WorldWideScience

Sample records for alternative factor models

  1. Confirmatory Factor Analysis of the Structure of Statistics Anxiety Measure: An Examination of Four Alternative Models

    Directory of Open Access Journals (Sweden)

    Hossein Bevrani, PhD

    2011-09-01

    Full Text Available Objective: The aim of this study is to explore the confirmatory factor analysis results of the Persian adaptation of Statistics Anxiety Measure (SAM, proposed by Earp.Method: The validity and reliability assessments of the scale were performed on 298 college students chosen randomly from Tabriz University in Iran. Confirmatory factor analysis (CFA was carried out to determine the factor structures of the Persian adaptation of SAM.Results: As expected, the second order model provided a better fit to the data than the three alternative models. Conclusions: Hence, SAM provides an equally valid measure for use among college students. The study both expands and adds support to the existing body of math anxiety literature.

  2. Heritability of dimensions of Eysenck's pen model and the alternative five-factor model of personality

    Directory of Open Access Journals (Sweden)

    Smederevac Snežana

    2006-01-01

    Full Text Available The main aim of this study is to estimate the heritability of AFFM and PEN dimensions, including 67 pairs of twins (34 monozygotic and 33 dizygotic of both genders, aged 18 - 44. The heritability has been estimated by the biometric method, two full (ACE and ADE and three reduced (AE, DE and CE models tested for each personality trait. Taking into consideration the AFFM dimensions, additive genetic factors and a non-shared environment contribute the most significantly to the phenotypic variation of activity, sociability and the impulsive sensation seeking; anxiety and aggressiveness are best accounted for by the dominant genetic effects. In the PEN domain, fit indicators suggest that ACE and the reduced AE models provide the best explanation for the phenotypic manifestations of neuroticism, while ACE and CE models account for the variation of L scale. Although the fit indicators calculated for extraversion and psychotic behavior are somewhat problematic, the parameter estimates show that extraversion is best accounted for by the additive genetic variance, shared environmental effects, and the non-shared environment, whereas psychotic behavior is the most adequately explained by both shared and non-shared environmental effects.

  3. Morningness-eveningness, sex, and the Alternative Five Factor Model of personality.

    Science.gov (United States)

    Muro, Anna; Gomà-i-Freixanet, Montserrat; Adan, Ana

    2009-08-01

    Recent research on personality and circadian typology indicates that evening-type subjects are more extraverted, impulsive, and novelty-seeking, while morning ones tend to be more introverted, conscientious, agreeable, and emotionally stable. The purpose of this study was to examine the differences between circadian typologies on the Zuckerman's Alternative Five Factor Model of personality (AFFM), which has a strong biological basis, controlling for sex and age. A sample of 533 university students (168 men) participated in the study. Results showed that morning-type subjects had significant higher scores than evening-type and neither-type subjects in Activity, and in its subscales General Activity and Work Activity. A significant interaction between circadian typology and sex was found for Neuroticism-Anxiety: morning-type men showed higher scores than evening-type and neither-type, who had the lowest scores. Women presented the opposite pattern: neither-type obtained the highest scores, while morning-type showed the lowest. This is the first time the AFFM has been used in the context of circadian rhythms research. The results suggest that activity is the only trait related to extraversion associated with morningness, while Neuroticism-Anxiety was modulated by sex. These results might help highlight previous results on the association between morningness-eveningness and other models of personality assessment, and they offer new data that calls for further research.

  4. Circadian typology, age, and the alternative five-factor personality model in an adult women sample.

    Science.gov (United States)

    Muro, Anna; Gomà-i-Freixanet, Montserrat; Adan, Ana; Cladellas, Ramon

    2011-10-01

    Research on personality and circadian typology indicates evening-type women are more impulsive and novelty seeking, neither types are more anxious, and morning types tend to be more active, conscientious, and persistent. The purpose of this study is to examine the differences between circadian typologies in the light of the Zuckerman's Alternative Five-Factor Model (AFFM) of personality, which has a strong biological basis, in an adult sample of 412 women 18 to 55 yrs of age. The authors found morning-type women had significant higher scores than evening-type and neither-type women on Activity, and its subscales General Activity and Work Activity. In contrast, evening-type women scored significantly higher than morning-type women on Aggression-Hostility, Impulsive Sensation Seeking, and its subscale Sensation Seeking. In all groups, results were independent of age. These findings are in accordance with those previously obtained in female student samples and add new data on the AFFM. The need of using personality models that are biologically based in the study of circadian rhythms is discussed.

  5. Loneliness and solitude in adolescence: A confirmatory factor analysis of alternative models

    DEFF Research Database (Denmark)

    Goossens, Luc; Lasgaard, Mathias; Luyckx, Koen;

    2009-01-01

    The present study tested a four-factor model of adolescent loneliness and solitude that comprises peer-related loneliness, family loneliness, negative attitude toward solitude, and positive attitude toward solitude. Nine different instruments for a total of 14 scales and derivative subscales were...... of the Loneliness and Aloneness Scale for Children and Adolescents (LACA) is recommended, because the instrument measures all four aspects of the model. Implications for current theories on adolescent loneliness and associated phenomena, such as adolescents' attitude toward being on their own, are briefly discussed....

  6. Janez Rugelj's alternative therapeutic community after the five-factor model of personality

    Directory of Open Access Journals (Sweden)

    Judita Bagon

    2000-12-01

    Full Text Available The Alternative Therapeutic Community (ATC of Dr. J. Rugelj is a specific social community consisting of people in distress (always consisting of about 120 people, who have all been handicapped in their lives in one way or another. The group is also specific because of their way towards recovery, i.e., intensively reactivating the mecanisms of healthy life to surmount their psychical and social deficiency. The results of measuring the structure of personality according to BFQ – the "Big Five" model of personality – show that the ATC as a whole achieves lower scores than the normal population on all dimensions and subdimensions. The difference is statistically significant regarding the dimension of Emotional stability as well as the subdimension Emotional control. The ATC is not a uniform group, so the results differ according to the diagnosis. The members with the diagnosis of 'a neurotic' or 'a psychotic' achieve below-average results, while the accompanying members achieve similar results as the control group (selected from the non-members of the ATC. The results of the members diagnosed as 'an alcoholic' are somewhat surprising – they do not differ considerably on any dimension or subdimension from the results achieved by the control group – not even on the Emotional stability scale. As regards the total period of staying in the program, the results of subdimensions remain mostly unchanged. However, during the time spent in the program the results on the subdimensions change: the group which has been in the program for 1 to 2 years generally scores higher than the group of beginners (the difference is statistically significant only for the dimension Emotional control, but the results of the group participating in the program for longer time (more than three years are lower again, until they stabilize in the central position (T=50. The results on theHonesty scale (which may also show positive or negative self-image show no

  7. Convergence, Admissibility, and Fit of Alternative Confirmatory Factor Analysis Models for MTMM Data

    Science.gov (United States)

    Lance, Charles E.; Fan, Yi

    2016-01-01

    We compared six different analytic models for multitrait-multimethod (MTMM) data in terms of convergence, admissibility, and model fit to 258 samples of previously reported data. Two well-known models, the correlated trait-correlated method (CTCM) and the correlated trait-correlated uniqueness (CTCU) models, were fit for reference purposes in…

  8. Alternative tsunami models

    Energy Technology Data Exchange (ETDEWEB)

    Tan, A; Lyatskaya, I [Department of Physics, Alabama A and M University, Normal, AL 35762 (United States)], E-mail: arjun.tan@aamu.edu

    2009-01-15

    The interesting papers by Margaritondo (2005 Eur. J. Phys. 26 401) and by Helene and Yamashita (2006 Eur. J. Phys. 27 855) analysed the great Indian Ocean tsunami of 2004 using a simple one-dimensional canal wave model, which was appropriate for undergraduate students in physics and related fields of discipline. In this paper, two additional, easily understandable models, suitable for the same level of readership, are proposed: one, a two-dimensional model in flat space, and two, the same on a spherical surface. The models are used to study the tsunami produced by the central Kuril earthquake of November 2006. It is shown that the two alternative models, especially the latter one, give better representations of the wave amplitude, especially at far-flung locations. The latter model further demonstrates the enhancing effect on the amplitude due to the curvature of the Earth for far-reaching tsunami propagation.

  9. Alternate Gauge Electroweak Model

    CERN Document Server

    Dalton, Bill

    2010-01-01

    We describe an alternate gauge electroweak model that permits neutrinos with mass, and at the same time explains why right-handed neutrinos do not appear in weak interactions. This is a local gauge theory involving a space [V ] of three scalar functions. The standard Lagrangian density for the Yang-Mills field part and Higgs doublet remain invariant. A ma jor change is made in the transformation and corresponding Lagrangian density parts involving the right-handed leptons. A picture involving two types of right-handed leptons emerges. A dichotomy of matter on the [V ] space corresponds to coupled and uncoupled right-handed Leptons. Here, we describe a covariant dipole-mode solution in which the neutral bosons A{\\mu} and Z{\\mu} produce precessions on [V ]. The W {\\pm} {\\mu} bosons provide nutations on [V ], and consequently, provide transitions between the coupled and uncoupled regions. To elucidate the [V ] space matter dichotomy, and to generate the boson masses, we also provide an alternate potential Lagran...

  10. An Alternative to the Search for Single Polymorphisms: Toward Molecular Personality Scales for the Five-Factor Model

    Science.gov (United States)

    McCrae, Robert R.; Scally, Matthew; Terracciano, Antonio; Abecasis, Gonçalo R.; Costa, Paul T.

    2011-01-01

    There is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely-unsuccessful search for individual polymorphisms associated with personality traits, we identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two-thirds of a large (N = 3,972) sample of individuals from Sardinia who completed the Revised NEO Personality Inventory and were assessed in a genome-wide association scan. When MPSs were correlated with the phenotype in the remaining third of the sample, very small but significant associations were found for four of the five personality factors when the longest scales were examined. These data suggest that MPSs for Neuroticism, Openness to Experience, Agreeableness, and Conscientiousness (but not Extraversion) contain genetic information that can be refined in future studies, and the procedures described here should be applicable to other quantitative traits. PMID:21114353

  11. An alternative to the search for single polymorphisms: toward molecular personality scales for the five-factor model.

    Science.gov (United States)

    McCrae, Robert R; Scally, Matthew; Terracciano, Antonio; Abecasis, Gonçalo R; Costa, Paul T

    2010-12-01

    There is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely unsuccessful search for individual polymorphisms associated with personality traits, the authors identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two thirds of a large (N = 3,972) sample of individuals from Sardinia who completed the Revised NEO Personality Inventory (P. T. Costa, Jr., & R. R. McCrae, 1992) and were assessed in a genomewide association scan. When MPSs were correlated with the phenotype in the remaining one third of the sample, very small but significant associations were found for 4 of the 5e personality factors when the longest scales were examined. These data suggest that MPSs for Neuroticism, Openness to Experience, Agreeableness, and Conscientiousness (but not Extraversion) contain genetic information that can be refined in future studies, and the procedures described here should be applicable to other quantitative traits. PMID:21114353

  12. An Alternative to the Search for Single Polymorphisms: Toward Molecular Personality Scales for the Five-Factor Model

    OpenAIRE

    McCrae, Robert R.; Scally, Matthew; Terracciano, Antonio; Abecasis, Gonçalo R; Costa, Paul T.

    2010-01-01

    There is growing evidence that personality traits are affected by many genes, all of which have very small effects. As an alternative to the largely-unsuccessful search for individual polymorphisms associated with personality traits, we identified large sets of potentially related single nucleotide polymorphisms (SNPs) and summed them to form molecular personality scales (MPSs) with from 4 to 2,497 SNPs. Scales were derived from two-thirds of a large (N = 3,972) sample of individuals from Sar...

  13. Do different circadian typology measures modulate their relationship with personality? A test using the Alternative Five Factor Model.

    Science.gov (United States)

    Randler, Christoph; Gomà-i-Freixanet, Montserrat; Muro, Anna; Knauber, Christina; Adan, Ana

    2015-03-01

    The relationship between personality and circadian typology shows some inconsistent results and it has been hypothesized that the model used to measure personality might have a moderating effect on this relationship. However, it has never been explored if this inconsistency was dependent on the questionnaire used to measure differences in circadian rhythms as well. We explored this issue in a sample of 564 university students (32% men; 19-40 years) using the Zuckerman-Kuhlman Personality Questionnaire, which is based on an evolutionary-biological approach, in combination with the Composite Scale of Morningness (CSM) and the reduced Morningness-Eveningness Questionnaire (rMEQ). Both questionnaires detected differences between circadian typologies in Sociability (highest in evening types; ET) and Impulsive Sensation-Seeking scales (highest in ET), while the CSM also detected differences in Activity (lowest in ET) and Aggression-Hostility (highest in ET). Further, both questionnaires detected differences between circadian typologies in the subscales General Activity (morning types [MT] higher than ET), Impulsivity (ET highest) and Sensation-Seeking (highest in ET). Differences between circadian typologies/groups in the subscales Parties (highest in ET) and Isolation Intolerance (lowest in MT) were only detected by the rMEQ. The CSM clearly separated evening types from neither and morning types while the rMEQ showed that neither types are not intermediate but closer to evening types in General Activity and Isolation Intolerance, and closer to morning types in Impulsive Sensation-Seeking, Parties, Impulsivity and Sensation Seeking. The obtained results indicate that the relationship between circadian typology and personality may be dependent on the instrument used to assess circadian typology. This fact may help to explain some of the conflicting data available on the relationship between these two concepts.

  14. Scaled Quantum Mechanical scale factors for vibrational calculations using alternate polarized and augmented basis sets with the B3LYP density functional calculation model

    Science.gov (United States)

    Legler, C. R.; Brown, N. R.; Dunbar, R. A.; Harness, M. D.; Nguyen, K.; Oyewole, O.; Collier, W. B.

    2015-06-01

    The Scaled Quantum Mechanical (SQM) method of scaling calculated force constants to predict theoretically calculated vibrational frequencies is expanded to include a broad array of polarized and augmented basis sets based on the split valence 6-31G and 6-311G basis sets with the B3LYP density functional. Pulay's original choice of a single polarized 6-31G(d) basis coupled with a B3LYP functional remains the most computationally economical choice for scaled frequency calculations. But it can be improved upon with additional polarization functions and added diffuse functions for complex molecular systems. The new scale factors for the B3LYP density functional and the 6-31G, 6-31G(d), 6-31G(d,p), 6-31G+(d,p), 6-31G++(d,p), 6-311G, 6-311G(d), 6-311G(d,p), 6-311G+(d,p), 6-311G++(d,p), 6-311G(2d,p), 6-311G++(2d,p), 6-311G++(df,p) basis sets are shown. The double d polarized models did not perform as well and the source of the decreased accuracy was investigated. An alternate system of generating internal coordinates that uses the out-of plane wagging coordinate whenever it is possible; makes vibrational assignments via potential energy distributions more meaningful. Automated software to produce SQM scaled vibrational calculations from different molecular orbital packages is presented.

  15. Alternative Asymmetric Stochastic Volatility Models

    NARCIS (Netherlands)

    M. Asai (Manabu); M.J. McAleer (Michael)

    2010-01-01

    textabstractThe stochastic volatility model usually incorporates asymmetric effects by introducing the negative correlation between the innovations in returns and volatility. In this paper, we propose a new asymmetric stochastic volatility model, based on the leverage and size effects. The model is

  16. Alternative dimensional models of personality disorder

    DEFF Research Database (Denmark)

    Widiger, Thomas A; Simonsen, Erik

    2005-01-01

    The recognition of the many limitations of the categorical model of personality disorder classification has led to the development of quite a number of alternative proposals for a dimensional classification. The purpose of this article is to suggest that future research work toward the integration...... of these alternative proposals within a common hierarchical structure. An illustration of a potential integration is provided using the constructs assessed within existing dimensional models. Suggestions for future research that will help lead toward a common, integrative dimensional model of personality disorder...

  17. Modeling dative alternations of individual children

    OpenAIRE

    Bosch, A.P.J. van den; Bresnan, J.

    2015-01-01

    We address the question whether children can acquire mature use of higher-level grammatical choices from the linguistic input, given only general prior knowledge and learning biases. We do so on the basis of a case study with the dative alternation in English, building on a study by de Marneffe et al. (2012) who model the production of the dative alternation by seven young children, using data from the Child Language Data Exchange System corpus. Using mixed-effects logistic modelling on the a...

  18. Alternative Local Development models from the periphery

    Directory of Open Access Journals (Sweden)

    Mauricio Lopez Oropeza

    2013-09-01

    Full Text Available As neoliberal capitalism continues to fail on reducing inequities, and continues to fail on fulfilling its promise of a kind of “development” that would allow impoverished men and women to improve their situation and be able to experience a “freedom” which would empower them with new and better opportunities to vanish their many types of “poverties”, new and alternative models raise, presenting a different and inclusive type of development which intends to respond to their particular situations of exclusion and build on an alternative model.

  19. Factoring, a Financing Alternative for Romanian Exporters During Crisis

    OpenAIRE

    Dugan Silvia; Pepenel Madelaine-Lorelai

    2011-01-01

    Factoring, a product used in dynamic business environments worldwide, is a quick solution for the issue of working capital locked in the loan provider, ensuring a productive use of financial resources. During the economic crisis and given the very limited access to traditional financing schemes, factoring may be a suitable alternative for some companies in Romania, particularly those operating in the provision of goods or services. Factoring is therefore a solution to short-term finance compa...

  20. Alternative modeling schemes for propositional calculus problem

    Directory of Open Access Journals (Sweden)

    Anupama Chanda

    2016-08-01

    Full Text Available The main objective of this paper is to discuss alternative approaches to convert a propositional logic problem into a 0-1 integer program. The substitution method proposed by Williams and CNF method is used for modeling and representation of logical inference problem. The similarity between the two fields viz. optimization problems or mathematical programming and deductive logic are shown.

  1. ALTERNATIVE VALUE-AT-RISK MODELS FOR OPTIONS

    OpenAIRE

    Alfred Lehar

    2000-01-01

    Risk management has become an important issue for banks and corporations, not only because of regulation but also because of risk adjusted performance measurement. Value-at-risk has become an industry standard in risk measurement. The aim of this paper is to evaluate the performance of different value-at-risk models and find out the driving factors of model performance. While most previous studies focus on linear positions, this paper investigates the suitability of alternative approaches for...

  2. Alternative models for academic family practices

    Directory of Open Access Journals (Sweden)

    Yarnall Kimberly SH

    2006-03-01

    Full Text Available Abstract Background The Future of Family Medicine Report calls for a fundamental redesign of the American family physician workplace. At the same time, academic family practices are under economic pressure. Most family medicine departments do not have self-supporting practices, but seek support from specialty colleagues or hospital practice plans. Alternative models for academic family practices that are economically viable and consistent with the principles of family medicine are needed. This article presents several "experiments" to address these challenges. Methods The basis of comparison is a traditional academic family medicine center. Apart of the faculty practice plan, our center consistently operated at a deficit despite high productivity. A number of different practice types and alternative models of service delivery were therefore developed and tested. They ranged from a multi-specialty office arrangement, to a community clinic operated as part of a federally-qualified health center, to a team of providers based in and providing care for residents of an elderly public housing project. Financial comparisons using consistent accounting across models are provided. Results Academic family practices can, at least in some settings, operate without subsidy while providing continuity of care to a broad segment of the community. The prerequisites are that the clinicians must see patients efficiently, and be able to bill appropriately for their payer mix. Conclusion Experimenting within academic practice structure and organization is worthwhile, and can result in economically viable alternatives to traditional models.

  3. Alternating proximal gradient method for nonnegative matrix factorization

    CERN Document Server

    Xu, Yangyang

    2011-01-01

    Nonnegative matrix factorization has been widely applied in face recognition, text mining, as well as spectral analysis. This paper proposes an alternating proximal gradient method for solving this problem. With a uniformly positive lower bound assumption on the iterates, any limit point can be proved to satisfy the first-order optimality conditions. A Nesterov-type extrapolation technique is then applied to accelerate the algorithm. Though this technique is at first used for convex program, it turns out to work very well for the non-convex nonnegative matrix factorization problem. Extensive numerical experiments illustrate the efficiency of the alternating proximal gradient method and the accleration technique. Especially for real data tests, the accelerated method reveals high superiority to state-of-the-art algorithms in speed with comparable solution qualities.

  4. An alternative to the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Seungwon; Ko, Pyungwon; Park, Wan-Il [School of Physics, KIAS, Seoul 130-722 (Korea, Republic of)

    2014-06-24

    We present an extension of the standard model to dark sector with an unbroken local dark U(1){sub X} symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken U(1){sub X} case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1){sub X} is spontaneously broken, because of a mixing with a new neutral scalar boson in the models.

  5. Interest rates factor model

    Science.gov (United States)

    Lee, Sangwook; Kim, Min Jae; Kim, Soo Yong

    2011-07-01

    Interdependence of the interest rates of the US, the UK, and Japan is analyzed in this work by means of spectral analysis and network methods. A predominant effective factor in the interest rate market is which country floats a bond issue, and a minor effective factor is time to maturity of bonds. Power-law cross-correlation among different countries is analyzed by the detrended cross-correlation analysis method. Long-range cross-correlation is found between the first factors of interest rate, while there is no cross-correlation between some of the second factors. The tail dependency is indicated by tail indices from Archimedean copulas, including an empirical copula. In contrast to other pairs, the US-UK first factor pair has tail dependencies in both the upper-tail and lower-tail. Dynamic properties of interest rate are modeled by a stochastic volatility model. The properties of mean reverting and volatility clustering are observed and reflected in this model. The proposed simulation method combines the dependence structures and the factor dynamics model; it simultaneously describes the interest rates of different countries.

  6. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods...

  7. Candidiasis: predisposing factors, prevention, diagnosis and alternative treatment.

    Science.gov (United States)

    Martins, Natália; Ferreira, Isabel C F R; Barros, Lillian; Silva, Sónia; Henriques, Mariana

    2014-06-01

    Candidiasis is the most common opportunistic yeast infection. Candida species and other microorganisms are involved in this complicated fungal infection, but Candida albicans continues to be the most prevalent. In the past two decades, it has been observed an abnormal overgrowth in the gastrointestinal, urinary and respiratory tracts, not only in immunocompromised patients, but also related to nosocomial infections and even in healthy individuals. There is a widely variety of causal factors that contribute to yeast infection which means that candidiasis is a good example of a multifactorial syndrome. Due to rapid increase in the incidence in these infections, this is the subject of numerous studies. Recently, the focus of attention is the treatment and, above all, the prevention of those complications. The diagnosis of candidiasis could become quite complicated. Prevention is the most effective "treatment," much more than eradication of the yeast with antifungal agents. There are several aspects to consider in the daily routine that can provide a strength protection. However, a therapeutic approach is necessary when the infection is established, and therefore, other alternatives should be explored. This review provides an overview on predisposition factors, prevention and diagnosis of candidiasis, highlighting alternative approaches for candidiasis treatment.

  8. Cleavage factor Im (CFIm) as a regulator of alternative polyadenylation.

    Science.gov (United States)

    Hardy, Jessica G; Norbury, Chris J

    2016-08-15

    Most mammalian protein coding genes are subject to alternative cleavage and polyadenylation (APA), which can generate distinct mRNA 3'UTRs with differing regulatory potential. Although this process has been intensely studied in recent years, it remains unclear how and to what extent cleavage site selection is regulated under different physiological conditions. The cleavage factor Im (CFIm) complex is a core component of the mammalian cleavage machinery, and the observation that its depletion causes transcriptome-wide changes in cleavage site use makes it a key candidate regulator of APA. This review aims to summarize current knowledge of the CFIm complex, and explores the evidence surrounding its potential contribution to regulation of APA. PMID:27528751

  9. A hierarchical model for ordinal matrix factorization

    DEFF Research Database (Denmark)

    Paquet, Ulrich; Thomson, Blaise; Winther, Ole

    2012-01-01

    their ratings for other movies. The Netflix data set is used for evaluation, which consists of around 100 million ratings. Using root mean-squared error (RMSE) as an evaluation metric, results show that the suggested model outperforms alternative factorization techniques. Results also show how Gibbs sampling...

  10. SR 97. Alternative models project. Stochastic continuum modelling of Aberg

    Energy Technology Data Exchange (ETDEWEB)

    Widen, H. [Kemakta AB, Stockholm (Sweden); Walker, D. [INTERA KB/DE and S (Sweden)

    1999-08-01

    As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modelling approaches to bedrock performance assessment for a single hypothetical repository, arbitrarily named Aberg. The Aberg repository will adopt input parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The models are restricted to an explicit domain, boundary conditions and canister location to facilitate the comparison. The boundary conditions are based on the regional groundwater model provided in digital format. This study is the application of HYDRASTAR, a stochastic continuum groundwater flow and transport-modelling program. The study uses 34 realisations of 945 canister locations in the hypothetical repository to evaluate the uncertainty of the advective travel time, canister flux (Darcy velocity at a canister) and F-ratio. Several comparisons of variability are constructed between individual canister locations and individual realisations. For the ensemble of all realisations with all canister locations, the study found a median travel time of 27 years, a median canister flux of 7.1 x 10{sup -4} m/yr and a median F-ratio of 3.3 x 10{sup 5} yr/m. The overall pattern of regional flow is preserved in the site-scale model, as is reflected in flow paths and exit locations. The site-scale model slightly over-predicts the boundary fluxes from the single realisation of the regional model. The explicitly prescribed domain was seen to be slightly restrictive, with 6% of the stream tubes failing to exit the upper surface of the model. Sensitivity analysis and calibration are suggested as possible extensions of the modelling study.

  11. SR 97. Alternative models project. Stochastic continuum modelling of Aberg

    International Nuclear Information System (INIS)

    As part of studies into the siting of a deep repository for nuclear waste, Swedish Nuclear Fuel and Waste Management Company (SKB) has commissioned the Alternative Models Project (AMP). The AMP is a comparison of three alternative modelling approaches to bedrock performance assessment for a single hypothetical repository, arbitrarily named Aberg. The Aberg repository will adopt input parameters from the Aespoe Hard Rock Laboratory in southern Sweden. The models are restricted to an explicit domain, boundary conditions and canister location to facilitate the comparison. The boundary conditions are based on the regional groundwater model provided in digital format. This study is the application of HYDRASTAR, a stochastic continuum groundwater flow and transport-modelling program. The study uses 34 realisations of 945 canister locations in the hypothetical repository to evaluate the uncertainty of the advective travel time, canister flux (Darcy velocity at a canister) and F-ratio. Several comparisons of variability are constructed between individual canister locations and individual realisations. For the ensemble of all realisations with all canister locations, the study found a median travel time of 27 years, a median canister flux of 7.1 x 10-4 m/yr and a median F-ratio of 3.3 x 105 yr/m. The overall pattern of regional flow is preserved in the site-scale model, as is reflected in flow paths and exit locations. The site-scale model slightly over-predicts the boundary fluxes from the single realisation of the regional model. The explicitly prescribed domain was seen to be slightly restrictive, with 6% of the stream tubes failing to exit the upper surface of the model. Sensitivity analysis and calibration are suggested as possible extensions of the modelling study

  12. A proposal for a novel impact factor as an alternative to the JCR impact factor.

    Science.gov (United States)

    Yang, Zu-Guo; Zhang, Chun-Ting

    2013-12-03

    One disadvantage of the JCR impact factor, the most commonly used assessment tool for ranking and evaluating scientific journals, is its inability in distinguishing among different shapes of citation distribution curves, leading to unfair evaluation of journals in some cases. This paper aims to put forward an alternative impact factor (IF') that can properly reflect citation distributions. The two impact factors are linearly and positively correlated, and have roughly the same order of magnitude. Because of the ability of IF' in distinguishing among different shapes of citation distribution curves, IF' may properly reflect the academic performance of a scientific journal in a way that is different from the JCR impact factor with some unique features that reward journals with highly cited papers. Therefore, it is suggested that IF' could be used to complement the JCR impact factor.

  13. Modeling dative alternations of individual children

    NARCIS (Netherlands)

    Bosch, A.P.J. van den; Bresnan, J.

    2015-01-01

    We address the question whether children can acquire mature use of higher-level grammatical choices from the linguistic input, given only general prior knowledge and learning biases. We do so on the basis of a case study with the dative alternation in English, building on a study by de Marneffe et a

  14. Examining Pedestrian Injury Severity Using Alternative Disaggregate Models

    DEFF Research Database (Denmark)

    Abay, Kibrom Araya

    2013-01-01

    This paper investigates the injury severity of pedestrians considering detailed road user characteristics and alternative model specification using a high-quality Danish road accident data. Such detailed and alternative modeling approach helps to assess the sensitivity of empirical inferences to ...

  15. A methodology for assessing the market benefits of alternative motor fuels: The Alternative Fuels Trade Model

    Energy Technology Data Exchange (ETDEWEB)

    Leiby, P.N.

    1993-09-01

    This report describes a modeling methodology for examining the prospective economic benefits of displacing motor gasoline use by alternative fuels. The approach is based on the Alternative Fuels Trade Model (AFTM). AFTM development was undertaken by the US Department of Energy (DOE) as part of a longer term study of alternative fuels issues. The AFTM is intended to assist with evaluating how alternative fuels may be promoted effectively, and what the consequences of substantial alternative fuels use might be. Such an evaluation of policies and consequences of an alternative fuels program is being undertaken by DOE as required by Section 502(b) of the Energy Policy Act of 1992. Interest in alternative fuels is based on the prospective economic, environmental and energy security benefits from the substitution of these fuels for conventional transportation fuels. The transportation sector is heavily dependent on oil. Increased oil use implies increased petroleum imports, with much of the increase coming from OPEC countries. Conversely, displacement of gasoline has the potential to reduce US petroleum imports, thereby reducing reliance on OPEC oil and possibly weakening OPEC`s ability to extract monopoly profits. The magnitude of US petroleum import reduction, the attendant fuel price changes, and the resulting US benefits, depend upon the nature of oil-gas substitution and the supply and demand behavior of other world regions. The methodology applies an integrated model of fuel market interactions to characterize these effects.

  16. TAFV Alternative Fuels and Vehicles Choice Model Documentation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L.

    2001-07-27

    A model for predicting choice of alternative fuel and among alternative vehicle technologies for light-duty motor vehicles is derived. The nested multinomial logit (NML) mathematical framework is used. Calibration of the model is based on information in the existing literature and deduction based on assuming a small number of key parameters, such as the value of time and discount rates. A spreadsheet model has been developed for calibration and preliminary testing of the model.

  17. Alternative Instructional Models for IVN Delivery.

    Science.gov (United States)

    Jackman, Diane H.; Swan, Michael K.

    This handbook identifies the instructional models found to be effective for distance education using the Interactive Video Network (IVN) system. Each model is summarized briefly and followed by specific suggestions for the use of the model over the IVN system. For each model, information is given on instructor responsibility prior to, during, and…

  18. Supermodeling by Synchronization of Alternative SPEEDO Models

    Science.gov (United States)

    Duane, Gregory; Selten, Frank

    2016-04-01

    The supermodeling approach, wherein different imperfect models of the same objective process are dynamically combined in run-time to reduce systematic error, is tested using SPEEDO - a primitive equation atmospheric model coupled to the CLIO ocean model. Three versions of SPEEDO are defined by parameters that differ in a range that arguably mimics differences among state-of-the-art climate models. A fourth model is taken to represent truth. The "true" ocean drives all three model atmospheres. The three models are also connected to one another at every level, with spatially uniform nudging coefficients that are trained so that the three models, which synchronize with one another, also synchronize with truth when data is continuously assimilated, as in weather prediction. The SPEEDO supermodel is evaluated in weather-prediction mode, with nudging to truth. It is found that the supemodel performs better than any of the three models and marginally better than the best weighted average of the outputs of the three models run separately. To evaluate the utility for climate projection, parameters corresponding to green house gas levels are changed in truth and in the three models. The supermodel formed with inter-model connections from the present-CO2 runs no longer give the optimal configuration for the supermodel in the doubled-CO2 realm, but the supermodel with the previously trained connections is still useful as compared to the separate models or averages of their outputs. In ongoing work, a training algorithm is examined that attempts to match the blocked-zonal index cycle of the SPEEDO model atmosphere to truth, rather than simply minimizing the RMS error in the various fields. Such an approach comes closer to matching the model attractor to the true attractor - the desired effect in climate projection - rather than matching instantaneous states. Gradient descent in a cost function defined over a finite temporal window can indeed be done efficiently. Preliminary

  19. Prediction of survival with alternative modeling techniques using pseudo values

    NARCIS (Netherlands)

    T. van der Ploeg (Tjeerd); F.R. Datema (Frank); R.J. Baatenburg de Jong (Robert Jan); E.W. Steyerberg (Ewout)

    2014-01-01

    textabstractBackground: The use of alternative modeling techniques for predicting patient survival is complicated by the fact that some alternative techniques cannot readily deal with censoring, which is essential for analyzing survival data. In the current study, we aimed to demonstrate that pseudo

  20. Auxiliary splice factor U2AF26 and transcription factor Gfi1 cooperate directly in regulating CD45 alternative splicing.

    NARCIS (Netherlands)

    Heyd, F.; Dam, G.B. ten; Moroy, T.

    2006-01-01

    By alternative splicing, different isoforms of the transmembrane tyrosine phosphatase CD45 are generated that either enhance or limit T cell receptor signaling. We report here that CD45 alternative splicing is regulated by cooperative action of the splice factor U2AF26 and the transcription factor G

  1. Bayesian Factor Analysis as a Variable-Selection Problem: Alternative Priors and Consequences.

    Science.gov (United States)

    Lu, Zhao-Hua; Chow, Sy-Miin; Loken, Eric

    2016-01-01

    Factor analysis is a popular statistical technique for multivariate data analysis. Developments in the structural equation modeling framework have enabled the use of hybrid confirmatory/exploratory approaches in which factor-loading structures can be explored relatively flexibly within a confirmatory factor analysis (CFA) framework. Recently, Muthén & Asparouhov proposed a Bayesian structural equation modeling (BSEM) approach to explore the presence of cross loadings in CFA models. We show that the issue of determining factor-loading patterns may be formulated as a Bayesian variable selection problem in which Muthén and Asparouhov's approach can be regarded as a BSEM approach with ridge regression prior (BSEM-RP). We propose another Bayesian approach, denoted herein as the Bayesian structural equation modeling with spike-and-slab prior (BSEM-SSP), which serves as a one-stage alternative to the BSEM-RP. We review the theoretical advantages and disadvantages of both approaches and compare their empirical performance relative to two modification indices-based approaches and exploratory factor analysis with target rotation. A teacher stress scale data set is used to demonstrate our approach. PMID:27314566

  2. Bayesian Factor Analysis as a Variable-Selection Problem: Alternative Priors and Consequences.

    Science.gov (United States)

    Lu, Zhao-Hua; Chow, Sy-Miin; Loken, Eric

    2016-01-01

    Factor analysis is a popular statistical technique for multivariate data analysis. Developments in the structural equation modeling framework have enabled the use of hybrid confirmatory/exploratory approaches in which factor-loading structures can be explored relatively flexibly within a confirmatory factor analysis (CFA) framework. Recently, Muthén & Asparouhov proposed a Bayesian structural equation modeling (BSEM) approach to explore the presence of cross loadings in CFA models. We show that the issue of determining factor-loading patterns may be formulated as a Bayesian variable selection problem in which Muthén and Asparouhov's approach can be regarded as a BSEM approach with ridge regression prior (BSEM-RP). We propose another Bayesian approach, denoted herein as the Bayesian structural equation modeling with spike-and-slab prior (BSEM-SSP), which serves as a one-stage alternative to the BSEM-RP. We review the theoretical advantages and disadvantages of both approaches and compare their empirical performance relative to two modification indices-based approaches and exploratory factor analysis with target rotation. A teacher stress scale data set is used to demonstrate our approach.

  3. Constraints on alternative models to dark energy

    International Nuclear Information System (INIS)

    Recent observations of type Ia supernovae strongly support that the universe is accelerating now and decelerated in the recent past. This may be evidence of the breakdown of the standard Friedmann equation. We consider a general modified Friedmann equation. Three different models are analysed in detail. The current supernova data and the Wilkinson microwave anisotropy probe data are used to constrain these models. A detailed analysis of the transition from the deceleration to acceleration phase is also performed

  4. Implications of Alternative Operational Risk Modeling Techniques

    OpenAIRE

    Patrick de Fontnouvelle; Eric Rosengren; John Jordan

    2005-01-01

    Quantification of operational risk has received increased attention with the inclusion of an explicit capital charge for operational risk under the new Basle proposal. The proposal provides significant flexibility for banks to use internal models to estimate their operational risk, and the associated capital needed for unexpected losses. Most banks have used variants of value at risk models that estimate frequency, severity, and loss distributions. This paper examines the empirical regulariti...

  5. An alternative QSAR-based approach for predicting the bioconcentration factor for regulatory purposes.

    Science.gov (United States)

    Gissi, Andrea; Gadaleta, Domenico; Floris, Matteo; Olla, Stefania; Carotti, Angelo; Novellino, Ettore; Benfenati, Emilio; Nicolotti, Orazio

    2014-01-01

    The REACH (Registration, Evaluation, Authorization and restriction of Chemicals) and BPR (Biocide Product Regulation) regulations strongly promote the use of non-animal testing techniques to evaluate chemical risk. This has renewed the interest towards alternative methods such as QSAR in the regulatory context. The assessment of Bioconcentration Factor (BCF) required by these regulations is expensive, in terms of costs, time, and laboratory animal sacrifices. Herein, we present QSAR models based on the ANTARES dataset, which is a large collection of known and verified experimental BCF data. Among the models developed, the best results were obtained from a nine-descriptor highly predictive model. This model was derived from a training set of 608 chemicals and challenged against a validation and blind set containing 152 and 76 chemicals. The model's robustness was further controlled through several validation strategies and the implementation of a multi-step approach for the applicability domain. Suitable safety margins were used to increase sensitivity. The easy interpretability of the model is ensured by the use of meaningful biokinetics descriptors. The satisfactory predictive power for external compounds suggests that the new models could represent a reliable alternative to the in vivo assay, helping the registrants to fulfill regulatory requirements in compliance with the ethical and economic necessity to reduce animal testing. PMID:24247988

  6. Big bang nucleosynthesis - The standard model and alternatives

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    The standard homogeneous-isotropic calculation of the big bang cosmological model is reviewed, and alternate models are discussed. The standard model is shown to agree with the light element abundances for He-4, H-2, He-3, and Li-7 that are available. Improved observational data from recent LEP collider and SLC results are discussed. The data agree with the standard model in terms of the number of neutrinos, and provide improved information regarding neutron lifetimes. Alternate models are reviewed which describe different scenarios for decaying matter or quark-hadron induced inhomogeneities. The baryonic density relative to the critical density in the alternate models is similar to that of the standard model when they are made to fit the abundances. This reinforces the conclusion that the baryonic density relative to critical density is about 0.06, and also reinforces the need for both nonbaryonic dark matter and dark baryonic matter.

  7. USE OF NON-MAMMALIAN ALTERNATIVE MODELS FOR NEUROTOXICOLOGICAL STUDY

    OpenAIRE

    Peterson, Randall T.; Nass, Richard; Boyd, Windy A; Jonathan H Freedman; Dong, Ke; Narahashi, Toshio

    2008-01-01

    The field of neurotoxicology needs to satisfy two opposing demands: the testing of a growing list of chemicals, and resource limitations and ethical concerns associated with testing using traditional mammalian species. National and international government agencies have defined a need to reduce, refine or replace mammalian species in toxicological testing with alternative testing methods and non-mammalian models. Toxicological assays using alternative animal models may relieve some of this pr...

  8. An alternative to multiregional two-sex model.

    Science.gov (United States)

    Nath, D C; Datta, J

    1992-01-01

    Factors such as female fertility, male fertility, female survival rate, and male survival rate affect the replacement of the present generation by the next generation. This realization led to the formulation of the two-sex population model to replace the one-sex model based on age composition of females alone. In 1975 Rogers introduced the study of one-sex multiregional stable population. In 1987 Nath extended the study of multiregional stable population to two-sex cases. An alternative approach of incorporating the age structure of both the sexes, considering age difference of parents and making use of sex ratio(s), making certain assumptions on female birth rates of the regions constituting the multiregional stable population, was employed to obtain a few female birth models that become stable. In the 4 models the effect on the female birth trajectory was studies using: 1) constant age difference between the parents when the survivors of male cohort are obtained from male cohort; 2) variable age difference between the parents as in 1) ; ; 3) constant age difference between the parents when survivors of male cohort are obtained from survivors of female cohort; and 4) variable age difference between the parents as in 3). The analyzed 4 models consist of female birth models of a multiregional stable population reflecting the effect of constant/variable age difference of parents when survivors of male cohort are obtained from male/female cohort. Models obtained are neither ordinary one-sex models nor ordinary two-sex models. In all the models paternity linked maternity (PLM) function was obtained in place of simple maternity function of the one-sex model and net parenthood function of the two-sex model. With the help of the PLM function, forecasts on future births can be made. As data for PLM function can be obtained more easily than those for net parenthood function, it is expected that the above models will be more suitable for practical applications than the

  9. Developing an Alternative Model for Dental Education.

    Science.gov (United States)

    Rayborn, G. Wayne; And Others

    1996-01-01

    The restructuring of the oral health sciences program at the University of Alberta (Canada), in response to drastically reduced funding, is described. Major objectives were to reduce program cost to the university and enhance the institution's scholarly/research profile. The model, used in other countries, separates clinical from academic costs.…

  10. Modeling Equity for Alternative Water Rate Structures

    Science.gov (United States)

    Griffin, R.; Mjelde, J.

    2011-12-01

    The rising popularity of increasing block rates for urban water runs counter to mainstream economic recommendations, yet decision makers in rate design forums are attracted to the notion of higher prices for larger users. Among economists, it is widely appreciated that uniform rates have stronger efficiency properties than increasing block rates, especially when volumetric prices incorporate intrinsic water value. Yet, except for regions where water market purchases have forced urban authorities to include water value in water rates, economic arguments have weakly penetrated policy. In this presentation, recent evidence will be reviewed regarding long term trends in urban rate structures while observing economic principles pertaining to these choices. The main objective is to investigate the equity of increasing block rates as contrasted to uniform rates for a representative city. Using data from four Texas cities, household water demand is established as a function of marginal price, income, weather, number of residents, and property characteristics. Two alternative rate proposals are designed on the basis of recent experiences for both water and wastewater rates. After specifying a reasonable number (~200) of diverse households populating the city and parameterizing each household's characteristics, every household's consumption selections are simulated for twelve months. This procedure is repeated for both rate systems. Monthly water and wastewater bills are also computed for each household. Most importantly, while balancing the budget of the city utility we compute the effect of switching rate structures on the welfares of households of differing types. Some of the empirical findings are as follows. Under conditions of absent water scarcity, households of opposing characters such as low versus high income do not have strong preferences regarding rate structure selection. This changes as water scarcity rises and as water's opportunity costs are allowed to

  11. Modeling and Solving Alternative Financial Solutions Seeking

    OpenAIRE

    Frenod, Emmanuel; Gouigoux, Jean-Philippe; Touré, Landry

    2015-01-01

    International audience In this paper we build a method to optimize Multi-Year Prospective Budgets. First we present a systemic model of Local Community Finances. Then, from two acceptable Multi-Year Prospective Budgets the method implements a Genetic Algorithm to generate a collection of admissible Multi-Year Prospective Budgets among which Decision-Makers can choose. The method is tested on simplified cases and on in operational situation and gives satisfactory results.

  12. Alternative pre-mRNA splicing in Drosophila spliceosomal assembly factor RNP-4F during development.

    Science.gov (United States)

    Fetherson, Rebecca A; Strock, Stephen B; White, Kristen N; Vaughn, Jack C

    2006-04-26

    The 5'- and 3'-UTR regions in pre-mRNAs play a variety of roles in controlling eukaryotic gene expression, including translational modulation. Here we report the results of a systematic study of alternative splicing in rnp-4f, which encodes a Drosophila spliceosomal assembly factor. We show that most of the nine introns are constitutively spliced, but several patterns of alternative splicing are observed in two pre-mRNA regions including the 5'-UTR. Intron V is shown to be of recent evolutionary origin and is infrequently spliced, resulting in generation of an in-frame stop codon and a predicted truncated protein lacking a nuclear localization signal, so that alternative splicing regulates its subcellular localization. Intron 0, located in the 5'-UTR, is subject to three different splicing decisions in D. melanogaster. Northern analysis of poly(A+) mRNAs reveals two differently sized rnp-4f mRNA isoforms in this species. A switch in relative isoform abundance occurs during mid-embryo stages, when the larger isoform becomes more abundant. This isoform is shown to represent intron 0 unspliced mRNA, whereas the smaller transcript represents the product of alternative splicing. Comparative genomic analysis predicts that intron 0 is present in diverse Drosophila species. Intron 0 splicing results in loss of an evolutionarily conserved stem-loop constituting a potential cis-regulatory element at the 3'-splice site. A model is proposed for the role of this element both in 5'-UTR alternative splicing decisions and in RNP-4F translational modulation. Preliminary evidences in support of our model are discussed.

  13. Alternative models for restructuring Ontario's electric sector

    International Nuclear Information System (INIS)

    The future of Ontario Hydro and the provincial electrical sector was discussed. Various models proposed for restructuring Ontario's electric sector were described and views of some of the stake holders were presented, among them the views of AMPCO, MEA, the Ontario Chamber of Commerce, IPPSO, Ontario Hydro Management, Energy Probe and the Power Workers' Union. In general, most stake holders were in favour of privatization to some degree except for the Power Workers' Union which was unalterably opposed to privatization, claiming that it would lead to quantum increases in electricity rates. 2 figs

  14. Alternative Dark Energy Models: An Overview

    CERN Document Server

    Lima, J A S

    2004-01-01

    A large number of recent observational data strongly suggest that we live in a flat, accelerating Universe composed of $\\sim$ 1/3 of matter (baryonic + dark) and $\\sim$ 2/3 of an exotic component with large negative pressure, usually named {\\bf Dark Energy} or {\\bf Quintessence}. The basic set of experiments includes: observations from SNe Ia, CMB anisotropies, large scale structure, X-ray data from galaxy clusters, age estimates of globular clusters and old high redshift galaxies (OHRG's). Such results seem to provide the remaining piece of information connecting the inflationary flatness prediction ($\\Omega_{\\rm{T}} = 1$) with astronomical observations. Theoretically, they have also stimulated the current interest for more general models containing an extra component describing this unknown dark energy, and simultaneously accounting for the present accelerating stage of the Universe. An overlook in the literature shows that at least five dark energy candidates have been proposed in the context of general re...

  15. Modeling the Effects of Harvest Alternatives on Mitigating Oak Decline in a Central Hardwood Forest Landscape.

    Directory of Open Access Journals (Sweden)

    Wen J Wang

    Full Text Available Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removing susceptible species and declining trees. However, the long-term, landscape-scale effects of these different harvest alternatives are not well studied because of the limited availability of experimental data. In this study, we applied a forest landscape model in combination with field studies to evaluate the effects of the three harvest alternatives on mitigating oak decline in a Central Hardwood Forest landscape. Results showed that the potential oak decline in high risk sites decreased strongly in the next five decades irrespective of harvest alternatives. This is because oak decline is a natural process and forest succession (e.g., high tree mortality resulting from intense competition would eventually lead to the decrease in oak decline in this area. However, forest harvesting did play a role in mitigating oak decline and the effectiveness varied among the three harvest alternatives. The group selection and clearcutting alternatives were most effective in mitigating oak decline in the short and medium terms, respectively. The long-term effects of the three harvest alternatives on mitigating oak decline became less discernible as the role of succession increased. The thinning alternative had the highest biomass retention over time, followed by the group selection and clearcutting alternatives. The group selection alternative that balanced treatment effects and retaining biomass was the most viable alternative for managing oak decline. Insights from this study may be useful in developing effective and informed forest harvesting plans for managing oak

  16. Alternatives to Multilevel Modeling for the Analysis of Clustered Data

    Science.gov (United States)

    Huang, Francis L.

    2016-01-01

    Multilevel modeling has grown in use over the years as a way to deal with the nonindependent nature of observations found in clustered data. However, other alternatives to multilevel modeling are available that can account for observations nested within clusters, including the use of Taylor series linearization for variance estimation, the design…

  17. Increased dosage of Dyrk1A alters alternative splicing factor (ASF)-regulated alternative splicing of tau in Down syndrome.

    Science.gov (United States)

    Shi, Jianhua; Zhang, Tianyi; Zhou, Chunlei; Chohan, Muhammad Omar; Gu, Xiaosong; Wegiel, Jerzy; Zhou, Jianhua; Hwang, Yu-Wen; Iqbal, Khalid; Grundke-Iqbal, Inge; Gong, Cheng-Xin; Liu, Fei

    2008-10-17

    Two groups of tau, 3R- and 4R-tau, are generated by alternative splicing of tau exon 10. Normal adult human brain expresses equal levels of them. Disruption of the physiological balance is a common feature of several tauopathies. Very early in their life, individuals with Down syndrome (DS) develop Alzheimer-type tau pathology, the molecular basis for which is not fully understood. Here, we demonstrate that Dyrk1A, a kinase encoded by a gene in the DS critical region, phosphorylates alternative splicing factor (ASF) at Ser-227, Ser-234, and Ser-238, driving it into nuclear speckles and preventing it from facilitating tau exon 10 inclusion. The increased dosage of Dyrk1A in DS brain due to trisomy of chromosome 21 correlates to an increase in 3R-tau level, which on abnormal hyperphosphorylation and aggregation of tau results in neurofibrillary degeneration. Imbalance of 3R- and 4R-tau in DS brain by Dyrk1A-induced dysregulation of alternative splicing factor-mediated alternative splicing of tau exon 10 represents a novel mechanism of neurofibrillary degeneration and may help explain early onset tauopathy in individuals with DS.

  18. Male infertility: lifestyle factors and holistic, complementary, and alternative therapies

    Science.gov (United States)

    Yao, David F; Mills, Jesse N

    2016-01-01

    While we may be comfortable with an allopathic approach to male infertility, we are also responsible for knowledge about lifestyle modifications and holistic, complementary, and alternative therapies that are used by many of our patients. This paper provides an evidence-based review separating fact from fiction for several of these therapies. There is sufficient literature to support weight reduction by diet and exercise, smoking cessation, and alcohol moderation. Supplements that have demonstrated positive effects on male fertility on small randomized controlled trial (RCT) include aescin, coenzyme Q10, glutathione, Korean red ginseng, L-carnitine, nigella sativa, omega-3, selenium, a combination of zinc and folate, and the Menevit antioxidant. There is no support for the use of Vitamin C, Vitamin E, or saffron. The data for Chinese herbal medications, acupuncture, mind-body practice, scrotal cooling, and faith-based healing are sparse or inconclusive. PMID:26952957

  19. Male infertility: lifestyle factors and holistic, complementary, and alternative therapies

    Directory of Open Access Journals (Sweden)

    David F Yao

    2016-01-01

    Full Text Available While we may be comfortable with an allopathic approach to male infertility, we are also responsible for knowledge about lifestyle modifications and holistic, complementary, and alternative therapies that are used by many of our patients. This paper provides an evidence-based review separating fact from fiction for several of these therapies. There is sufficient literature to support weight reduction by diet and exercise, smoking cessation, and alcohol moderation. Supplements that have demonstrated positive effects on male fertility on small randomized controlled trial (RCT include aescin, coenzyme Q 10 , glutathione, Korean red ginseng, L-carnitine, nigella sativa, omega-3, selenium, a combination of zinc and folate, and the Menevit antioxidant. There is no support for the use of Vitamin C, Vitamin E, or saffron. The data for Chinese herbal medications, acupuncture, mind-body practice, scrotal cooling, and faith-based healing are sparse or inconclusive.

  20. Male infertility: lifestyle factors and holistic, complementary, and alternative therapies.

    Science.gov (United States)

    Yao, David F; Mills, Jesse N

    2016-01-01

    While we may be comfortable with an allopathic approach to male infertility, we are also responsible for knowledge about lifestyle modifications and holistic, complementary, and alternative therapies that are used by many of our patients. This paper provides an evidence-based review separating fact from fiction for several of these therapies. There is sufficient literature to support weight reduction by diet and exercise, smoking cessation, and alcohol moderation. Supplements that have demonstrated positive effects on male fertility on small randomized controlled trial (RCT) include aescin, coenzyme Q 10 , glutathione, Korean red ginseng, L-carnitine, nigella sativa, omega-3, selenium, a combination of zinc and folate, and the Menevit antioxidant. There is no support for the use of Vitamin C, Vitamin E, or saffron. The data for Chinese herbal medications, acupuncture, mind-body practice, scrotal cooling, and faith-based healing are sparse or inconclusive. PMID:26952957

  1. Quantitative Modeling of the Alternative Pathway of the Complement System.

    Science.gov (United States)

    Zewde, Nehemiah; Gorham, Ronald D; Dorado, Angel; Morikis, Dimitrios

    2016-01-01

    The complement system is an integral part of innate immunity that detects and eliminates invading pathogens through a cascade of reactions. The destructive effects of the complement activation on host cells are inhibited through versatile regulators that are present in plasma and bound to membranes. Impairment in the capacity of these regulators to function in the proper manner results in autoimmune diseases. To better understand the delicate balance between complement activation and regulation, we have developed a comprehensive quantitative model of the alternative pathway. Our model incorporates a system of ordinary differential equations that describes the dynamics of the four steps of the alternative pathway under physiological conditions: (i) initiation (fluid phase), (ii) amplification (surfaces), (iii) termination (pathogen), and (iv) regulation (host cell and fluid phase). We have examined complement activation and regulation on different surfaces, using the cellular dimensions of a characteristic bacterium (E. coli) and host cell (human erythrocyte). In addition, we have incorporated neutrophil-secreted properdin into the model highlighting the cross talk of neutrophils with the alternative pathway in coordinating innate immunity. Our study yields a series of time-dependent response data for all alternative pathway proteins, fragments, and complexes. We demonstrate the robustness of alternative pathway on the surface of pathogens in which complement components were able to saturate the entire region in about 54 minutes, while occupying less than one percent on host cells at the same time period. Our model reveals that tight regulation of complement starts in fluid phase in which propagation of the alternative pathway was inhibited through the dismantlement of fluid phase convertases. Our model also depicts the intricate role that properdin released from neutrophils plays in initiating and propagating the alternative pathway during bacterial infection.

  2. Grasses use an alternatively wired bHLH transcription factor network to establish stomatal identity.

    Science.gov (United States)

    Raissig, Michael T; Abrash, Emily; Bettadapur, Akhila; Vogel, John P; Bergmann, Dominique C

    2016-07-19

    Stomata, epidermal valves facilitating plant-atmosphere gas exchange, represent a powerful model for understanding cell fate and pattern in plants. Core basic helix-loop-helix (bHLH) transcription factors regulating stomatal development were identified in Arabidopsis, but this dicot's developmental pattern and stomatal morphology represent only one of many possibilities in nature. Here, using unbiased forward genetic screens, followed by analysis of reporters and engineered mutants, we show that stomatal initiation in the grass Brachypodium distachyon uses orthologs of stomatal regulators known from Arabidopsis but that the function and behavior of individual genes, the relationships among genes, and the regulation of their protein products have diverged. Our results highlight ways in which a kernel of conserved genes may be alternatively wired to produce diversity in patterning and morphology and suggest that the stomatal transcription factor module is a prime target for breeding or genome modification to improve plant productivity. PMID:27382177

  3. Grasses use an alternatively wired bHLH transcription factor network to establish stomatal identity

    Science.gov (United States)

    Raissig, Michael T.; Abrash, Emily; Bettadapur, Akhila; Bergmann, Dominique C.

    2016-01-01

    Stomata, epidermal valves facilitating plant–atmosphere gas exchange, represent a powerful model for understanding cell fate and pattern in plants. Core basic helix–loop–helix (bHLH) transcription factors regulating stomatal development were identified in Arabidopsis, but this dicot’s developmental pattern and stomatal morphology represent only one of many possibilities in nature. Here, using unbiased forward genetic screens, followed by analysis of reporters and engineered mutants, we show that stomatal initiation in the grass Brachypodium distachyon uses orthologs of stomatal regulators known from Arabidopsis but that the function and behavior of individual genes, the relationships among genes, and the regulation of their protein products have diverged. Our results highlight ways in which a kernel of conserved genes may be alternatively wired to produce diversity in patterning and morphology and suggest that the stomatal transcription factor module is a prime target for breeding or genome modification to improve plant productivity. PMID:27382177

  4. Forecasting Stock Prices by Using Alternative Time Series Models

    OpenAIRE

    Kivilcim Metin; Gulnur Muradoglu

    2000-01-01

    The purpose of this paper is to compare the forecast performance of alternative time series models, namely VAR in levels, stochastic seasonal models (SSM) and error correction models (ECM) at the Istanbul Stock Exchange (ISE). Considering the emerging market characteristic of the ISE, stock prices are estimated by using, money supply, inflation rate, interest rates, exchange rates and budget deficits. Then, in an out-of-sample forecasting exercise from January 1995 through December 1995, comp...

  5. ALTERNATING DIRECTION FINITE ELEMENT METHOD FOR SOME REACTION DIFFUSION MODELS

    Institute of Scientific and Technical Information of China (English)

    江成顺; 刘蕴贤; 沈永明

    2004-01-01

    This paper is concerned with some nonlinear reaction - diffusion models. To solve this kind of models, the modified Laplace finite element scheme and the alternating direction finite element scheme are established for the system of patrical differential equations. Besides, the finite difference method is utilized for the ordinary differential equation in the models. Moreover, by the theory and technique of prior estimates for the differential equations, the convergence analyses and the optimal L2- norm error estimates are demonstrated.

  6. A Viable Alternative: the Scandinavian Model of "Social Democracy"

    OpenAIRE

    Gobbi, Michela

    2003-01-01

    This paper aims at discussing how far the Scandinavian model of "social democracy", which is assumed to be the Swedish model, still represents a viable alternative for the development of other industrial relations systems. The Scandinavian model, characterised by labour market peace and centralised bargaining, is based on two main pillars: "active labour market" and "solidaristic wage" policies. Its "golden age" lasted more than forty years targeting full employment, therefore here it is argu...

  7. An Alternative to Free Entropy for Free Group Factors

    Institute of Scientific and Technical Information of China (English)

    Michal DOSTAL; Don HADWIN

    2003-01-01

    In this paper we defiue a very simple invariant η(V→) for a k-tuple V→ of unitaries in a finitefactor von Neumann algebra, and we show how this invariant can replace free entropy in many of theimportant applications. We also introduce a notion of metric free entropy and some related concepts.We include proofs, using η, of the theorems of Liming Ge and of D. Voiculescu, respectively, on theprimeness of and on the absence of Cartan subalgebras in the noncommutative free group factors.

  8. A study of the diffusion of alternative fuel vehicles : An agent-based modeling approach

    NARCIS (Netherlands)

    Zhang, Ting; Gensler, Sonja; Garcia, Rosanna

    2011-01-01

    This paper demonstrates the use of an agent-based model (ABM) to investigate factors that can speed the diffusion of eco-innovations, namely alternative fuel vehicles (AFVs). The ABM provides the opportunity to consider the interdependencies inherent between key participants in the automotive indust

  9. Mathematical model of alternative mechanism of telomere length maintenance

    Science.gov (United States)

    Kollár, Richard; Bod'ová, Katarína; Nosek, Jozef; Tomáška, L'ubomír

    2014-03-01

    Biopolymer length regulation is a complex process that involves a large number of biological, chemical, and physical subprocesses acting simultaneously across multiple spatial and temporal scales. An illustrative example important for genomic stability is the length regulation of telomeres—nucleoprotein structures at the ends of linear chromosomes consisting of tandemly repeated DNA sequences and a specialized set of proteins. Maintenance of telomeres is often facilitated by the enzyme telomerase but, particularly in telomerase-free systems, the maintenance of chromosomal termini depends on alternative lengthening of telomeres (ALT) mechanisms mediated by recombination. Various linear and circular DNA structures were identified to participate in ALT, however, dynamics of the whole process is still poorly understood. We propose a chemical kinetics model of ALT with kinetic rates systematically derived from the biophysics of DNA diffusion and looping. The reaction system is reduced to a coagulation-fragmentation system by quasi-steady-state approximation. The detailed treatment of kinetic rates yields explicit formulas for expected size distributions of telomeres that demonstrate the key role played by the J factor, a quantitative measure of bending of polymers. The results are in agreement with experimental data and point out interesting phenomena: an appearance of very long telomeric circles if the total telomere density exceeds a critical value (excess mass) and a nonlinear response of the telomere size distributions to the amount of telomeric DNA in the system. The results can be of general importance for understanding dynamics of telomeres in telomerase-independent systems as this mode of telomere maintenance is similar to the situation in tumor cells lacking telomerase activity. Furthermore, due to its universality, the model may also serve as a prototype of an interaction between linear and circular DNA structures in various settings.

