Using R and WinBUGS to fit a Generalized Partial Credit Model for developing and evaluating patient-reported outcomes assessments

PubMed Central

Li, Yuelin; Baser, Ray

2013-01-01

The US Food and Drug Administration recently announced the final guidelines on the development and validation of Patient-Reported Outcomes (PROs) assessments in drug labeling and clinical trials. This guidance paper may boost the demand for new PRO survey questionnaires. Henceforth biostatisticians may encounter psychometric methods more frequently, particularly Item Response Theory (IRT) models to guide the shortening of a PRO assessment instrument. This article aims to provide an introduction on the theory and practical analytic skills in fitting a Generalized Partial Credit Model in IRT (GPCM). GPCM theory is explained first, with special attention to a clearer exposition of the formal mathematics than what is typically available in the psychometric literature. Then a worked example is presented, using self-reported responses taken from the International Personality Item Pool. The worked example contains step-by-step guides on using the statistical languages R and WinBUGS in fitting the GPCM. Finally, the Fisher information function of the GPCM model is derived and used to evaluate, as an illustrative example, the usefulness of assessment items by their information contents. This article aims to encourage biostatisticians to apply IRT models in the re-analysis of existing data and in future research. PMID:22362655

Using R and WinBUGS to fit a generalized partial credit model for developing and evaluating patient-reported outcomes assessments.

PubMed

Li, Yuelin; Baser, Ray

2012-08-15

The US Food and Drug Administration recently announced the final guidelines on the development and validation of patient-reported outcomes (PROs) assessments in drug labeling and clinical trials. This guidance paper may boost the demand for new PRO survey questionnaires. Henceforth, biostatisticians may encounter psychometric methods more frequently, particularly item response theory (IRT) models to guide the shortening of a PRO assessment instrument. This article aims to provide an introduction on the theory and practical analytic skills in fitting a generalized partial credit model (GPCM) in IRT. GPCM theory is explained first, with special attention to a clearer exposition of the formal mathematics than what is typically available in the psychometric literature. Then, a worked example is presented, using self-reported responses taken from the international personality item pool. The worked example contains step-by-step guides on using the statistical languages r and WinBUGS in fitting the GPCM. Finally, the Fisher information function of the GPCM model is derived and used to evaluate, as an illustrative example, the usefulness of assessment items by their information contents. This article aims to encourage biostatisticians to apply IRT models in the re-analysis of existing data and in future research. Copyright © 2012 John Wiley & Sons, Ltd.

Analytical-Based Partial Volume Recovery in Mouse Heart Imaging

NASA Astrophysics Data System (ADS)

Dumouchel, Tyler; deKemp, Robert A.

2011-02-01

Positron emission tomography (PET) is a powerful imaging modality that has the ability to yield quantitative images of tracer activity. Physical phenomena such as photon scatter, photon attenuation, random coincidences and spatial resolution limit quantification potential and must be corrected to preserve the accuracy of reconstructed images. This study focuses on correcting the partial volume effects that arise in mouse heart imaging when resolution is insufficient to resolve the true tracer distribution in the myocardium. The correction algorithm is based on fitting 1D profiles through the myocardium in gated PET images to derive myocardial contours along with blood, background and myocardial activity. This information is interpolated onto a 2D grid and convolved with the tomograph's point spread function to derive regional recovery coefficients enabling partial volume correction. The point spread function was measured by placing a line source inside a small animal PET scanner. PET simulations were created based on noise properties measured from a reconstructed PET image and on the digital MOBY phantom. The algorithm can estimate the myocardial activity to within 5% of the truth when different wall thicknesses, backgrounds and noise properties are encountered that are typical of healthy FDG mouse scans. The method also significantly improves partial volume recovery in simulated infarcted tissue. The algorithm offers a practical solution to the partial volume problem without the need for co-registered anatomic images and offers a basis for improved quantitative 3D heart imaging.

Eliminating the blood-flow confounding effect in intravoxel incoherent motion (IVIM) using the non-negative least square analysis in liver.

PubMed

Gambarota, Giulio; Hitti, Eric; Leporq, Benjamin; Saint-Jalmes, Hervé; Beuf, Olivier

2017-01-01

Tissue perfusion measurements using intravoxel incoherent motion (IVIM) diffusion-MRI are of interest for investigations of liver pathologies. A confounding factor in the perfusion quantification is the partial volume between liver tissue and large blood vessels. The aim of this study was to assess and correct for this partial volume effect in the estimation of the perfusion fraction. MRI experiments were performed at 3 Tesla with a diffusion-MRI sequence at 12 b-values. Diffusion signal decays in liver were analyzed using the non-negative least square (NNLS) method and the biexponential fitting approach. In some voxels, the NNLS analysis yielded a very fast-decaying component that was assigned to partial volume with the blood flowing in large vessels. Partial volume correction was performed by biexponential curve fitting, where the first data point (b = 0 s/mm 2 ) was eliminated in voxels with a very fast-decaying component. Biexponential fitting with partial volume correction yielded parametric maps with perfusion fraction values smaller than biexponential fitting without partial volume correction. The results of the current study indicate that the NNLS analysis in combination with biexponential curve fitting allows to correct for partial volume effects originating from blood flow in IVIM perfusion fraction measurements. Magn Reson Med 77:310-317, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Tracking of BMI, fatness and cardiorespiratory fitness from adolescence to middle adulthood: the Zagreb Growth and Development Longitudinal Study.

PubMed

Sorić, Maroje; Jembrek Gostović, Mirjana; Gostović, Mladen; Hočevar, Marija; Mišigoj-Duraković, Marjeta

2014-01-01

Effective intervention strategies aiming to improve cardiorespiratory fitness and to decrease body fatness are needed. However, long-term stability of these traits is not well understood. To assess long-term tracking of cardiorespiratory fitness and body fatness from late adolescence to middle adulthood. The sample consisted of 50 participants (31 boys) from the Zagreb Growth and Development Longitudinal Study who were followed up in adulthood (median age = 43). Fatness was evaluated through BMI and skin-folds, while cardiorespiratory fitness was assessed using a cardiopulmonary exercise test. Inter-age partial correlation coefficients were calculated to evaluate tracking. Body mass index and skin-folds showed moderate tracking from age 15 years to middle adulthood (partial r = 0.55, p < 0.001 and partial r = 0.52, p < 0.001, respectively), while tracking of subcutaneous fat distribution was somewhat lower (partial r = 0.38, p < 0.01). At the same time, the observed tracking of peak oxygen uptake was low-to-moderate (partial r = 0.30, p = 0.03), while ventilatory aerobic and anaerobic thresholds did not show significant tracking. The results of this study indicate that preventive efforts aiming to increase cardiorespiratory fitness should include all adolescents, irrespective of their cardiorespiratory fitness status. Conversely, strategies aiming at obesity prevention should focus on high-risk groups of adolescents.

Revisiting the Short-term X-ray Spectral Variability of NGC 4151 with Chandra

NASA Astrophysics Data System (ADS)

Wang, Junfeng; Risaliti, G.; Fabbiano, G.; Elvis, M.; Zezas, A.; Karovska, M.

2010-05-01

We present new X-ray spectral data for the Seyfert 1 nucleus in NGC 4151 observed with Chandra for ~200 ks. A significant ACIS pileup is present, resulting in a nonlinear count rate variation during the observation. With pileup corrected spectral fitting, we are able to recover the spectral parameters and find consistency with those derived from unpiled events in the ACIS readout streak and outer region from the bright nucleus. The absorption corrected 2-10 keV flux of the nucleus varied between 6 × 10-11 erg s-1 cm-2 and 10-10 erg s-1 cm-2 (L 2-10 keV ~ 1.3-2.1 × 1042 erg s-1). Similar to earlier Chandra studies of NGC 4151 at a historical low state, the photon indices derived from the same absorbed power-law model are Γ ~ 0.7-0.9. However, we show that Γ is highly dependent on the adopted spectral models. Fitting the power-law continuum with a Compton reflection component gives Γ ~ 1.1. By including passage of non-uniform X-ray obscuring clouds, we can reproduce the apparent flat spectral states with Γ ~ 1.7, typical for Seyfert 1 active galactic nuclei. The same model also fits the hard spectra from previous ASCA "long look" observation of NGC 4151 in the lowest flux state. The spectral variability during our observation can be interpreted as variations in intrinsic soft continuum flux relative to a Compton reflection component that is from distant cold material and constant on short timescale, or variations of partially covering absorber in the line of sight toward the nucleus. An ionized absorber model with ionization parameter log ξ ~ 0.8-1.1 can also fit the low-resolution ACIS spectra. If the partial covering model is correct, adopting a black hole mass M_{BH}˜ 4.6× 10^7 M sun we constrain the distance of the obscuring cloud from the central black hole to be r <~ 9 lt-day, consistent with the size of the broad emission line region of NGC 4151 from optical reverberation mapping.

An index of effluent aquatic toxicity designed by partial least squares regression, using acute and chronic tests and expert judgements.

PubMed

Vindimian, Éric; Garric, Jeanne; Flammarion, Patrick; Thybaud, Éric; Babut, Marc

1999-10-01

The evaluation of the ecotoxicity of effluents requires a battery of biological tests on several species. In order to derive a summary parameter from such a battery, a single endpoint was calculated for all the tests: the EC10, obtained by nonlinear regression, with bootstrap evaluation of the confidence intervals. Principal component analysis was used to characterize and visualize the correlation between the tests. The table of the toxicity of the effluents was then submitted to a panel of experts, who classified the effluents according to the test results. Partial least squares (PLS) regression was used to fit the average value of the experts' judgements to the toxicity data, using a simple equation. Furthermore, PLS regression on partial data sets and other considerations resulted in an optimum battery, with two chronic tests and one acute test. The index is intended to be used for the classification of effluents based on their toxicity to aquatic species. Copyright © 1999 SETAC.

An index of effluent aquatic toxicity designed by partial least squares regression, using acute and chronic tests and expert judgments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vindimian, E.; Garric, J.; Flammarion, P.

1999-10-01

The evaluation of the ecotoxicity of effluents requires a battery of biological tests on several species. In order to derive a summary parameter from such a battery, a single endpoint was calculated for all the tests: the EC10, obtained by nonlinear regression, with bootstrap evaluation of the confidence intervals. Principal component analysis was used to characterize and visualize the correlation between the tests. The table of the toxicity of the effluents was then submitted to a panel of experts, who classified the effluents according to the test results. Partial least squares (PLS) regression was used to fit the average valuemore » of the experts' judgments to the toxicity data, using a simple equation. Furthermore, PLS regression on partial data sets and other considerations resulted in an optimum battery, with two chronic tests and one acute test. The index is intended to be used for the classification of effluents based on their toxicity to aquatic species.« less

Experts' Understanding of Partial Derivatives Using the Partial Derivative Machine

ERIC Educational Resources Information Center

Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

2015-01-01

Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of…

Light field creating and imaging with different order intensity derivatives

NASA Astrophysics Data System (ADS)

Wang, Yu; Jiang, Huan

2014-10-01

Microscopic image restoration and reconstruction is a challenging topic in the image processing and computer vision, which can be widely applied to life science, biology and medicine etc. A microscopic light field creating and three dimensional (3D) reconstruction method is proposed for transparent or partially transparent microscopic samples, which is based on the Taylor expansion theorem and polynomial fitting. Firstly the image stack of the specimen is divided into several groups in an overlapping or non-overlapping way along the optical axis, and the first image of every group is regarded as reference image. Then different order intensity derivatives are calculated using all the images of every group and polynomial fitting method based on the assumption that the structure of the specimen contained by the image stack in a small range along the optical axis are possessed of smooth and linear property. Subsequently, new images located any position from which to reference image the distance is Δz along the optical axis can be generated by means of Taylor expansion theorem and the calculated different order intensity derivatives. Finally, the microscopic specimen can be reconstructed in 3D form using deconvolution technology and all the images including both the observed images and the generated images. The experimental results show the effectiveness and feasibility of our method.

Experts' understanding of partial derivatives using the partial derivative machine

NASA Astrophysics Data System (ADS)

Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

2015-12-01

[This paper is part of the Focused Collection on Upper Division Physics Courses.] Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of students in STEM disciplines. In this paper, we report on an initial study of expert understanding of partial derivatives across three disciplines: physics, engineering, and mathematics. We report on the central research question of how disciplinary experts understand partial derivatives, and how their concept images of partial derivatives differ, with a focus on experimentally measured quantities. Using the partial derivative machine (PDM), we probed expert understanding of partial derivatives in an experimental context without a known functional form. In particular, we investigated which representations were cued by the experts' interactions with the PDM. Whereas the physicists and engineers were quick to use measurements to find a numeric approximation for a derivative, the mathematicians repeatedly returned to speculation as to the functional form; although they were comfortable drawing qualitative conclusions about the system from measurements, they were reluctant to approximate the derivative through measurement. On a theoretical front, we found ways in which existing frameworks for the concept of derivative could be expanded to include numerical approximation.

Frequency-dependent sexual selection.

PubMed

O'Donald, P; Majerus, M E

1988-07-06

Sexual selection by female choice is expected to give rise to a frequency-dependent sexual advantage in favour of preferred male phenotypes: the rarer the preferred phenotypes, the more often they are chosen as mates. This 'rare-male advantage' can maintain a polymorphism when two or more phenotypes are mated preferentially: each phenotype gains an advantage when it is rarer than the others; no preferred phenotype can then be lost from the population. Expression of preference may be complete or partial. In models of complete preference, females with a preference always mate preferentially. Models of partial preference are more realistic: in these models, the probability that a female mates preferentially depends on the frequency with which she encounters the males she prefers. Two different 'encounter models' of partial preference have been derived: the O'Donald model and the Charlesworth model. The encounter models contain the complete preference model as a limiting case. In this paper, the Charlesworth model is generalized to allow for female preference of more than one male phenotype. Levels of frequency dependence can then be compared in the O'Donald and Charlesworth models. The complete preference model and both encounter models are formulated in the same genetical terms of preferences for dominant and recessive male phenotypes. Polymorphic equilibria and conditions for stability are derived for each of the three models. The models are then fitted to data of frequencies of matings observed in experiments with the two-spot ladybird. The complete preference model gives as good a fit as the encounter models to the data of these and other experiments. The O'Donald and Charlesworth encounter models are shown to produce a very similar frequency-dependent relation. Generally, as females become less choosy, they express their preference with more dependence on male frequency, whereas the resulting selection of the males becomes less frequency dependent. More choosy females are more constant in expressing their preference, producing greater frequency dependence in the selection of the males.

On the derivation of flow rating curves in data-scarce environments

NASA Astrophysics Data System (ADS)

Manfreda, Salvatore

2018-07-01

River monitoring is a critical issue for hydrological modelling that relies strongly on the use of flow rating curves (FRCs). In most cases, these functions are derived by least-squares fitting which usually leads to good performance indices, even when based on a limited range of data that especially lack high flow observations. In this context, cross-section geometry is a controlling factor which is not fully exploited in classical approaches. In fact, river discharge is obtained as the product of two factors: 1) the area of the wetted cross-section and 2) the cross-sectionally averaged velocity. Both factors can be expressed as a function of the river stage, defining a viable alternative in the derivation of FRCs. This makes it possible to exploit information about cross-section geometry limiting, at least partially, the uncertainty in the extrapolation of discharge at higher flow values. Numerical analyses and field data confirm the reliability of the proposed procedure for the derivation of FRCs.

Rasch fit statistics and sample size considerations for polytomous data.

