniaxial plastic cycling tests were performed on 2 1/4Cr-1Mo steel to investigate the correspondence between the cyclic stress-strain curve and the hysteresis loop, and also to determine what mathematical model should be used for analysis of deformation at stress reversal. Furthermore, a cyclic in-plane bending test was performed on a flat plate to clarify the validity of the cyclic stress-strain curve-based theoretical analysis. The results obtained are as follows: (1) The cyclic stress-strain curve corresponds nearly to the ascending curve of hysteresis loop scaled by a factor of 1/2 for both stress and strain. Therefore, the cyclic stress-strain curve can be determined from the shape of hysteresis loop, for simplicity. (2) To perform the elastic-plastic deformation analysis using the cyclic stress-strain curve is both practical and effective for predicting the cyclic elastic-plastic deformation of structures at the stage of advanced cycles. And Masing model can serve as a suitable mathematical model for such a deformation analysis. (author)
Dong, Jianghu J; Wang, Liangliang; Gill, Jagbir; Cao, Jiguo
2017-01-01
This article is motivated by some longitudinal clinical data of kidney transplant recipients, where kidney function progression is recorded as the estimated glomerular filtration rates at multiple time points post kidney transplantation. We propose to use the functional principal component analysis method to explore the major source of variations of glomerular filtration rate curves. We find that the estimated functional principal component scores can be used to cluster glomerular filtration rate curves. Ordering functional principal component scores can detect abnormal glomerular filtration rate curves. Finally, functional principal component analysis can effectively estimate missing glomerular filtration rate values and predict future glomerular filtration rate values.
International Nuclear Information System (INIS)
Spang-Thomsen, M.; Visfeldt, J.; Nielsen, A.
1981-01-01
A human malignant melanoma transplanted into nude mice was exposed to single-dose x irradiation. Experimental growth data described mathematically according to a transformed Gompertz function were used to determine the effect of irradiation on growth delay, growth rate, and tumor shrinkage. The radiation-induced changes in the histology of the tumors were also described. The results showed that irradiation induced a dose-dependent growth delay; this parameter was therefore found suitable for the assessment of relative therapeutic effect. The treatment also induced a dose-dependent reduction in growth rate during regrowth. As a result of this effect on growth rate, extrapolation of tumor shrinkage to the time of treatment became directly misleading as a measure of the effect of the treatment. From this it can be deduced that in therapeutic studies where treatment induces nonparallel posttherapeutic growth curves, growth delay for various tumors and therapies cannot be compared directly. The transformed Gompertz function proved to be extremely well suited for evaluating these conditions
Estimating water use of mature pecan orchards: A six stage crop growth curve approach
CSIR Research Space (South Africa)
Ibraimo, NA
2016-11-01
Full Text Available previous study in New Mexico, revealed that a six stage crop coefficient curve should be considered for pecans, together with higher mid-season crop coefficient (K(subc)) values for mature orchards. More accurate estimates of monthly ET for mature pecan...
International Nuclear Information System (INIS)
Bergmann, H.; Mostbeck, A.; Samal, M.; Nimmon, C.C.; Staudenherz, A.; Dudczak, R.
2002-01-01
Aim: In a previous work, we have confirmed earlier reports that time-activity curves of renal cortex provide additional useful diagnostic information. The aim of this experiment was to support the finding quantitatively using multiple regression. Materials and Methods: In a retrospective study, we have analyzed MAG3 renal data (90 kidneys in 57 children). Whole-kidney (WK) and parenchymal (PA) time-activity curves were extracted from 20 min pre-diuretic phase using standard WK and parenchymal fuzzy ROIs. Using multiple regression analysis, peak time, mean transit time, output efficiency, and four additional indices of residual activity in WK and PA ROIs were related to the maximum elimination rate (EM) of urine after the diuretic. The kidneys were divided into four groups according to the WK peak time (WKPT): WKPT longer than 0 (all kidneys), 5, 10, and 15 min. Results: Multiple correlation coefficients between the set of WK, PA, and WK+PA curve parameters (independent variables) and the log EM (dependent variable) for each group are summarized. Conclusions: Using pre-diuretic time-activity curves, it is possible to predict diuretic response. This can be useful when interpreting dubious results. Parenchymal curves predict diuretic response better than the whole-kidney curves. With increasing WKPT the whole-kidney curves become useless, while the parenchymal curves are still useful. Using both WK and PA curves produces the best results. This demonstrates that both WK and PA curves carry independent diagnostic information. The contribution obtained from the parenchymal curves certainly worth the difficulties and time required to draw additional ROIs. However, substantial efforts have to be given to the accurate and reproducible definition of parenchymal ROIs
International Nuclear Information System (INIS)
Orubu, Christopher O.; Omotor, Douglason G.
2011-01-01
This study investigated the relationship between per capita income and environmental degradation in Africa, using longitudinal data on suspended particulate matter and organic water pollutants. The specific objective was to estimate environmental Kuznets curves for two indicators of environmental quality and to establish whether the estimated relationships conform to the inverted U-shape hypothesis. The results of the empirical investigation generally suggest the existence of an environmental Kuznets curve for suspended particulate matter. In the case of organic water pollutants, the evidence weighs more in favor of rising pollution as per capita income increases. The turning point levels of income established for the two indicators of environmental quality were however generally low, when compared to evidence from existing studies. On the face value, this suggests that African countries may be turning the corner of the environmental Kuznets curve, much faster, and at lower levels of income, much in line with the emerging idea of a 'revised environmental Kuznets curve'. The results also suggest that economic growth and rising incomes may matter in African countries in order to curb pollution from these pollutants, but more stringent policy measures, particularly at the industrial level would be required to curb environmental degradation from organic water pollutants. - Highlights: → The specific objective was to establish whether the relationships conform to the inverted U-shape hypothesis. → Evidence suggests the existence of an environmental Kuznets curve for suspended particulate matter. → The turning point levels of income established for the two indicators were however generally low. → We conclude that African countries may be turning the corner of the environmental Kuznets curve, much faster, and at lower levels of income.
Energy Technology Data Exchange (ETDEWEB)
Orubu, Christopher O. [Department of Economics, Delta State University, Abraka (Nigeria); Omotor, Douglason G., E-mail: yomotor@yahoo.com [Department of Economics, Delta State University, Abraka (Nigeria)
2011-07-15
This study investigated the relationship between per capita income and environmental degradation in Africa, using longitudinal data on suspended particulate matter and organic water pollutants. The specific objective was to estimate environmental Kuznets curves for two indicators of environmental quality and to establish whether the estimated relationships conform to the inverted U-shape hypothesis. The results of the empirical investigation generally suggest the existence of an environmental Kuznets curve for suspended particulate matter. In the case of organic water pollutants, the evidence weighs more in favor of rising pollution as per capita income increases. The turning point levels of income established for the two indicators of environmental quality were however generally low, when compared to evidence from existing studies. On the face value, this suggests that African countries may be turning the corner of the environmental Kuznets curve, much faster, and at lower levels of income, much in line with the emerging idea of a 'revised environmental Kuznets curve'. The results also suggest that economic growth and rising incomes may matter in African countries in order to curb pollution from these pollutants, but more stringent policy measures, particularly at the industrial level would be required to curb environmental degradation from organic water pollutants. - Highlights: > The specific objective was to establish whether the relationships conform to the inverted U-shape hypothesis. > Evidence suggests the existence of an environmental Kuznets curve for suspended particulate matter. > The turning point levels of income established for the two indicators were however generally low. > We conclude that African countries may be turning the corner of the environmental Kuznets curve, much faster, and at lower levels of income.
Saeidabadi, Mohammad Sadegh; Nili, Hassan; Dadras, Habibollah; Sharifiyazdi, Hassan; Connolly, Joanne; Valcanis, Mary; Raidal, Shane; Ghorashi, Seyed Ali
2017-06-01
Consumption of poultry products contaminated with Salmonella is one of the major causes of foodborne diseases worldwide and therefore detection and differentiation of Salmonella spp. in poultry is important. In this study, oligonucleotide primers were designed from hemD gene and a PCR followed by high-resolution melt (HRM) curve analysis was developed for rapid differentiation of Salmonella isolates. Amplicons of 228 bp were generated from 16 different Salmonella reference strains and from 65 clinical field isolates mainly from poultry farms. HRM curve analysis of the amplicons differentiated Salmonella isolates and analysis of the nucleotide sequence of the amplicons from selected isolates revealed that each melting curve profile was related to a unique DNA sequence. The relationship between reference strains and tested specimens was also evaluated using a mathematical model without visual interpretation of HRM curves. In addition, the potential of the PCR-HRM curve analysis was evaluated for genotyping of additional Salmonella isolates from different avian species. The findings indicate that PCR followed by HRM curve analysis provides a rapid and robust technique for genotyping of Salmonella isolates to determine the serovar/serotype.
Directory of Open Access Journals (Sweden)
Fernanda Gomes da Silveira
2011-04-01
Full Text Available Este estudo teve como objetivo utilizar a análise de agrupamento para classificar modelos de regressão não-lineares usados para descrever a curva de crescimento de ovinos cruzados, tendo em vista os resultados de diferentes avaliadores de qualidade de ajuste. Para tanto, utilizaram-se dados de peso-idade dos seguintes cruzamentos entre raças de ovinos de corte: Dorper x Morada Nova, Dorper x Rabo Largo e Dorper x Santa Inês. Após a indicação do melhor modelo, objetivou-se ainda aplicar a técnica de identidade de modelos a fim de identificar o cruzamento mais produtivo. Foram ajustados doze modelos não-lineares, cuja qualidade de ajuste foi medida pelo coeficiente de determinação ajustado, critérios de informação de Akaike e Bayesiano, erro quadrático médio de predição e coeficiente de determinação de predição. A análise de agrupamento indicou o modelo Richards como o mais adequado para descrever as curvas de crescimento dos três grupos genéticos considerados, e os testes de identidade de modelos indicaram o cruzamento Dorper x Santa Inês como sendo o mais indicado para a pecuária local.This study had the objectives to use the cluster analysis in order to classify nonlinear regression models used to describe the growth curve in relation to different quality fit evaluators. Were utilized weight-age data from the following crossbred beef lambs Dorper x Morada Nova, Dorper x Rabo Largo e Dorper x Santa Inês. After the choice of the best model, we aimed also to apply the model identity in order to identify the most efficient crossbred group. Eleven nonlinear models were used, whose fit quality was measured by determination coefficient, Akaike information criterion, Bayesian information criterion, mean quadratic error of prediction and predicted determination coefficient. The cluster analysis indicated the Richards as the best model for the three data sets, and the model identity tests revealed that the Dorper x Santa In
A method of non-destructive quantitative analysis of the ancient ceramics with curved surface
International Nuclear Information System (INIS)
He Wenquan; Xiong Yingfei
2002-01-01
Generally the surface of the sample should be smooth and flat in XRF analysis, but the ancient ceramics and hardly match this condition. Two simple methods are put forward in fundamental method and empirical correction method of XRF analysis, so the analysis of little sample or the sample with curved surface can be easily completed
Changing curves. Monitoring growth of children and adolescents in The Netherlands
Schonbeck, Y.
2015-01-01
Background: Monitoring human growth is important. It is used to detection of abnormal growth trajectories of children, which may reflect nutritional problems or underlying illness. In a larger population, it can provide information about the health status of this population, for example the
Changing curves: monitoring growth of children and adolescents in The Netherlands
Schonbeck, Y.
2015-01-01
Background: Monitoring human growth is important. It is used to detection of abnormal growth trajectories of children, which may reflect nutritional problems or underlying illness. In a larger population, it can provide information about the health status of this population, for example the
Time Alignment as a Necessary Step in the Analysis of Sleep Probabilistic Curves
Rošt'áková, Zuzana; Rosipal, Roman
2018-02-01
Sleep can be characterised as a dynamic process that has a finite set of sleep stages during the night. The standard Rechtschaffen and Kales sleep model produces discrete representation of sleep and does not take into account its dynamic structure. In contrast, the continuous sleep representation provided by the probabilistic sleep model accounts for the dynamics of the sleep process. However, analysis of the sleep probabilistic curves is problematic when time misalignment is present. In this study, we highlight the necessity of curve synchronisation before further analysis. Original and in time aligned sleep probabilistic curves were transformed into a finite dimensional vector space, and their ability to predict subjects' age or daily measures is evaluated. We conclude that curve alignment significantly improves the prediction of the daily measures, especially in the case of the S2-related sleep states or slow wave sleep.
Product differentiation by analysis of DNA melting curves during the polymerase chain reaction.
Ririe, K M; Rasmussen, R P; Wittwer, C T
1997-02-15
A microvolume fluorometer integrated with a thermal cycler was used to acquire DNA melting curves during polymerase chain reaction by fluorescence monitoring of the double-stranded DNA specific dye SYBR Green I. Plotting fluorescence as a function of temperature as the thermal cycler heats through the dissociation temperature of the product gives a DNA melting curve. The shape and position of this DNA melting curve are functions of the GC/AT ratio, length, and sequence and can be used to differentiate amplification products separated by less than 2 degrees C in melting temperature. Desired products can be distinguished from undesirable products, in many cases eliminating the need for gel electrophoresis. Analysis of melting curves can extend the dynamic range of initial template quantification when amplification is monitored with double-stranded DNA specific dyes. Complete amplification and analysis of products can be performed in less than 15 min.
Methodology of demand forecast by market analysis of electric power and load curves
International Nuclear Information System (INIS)
Barreiro, C.J.; Atmann, J.L.
1989-01-01
A methodology for demand forecast of consumer classes and their aggregation is presented. An analysis of the actual attended market can be done by appropriate measures and load curves studies. The suppositions for the future market behaviour by consumer classes (industrial, residential, commercial, others) are shown, and the actions for optimise this market are foreseen, obtained by load curves modulations. The process of future demand determination is obtained by the appropriate aggregation of this segmented demands. (C.G.C.)
TYPE Ia SUPERNOVA LIGHT-CURVE INFERENCE: HIERARCHICAL BAYESIAN ANALYSIS IN THE NEAR-INFRARED
International Nuclear Information System (INIS)
Mandel, Kaisey S.; Friedman, Andrew S.; Kirshner, Robert P.; Wood-Vasey, W. Michael
2009-01-01
We present a comprehensive statistical analysis of the properties of Type Ia supernova (SN Ia) light curves in the near-infrared using recent data from Peters Automated InfraRed Imaging TELescope and the literature. We construct a hierarchical Bayesian framework, incorporating several uncertainties including photometric error, peculiar velocities, dust extinction, and intrinsic variations, for principled and coherent statistical inference. SN Ia light-curve inferences are drawn from the global posterior probability of parameters describing both individual supernovae and the population conditioned on the entire SN Ia NIR data set. The logical structure of the hierarchical model is represented by a directed acyclic graph. Fully Bayesian analysis of the model and data is enabled by an efficient Markov Chain Monte Carlo algorithm exploiting the conditional probabilistic structure using Gibbs sampling. We apply this framework to the JHK s SN Ia light-curve data. A new light-curve model captures the observed J-band light-curve shape variations. The marginal intrinsic variances in peak absolute magnitudes are σ(M J ) = 0.17 ± 0.03, σ(M H ) = 0.11 ± 0.03, and σ(M Ks ) = 0.19 ± 0.04. We describe the first quantitative evidence for correlations between the NIR absolute magnitudes and J-band light-curve shapes, and demonstrate their utility for distance estimation. The average residual in the Hubble diagram for the training set SNe at cz > 2000kms -1 is 0.10 mag. The new application of bootstrap cross-validation to SN Ia light-curve inference tests the sensitivity of the statistical model fit to the finite sample and estimates the prediction error at 0.15 mag. These results demonstrate that SN Ia NIR light curves are as effective as corrected optical light curves, and, because they are less vulnerable to dust absorption, they have great potential as precise and accurate cosmological distance indicators.
Growth curves of three human malignant tumors transplanted to nude mice
DEFF Research Database (Denmark)
Spang-Thomsen, M; Nielsen, A; Visfeldt, J
1980-01-01
Experimental growth data for three human malignant tumors transplanted to nude mice of BALB/c origin are analyzed statistically in order to investigate whether they can be described according to the Gompertz function. The aim is to set up unequivocal standards for planned therapeutic experiments...... as a standard, e.g. in therapeutic experiments. The course of tumor growth is independent of the size of the transplant, and whether tumors are transplanted in the right or left or both flanks of the recipient mice. Furthermore, the growth does not vary in a systematic way with the number of passages in nude...
Directory of Open Access Journals (Sweden)
Esteban Pérez-López
2014-11-01
Full Text Available Because of the importance of quantitative chemical analysis in research, quality control, sales of services and other areas of interest , and the limiting of some instrumental analysis methods for quantification with linear calibration curve, sometimes because the short linear dynamic ranges of the analyte, and sometimes by limiting the technique itself, is that there is a need to investigate a little more about the convenience of using quadratic curves for analytical quantification, which seeks demonstrate that it is a valid calculation model for chemical analysis instruments. To this was taken as an analysis method based on the technique and atomic absorption spectroscopy in particular a determination of magnesium in a sample of drinking water Tacares sector Northern Grecia, employing a nonlinear calibration curve and a curve specific quadratic behavior, which was compared with the test results obtained for the same analysis with a linear calibration curve. The results show that the methodology is valid for the determination referred to, with all confidence, since the concentrations are very similar, and as used hypothesis testing can be considered equal.
He, Shiyuan; Wang, Lifan; Huang, Jianhua Z.
2018-04-01
With growing data from ongoing and future supernova surveys, it is possible to empirically quantify the shapes of SNIa light curves in more detail, and to quantitatively relate the shape parameters with the intrinsic properties of SNIa. Building such relationships is critical in controlling systematic errors associated with supernova cosmology. Based on a collection of well-observed SNIa samples accumulated in the past years, we construct an empirical SNIa light curve model using a statistical method called the functional principal component analysis (FPCA) for sparse and irregularly sampled functional data. Using this method, the entire light curve of an SNIa is represented by a linear combination of principal component functions, and the SNIa is represented by a few numbers called “principal component scores.” These scores are used to establish relations between light curve shapes and physical quantities such as intrinsic color, interstellar dust reddening, spectral line strength, and spectral classes. These relations allow for descriptions of some critical physical quantities based purely on light curve shape parameters. Our study shows that some important spectral feature information is being encoded in the broad band light curves; for instance, we find that the light curve shapes are correlated with the velocity and velocity gradient of the Si II λ6355 line. This is important for supernova surveys (e.g., LSST and WFIRST). Moreover, the FPCA light curve model is used to construct the entire light curve shape, which in turn is used in a functional linear form to adjust intrinsic luminosity when fitting distance models.
Analysis of diffusion paths for photovoltaic technology based on experience curves
International Nuclear Information System (INIS)
Poponi, Daniele
2003-04-01
This paper assesses the prospects for diffusion of photovoltaic (PV) technology for electricity generation in grid-connected systems. The analysis begins with the calculation of the break-even price of PV systems and modules, which is the price that can assure commercial viability without incentives or subsidies. The calculated average break-even price of PV systems for building-integrated applications is about US dollars 3.2/W p but can go up to about US dollars 4.5/W p in areas with very good solar irradiation and if a low real discount rate is applied. These are higher values than the break-even prices estimated in the literature to date. PV system break-even prices for intermediate load generation in utility-owned systems are also calculated, their average being about US dollars 1/W p The methodology of experience curves is used to predict what would be the different levels of cumulative world PV shipments required to reach the calculated break-even prices of PV systems, assuming different trends in the relationship between price and the increase in cumulative shipments. The years in which the break-even levels of cumulative shipments could be theoretically obtained are then calculated by considering different market growth rates. Photovoltaics could enter the niche of building-integrated applications without incentives in the first years of the next decade, provided that the PR is 80% and the average annual world market growth rate is at least 15%. The final part of the paper analyzes the niche markets or applications that seem promising for the diffusion of photovoltaics in the next few years (Author)
International Nuclear Information System (INIS)
Davidsson, Simon; Grandell, Leena; Wachtmeister, Henrik; Höök, Mikael
2014-01-01
Several recent studies have proposed fast transitions to energy systems based on renewable energy technology. Many of them dismiss potential physical constraints and issues with natural resource supply, and do not consider the growth rates of the individual technologies needed or how the energy systems are to be sustained over longer time frames. A case study is presented modelling potential growth rates of the wind energy required to reach installed capacities proposed in other studies, taking into account the expected service life of wind turbines. A sustained commissioning model is proposed as a theoretical foundation for analysing reasonable growth patterns for technologies that can be sustained in the future. The annual installation and related resource requirements to reach proposed wind capacity are quantified and it is concluded that these factors should be considered when assessing the feasibility, and even the sustainability, of fast energy transitions. Even a sustained commissioning scenario would require significant resource flows, for the transition as well as for sustaining the system, indefinitely. Recent studies that claim there are no potential natural resource barriers or other physical constraints to fast transitions to renewable energy appear inadequate in ruling out these concerns. - Highlights: • Growth rates and service life is important when evaluating energy transitions. • A sustained commissioning model is suggested for analysing renewable energy. • Natural resource requirements for renewable energy are connected to growth rates. • Arguments by recent studies ruling out physical constraints appear inadequate
Theoretical and computational analysis of IFR beam transport on curved channels
International Nuclear Information System (INIS)
Rienstra, W.W.
1987-01-01
With the successful demonstration at Sandia National Laboratory and at Lawrence Livermore Laboratory of ion focused regime (IFR) electron beam guiding in accelerators there has developed interest in using IFR channels to steer beams along curved paths. The authors report the calculations of the expected emittance growth from such channels and the results of the TRACKER code simulations of IFR steering with the assistance of strong focus sector magnets
Torres, D Diego
2015-03-01
Regarding the methods used to examine the early maternal age-child academic outcomes relationship, the extant literature has tended to examine change using statistical analyses that fail to appreciate that individuals vary in their rates of growth. Of the one study I have been able to find that employs a true growth model to estimate this relationship, the authors only controlled for characteristics of the maternal household after family formation; confounding background factors of mothers that might select them into early childbearing, a possible source of bias, were ignored. The authors' findings nonetheless suggested an inverse relationship between early maternal age, i.e., a first birth between the ages of 13 and 17, and Canadian adolescents' mean math performance at age 10. Early maternal age was not related to the linear slope of age. To elucidate whether the early maternal age-child academic outcomes association, treated in a growth context, is consistent with this finding, the present study built on it using US data and explored children's mathematics and reading trajectories from age 5 on. Its unique contribution is that it further explicitly controlled for maternal background factors and employed a three-level growth model with repeated measures of children nested within their mothers. Though the strength of the relationship varied between mean initial academic performance and mean academic growth, results confirmed that early maternal age was negatively related to children's mathematics and reading achievement, net of post-teen first birth child-specific and maternal household factors. Once maternal background factors were included, there was no statistically significant relationship between early maternal age and either children's mean initial mathematics and reading scores or their mean mathematics and reading growth. Copyright © 2014 Elsevier Inc. All rights reserved.
Directory of Open Access Journals (Sweden)
Mahalingam Vasantha
Full Text Available Tuberculosis still remains a major public health problem even though it is treatable and curable. Weight gain measurement during anti tuberculosis (TB treatment period is an important component to assess the progress of TB patients. In this study, Latent Growth Models (LGMs were implemented in a longitudinal design to predict the change in weight of TB patients who were given three different regimens under randomized controlled clinical trial for anti-TB treatment. Linear and Quadratic LGMs were fitted using Mplus software. The age, sex and treatment response of the TB patients were used as time invariant independent variables of the growth trajectories. The quadratic trend was found to be better in explaining the changes in weight without grouping than the quadratic model for three group comparisons. A significant increase in the change of weight over time was identified while a significant quadratic effect indicated that weights were sustained over time. The growth rate was similar in both the groups. The treatment response had significant association with the growth rate of weight scores of the patients.
Czech Academy of Sciences Publication Activity Database
Hyánková, L.; Novotná, Božena; Darras, V.M.
2008-01-01
Roč. 49, č. 2 (2008). s. 96-102 ISSN 0007-1668 R&D Projects: GA ČR GA523/99/1262 Institutional research plan: CEZ:AV0Z50390512 Keywords : Japanese quail * Growth phases * Carcase quality Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.134, year: 2008
Effects of growth curve plasticity on size-structured population dynamics
DEFF Research Database (Denmark)
Zhang, Lai; Lin, Zhigui; Pedersen, Michael
2011-01-01
The physiological-structured population models assume that a fixed fraction of energy intake is utilized for individual growth and maintenance while the remaining for adult fertility. The assumption results in two concerns: energy loss for juveniles and a reproduction dilemma for adults. The dile...
Structural Change, Economic Growth and the Environmental Kuznets Curve: A Theoretical Perspective
H.L.F. de Groot (Henri)
2003-01-01
textabstractThe question of whether economic growth will ultimately resolve environmental problems has recently been discussed in a mainly empirical literature. One of the mechanisms that can explain the finding of an inverted U-shaped relationship between income and emissions relies on the changes
Energy Technology Data Exchange (ETDEWEB)
McClure, M. K.; Calvet, N.; Hartmann, L.; Ingleby, L. [Department of Astronomy, The University of Michigan, 500 Church Street, 830 Dennison Building., Ann Arbor, MI 48109 (United States); D' Alessio, P. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, 58089 Morelia, Michoacán (Mexico); Espaillat, C. [Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Sargent, B. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Watson, D. M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Hernández, J., E-mail: melisma@umich.edu, E-mail: ncalvet@umich.edu, E-mail: lhartm@umich.edu, E-mail: lingleby@umich.edu, E-mail: p.dalessio@astrosmo.unam.mx, E-mail: cespaillat@cfa.harvard.edu, E-mail: baspci@rit.edu, E-mail: dmw@pas.rochester.edu, E-mail: hernandj@cida.ve [Centro de Investigaciones de Astronomía (CIDA), Mérida 5101-A (Venezuela, Bolivarian Republic of)
2013-10-01
The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the innermost regions of the disk, where terrestrial planets form. Here we calculate the inner dust sublimation wall properties for four classical T Tauri stars with a narrow range of spectral types and inclination angles and a wide range of mass accretion rates to determine the extent to which the walls are radially curved. Best fits to the near- and mid-IR excesses are found for curved, two-layer walls in which the lower layer contains larger, hotter, amorphous pyroxene grains with Mg/(Mg+Fe) = 0.6 and the upper layer contains submicron, cooler, mixed amorphous olivine and forsterite grains. As the mass accretion rates decrease from 10{sup –8} to 10{sup –10} M{sub ☉} yr{sup –1}, the maximum grain size in the lower layer decreases from ∼3 to 0.5 μm. We attribute this to a decrease in fragmentation and turbulent support for micron-sized grains with decreasing viscous heating. The atmosphere of these disks is depleted of dust with dust-gas mass ratios 1 × 10{sup –4} of the interstellar medium (ISM) value, while the midplane is enhanced to eight times the ISM value. For all accretion rates, the wall contributes at least half of the flux in the optically thin 10 μm silicate feature. Finally, we find evidence for an iron gradient in the disk, suggestive of that found in our solar system.
International Nuclear Information System (INIS)
McClure, M. K.; Calvet, N.; Hartmann, L.; Ingleby, L.; D'Alessio, P.; Espaillat, C.; Sargent, B.; Watson, D. M.; Hernández, J.
2013-01-01
The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the innermost regions of the disk, where terrestrial planets form. Here we calculate the inner dust sublimation wall properties for four classical T Tauri stars with a narrow range of spectral types and inclination angles and a wide range of mass accretion rates to determine the extent to which the walls are radially curved. Best fits to the near- and mid-IR excesses are found for curved, two-layer walls in which the lower layer contains larger, hotter, amorphous pyroxene grains with Mg/(Mg+Fe) = 0.6 and the upper layer contains submicron, cooler, mixed amorphous olivine and forsterite grains. As the mass accretion rates decrease from 10 –8 to 10 –10 M ☉ yr –1 , the maximum grain size in the lower layer decreases from ∼3 to 0.5 μm. We attribute this to a decrease in fragmentation and turbulent support for micron-sized grains with decreasing viscous heating. The atmosphere of these disks is depleted of dust with dust-gas mass ratios 1 × 10 –4 of the interstellar medium (ISM) value, while the midplane is enhanced to eight times the ISM value. For all accretion rates, the wall contributes at least half of the flux in the optically thin 10 μm silicate feature. Finally, we find evidence for an iron gradient in the disk, suggestive of that found in our solar system
AtomicJ: An open source software for analysis of force curves
Hermanowicz, Paweł; Sarna, Michał; Burda, Kvetoslava; Gabryś, Halina
2014-06-01
We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh.
AtomicJ: An open source software for analysis of force curves
International Nuclear Information System (INIS)
Hermanowicz, Paweł; Gabryś, Halina; Sarna, Michał; Burda, Kvetoslava
2014-01-01
We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh
Retrospective North American CFL Experience Curve Analysis and Correlation to Deployment Programs
Energy Technology Data Exchange (ETDEWEB)
Smith, Sarah J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2015-07-01
Retrospective experience curves are a useful tool for understanding historic technology development, and can contribute to investment program analysis and future cost estimation efforts. This work documents our development of an analysis approach for deriving retrospective experience curves with a variable learning rate, and its application to develop an experience curve for compact fluorescent lamps for the global and North American markets over the years 1990-2007. Uncertainties and assumptions involved in interpreting data for our experience curve development are discussed, including the processing and transformation of empirical data, the selection of system boundaries, and the identification of historical changes in the learning rate over the course of 15 years. In the results that follow, we find that that the learning rate has changed at least once from 1990-2007. We also explore if, and to what degree, public deployment programs may have contributed to an increased technology learning rate in North America. We observe correlations between the changes in the learning rate and the initiation of new policies, abrupt technological advances, including improvements to ballast technology, and economic and political events such as trade tariffs and electricity prices. Finally, we discuss how the findings of this work (1) support the use of segmented experience curves for retrospective and prospective analysis and (2) may imply that investments in technological research and development have contributed to a change in market adoption and penetration.
TL glow curve analysis of UV, beta and gamma induced limestone collected from Amarnath holy cave
Directory of Open Access Journals (Sweden)
Vikas Dubey
2015-01-01
Full Text Available The paper reports themoluminescence glow curve analysis of UV (ultraviolet, β (beta and γ (gamma induced limestone collected from Amarnath holy cave. The collected natural sample was characterized by X-ray diffraction (XRD technique and crystallite size calculated by Scherer's formula. Surface morphology and particle size was calculated by transmission electron microscopy (TEM study. Effect of annealing temperature on collected lime stone examined by TL glow curve study. The limestone was irradiated by UV radiation (254 nm source and the TL glow curve recorded for different UV exposure time. For beta irradiation Sr90 source was used and is shows intense peak at 256 °C with a shoulder peak at higher temperature range. For gamma radiation Co60 source and TL glow curve recorded for different doses of gamma. The kinetic parameters calculation was performed for different glow curve by computerized glow curve deconvolution (CGCD technique. The chemical composition of natural limestone was analyzed by energy dispersive X-ray spectroscopy (EDXS.
International Nuclear Information System (INIS)
Lutz, B.L.; Owen, T.
1980-01-01
We report room-temperature laboratory studies of the 5520 A (6ν 1 ) and 6475 A (5ν 1 ) bands of self-broadened ammonia at column densities ranging from 1.7--435.7 meter-amagats (m-am). Detailed equivalent-width measurements at 24 different pressure-pathlength combinations corresponding to four pressures between 44 and 689 torr and pathlengths between 32 and 512 m are used to determin curves of growth and integrated band strengths. The band strengths for the 6ν 1 and 5ν 1 overtones are 5520 A: S=0.096 +- 0.005 cm -1 (m-am) -1 and 6475 A: S=0.63 +- 0.03 cm -1 (m-am) -1 , respectively.Using these band strengths and curves of growth, we analyze new spatially resolved spectra of Jupiter showing a nonhomogeneous distribution of ammonia in the Jovian atmosphere. The observed variations in the CH 4 /NH 3 mixing ratio are interpreted as evidence of altitude-dependent depletion of ammonia in the atmosphere
Structural Change, Economic Growth and the Environmental Kuznets Curve. A Theoretical Perspective
International Nuclear Information System (INIS)
De Groot, H.L.F.
1999-01-01
The question of whether economic growth will ultimately resolve environmental problems has recently been discussed in a mainly empirical literature. One of the mechanisms that can explain the finding of an inverted U-shaped relationship between income and emissions relies on the changes in the sectoral composition of economies associated with economic growth. This paper develops a multi-sector general-equilibrium model to study the dynamic relationships between technological progress, economic development, the sectoral composition of economies and emissions. In the model, structural change is the outcome of a complex interplay between factors of demand and supply, and results from both differences in technological progress on a sectoral level and from differences in income elasticities of demand for different goods. We will derive under what conditions such changes can give rise to a hump-shaped relationship between per capita income and emissions. 39 refs
Wilkinson, John T; Songy, Chad E; Bumpass, David B; McCullough, Francis L; McCarthy, Richard E
2017-04-03
The Shilla procedure was designed to correct and control early-onset spinal deformity while harnessing a child's remaining spinal growth. It allows for controlled axial skeletal growth within the construct, avoiding the need for frequent surgeries to lengthen implants. We hypothesized that curve characteristics evolve over time after initial apex fusion and placement of the Shilla implants. The purpose of this study was to identify trends in curve evolution after Shilla implantation and understand how these changes influence ultimate outcome. A single-center, retrospective review of all patients with Shilla implants in place for ≥5 years yielded 21 patients. Charts and radiographs were reviewed to compare coronal curve characteristics preoperatively, postoperatively, and at last follow-up to note changes in the apex of the primary curve. Also noted were the development of adjacent compensatory curves, the overall vertical spinal growth, and the need for definitive spinal fusion once skeletal maturity was reached. Of the 21 patients, the curve apex migrated caudally in 12 patients (57%) and cephalad in 1 patient (5%), with a mean migration of 2.7 vertebral levels. Two patients (10%) developed new, significant compensatory curves (1 caudal and 1 cephalad). All patients demonstrated spinal growth in T1-S1 length following index surgery (mean, 45 mm). At skeletal maturity, 10 patients underwent definitive posterior spinal fusion and instrumentation, and 3 underwent implant removal alone. This study constitutes the longest follow-up of Shilla patients evaluating curve and implant behavior. Results of this review suggest that the apex of the fused primary curve shifts in approximately 62% of patients, with nearly all of these (92%) involving a distal migration. Compensatory curves did develop after Shilla placement as well. Overall, these findings represent adding-on distal to the apex after Shilla instrumentation rather than a crankshaft phenomenon about the apex. A
Law, Tameeka L; Katikaneni, Lakshmi D; Taylor, Sarah N; Korte, Jeffrey E; Ebeling, Myla D; Wagner, Carol L; Newman, Roger B
2012-07-01
Compare customized versus population-based growth curves for identification of small-for-gestational-age (SGA) and body fat percent (BF%) among preterm infants. Prospective cohort study of 204 preterm infants classified as SGA or appropriate-for-gestational-age (AGA) by population-based and customized growth curves. BF% was determined by air-displacement plethysmography. Differences between groups were compared using bivariable and multivariable linear and logistic regression analyses. Customized curves reclassified 30% of the preterm infants as SGA. SGA infants identified by customized method only had significantly lower BF% (13.8 ± 6.0) than the AGA (16.2 ± 6.3, p = 0.02) infants and similar to the SGA infants classified by both methods (14.6 ± 6.7, p = 0.51). Customized growth curves were a significant predictor of BF% (p = 0.02), whereas population-based growth curves were not a significant independent predictor of BF% (p = 0.50) at term corrected gestational age. Customized growth potential improves the differentiation of SGA infants and low BF% compared with a standard population-based growth curve among a cohort of preterm infants.
International Nuclear Information System (INIS)
Harvey, John A.; Rodrigues, Miesher L.; Kearfott, Kimberlee J.
2011-01-01
A computerized glow curve analysis (GCA) program for handling of thermoluminescence data originating from WinREMS is presented. The MATLAB program fits the glow peaks using the first-order kinetics model. Tested materials are LiF:Mg,Ti, CaF 2 :Dy, CaF 2 :Tm, CaF 2 :Mn, LiF:Mg,Cu,P, and CaSO 4 :Dy, with most having an average figure of merit (FOM) of 1.3% or less, with CaSO 4 :Dy 2.2% or less. Output is a list of fit parameters, peak areas, and graphs for each fit, evaluating each glow curve in 1.5 s or less. - Highlights: → Robust algorithm for performing thermoluminescent dosimeter glow curve analysis. → Written in MATLAB so readily implemented on variety of computers. → Usage of figure of merit demonstrated for six different materials.
International Nuclear Information System (INIS)
Smith, Sarah Josephine; Wei, Max; Sohn, Michael D.
2016-01-01
Experience curves are useful for understanding technology development and can aid in the design and analysis of market transformation programs. Here, we employ a novel approach to create experience curves, to examine both global and North American compact fluorescent lamp (CFL) data for the years 1990–2007. We move away from the prevailing method of fitting a single, constant, exponential curve to data and instead search for break points where changes in the learning rate may have occurred. Our analysis suggests a learning rate of approximately 21% for the period of 1990–1997, and 51% and 79% in global and North American datasets, respectively, after 1998. We use price data for this analysis; therefore our learning rates encompass developments beyond typical “learning by doing”, including supply chain impacts such as market competition. We examine correlations between North American learning rates and the initiation of new programs, abrupt technological advances, and economic and political events, and find an increased learning rate associated with design advancements and federal standards programs. Our findings support the use of segmented experience curves for retrospective and prospective technology analysis, and may imply that investments in technology programs have contributed to an increase of the CFL learning rate. - Highlights: • We develop a segmented regression technique to estimate historical CFL learning curves. • CFL experience curves do not have a constant learning rate. • CFLs exhibited a learning rate of approximately 21% from 1990 to 1997. • The CFL learning rate significantly increased after 1998. • Increased CFL learning rate is correlated to technology deployment programs.
Energy Technology Data Exchange (ETDEWEB)
Gomez Ros, J M; Delgado, A
1989-07-01
This report presents a method for the numerical analysis of complex thermoluminescence glow curves resolving the individual glow peak components. The method employs first order kinetics analytical expressions and is based In a Marquart-Levenberg minimization procedure. A simplified version of this method for thermoluminescence dosimetry (TLD) is also described and specifically developed to operate whit Lithium Fluoride TLD-100. (Author). 36 refs.
Preacher, Kristopher J.; Curran, Patrick J.; Bauer, Daniel J.