  10. Early Childhood Educators' Experience of an Alternative Physical Education Model

    Science.gov (United States)

    Tsangaridou, Niki; Genethliou, Nicholas

    2016-01-01

    Alternative instructional and curricular models are regarded as more comprehensive and suitable approaches to providing quality physical education (Kulinna 2008; Lund and Tannehill 2010; McKenzie and Kahan 2008; Metzler 2011; Quay and Peters 2008). The purpose of this study was to describe the impact of the Early Steps Physical Education…

  11. The Costs and Potential Benefits of Alternative Scholarly Publishing Models

    Science.gov (United States)

    Houghton, John W.

    2011-01-01

    Introduction: This paper reports on a study undertaken for the UK Joint Information Systems Committee (JISC), which explored the economic implications of alternative scholarly publishing models. Rather than simply summarising the study's findings, this paper focuses on the approach and presents a step-by-step account of the research process,…

  12. Rethinking borders in a mobile world: An alternative model

    DEFF Research Database (Denmark)

    Walther, Olivier; Retaillé, Denis

    2015-01-01

    national borders. The second section elaborates the fundamentals of an alternative model that is not reliant, as is classical spatial analysis, on points, lines and surfaces to represent movement. The article then presents three types of limits: the confines, the threshold and the horizon, which result...

  13. Rethinking borders in a mobile world: An alternative model

    DEFF Research Database (Denmark)

    Walther, Olivier; Retaillé, Denis

    national borders. The second section elaborates the fundamentals of an alternative model that is not reliant, as is classical spatial analysis, on points, lines and surfaces to represent movement. The article then presents three types of limits: the confines, the threshold and the horizon, which result...

  14. Alternative Pathway Inhibition by Exogenous Factor H Fails to Attenuate Inflammation and Vascular Leakage in Experimental Pneumococcal Sepsis in Mice.

    Science.gov (United States)

    van der Maten, Erika; van Selm, Saskia; Langereis, Jeroen D; Bootsma, Hester J; van Opzeeland, Fred J H; de Groot, Ronald; de Jonge, Marien I; van der Flier, Michiel

    2016-01-01

    Streptococcus pneumoniae is a common cause of sepsis. Effective complement activation is an important component of host defence against invading pathogens, whilst excessive complement activation has been associated with endothelial dysfunction and organ damage. The alternative pathway amplification loop is important for the enhancement of complement activation. Factor H is a key negative regulator of the alternative pathway amplification loop and contributes to tight control of complement activation. We assessed the effect of inhibition of the alternative pathway on sepsis associated inflammation and disease severity using human factor H treatment in a clinically relevant mice model of pneumococcal sepsis. Mice were infected intravenously with live Streptococcus pneumoniae. At the first clinical signs of infection, 17 hours post-infection, mice were treated with ceftriaxone antibiotic. At the same time purified human factor H or in controls PBS was administered. Treatment with human factor H did not attenuate disease scores, serum pro-inflammatory cytokines, or vascular permeability and did not significantly affect C3 and C3a production at 26 h post-infection. Therefore, we conclude that inhibition of the alternative complement pathway by exogenous human factor H fails to attenuate inflammation and vascular leakage at a clinically relevant intervention time point in pneumococcal sepsis in mice. PMID:26872035

  15. An innovation resistance factor model

    Directory of Open Access Journals (Sweden)

    Siti Salwa Mohd Ishak

    2016-09-01

    Full Text Available The process and implementation strategy of information technology in construction is generally considered through the limiting prism of theoretical contexts generated from innovation diffusion and acceptance. This research argues that more attention should be given to understanding the positive effects of resistance. The study develops a theoretical framing for the Integrated Resistance Factor Model (IRFM. The framing uses a combination of diffusion of innovation theory, technology acceptance model and social network perspective. The model is tested to identify the most significant resistance factors using Partial Least Square (PLS technique. All constructs proposed in the model are found to be significant, valid and consistent with the theoretical framework. IRFM is shown to be an effective and appropriate model of user resistance factors. The most critical factors to influence technology resistance in the online project information management system (OPIMS context are: support from leaders and peers, complexity of the technology, compatibility with key work practices; and pre-trial of the technology before it is actually deployed. The study provides a new model for further research in technology innovation specific to the construction industry.

  16. Improvements in quench factor modelling

    OpenAIRE

    Rometsch, P.A.; Starink, M.J.; Gregson, P.J.

    2003-01-01

    In this contribution, the validity of a number of key quench factor analysis (QFA) assumptions is discussed. It is shown that the incorporation of a square root dependency of yield strength on precipitate volume fraction provides a sounder physical basis for quench factor modelling. Peak-aged strength/hardness prediction accuracies are not affected, but C-curve positions are. It is also demonstrated that transformation kinetics are described more correctly by a modified Starink–Zahra equation...

  17. Report of the subgroup on alternative models and new ideas

    International Nuclear Information System (INIS)

    We summarize some of the work done by the P3 subgroup on Alternative Models and New Ideas. The working group covered a broad range of topics including a constrained Standard Model from an extra dimension, a discussion of recent ideas addressing the strong CP problem, searches for doubly charged higgs bosons in eγ collisions, and an update on discovery limits for extra neutral gauge bosons at hadron colliders. The breadth of topics rejects the many ideas and approaches to physics beyond the Standard Model

  18. Alternative Liquid Fuels Simulation Model (AltSim).

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Ryan; Baker, Arnold Barry; Drennen, Thomas E.

    2009-12-01

    The Alternative Liquid Fuels Simulation Model (AltSim) is a high-level dynamic simulation model which calculates and compares the production and end use costs, greenhouse gas emissions, and energy balances of several alternative liquid transportation fuels. These fuels include: corn ethanol, cellulosic ethanol from various feedstocks (switchgrass, corn stover, forest residue, and farmed trees), biodiesel, and diesels derived from natural gas (gas to liquid, or GTL), coal (coal to liquid, or CTL), and coal with biomass (CBTL). AltSim allows for comprehensive sensitivity analyses on capital costs, operation and maintenance costs, renewable and fossil fuel feedstock costs, feedstock conversion ratio, financial assumptions, tax credits, CO{sub 2} taxes, and plant capacity factor. This paper summarizes the structure and methodology of AltSim, presents results, and provides a detailed sensitivity analysis. The Energy Independence and Security Act (EISA) of 2007 sets a goal for the increased use of biofuels in the U.S., ultimately reaching 36 billion gallons by 2022. AltSim's base case assumes EPA projected feedstock costs in 2022 (EPA, 2009). For the base case assumptions, AltSim estimates per gallon production costs for the five ethanol feedstocks (corn, switchgrass, corn stover, forest residue, and farmed trees) of $1.86, $2.32, $2.45, $1.52, and $1.91, respectively. The projected production cost of biodiesel is $1.81/gallon. The estimates for CTL without biomass range from $1.36 to $2.22. With biomass, the estimated costs increase, ranging from $2.19 per gallon for the CTL option with 8% biomass to $2.79 per gallon for the CTL option with 30% biomass and carbon capture and sequestration. AltSim compares the greenhouse gas emissions (GHG) associated with both the production and consumption of the various fuels. EISA allows fuels emitting 20% less greenhouse gases (GHG) than conventional gasoline and diesels to qualify as renewable fuels. This allows several of the

  19. Alternative Liquid Fuels Simulation Model (AltSim).

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Ryan; Baker, Arnold Barry; Drennen, Thomas E.

    2009-12-01

    The Alternative Liquid Fuels Simulation Model (AltSim) is a high-level dynamic simulation model which calculates and compares the production and end use costs, greenhouse gas emissions, and energy balances of several alternative liquid transportation fuels. These fuels include: corn ethanol, cellulosic ethanol from various feedstocks (switchgrass, corn stover, forest residue, and farmed trees), biodiesel, and diesels derived from natural gas (gas to liquid, or GTL), coal (coal to liquid, or CTL), and coal with biomass (CBTL). AltSim allows for comprehensive sensitivity analyses on capital costs, operation and maintenance costs, renewable and fossil fuel feedstock costs, feedstock conversion ratio, financial assumptions, tax credits, CO{sub 2} taxes, and plant capacity factor. This paper summarizes the structure and methodology of AltSim, presents results, and provides a detailed sensitivity analysis. The Energy Independence and Security Act (EISA) of 2007 sets a goal for the increased use of biofuels in the U.S., ultimately reaching 36 billion gallons by 2022. AltSim's base case assumes EPA projected feedstock costs in 2022 (EPA, 2009). For the base case assumptions, AltSim estimates per gallon production costs for the five ethanol feedstocks (corn, switchgrass, corn stover, forest residue, and farmed trees) of $1.86, $2.32, $2.45, $1.52, and $1.91, respectively. The projected production cost of biodiesel is $1.81/gallon. The estimates for CTL without biomass range from $1.36 to $2.22. With biomass, the estimated costs increase, ranging from $2.19 per gallon for the CTL option with 8% biomass to $2.79 per gallon for the CTL option with 30% biomass and carbon capture and sequestration. AltSim compares the greenhouse gas emissions (GHG) associated with both the production and consumption of the various fuels. EISA allows fuels emitting 20% less greenhouse gases (GHG) than conventional gasoline and diesels to qualify as renewable fuels. This allows several of the

  20. Alternative(s) to fractional-diffusion equations in bedload-transport models

    Science.gov (United States)

    Ancey, Christophe; Mettra, François; Mettraux, Valentin

    2010-05-01

    The idea of stochastic sediment transport models emerged in the 1930s, notably with the doctoral work of Hans A. Einstein (1936). Einstein's seminal work gave impulse to several stochastic models, which usually led to thin-tailed or bounded distributions for the particle-transport rate. Experimental observations together with field surveys suggest that particle-transport rate exhibits frequent and large fluctuations, in particular at low flow rates (i.e., when the bottom shear just exceeds the threshold of incipient motion), which cannot be described using classic distributions used so far for modelling bedload transport (e.g., Hamamori's distribution). The existence of these large and frequent fluctuations could offer a wide field of applications to fractional-derivative theory. Alternative approaches exist as well: in this talk, we explore the potentialities of a birth-death Markov model to model sediment transport within a fixed volume of control. Under steady-uniform-flow conditions, the model predicts that the number of moving particles inside the control volume follows a negative binomial distribution. Although this probability distribution does not enter the family of heavy-tailed distributions, it may give rise to large and frequent fluctuations. We investigate the consequences of these fluctuations on bed dynamics, more especially on the features (growth rate and probability distribution) of nascent bedforms that develop on initially planar beds as a result of intermittent bedload transport.

  1. Alternative splicing regulation during C. elegans development: splicing factors as regulated targets.

    Directory of Open Access Journals (Sweden)

    Sergio Barberan-Soler

    2008-02-01

    Full Text Available Alternative splicing generates protein diversity and allows for post-transcriptional gene regulation. Estimates suggest that 10% of the genes in Caenorhabditis elegans undergo alternative splicing. We constructed a splicing-sensitive microarray to detect alternative splicing for 352 cassette exons and tested for changes in alternative splicing of these genes during development. We found that the microarray data predicted that 62/352 (approximately 18% of the alternative splicing events studied show a strong change in the relative levels of the spliced isoforms (>4-fold during development. Confirmation of the microarray data by RT-PCR was obtained for 70% of randomly selected genes tested. Among the genes with the most developmentally regulated alternatively splicing was the hnRNP F/H splicing factor homolog, W02D3.11 - now named hrpf-1. For the cassette exon of hrpf-1, the inclusion isoform comprises 65% of hrpf-1 steady state messages in embryos but only 0.1% in the first larval stage. This dramatic change in the alternative splicing of an alternative splicing factor suggests a complex cascade of splicing regulation during development. We analyzed splicing in embryos from a strain with a mutation in the splicing factor sym-2, another hnRNP F/H homolog. We found that approximately half of the genes with large alternative splicing changes between the embryo and L1 stages are regulated by sym-2 in embryos. An analysis of the role of nonsense-mediated decay in regulating steady-state alternative mRNA isoforms was performed. We found that 8% of the 352 events studied have alternative isoforms whose relative steady-state levels in embryos change more than 4-fold in a nonsense-mediated decay mutant, including hrpf-1. Strikingly, 53% of these alternative splicing events that are affected by NMD in our experiment are not obvious substrates for NMD based on the presence of premature termination codons. This suggests that the targeting of splicing factors

  2. Human factors in design modifications: panel alternative stop in Almaraz; Factores humanos en modificaciones de diseno: panel deparada alternativa en CN Almaraz

    Energy Technology Data Exchange (ETDEWEB)

    Roman, Y.; Bote, J.

    2015-07-01

    Human Factors Engineering has acquired a crucial role in the development of any design modification (DM), where every aspect relative to any interaction with the human user has to be taken into account at any stage thereof. Considering this, during the last years, Almaraz Nuclear Powe Plants has developed a program of Human Factors Engineering in order to reach the internationally recognized standards or systematic collected on NUREG 0711 Human Factors Engineering Program Review Model (NRC). One of the most important projects of this program at Almaraz Nuclear Power Plant has been the implementation of the Alternative Stop Panel and their corresponding Transfer Panels. (Author)

  3. Modeling alternative clad behavior for accident tolerant systems

    International Nuclear Information System (INIS)

    The US Department of Energy Fuel Cycle Research and Development program has a key goal of helping develop accident tolerant fuels (ATF) through investigating fuel and clad forms. In the current work thermochemical modeling and experiment are being used to assess fuel and clad alternatives. Cladding alternatives that have promise to improve fuel performance under accident conditions include the FeCrAl family of alloys and SiC-based composites. These are high strength and radiation resistant alloys and ceramics that have increased resistance to oxidation as compared to zirconium alloys. Accident modeling codes have indicated substantially increased time to failure and resulting effects. In the current work the thermochemical behavior of these materials are being assessed and the work reported here. (author)

  4. Regulation of Splicing Factors by Alternative Splicing and NMD Is Conserved between Kingdoms Yet Evolutionarily Flexible

    OpenAIRE

    Liana F Lareau; Brenner, Steven E.

    2015-01-01

    Ultraconserved elements, unusually long regions of perfect sequence identity, are found in genes encoding numerous RNA-binding proteins including arginine-serine rich (SR) splicing factors. Expression of these genes is regulated via alternative splicing of the ultraconserved regions to yield mRNAs that are degraded by nonsense-mediated mRNA decay (NMD), a process termed unproductive splicing (Lareau et al. 2007; Ni et al. 2007). As all human SR genes are affected by alternative splicing and N...

  5. Method for exploiting bias in factor analysis using constrained alternating least squares algorithms

    Science.gov (United States)

    Keenan, Michael R.

    2008-12-30

    Bias plays an important role in factor analysis and is often implicitly made use of, for example, to constrain solutions to factors that conform to physical reality. However, when components are collinear, a large range of solutions may exist that satisfy the basic constraints and fit the data equally well. In such cases, the introduction of mathematical bias through the application of constraints may select solutions that are less than optimal. The biased alternating least squares algorithm of the present invention can offset mathematical bias introduced by constraints in the standard alternating least squares analysis to achieve factor solutions that are most consistent with physical reality. In addition, these methods can be used to explicitly exploit bias to provide alternative views and provide additional insights into spectral data sets.

  6. Uncertain hybrid model for the response calculation of an alternator

    International Nuclear Information System (INIS)

    The complex structural dynamic behavior of alternator must be well understood in order to insure their reliable and safe operation. The numerical model is however difficult to construct mainly due to the presence of a high level of uncertainty. The objective of this work is to provide decision support tools in order to assess the vibratory levels in operation before to restart the alternator. Based on info-gap theory, a first decision support tool is proposed: the objective here is to assess the robustness of the dynamical response to the uncertain modal model. Based on real data, the calibration of an info-gap model of uncertainty is also proposed in order to enhance its fidelity to reality. Then, the extended constitutive relation error is used to expand identified mode shapes which are used to assess the vibratory levels. The robust expansion process is proposed in order to obtain robust expanded mode shapes to parametric uncertainties. In presence of lack-of knowledge, the trade-off between fidelity-to-data and robustness-to-uncertainties which expresses that robustness improves as fidelity deteriorates is emphasized on an industrial structure by using both reduced order model and surrogate model techniques. (author)

  7. An Introduction to Alternative Experimental Models in Monitoring Economic Failures

    Directory of Open Access Journals (Sweden)

    Mario Arturo Ruiz Estrada

    2015-04-01

    Full Text Available This research paper presents four alternative experimental models for monitoring economic failures. These models include the national production function (NP-Function, the multi-level trade creation and trade diversion analytical framework, the mega-economic structures vulnerability analysis (MSV-Analysis, and the mega-economic surface interactive system. The main objective behind the proposed experimental models in economics is to analyze different macroeconomic scenarios in monitoring and warning of possible unexpected economic failure(s under the use of a new mathematical framework and the application of multidimensional graphs. The proposed alternative experimental models are based on the application of Econographicology. Hence, our models are expected to offer policy-makers and researchers new analytical tools to study the impact and trend of economic failures in the economy of any country from a new perspective. Finally, we suggest the application of three new concepts in the study of economic failures such as Omnia Mobilis (everything is moving, the global structural imbalance principle, and the dynamic imbalance state. Therefore, our findings would certainly help both policy makers and researchers to implement and execute appropriate policies to develop their economies and to protect them from unwanted situations.

  8. Outcome modelling strategies in epidemiology: traditional methods and basic alternatives.

    Science.gov (United States)

    Greenland, Sander; Daniel, Rhian; Pearce, Neil

    2016-04-01

    Controlling for too many potential confounders can lead to or aggravate problems of data sparsity or multicollinearity, particularly when the number of covariates is large in relation to the study size. As a result, methods to reduce the number of modelled covariates are often deployed. We review several traditional modelling strategies, including stepwise regression and the 'change-in-estimate' (CIE) approach to deciding which potential confounders to include in an outcome-regression model for estimating effects of a targeted exposure. We discuss their shortcomings, and then provide some basic alternatives and refinements that do not require special macros or programming. Throughout, we assume the main goal is to derive the most accurate effect estimates obtainable from the data and commercial software. Allowing that most users must stay within standard software packages, this goal can be roughly approximated using basic methods to assess, and thereby minimize, mean squared error (MSE).

  9. Outcome modelling strategies in epidemiology: traditional methods and basic alternatives.

    Science.gov (United States)

    Greenland, Sander; Daniel, Rhian; Pearce, Neil

    2016-04-01

    Controlling for too many potential confounders can lead to or aggravate problems of data sparsity or multicollinearity, particularly when the number of covariates is large in relation to the study size. As a result, methods to reduce the number of modelled covariates are often deployed. We review several traditional modelling strategies, including stepwise regression and the 'change-in-estimate' (CIE) approach to deciding which potential confounders to include in an outcome-regression model for estimating effects of a targeted exposure. We discuss their shortcomings, and then provide some basic alternatives and refinements that do not require special macros or programming. Throughout, we assume the main goal is to derive the most accurate effect estimates obtainable from the data and commercial software. Allowing that most users must stay within standard software packages, this goal can be roughly approximated using basic methods to assess, and thereby minimize, mean squared error (MSE). PMID:27097747

  10. Life cycle models of conventional and alternative-fueled automobiles

    Science.gov (United States)

    Maclean, Heather Louise

    This thesis reports life cycle inventories of internal combustion engine automobiles with feasible near term fuel/engine combinations. These combinations include unleaded gasoline, California Phase 2 Reformulated Gasoline, alcohol and gasoline blends (85 percent methanol or ethanol combined with 15 percent gasoline), and compressed natural gas in spark ignition direct and indirect injection engines. Additionally, I consider neat methanol and neat ethanol in spark ignition direct injection engines and diesel fuel in compression ignition direct and indirect injection engines. I investigate the potential of the above options to have a lower environmental impact than conventional gasoline-fueled automobiles, while still retaining comparable pricing and consumer benefits. More broadly, the objective is to assess whether the use of any of the alternative systems will help to lead to the goal of a more sustainable personal transportation system. The principal tool is the Economic Input-Output Life Cycle Analysis model which includes inventories of economic data, environmental discharges, and resource use. I develop a life cycle assessment framework to assemble the array of data generated by the model into three aggregate assessment parameters; economics, externalities, and vehicle attributes. The first step is to develop a set of 'comparable cars' with the alternative fuel/engine combinations, based on characteristics of a conventional 1998 gasoline-fueled Ford Taurus sedan, the baseline vehicle for the analyses. I calculate the assessment parameters assuming that these comparable cars can attain the potential thermal efficiencies estimated by experts for each fuel/engine combination. To a first approximation, there are no significant differences in the assessment parameters for the vehicle manufacture, service, fixed costs, and the end-of-life for any of the options. However, there are differences in the vehicle operation life cycle components and the state of technology

  11. A statistical method for descriminating between alternative radiobiological models

    International Nuclear Information System (INIS)

    Radiobiological models assist understanding of the development of radiation damage, and may provide a basis for extrapolating dose-effect curves from high to low dose regions. Many models have been proposed such as multitarget and its modifications, enzymatic models, and those with a quadratic dose response relationship (i.e. αD + βD2 forms). It is difficult to distinguish between these because the statistical techniques used are almost always limited, in that one method can rarely be applied to the whole range of models. A general statistical procedure for parameter estimation (Maximum Liklihood Method) has been found applicable to a wide range of radiobiological models. The curve parameters are estimated using a computerised search that continues until the most likely set of values to fit the data is obtained. When the search is complete two procedures are carried out. First a goodness of fit test is applied which examines the applicability of an individual model to the data. Secondly an index is derived which provides an indication of the adequacy of any model compared with alternative models. Thus the models may be ranked according to how well they fit the data. For example, with one set of data, multitarget types were found to be more suitable than quadratic types (αD + βD2). This method should be of assitance is evaluating various models. It may also be profitably applied to selection of the most appropriate model to use, when it is necessary to extrapolate from high to low doses

  12. Model for the ready definition and approximate comparison of alternative high voltage transmission systems

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    A model of generic overhead transmission systems in the range of 362 to 1200 kV ac, and +-400 to +-800 kV dc is developed. Such generic systems are to include (a) transmission from generation to load, and (b) interconnection of two large integrated systems, with and without the existence of an underlying, lower voltage network in either case. The model provides a means whereby an engineer with some experience in power systems planning can make a reconnaissance study of alternatives within a relatively short span of time and with fair accuracy. Given an amount of power to be transferred over a specified distance, the model can be used: to define the workable alternatives in terms of voltages, number of lines, series compensation, and certain other factors affecting transfer capability; to delineate other salient features of the selected alternatives, notably shunt compensation requirements; and to compare the alternatives in terms of potentially relevant benefits and costs. The significant properties of the model, the basis and assumptions necessary to its formulation, instructions for its use, and inherent limitations upon the accuracy to be expected are described.

  13. Alternative regression models to assess increase in childhood BMI

    Directory of Open Access Journals (Sweden)

    Mansmann Ulrich

    2008-09-01

    Full Text Available Abstract Background Body mass index (BMI data usually have skewed distributions, for which common statistical modeling approaches such as simple linear or logistic regression have limitations. Methods Different regression approaches to predict childhood BMI by goodness-of-fit measures and means of interpretation were compared including generalized linear models (GLMs, quantile regression and Generalized Additive Models for Location, Scale and Shape (GAMLSS. We analyzed data of 4967 children participating in the school entry health examination in Bavaria, Germany, from 2001 to 2002. TV watching, meal frequency, breastfeeding, smoking in pregnancy, maternal obesity, parental social class and weight gain in the first 2 years of life were considered as risk factors for obesity. Results GAMLSS showed a much better fit regarding the estimation of risk factors effects on transformed and untransformed BMI data than common GLMs with respect to the generalized Akaike information criterion. In comparison with GAMLSS, quantile regression allowed for additional interpretation of prespecified distribution quantiles, such as quantiles referring to overweight or obesity. The variables TV watching, maternal BMI and weight gain in the first 2 years were directly, and meal frequency was inversely significantly associated with body composition in any model type examined. In contrast, smoking in pregnancy was not directly, and breastfeeding and parental social class were not inversely significantly associated with body composition in GLM models, but in GAMLSS and partly in quantile regression models. Risk factor specific BMI percentile curves could be estimated from GAMLSS and quantile regression models. Conclusion GAMLSS and quantile regression seem to be more appropriate than common GLMs for risk factor modeling of BMI data.

  14. The Infinite Hierarchical Factor Regression Model

    CERN Document Server

    Rai, Piyush

    2009-01-01

    We propose a nonparametric Bayesian factor regression model that accounts for uncertainty in the number of factors, and the relationship between factors. To accomplish this, we propose a sparse variant of the Indian Buffet Process and couple this with a hierarchical model over factors, based on Kingman's coalescent. We apply this model to two problems (factor analysis and factor regression) in gene-expression data analysis.

  15. The Swedish model: an alternative to macroeconomic policy

    Directory of Open Access Journals (Sweden)

    ALEXANDRE GUEDES VIANA

    2016-06-01

    Full Text Available ABSTRACT This paper describes the main details of the Swedish economic model, which began to be structured on the 1930s and achieved its consolidation on the 1950s. The Swedish model is characterized by a macroeconomic policy which provides price stability, fiscal results for selective industrial policies and social active policies, the latter being recognized as a wide universal welfare state. This combination, which contradicts the traditional economic prescriptions, has been successful given the country was agrarian and underdeveloped until the beginni.ng of 20th century and achieved a high social-economic development level on the 1970s. Afterwards, we present the Swedish experiment as an alternative to macroeconomic management, especially due to its uniqueness.

  16. Coordination of RNA Polymerase II Pausing and 3' End Processing Factor Recruitment with Alternative Polyadenylation.

    Science.gov (United States)

    Fusby, Becky; Kim, Soojin; Erickson, Benjamin; Kim, Hyunmin; Peterson, Martha L; Bentley, David L

    2015-01-01

    Most mammalian genes produce transcripts whose 3' ends are processed at multiple alternative positions by cleavage/polyadenylation (CPA). Poly(A) site cleavage frequently occurs cotranscriptionally and is facilitated by CPA factor binding to the RNA polymerase II (Pol II) C-terminal domain (CTD) phosphorylated on Ser2 residues of its heptad repeats (YS2PTSPS). The function of cotranscriptional events in the selection of alternative poly(A) sites is poorly understood. We investigated Pol II pausing, CTD Ser2 phosphorylation, and processing factor CstF recruitment at wild-type and mutant IgM transgenes that use alternative poly(A) sites to produce mRNAs encoding the secreted and membrane-bound forms of the immunoglobulin (Ig) heavy chain. The results show that the sites of Pol II pausing and processing factor recruitment change depending on which poly(A) site is utilized. In contrast, the extent of Pol II CTD Ser2 phosphorylation does not closely correlate with poly(A) site selection. We conclude that changes in properties of the transcription elongation complex closely correlate with utilization of different poly(A) sites, suggesting that cotranscriptional events may influence the decision between alternative modes of pre-mRNA 3' end processing. PMID:26527620

  17. Alternative modeling methods for plasma-based Rf ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Veitzer, Seth A., E-mail: veitzer@txcorp.com; Kundrapu, Madhusudhan, E-mail: madhusnk@txcorp.com; Stoltz, Peter H., E-mail: phstoltz@txcorp.com; Beckwith, Kristian R. C., E-mail: beckwith@txcorp.com [Tech-X Corporation, Boulder, Colorado 80303 (United States)

    2016-02-15

    Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H{sup −} source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. In particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H{sup −} ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two

  18. Alternative modeling methods for plasma-based Rf ion sources.

    Science.gov (United States)

    Veitzer, Seth A; Kundrapu, Madhusudhan; Stoltz, Peter H; Beckwith, Kristian R C

    2016-02-01

    Rf-driven ion sources for accelerators and many industrial applications benefit from detailed numerical modeling and simulation of plasma characteristics. For instance, modeling of the Spallation Neutron Source (SNS) internal antenna H(-) source has indicated that a large plasma velocity is induced near bends in the antenna where structural failures are often observed. This could lead to improved designs and ion source performance based on simulation and modeling. However, there are significant separations of time and spatial scales inherent to Rf-driven plasma ion sources, which makes it difficult to model ion sources with explicit, kinetic Particle-In-Cell (PIC) simulation codes. In particular, if both electron and ion motions are to be explicitly modeled, then the simulation time step must be very small, and total simulation times must be large enough to capture the evolution of the plasma ions, as well as extending over many Rf periods. Additional physics processes such as plasma chemistry and surface effects such as secondary electron emission increase the computational requirements in such a way that even fully parallel explicit PIC models cannot be used. One alternative method is to develop fluid-based codes coupled with electromagnetics in order to model ion sources. Time-domain fluid models can simulate plasma evolution, plasma chemistry, and surface physics models with reasonable computational resources by not explicitly resolving electron motions, which thereby leads to an increase in the time step. This is achieved by solving fluid motions coupled with electromagnetics using reduced-physics models, such as single-temperature magnetohydrodynamics (MHD), extended, gas dynamic, and Hall MHD, and two-fluid MHD models. We show recent results on modeling the internal antenna H(-) ion source for the SNS at Oak Ridge National Laboratory using the fluid plasma modeling code USim. We compare demonstrate plasma temperature equilibration in two-temperature MHD

  19. Regulation of Alternative Splicing in Vivo by Overexpression of Antagonistic Splicing Factors

    Science.gov (United States)

    Caceres, Javier F.; Stamm, Stefan; Helfman, David M.; Krainer, Adrian R.

    1994-09-01

    The opposing effects of SF2/ASF and heterogeneous nuclear ribonucleoprotein (hnRNP) A1 influence alternative splicing in vitro. SF2/ASF or hnRNP A1 complementary DNAs were transiently overexpressed in HeLa cells, and the effect on alternative splicing of several cotransfected reporter genes was measured. Increased expression of SF2/ASF activated proximal 5' splice sites, promoted inclusion of a neuron-specific exon, and prevented abnormal exon skipping. Increased expression of hnRNP A1 activated distal 5' splice sites. Therefore, variations in the intracellular levels of antagonistic splicing factors influence different modes of alternative splicing in vivo and may be a natural mechanism for tissue-specific or developmental regulation of gene expression.

  20. The multitrace matrix model: An alternative to Connes NCG and IKKT model

    CERN Document Server

    Ydri, Badis

    2016-01-01

    We present a new multitrace matrix model, which is a generalization of the real quartic one matrix model, exhibiting dynamical emergence of a fuzzy two-sphere and its non-commutative gauge theory. This provides a novel and a much simpler alternative to Connes non-commutative geometry and to the IKKT matrix model for emergent geometry in two dimensions.

  1. Mathematical model of alternative mechanism of telomere length maintenance

    CERN Document Server

    Kollár, Richard; Nosek, Jozef; Tomaska, Lubomir

    2014-01-01

    Biopolymer length regulation is a complex process that involves a large number of subprocesses acting simultaneously across multiple spatial and temporal scales. An illustrative example important for genomic stability is the length regulation of telomeres---nucleo-protein structures at the ends of linear chromosomes. Maintenance of telomeres is often facilitated by the enzyme telomerase but, particularly in telomerase-free systems, the maintenance of chromosomal termini depends on alternative lengthening of telomeres (ALT) mechanisms mediated by recombination. Various linear and circular DNA structures were identified to participate in ALT, however, dynamics of the whole process is still poorly understood. We propose a chemical kinetics model of ALT with kinetic rates systematically derived from the biophysics of DNA diffusion and looping. The reaction system is reduced to a coagulation-fragmentation system by quasi-steady state approximation. The detailed treatment of kinetic rates yields explicit formulae f...

  2. Predicting Language Outcomes for Children Learning Augmentative and Alternative Communication: Child and Environmental Factors

    Science.gov (United States)

    Brady, Nancy C.; Thiemann-Bourque, Kathy; Fleming, Kandace; Matthews, Kris

    2013-01-01

    Purpose: To investigate a model of language development for nonverbal preschool-age children learning to communicate with augmentative or alternative communication. Method: Ninety-three preschool children with intellectual disabilities were assessed at Time 1, and 82 of these children were assessed 1 year later, at Time 2. The outcome variable was…

  3. The alternative sigma factor σL of L. monocytogenes promotes growth under diverse environmental stresses

    OpenAIRE

    Raimann, Eveline

    2009-01-01

    Listeria monocytogenes are important food-borne pathogens that can cause outbreaks of serious human disease. These organisms frequently colonize and proliferate on preserved food products despite exposure to stress conditions induced by low storage temperatures, inclusion of organic acid based preservatives and high osmolarity. To assess alternative sigma factor σL contributions to such stress resistance of L.monocytogenes, quantitative RT-PCR assays and sigL gene deletion mutagenesis were ap...

  4. Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

    Energy Technology Data Exchange (ETDEWEB)

    Bitencourt, C.S. [Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Duarte, C.G.; Azzolini, A.E.C.S.; Assis-Pandochi, A.I. [Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-03-02

    Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.

  5. Robust and Sparse Factor Modelling

    DEFF Research Database (Denmark)

    Croux, Christophe; Exterkate, Peter

    Factor construction methods are widely used to summarize a large panel of variables by means of a relatively small number of representative factors. We propose a novel factor construction procedure that enjoys the properties of robustness to outliers and of sparsity; that is, having relatively few...... nonzero factor loadings. Compared to the traditional factor construction method, we find that this procedure leads to a favorable forecasting performance in the presence of outliers and to better interpretable factors. We investigate the performance of the method in a Monte Carlo experiment and in an...

  6. Alternative Reimbursement Models: Bundled Payment and Beyond: AOA Critical Issues.

    Science.gov (United States)

    Greenwald, A Seth; Bassano, Amy; Wiggins, Stephen; Froimson, Mark I

    2016-06-01

    The Bundled Payments for Care Improvement (BPCI) initiative was begun in January 2013 by the U.S. Centers for Medicare & Medicaid Services (CMS) through its Innovation Center authority, which was created by the U.S. Patient Protection and Affordable Care Act (PPACA). The BPCI program seeks to improve health-care delivery and to ultimately reduce costs by allowing providers to enter into prenegotiated payment arrangements that include financial and performance accountability for a clinical episode in which a risk-and-reward calculus must be determined. BPCI is a contemporary 3-year experiment designed to test the applicability of episode-based payment models as a viable strategy to transform the CMS payment methodology while improving health outcomes. A summary of the 4 models being evaluated in the BPCI initiative is presented in addition to the awardee types and the number of awardees in each model. Data from one of the BPCI-designated pilot sites demonstrate that strategies do exist for successful implementation of an alternative payment model by keeping patients first while simultaneously improving coordination, alignment of care, and quality and reducing cost. Providers will need to embrace change and their areas of opportunity to gain a competitive advantage. Health-care providers, including orthopaedic surgeons, health-care professionals at post-acute care institutions, and product suppliers, all have a role in determining the strategies for success. Open dialogue between CMS and awardees should be encouraged to arrive at a solution that provides opportunity for gainsharing, as this program continues to gain traction and to evolve. PMID:27252442

  7. Analytic Couple Modeling Introducing Device Design Factor, Fin Factor, Thermal Diffusivity Factor, and Inductance Factor

    Science.gov (United States)

    Mackey, Jon; Sehirlioglu, Alp; Dynys, Fred

    2014-01-01

    A set of convenient thermoelectric device solutions have been derived in order to capture a number of factors which are previously only resolved with numerical techniques. The concise conversion efficiency equations derived from governing equations provide intuitive and straight-forward design guidelines. These guidelines allow for better device design without requiring detailed numerical modeling. The analytical modeling accounts for factors such as i) variable temperature boundary conditions, ii) lateral heat transfer, iii) temperature variable material properties, and iv) transient operation. New dimensionless parameters, similar to the figure of merit, are introduced including the device design factor, fin factor, thermal diffusivity factor, and inductance factor. These new device factors allow for the straight-forward description of phenomenon generally only captured with numerical work otherwise. As an example a device design factor of 0.38, which accounts for thermal resistance of the hot and cold shoes, can be used to calculate a conversion efficiency of 2.28 while the ideal conversion efficiency based on figure of merit alone would be 6.15. Likewise an ideal couple with efficiency of 6.15 will be reduced to 5.33 when lateral heat is accounted for with a fin factor of 1.0.

  8. Alternative face models for 3D face registration

    Science.gov (United States)

    Salah, Albert Ali; Alyüz, Neşe; Akarun, Lale

    2007-01-01

    3D has become an important modality for face biometrics. The accuracy of a 3D face recognition system depends on a correct registration that aligns the facial surfaces and makes a comparison possible. The best results obtained so far use a one-to-all registration approach, which means each new facial surface is registered to all faces in the gallery, at a great computational cost. We explore the approach of registering the new facial surface to an average face model (AFM), which automatically establishes correspondence to the pre-registered gallery faces. Going one step further, we propose that using a couple of well-selected AFMs can trade-off computation time with accuracy. Drawing on cognitive justifications, we propose to employ category-specific alternative average face models for registration, which is shown to increase the accuracy of the subsequent recognition. We inspect thin-plate spline (TPS) and iterative closest point (ICP) based registration schemes under realistic assumptions on manual or automatic landmark detection prior to registration. We evaluate several approaches for the coarse initialization of ICP. We propose a new algorithm for constructing an AFM, and show that it works better than a recent approach. Finally, we perform simulations with multiple AFMs that correspond to different clusters in the face shape space and compare these with gender and morphology based groupings. We report our results on the FRGC 3D face database.

  9. Alternative management structures for municipal waste collection services: The influence of economic and political factors

    Energy Technology Data Exchange (ETDEWEB)

    Plata-Díaz, Ana María, E-mail: amplata@ugr.es; Zafra-Gómez, José Luis, E-mail: jlzafra@ugr.es; Pérez-López, Gemma, E-mail: gemmapl@ugr.es; López-Hernández, Antonio Manuel, E-mail: alopezh@ugr.es

    2014-11-15

    Highlights: • We analyzed the factors that influence on the restructuring of MSW services. • We evaluated five different alternatives for public and private service. • Our analysis covers a broad time horizon, 2002–2010. • We used a conditional fixed-effects logistic regression as the evaluation method. • Municipalities tend to contract out the MSW service in the presence of high costs and fiscal stress. - Abstract: Identifying and characterising the factors that determine why a local authority opts for a particular way of managing its waste collection service is an important issue, warranting research interest in the field of municipal solid waste (MSW) management. This paper presents empirical evidence spanning a broad time horizon (2002–2010) showing that economic and political factors impact in different ways on the provision of waste management services. We examine five alternatives in this area, including public and private service delivery formulas and, within each field, individual and joint options. Our findings highlight the importance of the service cost and that of the various indicators of fiscal stress as determinant factors of management decisions regarding the provision of MSW management services.

  10. Alternative management structures for municipal waste collection services: The influence of economic and political factors

    International Nuclear Information System (INIS)

    Highlights: • We analyzed the factors that influence on the restructuring of MSW services. • We evaluated five different alternatives for public and private service. • Our analysis covers a broad time horizon, 2002–2010. • We used a conditional fixed-effects logistic regression as the evaluation method. • Municipalities tend to contract out the MSW service in the presence of high costs and fiscal stress. - Abstract: Identifying and characterising the factors that determine why a local authority opts for a particular way of managing its waste collection service is an important issue, warranting research interest in the field of municipal solid waste (MSW) management. This paper presents empirical evidence spanning a broad time horizon (2002–2010) showing that economic and political factors impact in different ways on the provision of waste management services. We examine five alternatives in this area, including public and private service delivery formulas and, within each field, individual and joint options. Our findings highlight the importance of the service cost and that of the various indicators of fiscal stress as determinant factors of management decisions regarding the provision of MSW management services

  11. Alternative sigma factor σH activates competence gene expression in Lactobacillus sakei

    Directory of Open Access Journals (Sweden)

    Schmid Solveig

    2012-03-01

    Full Text Available Abstract Background Alternative sigma factors trigger various adaptive responses. Lactobacillus sakei, a non-sporulating meat-borne bacterium, carries an alternative sigma factor seemingly orthologous to σH of Bacillus subtilis, best known for its contribution to the initiation of a large starvation response ultimately leading to sporulation. As the role of σH-like factors has been little studied in non-sporulating bacteria, we investigated the function of σH in L. sakei. Results Transcription of sigH coding for σH was hardly affected by entry into stationary phase in our laboratory conditions. Twenty-five genes potentially regulated by σH in L. sakei 23 K were revealed by genome-wide transcriptomic profiling of sigH overexpression and/or quantitative PCR analysis. More than half of them are involved in the synthesis of a DNA uptake machinery linked to genetic competence, and in DNA metabolism; however, σH overproduction did not allow detectable genetic transformation. σH was found to be conserved in the L. sakei species. Conclusion Our results are indicative of the existence of a genetic competence state activated by σH in L. sakei, and sustain the hypothesis that σH-like factors in non sporulating Firmicutes share this common function with the well-known ComX of naturally transformable streptococci.

  12. Freshwater Planarians as an Alternative Animal Model for Neurotoxicology.

    Science.gov (United States)

    Hagstrom, Danielle; Cochet-Escartin, Olivier; Zhang, Siqi; Khuu, Cindy; Collins, Eva-Maria S

    2015-09-01

    Traditional toxicology testing has relied on low-throughput, expensive mammalian studies; however, timely testing of the large number of environmental toxicants requires new in vitro and in vivo platforms for inexpensive medium- to high-throughput screening. Herein, we describe the suitability of the asexual freshwater planarian Dugesia japonica as a new animal model for the study of developmental neurotoxicology. As these asexual animals reproduce by binary fission, followed by regeneration of missing body structures within approximately 1 week, development and regeneration occur through similar processes allowing us to induce neurodevelopment "at will" through amputation. This short time scale and the comparable sizes of full and regenerating animals enable parallel experiments in adults and developing worms to determine development-specific aspects of toxicity. Because the planarian brain, despite its simplicity, is structurally and molecularly similar to the mammalian brain, we are able to ascertain neurodevelopmental toxicity that is relevant to humans. As a proof of concept, we developed a 5-step semiautomatic screening platform to characterize the toxicity of 9 known neurotoxicants (consisting of common solvents, pesticides, and detergents) and a neutral agent, glucose, and quantified effects on viability, stimulated and unstimulated behavior, regeneration, and brain structure. Comparisons of our findings with other alternative toxicology animal models, such as zebrafish larvae and nematodes, demonstrated that planarians are comparably sensitive to the tested chemicals. In addition, we found that certain compounds induced adverse effects specifically in developing animals. We thus conclude that planarians offer new complementary opportunities for developmental neurotoxicology animal models. PMID:26116028

  13. Emission factors for vehicles propelled by fossil or alternative fuels. Main report

    International Nuclear Information System (INIS)

    The aim of the project was to develop emission factors for commercial and alternative fuels such as alcohols and methane. The background to the decision to carry out the project was that there was a need for emission factors for some other KFB projects organized within the 'system study' carried out by KFB. The method used for the project was to use the today's emission levels and the knowledge about the emission control technology as a base for the estimation of future emission levels and the coming development of vehicles and the emission control technology. The results of the analysis and the estimation show that there exists a positive development concerning emission control technology and emission levels. However, the future positive development for alternative fuels strongly depends on the possibility of these fuels to capture a market which will have certain impact on the willingness and the economic possibilities of the car manufacturers to also invest in the development of alternative fuels. 70 refs

  14. Big bang nucleosynthesis: The standard model and alternatives

    Science.gov (United States)

    Schramm, David N.

    1991-01-01

    Big bang nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the big bang cosmological model. This paper reviews the standard homogeneous-isotropic calculation and shows how it fits the light element abundances ranging from He-4 at 24% by mass through H-2 and He-3 at parts in 10(exp 5) down to Li-7 at parts in 10(exp 10). Furthermore, the recent large electron positron (LEP) (and the stanford linear collider (SLC)) results on the number of neutrinos are discussed as a positive laboratory test of the standard scenario. Discussion is presented on the improved observational data as well as the improved neutron lifetime data. Alternate scenarios of decaying matter or of quark-hadron induced inhomogeneities are discussed. It is shown that when these scenarios are made to fit the observed abundances accurately, the resulting conlusions on the baryonic density relative to the critical density, omega(sub b) remain approximately the same as in the standard homogeneous case, thus, adding to the robustness of the conclusion that omega(sub b) approximately equals 0.06. This latter point is the driving force behind the need for non-baryonic dark matter (assuming omega(sub total) = 1) and the need for dark baryonic matter, since omega(sub visible) is less than omega(sub b).

  15. Skewed factor models using selection mechanisms

    KAUST Repository

    Kim, Hyoung-Moon

    2015-12-21

    Traditional factor models explicitly or implicitly assume that the factors follow a multivariate normal distribution; that is, only moments up to order two are involved. However, it may happen in real data problems that the first two moments cannot explain the factors. Based on this motivation, here we devise three new skewed factor models, the skew-normal, the skew-tt, and the generalized skew-normal factor models depending on a selection mechanism on the factors. The ECME algorithms are adopted to estimate related parameters for statistical inference. Monte Carlo simulations validate our new models and we demonstrate the need for skewed factor models using the classic open/closed book exam scores dataset.

  16. Over-Reporting in Handwashing Self-Reports: Potential Explanatory Factors and Alternative Measurements.

    Directory of Open Access Journals (Sweden)

    Nadja Contzen

    Full Text Available Handwashing interventions are a priority in development and emergency aid programs. Evaluation of these interventions is essential to assess the effectiveness of programs; however, measuring handwashing is quite difficult. Although observations are considered valid, they are time-consuming and cost-ineffective; self-reports are highly efficient but considered invalid because desirable behaviour tends to be over-reported. Socially desirable responding has been claimed to be the main cause of inflated self-reports, but its underlying factors and mechanisms are understudied. The present study investigated socially desirable responding and additional potential explanatory factors for over-reported handwashing to identify indications for measures which mitigate over-reporting. Additionally, a script-based covert recall, an alternative interview question intended to mitigate recall errors and socially desirable responding, was developed and tested. Cross-sectional data collection was conducted in the Borena Zone, Ethiopia, through 2.5-hour observations and 1-hour interviews with the primary caregivers in households. A total sample of N = 554 was surveyed. Data were analysed with correlation and multiple regression analyses and dependent t-tests. Over-reporting of handwashing was associated with factors assumed to be involved in (1 socially desirable responding, (2 encoding and recall of information, and (3 dissonance processes. The latter two factor groups explained over-reported handwashing beyond socially desirable responding. The alternative interview question--script-based covert recall--reduced over-reporting compared to conventional self-reports. Although the difficulties involved in measuring handwashing by self-reports and observations are widely known, the present study is the first to investigate the factors which explain over-reporting of handwashing. This research contributes to the limited evidence base on a highly important subject: how

  17. Over-Reporting in Handwashing Self-Reports: Potential Explanatory Factors and Alternative Measurements.

    Science.gov (United States)

    Contzen, Nadja; De Pasquale, Sandra; Mosler, Hans-Joachim

    2015-01-01

    Handwashing interventions are a priority in development and emergency aid programs. Evaluation of these interventions is essential to assess the effectiveness of programs; however, measuring handwashing is quite difficult. Although observations are considered valid, they are time-consuming and cost-ineffective; self-reports are highly efficient but considered invalid because desirable behaviour tends to be over-reported. Socially desirable responding has been claimed to be the main cause of inflated self-reports, but its underlying factors and mechanisms are understudied. The present study investigated socially desirable responding and additional potential explanatory factors for over-reported handwashing to identify indications for measures which mitigate over-reporting. Additionally, a script-based covert recall, an alternative interview question intended to mitigate recall errors and socially desirable responding, was developed and tested. Cross-sectional data collection was conducted in the Borena Zone, Ethiopia, through 2.5-hour observations and 1-hour interviews with the primary caregivers in households. A total sample of N = 554 was surveyed. Data were analysed with correlation and multiple regression analyses and dependent t-tests. Over-reporting of handwashing was associated with factors assumed to be involved in (1) socially desirable responding, (2) encoding and recall of information, and (3) dissonance processes. The latter two factor groups explained over-reported handwashing beyond socially desirable responding. The alternative interview question--script-based covert recall--reduced over-reporting compared to conventional self-reports. Although the difficulties involved in measuring handwashing by self-reports and observations are widely known, the present study is the first to investigate the factors which explain over-reporting of handwashing. This research contributes to the limited evidence base on a highly important subject: how to evaluate

  18. Convolutional Factor Graphs as Probabilistic Models

    OpenAIRE

    Mao, Yongyi; Kschischang, Frank; Frey, Brendan J.

    2012-01-01

    Based on a recent development in the area of error control coding, we introduce the notion of convolutional factor graphs (CFGs) as a new class of probabilistic graphical models. In this context, the conventional factor graphs are referred to as multiplicative factor graphs (MFGs). This paper shows that CFGs are natural models for probability functions when summation of independent latent random variables is involved. In particular, CFGs capture a large class of linear models, where the linea...

  19. Alternative sigma factor RpoN and its modulation protein YhbH are indispensable for Erwinia amylovora virulence.

    Science.gov (United States)

    Ancona, Veronica; Li, Wenting; Zhao, Youfu

    2014-01-01

    In Erwinia amylovora, ECF (extracytoplasmic functions) alternative sigma factor HrpL regulates the transcription of hrp (hypersensitive response and pathogenicity)-type III secretion system (T3SS) genes by binding to a consensus sequence known as the hrp box in hrp gene promoters. In turn, the expression of hrpL has been proposed to be positively controlled by alternative sigma factor 54 (σ(54)) (RpoN) and HrpS, a member of the σ(54) enhancer-binding proteins (EBPs). However, the function of RpoN has not been characterized genetically in E. amylovora. In this study, we investigated the role of RpoN, a nitrogen limitation sigma factor, and its modulation protein YhbH, a novel ribosome-associated protein, in E. amylovora virulence. Our results showed that mutations in hrpS, hrpL, rpoN and yhbH, but not yfiA and rmf3, resulted in a nonpathogenic phenotype on immature pear fruits and apple shoots. Consistently, the expression of T3SS genes, including hrpL, dspE, hrpN and hrpA, was barely detected in hrpS, hrpL, rpoN and yhbH mutants. These mutants were also not capable of eliciting a hypersensitive response (HR) on tobacco; however, the overexpression of hrpL using an inducible promoter rescued the HR-eliciting abilities of these mutants. These results suggest that a sigma factor cascade exists in the regulatory networks of E. amylovora and regulates important virulence factors. On the basis of this study and previously reported data, a model is proposed for the regulation of T3SS in E. amylovora.

  20. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    -based models are both rejected against the general dynamic factor model, (ii) the factors driving the surface are highly persistent, (iii) for the restricted models option Delta is preferred over the more often used strike relative to spot price as measure for moneyness.......The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...... features for representing the surface and its dynamics: a general dynamic factor model, restricted factor models designed to capture the key features of the surface along the moneyness and maturity dimensions, and in-between spline-based methods. Key findings are that: (i) the restricted and spline...

  1. An alternative tectonic model for the Yarlung Zangbo suture zone

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The new field investigations along the Yarlung Zangbo ophiolites zone show that these series underwent low green-schist metamorphism and were then fractured and occurred as slabs in tectonic melanges,without regional tectonic polarity.No large shear zone in north-south direction has been identified between ophiolite bodies and flysch layers on both side and a conformable contact relationship can be observed locally between them.A great mass of tectonic mélange has been substantiated as submarine olistolith bodies.The Mesozoic sedimentary facies and its evolution in both north and south of the ophiolite zone are corresponding in time.The ophiolite zone has often been divided into parallel branches,separated by narrow flysch slats.There is also a similarity of the Paleozoic and the basement of the High Himalaya,Lhasa and Qiangtang Terranes,and they are distinctly different from those of the Indian continent.The geologic information does not warrant a postulate that the Himalaya and Tibet were once separated by a great ocean;it is therefore consistent with an alternative tectonic model by back-arc basin collapse with its juvenile narrow oceanic crust.The real plate tectonic suture,the Neotethys might be covered under the Miocene Siwalik molasse in the southern slope of the High Himalaya range.Based on the new model,the Neotethyan ocean floor was subducted beneath the Asia since the Late Triassic.The outer continental margin of Eurasia was split from the Lhasa Terrane so that a back-arc basin came into existence.Hemi-pelagic and deep sea sediments were deposited before the Late Cretaceous flysch sedimentation,with the linear juvenile oceanic crust when back-arc volcanism occurred in the Gandese region.The Yarlung Zangbo back-arc basin was eventually eliminated when the High Himalayas were sutured onto Eurasia.The ocean floor lightly underthrusted to north and south sides,sediments of the basin were deformed as fold-thrusting.The Neotethys was eliminated during the

  2. The bifactor model of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS)--an alternative measurement model of burnout.

    Science.gov (United States)

    Mészáros, V; Adám, Sz; Szabó, M; Szigeti, R; Urbán, R

    2014-02-01

    The purpose of the present study was to examine the construct validity of the Hungarian language version of the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). A sample of 653 healthcare professionals (420 physicians and 233 nurses and nursing assistants) completed the MBI-HSS. A series of confirmatory factor analyses showed that a hierarchical bifactor model including a global burnout factor and three specific factors of emotional exhaustion, depersonalization and reduced personal accomplishment had the closest fit to the data, compared with an alternative second-order three-factor hierarchical model as well as to non-hierarchical one-factor, two-factor, three-factor, four-factor and five-factor models. However, only the global burnout factor and the specific personal accomplishment factor explained a considerable unique proportion of variance in observed scores. Our study confirms the validity of the MBI-HSS and suggests an alternative structural model, which may contribute to further understanding of the burnout construct.

  3. Testing multi-alternative decision models with non-stationary evidence

    Directory of Open Access Journals (Sweden)

    Konstantinos eTsetsos

    2011-05-01

    Full Text Available Recent research has investigated the process of integrating perceptual evidence towards a decision, converging on a number of sequential sampling choice models, such as variants of race and diffusion models and the non-linear leaky competing accumulator (LCA model. Here we study extensions of these models to multi-alternative choice, considering how well they can account for data from a psychophysical experiment in which the evidence supporting each of the alternatives changes dynamically during the trial, in a way that creates temporal correlations. We find that participants exhibit a tendency to choose an alternative whose evidence profile is temporally anti-correlated with (or dissimilar from that of other alternatives. This advantage of the anti-correlated alternative is well accounted for in the LCA, and provides constraints that challenge several other models of multi-alternative choice.

  4. Human factors evaluation of teletherapy: Identification of problems and alternative approaches. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Henriksen, K.; Kaye, R.D.; Jones, R. [Hughes Training, Inc., Falls Church, VA (United States); Morisseau, D.S.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology

    1995-07-01

    A series of human factors evaluations was undertaken to better understand the contributing factors to human error in the teletherapy environment. Teletherapy is a multi-disciplinary methodology for treating cancerous tissue through selective exposure to an external beam of ionizing radiation. The principal sources of radiation are a radioactive isotope, typically cobalt60 (Co-60), or a linear accelerator device capable of producing very high energy x-ray and electron beams. A team of human factors specialists, assisted by a panel of radiation oncologists, medical physicists, and radiation technologists, conducted site visits to radiation oncology departments at community hospitals, university centers, and free-standing clinics. A function and task analysis was initially performed to guide subsequent evaluations in the areas of user-system interfaces, procedures, training and qualifications, and organizational policies and practices. The final phase of the project focused on identification of the most significant human factors problems with respect to safe and effective operation of the teletherapy system and an identification and assessment of alternative approaches for resolving the problems. This report presents the findings of this final phase.

  5. Human factors evaluation of teletherapy: Identification of problems and alternative approaches. Volume 1

    International Nuclear Information System (INIS)

    A series of human factors evaluations was undertaken to better understand the contributing factors to human error in the teletherapy environment. Teletherapy is a multi-disciplinary methodology for treating cancerous tissue through selective exposure to an external beam of ionizing radiation. The principal sources of radiation are a radioactive isotope, typically cobalt60 (Co-60), or a linear accelerator device capable of producing very high energy x-ray and electron beams. A team of human factors specialists, assisted by a panel of radiation oncologists, medical physicists, and radiation technologists, conducted site visits to radiation oncology departments at community hospitals, university centers, and free-standing clinics. A function and task analysis was initially performed to guide subsequent evaluations in the areas of user-system interfaces, procedures, training and qualifications, and organizational policies and practices. The final phase of the project focused on identification of the most significant human factors problems with respect to safe and effective operation of the teletherapy system and an identification and assessment of alternative approaches for resolving the problems. This report presents the findings of this final phase

  6. Factors Associated With Complementary and Alternative Medicine Use in Irritable Bowel Syndrome: A Literature Review

    Directory of Open Access Journals (Sweden)

    Lee Usher

    2013-11-01

    Full Text Available Aim: Irritable Bowel Syndrome (IBS is a chronic functional bowel condition, which has substantial impact on quality of life and use of healthcare services. Patients often report using complementary and alternative medicine (CAM for symptom management despite limited evidence to support its use. Psychological factors have been shown to be important in both influencing CAM use and as avenues of intervention to assist in managing IBS symptoms. Therefore, this review assessed prevalence of and psychological factors associated with CAM use by people with IBS. Method: Five electronic databases (including AMED, EMBASE and PsychINFO were searched for studies that examined both the extent of and the reasons for CAM use. Five studies met the inclusion criteria. Results: Prevalence of CAM use ranged from 9% to 38%. CAM use was associated with psychosocial factors, including concerns about conventional medical care (i.e., the perceived harmful effects of medication, perception that conventional medicine had failed, and lack of satisfaction with conventional care and anxiety. Conclusion: These findings identify psychological factors associated with CAM use which could be targeted through psychologically oriented management strategies for those affected with IBS.

  7. The Critical Role of Complement Alternative Pathway Regulator Factor H in Allergen-Induced Airway Hyperresponsiveness (AHR) and Inflammation

    OpenAIRE

    Takeda, Katsuyuki; Thurman, Joshua M.; Tomlinson, Stephen; Okamoto, Masakazu; Shiraishi, Yoshiki; Ferreira, Viviana P.; Cortes, Claudio; Pangburn, Michael K.; Holers, V. Michael; Gelfand, Erwin W.

    2011-01-01

    Activation of the alternative pathway of complement plays a critical role in the development of allergen-induced airway hyperresponsiveness (AHR) and inflammation in mice. Endogenous factor H, a potent inhibitor of the alternative pathway, is increased in the airways of sensitized and challenged mice, but its role in regulating inflammation or AHR has been unknown. We found that blocking the tissue-binding function of factor H with a competitive antagonist increased complement activation and ...