PubMed

Smith, Adam B; Rush, Robert; Fallowfield, Lesley J; Velikova, Galina; Sharpe, Michael

2008-05-29

Previous research on educational data has demonstrated that Rasch fit statistics (mean squares and t-statistics) are highly susceptible to sample size variation for dichotomously scored rating data, although little is known about this relationship for polytomous data. These statistics help inform researchers about how well items fit to a unidimensional latent trait, and are an important adjunct to modern psychometrics. Given the increasing use of Rasch models in health research the purpose of this study was therefore to explore the relationship between fit statistics and sample size for polytomous data. Data were collated from a heterogeneous sample of cancer patients (n = 4072) who had completed both the Patient Health Questionnaire - 9 and the Hospital Anxiety and Depression Scale. Ten samples were drawn with replacement for each of eight sample sizes (n = 25 to n = 3200). The Rating and Partial Credit Models were applied and the mean square and t-fit statistics (infit/outfit) derived for each model. The results demonstrated that t-statistics were highly sensitive to sample size, whereas mean square statistics remained relatively stable for polytomous data. It was concluded that mean square statistics were relatively independent of sample size for polytomous data and that misfit to the model could be identified using published recommended ranges.

Rasch fit statistics and sample size considerations for polytomous data

PubMed Central

Smith, Adam B; Rush, Robert; Fallowfield, Lesley J; Velikova, Galina; Sharpe, Michael

2008-01-01

Background Previous research on educational data has demonstrated that Rasch fit statistics (mean squares and t-statistics) are highly susceptible to sample size variation for dichotomously scored rating data, although little is known about this relationship for polytomous data. These statistics help inform researchers about how well items fit to a unidimensional latent trait, and are an important adjunct to modern psychometrics. Given the increasing use of Rasch models in health research the purpose of this study was therefore to explore the relationship between fit statistics and sample size for polytomous data. Methods Data were collated from a heterogeneous sample of cancer patients (n = 4072) who had completed both the Patient Health Questionnaire – 9 and the Hospital Anxiety and Depression Scale. Ten samples were drawn with replacement for each of eight sample sizes (n = 25 to n = 3200). The Rating and Partial Credit Models were applied and the mean square and t-fit statistics (infit/outfit) derived for each model. Results The results demonstrated that t-statistics were highly sensitive to sample size, whereas mean square statistics remained relatively stable for polytomous data. Conclusion It was concluded that mean square statistics were relatively independent of sample size for polytomous data and that misfit to the model could be identified using published recommended ranges. PMID:18510722

Experimental mutation-accumulation on the X chromosome of Drosophila melanogaster reveals stronger selection on males than females.

PubMed

Mallet, Martin A; Bouchard, Jessica M; Kimber, Christopher M; Chippindale, Adam K

2011-06-06

Sex differences in the magnitude or direction of mutational effect may be important to a variety of population processes, shaping the mutation load and affecting the cost of sex itself. These differences are expected to be greatest after sexual maturity. Mutation-accumulation (MA) experiments provide the most direct way to examine the consequences of new mutations, but most studies have focused on juvenile viability without regard to sex, and on autosomes rather than sex chromosomes; both adult fitness and X-linkage have been little studied. We therefore investigated the effects of 50 generations of X-chromosome mutation accumulation on the fitness of males and females derived from an outbred population of Drosophila melanogaster. Fitness declined rapidly in both sexes as a result of MA, but adult males showed markedly greater fitness loss relative to their controls compared to females expressing identical genotypes, even when females were made homozygous for the X. We estimate that these mutations are partially additive (h ~ 0.3) in females. In addition, the majority of new mutations appear to harm both males and females. Our data helps fill a gap in our understanding of the consequences of sexual selection for genetic load, and suggests that stronger selection on males may indeed purge deleterious mutations affecting female fitness.

Evaluating Descent and Ascent Trajectories Near Non-Spherical Bodies

NASA Technical Reports Server (NTRS)

Werner, Robert A.

2010-01-01

Spacecraft landing on small bodies pass through regions where conventional gravitation formulations using exterior spherical harmonics are inaccurate. An investigation shows that a formulation using interior solid spherical harmonics might be satisfactory. Interior spherical harmonic expansions are usable inside an imaginary, empty sphere. For this application, such a sphere could be positioned in empty space above the intended landing site and rotating with the body. When the spacecraft is inside this sphere, the interior harmonic expansion would be used instead of the conventional, exterior harmonic expansion. Coefficients can be determined by a least-squares fit to gravitation measurements synthesized from conventional formulations. Due to their unfamiliarity, recurrences for interior, as well as exterior, expansions are derived. Hotine's technique for partial derivatives of exterior spherical harmonics is extended to interior harmonics.

Efficient Power Network Analysis with Modeling of Inductive Effects

NASA Astrophysics Data System (ADS)

Zeng, Shan; Yu, Wenjian; Hong, Xianlong; Cheng, Chung-Kuan

In this paper, an efficient method is proposed to accurately analyze large-scale power/ground (P/G) networks, where inductive parasitics are modeled with the partial reluctance. The method is based on frequency-domain circuit analysis and the technique of vector fitting [14], and obtains the time-domain voltage response at given P/G nodes. The frequency-domain circuit equation including partial reluctances is derived, and then solved with the GMRES algorithm with rescaling, preconditioning and recycling techniques. With the merit of sparsified reluctance matrix and iterative solving techniques for the frequency-domain circuit equations, the proposed method is able to handle large-scale P/G networks with complete inductive modeling. Numerical results show that the proposed method is orders of magnitude faster than HSPICE, several times faster than INDUCTWISE [4], and capable of handling the inductive P/G structures with more than 100, 000 wire segments.

Dispersion relation for hadronic light-by-light scattering: two-pion contributions

DOE PAGES

Colangelo, Gilberto; Hoferichter, Martin; Procura, Massimiliano; ...

2017-04-27

In our third paper of a series dedicated to a dispersive treatment of the hadronic light-by-light (HLbL) tensor, we derive a partial-wave formulation for two-pion intermediate states in the HLbL contribution to the anomalous magnetic moment of the muon (g - 2) μ, including a detailed discussion of the unitarity relation for arbitrary partial waves. We show that obtaining a final expression free from unphysical helicity partial waves is a subtle issue, which we thoroughly clarify. As a by-product, we obtain a set of sum rules that could be used to constrain future calculations of γ*γ* → ππ. We validate the formalism extensively using the pion-box contribution, defined by two-pion intermediate states with a pion-pole left-hand cut, and demonstrate how the full known result is reproduced when resumming the partial waves. Using dispersive fits to high-statistics data for the pion vector form factor, we provide an evaluation of the full pion box, amore » $$π-box\\atop{μ}$$ =-15.9(2) × 10 -11. As an application of the partial-wave formalism, we present a first calculation of ππ-rescattering effects in HLbL scattering, with γ*γ* → ππ helicity partial waves constructed dispersively using ππ phase shifts derived from the inverse-amplitude method. In this way, the isospin-0 part of our calculation can be interpreted as the contribution of the f0(500) to HLbL scattering in (g - 2) μ. We also argue that the contribution due to charged-pion rescattering implements corrections related to the corresponding pion polarizability and show that these are moderate. Our final result for the sum of pion-box contribution and its S-wave rescattering corrections reads a$$π-box\\atop{μ}$$ + a$$ππ, π-pole LHC\\atop{μ, J=0}$$ = -24(1) × 10 -11.« less

Dispersion relation for hadronic light-by-light scattering: two-pion contributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colangelo, Gilberto; Hoferichter, Martin; Procura, Massimiliano

In our third paper of a series dedicated to a dispersive treatment of the hadronic light-by-light (HLbL) tensor, we derive a partial-wave formulation for two-pion intermediate states in the HLbL contribution to the anomalous magnetic moment of the muon (g - 2) μ, including a detailed discussion of the unitarity relation for arbitrary partial waves. We show that obtaining a final expression free from unphysical helicity partial waves is a subtle issue, which we thoroughly clarify. As a by-product, we obtain a set of sum rules that could be used to constrain future calculations of γ*γ* → ππ. We validate the formalism extensively using the pion-box contribution, defined by two-pion intermediate states with a pion-pole left-hand cut, and demonstrate how the full known result is reproduced when resumming the partial waves. Using dispersive fits to high-statistics data for the pion vector form factor, we provide an evaluation of the full pion box, amore » $$π-box\\atop{μ}$$ =-15.9(2) × 10 -11. As an application of the partial-wave formalism, we present a first calculation of ππ-rescattering effects in HLbL scattering, with γ*γ* → ππ helicity partial waves constructed dispersively using ππ phase shifts derived from the inverse-amplitude method. In this way, the isospin-0 part of our calculation can be interpreted as the contribution of the f0(500) to HLbL scattering in (g - 2) μ. We also argue that the contribution due to charged-pion rescattering implements corrections related to the corresponding pion polarizability and show that these are moderate. Our final result for the sum of pion-box contribution and its S-wave rescattering corrections reads a$$π-box\\atop{μ}$$ + a$$ππ, π-pole LHC\\atop{μ, J=0}$$ = -24(1) × 10 -11.« less

Adjoint-based constant-mass partial derivatives

DOE PAGES

Favorite, Jeffrey A.

2017-09-01

In transport theory, adjoint-based partial derivatives with respect to mass density are constant-volume derivatives. Likewise, adjoint-based partial derivatives with respect to surface locations (i.e., internal interface locations and the outer system boundary) are constant-density derivatives. This study derives the constant-mass partial derivative of a response with respect to an internal interface location or the outer system boundary and the constant-mass partial derivative of a response with respect to the mass density of a region. Numerical results are given for a multiregion two-dimensional (r-z) cylinder for three very different responses: the uncollided gamma-ray flux at an external detector point, k effmore » of the system, and the total neutron leakage. Finally, results from the derived formulas compare extremely well with direct perturbation calculations.« less

A method for evaluating models that use galaxy rotation curves to derive the density profiles

NASA Astrophysics Data System (ADS)

de Almeida, Álefe O. F.; Piattella, Oliver F.; Rodrigues, Davi C.

2016-11-01

There are some approaches, either based on General Relativity (GR) or modified gravity, that use galaxy rotation curves to derive the matter density of the corresponding galaxy, and this procedure would either indicate a partial or a complete elimination of dark matter in galaxies. Here we review these approaches, clarify the difficulties on this inverted procedure, present a method for evaluating them, and use it to test two specific approaches that are based on GR: the Cooperstock-Tieu (CT) and the Balasin-Grumiller (BG) approaches. Using this new method, we find that neither of the tested approaches can satisfactorily fit the observational data without dark matter. The CT approach results can be significantly improved if some dark matter is considered, while for the BG approach no usual dark matter halo can improve its results.

Measuring everyday functional competence using the Rasch assessment of everyday activity limitations (REAL) item bank.

PubMed

Oude Voshaar, Martijn A H; Ten Klooster, Peter M; Vonkeman, Harald E; van de Laar, Mart A F J

2017-11-01

Traditional patient-reported physical function instruments often poorly differentiate patients with mild-to-moderate disability. We describe the development and psychometric evaluation of a generic item bank for measuring everyday activity limitations in outpatient populations. Seventy-two items generated from patient interviews and mapped to the International Classification of Functioning, Disability and Health (ICF) domestic life chapter were administered to 1128 adults representative of the Dutch population. The partial credit model was fitted to the item responses and evaluated with respect to its assumptions, model fit, and differential item functioning (DIF). Measurement performance of a computerized adaptive testing (CAT) algorithm was compared with the SF-36 physical functioning scale (PF-10). A final bank of 41 items was developed. All items demonstrated acceptable fit to the partial credit model and measurement invariance across age, sex, and educational level. Five- and ten-item CAT simulations were shown to have high measurement precision, which exceeded that of SF-36 physical functioning scale across the physical function continuum. Floor effects were absent for a 10-item empirical CAT simulation, and ceiling effects were low (13.5%) compared with SF-36 physical functioning (38.1%). CAT also discriminated better than SF-36 physical functioning between age groups, number of chronic conditions, and respondents with or without rheumatic conditions. The Rasch assessment of everyday activity limitations (REAL) item bank will hopefully prove a useful instrument for assessing everyday activity limitations. T-scores obtained using derived measures can be used to benchmark physical function outcomes against the general Dutch adult population.

Partial-wave analysis of nucleon-nucleon elastic scattering data

DOE PAGES

Workman, Ron L.; Briscoe, William J.; Strakovsky, Igor I.

2016-12-19

Energy-dependent and single-energy fits to the existing nucleon-nucleon database have been updated to incorporate recent measurements. The fits cover a region from threshold to 3 GeV, in the laboratory kinetic energy, for proton-proton scattering, with an upper limit of 1.3 GeV for neutron-proton scattering. Experiments carried out at the COSY-WASA and COSY-ANKE facilities have had a significant impact on the partial-wave solutions. Lastly, results are discussed in terms of both partial-wave and direct reconstruction amplitudes.

Exponential Approximations Using Fourier Series Partial Sums

NASA Technical Reports Server (NTRS)

Banerjee, Nana S.; Geer, James F.

1997-01-01

The problem of accurately reconstructing a piece-wise smooth, 2(pi)-periodic function f and its first few derivatives, given only a truncated Fourier series representation of f, is studied and solved. The reconstruction process is divided into two steps. In the first step, the first 2N + 1 Fourier coefficients of f are used to approximate the locations and magnitudes of the discontinuities in f and its first M derivatives. This is accomplished by first finding initial estimates of these quantities based on certain properties of Gibbs phenomenon, and then refining these estimates by fitting the asymptotic form of the Fourier coefficients to the given coefficients using a least-squares approach. It is conjectured that the locations of the singularities are approximated to within O(N(sup -M-2), and the associated jump of the k(sup th) derivative of f is approximated to within O(N(sup -M-l+k), as N approaches infinity, and the method is robust. These estimates are then used with a class of singular basis functions, which have certain 'built-in' singularities, to construct a new sequence of approximations to f. Each of these new approximations is the sum of a piecewise smooth function and a new Fourier series partial sum. When N is proportional to M, it is shown that these new approximations, and their derivatives, converge exponentially in the maximum norm to f, and its corresponding derivatives, except in the union of a finite number of small open intervals containing the points of singularity of f. The total measure of these intervals decreases exponentially to zero as M approaches infinity. The technique is illustrated with several examples.

A partition function-based weighting scheme in force field parameter development using ab initio calculation results in global configurational space.

PubMed

Wu, Yao; Dai, Xiaodong; Huang, Niu; Zhao, Lifeng

2013-06-05

In force field parameter development using ab initio potential energy surfaces (PES) as target data, an important but often neglected matter is the lack of a weighting scheme with optimal discrimination power to fit the target data. Here, we developed a novel partition function-based weighting scheme, which not only fits the target potential energies exponentially like the general Boltzmann weighting method, but also reduces the effect of fitting errors leading to overfitting. The van der Waals (vdW) parameters of benzene and propane were reparameterized by using the new weighting scheme to fit the high-level ab initio PESs probed by a water molecule in global configurational space. The molecular simulation results indicate that the newly derived parameters are capable of reproducing experimental properties in a broader range of temperatures, which supports the partition function-based weighting scheme. Our simulation results also suggest that structural properties are more sensitive to vdW parameters than partial atomic charge parameters in these systems although the electrostatic interactions are still important in energetic properties. As no prerequisite conditions are required, the partition function-based weighting method may be applied in developing any types of force field parameters. Copyright © 2013 Wiley Periodicals, Inc.

Thermodynamic aspect in using modified Boltzmann model as an acoustic probe for URu2Si2

NASA Astrophysics Data System (ADS)

Kwang-Hua, Chu Rainer

2018-05-01

The approximate system of equations describing ultrasonic attenuation propagating in many electrons of the heavy-fermion materials URu2Si2 under high magnetic fields were firstly derived and then calculated based on the modified Boltzmann model considering the microscopic contributions due to electronic fluids. A system of nonlinear partial differential coupled with integral equations were linearized firstly and approximately solved considering the perturbed thermodynamic equilibrium states. Our numerical data were compared with previous measurements using non-dimensional or normalized physical values. The rather good fit of our numerical calculations with experimental measurements confirms our present approach.

[Krigle estimation and its simulated sampling of Chilo suppressalis population density].