2006-01-01
Simple slopes, regions of significance, and confidence bands are commonly used to evaluate interactions in multiple linear regression (MLR) models, and the use of these techniques has recently been extended to multilevel or hierarchical linear modeling (HLM) and latent curve analysis (LCA). However, conducting these tests and plotting the…
Hosseini, Seyed Farhad; Hashemian, Ali; Moetakef-Imani, Behnam; Hadidimoud, Saied
2018-03-01
In the present paper, the isogeometric analysis (IGA) of free-form planar curved beams is formulated based on the nonlinear Timoshenko beam theory to investigate the large deformation of beams with variable curvature. Based on the isoparametric concept, the shape functions of the field variables (displacement and rotation) in a finite element analysis are considered to be the same as the non-uniform rational basis spline (NURBS) basis functions defining the geometry. The validity of the presented formulation is tested in five case studies covering a wide range of engineering curved structures including from straight and constant curvature to variable curvature beams. The nonlinear deformation results obtained by the presented method are compared to well-established benchmark examples and also compared to the results of linear and nonlinear finite element analyses. As the nonlinear load-deflection behavior of Timoshenko beams is the main topic of this article, the results strongly show the applicability of the IGA method to the large deformation analysis of free-form curved beams. Finally, it is interesting to notice that, until very recently, the large deformations analysis of free-form Timoshenko curved beams has not been considered in IGA by researchers.
Computer aided cooling curve analysis for Al-5Si and Al-11Si alloys ...
African Journals Online (AJOL)
The effect of grain refiner, modifier, and combination of grain refiner cum modifier was studied on Al-5Si and Al-11Si alloys using computer aided cooling curve analysis. For combined grain refinement and modification effect, Al-Ti-B-Sr single master alloy was developed that acted as both grain refiner and modifier.
Gao, C Q; Yang, J X; Chen, M X; Yan, H C; Wang, X Q
2016-04-01
Two experiments were conducted to fit growth curves, and determine age-related changes in carcass characteristics, organs, serum biochemical parameters, and gene expression of intestinal nutrient transporters in domestic pigeon (Columba livia). In experiment 1, body weight (BW) of 30 pigeons was respectively determined at 1, 3, 7, 14, 21, 28, and 35 days old to fit growth curves and to describe the growth of pigeons. In experiment 2, eighty-four 1-day-old squabs were grouped by weight into 7 groups. On d 1, 3, 7, 14, 21, 28, and 35, twelve birds from each group were randomly selected for slaughter and post-slaughter analysis. The results showed that BW of pigeons increased rapidly from d 1 to d 28 (a 25.7-fold increase), and then had little change until d 35. The Logistic, Gompertz, and Von Bertalanffy functions can all be well fitted with the growth curve of domestic pigeons (R2>0.90) and the Gompertz model showed the highest R2value among the models (R2=0.9997). The equation of Gompertz model was Y=507.72×e-(3.76exp(-0.17t))(Y=BW of pigeon (g); t=time (day)). In addition, breast meat yield (%) increased with age throughout the experiment, whereas the leg meat yield (%) reached to the peak on d 14. Serum total protein, albumin, globulin, and glucose concentration were increased with age, whereas serum uric acid concentration was decreased (P<0.05). Furthermore, the gene expressions of nutrient transporters (y+LAT2, LAT1, B0AT1, PepT1, and NHE2) in jejunum of pigeon were increased with age. The results of correlation analysis showed the gene expressions of B0AT1, PepT1, and NHE2 had positive correlations with BW (0.73
Light curve analysis of the late type binary V523 Cassiopeiae
Directory of Open Access Journals (Sweden)
Latković O.
2009-01-01
Full Text Available We present the analysis of V and R light curves of the late type contact binary V523 Cas for the season of 2006. These observations make part of the monitoring program aimed at studying the long-term light curve variability in this system. Our results confirm that the system is in an over contact configuration, and include a bright spot in the neck region of the cooler and larger primary. We compare these results with the previous solution, obtained for the season 2005 dataset and discuss the differences.
IMAGE-PLANE ANALYSIS OF n-POINT-MASS LENS CRITICAL CURVES AND CAUSTICS
Energy Technology Data Exchange (ETDEWEB)
Danek, Kamil; Heyrovský, David, E-mail: kamil.danek@utf.mff.cuni.cz, E-mail: heyrovsky@utf.mff.cuni.cz [Institute of Theoretical Physics, Faculty of Mathematics and Physics, Charles University in Prague (Czech Republic)
2015-06-10
The interpretation of gravitational microlensing events caused by planetary systems or multiple stars is based on the n-point-mass lens model. The first planets detected by microlensing were well described by the two-point-mass model of a star with one planet. By the end of 2014, four events involving three-point-mass lenses had been announced. Two of the lenses were stars with two planetary companions each; two were binary stars with a planet orbiting one component. While the two-point-mass model is well understood, the same cannot be said for lenses with three or more components. Even the range of possible critical-curve topologies and caustic geometries of the three-point-mass lens remains unknown. In this paper we provide new tools for mapping the critical-curve topology and caustic cusp number in the parameter space of n-point-mass lenses. We perform our analysis in the image plane of the lens. We show that all contours of the Jacobian are critical curves of re-scaled versions of the lens configuration. Utilizing this property further, we introduce the cusp curve to identify cusp-image positions on all contours simultaneously. In order to track cusp-number changes in caustic metamorphoses, we define the morph curve, which pinpoints the positions of metamorphosis-point images along the cusp curve. We demonstrate the usage of both curves on simple two- and three-point-mass lens examples. For the three simplest caustic metamorphoses we illustrate the local structure of the image and source planes.
Energy Technology Data Exchange (ETDEWEB)
Wang, Qi, E-mail: wq20@hotmail.com; Shi, Gaofeng, E-mail: gaofengs62@sina.com; Qi, Xiaohui, E-mail: qixiaohui1984@163.com; Fan, Xueli, E-mail: 407849960@qq.com; Wang, Lijia, E-mail: 893197597@qq.com
2014-10-15
Highlights: • We establish a feasible method using the virtual spectral curves (VSC) to differentiate focal liver lesions using DECT. • Our study shows the slope of the VSC can be used to differentiate between hemangioma, HCC, metastasis and cyst. • Importantly, the diagnostic specificities associated with using the slope to diagnose both hemangioma and cysts were 100%. - Abstract: Objective: To assess the usefulness of the spectral curve slope of dual-energy CT (DECT) for differentiating between hepatocellular carcinoma (HCC), hepatic metastasis, hemangioma (HH) and cysts. Methods: In total, 121 patients were imaged in the portal venous phase using dual-energy mode. Of these patients, 23 patients had HH, 28 patients had HCC, 40 patients had metastases and 30 patients had simple cysts. The spectral curves of the hepatic lesions were derived from the 40–190 keV levels of virtual monochromatic spectral imaging. The spectral curve slopes were calculated from 40 to 110 keV. The slopes were compared using the Kruskal–Wallis test. Receiver operating characteristic curves (ROC) were used to determine the optimal cut-off value of the slope of the spectral curve to differentiate between the lesions. Results: The spectral curves of the four lesion types had different baseline levels. The HH baseline level was the highest followed by HCC, metastases and cysts. The slopes of the spectral curves of HH, HCC, metastases and cysts were 3.81 ± 1.19, 1.49 ± 0.57, 1.06 ± 0.76 and 0.13 ± 0.17, respectively. These values were significantly different (P < 0.008). Based on ROC analysis, the respective diagnostic sensitivity and specificity were 87% and 100% for hemangioma (cut-off value ≥ 2.988), 82.1% and 65.9% for HCC (cut-off value 1.167–2.998), 65.9% and 59% for metastasis (cut-off value 0.133–1.167) and 44.4% and 100% for cysts (cut-off value ≤ 0.133). Conclusion: Quantitative analysis of the DECT spectral curve in the portal venous phase can be used to
Analysis of the nonlinear dynamics of a 2-axle freight wagon in curves
DEFF Research Database (Denmark)
Di Gialleonardo, Egidio; Bruni, Stefano; True, Hans
2014-01-01
This paper deals with the study of the nonlinear dynamic behaviour of 2-axle freight wagons in curves, considering the case of one single wagon (neglecting inter-car coupling forces) and of multiple wagons interacting through the buffers and the couplers. A multi-body model of a single wagon...... and of a three-car assembly is introduced, paying particular attention to the nonlinear and nonsmooth modelling of the suspensions and of the inter-car coupling elements. Using this model, a numerical analysis of the steady-state solution reached after the negotiation of curve transition is presented......, it is shown that the coupling forces exchanged by the wagons significantly affect their dynamics in a curve, reducing the amplitude of vibration....
Analysis of the radial distribution curves of partially ordered condensed carbon films
International Nuclear Information System (INIS)
Palatnik, L.S.; Derevyanchenko, A.S.; Nechitajlo, A.A.; Stetsenko, A.N.; Gorbenko, N.I.
1977-01-01
The Fourier analysis of the electron scattering curves has been carried out to determine the short-range order structure of carbon condensates. The intensity curves for carbon films condensed in a approximately 10 -6 Torr vacuum upon a substrate heated up to 600 deg C were obtained by diffraction techniques with filtration of the inelastic scattered electron background. The radial distribution curve errors were analyzed and quantified with the aid of a computer to determine the short-range order of the condensed carbon. It has been shown that carbon films consist of regions measuring approximately 20 A formed by parallelly packed graphite nets with azimuthal orientation different from that in ideal graphite crystals
A semi-analytical three-dimensional free vibration analysis of functionally graded curved panels
Energy Technology Data Exchange (ETDEWEB)
Zahedinejad, P. [Department of Mechanical Engineering, Islamic Azad University, Branch of Shiraz, Shiraz (Iran, Islamic Republic of); Malekzadeh, P., E-mail: malekzadeh@pgu.ac.i [Department of Mechanical Engineering, Persian Gulf University, Persian Gulf University Boulevard, Bushehr 75168 (Iran, Islamic Republic of); Center of Excellence for Computational Mechanics, Shiraz University, Shiraz (Iran, Islamic Republic of); Farid, M. [Department of Mechanical Engineering, Islamic Azad University, Branch of Shiraz, Shiraz (Iran, Islamic Republic of); Karami, G. [Department of Mechanical Engineering and Applied Mechanics, North Dakota State University, Fargo, ND 58105-5285 (United States)
2010-08-15
Based on the three-dimensional elasticity theory, free vibration analysis of functionally graded (FG) curved thick panels under various boundary conditions is studied. Panel with two opposite edges simply supported and arbitrary boundary conditions at the other edges are considered. Two different models of material properties variations based on the power law distribution in terms of the volume fractions of the constituents and the exponential distribution of the material properties through the thickness are considered. Differential quadrature method in conjunction with the trigonometric functions is used to discretize the governing equations. With a continuous material properties variation assumption through the thickness of the curved panel, differential quadrature method is efficiently used to discretize the governing equations and to implement the related boundary conditions at the top and bottom surfaces of the curved panel and in strong form. The convergence of the method is demonstrated and to validate the results, comparisons are made with the solutions for isotropic and FG curved panels. By examining the results of thick FG curved panels for various geometrical and material parameters and subjected to different boundary conditions, the influence of these parameters and in particular, those due to functionally graded material parameters are studied.
Study on characteristic points of boiling curve by using wavelet analysis and genetic algorithm
International Nuclear Information System (INIS)
Wei Huiming; Su Guanghui; Qiu Suizheng; Yang Xingbo
2009-01-01
Based on the wavelet analysis theory of signal singularity detection,the critical heat flux (CHF) and minimum film boiling starting point (q min ) of boiling curves can be detected and analyzed by using the wavelet multi-resolution analysis. To predict the CHF in engineering, empirical relations were obtained based on genetic algorithm. The results of wavelet detection and genetic algorithm prediction are consistent with experimental data very well. (authors)
Using a Simple "Escherichia Coli" Growth Curve Model to Teach the Scientific Method
McKernan, Lisa N.
2015-01-01
The challenge of teaching in the sciences is not only conveying knowledge in the discipline, but also developing essential critical thinking, data analysis, and scientific writing skills. I outline an exercise that can be done easily as part of a microbiology laboratory course. It teaches the nature of the research process, from asking questions…
International Nuclear Information System (INIS)
Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil
2009-01-01
In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.
Energy Technology Data Exchange (ETDEWEB)
Lee, Kyoung Yoon; Kim, Tae Hyung; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of)
2009-07-01
In this work, we predict a true fracture strain using load-displacement curves from tensile test and Finite Element Analysis (FEA), and suggest a method for acquiring true Stress-Strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.
Energy Technology Data Exchange (ETDEWEB)
Lee, Kyoung Yoon; Lee, Hyung Yil [Sogang University, Seoul (Korea, Republic of); Kim, Tae Hyung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2009-10-15
In this work, we predict a true fracture strain using load-displacement curves from tensile test and finite element analysis (FEA), and suggest a method for acquiring true stress-strain (SS) curves by predicted fracture strain. We first derived the true SS curve up to necking point from load-displacement curve. As the beginning, the posterior necking part of true SS curve is linearly extrapolated with the slope at necking point. The whole SS curve is then adopted for FE simulation of tensile test. The Bridgman factor or suitable plate correction factors are applied to pre and post FEA. In the load-true strain curve from FEA, the true fracture strain is determined as the matching point to test fracture load. The determined true strain is validated by comparing with test fracture strain. Finally, we complete the true SS curve by combining the prior necking part and linear part, the latter of which connects necking and predicted fracture points.
GROWTH CHARACTERISTICS OF HYBRID PIG PREDICTED BY MEANS OF ASYMMETRIC S-CURVE
Directory of Open Access Journals (Sweden)
Goran Kušec
2008-12-01
Full Text Available The present study was performed on 24 pigs distributed over two MHS-genotypes (NN, Nn and two feeding regimes (intensive, restrictive. These pigs were investigated as the last of four trials in the experiment carried out by Kušec et al. (2005. The data on muscle and fatty tissue volumes were obtained by means of Magnetic Resonance Imaging (MRI. For the growth depiction and for the predictions of live weight as well as of muscle and fat tissue, four models developed by Kušec et al. (2007 were used. These models were set up on the basis of the general form of asymmetric S-function. This function seemed to fit well to the data collected in the present study; but the inaccuracy of the models appeared to increase with age. At the age of 124 days, the estimated values of live weight, muscle and fat volumes were close to the actual values measured in the group of intensively fed pigs; in the group of restrictively fed pigs live weight and muscle volume were underestimated while the volume of fat was overestimated. At the time of the last MR imaging (154 days of age, live weight and muscle volume was to some extent overestimated in the pigs fed intensively and underestimated in those fed restrictively. The volume of fatty tissue was estimated with favourable accuracy in all investigated groups of pigs. For further predictions, two approaches were used. In the first approach to predict individual live weights, at the age of 124 days, the predictions were fairly accurate for most of the pigs, falling in the range within one week; 4 of them being estimated falsely by more than ±7 days. Generally, when expressed as absolute value, the average misestimate was ~4 days in all groups, except for the restrictively fed MHS-gene carrier pigs which were estimated with 6 days difference on the average. At the age of 154 days, the predictions were to some extent less accurate; 7 pigs (in total were incorrectly predicted by more than a week. The prediction accuracy
Relationship between the curve of Spee and craniofacial variables: A regression analysis.
Halimi, Abdelali; Benyahia, Hicham; Azeroual, Mohamed-Faouzi; Bahije, Loubna; Zaoui, Fatima
2018-06-01
The aim of this regression analysis was to identify the determining factors, which impact the curve of Spee during its genesis, its therapeutic reconstruction, and its stability, within a continuously evolving craniofacial morphology throughout life. We selected a total of 107 patients, according to the inclusion criteria. A morphological and functional clinical examination was performed for each patient: plaster models, tracing of the curve of Spee, crowding, Angle's classification, overjet and overbite were thus recorded. Then, we made a cephalometric analysis based on the standardized lateral cephalograms. In the sagittal dimension, we measured the values of angles ANB, SNA, SNB, SND, I/i; and the following distances: AoBo, I/NA, i/NB, SE and SL. In the vertical dimension, we measured the values of angles FMA, GoGn/SN, the occlusal plane, and the following distances: SAr, ArD, Ar/Con, Con/Gn, GoPo, HFP, HFA and IF. The statistical analysis was performed using the SPSS software with a significance level of 0.05. Our sample including 107 subjects was composed of 77 female patients (71.3%) and 30 male patients (27.8%) 7 hypodivergent patients (6.5%), 56 hyperdivergent patients (52.3%) and 44 normodivergent patients (41.1%). Patients' mean age was 19.35±5.95 years. The hypodivergent patients presented more pronounced curves of Spee compared to the normodivergent and the hyperdivergent populations; patients in skeletal Class I presented less pronounced curves of Spee compared to patients in skeletal Class II and Class III. These differences were non significant (P>0.05). The curve of Spee was positively and moderately correlated with Angle's classification, overjet, overbite, sellion-articulare distance, and breathing type (P0.05). Seventy five percent (75%) of the hyperdivergent patients with an oral breathing presented an overbite of 3mm, which is quite excessive given the characteristics often admitted for this typology; this parameter could explain the overbite
Simonsohn, Uri; Simmons, Joseph P; Nelson, Leif D
2015-12-01
When studies examine true effects, they generate right-skewed p-curves, distributions of statistically significant results with more low (.01 s) than high (.04 s) p values. What else can cause a right-skewed p-curve? First, we consider the possibility that researchers report only the smallest significant p value (as conjectured by Ulrich & Miller, 2015), concluding that it is a very uncommon problem. We then consider more common problems, including (a) p-curvers selecting the wrong p values, (b) fake data, (c) honest errors, and (d) ambitiously p-hacked (beyond p < .05) results. We evaluate the impact of these common problems on the validity of p-curve analysis, and provide practical solutions that substantially increase its robustness. (c) 2015 APA, all rights reserved).
Zong, Xinnan; Li, Hui; Zhang, Yaqin; Wu, Huahong
2017-05-01
It is important to update weight-for-length/height growth curves in China and re-examine their performance in screening malnutrition. To develop weight-for-length/height growth curves for Chinese children and adolescents. A total of 94 302 children aged 0-19 years with complete sex, age, weight and length/height data were obtained from two cross-sectional large-scaled national surveys in China. Weight-for-length/height growth curves were constructed using the LMS method before and after average spermarcheal/menarcheal ages, respectively. Screening performance in prevalence estimates of wasting, overweight and obesity was compared between weight-for-height and body mass index (BMI) criteria based on a test population of 21 416 children aged 3-18. The smoothed weight-for-length percentiles and Z-scores growth curves with length 46-110 cm for both sexes and weight-for-height with height 70-180 cm for boys and 70-170 cm for girls were established. The weight-for-height and BMI-for-age had strong correlation in screening wasting, overweight and obesity in each age-sex group. There was no striking difference in prevalence estimates of wasting, overweight and obesity between two indicators except for obesity prevalence at ages 6-11. This set of smoothed weight-for-length/height growth curves may be useful in assessing nutritional status from infants to post-pubertal adolescents.
Directory of Open Access Journals (Sweden)
Daniel Armeanu
Full Text Available This study examines the Environmental Kuznets Curve hypothesis (EKC, considering the primary energy consumption among other country-specific variables, for a panel of the EU-28 countries during the period 1990-2014. By estimating pooled OLS regressions with Driscoll-Kraay standard errors in order to account for cross-sectional dependence, the results confirm the EKC hypothesis in the case of emissions of sulfur oxides and emissions of non-methane volatile organic compounds. In addition to pooled estimations, the output of fixed-effects regressions with Driscoll-Kraay standard errors support the EKC hypothesis for greenhouse gas emissions, greenhouse gas emissions intensity of energy consumption, emissions of nitrogen oxides, emissions of non-methane volatile organic compounds and emissions of ammonia. Additionally, the empirical findings from panel vector error correction model reveal a short-run unidirectional causality from GDP per capita growth to greenhouse gas emissions, as well as a bidirectional causal link between primary energy consumption and greenhouse gas emissions. Furthermore, since there occurred no causal link between economic growth and primary energy consumption, the neo-classical view was confirmed, namely the neutrality hypothesis.
Armeanu, Daniel; Vintilă, Georgeta; Andrei, Jean Vasile; Gherghina, Ştefan Cristian; Drăgoi, Mihaela Cristina; Teodor, Cristian
2018-01-01
This study examines the Environmental Kuznets Curve hypothesis (EKC), considering the primary energy consumption among other country-specific variables, for a panel of the EU-28 countries during the period 1990-2014. By estimating pooled OLS regressions with Driscoll-Kraay standard errors in order to account for cross-sectional dependence, the results confirm the EKC hypothesis in the case of emissions of sulfur oxides and emissions of non-methane volatile organic compounds. In addition to pooled estimations, the output of fixed-effects regressions with Driscoll-Kraay standard errors support the EKC hypothesis for greenhouse gas emissions, greenhouse gas emissions intensity of energy consumption, emissions of nitrogen oxides, emissions of non-methane volatile organic compounds and emissions of ammonia. Additionally, the empirical findings from panel vector error correction model reveal a short-run unidirectional causality from GDP per capita growth to greenhouse gas emissions, as well as a bidirectional causal link between primary energy consumption and greenhouse gas emissions. Furthermore, since there occurred no causal link between economic growth and primary energy consumption, the neo-classical view was confirmed, namely the neutrality hypothesis.
Armeanu, Daniel; Vintilă, Georgeta; Gherghina, Ştefan Cristian; Drăgoi, Mihaela Cristina; Teodor, Cristian
2018-01-01
This study examines the Environmental Kuznets Curve hypothesis (EKC), considering the primary energy consumption among other country-specific variables, for a panel of the EU-28 countries during the period 1990–2014. By estimating pooled OLS regressions with Driscoll-Kraay standard errors in order to account for cross-sectional dependence, the results confirm the EKC hypothesis in the case of emissions of sulfur oxides and emissions of non-methane volatile organic compounds. In addition to pooled estimations, the output of fixed-effects regressions with Driscoll-Kraay standard errors support the EKC hypothesis for greenhouse gas emissions, greenhouse gas emissions intensity of energy consumption, emissions of nitrogen oxides, emissions of non-methane volatile organic compounds and emissions of ammonia. Additionally, the empirical findings from panel vector error correction model reveal a short-run unidirectional causality from GDP per capita growth to greenhouse gas emissions, as well as a bidirectional causal link between primary energy consumption and greenhouse gas emissions. Furthermore, since there occurred no causal link between economic growth and primary energy consumption, the neo-classical view was confirmed, namely the neutrality hypothesis. PMID:29742169
Directory of Open Access Journals (Sweden)
Božidar V Krstić
2010-01-01
Full Text Available Analysis of output quality of power transmitters is possible in position when characteristics are determined earlier. This is the reason why we focused on determination of these characteristics for a concrete power hydro-transmitter. This means that the investigation task primarily consisted of determination of functional characteristics, defining of the sliding curves and temperature regimes of a concrete hydrodynamic clutch. Results of velocity and pressure field investigations in the working space of this clutch, obtained by use of the same test setup, are the basis for determination and analysis of the functional characteristics, sliding curves and temperature regimes. In this work we also analyzed function of the hydrodynamic transmitter in assembly with an internal combustion engine, as well as a process of acceleration and deceleration of a vehicle with this assembly in it.
Maximum likelihood fitting of FROC curves under an initial-detection-and-candidate-analysis model
International Nuclear Information System (INIS)
Edwards, Darrin C.; Kupinski, Matthew A.; Metz, Charles E.; Nishikawa, Robert M.
2002-01-01
We have developed a model for FROC curve fitting that relates the observer's FROC performance not to the ROC performance that would be obtained if the observer's responses were scored on a per image basis, but rather to a hypothesized ROC performance that the observer would obtain in the task of classifying a set of 'candidate detections' as positive or negative. We adopt the assumptions of the Bunch FROC model, namely that the observer's detections are all mutually independent, as well as assumptions qualitatively similar to, but different in nature from, those made by Chakraborty in his AFROC scoring methodology. Under the assumptions of our model, we show that the observer's FROC performance is a linearly scaled version of the candidate analysis ROC curve, where the scaling factors are just given by the FROC operating point coordinates for detecting initial candidates. Further, we show that the likelihood function of the model parameters given observational data takes on a simple form, and we develop a maximum likelihood method for fitting a FROC curve to this data. FROC and AFROC curves are produced for computer vision observer datasets and compared with the results of the AFROC scoring method. Although developed primarily with computer vision schemes in mind, we hope that the methodology presented here will prove worthy of further study in other applications as well
A disaggregated analysis of the environmental Kuznets curve for industrial CO_2 emissions in China
International Nuclear Information System (INIS)
Wang, Yuan; Zhang, Chen; Lu, Aitong; Li, Li; He, Yanmin; ToJo, Junji; Zhu, Xiaodong
2017-01-01
Highlights: • The existence of EKC hypothesis for industrial carbon emissions is tested for China. • A semi-parametric panel regression is used along with the STIRPAT model. • The validity of the EKC hypothesis varies across industry sectors. • The EKC relation to income exists in the electricity and heat production sector. • The EKC relation to urbanization exists in the manufacturing sector. - Abstract: The present study concentrates on a Chinese context and attempts to explicitly examine the impacts of economic growth and urbanization on various industrial carbon emissions through investigation of the existence of an environmental Kuznets curve. Within the Stochastic Impacts by Regression on Population, Affluence and Technology framework, this is the first attempt to simultaneously explore the income/urbanization and disaggregated industrial carbon dioxide emissions nexus, using panel data together with semi-parametric panel fixed effects regression. Our dataset is referred to a provincial panel of China spanning the period 2000–2013. With this information, we find evidence in support of an inverted U-shaped curve relationship between economic growth and carbon dioxide emissions in the electricity and heat production sector, but a similar inference only for urbanization and those emissions in the manufacturing sector. The heterogeneity in the EKC relationship across industry sectors implies that there is urgent need to design more specific policies related to carbon emissions reduction for various industry sectors. Also, these findings contribute to advancing the emerging literature on the development-pollution nexus.
Energy Technology Data Exchange (ETDEWEB)
Balakrishna, C; Sarma, B S [Defence Research and Development Laboratory, Hyderabad (India)
1989-02-01
A formulation for axisymmetric shell analysis under asymmetric load based on Fourier series representation and using field consistent 3 noded curved axisymmetric shell element is presented. Different field inconsistent/consistent interpolations for an element based on shear flexible theory have been studied for thick and thin shells under asymmetric loads. Various examples covering axisymmetric as well as asymmetric loading cases have been analyzed and numerical results show a good agreement with the available results in the case of thin shells. 12 refs.
Thin-plate spline analysis of mandibular growth.
Franchi, L; Baccetti, T; McNamara, J A
2001-04-01
The analysis of mandibular growth changes around the pubertal spurt in humans has several important implications for the diagnosis and orthopedic correction of skeletal disharmonies. The purpose of this study was to evaluate mandibular shape and size growth changes around the pubertal spurt in a longitudinal sample of subjects with normal occlusion by means of an appropriate morphometric technique (thin-plate spline analysis). Ten mandibular landmarks were identified on lateral cephalograms of 29 subjects at 6 different developmental phases. The 6 phases corresponded to 6 different maturational stages in cervical vertebrae during accelerative and decelerative phases of the pubertal growth curve of the mandible. Differences in shape between average mandibular configurations at the 6 developmental stages were visualized by means of thin-plate spline analysis and subjected to permutation test. Centroid size was used as the measure of the geometric size of each mandibular specimen. Differences in size at the 6 developmental phases were tested statistically. The results of graphical analysis indicated a statistically significant change in mandibular shape only for the growth interval from stage 3 to stage 4 in cervical vertebral maturation. Significant increases in centroid size were found at all developmental phases, with evidence of a prepubertal minimum and of a pubertal maximum. The existence of a pubertal peak in human mandibular growth, therefore, is confirmed by thin-plate spline analysis. Significant morphological changes in the mandible during the growth interval from stage 3 to stage 4 in cervical vertebral maturation may be described as an upward-forward direction of condylar growth determining an overall "shrinkage" of the mandibular configuration along the measurement of total mandibular length. This biological mechanism is particularly efficient in compensating for major increments in mandibular size at the adolescent spurt.
Tabelow, Karsten; König, Reinhard; Polzehl, Jörg
2016-01-01
Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning. PMID:27303809
Directory of Open Access Journals (Sweden)
Matthias Deliano
Full Text Available Estimation of learning curves is ubiquitously based on proportions of correct responses within moving trial windows. Thereby, it is tacitly assumed that learning performance is constant within the moving windows, which, however, is often not the case. In the present study we demonstrate that violations of this assumption lead to systematic errors in the analysis of learning curves, and we explored the dependency of these errors on window size, different statistical models, and learning phase. To reduce these errors in the analysis of single-subject data as well as on the population level, we propose adequate statistical methods for the estimation of learning curves and the construction of confidence intervals, trial by trial. Applied to data from an avoidance learning experiment with rodents, these methods revealed performance changes occurring at multiple time scales within and across training sessions which were otherwise obscured in the conventional analysis. Our work shows that the proper assessment of the behavioral dynamics of learning at high temporal resolution can shed new light on specific learning processes, and, thus, allows to refine existing learning concepts. It further disambiguates the interpretation of neurophysiological signal changes recorded during training in relation to learning.
Energy Technology Data Exchange (ETDEWEB)
Jenkin, Thomas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Larson, Andrew [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ruth, Mark F [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ben [U.S. Department of Energy; Spitsen, Paul [U.S. Department of Energy
2018-03-27
In light of the changing electricity resource mixes across the United States, an important question in electricity modeling is how additions and retirements of generation, including additions in variable renewable energy (VRE) generation could impact markets by changing hourly wholesale energy prices. Instead of using resource-intensive production cost models (PCMs) or building and using simple generator supply curves, this analysis uses a 'top-down' approach based on regression analysis of hourly historical energy and load data to estimate the impact of supply changes on wholesale electricity prices, provided the changes are not so substantial that they fundamentally alter the market and dispatch-order driven behavior of non-retiring units. The rolling supply curve (RSC) method used in this report estimates the shape of the supply curve that fits historical hourly price and load data for given time intervals, such as two-weeks, and then repeats this on a rolling basis through the year. These supply curves can then be modified on an hourly basis to reflect the impact of generation retirements or additions, including VRE and then reapplied to the same load data to estimate the change in hourly electricity price. The choice of duration over which these RSCs are estimated has a significant impact on goodness of fit. For example, in PJM in 2015, moving from fitting one curve per year to 26 rolling two-week supply curves improves the standard error of the regression from 16 dollars/MWh to 6 dollars/MWh and the R-squared of the estimate from 0.48 to 0.76. We illustrate the potential use and value of the RSC method by estimating wholesale price effects under various generator retirement and addition scenarios, and we discuss potential limits of the technique, some of which are inherent. The ability to do this type of analysis is important to a wide range of market participants and other stakeholders, and it may have a role in complementing use of or providing
Bayesian analysis of stage-fall-discharge rating curves and their uncertainties
Mansanarez, Valentin; Le Coz, Jérôme; Renard, Benjamin; Lang, Michel; Pierrefeu, Gilles; Le Boursicaud, Raphaël; Pobanz, Karine
2016-04-01
Stage-fall-discharge (SFD) rating curves are traditionally used to compute streamflow records at sites where the energy slope of the flow is variable due to variable backwater effects. Building on existing Bayesian approaches, we introduce an original hydraulics-based method for developing SFD rating curves used at twin gauge stations and estimating their uncertainties. Conventional power functions for channel and section controls are used, and transition to a backwater-affected channel control is computed based on a continuity condition, solved either analytically or numerically. The difference between the reference levels at the two stations is estimated as another uncertain parameter of the SFD model. The method proposed in this presentation incorporates information from both the hydraulic knowledge (equations of channel or section controls) and the information available in the stage-fall-discharge observations (gauging data). The obtained total uncertainty combines the parametric uncertainty and the remnant uncertainty related to the model of rating curve. This method provides a direct estimation of the physical inputs of the rating curve (roughness, width, slope bed, distance between twin gauges, etc.). The performance of the new method is tested using an application case affected by the variable backwater of a run-of-the-river dam: the Rhône river at Valence, France. In particular, a sensitivity analysis to the prior information and to the gauging dataset is performed. At that site, the stage-fall-discharge domain is well documented with gaugings conducted over a range of backwater affected and unaffected conditions. The performance of the new model was deemed to be satisfactory. Notably, transition to uniform flow when the overall range of the auxiliary stage is gauged is correctly simulated. The resulting curves are in good agreement with the observations (gaugings) and their uncertainty envelopes are acceptable for computing streamflow records. Similar
Thermoluminescence glow curve analysis and CGCD method for erbium doped CaZrO{sub 3} phosphor
Energy Technology Data Exchange (ETDEWEB)
Tiwari, Ratnesh, E-mail: 31rati@gmail.com [Department of Physics, Bhilai Institute of Technology, Raipur, 493661 (India); Chopra, Seema [Department Physics, G.D Goenka Public School (India)
2016-05-06
The manuscript report the synthesis, thermoluminescence study at fixed concentration of Er{sup 3+} (1 mol%) doped CaZrO{sub 3} phosphor. The phosphors were prepared by modified solid state reaction method. The powder sample was characterized by thermoluminescence (TL) glow curve analysis. In TL glow curve the optimized concentration in 1mol% for UV irradiated sample. The kinetic parameters were calculated by computerized glow curve deconvolution (CGCD) techniaue. Trapping parameters gives the information of dosimetry loss in prepared phosphor and its usability in environmental monitoring and for personal monitoring. CGCD is the advance tool for analysis of complicated TL glow curves.
Directory of Open Access Journals (Sweden)
Juan Carlos Muñoz
2008-12-01
Full Text Available The Environmental Kuznets Curve hypothesis suggests the existence of an inverted U-shaped relationship between environmental degradation and income. Several economists assume that the environmental impacts occurred during the first stages of the development process will be reverted as a result of economic growth. Yet Perman and Stern (2003 have argued that the econometric methods used in the earlier analysis of the EKC are inappropriate, given the time properties of the series. This article examines the appropriateness of the EKC for a panel of 46 countries and 21 periods by implementing individual and panel tests for unit roots and cointegration. An error correction model is also estimated. The results do not support evidence of a common EKC for the countries analyzed.
de Los Mozos, J; García-Ruiz, A I; den Hartog, L A; Villamide, M J
2017-08-01
The aim of this work has been to assess the effect of diet density [control (CON) or 15% diluted (DIL)] and growth curve [recommended by the genetic line (RBW) or 15% heavier (HBW)] and their interaction on BW uniformity, feeding motivation, behavior, and body composition of broiler breeder pullets. A total of 3,000 one-day-old female breeders Ross 308, distributed in 20 pens, was randomly assigned to each treatment. Feed allowance was weekly adjusted to reach the desired BW. Feed was provided as pelleted (zero to 3 wk) and crumble (4 to 19 wk). Time eating was measured at 7, 11, and 19 weeks. A feeding rate test was performed after 11 weeks. Behavior was observed at 9 and 15 wk, by visual scan. At 6, 13, and 19 wk of age, one bird/pen was slaughtered for weighing different organs and analyzing the composition of empty whole bodies. Treatments did not affect BW uniformity; relative weights of the ovary, oviduct, or gizzard; or protein content of empty BW. Time eating varied with the growth curve at 19 wk (P motivation. Behavior was affected by the age and by the time of the d measured, but it did not change with the treatments. Birds spent most time pecking objects (50%), feeding (28%), and drinking (17%). Pullets fed DIL had 8% lower breast yield at different ages and higher empty digestive tracts at 6 weeks. Body composition varied with age; fat content increased from 12.7 to 15.9 to 19.8% for 6, 13, and 19 wk, respectively. The lowest body fat was observed for RBW pullets fed DIL (P = 0.003) at 19 weeks. Feeding DIL diets to HBW pullets could be done to increase the time spent eating and reduce their feeling of hunger without negative effects on body composition. However, its influence on behavior and BW uniformity was not proved. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.
International Nuclear Information System (INIS)
Melichar, F.; Neumann, L.
1977-01-01
Methods are presented for the analysis of normalized-characteristic curves, which make it possible to determine the granulometric composition of a dissolved polydispersion - the cumulative mass distribution of particles - as a function of the relative particle size. If the size of the largest particle in the dissolved polydispersion is known, these methods allow the determination of the dependence of cumulative mass ratios of particles on their absolute sizes. In the inverse method of the geometrical model for determining the granulometric composition of a dissolved polydispersion, the polydispersion is represented by a finite number of monodispersions. An accurate analysis of normalized-characteristic equations leads to the Akselrud dissolution model. As against the other two methods, the latter allows the determination of the granulometric composition for an arbitrary number of particle sizes. The method of the granulometric atlas is a method for estimating the granulometric composition of a dissolved polydispersion and is based on comparison of a normalized-characteristic curve for an unknown granulometric composition with an atlas of normalized-characteristic curves for selected granulometric spectra of polydispersions. (author)
Marginal abatement cost curves for policy recommendation – A method for energy system analysis
International Nuclear Information System (INIS)
Tomaschek, Jan
2015-01-01
The transport sector is seen as one of the key factors for driving future energy consumption and greenhouse gas (GHG) emissions. In order to rank possible measures marginal abatement cost curves have become a tool to graphically represent the relationship between abatement costs and emission reduction. This paper demonstrates how to derive marginal abatement cost curves for well-to-wheel GHG emissions of the transport sector considering the full energy provision chain and the interlinkages and interdependencies within the energy system. Presented marginal abatement cost curves visualize substitution effects between measures for different marginal mitigation costs. The analysis makes use of an application of the energy system model generator TIMES for South Africa (TIMES-GEECO). For the example of Gauteng province, this study exemplary shows that the transport sector is not the first sector to address for cost-efficient reduction of GHG emissions. However, the analysis also demonstrates that several options are available to mitigate transport related GHG emissions at comparable low marginal abatement costs. This methodology can be transferred to other economic sectors as well as to other regions in the world to derive cost-efficient GHG reduction strategies
MCNP calculation for calibration curve of X-ray fluorescence analysis
International Nuclear Information System (INIS)
Tan Chunming; Wu Zhifang; Guo Xiaojing; Xing Guilai; Wang Zhentao
2011-01-01
Due to the compositional variation of the sample, linear relationship between the element concentration and fluorescent intensity will not be well maintained in most X-ray fluorescence analysis. To overcome this, we use MCNP program to simulate fluorescent intensity of Fe (0∼100% concentration range) within binary mixture of Cr and O which represent typical strong absorption and weak absorption conditions respectively. The theoretic calculation shows that the relationship can be described as a curve determined by parameter p and value of p can be obtained with given absorption coefficient of substrate elements and element under detection. MCNP simulation results are consistent with theoretic calculation. Our research reveals that MCNP program can calculate the Calibration Curve of X-ray fluorescence very well. (authors)
Obtaining DDF Curves of Extreme Rainfall Data Using Bivariate Copula and Frequency Analysis
DEFF Research Database (Denmark)
Sadri, Sara; Madsen, Henrik; Mikkelsen, Peter Steen
2009-01-01
, situated near Copenhagen in Denmark. For rainfall extracted using method 2, the marginal distribution of depth was found to fit the Generalized Pareto distribution while duration was found to fit the Gamma distribution, using the method of L-moments. The volume was fit with a generalized Pareto...... with duration for a given return period and name them DDF (depth-duration-frequency) curves. The copula approach does not assume the rainfall variables are independent or jointly normally distributed. Rainfall series are extracted in three ways: (1) by maximum mean intensity; (2) by depth and duration...... distribution and the duration was fit with a Pearson type III distribution for rainfall extracted using method 3. The Clayton copula was found to be appropriate for bivariate analysis of rainfall depth and duration for both methods 2 and 3. DDF curves derived using the Clayton copula for depth and duration...