  8. Extensive alternative splicing of the repressor element silencing transcription factor linked to cancer.

    Directory of Open Access Journals (Sweden)

    Guo-Lin Chen

    Full Text Available The repressor element silencing transcription factor (REST is a coordinate transcriptional and epigenetic regulator which functions as a tumor suppressor or an oncogene depending on cellular context, and a truncated splice variant REST4 has been linked to various types of cancer. We performed a comprehensive analysis of alternative splicing (AS of REST by rapid amplification of cDNA ends and PCR amplification of cDNAs from various tissues and cell lines with specific primers. We identified 8 novel alternative exons including an alternate last exon which doubles the REST gene boundary, along with numerous 5'/3' splice sites and ends in the constitutive exons. With the combination of various splicing patterns (e.g. exon skipping and alternative usage of the first and last exons that are predictive of altered REST activity, at least 45 alternatively spliced variants of coding and non-coding mRNA were expressed in a species- and cell-type/tissue-specific manner with individual differences. By examining the repertoire of REST pre-mRNA splicing in 27 patients with kidney, liver and lung cancer, we found that all patients without exception showed differential expression of various REST splice variants between paired tumor and adjacent normal tissues, with striking cell-type/tissue and individual differences. Moreover, we revealed that exon 3 skipping, which causes no frame shift but loss of a domain essential for nuclear translocation, was affected by pioglitazone, a highly selective activator of the peroxisome proliferator-activated receptor gamma (PPARγ which contributes to cell differentiation and tumorigenesis besides its metabolic actions. Accordingly, this study demonstrates an extensive AS of REST pre-mRNA which redefines REST gene boundary and structure, along with a general but differential link between REST pre-mRNA splicing and various types of cancer. These findings advance our understanding of the complex, context-dependent regulation of

  9. Alternative Splicing of Rice WRKY62 and WRKY76 Transcription Factor Genes in Pathogen Defense.

    Science.gov (United States)

    Liu, Jiqin; Chen, Xujun; Liang, Xiaoxing; Zhou, Xiangui; Yang, Fang; Liu, Jia; He, Sheng Yang; Guo, Zejian

    2016-06-01

    The WRKY family of transcription factors (TFs) functions as transcriptional activators or repressors in various signaling pathways. In this study, we discovered that OsWRKY62 and OsWRKY76, two genes of the WRKY IIa subfamily, undergo constitutive and inducible alternative splicing. The full-length OsWRKY62.1 and OsWRKY76.1 proteins formed homocomplexes and heterocomplexes, and the heterocomplex dominates in the nuclei when analyzed in Nicotiana benthamiana leaves. Transgenic overexpression of OsWRKY62.1 and OsWRKY76.1 in rice (Oryza sativa) enhanced plant susceptibility to the blast fungus Magnaporthe oryzae and the leaf blight bacterium Xanthomonas oryzae pv oryzae, whereas RNA interference and loss-of-function knockout plants exhibited elevated resistance. The dsOW62/76 and knockout lines of OsWRKY62 and OsWRKY76 also showed greatly increased expression of defense-related genes and the accumulation of phytoalexins. The ratio of full-length versus truncated transcripts changed in dsOW62/76 plants as well as in response to pathogen infection. The short alternative OsWRKY62.2 and OsWRKY76.2 isoforms could interact with each other and with full-length proteins. OsWRKY62.2 showed a reduced repressor activity in planta, and two sequence determinants required for the repressor activity were identified in the amino terminus of OsWRKY62.1. The amino termini of OsWRKY62 and OsWRKY76 splice variants also showed reduced binding to the canonical W box motif. These results not only enhance our understanding of the DNA-binding property, the repressor sequence motifs, and the negative feedback regulation of the IIa subfamily of WRKYs but also provide evidence for alternative splicing of WRKY TFs during the plant defense response. PMID:27208272

  10. From Geocentric to Heliocentric Model of the Universe, and the Alternative Perspectives

    Science.gov (United States)

    Liu, Shu-Chiu

    2005-01-01

    A recent study (Liu, 2005a, 2005b) revealed a limited number of alternative models of the universe held by young students in Taiwan and in Germany. In line with the previous findings, these alternative models frequently fall into two groups: earth-centred and sun-centred views, which draw a correspondence to the ideas in the European history of…

  11. Alternative Models of Service, Centralized Machine Operations. Phase II Report. Volume II.

    Science.gov (United States)

    Technology Management Corp., Alexandria, VA.

    A study was conducted to determine if the centralization of playback machine operations for the national free library program would be feasible, economical, and desirable. An alternative model of playback machine services was constructed and compared with existing network operations considering both cost and service. The alternative model was…

  12. The Interaction of Language-Specific and Universal Factors During the Acquisition of Morphophonemic Alternations With Exceptions.

    Science.gov (United States)

    Baer-Henney, Dinah; Kügler, Frank; van de Vijver, Ruben

    2015-09-01

    Using the artificial language paradigm, we studied the acquisition of morphophonemic alternations with exceptions by 160 German adult learners. We tested the acquisition of two types of alternations in two regularity conditions while additionally varying length of training. In the first alternation, a vowel harmony, backness of the stem vowel determines backness of the suffix. This process is grounded in substance (phonetic motivation), and this universal phonetic factor bolsters learning a generalization. In the second alternation, tenseness of the stem vowel determines backness of the suffix vowel. This process is not based in substance, but it reflects a phonotactic property of German and our participants benefit from this language-specific factor. We found that learners use both cues, while substantive bias surfaces mainly in the most unstable situation. We show that language-specific and universal factors interact in learning.

  13. Protein interaction network of alternatively spliced isoforms from brain links genetic risk factors for autism.

    Science.gov (United States)

    Corominas, Roser; Yang, Xinping; Lin, Guan Ning; Kang, Shuli; Shen, Yun; Ghamsari, Lila; Broly, Martin; Rodriguez, Maria; Tam, Stanley; Trigg, Shelly A; Fan, Changyu; Yi, Song; Tasan, Murat; Lemmens, Irma; Kuang, Xingyan; Zhao, Nan; Malhotra, Dheeraj; Michaelson, Jacob J; Vacic, Vladimir; Calderwood, Michael A; Roth, Frederick P; Tavernier, Jan; Horvath, Steve; Salehi-Ashtiani, Kourosh; Korkin, Dmitry; Sebat, Jonathan; Hill, David E; Hao, Tong; Vidal, Marc; Iakoucheva, Lilia M

    2014-04-11

    Increased risk for autism spectrum disorders (ASD) is attributed to hundreds of genetic loci. The convergence of ASD variants have been investigated using various approaches, including protein interactions extracted from the published literature. However, these datasets are frequently incomplete, carry biases and are limited to interactions of a single splicing isoform, which may not be expressed in the disease-relevant tissue. Here we introduce a new interactome mapping approach by experimentally identifying interactions between brain-expressed alternatively spliced variants of ASD risk factors. The Autism Spliceform Interaction Network reveals that almost half of the detected interactions and about 30% of the newly identified interacting partners represent contribution from splicing variants, emphasizing the importance of isoform networks. Isoform interactions greatly contribute to establishing direct physical connections between proteins from the de novo autism CNVs. Our findings demonstrate the critical role of spliceform networks for translating genetic knowledge into a better understanding of human diseases.

  14. Alternative Splicing Regulation During C. elegans Development: Splicing Factors as Regulated Targets

    OpenAIRE

    Sergio Barberan-Soler; Zahler, Alan M.

    2008-01-01

    Alternative splicing generates protein diversity and allows for post-transcriptional gene regulation. Estimates suggest that 10% of the genes in Caenorhabditis elegans undergo alternative splicing. We constructed a splicing-sensitive microarray to detect alternative splicing for 352 cassette exons and tested for changes in alternative splicing of these genes during development. We found that the microarray data predicted that 62/352 (approximately 18%) of the alternative splicing events studi...

  15. Mathematical model of alternative mechanism of telomere length maintenance

    OpenAIRE

    Kollár, Richard; Bodova, Katarina; Nosek, Jozef; Tomaska, Lubomir

    2014-01-01

    Biopolymer length regulation is a complex process that involves a large number of subprocesses acting simultaneously across multiple spatial and temporal scales. An illustrative example important for genomic stability is the length regulation of telomeres---nucleo-protein structures at the ends of linear chromosomes. Maintenance of telomeres is often facilitated by the enzyme telomerase but, particularly in telomerase-free systems, the maintenance of chromosomal termini depends on alternative...

  16. Comparison of Transcription Factor Binding Site Models

    KAUST Repository

    Bhuyan, Sharifulislam

    2012-05-01

    Modeling of transcription factor binding sites (TFBSs) and TFBS prediction on genomic sequences are important steps to elucidate transcription regulatory mechanism. Dependency of transcription regulation on a great number of factors such as chemical specificity, molecular structure, genomic and epigenetic characteristics, long distance interaction, makes this a challenging problem. Different experimental procedures generate evidence that DNA-binding domains of transcription factors show considerable DNA sequence specificity. Probabilistic modeling of TFBSs has been moderately successful in identifying patterns from a family of sequences. In this study, we compare performances of different probabilistic models and try to estimate their efficacy over experimental TFBSs data. We build a pipeline to calculate sensitivity and specificity from aligned TFBS sequences for several probabilistic models, such as Markov chains, hidden Markov models, Bayesian networks. Our work, containing relevant statistics and evaluation for the models, can help researchers to choose the most appropriate model for the problem at hand.

  17. Developing a Hierarchical Decision Model to Evaluate Nuclear Power Plant Alternative Siting Technologies

    Science.gov (United States)

    Lingga, Marwan Mossa

    A strong trend of returning to nuclear power is evident in different places in the world. Forty-five countries are planning to add nuclear power to their grids and more than 66 nuclear power plants are under construction. Nuclear power plants that generate electricity and steam need to improve safety to become more acceptable to governments and the public. One novel practical solution to increase nuclear power plants' safety factor is to build them away from urban areas, such as offshore or underground. To date, Land-Based siting is the dominant option for siting all commercial operational nuclear power plants. However, the literature reveals several options for building nuclear power plants in safer sitings than Land-Based sitings. The alternatives are several and each has advantages and disadvantages, and it is difficult to distinguish among them and choose the best for a specific project. In this research, we recall the old idea of using the alternatives of offshore and underground sitings for new nuclear power plants and propose a tool to help in choosing the best siting technology. This research involved the development of a decision model for evaluating several potential nuclear power plant siting technologies, both those that are currently available and future ones. The decision model was developed based on the Hierarchical Decision Modeling (HDM) methodology. The model considers five major dimensions, social, technical, economic, environmental, and political (STEEP), and their related criteria and sub-criteria. The model was designed and developed by the author, and its elements' validation and evaluation were done by a large number of experts in the field of nuclear energy. The decision model was applied in evaluating five potential siting technologies and ranked the Natural Island as the best in comparison to Land-Based, Floating Plant, Artificial Island, and Semi-Embedded plant.

  18. Alternative Splicing of Neuronal Differentiation Factor TRF2 Regulated by HNRNPH1/H2

    Directory of Open Access Journals (Sweden)

    Ioannis Grammatikakis

    2016-05-01

    Full Text Available During neuronal differentiation, use of an alternative splice site on the rat telomere repeat-binding factor 2 (TRF2 mRNA generates a short TRF2 protein isoform (TRF2-S capable of derepressing neuronal genes. However, the RNA-binding proteins (RBPs controlling this splicing event are unknown. Here, using affinity pull-down analysis, we identified heterogeneous nuclear ribonucleoproteins H1 and H2(HNRNPH as RBPs specifically capable of interacting with the spliced RNA segment (exon 7 of Trf2 pre-mRNA. HNRNPH proteins prevent the production of the short isoform of Trf2 mRNA, as HNRNPH silencing selectively elevates TRF2-S levels. Accordingly, HNRNPH levels decline while TRF2-S levels increase during neuronal differentiation. In addition, CRISPR/Cas9-mediated deletion of hnRNPH2 selectively accelerates the NGF-triggered differentiation of rat pheochromocytoma cells into neurons. In sum, HNRNPH is a splicing regulator of Trf2 pre-mRNA that prevents the expression of TRF2-S, a factor implicated in neuronal differentiation.

  19. Contextual and psychological factors shaping evaluations and acceptability of energy alternatives : Integrated review and research agenda

    NARCIS (Netherlands)

    Perlaviciute, Goda; Steg, Linda

    2014-01-01

    Sustainable energy transitions will be hampered without sufficient public support. Hence, it is important to understand what drives public acceptability of (sustainable) energy alternatives. Evaluations of specific costs, including risks, and benefits of different energy alternatives have been linke

  20. On principal factors in substorm models

    Institute of Scientific and Technical Information of China (English)

    朱岗; 洪明华

    2001-01-01

    This paper gives a brief account of substorm modeling with different key elements or factors. The progress of our understanding of substorms consists of three chief stages during this century. Nine previous substorm models are briefly recapitulated, and then a recent two neutral-points model by Prof. C.T. Russell is introduced. In order to test or to strengthen this new model, several correlated examples of meaningful data are duly given in this short paper.

  1. The Money-Creation Model: An Alternative Pedagogy.

    Science.gov (United States)

    Thornton, Mark; And Others

    1991-01-01

    Presents a teaching model that is consistent with the traditional approach to demonstrating the expansion and contraction of the money supply. Suggests that the model provides a simple and convenient visual image of changes in the monetary system. Describes the model as juxtaposing the behavior of the moneyholding public with that of the…

  2. Alternative Multiple Imputation Inference for Mean and Covariance Structure Modeling

    Science.gov (United States)

    Lee, Taehun; Cai, Li

    2012-01-01

    Model-based multiple imputation has become an indispensable method in the educational and behavioral sciences. Mean and covariance structure models are often fitted to multiply imputed data sets. However, the presence of multiple random imputations complicates model fit testing, which is an important aspect of mean and covariance structure…

  3. Perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry.

    Science.gov (United States)

    Redondo, Leandro M; Chacana, Pablo A; Dominguez, Johana E; Fernandez Miyakawa, Mariano E

    2014-01-01

    Antibiotics have been included in the formulation of feed for livestock production for more than 40 years as a strategy to improve feed conversion rates and to reduce costs. The use of antimicrobials as growth-promoting factors (AGP) in sub-therapeutic doses for long periods is particularly favorable for the selection of antimicrobial resistant microorganisms. In the last years, global concern about development of antimicrobial resistance and transference of resistance genes from animal to human strains has been rising. Removal of AGP from animal diets involves tremendous pressure on the livestock and poultry farmers, one of the main consequences being a substantial increase in the incidence of infectious diseases with the associated increase in the use of antibiotics for therapy, and concomitantly, economic cost. Therefore, alternatives to AGP are urgently needed. The challenge is to implement new alternatives without affecting the production performances of livestock and avoiding the increase of antimicrobial resistant microorganisms. Plant extracts and purified derived substances are showing promising results for animal nutrition, either from their efficacy as well as from an economical point of view. Tannins are plant derived compounds that are being successfully used as additives in poultry feed to control diseases and to improve animal performance. Successful use of any of these extracts as feed additives must ensure a product of consistent quality in enough quantity to fulfill the actual requirements of the poultry industry. Chestnut (hydrolysable) and Quebracho (condensed) tannins are probably the most readily available commercial products that are covering those needs. The present report intends to analyze the available data supporting their use. PMID:24723916

  4. Perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry

    Directory of Open Access Journals (Sweden)

    Leandro M Redondo

    2014-03-01

    Full Text Available Antibiotics have been included in the formulation of feed for livestock production for more than 40 years as a strategy to improve feed conversion rates and to reduce costs. The use of antimicrobials as growth-promoting factors (AGP in sub-therapeutic doses for long periods is particularly favorable to select antimicrobial-resistant microorganisms. In the last years, global concern about development of antimicrobial resistance and transference of resistance genes from animal to human strains has been arising. Removal of AGP from animal diets involves a tremendous pressure on the livestock and poultry farmers, one of the main consequences being a substantial increase in the incidence of infectious diseases with the related increase in the use of antibiotics for therapy and, concomitantly, economic cost. Therefore, alternatives to AGP are urgently needed. The challenge is to implement new alternatives without affecting the production performances of livestock and also avoiding the increase of antimicrobial resistant microorganisms. Plant extracts and purified derived substances are showing promising results for food animal production, either from their efficacy as well as from an economical point of view. Tannins are plant derived compounds that are being successfully used as additives in feed poultry to control diseases and to improve animal performance. Successful use of any of these extracts as feed additive must ensure a product of consistent quality in enough quantities to fulfill the actual requirements of the poultry industry. Chestnut (hydrolizable and Quebracho (condennsed tannins are probably the most readily available commercial products that are covering those needs. The present report intends to analyze the available data supporting their use.

  5. Perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry.

    Science.gov (United States)

    Redondo, Leandro M; Chacana, Pablo A; Dominguez, Johana E; Fernandez Miyakawa, Mariano E

    2014-01-01

    Antibiotics have been included in the formulation of feed for livestock production for more than 40 years as a strategy to improve feed conversion rates and to reduce costs. The use of antimicrobials as growth-promoting factors (AGP) in sub-therapeutic doses for long periods is particularly favorable for the selection of antimicrobial resistant microorganisms. In the last years, global concern about development of antimicrobial resistance and transference of resistance genes from animal to human strains has been rising. Removal of AGP from animal diets involves tremendous pressure on the livestock and poultry farmers, one of the main consequences being a substantial increase in the incidence of infectious diseases with the associated increase in the use of antibiotics for therapy, and concomitantly, economic cost. Therefore, alternatives to AGP are urgently needed. The challenge is to implement new alternatives without affecting the production performances of livestock and avoiding the increase of antimicrobial resistant microorganisms. Plant extracts and purified derived substances are showing promising results for animal nutrition, either from their efficacy as well as from an economical point of view. Tannins are plant derived compounds that are being successfully used as additives in poultry feed to control diseases and to improve animal performance. Successful use of any of these extracts as feed additives must ensure a product of consistent quality in enough quantity to fulfill the actual requirements of the poultry industry. Chestnut (hydrolysable) and Quebracho (condensed) tannins are probably the most readily available commercial products that are covering those needs. The present report intends to analyze the available data supporting their use.

  6. Alternative Functional In Vitro Models of Human Intestinal Epithelia

    Directory of Open Access Journals (Sweden)

    Amanda L Kauffman

    2013-07-01

    Full Text Available Physiologically relevant sources of absorptive intestinal epithelial cells are crucial for human drug transport studies. Human adenocarcinoma-derived intestinal cell lines, such as Caco-2, offer conveniences of easy culture maintenance and scalability, but do not fully recapitulate in vivo intestinal phenotypes. Additional sources of renewable physiologically relevant human intestinal cells would provide a much needed tool for drug discovery and intestinal physiology. We sought to evaluate and compare two alternative sources of human intestinal cells, commercially available primary human intestinal epithelial cells (hInEpCs and induced pluripotent stem cell (iPSC-derived intestinal cells to Caco-2, for use in in vitro transwell monolayer intestinal transport assays. To achieve this for iPSC-derived cells, our previously described 3-dimensional intestinal organogenesis method was adapted to transwell differentiation. Intestinal cells were assessed by marker expression through immunocytochemical and mRNA expression analyses, monolayer integrity through Transepithelial Electrical Resistance (TEER measurements and molecule permeability, and functionality by taking advantage the well-characterized intestinal transport mechanisms. In most cases, marker expression for primary hInEpCs and iPSC-derived cells appeared to be as good as or better than Caco-2. Furthermore, transwell monolayers exhibited high TEER with low permeability. Primary hInEpCs showed molecule efflux indicative of P-glycoprotein transport. Primary hInEpCs and iPSC-derived cells also showed neonatal Fc receptor-dependent binding of immunoglobulin G variants. Primary hInEpCs and iPSC-derived intestinal cells exhibit expected marker expression and demonstrate basic functional monolayer formation, similar to or better than Caco-2. These cells could offer an alternative source of human intestinal cells for understanding normal intestinal epithelial physiology and drug transport.

  7. Evaluating Alternate Biokinetic Models for Trace Pollutant Cometabolism

    DEFF Research Database (Denmark)

    Liu, Li; Binning, Philip John; Smets, Barth F.

    2015-01-01

    Mathematical models of cometabolic biodegradation kinetics can improve our understanding of the relevant microbial reactions and allow us to design in situ or in-reactor applications of cometabolic bioremediation. A variety of models are available, but their ability to describe experimental data...... has not been systematically evaluated for a variety of operational/experimental conditions. Here five different models were considered: first-order; MichaelisMenten; reductant; competition; and combined models. The models were assessed on their ability to fit data from simulated batch experiments...... different parameter sets to simulate each experiment. Parameter nonuniqueness was likely to be due to the parameter correlation. These results suggest that the cometabolic models must be further developed if they are to reliably simulate experimental and operational data....

  8. Evaluation of the impact of planning alternative strategies on urban metabolism with the ACASA model

    Science.gov (United States)

    Marras, S.; Casula, M.; Pyles, R. D.; Paw U, K. T.; Spano, D.

    2011-12-01

    A crucial point in urban sustainable development is to evaluate the impact that future planning alternatives has on the main factors affecting the citizens liveableness, as the development of the urban heat island or the carbon emissions level. Recent advances in bio-physical sciences have led to new methods and models to estimate energy, water, and carbon fluxes. Also, several studies have addressed urban metabolism issues, but few have integrated the development of numerical tools and methodologies for the analysis of fluxes between a city and its environment with its validation and application in terms of future development alternatives. Over the past several years and most recently within the European Project "BRIDGE", CMCC tested the ACASA (Advanced-Canopy-Atmosphere-Soil Algorithm) land-surface model over agricultural ecosystems (grapes), wild vegetation (forests and Mediterranean maquis), and urban (Florence) or mixed urban/vegetated land (Helsinki). Preliminary results show success in adapting the model to mixed urban systems in each of the main fluxes of interest. The model was improved to adapt it for urban environment, and key parameterizations of leaf-facet scale interactions permit separate accounting of both biogenic and anthropogenic flux sources and sinks, and allow for easy scenario building for simulations designed to test changes in land use or urban planning. In this way, sustainable planning strategies are proposed based on quantitative assessments of energy, water, and carbon fluxes. In this research, three planning alternatives accounting for an increase in urbanization intensity were tested by ACASA in Helsinki (Finland) for the year 2008. Helsinki is located at a high latitude and is characterized by a rapid urbanization that requires a substantial amount of energy for heating. The model behavior for the baseline and alternatives scenarios (i.e., urban classes with low, mid, and high residential intensity) during the entire year was

  9. On an Estimation Method for an Alternative Fractionally Cointegrated Model

    DEFF Research Database (Denmark)

    Carlini, Federico; Łasak, Katarzyna

    In this paper we consider the Fractional Vector Error Correction model proposed in Avarucci (2007), which is characterized by a richer lag structure than models proposed in Granger (1986) and Johansen (2008, 2009). We discuss the identification issues of the model of Avarucci (2007), following...... the ideas in Carlini and Santucci de Magistris (2014) for the model of Johansen (2008, 2009). We propose a 4-step estimation procedure that is based on the switching algorithm employed in Carlini and Mosconi (2014) and the GLS procedure in Mosconi and Paruolo (2014). The proposed procedure provides...

  10. A Bayesian Alternative for Multi-objective Ecohydrological Model Specification

    Science.gov (United States)

    Tang, Y.; Marshall, L. A.; Sharma, A.; Ajami, H.

    2015-12-01

    Process-based ecohydrological models combine the study of hydrological, physical, biogeochemical and ecological processes of the catchments, which are usually more complex and parametric than conceptual hydrological models. Thus, appropriate calibration objectives and model uncertainty analysis are essential for ecohydrological modeling. In recent years, Bayesian inference has become one of the most popular tools for quantifying the uncertainties in hydrological modeling with the development of Markov Chain Monte Carlo (MCMC) techniques. Our study aims to develop appropriate prior distributions and likelihood functions that minimize the model uncertainties and bias within a Bayesian ecohydrological framework. In our study, a formal Bayesian approach is implemented in an ecohydrological model which combines a hydrological model (HyMOD) and a dynamic vegetation model (DVM). Simulations focused on one objective likelihood (Streamflow/LAI) and multi-objective likelihoods (Streamflow and LAI) with different weights are compared. Uniform, weakly informative and strongly informative prior distributions are used in different simulations. The Kullback-leibler divergence (KLD) is used to measure the dis(similarity) between different priors and corresponding posterior distributions to examine the parameter sensitivity. Results show that different prior distributions can strongly influence posterior distributions for parameters, especially when the available data is limited or parameters are insensitive to the available data. We demonstrate differences in optimized parameters and uncertainty limits in different cases based on multi-objective likelihoods vs. single objective likelihoods. We also demonstrate the importance of appropriately defining the weights of objectives in multi-objective calibration according to different data types.

  11. A clinically based service limitation option for alternative model rural hospitals.

    Science.gov (United States)

    Moscovice, I; Wellever, A; Sales, A; Chen, M M; Christianson, J

    1993-01-01

    Alternative model rural hospitals are designed to address problems faced by small, isolated rural hospitals. Typically, hospital regulations are reduced in exchange for a limit on the services that alternative models may offer. The most common service limitation is a limit on length of stay (LOS), a method with little empirical or conceptual support. The purpose of this article is to present a clinically based service limitation for alternative model rural hospitals, such as the rural primary care hospital. The proposal is based on an analysis of Medicare discharges from rural hospitals most likely to convert and the judgments of a technical advisory panel of rural clinicians. PMID:10135339

  12. Stochastic Greybox Modeling of an Alternating Activated Sludge Process

    DEFF Research Database (Denmark)

    Halvgaard, Rasmus Fogtmann; Munk-Nielsen, T.; Tychsen, P.;

    Summary of key findings We found a greybox model for state estimation and control of the BioDenitro process based on a reduced ASM1. We then applied Maximum Likelihood Estimation on measurements from a real full-scale waste water treatment plant to estimate the model parameters. The estimation...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    New prognostic models are traditionally evaluated using measures of discrimination and risk reclassification, but these do not take full account of the clinical and health economic context. We propose a framework for comparing prognostic models by quantifying the public health impact (net benefit...

  14. Continuous utility factor in segregation models

    Science.gov (United States)

    Roy, Parna; Sen, Parongama

    2016-02-01

    We consider the constrained Schelling model of social segregation in which the utility factor of agents strictly increases and nonlocal jumps of the agents are allowed. In the present study, the utility factor u is defined in a way such that it can take continuous values and depends on the tolerance threshold as well as the fraction of unlike neighbors. Two models are proposed: in model A the jump probability is determined by the sign of u only, which makes it equivalent to the discrete model. In model B the actual values of u are considered. Model A and model B are shown to differ drastically as far as segregation behavior and phase transitions are concerned. In model A, although segregation can be achieved, the cluster sizes are rather small. Also, a frozen state is obtained in which steady states comprise many unsatisfied agents. In model B, segregated states with much larger cluster sizes are obtained. The correlation function is calculated to show quantitatively that larger clusters occur in model B. Moreover for model B, no frozen states exist even for very low dilution and small tolerance parameter. This is in contrast to the unconstrained discrete model considered earlier where agents can move even when utility remains the same. In addition, we also consider a few other dynamical aspects which have not been studied in segregation models earlier.

  15. Human Serum-Specific Activation of Alternative Sigma Factors, the Stress Responders in Aggregatibacter actinomycetemcomitans

    Science.gov (United States)

    Tang-Siegel, Gaoyan; Bumgarner, Roger; Ruiz, Teresa; Kittichotirat, Weerayuth; Chen, Weizhen; Chen, Casey

    2016-01-01

    Aggregatibacter actinomycetemcomitans, a known pathogen causing periodontal disease and infective endocarditis, is a survivor in the periodontal pocket and blood stream; both environments contain serum as a nutrient source. To screen for unknown virulence factors associated with this microorganism, A. actinomycetemcomitans was grown in serum-based media to simulate its in vivo environment. Different strains of A. actinomycetemcomitans showed distinct growth phenotypes only in the presence of human serum, and they were grouped into high- and low-responder groups. High-responders comprised mainly serotype c strains, and showed an unusual growth phenomenon, featuring a second, rapid increase in turbidity after 9-h incubation that reached a final optical density 2- to 7-fold higher than low-responders. Upon further investigation, the second increase in turbidity was not caused by cell multiplication, but by cell death. Whole transcriptomic analysis via RNA-seq identified 35 genes that were up-regulated by human serum, but not horse serum, in high-responders but not in low-responders, including prominently an alternative sigma factor rpoE (σE). A lacZ reporter construct driven by the 132-bp rpoE promoter sequence of A. actinomycetemcomitans responded dramatically to human serum within 90 min of incubation only when the construct was carried by a high responder strain. The rpoE promoter is 100% identical among high- and low-responder strains. Proteomic investigation showed potential interactions between human serum protein, e.g. apolipoprotein A1 (ApoA1) and A. actinomycetemcomitans. The data clearly indicated a different activation process for rpoE in high- versus low-responder strains. This differential human serum-specific activation of rpoE, a putative extra-cytoplasmic stress responder and global regulator, suggests distinct in vivo adaptations among different strains of A. actinomycetemcomitans. PMID:27490177

  16. Application of Decision Alternatives Evaluation Models to the Selection of Computer Systems

    Directory of Open Access Journals (Sweden)

    Jackson AKPOJARO

    2013-03-01

    Full Text Available The selection of a computer system is a process dependent on many factors and irrespective of how the process proceeds; ultimately the monetary factors will play a major role. It is important to recognize the initial costs of the acquisition of the new hardware and the immediate attendance software, and also the continuing costs associated with the maintenance of hardware, software and upgrading devices that must be budgeted for to continue the infusion of viable applications. However, the selection of a given computer system from a choice set is becoming a difficult task following the proliferation of computer brands by various computer manufactures. This paper reviews different computer systems selection methodologies, draws from this background, and provides alternative models with illustrative examples to assist organizations, individual consumers or prospective buyers in arriving at specification or configurations that meet their established needs or requirements. The paper helps to educate the consumers or prospective buyers on the selection criteria and evaluation procedures for analyzing proposal submitted by vendors. The selection models adopted in this paper are evaluated using the weighted values of the different attributes submitted by vendors.

  17. Health, Islam and Alternative Capitalism. Three possible Key Factors in Developing Somaliland

    Directory of Open Access Journals (Sweden)

    Daria Zizzola

    2012-02-01

    Full Text Available The main aim of this paper is to investigate the socio, political and economic dynamics that have occurred in Somaliland in the last decades. Even though this country is still unrecognized by the international community, Somaliland’s economy has undertaken an enduring growth, above all in the private entrepreneurial sector. The author argues that religion has had an important role in the Somali cultural and social identification. According to this assumption, the article analyzes the Islamic factor by showing how it has led to the creation of many alternative connections supported by mutual trust and religious solidarity among involved communities. These connections are somehow fulfilling the absence of political legitimacy while progressively substituting conventional routes of intra-national negotiation, like diplomacy. To confirm this tendency, specific arguments are drawn from Somaliland’s health sector. The health care system is considered a preferential index to evaluate the level of national development. Above all, the private non-profit sector gives some evidence of the Somali capacity of running competitive private businesses while multiplying simultaneously their resources and suppliers with a consequent increase in autonomy and efficiency. This successful compromise bears the fruits of Somali engagement and can be identified by their inexhaustible adaptability to adverse conditions and their ability to avoid, not deny, the rational rules imposed by external actors and their ostensible, insurmountable interests.

  18. The asset pricing model of musharakah factors

    Science.gov (United States)

    Simon, Shahril; Omar, Mohd; Lazam, Norazliani Md

    2015-02-01

    The existing three-factor model developed by Fama and French for conventional investment was formulated based on risk-free rates element in which contradict with Shariah principles. We note that the underlying principles that govern Shariah investment were mutual risk and profit sharing between parties, the assurance of fairness for all and that transactions were based on an underlying asset. In addition, the three-factor model did not exclude stock that was not permissible by Shariah such as financial services based on riba (interest), gambling operator, manufacture or sale of non-halal products or related products and other activities deemed non-permissible according to Shariah. Our approach to construct the factor model for Shariah investment was based on the basic tenets of musharakah in tabulating the factors. We start by noting that Islamic stocks with similar characteristics should have similar returns and risks. This similarity between Islamic stocks was defined by the similarity of musharakah attributes such as business, management, profitability and capital. These attributes define factor exposures (or betas) to factors. The main takeaways were that musharakah attributes we chose had explain stock returns well in cross section and were significant in different market environments. The management factor seemed to be responsible for the general dynamics of the explanatory power.

  19. Volatility Asset Pricing Model as an Alternative Approach?

    OpenAIRE

    Kuklik, Robert G.; Vacek, Vladislav

    2013-01-01

    The reality of contemporary developments in the capital markets indicates that they do not lend themselves to the deductive theory based on simplified rationality of the physical world. The behaviour of the markets cannot be derived from rather bare postulates of the so called “random walk” process and the “normal distribution” of investments´ returns. It in fact relates to a variety of different. even behavioural factors. The riskreturn relationship is not therefore stable over time and inve...

  20. Alternative GMM Methods for Nonlinear Panel Data Models

    OpenAIRE

    Breitung, Jörg; Lechner, Michael

    1999-01-01

    Not available in German. Frühere Version: Breitung, J. and M. Lechner (1998), Altenative GMM Methods for Nonlinear Panel Data models, discussion paper 81, SFB 373 Humbold-Universität zu Berlin. Download Volltext: (pdf, 263 kb)

  1. Pluralism an an Alternative Model for the Human Ecologist.

    Science.gov (United States)

    Klaff, Vivian Z.

    1980-01-01

    Examines some of the arguments used to support the view that residential segregation of ethnic and racial groups is necessarily disintegrative. Suggests that pluralism should receive greater attention as a model of residential segregation. (Author/JLF)

  2. Evaluation and comparison of alternative fleet-level selective maintenance models

    International Nuclear Information System (INIS)

    Fleet-level selective maintenance refers to the process of identifying the subset of maintenance actions to perform on a fleet of repairable systems when the maintenance resources allocated to the fleet are insufficient for performing all desirable maintenance actions. The original fleet-level selective maintenance model is designed to maximize the probability that all missions in a future set are completed successfully. We extend this model in several ways. First, we consider a cost-based optimization model and show that a special case of this model maximizes the expected value of the number of successful missions in the future set. We also consider the situation in which one or more of the future missions may be canceled. These models and the original fleet-level selective maintenance optimization models are nonlinear. Therefore, we also consider an alternative model in which the objective function can be linearized. We show that the alternative model is a good approximation to the other models. - Highlights: • Investigate nonlinear fleet-level selective maintenance optimization models. • A cost based model is used to maximize the expected number of successful missions. • Another model is allowed to cancel missions if reliability is sufficiently low. • An alternative model has an objective function that can be linearized. • We show that the alternative model is a good approximation to the other models

  3. Configurational analysis as an alternative way of modeling sales response

    OpenAIRE

    Aarnio, Susanna

    2013-01-01

    Objectives of the Study The objectives of the study are both managerial and methodological. On the one hand, the aim is to apply a novel research approach, fuzzy set qualitative comparative analysis or fsQCA (see f. ex. Ragin, 2000; Rihoux & Ragin, 2009), to sales response modeling and thus, create a response model for the case company to identify complex, configurational causalities affecting the company's sales volumes within the chosen product category. On the other hand, to goal is to ...

  4. Epstein-Barr Virus SM Protein Functions as an Alternative Splicing Factor

    OpenAIRE

    Verma, Dinesh; Swaminathan, Sankar

    2008-01-01

    Alternative splicing of RNA increases the coding potential of the genome and allows for additional regulatory control over gene expression. The full extent of alternative splicing remains to be defined but is likely to significantly expand the size of the human transcriptome. There are several examples of mammalian viruses regulating viral splicing or inhibiting cellular splicing in order to facilitate viral replication. Here, we describe a viral protein that induces alternative splicing of a...

  5. Modeling mixtures of thyroid gland function disruptors in a vertebrate alternative model, the zebrafish eleutheroembryo

    International Nuclear Information System (INIS)

    Maternal thyroxine (T4) plays an essential role in fetal brain development, and even mild and transitory deficits in free-T4 in pregnant women can produce irreversible neurological effects in their offspring. Women of childbearing age are daily exposed to mixtures of chemicals disrupting the thyroid gland function (TGFDs) through the diet, drinking water, air and pharmaceuticals, which has raised the highest concern for the potential additive or synergic effects on the development of mild hypothyroxinemia during early pregnancy. Recently we demonstrated that zebrafish eleutheroembryos provide a suitable alternative model for screening chemicals impairing the thyroid hormone synthesis. The present study used the intrafollicular T4-content (IT4C) of zebrafish eleutheroembryos as integrative endpoint for testing the hypotheses that the effect of mixtures of TGFDs with a similar mode of action [inhibition of thyroid peroxidase (TPO)] was well predicted by a concentration addition concept (CA) model, whereas the response addition concept (RA) model predicted better the effect of dissimilarly acting binary mixtures of TGFDs [TPO-inhibitors and sodium-iodide symporter (NIS)-inhibitors]. However, CA model provided better prediction of joint effects than RA in five out of the six tested mixtures. The exception being the mixture MMI (TPO-inhibitor)-KClO4 (NIS-inhibitor) dosed at a fixed ratio of EC10 that provided similar CA and RA predictions and hence it was difficult to get any conclusive result. There results support the phenomenological similarity criterion stating that the concept of concentration addition could be extended to mixture constituents having common apical endpoints or common adverse outcomes. - Highlights: • Potential synergic or additive effect of mixtures of chemicals on thyroid function. • Zebrafish as alternative model for testing the effect of mixtures of goitrogens. • Concentration addition seems to predict better the effect of mixtures of

  6. Modeling mixtures of thyroid gland function disruptors in a vertebrate alternative model, the zebrafish eleutheroembryo

    Energy Technology Data Exchange (ETDEWEB)

    Thienpont, Benedicte; Barata, Carlos [Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Jordi Girona, 18-26, 08034 Barcelona (Spain); Raldúa, Demetrio, E-mail: drpqam@cid.csic.es [Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA, CSIC), Jordi Girona, 18-26, 08034 Barcelona (Spain); Maladies Rares: Génétique et Métabolisme (MRGM), University of Bordeaux, EA 4576, F-33400 Talence (France)

    2013-06-01

    Maternal thyroxine (T4) plays an essential role in fetal brain development, and even mild and transitory deficits in free-T4 in pregnant women can produce irreversible neurological effects in their offspring. Women of childbearing age are daily exposed to mixtures of chemicals disrupting the thyroid gland function (TGFDs) through the diet, drinking water, air and pharmaceuticals, which has raised the highest concern for the potential additive or synergic effects on the development of mild hypothyroxinemia during early pregnancy. Recently we demonstrated that zebrafish eleutheroembryos provide a suitable alternative model for screening chemicals impairing the thyroid hormone synthesis. The present study used the intrafollicular T4-content (IT4C) of zebrafish eleutheroembryos as integrative endpoint for testing the hypotheses that the effect of mixtures of TGFDs with a similar mode of action [inhibition of thyroid peroxidase (TPO)] was well predicted by a concentration addition concept (CA) model, whereas the response addition concept (RA) model predicted better the effect of dissimilarly acting binary mixtures of TGFDs [TPO-inhibitors and sodium-iodide symporter (NIS)-inhibitors]. However, CA model provided better prediction of joint effects than RA in five out of the six tested mixtures. The exception being the mixture MMI (TPO-inhibitor)-KClO{sub 4} (NIS-inhibitor) dosed at a fixed ratio of EC{sub 10} that provided similar CA and RA predictions and hence it was difficult to get any conclusive result. There results support the phenomenological similarity criterion stating that the concept of concentration addition could be extended to mixture constituents having common apical endpoints or common adverse outcomes. - Highlights: • Potential synergic or additive effect of mixtures of chemicals on thyroid function. • Zebrafish as alternative model for testing the effect of mixtures of goitrogens. • Concentration addition seems to predict better the effect of

  7. Identification of Errors in the Hanford Site-Wide Groundwater Flow Model by Inverse Modeling of Alternative Conceptual Models

    Science.gov (United States)

    Cole, C. R.; Scheibe, T. D.; Vermeul, V. R.; Wurstner, S. K.; Thorne, P. D.; Freedman, V. L.; Murray, C. J.; Bergeron, M. P.

    2002-12-01

    A regional-scale, three-dimensional groundwater flow and transport modeling effort has been undertaken to quantify the environmental consequences of past waste disposal activities and support ongoing environmental management activities at the U.S. Department of Energy's Hanford Site. An important aspect of this effort is the identification and quantification of uncertainties associated with model predictions. It is recognized that such uncertainties arise not only from selection of inappropriate groundwater model parameters (parameter error), but also from the underlying conceptualization of the groundwater system (model error). Therefore, we have adopted an approach to uncertainty characterization that involves the evaluation of multiple alternative conceptual models (ACMs) within an inverse modeling framework. The initial step in implementation of the framework was the development of a multi-processor implementation of the UCODE inverse modeling system and application of the inverse framework to update parameter estimates from a prior deterministic model. A preliminary first-order uncertainty analysis was performed based on the model results. At the same time, site geologists developed an improved conceptual model of the 3D structure of the aquifer system. Inverse modeling of the updated conceptual model led to estimates of some parameters, especially specific yield, that were not plausible, indicating that there were problems with the conceptual model. As a result, additional ACMs were developed and subjected to inverse analysis, including an alternative with modified boundary conditions (leaky underlying bedrock), an alternative incorporating surface recharge modifications based on surface run-on from an adjacent topographic feature, and an alternative incorporating an improved description of the timing and volume of waste discharges arriving at the water table (upper model boundary). Model predictions of transient hydraulic heads under each ACM were compared

  8. The Confidence Model: An Alternative Approach to Alleviating Communication Apprehension.

    Science.gov (United States)

    Watson, Arden K.

    Recognizing that each student is different in terms of communication apprehension and needed skills, the confidence model attempts to provide instruction in anxiety reduction and skill development, combining the features of both the behavior therapy and the rhetoritherapy theories of communication apprehension. The rational emotive therapy used in…

  9. Modeling Health Insurance Expansions: Effects of Alternate Approaches

    Science.gov (United States)

    Remler, Dahlia K.; Zivin, Joshua Graff; Glied, Sherry A.

    2004-01-01

    Estimates of the costs and consequences of many types of public policy proposals play an important role in the development and adoption of particular policy programs. Estimates of the same, or similar, policies that employ different modeling approaches can yield widely divergent results. Such divergence often undermines effective policymaking.…

  10. Culture-Specific Counseling: An Alternative Training Model.

    Science.gov (United States)

    Nwachuku, Uchenna T.; Ivey, Allen E.

    1991-01-01

    Promotes culture-specific counseling approach, which starts with the culture and its people and searches out natural helping styles. Uses case model drawn from African-Igbo culture and applies anthropological constructs that seek to discover more culturally sensitive approach to counseling theory, to training in counseling skills and knowledge,…

  11. The alternative Iranian model of living renal transplantation.

    Science.gov (United States)

    Delmonico, Francis L

    2012-09-01

    The experience of the Iranian model should be carefully considered by those who suggest a pilot trial of a regulated market in organ sales. Mahdavi-Mazdeh's candid report makes clear that a fixed price as the basis of regulation is not possible. Iran is proceeding with an independent program of deceased organ donation in cities such as Shiraz. Mahdavi-Mazdeh's report is encouraging for the prospect of a revitalized expansion of deceased donation.

  12. Site characterization alternatives for numerical models of a deep excavation

    OpenAIRE

    Sau, Núria; Arroyo Alvarez de Toledo, Marcos; Gens Solé, Antonio

    2012-01-01

    A cut-and-cover railway tunnel site on the outskirts of Barcelona benefited from an extensive site investigation campaign. During the construction of the tunnel, the displacement of the wall as well as the of soil beneath was recorded. A 2D numerical model of the excavation sequence was established. The large amount of site investigation data allowed a systematic comparative approach. Four different soil characterization strategies were mimicked, deliberately ignoring one or another subset...

  13. A STUDY ON LIMITATION OF GOVERNMENT INITIATIVE MODEL FOR ALTERNATIVE FUEL VEHICLE (AFV PROMOTION IN CHINA

    Directory of Open Access Journals (Sweden)

    Byunghun Choi

    2016-04-01

    Full Text Available Chinese responsibility for reducing Greenhouse Gas or carbon dioxide emission increases continuously. Chinese government suggested two targets; Alternative Fuel Vehicle output volume 500 thousand and AFV market share 5% by the end of 2011. However any of two targets did not come true. Therefore this study accessed the question, ‘why Chinese government initiative model for AFV promotion has been so poor?’ This study reviewed the transition process for AFV policies in China and made a structural analysis for three key policies since 2009. As a result the number of articles for related industries or factor endowments was relatively more than firm strategy or demand conditions. Also this study accessed the AFV strategy of Six SOEs from the perspective of social responsibility. Six SOEs have more concentrated on electric vehicle rather than hybrid vehicle with following the government leadership. However major EV or HEV models of them mostly were made by Joint Ventures being under control of foreign makers and the JVs have actually controlled over AFV business. So the limitation of Chinese government initiative model resulted from supplier-centric approach with targeting for public transportation and institution consumer, and it caused a failure to create the demand conditions of general customers.

  14. Personality disorders in DSM-5: emerging research on the alternative model.

    Science.gov (United States)

    Morey, Leslie C; Benson, Kathryn T; Busch, Alexander J; Skodol, Andrew E

    2015-04-01

    The current categorical classification of personality disorders, originally introduced in the Diagnostic and Statistical Manual of Mental Disorders (DSM-III), has been found to suffer from numerous shortcomings that hamper its usefulness for research and for clinical application. The Personality and Personality Disorders Work Group for DSM-5 was charged with developing an alternative model that would address many of these concerns. The developed model involved a hybrid dimensional/categorical model that represented personality disorders as combinations of core impairments in personality functioning with specific configurations of problematic personality traits. The Board of Trustees of the American Psychiatric Association did not accept the Task Force recommendation to implement this novel approach, and thus this alternative model was included in Sect. III of the DSM-5 among concepts requiring additional study. This review provides an overview of the emerging research on this alternative model, addressing each of the primary components of the model.

  15. Alternative DFN model based on initial site investigations at Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    Darcel, C. [Itasca Consultants, Ecully (France); Davy, S.A.P.; Bour, O.; Dreuzy, J.R. de [Geosciences, Rennes (France)

    2004-12-01

    In this report, we provide a first-order analysis of the fracture network at the Simpevarp site. The first order model is the fracture distribution function, noted, fdf, which provides the number of fractures having a given orientation and length, and belonging to a given volume of observation. The first-order distribution model does not describe higher-order correlation between fracture parameters, such as a possible dependency of fracture length distribution with orientations. We also check that most of the information is contained in this 1st-order distribution model, and that dividing the fracture networks into different sets do not bring a better statistical description. The fracture distribution function contains 3 main distributions: the probability distribution of fracture orientations, the dependency on the size of the sampling domain that may exhibit non-trivial scaling in case of fractal correlations, and the fracture-length density distribution, which appears to be well fitted by a power law. The main scaling parameters are the fractal dimension and the power-law exponent of the fracture length distribution. The former was found to be about equal to the embedding dimension, meaning that fractal correlations are weak and can be neglected in the DFN model. The latter depends on geology, that is either lithology or grain size, with values that ranges from 3.2 for granite-like outcrops to 4 for diorite or monzodiorite outcrops, as well as for the large-scale lineament maps. When analyzing the consistency of the different datasets (boreholes, outcrops, lineament maps), we found that two different DFNs can be described: the first one is derived from the fdf of the outcrop with fine-grained size lithology, and is valid across all scales investigated in this study, from the highly-fractured cores to large-scale maps; the second one is derived from the fdf of the outcrops with coarse-grained size lithology, and is found consistent with cores that present the

  16. Schools as Sanctuaries: A Systematic Review of Contextual Factors Which Contribute to Student Retention in Alternative Education

    Science.gov (United States)

    O'Gorman, Eva; Salmon, Nancy; Murphy, Carol-Anne

    2016-01-01

    Early school leaving is an international concern. Previous research indicates that the school context contributes to early school leaving. This systematic review is aimed to gather marginalised young peoples' perceptions concerning contextual factors that contributed to and interfered with their decisions to stay in alternative education.…

  17. The transcription factor PU.1 promotes alternative macrophage polarization and asthmatic airway inflammation.

    Science.gov (United States)

    Qian, Feng; Deng, Jing; Lee, Yong Gyu; Zhu, Jimmy; Karpurapu, Manjula; Chung, Sangwoon; Zheng, Jun-Nian; Xiao, Lei; Park, Gye Young; Christman, John W

    2015-12-01

    The transcription factor PU.1 is involved in regulation of macrophage differentiation and maturation. However, the role of PU.1 in alternatively activated macrophage (AAM) and asthmatic inflammation has yet been investigated. Here we report that PU.1 serves as a critical regulator of AAM polarization and promotes the pathological progress of asthmatic airway inflammation. In response to the challenge of DRA (dust mite, ragweed, and Aspergillus) allergens, conditional PU.1-deficient (PU/ER(T)(+/-)) mice displayed attenuated allergic airway inflammation, including decreased alveolar eosinophil infiltration and reduced production of IgE, which were associated with decreased mucous glands and goblet cell hyperplasia. The reduced asthmatic inflammation in PU/ER(T)(+/-) mice was restored by adoptive transfer of IL-4-induced wild-type (WT) macrophages. Moreover, after treating PU/ER(T)(+/-) mice with tamoxifen to rescue PU.1 function, the allergic asthmatic inflammation was significantly restored. In vitro studies demonstrate that treatment of PU.1-deficient macrophages with IL-4 attenuated the expression of chitinase 3-like 3 (Ym-1) and resistin-like molecule alpha 1 (Fizz-1), two specific markers of AAM polarization. In addition, PU.1 expression in macrophages was inducible in response to IL-4 challenge, which was associated with phosphorylation of signal transducer and activator of transcription 6 (STAT6). Furthermore, DRA challenge in sensitized mice almost abrogated gene expression of Ym-1 and Fizz-1 in lung tissues of PU/ER(T)(+/-) mice compared with WT mice. These data, all together, indicate that PU.1 plays a critical role in AAM polarization and asthmatic inflammation.

  18. Modeling the impacts of alternative fertilization methods on nitrogen loading in rice production in Shanghai.

    Science.gov (United States)

    Zhao, Zheng; Sha, Zhimin; Liu, Yibo; Wu, Shuhang; Zhang, Hanlin; Li, Changsheng; Zhao, Qi; Cao, Linkui

    2016-10-01

    Nitrogen (N) loss from paddy fields is an important source of agricultural non-point source pollution that leads to eutrophication of water bodies and degradation of water quality. The impacts of alternative N fertilizer management practices on N loading (N loss through runoff and leaching) from paddy fields in Shanghai were assessed using a process-based biogeochemical model, DNDC. The results indicated that the current fertilization rate in paddy fields of Shanghai (300kgN/ha) exceeds the actual rice demand and has led to substantial N loading of 1142±276kg. The combined application of urea at 150kgN/ha and organic manure at 100kgN/ha was identified as the best fertilization method for rice cultivation in Shanghai; this application maintained optimal rice yields and significantly reduced N loading to 714±151kg in comparison with the current fertilization rate. A sensitivity test was conducted with various input parameters, and the results indicated that fertilization, precipitation and soil properties were the most sensitive factors that regulate N loss from paddy fields. The variability of soil properties, especially SOC led to high uncertainties in the simulated results. Therefore, the local climate conditions and soil properties should be taken into account in the identification of the best management practice (BMP) for rice cultivation, given the high spatially heterogeneous N loading values across all towns used in the simulation. The DNDC model is an effective approach for simulating and predicting N loading in paddy fields under alternative agricultural management practices. PMID:27317135

  19. Modeling the impacts of alternative fertilization methods on nitrogen loading in rice production in Shanghai.

    Science.gov (United States)

    Zhao, Zheng; Sha, Zhimin; Liu, Yibo; Wu, Shuhang; Zhang, Hanlin; Li, Changsheng; Zhao, Qi; Cao, Linkui

    2016-10-01

    Nitrogen (N) loss from paddy fields is an important source of agricultural non-point source pollution that leads to eutrophication of water bodies and degradation of water quality. The impacts of alternative N fertilizer management practices on N loading (N loss through runoff and leaching) from paddy fields in Shanghai were assessed using a process-based biogeochemical model, DNDC. The results indicated that the current fertilization rate in paddy fields of Shanghai (300kgN/ha) exceeds the actual rice demand and has led to substantial N loading of 1142±276kg. The combined application of urea at 150kgN/ha and organic manure at 100kgN/ha was identified as the best fertilization method for rice cultivation in Shanghai; this application maintained optimal rice yields and significantly reduced N loading to 714±151kg in comparison with the current fertilization rate. A sensitivity test was conducted with various input parameters, and the results indicated that fertilization, precipitation and soil properties were the most sensitive factors that regulate N loss from paddy fields. The variability of soil properties, especially SOC led to high uncertainties in the simulated results. Therefore, the local climate conditions and soil properties should be taken into account in the identification of the best management practice (BMP) for rice cultivation, given the high spatially heterogeneous N loading values across all towns used in the simulation. The DNDC model is an effective approach for simulating and predicting N loading in paddy fields under alternative agricultural management practices.

  20. Modeling of Alternative Compositions of Recycled Wrought Aluminum Alloys

    Science.gov (United States)

    Kevorkijan, Varužan

    2013-08-01

    Nowadays, a significant part of postconsumed wrought aluminum scrap is still used for the production of comparatively cheaper cast alloys, in that way losing an important part of the potential added value. The share of postconsumed scrap in wrought aluminum alloys could be increased either by sorting to fractions with the required chemical composition and/or by broadening the standard compositional tolerance limits of alloying elements. The first solution requires hand or automatic sorting of postconsumed scrap as alloys or groups of alloys to the degree of separation sufficient to enable the blending of standard compositions of wrought alloys; the second solution is much more radical, predicting changes in the existing standards for wrought aluminum alloys toward nonstandard alloys but yet having properties acceptable for customers. In this case, the degree of separation of incoming postconsumed scrap required is much less demanding. The model presented in this work enables the design of optimal (standard and nonstandard recycling-friendly) compositions and properties of wrought aluminum alloys with significantly increased amounts of postconsumed scrap. The following two routes were modeled in detail: (I) the blending of standard and nonstandard compositions of wrought aluminum alloys starting from postconsumed aluminum scrap sorted to various degrees simulated by the model and (II) changing the initial standard composition of wrought aluminum alloys to nonstandard "recycling-friendly" ones, with broader concentration tolerance limits of alloying elements and without influencing the selected alloy properties, specified in advance. The applied algorithms were found to be very useful in the industrial design of both procedures: (I) the computation of the required chemical composition of the scrap streams obtained by sorting (or, in other words, the postconsumed scrap sorting level), necessary for achieving the standard wrought alloy composition and (II) the

  1. The Asian Epidemic Model: a process model for exploring HIV policy and programme alternatives in Asia.

    Science.gov (United States)

    Brown, T; Peerapatanapokin, W

    2004-08-01

    Process models offer opportunities to explore the effectiveness of different programme and policy alternatives by varying input behaviours and model parameters to reflect programmatic/policy effects. The Asian Epidemic Model (AEM) has been designed to reflect the primary groups and transmission modes driving HIV transmission in Asia. The user adjusts AEM fitting parameters until HIV prevalence outputs from the model agree with observed epidemiological trends. The AEM resultant projections are closely tied to the epidemiological and behavioural data in the country. In Thailand and Cambodia they have shown good agreement with observed epidemiological trends in surveillance populations and with changes in HIV transmission modes, AIDS cases, male:female ratios over time, and other external validation checks. By varying the input behaviours and STI trends, one can examine the impact of different prevention efforts on the future course of the epidemic. In conclusion, the AEM is a semi-empirical model, which has worked well in Asian settings. It provides a useful tool for policy and programme analysis in Asian countries. PMID:15249695

  2. Key success factors for innovative business models

    OpenAIRE

    Marta Káradóttir 1987

    2015-01-01

    This MSc thesis seeks to uncover the fundamental key success factors, which new ventures or startups acquire to creating innovative business models. In particular the sector under investigation is design retailing, a B2B and B2C selling plan of design goods. The study aims to identify and analyse successful strategic approaches to the latter, more significantly how can new ventures achieve a sustainable business model. This subject is particularly relevant and significant for future business ...

  3. Matrix Model for Choosing Green Marketing Sustainable Strategic Alternatives

    Directory of Open Access Journals (Sweden)

    Cătălina Sitnikov

    2015-08-01

    Full Text Available Green marketing examines the symbiotic role played by marketing in ensuring sustainable business, exploring issues concerning the environment and the way strategic decisions can influence it. At present, the environmental issues concern more and more the competitive approach any organization can implement. Based on this approach, organizations can gain competitive advantage by managing environmental variables and by developing and implementing green marketing strategies. Considering the importance and impact of green marketing, by using theoretical concepts and defining a set of research directions, the paper and the research conducted were focused on creating a matrix model for choosing the optimal green marketing strategy, oriented towards competitive advantage. The model is based on the correlation that can be established among the generic strategies of competitive advantage, the variables of extended marketing mix (7Ps and the green marketing strategy matrix. There are also analyzed the implications that may be generated within a company by the adoption of a green marketing strategy and its role in promoting the environmental benefits of products.

  4. Editors View the Continuous Publication Model as a Satisfactory Alternative for Open Access LIS Journals

    Directory of Open Access Journals (Sweden)

    Richard Hayman

    2014-09-01

    provided 16 potential reasons for using a discrete-issue model, and 13 potential reasons for using a rolling-volume model. Respondents from both groups were asked to mark all reasons that applied for their respective journals. The survey also included questions about whether the journal had ever used the alternate publishing model, the editor’s satisfaction with their current model, and the likelihood of the journal switching to the alternate publishing model in the foreseeable future. Main Results – The authors collected complete responses from 21 of the original 29 journals invited to participate in the study, a response rate of 72%. For the 12 journals that identified as using discrete issues, ease of production workflow (91.7%, clear production deadlines (75.0%, and journal publicity and promotion (75.0% were the three most common reasons for using a discrete-issue model. For the nine journals using rolling volumes, improved production workflow (77.8%, decreased dependence on production deadlines (77.8%, and increased speed of research dissemination (66.7% were the three most common reasons cited for using a rolling-volume model. Findings show that overall satisfaction with a journal’s particular publication model was a common factor regardless of publishing model in use, though only the rolling-volume editors unanimously reported being very satisfied with their model. This high satisfaction rate is reflected in editors’ positions that they were very unlikely to switch away from the rolling-volume method. While a majority of editors of discrete-issue journals also reported being very satisfied or somewhat satisfied with their current model, the mixed responses to whether they would contemplate switching to the alternate model suggests that awareness of the benefits of rolling-volume publishing is increasing. Conclusion – Researchers discovered a greater incidence of rolling-volume model journals with open access LIS journals than anticipated, suggesting that

  5. Development of Versatile Compressor Modeling using Approximation Techniques for Alternative Refrigerants Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2014-01-01

    Refrigerants are the life-blood of vapor compression systems that are widely used in Heating, Ventilation, Air-Conditioning, and Refrigeration (HVAC&R) applications. The HVAC&R community is currently transitioning from main-stream refrigerants that have high Global Warming Potential (GWP) to alternative lower-GWP refrigerants. During this transition, it is important to account for the life cycle climate performance of alternative refrigerants since their performance will be different than that of higher-GWP refrigerants. This requires the evaluation of the system performance with the new refrigerants. Unfortunately, it is extremely difficult to predict the realistic performance of new alternative refrigerants without experimental validation. One of the main challenges in this regard is modeling the compressor performance with high fidelity due to the complex interaction of operating parameters, geometry, boundary conditions, and fluid properties. High fidelity compressor models are computationally expensive and require significant pre-processing to evaluate the performance of alternative refrigerants. This paper presents a new approach to modeling compressor performance when alternative refrigerants are used. The new modeling concept relies on using existing compressor performance to create an approximate model that captures the dependence of compressor performance on key operating parameters and fluid properties. The model can be built using a myriad of approximation techniques. This paper focuses on Kriging-based techniques to develop higher fidelity approximate compressor models. Baseline and at least one alternative refrigerant performance data are used to build the model. The model accuracy was evaluated by comparing the model results with compressor performance data using other refrigerants. Preliminary results show that the approximate model can predict the compressor mass flow rate and power consumption within 5%.

  6. Alternative models for two crystal structures of bovine rhodopsin

    Energy Technology Data Exchange (ETDEWEB)

    Stenkamp, Ronald E., E-mail: stenkamp@u.washington.edu [Departments of Biological Structure and Biochemistry, Biomolecular Structure Center, University of Washington, Seattle, WA 98195 (United States)

    2008-08-01

    Two crystal structures of rhodopsin that were originally described using trigonal symmetry can be interpreted in a hexagonal unit cell with a smaller asymmetric unit. The space-group symmetry of two crystal forms of rhodopsin (PDB codes 1gzm and 2j4y; space group P3{sub 1}) can be re-interpreted as hexagonal (space group P6{sub 4}). Two molecules of the G protein-coupled receptor are present in the asymmetric unit in the trigonal models. However, the noncrystallographic twofold axes parallel to the c axis can be treated as crystallographic symmetry operations in the hexagonal space group. This halves the asymmetric unit and makes all of the protein molecules equivalent in these structures. Corrections for merohedral twinning were also applied in the refinement in the higher symmetry space group for one of the structures (2j4y)

  7. Probabilistic Latent Variable Models as Nonnegative Factorizations

    Directory of Open Access Journals (Sweden)

    Madhusudana Shashanka

    2008-01-01

    factorization and this family, and provide some straightforward extensions which can help in dealing with shift invariances, higher-order decompositions and sparsity constraints. We argue through these extensions that the use of this approach allows for rapid development of complex statistical models for analyzing nonnegative data.