PubMed

Yuan, Zheming; Bai, Lianyang; Wang, Kuiwu; Hu, Xiangyue

2004-07-01

In order to draw up a rational sampling plan for the larvae population of Chilo suppressalis, an original population and its two derivative populations, random population and sequence population, were sampled and compared with random sampling, gap-range-random sampling, and a new systematic sampling integrated Krigle interpolation and random original position. As for the original population whose distribution was up to aggregative and dependence range in line direction was 115 cm (6.9 units), gap-range-random sampling in line direction was more precise than random sampling. Distinguishing the population pattern correctly is the key to get a better precision. Gap-range-random sampling and random sampling are fit for aggregated population and random population, respectively, but both of them are difficult to apply in practice. Therefore, a new systematic sampling named as Krigle sample (n = 441) was developed to estimate the density of partial sample (partial estimation, n = 441) and population (overall estimation, N = 1500). As for original population, the estimated precision of Krigle sample to partial sample and population was better than that of investigation sample. With the increase of the aggregation intensity of population, Krigel sample was more effective than investigation sample in both partial estimation and overall estimation in the appropriate sampling gap according to the dependence range.

Impact of digital impression techniques on the adaption of ceramic partial crowns in vitro.

PubMed

Schaefer, Oliver; Decker, Mike; Wittstock, Frank; Kuepper, Harald; Guentsch, Arndt

2014-06-01

To investigate the effects, digital impression procedures can have on the three-dimensional fit of ceramic partial crowns in vitro. An acrylic model of a mandibular first molar was prepared to receive a partial coverage all-ceramic crown (mesio-occlusal-distal inlay preparation with reduction of all cusps and rounded shoulder finish line of buccal wall). Digital impressions were taken using iTero (ITE), cara TRIOS (TRI), CEREC AC with Bluecam (CBC), and Lava COS (COS) systems, before restorations were designed and machined from lithium disilicate blanks. Both the preparation and the restorations were digitised using an optical reference-scanner. Data were entered into quality inspection software, which superimposed the records (best-fit-algorithm), calculated fit-discrepancies for every pixel, and colour-coded the results to aid visualisation. Furthermore, mean quadratic deviations (RMS) were computed and analysed statistically with a one-way ANOVA. Scheffé's procedure was applied for multiple comparisons (n=5, α=0.05). Mean marginal (internal) discrepancies were: ITE 90 (92) μm, TRI 128 (106) μm, CBC 146 (84) μm, and COS 109 (93) μm. Differences among impression systems were statistically significant at p<0.001 (p=0.039). Qualitatively, partial crowns were undersized especially around cusp tips or the occluso-approximal isthmus. By contrast, potential high-spots could be detected along the preparation finishline and at central occlusal boxes. Marginal and internal fit of milled lithium disilicate partial crowns depended on the employed digital impression technique. The investigated digital impression procedures demonstrated significant fit discrepancies. However, all fabricated restorations showed acceptable marginal and internal gap sizes, when considering clinically relevant thresholds reported in the literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Validation of MODIS Aerosol Optical Depth Retrieval Over Land

NASA Technical Reports Server (NTRS)

Chu, D. A.; Kaufman, Y. J.; Ichoku, C.; Remer, L. A.; Tanre, D.; Holben, B. N.; Einaudi, Franco (Technical Monitor)

2001-01-01

Aerosol optical depths are derived operationally for the first time over land in the visible wavelengths by MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the EOSTerra spacecraft. More than 300 Sun photometer data points from more than 30 AERONET (Aerosol Robotic Network) sites globally were used in validating the aerosol optical depths obtained during July - September 2000. Excellent agreement is found with retrieval errors within (Delta)tau=+/- 0.05 +/- 0.20 tau, as predicted, over (partially) vegetated surfaces, consistent with pre-launch theoretical analysis and aircraft field experiments. In coastal and semi-arid regions larger errors are caused predominantly by the uncertainty in evaluating the surface reflectance. The excellent fit was achieved despite the ongoing improvements in instrument characterization and calibration. This results show that MODIS-derived aerosol optical depths can be used quantitatively in many applications with cautions for residual clouds, snow/ice, and water contamination.

Fatness mediates the influence of muscular fitness on metabolic syndrome in Colombian collegiate students.

PubMed

García-Hermoso, Antonio; Carrillo, Hugo Alejandro; González-Ruíz, Katherine; Vivas, Andrés; Triana-Reina, Héctor Reynaldo; Martínez-Torres, Javier; Prieto-Benavidez, Daniel Humberto; Correa-Bautista, Jorge Enrique; Ramos-Sepúlveda, Jeison Alexander; Villa-González, Emilio; Peterson, Mark D; Ramírez-Vélez, Robinson

2017-01-01

The purpose of this study was two-fold: to analyze the association between muscular fitness (MF) and clustering of metabolic syndrome (MetS) components, and to determine if fatness parameters mediate the association between MF and MetS clustering in Colombian collegiate students. This cross-sectional study included a total of 886 (51.9% women) healthy collegiate students (21.4 ± 3.3 years old). Standing broad jump and isometric handgrip dynamometry were used as indicators of lower and upper body MF, respectively. Also, a MF score was computed by summing the standardized values of both tests, and used to classify adults as fit or unfit. We also assessed fat mass, body mass index, waist-to-height ratio, and abdominal visceral fat, and categorized individuals as low and high fat using international cut-offs. A MetS cluster score was derived by calculating the sum of the sample-specific z-scores from the triglycerides, HDL cholesterol, fasting glucose, waist circumference, and arterial blood pressure. Linear regression models were used to examine whether the association between MF and MetS cluster was mediated by the fatness parameters. Data were collected from 2013 to 2016 and the analysis was done in 2016. Findings revealed that the best profiles (fit + low fat) were associated with lower levels of the MetS clustering (p <0.001 in the four fatness parameters), compared with unfit and fat (unfit + high fat) counterparts. Linear regression models indicated a partial mediating effect for fatness parameters in the association of MF with MetS clustering. Our findings indicate that efforts to improve MF in young adults may decrease MetS risk partially through an indirect effect on improvements to adiposity levels. Thus, weight reduction should be taken into account as a complementary goal to improvements in MF within exercise programs.

Fatness mediates the influence of muscular fitness on metabolic syndrome in Colombian collegiate students

PubMed Central

Carrillo, Hugo Alejandro; González-Ruíz, Katherine; Vivas, Andrés; Triana-Reina, Héctor Reynaldo; Martínez-Torres, Javier; Prieto-Benavidez, Daniel Humberto; Ramos-Sepúlveda, Jeison Alexander; Villa-González, Emilio

2017-01-01

The purpose of this study was two-fold: to analyze the association between muscular fitness (MF) and clustering of metabolic syndrome (MetS) components, and to determine if fatness parameters mediate the association between MF and MetS clustering in Colombian collegiate students. This cross-sectional study included a total of 886 (51.9% women) healthy collegiate students (21.4 ± 3.3 years old). Standing broad jump and isometric handgrip dynamometry were used as indicators of lower and upper body MF, respectively. Also, a MF score was computed by summing the standardized values of both tests, and used to classify adults as fit or unfit. We also assessed fat mass, body mass index, waist-to-height ratio, and abdominal visceral fat, and categorized individuals as low and high fat using international cut-offs. A MetS cluster score was derived by calculating the sum of the sample-specific z-scores from the triglycerides, HDL cholesterol, fasting glucose, waist circumference, and arterial blood pressure. Linear regression models were used to examine whether the association between MF and MetS cluster was mediated by the fatness parameters. Data were collected from 2013 to 2016 and the analysis was done in 2016. Findings revealed that the best profiles (fit + low fat) were associated with lower levels of the MetS clustering (p <0.001 in the four fatness parameters), compared with unfit and fat (unfit + high fat) counterparts. Linear regression models indicated a partial mediating effect for fatness parameters in the association of MF with MetS clustering. Our findings indicate that efforts to improve MF in young adults may decrease MetS risk partially through an indirect effect on improvements to adiposity levels. Thus, weight reduction should be taken into account as a complementary goal to improvements in MF within exercise programs. PMID:28296952

The Association of Health-Related Fitness with Indicators of Academic Performance in Texas Schools

ERIC Educational Resources Information Center

Welk, Gregory J.; Jackson, Allen W.; Morrow, James R., Jr.; Haskell, William H.; Meredith, Marilu D.; Cooper, Kenneth H.

2010-01-01

This study examined the associations between indicators of health-related physical fitness (cardiovascular fitness and body mass index) and academic performance (Texas Assessment of Knowledge and Skills). Partial correlations were generally stronger for cardiovascular fitness than body mass index and consistently stronger in the middle school…

Structural effects in fluorinated cyclopropanes: A microwave study of cis-1,1,2,3-tetrafluorocyclopropane

NASA Astrophysics Data System (ADS)

Beauchamp, R. N.; Gillies, C. W.; Gillies, J. Z.

1990-12-01

Microwave and RFMDR spectra of cis- overlineCHFCHFCF 2, cis- 13overlineCHFCHFCF 2, cis- overlineCDFCDFCF 2, and cis- 13overlineCDFCDFCF 2 have been measured between 26.5 and 40.0 GHz using an HP 8400C spectrometer. The a- and c-type transitions were assigned and fit to the quartic Watson Hamiltonian giving A = 3450.445(2) MHz, B = 2402.831(3) MHz, C = 2060.247(3) MHz, Δ J = 0.39(3) kHz, Δ JK = 0.26(1) kHz, δK = 1.606(9) kHz, δJ = 0.059(1) kHz, and δJK = -0.58(2) kHz for cis- overlineCHFCHFCF 2. A structure is derived from the moment of inertia data by fixing three parameters associated with the CF 2 group. The rS parameters for the CHFCHF segment of the molecule in the overlineCHFCHFCF 2 isotopic frame are r (C 2C 3) = 1.533(3) Å, r (C 2,3H) = 1.099(3) Å, r (F 2 ⋯ F 3) = 2.775(2) Å, and r (H 2 ⋯ H 3) = 2.622(2) Å. Two algorithms describing the CC and CF bond distances are fitted to gas phase structural data for a series of fluorinated cyclopropane derivatives. A partial test of these algorithms is obtained from the structure of cis- overlineCHFCHFCF 2. The structural results are related to theoretical studies of fluorination effects in cyclopropane derivatives.

Correlations of π N partial waves for multireaction analyses

DOE PAGES

Doring, M.; Revier, J.; Ronchen, D.; ...

2016-06-15

In the search for missing baryonic resonances, many analyses include data from a variety of pion- and photon-induced reactions. For elastic πN scattering, however, usually the partial waves of the SAID (Scattering Analysis Interactive Database) or other groups are fitted, instead of data. We provide the partial-wave covariance matrices needed to perform correlated χ 2 fits, in which the obtained χ 2 equals the actual χ 2 up to nonlinear and normalization corrections. For any analysis relying on partial waves extracted from elastic pion scattering, this is a prerequisite to assess the significance of resonance signals and to assign anymore » uncertainty on results. Lastly, the influence of systematic errors is also considered.« less

Estimating of aquifer parameters from the single-well water-level measurements in response to advancing longwall mine by using particle swarm optimization

NASA Astrophysics Data System (ADS)

Buyuk, Ersin; Karaman, Abdullah

2017-04-01

We estimated transmissivity and storage coefficient values from the single well water-level measurements positioned ahead of the mining face by using particle swarm optimization (PSO) technique. The water-level response to the advancing mining face contains an semi-analytical function that is not suitable for conventional inversion shemes because the partial derivative is difficult to calculate . Morever, the logaritmic behaviour of the model create difficulty for obtaining an initial model that may lead to a stable convergence. The PSO appears to obtain a reliable solution that produce a reasonable fit between water-level data and model function response. Optimization methods have been used to find optimum conditions consisting either minimum or maximum of a given objective function with regard to some criteria. Unlike PSO, traditional non-linear optimization methods have been used for many hydrogeologic and geophysical engineering problems. These methods indicate some difficulties such as dependencies to initial model, evolution of the partial derivatives that is required while linearizing the model and trapping at local optimum. Recently, Particle swarm optimization (PSO) became the focus of modern global optimization method that is inspired from the social behaviour of birds of swarms, and appears to be a reliable and powerful algorithms for complex engineering applications. PSO that is not dependent on an initial model, and non-derivative stochastic process appears to be capable of searching all possible solutions in the model space either around local or global optimum points.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favorite, Jeffrey A.

In transport theory, adjoint-based partial derivatives with respect to mass density are constant-volume derivatives. Likewise, adjoint-based partial derivatives with respect to surface locations (i.e., internal interface locations and the outer system boundary) are constant-density derivatives. This study derives the constant-mass partial derivative of a response with respect to an internal interface location or the outer system boundary and the constant-mass partial derivative of a response with respect to the mass density of a region. Numerical results are given for a multiregion two-dimensional (r-z) cylinder for three very different responses: the uncollided gamma-ray flux at an external detector point, k effmore » of the system, and the total neutron leakage. Finally, results from the derived formulas compare extremely well with direct perturbation calculations.« less

The acquisition of conditioned responding.

PubMed

Harris, Justin A

2011-04-01

This report analyzes the acquisition of conditioned responses in rats trained in a magazine approach paradigm. Following the suggestion by Gallistel, Fairhurst, and Balsam (2004), Weibull functions were fitted to the trial-by-trial response rates of individual rats. These showed that the emergence of responding was often delayed, after which the response rate would increase relatively gradually across trials. The fit of the Weibull function to the behavioral data of each rat was equaled by that of a cumulative exponential function incorporating a response threshold. Thus, the growth in conditioning strength on each trial can be modeled by the derivative of the exponential--a difference term of the form used in many models of associative learning (e.g., Rescorla & Wagner, 1972). Further analyses, comparing the acquisition of responding with a continuously reinforced stimulus (CRf) and a partially reinforced stimulus (PRf), provided further evidence in support of the difference term. In conclusion, the results are consistent with conventional models that describe learning as the growth of associative strength, incremented on each trial by an error-correction process.

Three-dimensional quantitative structure-property relationship (3D-QSPR) models for prediction of thermodynamic properties of polychlorinated biphenyls (PCBs): enthalpy of vaporization.

PubMed

Puri, Swati; Chickos, James S; Welsh, William J

2002-01-01

Three-dimensional Quantitative Structure-Property Relationship (QSPR) models have been derived using Comparative Molecular Field Analysis (CoMFA) to correlate the vaporization enthalpies of a representative set of polychlorinated biphenyls (PCBs) at 298.15 K with their CoMFA-calculated physicochemical properties. Various alignment schemes, such as inertial, as is, and atom fit, were employed in this study. The CoMFA models were also developed using different partial charge formalisms, namely, electrostatic potential (ESP) charges and Gasteiger-Marsili (GM) charges. The most predictive model for vaporization enthalpy (Delta(vap)H(m)(298.15 K)), with atom fit alignment and Gasteiger-Marsili charges, yielded r2 values 0.852 (cross-validated) and 0.996 (conventional). The vaporization enthalpies of PCBs increased with the number of chlorine atoms and were found to be larger for the meta- and para-substituted isomers. This model was used to predict Delta(vap)H(m)(298.15 K) of the entire set of 209 PCB congeners.