Mathematical analysis of 51Cr-labelled red cell survival curves in congenital haemolytic anaemias
International Nuclear Information System (INIS)
Kasfiki, A.G.; Antipas, S.E.; Dimitriou, P.A.; Gritzali, F.A.; Melissinos, K.G.
1982-01-01
The parameters of 51 Cr labelled red cell survival curves were calculated in 26 patients with homozygous β-thalassaemia, 8 with sickle-cell anaemia and 3 with s-β-thalassaemia, using a non-linear weighted least squares analysis computer program. In thalassaemic children the calculated parameters denote that the shorting of the mean cell life is due to early senescence alone, while there is some evidence that in thalassaemic adults additional extracellular destruction mechanisms participate as well. Red cell survival curves from patients with sickle-cell anaemia and s-β-thalassaemia resemble each other, while their parameters indicate an initial rapid loss of radioactivity, early senescence and the presence of extracellular red cell destruction factors. (orig.)
International Nuclear Information System (INIS)
Schwachoefer, J.H.C.; Crooijmans, R.P.; van Gasteren, J.J.; Hoogenhout, J.; Jerusalem, C.R.; Kal, H.B.; Theeuwes, A.G.
1989-01-01
Five human tumor cell lines were grown as multicellular tumor spheroids (MTS) to determine whether multicellular tumor spheroids derived from different types of tumors would show tumor-type dependent differences in response to single-dose irradiation, and whether these differences paralleled clinical behavior. Multicellular tumor spheroids of two neuroblastoma, one lung adenocarcinoma, one melanoma, and a squamous cell carcinoma of the oral tongue, were studied in terms of growth delay, calculated cell survival, and spheroid control dose50 (SCD50). Growth delay and cell survival analysis for the tumor cell lines showed sensitivities that correlated well with clinical behavior of the tumor types of origin. Similar to other studies on melanoma multicellular tumor spheroids our spheroid control dose50 results for the melanoma cell line deviated from the general pattern of sensitivity. This might be due to the location of surviving cells, which prohibits proliferation of surviving cells and hence growth of melanoma multicellular tumor spheroids. This study demonstrates that radiosensitivity of human tumor cell lines can be evaluated in terms of growth delay, calculated cell survival, and spheroid control dose50 when grown as multicellular tumor spheroids. The sensitivity established from these evaluations parallels clinical behavior, thus offering a unique tool for the in vitro analysis of human tumor radiosensitivity
Evaluation of the learning curve for external cephalic version using cumulative sum analysis.
Kim, So Yun; Han, Jung Yeol; Chang, Eun Hye; Kwak, Dong Wook; Ahn, Hyun Kyung; Ryu, Hyun Mi; Kim, Moon Young
2017-07-01
We evaluated the learning curve for external cephalic version (ECV) using learning curve-cumulative sum (LC-CUSUM) analysis. This was a retrospective study involving 290 consecutive cases between October 2013 and March 2017. We evaluated the learning curve for ECV on nulli and over para 1 group using LC-CUSUM analysis on the assumption that 50% and 70% of ECV procedures succeeded by description a trend-line of quadratic function with reliable R 2 values. The overall success rate for ECV was 64.8% (188/290), while the success rate for nullipara and over para 1 groups was 56.2% (100/178) and 78.6% (88/112), respectively. 'H' value, that the actual failure rate does not differ from the acceptable failure rate, was -3.27 and -1.635 when considering ECV success rates of 50% and 70%, respectively. Consequently, in order to obtain a consistent 50% success rate, we would require 57 nullipara cases, and in order to obtain a consistent 70% success rate, we would require 130 nullipara cases. In contrast, 8 to 10 over para 1 cases would be required for an expected success rate of 50% and 70% on over para 1 group. Even a relatively inexperienced physician can experience success with multipara and after accumulating experience, they will manage nullipara cases. Further research is required for LC-CUSUM involving several practitioners instead of a single practitioner. This will lead to the gradual implementation of standard learning curve guidelines for ECV.
Growth modeling of Cryptomeria japonica by partial trunk analysis
Directory of Open Access Journals (Sweden)
Vinícius Morais Coutinho
2017-06-01
Full Text Available This study aimed to evaluate the growth pattern of Cryptomeria japonica increment (L. F. D. Don. and to describe the probability distribution in stands stablished at the municipality of Rio Negro, Paraná State. Twenty trees were sampled in a 34 years-old stand, with 3 m x 2 m spacing. Wood disks were taken from each tree at 1.3 m above the ground (DBH to perform partial stem analysis. Diameter growth series without bark were used to generate the average cumulative growth curves for DBH (cm, mean annual increment (MAI and current annual increment (CAI. From the increment data, the frequency distribution was evaluated by means of probability density functions (pdfs. The mean annual increment for DBH was 0.78 cm year-1 and the age of intersection of CAI and MAI curves was between the 7th and 8th years. It was found that near 43% of the species increments are concentrated bellow 0.5 cm. The results are useful to define appropriate management strategies for the species for sites similar to the studying regions, defining for example ages of silvicultural intervention, such as thinning.
Directory of Open Access Journals (Sweden)
Jisuk Bae
2015-03-01
Full Text Available Objectives: While epidemiologic research indicates that the prevalence of risk-taking behaviors including cigarette smoking among young people with asthma is substantial, the longitudinal patterns of cigarette smoking in this vulnerable population have received little attention. The aim of this study was to evaluate differences in the longitudinal trajectories of cigarette use behaviors from adolescence to adulthood between young people with and without asthma. Methods: Data from the National Longitudinal Study of Adolescent to Adult Health (Add Health during the years 1994 to 1995 (Wave I, adolescence, 2001 to 2002 (Wave III, young adulthood, and 2007 to 2008 (Wave IV, adulthood were analyzed (n=12 244. Latent growth curve models were used to examine the longitudinal trajectories of cigarette use behaviors during the transition to adulthood according to asthma status. Results: Regardless of asthma status, the trajectory means of cigarette use behaviors were found to increase, and then slightly decrease from adolescence to adulthood. In total participants, there were no statistically significant differences in initial levels and changes in cigarette use behaviors according to asthma status. However, in select sex and race subgroups (i.e., females and non-whites, former asthmatics showed greater escalation in cigarette use behaviors than did non-asthmatics or current asthmatics. Conclusions: This study indicated that the changing patterns of cigarette use behaviors during the transition to adulthood among young people with asthma are comparable to or even more drastic than those among young people without asthma.
Global collapse and J integral analysis for inner-diameter defected curved plates in tension
International Nuclear Information System (INIS)
Hertelé, Stijn; Verstraete, Matthias; Denys, Rudi; De Waele, Wim
2013-01-01
Reference stress equations are widely used to predict both the limit load and the J integral response of defected structures. Their validity is key to performing a safe assessment of structural integrity (plastic collapse and fracture). An analytical reference stress equation based upon global collapse has recently been developed for curved plates with a part-through defect located at the inner diameter surface. This equation predicts decreasing reference stress values as plate curvature increases. To qualify the predictions, the authors have performed a series of finite element analyses covering a wide range of possible geometries. This paper compares the numerically obtained limit loads and J integral responses with the analytical predictions of the reference stress equation. The finite element results generally confirm the decrease of reference stress with increasing plate curvature. Highly pronounced differences may occur between flat plates and slightly curved plates. Overall, the analytically predicted decrease in reference stress is overestimated for small defects but is representative for larger defects. -- Highlights: • A reference stress equation for inner-diameter defected curved plates in tension was developed earlier. • The equation predicts a lower reference stress as plate curvature increases. • The analytical predictions are validated through finite element analysis. • Collapse and J integral are insensitive to curvature for small defects. • For large defects, the analytically predicted trend is confirmed
Diagnostic tests’ decision-making rules based upon analysis of ROC-curves
Directory of Open Access Journals (Sweden)
Л. В. Батюк
2015-10-01
Full Text Available In this paper we propose the model which substantiates diagnostics decision making based on the analysis of Receiver Operating Characteristic curves (ROC-curves and predicts optimal values of diagnostic indicators of biomedical information. To assess the quality of the test result prediction the standard criteria of the sensitivity and specificity of the model were used. Values of these criteria were calculated for the cases when the sensitivity of the test was greater than specificity by several times, when the number of correct diagnoses was maximal, when the sensitivity of the test was equal to its specificity and the sensitivity of the test was several times greater than the specificity of the test. To assess the significance of the factor characteristics and to compare the prognostic characteristics of models we used mathematical modeling and plotting the ROC-curves. The optimal value of the diagnostic indicator was found to be achieved when the sensitivity of the test is equal to its specificity. The model was adapted to solve the case when the sensitivity of the test is greater than specificity of the test.
Numerical analysis of transient heat conduction in downward-facing curved sections during quenching
International Nuclear Information System (INIS)
Gao, C.; El-Genk, M.S.
1996-01-01
Pool boiling from downward-facing surfaces is of interest in many applications such as cooling of electric cables, handling of containers of hazardous liquids and external cooling of nuclear reactor vessels. Here, a two-dimensional numerical analysis was performed to determine pool boiling curves from downward-facing curved stainless-steel and copper surfaces during quenching in saturated water. To ensure stability and accuracy of the numerical solution, the alternating direction implicit (ADI) method based on finite control volume representations was employed. A time dependent boundary condition was provided by the measured temperature at nine interior locations near the boiling surface. Best results were obtained using a grid of 20x20 CVs and a non-iterative approach. Calculated temperatures near the top surface of the metal sections agreed with measured values to within 0.5 K and 2.5 K for the copper and stainless-steel sections, respectively. The running time on a Pentium 90 MHz PC for the entire boiling curve was 7% of the real transient time and 4% of that of a simplified Gaussian elimination (SGE) method for the Crank-Nicolson scheme
STR melting curve analysis as a genetic screening tool for crime scene samples.
Nguyen, Quang; McKinney, Jason; Johnson, Donald J; Roberts, Katherine A; Hardy, Winters R
2012-07-01
In this proof-of-concept study, high-resolution melt curve (HRMC) analysis was investigated as a postquantification screening tool to discriminate human CSF1PO and THO1 genotypes amplified with mini-STR primers in the presence of SYBR Green or LCGreen Plus dyes. A total of 12 CSF1PO and 11 HUMTHO1 genotypes were analyzed on the LightScanner HR96 and LS-32 systems and were correctly differentiated based upon their respective melt profiles. Short STR amplicon melt curves were affected by repeat number, and single-source and mixed DNA samples were additionally differentiated by the formation of heteroduplexes. Melting curves were shown to be unique and reproducible from DNA quantities ranging from 20 to 0.4 ng and distinguished identical from nonidentical genotypes from DNA derived from different biological fluids and compromised samples. Thus, a method is described which can assess both the quantity and the possible probative value of samples without full genotyping. 2012 American Academy of Forensic Sciences. Published 2012. This article is a U.S. Government work and is in the public domain in the U.S.A.
The Carnegie Supernova Project I. Analysis of stripped-envelope supernova light curves
Taddia, F.; Stritzinger, M. D.; Bersten, M.; Baron, E.; Burns, C.; Contreras, C.; Holmbo, S.; Hsiao, E. Y.; Morrell, N.; Phillips, M. M.; Sollerman, J.; Suntzeff, N. B.
2018-02-01
Stripped-envelope (SE) supernovae (SNe) include H-poor (Type IIb), H-free (Type Ib), and He-free (Type Ic) events thought to be associated with the deaths of massive stars. The exact nature of their progenitors is a matter of debate with several lines of evidence pointing towards intermediate mass (MinitCarnegie Supernova Project (CSP-I) that are unparalleled in terms of photometric accuracy and wavelength range. Light-curve parameters are estimated through the fits of an analytical function and trends are searched for among the resulting fit parameters. Detailed inspection of the dataset suggests a tentative correlation between the peak absolute B-band magnitude and Δm15(B), while the post maximum light curves reveals a correlation between the late-time linear slope and Δm15. Making use of the full set of optical and near-IR photometry, combined with robust host-galaxy extinction corrections, comprehensive bolometric light curves are constructed and compared to both analytic and hydrodynamical models. This analysis finds consistent results among the two different modeling techniques and from the hydrodynamical models we obtained ejecta masses of 1.1-6.2M⊙, 56Ni masses of 0.03-0.35M⊙, and explosion energies (excluding two SNe Ic-BL) of 0.25-3.0 × 1051 erg. Our analysis indicates that adopting κ = 0.07 cm2 g-1 as the mean opacity serves to be a suitable assumption when comparing Arnett-model results to those obtained from hydrodynamical calculations. We also find that adopting He I and O I line velocities to infer the expansion velocity in He-rich and He-poor SNe, respectively, provides ejecta masses relatively similar to those obtained by using the Fe II line velocities, although the use of Fe II as a diagnostic does imply higher explosion energies. The inferred range of ejecta masses are compatible with intermediate mass (MZAMS ≤ 20M⊙) progenitor stars in binary systems for the majority of SE SNe. Furthermore, our hydrodynamical modeling of the
Parameter Deduction and Accuracy Analysis of Track Beam Curves in Straddle-type Monorail Systems
Directory of Open Access Journals (Sweden)
Xiaobo Zhao
2015-12-01
Full Text Available The accuracy of the bottom curve of a PC track beam is strongly related to the production quality of the entire beam. Many factors may affect the parameters of the bottom curve, such as the superelevation of the curve and the deformation of a PC track beam. At present, no effective method has been developed to determine the bottom curve of a PC track beam; therefore, a new technique is presented in this paper to deduce the parameters of such a curve and to control the accuracy of the computation results. First, the domain of the bottom curve of a PC track beam is assumed to be a spindle plane. Then, the corresponding supposed top curve domain is determined based on a geometrical relationship that is the opposite of that identified by the conventional method. Second, several optimal points are selected from the supposed top curve domain according to the dichotomy algorithm; the supposed top curve is thus generated by connecting these points. Finally, one rigorous criterion is established in the fractal dimension to assess the accuracy of the assumed top curve deduced in the previous step. If this supposed curve coincides completely with the known top curve, then the assumed bottom curve corresponding to the assumed top curve is considered to be the real bottom curve. This technique of determining the bottom curve of a PC track beam is thus proven to be efficient and accurate.
Shaw, Benjamin A.; Krause, Neal
2002-01-01
The purpose of this study is twofold: 1) to model changes in health over time among older adults; and 2) to assess the degree to which stress arising in salient social roles accounts for individual variation in these changes. Individual growth curve analyses using Hierarchical Linear Modeling (HLM) software were employed with longitudinal data…
Yerdelen, Sündüs; McCaffrey, Adam; Klassen, Robert M.
2016-01-01
This study investigated the longitudinal association between students' anxiety and procrastination and the relation of self-efficacy for self-regulation to these constructs. Latent Growth Curve Modeling was used to analyze data gathered from 182 undergraduate students (134 female, 48 male) at 4 times during a semester. Our results showed that…
Sun, Yan; Strobel, Johannes; Newby, Timothy J.
2017-01-01
Adopting a two-phase explanatory sequential mixed methods research design, the current study examined the impact of student teaching experiences on pre-service teachers' readiness for technology integration. In phase-1 of quantitative investigation, 2-level growth curve models were fitted using online repeated measures survey data collected from…
Diagnostic accuracy of quantitative 99mTc-MIBI scintimammography according to ROC curve analysis
International Nuclear Information System (INIS)
Kim, J. H.; Lee, H. K.; Seo, J. W.; Cho, N. S.; Cha, K. H.; Lee, T. H.
1998-01-01
99mTc-sestamibi scintimammography (SMM) has been shown to be a useful diagnostic test in the detection of breast cancer and the receiver operating characteristic (ROC) curve analysis provides detailed information of a diagnostic test. The purpose of this study was to evaluate the feasibility and efficacy of quantitative indices of SMM in the detection of malignant breast lesions according to ROC analysis. Prone anterior, lateral planar and supine SPECT imagings were performed on 75 female patients (mean age=43.4 yr) with breast mass (size≥0.8cm) after intravenous injection of 20-30 mCi 99mTc-sestamibi. 45 Malignant (Invasive ductal ca(36), Inv lobular ca(5), Inv duc + lob (1), Inv tubular ca (3)) and 30 benign (fibroadenoma (13), fib cyst(12), Fat necrosis(3), papilloma(1), paraffinoma (1)) lesions were histologically proven. Data were analyzed by creating three regions of interest (ROIs) over designated areas: lesion, normal breast and right chest wall. Lesion to normal (L/NL) and lesion to chest wall (L/CW) ratios were calculated for each patient both on the planar and SPECT. The area under the ROC curve (AUC) was calculated and compared among four semiquantitative indices and an average scintimammographic index (SMM(mean)) from arithmatic mean. ROC curve analysis revealed planar L/N, SPECT L/N and L/CW ratios provide comparable better diagnostic accuracies for detection of breast cancer than planar L/CW ratio (p<0.05), respectively. For quantitative SMM of 75 lesions, malignancy rate was 60%, and Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value and Accuracy were 0.78, 0.77, 0.84, 0.72 and 0.77, respectively. Quantitative SMM is an useful objective method for differentiating malignant from benign breast lesions
Diagnostic accuracy of quantitative 99mTc-MIBI scintimammography according to ROC curve analysis
Energy Technology Data Exchange (ETDEWEB)
Kim, J. H.; Lee, H. K.; Seo, J. W.; Cho, N. S.; Cha, K. H.; Lee, T. H. [Gachon Medical College, Gil Medical Center, Inchon (Korea, Republic of)
1998-07-01
99mTc-sestamibi scintimammography (SMM) has been shown to be a useful diagnostic test in the detection of breast cancer and the receiver operating characteristic (ROC) curve analysis provides detailed information of a diagnostic test. The purpose of this study was to evaluate the feasibility and efficacy of quantitative indices of SMM in the detection of malignant breast lesions according to ROC analysis. Prone anterior, lateral planar and supine SPECT imagings were performed on 75 female patients (mean age=43.4 yr) with breast mass (size{>=}0.8cm) after intravenous injection of 20-30 mCi 99mTc-sestamibi. 45 Malignant (Invasive ductal ca(36), Inv lobular ca(5), Inv duc + lob (1), Inv tubular ca (3)) and 30 benign (fibroadenoma (13), fib cyst(12), Fat necrosis(3), papilloma(1), paraffinoma (1)) lesions were histologically proven. Data were analyzed by creating three regions of interest (ROIs) over designated areas: lesion, normal breast and right chest wall. Lesion to normal (L/NL) and lesion to chest wall (L/CW) ratios were calculated for each patient both on the planar and SPECT. The area under the ROC curve (AUC) was calculated and compared among four semiquantitative indices and an average scintimammographic index (SMM(mean)) from arithmatic mean. ROC curve analysis revealed planar L/N, SPECT L/N and L/CW ratios provide comparable better diagnostic accuracies for detection of breast cancer than planar L/CW ratio (p<0.05), respectively. For quantitative SMM of 75 lesions, malignancy rate was 60%, and Sensitivity, Specificity, Positive Predictive Value, Negative Predictive Value and Accuracy were 0.78, 0.77, 0.84, 0.72 and 0.77, respectively. Quantitative SMM is an useful objective method for differentiating malignant from benign breast lesions.
Directory of Open Access Journals (Sweden)
Guyot Patricia
2012-02-01
Full Text Available Abstract Background The results of Randomized Controlled Trials (RCTs on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios with statistics based on repeated reconstructions by multiple observers. Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. Conclusion The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.
Guyot, Patricia; Ades, A E; Ouwens, Mario J N M; Welton, Nicky J
2012-02-01
The results of Randomized Controlled Trials (RCTs) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio. These do not constitute the sufficient statistics required for meta-analysis or cost-effectiveness analysis, and their use in secondary analyses requires strong assumptions that may not have been adequately tested. In order to enhance the quality of secondary data analyses, we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated. We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations, using where available information on number of events and numbers at risk. The reproducibility and accuracy of survival probabilities, median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics (survival probabilities, medians and hazard ratios) with statistics based on repeated reconstructions by multiple observers. The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics. Accuracy was excellent for survival probabilities and medians, for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported. The algorithm is a reliable tool for meta-analysis and cost-effectiveness analyses of RCTs reporting time-to-event data. It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves.
Composite beam analysis linear analysis of naturally curved and twisted anisotropic beams
Borri, Marco; Ghiringhelli, Gian L.; Merlini, Teodoro
1992-05-01
The aim of this report is to present a consistent theory for the deformation of a naturally curved and twisted anisotropic beam. The proposed formulation naturally extends the classical Saint-Venant approach to the case of curved and twisted anisotropic beams. The mathematical model developed under the assumption of span-wise uniform cross-section, curvature and twist, can take into account any kind of elastic coupling due to the material properties and the curved geometry. The consistency of the presented math-model and its generality about the cross-sectional shape, make it a useful tool even in a preliminary design optimization context such as the aeroelastic tailoring of helicopter rotor blades. The advantage of the present procedure is that it only requires a two-dimensional discretization; thus, very detailed analyses can be performed and interlaminar stresses between laminae can be evaluated. Such analyses would be extremely time consuming if performed with standard finite element codes: that prevents their recursive use as for example when optimizing a beam design. Moreover, as a byproduct of the proposed formulation, one obtains the constitutive law of the cross-section in terms of stress resultant and moment and their conjugate strain measures. This constitutive law takes into account any kind of elastic couplings, e.g., torsion-tension, tension-shear, bending-shear, and constitutes a fundamental input in aeroelastic analyses of helicopter blades. Four simple examples are given in order to show the principal features of the method.
Polygonal approximation and scale-space analysis of closed digital curves
Ray, Kumar S
2013-01-01
This book covers the most important topics in the area of pattern recognition, object recognition, computer vision, robot vision, medical computing, computational geometry, and bioinformatics systems. Students and researchers will find a comprehensive treatment of polygonal approximation and its real life applications. The book not only explains the theoretical aspects but also presents applications with detailed design parameters. The systematic development of the concept of polygonal approximation of digital curves and its scale-space analysis are useful and attractive to scholars in many fi
Optimized curve design for image analysis using localized geodesic distance transformations
Braithwaite, Billy; Niska, Harri; Pöllänen, Irene; Ikonen, Tiia; Haataja, Keijo; Toivanen, Pekka; Tolonen, Teemu
2015-03-01
We consider geodesic distance transformations for digital images. Given a M × N digital image, a distance image is produced by evaluating local pixel distances. Distance Transformation on Curved Space (DTOCS) evaluates shortest geodesics of a given pixel neighborhood by evaluating the height displacements between pixels. In this paper, we propose an optimization framework for geodesic distance transformations in a pattern recognition scheme, yielding more accurate machine learning based image analysis, exemplifying initial experiments using complex breast cancer images. Furthermore, we will outline future research work, which will complete the research work done for this paper.
DEFF Research Database (Denmark)
Simons, Hugh; Daniels, John E.; Studer, Andrew J.
2014-01-01
This paper outlines measurement and analysis methodologies created for determining the structural responses of electroceramics to an electric field. A sample stage is developed to apply electric fields to ceramic materials at elevated temperatures during neutron diffraction experiments. The tested...... employing a curved positive sensitive detector. Methodologies are proposed to account for the geometrical effects when vector fields are applied to textured materials with angularly dispersive detector geometries. Representative results are presented for the ferroelectric (Bi1/2Na1/2)TiO3-6%BaTiO3 (BNT-6BT...
Analyzing Multiple-Choice Questions by Model Analysis and Item Response Curves
Wattanakasiwich, P.; Ananta, S.
2010-07-01
In physics education research, the main goal is to improve physics teaching so that most students understand physics conceptually and be able to apply concepts in solving problems. Therefore many multiple-choice instruments were developed to probe students' conceptual understanding in various topics. Two techniques including model analysis and item response curves were used to analyze students' responses from Force and Motion Conceptual Evaluation (FMCE). For this study FMCE data from more than 1000 students at Chiang Mai University were collected over the past three years. With model analysis, we can obtain students' alternative knowledge and the probabilities for students to use such knowledge in a range of equivalent contexts. The model analysis consists of two algorithms—concentration factor and model estimation. This paper only presents results from using the model estimation algorithm to obtain a model plot. The plot helps to identify a class model state whether it is in the misconception region or not. Item response curve (IRC) derived from item response theory is a plot between percentages of students selecting a particular choice versus their total score. Pros and cons of both techniques are compared and discussed.
Analysis of demand curves in the stock and financial markets of monopolistic competition
Directory of Open Access Journals (Sweden)
Mikhail I. Geras’kin
2016-01-01
Full Text Available Objective to identify patterns of monopolistic competition as applied to markets of household appliances consumer loans and insurance products in Russia. Methods econometric modeling trending regression analysis analysis of statistical significance. Results the statistical analysis of trends in the market of household appliances insurance and credit markets has been carried out the statistical significance and adequacy of the models has been assessed adequate and accurate regression models of price trends of household appliances and electronics have been developed as well as of the interest rates of consumer loans and insurance rates for loan debts. Scientific novelty the actual patterns of decreasing demand curves for household appliances consumer loans and insurance products were found for the relevant markets in the Russian Federation in 2009ndash2014. Practical significance the model can be used for solving problems of optimal planning strategies of retailers insurers and banks. nbsp
Analysis of the Validity of Environmental Kuznets Curve for the Baltic States
Lapinskienė, Giedrė; Tvaronavičienė, Manuela; Vaitkus, Pranas
2013-12-01
The paper analyses a traditional Environmental Kuznets Curve (EKC) relationship between greenhouse gases (GHG) and gross domestic product (GDP), extending the research to include some additional factors, such as environmental tax, research and development expenditure, implicit tax rate on energy, primary production of coal and lignite, energy intensity of the economy taken from the Eurostat database. The EKC indicates that, at the early stages of economic growth, pollution increases with the growing use of resources, but when a certain level of income per capita is reached, the trend reverses so that, at a higher development stage, further economic growth leads to the improvement of the environment. In the first part of the research, the validity of the reduced EKC for the Baltic region for the period 1995-2008 is determined. In the second part, the impact of selected factors is statistically tested. In both cases, the standard cubic equation is used because it is believed that this model is the most accurate for the development stage of this region. The research results may be useful for climate change policy design.
International Nuclear Information System (INIS)
Pujol-Nadal, Ramon; Martínez-Moll, Víctor
2014-01-01
Highlights: • We thermally modeled the Curved Slats Fixed Mirror Solar Concentrator (CSFMSC). • A parametric analysis for three climates and two axial orientations are given. • The optimum values are determined for a range of the design parameters. • The CSFMSC has been well characterized for medium range temperature operation. - Abstract: The Curved Slats Fixed Mirror Solar Concentrator (CSFMSC) is a solar concentrator with a static reflector and a moving receiver. An optical analysis using ray-tracing tools was presented in a previous study in function of three design parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the aperture concentration C a . However, less is known about the thermal behavior of this geometry. In this communication, the integrated thermal output of the CSFMSC has been determined in order to find the optimal values for the design parameters at a working temperature of 200 °C. The results were obtained for three different climates and two axial orientations (North–South, and East–West). The results show that CSFMSC can produce heat at 200 °C with an annual thermal efficiency of 41, 47, and 51%, dependent of the location considered (Munich, Palma de Mallorca, and Cairo). The best FMSC geometries in function of the design parameters are exhibited for medium temperature applications
Application of a logistic function to the analysis of contrast-detail curves
International Nuclear Information System (INIS)
Mumma, C.G.; Prince, J.R.
1987-01-01
A general logistic function has been applied to the regression analysis of radioscintigraphic contrast-detail (CD) curves obtained in the authors' laboratory and to previously published results in assorted imaging modalities. Regression analysis is based on the logistic function: d/sub min/ = d/sub min//sup sat/(1 - EXP - (K + CX)), where d/sub min/ is the minimum perceptible detail diameter at a primary contrast X, and d/sub min//sup sat/ is the saturation value of d/sub min/. K and C are regression parameters. Logistic regression in assorted imaging modalities yielded r 2 values ranging from 0.95 to 0.99. A figure of merit (FOM), the area under the CD curve (AUC), is obtained by integrating the logistic function over mathematically and clinically acceptable limits. For count densities of 200 countscm 2 and 1,000 countscm 2 , the AUC differed approximately by a factor of 2. Thus, the AUC may be a sensitive FOM
Nonlinear Analysis and Post-Test Correlation for a Curved PRSEUS Panel
Gould, Kevin; Lovejoy, Andrew E.; Jegley, Dawn; Neal, Albert L.; Linton, Kim, A.; Bergan, Andrew C.; Bakuckas, John G., Jr.
2013-01-01
The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept, developed by The Boeing Company, has been extensively studied as part of the National Aeronautics and Space Administration's (NASA s) Environmentally Responsible Aviation (ERA) Program. The PRSEUS concept provides a light-weight alternative to aluminum or traditional composite design concepts and is applicable to traditional-shaped fuselage barrels and wings, as well as advanced configurations such as a hybrid wing body or truss braced wings. Therefore, NASA, the Federal Aviation Administration (FAA) and The Boeing Company partnered in an effort to assess the performance and damage arrestments capabilities of a PRSEUS concept panel using a full-scale curved panel in the FAA Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility. Testing was conducted in the FASTER facility by subjecting the panel to axial tension loads applied to the ends of the panel, internal pressure, and combined axial tension and internal pressure loadings. Additionally, reactive hoop loads were applied to the skin and frames of the panel along its edges. The panel successfully supported the required design loads in the pristine condition and with a severed stiffener. The panel also demonstrated that the PRSEUS concept could arrest the progression of damage including crack arrestment and crack turning. This paper presents the nonlinear post-test analysis and correlation with test results for the curved PRSEUS panel. It is shown that nonlinear analysis can accurately calculate the behavior of a PRSEUS panel under tension, pressure and combined loading conditions.
Probing Birth-Order Effects on Narrow Traits Using Specification-Curve Analysis.
Rohrer, Julia M; Egloff, Boris; Schmukle, Stefan C
2017-12-01
The idea that birth-order position has a lasting impact on personality has been discussed for the past 100 years. Recent large-scale studies have indicated that birth-order effects on the Big Five personality traits are negligible. In the current study, we examined a variety of more narrow personality traits in a large representative sample ( n = 6,500-10,500 in between-family analyses; n = 900-1,200 in within-family analyses). We used specification-curve analysis to assess evidence for birth-order effects across a range of models implementing defensible yet arbitrary analytical decisions (e.g., whether to control for age effects or to exclude participants on the basis of sibling spacing). Although specification-curve analysis clearly confirmed the previously reported birth-order effect on intellect, we found no meaningful effects on life satisfaction, locus of control, interpersonal trust, reciprocity, risk taking, patience, impulsivity, or political orientation. The lack of meaningful birth-order effects on self-reports of personality was not limited to broad traits but also held for more narrowly defined characteristics.
Bizzarri, Anna Rita; Cannistraro, Salvatore
2014-08-22
Atomic force spectroscopy is able to extract kinetic and thermodynamic parameters of biomolecular complexes provided that the registered unbinding force curves could be reliably attributed to the rupture of the specific complex interactions. To this aim, a commonly used strategy is based on the analysis of the stretching features of polymeric linkers which are suitably introduced in the biomolecule-substrate immobilization procedure. Alternatively, we present a method to select force curves corresponding to specific biorecognition events, which relies on a careful analysis of the force fluctuations of the biomolecule-functionalized cantilever tip during its approach to the partner molecules immobilized on a substrate. In the low frequency region, a characteristic 1/f (α) noise with α equal to one (flickering noise) is found to replace white noise in the cantilever fluctuation power spectrum when, and only when, a specific biorecognition process between the partners occurs. The method, which has been validated on a well-characterized antigen-antibody complex, represents a fast, yet reliable alternative to the use of linkers which may involve additional surface chemistry and reproducibility concerns.
A Real-Time PCR with Melting Curve Analysis for Molecular Typing of Vibrio parahaemolyticus.
He, Peiyan; Wang, Henghui; Luo, Jianyong; Yan, Yong; Chen, Zhongwen
2018-05-23
Foodborne disease caused by Vibrio parahaemolyticus is a serious public health problem in many countries. Molecular typing has a great scientific significance and application value for epidemiological research of V. parahaemolyticus. In this study, a real-time PCR with melting curve analysis was established for molecular typing of V. parahaemolyticus. Eighteen large variably presented gene clusters (LVPCs) of V. parahaemolyticus which have different distributions in the genome of different strains were selected as targets. Primer pairs of 18 LVPCs were distributed into three tubes. To validate this newly developed assay, we tested 53 Vibrio parahaemolyticus strains, which were classified in 13 different types. Furthermore, cluster analysis using NTSYS PC 2.02 software could divide 53 V. parahaemolyticus strains into six clusters at a relative similarity coefficient of 0.85. This method is fast, simple, and conveniently for molecular typing of V. parahaemolyticus.
Spectral analysis of stellar light curves by means of neural networks
Tagliaferri, R.; Ciaramella, A.; Milano, L.; Barone, F.; Longo, G.
1999-06-01
Periodicity analysis of unevenly collected data is a relevant issue in several scientific fields. In astrophysics, for example, we have to find the fundamental period of light or radial velocity curves which are unevenly sampled observations of stars. Classical spectral analysis methods are unsatisfactory to solve the problem. In this paper we present a neural network based estimator system which performs well the frequency extraction in unevenly sampled signals. It uses an unsupervised Hebbian nonlinear neural algorithm to extract, from the interpolated signal, the principal components which, in turn, are used by the MUSIC frequency estimator algorithm to extract the frequencies. The neural network is tolerant to noise and works well also with few points in the sequence. We benchmark the system on synthetic and real signals with the Periodogram and with the Cramer-Rao lower bound. This work was been partially supported by IIASS, by MURST 40\\% and by the Italian Space Agency.
Bruno, Thomas J; Ott, Lisa S; Lovestead, Tara M; Huber, Marcia L
2010-04-16
The analysis of complex fluids such as crude oils, fuels, vegetable oils and mixed waste streams poses significant challenges arising primarily from the multiplicity of components, the different properties of the components (polarity, polarizability, etc.) and matrix properties. We have recently introduced an analytical strategy that simplifies many of these analyses, and provides the added potential of linking compositional information with physical property information. This aspect can be used to facilitate equation of state development for the complex fluids. In addition to chemical characterization, the approach provides the ability to calculate thermodynamic properties for such complex heterogeneous streams. The technique is based on the advanced distillation curve (ADC) metrology, which separates a complex fluid by distillation into fractions that are sampled, and for which thermodynamically consistent temperatures are measured at atmospheric pressure. The collected sample fractions can be analyzed by any method that is appropriate. The analytical methods we have applied include gas chromatography (with flame ionization, mass spectrometric and sulfur chemiluminescence detection), thin layer chromatography, FTIR, corrosivity analysis, neutron activation analysis and cold neutron prompt gamma activation analysis. By far, the most widely used analytical technique we have used with the ADC is gas chromatography. This has enabled us to study finished fuels (gasoline, diesel fuels, aviation fuels, rocket propellants), crude oils (including a crude oil made from swine manure) and waste oils streams (used automotive and transformer oils). In this special issue of the Journal of Chromatography, specifically dedicated to extraction technologies, we describe the essential features of the advanced distillation curve metrology as an analytical strategy for complex fluids. Published by Elsevier B.V.
Vibrational Analysis of Curved Single-Walled Carbon Nanotube on a Pasternak Elastic Foundation
DEFF Research Database (Denmark)
Mehdipour, I.; Barari, Amin; Kimiaeifar, Amin
2012-01-01
. By utilizing He’s Energy Balance Method (HEBM), the relationships of the nonlinear amplitude and frequency were expressed for a curved, single-walled carbon nanotube. The amplitude frequency response curves of the nonlinear free vibration were obtained for a curved, single-walled carbon nanotube embedded...
Growth characteristics and Otolith analysis on Age-0 American Shad
Sauter, Sally T.; Wetzel, Lisa A.
2011-01-01
Otolith microstructure analysis provides useful information on the growth history of fish (Campana and Jones 1992, Bang and Gronkjaer 2005). Microstructure analysis can be used to construct the size-at-age growth trajectory of fish, determine daily growth rates, and estimate hatch date and other ecologically important life history events (Campana and Jones 1992, Tonkin et al. 2008). This kind of information can be incorporated into bioenergetics modeling, providing necessary data for estimating prey consumption, and guiding the development of empirically-based modeling scenarios for hypothesis testing. For example, age-0 American shad co-occur with emigrating juvenile fall Chinook salmon originating from Hanford Reach and the Snake River in the lower Columbia River reservoirs during the summer and early fall. The diet of age-0 American shad appears to overlap with that of juvenile fall Chinook salmon (Chapter 1, this report), but juvenile fall Chinook salmon are also known to feed on age-0 American shad in the reservoirs (USGS unpublished data). Abundant, energy-dense age-0 American shad may provide juvenile fall Chinook salmon opportunities for rapid growth during the time period when large numbers of age-0 American shad are available. Otolith analysis of hatch dates and the growth curve of age-0 American shad could be used to identify when eggs, larvae, and juveniles of specific size classes are temporally available as food for fall Chinook salmon in the lower Columbia River reservoirs. This kind of temporally and spatially explicit life history information is important to include in bioenergetics modeling scenarios. Quantitative estimates of prey consumption could be used with spatially-explicit estimates of prey abundance to construct a quantitative assessment of the age-0 American shad impact on a reservoir food web.
Application of the Learning Curve Analysis to the LHC Main Dipole Production First Assessment
Fessia, P; Rossi, L
2006-01-01
About two third of the LHC main dipoles have been delivered by the three suppliers charged of the production. The training of the staff, mostly hired just for this manufacture, and the natural improvement of the procedures with the acquired experience, decrease naturally the time necessary for the assembly of a unit. The aim of this paper is to apply methodologies like the cost-based learning curves and the time-based learning curves to the LHC Main Dipole comparing the estimated learning percentage to the ones experienced in other industries. This type of analysis, still in a preliminary phase and here applied to about 40% of the total production of the LHC magnets that will end by 2006, shows that our production has a relatively high learning percentage and it is similar to aerospace and complex machine tools for new models. Therefore with the LHC project, accelerator magnets seem to have reached industrial maturity and this production can be used as bench mark for other large scientific projects implying s...