  8. Aging Successfully: A Four-Factor Model

    Science.gov (United States)

    Lee, Pai-Lin; Lan, William; Yen, Tung-Wen

    2011-01-01

    The study was designed to validate a model for a successful aging process and examine the gender differences in the aging process. Three hundred twelve participants who were 65 or older completed a Taiwan Social Change Survey that measures four factors that define successful aging process: including physical, psychological, social support, and…

  9. The natural alternative: protozoa as cellular models for Legionella infection.

    Science.gov (United States)

    Hoffmann, Christine; Harrison, Christopher F; Hilbi, Hubert

    2014-01-01

    The severe pneumonia known as Legionnaires' disease occurs following infection by the Gram-negative bacterium Legionella pneumophila. Normally resident in fresh-water sources, Legionella are subject to predation by eukaryotic phagocytes such as amoeba and ciliates. To counter this, L. pneumophila has evolved a complex system of effector proteins which allow the bacteria to hijack the phagocytic vacuole, hiding and replicating within their erstwhile killers. These same mechanisms allow L. pneumophila to hijack another phagocyte, lung-based macrophages, which thus avoids a vital part of the immune system and leads to infection. The course of infection can be divided into five main categories: pathogen uptake, formation of the replication-permissive vacuole, intracellular replication, host cell response, and bacterial exit. L. pneumophila effector proteins target every stage of this process, interacting with secretory, endosomal, lysosomal, retrograde and autophagy pathways, as well as with mitochondria. Each of these steps can be studied in protozoa or mammalian cells, and the knowledge gained can be readily applied to human pathogenicity. Here we describe the manner whereby L. pneumophila infects host protozoa, the various techniques which are available to analyse these processes and the implications of this model for Legionella virulence and the pathogenesis of Legionnaires' disease.

  10. The Barrett-Crane model: measure factor

    CERN Document Server

    Kaminski, Wojciech

    2013-01-01

    The original spin foam model construction for 4D gravity by Barrett and Crane suffers from several fatal issues. In the simple examples of the vertex amplitude they can be summarized as the existence of contributions to the asymptotics from non geometric configurations. Even restricted to geometric contributions the amplitude is not completely worked out. While the phase is known to be the Regge action, the so called measure factor has remained mysterious for a decade. In the toy model case of the 6j symbol this measure factor has a nice geometric interpretation of V^{-1/2} leading to speculations that a similar interpretation should be possible also in the 4D case. In this paper we provide the first geometric interpretation of the geometric part of the asymptotic for the spin foam consisting of two glued 4-simplices (decomposition of the 4-sphere) in the Barrett-Crane model in the large internal spin regime.

  11. An alternative to the standard spatial econometric approaches in hedonic house price models

    DEFF Research Database (Denmark)

    Veie, Kathrine Lausted; Panduro, Toke Emil

    Hedonic models are subject to spatially correlated errors which are a symptom of omitted spatial variables, mis-specification or mismeasurement. Methods have been developed to address this problem through the use of spatial econometrics or spatial fixed effects. However, often spatial correlation...... is modeled without much consideration of the theoretical implications of the chosen model or treated as a nuisance to be dealt with holding little interest of its own. We discuss the limitations of current standard spatial approaches and demonstrate, both empirically and theoretically the generalized...... additive model as an alternative. The generalized additive model is compared with the spatial error model and the fixed effects model. We find the generalized additive model to be a solid alternative to the standard approaches, having less restrictive assumptions about the omitted spatial processes while...

  12. Modelling silviculture alternatives for managing Pinus pinea L. forest in North-East Spain

    Energy Technology Data Exchange (ETDEWEB)

    Piqu-Nicalau, M.; Rio, M. del; Calama, R.; Montero, G.

    2011-07-01

    A yield model was developed to simulate silviculture alternatives for Pinus pinea L. in north-east Spain (Catalonia). The model uses several functions to estimate the main silvicultural parameters at stand level and a disaggregation system to predict diameter distributions. From a network of 75 temporary plots a system of equations to predict stand variables was simultaneously fitted for two stand density types, namely low and high density stands, using the three stage least-squares method (3SLS). The diameter distributions were estimated by the Weibull distribution function using the parameter recovery method (PRM) and the method of moments. Based on this yield model, two silviculture alternatives were simulated for each stand density type and site class, resulting in 16 silviculture scenarios. The yield model and silviculture alternatives offer a management tool and a guide for the sustainable forest management of even aged Pinus pinea forests in this region. (Author) 56 refs.

  13. An alternative method for modeling the size distribution of top wealth

    Science.gov (United States)

    Wang, Yuanjun; You, Shibing

    2016-09-01

    The Pareto distribution has been widely applied in modeling the distribution of wealth, as well as top incomes, cities and firms. However, recent evidence has shown that the Pareto distribution is not consistent with many situations in which it was previously considered applicable. We propose an alternative method for estimating the upper tail distribution of wealth and suggest a new Lorenz curve for building models to provide such estimates. Applying our new models to the Forbes World's Billionaire Lists, we show that they significantly outperform the Pareto Lorenz curve as well as some other popular alternatives.

  14. Alternative Models of Entrance Exams and Access to Higher Education: The Case of the Czech Republic

    Science.gov (United States)

    Konecny, Tomas; Basl, Josef; Myslivecek, Jan; Simonova, Natalie

    2012-01-01

    The study compares the potential effects of a university admission exam model based on program-specific knowledge and an alternative model relying on general study aptitude (GSA) in the context of a strongly stratified educational system with considerable excess of demand over supply of university education. Using results of the "Sonda Maturant…

  15. GY SAMPLING THEORY AND GEOSTATISTICS: ALTERNATE MODELS OF VARIABILITY IN CONTINUOUS MEDIA

    Science.gov (United States)

    In the sampling theory developed by Pierre Gy, sample variability is modeled as the sum of a set of seven discrete error components. The variogram used in geostatisties provides an alternate model in which several of Gy's error components are combined in a continuous mode...

  16. An alternative parameterization of Bayesian logistic hierarchical models for mixed treatment comparisons

    NARCIS (Netherlands)

    Pechlivanoglou, Petros; Abegaz, Fentaw; Postma, Maarten J; Wit, Ernst

    2015-01-01

    Mixed treatment comparison (MTC) models rely on estimates of relative effectiveness from randomized clinical trials so as to respect randomization across treatment arms. This approach could potentially be simplified by an alternative parameterization of the way effectiveness is modeled. We introduce

  17. Alternative energy as a factor of ecological and energy security: features of Russia

    Directory of Open Access Journals (Sweden)

    Boris Nikolaevich Porfiryev

    2011-06-01

    Full Text Available This paper analyzes the current situation in the sphere of alternative energy engineering in Russia. On the one hand, the national economy and the population in general do not have problems with energy supply and Russia in general is the world's largest exporter of energy. On the other hand, centralized energy supply covers only one third of its territory and two-thirds are in the area of decentralized and autonomous power supply. In the current situation, energy sources that are independent of centralized networks based on clean technologies are a promising alternative. The paper assesses the current state of alternative energy development in the world and in Russia, its potential and prospects. It was found out that development and qualitative improvement of the regulatory framework should have priority for alternative energy mastering in Russia as well as active joint action of government, business and civic leaders to gradually consolidate in public consciousness and behaviour of a new culture of energy consumption based on the rules of economy and environmental safety. The analysis of the proposals for the development of alternative energy industries in Russia was made. Particular attention is paid to energy saving experience and energy efficiency in housing services and public utilities. Questions on the creation and development of formal and informal institutions of non-conventional energy sources usage are asked.

  18. The developmental 'risk factor' model of schizophrenia.

    Science.gov (United States)

    Murray, R M; Fearon, P

    1999-01-01

    There is no single cause for schizophrenia. We believe that, as with other common chronic diseases such as diabetes and coronary artery disease, the appropriate aetiological model is one involving multiple genes and environmental risk factors; the latter can be divided into (a) predisposing and (b) precipitating. Our model is that genetic and/or early environmental factors cause the development of anomalous neural networks. We postulate that these interact in the growing child with inherited schizotypal traits to establish a trajectory towards an increasingly solitary and deviant life style. This ultimately projects the individual across the threshold for expression of schizophrenia, sometimes by causing the drug abuse and social adversity that appear to precipitate the psychosis. PMID:10628525

  19. Scale Factor Self-Dual Cosmological Models

    CERN Document Server

    dS, U Camara; Sotkov, G M

    2015-01-01

    We implement a conformal time scale factor duality for Friedmann-Robertson-Walker cosmological models, which is consistent with the weak energy condition. The requirement for self-duality determines the equations of state for a broad class of barotropic fluids. We study the example of a universe filled with two interacting fluids, presenting an accelerated and a decelerated period, with manifest UV/IR duality. The associated self-dual scalar field interaction turns out to coincide with the "radiation-like" modified Chaplygin gas models. We present an equivalent realization of them as gauged K\\"ahler sigma models (minimally coupled to gravity) with very specific and interrelated K\\"ahler- and super-potentials. Their applications in the description of hilltop inflation and also as quintessence models for the late universe are discussed.

  20. Progressive collapse analysis using updated models for alternate path analysis after a blast

    Science.gov (United States)

    Eskew, Edward; Jang, Shinae; Bertolaccini, Kelly

    2016-04-01

    Progressive collapse is of rising importance within the structural engineering community due to several recent cases. The alternate path method is a design technique to determine the ability of a structure to sustain the loss of a critical element, or elements, and still resist progressive collapse. However, the alternate path method only considers the removal of the critical elements. In the event of a blast, significant damage may occur to nearby members not included in the alternate path design scenarios. To achieve an accurate assessment of the current condition of the structure after a blast or other extreme event, it may be necessary to reduce the strength or remove additional elements beyond the critical members designated in the alternate path design method. In this paper, a rapid model updating technique utilizing vibration measurements is used to update the structural model to represent the real-time condition of the structure after a blast occurs. Based upon the updated model, damaged elements will either have their strength reduced, or will be removed from the simulation. The alternate path analysis will then be performed, but only utilizing the updated structural model instead of numerous scenarios. After the analysis, the simulated response from the analysis will be compared to failure conditions to determine the buildings post-event condition. This method has the ability to incorporate damage to noncritical members into the analysis. This paper will utilize numerical simulations based upon a unified facilities criteria (UFC) example structure subjected to an equivalent blast to validate the methodology.

  1. Modeling alternatives for basin-level hydropower development: 1. Optimization methods and applications

    Science.gov (United States)

    Chang, Shoou-Yuh; Liaw, Shu-Liang; Railsback, Steven F.; Sale, Michael J.

    1992-10-01

    Development of multiple hydroelectric projects at navigation dams on large river systems can result in a number of environmental impacts, including potential reductions in dissolved oxygen (DO) concentrations. This study presents a method for generating hydropower development alternatives for evaluation by planners by quantifying the trade-offs between water quality and power generation. This method employs a Streeter-Phelps model to simulate DO and the bounded implicit enumeration algorithm to solve an optimization model formulated to maximize hydroelectric energy production. A portion of the upper Ohio River basin was selected to illustrate the methodology. The results indicate that various alternatives that meet the specified DO constraints can be generated efficiently. These alternatives are nearly optimal solutions with respect to the modeled objectives but are different with respect to decision variables.

  2. Enhanced understanding of energy ratepayers: Factors influencing perceptions of government energy efficiency subsidies and utility alternative energy use

    International Nuclear Information System (INIS)

    This study explores factors related to energy consumers' perceptions of government subsidies for utility provided energy efficiency (EE) programs and for utility providers' use of more clean/alternative energy sources. Demographic factors, attitudes, planned purchases, and perceptions of utility provider motives in relation to governmental and utility provider EE initiatives (i.e. providing discounts and coupons for CFL bulbs), plus the influence of gain- and loss-framed messages are investigated. Over 2000 respondents completed a 16 item phone survey. Hierarchical regression explained 38% of the variance in reactions regarding government subsidies of the cost of utility provided EE programs and 43% of the variance in perceptions involving whether utility companies should use of more clean or alternative forms of energy. Gender and party differences emerged. Loss-framed messages were more important when the issue was government subsidies. Both gain- and loss-framed messages were important when clean/alternative energy was the issue. - Highlights: • Over 2000 ratepayers were surveyed on their attitudes, planned behaviors and perceptions towards energy efficiency programs. • Almost 40% of how ratepayers feel about government subsidies and utility use of clean/alternative energy was explained. • Loss-framed messages were more effective when the dependent variable was ratepayer perception of government subsidies

  3. The conserved splicing factor SUA controls alternative splicing of the developmental regulator ABI3 in Arabidopsis.

    NARCIS (Netherlands)

    Sugliani, M.; Brambilla, V.; Clerkx, E.J.M.; Koornneef, M.; Soppe, W.J.J.

    2010-01-01

    ABSCISIC ACID INSENSITIVE3 (ABI3) is a major regulator of seed maturation in Arabidopsis thaliana. We detected two ABI3 transcripts, ABI3- and ABI3-ß, which encode full-length and truncated proteins, respectively. Alternative splicing of ABI3 is developmentally regulated, and the ABI3-ß transcript a

  4. Finishing post-primary education: a systematic review of contextual factors which contribute to student retention in alternative education.

    OpenAIRE

    O'Gorman, Eva

    2014-01-01

    peer-reviewed Background: The EU set a target of reducing early school leaving to no more than 10% by the year 2020. Previous research indicates that the school context contributes to early school leaving. This systematic review aims to identify factors within the physical, social, cultural and virtual contexts which may contribute to student retention in alternative educational settings. This study contributes an important synthesis of existing evidence for policy makers, educators and ot...

  5. Adaptive-Wave Alternative for the Black-Scholes Option Pricing Model

    OpenAIRE

    Ivancevic, Vladimir G.

    2009-01-01

    A nonlinear wave alternative for the standard Black-Scholes option-pricing model is presented. The adaptive-wave model, representing 'controlled Brownian behavior' of financial markets, is formally defined by adaptive nonlinear Schr\\"odinger (NLS) equations, defining the option-pricing wave function in terms of the stock price and time. The model includes two parameters: volatility (playing the role of dispersion frequency coefficient), which can be either fixed or stochastic, and adaptive ma...

  6. An alternative to the standard spatial econometric approaches in hedonic house price models

    DEFF Research Database (Denmark)

    von Graevenitz, Kathrine; Panduro, Toke Emil

    2015-01-01

    Omitted, misspecified, or mismeasured spatially varying characteristics are a cause for concern in hedonic house price models. Spatial econometrics or spatial fixed effects have become popular ways of addressing these concerns. We discuss the limitations of standard spatial approaches to hedonic...... modeling and demonstrate the spatial generalized additive model as an alternative. Parameter estimates for several spatially varying regressors are shown to be sensitive to the scale of the fixed effects and bandwidth dimension used to control for omitted variables. This sensitivity reflects...

  7. Shape Modelling Using Maximum Autocorrelation Factors

    DEFF Research Database (Denmark)

    Larsen, Rasmus

    2001-01-01

    of Active Shape Models by Timothy Cootes and Christopher Taylor by building new information into the model. This new information consists of two types of prior knowledge. First, in many situation we will be given an ordering of the shapes of the training set. This situation occurs when the shapes......This paper addresses the problems of generating a low dimensional representation of the shape variation present in a training set after alignment using Procrustes analysis and projection into shape tangent space. We will extend the use of principal components analysis in the original formulation....... Both these types of knowledge may be used to defined Shape Maximum Autocorrelation Factors. The resulting point distribution models are compared to ordinary principal components analysis using leave-one-out validation....

  8. Are Free Ion Activity Models Sufficient Alternatives to Biotic Ligand Models in Evaluating Metal Toxic Impacts in Terrestrial Environments?

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Larsen, Henrik Fred;

    is low and alternatives must be found. In this study, we compared published terrestrial BLMs and their potential alternatives such as free ion activity models (FIAM), for applicability in addressing metal toxic impacts in terrestrial environments. A set of 1300 soils representative for the whole world......, respectively. In all cases, predictions of FIAMs fall within the range of values predicted with BLMs, and toxicity ratio of copper to nickel is accurately predicted with both models. us, both models are able to distinguish between the two metals in terms of their average toxicity. Given that the calculated...

  9. Transcription factors in pancreatic development. Animal models.

    Science.gov (United States)

    Martin, Merce; Hauer, Viviane; Messmer, Mélanie; Orvain, Christophe; Gradwohl, Gérard

    2007-01-01

    Through the analysis of genetically modified mice a hierarchy of transcription factors regulating pancreas specification, endocrine destiny as well as endocrine subtype specification and differentiation has been established. In addition to conventional approaches such as transgenic technologies and gene targeting, recombinase fate mapping in mice has been key in establishing the lineage relationship between progenitor cells and their progeny in understanding pancreas formation. Moreover, the design of specific mouse models to conditionally express transcription factors in different populations of progenitor cells has revealed to what extent transcription factors required for islet cell development are also sufficient to induce endocrine differentiation and the importance of the competence of progenitor cells to respond to the genetic program implemented by these factors. Taking advantage of this basic science knowledge acquired in rodents, immature insulin-producing cells have recently been differentiated in vitro from human embryonic stem cells. Taken together these major advances emphasize the need to gain further in-depth knowledge of the molecular and cellular mechanisms controlling beta-cell differentiation in mice to generate functional beta-cells in the future that could be used for cell therapy in diabetes. PMID:17923766

  10. An alternative strategy to generate coding sequence of macrophage migration inhibitory factor-2 of Wuchereria bancrofti

    OpenAIRE

    Nikhil Chauhan; Hoti, S.L.

    2016-01-01

    Background & objectives: Different developmental stages of Wuchereria bancrofti, the major causal organism of lymphatic filariasis (LF), are difficult to obtain. Beside this limitation, to obtain complete coding sequence (CDS) of a gene one has to isolate mRNA and perform subsequent cDNA synthesis which is laborious and not successful at times. In this study, an alternative strategy employing polymerase chain reaction (PCR) was optimized and validated, to generate CDS of Macrophage migration ...

  11. Suppression of the alternative lengthening of telomere pathway by the chromatin remodelling factor ATRX

    OpenAIRE

    Clynes, David; Jelinska, Clare; Xella, Barbara; Ayyub, Helena; Scott, Caroline; Mitson, Matthew; Taylor, Stephen; Higgs, Douglas R.; Gibbons, Richard J.

    2015-01-01

    Fifteen per cent of cancers maintain telomere length independently of telomerase by the homologous recombination (HR)-associated alternative lengthening of telomeres (ALT) pathway. A unifying feature of these tumours are mutations in ATRX. Here we show that expression of ectopic ATRX triggers a suppression of the pathway and telomere shortening. Importantly ATRX-mediated ALT suppression is dependent on the histone chaperone DAXX. Re-expression of ATRX is associated with a reduction in replica...

  12. Testing alternative ground water models using cross-validation and other methods

    Science.gov (United States)

    Foglia, L.; Mehl, S.W.; Hill, M.C.; Perona, P.; Burlando, P.

    2007-01-01

    Many methods can be used to test alternative ground water models. Of concern in this work are methods able to (1) rank alternative models (also called model discrimination) and (2) identify observations important to parameter estimates and predictions (equivalent to the purpose served by some types of sensitivity analysis). Some of the measures investigated are computationally efficient; others are computationally demanding. The latter are generally needed to account for model nonlinearity. The efficient model discrimination methods investigated include the information criteria: the corrected Akaike information criterion, Bayesian information criterion, and generalized cross-validation. The efficient sensitivity analysis measures used are dimensionless scaled sensitivity (DSS), composite scaled sensitivity, and parameter correlation coefficient (PCC); the other statistics are DFBETAS, Cook's D, and observation-prediction statistic. Acronyms are explained in the introduction. Cross-validation (CV) is a computationally intensive nonlinear method that is used for both model discrimination and sensitivity analysis. The methods are tested using up to five alternative parsimoniously constructed models of the ground water system of the Maggia Valley in southern Switzerland. The alternative models differ in their representation of hydraulic conductivity. A new method for graphically representing CV and sensitivity analysis results for complex models is presented and used to evaluate the utility of the efficient statistics. The results indicate that for model selection, the information criteria produce similar results at much smaller computational cost than CV. For identifying important observations, the only obviously inferior linear measure is DSS; the poor performance was expected because DSS does not include the effects of parameter correlation and PCC reveals large parameter correlations. ?? 2007 National Ground Water Association.

  13. Modeling of a sedimentary rock alternative for the siting of the radioactive waste disposal system

    International Nuclear Information System (INIS)

    Here are described the main concepts, the approximations, and all those simulation aspects that characterize the modeling performed using the unsaturated saturated approach for porous media. The objective of this work is to obtain a generic description of a sedimentary rock soil as an alternative site for the low and intermediate level radioactive waste disposal system. (author)

  14. Alternating Renewal Process Models for Behavioral Observation: Simulation Methods, Software, and Validity Illustrations

    Science.gov (United States)

    Pustejovsky, James E.; Runyon, Christopher

    2014-01-01

    Direct observation recording procedures produce reductive summary measurements of an underlying stream of behavior. Previous methodological studies of these recording procedures have employed simulation methods for generating random behavior streams, many of which amount to special cases of a statistical model known as the alternating renewal…

  15. The New Alternative DSM-5 Model for Personality Disorders: Issues and Controversies

    Science.gov (United States)

    Porter, Jeffrey S.; Risler, Edwin

    2014-01-01

    Purpose: Assess the new alternative "Diagnostic and Statistical Manual of Mental Disorders", fifth edition (DSM-5) model for personality disorders (PDs) as it is seen by its creators and critics. Method: Follow the DSM revision process by monitoring the American Psychiatric Association website and the publication of pertinent journal…

  16. Alternative Models to Deliver Developmental Math: Issues of Use and Student Access

    Science.gov (United States)

    Kosiewicz, Holly; Ngo, Federick; Fong, Kristen

    2016-01-01

    Objective: Changing how community colleges deliver developmental education has become a key policy lever to increase student achievement. Alternative development education models reduce the amount of time a student spends in remediation, provide students with supplemental instruction and support, and contextualize content to align with student…

  17. An Alternative Counseling Model for Alcohol Abuse in College: A Case Study

    Science.gov (United States)

    Hayes, B. Grant; Curry, Jennifer; Freeman, Mark S.; Kuch, Tyson H.

    2010-01-01

    Abstinence education remains a prevailing approach for addressing college student alcohol abuse. This case study illustrates an alternative method of intervening that combines motivational interviewing, harm reduction, and a brief solution-focused model. The counseling approach illustrated emphasizes reduction in, rather than abstinence from,…

  18. Logit model utilization in additional and alternative income estimation of farms

    Directory of Open Access Journals (Sweden)

    Piotr Bórawski

    2009-01-01

    Full Text Available Particular attention was paid to profitability of additional and alternative income sources, mainly ostrich and fallow deers. The analysis was presented using Logit model. The survey proved that the profitability of ostrich production was determined by basic herd, farmers’ age and own sawings. In fallow deers production the most important were basic herd and own savings.

  19. Clinical Utility of the DSM-5 Alternative Model of Personality Disorders

    DEFF Research Database (Denmark)

    Bach, Bo; Markon, Kristian; Simonsen, Erik;

    2015-01-01

    In Section III, Emerging Measures and Models, DSM-5 presents an Alternative Model of Personality Disorders, which is an empirically based model of personality pathology measured with the Level of Personality Functioning Scale (LPFS) and the Personality Inventory for DSM-5 (PID-5). These novel...... was to evaluate the clinical utility of this alternative model of personality disorders. Method. We administered the LPFS and the PID-5 to psychiatric outpatients diagnosed with personality disorders and other nonpsychotic disorders. The personality profiles of six characteristic patients were inspected...... (involving a comparison of presenting problems, history, and diagnoses) and used to formulate treatment considerations. We also considered 6 specific personality disorder types that could be derived from the profiles as defined in the DSM-5 Section III criteria. Results. Using the LPFS and PID-5, we were...

  20. A Simplified Technique for Scoring DSM-IV Personality Disorders with the Five-Factor Model

    Science.gov (United States)

    Miller, Joshua D.; Bagby, R. Michael; Pilkonis, Paul A.; Reynolds, Sarah K.; Lynam, Donald R.

    2005-01-01

    The current study compares the use of two alternative methodologies for using the Five-Factor Model (FFM) to assess personality disorders (PDs). Across two clinical samples, a technique using the simple sum of selected FFM facets is compared with a previously used prototype matching technique. The results demonstrate that the more easily…

  1. The polyadenylation code: a unified model for the regulation of mRNA alternative polyadenylation*

    OpenAIRE

    Davis, Ryan; Shi, Yongsheng

    2014-01-01

    The majority of eukaryotic genes produce multiple mRNA isoforms with distinct 3′ ends through a process called mRNA alternative polyadenylation (APA). Recent studies have demonstrated that APA is dynamically regulated during development and in response to environmental stimuli. A number of mechanisms have been described for APA regulation. In this review, we attempt to integrate all the known mechanisms into a unified model. This model not only explains most of previous results, but also prov...

  2. The macroeconomic forecasting performance of autoregressive models with alternative specifications of time-varying volatility

    OpenAIRE

    CLARK, Todd E.; Francesco Ravazzolo

    2012-01-01

    This paper compares alternative models of time-varying macroeconomic volatility on the basis of the accuracy of point and density forecasts of macroeconomic variables. In this analysis, we consider both Bayesian autoregressive and Bayesian vector autoregressive models that incorporate some form of time-varying volatility, precisely stochastic volatility (both with constant and time-varying autoregressive coeffi cients), stochastic volatility following a stationary AR process, stochastic volat...

  3. Alternative practices in curriculum design. Participation as a key factor and speaking out as right

    OpenAIRE

    Susana Barco

    2012-01-01

    During the 1990s, in the context of neo-liberal policies, curricular changes ocurred in Latin América which gave a leading role to technicians and experts in education, in the process of writing the curricular documents. Beyond the critiques these policies can receive, it is necessary to find alternative ways of elaborating curricular documents, based on democratic idea of teacher's real participation.In an action-research within the scope of a university and two experiences referred to in th...

  4. CAPM tests and alternative factor portfolio composition: getting the alphas right

    OpenAIRE

    De Moor, Lieven; Sercu, Piet

    2005-01-01

    We show that the results of a CAPM test are quite sensitive to the details of the test design. Especially crucial are the aspects related to the weight one gives to small, low-reputation stocks when constructing both the factor portfolios and the test or style portfolios whose returns are to be explained. To fit our observed returns we need to redesign the size and distress factor portfolios into two factor portfolios each, one for extremely small or distressed stocks relative to non-extreme ...

  5. An alternative factorization of the quantum harmonic oscillator and two-parameter family of self-adjoint operators

    Energy Technology Data Exchange (ETDEWEB)

    Arcos-Olalla, Rafael, E-mail: olalla@fisica.ugto.mx [Departamento de Física, DCI Campus León, Universidad de Guanajuato, Apdo. Postal E143, 37150 León, Gto. (Mexico); Reyes, Marco A., E-mail: marco@fisica.ugto.mx [Departamento de Física, DCI Campus León, Universidad de Guanajuato, Apdo. Postal E143, 37150 León, Gto. (Mexico); Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosí, S.L.P. (Mexico)

    2012-10-01

    We introduce an alternative factorization of the Hamiltonian of the quantum harmonic oscillator which leads to a two-parameter self-adjoint operator from which the standard harmonic oscillator, the one-parameter oscillators introduced by Mielnik, and the Hermite operator are obtained in certain limits of the parameters. In addition, a single Bernoulli-type parameter factorization, which is different from the one introduced by M.A. Reyes, H.C. Rosu, and M.R. Gutiérrez [Phys. Lett. A 375 (2011) 2145], is briefly discussed in the final part of this work. -- Highlights: ► Factorizations with operators which are not mutually adjoint are presented. ► New two-parameter and one-parameter self-adjoint oscillator operators are introduced. ► Their eigenfunctions are two- and one-parameter deformed Hermite functions.

  6. Using a GIS model to assess terrestrial salamander response to alternative forest management plans.

    Science.gov (United States)

    Gustafson, E J; Murphy, N L; Crow, T R

    2001-11-01

    A GIS model predicting the spatial distribution of terrestrial salamander abundance based on topography and forest age was developed using parameters derived from the literature. The model was tested by sampling salamander abundance across the full range of site conditions used in the model. A regression of the predictions of our GIS model against these sample data showed that the model has a modest but significant ability to predict both salamander abundance and mass per unit area. The model was used to assess the impacts of alternative management plans for the Hoosier National Forest (Indiana, USA) on salamanders. These plans differed in the spatial delineation of management areas where timber harvest was permitted, and the intensity of timber harvest within those management areas. The spatial pattern of forest openings produced by alternative forest management scenarios based on these plans was projected over 150 years using a timber-harvest simulator (HARVEST). We generated a predictive map of salamander abundance for each scenario over time, and summarized each map by calculating mean salamander abundance and the mean colonization distance (average distance from map cells with low predicted abundance to those with relatively high abundance). Projected salamander abundance was affected more by harvest rate (area harvested each decade) than by the management area boundaries. The alternatives had a varying effect on the mean distance salamanders would have to travel to colonize regenerating stands. Our GIS modeling approach is an example of a spatial analytical tool that could help resource management planners to evaluate the potential ecological impact of management alternatives. PMID:11775500

  7. Gene expression analyses implicate an alternative splicing program in regulating contractile gene expression and serum response factor activity in mice.

    Directory of Open Access Journals (Sweden)

    Twishasri Dasgupta

    Full Text Available Members of the CUG-BP, Elav-like family (CELF regulate alternative splicing in the heart. In MHC-CELFΔ transgenic mice, CELF splicing activity is inhibited postnatally in heart muscle via expression of a nuclear dominant negative CELF protein under an α-myosin heavy chain promoter. MHC-CELFΔ mice develop dilated cardiomyopathy characterized by alternative splicing defects, enlarged hearts, and severe contractile dysfunction. In this study, gene expression profiles in the hearts of wild type, high- and low-expressing lines of MHC-CELFΔ mice were compared using microarrays. Gene ontology and pathway analyses identified contraction and calcium signaling as the most affected processes. Network analysis revealed that the serum response factor (SRF network is highly affected. Downstream targets of SRF were up-regulated in MHC-CELFΔ mice compared to the wild type, suggesting an increase in SRF activity. Although SRF levels remained unchanged, known inhibitors of SRF activity were down-regulated. Conversely, we found that these inhibitors are up-regulated and downstream SRF targets are down-regulated in the hearts of MCKCUG-BP1 mice, which mildly over-express CELF1 in heart and skeletal muscle. This suggests that changes in SRF activity are a consequence of changes in CELF-mediated regulation rather than a secondary result of compensatory pathways in heart failure. In MHC-CELFΔ males, where the phenotype is only partially penetrant, both alternative splicing changes and down-regulation of inhibitors of SRF correlate with the development of cardiomyopathy. Together, these results strongly support a role for CELF-mediated alternative splicing in the regulation of contractile gene expression, achieved in part through modulating the activity of SRF, a key cardiac transcription factor.

  8. Establishment and application of minigene models for studying pre-mRNA alternative splicing

    Institute of Scientific and Technical Information of China (English)

    LI Jing; CHEN Xianhua; LIN Wanmin; LI Lishu; HAN Yu; XU Ping

    2004-01-01

    The objective of the present study is to establish a minigene model for studying pre-mRNA alternative splicing. To prepare the minigene DNA constructs, with human or mouse genomic DNA as templates, GluR-B , FGF-2R and Zis "minigene" fragments were amplified using PCR and cloned to the eukaryotic expression vectors. The three constructed minigenes and the expression vectors of Tra2?1 and Zis2 were co-transfected in Hela cells. RT-PCR analysis was performed to semi-quantitatively determine the spliced products from the minigenes. The results demonstrated that the constructed minigenes are useful in studying the pre-mRNA alternative splicing in cultured cells. With the established Zis minigene, we for the first time found that Zis2 isoform regulates the alternative splicing of Zis minigene.

  9. A structural dynamic factor model for the effects of monetary policy estimated by the EM algorithm

    DEFF Research Database (Denmark)

    Bork, Lasse

    This paper applies the maximum likelihood based EM algorithm to a large-dimensional factor analysis of US monetary policy. Specifically, economy-wide effects of shocks to the US federal funds rate are estimated in a structural dynamic factor model in which 100+ US macroeconomic and financial time...... factor loadings, which is important for the response heterogeneity. Thirdly, the monetary policy rate is not a latent factor representation but measured without error and interacts dynamically with the factors in the estimation. Finally, the dynamic factor model is estimated by the one-step maximum...... likelihood based EM algorithm as an alternative to Bayesian methods and two-step principal component methods. Based on a large panel from 1959:01 to 2012:06 I estimate a number of model specifications and find that the dynamic responses of a monetary policy shock are theoretically more plausible...

  10. The Omitted Factor in Risk Management: Corporate Foreign Debt as an Alternative to Currency Derivatives

    DEFF Research Database (Denmark)

    Aabo, Tom

    Empirical surveys on exchange rate risk management in non-financial companies focus on the use of currency derivatives while omitting the use of corporate debt denominated in foreign currency ("foreign debt") even though the latter in risk management terms is identical to one or a series of forward...... contracts. This empirical study of the risk management practices of non-financial companies shows (1) that foreign debt is an important alternative to the use of currency derivatives, (2) that the relative importance of foreign debt compared to currency derivatives increases the longer the hedging horizon...... and the higher the uncertainty, and (3) that companies with a low solvency ratio and stable earnings attribute an especially high importance to the use of foreign debt. The study further suggests that the relative importance attributed to foreign debt differs between companies in various economic sectors....

  11. Suppression of the alternative lengthening of telomere pathway by the chromatin remodelling factor ATRX.

    Science.gov (United States)

    Clynes, David; Jelinska, Clare; Xella, Barbara; Ayyub, Helena; Scott, Caroline; Mitson, Matthew; Taylor, Stephen; Higgs, Douglas R; Gibbons, Richard J

    2015-01-01

    Fifteen per cent of cancers maintain telomere length independently of telomerase by the homologous recombination (HR)-associated alternative lengthening of telomeres (ALT) pathway. A unifying feature of these tumours are mutations in ATRX. Here we show that expression of ectopic ATRX triggers a suppression of the pathway and telomere shortening. Importantly ATRX-mediated ALT suppression is dependent on the histone chaperone DAXX. Re-expression of ATRX is associated with a reduction in replication fork stalling, a known trigger for HR and loss of MRN from telomeres. A G-quadruplex stabilizer partially reverses the effect of ATRX, inferring ATRX may normally facilitate replication through these sequences that, if they persist, promote ALT. We propose that defective telomere chromatinization through loss of ATRX promotes the persistence of aberrant DNA secondary structures, which in turn present a barrier to DNA replication, leading to replication fork stalling, collapse, HR and subsequent recombination-mediated telomere synthesis in ALT cancers. PMID:26143912

  12. Space station crew safety alternatives study. Volume 3: Safety impact of human factors

    Science.gov (United States)

    Rockoff, L. A.; Raasch, R. F.; Peercy, R. L., Jr.

    1985-01-01

    The first 15 years of accumulated space station concepts for Initial Operational Capability (IOC) during the early 1990's was considered. Twenty-five threats to the space station are identified and selected threats addressed as impacting safety criteria, escape and rescue, and human factors safety concerns. Of the 25 threats identified, eight are discussed including strategy options for threat control: fire, biological or toxic contamination, injury/illness, explosion, loss of pressurization, radiation, meteoroid penetration and debris. Of particular interest here is volume three (of five volumes) pertaining to the safety impact of human factors.

  13. Inhibition of the alternative complement activation pathway in traumatic brain injury by a monoclonal anti-factor B antibody: a randomized placebo-controlled study in mice

    Directory of Open Access Journals (Sweden)

    Holers V Michael

    2007-05-01

    Full Text Available Abstract Background The posttraumatic response to traumatic brain injury (TBI is characterized, in part, by activation of the innate immune response, including the complement system. We have recently shown that mice devoid of a functional alternative pathway of complement activation (factor B-/- mice are protected from complement-mediated neuroinflammation and neuropathology after TBI. In the present study, we extrapolated this knowledge from studies in genetically engineered mice to a pharmacological approach using a monoclonal anti-factor B antibody. This neutralizing antibody represents a specific and potent inhibitor of the alternative complement pathway in mice. Methods A focal trauma was applied to the left hemisphere of C57BL/6 mice (n = 89 using a standardized electric weight-drop model. Animals were randomly assigned to two treatment groups: (1 Systemic injection of 1 mg monoclonal anti-factor B antibody (mAb 1379 in 400 μl phosphate-buffered saline (PBS at 1 hour and 24 hours after trauma; (2 Systemic injection of vehicle only (400 μl PBS, as placebo control, at identical time-points after trauma. Sham-operated and untreated mice served as additional negative controls. Evaluation of neurological scores and analysis of brain tissue specimens and serum samples was performed at defined time-points for up to 1 week. Complement activation in serum was assessed by zymosan assay and by murine C5a ELISA. Brain samples were analyzed by immunohistochemistry, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL histochemistry, and real-time RT-PCR. Results The mAb 1379 leads to a significant inhibition of alternative pathway complement activity and to significantly attenuated C5a levels in serum, as compared to head-injured placebo-treated control mice. TBI induced histomorphological signs of neuroinflammation and neuronal apoptosis in the injured brain hemisphere of placebo-treated control mice for up to 7 days. In contrast, the

  14. Human factors engineering program review model

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The staff of the Nuclear Regulatory Commission is performing nuclear power plant design certification reviews based on a design process plan that describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification and an acceptable implemented design. There are two principal reasons for this approach. First, the initial design certification applications submitted for staff review did not include detailed design information. Second, since human performance literature and industry experiences have shown that many significant human factors issues arise early in the design process, review of the design process activities and results is important to the evaluation of an overall design. However, current regulations and guidance documents do not address the criteria for design process review. Therefore, the HFE Program Review Model (HFE PRM) was developed as a basis for performing design certification reviews that include design process evaluations as well as review of the final design. A central tenet of the HFE PRM is that the HFE aspects of the plant should be developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The HFE PRM consists of ten component elements. Each element in divided into four sections: Background, Objective, Applicant Submittals, and Review Criteria. This report describes the development of the HFE PRM and gives a detailed description of each HFE review element.

  15. Human factors engineering program review model

    International Nuclear Information System (INIS)

    The staff of the Nuclear Regulatory Commission is performing nuclear power plant design certification reviews based on a design process plan that describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification and an acceptable implemented design. There are two principal reasons for this approach. First, the initial design certification applications submitted for staff review did not include detailed design information. Second, since human performance literature and industry experiences have shown that many significant human factors issues arise early in the design process, review of the design process activities and results is important to the evaluation of an overall design. However, current regulations and guidance documents do not address the criteria for design process review. Therefore, the HFE Program Review Model (HFE PRM) was developed as a basis for performing design certification reviews that include design process evaluations as well as review of the final design. A central tenet of the HFE PRM is that the HFE aspects of the plant should be developed, designed, and evaluated on the basis of a structured top-down system analysis using accepted HFE principles. The HFE PRM consists of ten component elements. Each element in divided into four sections: Background, Objective, Applicant Submittals, and Review Criteria. This report describes the development of the HFE PRM and gives a detailed description of each HFE review element

  16. Dynamical Complexity of a Spatial Phytoplankton-Zooplankton Model with an Alternative Prey and Refuge Effect

    Directory of Open Access Journals (Sweden)

    Weiwei Zhang

    2013-01-01

    Full Text Available The spatiotemporal dynamics of a phytoplankton-zooplankton model with an alternative prey and refuge effect is investigated mathematically and numerically. The stability of the equilibrium point and the traveling wave solution of the phytoplankton-zooplankton model are described based on theoretical mathematical work, which provides the basis of the numerical simulation. The numerical analysis shows that refuges have a strong effect on the spatiotemporal dynamics of the model according to the pattern formation. These results may help us to understand prey-predator interactions in water ecosystems. They are also relevant to research into phytoplankton-zooplankton ecosystems.

  17. Fluorescence Spectra of Model Compounds for Light-emitting Alternating Copolymers in Heterogeneous Environments

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers, M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compounds and ionic micelle-water interface was also investigated. It is found that (I) The fluorescence changes of M (TPA-PPV) are related to the state of CTAB and SDS solution. (II) Aggregated state can be formed in M (TPA-PAV) solution at low concentration of CTAB. (III) Higher concentration of KNO3 may affect the interaction between model compounds and ionic micelle-water interface.

  18. Partially Compensatory Multidimensional Item Response Theory Models: Two Alternate Model Forms

    Science.gov (United States)

    DeMars, Christine E.

    2016-01-01

    Partially compensatory models may capture the cognitive skills needed to answer test items more realistically than compensatory models, but estimating the model parameters may be a challenge. Data were simulated to follow two different partially compensatory models, a model with an interaction term and a product model. The model parameters were…

  19. Perspectives in the use of tannins as alternative to antimicrobial growth promoter factors in poultry

    OpenAIRE

    Redondo, Leandro M.; Chacana, Pablo A.; Dominguez, Johana E.; Mariano Enrique Fernandez Miyakawa

    2014-01-01

    Antibiotics have been included in the formulation of feed for livestock production for more than 40 years as a strategy to improve feed conversion rates and to reduce costs. The use of antimicrobials as growth-promoting factors (AGP) in sub-therapeutic doses for long periods is particularly favorable to select antimicrobial-resistant microorganisms. In the last years, global concern about development of antimicrobial resistance and transference of resistance genes from animal to human strains...

  20. Archaeal Transcription: Function of an Alternative Transcription Factor B from Pyrococcus furiosus▿

    OpenAIRE

    Micorescu, Michael; Grünberg, Sebastian; Franke, Andreas; Cramer, Patrick; Thomm, Michael; Bartlett, Michael

    2007-01-01

    The genome of the hyperthermophile archaeon Pyrococcus furiosus encodes two transcription factor B (TFB) paralogs, one of which (TFB1) was previously characterized in transcription initiation. The second TFB (TFB2) is unusual in that it lacks recognizable homology to the archaeal TFB/eukaryotic TFIIB B-finger motif. TFB2 functions poorly in promoter-dependent transcription initiation, but photochemical cross-linking experiments indicated that the orientation and occupancy of transcription com...

  1. Alternating optimization method based on nonnegative matrix factorizations for deep neural networks

    OpenAIRE

    Sakurai, Tetsuya; Imakura, Akira; Inoue, Yuto; Futamura, Yasunori

    2016-01-01

    The backpropagation algorithm for calculating gradients has been widely used in computation of weights for deep neural networks (DNNs). This method requires derivatives of objective functions and has some difficulties finding appropriate parameters such as learning rate. In this paper, we propose a novel approach for computing weight matrices of fully-connected DNNs by using two types of semi-nonnegative matrix factorizations (semi-NMFs). In this method, optimization processes are performed b...

  2. An alternative approach for addressing the failure probability-safety factor method with sensitivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castillo, Enrique; Conejo, Antonio J.; Minguez, Roberto; Castillo, Carmen

    2003-11-01

    The paper introduces a method for solving the failure probability-safety factor problem for designing engineering works proposed by Castillo et al. that optimizes an objective function subject to the standard geometric and code constraints, and two more sets of constraints that simultaneously guarantee given safety factors and failure probability bounds associated with a given set of failure modes. The method uses the dual variables and is especially convenient to perform a sensitivity analysis, because sensitivities of the objective function and the reliability indices can be obtained with respect to all data values. To this end, the optimization problems are transformed into other equivalent ones, in which the data parameters are converted into artificial variables, and locked to their actual values. In this way, some variables of the associated dual problems become the desired sensitivities. In addition, using the proposed methodology, calibration of codes based on partial safety factors can be done. The method is illustrated by its application to the design of a simple rubble mound breakwater and a bridge crane.

  3. Modelling the effect of an alternative host population on the spread of citrus Huanglongbing

    Science.gov (United States)

    d'A. Vilamiu, Raphael G.; Ternes, Sonia; Laranjeira, Francisco F.; de C. Santos, Tâmara T.

    2013-10-01

    The objective of this work was to model the spread of citrus Huanglongbing (HLB) considering the presence of a population of alternative hosts (Murraya paniculata). We developed a compartmental deterministic mathematical model for representing the dynamics of HLB disease in a citrus orchard, including delays in the latency and incubation phases of the disease in the plants and a delay period on the nymphal stage of Diaphorina citri, the insect vector of HLB in Brazil. The results of numerical simulations indicate that alternative hosts should not play a crucial role on HLB dynamics considering a typical scenario for the Recôncavo Baiano region in Brazil . Also, the current policy of removing symptomatic plants every three months should not be expected to significantly hinder HLB spread.

  4. Reservoir computing as an alternative to traditional artificial neural networks in rainfall-runoff modelling

    Directory of Open Access Journals (Sweden)

    N. J. de Vos

    2012-05-01

    Full Text Available Despite theoretical benefits of recurrent artificial neural networks over their feedforward counterparts, it is still unclear whether the former offer practical advantages as rainfall-runoff models. The main drawback of recurrent networks is the increased complexity of the training procedure due to their architecture. This work uses recently introduced, conceptually simple reservoir computing models for one-day-ahead forecasts on twelve river basins in the Eastern United States, and compares them to a variety of traditional feedforward and recurrent models. Two modifications on the reservoir computing models are made to increase the hydrologically relevant information content of their internal state. The results show that the reservoir computing networks outperform feedforward networks and are competitive with state-of-the-art recurrent networks, across a range of performance measures. This, along with their simplicity and ease of training, suggests that reservoir computing models can be considered promising alternatives to traditional artificial neural networks in rainfall-runoff modelling.

  5. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Moral, A. del, E-mail: delmoral@unizar.es [Laboratorio de Magnetismo, Departamento de Física de Materia Condensada and Instituto de Ciencia de Materiales, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza (Spain); Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain); Azanza, María J., E-mail: mjazanza@unizar.es [Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain)

    2015-03-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca{sup 2+} Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B{sub 0}≅0.2–15 mT) AC-MF of frequency f{sub M}=50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca{sup 2+} Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons.

  6. Ballistic aggregation: an alternative approach to modeling of silica sol-gel structures

    Energy Technology Data Exchange (ETDEWEB)

    Grzegorczyk, Marcin; Rybaczuk, Marek; Maruszewski, Krzysztof

    2004-03-01

    An algorithm based on ballistic aggregation is discussed as an alternative to the commonly used, much slower diffusion-based algorithms for modeling of atomic structure of silica gels. The algorithm is shown to be capable of producing a wide range of structures: from extremely porous to compact (dense) ones. The importance of capture distance as a controlling parameter is discussed. Electron microscope images of actual silica gels morphologically very similar to the rendered images of the simulated aggregates are shown.

  7. Alternate Service Delivery Models in Cancer Genetic Counseling: A Mini-Review

    OpenAIRE

    Buchanan, Adam Hudson; Rahm, Alanna Kulchak; Williams, Janet L.

    2016-01-01

    Demand for cancer genetic counseling has grown rapidly in recent years as germline genomic information has become increasingly incorporated into cancer care, and the field has entered the public consciousness through high-profile celebrity publications. Increased demand and existing variability in the availability of trained cancer genetics clinicians place a priority on developing and evaluating alternate service delivery models for genetic counseling. This mini-review summarizes the state o...

  8. Alternative Basic Income Mechanisms: An Evaluation Exercise with a Microeconometric Model

    OpenAIRE

    Colombino, Ugo; Locatelli, Marilena; Narazani, Edlira; Donoghue, Cathal

    2010-01-01

    We develop and estimate a microeconometric model of household labour supply in four European countries representative of different economies and welfare policy regimes: Denmark, Italy, Portugal and the United Kingdom. We then simulate, under the constraint of constant total net tax revenue (fiscal neutrality), the effects of various hypothetical tax-transfer reforms which include alternative versions of a Basic Income policy: Guaranteed Minimum Income, Work Fare, Participation Basic Income an...

  9. On an alternative framework for building virtual cities: supporting urban contextual modelling on demand

    OpenAIRE

    Chengzhi Peng; Chang, David C; Peter Blundell Jones; Bryan Lawson

    2002-01-01

    For various purposes, virtual city applications have been developed around the globe to provide users with online resources and services over the Internet. Following our research on the Sheffield Urban Contextual Databank (SUCoD) project, this paper presents an alternative framework for building virtual cities, which goes beyond conventional static urban modelling. A three-tier system framework is described in conjunction with the design and implementation of the SUCoD prototype. We demonstra...

  10. Evaluation of the zebrafish embryo as an alternative model for hepatotoxicity testing

    OpenAIRE

    Driessen, Marja

    2014-01-01

    In this thesis we showed the applicability of the zebrafish embryo as an alternative model for hepatotoxicity testing using analysis of mechanisms through toxicogenomics. By applying a variety of toxicogenomics techniques, we were able to characterize specific responses. NGS revealed that hepatotoxicity-associated gene expression remains detectable even in non-tissue specific analysis in whole body zebrafish embryo homogenates. Gene and protein expression profiling resulted in identification ...

  11. Brinzolamide-induced retinopathy in neonatal rats: an alternative animal model of retinal neovascularization

    OpenAIRE

    DYOMIN, Y. A.; BILETSKA, P.V.; GAPUNIN, I. D.

    2014-01-01

    Background and Purpose: Neovascular retinal pathology is steel uncertain. Thus, there is great need to investigate new modeling, diagnostic and treatment technologies. Brinzolamide induces a metabolic acidosis via an alternative biochemical mechanism (bicarbonate loss). In the present study the influence of brinzolamide-induced acidosis on preretinal neovascularization in neonatal rat was investigated. Materials and Methods. In our study we used newborn Wistar rats raised in two litter...

  12. Expression analysis of an evolutionarily conserved alternative splicing factor, Sfrs10, in age-related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Devi Krishna Priya Karunakaran

    Full Text Available Age-related macular degeneration (AMD is the most common cause of blindness in the elderly population. Hypoxic stress created in the micro-environment of the photoreceptors is thought to be the underlying cause that results in the pathophysiology of AMD. However, association of AMD with alternative splicing mediated gene regulation is not well explored. Alternative Splicing is one of the primary mechanisms in humans by which fewer protein coding genes are able to generate a vast proteome. Here, we investigated the expression of a known stress response gene and an alternative splicing factor called Serine-Arginine rich splicing factor 10 (Sfrs10. Sfrs10 is a member of the serine-arginine (SR rich protein family and is 100% identical at the amino acid level in most mammals. Immunoblot analysis on retinal extracts from mouse, rat, and chicken showed a single immunoreactive band. Further, immunohistochemistry on adult mouse, rat and chicken retinae showed pan-retinal expression. However, SFRS10 was not detected in normal human retina but was observed as distinct nuclear speckles in AMD retinae. This is in agreement with previous reports that show Sfrs10 to be a stress response gene, which is upregulated under hypoxia. The difference in the expression of Sfrs10 between humans and lower mammals and the upregulation of SFRS10 in AMD is further reflected in the divergence of the promoter sequence between these species. Finally, SFRS10+ speckles were independent of the SC35+ SR protein speckles or the HSF1+ stress granules. In all, our data suggests that SFRS10 is upregulated and forms distinct stress-induced speckles and might be involved in AS of stress response genes in AMD.

  13. Merging Alternate Remotely-Sensed Soil Moisture Retrievals Using a Non-Static Model Combination Approach

    Directory of Open Access Journals (Sweden)

    Seokhyeon Kim

    2016-06-01

    Full Text Available Soil moisture is an important variable in the coupled hydrologic and climate system. In recent years, microwave-based soil moisture products have been shown to be a viable alternative to in situ measurements. A popular way to measure the performance of soil moisture products is to calculate the temporal correlation coefficient (R against in situ measurements or other appropriate reference datasets. In this study, an existing linear combination method improving R was modified to allow for a non-static or nonstationary model combination as the basis for improving remotely-sensed surface soil moisture. Previous research had noted that two soil moisture products retrieved using the Japan Aerospace Exploration Agency (JAXA and Land Parameter Retrieval Model (LPRM algorithms from the same Advanced Microwave Scanning Radiometer 2 (AMSR2 sensor are spatially complementary in terms of R against a suitable reference over a fixed period. Accordingly, a linear combination was proposed to maximize R using a set of spatially-varying, but temporally-fixed weights. Even though this approach showed promising results, there was room for further improvements, in particular using non-static or dynamic weights that take account of the time-varying nature of the combination algorithm being approximated. The dynamic weighting was achieved by using a moving window. A number of different window sizes was investigated. The optimal weighting factors were determined for the data lying within the moving window and then used to dynamically combine the two parent products. We show improved performance for the dynamically-combined product over the static linear combination. Generally, shorter time windows outperform the static approach, and a 60-day time window is suggested to be the optimum. Results were validated against in situ measurements collected from 124 stations over different continents. The mean R of the dynamically-combined products was found to be 0.57 and 0

  14. Evaluating alternative models of intra-oceanic subduction of northeastern Panthalassa since the Jurassic

    Science.gov (United States)

    Shephard, Grace; Gurnis, Michael; Flament, Nicolas; Mihalynuk, Mitchell; Sigloch, Karin; Gaina, Carmen

    2014-05-01

    Renewed interest in the palaeogeography and deep mantle structure of North America, the Arctic and Northeastern Panthalassa has reignited a discussion of the region's Mesozoic subduction history. In particular, accounting for the origins of numerous accreted terranes, ranging from Gondwana, Laurentia, Baltica, the Tethys, Siberia, China and Panthalassa has facilitated several alternative tectonic scenarios. Kinematic variability is manifested in terms of the origin and timing of ocean basin opening and closure, the evolution of intra-oceanic and/or continental subduction, subduction polarities, relative plate velocities, convergence and the rate of subduction, age of subducting lithosphere and dip of subducting slabs. With ever-increasing detail of global plate motion models, advances in numerical modeling and the resolution of seismic tomography, these alterative plate reconstructions can now be robustly tested within a geodynamic framework. Having generated several alternative plate models since the start of the Jurassic, complete with self-consistent and dynamic plate boundaries, here, we test the spatial and temporal evolution of slabs through forward models of mantle flow. In turn, we undertake a qualitative and quantitative comparison of our modelled present-day mantle structure to that inferred from models of seismic tomography, therefore providing an additional dataset to which plate reconstructions of the region can be iteratively refined.

  15. Application of the Denitrification-Decomposition Model to Predict Carbon Dioxide Emissions under Alternative Straw Retention Methods

    Directory of Open Access Journals (Sweden)

    Can Chen

    2013-01-01

    Full Text Available Straw retention has been shown to reduce carbon dioxide (CO2 emission from agricultural soils. But it remains a big challenge for models to effectively predict CO2 emission fluxes under different straw retention methods. We used maize season data in the Griffith region, Australia, to test whether the denitrification-decomposition (DNDC model could simulate annual CO2 emission. We also identified driving factors of CO2 emission by correlation analysis and path analysis. We show that the DNDC model was able to simulate CO2 emission under alternative straw retention scenarios. The correlation coefficients between simulated and observed daily values for treatments of straw burn and straw incorporation were 0.74 and 0.82, respectively, in the straw retention period and 0.72 and 0.83, respectively, in the crop growth period. The results also show that simulated values of annual CO2 emission for straw burn and straw incorporation were 3.45 t C ha−1 y−1 and 2.13 t C ha−1 y−1, respectively. In addition the DNDC model was found to be more suitable in simulating CO2 mission fluxes under straw incorporation. Finally the standard multiple regression describing the relationship between CO2 emissions and factors found that soil mean temperature (SMT, daily mean temperature (Tmean, and water-filled pore space (WFPS were significant.

  16. Alternative conceptual models and codes for unsaturated flow in fractured tuff: Preliminary assessments for GWTT-95

    International Nuclear Information System (INIS)

    Groundwater travel time (GWTT) calculations will play an important role in addressing site-suitability criteria for the potential high-level nuclear waste repository at Yucca Mountain,Nevada. In support of these calculations, Preliminary assessments of the candidate codes and models are presented in this report. A series of benchmark studies have been designed to address important aspects of modeling flow through fractured media representative of flow at Yucca Mountain. Three codes (DUAL, FEHMN, and TOUGH 2) are compared in these benchmark studies. DUAL is a single-phase, isothermal, two-dimensional flow simulator based on the dual mixed finite element method. FEHMN is a nonisothermal, multiphase, multidimensional simulator based primarily on the finite element method. TOUGH2 is anon isothermal, multiphase, multidimensional simulator based on the integral finite difference method. Alternative conceptual models of fracture flow consisting of the equivalent continuum model (ECM) and the dual permeability (DK) model are used in the different codes

  17. Alternative model of the Antonov problem: Generalization with the presence of a mass spectrum

    Science.gov (United States)

    Velazquez, L.; García, S. Gómez; Guzmán, F.

    2009-01-01

    We extend the quasiergodic model proposed as an alternative version of the Antonov isothermal model [L. Velazquez and F. Guzman, Phys. Rev. E 68, 066116 (2003)] by including the incidence of a mass spectrum. We propose an iterative procedure inspired by the Newton-Raphson method to solve the resulting nonlinear structure equations. As an example of application, we assume the existence of a mass spectrum with a standard Salpeter form, dN=Cdm/mα . We analyze consequences of this realistic ingredient on the system thermodynamical behavior and perform a quantitative description of the mass segregation effect.

  18. Evaluating environmental and economic consequences of alternative pest management strategies: results of modeling workshops

    Science.gov (United States)

    Johnson, Richard L.; Andrews, Austin K.; Auble, Gregor T.L.; Ellison, Richard A.; Hamilton, David B.; Roelle, James E.; McNamee, Peter J.

    1983-01-01

    The U.S. Environmental Protection Agency (EPA) needs a comprehensive method to evaluate the human health and environmental effects of alternative agricultural pest management strategies. This project explored the utility of Adaptive Environmental Assessment (AEA) techniques for meeting this need. The project objectives were to produce models for environmental impact analysis, improve communications, identify research needs and data requirements, and demonstrate a process for resolving conflicts. The project was structured around the construction (in an initial 2 1/2-day workshop) and examination (in a second 2 1/2-day workshop) of a simulation model of a corn agroecosystem.

  19. Automated clustering of ensembles of alternative models in protein structure databases.

    Science.gov (United States)

    Domingues, Francisco S; Rahnenführer, Jörg; Lengauer, Thomas

    2004-06-01

    Experimentally determined protein structures have been classified in different public databases according to their structural and evolutionary relationships. Frequently, alternative structural models, determined using X-ray crystallography or NMR spectroscopy, are available for a protein. These models can present significant structural dissimilarity. Currently there is no classification available for these alternative structures. In order to classify them, we developed STRuster, an automated method for clustering ensembles of structural models according to their backbone structure. The method is based on the calculation of carbon alpha (Calpha) distance matrices. Two filters are applied in the calculation of the dissimilarity measure in order to identify both large and small (but significant) backbone conformational changes. The resulting dissimilarity value is used for hierarchical clustering and partitioning around medoids (PAM). Hierarchical clustering reflects the hierarchy of similarities between all pairs of models, while PAM groups the models into the 'optimal' number of clusters. The method has been applied to cluster the structures in each SCOP species level and can be easily applied to any other sets of conformers. The results are available at: http://bioinf.mpi-sb.mpg.de/projects/struster/. PMID:15319469

  20. An alternative to evaluate the efficiency of in vitro culture medium using a logistic regression model

    Directory of Open Access Journals (Sweden)

    Daniel Furtado Ferreira

    2003-01-01

    Full Text Available The evaluation of a culture medium for the in vitro culture of a species is performed using its physical and/or chemical properties. However, the analysis of the experimental results makes it possible to evaluate its quality. In this sense, this work presents an alternative using a logistic model to evaluate the culture medium to be used in vitro. The probabilities provided by this model will be used as a medium evaluator index. The importance of this index is based on the formalization of a statistical criterion for the selection of the adequate culture medium to be used on in vitro culture without excluding its physical and/or chemical properties. To demonstrate this procedure, an experiment determining the ideal medium for the in vitro culture of primary explants of Ipeca [Psychotria ipecacuanha (Brot. Stokes] was evaluated. The differentiation of the culture medium was based on the presence and absence of the growth regulator BAP (6-benzilaminopurine. A logistic model was adjusted as a function of the weight of fresh and dry matter. Minimum, medium and maximum probabilities obtained with this model showed that the culture medium containing BAP was the most adequate for the explant growth. Due to the high discriminative power of these mediums, detected by the model, their use is recommended as an alternative to select culture medium for similar experiments.