Thermal equation of state of TiC: A synchrotron x-ray diffraction study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu Xiaohui; National Lab for Condensed Matter Physics, Institute of Physics, CAS, Beijing 100080; Department of Physics, University of Science and Technology of China, Hefei 230026

2010-06-15

The pressure-volume-temperature measurements were carried out for titanium carbide (TiC) at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal pressure approach. With the pressure derivative of the bulk modulus, K{sub 0}{sup '}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0}=268(6) GPa, which is comparable to previously reported value; temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub P}=-0.026(9) GPa K{sup -1}, volumetric thermal expansivity {alpha}{sub T}(K{sup -1})=a+bT with a=1.62(12)x10{sup -5} K{supmore » -1} and b=1.07(17)x10{sup -8} K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}{alpha}/{partial_derivative}P){sub T}=(-3.62{+-}1.14)x10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub V}=-0.015(8) GPa K{sup -1}. These results provide fundamental thermophysical properties for TiC for the first time and are important to theoretical and computational modeling of transition metal carbides.« less

Thermal equation-of-state of TiC: a synchrotron x-ray diffraction study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Xiaohui; Lin, Zhijun; Zhang, Jianzhong

2009-01-01

The pressure (P)-volume (V)-temperature (T) measurements were carried out for titanium carbide at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal-pressure approach. With the pressure derivative of the bulk modulus, K'{sub 0}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0} = 268(6) GPa, temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub p} = -0.026(9) GPa K{sup -1}, volumetric thermal expansivity a{sub T}(K{sup -1}) = a + bT with a =more » 1.62(12) x 10{sup -5} K{sup -1} and b = 1.07(17) x 10{sup -8} K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}a/{partial_derivative}P){sub T} = (-3.62 {+-} 1.14) x 10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub v} = -0.015 (8) GPa K{sup -1}. These results provide fundamental thermo physical properties for TiC and are important to theoretical and computational modeling of transition metal carbides.« less

Monotonicity of fitness landscapes and mutation rate control.

PubMed

Belavkin, Roman V; Channon, Alastair; Aston, Elizabeth; Aston, John; Krašovec, Rok; Knight, Christopher G

2016-12-01

A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the performance of evolutionary algorithms. Much biological theory in this area is based on Ronald Fisher's work, who used Euclidean geometry to study the relation between mutation size and expected fitness of the offspring in infinite phenotypic spaces. Here we reconsider this theory based on the alternative geometry of discrete and finite spaces of DNA sequences. First, we consider the geometric case of fitness being isomorphic to distance from an optimum, and show how problems of optimal mutation rate control can be solved exactly or approximately depending on additional constraints of the problem. Then we consider the general case of fitness communicating only partial information about the distance. We define weak monotonicity of fitness landscapes and prove that this property holds in all landscapes that are continuous and open at the optimum. This theoretical result motivates our hypothesis that optimal mutation rate functions in such landscapes will increase when fitness decreases in some neighbourhood of an optimum, resembling the control functions derived in the geometric case. We test this hypothesis experimentally by analysing approximately optimal mutation rate control functions in 115 complete landscapes of binding scores between DNA sequences and transcription factors. Our findings support the hypothesis and find that the increase of mutation rate is more rapid in landscapes that are less monotonic (more rugged). We discuss the relevance of these findings to living organisms.

Peripheral Refraction, Peripheral Eye Length, and Retinal Shape in Myopia.

PubMed

Verkicharla, Pavan K; Suheimat, Marwan; Schmid, Katrina L; Atchison, David A

2016-09-01

To investigate how peripheral refraction and peripheral eye length are related to retinal shape. Relative peripheral refraction (RPR) and relative peripheral eye length (RPEL) were determined in 36 young adults (M +0.75D to -5.25D) along horizontal and vertical visual field meridians out to ±35° and ±30°, respectively. Retinal shape was determined in terms of vertex radius of curvature Rv, asphericity Q, and equivalent radius of curvature REq using a partial coherence interferometry method involving peripheral eye lengths and model eye raytracing. Second-order polynomial fits were applied to RPR and RPEL as functions of visual field position. Linear regressions were determined for the fits' second order coefficients and for retinal shape estimates as functions of central spherical refraction. Linear regressions investigated relationships of RPR and RPEL with retinal shape estimates. Peripheral refraction, peripheral eye lengths, and retinal shapes were significantly affected by meridian and refraction. More positive (hyperopic) relative peripheral refraction, more negative RPELs, and steeper retinas were found along the horizontal than along the vertical meridian and in myopes than in emmetropes. RPR and RPEL, as represented by their second-order fit coefficients, correlated significantly with retinal shape represented by REq. Effects of meridian and refraction on RPR and RPEL patterns are consistent with effects on retinal shape. Patterns derived from one of these predict the others: more positive (hyperopic) RPR predicts more negative RPEL and steeper retinas, more negative RPEL predicts more positive relative peripheral refraction and steeper retinas, and steeper retinas derived from peripheral eye lengths predict more positive RPR.

Incorporating partial shining effects in proton pencil-beam dose calculation

NASA Astrophysics Data System (ADS)

Li, Yupeng; Zhang, Xiaodong; Fwu Lii, Ming; Sahoo, Narayan; Zhu, Ron X.; Gillin, Michael; Mohan, Radhe

2008-02-01

A range modulator wheel (RMW) is an essential component in passively scattered proton therapy. We have observed that a proton beam spot may shine on multiple steps of the RMW. Proton dose calculation algorithms normally do not consider the partial shining effect, and thus overestimate the dose at the proximal shoulder of spread-out Bragg peak (SOBP) compared with the measurement. If the SOBP is adjusted to better fit the plateau region, the entrance dose is likely to be underestimated. In this work, we developed an algorithm that can be used to model this effect and to allow for dose calculations that better fit the measured SOBP. First, a set of apparent modulator weights was calculated without considering partial shining. Next, protons spilled from the accelerator reaching the modulator wheel were simplified as a circular spot of uniform intensity. A weight-splitting process was then performed to generate a set of effective modulator weights with the partial shining effect incorporated. The SOBPs of eight options, which are used to label different combinations of proton-beam energy and scattering devices, were calculated with the generated effective weights. Our algorithm fitted the measured SOBP at the proximal and entrance regions much better than the ones without considering partial shining effect for all SOBPs of the eight options. In a prostate patient, we found that dose calculation without considering partial shining effect underestimated the femoral head and skin dose.

The use of CT derived solid modelling of the pelvis in planning cancer resections.

PubMed

Bruns, J; Habermann, C R; Rüther, W; Delling, D

2010-06-01

Resection of malignant tumors of the pelvis is demanding. To avoid disabling hemipelvectomies, years ago internal hemipelvectomy combined with partial pelvic replacements had become a surgical procedure. To achieve adequate reconstructions custom-made replacements were recommended. In early stages of the surgical procedure using megaprostheses, individual pelvic models were manufactured. Since little is known about the accuracy of such models we analysed the charts of 24 patients (25 models) for whom an individual model of the osseous pelvis had been manufactured. Two patients refused surgery. In 23 patients partial resection of the bony pelvis was performed followed by a partial pelvic replacement (13x), hip transposition procedure (5x), ilio-sacral resection (4x), or revision surgery. In all patients who received a partial pelvic replacement, the fit of the replacement was optimal. No major unplanned resection was necessary. The same was observed in patients who received a hip transposition procedure or an ilio-sacral resection. Oncologically, in most of the patients we achieved wide resection margins (14x). In 5 patients the margins were marginal (4x) or intralesional (1x). In two cases the aim was a palliative resection because of a metastatic disease (1x) or benign entity (1x). Pelvic models are helpful tools to planning the manufacture of partial pelvic replacements and ensuring optimal osseous resection of the involved bone. Further attempts have to be made to evaluate the aim of navigational techniques regarding the accuracy of the osseous and soft-tissue resection.

A Novel Computer-Aided Design/Computer-Assisted Manufacture Method for One-Piece Removable Partial Denture and Evaluation of Fit.

PubMed

Ye, Hongqiang; Li, Xinxin; Wang, Guanbo; Kang, Jing; Liu, Yushu; Sun, Yuchun; Zhou, Yongsheng

2018-02-15

To investigate a computer-aided design/computer-aided manufacturing (CAD/CAM) process for producing one-piece removable partial dentures (RPDs) and to evaluate their fits in vitro. A total of 15 one-piece RPDs were designed using dental CAD and reverse engineering software and then fabricated with polyetheretherketone (PEEK) using CAM. The gaps between RPDs and casts were measured and compared with traditional cast framework RPDs. Gaps were lower for one-piece PEEK RPDs compared to traditional RPDs. One-piece RPDs can be manufactured by CAD/CAM, and their fits were better than those of traditional RPDs.

Planar Lattice Instability in LA2CUO4.1 across the Superconducting Transition

NASA Astrophysics Data System (ADS)

Acosta-Alejandro, Manuel; Mustre-de Leon, Jose; Conradson, Steven

2001-03-01

The local atomic structure of La2CuO4.1 around Cu K-edge is analyzed for 10

Comparison of three-parameter probability distributions for representing annual extreme and partial duration precipitation series

NASA Astrophysics Data System (ADS)

Wilks, Daniel S.

1993-10-01

Performance of 8 three-parameter probability distributions for representing annual extreme and partial duration precipitation data at stations in the northeastern and southeastern United States is investigated. Particular attention is paid to fidelity on the right tail, through use of a bootstrap procedure simulating extrapolation on the right tail beyond the data. It is found that the beta-κ distribution best describes the extreme right tail of annual extreme series, and the beta-P distribution is best for the partial duration data. The conventionally employed two-parameter Gumbel distribution is found to substantially underestimate probabilities associated with the larger precipitation amounts for both annual extreme and partial duration data. Fitting the distributions using left-censored data did not result in improved fits to the right tail.

Influence of Different CAM Strategies on the Fit of Partial Crown Restorations: A Digital Three-dimensional Evaluation.

PubMed

Zimmermann, M; Valcanaia, A; Neiva, G; Mehl, A; Fasbinder, D

2018-04-09

CAM fabrication is an important step within the CAD/CAM process. The internal fit of restorations is influenced by the accuracy of the subtractive CAM procedure. Little is known about how CAM strategies might influence the fit of CAD/CAM fabricated restorations. The aim of this study was to three-dimensionally evaluate the fit of CAD/CAM fabricated zirconia-reinforced lithium silicate ceramic partial crowns fabricated with three different CAM strategies. The null hypothesis was that different CAM strategies did not influence the fitting accuracy of CAD/CAM fabricated zirconia-reinforced lithium silicate ceramic partial crowns. Preparation for a partial crown was performed on a maxillary right first molar on a typodont. A chairside CAD/CAM system with the intraoral scanning device CEREC Omnicam (Dentsply Sirona, York, PA, USA) and the 3+1 axis milling unit CEREC MCXL was used. There were three groups with different CAM strategies: step bur 12 (12), step bur 12S (12S), and two step-mode (12TWO). The zirconia-reinforced lithium silicate ceramic Celtra Duo (Dentsply Sirona) was used as the CAD/CAM material. A new 3D method for evaluating the fit was applied, consisting of the quadrant scan with the intraoral scanning device CEREC Omnicam. The scan of the PVS material adherent to the preparation and the preparation scan were matched, and the difference analysis was performed with special software OraCheck (Cyfex AG, Zurich, Switzerland). Three areas were selected for analysis: margin (MA), axial (AX), and occlusal (OC). Statistical analysis was performed using 80% percentile, one-way ANOVA, and the post hoc Scheffé test with α=0.05. Statistically significant differences were found both within and between the test groups. The aspect axial fit results varied from 90.5 ± 20.1 μm for the two-step milling mode (12TWO_AX) to 122.8 ± 12.2 μm for the milling with step bur 12S (12S_AX). The worst result in all groups was found for the aspect occlusal fit with the highest value for group 12S of 222.8 ± 35.6 μm. Group two-step milling mode (12TWO) performed statistically significantly better from groups 12 and 12S for the occlusal fit ( p<0.05). Deviation patterns were visually analyzed with a color-coded scheme for each restoration. CAM strategy influenced the internal adaptation of zirconia-reinforced lithium silicate partial crowns fabricated with a chairside CAD/CAM system. Sensible selection of specific areas of internal adaptation and fit is an important factor for evaluating the CAM accuracy of CAD/CAM systems.

Antagonistic versus non-antagonistic models of balancing selection: Characterizing the relative timescales and hitchhiking effects of partial selective sweeps

PubMed Central

Connallon, Tim; Clark, Andrew G.

2012-01-01

Antagonistically selected alleles -- those with opposing fitness effects between sexes, environments, or fitness components -- represent an important component of additive genetic variance in fitness-related traits, with stably balanced polymorphisms often hypothesized to contribute to observed quantitative genetic variation. Balancing selection hypotheses imply that intermediate-frequency alleles disproportionately contribute to genetic variance of life history traits and fitness. Such alleles may also associate with population genetic footprints of recent selection, including reduced genetic diversity and inflated linkage disequilibrium at linked, neutral sites. Here, we compare the evolutionary dynamics of different balancing selection models, and characterize the evolutionary timescale and hitchhiking effects of partial selective sweeps generated under antagonistic versus non-antagonistic (e.g., overdominant and frequency-dependent selection) processes. We show that that the evolutionary timescales of partial sweeps tend to be much longer, and hitchhiking effects are drastically weaker, under scenarios of antagonistic selection. These results predict an interesting mismatch between molecular population genetic and quantitative genetic patterns of variation. Balanced, antagonistically selected alleles are expected to contribute more to additive genetic variance for fitness than alleles maintained by classic, non-antagonistic mechanisms. Nevertheless, classical mechanisms of balancing selection are much more likely to generate strong population genetic signatures of recent balancing selection. PMID:23461340

Thermal Equation of State of TiC: A Synchrotron X-ray Diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, X.; Lin, Z; Zhang, J

2010-01-01

The pressure-volume-temperature measurements were carried out for titanium carbide (TiC) at pressures and temperatures up to 8.1 GPa and 1273 K using energy-dispersive synchrotron x-ray diffraction. Thermoelastic parameters were derived for TiC based on a modified high-temperature Birch-Murnaghan equation of state and a thermal pressure approach. With the pressure derivative of the bulk modulus, K{prime}{sub 0}, fixed at 4.0, we obtain: the ambient bulk modulus K{sub 0} = 268(6) GPa, which is comparable to previously reported value; temperature derivative of bulk modulus at constant pressure ({partial_derivative}K{sub T}/{partial_derivative}T){sub P} = -0.026(9) GPa K{sup -1}, volumetric thermal expansivity {alpha}{sub T}(K{sup -1}) =more » a+b T with a = 1.62(12) x 10{sup -5} K{sup -1} and b = 1.07(17) x 10{sup -8}K{sup -2}, pressure derivative of thermal expansion ({partial_derivative}{sub {alpha}}/{partial_derivative}{sub P}){sub T} = (-3.62 {+-} 1.14) x 10{sup -7} GPa{sup -1} K{sup -1}, and temperature derivative of bulk modulus at constant volume ({partial_derivative}K{sub T}/{partial_derivative}T){sub V} = -0.015(8) GPa K{sup -1}. These results provide fundamental thermophysical properties for TiC for the first time and are important to theoretical and computational modeling of transition metal carbides.« less

Parental antagonism, relatedness asymmetries, and genomic imprinting.

PubMed Central

Haig, D

1997-01-01

The theory of inclusive fitness can be modified to consider separate coefficients of relatedness for an individual's maternal and paternal alleles. A gene is said to have parentally antagonistic effects if it has an inclusive fitness benefit when maternally derived, but an inclusive fitness cost when paternally derived (or vice versa). Parental antagonism favours the evolution of alleles that are expressed only when maternally derived or only when paternally derived (genomic imprinting). PMID:9404029

DOE Office of Scientific and Technical Information (OSTI.GOV)

Workman, Ron L.; Briscoe, William J.; Strakovsky, Igor I.

Energy-dependent and single-energy fits to the existing nucleon-nucleon database have been updated to incorporate recent measurements. The fits cover a region from threshold to 3 GeV, in the laboratory kinetic energy, for proton-proton scattering, with an upper limit of 1.3 GeV for neutron-proton scattering. Experiments carried out at the COSY-WASA and COSY-ANKE facilities have had a significant impact on the partial-wave solutions. Lastly, results are discussed in terms of both partial-wave and direct reconstruction amplitudes.