International Nuclear Information System (INIS)
Escobar, Freddy Humberto; Martinez, Javier Andres; Montealegre Matilde
2008-01-01
The analysis of injection tests under nonisothermic conditions is important for the accurate estimation of the reservoir permeability and the well's skin factor; since previously an isothermical system was assumed without taking into account a moving temperature front which expands with time plus the consequent changes in both viscosity and mobility between the cold and the hot zone of the reservoir which leads to unreliable estimation of the reservoir and well parameters. To construct the solution an analytical approach presented by Boughrara and Peres (2007) was used. That solution was initially introduced for the calculation of the injection pressure in an isothermic system. It was later modified by Boughrara and Reynolds (2007) to consider a system with variable temperature in vertical wells. In this work, the pressure response was obtained by numerical solution of the anisothermical model using the Gauss Quadrature method to solve the integrals, and assuming that both injection and reservoir temperatures were kept constant during the injection process and the water saturation is uniform throughout the reservoir. For interpretation purposes, a technique based upon the unique features of the pressure and pressure derivative curves were used without employing type-curve matching (TDS technique). The formulation was verified by its application to field and synthetic examples. As expected, increasing reservoir temperature causes a decrement in the mobility ratio, then estimation of reservoir permeability is some less accurate from the second radial flow, especially, as the mobility ratio increases
International Nuclear Information System (INIS)
Tiilikainen, J; Bosund, V; Tilli, J-M; Sormunen, J; Mattila, M; Hakkarainen, T; Lipsanen, H
2007-01-01
A novel genetic algorithm (GA) utilizing independent component analysis (ICA) was developed for x-ray reflectivity (XRR) curve fitting. EFICA was used to reduce mutual information, or interparameter dependences, during the combinatorial phase. The performance of the new algorithm was studied by fitting trial XRR curves to target curves which were computed using realistic multilayer models. The median convergence properties of conventional GA, GA using principal component analysis and the novel GA were compared. GA using ICA was found to outperform the other methods with problems having 41 parameters or more to be fitted without additional XRR curve calculations. The computational complexity of the conventional methods was linear but the novel method had a quadratic computational complexity due to the applied ICA method which sets a practical limit for the dimensionality of the problem to be solved. However, the novel algorithm had the best capability to extend the fitting analysis based on Parratt's formalism to multiperiodic layer structures
Calibration curves of a PGNAA system for cement raw material analysis using the MCNP code
International Nuclear Information System (INIS)
Oliveira, Carlos; Salgado, Jose
1998-01-01
In large samples, the γ-ray count rate of a prompt gamma neutron activation analysis system is a multi-variable function of the elemental dry composition, density, water content and thickness of the material. The experimental calibration curves require tremendous laboratory work, using a great number of standards with well-known compositions. Although a Monte Carlo simulation study does not avoid the experimental calibration work, it reduces the number of experimental calibration standards. This paper is part of a feasibility study for a PGNAA system for on-line continuous characterisation of cement raw material conveyed on a belt (Oliveira, C., Salgado, J. and Carvalho, F. G. (1997) Optimisation of PGNAA instrument design for cement raw materials using the MCNP code. J. Radioanal. Nucl. Chem. 216(2), 191-198; Oliveira, C., Salgado, J., Goncalves, I. F., Carvalho, F. G. and Leitao, F. (1997a) A Monte Carlo study of the influence of geometry arrangements and structural materials on a PGNAA system performance for cement raw materials analysis. Appl. Radiat. Isot. (accepted); Oliveira, C., Salgado, J. and Leitao, F. (1997b) Density and water content corrections in the gamma count rate of a PGNAA system for cement raw material analysis using the MCNP code. Appl. Radiat. Isot. (accepted).]. It reports on the influence of the density, mass water content and thickness on the calibration curves of the PGNAA system. The MCNP-4A code, running in a Pentium-PC and in a DEC workstation, was used to simulate the PGNAA configuration system
Wu, Miaoli; Rao, Dan; Zhu, Yujun; Wang, Jing; Yuan, Wen; Zhang, Yu; Huang, Ren; Guo, Pengju
2017-04-01
Enterohepatic Helicobacter species (EHS) are widespread in rodent species around the world. Several studies have demonstrated that infection with EHS can interfere with the outcomes of animal experiments in cancer research and significantly influence the study results. Therefore, it is essential to establish a rapid detection and identification of EHS for biomedical research using laboratory rodents. Our study aimed to develop a rapid and sensitive method to detect and distinguish five enterohepatic Helicobacter species. Nested PCR followed by high-resolution melting curve analysis (HRM) was developed for identification of H. bilis, H. rodentium, H. muridarum, H. typhlonius, as well as H. hepaticus. To validate the accuracy of nested PCR-HRM analysis, quantitative real-time PCR methods for five different enterohepatic Helicobacter species were developed. A total of 50 cecal samples were tested using both nested PCR-HRM analysis and qPCR method. The nested PCR-HRM method could distinguish five enterohepatic Helicobacter species by different melting temperatures. The melting curve were characterized by peaks of 78.7 ± 0.12°C for H. rodentium, 80.51 ± 0.09°C for H. bilis, 81.6 ± 0.1°C for H. typhlonius, 82.11 ± 0.18°C for H. muridarum, and 82.95 ± 0.09°C for H. hepaticus. The nested PCR-HRM assay is a simple, rapid, and cost-effective assay. This assay could be a useful tool for molecular epidemiology study of enterohepatic Helicobacter infection and an attractive alternative for genotyping of enterohepatic Helicobacter species. © 2016 John Wiley & Sons Ltd.
Kong, W J; Wang, J B; Jin, C; Zhao, Y L; Dai, C M; Xiao, X H; Li, Z L
2009-07-01
Using the 3114/3115 thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, the heat output of Candida albicans growth at 37 degrees C was measured, and the effect of emodin on C. albicans growth was evaluated by microcalorimetry coupled with chemometric methods. The similarities between the heat flow power (HFP)-time curves of C. albicans growth affected by different concentrations of emodin were calculated by similarity analysis (SA). In the correspondence analysis (CA) diagram of eight quantitative parameters taken from the HFP-time curves, it could be deduced that emodin had definite dose-effect relationship as the distance between different concentrations of it increased along with the dosage and the effect. From the principal component analysis (PCA) on eight quantitative parameters, the action of emodin on C. albicans growth could be easily evaluated by analyzing the change of values of the main two parameters, growth rate constant k (2) and maximum power output P(2)(m). The coherent results of SA, CA, and PCA showed that emodin at different concentrations had different effects on C. albicans growth metabolism: A low concentration (0-10 microg ml(-1)) poorly inhibited the growth of C. albicans, and a high concentration (15-35 microg ml(-1)) could notably inhibit growth of this fungus. This work provided a useful idea of the combination of microcalorimetry and chemometric analysis for investigating the effect of drug and other compounds on microbes.
International Nuclear Information System (INIS)
Halkos, George Emm.; Tzeremes, Nickolaos G.
2009-01-01
This paper, using data envelopment (DEA) window analysis and generalized method of moments (GMM) estimators, examines the existence of a Kuznets type relationship between countries' environmental efficiency and national income. Specifically, it measures the environmental efficiency of 17 OECD countries by constructing environmental efficiency ratios for the time period 1980-2002. The analysis with the application of dynamic panel data reveals that there isn't a Kuznets type relationship between environmental efficiency and income. Allowing for dynamic effects we find that the adjustment to the target ratio is instantaneous. We also find that increased economic activity does not always ensure environmental protection and thus the path of growth is important in addition to the growth itself. (author)
Energy Technology Data Exchange (ETDEWEB)
Halkos, George Emm.; Tzeremes, Nickolaos G. [Department of Economics, University of Thessaly, Korai 43, 38333, Volos (Greece)
2009-05-15
This paper, using data envelopment (DEA) window analysis and generalized method of moments (GMM) estimators, examines the existence of a Kuznets type relationship between countries' environmental efficiency and national income. Specifically, it measures the environmental efficiency of 17 OECD countries by constructing environmental efficiency ratios for the time period 1980-2002. The analysis with the application of dynamic panel data reveals that there isn't a Kuznets type relationship between environmental efficiency and income. Allowing for dynamic effects we find that the adjustment to the target ratio is instantaneous. We also find that increased economic activity does not always ensure environmental protection and thus the path of growth is important in addition to the growth itself. (author)
Negrini, Stefano; Donzelli, Sabrina; Lusini, Monia; Zaina, Fabio
2012-01-01
Recently it has been shown that idiopathic scoliosis (IS) curves can be reduced with bracing, and it has been proposed that this could be useful in non-surgically treated high degree curves even after Risser 3. Moreover, bracing has been shown to be able to improve aesthetics, and this could be another reason to treat some patients with cosmetic needs. Our aim is to preliminary check if results can be obtained in IS patients after Risser 3. Design. Retrospective uncontrolled cohort study. Inclusion criteria. All IS patients treated on a voluntary basis for aesthetic reasons and/or for curve reduction; Risser 4-5 at start; end of treatment reached. Population. 34 females and 2 males, age 16.2±1.6 years, Cobb angle 27.6°±8.9°. Treatment. Lyon or SPoRT braces 18 to 24 hours/day, specific SEAS exercises, rapid weaning (2-3 hours every 6 months). Outcome criteria: SRS (unchanged; worsened over 6°; over 45° at the end of treatment; surgically treated), radiographic and clinical. Statistics. ANOVA and chi-test. The reported compliance during the 2.8 ± 1.1 treatment years was 95.1%, while residual growth was 0.9 ± 1.1 cm. Improvements were found in 39% of this cohort, (46% in curves over 30°). Only 1 patient progressed 6°. We found highly statistically significant reductions of maximal (-4.4°), thoracic (-6.0°) and thoracolumbar (-6.6°) curves. Statistically significant improvements were found for Aesthetic Index. Before 20 years of age, even in skeletally mature patients, it is possible to reach radiographic and aesthetic improvements, although not as good as during growth. Correction is based on bone growth, but ligaments and neuromuscular control of posture can also be involved.
Rao, Dan; Wu, Miaoli; Wang, Jing; Yuan, Wen; Zhu, Yujun; Cong, Feng; Xu, Fengjiao; Lian, Yuexiao; Huang, Bihong; Wu, Qiwen; Chen, Meili; Zhang, Yu; Huang, Ren; Guo, Pengju
2017-12-01
Murine parvovirus is one of the most prevalent infectious pathogens in mouse colonies. A specific primer pair targeting the VP2 gene of minute virus of mice (MVM) and mouse parvovirus (MPV) was utilized for high resolution melting (HRM) analysis. The resulting melting curves could distinguish these two virus strains and there was no detectable amplification of the other mouse pathogens which included rat parvovirus (KRV), ectromelia virus (ECT), mouse adenovirus (MAD), mouse cytomegalovirus (MCMV), polyoma virus (Poly), Helicobactor hepaticus (H. hepaticus) and Salmonella typhimurium (S. typhimurium). The detection limit of the standard was 10 copies/μL. This study showed that the PCR-HRM assay could be an alternative useful method with high specificity and sensitivity for differentiating murine parvovirus strains MVM and MPV. Copyright © 2017 Elsevier B.V. All rights reserved.
International Nuclear Information System (INIS)
Kim, Ok Hwa; Bahk, Yong Whee; Kim, Chi Kyung
1987-01-01
The noninvasive nature of the radionuclide angiocardiography provided a useful approach for the evaluation of left-to-right cardiac shunts (LRCS). While the qualitative information can be obtained by inspection of serial radionuclide angiocardiograms, the quantitative information of radionuclide angiocardiography can be obtained by the analysis of time-activity curves using advanced computer system. The count ratios method and pulmonary-to-systemic flow ratio (QP/QS) by gamma variate fit method were used to evaluate the accuracy of detection and localization of LRCS. One hundred and ten time-activity curves were analyzed. There were 46 LRCS (atrial septal defects 11, ventricular septal defects 22, patent ductus arteriosus 13) and 64 normal subjects. By computer analysis of time-activity curves of the right atriurn, ventricle and the lungs separately, the count ratios modified by adding the mean cardiac transit time were calculated in each anatomic site. In normal subjects the mean count ratios in the right atrium, ventricle and lungs were 0.24 on average. In atrial septal defects, the count ratios were high in the right atrium, ventricle and lungs, whereas in ventricular septal defects the count ratios were higher only in the right ventricle and lungs. Patent ductus arteriosus showed normal count ratios in the heart but high count ratios were obtained in the lungs. Thus, this count ratios method could be separated normal from those with intracardiac or extracardiac shunts, and moreover, with this method the localization of the shunt level was possible in LRCS. Another method that could differentiate the intracardiac shunts from extracardiac shunts was measuring QP/QS in the left and right lungs. In patent ductus arteriosus, the left lung QP/QS was higher than those of the right lung, whereas in atrial septal defects and ventricular septal defects QP/ QS ratios were equal in both lungs. From this study, it was found that by measuring QP/QS separately in the lungs
Analysis of RIA standard curve by log-logistic and cubic log-logit models
International Nuclear Information System (INIS)
Yamada, Hideo; Kuroda, Akira; Yatabe, Tami; Inaba, Taeko; Chiba, Kazuo
1981-01-01
In order to improve goodness-of-fit in RIA standard analysis, programs for computing log-logistic and cubic log-logit were written in BASIC using personal computer P-6060 (Olivetti). Iterative least square method of Taylor series was applied for non-linear estimation of logistic and log-logistic. Hear ''log-logistic'' represents Y = (a - d)/(1 + (log(X)/c)sup(b)) + d As weights either 1, 1/var(Y) or 1/σ 2 were used in logistic or log-logistic and either Y 2 (1 - Y) 2 , Y 2 (1 - Y) 2 /var(Y), or Y 2 (1 - Y) 2 /σ 2 were used in quadratic or cubic log-logit. The term var(Y) represents squares of pure error and σ 2 represents estimated variance calculated using a following equation log(σ 2 + 1) = log(A) + J log(y). As indicators for goodness-of-fit, MSL/S sub(e)sup(2), CMD% and WRV (see text) were used. Better regression was obtained in case of alpha-fetoprotein by log-logistic than by logistic. Cortisol standard curve was much better fitted with cubic log-logit than quadratic log-logit. Predicted precision of AFP standard curve was below 5% in log-logistic in stead of 8% in logistic analysis. Predicted precision obtained using cubic log-logit was about five times lower than that with quadratic log-logit. Importance of selecting good models in RIA data processing was stressed in conjunction with intrinsic precision of radioimmunoassay system indicated by predicted precision. (author)
Analysis of Surface Plasmon Resonance Curves with a Novel Sigmoid-Asymmetric Fitting Algorithm
Directory of Open Access Journals (Sweden)
Daeho Jang
2015-09-01
Full Text Available The present study introduces a novel curve-fitting algorithm for surface plasmon resonance (SPR curves using a self-constructed, wedge-shaped beam type angular interrogation SPR spectroscopy technique. Previous fitting approaches such as asymmetric and polynomial equations are still unsatisfactory for analyzing full SPR curves and their use is limited to determining the resonance angle. In the present study, we developed a sigmoid-asymmetric equation that provides excellent curve-fitting for the whole SPR curve over a range of incident angles, including regions of the critical angle and resonance angle. Regardless of the bulk fluid type (i.e., water and air, the present sigmoid-asymmetric fitting exhibited nearly perfect matching with a full SPR curve, whereas the asymmetric and polynomial curve fitting methods did not. Because the present curve-fitting sigmoid-asymmetric equation can determine the critical angle as well as the resonance angle, the undesired effect caused by the bulk fluid refractive index was excluded by subtracting the critical angle from the resonance angle in real time. In conclusion, the proposed sigmoid-asymmetric curve-fitting algorithm for SPR curves is widely applicable to various SPR measurements, while excluding the effect of bulk fluids on the sensing layer.
Directory of Open Access Journals (Sweden)
Janaína Galvão Coelho
2009-12-01
Full Text Available O objetivo neste trabalho foi analisar as relações entre parâmetros da curva de crescimento (peso à maturidade e taxa de maturação e medidas da eficiência produtiva de 333 vacas da raça Holandesa nascidas de 1992 a 2002. Dados de idade ao primeiro parto, produção de leite e duração da primeira lactação, primeiro intervalo de partos e produção de leite por dia de intervalo de partos foram analisados por meio de um modelo linear generalizado com o efeito fixo de grupo contemporâneo (ano-estação de nascimento, os efeitos aleatórios de pai da vaca e erro e os efeitos lineares e quadráticos do peso à maturidade e da taxa de maturação. Nas análises de longevidade e de duração da vida útil, incluiu-se o efeito fixo de motivo de descarte da vaca. Houve efeitos linear e quadrático da taxa de maturação sobre a maioria das características, exceto o primeiro intervalo de partos e a produção de leite por dia de intervalo de partos. As estimativas das taxas de maturação ótimas variaram de 0,0896 a 0,1187 kg/kg de peso vivo/mês. O peso à maturidade influenciou a longevidade de forma linear e quadrática. A combinação ótima foi de 701 kg de peso à maturidade e 0,0934 kg/kg de peso vivo/mês de taxa de maturação. O peso à maturidade correlacionou-se de forma desfavorável com a duração da primeira lactação (-0,11. Coeficientes de correlação significativos foram obtidos entre taxa de maturação e idade ao primeiro parto (-0,22, produção de leite na primeira lactação (0,18, duração da primeira lactação (0,18 e longevidade (0,14, o que confirma a hipótese de que vacas com taxas de maturação mais rápidas apresentam maior eficiência produtiva.The objective of this study was to analyze the relationships between previously estimated individual growth curve parameters (mature weight and maturing rate and measures of productive efficiency of 333 Holstein-Friesian cows, born from 1992 to 2002. Data on age
Growth models and analysis of development
Energy Technology Data Exchange (ETDEWEB)
Mathur, G
1979-10-01
This paper deals with remnants of neoclassical elements in Keynesian and post-Keynesian thought, and attempts to demonstrate that the elimination of these elements from our modes of thinking would not impoverish economic analysis as a means of solving real problems. In the Keynesian analysis the causation from investment to savings is exhibited in terms of income determination. When put in terms of a capital-theory model, the vector of savings is represented in two ways: real savings and counterpart real savings. The former coincides with the investment vector and the latter with the vector of consumption goods foregone for diverting resources towards equipment making. Thus the Keynesian causation in capital theory terms makes the concept of national savings as an independent variable redudant. The Robinsonian causation in a golden age with full employment and its reversal of direction in a steady state with non-employment are then considered. But in each of these, variables like rate of savings and output/capital ratio are found to be dormant variables. They are termed as null variables which, being of no account in both full-employment and unemployment situations, could, without loss, be deleted from the repertory of analytical tools. The Harrod formula of warranted rate of growth, when put in causal form, thus becomes a redundant portion of economics of growth. The real determinants of the growth rate and real wage rate on which the analysis of growth or of development should be based, are also depicted.
Zhang, Chen; Wang, Yuan; Song, Xiaowei; Kubota, Jumpei; He, Yanmin; Tojo, Junji; Zhu, Xiaodong
2017-12-31
This paper concentrates on a Chinese context and makes efforts to develop an integrated process to explicitly elucidate the relationship between economic growth and water pollution discharge-chemical oxygen demand (COD) discharge and ammonia nitrogen (NH 3 -N), using two unbalanced panel data sets covering the period separately from 1990 to 2014, and 2001 to 2014. In our present study, the panel unit root tests, cointegration tests, and Granger causality tests allowing for cross-sectional dependence, nonstationary, and heterogeneity are conducted to examine the causal effects of economic growth on COD/NH 3 -N discharge. Further, we simultaneously apply semi-parametric fixed effects estimation and parametric fixed effects estimation to investigate environmental Kuznets curve relationship for COD/NH 3 -N discharge. Our empirical results show a long-term bidirectional causality between economic growth and COD/NH 3 -N discharge in China. Within the Stochastic Impacts by Regression on Population, Affluence and Technology framework, we find evidence in support of an inverted U-shaped curved link between economic growth and COD/NH 3 -N discharge. To the best of our knowledge, there have not been any efforts made in investigating the nexus of economic growth and water pollution in such an integrated manner. Therefore, this study takes a fresh look on this topic. Copyright © 2017 Elsevier B.V. All rights reserved.
Jahediesfanjani, Hossein
2017-07-17
IntroductionIn the decline curve analysis (DCA) method of estimating recoverable hydrocarbon volumes, the analyst uses historical production data from a well, lease, group of wells (or pattern), or reservoir and plots production rates against time or cumulative production for the analysis. The DCA of an individual well is founded on the same basis as the fluid-flow principles that are used for pressure-transient analysis of a single well in a reservoir domain and therefore can provide scientifically reasonable and accurate results. However, when used for a group of wells, a lease, or a reservoir, the DCA becomes more of an empirical method. Plots from the DCA reflect the reservoir response to the oil withdrawal (or production) under the prevailing operating and reservoir conditions, and they continue to be good tools for estimating recoverable hydrocarbon volumes and future production rates. For predicting the total recoverable hydrocarbon volume, the DCA results can help the analyst to evaluate the reservoir performance under any of the three phases of reservoir productive life—primary, secondary (waterflood), or tertiary (enhanced oil recovery) phases—so long as the historical production data are sufficient to establish decline trends at the end of the three phases.
Energy Technology Data Exchange (ETDEWEB)
Borglin, Sharon E; Joyner, Dominique; Jacobsen, Janet; Mukhopadhyay, Aindrila; Hazen, Terry C.
2008-10-04
Growing anaerobic microorganisms in phenotypic microarrays (PM) and 96-well microtiter plates is an emerging technology that allows high throughput survey of the growth and physiology and/or phenotype of cultivable microorganisms. For non-model bacteria, a method for phenotypic analysis is invaluable, not only to serve as a starting point for further evaluation, but also to provide a broad understanding of the physiology of an uncharacterized wild-type organism or the physiology/phenotype of a newly created mutant of that organism. Given recent advances in genetic characterization and targeted mutations to elucidate genetic networks and metabolic pathways, high-throughput methods for determining phenotypic differences are essential. Here we outline challenges presented in studying the physiology and phenotype of a sulfate reducing anaerobic delta proteobacterium, Desulfovibrio vulgaris Hildenborough. Modifications of the commercially available OmniLog(TM) system (Hayward, CA) for experimental setup, and configuration, as well as considerations in PM data analysis are presented. Also highlighted here is data viewing software that enables users to view and compare multiple PM data sets. The PM method promises to be a valuable strategy in our systems biology approach to D. vulgaris studies and is readily applicable to other anaerobic and aerobic bacteria.
Role of Melt Curve Analysis in Interpretation of Nutrigenomics' MicroRNA Expression Data.
Ahmed, Farid E; Gouda, Mostafa M; Hussein, Laila A; Ahmed, Nancy C; Vos, Paul W; Mohammad, Mahmoud A
2017-01-01
This article illustrates the importance of melt curve analysis (MCA) in interpretation of mild nutrogenomic micro(mi)RNA expression data, by measuring the magnitude of the expression of key miRNA molecules in stool of healthy human adults as molecular markers, following the intake of Pomegranate juice (PGJ), functional fermented sobya (FS), rich in potential probiotic lactobacilli, or their combination. Total small RNA was isolated from stool of 25 volunteers before and following a three-week dietary intervention trial. Expression of 88 miRNA genes was evaluated using Qiagen's 96 well plate RT 2 miRNA qPCR arrays. Employing parallel coordinates plots, there was no observed significant separation for the gene expression (Cq) values, using Roche 480® PCR LightCycler instrument used in this study, and none of the miRNAs showed significant statistical expression after controlling for the false discovery rate. On the other hand, melting temperature profiles produced during PCR amplification run, found seven significant genes (miR-184, miR-203, miR-373, miR-124, miR-96, miR-373 and miR-301a), which separated candidate miRNAs that could function as novel molecular markers of relevance to oxidative stress and immunoglobulin function, for the intake of polyphenol (PP)-rich, functional fermented foods rich in lactobacilli (FS), or their combination. We elaborate on these data, and present a detailed review on use of melt curves for analyzing nutigenomic miRNA expression data, which initially appear to show no significant expressions, but are actually more subtle than this simplistic view, necessitating the understanding of the role of MCA for a comprehensive understanding of what the collective expression and MCA data collectively imply. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.
High-throughput gender identification of penguin species using melting curve analysis.
Tseng, Chao-Neng; Chang, Yung-Ting; Chiu, Hui-Tzu; Chou, Yii-Cheng; Huang, Hurng-Wern; Cheng, Chien-Chung; Liao, Ming-Hui; Chang, Hsueh-Wei
2014-04-03
Most species of penguins are sexual monomorphic and therefore it is difficult to visually identify their genders for monitoring population stability in terms of sex ratio analysis. In this study, we evaluated the suitability using melting curve analysis (MCA) for high-throughput gender identification of penguins. Preliminary test indicated that the Griffiths's P2/P8 primers were not suitable for MCA analysis. Based on sequence alignment of Chromo-Helicase-DNA binding protein (CHD)-W and CHD-Z genes from four species of penguins (Pygoscelis papua, Aptenodytes patagonicus, Spheniscus magellanicus, and Eudyptes chrysocome), we redesigned forward primers for the CHD-W/CHD-Z-common region (PGU-ZW2) and the CHD-W-specific region (PGU-W2) to be used in combination with the reverse Griffiths's P2 primer. When tested with P. papua samples, PCR using P2/PGU-ZW2 and P2/PGU-W2 primer sets generated two amplicons of 148- and 356-bp, respectively, which were easily resolved in 1.5% agarose gels. MCA analysis indicated the melting temperature (Tm) values for P2/PGU-ZW2 and P2/PGU-W2 amplicons of P. papua samples were 79.75°C-80.5°C and 81.0°C-81.5°C, respectively. Females displayed both ZW-common and W-specific Tm peaks, whereas male was positive only for ZW-common peak. Taken together, our redesigned primers coupled with MCA analysis allows precise high throughput gender identification for P. papua, and potentially for other penguin species such as A. patagonicus, S. magellanicus, and E. chrysocome as well.
Directory of Open Access Journals (Sweden)
Janković Marko
2013-01-01
Full Text Available In this paper, we analyze the possibilities of the diagnosis of Parkinson's disease at an early stage, based on characteristics of the input-output curve. The input-output (IO curve was analyzed in two ways: we analyzed the gain of the curve for low-level transcranial stimulation and we analyzed the overall 'quality' of the IO curve. The 'quality' of the curve calculation is based on basic concepts from quantum mechanics and calculation of Tsallis entropy.
International Nuclear Information System (INIS)
Perez-Lopez, Esteban
2014-01-01
The quantitative chemical analysis has been importance in research. Also, aspects like: quality control, sales of services and other areas of interest. Some instrumental analysis methods for quantification with linear calibration curve have presented limitations, because the short liner dynamic ranges of the analyte, or sometimes, by limiting the technique itself. The need has been to investigate a little more about the convenience of using quadratic calibration curves for analytical quantification, with which it has seeked demonstrate that has been a valid calculation model for chemical analysis instruments. An analysis base method is used on the technique of atomic absorption spectroscopy and in particular a determination of magnesium in a drinking water sample of the Tacares sector North of Grecia. A nonlinear calibration curve was used and specifically a curve with quadratic behavior. The same was compared with the test results obtained for the equal analysis with a linear calibration curve. The results have showed that the methodology has been valid for the determination referred with all confidence, since the concentrations have been very similar and, according to the used hypothesis testing, can be considered equal. (author) [es
Georgiev, E.S.; Mihaylov, E.S.
2015-01-01
This paper tests the Environmental Kuznets Curve (EKC) hypothesis for four local (SOx, NOx , CO, VOC) and two global (CO2, GHG) air pollutants. Using a panel data set of thirty OECD countries, the paper finds that the postulated inverted U-shaped relationship between income and pollution does not
THE XMM-NEWTON/EPIC X-RAY LIGHT CURVE ANALYSIS OF WR 6
International Nuclear Information System (INIS)
Ignace, R.; Gayley, K. G.; Hamann, W.-R.; Oskinova, L. M.; Huenemoerder, D. P.; Pollock, A. M. T.; McFall, M.
2013-01-01
We obtained four pointings of over 100 ks each of the well-studied Wolf-Rayet star WR 6 with the XMM-Newton satellite. With a first paper emphasizing the results of spectral analysis, this follow-up highlights the X-ray variability clearly detected in all four pointings. However, phased light curves fail to confirm obvious cyclic behavior on the well-established 3.766 day period widely found at longer wavelengths. The data are of such quality that we were able to conduct a search for event clustering in the arrival times of X-ray photons. However, we fail to detect any such clustering. One possibility is that X-rays are generated in a stationary shock structure. In this context we favor a corotating interaction region (CIR) and present a phenomenological model for X-rays from a CIR structure. We show that a CIR has the potential to account simultaneously for the X-ray variability and constraints provided by the spectral analysis. Ultimately, the viability of the CIR model will require both intermittent long-term X-ray monitoring of WR 6 and better physical models of CIR X-ray production at large radii in stellar winds
THE XMM-NEWTON/EPIC X-RAY LIGHT CURVE ANALYSIS OF WR 6
Energy Technology Data Exchange (ETDEWEB)
Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37663 (United States); Gayley, K. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52245 (United States); Hamann, W.-R.; Oskinova, L. M. [Institute for Physics and Astronomy, University Potsdam, D-14476 Potsdam (Germany); Huenemoerder, D. P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar Street, Cambridge, MA 02139 (United States); Pollock, A. M. T. [European Space Agency XMM-Newton Science Operations Centre, European Space Astronomy Centre, Apartado 78, Villanueva de la Cañada, E-28691 Madrid (Spain); McFall, M., E-mail: ignace@etsu.edu [Department of Physics, 191 W. Woodruff Avenue, Ohio State University, Columbus, OH 43210 (United States)
2013-09-20
We obtained four pointings of over 100 ks each of the well-studied Wolf-Rayet star WR 6 with the XMM-Newton satellite. With a first paper emphasizing the results of spectral analysis, this follow-up highlights the X-ray variability clearly detected in all four pointings. However, phased light curves fail to confirm obvious cyclic behavior on the well-established 3.766 day period widely found at longer wavelengths. The data are of such quality that we were able to conduct a search for event clustering in the arrival times of X-ray photons. However, we fail to detect any such clustering. One possibility is that X-rays are generated in a stationary shock structure. In this context we favor a corotating interaction region (CIR) and present a phenomenological model for X-rays from a CIR structure. We show that a CIR has the potential to account simultaneously for the X-ray variability and constraints provided by the spectral analysis. Ultimately, the viability of the CIR model will require both intermittent long-term X-ray monitoring of WR 6 and better physical models of CIR X-ray production at large radii in stellar winds.
Reliability assessment of a manual-based procedure towards learning curve modeling and fmea analysis
Directory of Open Access Journals (Sweden)
Gustavo Rech
2013-03-01
Full Text Available Separation procedures in drug Distribution Centers (DC are manual-based activities prone to failures such as shipping exchanged, expired or broken drugs to the customer. Two interventions seem as promising in improving the reliability in the separation procedure: (i selection and allocation of appropriate operators to the procedure, and (ii analysis of potential failure modes incurred by selected operators. This article integrates Learning Curves (LC and FMEA (Failure Mode and Effect Analysis aimed at reducing the occurrence of failures in the manual separation of a drug DC. LCs parameters enable generating an index to identify the recommended operators to perform the procedures. The FMEA is then applied to the separation procedure carried out by the selected operators in order to identify failure modes. It also deployed the traditional FMEA severity index into two sub-indexes related to financial issues and damage to company´s image in order to characterize failures severity. When applied to a drug DC, the proposed method significantly reduced the frequency and severity of failures in the separation procedure.
Zhang, Xiaodong; Zhao, Yinxia; Hu, Shaoyong; Hao, Shuai; Yan, Jiewen; Zhang, Lingyan; Zhao, Jing; Li, Shaolin
2015-09-01
To investigate the correlation between the lumbar vertebra bone mineral density (BMD) and age, gender, height, weight, body mass index, waistline, hipline, bone marrow and abdomen fat, and to explore the key factor affecting the BMD. A total of 72 cases were randomly recruited. All the subjects underwent a spectroscopic examination of the third lumber vertebra with single-voxel method in 1.5T MR. Lipid fractions (FF%) were measured. Quantitative CT were also performed to get the BMD of L3 and the corresponding abdomen subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT). The statistical analysis were performed by SPSS 19.0. Multiple linear regression showed except the age and FF% showed significant difference (P0.05). The correlation of age and FF% with BMD was statistically negatively significant (r=-0.830, -0.521, P<0.05). The ROC curve analysis showed that the sensitivety and specificity of predicting osteoporosis were 81.8% and 86.9%, with a threshold of 58.5 years old. And it showed that the sensitivety and specificity of predicting osteoporosis were 90.9% and 55.7%, with a threshold of 52.8% for FF%. The lumbar vertebra BMD was significantly and negatively correlated with age and bone marrow FF%, but it was not significantly correlated with gender, height, weight, BMI, waistline, hipline, SAT and VAT. And age was the critical factor.
STRESS - STRAIN CURVE ANALYSIS OF WOVEN FABRICS MAD E FROM COMBED YARNS TYPE WOOL
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VÎLCU Adrian
2014-05-01
Full Text Available The paper analyses the tensile behavior of woven fabrics made from 45%Wool + 55% PES used for garments. Analysis of fabric behavior during wearing has shown that these are submitted to simple and repeated uni-axial or bi-axial tensile strains. The level of these strains is often within the elastic limit, rarely going over yielding. Therefore the designer must be able to evaluate the mechanical behavior of such fabrics in order to control the fabric behavior in the garment. This evaluation is carried out based on the tensile testing, using certain indexes specific to the stress-strain curve. The paper considers an experimental matrix based on woven fabrics of different yarn counts, different or equal yarn count for warp and weft systems and different structures. The fabrics were tested using a testing machine and the results were then compared in order to determine the fabrics’ tensile behavior and the factors of influence that affect it.From the point of view of tensile testing, the woven materials having twill weave are preferable because this type of structure is characterized by higher durability and better yarn stability in the fabric. In practice, the woven material must exhibit an optimum behavior to repeated strains, flexions and abrasions during wearing process. The analysis of fabrics tensile properties studied by investigation of stress-strain diagrams reveals that the main factors influencing the tensile strength are: yarns fineness, technological density of those two systems of yarns and the weaving type.
Aslan, Alper; Destek, Mehmet Akif; Okumus, Ilyas
2018-01-01
This study aims to examine the validity of inverted U-shaped Environmental Kuznets Curve by investigating the relationship between economic growth and environmental pollution for the period from 1966 to 2013 in the USA. Previous studies based on the assumption of parameter stability and obtained parameters do not change over the full sample. This study uses bootstrap rolling window estimation method to detect the possible changes in causal relations and also obtain the parameters for sub-sample periods. The results show that the parameter of economic growth has increasing trend in 1982-1996 sub-sample periods, and it has decreasing trend in 1996-2013 sub-sample periods. Therefore, the existence of inverted U-shaped Environmental Kuznets Curve is confirmed in the USA.
Dose-response curves with semiochemicals are reported in many articles in insect chemical ecology regarding neurophysiology and behavioral bioassays. Most such curves are shown in figures where the x-axis has order of magnitude increases in dosages versus responses on the y-axis represented by point...
International Nuclear Information System (INIS)
Leli, D.A.; Katholi, C.R.; Hazelrig, J.B.; Falgout, J.C.; Hannay, H.J.; Wilson, E.M.; Wills, E.L.; Halsey, J.H. Jr.
1985-01-01
An initial assessment of the differential sensitivity of total versus partial curve analysis in estimating task related focal changes in cortical blood flow measured by the 133 Xe inhalation technique was accomplished by comparing the patterns during the performance of two sensorimotor tasks by normal subjects. The validity of these patterns was evaluated by comparing them to the activation patterns expected from activation studies with the intra-arterial technique and the patterns expected from neuropsychological research literature. Subjects were 10 young adult nonsmoking healthy male volunteers. They were administered two tasks having identical sensory and cognitive components but different response requirements (oral versus manual). The regional activation patterns produced by the tasks varied with the method of curve analysis. The activation produced by the two tasks was very similar to that predicted from the research literature only for total curve analysis. To the extent that the predictions are correct, these data suggest that the 133 Xe inhalation technique is more sensitive to regional flow changes when flow parameters are estimated from the total head curve. The utility of the total head curve analysis will be strengthened if similar sensitivity is demonstrated in future studies assessing normal subjects and patients with neurological and psychiatric disorders
Directory of Open Access Journals (Sweden)
Liying Jiang
2011-12-01
Full Text Available In this work, the problem of a curved functionally graded piezoelectric (FGP actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.
Yan, Zhi; Zaman, Mostafa; Jiang, Liying
2011-12-12
In this work, the problem of a curved functionally graded piezoelectric (FGP) actuator with sandwich structure under electrical and thermal loads is investigated. The middle layer in the sandwich structure is functionally graded with the piezoelectric coefficient g 31 varying continuously along the radial direction of the curved actuator. Based on the theory of linear piezoelectricity, analytical solutions are obtained by using Airy stress function to examine the effects of material gradient and heat conduction on the performance of the curved actuator. It is found that the material gradient and thermal load have significant influence on the electroelastic fields and the mechanical response of the curved FGP actuator. Without the sacrifice of actuation deflection, smaller internal stresses are generated by using the sandwich actuator with functionally graded piezoelectric layer instead of the conventional bimorph actuator. This work is very helpful for the design and application of curved piezoelectric actuators under thermal environment.
Roentgen stereophotogrammetry for analysis of cranial growth
International Nuclear Information System (INIS)
Selvik, G.; Alberius, P.; Fahlman, M.