  1. Clinical utility of the DSM-5 alternative model of personality disorders: six cases from practice.

    Science.gov (United States)

    Bach, Bo; Markon, Kristian; Simonsen, Erik; Krueger, Robert F

    2015-01-01

    In Section III, Emerging Measures and Models, DSM-5 presents an Alternative Model of Personality Disorders, which is an empirically based model of personality pathology measured with the Level of Personality Functioning Scale (LPFS) and the Personality Inventory for DSM-5 (PID-5). These novel instruments assess level of personality impairment and pathological traits. Objective. A number of studies have supported the psychometric qualities of the LPFS and the PID-5, but the utility of these instruments in clinical assessment and treatment has not been extensively evaluated. The goal of this study was to evaluate the clinical utility of this alternative model of personality disorders. Method. We administered the LPFS and the PID-5 to psychiatric outpatients diagnosed with personality disorders and other nonpsychotic disorders. The personality profiles of six characteristic patients were inspected (involving a comparison of presenting problems, history, and diagnoses) and used to formulate treatment considerations. We also considered 6 specific personality disorder types that could be derived from the profiles as defined in the DSM-5 Section III criteria. Results. Using the LPFS and PID-5, we were able to characterize the 6 cases in a meaningful and useful manner with regard to understanding and treatment of the individual patient and to match the cases with 6 relevant personality disorder types. Implications for ease of use, communication, and psychotherapy are discussed. Conclusion. Our evaluation generally supported the utility for clinical purposes of the Alternative Model for Personality Disorders in Section III of the DSM-5, although it also identified some areas for refinement. (Journal of Psychiatric Practice 2015;21:3-25).

  2. Symbolic Models for Nonlinear Time-Varying Time-Delay Systems via Alternating Approximate Bisimulation

    CERN Document Server

    Pola, Giordano; Di Benedetto, Maria Domenica

    2010-01-01

    Time-delay systems are an important class of dynamical systems that provide a solid mathematical framework to deal with many application domains of interest. In this paper we focus on nonlinear control systems with unknown and time-varying delay signals and we propose one approach to the control design of such systems, which is based on the construction of symbolic models. Symbolic models are abstract descriptions of dynamical systems in which one symbolic state and one symbolic input correspond to an aggregate of states and an aggregate of inputs. We first introduce the notion of incremental input-delay-to-state stability and characterize it by means of Liapunov-Krasovskii functionals. We then derive sufficient conditions for the existence of symbolic models that are shown to be alternating approximately bisimilar to the original system. Further results are also derived which prove the computability of the proposed symbolic models in a finite number of steps.

  3. Comparison of Model Error for Alternative Conceptual Models of Sediment Geometry at the Hanford Site, Southeast Washington

    Science.gov (United States)

    Murray, C. J.; Savelieva-Trofimova, E. A.; Thorne, P. D.; Xie, Y.; Scheibe, T. D.; Cole, C. R.; Kanevski, M.

    2002-12-01

    A number of uncertainties exist in the hydrogeology of the Hanford Site, and the high costs and risks associated with cleanup of sites contaminated with radioactive wastes requires that the uncertainty associated with alternative remediation decisions must fully reflect the uncertainty associated with these decisions. Prior uncertainty analyses of Hanford groundwater model predictions have focused on uncertainties in model parameters (e.g., hydraulic conductivity) given an assumed conceptual model of hydrogeologic structure. In this study we evaluated predictive uncertainty related to the model structure conceptualization. Our study has focused on two major elements of the hydrogeologic structure of the Hanford Site: the geometry of mud units that occur within the aquifer, and the parameter zonation for hydrologic properties of the uppermost conductive portion of the aquifer. For each structural element, we have developed alternative conceptual models that have been evaluated by inverse modeling. The geometry and continuity of mud units exert a strong influence on groundwater flow and contaminant transport at the site. A detailed study of the spatial distribution of the three mud units was performed using a data set consisting of the presence/absence of each mud unit at several hundred boreholes, as well as the thickness if a mud unit was present. The spatial analysis proceeded in two stages. A series of stochastic simulations of the mud units were prepared using geostatistical methods. The stochastic simulations were numerically ranked and a subset of the best and worst simulations (as determined by the connectedness of the aquifer given the simulated mud distributions) was used as inputs to an inverse model. Inverse modeling was performed using UCODE and a finite element flow and transport code (CFEST) and used to test the fit of over 76,000 observed potentiometric head data for several alternative models of the mud distribution. Those conceptual models included

  4. Decoding Biomass-Sensing Regulons of Clostridium thermocellum Alternative Sigma-I Factors in a Heterologous Bacillus subtilis Host System.

    Directory of Open Access Journals (Sweden)

    Iván Muñoz-Gutiérrez

    Full Text Available The Gram-positive, anaerobic, cellulolytic, thermophile Clostridium (Ruminiclostridium thermocellum secretes a multi-enzyme system called the cellulosome to solubilize plant cell wall polysaccharides. During the saccharolytic process, the enzymatic composition of the cellulosome is modulated according to the type of polysaccharide(s present in the environment. C. thermocellum has a set of eight alternative RNA polymerase sigma (σ factors that are activated in response to extracellular polysaccharides and share sequence similarity to the Bacillus subtilis σI factor. The aim of the present work was to demonstrate whether individual C. thermocellum σI-like factors regulate specific cellulosomal genes, focusing on C. thermocellum σI6 and σI3 factors. To search for putative σI6- and σI3-dependent promoters, bioinformatic analysis of the upstream regions of the cellulosomal genes was performed. Because of the limited genetic tools available for C. thermocellum, the functionality of the predicted σI6- and σI3-dependent promoters was studied in B. subtilis as a heterologous host. This system enabled observation of the activation of 10 predicted σI6-dependent promoters associated with the C. thermocellum genes: sigI6 (itself, Clo1313_2778, xyn11B (Clo1313_0522, xyn10D (Clo1313_0177, xyn10Z (Clo1313_2635, xyn10Y (Clo1313_1305, cel9V (Clo1313_0349, cseP (Clo1313_2188, sigI1 (Clo1313_2174, cipA (Clo1313_0627, and rsgI5 (Clo1313_0985. Additionally, we observed the activation of 4 predicted σI3-dependent promoters associated with the C. thermocellum genes: sigI3 (itself, Clo1313_1911, pl11 (Clo1313_1983, ce12 (Clo1313_0693 and cipA. Our results suggest possible regulons of σI6 and σI3 in C. thermocellum, as well as the σI6 and σI3 promoter consensus sequences. The proposed -35 and -10 promoter consensus elements of σI6 are CNNAAA and CGAA, respectively. Additionally, a less conserved CGA sequence next to the C in the -35 element and a highly

  5. A water system model for exploring electric energy alternatives in southeastern US basins

    International Nuclear Information System (INIS)

    Electric power generation often involves the use of water for power plant cooling and steam generation, which typically involves the release of cooling water to nearby rivers and lakes. The resulting thermal pollution may negatively impact the ecosystems of these water bodies. Water resource systems models enable the examination of the implications of alternative electric generation on regional water resources. This letter documents the development, calibration, and validation of a climate-driven water resource systems model of the Apalachicola–Chattahoochee–Flint, the Alabama–Coosa–Tallapoosa, and the Tombigbee River basins in the states of Georgia, Alabama, and Florida, in the southeastern US. The model represents different water users, including power plants, agricultural water users, and municipal users. The model takes into account local population, per-capita use estimates, and changes in population growth. The water resources planning model was calibrated and validated against the observed, managed flows through the river systems of the three basins. Flow calibration was performed on land cover, water capacity, and hydraulic conductivity of soil horizons; river water temperature calibration was performed on channel width and slope properties. Goodness-of-fit statistics indicate that under 1980–2010 levels of water use, the model robustly represents major features of monthly average streamflow and water temperatures. The application of this integrated electricity generation–water resources planning model can be used to explore alternative electric generation and water implications. The implementation of this model is explored in the companion paper of this focus issue (Yates et al 2013 Environ. Res. Lett. 8 035042). (letter)

  6. A cumulative decision model for three-alternative choice in concurrent chains.

    Science.gov (United States)

    Grace, Randolph C; McLean, Anthony P

    2016-07-01

    Traditional models for choice in the concurrent-chains procedure have assumed that terminal-link stimuli acquire value as conditioned reinforcers, and that 2-alternative choice provides a measure of relative value according to the matching law. By contrast, the cumulative decision model (CDM; Christensen & Grace, 2010) explains choice as the aggregate effect of comparing delays to a criterion on initial-link responding, not conditioned reinforcement. Here we test whether the CDM can account for choice in 3-alternative concurrent-chains (3ACC) and compare it with the hyperbolic value-added model (HVA; Mazur, 2001), which assumes that choice depends on the increase in conditioned reinforcement value signaled by terminal-link stimuli and has been successful in previous 3ACC research (Mazur, 2000). In Experiment 1, 4 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules, and parameter estimates from fits of CDM and HVA were used to calculate predictions for conditions with variable-interval terminal links. The predictions of CDM were more accurate than those of HVA. In Experiment 2, 7 pigeons responded in 3ACC in which the terminal links were fixed-interval schedules. Although both models described the data well, residuals from HVA fits showed a systematic pattern predicted by CDM, characterized by a third-order polynomial with a negative cubic coefficient. Finally, we conducted a residual meta-analysis (Sutton, Grace, McLean, & Baum, 2008) of data from prior 3ACC studies. HVA residuals showed the same negative cubic pattern as in Experiment 2, whereas no systematic pattern was found in the CDM residuals. Overall, results support the CDM and suggest that the same principles which describe binary choice in concurrent chains generalize without modification to 3-alternative choice. (PsycINFO Database Record PMID:27379716

  7. Liquidity and Fama-French Three-Factor Model

    Institute of Scientific and Technical Information of China (English)

    陈政

    2012-01-01

      The Fama-French three-factor model was proposed to explain the expected return. In this paper,the author takes advantage of the recent data from NYSE, AMEX and NASDAQ stocks to examine whether the Fama-French three-factor model can explain the expected return well on the basis of reviewing the importance of liquidity and criticizing the Fama-French three-factor model. It turns out that the three-factor model can still reflect the factor in asset pricing to a certain degree.

  8. The Axolotl (Ambystoma mexicanum: Factors That Limit its Production and Alternatives for its Conservation

    Directory of Open Access Journals (Sweden)

    J. Toca-Ramirez

    2006-01-01

    Full Text Available Ambystoma mexicanum is an amphibian endemic to Xochimilco Lake in Mexico City. It has been declared in danger of extinction and is under special protection. Some chemical contaminants in the water are extremely high and could be the cause of its high mortality rate in certain areas of Xochimilco. In order to preserve this species it will not only be necessary and fundamental to prohibit fishing axolotls in their natural state, a market study and nutritional chemical analysis will also be necessary in order to establish the organoleptic properties and level of acceptance before a taste panel; that is to say, get to know more about the specie in order to give the product added value offering its meat as an unconventional delicacy. This way the creation of farms that will help its conservation will be justified. On the other hand it is important to mention that the axolotls are very important in scientific research. Since it serves as an amphibious model for many physiological and morphological processes that explain the regenerative process that this species possess. The objective of this study is to emphasize the advantages that the Ambystoma mexicanum has with the intention to rationally exploit these attributes in order to achieve its conservation.

  9. Testing alternative uses of electromagnetic data to reduce the prediction error of groundwater models

    Science.gov (United States)

    Kruse Christensen, Nikolaj; Christensen, Steen; Ferre, Ty Paul A.

    2016-05-01

    In spite of geophysics being used increasingly, it is often unclear how and when the integration of geophysical data and models can best improve the construction and predictive capability of groundwater models. This paper uses a newly developed HYdrogeophysical TEst-Bench (HYTEB) that is a collection of geological, groundwater and geophysical modeling and inversion software to demonstrate alternative uses of electromagnetic (EM) data for groundwater modeling in a hydrogeological environment consisting of various types of glacial deposits with typical hydraulic conductivities and electrical resistivities covering impermeable bedrock with low resistivity (clay). The synthetic 3-D reference system is designed so that there is a perfect relationship between hydraulic conductivity and electrical resistivity. For this system it is investigated to what extent groundwater model calibration and, often more importantly, model predictions can be improved by including in the calibration process electrical resistivity estimates obtained from TEM data. In all calibration cases, the hydraulic conductivity field is highly parameterized and the estimation is stabilized by (in most cases) geophysics-based regularization. For the studied system and inversion approaches it is found that resistivities estimated by sequential hydrogeophysical inversion (SHI) or joint hydrogeophysical inversion (JHI) should be used with caution as estimators of hydraulic conductivity or as regularization means for subsequent hydrological inversion. The limited groundwater model improvement obtained by using the geophysical data probably mainly arises from the way these data are used here: the alternative inversion approaches propagate geophysical estimation errors into the hydrologic model parameters. It was expected that JHI would compensate for this, but the hydrologic data were apparently insufficient to secure such compensation. With respect to reducing model prediction error, it depends on the type

  10. Regional on-road vehicle running emissions modeling and evaluation for conventional and alternative vehicle technologies.

    Science.gov (United States)

    Frey, H Christopher; Zhai, Haibo; Rouphail, Nagui M

    2009-11-01

    This study presents a methodology for estimating high-resolution, regional on-road vehicle emissions and the associated reductions in air pollutant emissions from vehicles that utilize alternative fuels or propulsion technologies. The fuels considered are gasoline, diesel, ethanol, biodiesel, compressed natural gas, hydrogen, and electricity. The technologies considered are internal combustion or compression engines, hybrids, fuel cell, and electric. Road link-based emission models are developed using modal fuel use and emission rates applied to facility- and speed-specific driving cycles. For an urban case study, passenger cars were found to be the largest sources of HC, CO, and CO(2) emissions, whereas trucks contributed the largest share of NO(x) emissions. When alternative fuel and propulsion technologies were introduced in the fleet at a modest market penetration level of 27%, their emission reductions were found to be 3-14%. Emissions for all pollutants generally decreased with an increase in the market share of alternative vehicle technologies. Turnover of the light duty fleet to newer Tier 2 vehicles reduced emissions of HC, CO, and NO(x) substantially. However, modest improvements in fuel economy may be offset by VMT growth and reductions in overall average speed.

  11. Alternative business models for establishing fast-charging stations - Part 2; Alternative forretningsmodeller for etablering av hurtigladestasjoner - Del 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    This section of the report describes and evaluates potential business models for fast-charging stations. Business models are developed on the basis of market development for electric vehicles and electric vehicle usage patterns analyzed in Part 1 of the project. This report describes a series of models in both the early and maturity stage, where we have distinguished between different user segments and payment models. With the estimated trends in the car fleet and charger use, the prerequisites for profitable quick charging in the downtown area are good, while, due to high construction contribution, you must have a relatively high proportion of subscriptions and a high charge rate to obtain adequate finances in the corridor points.(auth)

  12. Echo state networks as an alternative to traditional artificial neural networks in rainfall–runoff modelling

    Directory of Open Access Journals (Sweden)

    N. J. de Vos

    2013-01-01

    Full Text Available Despite theoretical benefits of recurrent artificial neural networks over their feedforward counterparts, it is still unclear whether the former offer practical advantages as rainfall–runoff models. The main drawback of recurrent networks is the increased complexity of the training procedure due to their architecture. This work uses the recently introduced and conceptually simple echo state networks for streamflow forecasts on twelve river basins in the Eastern United States, and compares them to a variety of traditional feedforward and recurrent approaches. Two modifications on the echo state network models are made that increase the hydrologically relevant information content of their internal state. The results show that the echo state networks outperform feedforward networks and are competitive with state-of-the-art recurrent networks, across a range of performance measures. This, along with their simplicity and ease of training, suggests that they can be considered promising alternatives to traditional artificial neural networks in rainfall–runoff modelling.

  13. Echo state networks as an alternative to traditional artificial neural networks in rainfall-runoff modelling

    Science.gov (United States)

    de Vos, N. J.

    2013-01-01

    Despite theoretical benefits of recurrent artificial neural networks over their feedforward counterparts, it is still unclear whether the former offer practical advantages as rainfall-runoff models. The main drawback of recurrent networks is the increased complexity of the training procedure due to their architecture. This work uses the recently introduced and conceptually simple echo state networks for streamflow forecasts on twelve river basins in the Eastern United States, and compares them to a variety of traditional feedforward and recurrent approaches. Two modifications on the echo state network models are made that increase the hydrologically relevant information content of their internal state. The results show that the echo state networks outperform feedforward networks and are competitive with state-of-the-art recurrent networks, across a range of performance measures. This, along with their simplicity and ease of training, suggests that they can be considered promising alternatives to traditional artificial neural networks in rainfall-runoff modelling.

  14. Alternative model for assessment administration and analysis: An example from the E-CLASS

    CERN Document Server

    Wilcox, Bethany R; Hobbs, Robert D; Aiken, John M; Welch, Nathan M; Lewandowski, H J

    2016-01-01

    The primary model for dissemination of conceptual and attitudinal assessments that has been used within the physics education research (PER) community is to create a high quality, validated assessment, make it available for a wide range of instructors to use, and provide minimal (if any) support to assist with administration or analysis of the results. Here, we present and discuss an alternative model for assessment dissemination, which is characterized by centralized data collection and analysis. This model also provides a greater degree of support for both researchers and instructors. Specifically, we describe our experiences developing a centralized, automated system for an attitudinal assessment we previously created to examine students' epistemologies and expectations about experimental physics. This system provides a proof-of-concept that we use to discuss the advantages associated with centralized administration and data collection for research-based assessments in PER. We also discuss the challenges t...

  15. A Distance Model of Intuitionistic Fuzzy Cross Entropy to Solve Preference Problem on Alternatives

    Directory of Open Access Journals (Sweden)

    Mei Li

    2016-01-01

    Full Text Available In the field of decision-making, for the multiple attribute decision-making problem with the partially unknown attribute weights, the evaluation information in the form of the intuitionistic fuzzy numbers, and the preference on alternatives, this paper proposes a comprehensive decision model based on the intuitionistic fuzzy cross entropy distance and the grey correlation analysis. The creative model can make up the deficiency that the traditional intuitionistic fuzzy distance measure is easy to cause the confusion of information and can improve the accuracy of distance measure; meanwhile, the grey correlation analysis method, suitable for the small sample and the poor information decision-making, is applied in the evaluation. This paper constructs a mathematical optimization model of maximizing the synthesis grey correlation coefficient between decision-making evaluation values and decision-makers’ subjective preference values, calculates the attribute weights with the known partial weight information, and then sorts the alternatives by the grey correlation coefficient values. Taking venture capital firm as an example, through the calculation and the variable disturbance, we can see that the methodology used in this paper has good stability and rationality. This research makes the decision-making process more scientific and further improves the theory of intuitionistic fuzzy multiple attribute decision-making.

  16. Challenges to complementary and alternative medical research: focal issues influencing integration into a cancer care model.

    Science.gov (United States)

    Giordano, James; Engebretson, Joan; Garcia, Mary K

    2005-09-01

    Complementary and alternative therapies are increasingly used by cancer patients for palliative and postcancer preventive and/or wellness care. It is critical that evidence-based models be employed to both provide information for patients' use and informed consent and for physicians to advise patients and assess relative risk:benefit ratios of using specific complementary and alternative medicine (CAM) approaches within the cancer care paradigm. Research models for biomedicine have been somewhat limited when applied to broader, more holistic conceptualizations of health common to many forms of CAM. Thus, while numerous challenges to studying CAM exist, a fundamental question is not just what CAM practices should be studied but how CAM should be studied. The authors propose a model that emphasizes methodologic rigor yet approaches CAM research according to relative levels of evidence, meaning, and context, ranging from experimental, quantitative studies of mechanism to qualitative, observational studies of noetic/salutogenic variables. Responsibility for training researchers prepared to meet such challenges rests on both CAM and mainstream academic institutions, and care must be taken to avoid philosophical and practical pitfalls that might befall a myopic perspective of integration. PMID:16113028

  17. An alternative functional renormalization group approach to the single impurity Anderson model

    OpenAIRE

    Kinza, Michael; Ortloff, Jutta; Bauer, Johannes; Honerkamp, Carsten

    2012-01-01

    We present an alternative functional renormalization group (fRG) approach to the single-impurity Anderson model at finite temperatures. Starting with the exact self-energy and interaction vertex of a small system ('core') containing a correlated site, we switch on the hybridization with a non-interacting bath in the fRG-flow and calculate spectra of the correlated site. Different truncations of the RG-flow-equations and choices of the core are compared and discussed. Furthermore we calculate ...

  18. Alternate site infusion: the physician-directed, office-based model.

    Science.gov (United States)

    Tice, A D

    1996-01-01

    The physician-directed, clinic-based system for alternate site infusion therapy offers the advantages of easy communication and integrated decision making through the close teamwork and particular expertise of the nurse, physician, and pharmacist. With this system, any type of delivery model for home or outpatient IV antibiotic can be administered safely and efficiently. Through the involvement of the physician, it is easy to do clinical outcomes studies and develop bundling of services for risk-sharing contracts under managed care. PMID:8852176

  19. Alternative model for administration and analysis of research-based assessments

    Science.gov (United States)

    Wilcox, Bethany R.; Zwickl, Benjamin M.; Hobbs, Robert D.; Aiken, John M.; Welch, Nathan M.; Lewandowski, H. J.

    2016-06-01

    Research-based assessments represent a valuable tool for both instructors and researchers interested in improving undergraduate physics education. However, the historical model for disseminating and propagating conceptual and attitudinal assessments developed by the physics education research (PER) community has not resulted in widespread adoption of these assessments within the broader community of physics instructors. Within this historical model, assessment developers create high quality, validated assessments, make them available for a wide range of instructors to use, and provide minimal (if any) support to assist with administration or analysis of the results. Here, we present and discuss an alternative model for assessment dissemination, which is characterized by centralized data collection and analysis. This model provides a greater degree of support for both researchers and instructors in order to more explicitly support adoption of research-based assessments. Specifically, we describe our experiences developing a centralized, automated system for an attitudinal assessment we previously created to examine students' epistemologies and expectations about experimental physics. This system provides a proof of concept that we use to discuss the advantages associated with centralized administration and data collection for research-based assessments in PER. We also discuss the challenges that we encountered while developing, maintaining, and automating this system. Ultimately, we argue that centralized administration and data collection for standardized assessments is a viable and potentially advantageous alternative to the default model characterized by decentralized administration and analysis. Moreover, with the help of online administration and automation, this model can support the long-term sustainability of centralized assessment systems.

  20. Evaluation of Alternative Conceptual Models Using Interdisciplinary Information: An Application in Shallow Groundwater Recharge and Discharge

    Science.gov (United States)

    Lin, Y.; Bajcsy, P.; Valocchi, A. J.; Kim, C.; Wang, J.

    2007-12-01

    Natural systems are complex, thus extensive data are needed for their characterization. However, data acquisition is expensive; consequently we develop models using sparse, uncertain information. When all uncertainties in the system are considered, the number of alternative conceptual models is large. Traditionally, the development of a conceptual model has relied on subjective professional judgment. Good judgment is based on experience in coordinating and understanding auxiliary information which is correlated to the model but difficult to be quantified into the mathematical model. For example, groundwater recharge and discharge (R&D) processes are known to relate to multiple information sources such as soil type, river and lake location, irrigation patterns and land use. Although hydrologists have been trying to understand and model the interaction between each of these information sources and R&D processes, it is extremely difficult to quantify their correlations using a universal approach due to the complexity of the processes, the spatiotemporal distribution and uncertainty. There is currently no single method capable of estimating R&D rates and patterns for all practical applications. Chamberlin (1890) recommended use of "multiple working hypotheses" (alternative conceptual models) for rapid advancement in understanding of applied and theoretical problems. Therefore, cross analyzing R&D rates and patterns from various estimation methods and related field information will likely be superior to using only a single estimation method. We have developed the Pattern Recognition Utility (PRU), to help GIS users recognize spatial patterns from noisy 2D image. This GIS plug-in utility has been applied to help hydrogeologists establish alternative R&D conceptual models in a more efficient way than conventional methods. The PRU uses numerical methods and image processing algorithms to estimate and visualize shallow R&D patterns and rates. It can provide a fast initial

  1. Factor Model Forecasting of Inflation in Croatia

    Directory of Open Access Journals (Sweden)

    Davor Kunovac

    2007-12-01

    Full Text Available This paper tests whether information derived from 144 economic variables (represented by only a few constructed factors can be used for the forecasting of consumer prices in Croatia. The results obtained show that the use of one factor enhances the precision of the benchmark model’s ability to forecast inflation. The methodology used is sufficiently general to be able to be applied directly for the forecasting of other economic variables.

  2. Considering too few alternatives: The mental model theory of extensional reasoning.

    Science.gov (United States)

    Chevalley, Thierry; Schaeken, Walter

    2016-01-01

    When solving a simple probabilistic problem, people tend to build an incomplete mental representation. We observe this pattern in responses to probabilistic problems over a set of premises using the conjunction, disjunction, and conditional propositional connectives. The mental model theory of extensional reasoning explains this bias towards underestimating the number of possibilities: In reckoning with different interpretations of the premises (logical rules, mental model theoretical, and, specific to conditional premises, conjunction and biconditional interpretation) the mental model theory accounts for the majority of observations. Different interpretations of a premise result in a build-up of mental models that are often incomplete. These mental models are processed using either an extensional strategy relying on proportions amongst models, or a conflict monitoring strategy. The consequence of considering too few possibilities is an erroneous probability estimate akin to that faced by decision makers who fail to generate and consider all alternatives, a characteristic of bounded rationality. We compare our results to the results published by Johnson-Laird, Legrenzi, Girotto, Legrenzi, and Caverni [Johnson-Laird, P., Legrenzi, P., Girotto, V., Legrenzi, M., & Caverni, J. (1999). Naive probability: A mental model theory of extensional reasoning. Psychological Review, 106, 62-88. doi: 10. 1037/0033-295X.106.1.62], and we observe lower performance levels than those in the original article. PMID:26046814

  3. Supervision in Factor Models Using a Large Number of Predictors

    DEFF Research Database (Denmark)

    Boldrini, Lorenzo; Hillebrand, Eric Tobias

    In this paper we investigate the forecasting performance of a particular factor model (FM) in which the factors are extracted from a large number of predictors. We use a semi-parametric state-space representation of the FM in which the forecast objective, as well as the factors, is included in the...... state vector. The factors are informed of the forecast target (supervised) through the state equation dynamics. We propose a way to assess the contribution of the forecast objective on the extracted factors that exploits the Kalman filter recursions. We forecast one target at a time based on the...... standard dynamic factor model with separate forecast and state equations....

  4. The West Central Alberta Woodland Caribou Landscape Plan: Using a Modeling Approach to Develop Alternative Scenarios

    Directory of Open Access Journals (Sweden)

    Anne Hubbs

    2011-09-01

    Full Text Available Woodland caribou (Rangifer tarandus are classified as threatened in Alberta. In support of Canada's Species at Risk Act, a Recovery Plan for Woodland Caribou in Alberta was completed in 2004 which required local implementation plans to be completed within 5 areas of the province. The West Central Alberta Caribou Landscape Plan (WCCLP is the first of these to be initiated and it addresses the recovery strategies for 4 herds. Two aspatial computer models built on the STELLA© modelling platform (ISee Systems, 2007 were used to assist the planning team in evaluating cumulative effects and alternative scenarios for caribou conservation. The ALCES© (Forem Technologies 2008 modelling tool was used to forecast potential changes in the west central Alberta landscape over time. Yearly landscape condition outputs from ALCES© were then exported into a caribou-specific population model, REMUS© (Weclaw, 2004, that was used to project potential population responses by woodland caribou, other primary prey species [moose (Alces alces, elk (Cervus elaphus and deer (Odocoileus sp.] and wolves (Canis lupus (Weclaw & Hudson, 2004. Simulated habitat management strategies that resulted in the highest likelihood of caribou recovery included the maintenance of a high proportion of old forest, the aggregation of industrial footprints and the reclamation of historic seismic lines (although the latter took decades to provide real dividends. Sharing of industrial roads, protection of fragments of old-growth, and expanding an already aggressive fire control strategy in Alberta had little additional effect on caribou recovery. Simulated population management strategies that were successful all involved decades of intensive wolf control, either directly or indirectly through intensive primary prey control (with the exception of woodland caribou until old-growth forests recovered to densities that provided caribou habitat and decreased alternate prey of wolves. Although

  5. Modeling the Impact of Alternative Immunization Strategies: Using Matrices as Memory Lanes.

    Directory of Open Access Journals (Sweden)

    Wladimir J Alonso

    Full Text Available Existing modeling approaches are divided between a focus on the constitutive (micro elements of systems or on higher (macro organization levels. Micro-level models enable consideration of individual histories and interactions, but can be unstable and subject to cumulative errors. Macro-level models focus on average population properties, but may hide relevant heterogeneity at the micro-scale. We present a framework that integrates both approaches through the use of temporally structured matrices that can take large numbers of variables into account. Matrices are composed of several bidimensional (time×age grids, each representing a state (e.g. physiological, immunological, socio-demographic. Time and age are primary indices linking grids. These matrices preserve the entire history of all population strata and enable the use of historical events, parameters and states dynamically in the modeling process. This framework is applicable across fields, but particularly suitable to simulate the impact of alternative immunization policies. We demonstrate the framework by examining alternative strategies to accelerate measles elimination in 15 developing countries. The model recaptured long-endorsed policies in measles control, showing that where a single routine measles-containing vaccine is employed with low coverage, any improvement in coverage is more effective than a second dose. It also identified an opportunity to save thousands of lives in India at attractively low costs through the implementation of supplementary immunization campaigns. The flexibility of the approach presented enables estimating the effectiveness of different immunization policies in highly complex contexts involving multiple and historical influences from different hierarchical levels.

  6. Factor Influencing Crude Palm Oil (CPO) Biodiesel Supply in Indonesia Using Error Correction Model (ECM)

    OpenAIRE

    Larasati Sukmadewi Wibowo

    2015-01-01

    Indonesia is in a good position to develop biodiesel industry for alternative energy supply. The government issued legislations to accelerate the development of biodiesel industry. However, the growth was relatively slow and unstable, especially during the initiating stage of the new policy. The purpose of this study was to know the factors affecting supply of biodiesel in Indonesia, using Error Correction Model (ECM) to determine the long term and short term relationship. Monthly data from J...

  7. Statistical count models for prognosis the risk factors of hepatitis C

    OpenAIRE

    Pourhoseingholi, Asma; Baghban, Alireza Akbarzadeh; Zayeri, Farid; Alavian, Seyed Moayed; Vahedi, Mohsen

    2013-01-01

    Aim The aim of this study was to compare alternatives methods for analysis of zero inflated count data and compare them with simple count models that are used by researchers frequently for such zero inflated data. Background Analysis of viral load and risk factors could predict likelihood of achieving sustain virological response (SVR). This information is useful to protect a person from acquiring Hepatitis C virus (HCV) infection. The distribution of viral load contains a large proportion of...

  8. Risk-adjusted capitation funding models for chronic disease in Australia: alternatives to casemix funding.

    Science.gov (United States)

    Antioch, K M; Walsh, M K

    2002-01-01

    Under Australian casemix funding arrangements that use Diagnosis-Related Groups (DRGs) the average price is policy based, not benchmarked. Cost weights are too low for State-wide chronic disease services. Risk-adjusted Capitation Funding Models (RACFM) are feasible alternatives. A RACFM was developed for public patients with cystic fibrosis treated by an Australian Health Maintenance Organization (AHMO). Adverse selection is of limited concern since patients pay solidarity contributions via Medicare levy with no premium contributions to the AHMO. Sponsors paying premium subsidies are the State of Victoria and the Federal Government. Cost per patient is the dependent variable in the multiple regression. Data on DRG 173 (cystic fibrosis) patients were assessed for heteroskedasticity, multicollinearity, structural stability and functional form. Stepwise linear regression excluded non-significant variables. Significant variables were 'emergency' (1276.9), 'outlier' (6377.1), 'complexity' (3043.5), 'procedures' (317.4) and the constant (4492.7) (R(2)=0.21, SE=3598.3, F=14.39, ProbService Federal payments for drugs and medical services; lump sum lung transplant payments and risk sharing through cost (loss) outlier payments. State and Federally funded home and palliative services are 'carved out'. The model, which has national application via Coordinated Care Trials and by Australian States for RACFMs may be instructive for Germany, which plans to use Australian DRGs for casemix funding. The capitation alternative for chronic disease can improve equity, allocative efficiency and distributional justice. The use of Diagnostic Cost Groups (DCGs) is a promising alternative classification system for capitation arrangements. PMID:15609134

  9. A preclinical mouse model of glioma with an alternative mechanism of telomere maintenance (ALT).

    Science.gov (United States)

    Jeitany, Maya; Pineda, Jose Ramon; Liu, Qingyuan; Porreca, Rosa Maria; Hoffschir, Françoise; Desmaze, Chantal; Silvestre, David C; Mailliet, Patrick; Junier, Marie-Pierre; Londoño-Vallejo, Arturo; Ségal-Bendirdjian, Evelyne; Chneiweiss, Hervé; Boussin, François D

    2015-04-01

    Glioblastoma multiforme is the most aggressive primary tumor of the central nervous system. Glioma stem cells (GSCs), a small population of tumor cells with stem-like properties, are supposedly responsible for glioblastoma multiforme relapse after current therapies. In approximately thirty percent of glioblastoma multiforme tumors, telomeres are not maintained by telomerase but through an alternative mechanism, termed alternative lengthening of telomere (ALT), suggesting potential interest in developing specific therapeutic strategies. However, no preclinical model of ALT glioma was available until the isolation of TG20 cells from a human ALT glioma. Herein, we show that TG20 cells exhibit a high level of telomeric recombination but a stable karyotype, indicating that their telomeres retain their protective function against chromosomal instability. TG20 cells possess all of the characteristic features of GSCs: the expression of neural stem cell markers, the generation of intracerebral tumors in NOD-SCID-IL2Rγ (NSG) mice as well as in nude mice, and the ability to sustain serial intracerebral transplantations without expressing telomerase, demonstrating the stability of the ALT phenotype in vivo. Furthermore, we also demonstrate that 360B, a G-quadruplex ligand of the pyridine derivative series that impairs telomere replication and mitotic progression in cancer cells, prevents the development of TG20 tumors. Together, our results show that intracerebral grafts of TG20 cells in immunodeficient mice constitute an efficient preclinical model of ALT glioblastoma multiforme and that G-quadruplex ligands are a potential therapy for this specific type of tumor. PMID:25175359

  10. Alternate Service Delivery Models in Cancer Genetic Counseling: A Mini-Review.

    Science.gov (United States)

    Buchanan, Adam Hudson; Rahm, Alanna Kulchak; Williams, Janet L

    2016-01-01

    Demand for cancer genetic counseling has grown rapidly in recent years as germline genomic information has become increasingly incorporated into cancer care, and the field has entered the public consciousness through high-profile celebrity publications. Increased demand and existing variability in the availability of trained cancer genetics clinicians place a priority on developing and evaluating alternate service delivery models for genetic counseling. This mini-review summarizes the state of science regarding service delivery models, such as telephone counseling, telegenetics, and group counseling. Research on comparative effectiveness of these models in traditional individual, in-person genetic counseling has been promising for improving access to care in a manner acceptable to patients. Yet, it has not fully evaluated the short- and long-term patient- and system-level outcomes that will help answer the question of whether these models achieve the same beneficial psychosocial and behavioral outcomes as traditional cancer genetic counseling. We propose a research agenda focused on comparative effectiveness of available service delivery models and how to match models to patients and practice settings. Only through this rigorous research can clinicians and systems find the optimal balance of clinical quality, ready and secure access to care, and financial sustainability. Such research will be integral to achieving the promise of genomic medicine in oncology. PMID:27242960

  11. Modeling the alternative oxidase from the human pathogen Blastocystis using automated hybrid structural template assembly

    Directory of Open Access Journals (Sweden)

    Standley DM

    2012-01-01

    Full Text Available Daron M Standley1, Mark van der Giezen21Laboratory of Systems Immunology, World Premier International Immunology Frontier Research Center, Osaka University, Osaka, Japan; 2Centre for Eukaryotic Evolutionary Microbiology, Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UKAbstract: Alternative oxidases (AOX of human parasites represent attractive drug targets due to their absence in humans. However, the lack of a structure has prevented structure-based drug design. Moreover, a large helical insertion proves difficult for automated structural modeling efforts. We have used a novel hybrid structural modeling approach to generate a model that is globally consistent with a previous model but based on a phylogenetically closer template and systematic sampling of known fragments in the helical insertion. Our model, in agreement with site-directed mutagenesis studies, clearly assigns E200 as the iron-ligating residue as opposed to the previously suggested E201. Crystallization of AOX from another species has recently been reported suggesting that our blind prediction can be independently validated in the near future.Keywords: homology modeling, protein structure, blind prediction, fragment assembly, active site, parasite, mitosome, hydrogenosome, evolution

  12. Alternate service delivery models in cancer genetic counseling: a mini-review

    Directory of Open Access Journals (Sweden)

    Adam Hudson Buchanan

    2016-05-01

    Full Text Available Demand for cancer genetic counseling has grown rapidly in recent years as germline genomic information has become increasingly incorporated into cancer care and the field has entered the public consciousness through high-profile celebrity publications. Increased demand and existing variability in the availability of trained cancer genetics clinicians place a priority on developing and evaluating alternate service delivery models for genetic counseling. This mini-review summarizes the state of science regarding service delivery models such as telephone counseling, telegenetics and group counseling. Research on comparative effectiveness of these models in traditional individual, in-person genetic counseling has been promising for improving access to care in a manner acceptable to patients. Yet, it has not fully evaluated the short- and long-term patient- and system-level outcomes that will help answer the question of whether these models achieve the same beneficial psychosocial and behavioral outcomes as traditional cancer genetic counseling. We propose a research agenda focused on comparative effectiveness of available service delivery models and how to match models to patients and practice settings. Only through this rigorous research can clinicians and systems find the optimal balance of clinical quality, ready and secure access to care, and financial sustainability. Such research will be integral to achieving the promise of genomic medicine in oncology.

  13. Traditional and alternative nonlinear models for estimating the growth of Morada Nova sheep

    Directory of Open Access Journals (Sweden)

    Laaina de Andrade Souza

    2013-09-01

    Full Text Available In the present study, alternative and traditional nonlinear models to describe growth curves of Morada Nova sheep reared in the state of Bahia, Brazil, were applied. The nonlinear models were: Schnute, Mitscherlich, Gompertz, Logistic, Meloun I Meloun II, III Meloun, Gamito and Meloun IV. The model adjustment was evaluated by using: Adjusted Coefficient of Determination (R²aj, Akaike Information Criterion (AIC, Bayesian Information Criterion (BIC, Mean Squared Error of Prediction (MEP and Coefficient of Determination of Prediction (R²p. The selection of the best model was based on cluster analysis, using the evaluators as variables. Six out of the nine tested models converged, while Meloun I and Meloun IV were equally effective in explaining animal growth, without significant influence of sex or type of parturition over the curve parameters. The models Meloun I and IV have the best adjustment and reveal a remarkable reduction of weight gain after 150 days of age, which indicates special attention should be given to feeding at this stage.

  14. Calibration of the modified Bartlett-Lewis model using global optimization techniques and alternative objective functions

    Directory of Open Access Journals (Sweden)

    W. J. Vanhaute

    2011-11-01

    Full Text Available The use of rainfall time series for various applications is widespread. However, in many cases historical rainfall records lack in length or quality for certain practical purposes, resulting in a reliance on rainfall models to supply simulated rainfall time series, e.g., in the design of hydraulic structures. One way to obtain such simulations is by means of stochastic point process rainfall models, such as the Bartlett-Lewis type of model. It is widely acknowledged that the calibration of such models suffers from the presence of multiple local minima which local search algorithms usually fail to avoid. To meet this shortcoming, four relatively new global optimization methods are presented and tested for their abilities to calibrate the Modified Bartlett-Lewis Model (MBL. The list of tested methods consists of: the Downhill Simplex Method (DSM, Simplex-Simulated Annealing (SIMPSA, Particle Swarm Optimization (PSO and Shuffled Complex Evolution (SCE-UA. The parameters of these algorithms are first optimized to ensure optimal performance, after which they are used for calibration of the MBL model. Furthermore, this paper addresses the issue of subjectivity in the choice of weights in the objective function. Three alternative weighing methods are compared to determine whether or not simulation results (obtained after calibration with the best optimization method are influenced by the choice of weights.

  15. Utilization of reconstructed cultured human skin models as an alternative skin for permeation studies of chemical compounds

    OpenAIRE

    Kano, Satoshi; 藤堂, 浩明; 杉江, 謙一; 藤本, 英哲; 中田, 圭一; 徳留, 嘉寛; 橋本, フミ惠; 杉林, 堅次

    2010-01-01

    Two reconstructed human skin models, EpiskinSM and EpiDermTM, have been approved as alternative membranes for skin corrosive/irritation experiments due to their close correlation with animal skin. Such reconstructed human skin models were evaluated as alternative membranes for skin permeation experiments. Seven drugs with different lipophilicities and almost the same molecular weight were used as test penetrants. Relationships were investigated between permeability coefficients (P values) of ...

  16. Reliability Analysis of a Composite Blade Structure Using the Model Correction Factor Method

    DEFF Research Database (Denmark)

    Dimitrov, Nikolay Krasimiroy; Friis-Hansen, Peter; Berggreen, Christian

    2010-01-01

    in a probabilistic sense is model corrected so that it, close to the design point, represents the same structural behaviour as a realistic FE model. This approach leads to considerable improvement of computational efficiency over classical response surface methods, because the numerically “cheap......” idealistic model is used as the response surface, while the time-consuming detailed model is called only a few times until the simplified model is calibrated to the detailed model.......This paper presents a reliability analysis of a composite blade profile. The so-called Model Correction Factor technique is applied as an effective alternate approach to the response surface technique. The structural reliability is determined by use of a simplified idealised analytical model which...

  17. Mortality model based on delays in progression of chronic diseases: alternative to cause elimination model.

    OpenAIRE

    Manton, K G; Patrick, C H; Stallard, E

    1980-01-01

    For the analysis of the impact of major chronic diseases on a population, a life table model is proposed in which the age at death due to specific cause (chronic disease) is postponed. Even though many of the major causes of death related to intrinsic aging processes are impossible to eliminate, these causes might be significantly delayed or retarded. To illustrate the use of this model, the effects of a delay of 5, 10, and 15 years in deaths due to three chronic degenerative diseases (cancer...

  18. Particle Reduction Strategies - PAREST. Traffic emission modelling. Model comparision and alternative scenarios. Sub-report

    International Nuclear Information System (INIS)

    The modeling of the reference scenario and the various reduction scenarios in PAREST was based on the Central System of Emissions (CSE) (CSE, 2007). Emissions from road traffic were calculated by using the traffic emission model TREMOD (Knoerr et al., 2005) and fed into the CSE. The version TREMOD 4.17 has been used. The resulting emission levels in PAREST reference scenario were supplemented by the emission-reducing effect of the implementation of the future Euro 5 and 6 emission standards for cars and light commercial vehicles and Euro VI for heavy commercial vehicles in combination with the truck toll extension.

  19. A drive-reinforcement model of single neuron function: An alternative to the Hebbian neuronal model

    Science.gov (United States)

    Klopf, A. Harry

    1986-08-01

    A neuronal learning mechanism is proposed that accounts for the basic animal learning phenomena that have been observed. Among the classical conditioning phenomena predicted by the neuronal model are delay conditioning, trace conditioning, simultaneous conditioning, conditioned stimulus duration and amplitude effects, unconditioned stimulus amplitude effects, interstimulus interval effects, second and higher order conditioning, conditioned inhibition, habituation and extinction, reacquisition effects, backward conditioning, blocking, overshadowing and serial compound conditioning. The proposed neuronal model and learning mechanism offer a new building block for constructing neural network-like computer arthitectures for artificial intelligence.

  20. Explicit boundary form factors: The scaling Lee–Yang model

    Energy Technology Data Exchange (ETDEWEB)

    Hollo, L. [MTA Lendület Holographic QFT Group, Wigner Research Centre for Physics, P.O.B. 49, H-1525 Budapest 114 (Hungary); Laczko, Z.B. [Roland Eötvös University, Pázmány Péter sétány 1/A, 1117 Budapest (Hungary); Bajnok, Z. [MTA Lendület Holographic QFT Group, Wigner Research Centre for Physics, P.O.B. 49, H-1525 Budapest 114 (Hungary)

    2014-09-15

    We provide explicit expressions for boundary form factors in the boundary scaling Lee–Yang model for operators with the mildest ultraviolet behavior for all integrable boundary conditions. The form factors of the boundary stress tensor take a determinant form, while the form factors of the boundary primary field contain additional explicit polynomials.

  1. Fitting the distribution of dry and wet spells with alternative probability models

    Science.gov (United States)

    Deni, Sayang Mohd; Jemain, Abdul Aziz

    2009-06-01

    The development of the rainfall occurrence model is greatly important not only for data-generation purposes, but also in providing informative resources for future advancements in water-related sectors, such as water resource management and the hydrological and agricultural sectors. Various kinds of probability models had been introduced to a sequence of dry (wet) days by previous researchers in the field. Based on the probability models developed previously, the present study is aimed to propose three types of mixture distributions, namely, the mixture of two log series distributions (LSD), the mixture of the log series Poisson distribution (MLPD), and the mixture of the log series and geometric distributions (MLGD), as the alternative probability models to describe the distribution of dry (wet) spells in daily rainfall events. In order to test the performance of the proposed new models with the other nine existing probability models, 54 data sets which had been published by several authors were reanalyzed in this study. Also, the new data sets of daily observations from the six selected rainfall stations in Peninsular Malaysia for the period 1975-2004 were used. In determining the best fitting distribution to describe the observed distribution of dry (wet) spells, a Chi-square goodness-of-fit test was considered. The results revealed that the new method proposed that MLGD and MLPD showed a better fit as more than half of the data sets successfully fitted the distribution of dry and wet spells. However, the existing models, such as the truncated negative binomial and the modified LSD, were also among the successful probability models to represent the sequence of dry (wet) days in daily rainfall occurrence.

  2. A comparison of alternative random regression and reaction norm models for whole genome predictions.

    Science.gov (United States)

    Yang, W; Chen, C; Steibel, J P; Ernst, C W; Bates, R O; Zhou, L; Tempelman, R J

    2015-06-01

    Whole genome prediction (WGP) based on high density SNP marker panels is known to improve the accuracy of breeding value (BV) prediction in livestock. However, these accuracies can be compromised when genotype by environment interaction (G×E) exists but is not accounted for. Reaction norm (RN) and random regression (RR) models have proven to be useful in accounting for G×E in pre-WGP evaluations by modeling BV as linear or higher order functions of environmental or temporal covariates. We extend these RR/RN models based on several alternative specifications for SNP-specific intercepts and linear slopes on environmental covariates. One specification is based on bivariate normality (BVN) of SNP-specific intercepts and slopes, whereas 2 others, IW-BayesA and based on inverted Wishart (IW) extensions IW-BayesB, are, respectively, bivariate Student t extensions of currently popular models without (BayesA) or with (BayesB) variable selection. We highlight alternative specifications based on the square root free Cholesky decomposition (CD) of SNP-specific variance-covariance (VCV) matrices in an attempt to better differentially model environmentally sensitive from environmentally robust QTL. Two CD specifications were considered with (CD-BayesB) or without (CD-BayesA) any variable selection on intercept and slope effects. We compared each of the 5 models based on an RN simulation study. Six scenarios were considered based on differences in overall genetic correlations between SNP-specific intercept and slope effects as well as on heritabilities and numbers of environmentally robust versus sensitive QTL. In most scenarios, IW-BayesA had the greatest accuracy, whereas CD-BayesB exhibited the greatest accuracy in low complexity architectures (i.e., low number of QTL). In an RR application of a Duroc × Pietrain resource population at Michigan State University, 5,271 SNP markers and 928 F2 animals with known pedigree were analyzed for backfat thickness at wk 10, 13, 16, 19

  3. Default Bayes Factors for Model Selection in Regression

    NARCIS (Netherlands)

    Rouder, J.N.; Morey, R.D.

    2012-01-01

    In this article, we present a Bayes factor solution for inference in multiple regression. Bayes factors are principled measures of the relative evidence from data for various models or positions, including models that embed null hypotheses. In this regard, they may be used to state positive evidence

  4. Study on neural network model for calculating subsidence factor

    Institute of Scientific and Technical Information of China (English)

    GUO Wen-bing; ZHANG Jie

    2007-01-01

    The major factors influencing subsidence factor were comprehensively analyzed. Then the artificial neural network model for calculating subsidence factor was set up with the theory of artificial neural network (ANN). A large amount of data from observation stations in China was collected and used as learning and training samples to train and test the artificial neural network model. The calculated results of the ANN model and the observed values were compared and analyzed in this paper. The results demonstrate that many factors can be considered in this model and the result is more precise and closer to observed values to calculate the subsidence factor by the ANN model. It can satisfy the need of engineering.

  5. An alternative approach to modeling genetic merit of feed efficiency in dairy cattle.

    Science.gov (United States)

    Lu, Y; Vandehaar, M J; Spurlock, D M; Weigel, K A; Armentano, L E; Staples, C R; Connor, E E; Wang, Z; Bello, N M; Tempelman, R J

    2015-09-01

    Genetic improvement of feed efficiency (FE) in dairy cattle requires greater attention given increasingly important resource constraint issues. A widely accepted yet occasionally contested measure of FE in dairy cattle is residual feed intake (RFI). The use of RFI is limiting for several reasons, including interpretation, differences in recording frequencies between the various component traits that define RFI, and potential differences in genetic versus nongenetic relationships between dry matter intake (DMI) and FE component traits. Hence, analyses focusing on DMI as the response are often preferred. We propose an alternative multiple-trait (MT) modeling strategy that exploits the Cholesky decomposition to provide a potentially more robust measure of FE. We demonstrate that our proposed FE measure is identical to RFI provided that genetic and nongenetic relationships between DMI and component traits of FE are identical. We assessed both approaches (MT and RFI) by simulation as well as by application to 26,383 weekly records from 50 to 200 d in milk on 2,470 cows from a dairy FE consortium study involving 7 institutions. Although the proposed MT model fared better than the RFI model when simulated genetic and nongenetic associations between DMI and FE component traits were substantially different from each other, no meaningful differences were found in predictive performance between the 2 models when applied to the consortium data. PMID:26210274

  6. Alternative 3D Modeling Approaches Based on Complex Multi-Source Geological Data Interpretation

    Institute of Scientific and Technical Information of China (English)

    李明超; 韩彦青; 缪正建; 高伟

    2014-01-01

    Due to the complex nature of multi-source geological data, it is difficult to rebuild every geological struc-ture through a single 3D modeling method. The multi-source data interpretation method put forward in this analysis is based on a database-driven pattern and focuses on the discrete and irregular features of geological data. The geological data from a variety of sources covering a range of accuracy, resolution, quantity and quality are classified and inte-grated according to their reliability and consistency for 3D modeling. The new interpolation-approximation fitting construction algorithm of geological surfaces with the non-uniform rational B-spline (NURBS) technique is then pre-sented. The NURBS technique can retain the balance among the requirements for accuracy, surface continuity and data storage of geological structures. Finally, four alternative 3D modeling approaches are demonstrated with reference to some examples, which are selected according to the data quantity and accuracy specification. The proposed approaches offer flexible modeling patterns for different practical engineering demands.

  7. Analysis of effect factors-based stochastic network planning model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Looking at all the indeterminate factors as a whole and regarding activity durations as independent random variables,the traditional stochastic network planning models ignore the inevitable relationship and dependence among activity durations when more than one activity is possibly affected by the same indeterminate factors.On this basis of analysis of indeterminate effect factors of durations,the effect factors-based stochastic network planning (EFBSNP) model is proposed,which emphasizes on the effects of not only logistic and organizational relationships,but also the dependent relationships,due to indeterminate factors among activity durations on the project period.By virtue of indeterminate factor analysis the model extracts and describes the quantitatively indeterminate effect factors,and then takes into account the indeterminate factors effect schedule by using the Monte Carlo simulation technique.The method is flexible enough to deal with effect factors and is coincident with practice.A software has been developed to simplify the model-based calculation,in VisualStudio.NET language.Finally,a case study is included to demonstrate the applicability of the proposed model and comparison is made with some advantages over the existing models.

  8. HIV-1 infection induces changes in expression of cellular splicing factors that regulate alternative viral splicing and virus production in macrophages

    Directory of Open Access Journals (Sweden)

    Purcell Damian FJ

    2008-02-01

    Full Text Available Abstract Background Macrophages are important targets and long-lived reservoirs of HIV-1, which are not cleared of infection by currently available treatments. In the primary monocyte-derived macrophage model of infection, replication is initially productive followed by a decline in virion output over ensuing weeks, coincident with a decrease in the levels of the essential viral transactivator protein Tat. We investigated two possible mechanisms in macrophages for regulation of viral replication, which appears to be primarily regulated at the level of tat mRNA: 1 differential mRNA stability, used by cells and some viruses for the rapid regulation of gene expression and 2 control of HIV-1 alternative splicing, which is essential for optimal viral replication. Results Following termination of transcription at increasing times after infection in macrophages, we found that tat mRNA did indeed decay more rapidly than rev or nef mRNA, but with similar kinetics throughout infection. In addition, tat mRNA decayed at least as rapidly in peripheral blood lymphocytes. Expression of cellular splicing factors in uninfected and infected macrophage cultures from the same donor showed an inverse pattern over time between enhancing factors (members of the SR family of RNA binding proteins and inhibitory factors (members of the hnRNP family. While levels of the SR protein SC35 were greatly up-regulated in the first week or two after infection, hnRNPs of the A/B and H groups were down-regulated. Around the peak of virus production in each culture, SC35 expression declined to levels in uninfected cells or lower, while the hnRNPs increased to control levels or above. We also found evidence for increased cytoplasmic expression of SC35 following long-term infection. Conclusion While no evidence of differential regulation of tat mRNA decay was found in macrophages following HIV-1 infection, changes in the balance of cellular splicing factors which regulate alternative

  9. An alternative order-parameter for non-equilibrium generalized spin models on honeycomb lattices

    Science.gov (United States)

    Sastre, Francisco; Henkel, Malte

    2016-04-01

    An alternative definition for the order-parameter is proposed, for a family of non-equilibrium spin models with up-down symmetry on honeycomb lattices, and which depends on two parameters. In contrast to the usual definition, our proposal takes into account that each site of the lattice can be associated with a local temperature which depends on the local environment of each site. Using the generalised voter motel as a test case, we analyse the phase diagram and the critical exponents in the stationary state and compare the results of the standard order-parameter with the ones following from our new proposal, on the honeycomb lattice. The stationary phase transition is in the Ising universality class. Finite-size corrections are also studied and the Wegner exponent is estimated as ω =1.06(9).

  10. Prospects for bioenergy use in Ghana using Long-range Energy Alternatives Planning model

    DEFF Research Database (Denmark)

    Kemausuor, Francis; Nygaard, Ivan; Mackenzie, Gordon A.

    2015-01-01

    As Ghana's economy grows, the choice of future energy paths and policies in the coming years will have a significant influence on its energy security. A Renewable Energy Act approved in 2011 seeks to encourage the influx of renewable energy sources in Ghana's energy mix. The new legal framework...... combined with increasing demand for energy has created an opportunity for dramatic changes in the way energy is generated in Ghana. However, the impending changes and their implication remain uncertain. This paper examines the extent to which future energy scenarios in Ghana could rely on energy from...... biomass sources, through the production of biogas, liquid biofuels and electricity. Analysis was based on moderate and high use of bioenergy for transportation, electricity generation and residential fuel using the LEAP (Long-range Energy Alternatives Planning) model. Results obtained indicate...

  11. Combustion instability and active control: Alternative fuels, augmentors, and modeling heat release

    Science.gov (United States)

    Park, Sammy Ace

    Experimental and analytical studies were conducted to explore thermo-acoustic coupling during the onset of combustion instability in various air-breathing combustor configurations. These include a laboratory-scale 200-kW dump combustor and a 100-kW augmentor featuring a v-gutter flame holder. They were used to simulate main combustion chambers and afterburners in aero engines, respectively. The three primary themes of this work includes: 1) modeling heat release fluctuations for stability analysis, 2) conducting active combustion control with alternative fuels, and 3) demonstrating practical active control for augmentor instability suppression. The phenomenon of combustion instabilities remains an unsolved problem in propulsion engines, mainly because of the difficulty in predicting the fluctuating component of heat release without extensive testing. A hybrid model was developed to describe both the temporal and spatial variations in dynamic heat release, using a separation of variables approach that requires only a limited amount of experimental data. The use of sinusoidal basis functions further reduced the amount of data required. When the mean heat release behavior is known, the only experimental data needed for detailed stability analysis is one instantaneous picture of heat release at the peak pressure phase. This model was successfully tested in the dump combustor experiments, reproducing the correct sign of the overall Rayleigh index as well as the remarkably accurate spatial distribution pattern of fluctuating heat release. Active combustion control was explored for fuel-flexible combustor operation using twelve different jet fuels including bio-synthetic and Fischer-Tropsch types. Analysis done using an actuated spray combustion model revealed that the combustion response times of these fuels were similar. Combined with experimental spray characterizations, this suggested that controller performance should remain effective with various alternative fuels

  12. Nucleon tensor form factors in a relativistic confined quark model

    CERN Document Server

    Gutsche, Thomas; Korner, Jurgen G; Kovalenko, Sergey; Lyubovitskij, Valery E

    2016-01-01

    We present results for the isotriplet and isosinglet tensor form factors of the nucleon in the relativistic confined quark model. The model allows us to calculate not only their normalizations at $Q^2=0$ and the related tensor charges, but also the full $Q^2$-dependence. Our results are compared to existing data and predictions of other theoretical approaches. We stress the importance of these form factors for the phenomenology of physics beyond the Standard Model.

  13. Linear, Non-Linear and Alternative Algorithms in the Correlation of IEQ Factors with Global Comfort: A Case Study

    Directory of Open Access Journals (Sweden)

    Francesco Fassio

    2014-11-01

    Full Text Available Indoor environmental quality (IEQ factors usually considered in engineering studies, i.e., thermal, acoustical, visual comfort and indoor air quality are individually associated with the occupant satisfaction level on the basis of well-established relationships. On the other hand, the full understanding of how single IEQ factors contribute and interact to determine the overall occupant satisfaction (global comfort is currently an open field of research. The lack of a shared approach in treating the subject depends on many aspects: absence of established protocols for the collection of subjective and objective measurements, the amount of variables to consider and in general the complexity of the technical issues involved. This case study is aimed to perform a comparison between some of the models available, studying the results of a survey conducted with objective and subjective method on a classroom within University of Roma TRE premises. Different models are fitted on the same measured values, allowing comparison between different weighting schemes between IEQ categories obtained with different methods. The critical issues, like differences in the weighting scheme obtained with different IEQ models and the variability of the weighting scheme with respect to the time of exposure of the users in the building, identified during this small scale comfort assessment study, provide the basis for a survey activity on a larger scale, basis for the development of an improved IEQ assessment method.

  14. Exploring alternative wind vulnerability and loss modeling methods - application to Europe extra-tropical cyclones

    Science.gov (United States)

    Peiris, N.