Relevance of Variations in the Opposing Dentition for the Functionality of Fixed and Removable Partial Dentures: A Systematic Review

PubMed Central

Pommer, Bernhard; Krainhöfner, Martin; Watzek, Georg; Tepper, Gabor; Dintsios, Charalabos-Markos

2012-01-01

The aim of this systematic review was to evaluate the functionality of fixed and removable partial dentures as test interventions in relation to variations in the opposing dentition and their prosthetic restoration. The abstracts identified in the respective databases were screened independently by two investigators. RCTs and uncontrolled studies were considered, provided the patients were included consecutively and the confounding variables were adequately monitored. Seventeen papers were included. The study and publication quality was assessed using a “biometric quality” tool showing an overall poor quality. The reported outcomes, such as survival rates, were in each case obtained from a single study. Two possible trends could be deduced for the endpoint longevity: (a) the first trend in favor of removable partial dentures, compared to fixed partial dentures, with a fully edentulous opposing arch fitted with a removable prosthesis; (b) the second trend in favor of implant-supported partial dentures, compared to conventionally fixed partial dentures, with natural opposing dentition or with a removable partial denture in the opposing arch. No evidence could be generated as to whether, and if so how, variations in the opposing dentition have a bearing on the decision to fit a partially edentulous arch with a fixed or removable partial denture. PMID:23193407

Radioecological modelling of Polonium-210 and Caesium-137 in lichen-reindeer-man and top predators.

PubMed

Persson, Bertil R R; Gjelsvik, Runhild; Holm, Elis

2018-06-01

This work deals with analysis and modelling of the radionuclides 210 Pb and 210 Po in the food-chain lichen-reindeer-man in addition to 210 Po and 137 Cs in top predators. By using the methods of Partial Least Square Regression (PLSR) the atmospheric deposition of 210 Pb and 210 Po is predicted at the sample locations. Dynamic modelling of the activity concentration with differential equations is fitted to the sample data. Reindeer lichen consumption, gastrointestinal absorption, organ distribution and elimination is derived from information in the literature. Dynamic modelling of transfer of 210 Pb and 210 Po to reindeer meat, liver and bone from lichen consumption, fitted well with data from Sweden and Finland from 1966 to 1971. The activity concentration of 210 Pb in the skeleton in man is modelled by using the results of studying the kinetics of lead in skeleton and blood in lead-workers after end of occupational exposure. The result of modelling 210 Pb and 210 Po activity in skeleton matched well with concentrations of 210 Pb and 210 Po in teeth from reindeer-breeders and autopsy bone samples in Finland. The results of 210 Po and 137 Cs in different tissues of wolf, wolverine and lynx previously published, are analysed with multivariate data processing methods such as Principal Component Analysis PCA, and modelled with the method of Projection to Latent Structures, PLS, or Partial Least Square Regression PLSR. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hard X-Ray Emission from Partially Occulted Solar Flares: RHESSI Observations in Two Solar Cycles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Effenberger, Frederic; Costa, Fatima Rubio da; Petrosian, Vahé

2017-02-01

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal looptop source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their acceleration site, without footpoint contamination. To this end, a statistical study of partially occulted flares observed with Reuven Ramaty High-Energy Solar Spectroscopic Imager is presented here, covering a large part of solar cycles 23 and 24. We perform detailed spectra, imaging, and light curve analyses for 116 flares and include contextual observations from SDO and STEREO when available, providing further insights into flaremore » emission that were previously not accessible. We find that most spectra are fitted well with a thermal component plus a broken power-law, non-thermal component. A thin-target kappa distribution model gives satisfactory fits after the addition of a thermal component. X-ray imaging reveals small spatial separation between the thermal and non-thermal components, except for a few flares with a richer coronal source structure. A comprehensive light curve analysis shows a very good correlation between the derivative of the soft X-ray flux (from GOES ) and the hard X-rays for a substantial number of flares, indicative of the Neupert effect. The results confirm that non-thermal particles are accelerated in the corona and estimated timescales support the validity of a thin-target scenario with similar magnitudes of thermal and non-thermal energy fluxes.« less

"A Vegetarian vs. Conventional Hypocaloric Diet: The Effect on Physical Fitness in Response to Aerobic Exercise in Patients with Type 2 Diabetes." A Parallel Randomized Study.

PubMed

Veleba, Jiri; Matoulek, Martin; Hill, Martin; Pelikanova, Terezie; Kahleova, Hana

2016-10-26

It has been shown that it is possible to modify macronutrient oxidation, physical fitness and resting energy expenditure (REE) by changes in diet composition. Furthermore, mitochondrial oxidation can be significantly increased by a diet with a low glycemic index. The purpose of our trial was to compare the effects of a vegetarian (V) and conventional diet (C) with the same caloric restriction (-500 kcal/day) on physical fitness and REE after 12 weeks of diet plus aerobic exercise in 74 patients with type 2 diabetes (T2D). An open, parallel, randomized study design was used. All meals were provided for the whole study duration. An individualized exercise program was prescribed to the participants and was conducted under supervision. Physical fitness was measured by spiroergometry and indirect calorimetry was performed at the start and after 12 weeks Repeated-measures ANOVA (Analysis of variance) models with between-subject (group) and within-subject (time) factors and interactions were used for evaluation of the relationships between continuous variables and factors. Maximal oxygen consumption (VO 2max ) increased by 12% in vegetarian group (V) (F = 13.1, p < 0.001, partial η ² = 0.171), whereas no significant change was observed in C (F = 0.7, p = 0.667; group × time F = 9.3, p = 0.004, partial η ² = 0.209). Maximal performance (Watt max) increased by 21% in V (F = 8.3, p < 0.001, partial η ² = 0.192), whereas it did not change in C (F = 1.0, p = 0.334; group × time F = 4.2, p = 0.048, partial η ² = 0.116). Our results indicate that V leads more effectively to improvement in physical fitness than C after aerobic exercise program.

Practical training framework for fitting a function and its derivatives.

PubMed

Pukrittayakamee, Arjpolson; Hagan, Martin; Raff, Lionel; Bukkapatnam, Satish T S; Komanduri, Ranga

2011-06-01

This paper describes a practical framework for using multilayer feedforward neural networks to simultaneously fit both a function and its first derivatives. This framework involves two steps. The first step is to train the network to optimize a performance index, which includes both the error in fitting the function and the error in fitting the derivatives. The second step is to prune the network by removing neurons that cause overfitting and then to retrain it. This paper describes two novel types of overfitting that are only observed when simultaneously fitting both a function and its first derivatives. A new pruning algorithm is proposed to eliminate these types of overfitting. Experimental results show that the pruning algorithm successfully eliminates the overfitting and produces the smoothest responses and the best generalization among all the training algorithms that we have tested.

A comparison of Redlich-Kister polynomial and cubic spline representations of the chemical potential in phase field computations

DOE PAGES

Teichert, Gregory H.; Gunda, N. S. Harsha; Rudraraju, Shiva; ...

2016-12-18

Free energies play a central role in many descriptions of equilibrium and non-equilibrium properties of solids. Continuum partial differential equations (PDEs) of atomic transport, phase transformations and mechanics often rely on first and second derivatives of a free energy function. The stability, accuracy and robustness of numerical methods to solve these PDEs are sensitive to the particular functional representations of the free energy. In this communication we investigate the influence of different representations of thermodynamic data on phase field computations of diffusion and two-phase reactions in the solid state. First-principles statistical mechanics methods were used to generate realistic free energymore » data for HCP titanium with interstitially dissolved oxygen. While Redlich-Kister polynomials have formed the mainstay of thermodynamic descriptions of multi-component solids, they require high order terms to fit oscillations in chemical potentials around phase transitions. Here, we demonstrate that high fidelity fits to rapidly fluctuating free energy functions are obtained with spline functions. As a result, spline functions that are many degrees lower than Redlich-Kister polynomials provide equal or superior fits to chemical potential data and, when used in phase field computations, result in solution times approaching an order of magnitude speed up relative to the use of Redlich-Kister polynomials.« less

Power-law partition and entropy production of high-energy cosmic rays: Knee-ankle structure of the all-particle spectrum

NASA Astrophysics Data System (ADS)

Tomaschitz, Roman

2013-10-01

A statistical description of the all-particle cosmic-ray spectrum is given in the 10^{14}\\ \\text{eV} to 10^{20}\\ \\text{eV} interval. The high-energy cosmic-ray flux is modeled as an ultra-relativistic multi-component plasma, whose components constitute a mixture of nearly ideal but nonthermal gases of low density and high temperature. Each plasma component is described by an ultra-relativistic power-law density manifested as spectral peak in the wideband fit. The “knee” and “ankle” features of the high- and ultra-high-energy spectrum turn out to be the global and local extrema of the double-logarithmic E3-scaled flux representation in which the spectral fit is performed. The all-particle spectrum is covered by recent data sets from several air shower arrays, and can be modeled as three-component plasma in the indicated energy range extending over six decades. The temperature, specific number density, internal energy and entropy of each plasma component are extracted from the partial fluxes in the broadband fit. The grand partition function and the extensive entropy functional of a non-equilibrated gas mixture with power-law components are derived in phase space by ensemble averaging.

Derivative Sign Patterns in Two Dimensions

ERIC Educational Resources Information Center

Schilling, Kenneth

2013-01-01

Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

Why is muscularity sexy? Tests of the fitness indicator hypothesis.

PubMed

Frederick, David A; Haselton, Martie G

2007-08-01

Evolutionary scientists propose that exaggerated secondary sexual characteristics are cues of genes that increase offspring viability or reproductive success. In six studies the hypothesis that muscularity is one such cue is tested. As predicted, women rate muscular men as sexier, more physically dominant and volatile, and less committed to their mates than nonmuscular men. Consistent with the inverted-U hypothesis of masculine traits, men with moderate muscularity are rated most attractive. Consistent with past research on fitness cues, across two measures, women indicate that their most recent short-term sex partners were more muscular than their other sex partners (ds = .36, .47). Across three studies, when controlling for other characteristics (e.g., body fat), muscular men rate their bodies as sexier to women (partial rs = .49-.62) and report more lifetime sex partners (partial rs = .20-.27), short-term partners (partial rs = .25-.28), and more affairs with mated women (partial r = .28).

The effect of 2,3-diphosphoglycerate on the oxygen dissociation curve of human haemoglobin.

PubMed Central

Goodford, P J; Norrington, F E; Paterson, R A; Wootton, R

1977-01-01

1. Oxygen dissociation curves for concentrated human haemoglobin solutions (1.6 mmol dm-3 in haem) have been measured by mixing known quantities of oxy- and deoxyhaemoglobin solutions and measuring the resulting partial pressure of oxygen with an oxygen electrode. 2. Observations in the presence of 2,3-diphosphoglycerate support previous conclusions derived from experiments at low haemoglobin concentrations, the validity of which has been questioned. 3. The two affinity state model of Monod, Wyman & Changeux (1965) does not fully describe the actions of 2,3-diphosphoglycerate and a model in which this allosteric effector not only binds preferentially to the T state but also lowers the oxygen affinity of this state gives an improved fit to the data. PMID:604451

Max Planck and the birth of the quantum hypothesis

NASA Astrophysics Data System (ADS)

Nauenberg, Michael

2016-09-01

Based on the functional dependence of entropy on energy, and on Wien's distribution for black-body radiation, Max Planck obtained a formula for this radiation by an interpolation relation that fitted the experimental measurements of thermal radiation at the Physikalisch Technishe Reichanstalt (PTR) in Berlin in the late 19th century. Surprisingly, his purely phenomenological result turned out to be not just an approximation, as would have been expected, but an exact relation. To obtain a physical interpretation for his formula, Planck then turned to Boltzmann's 1877 paper on the statistical interpretation of entropy, which led him to introduce the fundamental concept of energy discreteness into physics. A novel aspect of our account that has been missed in previous historical studies of Planck's discovery is to show that Planck could have found his phenomenological formula partially derived in Boltzmann's paper in terms of a variational parameter. But the dependence of this parameter on temperature is not contained in this paper, and it was first derived by Planck.

Linking habitat selection to fitness-related traits in herbivores: the role of the energy landscape

Treesearch

Ryan A. Long; R. T. Bowyer; Warren P. Porter; Paul Mathewson; Kevin L. Monteith; Scott L. Findholt; Brian L. Dick; John G. Kie

2016-01-01

Animals may partially overcome environmental constraints on fitness by behaviorally adjusting their exposure to costs and supplies of energy. Few studies, however, have linked spatiotemporal variation in the energy landscape to behaviorally mediated measures of performance that ostensibly influence individual fitness. We hypothesized that strength of selection by North...

Partial molar volumes and viscosities of aqueous hippuric acid solutions containing LiCl and MnCl2 · 4H2O at 303.15 K

NASA Astrophysics Data System (ADS)

Deosarkar, S. D.; Tawde, P. D.; Zinjade, A. B.; Shaikh, A. I.

2015-09-01

Density (ρ) and viscosity (η) of aqueous hippuric acid (HA) solutions containing LiCl and MnCl2 · 4H2O have been studied at 303.15 K in order to understand volumetric and viscometric behavior of these systems. Apparent molar volume (φv) of salts were calculated from density data and fitted to Massons relation and partial molar volumes (φ{v/0}) at infinite dilution were determined. Relative viscosity data has been used to determine viscosity A and B coefficients using Jones-Dole relation. Partial molar volume and viscosity coefficients have been discussed in terms of ion-solvent interactions and overall structural fittings in solution.

Clinical Fit of Partial Removable Dental Prostheses Based on Alginate or Polyvinyl Siloxane Impressions.

PubMed

Fokkinga, Wietske A; Witter, Dick J; Bronkhorst, Ewald M; Creugers, Nico H

The aim of this study was to analyze the clinical fit of metal-frame partial removable dental prostheses (PRDPs) based on custom trays used with alginate or polyvinyl siloxane impression material. Fifth-year students of the Nijmegen Dental School made 25 correct impressions for 23 PRDPs for 21 patients using alginate, and 31 correct impressions for 30 PRDPs for 28 patients using polyvinyl siloxane. Clinical fit of the framework as a whole and of each retainer separately were evaluated by calibrated supervisors during framework try-in before (first evaluation) and after (second evaluation) possible adjustments (score 0 = poor fit, up to score 3 = good fit). Framework fit and fit of the denture base were evaluated at delivery (third evaluation). Finally, postinsertion sessions were evaluated and total number of sessions needed, sore spots, adjustments to the denture base, and reported food-impaction were recorded. No significant differences in clinical fit (of the framework as a whole, for the retainers, or for the denture base) were found between the groups in the three evaluation sessions. Differences were not found for postinsertion sessions with one exception: in the alginate group, four subjects reported food impaction, versus none in the polyvinyl siloxane group. Clinical fit of metal-frame PRDPs based on impressions with custom trays combined with alginate or polyvinyl siloxane was similar.

Fitting the curve in Excel®: Systematic curve fitting of laboratory and remotely sensed planetary spectra

NASA Astrophysics Data System (ADS)

McCraig, Michael A.; Osinski, Gordon R.; Cloutis, Edward A.; Flemming, Roberta L.; Izawa, Matthew R. M.; Reddy, Vishnu; Fieber-Beyer, Sherry K.; Pompilio, Loredana; van der Meer, Freek; Berger, Jeffrey A.; Bramble, Michael S.; Applin, Daniel M.

2017-03-01

Spectroscopy in planetary science often provides the only information regarding the compositional and mineralogical make up of planetary surfaces. The methods employed when curve fitting and modelling spectra can be confusing and difficult to visualize and comprehend. Researchers who are new to working with spectra may find inadequate help or documentation in the scientific literature or in the software packages available for curve fitting. This problem also extends to the parameterization of spectra and the dissemination of derived metrics. Often, when derived metrics are reported, such as band centres, the discussion of exactly how the metrics were derived, or if there was any systematic curve fitting performed, is not included. Herein we provide both recommendations and methods for curve fitting and explanations of the terms and methods used. Techniques to curve fit spectral data of various types are demonstrated using simple-to-understand mathematics and equations written to be used in Microsoft Excel® software, free of macros, in a cut-and-paste fashion that allows one to curve fit spectra in a reasonably user-friendly manner. The procedures use empirical curve fitting, include visualizations, and ameliorates many of the unknowns one may encounter when using black-box commercial software. The provided framework is a comprehensive record of the curve fitting parameters used, the derived metrics, and is intended to be an example of a format for dissemination when curve fitting data.