1986-01-01
A system of roentgen stereophotogrammetric analysis (RSA) has been developed and its value in studies of cranial growth in both man and the experimental animal (rabbit) has been delineated. This method is based on measurements from metal bone marker images on roentgenograms. Two roentgen tubes simultaneously expose the object, which is placed in one of two types of calibration cages. The object position does not need to be identical from one examination to the next. The cage, holding indicators of predetermined internal positions (in two or four planes), defines a laboratory coordinate system. Two-dimensional image coordinates are obtained by means of a highly accurate cartographic instrument. By computer reconstruction of the x-ray beams through the markers, 3-D object coordinates are calculated. For subsequent analysis of growth processes, extensive software is necessary. To control intrasegmental stability (routinely performed at each examination), a minimum of two markers is required, whereas three markers are needed in each skeletal segment for kinematic analysis using the rigid-body concept. Careful planning of marker placement before implantation minimizes implant loss and instability that otherwise might be a problem. Complications other than bone marker loosening have been nonexistent. The technical accuracy is high. Consequently, roentgen stereophotogrammetry, with the aid of metallic implants, is a superior means to obtain biometric information on cranial growth with relative ease
A Literature-Based Analysis of the Learning Curves of Laparoscopic Radical Prostatectomy
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Daniel W. Good
2014-05-01
Full Text Available There is a trend for the increased adoption of minimally invasive techniques of radical prostatectomy (RP – laparoscopic (LRP and robotic assisted (RARP – from the traditional open radical retropubic prostatectomy (ORP, popularised by Partin et al. Recently there has been a dramatic expansion in the rates of RARP being performed, and there have been many early reports postulating that the learning curve for RARP is shorter than for LRP. The aim of this study was to review the literature and analyse the length of the LRP learning curves for the various outcome measures: perioperative, oncologic, and functional outcomes. A broad search of the literature was performed in November 2013 using the PubMed database. Only studies of real patients and those from 2004 until 2013 were included; those on simulators were excluded. In total, 239 studies were identified after which 13 were included. The learning curve is a heterogeneous entity, depending entirely on the criteria used to define it. There is evidence of multiple learning curves; however the length of these is dependent on the definitions used by the authors. Few studies use the more rigorous definition of plateauing of the curve. Perioperative learning curve takes approximately 150-200 cases to plateau, oncologic curve approximately 200 cases, and the functional learning curve up to 700 cases to plateau (700 for potency, 200 cases for continence. In this review, we have analysed the literature with respect to the learning curve for LRP. It is clear that the learning curve is long. This necessitates centralising LRP to high volume centres such that surgeons, trainees, and patients are able to utilise the benefits of LRP.
Periodicity Analysis of X-ray Light Curves of SS 433
Wang, Jun-yi; Lu, Xiang-long; Zhao, Qiu-wen; Dong, Dian-qiao; Lao, Bao-qiang; Lu, Yang; Wei, Yan-heng; Wu, Xiao-cong; An, Tao
2017-01-01
SS 433 is sofar the unique X-ray binary that has the simultaneously detected orbital period, super-orbital period, and nutation period, as well as a bidirectional spiral jet. The study on its X-ray light variability is helpful for understanding the dynamic process of the system, and the correlations between the different wavebands. In this paper, two time-series analysis techniques, i.e., the Lomb-Scargle periodogram and weighted wavelet Z-transform, are employed to search for the periods in the Swift/BAT (Burst Alert Telescope) (15-50 keV) and RXTE/ASM (Rose X-ray Timing Explorer/All Sky Monitor) (1.5-3, 3- 4, and 5-12 keV) light curves of SS 433, and the Monte Carlo simulation is performed for the obtained periodical components. For the 15-50 keV energy band, five significant periodical components are detected, which are P1(∼6.29 d), P2 (∼6.54 d), P3 (∼13.08 d), P4 (∼81.50 d), and P5 (∼162.30 d). For the 3-5 and 5-12 keV energy bands, the periodical components P3 (∼13 d) and P5 (∼162 d) are detected in both energy bands. However, for the 1.5-3 keV energy band, no significant periodic signal is detected. P5 is the strongest periodic signal in the power spectrum for all the energy bands of 3-5, 5-12, and 15-50 keV, and it is consistent with the previous result obtained from the study of optical light curves. Furthermore, in combination with the radio spiral jet of SS 433, it is suggested that the X-ray and optical variability of P5 (∼162 d) is probably related to the precession of its relativistic jet. The high correlation between the X-ray and optical light curves may also imply that the X-ray and optical radiations are of the same physical origin. P3 shows a good agreement with the orbital period (∼13.07 d) obtained by the previous study, and P2 and P4 are respectively the high-frequency harmonics of P3 and P5. P1 is detected only in the power spectrum of the 15-50 keV energy band, and it is consistent with the nutation period of the system. As
Rodríguez-Reyes, Juan Carlos F.; Teplyakov, Andrew V.; Brown, Steven D.
2010-10-01
The substantial amount of information carried in temperature-programmed desorption (TPD) experiments is often difficult to mine due to the occurrence of competing reaction pathways that produce compounds with similar mass spectrometric features. Multivariate curve resolution (MCR) is introduced as a tool capable of overcoming this problem by mathematically detecting spectral variations and correlations between several m/z traces, which is later translated into the extraction of the cracking pattern and the desorption profile for each desorbate. Different from the elegant (though complex) methods currently available to analyze TPD data, MCR analysis is applicable even when no information regarding the specific surface reaction/desorption process or the nature of the desorbing species is available. However, when available, any information can be used as constraints that guide the outcome, increasing the accuracy of the resolution. This approach is especially valuable when the compounds desorbing are different from what would be expected based on a chemical intuition, when the cracking pattern of the model test compound is difficult or impossible to obtain (because it could be unstable or very rare), and when knowing major components desorbing from the surface could in more traditional methods actually bias the quantification of minor components. The enhanced level of understanding of thermal processes achieved through MCR analysis is demonstrated by analyzing three phenomena: i) the cryogenic desorption of vinyltrimethylsilane from silicon, an introductory system where the known multilayer and monolayer components are resolved; ii) acrolein hydrogenation on a bimetallic Pt-Ni-Pt catalyst, where a rapid identification of hydrogenated products as well as other desorbing species is achieved, and iii) the thermal reaction of Ti[N(CH 3) 2] 4 on Si(100), where the products of surface decomposition are identified and an estimation of the surface composition after the
Antinoro, Chiara; Arnone, Elisa; Noto, Leonardo V.
2015-04-01
The mechanisms of rainwater infiltration causing slope instability had been analyzed and reviewed in many scientific works. Rainwater infiltration into unsaturated soil increases the degree of saturation, hence affecting the shear strength properties and thus the probability of slope failure. It has been widely proved that the shear strength properties change with the soil water suction in unsaturated soils; therefore, the accuracy to predict the relationship between soil water content and soil water suction, parameterized by the soil-water characteristic curve, has significant effects on the slope stability analysis. The aim of this study is to investigate how the characterization of SWRC of differently structured unsaturated soils affects the slope stability on a simple infinite slope. In particular, the unimodal and bimodal distributions of the soil pore size were compared. Samples of 40 soils, highly different in terms of structure and texture, were collected and used to calibrate two bimodal SWRCs, i.e. Ross and Smettem (1993) and Dexter et al., (2008). The traditional unimodal van Genuchten (1980) model was also applied for comparison. Slope stability analysis was conducted in terms of Factor of Safety (FS) by applying the infinite slope model for unsaturated soils. In the used formulation, the contribution of the suction effect is tuned by a parameter 'chi' in a rate proportional to the saturation conditions. Different parameterizations of this term were also compared and analyzed. Results indicated that all three SWRC models showed good overall performance in fitting the sperimental SWRCs. Both the RS and DE models described adequately the water retention data for soils with a bimodal behavior confirmed from the analysis of pore size distribution, but the best performance was obtained by DE model confirmed. In terms of FS, the tree models showed very similar results as soil moisture approached to the saturated condition; however, within the residual zone
Appetite and growth: a longitudinal sibling analysis.
van Jaarsveld, Cornelia H M; Boniface, David; Llewellyn, Clare H; Wardle, Jane
2014-04-01
Identifying early markers of future obesity risk can help target preventive interventions. Several studies have shown that a heartier appetite in infancy is a risk factor for more rapid weight gain, but to date no investigations have been able to rule out familial confounding. To use a sibling design (data from same-sex, dizygotic twin pairs) to test the hypothesis that sibling differences in infant appetite predicted differential weight gain during childhood. Gemini is a population-based twin cohort among the general United Kingdom population born between March 1, 2007, and December 15, 2007. Growth trajectories were analyzed from birth to age 15 months. Appetite-discordant pairs were selected from 800 nonidentical, same-sex twin pairs. Appetite during the first 3 months of life was assessed with the food responsiveness (FR) and satiety responsiveness (SR) subscales from the Baby Eating Behaviour Questionnaire. Discordance was defined as a within-pair difference of at least 1 SD. A mean of 11.5 weight measurements per child were available between birth and age 15 months. Multilevel models, adjusted for sex and birth weight, compared growth curves for the higher-appetite vs lower-appetite twins. In total, 172 pairs were discordant for SR and 121 pairs for FR. Within-pair analyses showed that those with higher FR and those with lower SR grew faster than their sibling. At age 6 months, those with higher FR were 654 (95% CI, 395-913) g heavier and at age 15 months were 991 (95% CI, 484-1498) g heavier. For sibling pairs discordant for SR, the weight differences between siblings were 637 (95% CI, 438-836) g at age 6 months and 918 (95% CI, 569-1267) g at age 15 months. A heartier appetite (indexed with higher FR or lower SR) in early infancy is prospectively associated with more rapid growth up to age 15 months in a design controlling for potential familial confounding, supporting a causal role for appetite in childhood weight gain. Appetite could be an early marker
Shin, Myoungjin; Kim, Inwoo; Kwon, Sungho
2014-12-01
Understanding the relationship between affect and exercise is helpful in predicting human behavior with respect to exercise participation. The goals of the present study were to investigate individual differences in affective response during and after exercise and to identify the role of intrinsic motivation in affective changes. 30 active male college students (M age = 21.4 yr.) who regularly participated in sports activities volunteered to answer a questionnaire measuring intrinsic motivation toward running activities and performed a 20-min. straight running protocol at heavy intensity (about 70% of VO2max). Participants' affective responses were measured every 5 min. from the beginning of the run to 10 min. after completing the run. Latent curve model analysis indicated that individuals experienced different changes in affective state during exercise, moderated by intrinsic motivation. Higher intrinsic motivation was associated with more positive affect during exercise. There were no significant individual differences in the positive tendency of the participants' affective responses after exercise over time. Intrinsic motivation seems to facilitate positive feelings during exercise and encourages participation in exercise.
The application of latent curve analysis to testing developmental theories in intervention research.
Curran, P J; Muthén, B O
1999-08-01
The effectiveness of a prevention or intervention program has traditionally been assessed using time-specific comparisons of mean levels between the treatment and the control groups. However, many times the behavior targeted by the intervention is naturally developing over time, and the goal of the treatment is to alter this natural or normative developmental trajectory. Examining time-specific mean levels can be both limiting and potentially misleading when the behavior of interest is developing systematically over time. It is argued here that there are both theoretical and statistical advantages associated with recasting intervention treatment effects in terms of normative and altered developmental trajectories. The recently developed technique of latent curve (LC) analysis is reviewed and extended to a true experimental design setting in which subjects are randomly assigned to a treatment intervention or a control condition. LC models are applied to both artificially generated and real intervention data sets to evaluate the efficacy of an intervention program. Not only do the LC models provide a more comprehensive understanding of the treatment and control group developmental processes compared to more traditional fixed-effects models, but LC models have greater statistical power to detect a given treatment effect. Finally, the LC models are modified to allow for the computation of specific power estimates under a variety of conditions and assumptions that can provide much needed information for the planning and design of more powerful but cost-efficient intervention programs for the future.
M DWARFS IN SLOAN DIGITAL SKY SURVEY STRIPE 82: PHOTOMETRIC LIGHT CURVES AND FLARE RATE ANALYSIS
International Nuclear Information System (INIS)
Kowalski, Adam F.; Hawley, Suzanne L.; Hilton, Eric J.; Becker, Andrew C.; Sesar, Branimir; West, Andrew A.; Bochanski, John J.
2009-01-01
We present a flare rate analysis of 50,130 M dwarf light curves in Sloan Digital Sky Survey Stripe 82. We identified 271 flares using a customized variability index to search ∼2.5 million photometric observations for flux increases in the u and g bands. Every image of a flaring observation was examined by eye and with a point-spread function-matching and image subtraction tool to guard against false positives. Flaring is found to be strongly correlated with the appearance of Hα in emission in the quiet spectrum. Of the 99 flare stars that have spectra, we classify eight as relatively inactive. The flaring fraction is found to increase strongly in stars with redder colors during quiescence, which can be attributed to the increasing flare visibility and increasing active fraction for redder stars. The flaring fraction is strongly correlated with |Z| distance such that most stars that flare are within 300 pc of the Galactic plane. We derive flare u-band luminosities and find that the most luminous flares occur on the earlier-type m dwarfs. Our best estimate of the lower limit on the flaring rate (averaged over Stripe 82) for flares with Δu ≥ 0.7 mag on stars with u -1 deg -2 but can vary significantly with the line of sight.
Left ventricular time volume curve analysis in the detection of limited ischaemic heart disease
International Nuclear Information System (INIS)
Liechtenstein, M.; Blanchett, W.; Andrews, J.; Hunt, D.
1982-01-01
The aim of the study was to determine whether limited coronary artery disease (CAD) could be accurately detected using the Cardiac Gated Blood Pool (CGBP) scan with exercise. Regional left ventricular time volume curves (RLTVD) were generated from 52 studies (46 patients: 22 normals, 24 abnormals). The parameters assessed both globally and regionally and at rest (R) and exercise (Ex) were: (1) the ejection fraction (EF) (2) the change in ejection fraction from R to Ex (δEF) (3) an early contraction index (ECI) (4) a maximal emptying index (DR) and (5) a maximal refilling index (AR). After careful analysis of these parameters it was decided that our diagnostic criteria would rely on the following: (1) the EF at R and Ex (2) the δ EF (3) the ECI at Ex (4) the AR at Ex This study showed that both the sensitivity and the specificity of the CGBP scan can be improved considerably with the inclusion of RLTVC from the levels obtained when the EF parameters alone are considered. It is possible with this technique to accurately diagnose limited CAD. (Author)
Cognitive Vulnerabilities and Depression in Young Adults: An ROC Curves Analysis.
Balsamo, Michela; Imperatori, Claudio; Sergi, Maria Rita; Belvederi Murri, Martino; Continisio, Massimo; Tamburello, Antonino; Innamorati, Marco; Saggino, Aristide
2013-01-01
Objectives and Methods. The aim of the present study was to evaluate, by means of receiver operating characteristic (ROC) curves, whether cognitive vulnerabilities (CV), as measured by three well-known instruments (the Beck Hopelessness Scale, BHS; the Life Orientation Test-Revised, LOT-R; and the Attitudes Toward Self-Revised, ATS-R), independently discriminate between subjects with different severities of depression. Participants were 467 young adults (336 females and 131 males), recruited from the general population. The subjects were also administered the Beck Depression Inventory-II (BDI-II). Results. Four first-order (BHS Optimism/Low Standard; BHS Pessimism; Generalized Self-Criticism; and LOT Optimism) and two higher-order factors (Pessimism/Negative Attitudes Toward Self, Optimism) were extracted using Principal Axis Factoring analysis. Although all first-order and second-order factors were able to discriminate individuals with different depression severities, the Pessimism factor had the best performance in discriminating individuals with moderate to severe depression from those with lower depression severity. Conclusion. In the screening of young adults at risk of depression, clinicians have to pay particular attention to the expression of pessimism about the future.
Directory of Open Access Journals (Sweden)
Qiuying Huang
2011-04-01
Full Text Available Probe-based fluorescence melting curve analysis (FMCA is a powerful tool for mutation detection based on melting temperature generated by thermal denaturation of the probe-target hybrid. Nevertheless, the color multiplexing, probe design, and cross-platform compatibility remain to be limited by using existing probe chemistries. We hereby explored two dual-labeled, self-quenched probes, TaqMan and shared-stem molecular beacons, in their ability to conduct FMCA. Both probes could be directly used for FMCA and readily integrated with closed-tube amplicon hybridization under asymmetric PCR conditions. Improved flexibility of FMCA by using these probes was illustrated in three representative applications of FMCA: mutation scanning, mutation identification and mutation genotyping, all of which achieved improved color-multiplexing with easy probe design and versatile probe combination and all were validated with a large number of real clinical samples. The universal cross-platform compatibility of these probes-based FMCA was also demonstrated by a 4-color mutation genotyping assay performed on five different real-time PCR instruments. The dual-labeled, self-quenched probes offered unprecedented combined advantage of enhanced multiplexing, improved flexibility in probe design, and expanded cross-platform compatibility, which would substantially improve FMCA in mutation detection of various applications.
On the applicability of numerical image mapping for PIV image analysis near curved interfaces
International Nuclear Information System (INIS)
Masullo, Alessandro; Theunissen, Raf
2017-01-01
This paper scrutinises the general suitability of image mapping for particle image velocimetry (PIV) applications. Image mapping can improve PIV measurement accuracy by eliminating overlap between the PIV interrogation windows and an interface, as illustrated by some examples in the literature. Image mapping transforms the PIV images using a curvilinear interface-fitted mesh prior to performing the PIV cross correlation. However, degrading effects due to particle image deformation and the Jacobian transformation inherent in the mapping along curvilinear grid lines have never been deeply investigated. Here, the implementation of image mapping from mesh generation to image resampling is presented in detail, and related error sources are analysed. Systematic comparison with standard PIV approaches shows that image mapping is effective only in a very limited set of flow conditions and geometries, and depends strongly on a priori knowledge of the boundary shape and streamlines. In particular, with strongly curved geometries or streamlines that are not parallel to the interface, the image-mapping approach is easily outperformed by more traditional image analysis methodologies invoking suitable spatial relocation of the obtained displacement vector. (paper)
International Nuclear Information System (INIS)
Al Achkar, W.
2002-01-01
In order to draw a dose-effect curve, blood from eight healthy people were studied. Samples were irradiated in tubes with 0.15-2.5 gray of gamma ray.Irradiated and control samples were incubated for cell cultures. Chromosomal aberrations from 67888 metaphases were scored. Curves from the total number of dicentrics, dicentrics+ rings and total numbers of breaks were drawn. The yield of chromosome aberrations is related to the dose used. These curves give a quick useful estimation of the accidentally radiation exposure. (author)
Simulation and analysis of the transmission properties of curved-straight neutron guide systems
International Nuclear Information System (INIS)
Copley, J.R.D.; Mildner, D.F.R.
1992-01-01
This paper reports that the spatial intensity distribution of neutrons emerging from a curved guide is far from uniform, particularly at short wavelengths, and curved guides are sometimes followed by a straight section of guide to make the intensity distribution more uniform. The behavior of neutrons within curved-straight neutron guide systems is examined using both ray-tracing and analytical approaches to the problem. The intensity distribution within the straight guide tends to wash from one side of the guide to the other. The amplitude of this transverse wave decreases with increasing guide length, and the characteristic length of the wave decreases with increasing neutron wavelength
ANALYSIS OF THE SECONDARY CURVES IN PATIENTS UNDERGOING SELECTIVE ARTHRODESIS LENKE I
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TADEU GERVAZONI DEBOM
2015-12-01
Full Text Available Objective : To radiographically evaluate the behavior of the secondary curves in the coronal and sagittal planes in patients with AIS classified as Lenke I, who underwent surgical treatment of selective arthrodesis by posterior approach. Methods : Retrospective study which analyzed 40 patients with AIS, being 33 female. The measurement of the radiographic parameters used followed the recommendations by Cobb. Results : The average correction of the thoracic proximal, primary and lumbar curves was 34.73%, 75.06% and 64.64%, respectively. Conclusion : Surgical treatment by selective arthrodesis in cases of AIS Lenke type I provide correction of compensatory curves in the coronal and maintenance in the sagittal plane.
On the analysis of glycomics mass spectrometry data via the regularized area under the ROC curve
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Lebrilla Carlito B
2007-12-01
Full Text Available Abstract Background Novel molecular and statistical methods are in rising demand for disease diagnosis and prognosis with the help of recent advanced biotechnology. High-resolution mass spectrometry (MS is one of those biotechnologies that are highly promising to improve health outcome. Previous literatures have identified some proteomics biomarkers that can distinguish healthy patients from cancer patients using MS data. In this paper, an MS study is demonstrated which uses glycomics to identify ovarian cancer. Glycomics is the study of glycans and glycoproteins. The glycans on the proteins may deviate between a cancer cell and a normal cell and may be visible in the blood. High-resolution MS has been applied to measure relative abundances of potential glycan biomarkers in human serum. Multiple potential glycan biomarkers are measured in MS spectra. With the objection of maximizing the empirical area under the ROC curve (AUC, an analysis method was considered which combines potential glycan biomarkers for the diagnosis of cancer. Results Maximizing the empirical AUC of glycomics MS data is a large-dimensional optimization problem. The technical difficulty is that the empirical AUC function is not continuous. Instead, it is in fact an empirical 0–1 loss function with a large number of linear predictors. An approach was investigated that regularizes the area under the ROC curve while replacing the 0–1 loss function with a smooth surrogate function. The constrained threshold gradient descent regularization algorithm was applied, where the regularization parameters were chosen by the cross-validation method, and the confidence intervals of the regression parameters were estimated by the bootstrap method. The method is called TGDR-AUC algorithm. The properties of the approach were studied through a numerical simulation study, which incorporates the positive values of mass spectrometry data with the correlations between measurements within person
Energy Technology Data Exchange (ETDEWEB)
Michoux, N.; Montet, X.; Pechere, A.; Ivancevic, M.K.; Martin, P.-Y.; Keller, A.; Didier, D.; Terrier, F.; Vallee, J.-P
2005-04-01
The aim of this study was to refine the description of the renal function based on MR images and through transit-time curve analysis on a normal population and on a population with renal failure, using the quantitative model of the up-slope. Thirty patients referred for a kidney MR exam were divided in a first population with well-functioning kidneys and in a second population with renal failure from ischaemic kidney disease. The perfusion sequence consisted of an intravenous injection of Gd-DTPA and of a fast GRE sequence T1-TFE with 90 deg. magnetisation preparation (Intera 1.5 T MR System, Philips Medical System). To convert the signal intensity into 1/T1, which is proportional to the contrast media concentration, a flow-corrected calibration procedure was used. Following segmentation of regions of interest in the cortex and medulla of the kidney and in the abdominal aorta, outflow curves were obtained and filtered to remove the high frequency fluctuations. The model of the up-slope method was then applied. Significant reduction of the cortical perfusion (Q{sub c}=0.057{+-}0.030 ml/(s 100 g) to Q{sub c}=0.030{+-}0.017 ml/(s 100 g), P<0.013), of the medullary perfusion (Q{sub m}=0.023{+-}0.018 ml/(s 100 g) to Q{sub m}=0.011{+-}0.006 ml/(s 100 g), P<0.046) and of the accumulation of contrast media in the medulla (Q{sub a}=0.005{+-}0.003 ml/(s 100 g) to Q{sub a}=0.0009{+-}0.0008 ml/(s 100 g), P<0.001) were found in presence of renal failure. High correlations were found between the creatinine level and the accumulation Q{sub a} in the medulla (r{sup 2}=0.72, P<0.05), and between the perfusion ratio Q{sub c}/Q{sub m} and the accumulation Q{sub a} in the medulla (r{sup 2}=0.81, P<0.05). No significant difference was found in times to peak between both populations despite a trend showing T{sub a} the time to the end of the increasing contrast accumulation period in the medulla, arriving later for renal failure. Advances in MR signal calibration with the building of
Jiang, Chao; Huang, Lu-Qi; Yuan, Yuan; Chen, Min; Hou, Jing-Yi; Wu, Zhi-Gang; Lin, Shu-Fang
2014-04-01
Single nucleotide polymorphisms (SNP) is an important molecular marker in traditional Chinese medicine research, and it is widely used in TCM authentication. The present study created a new genotyping method by combining restriction endonuclease digesting with melting curve analysis, which is a stable, rapid and easy doing SNP genotyping method. The new method analyzed SNP genotyping of two chloroplast SNP which was located in or out of the endonuclease recognition site, the results showed that when attaching a 14 bp GC-clamp (cggcgggagggcgg) to 5' end of the primer and selecting suited endonuclease to digest the amplification products, the melting curve of Lonicera japonica and Atractylodes macrocephala were all of double peaks and the adulterants Shan-yin-hua and A. lancea were of single peaks. The results indicated that the method had good stability and reproducibility for identifying authentic medicines from its adulterants. It is a potential SNP genotyping method and named restriction endonuclease digest - melting curve analysis.
International Nuclear Information System (INIS)
Primo, S.; Datz, H.; Dar, A.
2014-01-01
The External Dosimetry Lab (EDL) at the Radiation Safety Division at Soreq Nuclear Research Center (SNRC) is ISO 17025 certified and provides its services to approximately 13,000 users throughout the country from various sectors such as medical, industrial and academic. About 95% of the users are monitored monthly for X-rays, radiation using Thermoluminescence Dosimeter (TLD) cards that contain three LiF:Mg,Ti elements and the other users, who work also with thermal neutrons, use TLD cards that contain four LiF:Mg,Ti elements. All TLD cards are measured with the Thermo 8800pc reader. Suspicious TLD glow curve (GC) can cause wrong dose estimation so the EDL makes great efforts to ensure that each GC undergoes a careful QC procedure. The current QC procedure is performed manually and through a few steps using different softwares and databases in a long and complicated procedure: EDL staff needs to export all the results/GCs to be checked to an Excel file, followed by finding the suspicious GCs, which is done in a different program (WinREMS), According to the GC shapes (Figure 1 illustrates suitable and suspicious GC shapes) and the ratio between the elements result values, the inspecting technician corrects the data. The motivation for developing the new program is the complicated and time consuming process of our the manual procedure to the large amount of TLDs each month (13,000), similarly to other Dosimetry services that use computerized QC GC analysis. it is important to note that only ~25% of the results are above the EDL recorded level (0.10 mSv) and need to be inspected. Thus, the purpose of this paper is to describe a new program, TagQC, which allows a computerized QC GC analysis that identifies automatically, swiftly, and accurately suspicious TLD GC
Size of government and economic growth: A nonlinear analysis
Directory of Open Access Journals (Sweden)
Herath Shanaka
2012-01-01
Full Text Available The new growth theory establishes, among other things, that government expenditure can manipulate the economic growth of a country. This study attempts to explain whether government expenditure increases or decreases economic growth in the context of Sri Lanka. Results obtained employing a productive output series and applying an analytical framework based on second degree polynomial regression are generally consistent with previous findings: government expenditure and economic growth are positively correlated; excessive government expenditure is negatively correlated with economic growth; and investment promotes growth. In a separate section, the article examines Armey’s idea of a quadratic curve that explains the level of government expenditure in an economy and the corresponding level of economic growth [Armey, D. (1995. The Freedom Revolution. Washington, D.C.: Regnery Publishing Co.]. The findings confirm the possibility of constructing the Armey curve for Sri Lanka, and it estimates the optimal level of government expenditure to be approximately 27%. This article adds to the literature indicating that the Armey curve is a reality not only for developed economies, but also for developing economies.
Size-dependent analysis of a sandwich curved nanobeam integrated with piezomagnetic face-sheets
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Ashraf M. Zenkour
Full Text Available The aim of this research is to develop nonlocal transient magneto-electro-elastic formulation of a sandwich curved nanobeam including a nano-core and two piezo-magnetic face-sheets subjected to transverse mechanical loads and applied electric and magnetic potentials rest on Pasternak’s foundation. Nonlocal magneto-electro-elastic relations and Hamilton’s principle are used for derivation of the governing equations of motion. The analytical solution based on Fourier solution is presented for a simply-supported sandwich curved nanobeam. The numerical results are presented to investigate influence of significant parameters such as nonlocal parameter, radius of curvature, applied electric and magnetic potentials and two parameters of Pasternak's foundation on the dynamic responses of sandwich curved nanobeam. Keywords: Sandwich curved nanobeam, Dynamic responses, Piezo-magnetic face-sheets, Pasternak’s foundation, Radius of curvature, Nonlocal parameter
New Light Curves and Analysis of the Overcontact Binaries PP Lac and DK Sge
Sanders, S. J.; Hargis, J. R.; Bradstreet, D. H.
2004-12-01
As a by-product of the ongoing work with the Catalog and AtLas of Eclipsing Binaries database (CALEB; Bradstreet et al. 2004), several hundred eclipsing binary systems have been identified that have either unpublished or poor quality light curves. We present new V & Rc light curves for the overcontact systems PP Lac and DK Sge, both chosen because their deep eclipses (peak-to-peak amplitudes of nearly 0.7 mag) help constrain the light curve modelling. Data were obtained using the 41-cm telescope at the Eastern University Observatory equipped with an SBIG ST-10XME CCD. PP Lac (P= 0.40116 d) is a W-type contact binary with only one previously published light curve (Dumont & Maraziti 1990), but the data are sparse and almost non-existent at primary eclipse. Modelling of these data gave varying results; the published mass ratios differ by nearly 0.3. Our data confirms the noted differing eclipse depths but we find the primary eclipse to be total. We present a new light curve solution using Binary Maker 3 (Bradstreet & Steelman 2002) and Wilson-Devinney, finding the mass ratio to be well-constrained by the duration of total eclipse. A period study will be presented using previously existing and newly derived times of minimum light. DK Sge (P=0.62182 d) appears to be an A-type contact binary with no published light curve. The eclipses are partial, with the primary eclipse being deeper by about 0.08 mag. The maxima show evidence of a slight asymmetry, although the light curve appears to be repeatable over the 1 month of observations. We present the first light curve solution using Binary Maker 3 and Wilson-Devinney, but have limited mass ratio constraints due to the absence of radial velocity data. A period study will be presented using previously existing and newly derived times of minimum light.
Yang, Zhichun; Zhou, Jian; Gu, Yingsong
2014-10-01
A flow field modified local piston theory, which is applied to the integrated analysis on static/dynamic aeroelastic behaviors of curved panels, is proposed in this paper. The local flow field parameters used in the modification are obtained by CFD technique which has the advantage to simulate the steady flow field accurately. This flow field modified local piston theory for aerodynamic loading is applied to the analysis of static aeroelastic deformation and flutter stabilities of curved panels in hypersonic flow. In addition, comparisons are made between results obtained by using the present method and curvature modified method. It shows that when the curvature of the curved panel is relatively small, the static aeroelastic deformations and flutter stability boundaries obtained by these two methods have little difference, while for curved panels with larger curvatures, the static aeroelastic deformation obtained by the present method is larger and the flutter stability boundary is smaller compared with those obtained by the curvature modified method, and the discrepancy increases with the increasing of curvature of panels. Therefore, the existing curvature modified method is non-conservative compared to the proposed flow field modified method based on the consideration of hypersonic flight vehicle safety, and the proposed flow field modified local piston theory for curved panels enlarges the application range of piston theory.
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Carvalho Humberto M.
2015-12-01
Full Text Available The aim of this paper was to outline a multilevel modeling approach to fit individual angle-specific torque curves describing concentric knee extension and flexion isokinetic muscular actions in Master athletes. The potential of the analytical approach to examine between individual differences across the angle-specific torque curves was illustrated including between-individuals variation due to gender differences at a higher level. Torques in concentric muscular actions of knee extension and knee extension at 60°·s-1 were considered within a range of motion between 5°and 85° (only torques “truly” isokinetic. Multilevel time series models with autoregressive covariance structures with standard multilevel models were superior fits compared with standard multilevel models for repeated measures to fit anglespecific torque curves. Third and fourth order polynomial models were the best fits to describe angle-specific torque curves of isokinetic knee flexion and extension concentric actions, respectively. The fixed exponents allow interpretations for initial acceleration, the angle at peak torque and the decrement of torque after peak torque. Also, the multilevel models were flexible to illustrate the influence of gender differences on the shape of torque throughout the range of motion and in the shape of the curves. The presented multilevel regression models may afford a general framework to examine angle-specific moment curves by isokinetic dynamometry, and add to the understanding mechanisms of strength development, particularly the force-length relationship, both related to performance and injury prevention.
Rodríguez-Álvarez, María Xosé; Roca-Pardiñas, Javier; Cadarso-Suárez, Carmen; Tahoces, Pablo G
2018-03-01
Prior to using a diagnostic test in a routine clinical setting, the rigorous evaluation of its diagnostic accuracy is essential. The receiver-operating characteristic curve is the measure of accuracy most widely used for continuous diagnostic tests. However, the possible impact of extra information about the patient (or even the environment) on diagnostic accuracy also needs to be assessed. In this paper, we focus on an estimator for the covariate-specific receiver-operating characteristic curve based on direct regression modelling and nonparametric smoothing techniques. This approach defines the class of generalised additive models for the receiver-operating characteristic curve. The main aim of the paper is to offer new inferential procedures for testing the effect of covariates on the conditional receiver-operating characteristic curve within the above-mentioned class. Specifically, two different bootstrap-based tests are suggested to check (a) the possible effect of continuous covariates on the receiver-operating characteristic curve and (b) the presence of factor-by-curve interaction terms. The validity of the proposed bootstrap-based procedures is supported by simulations. To facilitate the application of these new procedures in practice, an R-package, known as npROCRegression, is provided and briefly described. Finally, data derived from a computer-aided diagnostic system for the automatic detection of tumour masses in breast cancer is analysed.
Stewart, David J.; Behrens, Carmen; Roth, Jack; Wistuba, Ignacio I.
2010-01-01
Background For processes that follow first order kinetics, exponential decay nonlinear regression analysis (EDNRA) may delineate curve characteristics and suggest processes affecting curve shape. We conducted a preliminary feasibility assessment of EDNRA of patient survival curves. Methods EDNRA was performed on Kaplan-Meier overall survival (OS) and time-to-relapse (TTR) curves for 323 patients with resected NSCLC and on OS and progression-free survival (PFS) curves from selected publications. Results and Conclusions In our resected patients, TTR curves were triphasic with a “cured” fraction of 60.7% (half-life [t1/2] >100,000 months), a rapidly-relapsing group (7.4%, t1/2=5.9 months) and a slowly-relapsing group (31.9%, t1/2=23.6 months). OS was uniphasic (t1/2=74.3 months), suggesting an impact of co-morbidities; hence, tumor molecular characteristics would more likely predict TTR than OS. Of 172 published curves analyzed, 72 (42%) were uniphasic, 92 (53%) were biphasic, 8 (5%) were triphasic. With first-line chemotherapy in advanced NSCLC, 87.5% of curves from 2-3 drug regimens were uniphasic vs only 20% of those with best supportive care or 1 drug (p<0.001). 54% of curves from 2-3 drug regimens had convex rapid-decay phases vs 0% with fewer agents (p<0.001). Curve convexities suggest that discontinuing chemotherapy after 3-6 cycles “synchronizes” patient progression and death. With postoperative adjuvant chemotherapy, the PFS rapid-decay phase accounted for a smaller proportion of the population than in controls (p=0.02) with no significant difference in rapid-decay t1/2, suggesting adjuvant chemotherapy may move a subpopulation of patients with sensitive tumors from the relapsing group to the cured group, with minimal impact on time to relapse for a larger group of patients with resistant tumors. In untreated patients, the proportion of patients in the rapid-decay phase increased (p=0.04) while rapid-decay t1/2 decreased (p=0.0004) with increasing
High-resolution melting-curve (HRM) analysis for C. meleagridis identification in stool samples.
Chelbi, Hanen; Essid, Rym; Jelassi, Refka; Bouzekri, Nesrine; Zidi, Ines; Ben Salah, Hamza; Mrad, Ilhem; Ben Sghaier, Ines; Abdelmalek, Rym; Aissa, Sameh; Bouratbine, Aida; Aoun, Karim
2018-02-01
Cryptosporidiosis represents a major public health problem. This infection, caused by a protozoan parasite of the genus Cryptosporidium, has been reported worldwide as a frequent cause of diarrhoea. In the immunocompetent host, the typical watery diarrhea can be self-limiting. However, it is severe and chronic, in the immunocompromised host and may cause death. Cryptosporidium spp. are coccidians, which complete their life cycle in both humans and animals. The two species C. hominis and C. parvum are the major cause of human infection. Compared to studies on C. hominis and C. parvum, only a few studies have developed methods to identify C. meleagridis. To develop a new real time PCR-coupled High resolution melting assay allowing the detection for C. meleagridis, in addition of the other dominant species (C. hominis and C. parvum). The polymorphic sequence on the dihydrofolate reductase gene (DHFR) of three species was sequenced to design primers pair and establish a sensitive real-time PCR coupled to a high-resolution melting-curve (HRM) analysis method, allowing the detection of Cryptosporidium sp. and discrimination between three prevalent species in Tunisia. We analyzed a collection of 42 archived human isolates of the three studied species. Real-time PCR coupled to HRM assay allowed detection of Cryptosporidium, using the new designed primers, and basing on melting profile, we can distinguish C. meleagridis species in addition to C. parvum and C. hominis. We developed a qPCR-HRM assay that allows Cryptosporidium genotyping. This method is sensitive and able to distinguish three Cryptosporidium species. Copyright © 2017. Published by Elsevier Ltd.
Energy Technology Data Exchange (ETDEWEB)
Barros, Thaisa C. de; Castrillo, Lazara S.; Xavier, Aline G.; Goncalves, Gabriela de L.; Melo, Julio Angelo, E-mail: barros.camara@gmail.com, E-mail: lazaracastrillo@hotmail.com, E-mail: alinegxavier@gmail.com, E-mail: gabilimag_@hotmail.com, E-mail: angelo_mecanic@hotmail.com [Escola Politecnica de Pernambuco (UPE), Recife, PE (Brazil). Departamento de Engenharia Mecanica Industrial
2017-11-01
To meet the demand for electric consumption, it is fundamental to prepare an efficient energy planning that guarantees the safe supply of energy, so that the price of kilowatt-hours for the consumer respects the tariff modality and the socio-environmental impact is the smallest possible. In recent years, alternative sources of energy have been gaining considerable space in the Brazilian generating park. Among the many options for energy supply, choosing the most feasible involves the use of techniques that compare all the costs involved in generating electricity from the sources available in the Brazilian energy matrix. The objective of the work is to show a quick, practical and objective tool that performs this comparison and assists in decision making. The method based on the comparison is the Cost of Energy and the tool for the application of the same are the Screening curves, widely used by the International Atomic Energy Agency (IAEA). In this analysis, the following parameters are considered: operating capacity, toxic gas emission rate, fuel consumption and values, fixed and variable costs of operation and maintenance, investment values for each source, construction time and useful life. It is worth noting that the method does not consider in calculations aspects such as inflation, forced interruptions of the plant and other more specific factors. With the work, it was possible to perform an examination of the costs of the generation technologies available in Brazil and, through the obtained data, the economic viability of the generating parks was discussed through simulations in different scenarios, comparing the sources among themselves. (author)
International Nuclear Information System (INIS)
Barros, Thaisa C. de; Castrillo, Lazara S.; Xavier, Aline G.; Goncalves, Gabriela de L.; Melo, Julio Angelo
2017-01-01
To meet the demand for electric consumption, it is fundamental to prepare an efficient energy planning that guarantees the safe supply of energy, so that the price of kilowatt-hours for the consumer respects the tariff modality and the socio-environmental impact is the smallest possible. In recent years, alternative sources of energy have been gaining considerable space in the Brazilian generating park. Among the many options for energy supply, choosing the most feasible involves the use of techniques that compare all the costs involved in generating electricity from the sources available in the Brazilian energy matrix. The objective of the work is to show a quick, practical and objective tool that performs this comparison and assists in decision making. The method based on the comparison is the Cost of Energy and the tool for the application of the same are the Screening curves, widely used by the International Atomic Energy Agency (IAEA). In this analysis, the following parameters are considered: operating capacity, toxic gas emission rate, fuel consumption and values, fixed and variable costs of operation and maintenance, investment values for each source, construction time and useful life. It is worth noting that the method does not consider in calculations aspects such as inflation, forced interruptions of the plant and other more specific factors. With the work, it was possible to perform an examination of the costs of the generation technologies available in Brazil and, through the obtained data, the economic viability of the generating parks was discussed through simulations in different scenarios, comparing the sources among themselves. (author)
Directory of Open Access Journals (Sweden)
Mehri Rejali
2017-01-01
Full Text Available Background: In this study, we evaluated assessed elements connected with low birth weight (LBW and used decision curve analysis (DCA to define a scale to anticipate the probability of having a LBW newborn child. Methods: This hospital-based case–control study was led in Arak Hospital in Iran. The study included 470 mothers with LBW neonate and 470 mothers with natural neonates. Information were gathered by meeting moms utilizing preplanned organized questionnaire and from hospital records. The estimated probabilities of detecting LBW were calculated using the logistic regression and DCA to quantify the clinical consequences and its validation. Results: Factors significantly associated with LBW were premature membrane rupture (odds ratio [OR] = 3.18 [1.882–5.384], former LBW infants (OR = 2.99 [1.510–5.932], premature pain (OR = 2.70 [1.659–4.415], hypertension in pregnancy (OR = 2.39 [1.429–4.019], last trimester of pregnancy bleeding (OR = 2.58 [1.018–6.583], mother age >30 (OR = 2.17 [1.350–3.498]. However, with DCA, the prediction model made on these 15 variables has a net benefit (NB of 0.3110 is best predictive with the highest NB. NB has simple clinical interpretation and utilizing the model is what might as well be called a procedure that distinguished what might as well be called 31.1 LBW per 100 cases with no superfluous recognize. Conclusions: It is conceivable to foresee LBW utilizing a prediction model show in light of noteworthy hazard components connected with LBW. The majority of the hazard elements for LBW are preventable, and moms can be alluded amid early pregnancy to a middle which is furnished with facilities for administration of high hazard pregnancy and LBW infant.