    2009-04-01

    loss over the event footprint and the associated uncertainty. Now, the actual loss in the building portfolio may not occur at every location, i.e. there are locations with and without loss. It is anticipated that the total incurred loss over the footprint falls within the range of modeled footprint loss and closer to the expected modeled loss value. An alternative methodology to the above was explored where it was attempted to model realizations of actual losses expected at each location. Firstly the building vulnerability was represented by its underlying fragility functions where each fragility function characterizes the likely damage mode and hence the loss ratio the building could experience during a windstorm and the associated probability of occurrence conditional on the wind speed. The damage modes considered are mutually exclusive and engineering considerations determine the extent of correlation between each damage mode (or sub-damage state). The fragility functions therefore describe the damage matrix for a building subjected to the wind hazard and this matrix produces the probability of damage as well as no damage. Hence at a building location subjected to a certain wind speed within the hazard footprint, one could sample from the damage matrix the actual damage ratio, which could range from zero (where no damage could occur) to the maximum likely damage ratio. By sampling all locations N times, one could subsequently obtain N realizations of the loss footprint hence obtain the expected total event loss and the loss distribution quantifying the uncertainty. In evaluating the insured loss or gross loss, the calculated ground-up loss at a location is used in the expected mode to estimate the gross loss based on the deductibles, limits and other relevant financial structures. This is in contrast to the conventional catastrophe model where the gross loss is calculated as a distributed loss using MDR and SD. The location correlation modeling was explored in the

  15. Probabilistic and Multivariate Modelling in Latin Grammar: the Participle-Auxiliary Alternation as a Case Study

    OpenAIRE

    Brookes, James William Rowe

    2014-01-01

    Recent research has shown that language is sensitive to probabilities and a whole host of multivariate conditioning factors. However, most of the research in this arena centres on the grammar of English, and, as yet, there is no statistical modelling on the grammar of Latin, studies of which have to date been largely philological. The rise in advanced statistical methodologies allows us to capture the underlying structure of the rich datasets which this corpus only language can potentially of...

  16. Alternative free volume models and positron cages for the characterisation of nanoporosity in materials

    International Nuclear Information System (INIS)

    Three semi-empirical positron stationary Quantum Models were developed for the study of nanoporosity in a wide range of solid porous materials. The cubic, conic and cylindrical well potentials were considered and their geometric parameters related to the Positron Annihilation LifeTime (PALT) measurements. If a conic or a cubic symmetry is assumed, a resonance lifetime phenomenon was found, which enables proposal of a technique to catch positrons in free volume sites. In the cylindrical case, an alternative method to determine free volume sizes in materials was developed. The free volume equations of these new models were then compared to the well-known and widely utilised Spherical Free Volume Model (SFVM) and remarkable differences were found. A strong variation of the free volume size-positron lifetime relation with the geometry involved was observed and a remarkable dependence of the electron layer thickness parameter ΔR with the hole-shape under study and with the nature of the material considered. The mathematical functions appearing in the conic and cylindrical cases are the superposition of Bessel functions of the first kind and trigonometric functions in the cubic case. Generalised free volume diagrams were constructed and a brief geometrical scheme of the diverse cases considered was obtained. (author)

  17. An Educational Look at an Alternative to the Simple Big Bang Model

    Science.gov (United States)

    Kriske, Richard

    2009-10-01

    The author often toys with a Positively Curved surface resembling a globe as an alternative to the simple Big Bang model on a flat surface. When one looks at the Horizon of the earth, say at the ocean, masts in the distance tip away from the observer. If three dimensions of space where curved with a perpendicular mast at each vertex, those time masts would tip away from the observer and be cut-off. A new optical effect would be observed, in which vertices in the distance, say pair annihilation, would result in gamma rays appearing to be redshifted, since by parallel displacement, their time axis would progressively tilt away from the observer and give them a red shift until they reached a distance were they where non- magnifiable. Just as the Earth's Horizon is a non-magnifiable line (since the objects are tilted over and cut-off), so should be the Universe's Horizon be tilted and cut-off (but like a Black-Hole, the Horizon will be an area). The tilt and cut-off can be used to calculate the size and mass of the Universe,given that the cutoff is taken to be 2.725K, the CMBR. This model turns out to be a model of constants and gives absolute meaning to spin. Since this is a brand new theory developed solely by the author at his coffee breaks, looking out the window, he presents it as an exercise.

  18. Dispersion modeling to compare alternative technologies for odor remediation at swine facilities.

    Science.gov (United States)

    Schiffman, Susan S; Graham, Brevick G; Williams, C Mike

    2008-09-01

    The effectiveness of 18 alternative technologies for reducing odor dispersion at and beyond the boundary of swine facilities was assessed in conjunction with an initiative sponsored through agreements between the Attorney General of North Carolina and Smithfield Foods, Premium Standard Farms, and Frontline Farmers. The trajectory and spatial distribution of odor emitted at each facility were modeled at 200 and 400 m downwind from each site under two meteorological conditions (daytime and nighttime) using a Eulerian-Lagrangian model. To predict the dispersion of odor downwind, the geographical area containing the odorant sources at each facility was partitioned into 10-m2 grids on the basis of satellite photographs and architectural drawings. Relative odorant concentrations were assigned to each grid point on the basis of intensity measurements made by the trained odor panel at each facility using a 9-point rating scale. The results of the modeling indicated that odor did not extend significantly beyond 400 m downwind of any of the test sites during the daytime when the layer of air above the earth's surface is usually turbulent. However, modeling indicated that odor from all full-scale farms extended beyond 400 m onto neighboring property in the evenings when deep surface cooling through long-wave radiation to space produces a stable (nocturnal) boundary layer. The results also indicated that swine housing, independent of waste management type, plays a significant role in odor downwind, as do odor sources of moderate to moderately high intensity that emanate from a large surface area such as a lagoon. Human odor assessments were utilized for modeling rather than instrument measurements of volatile organic compounds (VOCs), hydrogen sulfide, ammonia, or particulates less than 10 microm in diameter (PM10) because these physical measurements obtained simultaneously with human panel ratings were not found to accurately predict human odor intensity in the field.

  19. On the analysis of clonogenic survival data: Statistical alternatives to the linear-quadratic model

    International Nuclear Information System (INIS)

    the extraction of scores of radioresistance, which displayed significant correlations with the estimated parameters of the regression models. Undoubtedly, LQ regression is a robust method for the analysis of clonogenic survival data. Nevertheless, alternative approaches including non-linear regression and multivariate techniques such as cluster analysis and principal component analysis represent versatile tools for the extraction of parameters and/or scores of the cellular response towards ionizing irradiation with a more intuitive biological interpretation. The latter are highly informative for correlation analyses with other types of data, including functional genomics data that are increasingly beinggenerated

  20. Reconciling the Characteristics vs. Factors Models for Explaining Stock Returns

    Directory of Open Access Journals (Sweden)

    Lt Col Brian C. Payne

    2015-02-01

    Full Text Available Daniel and Titman (DT (1997 disclaim the Fama-French three factor model in favor of a firm characteristics based model to explain stock returns. Davis, Fama, and French (2000 find this characteristics-based model outperforms their model only for the 20.5 year time period from July 1973-December 1993, but the three factor model is robust for the 68-year period from 1929-1997. We find the DT period represents a unique macroeconomic environment in that significant interaction effects exist between the default (and term risk premia innovations and returns. Incorporating these effects into a traditional three-factor model help explain the 1973-1993 “characteristics model puzzle,” providing insight into market returns for portfolio managers during economic environments comparable to the DT period.

  1. Evaluation of the Thermodynamic Models for the Thermal Diffusion Factor

    DEFF Research Database (Denmark)

    Gonzalez-Bagnoli, Mariana G.; Shapiro, Alexander; Stenby, Erling Halfdan

    2003-01-01

    Over the years, several thermodynamic models for the thermal diffusion factors for binary mixtures have been proposed. The goal of this paper is to test some of these models in combination with different equations of state. We tested the following models: those proposed by Rutherford and Drickamer...

  2. Paying for Primary Care: The Factors Associated with Physician Self-selection into Payment Models.

    Science.gov (United States)

    Rudoler, David; Deber, Raisa; Barnsley, Janet; Glazier, Richard H; Dass, Adrian Rohit; Laporte, Audrey

    2015-09-01

    To determine the factors associated with primary care physician self-selection into different payment models, we used a panel of eight waves of administrative data for all primary care physicians who practiced in Ontario between 2003/2004 and 2010/2011. We used a mixed effects logistic regression model to estimate physicians' choice of three alternative payment models: fee for service, enhanced fee for service, and blended capitation. We found that primary care physicians self-selected into payment models based on existing practice characteristics. Physicians with more complex patient populations were less likely to switch into capitation-based payment models where higher levels of effort were not financially rewarded. These findings suggested that investigations aimed at assessing the impact of different primary care reimbursement models on outcomes, including costs and access, should first account for potential selection effects. PMID:26190516

  3. Alternative Fabrication Routes toward Oxide-Dispersion-Strengthened Steels and Model Alloys

    Science.gov (United States)

    Bergner, Frank; Hilger, Isabell; Virta, Jouko; Lagerbom, Juha; Gerbeth, Gunter; Connolly, Sarah; Hong, Zuliang; Grant, Patrick S.; Weissgärber, Thomas

    2016-07-01

    The standard powder metallurgy (PM) route for the fabrication of oxide-dispersion-strengthened (ODS) steels involves gas atomization to produce a prealloyed powder, mechanical alloying (MA) with fine oxide powders, consolidation, and finally thermal/thermomechanical treatment (TMT). It is well established that ODS steels with superior property combinations, for example, creep and tensile strength, can be produced by this PM/MA route. However, the fabrication process is complex and expensive, and the fitness for scaling up to the industrial scale is limited. At the laboratory scale, production of small amounts of well-controlled model systems continues to be desirable for specific purposes, such as modeling-oriented experiments. Thus, from the laboratory to industrial application, there is growing interest in complementary or alternative fabrication routes for ODS steels and related model systems, which offer a different balance of cost, convenience, properties, and scalability. This article reviews the state of the art in ODS alloy fabrication and identifies promising new routes toward ODS steels. The PM/AM route for the fabrication of ODS steels is also described, as it is the current default process. Hybrid routes that comprise aspects of both the PM route and more radical liquid metal (LM) routes are suggested to be promising approaches for larger volumes and higher throughput of fabricated material. Although similar uniformity and refinement of the critical nanometer-sized oxide particles has not yet been demonstrated, ongoing innovations in the LM route are described, along with recent encouraging preliminary results for both extrinsic nano-oxide additions and intrinsic nano-oxide formation in variants of the LM route. Finally, physicochemical methods such as ion beam synthesis are shown to offer interesting perspectives for the fabrication of model systems. As well as literature sources, examples of progress in the authors' groups are also highlighted.

  4. Alternative Fabrication Routes toward Oxide-Dispersion-Strengthened Steels and Model Alloys

    Science.gov (United States)

    Bergner, Frank; Hilger, Isabell; Virta, Jouko; Lagerbom, Juha; Gerbeth, Gunter; Connolly, Sarah; Hong, Zuliang; Grant, Patrick S.; Weissgärber, Thomas

    2016-11-01

    The standard powder metallurgy (PM) route for the fabrication of oxide-dispersion-strengthened (ODS) steels involves gas atomization to produce a prealloyed powder, mechanical alloying (MA) with fine oxide powders, consolidation, and finally thermal/thermomechanical treatment (TMT). It is well established that ODS steels with superior property combinations, for example, creep and tensile strength, can be produced by this PM/MA route. However, the fabrication process is complex and expensive, and the fitness for scaling up to the industrial scale is limited. At the laboratory scale, production of small amounts of well-controlled model systems continues to be desirable for specific purposes, such as modeling-oriented experiments. Thus, from the laboratory to industrial application, there is growing interest in complementary or alternative fabrication routes for ODS steels and related model systems, which offer a different balance of cost, convenience, properties, and scalability. This article reviews the state of the art in ODS alloy fabrication and identifies promising new routes toward ODS steels. The PM/AM route for the fabrication of ODS steels is also described, as it is the current default process. Hybrid routes that comprise aspects of both the PM route and more radical liquid metal (LM) routes are suggested to be promising approaches for larger volumes and higher throughput of fabricated material. Although similar uniformity and refinement of the critical nanometer-sized oxide particles has not yet been demonstrated, ongoing innovations in the LM route are described, along with recent encouraging preliminary results for both extrinsic nano-oxide additions and intrinsic nano-oxide formation in variants of the LM route. Finally, physicochemical methods such as ion beam synthesis are shown to offer interesting perspectives for the fabrication of model systems. As well as literature sources, examples of progress in the authors' groups are also highlighted.

  5. iGEMS: an integrated model for identification of alternative exon usage events.

    Science.gov (United States)

    Sood, Sanjana; Szkop, Krzysztof J; Nakhuda, Asif; Gallagher, Iain J; Murie, Carl; Brogan, Robert J; Kaprio, Jaakko; Kainulainen, Heikki; Atherton, Philip J; Kujala, Urho M; Gustafsson, Thomas; Larsson, Ola; Timmons, James A

    2016-06-20

    DNA microarrays and RNAseq are complementary methods for studying RNA molecules. Current computational methods to determine alternative exon usage (AEU) using such data require impractical visual inspection and still yield high false-positive rates. Integrated Gene and Exon Model of Splicing (iGEMS) adapts a gene-level residuals model with a gene size adjusted false discovery rate and exon-level analysis to circumvent these limitations. iGEMS was applied to two new DNA microarray datasets, including the high coverage Human Transcriptome Arrays 2.0 and performance was validated using RT-qPCR. First, AEU was studied in adipocytes treated with (n = 9) or without (n = 8) the anti-diabetes drug, rosiglitazone. iGEMS identified 555 genes with AEU, and robust verification by RT-qPCR (∼90%). Second, in a three-way human tissue comparison (muscle, adipose and blood, n = 41) iGEMS identified 4421 genes with at least one AEU event, with excellent RT-qPCR verification (95%, n = 22). Importantly, iGEMS identified a variety of AEU events, including 3'UTR extension, as well as exon inclusion/exclusion impacting on protein kinase and extracellular matrix domains. In conclusion, iGEMS is a robust method for identification of AEU while the variety of exon usage between human tissues is 5-10 times more prevalent than reported by the Genotype-Tissue Expression consortium using RNA sequencing. PMID:27095197

  6. Expression of the alternative oxidase mitigates beta-amyloid production and toxicity in model systems.

    Science.gov (United States)

    El-Khoury, Riyad; Kaulio, Eveliina; Lassila, Katariina A; Crowther, Damian C; Jacobs, Howard T; Rustin, Pierre

    2016-07-01

    Mitochondrial dysfunction has been widely associated with the pathology of Alzheimer's disease, but there is no consensus on whether it is a cause or consequence of disease, nor on the precise mechanism(s). We addressed these issues by testing the effects of expressing the alternative oxidase AOX from Ciona intestinalis, in different models of AD pathology. AOX can restore respiratory electron flow when the cytochrome segment of the mitochondrial respiratory chain is inhibited, supporting ATP synthesis, maintaining cellular redox homeostasis and mitigating excess superoxide production at respiratory complexes I and III. In human HEK293-derived cells, AOX expression decreased the production of beta-amyloid peptide resulting from antimycin inhibition of respiratory complex III. Because hydrogen peroxide was neither a direct product nor substrate of AOX, the ability of AOX to mimic antioxidants in this assay must be indirect. In addition, AOX expression was able to partially alleviate the short lifespan of Drosophila models neuronally expressing human beta-amyloid peptides, whilst abrogating the induction of markers of oxidative stress. Our findings support the idea of respiratory chain dysfunction and excess ROS production as both an early step and as a pathologically meaningful target in Alzheimer's disease pathogenesis, supporting the concept of a mitochondrial vicious cycle underlying the disease.

  7. Expression of the alternative oxidase mitigates beta-amyloid production and toxicity in model systems.

    Science.gov (United States)

    El-Khoury, Riyad; Kaulio, Eveliina; Lassila, Katariina A; Crowther, Damian C; Jacobs, Howard T; Rustin, Pierre

    2016-07-01

    Mitochondrial dysfunction has been widely associated with the pathology of Alzheimer's disease, but there is no consensus on whether it is a cause or consequence of disease, nor on the precise mechanism(s). We addressed these issues by testing the effects of expressing the alternative oxidase AOX from Ciona intestinalis, in different models of AD pathology. AOX can restore respiratory electron flow when the cytochrome segment of the mitochondrial respiratory chain is inhibited, supporting ATP synthesis, maintaining cellular redox homeostasis and mitigating excess superoxide production at respiratory complexes I and III. In human HEK293-derived cells, AOX expression decreased the production of beta-amyloid peptide resulting from antimycin inhibition of respiratory complex III. Because hydrogen peroxide was neither a direct product nor substrate of AOX, the ability of AOX to mimic antioxidants in this assay must be indirect. In addition, AOX expression was able to partially alleviate the short lifespan of Drosophila models neuronally expressing human beta-amyloid peptides, whilst abrogating the induction of markers of oxidative stress. Our findings support the idea of respiratory chain dysfunction and excess ROS production as both an early step and as a pathologically meaningful target in Alzheimer's disease pathogenesis, supporting the concept of a mitochondrial vicious cycle underlying the disease. PMID:27094492

  8. Alternative Models of Self-regulation and Implications for L2 Strategy Research

    Directory of Open Access Journals (Sweden)

    Jim Ranalli

    2012-12-01

    Full Text Available In this paper I discuss the proposal of Dörnyei and colleagues (Dörnyei, 2005; Tseng, Dörnyei, & Schmitt, 2006 to replace the construct of learning strategy with that of self-regulation and thus shift the research focus from specific strategic behaviors to a trait that is seen to underlie them. I argue that before doing so, we need a fuller understanding of what self-regulation entails and how it might intersect with traditional concerns of second language strategy research. To contribute to this understanding, I highlight alternative conceptualizations of self-regulation and then use data from my doctoral research to illustrate one in particular, the COPES model of self-regulated learning (Winne & Hadwin, 1998. This model’s explanatory power is contrasted with that of Dörnyei and colleagues’ conceptualization to show that, depending on the model one adopts, self-regulation is not only compatible with the study of specific strategies but useful for shedding new light on strategy research and integrating it with research in other related areas, such as L2 motivation.

  9. Unitarity alternatives in the reduced-action model for gravitational collapse

    Science.gov (United States)

    Ciafaloni, M.; Colferai, D.; Falcioni, G.

    2011-09-01

    Based on the ACV approach to transplanckian energies, the reduced-action model for the gravitational S-matrix predicts a critical impact parameter {b_c} ˜ R equiv 2Gsqrt {s} such that S-matrix unitarity is satisfied in the perturbative region b > b c , while it is exponentially suppressed with respect to s in the region b < b c that we think corresponds to gravitational collapse. Here we definitely confirm this statement by a detailed analysis of both the critical region b ≃ b c and of further possible contributions due to quantum transitions for b < b c . We point out, however, that the subcritical unitarity suppression is basically due to the boundary condition which insures that the solutions of the model be ultraviolet-safe. As an alternative, relaxing such condition leads to solutions which carry short-distance singularities presumably regularized by the string. We suggest that through such solutions — depending on the detailed dynamics at the string scale — the lost probability may be recovered.

  10. Unitarity alternatives in the reduced-action model for gravitational collapse

    CERN Document Server

    Ciafaloni, M; Falcioni, G

    2011-01-01

    Based on the ACV approach to transplanckian energies, the reduced-action model for the gravitational S-matrix predicts a critical impact parameter b_c ~ R = 2 G sqrt{s} such that S-matrix unitarity is satisfied in the perturbative region b > b_c, while it is exponentially suppressed with respect to s in the region b < b_c that we think corresponds to gravitational collapse. Here we definitely confirm this statement by a detailed analysis of both the critical region b ~ b_c and of further possible contributions due to quantum transitions for b < b_c. We point out, however, that the subcritical unitarity suppression is basically due to the boundary condition which insures that the solutions of the model be ultraviolet-safe. As an alternative, relaxing such condition leads to solutions which carry short-distance singularities presumably regularized by the string. We suggest that through such solutions - depending on the detailed dynamics at the string scale - the lost probability may be recovered.

  11. Personality organization, five-factor model, and mental health.

    Science.gov (United States)

    Laverdière, Olivier; Gamache, Dominick; Diguer, Louis; Hébert, Etienne; Larochelle, Sébastien; Descôteaux, Jean

    2007-10-01

    Otto Kernberg has developed a model of personality and psychological functioning centered on the concept of personality organization. The purpose of this study is to empirically examine the relationships between this model, the five-factor model, and mental health. The Personality Organization Diagnostic Form (Diguer et al., The Personality Organization Diagnostic Form-II (PODF-II), 2001), the NEO Five-Factor Inventory (Costa and McCrae, Revised NEO Personality Inventory (NEO-PI-R) and NEO Five-Factor Inventory (NEO-FFI) Professional Manual. 1992a), and the Health-Sickness Rating Scale (Luborsky, Arch Gen Psychiatry. 1962;7:407-417) were used to assess these constructs. Results show that personality organization and personality factors are distinct but interrelated constructs and that both contribute in similar proportion to mental health. Results also suggest that the integration of personality organization and factors can provide clinicians and researchers with an enriched understanding of psychological functioning. PMID:18043522

  12. Model of key success factors for Business Intelligence implementation

    Directory of Open Access Journals (Sweden)

    Peter Mesaros

    2016-07-01

    Full Text Available New progressive technologies recorded growth in every area. Information-communication technologies facilitate the exchange of information and it facilitates management of everyday activities in enterprises. Specific modules (such as Business Intelligence facilitate decision-making. Several studies have demonstrated the positive impact of Business Intelligence to decision-making. The first step is to put in place the enterprise. The implementation process is influenced by many factors. This article discusses the issue of key success factors affecting to successful implementation of Business Intelligence. The article describes the key success factors for successful implementation and use of Business Intelligence based on multiple studies. The main objective of this study is to verify the effects and dependence of selected factors and proposes a model of key success factors for successful implementation of Business Intelligence. Key success factors and the proposed model are studied in Slovak enterprises.

  13. Comparing exploratory and confirmatory factor analysis: A study on the five-factor model of personality

    OpenAIRE

    Borkenau, Peter; Ostendorf, Fritz

    1990-01-01

    Several authors claim that widespread support exists for a 5-factor model of personality ratings. In the present study, structural equation modeling was used to investigate this issue. The subjects (128 males and 128 females) were administered Costa and McCrae's NEO Personality Inventory, and they rated themselves, and were rated by three acquaintances, on the 20 adjective scales suggested by Norman as marker variables for the Big Five. Coefficients of factor comparability indicated that a 5-...

  14. The structure of an alternate form of complement C3 that displays costimulatory growth factor activity for B lymphocytes

    OpenAIRE

    1994-01-01

    In this study, the structure of a novel 1.9-kb transcript coding for complement component 3 (C3) is described. This alternate C3 is identical to the 3' end of the C3 message beginning at position 3300 of the C3 cDNA. Its transcription appears to be driven by an alternate promoter located within intron 8 of the C3 gene. This alternate C3 message contains an open reading frame that may encode a 536-amino acid- long protein identical to the 3' part of the C3 alpha chain. The resulting protein co...

  15. Rethinking "Harmonious Parenting" Using a Three-Factor Discipline Model

    Science.gov (United States)

    Greenspan, Stephen

    2006-01-01

    Diana Baumrind's typology of parenting is based on a two-factor model of "control" and "warmth". Her recommended discipline style, labeled "authoritative parenting", was constructed by taking high scores on these two factors. A problem with authoritative parenting is that it does not allow for flexible and differentiated responses to discipline…

  16. Detecting Social Desirability Bias Using Factor Mixture Models

    Science.gov (United States)

    Leite, Walter L.; Cooper, Lou Ann

    2010-01-01

    Based on the conceptualization that social desirable bias (SDB) is a discrete event resulting from an interaction between a scale's items, the testing situation, and the respondent's latent trait on a social desirability factor, we present a method that makes use of factor mixture models to identify which examinees are most likely to provide…

  17. Form factors in an algebraic model of the nucleon

    CERN Document Server

    Bijker, R

    1995-01-01

    We study the electromagnetic form factors of the nucleon in a collective model of baryons. In an algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction.

  18. Selection between Linear Factor Models and Latent Profile Models Using Conditional Covariances

    Science.gov (United States)

    Halpin, Peter F.; Maraun, Michael D.

    2010-01-01

    A method for selecting between K-dimensional linear factor models and (K + 1)-class latent profile models is proposed. In particular, it is shown that the conditional covariances of observed variables are constant under factor models but nonlinear functions of the conditioning variable under latent profile models. The performance of a convenient…

  19. Are feedback factors important in modelling financial data?

    OpenAIRE

    Veiga, Helena

    2006-01-01

    This paper provides empirical evidence that continuous time models with one factor of volatility are, in some circumstances, able to fit the main characteristics of financial data and reports insights about the importance of introducing feedback factors for capturing the strong persistence caused by the presence of changes in the variance. We use the Efficient Method of Moments (EMM) by Gallant and Tauchen (1996) to estimate and to select among logarithmic models with one and two stochastic v...

  20. On penalized maximum likelihood estimation of approximate factor models

    OpenAIRE

    Wang, Shaoxin; Yang, Hu; Yao, Chaoli

    2016-01-01

    In this paper, we mainly focus on the estimation of high-dimensional approximate factor model. We rewrite the estimation of error covariance matrix as a new form which shares similar properties as the penalized maximum likelihood covariance estimator given by Bien and Tibshirani(2011). Based on the lagrangian duality, we propose an APG algorithm to give a positive definite estimate of the error covariance matrix. The new algorithm for the estimation of approximate factor model has a desirable...

  1. Hidden Markov Models with Factored Gaussian Mixtures Densities

    Institute of Scientific and Technical Information of China (English)

    LI Hao-zheng; LIU Zhi-qiang; ZHU Xiang-hua

    2004-01-01

    We present a factorial representation of Gaussian mixture models for observation densities in Hidden Markov Models(HMMs), which uses the factorial learning in the HMM framework. We derive the reestimation formulas for estimating the factorized parameters by the Expectation Maximization (EM) algorithm. We conduct several experiments to compare the performance of this model structure with Factorial Hidden Markov Models(FHMMs) and HMMs, some conclusions and promising empirical results are presented.

  2. Factorized domain wall partition functions in trigonometric vertex models

    CERN Document Server

    Foda, O; Zuparic, M

    2007-01-01

    We obtain factorized domain wall partition functions for two sets of trigonometric vertex models: 1. The N-state Deguchi-Akutsu models, for N = {2, 3, 4} (and conjecture the result for all N >= 5), and 2. The sl(r+1|s+1) Perk-Schultz models, for {r, s = \\N}, where (given the symmetries of these models) the result is independent of {r, s}.

  3. A stochastic population model to evaluate Moapa dace (Moapa coriacea) population growth under alternative management scenarios

    Science.gov (United States)

    Perry, Russell W.; Jones, Edward; Scoppettone, G. Gary

    2015-07-14

    The primary goal of this research project was to evaluate the response of Moapa dace (Moapa coriacea) to the potential effects of changes in the amount of available habitat due to human influences such as ground water pumping, barriers to movement, and extirpation of Moapa dace from the mainstem Muddy River. To understand how these factors affect Moapa dace populations and to provide a tool to guide recovery actions, we developed a stochastic model to simulate Moapa dace population dynamics. Specifically, we developed an individual based model (IBM) to incorporate the critical components that drive Moapa dace population dynamics. Our model is composed of several interlinked submodels that describe changes in Moapa dace habitat as translated into carrying capacity, the influence of carrying capacity on demographic rates of dace, and the consequent effect on equilibrium population sizes. The model is spatially explicit and represents the stream network as eight discrete stream segments. The model operates at a monthly time step to incorporate seasonally varying reproduction. Growth rates of individuals vary among stream segments, with growth rates increasing along a headwater to mainstem gradient. Movement and survival of individuals are driven by density-dependent relationships that are influenced by the carrying capacity of each stream segment.

  4. Nuclear electricity and Canada's domestic response to the Kyoto Protocol: modeling the economics of alternative scenarios

    International Nuclear Information System (INIS)

    results demonstrate that nuclear electricity has a legitimate place in the analysis of options for Canada to meet its Kyoto commitment. A relatively modest (compared to fluctuations and changes in energy commodities) cost reduction leads to the model choosing nuclear over other competing technologies thus confirming basic competitiveness. Precluding the selection of nuclear energy in forward looking economic analyses may lead to underestimating its potential as a greenhouse gas reducing energy source for the future. We conclude that future modeling work, which is intended to help guide Canada's course with respect to greenhouse gas reductions should include nuclear technology - and any other relevant technology. The assumptions about nuclear plant capital costs and decision and construction times included in the original modeling were based on inferences from the history of nuclear development, from then current nuclear energy research, from recognition of the historical timelines and complexities of regulation and from observations of the public ambivalence concerning nuclear power. An alternative but perhaps more realistic and now more timely set of assumptions leads to interesting results, as we demonstrate in this study. (author)

  5. Prediction of gas compressibility factor using intelligent models

    Directory of Open Access Journals (Sweden)

    Mohamad Mohamadi-Baghmolaei

    2015-10-01

    Full Text Available The gas compressibility factor, also known as Z-factor, plays the determinative role for obtaining thermodynamic properties of gas reservoir. Typically, empirical correlations have been applied to determine this important property. However, weak performance and some limitations of these correlations have persuaded the researchers to use intelligent models instead. In this work, prediction of Z-factor is aimed using different popular intelligent models in order to find the accurate one. The developed intelligent models are including Artificial Neural Network (ANN, Fuzzy Interface System (FIS and Adaptive Neuro-Fuzzy System (ANFIS. Also optimization of equation of state (EOS by Genetic Algorithm (GA is done as well. The validity of developed intelligent models was tested using 1038 series of published data points in literature. It was observed that the accuracy of intelligent predicting models for Z-factor is significantly better than conventional empirical models. Also, results showed the improvement of optimized EOS predictions when coupled with GA optimization. Moreover, of the three intelligent models, ANN model outperforms other models considering all data and 263 field data points of an Iranian offshore gas condensate with R2 of 0.9999, while the R2 for best empirical correlation was about 0.8334.

  6. An alternative method for calibration of narrow band radiometer using a radiative transfer model

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, J; Wolfram, E; D' Elia, R [Centro de Investigaciones en Laseres y Aplicaciones, CEILAP (CITEFA-CONICET), Juan B. de La Salle 4397 (B1603ALO), Villa Martelli, Buenos Aires (Argentina); Zamorano, F; Casiccia, C [Laboratorio de Ozono y Radiacion UV, Universidad de Magallanes, Punta Arenas (Chile) (Chile); Rosales, A [Universidad Nacional de la Patagonia San Juan Bosco, UNPSJB, Facultad de Ingenieria, Trelew (Argentina) (Argentina); Quel, E, E-mail: jsalvador@citefa.gov.ar [Universidad Nacional de la Patagonia Austral, Unidad Academica Rio Gallegos Avda. Lisandro de la Torre 1070 ciudad de Rio Gallegos-Sta Cruz (Argentina) (Argentina)

    2011-01-01

    The continual monitoring of solar UV radiation is one of the major objectives proposed by many atmosphere research groups. The purpose of this task is to determine the status and degree of progress over time of the anthropogenic composition perturbation of the atmosphere. Such changes affect the intensity of the UV solar radiation transmitted through the atmosphere that then interacts with living organisms and all materials, causing serious consequences in terms of human health and durability of materials that interact with this radiation. One of the many challenges that need to be faced to perform these measurements correctly is the maintenance of periodic calibrations of these instruments. Otherwise, damage caused by the UV radiation received will render any one calibration useless after the passage of some time. This requirement makes the usage of these instruments unattractive, and the lack of frequent calibration may lead to the loss of large amounts of acquired data. Motivated by this need to maintain calibration or, at least, know the degree of stability of instrumental behavior, we have developed a calibration methodology that uses the potential of radiative transfer models to model solar radiation with 5% accuracy or better relative to actual conditions. Voltage values in each radiometer channel involved in the calibration process are carefully selected from clear sky data. Thus, tables are constructed with voltage values corresponding to various atmospheric conditions for a given solar zenith angle. Then we model with a radiative transfer model using the same conditions as for the measurements to assemble sets of values for each zenith angle. The ratio of each group (measured and modeled) allows us to calculate the calibration coefficient value as a function of zenith angle as well as the cosine response presented by the radiometer. The calibration results obtained by this method were compared with those obtained with a Brewer MKIII SN 80 located in the

  7. An alternative method for calibration of narrow band radiometer using a radiative transfer model

    International Nuclear Information System (INIS)

    The continual monitoring of solar UV radiation is one of the major objectives proposed by many atmosphere research groups. The purpose of this task is to determine the status and degree of progress over time of the anthropogenic composition perturbation of the atmosphere. Such changes affect the intensity of the UV solar radiation transmitted through the atmosphere that then interacts with living organisms and all materials, causing serious consequences in terms of human health and durability of materials that interact with this radiation. One of the many challenges that need to be faced to perform these measurements correctly is the maintenance of periodic calibrations of these instruments. Otherwise, damage caused by the UV radiation received will render any one calibration useless after the passage of some time. This requirement makes the usage of these instruments unattractive, and the lack of frequent calibration may lead to the loss of large amounts of acquired data. Motivated by this need to maintain calibration or, at least, know the degree of stability of instrumental behavior, we have developed a calibration methodology that uses the potential of radiative transfer models to model solar radiation with 5% accuracy or better relative to actual conditions. Voltage values in each radiometer channel involved in the calibration process are carefully selected from clear sky data. Thus, tables are constructed with voltage values corresponding to various atmospheric conditions for a given solar zenith angle. Then we model with a radiative transfer model using the same conditions as for the measurements to assemble sets of values for each zenith angle. The ratio of each group (measured and modeled) allows us to calculate the calibration coefficient value as a function of zenith angle as well as the cosine response presented by the radiometer. The calibration results obtained by this method were compared with those obtained with a Brewer MKIII SN 80 located in the

  8. Explaining the diphoton excess in Alternative Left-Right Symmetric Model

    CERN Document Server

    Hati, Chandan

    2016-01-01

    We propose a possible explanation of the recent diphoton excess reported by ATLAS and CMS collaborations, at around 750 GeV diphoton invariant mass, within the framework of $E_{6}$ motivated Alternative Left-Right Symmetric Model (ALRSM), which is capable of addressing the $B$ decay anomalies in the flavor sector, the $eejj$ and $e$ missing $p_{T}jj$ excesses reported by CMS in run 1 of LHC and has the feature of high scale leptogenesis. We find that gluon-gluon fusion can give the observed production rate of the 750 GeV resonance, $\\tilde{n}$, through a loop of scalar leptoquarks ($\\tilde{h}^{(c)}$) with mass below a few TeV range, while $\\tilde{n}$ can subsequently decay into $\\gamma\\gamma$ final state via loops of $\\tilde{h}^{(c)}$ and $\\tilde{E}^{(c)}$. Interestingly, the $\\tilde{E}^{(c)}$ loop can enhance the diphoton branching ratio significantly to successfully explain the observed cross section of the diphoton signal.

  9. Entanglement convertibility by sweeping through the phase diagram of one dimensional $XXZ$ model with bond alternation

    CERN Document Server

    Tzeng, Yu-Chin; Chung, Ming-Chiang; Amico, Luigi; Kwek, Leong-Chuan

    2016-01-01

    We study the entanglement structure and the topological edge states of the ground state of the spin-1/2 XXZ model with bond alternation. We employ density matrix renormalization group with periodic boundary conditions. The finite-size scaling of R\\'enyi entropies $S_2$ and $S_\\infty$ are used to construct the phase diagram of the system. The phase diagram displays three possible phases: Haldane type (an example of symmetry protected topological ordered phases), dimer and N\\'eel phases, the latter bounded by two continuous quantum phase transitions. The entanglement and non-locality in the ground state are studied by looking at the response of the ground state entanglement to a change of the control parameter. Such a response is quantified by the so called entanglement convertibility. We found that, at small spatial scales, the ground state is not convertible within the topological Haldane dimer phase. The phenomenology we observe can be described in terms of correlations between edge states. We found that the...

  10. Continuous utility factor in segregation models: a few surprises

    CERN Document Server

    Roy, Parna

    2015-01-01

    We consider the constrained Schelling model of social segregation which allows non-local jumps of the agents. In the present study, the utility factor u is defined in a way such that it can take continuous values and depends on the tolerance threshold as well as fraction of unlike neighbours. Two models are proposed: in model A the jump probability is determined by the sign of u only which makes it equivalent to the discrete model. In model B the actual values of u are considered. Model A and model B are shown to differ drastically as far as segregation behaviour and phase transitions are concerned. The constrained model B turns out to be as efficient as the unconstrained discrete model, if not more. In addition, we also consider a few other dynamical aspects which have not been studied in segregation models earlier.

  11. Model of complex integrated use of alternative energy sources for highly urbanized areas

    Directory of Open Access Journals (Sweden)

    Ivanova Elena Ivanovna

    2014-04-01

    Full Text Available The increase of population and continuous development of highly urbanized territories poses new challenges to experts in the field of energy saving technologies. Only a multifunctional and autonomous system of building engineering equipment formed by the principles of energy efficiency and cost-effectiveness meets the needs of modern urban environment. Alternative energy sources, exploiting the principle of converting thermal energy into electrical power, show lack of efficiency, so it appears to be necessary for reaching a visible progress to skip this middle step. A fuel cell, converting chemical energy straight into electricity, and offering a vast diversity of both fuel types and oxidizing agents, gives a strong base for designing a complex integrated system. Regarding the results of analysis and comparison conducted among the most types of fuel cells proposed by contemporary scholars, a solid oxide fuel cell (SOFC is approved to be able to ensure the smooth operation of such a system. While the advantages of this device meet the requirements of engineering equipment for modern civil and, especially, dwelling architecture, its drawbacks do not contradict with the operating regime of the proposed system. The article introduces a model of a multifunctional system based on solid oxide fuel cell (SOFC and not only covering the energy demand of a particular building, but also providing the opportunity for proper and economical operation of several additional sub-systems. Air heating and water cooling equipment, ventilating and conditioning devices, the circle of water supply and preparation of water discharge for external use (e.g. agricultural needs included into a closed circuit of the integrated system allow evaluating it as a promising model of further implementation of energy saving technologies into architectural and building practice. This, consequently, will positively affect both ecological and economic development of urban environment.

  12. Modeling climate change mitigation from alternative methods of charcoal production in Kenya

    Energy Technology Data Exchange (ETDEWEB)

    Bailis, Rob [Yale School of Forestry and Environmental Studies, 195 Prospect St, New Haven, CT 06511 (United States)

    2009-11-15

    Current carbon accounting methodologies do not accommodate activities that involve emissions reductions from both land-use change and energy production. This paper analyzes the climate change mitigation potential of charcoal production in East Africa by examining the impact of changing both land management and technology. Current production in a major charcoal producing region of Kenya where charcoal is made as a by-product of land clearance for commercial grain production is modeled as the ''business-as-usual'' scenario. Alternative production systems are proposed based on coppice management of native or exotic trees. Improved kilns are also considered. Changes in aboveground, belowground, and soil carbon are modeled and two distinct baseline assessments are analyzed: one is based on a fixed area of land and one is based on the quantity of non-renewable fuel that is displaced by project activities. The magnitude of carbon emissions reductions varies depending on land management as well as the choice of carbonization technology. However, these variations are smaller than the variations arising from the choice of baseline methodology. The fixed-land baseline yields annualized carbon emission reductions equivalent to 0.5-2.8 tons per year (t y{sup -1}) with no change in production technology and 0.7-3.5 t y{sup -1} with improved kilns. In contrast, the baseline defined by the quantity of displaced non-renewable fuel is 2-6 times larger, yielding carbon emissions reductions of 1.4-12.9 t y{sup -1} with no change in production technology and 3.2-20.4 t y{sup -1} with improved kilns. The results demonstrate the choice of baseline, often a political rather than scientific decision, is critical in assessing carbon emissions reductions. (author)

  13. Loss of Pnn expression attenuates expression levels of SR family splicing factors and modulates alternative pre-mRNA splicing in vivo

    International Nuclear Information System (INIS)

    SR and SR-related proteins have been implicated as trans-acting factors that play an important role in splice selection and are involved at specific stages of spliceosome formation. A well-established property of SR protein splicing factors is their ability to influence selection of alternative splice sites in a concentration-dependent manner. Identification of molecules that regulate SR family protein expression is therefore of vital importance in RNA biology. Here we report that depletion of Pnn expression, a SR-related protein with functions involved in pre-mRNA splicing and mRNA export, induces reduced expression of a subset of cellular proteins, especially that of SR family proteins, including SC35, SRm300, SRp55, and SRp40, but not that of other nuclear proteins, such as p53, Mdm2, and ki67. Knocking down Pnn expression was achieved in vitro by siRNA transfection. Expression levels of SR and SR-related proteins in Pnn-depleted cells as compared to those in control cells were evaluated by immunofluorescent staining and Western blot with specific antibodies. In addition, we also demonstrate that loss of Pnn expression could modulate splice site selection of model reporter gene in vivo. Our finding is significant in terms of regulation of SR protein cellular concentration because it reveals that Pnn may play a general role in the control of the cellular amount of family SR proteins through down-regulation of its own expression, thereby providing us with a better understanding of the cellular mechanism by which Pnn fulfills its biological function

  14. Evaluation of methods for modeling transcription factor sequence specificity

    OpenAIRE

    Weirauch, Matthew T; Cote, Atina; Norel, Raquel; Annala, Matti; Zhao, Yue; Riley, Todd R; Saez-Rodriguez, Julio; Cokelaer, Thomas; Vedenko, Anastasia; Talukder, Shaheynoor; Agius, Phaedra; Arvey, Aaron; Bucher, Philipp; Callan, Curtis G.; Chang, Cheng Wei

    2013-01-01

    Genomic analyses often involve scanning for potential transcription factor (TF) binding sites using models of the sequence specificity of DNA binding proteins. Many approaches have been developed to model and learn a protein's DNA-binding specificity, but these methods have not been systematically compared. Here we applied 26 such approaches to in vitro protein binding microarray data for 66 mouse TFs belonging to various families. For nine TFs, we also scored the resulting motif models on in...

  15. Person-fit to the Five Factor Model of personality

    OpenAIRE

    Allik, J.; Realo, A; Mõttus, R.; Borkenau, P.; Kuppens, P.; Hřebíčková, M.

    2012-01-01

    The Five Factor Model (FFM), a valid model of interindividual differences in the personality of a group of people, reportedly does not always provide a good fit for the individuals of that group. In addition to intraindividual variation across a considerable period of time, meaningful intraindividual variation can be observed within a single test administration. Two person-fit indices showed that the FFM is an adequate model for 95% of the 1,765 target-judge pairs in four different countries ...

  16. The development of an in vitro model for studying mechanisms of nephrotoxicity as an alternative for animal experiments.

    NARCIS (Netherlands)

    Mertens, J.J.W.M.

    1991-01-01

    SUMMARYPresently in our society animal tests still form the main starting point for the assessment of the possible risks of chemicals with regard to human and animal health. For scientific. economic, and ethical reasons. attempts are undertaken continuously to develop cell models as alternatives to

  17. The building of the kitchen table : In search of an alternative model for in-company leadership development programs

    NARCIS (Netherlands)

    Sigaloff, C.L.; Nabben, E.H. (Iselien); Bergsma, E.

    2007-01-01

    The purpose of this paper is to provide an alternative model of a leadership-development program. Design/methodology/approach: A leadership-development program based on a "closure-type description" instead of an "input-type description" (Varela) was designed and executed for an organization. The res

  18. Observational Learning from Animated Models: Effects of Studying-Practicing Alternation and Illusion of Control on Transfer

    NARCIS (Netherlands)

    Wouters, Pieter; Paas, Fred; Van Merriënboer, Jeroen

    2008-01-01

    Wouters, P. J. M., Paas, F., & Van Merriënboer, J. J. G. (2010). Observational learning from animated models: effects of studying-practicing alternation and illusion of control on transfer. Instructional Science, 38(1), 89-104. doi:10.1007/s11251-008-9079-0

  19. On the Complexity of Model-Checking Branching and Alternating-Time Temporal Logics in One-Counter Systems

    DEFF Research Database (Denmark)

    Vester, Steen

    2015-01-01

    We study the complexity of the model-checking problem for the branching-time logic CTL ∗  and the alternating-time temporal logics ATL/ATL ∗  in one-counter processes and one-counter games respectively. The complexity is determined for all three logics when integer weights are input in unary (non...

  20. Evidence for a continental unstable triple junction as an alternate model for Vrancea seismicity

    International Nuclear Information System (INIS)

    The Vrancea active seismic zone located in the bending area of Romanian Carpathians stands for a long time as a challenge to geoscientists all over the world. Deep seismicity in continental collision circumstances is rather rare and always constraints on dynamics of subduction. The pattern of the intermediate-depth seismicity in the Vrancea region suggests a confined prismatic nearly vertical seismic body. The small size and geometry of the seismic zone have made it difficult to interpret the kinematics of subduction and continental collision in the area. During the years, several models, almost all subduction-related, have more or less successfully tried to explain this phenomenon. The paper represents an attempt to explain the Vrancea intermediate depth seismicity starting from a new concept, as introduced by the plate tectonics theory: the triple junction. A continental unstable triple junction is proposed as an alternate model to explain the unusual seismicity in the Vrancea seismic area. Three tectonic plates / microplates seem to join in the region: East European Plate (EEP), Moesian microplate (MoP), and the Intra-Alpine microplate (IaP). Their edges are geophysically documented and their motion is evidenced. The differentiation in their relative velocities generated an unstable transform-transform-compression triple junction that determined the vertical collapse of the lithospheric segment to which the intermediate seismicity within Vrancea zone is associated. Three major plates' wedges bound the seismic body: Tornquist-Teissyere zone, Peceneaga-Camena fault, and Trans-Getica fault. Temperature accommodation phenomena associated to the sinking lithospheric body into the hotter upper mantle environment (such as convective cells, phase-transform processes, and devolatilization) could be responsible for the earthquakes occurrence. The problem of the missing subduction related volcanism within Vrancea triple junction (VTJ) area is definitely solved in the case

  1. Evaluation of alternate outreach models for cataract services in rural Nepal

    Directory of Open Access Journals (Sweden)

    Gautam Maria

    2010-03-01

    Full Text Available Abstract Background Bharatpur Eye Hospital in Chitwan District, a primarily agrarian setting in south-central Nepal, reduced the number of diagnostic screening and treatment (DST camps by one half (151 to 75 in an attempt to increase both the efficiency of its outreach program and the number of people that go directly to the hospital for service. The Hospital evaluated the two program models in terms of program costs, cataract surgical utilization, hospital direct payment and patient equity. Methods The study is a prospective, before and after, study of the impact of an alternate outreach model on cataract service utilization patterns and cost per outreach camp and cost per cataract surgery at Bharatpur Eye Hospital, comparing the service years July 2006 to June 2007, with July 2007 to June 2008. Study findings were based on routinely gathered hospital and outreach administrative data. Results The total cost of the DST camps decreased by approximately US$2000. The cost per camp increased from US$52 to $78 and the cost per cataract surgery decreased from US$ 3.80 to $3.20. The number of patients who went directly to the hospital, and paid for cataract surgery, increased from 432 (17% to 623 (25%. The total number of cataract surgical procedures at Bharatpur Eye Hospital remained very similar between the two service years (2501 and 2449, respectively. The presenting visual acuity and sex of the two cataract surgical populations were very similar (favouring women, 53 and 55% in the two years, respectively. A shift toward younger men and women occurred with a 245 (64% increase in people age 50-59 years, and shift away from people age 70 years and older with a 236 (22% reduction. The age and sex distribution of the direct paying patients were very similar in the two years. Conclusion The new, more concentrated, more rural DST model of service delivery reduced overall outreach program costs, cost per cataract surgery transported, while increasing

  2. Fuzzy MCDM Model for Risk Factor Selection in Construction Projects

    Directory of Open Access Journals (Sweden)

    Pejman Rezakhani

    2012-11-01

    Full Text Available Risk factor selection is an important step in a successful risk management plan. There are many risk factors in a construction project and by an effective and systematic risk selection process the most critical risks can be distinguished to have more attention. In this paper through a comprehensive literature survey, most significant risk factors in a construction project are classified in a hierarchical structure. For an effective risk factor selection, a modified rational multi criteria decision making model (MCDM is developed. This model is a consensus rule based model and has the optimization property of rational models. By applying fuzzy logic to this model, uncertainty factors in group decision making such as experts` influence weights, their preference and judgment for risk selection criteria will be assessed. Also an intelligent checking process to check the logical consistency of experts` preferences will be implemented during the decision making process. The solution inferred from this method is in the highest degree of acceptance of group members. Also consistency of individual preferences is checked by some inference rules. This is an efficient and effective approach to prioritize and select risks based on decisions made by group of experts in construction projects. The applicability of presented method is assessed through a case study.

  3. The Dirac form factor predicts the Pauli form factor in the Endpoint Model

    Science.gov (United States)

    Dagaonkar, Sumeet K.; Jain, Pankaj; Ralston, John P.

    2016-07-01

    We compute the momentum-transfer dependence of the proton Pauli form factor F2 in the Endpoint overlap Model. We find the model correctly reproduces the scaling of the ratio of F2 with the Dirac form factor F1 observed at the Jefferson Laboratory. The calculation uses the leading-power, leading-twist Dirac structure of the quark light-cone wave function and the same endpoint dependence previously determined from the Dirac form factor F1. There are no parameters and no adjustable functions in the Endpoint Model's prediction for the scaling behavior of F2. The model's predicted momentum dependence of the ratio F2(Q2)/F1(Q2) is quite insensitive to the endpoint wave function, which explains why the observed ratio scales like 1 / Q down to rather low momentum transfers. We also fit the magnitude of this ratio by adjusting the parameters of the wave function. The Endpoint Model appears to be the only comprehensive model consistent with all form factor information as well as reproducing fixed-angle proton-proton scattering at large momentum transfer. Any one of the processes is capable of predicting the others.

  4. Game Factors and Game-Based Learning Design Model

    Directory of Open Access Journals (Sweden)

    Yen-Ru Shi

    2015-01-01

    Full Text Available How to design useful digital game-based learning is a topic worthy of discussion. Past research focused on specific game genres design, but it is difficult to use when the target game genre differs from the default genres used in the research. This study presents macrodesign concepts that elucidates 11 crucial game-design factors, including game goals, game mechanism, game fantasy, game value, interaction, freedom, narrative, sensation, challenges, sociality, and mystery. We clearly define each factor and analyze the relationships among the 11 factors to construct a game-based learning design model. Two application examples are analyzed to verify the usability of the model and the performance of these factors. It can assist educational game designers in developing interesting games.

  5. High-dimensional covariance matrix estimation in approximate factor models

    CERN Document Server

    Fan, Jianqing; Mincheva, Martina; 10.1214/11-AOS944

    2012-01-01

    The variance--covariance matrix plays a central role in the inferential theories of high-dimensional factor models in finance and economics. Popular regularization methods of directly exploiting sparsity are not directly applicable to many financial problems. Classical methods of estimating the covariance matrices are based on the strict factor models, assuming independent idiosyncratic components. This assumption, however, is restrictive in practical applications. By assuming sparse error covariance matrix, we allow the presence of the cross-sectional correlation even after taking out common factors, and it enables us to combine the merits of both methods. We estimate the sparse covariance using the adaptive thresholding technique as in Cai and Liu [J. Amer. Statist. Assoc. 106 (2011) 672--684], taking into account the fact that direct observations of the idiosyncratic components are unavailable. The impact of high dimensionality on the covariance matrix estimation based on the factor structure is then studi...

  6. Electrospun polyurethane as an alternative ventricular catheter and in vitro model of shunt obstruction.

    Science.gov (United States)

    Suresh, Supraja; Black, Richard A

    2015-02-01

    Intracranial pressure and volume vary considerably between hydrocephalic patients, and with age, health and haemodynamic status; if left untreated, intracranial pressure rises and the ventricular system expands to accommodate the excess cerebrospinal fluid, with significant morbidity and mortality. Cerebrospinal fluid shunts in use today have a high incidence of failure with shunt obstruction being the most serious. Conventional proximal shunt catheters are made from poly(dimethyl)siloxane, the walls of which are perforated with holes for the cerebrospinal fluid to pass through. The limited range of catheters, in terms of material selection and flow distribution, is responsible in large part for their poor performance. In this study, we present an alternative design of proximal catheter made of electrospun polyether urethane, and evaluate its performance in the presence of glial cells, which are responsible for shunt blockage. The viability and growth of cells on catheter materials such as poly(dimethyl)siloxane and polyurethane in the form of cast films, microfibrous mats and porous sponges were studied in the presence of proteins present in cerebrospinal fluid after 48 h and 96 h in culture. The numbers of viable cells on each substrate were comparable to untreated poly(dimethyl)siloxane, both in the presence and absence of serum proteins found in cerebrospinal fluid. A cell culture model of shunt obstruction was developed in which cells on electrospun polyether urethane catheters were subjected to flow during culture in vitro, and the degree of obstruction quantified in terms of hydraulic permeability after static and perfusion culture. The results indicate that a catheter made of electrospun polyether urethane would be able to maintain cerebrospinal fluid flow even with the presence of cells for the time period chosen for this study. These findings have implications for the design and deployment of microporous shunt catheter systems for the treatment of

  7. Uncovering Transcriptional Regulatory Networks by Sparse Bayesian Factor Model

    Science.gov (United States)

    Meng, Jia; Zhang, Jianqiu(Michelle); Qi, Yuan(Alan); Chen, Yidong; Huang, Yufei

    2010-12-01

    The problem of uncovering transcriptional regulation by transcription factors (TFs) based on microarray data is considered. A novel Bayesian sparse correlated rectified factor model (BSCRFM) is proposed that models the unknown TF protein level activity, the correlated regulations between TFs, and the sparse nature of TF-regulated genes. The model admits prior knowledge from existing database regarding TF-regulated target genes based on a sparse prior and through a developed Gibbs sampling algorithm, a context-specific transcriptional regulatory network specific to the experimental condition of the microarray data can be obtained. The proposed model and the Gibbs sampling algorithm were evaluated on the simulated systems, and results demonstrated the validity and effectiveness of the proposed approach. The proposed model was then applied to the breast cancer microarray data of patients with Estrogen Receptor positive ([InlineEquation not available: see fulltext.]) status and Estrogen Receptor negative ([InlineEquation not available: see fulltext.]) status, respectively.

  8. Uncovering Transcriptional Regulatory Networks by Sparse Bayesian Factor Model

    Directory of Open Access Journals (Sweden)

    Qi Yuan(Alan

    2010-01-01

    Full Text Available Abstract The problem of uncovering transcriptional regulation by transcription factors (TFs based on microarray data is considered. A novel Bayesian sparse correlated rectified factor model (BSCRFM is proposed that models the unknown TF protein level activity, the correlated regulations between TFs, and the sparse nature of TF-regulated genes. The model admits prior knowledge from existing database regarding TF-regulated target genes based on a sparse prior and through a developed Gibbs sampling algorithm, a context-specific transcriptional regulatory network specific to the experimental condition of the microarray data can be obtained. The proposed model and the Gibbs sampling algorithm were evaluated on the simulated systems, and results demonstrated the validity and effectiveness of the proposed approach. The proposed model was then applied to the breast cancer microarray data of patients with Estrogen Receptor positive ( status and Estrogen Receptor negative ( status, respectively.

  9. Impact of festival factor on electric quantity multiplication forecast model

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This research aims to improve the forecasting precision of electric quantity. It is discovered that the total electricity consumption considerably increased during the Spring Festival by the analysis of the electric quantity time series from 2002 to 2007 in Shandong province. The festival factor is ascertained to be one of the important seasonal factors affecting the electric quantity fluctuations, and the multiplication model for forecasting is improved by introducing corresponding variables and parameters...

  10. Estimating degree day factors from MODIS for snowmelt runoff modeling

    OpenAIRE

    He, Z H; Parajka, J.; Tian, F. Q.; Blöschl, G.

    2014-01-01

    Degree-day factors are widely used to estimate snowmelt runoff in operational hydrological models. Usually, they are calibrated on observed runoff, and sometimes on satellite snow cover data. In this paper, we propose a new method for estimating the snowmelt degree-day factor (DDFS) directly from MODIS snow covered area (SCA) and ground based snow depth data without calibration. Subcatchment snow volume is estimated by combining SCA and snow depths. Snow density is e...

  11. Electromagnetic form factors in a collective model of the nucleon

    CERN Document Server

    Bijker, R; Leviatan, A

    1995-01-01

    We study the electromagnetic form factors of the nucleon in a collective model of baryons. Using the algebraic approach to hadron structure, we derive closed expressions for both elastic and transition form factors, and consequently for the helicity amplitudes that can be measured in electro- and photoproduction. Effects of spin-flavor symmetry breaking and of swelling of hadrons with increasing excitation energy are considered.

  12. Modelling leadership and institutional factors in endogenous regional development.

    OpenAIRE

    Stimson, Robert J; Stough, Roger R.

    2004-01-01

    Theories and approaches to endogenous growth and regional development tend to neglect or at best underplay the role of leadership and the way institutional factors are considered is usually simplistic. This paper builds on work the authors have been developing over the last year or so to develop a model framework of regional economic development that explicitly incorporates leadership and institutional factors along with the consideration of resource endowments and market fit and of entrepren...

  13. A quality metric for homology modeling: the H-factor

    Directory of Open Access Journals (Sweden)

    di Luccio Eric

    2011-02-01

    Full Text Available Abstract Background The analysis of protein structures provides fundamental insight into most biochemical functions and consequently into the cause and possible treatment of diseases. As the structures of most known proteins cannot be solved experimentally for technical or sometimes simply for time constraints, in silico protein structure prediction is expected to step in and generate a more complete picture of the protein structure universe. Molecular modeling of protein structures is a fast growing field and tremendous works have been done since the publication of the very first model. The growth of modeling techniques and more specifically of those that rely on the existing experimental knowledge of protein structures is intimately linked to the developments of high resolution, experimental techniques such as NMR, X-ray crystallography and electron microscopy. This strong connection between experimental and in silico methods is however not devoid of criticisms and concerns among modelers as well as among experimentalists. Results In this paper, we focus on homology-modeling and more specifically, we review how it is perceived by the structural biology community and what can be done to impress on the experimentalists that it can be a valuable resource to them. We review the common practices and provide a set of guidelines for building better models. For that purpose, we introduce the H-factor, a new indicator for assessing the quality of homology models, mimicking the R-factor in X-ray crystallography. The methods for computing the H-factor is fully described and validated on a series of test cases. Conclusions We have developed a web service for computing the H-factor for models of a protein structure. This service is freely accessible at http://koehllab.genomecenter.ucdavis.edu/toolkit/h-factor.

  14. Factor selection and structural identification in the interaction ANOVA model.

    Science.gov (United States)

    Post, Justin B; Bondell, Howard D

    2013-03-01

    When faced with categorical predictors and a continuous response, the objective of an analysis often consists of two tasks: finding which factors are important and determining which levels of the factors differ significantly from one another. Often times, these tasks are done separately using Analysis of Variance (ANOVA) followed by a post hoc hypothesis testing procedure such as Tukey's Honestly Significant Difference test. When interactions between factors are included in the model the collapsing of levels of a factor becomes a more difficult problem. When testing for differences between two levels of a factor, claiming no difference would refer not only to equality of main effects, but also to equality of each interaction involving those levels. This structure between the main effects and interactions in a model is similar to the idea of heredity used in regression models. This article introduces a new method for accomplishing both of the common analysis tasks simultaneously in an interaction model while also adhering to the heredity-type constraint on the model. An appropriate penalization is constructed that encourages levels of factors to collapse and entire factors to be set to zero. It is shown that the procedure has the oracle property implying that asymptotically it performs as well as if the exact structure were known beforehand. We also discuss the application to estimating interactions in the unreplicated case. Simulation studies show the procedure outperforms post hoc hypothesis testing procedures as well as similar methods that do not include a structural constraint. The method is also illustrated using a real data example.