Comparison of Apparent Diffusion Coefficient and Intravoxel Incoherent Motion for Differentiating among Glioblastoma, Metastasis, and Lymphoma Focusing on Diffusion-Related Parameter.

PubMed

Shim, Woo Hyun; Kim, Ho Sung; Choi, Choong-Gon; Kim, Sang Joon

2015-01-01

Brain tumor cellularity has been assessed by using apparent diffusion coefficient (ADC). However, the ADC value might be influenced by both perfusion and true molecular diffusion, and the perfusion effect on ADC can limit the reliability of ADC in the characterization of tumor cellularity, especially, in hypervascular brain tumors. In contrast, the IVIM technique estimates parameter values for diffusion and perfusion effects separately. The purpose of our study was to compare ADC and IVIM for differentiating among glioblastoma, metastatic tumor, and primary CNS lymphoma (PCNSL) focusing on diffusion-related parameter. We retrospectively reviewed the data of 128 patients with pathologically confirmed glioblastoma (n = 55), metastasis (n = 31), and PCNSL (n = 42) prior to any treatment. Two neuroradiologists independently calculated the maximum IVIM-f (fmax) and minimum IVIM-D (Dmin) by using 16 different b-values with a bi-exponential fitting of diffusion signal decay, minimum ADC (ADCmin) by using 0 and 1000 b-values with a mono-exponential fitting and maximum normalized cerebral blood volume (nCBVmax). The differences in fmax, Dmin, nCBVmax, and ADCmin among the three tumor pathologies were determined by one-way ANOVA with multiple comparisons. The fmax and Dmin were correlated to the corresponding nCBV and ADC using partial correlation analysis, respectively. Using a mono-exponential fitting of diffusion signal decay, the mean ADCmin was significantly lower in PCNSL than in glioblastoma and metastasis. However, using a bi-exponential fitting, the mean Dmin did not significantly differ in the three groups. The mean fmax significantly increased in the glioblastomas (reader 1, 0.103; reader 2, 0.109) and the metastasis (reader 1, 0.105; reader 2, 0.107), compared to the primary CNS lymphomas (reader 1, 0.025; reader 2, 0.023) (P < .001 for each). The correlation between fmax and the corresponding nCBV was highest in glioblastoma group, and the correlation between Dmin and the corresponding ADC was highest in primary CNS lymphomas group. Unlike ADC value derived from a mono-exponential fitting of diffusion signal, diffusion-related parametric value derived from a bi-exponential fitting with separation of perfusion effect doesn't differ among glioblastoma, metastasis, and PCNSL.

Sterile neutrinos and flavor ratios in IceCube

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brdar, Vedran; Kopp, Joachim; Wang, Xiao-Ping, E-mail: vbrdar@uni-mainz.de, E-mail: jkopp@uni-mainz.de, E-mail: xiaowang@uni-mainz.de

2017-01-01

The flavor composition of astrophysical neutrinos observed in neutrino telescopes is a powerful discriminator between different astrophysical neutrino production mechanisms and can also teach us about the particle physics properties of neutrinos. In this paper, we investigate how the possible existence of light sterile neutrinos can affect these flavor ratios. We consider two scenarios: (i) neutrino production in conventional astrophysical sources, followed by partial oscillation into sterile states; (ii) neutrinos from dark matter decay with a primary flavor composition enhanced in tau neutrinos or sterile neutrinos. Throughout the paper, we constrain the sterile neutrino mixing parameters from a full globalmore » fit to short and long baseline data. We present our results in the form of flavor triangles and, for scenario (ii), as exclusion limits on the dark matter mass and lifetime, derived from a fit to IceCube high energy starting events and through-going muons. We argue that identifying a possible flux of neutrinos from dark matter decay may require analyzing the flavor composition as a function of neutrino energy.« less

Pressure for Pattern-Specific Intertypic Recombination between Sabin Polioviruses: Evolutionary Implications.

PubMed

Korotkova, Ekaterina; Laassri, Majid; Zagorodnyaya, Tatiana; Petrovskaya, Svetlana; Rodionova, Elvira; Cherkasova, Elena; Gmyl, Anatoly; Ivanova, Olga E; Eremeeva, Tatyana P; Lipskaya, Galina Y; Agol, Vadim I; Chumakov, Konstantin

2017-11-22

Complete genomic sequences of a non-redundant set of 70 recombinants between three serotypes of attenuated Sabin polioviruses as well as location (based on partial sequencing) of crossover sites of 28 additional recombinants were determined and compared with the previously published data. It is demonstrated that the genomes of Sabin viruses contain distinct strain-specific segments that are eliminated by recombination. The presumed low fitness of these segments could be linked to mutations acquired upon derivation of the vaccine strains and/or may have been present in wild-type parents of Sabin viruses. These "weak" segments contribute to the propensity of these viruses to recombine with each other and with other enteroviruses as well as determine the choice of crossover sites. The knowledge of location of such segments opens additional possibilities for the design of more genetically stable and/or more attenuated variants, i.e., candidates for new oral polio vaccines. The results also suggest that the genome of wild polioviruses, and, by generalization, of other RNA viruses, may harbor hidden low-fitness segments that can be readily eliminated only by recombination.

Extracting the differential inverse inelastic mean free path and differential surface excitation probability of Tungsten from X-ray photoelectron spectra and electron energy loss spectra

NASA Astrophysics Data System (ADS)

Afanas'ev, V. P.; Gryazev, A. S.; Efremenko, D. S.; Kaplya, P. S.; Kuznetcova, A. V.

2017-12-01

Precise knowledge of the differential inverse inelastic mean free path (DIIMFP) and differential surface excitation probability (DSEP) of Tungsten is essential for many fields of material science. In this paper, a fitting algorithm is applied for extracting DIIMFP and DSEP from X-ray photoelectron spectra and electron energy loss spectra. The algorithm uses the partial intensity approach as a forward model, in which a spectrum is given as a weighted sum of cross-convolved DIIMFPs and DSEPs. The weights are obtained as solutions of the Riccati and Lyapunov equations derived from the invariant imbedding principle. The inversion algorithm utilizes the parametrization of DIIMFPs and DSEPs on the base of a classical Lorentz oscillator. Unknown parameters of the model are found by using the fitting procedure, which minimizes the residual between measured spectra and forward simulations. It is found that the surface layer of Tungsten contains several sublayers with corresponding Langmuir resonances. The thicknesses of these sublayers are proportional to the periods of corresponding Langmuir oscillations, as predicted by the theory of R.H. Ritchie.

Regional frequency analysis of extreme rainfalls using partial L moments method

NASA Astrophysics Data System (ADS)

Zakaria, Zahrahtul Amani; Shabri, Ani

2013-07-01

An approach based on regional frequency analysis using L moments and LH moments are revisited in this study. Subsequently, an alternative regional frequency analysis using the partial L moments (PL moments) method is employed, and a new relationship for homogeneity analysis is developed. The results were then compared with those obtained using the method of L moments and LH moments of order two. The Selangor catchment, consisting of 37 sites and located on the west coast of Peninsular Malaysia, is chosen as a case study. PL moments for the generalized extreme value (GEV), generalized logistic (GLO), and generalized Pareto distributions were derived and used to develop the regional frequency analysis procedure. PL moment ratio diagram and Z test were employed in determining the best-fit distribution. Comparison between the three approaches showed that GLO and GEV distributions were identified as the suitable distributions for representing the statistical properties of extreme rainfall in Selangor. Monte Carlo simulation used for performance evaluation shows that the method of PL moments would outperform L and LH moments methods for estimation of large return period events.

An alternative model for a partially coherent elliptical dark hollow beam

NASA Astrophysics Data System (ADS)

Li, Xu; Wang, Fei; Cai, Yangjian

2011-04-01

An alternative theoretical model named partially coherent hollow elliptical Gaussian beam (HEGB) is proposed to describe a partially coherent beam with an elliptical dark hollow profile. Explicit expression for the propagation factors of a partially coherent HEGB is derived. Based on the generalized Collins formula, analytical formulae for the cross-spectral density and mean-squared beam width of a partially coherent HEGB, propagating through a paraxial ABCD optical system, are derived. Propagation properties of a partially coherent HEGB in free space are studied as a numerical example.

Generalized Second-Order Partial Derivatives of 1/r

ERIC Educational Resources Information Center

Hnizdo, V.

2011-01-01

The generalized second-order partial derivatives of 1/r, where r is the radial distance in three dimensions (3D), are obtained using a result of the potential theory of classical analysis. Some non-spherical-regularization alternatives to the standard spherical-regularization expression for the derivatives are derived. The utility of a…

Modelling and Computation in the Valuation of Carbon Derivatives with Stochastic Convenience Yields

PubMed Central

Chang, Shuhua; Wang, Xinyu

2015-01-01

The anthropogenic greenhouse gas (GHG) emission has risen dramatically during the last few decades, which mainstream researchers believe to be the main cause of climate change, especially the global warming. The mechanism of market-based carbon emission trading is regarded as a policy instrument to deal with global climate change. Although several empirical researches about the carbon allowance and its derivatives price have been made, theoretical results seem to be sparse. In this paper, we theoretically develop a mathematical model to price the CO2 emission allowance derivatives with stochastic convenience yields by the principle of absence of arbitrage opportunities. In the case of American options, we formulate the pricing problem to a linear parabolic variational inequality (VI) in two spatial dimensions and develop a power penalty method to solve it. Then, a fitted finite volume method is designed to solve the nonlinear partial differential equation (PDE) resulting from the power penalty method and governing the futures, European and American option valuation. Moreover, some numerical results are performed to illustrate the efficiency and usefulness of this method. We find that the stochastic convenience yield does effect the valuation of carbon emission derivatives. In addition, some sensitivity analyses are also made to examine the effects of some parameters on the valuation results. PMID:26010900

Modelling and computation in the valuation of carbon derivatives with stochastic convenience yields.

PubMed

Chang, Shuhua; Wang, Xinyu

2015-01-01

The anthropogenic greenhouse gas (GHG) emission has risen dramatically during the last few decades, which mainstream researchers believe to be the main cause of climate change, especially the global warming. The mechanism of market-based carbon emission trading is regarded as a policy instrument to deal with global climate change. Although several empirical researches about the carbon allowance and its derivatives price have been made, theoretical results seem to be sparse. In this paper, we theoretically develop a mathematical model to price the CO2 emission allowance derivatives with stochastic convenience yields by the principle of absence of arbitrage opportunities. In the case of American options, we formulate the pricing problem to a linear parabolic variational inequality (VI) in two spatial dimensions and develop a power penalty method to solve it. Then, a fitted finite volume method is designed to solve the nonlinear partial differential equation (PDE) resulting from the power penalty method and governing the futures, European and American option valuation. Moreover, some numerical results are performed to illustrate the efficiency and usefulness of this method. We find that the stochastic convenience yield does effect the valuation of carbon emission derivatives. In addition, some sensitivity analyses are also made to examine the effects of some parameters on the valuation results.

Thermal remote sensing of surface soil water content with partial vegetation cover for incorporation into climate models

NASA Technical Reports Server (NTRS)

Gillies, Robert R.; Carlson, Toby N.

1995-01-01

This study outlines a method for the estimation of regional patterns of surface moisture availability (M(sub 0)) and fractional vegetation (Fr) in the presence of spatially variable vegetation cover. The method requires relating variations in satellite-derived (NOAA, Advanced Very High Resolution Radiometer (AVHRR)) surface radiant temperature to a vegetation index (computed from satellite visible and near-infrared data) while coupling this association to an inverse modeling scheme. More than merely furnishing surface soil moisture values, the method constitues a new conceptual and practical approach for combining thermal infrared and vegetation index measurements for incorporating the derived values of M(sub 0) into hydrologic and atmospheric prediction models. Application of the technique is demonstrated for a region in and around the city of Newcastle upon Tyne situated in the northeast of England. A regional estimate of M(sub 0) is derived and is probabbly good for fractional vegetation cover up to 80% before errors in the estimated soil water content become unacceptably large. Moreover, a normalization scheme is suggested from which a nomogram, `universal triangle,' is constructed and is seen to fit the observed data well. The universal triangle also simplifies the inclusion of remotely derived M(sub 0) in hydrology and meteorological models and is perhaps a practicable step toward integrating derived data from satellite measurements in weather forecasting.

Constraints on Martian Aerosol Particles Using MGS/TES and HST Data: Shapes

NASA Astrophysics Data System (ADS)

Wolff, M. J.; Clancy, R. T.; Pitman, K. M.; Bell, J. F.; James, P. B.

2001-12-01

In order to constrain the shape of water ice and dust aerosols, we have combined a numerical approach for axisymmetric particle shapes, i.e., cylinders, disks, spheroids (Waterman's T-Matrix approach as improved by Mishchenko and collaborators; cf., Mishchenko et al. 1997, JGR, 102, D14, 16,831), with a multiple-scattering radiative transfer algorithm. We utilize a two-stage iterative process. First, we empirically derive a scattering phase function for each aerosol component from radiative transfer models of Mars Global Surveyor Thermal Emission Spectrometer Emission Phase Function (EPF) sequences. Next, we perform a series of scattering calculations, adjusting our parameters to arrive at a ``best-fit'' theoretical phase function. It is important to note that in addition to randomly-oriented particles, we explicitly consider the possibility of (partially) aligned aerosol particles as well. Thus far, we have been analyzing the three empirically-derived presented by Clancy et al. (this meeting): dust, Type I ice particles (effective radii ~ 1-2 microns), and Type II ice particles (effective radii ~ 3-4 microns). We find that the ``dust'' phase function is best fit by randomly-oriented cylinders with an axial ratio (D/L = diameter-to-length) of either 2.3 or 0.6. Similarly, the shape of the Type II ice curve is reasonably reproduced by randomly-oriented spheroids with an axial ratio of either 0.7 or 1.4. However, neither of the two shapes (nor that of spheres or randomly-oriented hexagonal prisms) can reproduce the phase function derived for the Type I ice. This led to the direct consideration of oriented or aligned particles. which, at least qualitatively, have the ability to account for the phase function shapes for both Type I and II ice particles. The difference between these two phase functions may represent the degree of alignment, with the Type II particles being much less-aligned. The calculations for partially aligned particles is quite numerically intensive and this avenue of research is currently in progress. Additional work is also being done to further constrain the dust aerosol properties using both TES visible/IR and Hubble Space Telescope UV-NIR spectroscopy/imaging data of the recent (and ongoing) Martian global dust storm. Our work has been supported through NASA (MDAP) grant NAG5-9820, (MED) JPL contract 961471, STScI GO programs #8577 and #9052.

N* resonances from KΛ amplitudes in sliced bins in energy

NASA Astrophysics Data System (ADS)

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.; Ireland, D. G.; Klempt, E.; Nikonov, V. A.; Omerović, R.; Sarantsev, A. V.; Stahov, J.; Švarc, A.; Thoma, U.

2017-12-01

The two reactions γ p→ K+Λ and π- p→ K0Λ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9 GeV with quantum numbers JP = 1/2+, 3/2+, 1/2-, 3/2-, 5/2-.

A comparison of Rasch item-fit and Cronbach's alpha item reduction analysis for the development of a Quality of Life scale for children and adolescents.