DEFF Research Database (Denmark)
Studer, Bruno; Jensen, Louise Bach; Fiil, Alice
2009-01-01
High resolution melting curve analysis (HRM) measures dissociation of double stranded DNA of a PCR product amplified in the presence of a saturating fluorescence dye. Recently, HRM proved successful to genotype DNA sequence polymorphisms such as SSRs and SNPs based on the shape of the melting...... curves. In this study, HRM was used for simultaneous screening and genotyping of genic DNA sequence polymorphisms identified in the Lolium perenne F2 mapping population VrnA. Melting profiles of PCR products amplified from previously published gene loci and from a novel gene putatively involved...
More basic approach to the analysis of multiple specimen R-curves for determination of J/sub c/
International Nuclear Information System (INIS)
Carlson, K.W.; Williams, J.A.
1980-02-01
Multiple specimen J-R curves were developed for groups of 1T compact specimens with different a/W values and depth of side grooving. The purpose of this investigation was to determine J/sub c/ (J at onset of crack extension) for each group. Judicious selection of points on the load versus load-line deflection record at which to unload and heat tint specimens permitted direct observation of approximate onset of crack extension. It was found that the present recommended procedure for determining J/sub c/ from multiple specimen R-curves, which is being considered for standardization, consistently yielded nonconservative J/sub c/ values. A more basic approach to analyzing multiple specimen R-curves is presented, applied, and discussed. This analysis determined J/sub c/ values that closely corresponded to actual observed onset of crack extension
International Nuclear Information System (INIS)
Jo, Jong Chull; Kim, Wee Kyung; Kim, Yun Il; Cho, Sang Jin; Choi, Seok Ki
2000-01-01
A detailed numerical analysis of initial evolution of thermal stratification in a curved pipe with a finite wall thickness is performed. A primary emphasis of the present study is placed on the investigation of the effect of existence of pipe wall thickness on the evolution of thermal stratification. A simple and convenient numerical method of treating the unsteady conjugate heat transfer in Cartesian as well as non-orthogonal coordinate systems is presented. The proposed unsteady conjugate heat transfer analysis method is implemented in a finite volume thermal-hydraulic computer code based on a cell-centered, non-staggered grid arrangement, the SIMPLEC algorithm and a higher-order bounded convection scheme. Calculations are performed for initial evolution of thermal stratification with high Richardson number in a curved pipe. The predicted results show that the thermally stratified flow and transient conjugate heat transfer in a curved pipe with a specified wall thickness can be satisfactorily analyzed by using the numerical method presented in this paper. As the result, the present analysis method is considered to be effective for the determination of transient temperature distributions in the wall of curved piping system subjected to internally thermal stratification. In addition, the method can be extended to be applicable for the simulation of turbulent flow of thermally stratified fluid
Cheung, J.; Veldhuizen, A.G.; Halbertsma, J.P.; Maurits, N.M.; Sluiter, W.J.; Cool, J.C.; van Horn, J.R.
2004-01-01
Study Design. A prospective study in which patients with idiopathic scoliosis were examined longitudinally by radiographic and electromyographic measurements according to a protocol. Objectives. To measure the growth velocity of the spine and the electromyographic ratio of the paraspinal muscles to
International Nuclear Information System (INIS)
Moutinho, Victor; Varum, Celeste; Madaleno, Mara
2017-01-01
It is a disquieting reality that increased economic growth for many years now in the Western world is at odds with environmental degradation. In this paper the relationship between economic growth and environmental variables is analyzed under two non-linear specifications, a quadratic and a cubic specification. The study is conducted for Portugal and Spain in the period 1975–2012, using data for 13 sectors. GVA is used as proxy for income, while energy use and carbon dioxide account for environmental degradation. There is evidence for an inverted U-shaped EKC. However, there are also other inverted N–shaped functions that explain the relationship between economic growth and emissions. Altogether, empirical results do indicate particular differences between Portuguese and Spanish sectors. The results are of interest not only for researchers but also for policy-makers. Political mitigation measures are also analyzed. - Highlights: • We study the EKC hypothesis using economic activity sectors in the Iberian Market. • There is evidence for a clear N-shaped EKC in Portugal. • Inverted N–shaped function explains the economic growth and emissions relationship. • Positive and significant effect of energy consumption in emissions for sectors. • Promote renewables substitution and tax benefits are urgent to accomplish goals.
Tracer concentration curves and residence time analysis in technological flow systems. 2
International Nuclear Information System (INIS)
Pippel, W.
1976-01-01
Tracer concentration curves measured in flow systems by means of radioactive isotopes are treated as a two dimensional random process. Comparing them with the family distribution functions described in part I, it follows that only in case of ergodic behaviour of the system tracer curves can be considered as age distribution functions. The conception of ergodicity in residence time systems has been explained with the aid of a time function measurable by a special method of radioactive tracer technique and by the mean value of the residence time obtainable from this function. Furthermore, technological consequences in evaluating tracer concentration curves of real flow systems are discussed with respect to supposed ergodic or nonergodic behaviour. These considerations are of special importance for flow systems with temporary fluctuations in structure. (author)
Energy Technology Data Exchange (ETDEWEB)
Matos, R S; Cardoso, A F; Fleury, M E.V. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)
1988-12-31
This work aims to present the analysis of load curves performed by the short term planning sectors of several subsidiaries, independently of the methodologies used. In order to do so some peculiar occurrences were selected which show the influence of factors that are external to the electric power system. In such way, the analysis of past situations proves to be an important tool in the forecasting work so that a better planning may be achieved. 13 figs., 2 tabs.
International Nuclear Information System (INIS)
Shih, C.F.; Xia, L.; Hutchinson, J.W.
1995-02-01
In this report, Volume 2, Mode I crack initiation and growth under plane strain conditions in tough metals are computed using an elastic/plastic continuum model which accounts for void growth and coalescence ahead of the crack tip. The material parameters include the stress-strain properties, along with the parameters characterizing the spacing and volume fraction of voids in material elements lying in the plane of the crack. For a given set of these parameters and a specific specimen, or component, subject to a specific loading, relationships among load, load-line displacement and crack advance can be computed with no restrictions on the extent of plastic deformation. Similarly, there is no limit on crack advance, except that it must take place on the symmetry plane ahead of the initial crack. Suitably defined measures of crack tip loading intensity, such as those based on the J-integral, can also be computed, thereby directly generating crack growth resistance curves. In this report, the model is applied to five specimen geometries which are known to give rise to significantly different crack tip constraints and crack growth resistance behaviors. Computed results are compared with sets of experimental data for two tough steels for four of the specimen types. Details of the load, displacement and crack growth histories are accurately reproduced, even when extensive crack growth takes place under conditions of fully plastic yielding. A description of material resistance to crack initiation and subsequent growth is essential for assessing structural integrity such as nuclear pressure vessels and piping
Polynomial curve fitting for control rod worth using least square numerical analysis
International Nuclear Information System (INIS)
Muhammad Husamuddin Abdul Khalil; Mark Dennis Usang; Julia Abdul Karim; Mohd Amin Sharifuldin Salleh
2012-01-01
RTP must have sufficient excess reactivity to compensate the negative reactivity feedback effects such as those caused by the fuel temperature and power defects of reactivity, fuel burn-up and to allow full power operation for predetermined period of time. To compensate this excess reactivity, it is necessary to introduce an amount of negative reactivity by adjusting or controlling the control rods at will. Control rod worth depends largely upon the value of the neutron flux at the location of the rod and reflected by a polynomial curve. Purpose of this paper is to rule out the polynomial curve fitting using least square numerical techniques via MATLAB compatible language. (author)
Liao, Yue; Shonkoff, Eleanor T; Barnett, Elizabeth; Wen, C K Fred; Miller, Kimberly A; Eddy, J Mark
2015-10-01
School shootings may have serious negative impacts on children years after the event. Previous research suggests that children exposed to traumatic events experience heightened fear, anxiety, and feelings of vulnerability, but little research has examined potential aggressive and disruptive behavioral reactions. Utilizing a longitudinal dataset in which a local school shooting occurred during the course of data collection, this study sought to investigate whether the trajectory of disruptive behaviors was affected by the shooting. A two-piece growth curve model was used to examine the trajectory of disruptive behaviors during the pre-shooting years (i.e., piece one) and post-shooting years (i.e., piece two). Results indicated that the two-piece growth curve model fit the data better than the one-piece model and that the school shooting precipitated a faster decline in aggressive behaviors. This study demonstrated a novel approach to examining effects of an unexpected traumatic event on behavioral trajectories using an existing longitudinal data set. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Liao, Yue; Shonkoff, Eleanor T.; Barnett, Elizabeth; Wen, CK Fred; Miller, Kimberly A.; Eddy, J. Mark
2015-01-01
School shootings may have serious negative impacts on children years after the event. Previous research suggests that children exposed to traumatic events experience heightened fear, anxiety, and feelings of vulnerability, but little research has examined potential aggressive and disruptive behavioral reactions. Utilizing a longitudinal dataset in which a local school shooting occurred during the course of data collection, this study sought to investigate whether the trajectory of disruptive behaviors was affected by the shooting. A two-piece growth curve model was used to examine the trajectory of disruptive behaviors during the pre-shooting years (i.e., piece one) and post-shooting years (i.e., piece two). Results indicated that the two-piece growth curve model fit the data better than the one-piece model and that the school shooting precipitated a faster decline in aggressive behaviors. This study demonstrated a novel approach to examining effects of an unexpected traumatic event on behavioral trajectories using an existing longitudinal data set. PMID:26298676
Directory of Open Access Journals (Sweden)
Jens Jirschitzka
Full Text Available In four studies we tested a new methodological approach to the investigation of evaluation bias. The usage of piecewise growth curve modeling allowed for investigation into the impact of people's attitudes on their persuasiveness ratings of pro- and con-arguments, measured over the whole range of the arguments' polarity from an extreme con to an extreme pro position. Moreover, this method provided the opportunity to test specific hypotheses about the course of the evaluation bias within certain polarity ranges. We conducted two field studies with users of an existing online information portal (Studies 1a and 2a as participants, and two Internet laboratory studies with mostly student participants (Studies 1b and 2b. In each of these studies we presented pro- and con-arguments, either for the topic of MOOCs (massive open online courses, Studies 1a and 1b or for the topic of M-learning (mobile learning, Studies 2a and 2b. Our results indicate that using piecewise growth curve models is more appropriate than simpler approaches. An important finding of our studies was an asymmetry of the evaluation bias toward pro- or con-arguments: the evaluation bias appeared over the whole polarity range of pro-arguments and increased with more and more extreme polarity. This clear-cut result pattern appeared only on the pro-argument side. For the con-arguments, in contrast, the evaluation bias did not feature such a systematic picture.
Griebeler, Eva Maria; Klein, Nicole; Sander, P Martin
2013-01-01
Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp.) and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti). Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM), all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average mammals, but
Directory of Open Access Journals (Sweden)
Eva Maria Griebeler
Full Text Available Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp. and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti. Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM, all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average
Limitations of acceptability curves for presenting uncertainty in cost-effectiveness analysis
Groot Koerkamp, Bas; Hunink, M. G. Myriam; Stijnen, Theo; Hammitt, James K.; Kuntz, Karen M.; Weinstein, Milton C.
2007-01-01
Clinical journals increasingly illustrate uncertainty about the cost and effect of health care interventions using cost-effectiveness acceptability curves (CEACs). CEACs present the probability that each competing alternative is optimal for a range of values of the cost-effectiveness threshold. The
Smit, J.P.A.; Rutten, Wim; Boom, H.B.K.
1996-01-01
In acute experiments on six Wistar rats, a wire-microelectrode array was inserted into the common peroneal nerve. A 5-channel array and a 24-channel array were available. Each electrode in the array was used to generate a twitch contraction force recruitment curve for the extensor digitorum longus
The Impact of Grading on a Curve: Assessing the Results of Kulick and Wright's Simulation Analysis
Bailey, Gary L.; Steed, Ronald C.
2012-01-01
Kulick and Wright concluded, based on theoretical mathematical simulations of hypothetical student exam scores, that assigning exam grades to students based on the relative position of their exam performance scores within a normal curve may be unfair, given the role that randomness plays in any given student's performance on any given exam.…
Analysis of flux-flow curves in superconductors as a function of temperature
International Nuclear Information System (INIS)
Boboshko, N.
1978-01-01
A phenomenological method to analyse the experimental data of flux-flow resistivity in superconductors as a function of temperature is proposed and successfully applied to existing data for t = kappa >= 0.07. An empirical curve relating the flux-flow resistivity with the Ginsburg-Landau parameter kappa was obtained. (author)
Sexual Bias and Household Consumption : A Semiparametic Analysis of Engel curves in Rural China
Gong, X.; van Soest, A.H.O.; Zhang, P.
2000-01-01
We analyze Engel curves for nuclear households in rural China. The sample includes more than 5000 nuclear families covering nineteen out of thirty Chinese provinces. We consider expenditures on food, also subdivided into several food subcategories such as cereals, or meat and fish, and other
Mou, Yi; Athar, Muhammad Ammar; Wu, Yuzhen; Xu, Ye; Wu, Jianhua; Xu, Zhenxing; Hayder, Zulfiqar; Khan, Saeed; Idrees, Muhammad; Nasir, Muhammad Israr; Liao, Yiqun; Li, Qingge
2016-11-01
Detection of anti-hepatitis B virus (HBV) drug resistance mutations is critical for therapeutic decisions for chronic hepatitis B virus infection. We describe a real-time PCR-based assay using multicolor melting curve analysis (MMCA) that could accurately detect 24 HBV nucleotide mutations at 10 amino acid positions in the reverse transcriptase region of the HBV polymerase gene. The two-reaction assay had a limit of detection of 5 copies per reaction and could detect a minor mutant population (5% of the total population) with the reverse transcriptase M204V amino acid mutation in the presence of the major wild-type population when the overall concentration was 10 4 copies/μl. The assay could be finished within 3 h, and the cost of materials for each sample was less than $10. Clinical validation studies using three groups of samples from both nucleos(t)ide analog-treated and -untreated patients showed that the results for 99.3% (840/846) of the samples and 99.9% (8,454/8,460) of the amino acids were concordant with those of Sanger sequencing of the PCR amplicon from the HBV reverse transcriptase region (PCR Sanger sequencing). HBV DNA in six samples with mixed infections consisting of minor mutant subpopulations was undetected by the PCR Sanger sequencing method but was detected by MMCA, and the results were confirmed by coamplification at a lower denaturation temperature-PCR Sanger sequencing. Among the treated patients, 48.6% (103/212) harbored viruses that displayed lamivudine monoresistance, adefovir monoresistance, entecavir resistance, or lamivudine and adefovir resistance. Among the untreated patients, the Chinese group had more mutation-containing samples than did the Pakistani group (3.3% versus 0.56%). Because of its accuracy, rapidness, wide-range coverage, and cost-effectiveness, the real-time PCR assay could be a robust tool for the detection if anti-HBV drug resistance mutations in resource-limited countries. Copyright © 2016, American Society for
Duclos, Antoine; Herquelot, Eléonore; Polazzi, Stéphanie; Malbezin, Muriel; Claris, Olivier
2017-02-24
To establish the pattern of change in individual scientific production over the career of medical researchers. Retrospective cohort based on prospectively collected data in a hospital information system. Multicentre university hospital in France. Two distinct populations of 1835 researchers (full professors vs non-academic physicians) having produced 44 723 publications between 1995 and 2014. Annual number of publications referenced in Medline/PubMed with a sensitivity analysis based on publications as first/last author and in high impact journals. The individual volume of publications was modelled by age using generalised estimating equations adjusted for birth cohort, biomedical discipline and academic position of researchers. Averaged over the whole career, the annual number of publications was 5.28 (95% CI 4.90 to 5.69) among professors compared to 0.82 (95% CI 0.76 to 0.89) among non-academic physicians (pscientific production between 25 and 35 years (adjusted incidence rate ratio 102.20, 95% CI 60.99 to 171.30), a maturation phase with a slower increase from 35 to 50 years (2.10, 95% CI 1.75 to 2.51) until a stabilisation phase with constant production followed by a potential decline at the end of career (0.90, 95% CI 0.77 to 1.06). The non-academic physicians experienced a slower pace of learning curve at the beginning of their careers (42.38, 95% CI 25.37 to 70.81) followed by a smaller increase in the annual number of publications (1.29, 95% CI 1.11 to 1.51). Compared to full professors, non-academic physicians had a poor capacity to publish, indicating a low productivity when medical doctors have limited time or little interest in undertaking research. This finding highlights the potential for rethinking the missions of medical doctors towards an enlargement of scientific prerogatives in favour of progress in global knowledge. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go
Directory of Open Access Journals (Sweden)
Luís Orlindo Tedeschi
2000-04-01
Full Text Available RESUMO - O objetivo deste trabalho foi analisar sete funções não-lineares para descrever o crescimento de machos e fêmeas da raça Guzerá e seus cruzamentos (3/4Guzerá-1/4Pardo Suíço, 1/2Nelore-1/4Pardo Suíço-1/4Guzerá, 1/2Pardo Suíço-1/2Guzerá, 1/2Chianina-1/4Pardo Suíço-1/4Guzerá, 1/2Caracú-1/2Guzerá, 1/2Caracu-1/4Pardo Suíço-1/4Guzerá submetidos a três níveis de suplementação (sem, durante o período seco e o ano todo, a fim de analisar e selecionar uma função que apresentasse menores desvios de regressão, menor variação residual, maior coeficiente de determinação, menor variação entre os parâmetros dos animais, maior convergência e valor assintótico compatível com o peso adulto observado. A função que melhor se enquadrou nesses parâmetros de seleção foi a função de Gompertz, seguida da função de Von Bertalanffy. A função de Richards apresentou grande dificuldade computacional para o ajuste, resultando em baixa convergência. As funções de Brody apresentaram as maiores estimativas de peso adulto e a função de Gompertz modificada e Logística, as menores.ABSTRACT - The objective of this work was to evaluate seven non linear functions to describe Guzera male and female growth curves, and their crossbreds (3/4Guzera-1/4Brown Swiss, 1/2Nellore-1/4Brown Swiss-1/4Guzera, 1/2Guzera-1/2Brown Swiss, 1/2Chianina- 1/4Brown Swiss-1/4Guzera, 1/2Caracu-1/2Guzera, 1/2Caracu-1/4Brown Swiss-1/4Guzera submitted to three levels of supplementation (without, during the dry period and the whole year, to analize and to select one function which presented lower regression deviation, lower residual sum of squares, higher coefficient of determination, lower variation among animal parameters, higher convergence and assintotic compatible value with the observed mature weight. The function that best express these parameters of selection was the Gompertz, followed by the Von Bertalanffy function. The Richards function
Moestue, Helen
2009-08-01
To examine the potential of anthropometry as a tool to measure gender discrimination, with particular attention to the WHO growth standards. Surveillance data collected from 1990 to 1999 were analysed. Height-for-age Z-scores were calculated using three norms: the WHO standards, the 1978 National Center for Health Statistics (NCHS) reference and the 1990 British growth reference (UK90). Bangladesh. Boys and girls aged 6-59 months (n 504 358). The three sets of growth curves provided conflicting pictures of the relative growth of girls and boys by age and over time. Conclusions on sex differences in growth depended also on the method used to analyse the curves, be it according to the shape or the relative position of the sex-specific curves. The shapes of the WHO-generated curves uniquely implied that Bangladeshi girls faltered faster or caught up slower than boys throughout their pre-school years, a finding consistent with the literature. In contrast, analysis of the relative position of the curves suggested that girls had higher WHO Z-scores than boys below 24 months of age. Further research is needed to help establish whether and how the WHO international standards can measure gender discrimination in practice, which continues to be a serious problem in many parts of the world.
Lensing, Nele; Elsner, Birgit
2018-05-07
Although middle childhood is an important period for the development of hot and cool executive functions (EFs), longitudinal studies investigating trajectories of childhood EF development are still limited and little is known about predictors for individual developmental trajectories. The current study examined the development of two typical facets of cool and hot EFs over a 3-year period during middle childhood, comparing a younger cohort (6- and 7-year-olds at the first wave [T1]; n = 621) and an older cohort (8- and 9-year-olds at T1; n = 975) of children. "Cool" working memory updating (WM) was assessed using a backward digit span task, and "hot" decision making (DM) was assessed using a child variant of the Iowa Gambling Task. Linear latent growth curve analyses revealed evidence for developmental growth as well as interindividual variance in the initial level and rate of change in both EF facets. Initial level of WM was positively associated with age (both between and within cohorts), socioeconomic status, verbal ability, and processing speed, whereas initial levels of DM were, in addition to a (potentially age-related) cohort effect, exclusively predicted by gender, with boys outperforming girls. None of the variables predicted the rate of change, that is, the developmental trajectories. However, younger children, as compared with older children, had slightly steeper WM growth curves over time, hinting at a leveling off in the development of WM during middle childhood. In sum, these data add important evidence to the understanding of hot and cool EF development during middle childhood. Copyright © 2018 Elsevier Inc. All rights reserved.
Zaman, Khalid
2017-11-01
This study examined the relationship between biofuel consumption, forest biodiversity, and a set of national scale indicators of per capita income, foreign direct investment (FDI) inflows, trade openness, and population density with a panel data of 12 biofuels consuming countries for a period of 2000 to 2013. The study used Global Environmental Facility (GEF) biodiversity benefits index and forest biodiversity index in an environmental Kuznets curve (EKC) framework. The results confirmed an inverted U-shaped relationship between GEF biodiversity index and per capita income, while there is flat/no relationship between carbon emissions and economic growth, and between forest biodiversity and economic growth models. FDI inflows and trade openness both reduce carbon emissions while population density and biofuel consumption increase carbon emissions and decrease GEF biodiversity index. Trade openness supports to increases GEF biodiversity index while it decreases forest biodiversity index and biofuel consumption in a region.
Kondo, M; Nagao, Y; Mahbub, M H; Tanabe, Tsuyoshi; Tanizawa, Y
2018-04-29
To identify factors predicting early postpartum glucose intolerance in Japanese women with gestational diabetes mellitus, using decision-curve analysis. A retrospective cohort study was performed. The participants were 123 Japanese women with gestational diabetes who underwent 75-g oral glucose tolerance tests at 8-12 weeks after delivery. They were divided into a glucose intolerance and a normal glucose tolerance group based on postpartum oral glucose tolerance test results. Analysis of the pregnancy oral glucose tolerance test results showed predictive factors for postpartum glucose intolerance. We also evaluated the clinical usefulness of the prediction model based on decision-curve analysis. Of 123 women, 78 (63.4%) had normoglycaemia and 45 (36.6%) had glucose intolerance. Multivariable logistic regression analysis showed insulinogenic index/fasting immunoreactive insulin and summation of glucose levels, assessed during pregnancy oral glucose tolerance tests (total glucose), to be independent risk factors for postpartum glucose intolerance. Evaluating the regression models, the best discrimination (area under the curve 0.725) was obtained using the basic model (i.e. age, family history of diabetes, BMI ≥25 kg/m 2 and use of insulin during pregnancy) plus insulinogenic index/fasting immunoreactive insulin intolerance. Insulinogenic index/fasting immunoreactive insulin calculated using oral glucose tolerance test results during pregnancy is potentially useful for predicting early postpartum glucose intolerance in Japanese women with gestational diabetes. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Fitting sediment rating curves using regression analysis: a case study of Russian Arctic rivers
Directory of Open Access Journals (Sweden)
N. I. Tananaev
2015-03-01
Full Text Available Published suspended sediment data for Arctic rivers is scarce. Suspended sediment rating curves for three medium to large rivers of the Russian Arctic were obtained using various curve-fitting techniques. Due to the biased sampling strategy, the raw datasets do not exhibit log-normal distribution, which restricts the applicability of a log-transformed linear fit. Non-linear (power model coefficients were estimated using the Levenberg-Marquardt, Nelder-Mead and Hooke-Jeeves algorithms, all of which generally showed close agreement. A non-linear power model employing the Levenberg-Marquardt parameter evaluation algorithm was identified as an optimal statistical solution of the problem. Long-term annual suspended sediment loads estimated using the non-linear power model are, in general, consistent with previously published results.
Fitting sediment rating curves using regression analysis: a case study of Russian Arctic rivers
Tananaev, N. I.
2015-03-01
Published suspended sediment data for Arctic rivers is scarce. Suspended sediment rating curves for three medium to large rivers of the Russian Arctic were obtained using various curve-fitting techniques. Due to the biased sampling strategy, the raw datasets do not exhibit log-normal distribution, which restricts the applicability of a log-transformed linear fit. Non-linear (power) model coefficients were estimated using the Levenberg-Marquardt, Nelder-Mead and Hooke-Jeeves algorithms, all of which generally showed close agreement. A non-linear power model employing the Levenberg-Marquardt parameter evaluation algorithm was identified as an optimal statistical solution of the problem. Long-term annual suspended sediment loads estimated using the non-linear power model are, in general, consistent with previously published results.
Czech Academy of Sciences Publication Activity Database
Hyánková, L.; Novotná, Božena; Starosta, F.
2015-01-01
Roč. 56, č. 2 (2015), s. 184-194 ISSN 0007-1668 Institutional support: RVO:68378041 Keywords : chick juvenile growth * egg storage * sex-differences * body-weight * hatchability * age * quality * hatch * fluid * time Subject RIV: FP - Other Medical Disciplines Impact factor: 0.933, year: 2015
International Nuclear Information System (INIS)
Al-Achkar, W.
2001-09-01
In order to draw a dose-effect curve, experimentally gamma ray induced chromosomal aberrations in human peripheral lymphocytes from eight healthy people were studied. Samples from 4 males and 4 females were irradiated in tubes with 0.15, 0.25, 0.5, 1, 1.5, 2, 2.5 gray of gamma ray (Co 60 at dose rate 0.3 Gy/min). Irradiated and control samples were incubated in 37 centigrade for 48 hours cell cultures. Cell cultures then were stopped and metaphases spread, Giemsa stained to score the induced chromosomal aberrations. Chromosomal aberrations from 67888 metaphases were scored. Curves from the total number of dicentrics, dicentrics + rings and total numbers of breaks in cell for each individual or for all people were drawn. An increase of all chromosomal aberrations types with the elevation of the doses was observed. The yield of chromosome aberrations is related to the dose used. These curves give a quick useful estimation of the accidentally radiation exposure. (author)
CONFIRMATION OF HOT JUPITER KEPLER-41b VIA PHASE CURVE ANALYSIS
International Nuclear Information System (INIS)
Quintana, Elisa V.; Rowe, Jason F.; Caldwell, Douglas A.; Christiansen, Jessie L.; Jenkins, Jon M.; Morris, Robert L.; Smith, Jeffrey C.; Thompson, Susan E.; Barclay, Thomas; Howell, Steve B.; Borucki, William J.; Sanderfer, Dwight T.; Still, Martin; Ciardi, David R.; Demory, Brice-Olivier; Klaus, Todd C.; Fulton, Benjamin J.; Shporer, Avi
2013-01-01
We present high precision photometry of Kepler-41, a giant planet in a 1.86 day orbit around a G6V star that was recently confirmed through radial velocity measurements. We have developed a new method to confirm giant planets solely from the photometric light curve, and we apply this method herein to Kepler-41 to establish the validity of this technique. We generate a full phase photometric model by including the primary and secondary transits, ellipsoidal variations, Doppler beaming, and reflected/emitted light from the planet. Third light contamination scenarios that can mimic a planetary transit signal are simulated by injecting a full range of dilution values into the model, and we re-fit each diluted light curve model to the light curve. The resulting constraints on the maximum occultation depth and stellar density combined with stellar evolution models rules out stellar blends and provides a measurement of the planet's mass, size, and temperature. We expect about two dozen Kepler giant planets can be confirmed via this method.
International Nuclear Information System (INIS)
Schilling, Melissa A.; Esmundo, Melissa
2009-01-01
Plotting the performance of a technology against the money or effort invested in it most often yields an S-shaped curve: slow initial improvement, then accelerated improvement, then diminishing improvement. These S-curves can be used to gain insight into the relative payoff of investment in competing technologies, as well as providing some insight into when and why some technologies overtake others in the race for dominance. Analyzing renewable energies from such a technology S-curve perspective reveals some surprising and important implications for both government and industry. Using data on government R and D investment and technological improvement (in the form of cost reductions), we show that both wind energy and geothermal energy are poised to become more economical than fossil fuels within a relatively short time frame. The evidence further suggests that R and D for wind and geothermal technologies has been under-funded by national governments relative to funding for solar technologies, and government funding of fossil fuel technologies might be excessive given the diminishing performance of those technologies.
Statistically generated weighted curve fit of residual functions for modal analysis of structures
Bookout, P. S.
1995-01-01
A statistically generated weighting function for a second-order polynomial curve fit of residual functions has been developed. The residual flexibility test method, from which a residual function is generated, is a procedure for modal testing large structures in an external constraint-free environment to measure the effects of higher order modes and interface stiffness. This test method is applicable to structures with distinct degree-of-freedom interfaces to other system components. A theoretical residual function in the displacement/force domain has the characteristics of a relatively flat line in the lower frequencies and a slight upward curvature in the higher frequency range. In the test residual function, the above-mentioned characteristics can be seen in the data, but due to the present limitations in the modal parameter evaluation (natural frequencies and mode shapes) of test data, the residual function has regions of ragged data. A second order polynomial curve fit is required to obtain the residual flexibility term. A weighting function of the data is generated by examining the variances between neighboring data points. From a weighted second-order polynomial curve fit, an accurate residual flexibility value can be obtained. The residual flexibility value and free-free modes from testing are used to improve a mathematical model of the structure. The residual flexibility modal test method is applied to a straight beam with a trunnion appendage and a space shuttle payload pallet simulator.
Making the Most of Kepler Photometry: Characterizing Exoplanets through Phase Curve Analysis
Directory of Open Access Journals (Sweden)
Esteves Lisa J.
2015-01-01
Full Text Available The Kepler mission’s long-term monitoring of stars through high-precision photometry has not only revealed a plethora of exoplanet transits but also provided valuable data for characterizing a subset of these planets. Using over four years of Kepler observations, we have derived phase curves for over a dozen planets, and use these measurements to constrain their mass, brightness/temperature and energy redistribution between the day and the night sides. In our new study, we also investigate possible offsets of the peak brightness of the phase curve, which could be indicative of inhomogeneous clouds and/or substantial winds in the planet’s atmosphere. We find significant offsets for over a half-dozen planets. With this growing sample of measured phase curves, we are able to better examine the trends of hot Jupiter energy budgets and albedos, and for the first time relate these properties to the presence of clouds or winds on a planet.
The thermoluminescence glow-curve analysis using GlowFit - the new powerful tool for deconvolution
International Nuclear Information System (INIS)
Puchalska, M.; Bilski, P.
2005-10-01
A new computer program, GlowFit, for deconvoluting first-order kinetics thermoluminescence (TL) glow-curves has been developed. A non-linear function describing a single glow-peak is fitted to experimental points using the least squares Levenberg-Marquardt method. The main advantage of GlowFit is in its ability to resolve complex TL glow-curves consisting of strongly overlapping peaks, such as those observed in heavily doped LiF:Mg,Ti (MTT) detectors. This resolution is achieved mainly by setting constraints or by fixing selected parameters. The initial values of the fitted parameters are placed in the so-called pattern files. GlowFit is a Microsoft Windows-operated user-friendly program. Its graphic interface enables easy intuitive manipulation of glow-peaks, at the initial stage (parameter initialization) and at the final stage (manual adjustment) of fitting peak parameters to the glow-curves. The program is freely downloadable from the web site www.ifj.edu.pl/NPP/deconvolution.htm (author)
Directory of Open Access Journals (Sweden)
Mahmut Zortuk
2016-08-01
Full Text Available The Environmental Kuznets Curve (EKC introduces an inverted U-shaped relationship between environmental pollution and economic development. The inverted U-shaped curve is seen as complete pattern for developed economies. However, our study tests the EKC for developing transition economies of European Union, therefore, our results could make a significant contribution to the literature. In this paper, the relationship between carbon dioxide (CO2 emissions, gross domestic product (GDP, energy use and urban population is investigated in the Transition Economies (Bulgaria, Croatia, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia and Slovenia. Environmental Kuznets Curve is tested by panel smooth transition regression for these economies for 1993 – 2010 periods. As a result of study, the null hypothesis of linearity was rejected and no-remaining nonlinearity test showed that there is a smooth transition exists between two regimes (below $5176 GDP per capita is first one and above $5176 GDP per capita is second one in the related period for these economies.
Dynamic analysis of savings and economic growth in Nigeria ...
African Journals Online (AJOL)
Dynamic analysis of savings and economic growth in Nigeria. ... a trivariate dynamic Granger causality model with savings, economic growth and foreign ... It is recommended that in the short run, policies in Nigeria should be geared towards ...
Boulet, Sebastien; Boudot, Elsa; Houel, Nicolas
2016-05-03
Back pain is a common reason for consultation in primary healthcare clinical practice, and has effects on daily activities and posture. Relationships between the whole spine and upright posture, however, remain unknown. The aim of this study was to identify the relationship between each spinal curve and centre of pressure position as well as velocity for healthy subjects. Twenty-one male subjects performed quiet stance in natural position. Each upright posture was then recorded using an optoelectronics system (Vicon Nexus) synchronized with two force plates. At each moment, polynomial interpolations of markers attached on the spine segment were used to compute cervical lordosis, thoracic kyphosis and lumbar lordosis angle curves. Mean of centre of pressure position and velocity was then computed. Multiple stepwise linear regression analysis showed that the position and velocity of centre of pressure associated with each part of the spinal curves were defined as best predictors of the lumbar lordosis angle (R(2)=0.45; p=1.65*10-10) and the thoracic kyphosis angle (R(2)=0.54; p=4.89*10-13) of healthy subjects in quiet stance. This study showed the relationships between each of cervical, thoracic, lumbar curvatures, and centre of pressure's fluctuation during free quiet standing using non-invasive full spinal curve exploration. Copyright © 2016 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Fang Junchu; Chen Ming; Sun Huifen
2008-01-01
Objective: To study the characters of time-intensity curve of contrast-enhanced ultrasonography in benign prostate hyperplasia (BPH) and prostate cancer. Methods: 2.4 ml Sono Vue were injected as a bolus in 40 patients, 23 patients with BPH and 17 with prostate cancer. High perfusion area in both inner and outer gland were measured with time-intensity curves. Results: It was proved by the time-intensity curves that, in BPH cases, the outer prostate gland presented with mild enhancedment and slow wash-off, while the inner gland presented with moderate enhancedment and fast wash-off. Otherwise, both the inner and outer gland in prostate cancer cases presented with high-intensitive enhancedment and slow wash-off. There was marked difference statistical significance on the up slop, average intensity and area under the time-intensity curves in 90 s and 150 s between the cases of BPH and prostate cancer (P<0.05, P<0.01). Conclusion: Quantitative analysis of high perfusion area in both inner and outer glands is helpful for diagnosing BPH and prostate cancer. (authors)
Vickers Andrew; Hozo Iztok; Tsalatsanis Athanasios; Djulbegovic Benjamin
2010-01-01
Abstract Background Decision curve analysis (DCA) has been proposed as an alternative method for evaluation of diagnostic tests, prediction models, and molecular markers. However, DCA is based on expected utility theory, which has been routinely violated by decision makers. Decision-making is governed by intuition (system 1), and analytical, deliberative process (system 2), thus, rational decision-making should reflect both formal principles of rationality and intuition about good decisions. ...
International Nuclear Information System (INIS)
Chanda, S.
2004-01-01
The present study concerns with the effects of material orthotropy,curvature, shear ratio and circumferential modulus under the influence of a temperature distribution throughout the shell structure. Here analysis is restricted to the study of nonlinear vibration of a doubly curved shell structure considering the periodic response of a simple bending mode due to curtailment of pages. Solutions of the problems with suitable illustrations are also presented
Bohling, Sandra D.; King, Thomas C.; Wittwer, Carl T.; Elenitoba-Johnson, Kojo S. J.