  15. DISTANCE AS KEY FACTOR IN MODELLING STUDENTS’ RECRUITMENT BY UNIVERSITIES

    Directory of Open Access Journals (Sweden)

    SIMONA MĂLĂESCU

    2015-10-01

    Full Text Available Distance as Key Factor in Modelling Students’ Recruitment by Universities. In a previous paper analysing the challenge of keeping up with the current methodologies in the analysis and modelling of students’ recruitment by universities in the case of some ECE countries which still don’t register or develop key data to take advantage from the state of the art knowledge on the domain, we have promised to approach the factor distance in a future work due to the extent of the topic. This paper fulfill that promise bringing a review of the literature especially dealing with modelling the geographical area of recruiting students of an university, where combining distance with the proximate key factors previously reviewed, complete the meta-analysis of existing literature we have started a year ago. Beyond the theoretical benefit from a practical perspective, the metaanalysis aimed at synthesizing elements of good practice that can be applied to the local university system.

  16. Consumer's Online Shopping Influence Factors and Decision-Making Model

    Science.gov (United States)

    Yan, Xiangbin; Dai, Shiliang

    Previous research on online consumer behavior has mostly been confined to the perceived risk which is used to explain those barriers for purchasing online. However, perceived benefit is another important factor which influences consumers’ decision when shopping online. As a result, an integrated consumer online shopping decision-making model is developed which contains three elements—Consumer, Product, and Web Site. This model proposed relative factors which influence the consumers’ intention during the online shopping progress, and divided them into two different dimensions—mentally level and material level. We tested those factors with surveys, from both online volunteers and offline paper surveys with more than 200 samples. With the help of SEM, the experimental results show that the proposed model and method can be used to analyze consumer’s online shopping decision-making process effectively.

  17. Assessing the five-factor model of personality description.

    Science.gov (United States)

    Briggs, S R

    1992-06-01

    Several approaches to assessing the dimensions of the five-factor model are reviewed and evaluated. The items in the assessment instrument may be adjectives or phrases, and the instrument itself may have been developed specifically to measure the five factors or may have been reinterpreted in terms of the five-factor model. Data are presented comparing an adjective-based measure of the model (Goldberg, 1990) with two phrase-based measures (Costa & McCrae, 1985; Hogan, 1986), and recommendations are made for the choice of an instrument in different research contexts. Allport's (1937) distinctions between the structure of the trait lexicon and the structure of personality in individuals are reiterated. PMID:1635044

  18. BIB-SEM of representative area clay structures paving towards an alternative model of porosity

    Science.gov (United States)

    Desbois, G.; Urai, J. L.; Houben, M.; Hemes, S.; Klaver, J.

    2012-04-01

    A major contribution to understanding the sealing capacity, coupled flow, capillary processes and associated deformation in clay-rich geomaterials is based on detailed investigation of the rock microstructures. However, the direct characterization of pores in representative elementary area (REA) and below µm-scale resolution remains challenging. To investigate directly the mm- to nm-scale porosity, SEM is certainly the most direct approach, but it is limited by the poor quality of the investigated surfaces. The recent development of ion milling tools (BIB and FIB; Desbois et al, 2009, 2011; Heath et al., 2011; Keller et al., 2011) and cryo-SEM allows respectively producing exceptional high quality polished cross-sections suitable for high resolution porosity SEM-imaging at nm-scale and investigating samples under wet conditions by cryogenic stabilization. This contribution focuses mainly on the SEM description of pore microstructures in 2D BIB-polished cross-sections of Boom (Mol site, Belgium) and Opalinus (Mont Terri, Switzerland) clays down to the SEM resolution. Pores detected in images are statistically analyzed to perform porosity quantification in REA. On the one hand, BIB-SEM results allow retrieving MIP measurements obtained from larger sample volumes. On the other hand, the BIB-SEM approach allows characterizing porosity-homogeneous and -predictable islands, which form the elementary components of an alternative concept of porosity/permeability model based on pore microstructures. Desbois G., Urai J.L. and Kukla P.A. (2009) Morphology of the pore space in claystones - evidence from BIB/FIB ion beam sectioning and cryo-SEM observations. E-Earth, 4, 15-22. Desbois G., Urai J.L., Kukla P.A., Konstanty J. and Baerle C. (2011). High-resolution 3D fabric and porosity model in a tight gas sandstone reservoir: a new approach to investigate microstructures from mm- to nm-scale combining argon beam cross-sectioning and SEM imaging . Journal of Petroleum Science

  19. K factor estimation in distribution transformers using linear regression models

    Directory of Open Access Journals (Sweden)

    Juan Miguel Astorga Gómez

    2016-06-01

    Full Text Available Background: Due to massive incorporation of electronic equipment to distribution systems, distribution transformers are subject to operation conditions other than the design ones, because of the circulation of harmonic currents. It is necessary to quantify the effect produced by these harmonic currents to determine the capacity of the transformer to withstand these new operating conditions. The K-factor is an indicator that estimates the ability of a transformer to withstand the thermal effects caused by harmonic currents. This article presents a linear regression model to estimate the value of the K-factor, from total current harmonic content obtained with low-cost equipment.Method: Two distribution transformers that feed different loads are studied variables, current total harmonic distortion factor K are recorded, and the regression model that best fits the data field is determined. To select the regression model the coefficient of determination R2 and the Akaike Information Criterion (AIC are used. With the selected model, the K-factor is estimated to actual operating conditions.Results: Once determined the model it was found that for both agricultural cargo and industrial mining, present harmonic content (THDi exceeds the values that these transformers can drive (average of 12.54% and minimum 8,90% in the case of agriculture and average value of 18.53% and a minimum of 6.80%, for industrial mining case.Conclusions: When estimating the K factor using polynomial models it was determined that studied transformers can not withstand the current total harmonic distortion of their current loads. The appropriate K factor for studied transformer should be 4; this allows transformers support the current total harmonic distortion of their respective loads.

  20. A Right Coprime Factorization of Neural State Space Models

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon

    2007-01-01

    In recent years, various methods for identification of nonlinear systems in closed loop using open-loop approaches have received considerable attention. However, these methods rely on differentially coprime factorizations of the nonlinear plants, which can be difficult to compute in practice....... To address this issue, this paper presents various technical results leading up to explicit formulae for right coprime factorizations of neural state space models, i.e., nonlinear system models represented in state space using neural networks, which satisfy a Bezout identity. ...

  1. Factor models on locally tree-like graphs

    OpenAIRE

    Dembo, Amir; Montanari, Andrea; Sun, Nike

    2011-01-01

    We consider homogeneous factor models on uniformly sparse graph sequences converging locally to a (unimodular) random tree $T$, and study the existence of the free energy density $\\phi$, the limit of the log-partition function divided by the number of vertices $n$ as $n$ tends to infinity. We provide a new interpolation scheme and use it to prove existence of, and to explicitly compute, the quantity $\\phi$ subject to uniqueness of a relevant Gibbs measure for the factor model on $T$. By way o...

  2. Applying the Five-Factor Model to Game Design

    OpenAIRE

    Bildtgård, Marcus

    2014-01-01

    What makes us like or dislike certain games? Is there relation between our tastes in games and our personalities and can it be measured? This dissertation examines gamer personalities and game attributes with the help of the Five-Factor Model, also called The Big Five. It treats an experiment on how to apply the Five-Factor Model to games and their players and what it may be used for. By interviewing gamers, recording their favored and unfavored games, letting the gamers take a Big Five perso...

  3. Alternating Coordinate-Momentum Representation for Quantum States Based on Bopp Operators for Modelling Long-Distance Coherence Aspects

    Directory of Open Access Journals (Sweden)

    Ezzat G. Bakhoum

    2015-01-01

    Full Text Available This study presents an alternating coordinate-momentum representation for propagation and transition of associated wave function, based on Bopp operators and on a certain symbolic determinant corresponding to a set of two linear equations with null free terms. It is shown that this alternating representation can justify in a good manner the patterns created through reflection/refraction of waves on nonperfectly smooth interfaces and phase correspondence of diffracted beams without the need of supplementary support functions. Correlations with Lorentz transformation of wave functions by interaction with a certain material medium (the space-time origin of a wave-train being adjusted are also presented, and supplementary aspects regarding the use of electromagnetic scalar and vector potentials for modelling evolution within this alternating representation are added.

  4. Particle Reduction Strategies - PAREST. Traffic emission modelling. Model comparision and alternative scenarios. Sub-report; Strategien zur Verminderung der Feinstaubbelastung - PAREST. Verkehrsemissionsmodellierung. Modellvergleich und Alternative Szenarien. Teilbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kugler, Ulrike; Theloke, Jochen [Stuttgart Univ. (Germany). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER); Joerss, Wolfram [Institut fuer Zukunftsstudien und Technologiebewertung gGmbH (IZT), Berlin (Germany)

    2013-06-15

    The modeling of the reference scenario and the various reduction scenarios in PAREST was based on the Central System of Emissions (CSE) (CSE, 2007). Emissions from road traffic were calculated by using the traffic emission model TREMOD (Knoerr et al., 2005) and fed into the CSE. The version TREMOD 4.17 has been used. The resulting emission levels in PAREST reference scenario were supplemented by the emission-reducing effect of the implementation of the future Euro 5 and 6 emission standards for cars and light commercial vehicles and Euro VI for heavy commercial vehicles in combination with the truck toll extension. [German] Die Modellierung des Referenzszenarios und der verschiedenen Minderungsszenarien in PAREST erfolgte auf Grundlage des Zentralen System Emissionen (ZSE) (ZSE, 2007). Emissionen aus dem Strassenverkehr wurden mit Hilfe des Verkehrsemissionsmodells TREMOD (Knoerr et al., 2005) berechnet und in das ZSE eingespeist. Dabei wurde die Version TREMOD 4.17 verwendet. Die daraus resultierenden Emissionsmengen wurden im PAREST-Referenzszenario um die emissionsmindernde Wirkung der zukuenftigen Implementierung der Abgasnormen Euro 5 und 6 fuer Pkw und leichte Nutzfahrzeuge sowie Euro VI fuer schwere Nutzfahrzeuge in Kombination einer Erweiterung der Lkw-Maut ergaenzt. Die Berechnung der Emissionen des Referenzszenarios wurde auf Grundlage des Inlandsprinzips sowie des Energiebilanzprinzips durchgefuehrt. Die auf dieser Grundlage berechneten Emissionen fuer das Basisjahr 2005 und fuer die Referenzjahre 2010, 2015 und 2020 unterscheiden sich teilweise erheblich von den mit Hilfe des Modells TREMOVE (dem von der EU Kommission verwendeten Modell fuer mobile Quellen) berechneten Emissionen.

  5. Functional dynamic factor models with application to yield curve forecasting

    KAUST Repository

    Hays, Spencer

    2012-09-01

    Accurate forecasting of zero coupon bond yields for a continuum of maturities is paramount to bond portfolio management and derivative security pricing. Yet a universal model for yield curve forecasting has been elusive, and prior attempts often resulted in a trade-off between goodness of fit and consistency with economic theory. To address this, herein we propose a novel formulation which connects the dynamic factor model (DFM) framework with concepts from functional data analysis: a DFM with functional factor loading curves. This results in a model capable of forecasting functional time series. Further, in the yield curve context we show that the model retains economic interpretation. Model estimation is achieved through an expectation- maximization algorithm, where the time series parameters and factor loading curves are simultaneously estimated in a single step. Efficient computing is implemented and a data-driven smoothing parameter is nicely incorporated. We show that our model performs very well on forecasting actual yield data compared with existing approaches, especially in regard to profit-based assessment for an innovative trading exercise. We further illustrate the viability of our model to applications outside of yield forecasting.

  6. Solutions of two-factor models with variable interest rates

    Science.gov (United States)

    Li, Jinglu; Clemons, C. B.; Young, G. W.; Zhu, J.

    2008-12-01

    The focus of this work is on numerical solutions to two-factor option pricing partial differential equations with variable interest rates. Two interest rate models, the Vasicek model and the Cox-Ingersoll-Ross model (CIR), are considered. Emphasis is placed on the definition and implementation of boundary conditions for different portfolio models, and on appropriate truncation of the computational domain. An exact solution to the Vasicek model and an exact solution for the price of bonds convertible to stock at expiration under a stochastic interest rate are derived. The exact solutions are used to evaluate the accuracy of the numerical simulation schemes. For the numerical simulations the pricing solution is analyzed as the market completeness decreases from the ideal complete level to one with higher volatility of the interest rate and a slower mean-reverting environment. Simulations indicate that the CIR model yields more reasonable results than the Vasicek model in a less complete market.

  7. Modeling Image Structure with Factorized Phase-Coupled Boltzmann Machines

    CERN Document Server

    Cadieu, Charles F

    2010-01-01

    We describe a model for capturing the statistical structure of local amplitude and local spatial phase in natural images. The model is based on a recently developed, factorized third-order Boltzmann machine that was shown to be effective at capturing higher-order structure in images by modeling dependencies among squared filter outputs (Ranzato and Hinton, 2010). Here, we extend this model to $L_p$-spherically symmetric subspaces. In order to model local amplitude and phase structure in images, we focus on the case of two dimensional subspaces, and the $L_2$-norm. When trained on natural images the model learns subspaces resembling quadrature-pair Gabor filters. We then introduce an additional set of hidden units that model the dependencies among subspace phases. These hidden units form a combinatorial mixture of phase coupling distributions, concentrated in the sum and difference of phase pairs. When adapted to natural images, these distributions capture local spatial phase structure in natural images.

  8. The structure of musical preferences: a five-factor model.

    Science.gov (United States)

    Rentfrow, Peter J; Goldberg, Lewis R; Levitin, Daniel J

    2011-06-01

    Music is a cross-cultural universal, a ubiquitous activity found in every known human culture. Individuals demonstrate manifestly different preferences in music, and yet relatively little is known about the underlying structure of those preferences. Here, we introduce a model of musical preferences based on listeners' affective reactions to excerpts of music from a wide variety of musical genres. The findings from 3 independent studies converged to suggest that there exists a latent 5-factor structure underlying music preferences that is genre free and reflects primarily emotional/affective responses to music. We have interpreted and labeled these factors as (a) a Mellow factor comprising smooth and relaxing styles; (b) an Unpretentious factor comprising a variety of different styles of sincere and rootsy music such as is often found in country and singer-songwriter genres; (c) a Sophisticated factor that includes classical, operatic, world, and jazz; (d) an Intense factor defined by loud, forceful, and energetic music; and (e) a Contemporary factor defined largely by rhythmic and percussive music, such as is found in rap, funk, and acid jazz. The findings from a fourth study suggest that preferences for the MUSIC factors are affected by both the social and the auditory characteristics of the music. PMID:21299309

  9. Evaluation of alternative age-based methods for estimating relative abundance from survey data in relation to assessment models

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte; Nielsen, Anders; Kristensen, Kasper

    2014-01-01

    Indices of abundance from fishery-independent trawl surveys constitute an important source of information for many fish stock assessments. Indices are often calculated using area stratified sample means on age-disaggregated data, and finally treated in stock assessment models as independent...... observations. We evaluate a series of alternative methods for calculating indices of abundance from trawl survey data (delta-lognormal, delta-gamma, and Tweedie using Generalized Additive Models) as well as different error structures for these indices when used as input in an age-based stock assessment model...... different indices produced. The stratified mean method is found much more imprecise than the alternatives based on GAMs, which are found to be similar. Having time-varying index variances is found to be of minor importance, whereas the independence assumption is not only violated but has significant impact...

  10. A model of a patient-derived IDH1 mutant anaplastic astrocytoma with alternative lengthening of telomeres.

    Science.gov (United States)

    Borodovsky, Alexandra; Meeker, Alan K; Kirkness, Ewen F; Zhao, Qi; Eberhart, Charles G; Gallia, Gary L; Riggins, Gregory J

    2015-02-01

    Mutations in isocitrate dehydrogenase 1 (IDH1) have been found in the vast majority of low grade and progressive infiltrating gliomas and are characterized by the production of 2-hydroxyglutarate from α-ketoglutarate. Recent investigations of malignant gliomas have identified additional genetic and chromosomal abnormalities which cluster with IDH1 mutations into two distinct subgroups. The astrocytic subgroup was found to have frequent mutations in ATRX, TP53 and displays alternative lengthening of telomeres. The second subgroup with oligodendrocytic morphology has frequent mutations in CIC or FUBP1, and is linked to co-deletion of the 1p/19q arms. These mutations reflect the development of two distinct molecular pathways representing the majority of IDH1 mutant gliomas. Unfortunately, due to the scarcity of endogenously derived IDH1 mutant models, there is a lack of accurate models to study mechanism and develop new therapy. Here we report the generation of an endogenous IDH1 anaplastic astrocytoma in vivo model with concurrent mutations in TP53, CDKN2A and ATRX. The model has a similar phenotype and histopathology as the original patient tumor, expresses the IDH1 (R132H) mutant protein and exhibits an alternative lengthening of telomeres phenotype. The JHH-273 model is characteristic of anaplastic astrocytoma and represents a valuable tool for investigating the pathogenesis of this distinct molecular subset of gliomas and for preclinical testing of compounds targeting IDH1 mutations or alternative lengthening of telomeres. PMID:25471051

  11. The epithelial splicing factors ESRP1 and ESRP2 positively and negatively regulate diverse types of alternative splicing events

    OpenAIRE

    Warzecha, Claude C.; Shen, Shihao; Xing, Yi; Carstens, Russ P.

    2009-01-01

    Cell-type and tissue-specific alternative splicing events are regulated by combinatorial control involving both abundant RNA binding proteins as well as those with more discrete expression and specialized functions. Epithelial Splicing Regulatory Proteins 1 and 2 (ESRP1 and ESRP2) are recently discovered epithelial-specific RNA binding proteins that promote splicing of the epithelial variant of the FGFR2, ENAH, CD44 and CTNND1 transcripts. To catalogue a larger set of splicing events under th...

  12. Development of the Model of Decision Support for Alternative Choice in the Transportation Transit System

    Directory of Open Access Journals (Sweden)

    Kabashkin Igor

    2015-02-01

    Full Text Available The decision support system is one of the instruments for choosing the most effective decision for cargo owner in constant fluctuated business environment. The objective of this Paper is to suggest the multiple-criteria approach for evaluation and choice the alternatives of cargo transportation in the large scale transportation transit system for the decision makers - cargo owners. The large scale transportation transit system is presented by directed finite graph. Each of 57 alternatives is represented by the set of key performance indicators Kvi and set of parameters Paj. There has been developed a two-level hierarchy system of criteria with ranging expert evaluations based on Analytic Hierarchy Process Method. The best alternatives were suggested according to this method.

  13. Factors Influencing RBC Alloimmunization: Lessons Learned from Murine Models

    OpenAIRE

    Ryder, Alex B.; Zimring, James C.; Hendrickson, Jeanne E

    2014-01-01

    Red blood cell (RBC) alloimmunization may occur following transfusion or pregnancy/delivery. Although observational human studies have described the immunogenicity of RBC antigens and the clinical significance of RBC alloantibodies, studies of factors influencing RBC alloimmunization in humans are inherently limited by the large number of independent variables involved. This manuscript reviews data generated in murine models that utilize transgenic donor mice, which express RBC-specific model...

  14. Antibody directs properdin-dependent activation of the complement alternative pathway in a mouse model of abdominal aortic aneurysm.

    Science.gov (United States)

    Zhou, Hui-Fang; Yan, Huimin; Stover, Cordula M; Fernandez, Tamara Montes; Rodriguez de Cordoba, Santiago; Song, Wen-Chao; Wu, Xiaobo; Thompson, Robert W; Schwaeble, Wilhelm J; Atkinson, John P; Hourcade, Dennis E; Pham, Christine T N

    2012-02-14

    Abdominal aortic aneurysm (AAA) is a complex inflammatory vascular disease. There are currently limited treatment options for AAA when surgery is inapplicable. Therefore, insights into molecular mechanisms underlying AAA pathogenesis may reveal therapeutic targets that could be manipulated pharmacologically or biologically to halt disease progression. Using an elastase-induced AAA mouse model, we previously established that the complement alternative pathway (AP) plays a critical role in the development of AAA. However, the mechanism by which complement AP is initiated remains undefined. The complement protein properdin, traditionally viewed as a positive regulator of the AP, may also initiate complement activation by binding directly to target surfaces. In this study, we sought to determine whether properdin serves as a focal point for the initiation of the AP complement activation in AAA. Using a properdin loss of function mutation in mice and a mutant form of the complement factor B protein that produces a stable, properdin-free AP C3 convertase, we show that properdin is required for the development of elastase-induced AAA in its primary role as a convertase stabilizer. Unexpectedly, we find that, in AAA, natural IgG antibodies direct AP-mediated complement activation. The absence of IgG abrogates C3 deposition in elastase-perfused aortic wall and protects animals from AAA development. We also determine that blockade of properdin activity prevents aneurysm formation. These results indicate that an innate immune response to self-antigens activates the complement system and initiates the inflammatory cascade in AAA. Moreover, the study suggests that properdin-targeting strategies may halt aneurysmal growth.

  15. Factors of home dream recall: a structural equation model.

    Science.gov (United States)

    Schredl, Michael; Wittmann, Lutz; Ciric, Petra; Götz, Simon

    2003-06-01

    Previous research has indicated that personality factors such as openness to experience, creativity, visual memory, attitude toward dreams, and sleep behavior is related to home dream recall frequency (DRF). However, a study investigating all areas simultaneously within one sample in order to determine the percentage of variance explained by all variables and to take intercorrelations between the influencing factors into account has not been performed till now. The present study with 444 participants fills this gap. Using several indicators for each of the variables mentioned above, a structural equation model was tested. Although the model fit was satisfying, the four factors which were significantly related to DRF: personality (openness to experience, thin boundaries, absorption), creativity, nocturnal awakenings, and attitude toward dreams, explained only 8.4% of the total variance. As this value is considerably lower than those of studies investigating a single influencing factor and using similar measurement instruments in similar samples, one might speculate about possible expectancy effects in these previous studies, an effect which has been demonstrated for DRF in the laboratory setting. In addition, the small percentage of explained variance of each single factors (inertia) show substantial covariance with the interindividual differences in DRF. Future studies should focus on longitudinal aspects in order to differentiate between state versus trait factors (although methodologic issues, e.g. the effect of the measurement technique on DRF itself, have to be clarified) and investigate additional variables which might be associated with DRF (see above). PMID:12753350

  16. Analysis of Korean Students' International Mobility by 2-D Model: Driving Force Factor and Directional Factor

    Science.gov (United States)

    Park, Elisa L.

    2009-01-01

    The purpose of this study is to understand the dynamics of Korean students' international mobility to study abroad by using the 2-D Model. The first D, "the driving force factor," explains how and what components of the dissatisfaction with domestic higher education perceived by Korean students drives students' outward mobility to seek foreign…

  17. An alternative modeling framework for better interpretation of the observed volcano-hydrothermal system data

    Science.gov (United States)

    Yue, Z. Q. Q.

    2015-12-01

    Many phenomena and data related to volcanoes and volcano eruptions have been observed and collected over the past four hundred years. They have been interpreted with the conventional and widely accepted hypothesis or theory of hot magma fluid from mantle. However, the prediction of volcano eruption sometimes is incorrect. For example, the devastating eruption of the Mount Ontake on Sept. 27, 2014 was not predicted and/or warned at all, which caused 55 fatalities, 9 missing and more than 60 injured. Therefore, there is a need to reconsider the cause and mechanism of active volcano and its hydrothermal system. On the basis of more than 30 year study and research in geology, volcano, earthquake, geomechanics, geophysics, geochemistry and geohazards, the author has developed a new and alternative modeling framework (or hypothesis) to better interpret the observed volcano-hydrothermal system data and to more accurately predict the occurrence of volcano explosion. An active volcano forms a cone-shape mountain and has a crater with vertical pipe conduit to allow hot lava, volcanic ash and gases to escape or erupt from its chamber (Figure). The chamber locates several kilometers below the ground rocks. The active volcanos are caused by highly compressed and dense gases escaped from the Mantle of the Earth. The gases are mainly CH4 and further trapped in the upper crustal rock mass. They make chemical reactions with the surrounding rocks in the chamber. The chemical reactions are the types of reduction and decomposition. The reactions change the gas chemical compounds into steam water gas H2O, CO2, H2S, SO2 and others. The oxygen in the chemical reaction comes from the surrounding rocks. So, the product lava has a less amount of oxygen than that of the surrounding rocks. The gas-rock chemical reactions produce heat. The gas expansion and penetration power and the heat further break and crack the surrounding rock mass and make them into lavas, fragments, ashes or bombs. The

  18. Alternative least square solutions for a two-sex stable population model.

    Science.gov (United States)

    Mitra, S

    1982-01-01

    The effect of minimizing the sum of squares of deviations between births generated by the sex-age specific brithrates of a given period of time and that obtained by adjusting these same rates proportionately so as to maintain a constant sex-ratio at birth at all times is examined. An alternative function is presented, defined in terms of a uniform relative rate of change in the specific rates for all ages for females and another such rate for male counterparts. This model provides unique solutions for the age specific birthrates that also approach stability over time. These changes have been shown to take place in a manner so that the total number of births remain the same with what the reproductive population of both sexes would have given birth to had they experienced an average of the net maternity and net paternity rates. The method outlined in this paper is based on a definition of the problem that is different from those used by the earlier researchers. In the attempt to hold the variations of the net maternity and paternity rates to a minimum, subject to a constant sex-ratio at birth, the authors found the importance of the average of the 2 functions, the net parenthood rates. A few years from the beginning of the process, determined normally by the highest age of the reproductive males, the trajectory of births becomes equivalent to that generated by a situation in which birth cohorts of both sexes are subjected to experience a simple average of the initial net maternity and net paternity rates at all times. While in reality each sex experiences its own set of rates consistent with that of the other sex at any given time, the result in terms of the actual number of births remains the same if each sex has to experience a set of rates obtained by averaging the 2 rates not only at the initial time period but also that at the time in question. PMID:12312902

  19. An alternant method to the traditional NASA hindlimb unloading model in mice.

    Science.gov (United States)

    Ferreira, J Andries; Crissey, Jacqueline M; Brown, Marybeth

    2011-03-10

    The Morey-Holton hindlimb unloading (HU) method is a widely accepted National Aeronautics and Space Administration (NASA) ground-based model for studying disuse-atrophy in rodents. Our study evaluated an alternant method to the gold-standard Morey-Holton HU tail-traction technique in mice. Fifty-four female mice (4-8 mo.) were HU for 14 days (n=34) or 28 days (n=20). Recovery from HU was assessed after 3 days of normal cage ambulation following HU (n=22). Aged matched mice (n=76) served as weight-bearing controls. Prior to HU a tail ring was formed with a 2-0 sterile surgical steel wire that was passed through the 5(th), 6(th), or 7(th) inter-vertebral disc space and shaped into a ring from which the mice were suspended. Vertebral location for the tail-ring was selected to appropriately balance animal body weight without interfering with defecation. We determined the success of this novel HU technique by assessing body weight before and after HU, degree of soleus atrophy, and adrenal mass following HU. Body weight of the mice prior to HU (24.3 ± 2.9g) did not significantly decline immediately after 14d of HU (22.7 ± 1.9g), 28d of HU (21.3 + 2.1g) or after 3 days recovery (24.0 ± 1.8g). Soleus muscle mass significantly declined (-39.1%, and -46.6%) following HU for 14 days and 28 days respectively (pmaintenance of animal body weight, comparable adrenal gland weights, and soleus atrophy following HU, corresponding to expected literature values. The primary advantages of this HU method include: 1) ease of tail examination during suspension; 2) decreased likelihood of cyanotic, inflamed, and/or necrotic tails frequently observed with tail-taping and HU; 3) no possibility of mice chewing the traction tape and coming out of the suspension apparatus; and 4) rapid recovery and normal cage activity immediately after HU.

  20. The latent structure of loneliness: testing competing factor models of the UCLA Loneliness Scale in a large adolescent sample.

    Science.gov (United States)

    Shevlin, Mark; Murphy, Siobhan; Murphy, Jamie

    2015-04-01

    This study assessed the dimensional structure of the UCLA Loneliness Scale ([UCLA-LS], UCLA-3). Data from the Northern Ireland Young Life and Times Survey (2011), a survey of 1,434 16-year-olds, was used to examine the underlying factor structure of the scale. Confirmatory factor analysis was employed to compare alternative factor analytical models that can inform the scoring of the measure and determine the degree to which different factors provided unique predictive utility. Fit statistics indicated that the best fitting model comprised three correlated factors: Isolation, Related Connectedness, and Collective Connectedness. These findings were consistent with previous findings that identified the multidimensional nature of the UCLA-LS. The study also found evidence that the subscales were differentially associated with psychiatric morbidity as measured by the General Health Questionnaire (GHQ-12) and provides a more reliable and comprehensive framework to assess the clinical significance of loneliness.

  1. Linear Factor Models and the Estimation of Expected Returns

    NARCIS (Netherlands)

    Sarisoy, Cisil; de Goeij, Peter; Werker, Bas

    2015-01-01

    Estimating expected returns on individual assets or portfolios is one of the most fundamental problems of finance research. The standard approach, using historical averages,produces noisy estimates. Linear factor models of asset pricing imply a linear relationship between expected returns and exposu

  2. The Five-Factor Model and Self-Determination Theory

    DEFF Research Database (Denmark)

    Olesen, Martin Hammershøj; Thomsen, Dorthe Kirkegaard; Schnieber, Anette;

    This study investigates conceptual overlap vs. distinction between individual differences in personality traits, i.e. the Five-Factor Model; and Self-determination Theory, i.e. general causality orientations. Twelve-hundred-and-eighty-seven freshmen (mean age 21.71; 64% women) completed electronic...

  3. Bayesian Gaussian Copula Factor Models for Mixed Data.

    Science.gov (United States)

    Murray, Jared S; Dunson, David B; Carin, Lawrence; Lucas, Joseph E

    2013-06-01

    Gaussian factor models have proven widely useful for parsimoniously characterizing dependence in multivariate data. There is a rich literature on their extension to mixed categorical and continuous variables, using latent Gaussian variables or through generalized latent trait models acommodating measurements in the exponential family. However, when generalizing to non-Gaussian measured variables the latent variables typically influence both the dependence structure and the form of the marginal distributions, complicating interpretation and introducing artifacts. To address this problem we propose a novel class of Bayesian Gaussian copula factor models which decouple the latent factors from the marginal distributions. A semiparametric specification for the marginals based on the extended rank likelihood yields straightforward implementation and substantial computational gains. We provide new theoretical and empirical justifications for using this likelihood in Bayesian inference. We propose new default priors for the factor loadings and develop efficient parameter-expanded Gibbs sampling for posterior computation. The methods are evaluated through simulations and applied to a dataset in political science. The models in this paper are implemented in the R package bfa.

  4. Bayesian Estimation of Random Coefficient Dynamic Factor Models

    Science.gov (United States)

    Song, Hairong; Ferrer, Emilio

    2012-01-01

    Dynamic factor models (DFMs) have typically been applied to multivariate time series data collected from a single unit of study, such as a single individual or dyad. The goal of DFMs application is to capture dynamics of multivariate systems. When multiple units are available, however, DFMs are not suited to capture variations in dynamics across…

  5. Tests of risk premia in linear factor models

    NARCIS (Netherlands)

    F. Kleibergen

    2009-01-01

    We show that statistical inference on the risk premia in linear factor models that is based on the Fama-MacBeth (FM) and generalized least squares (GLS) two-pass risk premia estimators is misleading when the β’s are small and/or the number of assets is large. We propose novel statistics, that are ba

  6. Tests of risk premia in linear factor models

    NARCIS (Netherlands)

    F.R. Kleibergen

    2005-01-01

    We show that inference on risk premia in linear factor models that is based on the Fama-MacBeth and GLS risk premia estimators is misleading when the ß’s are small and/or the number of assets is large. We propose some novel statistics that remain trustworthy in these cases. The inadequacy of Fama-Ma

  7. Five-Factor Model of Personality and Career Exploration

    Science.gov (United States)

    Reed, Mary Beth; Bruch, Monroe A.; Haase, Richard F.

    2004-01-01

    This study investigates whether the dimensions of the five-factor model (FFM) of personality are related to specific career exploration variables. Based on the FFM, predictions were made about the relevance of particular traits to career exploration variables. Results from a canonical correlation analysis showed that variable loadings on three…

  8. Reproductive Behavior and Personality Traits of the Five Factor Model

    NARCIS (Netherlands)

    Jokela, Markus; Alvergne, Alexandra; Pollet, Thomas V.; Lummaa, Virpi

    2011-01-01

    We examined associations between Five Factor Model personality traits and various outcomes of reproductive behavior in a sample of 15 729 women and men from the Wisconsin Longitudinal Study (WLS) and Midlife Development in the United States (MIDUS) survey. Personality and reproductive history was se

  9. Analogy, an Alternative Model.
 Critics to the standard model of analogical problems solving and proposals for an alternative one

    Directory of Open Access Journals (Sweden)

    Ricardo A. Minervino

    2016-02-01

    Full Text Available The authors made an extension of Hofstadter‘s criticisms against the standard approach in analogical thinking represented by the structure-mapping theory of Gentner and the multiconstraint theory of Holyoak and Thagard. Based on this extension, they proposed a non-serial model of analogical problem solving. Against the standard approach, the model postulates that: (a people detect and evaluate differences between mapped elements before the subprocess of inference generation and consider them in order to control it, and (b properties of an element that explain why the element could fill a certain role in the base problem resolution (PERs play a crucial role in these detection and evaluation operations, and also in post-inferences subprocesses. An experiment showed that: (a people detect and evaluate the relevance of differences between mapped elements before inference generation, (b that they inhibit the generation of literal inferences when they face relevant differences, and (c that they stop the subprocess when they recognize insuperable ones. The results also showed that base PERs are reactivated at different moments of analogical transfer. The data obtained are incompatible with the standard theories of analogical thinking, which treat inference generation as a syntactic mechanism and exclude contextual semantic analysis from the study of analogy. 

  10. The Interpersonal Style Inventory and the five-factor model.

    Science.gov (United States)

    Lorr, M; Youniss, R P; Kluth, C

    1992-03-01

    The study examined relations between the 15 scale scores of the Interpersonal Style Inventory (Lorr & Youniss, 1985) and the domain measures of the five-factor model provided by the NEO Personality Inventory (Costa & McCrae, 1985). A sample of 236 college students were administered both inventories. A principal component analysis of the 5 NEO-PI domain scores and the 15 ISI scale scores followed by a Varimax rotation disclosed the expected five higher-order factors. Four factors, Neuroticism, Extraversion, Conscientiousness and Ageeableness, were defined by both NEO and ISI scales. Openness to Experience, however, was represented in the ISI by Independence and Directiveness, which define its Autonomy dimension. Thus, the ISI measures four of the five factors assessed by the NEO-PI. PMID:1573019

  11. The SAM framework: modeling the effects of management factors on human behavior in risk analysis.

    Science.gov (United States)

    Murphy, D M; Paté-Cornell, M E

    1996-08-01

    Complex engineered systems, such as nuclear reactors and chemical plants, have the potential for catastrophic failure with disastrous consequences. In recent years, human and management factors have been recognized as frequent root causes of major failures in such systems. However, classical probabilistic risk analysis (PRA) techniques do not account for the underlying causes of these errors because they focus on the physical system and do not explicitly address the link between components' performance and organizational factors. This paper describes a general approach for addressing the human and management causes of system failure, called the SAM (System-Action-Management) framework. Beginning with a quantitative risk model of the physical system, SAM expands the scope of analysis to incorporate first the decisions and actions of individuals that affect the physical system. SAM then links management factors (incentives, training, policies and procedures, selection criteria, etc.) to those decisions and actions. The focus of this paper is on four quantitative models of action that describe this last relationship. These models address the formation of intentions for action and their execution as a function of the organizational environment. Intention formation is described by three alternative models: a rational model, a bounded rationality model, and a rule-based model. The execution of intentions is then modeled separately. These four models are designed to assess the probabilities of individual actions from the perspective of management, thus reflecting the uncertainties inherent to human behavior. The SAM framework is illustrated for a hypothetical case of hazardous materials transportation. This framework can be used as a tool to increase the safety and reliability of complex technical systems by modifying the organization, rather than, or in addition to, re-designing the physical system.

  12. Alternate stresses and temperature variation as factors of influence of ultrasonic vibration on mechanical and functional properties of shape memory alloys.

    Science.gov (United States)

    Belyaev, Sergey; Volkov, Alexander; Resnina, Natalia

    2014-01-01

    It is known that the main factors in a variation in the shape memory alloy properties under insonation are heating of the material and alternate stresses action. In the present work the experimental study of the mechanical behaviour and functional properties of shape memory alloy under the action of alternate stresses and varying temperature was carried out. The data obtained had demonstrated that an increase in temperature of the sample resulted in a decrease or increase in deformation stress depending on the structural state of the TiNi sample. It was shown that in the case of the alloy in the martensitic state, a decrease in stress was observed, and on the other hand, in the austenitic state an increase in stress took place. It was found that action of alternate stresses led to appearance of strain jumps on the strain-temperature curves during cooling and heating the sample through the temperature range of martensitic transformation under the constant stress. The value of the strain jumps depended on the amplitude of alternate stresses and the completeness of martensitic transformation. It was shown that the heat action of ultrasonic vibration to the mechanical behaviour of shape memory alloys was due to the non-monotonic dependence of yield stress on the temperature. The force action of ultrasonic vibration to the functional properties was caused by formation of additional oriented martensite.

  13. 3D analytical model for the SOI LDMOS with alternating silicon and high-k dielectric pillars

    Science.gov (United States)

    Yao, Jia-fei; Guo, Yu-feng; Xia, Tian; Zhang, Jun; Lin, Hong

    2016-08-01

    In this paper, a 3D analytical model for the SOI LDMOS with alternating silicon and high-k dielectric pillars (HK LDMOS) is presented. By solving the 3D Poisson's equation, the surface potential and electric field distribution are derived. A criterion for obtaining the optimal breakdown voltage and drift region doping concentration is obtained. The analytical results are well matched with the numerical results, which confirms the model validity. Based on these models and the numerical simulation, the electric field modulation mechanism and the breakdown characteristics of HK LDMOS are investigated.

  14. Effects of Bond Alternation on the Ground-State Phase Diagram of One-Dimensional XXZ Model

    Institute of Scientific and Technical Information of China (English)

    QIANG Ling; LIU Guang-Hua; TIAN Guang-Shan

    2013-01-01

    The ground-state properties and quantum phase transitions (QPTs) of the one-dimensional bond-alternative XXZ model are investigated by the infinite time-evolving block decimation (iTEBD) method.The bond-alternative effects on its ground-state phase diagram are discussed in detail.Once the bond alternation is taken into account,the antiferromagnetic phase (△ > 1) will be destroyed at a given critical point and change into a disordered phase without nonlocal string order.The QPT is shown to be second-order,and the whole phase diagram is provided.For the ferromagnetic phase region (△ <-1),the critical point rc always equals 1 (independent of △),and the QPT for this case is shown to be first-order.The dimerized Heisenberg model is also discussed,and two disordered phases can be distinguished by with or without nonlocal string orders.Both the bipartite entanglement and the fidelity per site,as two kinds of model-independent measures,are capable of describing all the QPTs in such a quantum model.

  15. MODELING AND DESIGN STUDY USING HFC-236EA AS AN ALTERNATIVE REFRIGERANT IN A CENTRIFUGAL COMPRESSOR

    Science.gov (United States)

    The report gives results of an investigation of the operation of a centrifugal compressor--part of a chlorofluorocarbon (CFC)-114 chiller installation--with the new refrigerant hydrofluorocarbon (HFC)-236ea, a proposed alternative to CFC-114. A large set of CFC-236ea operating da...

  16. Input-constrained model predictive control via the alternating direction method of multipliers

    DEFF Research Database (Denmark)

    Sokoler, Leo Emil; Frison, Gianluca; Andersen, Martin S.;

    2014-01-01

    ) with input and input-rate limits. The algorithm alternates between solving an extended LQCP and a highly structured quadratic program. These quadratic programs are solved using a Riccati iteration procedure, and a structure-exploiting interior-point method, respectively. The computational cost per iteration...

  17. Workshop IV – Cosmology-theoretical models/alternative scenarios: A report

    Indian Academy of Sciences (India)

    Asit Banerjee; Reza Tavakol

    2000-10-01

    Due to its subject matter, this workshop included a number of rather disjointed contributions in a number of areas, including exact solutions, mathematical cosmology and alternative theories. We shall therefore give a brief summary of each talk in this section in alphabetical order.

  18. Life Skills Training through Situated Learning Experiences: An Alternative Instructional Model

    Science.gov (United States)

    Meyers, Shelly

    2011-01-01

    This article examines the value of situated learning as an alternative to the traditional college course instructional approach for pre-service teachers. The situated learning mode of teaching immerses students in the actual setting, practicing the skills and concepts emphasized in the curriculum. Through a partnership with a college, community…

  19. Alternative Scheduling Models and Their Effect on Science Achievement at the High School Level

    Science.gov (United States)

    Dostal, Jay Roland

    2010-01-01

    This study will evaluate alternative scheduling methods implemented in secondary level schools. Students were selected based on parent selection of programs. Traditional scheduling involves numerous academic subjects with small increments of time in each class and block scheduling focuses on fewer academic subjects and more instructional time.…

  20. Free-free Gaunt factors: comparison of various models

    International Nuclear Information System (INIS)

    We develop the general theory of free-free absorption processes in terms of basic quantum mechanical principles. We perform calculations of the free-free Gaunt factor for several models of the electron-atom (ion) interaction in a variety of systems including rare gases, alkali, and aluminum. In addition, we investigate plasma-screening effects in such models as the Yukawa potential. Our calculations compare well with those of other authors, and our comparative study of various models allows a more thorough understanding of their range of validity. 38 refs., 2 figs., 14 tabs

  1. Free-free Gaunt factors: comparison of various models

    Energy Technology Data Exchange (ETDEWEB)

    Collins, L.A.; Merts, A.L.

    1986-01-01

    We develop the general theory of free-free absorption processes in terms of basic quantum mechanical principles. We perform calculations of the free-free Gaunt factor for several models of the electron-atom (ion) interaction in a variety of systems including rare gases, alkali, and aluminum. In addition, we investigate plasma-screening effects in such models as the Yukawa potential. Our calculations compare well with those of other authors, and our comparative study of various models allows a more thorough understanding of their range of validity. 38 refs., 2 figs., 14 tabs.

  2. Modeling impacts of management alternatives on soil carbon storage of farmland in Northwest China

    Directory of Open Access Journals (Sweden)

    F. Zhang

    2006-05-01

    Full Text Available Long-term losses of soil organic carbon (SOC have been observed in many agriculture lands in Northwest China, one of the regions with the longest cultivation history in the world. The decline of SOC contents not only impaired the soil fertility but also increased the amount of carbon dioxide (CO2 emitted from terrestrial ecosystems into the atmosphere. However, quantifying the SOC losses at regional scale has long been remaining unsolved. A process-based model, Denitrification-Decomposition or DNDC, was adopted in the study to quantify impacts of farming management practices on SOC dynamics for a selected region, Shaanxi Province. The selected domain, with 3 million hectares of cropland across different climatic and farming management regimes, is representative for the major agricultural areas in Northwest China. The DNDC model was tested against long-term SOC dynamics observed at five agricultural sites in China. The agreement between the observed and modeled results indicate that DNDC was capable of capturing patterns and magnitudes of SOC changes across the climate zones, soil types, and management regimes in China. To quantify SOC dynamics for Shaanxi, we constructed a GIS database to hold all of the DNDC-required input information (e.g., weather, soil properties, crop acreage, and farming practices for all the farmland in the studied domain. Sensitivity tests indicated the spatial heterogeneity of soil properties, especially initial SOC content, was the major source of uncertainty for the modeled SOC dynamics at regional scale. The Most Sensitive Factor (MSF method was employed in the study to quantify the uncertainties produced from the upscaling process. The results from the regional simulations for Shaanxi indicated that (1 the overall 3 million hectares of farmland in the province was a source of atmospheric CO2 with 0.5 Tg C yr−1 lost in 2000 under the current farming

  3. Two Empirical Models for Land-falling Hurricane Gust Factors

    Science.gov (United States)

    Merceret, Franics J.

    2008-01-01

    Gaussian and lognormal models for gust factors as a function of height and mean windspeed in land-falling hurricanes are presented. The models were empirically derived using data from 2004 hurricanes Frances and Jeanne and independently verified using data from 2005 hurricane Wilma. The data were collected from three wind towers at Kennedy Space Center and Cape Canaveral Air Force Station with instrumentation at multiple levels from 12 to 500 feet above ground level. An additional 200-foot tower was available for the verification. Mean wind speeds from 15 to 60 knots were included in the data. The models provide formulas for the mean and standard deviation of the gust factor given the mean windspeed and height above ground. These statistics may then be used to assess the probability of exceeding a specified peak wind threshold of operational significance given a specified mean wind speed.

  4. Multi-factor energy price models and exotic derivatives pricing

    Science.gov (United States)

    Hikspoors, Samuel

    The high pace at which many of the world's energy markets have gradually been opened to competition have generated a significant amount of new financial activity. Both academicians and practitioners alike recently started to develop the tools of energy derivatives pricing/hedging as a quantitative topic of its own. The energy contract structures as well as their underlying asset properties set the energy risk management industry apart from its more standard equity and fixed income counterparts. This thesis naturally contributes to these broad market developments in participating to the advances of the mathematical tools aiming at a better theory of energy contingent claim pricing/hedging. We propose many realistic two-factor and three-factor models for spot and forward price processes that generalize some well known and standard modeling assumptions. We develop the associated pricing methodologies and propose stable calibration algorithms that motivate the application of the relevant modeling schemes.

  5. Alternative security

    International Nuclear Information System (INIS)

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview

  6. Self-pathology, the five-factor model, and bloated specific factors: A cautionary tale.

    Science.gov (United States)

    Oltmanns, Joshua R; Widiger, Thomas A

    2016-04-01

    The five-factor model (FFM) is widely regarded as a useful model for the structure of both normal and maladaptive personality traits. However, recent factor analytic studies have suggested that deficits in the sense of self fall outside the FFM. The current study replicates and extends these findings, illustrating that factors can be situated outside a higher-order domain by including a relatively large number of closely related scales, forming what is known as a bloated specific factor. A total of 1,553 participants (M age = 37.8 years, SD = 13.1) were recruited across 3 studies. One measure of self-pathology (including 15 scales) and 2 measures of the FFM were administered, along with 17 measures of anxiousness and 12 measures of social withdrawal/sociability. Across 2 independent samples and 2 different measures of the FFM, deficits in the sense of self separated from neuroticism when all 15 scales of self-pathology were included. However, self-pathology loaded with FFM neuroticism when only a subset of the self-pathology scales was included. This finding was replicated with measures of social withdrawal/sociability, although only partially replicated with measures of anxiousness. Implications of these findings for past and future factor analytic studies of the structure of psychopathology are discussed.

  7. Self-pathology, the five-factor model, and bloated specific factors: A cautionary tale.

    Science.gov (United States)

    Oltmanns, Joshua R; Widiger, Thomas A

    2016-04-01

    The five-factor model (FFM) is widely regarded as a useful model for the structure of both normal and maladaptive personality traits. However, recent factor analytic studies have suggested that deficits in the sense of self fall outside the FFM. The current study replicates and extends these findings, illustrating that factors can be situated outside a higher-order domain by including a relatively large number of closely related scales, forming what is known as a bloated specific factor. A total of 1,553 participants (M age = 37.8 years, SD = 13.1) were recruited across 3 studies. One measure of self-pathology (including 15 scales) and 2 measures of the FFM were administered, along with 17 measures of anxiousness and 12 measures of social withdrawal/sociability. Across 2 independent samples and 2 different measures of the FFM, deficits in the sense of self separated from neuroticism when all 15 scales of self-pathology were included. However, self-pathology loaded with FFM neuroticism when only a subset of the self-pathology scales was included. This finding was replicated with measures of social withdrawal/sociability, although only partially replicated with measures of anxiousness. Implications of these findings for past and future factor analytic studies of the structure of psychopathology are discussed. PMID:26845254

  8. The development of an in vitro model for studying mechanisms of nephrotoxicity as an alternative for animal experiments.

    OpenAIRE

    Mertens, J.J.W.M.

    1991-01-01

    SUMMARYPresently in our society animal tests still form the main starting point for the assessment of the possible risks of chemicals with regard to human and animal health. For scientific. economic, and ethical reasons. attempts are undertaken continuously to develop cell models as alternatives to animal testing. However, the predictive value of in vitro test systems is often limited due to the unawareness about the mechanisms of toxicity and the complexity of organisms. As a consequence, a ...

  9. Form factor approach to dynamical correlation functions in critical models

    CERN Document Server

    Kitanine, N; Maillet, J M; Slavnov, N A; Terras, V

    2012-01-01

    We develop a form factor approach to the study of dynamical correlation functions of quantum integrable models in the critical regime. As an example, we consider the quantum non-linear Schr\\"odinger model. We derive long-distance/long-time asymptotic behavior of various two-point functions of this model. We also compute edge exponents and amplitudes characterizing the power-law behavior of dynamical response functions on the particle/hole excitation thresholds. These last results confirm predictions based on the non-linear Luttinger liquid method. Our results rely on a first principles derivation, based on the microscopic analysis of the model, without invoking, at any stage, some correspondence with a continuous field theory. Furthermore, our approach only makes use of certain general properties of the model, so that it should be applicable, with possibly minor modifications, to a wide class of (not necessarily integrable) gapless one dimensional Hamiltonians.

  10. An Alternative Model of Music Learning and "Last Night's Fun": Participatory Music Making In/As Participatory Culture in Irish Traditional Music

    Science.gov (United States)

    Waldron, Janice

    2016-01-01

    Exploring emergent music learning and teaching models facilitated by global Web access can reveal alternative music education practices and delivery systems not seen in "traditional" conservatories and schools. One example of an alternative music learning model comes from the Online Academy of Irish Music (OAIM), a community music…

  11. Chronic gastritis rat model and role of inducing factors

    Institute of Scientific and Technical Information of China (English)

    Zun Xiang; Jian-Min Si; Huai-De Huang

    2004-01-01

    AIM: To establish an experimental animal model of chronic gastritis in a short term and to investigate the effects of several potential inflammation-inducing factors on rat gastric mucosa.METHODS: Twenty-four healthy, male SD rats were treated with intragastric administration of 600 mL/L alcohol, 20mmol/L sodium deoxycholate and 0.5 g/L ammonia (factor A), forage containing low levels of vitamins (factor B), and/or indomethacin (factor C), according to an L8(27)orthogonal design. After 12 wk, gastric antral and body mucosae were pathologically examined.RESULTS: Chronic gastritis model was successfully induced in rats treated with factor A for 12 wk. After the treatment of animals, the gastric mucosal inflammation was significantly different from that in controls, and the number of pyloric glands at antrum and parietal cells at body were obviously reduced (P<0.01). Indomethacin induced gastritis but without atrophy, and short-term vitamin deficiency failed to induce chronic gastritis and gastric atrophy, In addition,indomethacin and vitamin deficiency had no synergistic effect in inducing gastritis with the factor A. No atypical hyperplasia and intestinal metaplasia in the gastric antrum and body were observed in all rats studied.CONCLUSION: Combined intragastric administration of 600 mL/L alcohol, 20 mmol/L sodium deoxycholate and 0.5 g/L ammonia induces chronic gastritis and gastric atrophy in rats. Indomethacin induces chronic gastritis only.The long-term roles of these factors in gastric inflammation and carcinogenesis need to be further elucidated.

  12. Replicating hedge fund returns: A factor model approach

    OpenAIRE

    Naser, Omar

    2007-01-01

    Growth in the Hedge Fund industry mirrors the growth in the Mutual Fund industry. This raises the possibility of creating a passive strategy that replicates Hedge Fund returns at lower cost using liquid, exchange-traded instruments. Using monthly returns for the period 1991-2005 on thirteen Hedge Fund strategies, I build a linear factor models (“clones”) that replicate Hedge Fund returns. I use six common factors to determine the amount of expected return and variation in returns that can be ...

  13. Cluster analysis in kinetic modelling of the brain: A noninvasive alternative to arterial sampling

    DEFF Research Database (Denmark)

    Liptrot, Matthew George; Adams, K.H.; Martiny, L.;

    2004-01-01

    In emission tomography, quantification of brain tracer uptake, metabolism or binding requires knowledge of the cerebral input function. Traditionally, this is achieved with arterial blood sampling. We propose a noninvasive alternative via the use of a blood vessel time-activity curve (TAC......) extracted directly from dynamic positron emission tomography (PET) scans by cluster analysis. Five healthy subjects were injected with the 5HT2A- receptor ligand [18F]-altanserin and blood samples were subsequently taken from the radial artery and cubital vein. Eight regions-of-interest (ROI) TACs were...... by the 'within-variance' measure and by 3D visual inspection of the homogeneity of the determined clusters. The cluster-determined input curve was then used in Logan plot analysis and compared with the arterial and venous blood samples, and additionally with one of the currently used alternatives to arterial...

  14. Mental Accounting: A Closed-Form Alternative to the Black Scholes Model

    OpenAIRE

    Siddiqi, Hammad

    2013-01-01

    The principle of no arbitrage says that identical assets should offer the same returns. However, experimental and anecdotal evidence suggests that people often rely on analogy making while valuing assets. The principle of analogy making says that similar assets should offer the same returns. I show that the principle of analogy making generates a closed-form alternative to the Black Scholes formula that does not require a complete market. The new formula differs from the Black Scholes formula...

  15. MODELLING ECONOMIC ALTERNATIVES FOR TOBACCO PRODUCERS: THE CASE OF SHEEP FARMING

    OpenAIRE

    Tzouramani, Irene; Karanikolas, Pavlos; Alexopoulos, George; Sintori, Alexandra; Liontakis, Angelos E.

    2008-01-01

    After the introduction of the new tobacco regime, many regions in Greece, formerly specialized in tobacco cultivation, are now facing serious threats of economic and social decline. Sheep farming is considered by many analysts as a viable alternative to tobacco. This study analyses the financial performance of sheep production and the risk that producers are taking. Through a stochastic efficiency analysis with respect to a function we explore the economic viability of conventional and organi...

  16. Influence of models and scales on the ranking of multiattribute alternatives

    Directory of Open Access Journals (Sweden)

    Helen M. Moshkovich

    2012-12-01

    Full Text Available This paper presents an application of three multiple criteria methods to determining rank of residential real estate options. Methods SAW and TODIM are based on eliciting the decision maker's preferences (weights and values directly in a quantitative form while using linear (SAW and non-linear (TODIM aggregation functions for alternatives' evaluation. ZAPROS seeks and uses preferences in an ordinal form as an indirect comparison of trade-offs between criteria. Advantages and disadvantages of different approaches are discussed.

  17. Studying Effective Factors on Corporate Entrepreneurship: Representing a Model

    Directory of Open Access Journals (Sweden)

    Maryam Soleimani

    2013-02-01

    Full Text Available Development and advancement of current organizations depends on Corporate Entrepreneurship (CE and its anticipants considerably. Therefore purpose of conducting this survey is to study effective factors on corporate entrepreneurship (personal characteristics of entrepreneurship, human resource practices, organizational culture and employees' satisfaction. This survey was conducted using descriptive-field methodology. Statistical population included managers and experts of Hexa Consulting Engineers Company (Tehran/Iran and the sample consisted of forty seven of them. Questionnaire was tool of data collection. Data was collected in cross-sectional form in July-August 2011. Descriptive and inferential (spearman correlation statistics methods were used for data analysis. According to results, there is a positive significant relationship among all factors (personal characteristics of entrepreneurship, human resource practices, organizational culture and employees' satisfaction and corporate entrepreneurship. In other words, the proposed variables as effective factors on corporate entrepreneurship were confirmed in conceptual model of survey.

  18. Proposition Factor Model of World Class Manufacturing in Brazilian Enterprises

    Directory of Open Access Journals (Sweden)

    Paulo Sergio Gonçalves de Oliveira

    2016-05-01

    Full Text Available The present paper aims to develop a model of World Class Manufacturing, to achieve this goal was elaborated a questionnaire with 35 assertive divided in 7 areas suggested by literature review. This questionnaire was send to manufacture specialists, product developers and technician through LinkedIn the participants was select by researchers in discussion groups taking in consideration their experience using the professional profile. About 1000 invite was send to professional from metal-mechanic sector which returned 180 valid questionnaires. The data was analyzed through factor analyses and was obtained 7 constructs, which explained 67% of data variance. The KMO was 0,84, which is considered good for, analyzes purpose. The seventh factor was eliminated because it Cranach’s Alpha was below 0,6 and the remained factor was nominated as: Lean Manufacturing, Human Resources Management to achieve flexibility, Marketing Integration, Costs Reduction and Flexibility.

  19. World Urbanization Prospects: an alternative to the UN model of projection compatible with the mobility transition theory

    Directory of Open Access Journals (Sweden)

    Philippe Bocquier

    2005-05-01

    Full Text Available This paper proposes to critically examine the United Nations projections on urbanisation. Both the estimates of current trends based on national data and the method of projection are evaluated. The theory of mobility transition is used as an alternative hypothesis. Projections are proposed using a polynomial model and compared to the UN projections, which are based on a linear model. The conclusion is that UN projections may overestimate the urban population for the year 2030 by almost one billion, or 19% in relative term. The overestimation would be particularly more pronounced for developing countries and may exceed 30% in Africa, India and Oceania.

  20. Alternative energies; Energies alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Bonal, J.; Rossetti, P

    2007-07-01

    The earth took millions years to made the petroleum, the gas the coal and the uranium. Only a few centuries will be needed to exhaust these fossil fuels and some years to reach expensive prices. Will the wold continue on this way of energy compulsive consumption? The renewable energies and some citizen attitudes are sufficient to break this spiral. This book proposes to discuss these alternative energies. It shows that this attitude must be supported by the government. It takes stock on the more recent information concerning the renewable energies. it develops three main points: the electricity storage, the housing and the transports. (A.L.B.)

  1. BEGA Starter/Alternator - Vector Control Implementation and Performance for Wide Speed Range at Unity Power Factor Operation

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Boldea, Ion; Coroban-Schramel, Vasile;

    2008-01-01

    to infinite. A vector control structure is proposed for BEGA operation during motoring and generating, at unity power factor with zero d-axis current (id) and zero q-axis flux (Ψq) control. In such conditions BEGA behaves like a truly dc. brush machine (with zero reactance in steady state !). A high iq...... current is required in order to cancel the q-axis flux, during unity power factor operation. This engages higher copper losses in the machine. In order to minimize the copper losses, for lower load levels, a current referencer is proposed. Due to higher dc field excitation time constant, the dc field...

  2. Are the symptoms of cannabis use disorder best accounted for by dimensional, categorical, or factor mixture models? A comparison of male and female young adults

    OpenAIRE

    Gillespie, Nathan A; Neale, Michael C.; Legrand, Lisa N.; Iacono, William G.; McGue, Matt

    2011-01-01

    Despite the consensus that criteria for cannabis abuse and dependence and symptoms of withdrawal are best explained by a single latent liability, it remains unknown whether alternate models provide a better explanation of these criteria. A series of latent factor, latent class and hybrid factor mixture models were fitted to data from 872 recent cannabis users from the Minnesota Twin Family Study who completed DSM-III-R and DSM-IV diagnostic criteria for cannabis abuse, dependence and symptoms...

  3. The FIRO model of family therapy: implications of factor analysis.

    Science.gov (United States)

    Hafner, R J; Ross, M W

    1989-11-01

    Schutz's FIRO model contains three main elements: inclusion, control, and affection. It is used widely in mental health research and practice, but has received little empirical validation. The present study is based on factor analysis of the resources to FIRO questionnaire of 120 normal couples and 191 couples who were attending a clinic for marital/psychiatric problems. Results confirmed the validity of the FIRO model for women only. The differences between the sexes reflected a considerable degree of sex-role stereotyping, the clinical implications of which are discussed.

  4. Baryon octet electromagnetic form factors in a confining NJL model

    Science.gov (United States)

    Carrillo-Serrano, Manuel E.; Bentz, Wolfgang; Cloët, Ian C.; Thomas, Anthony W.

    2016-08-01

    Electromagnetic form factors of the baryon octet are studied using a Nambu-Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp based on the dressed quark masses.