PubMed

Erhart, M; Hagquist, C; Auquier, P; Rajmil, L; Power, M; Ravens-Sieberer, U

2010-07-01

This study compares item reduction analysis based on classical test theory (maximizing Cronbach's alpha - approach A), with analysis based on the Rasch Partial Credit Model item-fit (approach B), as applied to children and adolescents' health-related quality of life (HRQoL) items. The reliability and structural, cross-cultural and known-group validity of the measures were examined. Within the European KIDSCREEN project, 3019 children and adolescents (8-18 years) from seven European countries answered 19 HRQoL items of the Physical Well-being dimension of a preliminary KIDSCREEN instrument. The Cronbach's alpha and corrected item total correlation (approach A) were compared with infit mean squares and the Q-index item-fit derived according to a partial credit model (approach B). Cross-cultural differential item functioning (DIF ordinal logistic regression approach), structural validity (confirmatory factor analysis and residual correlation) and relative validity (RV) for socio-demographic and health-related factors were calculated for approaches (A) and (B). Approach (A) led to the retention of 13 items, compared with 11 items with approach (B). The item overlap was 69% for (A) and 78% for (B). The correlation coefficient of the summated ratings was 0.93. The Cronbach's alpha was similar for both versions [0.86 (A); 0.85 (B)]. Both approaches selected some items that are not strictly unidimensional and items displaying DIF. RV ratios favoured (A) with regard to socio-demographic aspects. Approach (B) was superior in RV with regard to health-related aspects. Both types of item reduction analysis should be accompanied by additional analyses. Neither of the two approaches was universally superior with regard to cultural, structural and known-group validity. However, the results support the usability of the Rasch method for developing new HRQoL measures for children and adolescents.

Full-dimensional global potential energy surfaces describing abstraction and exchange for the H + H{sub 2}S reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Dandan; Li, Jun, E-mail: jli15@cqu.edu.edu

2016-07-07

For the H + H{sub 2}S system, ∼34 000 data points are sampled over a large configuration space including both abstraction and exchange channels, and calculated at the level of explicitly correlated unrestricted coupled cluster method with singles, doubles, and perturbative triples excitations with the augmented correlation-consistent polarized triple zeta basis set (UCCSD(T)-F12a/aug-cc-pVTZ). The data set was fit using the newly proposed permutation invariant polynomial-neural network (PIP-NN) method with three different vectors as the input: two redundant sets of PIPs, one with the maximum order four (PES-I) and one with the maximum order three (PES-II), and nine non-redundant PIPs (PES-III). Allmore » these PESs show small fitting errors and essentially the same performance in representing the title system. Various kinetics and dynamical properties are calculated using the tunneling corrected transition state theory and quasi-classical trajectory, and compared with available experimental results. At a collision energy of 10 kcal/mol, both the H{sub 2} and SH products are found to be internally cold, with ∼20% of H{sub 2} at its first vibrational excited state, while SH is essentially a spectator. The angular distributions of the products are mainly in backward with considerable contributions from sideway direction. In addition, analytical partial derivatives of any PIP-NN PES with respect to the coordinates of atoms are derived by making use of the monomial symmetrization algorithm [Z. Xie and J. M. Bowman, J. Chem. Theory Comput. 6, 26–34 (2010)]. It can not only accelerate the evaluation of the derivatives, but also improve the energy convergence significantly.« less

Laser welding of removable partial denture frameworks.

PubMed

Brudvik, James S; Lee, Seungbum; Croshaw, Steve N; Reimers, Donald L; Reimers, Dave L

2008-01-01

To identify and measure distortions inherent in the casting process of a Class III mandibular cobalt-chromium (Co-Cr) framework to illustrate the problems faced by the laboratory technician and the clinician and to measure the changes that occur during the correction of the fit discrepancy using laser welding. Five identical castings of a Co-Cr alloy partial denture casting were made and measured between 3 widely separated points using the x, y, and z adjustments of a Nikon Measurescope. The same measurements were made after each of the following clinical and laboratory procedures: sprue removal, sectioning of the casting into 3 parts through the posterior meshwork, fitting the segments to the master cast, picking up the segments using resin, and laser welding of the 3 segments. Measurements of all 5 castings showed a cross-arch decrease after sprue removal, an increase after fitting the segments to the master cast, and a slight decrease after resin pickup and laser welding. Within the limitations of this study, the findings suggest that precise tooth-frame relations can be established by resin pickup and laser welding of segments of Co-Cr removable partial denture frameworks.

Density perturbations in general modified gravitational theories

DOE Office of Scientific and Technical Information (OSTI.GOV)

De Felice, Antonio; Tsujikawa, Shinji; Mukohyama, Shinji

2010-07-15

We derive the equations of linear cosmological perturbations for the general Lagrangian density f(R,{phi},X)/2+L{sub c}, where R is a Ricci scalar, {phi} is a scalar field, and X=-{partial_derivative}{sup {mu}{phi}{partial_derivative}}{sub {mu}{phi}/}2 is a field kinetic energy. We take into account a nonlinear self-interaction term L{sub c}={xi}({phi}) {open_square}{phi}({partial_derivative}{sup {mu}{phi}{partial_derivative}}{sub {mu}{phi}}) recently studied in the context of ''Galileon'' cosmology, which keeps the field equations at second order. Taking into account a scalar-field mass explicitly, the equations of matter density perturbations and gravitational potentials are obtained under a quasistatic approximation on subhorizon scales. We also derive conditions for the avoidance of ghosts and Laplacianmore » instabilities associated with propagation speeds. Our analysis includes most of modified gravity models of dark energy proposed in literature; and thus it is convenient to test the viability of such models from both theoretical and observational points of view.« less

The effects of nonuniform magnetic field strength on density flux and test particle transport in drift wave turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewhurst, J. M.; Hnat, B.; Dendy, R. O.

2009-07-15

The extended Hasegawa-Wakatani equations generate fully nonlinear self-consistent solutions for coupled density n and vorticity {nabla}{sup 2}{phi}, where {phi} is electrostatic potential, in a plasma with background density inhomogeneity {kappa}=-{partial_derivative} ln n{sub 0}/{partial_derivative}x and magnetic field strength inhomogeneity C=-{partial_derivative} ln B/{partial_derivative}x. Finite C introduces interchange effects and {nabla}B drifts into the framework of drift turbulence through compressibility of the ExB and diamagnetic drifts. This paper addresses the direct computation of the radial ExB density flux {gamma}{sub n}=-n{partial_derivative}{phi}/{partial_derivative}y, tracer particle transport, the statistical properties of the turbulent fluctuations that drive {gamma}{sub n} and tracer motion, and analytical underpinnings. Systematic trends emergemore » in the dependence on C of the skewness of the distribution of pointwise {gamma}{sub n} and in the relative phase of density-velocity and density-potential pairings. It is shown how these effects, together with conservation of potential vorticity {pi}={nabla}{sup 2}{phi}-n+({kappa}-C)x, account for much of the transport phenomenology. Simple analytical arguments yield a Fickian relation {gamma}{sub n}=({kappa}-C)D{sub x} between the radial density flux {gamma}{sub n} and the radial tracer diffusivity D{sub x}, which is shown to explain key trends in the simulations.« less

Unsupervised ensemble ranking of terms in electronic health record notes based on their importance to patients.

PubMed

Chen, Jinying; Yu, Hong

2017-04-01

Allowing patients to access their own electronic health record (EHR) notes through online patient portals has the potential to improve patient-centered care. However, EHR notes contain abundant medical jargon that can be difficult for patients to comprehend. One way to help patients is to reduce information overload and help them focus on medical terms that matter most to them. Targeted education can then be developed to improve patient EHR comprehension and the quality of care. The aim of this work was to develop FIT (Finding Important Terms for patients), an unsupervised natural language processing (NLP) system that ranks medical terms in EHR notes based on their importance to patients. We built FIT on a new unsupervised ensemble ranking model derived from the biased random walk algorithm to combine heterogeneous information resources for ranking candidate terms from each EHR note. Specifically, FIT integrates four single views (rankers) for term importance: patient use of medical concepts, document-level term salience, word co-occurrence based term relatedness, and topic coherence. It also incorporates partial information of term importance as conveyed by terms' unfamiliarity levels and semantic types. We evaluated FIT on 90 expert-annotated EHR notes and used the four single-view rankers as baselines. In addition, we implemented three benchmark unsupervised ensemble ranking methods as strong baselines. FIT achieved 0.885 AUC-ROC for ranking candidate terms from EHR notes to identify important terms. When including term identification, the performance of FIT for identifying important terms from EHR notes was 0.813 AUC-ROC. Both performance scores significantly exceeded the corresponding scores from the four single rankers (P<0.001). FIT also outperformed the three ensemble rankers for most metrics. Its performance is relatively insensitive to its parameter. FIT can automatically identify EHR terms important to patients. It may help develop future interventions to improve quality of care. By using unsupervised learning as well as a robust and flexible framework for information fusion, FIT can be readily applied to other domains and applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Anisotropic singularities in modified gravity models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Figueiro, Michele Ferraz; Saa, Alberto; Departamento de Matematica Aplicada, IMECC-UNICAMP, C.P. 6065, 13083-859 Campinas, SP

2009-09-15

We show that the common singularities present in generic modified gravity models governed by actions of the type S={integral}d{sup 4}x{radical}(-g)f(R,{phi},X), with X=-(1/2)g{sup ab}{partial_derivative}{sub a}{phi}{partial_derivative}{sub b}{phi}, are essentially the same anisotropic instabilities associated to the hypersurface F({phi})=0 in the case of a nonminimal coupling of the type F({phi})R, enlightening the physical origin of such singularities that typically arise in rather complex and cumbersome inhomogeneous perturbation analyses. We show, moreover, that such anisotropic instabilities typically give rise to dynamically unavoidable singularities, precluding completely the possibility of having physically viable models for which the hypersurface ({partial_derivative}f/{partial_derivative}R)=0 is attained. Some examples are explicitly discussed.

Physical Fitness and Serum Vitamin D and Cognition in Elderly Koreans.

PubMed

Ahn, Jeong-Deok; Kang, Hyunsik

2015-12-01

Poor physical fitness and low serum vitamin D are known to be modifiable risk factors for cognitive declines with normal aging. We investigated the association of physical fitness and serum vitamin D levels with global cognitive function in older adults. In this cross-sectional study, a total of 412 older Korean adults (108 men aged 74.4 ± 6.0 years and 304 women aged 73.1 ± 5.4 years) completed the Korean version of Mini-Mental State Examination (MMSE) to assess global cognitive performance and the senior fitness test to assess strength, flexibility, agility, and endurance domains of physical fitness. Body mass index, percent body fat, serum vitamin D, geriatric depression scale (GDS), level of education, smoking, and history of cardiovascular or cerebrovascular disease were also assessed as covariates. Age, sex, GDS, and body fatness were negatively associated with MMSE-based cognitive performance. Serum vitamin D and physical fitness were positively associated with MMSE-based cognitive performance. Multivariate linear regression showed that agility (partial R(2) = -0.184, p = 0.029) and endurance (partial R(2) = 0.191, p = 0.022) domains of physical fitness along with serum vitamin D (partial R(2) = 0.210, p = 0.012) were significant predictors for global cognitive performance after controlling for covariates (i.e., age, sex, education, GDS, body fatness, and comorbidity index). The current findings of the study suggest that promotion of physical fitness and vitamin D supplementation should be key components of interventions to prevent cognitive decline with normal aging. Key pointsCognitive declines are associated with normal aging as well as modifiable lifestyle risk factors, and there is an increasing need to identify the modifiable risk factors for the onset of cognitive declines and to provide evidence-based strategies for healthy and successful aging.In Korea, little is known about the relationships of physical fitness and serum vitamin D with cognitive function in older adults, and we determined the associations between a) serum vitamin D levels and cognitive function and b) physical fitness and cognitive function among community-dwelling elderly Koreans.The current findings of the study suggest that agility and endurance domains of physical fitness along with serum vitamin D were significant predictors for global cognitive performance after controlling for covariates.

Physical Fitness and Serum Vitamin D and Cognition in Elderly Koreans

PubMed Central

Ahn, Jeong-Deok; Kang, Hyunsik

2015-01-01

Poor physical fitness and low serum vitamin D are known to be modifiable risk factors for cognitive declines with normal aging. We investigated the association of physical fitness and serum vitamin D levels with global cognitive function in older adults. In this cross-sectional study, a total of 412 older Korean adults (108 men aged 74.4 ± 6.0 years and 304 women aged 73.1 ± 5.4 years) completed the Korean version of Mini-Mental State Examination (MMSE) to assess global cognitive performance and the senior fitness test to assess strength, flexibility, agility, and endurance domains of physical fitness. Body mass index, percent body fat, serum vitamin D, geriatric depression scale (GDS), level of education, smoking, and history of cardiovascular or cerebrovascular disease were also assessed as covariates. Age, sex, GDS, and body fatness were negatively associated with MMSE-based cognitive performance. Serum vitamin D and physical fitness were positively associated with MMSE-based cognitive performance. Multivariate linear regression showed that agility (partial R2 = -0.184, p = 0.029) and endurance (partial R2 = 0.191, p = 0.022) domains of physical fitness along with serum vitamin D (partial R2 = 0.210, p = 0.012) were significant predictors for global cognitive performance after controlling for covariates (i.e., age, sex, education, GDS, body fatness, and comorbidity index). The current findings of the study suggest that promotion of physical fitness and vitamin D supplementation should be key components of interventions to prevent cognitive decline with normal aging. Key points Cognitive declines are associated with normal aging as well as modifiable lifestyle risk factors, and there is an increasing need to identify the modifiable risk factors for the onset of cognitive declines and to provide evidence-based strategies for healthy and successful aging. In Korea, little is known about the relationships of physical fitness and serum vitamin D with cognitive function in older adults, and we determined the associations between a) serum vitamin D levels and cognitive function and b) physical fitness and cognitive function among community-dwelling elderly Koreans. The current findings of the study suggest that agility and endurance domains of physical fitness along with serum vitamin D were significant predictors for global cognitive performance after controlling for covariates. PMID:26664270

Analytic computation of energy derivatives - Relationships among partial derivatives of a variationally determined function

NASA Technical Reports Server (NTRS)

King, H. F.; Komornicki, A.

1986-01-01

Formulas are presented relating Taylor series expansion coefficients of three functions of several variables, the energy of the trial wave function (W), the energy computed using the optimized variational wave function (E), and the response function (lambda), under certain conditions. Partial derivatives of lambda are obtained through solution of a recursive system of linear equations, and solution through order n yields derivatives of E through order 2n + 1, extending Puley's application of Wigner's 2n + 1 rule to partial derivatives in couple perturbation theory. An examination of numerical accuracy shows that the usual two-term second derivative formula is less stable than an alternative four-term formula, and that previous claims that energy derivatives are stationary properties of the wave function are fallacious. The results have application to quantum theoretical methods for the computation of derivative properties such as infrared frequencies and intensities.