1999-01-01
Polymerase chain reaction (PCR) amplification and product analysis for the detection of chromosomal translocations, such as the t(14;18), has traditionally been a two-step process. PCR product detection has generally entailed gel electrophoresis and/or hybridization or sequencing for confirmation of assay specificity. Using a microvolume fluorimeter integrated with a thermal cycler and a PCR-compatible double-stranded DNA (dsDNA) binding fluorescent dye (SYBR Green I), we investigated the feasibility of simultaneous thermal amplification and detection of MBR/JH translocation products by fluorescence melting curve analysis. We analyzed DNA from 30 cases of lymphoproliferative disorders comprising 19 cases of previously documented MBR/JH-positive follicle center lymphoma and 11 reactive lymphadenopathies. The samples were coded and analyzed blindly for the presence of MBR/JH translocations by fluorescence melting curve analysis. We also performed dilutional assays using the MBR/JH-positive cell line SUDHL-6. Multiplex PCR for MBR/JH and β-globin was used to simultaneously assess sample adequacy. All (100%) of the 19 cases previously determined to be MBR/JH positive by conventional PCR analysis showed a characteristic sharp decrease in fluorescence at ∼90°C by melting curve analysis after amplification. Fluorescence melting peaks obtained by plotting the negative derivative of fluorescence over temperature (−dF/dT) versus temperature (T) showed melting temperatures (Tm) at 88.85 ± 1.15°C. In addition, multiplex assays using both MBR/JH and β-globin primers yielded easily distinguishable fluorescence melting peaks at ∼90°C and 81.2°C, respectively. Dilutional assays revealed that fluorescence melting curve analysis was more sensitive than conventional PCR and agarose gel electrophoresis with ultraviolet transillumination by as much as 100-fold. Simultaneous amplification and fluorescence melting curve analysis is a simple, reliable, and sensitive method
AN ANALYSIS OF THE SHAPES OF INTERSTELLAR EXTINCTION CURVES. VI. THE NEAR-IR EXTINCTION LAW
International Nuclear Information System (INIS)
Fitzpatrick, E. L.; Massa, D.
2009-01-01
We combine new observations from the Hubble Space Telescope's Advanced Camera of Survey with existing data to investigate the wavelength dependence of near-IR (NIR) extinction. Previous studies suggest a power law form for NIR extinction, with a 'universal' value of the exponent, although some recent observations indicate that significant sight line-to-sight line variability may exist. We show that a power-law model for the NIR extinction provides an excellent fit to most extinction curves, but that the value of the power, β, varies significantly from sight line to sight line. Therefore, it seems that a 'universal NIR extinction law' is not possible. Instead, we find that as β decreases, R(V) ≡ A(V)/E(B - V) tends to increase, suggesting that NIR extinction curves which have been considered 'peculiar' may, in fact, be typical for different R(V) values. We show that the power-law parameters can depend on the wavelength interval used to derive them, with the β increasing as longer wavelengths are included. This result implies that extrapolating power-law fits to determine R(V) is unreliable. To avoid this problem, we adopt a different functional form for NIR extinction. This new form mimics a power law whose exponent increases with wavelength, has only two free parameters, can fit all of our curves over a longer wavelength baseline and to higher precision, and produces R(V) values which are consistent with independent estimates and commonly used methods for estimating R(V). Furthermore, unlike the power-law model, it gives R(V)s that are independent of the wavelength interval used to derive them. It also suggests that the relation R(V) = -1.36 E(K-V)/(E(B-V)) - 0.79 can estimate R(V) to ±0.12. Finally, we use model extinction curves to show that our extinction curves are in accord with theoretical expectations, and demonstrate how large samples of observational quantities can provide useful constraints on the grain properties.
Hsu, Shu-Hui; Kulasekere, Ravi; Roberson, Peter L
2010-08-05
Film calibration is time-consuming work when dose accuracy is essential while working in a range of photon scatter environments. This study uses the single-target single-hit model of film response to fit the calibration curves as a function of calibration method, processor condition, field size and depth. Kodak XV film was irradiated perpendicular to the beam axis in a solid water phantom. Standard calibration films (one dose point per film) were irradiated at 90 cm source-to-surface distance (SSD) for various doses (16-128 cGy), depths (0.2, 0.5, 1.5, 5, 10 cm) and field sizes (5 × 5, 10 × 10 and 20 × 20 cm²). The 8-field calibration method (eight dose points per film) was used as a reference for each experiment, taken at 95 cm SSD and 5 cm depth. The delivered doses were measured using an Attix parallel plate chamber for improved accuracy of dose estimation in the buildup region. Three fitting methods with one to three dose points per calibration curve were investigated for the field sizes of 5 × 5, 10 × 10 and 20 × 20 cm². The inter-day variation of model parameters (background, saturation and slope) were 1.8%, 5.7%, and 7.7% (1 σ) using the 8-field method. The saturation parameter ratio of standard to 8-field curves was 1.083 ± 0.005. The slope parameter ratio of standard to 8-field curves ranged from 0.99 to 1.05, depending on field size and depth. The slope parameter ratio decreases with increasing depth below 0.5 cm for the three field sizes. It increases with increasing depths above 0.5 cm. A calibration curve with one to three dose points fitted with the model is possible with 2% accuracy in film dosimetry for various irradiation conditions. The proposed fitting methods may reduce workload while providing energy dependence correction in radiographic film dosimetry. This study is limited to radiographic XV film with a Lumisys scanner.
Directory of Open Access Journals (Sweden)
María Ballester
Full Text Available BACKGROUND: Real-time quantitative PCR (qPCR is still the gold-standard technique for gene-expression quantification. Recent technological advances of this method allow for the high-throughput gene-expression analysis, without the limitations of sample space and reagent used. However, non-commercial and user-friendly software for the management and analysis of these data is not available. RESULTS: The recently developed commercial microarrays allow for the drawing of standard curves of multiple assays using the same n-fold diluted samples. Data Analysis Gene (DAG Expression software has been developed to perform high-throughput gene-expression data analysis using standard curves for relative quantification and one or multiple reference genes for sample normalization. We discuss the application of DAG Expression in the analysis of data from an experiment performed with Fluidigm technology, in which 48 genes and 115 samples were measured. Furthermore, the quality of our analysis was tested and compared with other available methods. CONCLUSIONS: DAG Expression is a freely available software that permits the automated analysis and visualization of high-throughput qPCR. A detailed manual and a demo-experiment are provided within the DAG Expression software at http://www.dagexpression.com/dage.zip.
International Nuclear Information System (INIS)
David, M.; Karmrodt, J.; Herwelling, A.; Bletz, C.; David, S.; Heussel, C.P.; Markstaller, K.
2005-01-01
Purpose: To study quantitative changes of lung density distributions when recording in- and expiratory static pressure-volume curves by single slice computed tomography (CT). Materials and Methods: Static in- and expiratory pressure volume curves (0 to 1000 ml, increments of 100 ml) were obtained in random order in 10 pigs after induction of lung damage by saline lavage. Simultaneously, CT acquisitions (slice thickness 1 mm, temporal increment 2 s) were performed in a single slice (3 cm below the carina). In each CT image lung segmentation and planimetry of defined density ranges were achieved. The lung density ranges were defined as: hyperinflated (-1024 to -910 HU), normal aerated (-910 to -600 HU), poorly aerated (-600 to -300 HU), and non aerated (-300 to 200 HU) lung. Fractional areas of defined density ranges in percentage of total lung area were compared to recorded volume increments and airway pressures (atmospheric pressure, lower inflection point (LIP), LIP*0.5, LIP*1.5, peak airway pressure) of in- and expiratory pressure-volume curves. Results: Quantitative analysis of defined density ranges showed no differences between in- and expiratory pressure-volume curves. The amount of poorly aerated lung decreased and normal aerated lung increased constantly when airway pressure and volume were increased during inspiratory pressure-volume curves and vice versa during expiratory pressure-volume loops. Conclusion: Recruitment and derecruitment of lung atelectasis during registration of static in- and expiratory pressure-volume loops occurred constantly, but not in a stepwise manner. CT was shown to be an appropriate method to analyse these recruitment process. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Garces, F; Vidania, R de
1984-07-01
In this work an integral parametrization of the bacterial growth curve is presented. The values of the parameters are obtained by fitting to the experimental data. Those parameters, with allow to describe the growth in its different phases, are the followings: slopes of the curve in its three parts and the time which divides the last two phases of the bacterial growth. The experimental data are bacterial densities measured by optical methods. The bacteria used was the E. coli C{sub 6}00. (Author)
International Nuclear Information System (INIS)
Pradhan, S.M.; Sneha, C.; Adtani, M.M.
2010-01-01
The facility of glow curve storage and recall provided in the reader software is helpful for manual screening of the glow curves; however no further analysis is possible due to absence of numerical TL data at the sampling intervals. In the present study glow curves are digitized by modifying the reader software and then normalized to make them independent of the dose. The normalized glow curves are then analyzed by dividing them into five equal parts on time scale. This method of analysis is used to correlate the variation of total TL counts of the three discs with time elapsed post irradiation
Learning Curve Analysis and Surgical Outcomes of Single-port Laparoscopic Myomectomy.
Lee, Hee Jun; Kim, Ju Yeong; Kim, Seul Ki; Lee, Jung Ryeol; Suh, Chang Suk; Kim, Seok Hyun
2015-01-01
To identify learning curves for single-port laparoscopic myomectomy (SPLM) and evaluate surgical outcomes according to the sequence of operation. A retrospective study. A university-based hospital (Canadian Task Force classification II-2). The medical records from 205 patients who had undergone SPLM from October 2009 to May 2013 were reviewed. Because the myomectomy time was significantly affected by the size and number of myomas removed by SPLM, cases in which 2 or more of the myomas removed were >7 cm in diameter were excluded. Furthermore, cases involving additional operations performed simultaneously (e.g., ovarian or hysteroscopic surgery) were also excluded. A total of 161 cases of SPLM were included. None. We assessed the SPLM learning curve via a graph based on operation time versus sequence of cases. Patients were chronologically arranged according to their surgery dates and were then placed into 1 of 4 groups according to their operation sequence. SPLM was completed successfully in 160 of 161 cases (99.4%). One case was converted to multiport surgery. Basal characteristics of the patients between the 4 groups did not differ. The median operation times for the 4 groups were 112.0, 92.8, 83.7, and 90.0 minutes, respectively. Operation time decreased significantly in the second, third, and fourth groups compared with that in the first group (p learning curve became less steep, was evident after about 45 operations. Results from the current study suggested that proficiency for SPLM was achieved after about 45 operations. Additionally, operation time decreased with experience without an increase in complication rate. Copyright © 2015 AAGL. Published by Elsevier Inc. All rights reserved.
The Development of Complex Problem Solving in Adolescence: A Latent Growth Curve Analysis
Frischkorn, Gidon T.; Greiff, Samuel; Wüstenberg, Sascha
2014-01-01
Complex problem solving (CPS) as a cross-curricular competence has recently attracted more attention in educational psychology as indicated by its implementation in international educational large-scale assessments such as the Programme for International Student Assessment. However, research on the development of CPS is scarce, and the few…
A Growth Curve Analysis of Housing Quality among Transition-Aged Foster Youth
Tyrell, Fanita A.; Yates, Tuppett M.
2017-01-01
Background: Procuring safe housing is a salient developmental task during emerging adulthood, one that is especially challenging for emancipated foster youth. Yet, little is known about factors that influence foster youths' housing experiences. Objective: This investigation documented changes in foster youth's housing quality during the first…
Directory of Open Access Journals (Sweden)
Susie Kim, APRN, DNSc, FAAN
2007-12-01
Conclusion: This study suggests that the intensity, specificity, and longitudinality of interpersonal caring interventions in community psychiatric service programs deserve attention in order to improve and maintain patient functional outcomes.
Emotions, Self-Regulated Learning, and Achievement in Mathematics : A Growth Curve Analysis
Ahmed, Wondimu; van der Werf, Greetje; Kuyper, Hans; Minnaert, Alexander
The purpose of the current study was twofold: (a) to investigate the developmental trends of 4 academic emotions (anxiety, boredom, enjoyment, and pride) and (b) to examine whether changes in emotions are linked to the changes in students' self-regulatory strategies (shallow, deep, and
Emotions, Self-Regulated Learning, and Achievement in Mathematics: A Growth Curve Analysis
Ahmed, Wondimu; van der Werf, Greetje; Kuyper, Hans; Minnaert, Alexander
2013-01-01
The purpose of the current study was twofold: (a) to investigate the developmental trends of 4 academic emotions (anxiety, boredom, enjoyment, and pride) and (b) to examine whether changes in emotions are linked to the changes in students' self-regulatory strategies (shallow, deep, and meta-cognitive) and achievement in mathematics. Four hundred…
Kort-Butler, Lisa A.; Hagewen, Kellie J.
2011-01-01
Research on adolescent self-esteem indicates that adolescence is a time in which individuals experience important changes in their physical, cognitive, and social identities. Prior research suggests that there is a positive relationship between an adolescent's participation in structured extracurricular activities and well-being in a variety of…
Image Analysis of a Negatively Curved Graphitic Sheet Model for Amorphous Carbon
Bursill, L. A.; Bourgeois, Laure N.
High-resolution electron micrographs are presented which show essentially curved single sheets of graphitic carbon. Image calculations are then presented for the random surface schwarzite-related model of Townsend et al. (Phys. Rev. Lett. 69, 921-924, 1992). Comparison with experimental images does not rule out the contention that such models, containing surfaces of negative curvature, may be useful for predicting some physical properties of specific forms of nanoporous carbon. Some difficulties of the model predictions, when compared with the experimental images, are pointed out. The range of application of this model, as well as competing models, is discussed briefly.
On-chip magnetic bead-based DNA melting curve analysis using a magnetoresistive sensor
DEFF Research Database (Denmark)
Rizzi, Giovanni; Østerberg, Frederik Westergaard; Henriksen, Anders Dahl
2014-01-01
We present real-time measurements of DNA melting curves in a chip-based system that detects the amount of surface-bound magnetic beads using magnetoresistive magnetic field sensors. The sensors detect the difference between the amount of beads bound to the top and bottom sensor branches....... The beads are magnetized by the field arising from the bias current passed through the sensors. We demonstrate the first on-chip measurements of the melting of DNA hybrids upon a ramping of the temperature. This overcomes the limitation of using a single washing condition at constant temperature. Moreover...
Analysis of survival curves for Rhizopus, Mucor and Penicillia irradiated with gamma radiation
International Nuclear Information System (INIS)
Ishiguro, Etsuji; Danno, Akibumi; Miyazato, Mitsuru
1994-01-01
This study was aimed to understand the survival pattern of some microorganisms which were treated by γ-sterilization. Though most of the works were concentrated and reported with D 10 -values, it was presently found that the γ-irradiated survival curves showed sigmoid pattern and L-values were reached about half of the D 10 -value for each strains. It was further confirmed that if L-values were used for practical sterilization with D 10 -values, the estimation of sterilized levels would become more accurate. (author). 10 refs., 3 figs., 1 tab
International Nuclear Information System (INIS)
Cristakou, H.D.
1983-01-01
The difficulties involved in the control of biological and radioimmunological assay systems, and in the maintenance of standard, as well as, the usual heterogeneity of assayed samples require some evidence of similarity between the dose-response curves obtained with the standard and the sample. Nowadays the parallelism test is used to provide such evidence. However, some indications of non-normal errors distribution, such as the presence of out layers, render the parallelism test both conceptually implausible and statistically inefficient. In such a manner we suggest the non-parametric 'frequencial' test as a more sounding option. (author)
Jiang, Chao; Cao, Liang; Yuan, Yuan; Chen, Min; Jin, Yan; Huang, Luqi
2014-01-01
Saffron (Crocus sativus L.) is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA) that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C) and the adulterants: D. carota (81.60°C), C. tinctorius (80.10°C), C. officinalis (79.92°C), Dendranthema morifolium (Ramat.) Tzvel. (79.62°C), N. nucifera (80.58°C), Hemerocallis fulva (L.) L. (84.78°C), and Z. mays (84.33°C). The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.
Directory of Open Access Journals (Sweden)
Chao Jiang
2014-01-01
Full Text Available Saffron (Crocus sativus L. is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C and the adulterants: D. carota (81.60°C, C. tinctorius (80.10°C, C. officinalis (79.92°C, Dendranthema morifolium (Ramat. Tzvel. (79.62°C, N. nucifera (80.58°C, Hemerocallis fulva (L. L. (84.78°C, and Z. mays (84.33°C. The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.
Jamal Talabani, A; Endreseth, B H; Lydersen, S; Edna, T-H
2017-01-01
The study investigated the capability of clinical findings, temperature, C-reactive protein (CRP), and white blood cell (WBC) count to discern patients with acute colonic diverticulitis from all other patients admitted with acute abdominal pain. The probability of acute diverticulitis was assessed by the examining doctor, using a scale from 0 (zero probability) to 10 (100 % probability). Receiver operating characteristic (ROC) curves were used to assess the clinical diagnostic accuracy of acute colonic diverticulitis in patients admitted with acute abdominal pain. Of 833 patients admitted with acute abdominal pain, 95 had acute colonic diverticulitis. ROC curve analysis gave an area under the ROC curve (AUC) of 0.95 (CI 0.92 to 0.97) for ages patients. Separate analysis showed an AUC = 0.83 (CI 0.80 to 0.86) of CRP alone. White blood cell count and temperature were almost useless to discriminate acute colonic diverticulitis from other types of acute abdominal pain, AUC = 0.59 (CI 0.53 to 0.65) for white blood cell count and AUC = 0.57 (0.50 to 0.63) for temperature, respectively. This prospective study demonstrates that standard clinical evaluation by non-specialist doctors based on history, physical examination, and initial blood tests on admission provides a high degree of diagnostic precision in patients with acute colonic diverticulitis.
Neural network analysis of head-flow curves in deep well pumps
International Nuclear Information System (INIS)
Goelcue, Mustafa
2006-01-01
In impellers with splitter blades, the difficulty in calculation of the flow area of the impeller is because of the unknown flow rate occurring in the two separate areas when the splitter blades are added. Experimental studies were made to investigate the effects of splitter blade length on deep well pump performance for different numbers of blades. Head-flow curves of deep well pump impellers with splitter blades were investigated using artificial neural networks (ANNs). Gradient descent (GD), Gradient descent with momentum (GDM) and Levenberg-Marquardt (LM) learning algorithms were used in the networks. Experimental studies were completed to obtain training and test data. Blade number (z), non-dimensional splitter blade length (L-bar ) and flow rate (Q) were used as the input layer, while the output is head (H m ). For the testing data, the root mean squared error (RMSE), fraction of variance (R 2 ) and mean absolute percentage error (MAPE) were found to be 0.1285, 0.9999 and 1.6821%, respectively. With these results, we believe that the ANN can be used for prediction of head-flow curves as an appropriate method in deep well pump impellers with splitter blades.
International Nuclear Information System (INIS)
Rijssel, Jos van; Kuipers, Bonny W.M.; Erné, Ben H.
2014-01-01
A numerical inversion method known from the analysis of light scattering by colloidal dispersions is now applied to magnetization curves of ferrofluids. The distribution of magnetic particle sizes or dipole moments is determined without assuming that the distribution is unimodal or of a particular shape. The inversion method enforces positive number densities via a non-negative least squares procedure. It is tested successfully on experimental and simulated data for ferrofluid samples with known multimodal size distributions. The created computer program MINORIM is made available on the web. - Highlights: • A method from light scattering is applied to analyze ferrofluid magnetization curves. • A magnetic size distribution is obtained without prior assumption of its shape. • The method is tested successfully on ferrofluids with a known size distribution. • The practical limits of the method are explored with simulated data including noise. • This method is implemented in the program MINORIM, freely available online
International Nuclear Information System (INIS)
Schaeffer, G.J.; Seebregts, A.J.; Beurskens, L.W.M.; De Moor, H.H.C.; Alsema, E.; Sark, W.; Durstewicz, M.; Perrin, M.; Boulanger, P.; Laukamp, H.; Zuccaro, C.
2004-08-01
done scenario-wise. Doing this for grid-connected PV, the analysis shows that self-sustaining markets could be expected in Europe at specific locations before 2010. Reaching break-even for the wholesale electricity market will most probably not happen before 2030. To reach break-even within a reasonable time-frame, the market deployment growth rate should be at least 15%-20% over the next coming decades, assuming that the learning rate remains at the current 20%-25%. Because the learning rate is not fixed, it might be possible to influence it by a right combination of market deployment policy (learning investment) and R and D-policy supporting the market development (investment in learning). An experience curve analysis can contribute interesting information to policy discussions on the balance between market support and R and D. In the case of PV it seems that a substantially increased support for learning processes, such as R and D, and interactive learning networks within and between users, producers and component suppliers, which supports current and future market deployment instruments, can yield a huge public benefit in the longer term. Furthermore the experience curve approach shows that from a European perspective the cost-effectiveness of PV-policy could be improved. This effectiveness could be reached if a European-wide market-based incentive scheme were implemented. As cost-effectiveness is just one policy goal among many others, such a European market-based deployment instrument should not exclude additional Member State PV deployment policies
2012-01-01
Background The World Health Organization (WHO) is in the process of establishing a new global database on the growth of school children and adolescents. Limited national data exist from Asian children, notably those living in the Middle East and North Africa (MENA). This study aimed to generate the growth chart of a nationally representative sample of Iranian children aged 10–19 years, and to explore how well these anthropometric data match with international growth references. Methods In this nationwide study, the anthropometric data were recorded from Iranian students, aged 10–19 years, who were selected by multistage random cluster sampling from urban and rural areas. Prior to the analysis, outliers were excluded from the features height-for-age and body mass index (BMI)-for-age using the NCHS/WHO cut-offs. The Box-Cox power exponential (BCPE) method was used to calculate height-for-age and BMI-for-age Z-scores for our study participants. Then, children with overweight, obesity, thinness, and severe thinness were identified using the BMI-for-age z-scores. Moreover, stunted children were detected using the height-for-age z-scores. The growth curve of the Iranian children was then generated from the z-scores, smoothed by cubic S-plines. Results The study population comprised 5430 school students consisting of 2312 (44%) participants aged 10–14 years , and 3118 (58%) with 15–19 years of age. Eight percent of the participants had low BMI (thinness: 6% and severe thinness: 2%), 20% had high BMI (overweight: 14% and obesity: 6%), and 7% were stunted. The prevalence rates of low and high BMI were greater in boys than in girls (P growth curves generated from a national dataset may be included for establishing WHO global database on children’s growth. Similar to most low-and middle income populations, Iranian children aged 10–19 years are facing a double burden of weight disorders, notably under- and over- nutrition, which should be considered in
Mansourian, Marjan; Marateb, Hamid Reza; Kelishadi, Roya; Motlagh, Mohammad Esmaeil; Aminaee, Tahereh; Taslimi, Mahnaz; Majdzadeh, Reza; Heshmat, Ramin; Ardalan, Gelayol; Poursafa, Parinaz
2012-09-17
The World Health Organization (WHO) is in the process of establishing a new global database on the growth of school children and adolescents. Limited national data exist from Asian children, notably those living in the Middle East and North Africa (MENA). This study aimed to generate the growth chart of a nationally representative sample of Iranian children aged 10-19 years, and to explore how well these anthropometric data match with international growth references. In this nationwide study, the anthropometric data were recorded from Iranian students, aged 10-19 years, who were selected by multistage random cluster sampling from urban and rural areas. Prior to the analysis, outliers were excluded from the features height-for-age and body mass index (BMI)-for-age using the NCHS/WHO cut-offs. The Box-Cox power exponential (BCPE) method was used to calculate height-for-age and BMI-for-age Z-scores for our study participants. Then, children with overweight, obesity, thinness, and severe thinness were identified using the BMI-for-age z-scores. Moreover, stunted children were detected using the height-for-age z-scores. The growth curve of the Iranian children was then generated from the z-scores, smoothed by cubic S-plines. The study population comprised 5430 school students consisting of 2312 (44%) participants aged 10-14 years , and 3118 (58%) with 15-19 years of age. Eight percent of the participants had low BMI (thinness: 6% and severe thinness: 2%), 20% had high BMI (overweight: 14% and obesity: 6%), and 7% were stunted. The prevalence rates of low and high BMI were greater in boys than in girls (P < 0.001). The mean BMI-for-age, and the average height-for-age of Iranian children aged 10-19 years were lower than the WHO 2007 and United states Centers for Disease Control and Prevention 2000 (USCDC2000) references. The current growth curves generated from a national dataset may be included for establishing WHO global database on children's growth. Similar to most low
Directory of Open Access Journals (Sweden)
Mansourian Marjan
2012-09-01
Full Text Available Abstract Background The World Health Organization (WHO is in the process of establishing a new global database on the growth of school children and adolescents. Limited national data exist from Asian children, notably those living in the Middle East and North Africa (MENA. This study aimed to generate the growth chart of a nationally representative sample of Iranian children aged 10–19 years, and to explore how well these anthropometric data match with international growth references. Methods In this nationwide study, the anthropometric data were recorded from Iranian students, aged 10–19 years, who were selected by multistage random cluster sampling from urban and rural areas. Prior to the analysis, outliers were excluded from the features height-for-age and body mass index (BMI-for-age using the NCHS/WHO cut-offs. The Box-Cox power exponential (BCPE method was used to calculate height-for-age and BMI-for-age Z-scores for our study participants. Then, children with overweight, obesity, thinness, and severe thinness were identified using the BMI-for-age z-scores. Moreover, stunted children were detected using the height-for-age z-scores. The growth curve of the Iranian children was then generated from the z-scores, smoothed by cubic S-plines. Results The study population comprised 5430 school students consisting of 2312 (44% participants aged 10–14 years , and 3118 (58% with 15–19 years of age. Eight percent of the participants had low BMI (thinness: 6% and severe thinness: 2%, 20% had high BMI (overweight: 14% and obesity: 6%, and 7% were stunted. The prevalence rates of low and high BMI were greater in boys than in girls (P Conclusions The current growth curves generated from a national dataset may be included for establishing WHO global database on children’s growth. Similar to most low-and middle income populations, Iranian children aged 10–19 years are facing a double burden of weight disorders, notably under- and
International Nuclear Information System (INIS)
Ricke, F.; Gonzalez, P.; Pruzzo, R.; Nagel, J.
1987-01-01
To assess diastolic and systolic ventricular function, a computerized method was developed using Fourier analysis on left ventricular time activity curves. The ventricular raw curve obtained from radionuclide gate blood pool imaging was substituted by a four harmonics curve. Valuable parameters were then calculated specially peak ejection rate, filling fraction and peak filling rate, which allowed clear-cut differentiation normal subjects from patients with left ventricular hypertrophy. (author)
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Alan Oliveira do Ó
2011-06-01
Full Text Available Data of Anglo-Nubian goats from experimental herds of Empresa Estadual de Pesquisa Agropecuária da Paraíba (EMEPA-PB, recorded between 1980 and 2005 were used, with the objective to study the adjustment of Brody, Gompertz, Logístico, Richards and Von Bertalanffy functions on the growth curve and to estimate genetic parameters for the traits obtained from best fitting function. Functions were fitted using NLIN procedure of Statistical Analysis System software (SAS, by GAUSS method. The best fitting was obtained using the Brody function. The respective values of mature weight and maturation rate estimated by Brody function were 28.22kg and 0.0054/day. The Brody function was used to estimate genetic parameters and the (covariance components for traits of economic importance using the Derivative Free Restricted Maximum Likelihood method, using the WOMBAT software. The estimates direct heritability of mature weight and maturation rate were, respectively, 0.10, and 0.12, and the direct heritability of other weights recorded ranged from 0.10 to 0.28. The results observed in this study indicates small genetic progress using individual selection.Foram utilizados dados de caprinos da raça Anglo-Nubiana controlados entre os anos de 1980 e 2005 na Empresa Estadual de Pesquisa Agropecuária da Paraíba – EMEPA com o objetivo de estudar o ajuste das funções de Brody, Gompertz, Logístico, Richards e Von Bertalanffy sobre a curva de crescimento e estimar parâmetros genéticos para características obtidas a partir da função de melhor ajuste. Para o ajuste das curvas, foi utilizado o procedimento NLIN do software Statistical Analysis System (SAS, por meio do método de GAUSS. A curva de Brody foi a que promoveu melhor ajuste. Os valores do peso adulto e da taxa de maturação estimados pela função de Brody foram de 28,22kg e 0.0054/dia, respectivamente. A função de Brody foi usada para estimar parâmetros genéticos e componentes de (covari
Sivo, Stephen; Fan, Xitao
2008-01-01
Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…
Spectral analysis of the IntCal98 calibration curve: a Bayesian view
International Nuclear Information System (INIS)
Palonen, V.; Tikkanen, P.
2004-01-01
Preliminary results from a Bayesian approach to find periodicities in the IntCal98 calibration curve are given. It has been shown in the literature that the discrete Fourier transform (Schuster periodogram) corresponds to the use of an approximate Bayesian model of one harmonic frequency and Gaussian noise. Advantages of the Bayesian approach include the possibility to use models for variable, attenuated and multiple frequencies, the capability to analyze unevenly spaced data and the possibility to assess the significance and uncertainties of spectral estimates. In this work, a new Bayesian model using random walk noise to take care of the trend in the data is developed. Both Bayesian models are described and the first results of the new model are reported and compared with results from straightforward discrete-Fourier-transform and maximum-entropy-method spectral analyses
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D. A. GUJEL
Full Text Available ABSTRACT This work analyses the methodology "A" (item A.4 employed by the Brazilian Standard ABNT 8522 (ABNT, 2008 for determining the stress-strain behavior of cylindrical specimens of concrete, presenting considerations about possible enhancements aiming it use for concretes with recycled aggregates with automatic test equipment. The methodology specified by the Brazilian Standard presents methodological issues that brings distortions in obtaining the stress-strain curve, as the use of a very limited number of sampling points and by inducing micro cracks and fluency in the elastic behavior of the material due to the use of steady stress levels in the test. The use of a base stress of 0.5 MPa is too low for modern high load test machines designed do high strength concrete test. The work presents a discussion over these subjects, and a proposal of a modified test procedure to avoid such situations.
ROC curve analyses of eyewitness identification decisions: An analysis of the recent debate.
Rotello, Caren M; Chen, Tina
2016-01-01
How should the accuracy of eyewitness identification decisions be measured, so that best practices for identification can be determined? This fundamental question is under intense debate. One side advocates for continued use of a traditional measure of identification accuracy, known as the diagnosticity ratio , whereas the other side argues that receiver operating characteristic curves (ROCs) should be used instead because diagnosticity is confounded with response bias. Diagnosticity proponents have offered several criticisms of ROCs, which we show are either false or irrelevant to the assessment of eyewitness accuracy. We also show that, like diagnosticity, Bayesian measures of identification accuracy confound response bias with witnesses' ability to discriminate guilty from innocent suspects. ROCs are an essential tool for distinguishing memory-based processes from decisional aspects of a response; simulations of different possible identification tasks and response strategies show that they offer important constraints on theory development.
Zielesny, Achim
2016-01-01
This successful book provides in its second edition an interactive and illustrative guide from two-dimensional curve fitting to multidimensional clustering and machine learning with neural networks or support vector machines. Along the way topics like mathematical optimization or evolutionary algorithms are touched. All concepts and ideas are outlined in a clear cut manner with graphically depicted plausibility arguments and a little elementary mathematics. The major topics are extensively outlined with exploratory examples and applications. The primary goal is to be as illustrative as possible without hiding problems and pitfalls but to address them. The character of an illustrative cookbook is complemented with specific sections that address more fundamental questions like the relation between machine learning and human intelligence. All topics are completely demonstrated with the computing platform Mathematica and the Computational Intelligence Packages (CIP), a high-level function library developed with M...
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Sebastião Martins Filho
2008-09-01
Full Text Available Neste trabalho foi utilizada a metodologia Bayesiana para ajustar o modelo não-linear logístico para dados de crescimento de duas cultivares de feijoeiro, "Neguinho" e "Carioca". O delineamento experimental utilizado foi o inteiramente casualizado, com vinte repetições, no esquema de parcelas subdivididas, sendo que os tratamentos principais foram constituídos pelas cultivares e as subparcelas foram constituídas por 17 períodos de avaliações, do plantio até aos 85 dias. A metodologia permitiu comparar as curvas de crescimentos sem utilizar a teoria assintótica e estes resultados mostraram um maior incremento em altura para a cultivar "Carioca".In this paper the Bayesian methodology was used to fit the logistic nonlinear model to growth data of two common bean cultivars, 'Neguinho' and 'Carioca'. The experiment was a split plot under a completely randomized design with twenty replicates, being the main treatments constituted by cultivars and the sub plots constituted by seventeen periods of evaluations, from planting to 85 days. The methodology allowed comparing the growth curves without using the asymptotic theory, and these results showed a larger height increment for the 'Carioca' cultivar.
Zhu, Shijun; Nahm, Eun-Shim; Resnick, Barbara; Friedmann, Erika; Brown, Clayton; Park, Jumin; Cheon, Jooyoung; Park, DoHwan
2017-07-01
This secondary data analyses of a longitudinal study assessed whether self-efficacy for exercise (SEE) mediated online intervention effects on exercise among older adults and whether age (50-64 vs. ≥65 years) moderated the mediation. Data were from an online bone health intervention study. Eight hundred sixty-six older adults (≥50 years) were randomized to three arms: Bone Power (n = 301), Bone Power Plus (n = 302), or Control (n = 263). Parallel process latent growth curve modeling (LGCM) was used to jointly model growths in SEE and in exercise and to assess the mediating effect of SEE on the effect of intervention on exercise. SEE was a significant mediator in 50- to 64-year-old adults (0.061, 95 BCI: 0.011, 0.163) but not in the ≥65 age group (-0.004, 95% BCI: -0.047, 0.025). Promotion of SEE is critical to improve exercise among 50- to 64-year-olds.
High resolution melt curve analysis based on methylation status for human semen identification.
Fachet, Caitlyn; Quarino, Lawrence; Karnas, K Joy
2017-03-01
A high resolution melt curve assay to differentiate semen from blood, saliva, urine, and vaginal fluid based on methylation status at the Dapper Isoform 1 (DACT1) gene was developed. Stains made from blood, saliva, urine, semen, and vaginal fluid were obtained from volunteers and DNA was isolated using either organic extraction (saliva, urine, and vaginal fluid) or Chelex ® 100 extraction (blood and semen). Extracts were then subjected to bisulfite modification in order to convert unmethylated cytosines to uracil, consequently creating sequences whose amplicons have melt curves that vary depending on their initial methylation status. When primers designed to amplify the promoter region of the DACT1 gene were used, DNA from semen samples was distinguishable from other fluids by a having a statistically significant lower melting temperature. The assay was found to be sperm-significant since semen from a vasectomized man produced a melting temperature similar to the non-semen body fluids. Blood and semen stains stored up to 5 months and tested at various intervals showed little variation in melt temperature indicating the methylation status was stable during the course of the study. The assay is a more viable method for forensic science practice than most molecular-based methods for body fluid stain identification since it is time efficient and utilizes instrumentation common to forensic biology laboratories. In addition, the assay is advantageous over traditional presumptive chemical methods for body fluid identification since results are confirmatory and the assay offers the possibility of multiplexing which may test for multiple body fluids simultaneously.
Transit Timing Variation analysis with Kepler light curves of KOI 227 and Kepler 93b
Dulz, Shannon; Reed, Mike
2017-01-01
By searching for transit signals in approximately 150,000 stars, NASA’s Kepler Space telescope found thousands of exoplanets over its primary mission from 2009 to 2013 (Tenenbaum et al. 2014, ApJS, 211, 6). Yet, a detailed follow-up examination of Kepler light curves may contribute more evidence on system dynamics and planetary atmospheres of these objects. Kepler’s continuous observing of these systems over the mission duration produced light curves of sufficient duration to allow for the search for transit timing variations. Transit timing variations over the course of many orbits may indicate a precessing orbit or the existence of a non-transiting third body such as another exoplanet. Flux contributions of the planet just prior to secondary eclipse may provide a measurement of bond albedo from the day-side of the transiting planet. Any asymmetries of the transit shape may indicate thermal asymmetries which can measure upper atmosphere motion of the planet. These two factors can constrain atmospheric models of close orbiting exoplanets. We first establish our procedure with the well-documented TTV system, KOI 227 (Nesvorny et al. 2014, ApJ, 790, 31). Using the test case of KOI 227, we analyze Kepler-93b for TTVs and day-side flux contributions. Kepler-93b is likely a rocky planet with R = 1.50 ± 0.03 Earth Radii and M = 2.59 ± 2.0 Earth Masses (Marcy et al. 2014, ApJS, 210, 20). This research is funded by a NASA EPSCoR grant.
CFD and Thermo Mechanical Analysis on Effect of Curved vs Step Surface in IC Engine Cylinder Head
Balaji, S.; Ganesh, N.; Kumarasamy, A.
2017-05-01
Current research in IC engines mainly focus on various methods to achieve higher efficiency and high specific power. As a single design parameter, combustion chamber peak spring pressure has increased more than before. Apart from the structural aspects of withstanding these loads, designer faces challenges of resolving thermal aspects of cylinder head. Methods to enhance the heat transfer without compromising load withstanding capability are being constantly explored. Conventional cylinder heads have got sat inner surface. In this paper we have suggested a modification in inner surface to enhance the heat transfer capability. To increase the heat transfer rate, inner same deck surface is configured as a curved and stepped surface instead of sat. We have reported the effectiveness of extend of curvature in the inner same deck surface in a different technical paper. Here, we are making a direct comparison between stepped and curved surface only. From this analysis it has been observed that curved surface reduces the ame deck temperature considerably without compromising the structural strength factors compared to step and sat surface.
Directory of Open Access Journals (Sweden)
Luciane Stallivieri
2015-11-01
Full Text Available Students from around the world are increasingly interested in learning new languages and be inserted in different cultures, increasing the numbers of international mobility. However, when traveling to another country, cultural differences are strongly perceived, even if in different ways, influencing the adaptation process. Given the importance and growth of the international academic mobility, this study analyzes the process of cultural adaptation of students in mobility, considering the assumptions of the theory of curves "U" and "W". As for the methodology, it is a descriptive research with quantitative approach. Data collection was conducted through closed questionnaires sent to international students from different countries who have studied or are still studying in a Brazilian Institution of Higher Education. The results showed that after the stage of culture shock, students feel more connected to local culture, make more friends and feel more confident. It was confirmed also that almost all international students managed to adapt well to local customs.
Growth And Export Expansion In Mauritius - A Time Series Analysis ...
African Journals Online (AJOL)
Growth And Export Expansion In Mauritius - A Time Series Analysis. ... RV Sannassee, R Pearce ... Using Granger Causality tests, the short-run analysis results revealed that there is significant reciprocal causality between real export earnings ...
Brandfass, Christoph; Karlovsky, Petr
2006-01-23
Fusarium head blight (FHB) is a disease of cereal crops, which has a severe impact on wheat and barley production worldwide. Apart from reducing the yield and impairing grain quality, FHB leads to contamination of grain with toxic secondary metabolites (mycotoxins), which pose a health risk to humans and livestock. The Fusarium species primarily involved in FHB are F. graminearum and F. culmorum. A key prerequisite for a reduction in the incidence of FHB is an understanding of its epidemiology. We describe a duplex-PCR-based method for the simultaneous detection of F. culmorum and F. graminearum in plant material. Species-specific PCR products are identified by melting curve analysis performed in a real-time thermocycler in the presence of the fluorescent dye SYBR Green I. In contrast to multiplex real-time PCR assays, the method does not use doubly labeled hybridization probes. PCR with product differentiation by melting curve analysis offers a cost-effective means of qualitative analysis for the presence of F. culmorum and F. graminearum in plant material. This method is particularly suitable for epidemiological studies involving a large number of samples.