  5. One numerical procedure for two risk factors modeling

    OpenAIRE

    Cocozza, Rosa; De Simone, Antonio

    2011-01-01

    We propose a numerical procedure for the pricing of financial contracts whose contingent claims are exposed to two sources of risk: the stock price and the short interest rate. More precisely, in our pricing framework we assume that the stock price dynamics is described by the Cox, Ross Rubinstein (CRR, 1979) binomial model under a stochastic risk free rate, whose dynamics evolves over time accordingly to the Black, Derman and Toy (BDT, 1990) one-factor model. To this aim, we set the hypothes...

  6. Baryon octet electromagnetic form factors in a confining NJL model

    Science.gov (United States)

    Carrillo-Serrano, Manuel E.; Bentz, Wolfgang; Cloët, Ian C.; Thomas, Anthony W.

    2016-08-01

    Electromagnetic form factors of the baryon octet are studied using a Nambu-Jona-Lasinio model which utilizes the proper-time regularization scheme to simulate aspects of colour confinement. In addition, the model also incorporates corrections to the dressed quarks from vector meson correlations in the t-channel and the pion cloud. Comparison with recent chiral extrapolations of lattice QCD results shows a remarkable level of consistency. For the charge radii we find the surprising result that rEp quark masses.

  7. Factor models on locally tree-like graphs

    CERN Document Server

    Dembo, Amir; Sun, Nike

    2011-01-01

    We consider homogeneous factor models on uniformly sparse graph sequences converging locally to a (unimodular) random tree T, and study the existence of the free energy density phi, the limit of the log-partition function divided by the number of vertices n as n tends to infinity. We provide a new interpolation scheme and use it to prove existence of, and to explicitly compute, the quantity phi subject to uniqueness of a relevant Gibbs measure for the factor model on T. By way of example we compute phi for the independent set (or hard-core) model at low fugacity, for the ferromagnetic Ising model at all parameter values, and for the ferromagnetic Potts model with both weak enough and strong enough interactions. Even beyond uniqueness our interpolation provides useful explicit bounds on phi. In the regimes in which we establish existence of the limit, we show that it coincides with the Bethe free energy functional evaluated at a suitable fixed point of the belief propagation recursions on T. In the special cas...

  8. Modeling impact of environmental factors on photovoltaic array performance

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jie; Sun, Yize; Xu, Yang [College of Mechanical Engineering, Donghua University NO.2999, North Renmin Road, Shanghai (China)

    2013-07-01

    It is represented in this paper that a methodology to model and quantify the impact of the three environmental factors, the ambient temperature, the incident irradiance and the wind speed, upon the performance of photovoltaic array operating under outdoor conditions. First, A simple correlation correlating operating temperature with the three environmental variables is validated for a range of wind speed studied, 2-8, and for irradiance values between 200 and 1000. Root mean square error (RMSE) between modeled operating temperature and measured values is 1.19% and the mean bias error (MBE) is -0.09%. The environmental factors studied influence I-V curves, P-V curves, and maximum-power outputs of photovoltaic array. The cell-to-module-to-array mathematical model for photovoltaic panels is established in this paper and the method defined as segmented iteration is adopted to solve the I-V curve expression to relate model I-V curves. The model I-V curves and P-V curves are concluded to coincide well with measured data points. The RMSE between numerically calculated maximum-power outputs and experimentally measured ones is 0.2307%, while the MBE is 0.0183%. In addition, a multivariable non-linear regression equation is proposed to eliminate the difference between numerically calculated values and measured ones of maximum power outputs over the range of high ambient temperature and irradiance at noon and in the early afternoon. In conclusion, the proposed method is reasonably simple and accurate.

  9. On the Univariate Representation of BEKK Models with Common Factors

    OpenAIRE

    Hecq, A.W.; Palm, F.C.; Laurent, S.F.J.A.

    2012-01-01

    First, we investigate the minimal order univariate representation of some well known n-dimensionalconditional volatility models. Even simple low order systems (e.g. a multivariate GARCH(0,1)) forthe joint behavior of several variables imply individual processes with a lot of persistence inthe form of high order lags. However, we show that in the presence of common GARCH factors,parsimonious univariate representations (e.g. GARCH(1,1)) can result from large multivariatemodels generating the co...

  10. CAPACITY FACTOR BASED COST MODELS FOR BUILDINGS OF VARIOUS FUNCTIONS

    OpenAIRE

    Andreas Wibowo; Wahyu Wuryanti

    2007-01-01

    The desired accuracy level of an estimate heavily relies on the availability of data and information at the time of preparing the estimate. However, an estimate often must be made when data and information are not complete. At earlier stages of project implementation at which data and information are minimal, a client is often required to prepare a cost estimate. This paper discusses the capacity factor-based cost models for buildings with total areas serving as the proxy of capacity. A total...

  11. Positive Orientation and the Five-Factor Model

    OpenAIRE

    Miciuk Łukasz Roland; Jankowski Tomasz; Laskowska Agnieszka; Oleś Piotr

    2016-01-01

    The aim of the present study was to investigate the relationship between positive orientation (PO) defined as a basic predisposition to perceive and evaluate positive aspects of life, the future and oneself and the Five-Factor Model of personality (FFM). Hypotheses postulated positive correlations between PO and extraversion, conscientiousness, agreeableness and openness; a negative correlation was predicted between PO and neuroticism. Two hundred Polish students completed the following measu...

  12. Modelling the presence and identifying the determinant factors of dominant macroinvertebrate taxa in a karst river.

    Science.gov (United States)

    Lin, Yuqing; Chen, Qiuwen; Chen, Kai; Yang, Qingrui

    2016-06-01

    Modelling the macroinvertebrate community is important for evaluating the status of aquatic ecosystem health. Alternative to physical-based approaches, this study proposed two data-driven methods, support vector machine (SVM) and artificial neural network (ANN), to model the presence of macroinvertebrate species in rivers based on abiotic features. A famous karst river, Lijiang River, in Southwest China was selected as the study case. A total of 300 records containing data on 11 physicochemical parameters were collected from the upstream, midstream and downstream reaches of the river over a 2-year period (2009-2010) and were used for model construction and verification. Ten dominant macroinvertebrate taxa in the study area were modelled. In addition, the performance of the two methods was compared, and the relative importance of the independent variables was identified. The obtained results mapped abiotic factors to the species presence and could be used in combination with a two-dimensional hydro-environmental model to assess the impacts of flow regulation on macroinvertebrate dynamics. Furthermore, the SVM model performed slightly better than the ANN model in the studied case. PMID:27138003

  13. Establishment and Optimization of Rigorous Geometric Model of Push-broom Camera Using TDI CCD Arranged in an Alternating Pattern

    Directory of Open Access Journals (Sweden)

    MENG Weican

    2015-12-01

    Full Text Available Push-broom cameras using TDI CCD arranged in an alternating pattern are widely carried by typical high-resolution optical satellites in order to obtain high space resolution and enough strip width. For this kind of cameras, several TDI CCD are arranged in an alternating pattern in two lines on the focal plane and push-broom imaging mode is always adopted. Imaging principle and characteristic of this kind of camera is introduced. Exterior parameters of TDI CCD are modeled together based on their same values in any instant of time and an integrated geometric model is finally established. Error compensation methods are designed to remove exterior error and interior error based on this integrated geometric model. A series of tests are designed to verify models and methods proposed in this paper using original image of TH-1 Satellite HR Camera whose detectors are divided into 8 modules arranged in an alternating pattern. As the results, the imaging geometry of this kind of camera can be rigorously described by this integral geometrical model. The positioning accuracy can be obviously improved by our exterior error compensation method, however, different residual error would be remained for different TDI CCD. The positioning accuracy will not be obviously improved while systematic errors of different TDI CCD can be effectively removed by the interior error compensation method. 2 m positioning accuracy in X, Y and Z directions can be achieved and different systematic errors can be removed when both exterior and interior error were compensated. The same accuracy can be achieved in the other scenes when the calculated inner distortion parameters are adopted.

  14. Alternative modelling of brittle structures in a sub-area of the SKB candidate area at Forsmark, eastern Sweden.

    Energy Technology Data Exchange (ETDEWEB)

    Askling, Per; Tiren, Sven A.; Beckholmen, Monica; Straeng, Thomas (Geosigma AB, Uppsala (Sweden))

    2008-11-15

    One way to test the confidence of a presented model is to construct an alternative model. Such work is cognitive process of skill acquisition and also a process of understanding data in the sense of sorting and classifying data. This is of particular interest for the Swedish Radiation Safety Authority (SSM) in their technical review of SKB's on-going site investigation programme for potential repository sites. In this study, an alternative brittle deformation model of a selected part of the SKB candidate area in eastern Sweden was constructed. The input data set was obtained from SKB's database SICADA and is a selected set of data from five cored boreholes drilled from two drill-sites and comprises geophysical borehole logs, geological core-logs, hydrological logs (PFL; Posiva Flow Log) and borehole deviation measurements. Statistical cluster analysis applied on the geophysical borehole data were used to obtain the locations of bedrock with contrasting physical characteristics similar to those of brittle deformation zones. The cluster analysis is an objective procedure, contrasting with SKB's more subjective approach to the single-hole interpretation. Thus some differences are expected which could illustrate the effect of methodology that includes subjective 'expert judgement.' and indicate the possibility of alternative interpretations. The information about brittle structures in the geological boreholes logs was sorted and classification was made according to character of the structures (all fractures, open fractures, partly open fractures, frequency, orientate on/identification of fracture sets, sections of crush rock, and alteration). A separate study was performed to relate rock alteration with structures. The resolution applied in the fracture statistics is one metre, i.e. all studied entities were expressed per metre borehole length. All clusters were structurally characterized by the fractures inside the clusters (orientation and

  15. INNOVATIVE PRACTICES IN TOURISM. APOSSIBLE MODEL BY FOSTERING SHADOW FACTORS

    Directory of Open Access Journals (Sweden)

    Ada Mirela TOMESCU

    2015-08-01

    Full Text Available The paper is the result of an empirical research, a study that includes a theoretical framework. The data used to test our hypotheses come from 60 small tourism firms from Bihor County, Romania. The research conducted has revealed that actions focusing on innovation must be based on a solid analysis, supported by the knowledge and the understanding of the contextual factors (environment, culture as a mental programming, values also based on the organizational factors (the management commitment, systemic perspective, learning and practice of experimentation, rapid transfer of knowledge within the organization. For the purpose of this work, the contextual factors that are exogenous represent the shadow factors. The studies performed in three European projects implemented in tourism SMEs of Bihor County have allowed us to advance the idea that contextual and organizational factors, that are identified as the source of innovation are based on rationality, which is enlarged by affectivity and imagination. The identified correlations may be considered, in our opinion an element of novelty and originality. Finally, the purpose of this paper is to provide a possible model, based on the idea of building an innovative firm, the one that has learned how to determine their own employees to be innovative. O03, L2, L26

  16. Testing alternative conceptual models of seawater intrusion in a coastal aquifer using computer simulation, southern California, USA

    Science.gov (United States)

    Nishikawa, T.

    1997-01-01

    Two alternative conceptual models of the physical processes controlling seawater intrusion in a coastal basin in California, USA, were tested to identify a likely principal pathway for seawater intrusion. The conceptual models were tested by using a two-dimensional, finite-element groundwater flow and transport model. This pathway was identified by the conceptual model that best replicated the historical data. The numerical model was applied in cross section to a submarine canyon that is a main avenue for seawater to enter the aquifer system underlying the study area. Both models are characterized by a heterogeneous, layered, water-bearing aquifer. However, the first model is characterized by flat-lying aquifer layers and by a high value of hydraulic conductivity in the basal aquifer layer, which is thought to be a principal conduit for seawater intrusion. The second model is characterized by offshore folding, which was modeled as a very nearshore outcrop, thereby providing a shorter path for seawater to intrude. General conclusions are that: 1) the aquifer system is best modeled as a flat, heterogeneous, layered system; 2) relatively thin basal layers with relatively high values of hydraulic conductivity are the principal pathways for seawater intrusion; and 3) continuous clay layers of low hydraulic conductivity play an important role in controlling the movement of seawater.

  17. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  18. Characterization of a shortened model of diet alternation in female rats: effects of the CB1 receptor antagonist rimonabant on food intake and anxiety-like behavior.

    Science.gov (United States)

    Blasio, Angelo; Rice, Kenner C; Sabino, Valentina; Cottone, Pietro

    2014-10-01

    The prevalence of eating disorders and obesity in western societies is epidemic and increasing in severity. Preclinical research has focused on the development of animal models that can mimic the maladaptive patterns of food intake observed in certain forms of eating disorders and obesity. This study was aimed at characterizing a recently established model of palatable diet alternation in female rats. For this purpose, females rats were fed either continuously with a regular chow diet (Chow/Chow) or intermittently with a regular chow diet for 2 days and a palatable, high-sucrose diet for 1 day (Chow/Palatable). Following diet cycling, rats were administered rimonabant (0, 0.3, 1, 3 mg/kg intraperitoneally) during access to either palatable diet or chow diet and were assessed for food intake and body weight. Finally, rats were pretreated with rimonabant (0, 3 mg/kg, intraperitoneally) and tested in the elevated plus maze during withdrawal from the palatable diet. Female rats with alternating access to palatable food cycled their intake, overeating during access to the palatable diet and undereating upon returning to the regular chow diet. Rimonabant treatment resulted in increased chow hypophagia and anxiety-like behavior in Chow/Palatable rats. No effect of drug treatment was observed on the compulsive eating of palatable food in the diet-cycled rats. The results of this study suggest that withdrawal from alternating access to the palatable diet makes individuals vulnerable to the anxiogenic effects of rimonabant and provides etiological factors potentially responsible for the emergence of severe psychiatric side-effects following rimonabant treatment in obese patients. PMID:25011007

  19. Evaluating indoor exposure modeling alternatives for LCA: A case study in the vehicle repair industry

    Energy Technology Data Exchange (ETDEWEB)

    Demou, Evangelia; Hellweg, Stefanie; Wilson, Michael P.; Hammond, S. Katharine; McKone, Thomas E.

    2009-05-01

    We evaluated three exposure models with data obtained from measurements among workers who use"aerosol" solvent products in the vehicle repair industry and with field experiments using these products to simulate the same exposure conditions. The three exposure models were the: 1) homogeneously-mixed-one-box model, 2) multi-zone model, and 3) eddy-diffusion model. Temporally differentiated real-time breathing zone volatile organic compound (VOC) concentration measurements, integrated far-field area samples, and simulated experiments were used in estimating parameters, such as emission rates, diffusivity, and near-field dimensions. We assessed differences in model input requirements and their efficacy for predictive modeling. The One-box model was not able to resemble the temporal profile of exposure concentrations, but it performed well concerning time-weighted exposure over extended time periods. However, this model required an adjustment for spatial concentration gradients. Multi-zone models and diffusion-models may solve this problem. However, we found that the reliable use of both these models requires extensive field data to appropriately define pivotal parameters such as diffusivity or near-field dimensions. We conclude that it is difficult to apply these models for predicting VOC exposures in the workplace. However, for comparative exposure scenarios in life-cycle assessment they may be useful.

  20. Modeling Employees' Perceptions and Proportional Preferences of Work Locations: The Regular Workplace and Telecommuting Alternatives

    OpenAIRE

    Mokhtarian, Patricia; Bagley, Michael

    2000-01-01

    This paper develops measures of job and workplace perceptions, and examines the importance of those and other measures to the desired proportions of work time at each of three locations: regular workplace, home, and telecommuting center. Using data from 188 participants in the Neighborhood Telecenters Project, four job context perception factors were identified: productivity, job satisfaction, supervisor relationship, and co-worker interaction. Four generic workplace perception factors were i...

  1. An Alternative Interacting Boson Model Description of The N = 90 Nuclei

    Institute of Scientific and Technical Information of China (English)

    DAI Lian-Rong; TENG Wei-Xin; PAN Feng; WANG Sheng-Hua

    2011-01-01

    The SU(3) quadrupole-quadrupole interaction is replaced by the SO(6) cubic [Q(0) × Q(0) × Q(0)]0 interaction in fitting energy levels, some energy ratios and B(E2) ratios. It is shown that the alternative scheme can indeed be used to describe properties of the X(5) nuclei, for example, 150Nd, 152Sm, 154Gd. The results of the new scheme are compared with the corresponding experimental data and with those of the traditional U ( 5 )-SU ( 3 )transitional description. It is clearly shown that the results are better than those obtained from the traditional U ( 5)-SU (3) transitional description.%@@ The SU(3) quadrupole-quadrupole interaction is replaced by the SO(6) cubic[Q(0) × Q(0) × Q(0)]0 interaction in fitting energy levels,some energy ratios and B(E2) ratios.It is shown that the alternative scheme can indeed be used to describe properties of the X(5) nuclei,for example,150Nd,152Sm,154Gd.The results of the new scheme are compared with the corresponding experimental data and with those of the traditional U( 5 )-SU(3)transitional description.It is clearly shown that the results are better than those obtained from the traditional U( 5)-SU(3) transitional description.

  2. Opinion dynamics with confidence threshold: an alternative to the Axelrod model

    CERN Document Server

    Lanchier, Nicolas

    2010-01-01

    The voter model and the Axelrod model are two of the main stochastic processes that describe the spread of opinions on networks. The former includes social influence, the tendency of individuals to become more similar when they interact, while the latter also accounts for homophily, the tendency to interact more frequently with individuals which are more similar. The Axelrod model has been extensively studied during the past ten years based on numerical simulations. In contrast, we give rigorous analytical results for a generalization of the voter model that is closely related to the Axelrod model as it combines social influence and confidence threshold, which is modeled somewhat similarly to homophily. Each vertex of the network, represented by a finite connected graph, is characterized by an opinion and may interact with its adjacent vertices. Like the voter model, an interaction results in an agreement between both interacting vertices -- social influence -- but unlike the voter model, an interaction takes...

  3. Alternative splicing isoform of T cell factor 4K suppresses the proliferation and metastasis of non-small cell lung cancer cells.

    Science.gov (United States)

    Fan, Y C; Min, L; Chen, H; Liu, Y L

    2015-10-30

    The Wnt pathway has been implicated in the initiation, progression, and metastasis of lung cancer. T cell factor 4, a member of TCF/LEF family, acts as a transcriptional factor for Wnt pathways in lung cancer. Increasing amounts of evidence have shown that TCF-4 has multiple alternative splicing isoforms with transactivation or transrepression activity toward the Wnt pathway. Here, we found the presence of multiple TCF-4 isoforms in lung cancer cell lines and in normal bronchial epithelial cells. TCF-4K isoform expression was significantly decreased in lung cancer cells compared with normal bronchial epithelial cells and was identified as a transcriptional suppressor of the Wnt pathway in non-small cell lung carcinoma (NSCLC). Overexpression of TCF-4K significantly inhibited the proliferation and migration of NSCLC cells. Collectively, our data indicate that TCF-4K functions as a tumor suppressor in NSCLC by down-regulating the Wnt pathway.

  4. Faults architecture and growth in clay-limestone alternation. Examples in the S-E Basin alternations (France) and numerical modeling

    International Nuclear Information System (INIS)

    The following work has been carried out in the framework of the studies conducted by IRSN in support of its safety evaluation of the geological disposal programme of high and intermediate level, long-lived radioactive waste. Such a disposal is planned to be hosted by the Callovian-Oxfordian indurate clay formation between two limestone formations in eastern Paris basin, France. Hypothetical faults may cross-cut this layered section, decreasing the clay containment ability by creating preferential pathways for radioactive solute towards limestones. This study aims at characterising the fault architecture and the normal fault growth in clay/limestone layered sections. Structural analysis and displacement profiles have been carried out in normal faults crossing several decimetres to metre thick sedimentary alternations in the South-Eastern Basin (France) and petrophysical properties have been determined for each layer. The studied faults are simple fault planes or complex fault zones showing are significantly controlled by the layering. The analysis of the fault characteristics and the results obtained on numerical models enlighten several processes such as fault nucleation, fault restriction, and fault growth through layered section. Some studied faults nucleated in the limestone layers, without using pre-existing fractures such as joints, and according to our numerical analysis, a strong stiffness, a low strength contrast between the limestone and the clay layer, and/or s a greater thickness of the clay layer are conditions which favour nucleation of faults in limestone. The range of mechanical properties leading to the fault nucleation in one layer type or another was investigated using a 3D modelling approach. After its nucleation, the fault propagates within a homogeneous medium with a constant displacement gradient until its vertical propagation is stopped by a restrictor. The evidenced restrictors are limestone-clay interfaces or faults in clays, sub

  5. Decisionmaking between multiattribute choice alternatives : a model of spatial shopping-behaviour using conjoint measurements

    OpenAIRE

    Timmermans, HJP Harry; Heijden, van der, C.A.M.; Westerveld, J Hans

    1984-01-01

    In this paper the authors are concerned with the application of conjoint measurement models to predict consumer choice of shopping centres. First, conjoint measurement models are discussed in the context of the development of spatial shopping-models. Next, the conceptual framework underlying the model and conjoint measurement are discussed. The second part of the paper describes an application of the methodology. Conjoint measurement is used to estimate consumer utility functions and a multiv...

  6. Examining the DSM-5 alternative personality disorder model operationalization of antisocial personality disorder and psychopathy in a male correctional sample.

    Science.gov (United States)

    Wygant, Dustin B; Sellbom, Martin; Sleep, Chelsea E; Wall, Tina D; Applegate, Kathryn C; Krueger, Robert F; Patrick, Christopher J

    2016-07-01

    For decades, it has been known that the Diagnostic and Statistical Manual of Mental Disorders (DSM) diagnosis of Antisocial Personality Disorder (ASPD) is a nonadequate operationalization of psychopathy (Crego & Widiger, 2015). The DSM-5 alternative model of personality disorders provides an opportunity to rectify some of these long held concerns. The current study compared the Section III alternative model's trait-based conception of ASPD with the categorical model from the main diagnostic codes section of DSM-5 in terms of associations with differing models of psychopathy. We also evaluated the validity of the trait-based conception more broadly in relation to measures of antisocial tendencies as well as psychopathy. Participants were 200 male inmates who were administered a battery of self-report and interview-based researcher rating measures of relevant constructs. Analyses showed that Section III ASPD outperformed Section II ASPD in predicting scores on Hare's (2003) Psychopathy Checklist-Revised (PCL-R; r = .88 vs. .59). Additionally, aggregate scores for Section III ASPD performed well in capturing variance in differing ASPD and psychopathy measures. Finally, we found that the Section III ASPD impairment criteria added incrementally to the Section III ASPD traits in predicting PCL-R psychopathy and SCID-II ASPD. (PsycINFO Database Record

  7. Anisotropic dark energy model with a hybrid scale factor

    CERN Document Server

    Mishra, B

    2015-01-01

    Anisotropic dark energy model with dynamic pressure anisotropies along different spatial directions is constructed at the backdrop of a spatially homogeneous diagonal Bianchi type $V$ $(BV)$ space-time in the framework of General Relativity. A time varying deceleration parameter generating a hybrid scale factor is considered to simulate a cosmic transition from early deceleration to late time acceleration. We found that the pressure anisotropies along the $y-$ and $z-$ axes evolve dynamically and continue along with the cosmic expansion without being subsided even at late times. The anisotropic pressure along the $x-$axis becomes equal to the mean fluid pressure. At a late phase of cosmic evolution, the model enters into a phantom region. From a state finder diagnosis, it is found that the model overlaps with $\\Lambda$CDM at late phase of cosmic time.

  8. Clinical application of the five-factor model.

    Science.gov (United States)

    Widiger, Thomas A; Presnall, Jennifer Ruth

    2013-12-01

    The Five-Factor Model (FFM) has become the predominant dimensional model of general personality structure. The purpose of this paper is to suggest a clinical application. A substantial body of research indicates that the personality disorders included within the American Psychiatric Association's (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM) can be understood as extreme and/or maladaptive variants of the FFM (the acronym "DSM" refers to any particular edition of the APA DSM). In addition, the current proposal for the forthcoming fifth edition of the DSM (i.e., DSM-5) is shifting closely toward an FFM dimensional trait model of personality disorder. Advantages of this shifting conceptualization are discussed, including treatment planning. PMID:22924994

  9. Human Factors Engineering Review Model for advanced nuclear power reactors

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.; Higgins, J. [Brookhaven National Lab., Upton, NY (United States); Goodman, C.; Galletti, G.: Eckenrode, R. [Nuclear Regulatory Commission, Rockville, MD (United States)

    1993-05-01

    One of the major issues to emerge from the initial design reviews under the certification process was that detailed human-systems interface (HSI) design information was not available for staff review. To address the lack of design detail issue. The Nuclear Regulatory Commission (NRC) is performing the design certification reviews based on a design process plan which describes the human factors engineering (HFE) program elements that are necessary and sufficient to develop an acceptable detailed design specification. Since the review of a design process is unprecedented in the nuclear industry. The criteria for review are not addressed by current regulations or guidance documents and. therefore, had to be developed. Thus, an HFE Program Review Model was developed. This paper will describe the model`s rationale, scope, objectives, development, general characteristics. and application.

  10. Correspondence between five-factor and RIASEC models of personality.

    Science.gov (United States)

    Schinka, J A; Dye, D A; Curtiss, G

    1997-04-01

    In this study, we examined relationships between the full five-factor (FF; Costa & McCrae, 1985, 1992; Digman, 1990) and Holland's (1985a) RIASEC models of personality in a sample of 1,034 adults. The NEO Personality Inventory-Revised (Costa & McCrae, 1992) and the Self-Directed Search (Holland, 1985c) provided measures of the FF and RIASEC dimensions, respectively. Canonical correlation analyses provided evidence primarily for a pattern of linkages between the FF Extraversion, Openness, and Agreeableness measures and the RIASEC Enterprising, Artistic, and Social scales. Findings from this and previous studies indicated that the FF model appears to ignore the Realistic dimension and provides coverage of the Investigative and Conventional dimensions in women only. In turn, the RIASEC model appears to provide modest coverage of the FF Neuroticism and Conscientiousness domains for women and not at all for men. PMID:9107013

  11. Complement factor D homolog involved in the alternative complement pathway of rock bream (Oplegnathus fasciatus): Molecular and functional characterization and immune responsive mRNA expression analysis.

    Science.gov (United States)

    Godahewa, G I; Perera, N C N; Bathige, S D N K; Nam, Bo-Hye; Noh, Jae Koo; Lee, Jehee

    2016-08-01

    The complement system serves conventional role in the innate defense against common invading pathogens. Complement factor D (CfD) is vital to alternative complement pathway activation in cleaving complement factor B. This catalytic reaction forms the alternative C3 convertase that is crucial for complement-mediated pathogenesis. In this study, rock bream (Oplegnathus fasciatus) CfD (OfCfD) was characterized and OfCfD mRNA expression was investigated. OfCfD encodes 277 amino acids (aa) for a 30-kDa polypeptide. A domain analysis of the deduced OfCfD aa sequence showed a single serine protease trypsin superfamily domain, a serine active region, three active sites, and three substrate-binding sites. Pairwise sequence comparisons indicated that OfCfD has the highest identity (84.5%) with Oreochromis niloticus CfD. The phylogenetic tree revealed a common ancestral origin of CfD members, with fish CfD distinct from other vertebrate orthologs. The structural arrangement of the OfCfD gene (2451 bp) contained five exons interrupted by four introns. A spatial transcriptional analysis indicated that OfCfD transcripts constitutively expressed in all of the examined rock bream tissues, and that they were highest in the spleen and liver. In addition, OfCfD transcripts were immunologically upregulated by lipopolysaccharide (LPS) (12 h p.i.), Streptococcus iniae (12 h p.i.), rock bream iridovirus (RBIV) (6-12 h p.i.), and poly I:C (6 h p.i.) in spleen tissue. OfCfD is a trypsin protease and its recombinant protein showed strong protease activity similar to that of trypsin, indicating its catalytic function in the alternative pathway. Together, our findings suggest that OfCfD might be involved in immune responses in rock bream. PMID:27311435

  12. Factor analysis models via I-divergence optimization.

    Science.gov (United States)

    Finesso, Lorenzo; Spreij, Peter

    2016-09-01

    Given a positive definite covariance matrix [Formula: see text] of dimension n, we approximate it with a covariance of the form [Formula: see text], where H has a prescribed number [Formula: see text] of columns and [Formula: see text] is diagonal. The quality of the approximation is gauged by the I-divergence between the zero mean normal laws with covariances [Formula: see text] and [Formula: see text], respectively. To determine a pair (H, D) that minimizes the I-divergence we construct, by lifting the minimization into a larger space, an iterative alternating minimization algorithm (AML) à la Csiszár-Tusnády. As it turns out, the proper choice of the enlarged space is crucial for optimization. The convergence of the algorithm is studied, with special attention given to the case where D is singular. The theoretical properties of the AML are compared to those of the popular EM algorithm for exploratory factor analysis. Inspired by the ECME (a Newton-Raphson variation on EM), we develop a similar variant of AML, called ACML, and in a few numerical experiments, we compare the performances of the four algorithms. PMID:26608962

  13. Harmonic amplitude dependent dynamic stiffness of hydraulic bushings: Alternate nonlinear models and experimental validation

    Science.gov (United States)

    Fredette, Luke; Dreyer, Jason T.; Rook, Todd E.; Singh, Rajendra

    2016-06-01

    The dynamic stiffness properties of automotive hydraulic bushings exhibit significant amplitude sensitivity which cannot be captured by linear time-invariant models. Quasi-linear and nonlinear models are therefore proposed with focus on the amplitude sensitivity in magnitude and loss angle spectra (up to 50 Hz). Since production bushing model parameters are unknown, dynamic stiffness tests and laboratory experiments are utilized to extract model parameters. Nonlinear compliance and resistance elements are incorporated, including their interactions in order to improve amplitude sensitive predictions. New solution approximations for the new nonlinear system equations refine the multi-term harmonic balance term method. Quasi-linear models yield excellent accuracy but cannot predict trends in amplitude sensitivity since they rely on available dynamic stiffness measurements. Nonlinear models containing both nonlinear resistance and compliance elements yield superior predictions to those of prior models (with a single nonlinearity) while also providing more physical insight. Suggestion for further work is briefly mentioned.

  14. Muscle-specific splicing factors ASD-2 and SUP-12 cooperatively switch alternative pre-mRNA processing patterns of the ADF/cofilin gene in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Genta Ohno

    Full Text Available Pre-mRNAs are often processed in complex patterns in tissue-specific manners to produce a variety of protein isoforms from single genes. However, mechanisms orchestrating the processing of the entire transcript are not well understood. Muscle-specific alternative pre-mRNA processing of the unc-60 gene in Caenorhabditis elegans, encoding two tissue-specific isoforms of ADF/cofilin with distinct biochemical properties in regulating actin organization, provides an excellent in vivo model of complex and tissue-specific pre-mRNA processing; it consists of a single first exon and two separate series of downstream exons. Here we visualize the complex muscle-specific processing pattern of the unc-60 pre-mRNA with asymmetric fluorescence reporter minigenes. By disrupting juxtaposed CUAAC repeats and UGUGUG stretch in intron 1A, we demonstrate that these elements are required for retaining intron 1A, as well as for switching the processing patterns of the entire pre-mRNA from non-muscle-type to muscle-type. Mutations in genes encoding muscle-specific RNA-binding proteins ASD-2 and SUP-12 turned the colour of the unc-60 reporter worms. ASD-2 and SUP-12 proteins specifically and cooperatively bind to CUAAC repeats and UGUGUG stretch in intron 1A, respectively, to form a ternary complex in vitro. Immunohistochemical staining and RT-PCR analyses demonstrate that ASD-2 and SUP-12 are also required for switching the processing patterns of the endogenous unc-60 pre-mRNA from UNC-60A to UNC-60B in muscles. Furthermore, systematic analyses of partially spliced RNAs reveal the actual orders of intron removal for distinct mRNA isoforms. Taken together, our results demonstrate that muscle-specific splicing factors ASD-2 and SUP-12 cooperatively promote muscle-specific processing of the unc-60 gene, and provide insight into the mechanisms of complex pre-mRNA processing; combinatorial regulation of a single splice site by two tissue-specific splicing regulators

  15. Searching for a two-factor model of marriage duration: commentary on Gottman and Levenson.

    Science.gov (United States)

    DeKay, Michael L; Greeno, Catherine G; Houck, Patricia R

    2002-01-01

    Gottman and Levenson (2002) report a number of post hoc ordinary least squares regressions to "predict" the length of marriage, given that divorce has occurred. We argue that the type of statistical model they use is inappropriate for answering clinically relevant questions about the causes and timing of divorce, and present several reasons why an alternative family of models called duration models would be more appropriate. The distribution of marriage length is not bimodal, as Gottman and Levenson suggest, and their search for a two-factor model for explaining marriage length is misguided. Their regression models omit many variables known to affect marriage length, and instead use variables that were pre-screened for their predictive ability. Their final model is based on data for only 15 cases, including one unusual case that has undue influence on the results. For these and other technical reasons presented in the text, we believe that Gottman and Levenson's results are not replicable, and that they should not be used to guide interventions for couples in clinical settings.

  16. TEST OF THE CHEN-ROLL-ROSS MACROECONOMIC FACTOR MODEL: EVIDENCE FROM CROATIAN STOCK MARKET

    Directory of Open Access Journals (Sweden)

    Denis Dolinar

    2015-12-01

    Full Text Available This paper empirically examines the well-known Chen-Roll-Ross model on the Croatian stock market. Modifications of definitions of the Chen-Roll-Ross model variables showed as necessary because of doubtful availability and quality of input data needed. Namely, some macroeconomic and market variables are not available in the originally defined form or do not exist. In that sense this paper gives some alternative definitions for some model variables. Also, in order to improve statistical analysis, in this paper we have modified Fama-MacBeth technique in the way that second-pass regression was substituted with panel regression analysis. Based on the two-pass regression analysis of returns of 34 Croatian stocks on 4 macroeconomic variables during the seven-and-half-year observation period the following conclusion is made. In contrast to the results of Chen, Roll and Ross (1986 for the U.S. stock market, their model is not successful when describing a risk-return relation of Croatian stocks. Nevertheless, one observed version of the Chen-RollRoss model showed certain statistical significance. Namely, two risk factors in that version of the model were statistically significant: default premium, measured as risk premium for the corporate short-term bank loan financing, and term structure premium, measured on short-run basis.

  17. An Illumination Modeling System for Human Factors Analyses

    Science.gov (United States)

    Huynh, Thong; Maida, James C.; Bond, Robert L. (Technical Monitor)

    2002-01-01

    Seeing is critical to human performance. Lighting is critical for seeing. Therefore, lighting is critical to human performance. This is common sense, and here on earth, it is easily taken for granted. However, on orbit, because the sun will rise or set every 45 minutes on average, humans working in space must cope with extremely dynamic lighting conditions. Contrast conditions of harsh shadowing and glare is also severe. The prediction of lighting conditions for critical operations is essential. Crew training can factor lighting into the lesson plans when necessary. Mission planners can determine whether low-light video cameras are required or whether additional luminaires need to be flown. The optimization of the quantity and quality of light is needed because of the effects on crew safety, on electrical power and on equipment maintainability. To address all of these issues, an illumination modeling system has been developed by the Graphics Research and Analyses Facility (GRAF) and Lighting Environment Test Facility (LETF) in the Space Human Factors Laboratory at NASA Johnson Space Center. The system uses physically based ray tracing software (Radiance) developed at Lawrence Berkeley Laboratories, a human factors oriented geometric modeling system (PLAID) and an extensive database of humans and environments. Material reflectivity properties of major surfaces and critical surfaces are measured using a gonio-reflectometer. Luminaires (lights) are measured for beam spread distribution, color and intensity. Video camera performances are measured for color and light sensitivity. 3D geometric models of humans and the environment are combined with the material and light models to form a system capable of predicting lighting conditions and visibility conditions in space.

  18. Alternative splicing and expression of the insulin-like growth factor (IGF-1) gene in osteoblasts under mechanical stretch

    Institute of Scientific and Technical Information of China (English)

    XIAN Chengyu; WANG Yuanliang; ZHANG Bingbing; TANG Liling; PAN Jun; LUO Yanfeng; JIANG Peng; LI Dajun

    2006-01-01

    Insulin-like growth factor 1 (IGF-1) promotes osteoblasts differentiation and bone formation,and its expression is induced by mechanical stretch,thus IGF-1 has been considered an effector molecule that links mechanical stimulation and local tissue responses. In this study, a mechanical stretching device was designed to apply physiological level static or cyclic stretching stimulation to osteoblasts.Different isoforms of IGF-1 mRNA were amplified by RT-PCR from the cells using respective primers and these amplified products were sequenced. An isoform of IGF-1 splicing product was found to be selectively produced by osteoblasts under stretching stimulation. This IGF-1 isoform had identical sequence with the mechano growth factor (MGF) which was originally identified in muscle cells. Regulations of the expression of the liver-type IGF (L.IGF-1) and MGF in osteoblasts under stretch stimulation were further studied using semi-quantitative RT-PCR.Stretch stimulation was found to promot the expression of IGF-1 (L.IGF-1 and MGF), and for both isoforms expression was more effectively stimulated by cyclic stretch than static stretch. MGF was detected only in osteoblasts subjected to mechanical stretch,suggesting MGF was a stretch sensitive growth factor.Expression of MGF peaked earlier than that of L.IGF-1, which was similar to their regulation in muscie and suggested similar roles of MGF and L.IGF-1in bone as in muscle cells. The functions of MGF and L.IGF-1 in osteoblasts shall be established by further experimental studies.

  19. A personal vehicle transactions choice model for use in forecasting demand for future alternative-fuel vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Ren, W.; Brownstone, D.; Bunch, D.S.; Golob, T.F.

    1994-12-31

    A discrete choice model has been developed in which the choice alternatives consist of vehicle transactions rather than portfolios of vehicle holdings. The model is based on responses to customized stated preference questions involving both hypothetical future vehicles and the household`s current vehicle holdings. The stated choices were collected from 4747 survey respondents located throughout most of the urbanized portions of California. Respondents were asked what their next vehicle transaction would most likely be (replace a current vehicle, add another vehicle, or dispose of a current vehicle), and respondents who wanted to replace or add vehicles were asked to indicate their most preferred vehicle from a set of six hypothetical vehicles. The hypothetical vehicles were described in terms of fourteen attributes, manipulated according to an experimental design. The transactions model is a multinomial logic model of the choice of the hypothetical vehicles and whether or not the hypothetical vehicle will be a replacement or addition to the household fleet. The model is conditioned on the household`s current vehicle stock, and the characteristics of the current vehicles are important explanators of the stated preference choices. In addition to the model estimates, forecasts are given for a base case scenario in 1998. The model is one component in a micro-simulation demand forecasting system being designed to produce annual forecasts of new and used vehicle demand by type of vehicle and geographic area. The system will also forecast annual vehicle miles traveled for all vehicles and recharging demand by time of day for electric vehicles. These results are potentially useful to utility companies in their demand-side management planning, to public agencies in their evaluation incentive schemes, and to manufacturers faced with designing and marketing alternative-fuel vehicles.

  20. Social and Cultural Factors Affecting Complementary and Alternative Medicine (CAM Use during Menopause in Sydney and Bologna

    Directory of Open Access Journals (Sweden)

    Corinne van der Sluijs

    2013-01-01

    Full Text Available Background. Previous surveys found CAM use during menopause to be popular. This paper compares the results from two surveys (Sydney and Bologna to examine factors that determine the extent and pattern of CAM use to alleviate menopausal symptoms. Methods. Women, aged 45–65 years, who were symptomatic when transitioning through menopause or asymptomatic but taking menopause-specific treatments, were recruited in Sydney (n=1,296 and Bologna (n=1,106 to complete the same voluntary, anonymous, and self-administered questionnaire. The results were reanalysed using stratified analyses to determine similarities and differences. Results. Demographics of the two cohorts differed significantly. CAM was more popular in Sydney. The most significant determinants of CAM use were the use of CAM for other conditions besides menopause and the severity of vasomotor symptoms. Occupational status was a determinant of CAM use amongst Bologna respondents only. In order to relieve symptoms, Australian and Italian women used different CAM modalities whose effectiveness was generally perceived as good. Conclusion. CAM use is popular amongst menopausal women from Sydney and Bologna. Differences in the patterns of CAM use seem to depend on CAM availability and on the educational level and professional status of users. The complex interaction between market, social, and cultural factors of CAM use seems to be more influential on women’s choice of CAM than the available evidence of their effectiveness.

  1. How do alternative root water uptake models affect the inverse estimation of soil hydraulic parameters and the prediction of evapotranspiration?

    Science.gov (United States)

    Gayler, Sebastian; Salima-Sultana, Daisy; Selle, Benny; Ingwersen, Joachim; Wizemann, Hans-Dieter; Högy, Petra; Streck, Thilo

    2016-04-01

    Soil water extraction by roots affects the dynamics and distribution of soil moisture and controls transpiration, which influences soil-vegetation-atmosphere feedback processes. Consequently, root water uptake requires close attention when predicting water fluxes across the land surface, e.g., in agricultural crop models or in land surface schemes of weather and climate models. The key parameters for a successful simultaneous simulation of soil moisture dynamics and evapotranspiration in Richards equation-based models are the soil hydraulic parameters, which describe the shapes of the soil water retention curve and the soil hydraulic conductivity curve. As measurements of these parameters are expensive and their estimation from basic soil data via pedotransfer functions is rather inaccurate, the values of the soil hydraulic parameters are frequently inversely estimated by fitting the model to measured time series of soil water content and evapotranspiration. It is common to simulate root water uptake and transpiration by simple stress functions, which describe from which soil layer water is absorbed by roots and predict when total crop transpiration is decreased in case of soil water limitations. As for most of the biogeophysical processes simulated in crop and land surface models, there exist several alternative functional relationships for simulating root water uptake and there is no clear reason for preferring one process representation over another. The error associated with alternative representations of root water uptake, however, contributes to structural model uncertainty and the choice of the root water uptake model may have a significant impact on the values of the soil hydraulic parameters estimated inversely. In this study, we use the agroecosystem model system Expert-N to simulate soil moisture dynamics and evapotranspiration at three agricultural field sites located in two contrasting regions in Southwest Germany (Kraichgau, Swabian Alb). The Richards

  2. Modelling of a large-scale urban contamination situation and remediation alternatives

    International Nuclear Information System (INIS)

    The Urban Remediation Working Group of the International Atomic Energy Agency's EMRAS (Environmental Modelling for Radiation Safety) program was organized to address issues of remediation assessment modelling for urban areas contaminated with dispersed radionuclides. The present paper describes the first of two modelling exercises, which was based on Chernobyl fallout data in the town of Pripyat, Ukraine. Modelling endpoints for the exercise included radionuclide concentrations and external dose rates at specified locations, contributions to the dose rates from individual surfaces and radionuclides, and annual and cumulative external doses to specified reference individuals. Model predictions were performed for a 'no action' situation (with no remedial measures) and for selected countermeasures. The exercise provided a valuable opportunity to compare modelling approaches and parameter values, as well as to compare the predicted effectiveness of various countermeasures with respect to short-term and long-term reduction of predicted doses to people.

  3. f(T) modified teleparallel gravity models as an alternative for holographic and new agegraphic dark energy models

    OpenAIRE

    Karami, K.; Abdolmaleki, A.

    2010-01-01

    In the present work, we reconstruct different f(T)-gravity models corresponding to the original and entropy-corrected version of the holographic and new agegraphic dark energy models. We also obtain the equation of state parameters of the corresponding f(T)-gravity models. We conclude that the holographic and new agegraphic f(T)-gravity models behave like phantom or quintessence model. Whereas in the entropy-corrected models, the equation of state parameter can justify the transition from the...

  4. Styrofoam-and-Velcro: An Alternative to Ball-and-Stick Models

    OpenAIRE

    Sawyer Rowan Masonjones; Heather Dawne Masonjones; Malone, Megan C.; Anne H. Williams; Beemer, Margaret M.; Waggett, Rebecca J.

    2014-01-01

    For students learning biology at introductory levels, one of the most significant instructional barriers is their lack of preparation in chemistry. In upper-division college chemistry and biology courses, students employ ball-and-stick models in order to visualize molecular structures, but at the introductory biology level, models are inconsistently used and at the secondary level they are avoided altogether. Traditional ball-and-stick models perform poorly at all levels because they only sho...

  5. A Transactions Choice Model for Forecasting Demand for Alternative-Fuel Vehicles

    OpenAIRE

    Brownstone, David; Bunch, David S.; Golob, Thomas F.; Ren, Weiping

    1996-01-01

    The vehicle choice model developed here is one component in a micro-simulation demand forecasting system being designed to produce annual forecasts of new and used vehicle demand by vehicle type and geographic area in California. The system will also forecast annual vehicle miles traveled for all vehicles and recharging demand by time of day for electric vehicles. The choice model specification differs from past studies by directly modeling vehicle transactions rather than vehicle holdings. T...

  6. Cosine Based Latent Factor Model for Precision Oriented Recommendation

    Directory of Open Access Journals (Sweden)

    Bipul Kumar

    2016-01-01

    Full Text Available Recommender systems suggest a list of interesting items to users based on their prior purchase or browsing behaviour on e-commerce platforms. The continuing research in recommender systems have primarily focused on developing algorithms for rating prediction task. However, most e-commerce platforms provide ‘top-k’ list of interesting items for every user. In line with this idea, the paper proposes a novel machine learning algorithm to predict a list of ‘top-k’ items by optimizing the latent factors of users and items with the mapped scores from ratings. The basic idea is to learn latent factors based on the cosine similarity between the users and items latent features which is then used to predict the scores for unseen items for every user. Comprehensive empirical evaluations on publicly available benchmark datasets reveal that the proposed model outperforms the state-of-the-art algorithms in recommending good items to a user.

  7. Positive Orientation and the Five-Factor Model

    Directory of Open Access Journals (Sweden)

    Miciuk Łukasz Roland

    2016-04-01

    Full Text Available The aim of the present study was to investigate the relationship between positive orientation (PO defined as a basic predisposition to perceive and evaluate positive aspects of life, the future and oneself and the Five-Factor Model of personality (FFM. Hypotheses postulated positive correlations between PO and extraversion, conscientiousness, agreeableness and openness; a negative correlation was predicted between PO and neuroticism. Two hundred Polish students completed the following measures: SES (Self-Esteem Scale, Rosenberg, SWLS (The Satisfaction with Life Scale; Diener, Emmons, Larson & Griffin, LOT-R (The Life Orientation Test - Revised; Scheier, Carver & Bridges and NEOFFI (NEO Five Factor Inventory, Costa & McCrae. The results confirmed correlations between PO and extraversion, conscientiousness, and neuroticism; correlations with openness and agreeableness were not supported. According to canonical correlations, PO shows a clear affinity to the FFM.

  8. An origin of the universe: a model alternative to Big Bang

    OpenAIRE

    Mercik, Andrzej; Mercik, Szymon

    2006-01-01

    We propose a new approach to the model of an origin of the universe built by Oscar Klein and Hannes Alfv\\'{e}n. Some modifications of assumptions underlying the model result in a possible scenario of the universe creation consistent with observations. We explain the large scale structre of the universe and we estimate the Hubble constant value as well as the number of galaxies in the universe. The model does not require many assumptions made in the model based on the Big Bang idea.

  9. Styrofoam-and-Velcro: An Alternative to Ball-and-Stick Models

    Directory of Open Access Journals (Sweden)

    Sawyer Rowan Masonjones

    2014-07-01

    Full Text Available For students learning biology at introductory levels, one of the most significant instructional barriers is their lack of preparation in chemistry. In upper-division college chemistry and biology courses, students employ ball-and-stick models in order to visualize molecular structures, but at the introductory biology level, models are inconsistently used and at the secondary level they are avoided altogether. Traditional ball-and-stick models perform poorly at all levels because they only show bonds, never valence electrons. This poses a problem for students who are visual or kinesthetic learners, as modeling electrons in the bonding process may be critical to understanding the mechanisms behind the biochemical reactions that serve as a foundation for biological concepts. Our molecular modeling kits show the action of valence electrons and correctly deal with the issue of polarity and partial charge, while still illustrating structure and function similarly to ball-and-stick models, allowing students to model nearly every reaction or molecule they may need to learn.  Additionally, this kit will foster model building exercises required as part of the Next Generation Science Standards (http://www.nextgenscience.org/next-generation-science-standards. This model was devloped in conjunction with 'Molecular Twister: A Game for Exploring Solution Chemistry' (JMBE Vol 15, No 1; http://jmbe.asm.org/index.php/jmbe/article/view/652 by the same authors, which uses principles derived from the present paper.

  10. Alternative mRNA Splicing: Control by Combination

    OpenAIRE

    Mabon, Stephen A; Tom Misteli

    2005-01-01

    Alternative splicing in mammalian cells has been suggested to be largely controlled by combinatorial binding of basal splicing factors to pre-mRNA templates. This model predicts that distinct sets of pre-mRNA splicing factors are associated with alternatively spliced transcripts. However, no experimental evidence for differential recruitment of splicing factors to transcripts with distinct splicing fates is available. Here we have used quantitative single-cell imaging to test this key predict...

  11. Interfacial Friction Factor Model for Two-dimensional Film Flow

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin-Hwa; Cho, Hyoung-Kyu; Park, Goon-Cherl [Seoul National Univ., Seoul (Korea, Republic of); Euh, Dong-Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Using the one-dimensional models and correlations for multi-dimensional problems has limitations due to the compatibility. In this study, experimental study of upper downcomer two-phase flow which is also the multi-dimensional problem will be described and two-dimensional interfacial friction factor model will be also suggested.. The upper downcomer two-phase flow of a nuclear reactor is one of important multi-dimensional problems. In particular, in a Direct Vessel Injection (DVI) system of Advanced Power Reactor 1400 (APR 1400), the Emergency Core Coolant (ECC) is injected onto the upper downcomer from 2.1 m higher position than one of cold-leg. The injected ECC interacts with the lateral steam flow from the nuclear reactor core during the reflood phase in the Large Break Loss of Coolant accident (LBLOCA). The interaction between the falling film and lateral steam flow induces a two-phase multi-dimensional film flow.. The amount of reflood coolant was determined by the effect of the interfacial drag between two fluids. It can be dealt as annular flow or film flow regime in the aforementioned safety analysis codes. They have used interfacial drag coefficient model which was developed by one-dimensional experimental results. Wallis model is a representative one to deal the interfacial friction factor with void fraction (or film thickness). It was developed with experimental data of annular flow from a vertical pipe. Fore indicated that Wallis' model overestimates interfacial friction factor in thinner liquid film region and underestimates that in thicker liquid film region. Asali suggested interfacial drag model with a dimensionless film thickness considering a roll wave effect. These models have been incorporated in multi-dimensional module of safety analysis codes and the verification and validation (V-V) have also been carried out recently. However, it has some challenges because there are not sufficient local measurement experimental data to be used for

  12. Form factors in the Bullough-Dodd-related models: The Ising model in a magnetic field

    Science.gov (United States)

    Alekseev, O. V.

    2012-11-01

    We consider a certain modification of the free-field representation of the form factors in the Bullough-Dodd model. The two-particle minimal form factors are eliminated from the construction. We consequently obtain a convenient representation for the multiparticle form factors, establish recurrence relations between them, and study their properties. We use the proposed construction to obtain the free-field representation of form factors for the lightest particles in the Φ 1,2 -perturbed minimal models. As an important example, we consider the Ising model in a magnetic field. We verify that the results obtained in the framework of the proposed free-field representation agree with the corresponding results obtained by solving the bootstrap equations.

  13. Form factors in the Bullough-Dodd related models: The Ising model in a magnetic field

    Science.gov (United States)

    Alekseev, O. V.

    2012-04-01

    A particular modification of the free-field representation of the form factors in the Bullough-Dodd model is considered. The two-particles minimal form factors are excluded from the construction. As a consequence, a convenient representation for the multiparticle form factors has been obtained, recurrence relations between them have been established, and their properties have been studied. The proposed construction is used to obtain the free-field representation of the lightest particles form factors in the Φ1, 2 perturbed minimal models. The Ising model in a magnetic field is considered as a significant example. The results obtained in the framework of the proposed free-field representation are in agreement with the corresponding results obtained by solving the bootstrap equations.

  14. Investigating Impacts of Alternative Crop Market Scenarios on Land Use Change with an Agent-Based Model

    Directory of Open Access Journals (Sweden)

    Deng Ding

    2015-11-01

    Full Text Available We developed an agent-based model (ABM to simulate farmers’ decisions on crop type and fertilizer application in response to commodity and biofuel crop prices. Farm profit maximization constrained by farmers’ profit expectations for land committed to biofuel crop production was used as the decision rule. Empirical parameters characterizing farmers’ profit expectations were derived from an agricultural landowners and operators survey and integrated in the ABM. The integration of crop production cost models and the survey information in the ABM is critical to producing simulations that can provide realistic insights into agricultural land use planning and policy making. Model simulations were run with historical market prices and alternative market scenarios for corn price, soybean to corn price ratio, switchgrass price, and switchgrass to corn stover ratio. The results of the comparison between simulated cropland percentage and crop rotations with satellite-based land cover data suggest that farmers may be underestimating the effects that continuous corn production has on yields. The simulation results for alternative market scenarios based on a survey of agricultural land owners and operators in the Clear Creek Watershed in eastern Iowa show that farmers see cellulosic biofuel feedstock production in the form of perennial grasses or corn stover as a more risky enterprise than their current crop production systems, likely because of market and production risks and lock in effects. As a result farmers do not follow a simple farm-profit maximization rule.

  15. Modeling impact of environmental factors on photovoltaic array performance

    Directory of Open Access Journals (Sweden)

    Jie Yang, Yize Sun, Yang Xu

    2013-01-01

    Full Text Available It is represented in this paper that a methodology to model and quantify the impact of the three environmental factors, the ambient temperature, the incident irradiance and the wind speed, upon the performance of photovoltaic array operating under outdoor conditions. First, A simple correlation correlating operating temperature with the three environmental variables is validated for a range of wind speed studied, 2-8 m/s, and for irradiance values between 200 and 1000 W/m2. Root mean square error (RMSE between modeled operating temperature and measured values is 1.19% and the mean bias error (MBE is -0.09%. The environmental factors studied influence I-V curves, P-V curves, and maximum-power outputs of photovoltaic array. The cell-to-module-to-array mathematical model for photovoltaic panels is established in this paper and the method defined as segmented iteration is adopted to solve the I-V curve expression to relate model I-V curves. The model I-V curves and P-V curves are concluded to coincide well with measured data points. The RMSE between numerically calculated maximum-power outputs and experimentally measured ones is 0.2307%, while the MBE is 0.0183%. In addition, a multivariable non-linear regression equation is proposed to eliminate the difference between numerically calculated values and measured ones of maximum power outputs over the range of high ambient temperature and irradiance at noon and in the early afternoon. In conclusion, the proposed method is reasonably simple and accurate.

  16. Workforce scheduling: A new model incorporating human factors

    Directory of Open Access Journals (Sweden)

    Mohammed Othman

    2012-12-01

    Full Text Available Purpose: The majority of a company’s improvement comes when the right workers with the right skills, behaviors and capacities are deployed appropriately throughout a company. This paper considers a workforce scheduling model including human aspects such as skills, training, workers’ personalities, workers’ breaks and workers’ fatigue and recovery levels. This model helps to minimize the hiring, firing, training and overtime costs, minimize the number of fired workers with high performance, minimize the break time and minimize the average worker’s fatigue level.Design/methodology/approach: To achieve this objective, a multi objective mixed integer programming model is developed to determine the amount of hiring, firing, training and overtime for each worker type.Findings: The results indicate that the worker differences should be considered in workforce scheduling to generate realistic plans with minimum costs. This paper also investigates the effects of human fatigue and recovery on the performance of the production systems.Research limitations/implications: In this research, there are some assumptions that might affect the accuracy of the model such as the assumption of certainty of the demand in each period, and the linearity function of Fatigue accumulation and recovery curves. These assumptions can be relaxed in future work.Originality/value: In this research, a new model for integrating workers’ differences with workforce scheduling is proposed. To the authors' knowledge, it is the first time to study the effects of different important human factors such as human personality, skills and fatigue and recovery in the workforce scheduling process. This research shows that considering both technical and human factors together can reduce the costs in manufacturing systems and ensure the safety of the workers.

  17. A comparison of behavioural alternative models in the context of the theory of reasoned action

    NARCIS (Netherlands)

    B. van den Putte; J. Hoogstraten; R. Meertens

    1996-01-01

    In Fishbein & Ajzen's theory of reasoned action, behaviour is predicted by the behavioural intention, which in turn is determined by a personal attitudinal and a social normative factor. These variables are usually measured with respect to the behaviour of interest, ignoring the choice process betwe

  18. A viable mouse model of factor X deficiency provides evidence for maternal transfer of factor X

    OpenAIRE

    Tai, S.J.; HERZOG, R. W.; MARGARITIS, P.; ARRUDA, V R; CHU, K; Golden, J A; LABOSKY, P A; High, K A

    2008-01-01

    Background:Activated factor X (FXa) is a vitamin K-dependent serine protease that plays a pivotal role in blood coagulation by converting prothrombin to thrombin. There are no reports of humans with complete deficiency of FX, and knockout of murine F10 is embryonic or perinatal lethal. Objective:We sought to generate a viable mouse model of FX deficiency. Methods:We used a socket-targeting construct to generate F10-knockout mice by eliminating F10 exon 8 (knockout allele termed F10 tm1Ccmt, a...

  19. Human Factors Research for Space Exploration: Measurement, Modeling, and Mitigation

    Science.gov (United States)

    Kaiser, Mary K.; Allen, Christopher S.; Barshi, Immanuel; Billman, Dorrit; Holden, Kritina L.

    2010-01-01

    As part of NASA's Human Research Program, the Space Human Factors Engineering Project serves as the bridge between Human Factors research and Human Spaceflight applications. Our goal is to be responsive to the operational community while addressing issues at a sufficient level of abstraction to ensure that our tools and solutions generalize beyond the point design. In this panel, representatives from four of our research domains will discuss the challenges they face in solving current problems while also enabling future capabilities. Historically, engineering-dominated organizations have tended to view good Human Factors (HF) as a desire rather than a requirement in system design and development. Our field has made significant gains in the past decade, however; the Department of Defense, for example, now recognizes Human-System Integration (HSI), of which HF is a component, as an integral part of their divisions hardware acquisition processes. And our own agency was far more accepting of HF/HSI requirements during the most recent vehicle systems definition than in any prior cycle. Nonetheless, HF subject matter experts at NASA often find themselves in catch up mode... coping with legacy systems (hardware and software) and procedures that were designed with little regard for the human element, and too often with an attitude of we can deal with any operator issues during training. Our challenge, then, is to segregate the true knowledge gaps in Space Human Factors from the prior failures to incorporate best (or even good) HF design principles. Further, we strive to extract the overarching core HF issues from the point-design-specific concerns that capture the operators (and managers) attention. Generally, our approach embraces a 3M approach to Human Factors: Measurement, Modeling, and Mitigation. Our first step is to measure human performance, to move from subjective anecdotes to objective, quantified data. Next we model the phenomenon, using appropriate methods in

  20. Dimensional Model for Estimating Factors influencing Childhood Obesity: Path Analysis Based Modeling

    Directory of Open Access Journals (Sweden)

    Maryam Kheirollahpour

    2014-01-01

    Full Text Available The main objective of this study is to identify and develop a comprehensive model which estimates and evaluates the overall relations among the factors that lead to weight gain in children by using structural equation modeling. The proposed models in this study explore the connection among the socioeconomic status of the family, parental feeding practice, and physical activity. Six structural models were tested to identify the direct and indirect relationship between the socioeconomic status and parental feeding practice general level of physical activity, and weight status of children. Finally, a comprehensive model was devised to show how these factors relate to each other as well as to the body mass index (BMI of the children simultaneously. Concerning the methodology of the current study, confirmatory factor analysis (CFA was applied to reveal the hidden (secondary effect of socioeconomic factors on feeding practice and ultimately on the weight status of the children and also to determine the degree of model fit. The comprehensive structural model tested in this study suggested that there are significant direct and indirect relationships among variables of interest. Moreover, the results suggest that parental feeding practice and physical activity are mediators in the structural model.