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Karlovsky Petr
2006-01-01
Full Text Available Abstract Background Fusarium head blight (FHB is a disease of cereal crops, which has a severe impact on wheat and barley production worldwide. Apart from reducing the yield and impairing grain quality, FHB leads to contamination of grain with toxic secondary metabolites (mycotoxins, which pose a health risk to humans and livestock. The Fusarium species primarily involved in FHB are F. graminearum and F. culmorum. A key prerequisite for a reduction in the incidence of FHB is an understanding of its epidemiology. Results We describe a duplex-PCR-based method for the simultaneous detection of F. culmorum and F. graminearum in plant material. Species-specific PCR products are identified by melting curve analysis performed in a real-time thermocycler in the presence of the fluorescent dye SYBR Green I. In contrast to multiplex real-time PCR assays, the method does not use doubly labeled hybridization probes. Conclusion PCR with product differentiation by melting curve analysis offers a cost-effective means of qualitative analysis for the presence of F. culmorum and F. graminearum in plant material. This method is particularly suitable for epidemiological studies involving a large number of samples.
International Nuclear Information System (INIS)
Leontidis, V; Baldas, L; Colin, S; Brandner, J J
2012-01-01
The possibility to generate a gas flow inside a channel just by imposing a tangential temperature gradient along the walls without the existence of an initial pressure difference is well known. The gas must be under rarefied conditions, meaning that the system must operate between the slip and the free molecular flow regimes, either at low pressure or/and at micro/nano-scale dimensions. This phenomenon is at the basis of the operation principle of Knudsen pumps, which are actually compressors without any moving parts. Nowadays, gas flows in the slip flow regime through microchannels can be modeled using commercial Computational Fluid Dynamics softwares, because in this regime the compressible Navier-Stokes equations with appropriate boundary conditions are still valid. A simulation procedure has been developed for the modeling of thermal creep flow using ANSYS Fluent®. The implementation of the boundary conditions is achieved by developing User Defined Functions (UDFs) by means of C++ routines. The complete first order velocity slip boundary condition, including the thermal creep effects due to the axial temperature gradient and the effect of the wall curvature, and the temperature jump boundary condition are applied. The developed simulation tool is used for the preliminary design of Knudsen micropumps consisting of a sequence of curved and straight channels.
Luminescence characteristics and glow curves analysis of Cu"+ doped Li_3PO_4 phosphor
International Nuclear Information System (INIS)
Aghalte, G.A.; Dhoble, S.J.; Pawar, N.R.
2016-01-01
Li_3PO_4:Cu exhibits useful TL properties in personnel dosimetry of ionizing radiations. Cu is known to be one of the most efficient activator. The PL intensity is found to increase consistently with the increasing quenching temperature. Cu"+ doped Li_3PO_4 phosphor was synthesized by the wet chemical co-precipitation method. The crystal structure and particle morphology of the phosphor was investigated by using X-ray diffraction and scanning electron microscopy. Li_3PO_4:Cu is excellent phosphor for TL dosimetry. For the synthesis of Li_3PO_4:Cu phosphor the stoichiometric amounts of LiOH·H_2O and CuSO_4·"5H_2O were dissolved separately and then the solutions were mixed together. It was precipitated by using concentrated H_3PO_4. The precipitate was filtered out immediately and kept 12 hours below IR lamp. Prepared dry Li_3PO_4:Cu powder was then put on 2.5 wt% NH_4Cl in graphite crucible in preheated furnace at 800°C and was kept for 1 hour. It was then rapidly quenched to room temperature. Thermoluminescence (TL) glow curves were recorded on Nucleonix TL Reader with a heating rate of 2°C per second in the temperature range of 50-250°C. The PMT voltage was 750 volts. Photoluminescence (PL) studies were carried out by Hitachi F-4000 spectrophotometer with a spectral slit width of 1.5 nm
Experimental analysis of the power curve sensitivity test series at ROSA-III
International Nuclear Information System (INIS)
Koizumi, Y.; Iriko, M.; Yonomoto, T.; Tasaka, K.
1985-01-01
The rig of safety assessment (ROSA)-III facility is a volumetrically scaled (1/424) boiling water reactor (BWR/6) system with an electrically heated core designed for integral LOCA and ECCS tests. Seven recirculation pump suction line break LOCA experiments were conducted at the ROSA-III facility in order to examine the effect of the initial stored heat of a fuel rod on the peak cladding temperature (PCT). The break size was changed from 200% to 5% in the test series and a failure of a high pressure core spray (HPCS) diesel generator was assumed. Three power curves which represented conservative, realistic and zero initial stored heat, respectively, were used. In a large break LOCA such as 200% or 50% breaks, the initial stored heat in a fuel rod has a large effect on the cladding surface temperature because core uncovery occurs before all the initial stored heat is released, whereas in a small break LOCA such as a 5% break little effect is observed because core uncovery occurs after the initial stored heat is released. The maximum PCTs for the conservative initial stored heat case was 925 K, obtained in the 50% break experiment, and that for the realistic initial stored heat case was 835 K, obtained in the 5% break experiment. (orig./HP)
On-chip magnetic bead-based DNA melting curve analysis using a magnetoresistive sensor
International Nuclear Information System (INIS)
Rizzi, Giovanni; Østerberg, Frederik W.; Henriksen, Anders D.; Dufva, Martin; Hansen, Mikkel F.
2015-01-01
We present real-time measurements of DNA melting curves in a chip-based system that detects the amount of surface-bound magnetic beads using magnetoresistive magnetic field sensors. The sensors detect the difference between the amount of beads bound to the top and bottom sensor branches of the differential sensor geometry. The sensor surfaces are functionalized with wild type (WT) and mutant type (MT) capture probes, differing by a single base insertion (a single nucleotide polymorphism, SNP). Complementary biotinylated targets in suspension couple streptavidin magnetic beads to the sensor surface. The beads are magnetized by the field arising from the bias current passed through the sensors. We demonstrate the first on-chip measurements of the melting of DNA hybrids upon a ramping of the temperature. This overcomes the limitation of using a single washing condition at constant temperature. Moreover, we demonstrate that a single sensor bridge can be used to genotype a SNP. - Highlights: • We apply magnetoresistive sensors to study solid-surface hybridization kinetics of DNA. • We measure DNA melting profiles for perfectly matching DNA duplexes and for a single base mismatch. • We present a procedure to correct for temperature dependencies of the sensor output. • We reliably extract melting temperatures for the DNA hybrids. • We demonstrate direct measurement of differential binding signal for two probes on a single sensor
Post-Buckling Analysis of Curved Honeycomb Sandwich Panels Containing Interfacial Disbonds
Pineda, Evan J.; Bednarcyk, Brett A.; Krivanek, Thomas K.
2016-01-01
A numerical study on the effect of facesheet-core disbonds on the post-buckling response of curved honeycomb sandwich panels is presented herein. This work was conducted as part of the development of a damage tolerance plan for the next-generation Space Launch System heavy lift launch vehicle payload fairing. As such, the study utilized full-scale fairing barrel segments as the structure of interest. The panels were composed of carbon fiber reinforced polymer facesheets and aluminum honeycomb core. The panels were analyzed numerically using the finite element method incorporating geometric nonlinearity. In a predetermined circular region, facesheet and core nodes were detached to simulate a disbond, between the outer mold line facesheet and honeycomb core, induced via low-speed impact. Surface-to-surface contact in the disbonded region was invoked to prevent interpenetration of the facesheet and core elements and obtain realistic stresses in the core. The diameter of this disbonded region was varied and the effect of the size of the disbond on the post-buckling response was observed. Significant changes in the slope of the edge load-deflection response were used to determine the onset of global buckling and corresponding buckling load. Finally, several studies were conducted to determine the sensitivity of the numerical predictions to refinement in the finite element mesh.
Environmental Kuznets Curve in China: New evidence from dynamic panel analysis
International Nuclear Information System (INIS)
Li, Tingting; Wang, Yong; Zhao, Dingtao
2016-01-01
This paper applies a panel of 28 provinces of China from 1996 to 2012 to study the impacts of economic development, energy consumption, trade openness, and urbanization on the carbon dioxide, waste water, and waste solid emissions. By estimating a dynamic panel model with the system Generalized Method of Moments (GMM) estimator and an autoregressive distributed lag (ARDL) model with alternative panel estimators, respectively, we find that the Environmental Kuznets Curve (EKC) hypothesis is well supported for all three major pollutant emissions in China across different models and estimation methods. Our study also confirms positive effects of energy consumption on various pollutant emissions. In addition, we find some evidence that trade and urbanization may deteriorate environmental quality in the long run, albeit not in the short run. From policy perspective, our estimation results bode well for Chinese government's goal of capping greenhouse emissions by 2030 as outlined in the recent China-US climate accord, while containing energy consumption and harm effects from expanding trade and urbanization remains some environmental challenges that China faces. - Highlights: •We apply dynamic panel estimations to study the EKC hypothesis with Chinese panel data. •Our study covers three indicators: carbon dioxide, waste water, and waste solid emissions. •We find robust support for the EKC hypothesis for all three indicators of pollution. •Energy consumption has significantly positive effects on all three pollutant emissions. •Trade and urbanization may have harmful environmental impacts in the long run.
Harrysson, Iliana J; Cook, Jonathan; Sirimanna, Pramudith; Feldman, Liane S; Darzi, Ara; Aggarwal, Rajesh
2014-07-01
To determine how minimally invasive surgical learning curves are assessed and define an ideal framework for this assessment. Learning curves have implications for training and adoption of new procedures and devices. In 2000, a review of the learning curve literature was done by Ramsay et al and it called for improved reporting and statistical evaluation of learning curves. Since then, a body of literature is emerging on learning curves but the presentation and analysis vary. A systematic search was performed of MEDLINE, EMBASE, ISI Web of Science, ERIC, and the Cochrane Library from 1985 to August 2012. The inclusion criteria are minimally invasive abdominal surgery formally analyzing the learning curve and English language. 592 (11.1%) of the identified studies met the selection criteria. Time is the most commonly used proxy for the learning curve (508, 86%). Intraoperative outcomes were used in 316 (53%) of the articles, postoperative outcomes in 306 (52%), technical skills in 102 (17%), and patient-oriented outcomes in 38 (6%) articles. Over time, there was evidence of an increase in the relative amount of laparoscopic and robotic studies (P statistical evidence of a change in the complexity of analysis (P = 0.121). Assessment of learning curves is needed to inform surgical training and evaluate new clinical procedures. An ideal analysis would account for the degree of complexity of individual cases and the inherent differences between surgeons. There is no single proxy that best represents the success of surgery, and hence multiple outcomes should be collected.
Freetly, H C; Kuehn, L A; Cundiff, L V
2011-08-01
The objective of this study was to evaluate the growth curves of females to determine if mature size and relative rates of maturation among breeds differed. Body weight and hip height data were fitted to the nonlinear function BW = f(age) = A - Be(k×age), where A is an estimate of mature BW and k determines the rate that BW or height moves from B to A. Cows represented progeny from 28 Hereford, 38 Angus, 25 Belgian Blue, 34 Brahman, 8 Boran, and 9 Tuli sires. Bulls from these breeds were mated by AI to Angus, Hereford, and MARC III composite (1/4 Angus, 1/4 Hereford, 1/4 Red Poll, and 1/4 Pinzgauer) cows to produce calves in 1992, 1993, and 1994. These matings resulted in 516 mature cows whose growth curves were subsequently evaluated. Hereford-sired cows tended to have heavier mature BW, as estimated by parameter A, than Angus- (P=0.09) and Brahman-sired cows (P=0.06), and were heavier than the other breeds (P Angus-sired cows were heavier than Boran- (P Angus-sired cows did not differ from Brahman-sired cows (P=0.94). Brahman-sired cows had a heavier mature BW than Boran- (P Angus-sired cows matured faster (k) than cows sired by Hereford (P=0.03), Brahman (P Angus-sired cows (P=0.09), and had reached a greater proportion of their mature BW at puberty than had Hereford- (P < 0.001), Tuli- (P < 0.001), and Belgian Blue-sired cows (P < 0.001). Within species of cattle, the relative range in proportion of mature BW at puberty (Bos taurus 0.56 through 0.58, and Bos indicus 0.60) was highly conserved, suggesting that proportion of mature BW is a more robust predictor of age at puberty across breeds than is absolute weight or age. © 2011 American Society of Animal Science. All rights reserved.
Directory of Open Access Journals (Sweden)
Sidinei José Lopes
2007-10-01
Full Text Available O objetivo deste trabalho foi determinar o cronograma de amostragem de plantas de alface hidropônica, para ajuste de curvas de crescimento durante o período vegetativo. Foram realizados dois cultivos de alface, variedade Regina, de 8/9/2004 a 19/11/2004 (primavera/verão e 22/2/2005 a 24/5/2005 (verão/outono, em estufas de plástico do Dep. de Fitotecnia, da UFSM, Santa Maria, RS. A partir do ajuste do modelo co-seno com amostragem diária, registrada como padrão, diferentes intervalos entre as amostragens foram simulados para o ajuste do mesmo modelo. A fim de se encontrar o intervalo adequado, foi comparada a variância de falta de ajuste do modelo de amostragem diária com as variâncias de falta de ajuste dos modelos com diferentes intervalos de amostragens pelo teste F. Os cronogramas de amostragens para ajuste de curvas de crescimento de plantas de alface sob hidroponia, para experimentos de primavera/verão e verão/outono, possuem intervalos iguais a dois dias, para fitomassa seca total da planta e da folha; intervalos de quatro dias, para fitomassa de raiz; e, diariamente, para área foliar.The objective of this work was to determinate a sampling chronology to adjust lettuce hidroponic growth curves during its vegetative development. The variety Regina was grown from September 8, 2004 until November 19, 2004 (spring/summer and February 22, 2005 until May 24, 2005 (summer/fall. Plants were placed inside a plastic covered greenhouse in Santa Maria, RS, Brazil. Based on the adjusted cosine model, daily samples were taken as standard and different sampling intervals were simulated in order to better adjust the same model. To estimate de adequate sampling interval a comparison was conducted between the variance of lack of adjustment of the daily sampling with the variance of lack of adjustment of different samplings intervals using an F test. Sampling chronograms for adjusting crop growth curves of hydroponics lettuce plants for both
International Nuclear Information System (INIS)
Hong, Sungjun; Chung, Yanghon; Woo, Chungwon
2015-01-01
South Korea, as the 9th largest energy consuming in 2013 and the 7th largest greenhouse gas emitting country in 2011, established ‘Low Carbon Green Growth’ as the national vision in 2008, and is announcing various active energy policies that are set to gain the attention of the world. In this paper, we estimated the decrease of photovoltaic power generation cost in Korea based on the learning curve theory. Photovoltaic energy is one of the leading renewable energy sources, and countries all over the world are currently expanding R and D, demonstration and deployment of photovoltaic technology. In order to estimate the learning rate of photovoltaic energy in Korea, both conventional 1FLC (one-factor learning curve), which considers only the cumulative power generation, and 2FLC, which also considers R and D investment were applied. The 1FLC analysis showed that the cost of power generation decreased by 3.1% as the cumulative power generation doubled. The 2FCL analysis presented that the cost decreases by 2.33% every time the cumulative photovoltaic power generation is doubled and by 5.13% every time R and D investment is doubled. Moreover, the effect of R and D investment on photovoltaic technology took after around 3 years, and the depreciation rate of R and D investment was around 20%. - Highlights: • We analyze the learning effects of photovoltaic energy technology in Korea. • In order to calculate the learning rate, we use 1FLC (one-factor learning curve) and 2FLC methods, respectively. • 1FLC method considers only the cumulative power generation. • 2FLC method considers both cumulative power generation and knowledge stock. • We analyze a variety of scenarios by time lag and depreciation rate of R and D investment
Rapid screening for targeted genetic variants via high-resolution melting curve analysis.
Chambliss, Allison B; Resnick, Molly; Petrides, Athena K; Clarke, William A; Marzinke, Mark A
2017-03-01
Current methods for the detection of single nucleotide polymorphisms (SNPs) associated with aberrant drug-metabolizing enzyme function are hindered by long turnaround times and specialized techniques and instrumentation. In this study, we describe the development and validation of a high-resolution melting (HRM) curve assay for the rapid screening of variant genotypes for targeted genetic polymorphisms in the cytochrome P450 enzymes CYP2C9, CYP2C19, and CYP3A5. Sequence-specific primers were custom-designed to flank nine SNPs within the genetic regions of aforementioned drug metabolizing enzymes. PCR amplification was performed followed by amplicon denaturation by precise temperature ramping in order to distinguish genotypes by melting temperature (Tm). A standardized software algorithm was used to assign amplicons as 'reference' or 'variant' as compared to duplicate reference sequence DNA controls for each SNP. Intra-assay (n=5) precision of Tms for all SNPs was ≤0.19%, while inter-assay (n=20) precision ranged from 0.04% to 0.21%. When compared to a reference method of Sanger sequencing, the HRM assay produced no false negative results, and overcall frequency ranged from 0% to 26%, depending on the SNP. Furthermore, HRM genotyping displayed accuracy over input DNA concentrations ranging from 10 to 200 ng/μL. The presented assay provides a rapid method for the screening for genetic variants in targeted CYP450 regions with a result of 'reference' or 'variant' available within 2 h from receipt of extracted DNA. The method can serve as a screening approach to rapidly identify individuals with variant sequences who should be further investigated by reflexed confirmatory testing for aberrant cytochrome P450 enzymatic activity. Rapid knowledge of variant status may aid in the avoidance of adverse clinical events by allowing for dosing of normal metabolizer patients immediately while identifying the need to wait for confirmatory testing in those patients who are
Parametric analysis of fatigue crack growth
International Nuclear Information System (INIS)
Carden, A.E.
1975-01-01
The effect of temperature and frequency on fatigue crack growth were empirically observed and treated as a coefficient on a stress intensity factor term. The stress intensity factor term is a function of Ksub(max), Ksub(min) (or stress ratio) and a threshold K term. The apparent threshold values were selected in order to linearize the data. At 1000 0 F a constant da/dt (creep crack growth rate) is approached for cycle periods approaching 2000 s indicating a limiting and linear-inverse frequency effect. (author)
Footprint analysis during the growth period.
Volpon, J B
1994-01-01
Static footprints were obtained from 672 healthy white subjects ranging in age from newborn to 15 years. The length of the footprint was measured and the medial longitudinal arch was evaluated. The findings showed that the feet grew most rapidly up to 3 years of age. From age 3 onward, the feet maintained an almost constant growth rate, which was the same for both sexes until age 12 years, when girls' feet stopped growing, but boys' feet exhibited further growth. From birth up to 2 years of age, there was a higher incidence of flat feet. Rapid progression of plantar arch development was observed between 2 and 6 years of age.
Romano, N.; Petroselli, A.; Grimaldi, S.
2012-04-01
With the aim of combining the practical advantages of the Soil Conservation Service - Curve Number (SCS-CN) method and Green-Ampt (GA) infiltration model, we have developed a mixed procedure, which is referred to as CN4GA (Curve Number for Green-Ampt). The basic concept is that, for a given storm, the computed SCS-CN total net rainfall amount is used to calibrate the soil hydraulic conductivity parameter of the Green-Ampt model so as to distribute in time the information provided by the SCS-CN method. In a previous contribution, the proposed mixed procedure was evaluated on 100 observed events showing encouraging results. In this study, a sensitivity analysis is carried out to further explore the feasibility of applying the CN4GA tool in small ungauged catchments. The proposed mixed procedure constrains the GA model with boundary and initial conditions so that the GA soil hydraulic parameters are expected to be insensitive toward the net hyetograph peak. To verify and evaluate this behaviour, synthetic design hyetograph and synthetic rainfall time series are selected and used in a Monte Carlo analysis. The results are encouraging and confirm that the parameter variability makes the proposed method an appropriate tool for hydrologic predictions in ungauged catchments. Keywords: SCS-CN method, Green-Ampt method, rainfall excess, ungauged basins, design hydrograph, rainfall-runoff modelling.
Economic analysis of crystal growth in space
Ulrich, D. R.; Chung, A. M.; Yan, C. S.; Mccreight, L. R.
1972-01-01
Many advanced electronic technologies and devices for the 1980's are based on sophisticated compound single crystals, i.e. ceramic oxides and compound semiconductors. Space processing of these electronic crystals with maximum perfection, purity, and size is suggested. No ecomonic or technical justification was found for the growth of silicon single crystals for solid state electronic devices in space.
Growth and Inequality: A Meta-Analysis
de Groot, H.L.F.; de Dominicis, L.; Florax, R.J.G.M.
2008-01-01
In recent years there is a growing interest in determining the impact of inequality on economic growth. Theoretical papers as well as empirical applications have, however, produced controversial results. Although there is a considerable part of the literature that considers inequality detrimental to
Analysis, numerics, and optimization of algae growth
Kumar, K.; Pisarenco, M.; Rudnaya, M.; Savcenco, V.
2010-01-01
We extend the mathematical model for algae growth as described in [11] to include new effects. The roles of light, nutrients and acidity of the water body are taken into account. Important properties of the model such as existence and uniqueness of solution, as well as boundedness and positivity are
SECTORAL ANALYSIS: GROWTH ACCOUNTING OF TERTIARY INDUSTRIES
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Yahya Z. ALSHEHHI
2017-08-01
Full Text Available The tertiary sector is one of the modern styles of economic systems in view of the share it occupies in the field of production as well as employment occupied share. Hence, just like other lands, the UAE, witnessed an economic structural change similar to developed and developing nations, where the tertiary industries contributed 55.4% in 2015 to total country’s income. The empirical study aimed to analyze the contribution portion of growth in the tertiary industries through using the growth accounting framework in time-series from 1990 to 2015. The empirical study found that most of the industries contributed significantly to the growth of the tertiary sector. The contribution shares of growth due to labor and capital varied among industries. The main observed results show that there was a vice versa relationship between TFP performance and the size of labor, where the TFP positively corresponded with the decline in the size of labor specifically from 2010-2015.
Bleidorn, Wiebke; Kandler, Christian; Riemann, Rainer; Spinath, Frank M; Angleitner, Alois
2009-07-01
The present study examined the patterns and sources of 10-year stability and change of adult personality assessed by the 5 domains and 30 facets of the Revised NEO Personality Inventory. Phenotypic and biometric analyses were performed on data from 126 identical and 61 fraternal twins from the Bielefeld Longitudinal Study of Adult Twins (BiLSAT). Consistent with previous research, LGM analyses revealed significant mean-level changes in domains and facets suggesting maturation of personality. There were also substantial individual differences in the change trajectories of both domain and facet scales. Correlations between age and trait changes were modest and there were no significant associations between change and gender. Biometric extensions of growth curve models showed that 10-year stability and change of personality were influenced by both genetic as well as environmental factors. Regarding the etiology of change, the analyses uncovered a more complex picture than originally stated, as findings suggest noticeable differences between traits with respect to the magnitude of genetic and environmental effects. (PsycINFO Database Record (c) 2009 APA, all rights reserved).
Lv, Houning; Zhao, Ningning; Zheng, Zhongqing; Wang, Tao; Yang, Fang; Jiang, Xihui; Lin, Lin; Sun, Chao; Wang, Bangmao
2017-05-01
Peroral endoscopic myotomy (POEM) has emerged as an advanced technique for the treatment of achalasia, and defining the learning curve is mandatory. From August 2011 to June 2014, two operators in our institution (A&B) carried out POEM on 35 and 33 consecutive patients, respectively. Moving average and cumulative sum (CUSUM) methods were used to analyze the POEM learning curve for corrected operative time (cOT), referring to duration of per centimeter myotomy. Additionally, perioperative outcomes were compared among distinct learning curve phases. Using the moving average method, cOT reached a plateau at the 29th case and at the 24th case for operators A and B, respectively. CUSUM analysis identified three phases: initial learning period (Phase 1), efficiency period (Phase 2) and mastery period (Phase 3). The relatively smooth state in the CUSUM graph occurred at the 26th case and at the 24th case for operators A and B, respectively. Mean cOT of distinct phases for operator A were 8.32, 5.20 and 3.97 min, whereas they were 5.99, 3.06 and 3.75 min for operator B, respectively. Eckardt score and lower esophageal sphincter pressure significantly decreased during the 1-year follow-up period. Data were comparable regarding patient characteristics and perioperative outcomes. This single-center study demonstrated that expert endoscopists with experience in esophageal endoscopic submucosal dissection reached a plateau in learning of POEM after approximately 25 cases. © 2016 Japan Gastroenterological Endoscopy Society.
Bingga, Gali; Liu, Zhicheng; Zhang, Jianfeng; Zhu, Yujun; Lin, Lifeng; Ding, Shuangyang; Guo, Pengju
2014-01-01
A high resolution melting (HRM) curve method was developed to identify canine parvovirus type 2 (CPV-2) strains by nested PCR. Two sets of primers, CPV-426F/426R and CPV-87R/87F, were designed that amplified a 52 bp and 53 bp product from the viral VP2 capsid gene. The region amplified by CPV-426F/426R included the A4062G and T4064A mutations in CPV-2a, CPV-2b and CPV-2c. The region amplified by CPV-87F/87R included the A3045T mutation in the vaccine strains of CPV-2 and CPV-2a, CPV-2b and CPV-2c. Faecal samples were obtained from 30 dogs that were CPV antigen-positive. The DNA was isolated from the faecal samples and PCR-amplified using the two sets of primers, and genotyped by HRM curve analysis. The PCR-HRM assay was able to distinguish single nucleotide polymorphisms between CPV-2a, CPV-2b and CPV-2c using CPV-426F/426R. CPV-2a was distinguished from CPV-2b and CPV-2c by differences in the melting temperature. CPV-2b and CPV-2c could be distinguished based on the shape of the melting curve after generating heteroduplexes using a CPV-2b reference sample. The vaccine strains of CPV-2 were identified using CPV-87F/87R. Conventional methods for genotyping CPV strains are labor intensive, expensive or time consuming; the present PCR-based HRM assay might be an attractive alternative. Copyright © 2014 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Pistoia Vito
2008-10-01
Full Text Available Abstract Background Most microarray experiments are carried out with the purpose of identifying genes whose expression varies in relation with specific conditions or in response to environmental stimuli. In such studies, genes showing similar mean expression values between two or more groups are considered as not differentially expressed, even if hidden subclasses with different expression values may exist. In this paper we propose a new method for identifying differentially expressed genes, based on the area between the ROC curve and the rising diagonal (ABCR. ABCR represents a more general approach than the standard area under the ROC curve (AUC, because it can identify both proper (i.e., concave and not proper ROC curves (NPRC. In particular, NPRC may correspond to those genes that tend to escape standard selection methods. Results We assessed the performance of our method using data from a publicly available database of 4026 genes, including 14 normal B cell samples (NBC and 20 heterogeneous lymphomas (namely: 9 follicular lymphomas and 11 chronic lymphocytic leukemias. Moreover, NBC also included two sub-classes, i.e., 6 heavily stimulated and 8 slightly or not stimulated samples. We identified 1607 differentially expressed genes with an estimated False Discovery Rate of 15%. Among them, 16 corresponded to NPRC and all escaped standard selection procedures based on AUC and t statistics. Moreover, a simple inspection to the shape of such plots allowed to identify the two subclasses in either one class in 13 cases (81%. Conclusion NPRC represent a new useful tool for the analysis of microarray data.
Jalali-Heravi, Mehdi; Parastar, Hadi
2011-08-15
Essential oils (EOs) are valuable natural products that are popular nowadays in the world due to their effects on the health conditions of human beings and their role in preventing and curing diseases. In addition, EOs have a broad range of applications in foods, perfumes, cosmetics and human nutrition. Among different techniques for analysis of EOs, gas chromatography-mass spectrometry (GC-MS) is the most important one in recent years. However, there are some fundamental problems in GC-MS analysis including baseline drift, spectral background, noise, low S/N (signal to noise) ratio, changes in the peak shapes and co-elution. Multivariate curve resolution (MCR) approaches cope with ongoing challenges and are able to handle these problems. This review focuses on the application of MCR techniques for improving GC-MS analysis of EOs published between January 2000 and December 2010. In the first part, the importance of EOs in human life and their relevance in analytical chemistry is discussed. In the second part, an insight into some basics needed to understand prospects and limitations of the MCR techniques are given. In the third part, the significance of the combination of the MCR approaches with GC-MS analysis of EOs is highlighted. Furthermore, the commonly used algorithms for preprocessing, chemical rank determination, local rank analysis and multivariate resolution in the field of EOs analysis are reviewed. Copyright © 2011 Elsevier B.V. All rights reserved.
A finite element model for the stress and flexibility analysis of curved pipes
International Nuclear Information System (INIS)
Guerreiro, J.N.C.
1987-03-01
We present a finite element model for the analysis of pipe bends with flanged ends or flanged tangents. Comments are made on the consideration of the internal pressure load. Flexibility and stress instensification factores obtained with the present model are compared with others available. (Author) [pt
Brink, van den P.J.; Braak, ter C.J.F.
1999-01-01
In this paper a novel multivariate method is proposed for the analysis of community response data from designed experiments repeatedly sampled in time. The long-term effects of the insecticide chlorpyrifos on the invertebrate community and the dissolved oxygen (DO)–pH–alkalinity–conductivity
Economic Growth and Transboundary Pollution in Europe. An Empirical Analysis
Energy Technology Data Exchange (ETDEWEB)
Ansuategi, A. [Ekonomi Analisiaren Oinarriak I Saila, Ekonomi Zientzien Fakultatea, Lehendakari Agirre Etorbidea, 83, 48015 Bilbao (Spain)
2003-10-01
The existing empirical evidence suggests that environmental Kuznets curves only exist for pollutants with semi-local and medium term impacts. Ansuategi and Perrings (2000) have considered the behavioral basis for the correlation observed between different spatial incidence of environmental degradation and the relation between economic growth and environmental quality. They show that self-interested planners following a Nash-type strategy tend to address environmental effects sequentially: addressing those with the most immediate costs first, and those whose costs are displaced in space later. This paper tests such behavioral basis in the context of sulphur dioxide emissions in Europe.
Economic Growth and Transboundary Pollution in Europe. An Empirical Analysis
International Nuclear Information System (INIS)
Ansuategi, A.
2003-01-01
The existing empirical evidence suggests that environmental Kuznets curves only exist for pollutants with semi-local and medium term impacts. Ansuategi and Perrings (2000) have considered the behavioral basis for the correlation observed between different spatial incidence of environmental degradation and the relation between economic growth and environmental quality. They show that self-interested planners following a Nash-type strategy tend to address environmental effects sequentially: addressing those with the most immediate costs first, and those whose costs are displaced in space later. This paper tests such behavioral basis in the context of sulphur dioxide emissions in Europe
Directory of Open Access Journals (Sweden)
Ugur Ozturk
2016-07-01
Full Text Available Early-warning systems (EWSs are crucial to reduce the risk of landslide, especially where the structural measures are not fully capable of preventing the devastating impact of such an event. Furthermore, designing and successfully implementing a complete landslide EWS is a highly complex task. The main technical challenges are linked to the definition of heterogeneous material properties (geotechnical and geomechanical parameters as well as a variety of the triggering factors. In addition, real-time data processing creates a significant complexity, since data collection and numerical models for risk assessment are time consuming tasks. Therefore, uncertainties in the physical properties of a landslide together with the data management represent the two crucial deficiencies in an efficient landslide EWS. Within this study the application is explored of the concept of fragility curves to landslides; fragility curves are widely used to simulate systems response to natural hazards, i.e. floods or earthquakes. The application of fragility curves to landslide risk assessment is believed to simplify emergency risk assessment; even though it cannot substitute detailed analysis during peace-time. A simplified risk assessment technique can remove some of the unclear features and decrease data processing time. The method is based on synthetic samples which are used to define the approximate failure thresholds for landslides, taking into account the materials and the piezometric levels. The results are presented in charts. The method presented in this paper, which is called failure index fragility curve (FIFC, allows assessment of the actual real-time risk in a case study that is based on the most appropriate FIFC. The application of an FIFC to a real case is presented as an example. This method to assess the landslide risk is another step towards a more integrated dynamic approach to a potential landslide prevention system. Even if it does not define
Morphometric Analysis of Mandibular Growth in Skeletal Class III Malocclusion
Directory of Open Access Journals (Sweden)
Jenny Zwei-Chieng Chang
2006-01-01
Conclusion: We conclude that thin-plate spline analysis and the finite element morphometric method are efficient for the localization and quantification of size and shape changes that occur during mandibular growth. Plots of maximum and minimum principal directions can provide useful information about the trends of growth changes.
Energy Technology Data Exchange (ETDEWEB)
Aguilera, J.A.; Bengoechea, J.; Aragon, C. E-mail: carlos.aragon@unavarra.es
2003-02-03
The curves of growth (COG) of five Fe I lines emitted from a laser-induced plasma, generated with Fe-Ni alloys in air at atmospheric pressure, have been investigated. Spectral lines with different energy levels and line widths, emitted with a broad range of optical depths, have been included in the study in order to check the validity of theoretical models proposed for COG generation, based in the radiative transfer within a plasma in local thermodynamic equilibrium. The COGs have been measured at time windows of 4-5 {mu}s and 15-18 {mu}s. The Stark widths of the Fe I lines have been obtained, and the line widths have been determined by measuring the plasma electron density at the time windows selected. It is shown that at a time window of 4-5 {mu}s, the inhomogeneity of the plasma magnitudes has an important influence on the COGs of intense lines. For this time window, a two-region model of the plasma has been used to generate theoretical COGs that describe satisfactorily the experimental curves of all the lines using a single set of plasma parameters. The results reveal the existence of considerable gradients between the inner and the outer plasma regions in the temperature (9400-7800 K) and in the density of Fe atoms (4x10{sup 16}-0.02x10{sup 16} cm{sup -3} for a sample with 100% Fe). On the contrary, at the time window 15-18 {mu}s, at which the plasma has suffered most of its expansion and cooling process, the COGs of all the lines may be described by a single-region model, corresponding to a plasma with uniform temperature (6700 K) and density of Fe atoms (0.06x10{sup 16} cm{sup -3} for a sample with 100% Fe). It is also shown that at initial times, the plasma inhomogeneity has an important effect in the line profiles of intense spectral lines, which are described by using the two-region model of the laser-induced plasma.
Directory of Open Access Journals (Sweden)
Paulo Prochno
2004-07-01
Full Text Available Learning curves have been studied for a long time. These studies provided strong support to the hypothesis that, as organizations produce more of a product, unit costs of production decrease at a decreasing rate (see Argote, 1999 for a comprehensive review of learning curve studies. But the organizational mechanisms that lead to these results are still underexplored. We know some drivers of learning curves (ADLER; CLARK, 1991; LAPRE et al., 2000, but we still lack a more detailed view of the organizational processes behind those curves. Through an ethnographic study, I bring a comprehensive account of the first year of operations of a new automotive plant, describing what was taking place on in the assembly area during the most relevant shifts of the learning curve. The emphasis is then on how learning occurs in that setting. My analysis suggests that the overall learning curve is in fact the result of an integration process that puts together several individual ongoing learning curves in different areas throughout the organization. In the end, I propose a model to understand the evolution of these learning processes and their supporting organizational mechanisms.
A Short Integrated Presentation of Valuation, Profitability and Growth Analysis
DEFF Research Database (Denmark)
Pettersson, Kim; Sørensen, Ole
2016-01-01
We demonstrate how the valuation models used in finance theory and the profitability and growth analysis taught in financial statement analysis are related. Traditional textbooks on finance and financial statement analysis are often very comprehensive, comprising a vast number of chapters. However......, the learning cost associated to this seems to be that many students are unable to understand either the interrelations between the chapters in a financial statement analysis textbook, or the origins of financial information (i.e., financial statements) in applied finance. Thus, the underlying motivation...... of this teaching note is to highlight the purpose of profitability and growth analysis in financial statement analysis by incorporating the point of value relevance in applied finance. We hope this reduced presentation of valuation and profitability and growth analysis will help students to understand...
Energy Technology Data Exchange (ETDEWEB)
Salas C, P. [IMP, 07000 Mexico D.F. (Mexico); Estrada G, R. [Depto. de Fisica y Matematicas, UIA, Unidad Stanta Fe, 01000 Mexico D.F. (Mexico); Gonzalez M, P.R.; Mendoza A, D. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)
2003-07-01
In this work, we present a mathematical analysis of the behavior of the thermoluminescent curve (Tl) induced by gamma radiation in samples made of zirconium oxide doped with different amounts of graphite. In accordance with the results gamma radiation induces a Tl curve with two maximum of emission localized in the temperatures at 139 and 250 C, the area under the curve is increasing as a function of the time of exposition to the radiation. The analysis of curve deconvolution, in accordance with the theory which indicates that this behavior must be obey a Boltzmann distribution, we found that each one of them has a different growth velocity as the time of exposition increase. In the same way, we observed that after the irradiation was suspended each one of the maximum decrease with different velocity. The behaviour observed in the samples is very interesting because the zirconium oxide has attracted the interest of many research groups, this material has demonstrated to have many applications in thermoluminescent dosimetry and it can be used in the quantification of radiation. (Author)
Detection of icing on wind turbine blades by means of vibration and power curve analysis
DEFF Research Database (Denmark)
Skrimpas, Georgios Alexandros; Kleani, Karolina; Mijatovic, Nenad
2016-01-01
accelerometers and power performance analysis. Features extracted from these two techniques serve as inputs in a decision-making scheme, allowing early activation of de-icing systems or shut down of the wind turbine. An additional parameter is the month of operation, assuring consistent outcomes in both winter......Ice accretion on wind turbines' blades is one of the main challenges of systems installed in cold climate locations, resulting in power performance deterioration and excessive nacelle oscillation. In this work, consistent detection of icing events is achieved utilizing indications from the nacelle...
STRESS - STRAIN CURVE ANALYSIS OF WOVEN FABRICS MAD E FROM COMBED YARNS TYPE WOOL
VÎLCU Adrian; HRISTIAN Liliana; BORDEIANU Demetra L.; VÎLCU Catalin
2014-01-01
The paper analyses the tensile behavior of woven fabrics made from 45%Wool + 55% PES used for garments. Analysis of fabric behavior during wearing has shown that these are submitted to simple and repeated uni-axial or bi-axial tensile strains. The level of these strains is often within the elastic limit, rarely going over yielding. Therefore the designer must be able to evaluate the mechanical behavior of such fabrics in order to control the fabric behavior in the garment. This evaluation is ...