“A Vegetarian vs. Conventional Hypocaloric Diet: The Effect on Physical Fitness in Response to Aerobic Exercise in Patients with Type 2 Diabetes.” A Parallel Randomized Study

PubMed Central

Veleba, Jiri; Matoulek, Martin; Hill, Martin; Pelikanova, Terezie; Kahleova, Hana

2016-01-01

It has been shown that it is possible to modify macronutrient oxidation, physical fitness and resting energy expenditure (REE) by changes in diet composition. Furthermore, mitochondrial oxidation can be significantly increased by a diet with a low glycemic index. The purpose of our trial was to compare the effects of a vegetarian (V) and conventional diet (C) with the same caloric restriction (−500 kcal/day) on physical fitness and REE after 12 weeks of diet plus aerobic exercise in 74 patients with type 2 diabetes (T2D). An open, parallel, randomized study design was used. All meals were provided for the whole study duration. An individualized exercise program was prescribed to the participants and was conducted under supervision. Physical fitness was measured by spiroergometry and indirect calorimetry was performed at the start and after 12 weeks Repeated-measures ANOVA (Analysis of variance) models with between-subject (group) and within-subject (time) factors and interactions were used for evaluation of the relationships between continuous variables and factors. Maximal oxygen consumption (VO2max) increased by 12% in vegetarian group (V) (F = 13.1, p < 0.001, partial η2 = 0.171), whereas no significant change was observed in C (F = 0.7, p = 0.667; group × time F = 9.3, p = 0.004, partial η2 = 0.209). Maximal performance (Watt max) increased by 21% in V (F = 8.3, p < 0.001, partial η2 = 0.192), whereas it did not change in C (F = 1.0, p = 0.334; group × time F = 4.2, p = 0.048, partial η2 = 0.116). Our results indicate that V leads more effectively to improvement in physical fitness than C after aerobic exercise program. PMID:27792174

Crystal growth, structure and morphology of hydrocortisone methanol solvate

NASA Astrophysics Data System (ADS)

Chen, Jianxin; Wang, Jiangkang; Zhang, Ying; Wu, Hong; Chen, Wei; Guo, Zhichao

2004-04-01

Hydrocortisone (HC), an important grucocorticoid, was crystallized from methanol solvent in the form of its methanol solvate. Its crystal structure belongs to orthorhombic, space group P2 12 12 1, with the unit cell parameters a=7.712(3) Å, b=14.392(5) Å, c=18.408(6) Å, Z=4. The methanol takes part in intermolecular hydrogen bonding, so if we change the solvent, the crystal habit of HC maybe different. The long parallelepiped morphology was also predicted by Cerius 2TM simulation program. The influence of intermolecular interaction was taken into account in the attachment energy model. The morphology calculation performed on the potential energy minimized model using a generic DREIDING 2.21 force field and developed minimization protocol with derived partial charges fits the experimental crystal shape well.

A non-orthogonal decomposition of flows into discrete events

NASA Astrophysics Data System (ADS)

Boxx, Isaac; Lewalle, Jacques

1998-11-01

This work is based on the formula for the inverse Hermitian wavelet transform. A signal can be interpreted as a (non-unique) superposition of near-singular, partially overlapping events arising from Dirac functions and/or its derivatives combined with diffusion.( No dynamics implied: dimensionless diffusion is related to the definition of the analyzing wavelets.) These events correspond to local maxima of spectral energy density. We successfully fitted model events of various orders on a succession of fields, ranging from elementary signals to one-dimensional hot-wire traces. We document edge effects, event overlap and its implications on the algorithm. The interpretation of the discrete singularities as flow events (such as coherent structures) and the fundamental non-uniqueness of the decomposition are discussed. The dynamics of these events will be examined in the companion paper.

Transverse signal decay under the weak field approximation: Theory and validation.

PubMed

Berman, Avery J L; Pike, G Bruce

2018-07-01

To derive an expression for the transverse signal time course from systems in the motional narrowing regime, such as water diffusing in blood. This was validated in silico and experimentally with ex vivo blood samples. A closed-form solution (CFS) for transverse signal decay under any train of refocusing pulses was derived using the weak field approximation. The CFS was validated via simulations of water molecules diffusing in the presence of spherical perturbers, with a range of sizes and under various pulse sequences. The CFS was compared with more conventional fits assuming monoexponential decay, including chemical exchange, using ex vivo blood Carr-Purcell-Meiboom-Gill data. From simulations, the CFS was shown to be valid in the motional narrowing regime and partially into the intermediate dephasing regime, with increased accuracy with increasing Carr-Purcell-Meiboom-Gill refocusing rate. In theoretical calculations of the CFS, fitting for the transverse relaxation rate (R 2 ) gave excellent agreement with the weak field approximation expression for R 2 for Carr-Purcell-Meiboom-Gill sequences, but diverged for free induction decay. These same results were confirmed in the ex vivo analysis. Transverse signal decay in the motional narrowing regime can be accurately described analytically. This theory has applications in areas such as tissue iron imaging, relaxometry of blood, and contrast agent imaging. Magn Reson Med 80:341-350, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Estimating the Amount of Eroded Section in a Partially Exhumed Basin from Geophysical Well Logs: An Example from the North Slope

USGS Publications Warehouse

Burns, W. Matthew; Hayba, Daniel O.; Rowan, Elisabeth L.; Houseknecht, David W.

2007-01-01

The reconstruction of burial and thermal histories of partially exhumed basins requires an estimation of the amount of erosion that has occurred since the time of maximum burial. We have developed a method for estimating eroded thickness by using porosity-depth trends derived from borehole sonic logs of wells in the Colville Basin of northern Alaska. Porosity-depth functions defined from sonic-porosity logs in wells drilled in minimally eroded parts of the basin provide a baseline for comparison with the porosity-depth trends observed in other wells across the basin. Calculated porosities, based on porosity-depth functions, were fitted to the observed data in each well by varying the amount of section assumed to have been eroded from the top of the sedimentary column. The result is an estimate of denudation at the wellsite since the time of maximum sediment accumulation. Alternative methods of estimating exhumation include fission-track analysis and projection of trendlines through vitrinite-reflectance profiles. In the Colville Basin, the methodology described here provides results generally similar to those from fission-track analysis and vitrinite-reflectance profiles, but with greatly improved spatial resolution relative to the published fission-track data and with improved reliability relative to the vitrinite-reflectance data. In addition, the exhumation estimates derived from sonic-porosity logs are independent of the thermal evolution of the basin, allowing these estimates to be used as independent variables in thermal-history modeling.

Comparison of geoelectrical/tectonic models for suture zones in the western U.S.A. and eastern Europe: are black shales a possible source of high conductivities?

USGS Publications Warehouse

Stanley, W.D.

1989-01-01

Large-scale geoelectrical anomalies have been mapped with geomagnetic depth sounding (GDS) and magnetotelluric (MT) surveys in the Carpathian Mountains region. These anomalies are associated with the zone of closure between stable Europe and a complex of microplates in front of the converging African plate. The zone of closure, or suture zone, is largely occupied by an extensive deformed flysch belt. The models derived to fit the observed geoelectrical data are useful in the study of other suture zones, and Carpathian structures have been compared with areas currently being studied in the western Cordillera of the U.S.A. Models derived for a smaller-scale suture zone mapped in western Washington State have features that are similar to the Carpathian models. The geoelectrical models for both the Carpathian and Washington anomalies require dipping conductive slabs of 1-5 ?? m material that extends to depths > 20 km. In both instances there is evidence that these materials may merge with lower crustal-mantle conductors along the down-dip margins of the slab. The main conductive units are interpreted to be sedimentary rocks that have been partially subducted due to collisional processes. Heat flow is low in both regions and it is difficult to explain fully the deep conduction mechanisms; however, evidence suggests that the conduction at depth may include electronic conduction in sulfide mineral or carbon films as well as ionic conduction in fluids or partial melt. ?? 1989.

Investigations of student understanding of entropy and of mixed second-order partial derivatives in upper-level thermodynamics

NASA Astrophysics Data System (ADS)

Bucy, Brandon R.

While much of physics education research (PER) has traditionally been conducted in introductory undergraduate courses, researchers have begun to study student understanding of physics concepts at the upper-level. In this dissertation, we describe investigations conducted in advanced undergraduate thermodynamics courses. We present and discuss results pertaining to student understanding of two topics: entropy and the role of mixed second-order partial derivatives in thermodynamics. Our investigations into student understanding of entropy consisted of an analysis of written student responses to researcher-designed diagnostic questions. Data gathered in clinical interviews is employed to illustrate and extend results gathered from written responses. The question sets provided students with several ideal gas processes, and asked students to determine and compare the entropy changes of these processes. We administered the question sets to students from six distinct populations, including students enrolled in classical thermodynamics, statistical mechanics, thermal physics, physical chemistry, and chemical engineering courses, as well as a sample of physics graduate students. Data was gathered both before and after instruction in several samples. Several noteworthy features of student reasoning are identified and discussed. These features include student ideas about entropy prior to instruction, as well as specific difficulties and other aspects of student reasoning evident after instruction. As an example, students from various populations tended to emphasize either the thermodynamic or the statistical definition of entropy. Both approaches present students with a unique set of benefits as well as challenges. We additionally studied student understanding of partial derivatives in a thermodynamics context. We identified specific difficulties related to the mixed second partial derivatives of a thermodynamic state function, based on an analysis of student responses to homework and exam problems. Students tended to set these partial derivatives identically equal to zero. Students also displayed difficulties in relating the physical description of a material property to a corresponding mathematical statement involving partial derivatives. We describe the development of a guided-inquiry tutorial activity designed to address these specific difficulties. This tutorial focused on the graphical interpretation of partial derivatives. Preliminary results suggest that the tutorial was effective in addressing several student difficulties related to partial derivatives.

Estimating Dynamical Systems: Derivative Estimation Hints from Sir Ronald A. Fisher

ERIC Educational Resources Information Center

Deboeck, Pascal R.

2010-01-01

The fitting of dynamical systems to psychological data offers the promise of addressing new and innovative questions about how people change over time. One method of fitting dynamical systems is to estimate the derivatives of a time series and then examine the relationships between derivatives using a differential equation model. One common…

Estimating Dynamical Systems: Derivative Estimation Hints From Sir Ronald A. Fisher.

PubMed

Deboeck, Pascal R

2010-08-06

The fitting of dynamical systems to psychological data offers the promise of addressing new and innovative questions about how people change over time. One method of fitting dynamical systems is to estimate the derivatives of a time series and then examine the relationships between derivatives using a differential equation model. One common approach for estimating derivatives, Local Linear Approximation (LLA), produces estimates with correlated errors. Depending on the specific differential equation model used, such correlated errors can lead to severely biased estimates of differential equation model parameters. This article shows that the fitting of dynamical systems can be improved by estimating derivatives in a manner similar to that used to fit orthogonal polynomials. Two applications using simulated data compare the proposed method and a generalized form of LLA when used to estimate derivatives and when used to estimate differential equation model parameters. A third application estimates the frequency of oscillation in observations of the monthly deaths from bronchitis, emphysema, and asthma in the United Kingdom. These data are publicly available in the statistical program R, and functions in R for the method presented are provided.

Maximum-likelihood curve-fitting scheme for experiments with pulsed lasers subject to intensity fluctuations.

PubMed

Metz, Thomas; Walewski, Joachim; Kaminski, Clemens F

2003-03-20

Evaluation schemes, e.g., least-squares fitting, are not generally applicable to any types of experiments. If the evaluation schemes were not derived from a measurement model that properly described the experiment to be evaluated, poorer precision or accuracy than attainable from the measured data could result. We outline ways in which statistical data evaluation schemes should be derived for all types of experiment, and we demonstrate them for laser-spectroscopic experiments, in which pulse-to-pulse fluctuations of the laser power cause correlated variations of laser intensity and generated signal intensity. The method of maximum likelihood is demonstrated in the derivation of an appropriate fitting scheme for this type of experiment. Statistical data evaluation contains the following steps. First, one has to provide a measurement model that considers statistical variation of all enclosed variables. Second, an evaluation scheme applicable to this particular model has to be derived or provided. Third, the scheme has to be characterized in terms of accuracy and precision. A criterion for accepting an evaluation scheme is that it have accuracy and precision as close as possible to the theoretical limit. The fitting scheme derived for experiments with pulsed lasers is compared to well-established schemes in terms of fitting power and rational functions. The precision is found to be as much as three timesbetter than for simple least-squares fitting. Our scheme also suppresses the bias on the estimated model parameters that other methods may exhibit if they are applied in an uncritical fashion. We focus on experiments in nonlinear spectroscopy, but the fitting scheme derived is applicable in many scientific disciplines.

Fixation Times in Deme Structured, Finite Populations with Rare Migration

NASA Astrophysics Data System (ADS)

Hauert, Christoph; Chen, Yu-Ting; Imhof, Lorens A.

2014-08-01

Population structure affects both the outcome and the speed of evolutionary dynamics. Here we consider a finite population that is divided into subpopulations called demes. The dynamics within the demes are stochastic and frequency-dependent. Individuals can adopt one of two strategic types, or . The fitness of each individual is determined by interactions with other individuals in the same deme. With small probability, proportional to fitness, individuals migrate to other demes. The outcome of these dynamics has been studied earlier by analyzing the fixation probability of a single mutant in an otherwise homogeneous population. These results give only a partial picture of the dynamics, because the time when fixation occurs can be exceedingly large. In this paper, we study the impact of deme structures on the speed of evolution. We derive analytical approximations of fixation times in the limit of rare migration and rare mutation. In this limit, the conditional fixation time of a single mutant in a population is the same as that of a single in an population. For the prisoner's dilemma game, simulation results fit very well with our analytical predictions and demonstrate that fixation takes place in a moderate amount of time as compared to the expected waiting time until a mutant successfully invades and fixates. The simulations also confirm that the conditional fixation time of a single cooperator is indeed the same as that of a single defector.

Fit Analysis of Different Framework Fabrication Techniques for Implant-Supported Partial Prostheses.

PubMed

Spazzin, Aloísio Oro; Bacchi, Atais; Trevisani, Alexandre; Farina, Ana Paula; Dos Santos, Mateus Bertolini

2016-01-01

This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the frameworks and the abutments was evaluated with an optical microscope using the single-screw test. Data were analyzed using one-way analysis of variance and Tukey test (α = .05). The one-piece casted frameworks presented significantly higher vertical misfit values than those found for framework cemented on prepared abutments and laser welding techniques (P < .001 and P < .003, respectively). Laser welding and framework cemented on prepared abutments are effective techniques to improve the adaptation of three-unit implant-supported prostheses. These techniques presented similar fit.

Mapping of the Resistance of a Superconducting Transition Edge Sensor as a Function of Temperature, Current, and Applied Magnetic Field

NASA Technical Reports Server (NTRS)

Zhang, Shou; Eckart, Megan E.; Jaeckel, Felix; Kripps, Kari L.; McCammon, Dan; Zhou, Yu; Morgan, Kelsey M.

2017-01-01

We have measured the resistance R (T, I, B(sub ext) of a superconducting transition edge sensor over the entire transition region on a fine scale, producing a four-dimensional map of the resistance surface. The dimensionless temperature and current sensitivities (alpha equivalence partial derivative log R/partial derivative log T|(sub I) and beta equivalence partial derivative log R/partial derivative log I|(sub T) of the TES resistance have been determined at each point. alpha and beta are closely related to the sensor performance, but show a great deal of complex, large amplitude fine structure over large portions of the surface that is sensitive to the applied magnetic field. We discuss the relation of this structure to the presence of Josephson weak link fringes.

Fast gravity, gravity partials, normalized gravity, gravity gradient torque and magnetic field: Derivation, code and data

NASA Technical Reports Server (NTRS)

Gottlieb, Robert G.

1993-01-01

Derivation of first and second partials of the gravitational potential is given in both normalized and unnormalized form. Two different recursion formulas are considered. Derivation of a general gravity gradient torque algorithm which uses the second partial of the gravitational potential is given. Derivation of the geomagnetic field vector is given in a form that closely mimics the gravitational algorithm. Ada code for all algorithms that precomputes all possible data is given. Test cases comparing the new algorithms with previous data are given, as well as speed comparisons showing the relative efficiencies of the new algorithms.

Study of B¯→Xuℓν¯ decays in BB¯ events tagged by a fully reconstructed B-meson decay and determination of |Vub|

NASA Astrophysics Data System (ADS)

Lees, J. P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Tackmann, K.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Huard, Z.; Meadows, B. T.; Sokoloff, M. D.; Sun, L.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Santoro, V.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Prencipe, E.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Neri, N.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Pacetti, S.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Grünberg, O.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Benitez, J. F.; Burchat, P. R.; Miyashita, T. S.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Lanceri, L.; Vitale, L.; Azzolini, V.; Martinez-Vidal, F.; Oyanguren, A.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lindsay, C.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Tasneem, N.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Puccio, E. M. T.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Wu, S. L.

2012-08-01

We report measurements of partial branching fractions for inclusive charmless semileptonic B decays B¯→Xuℓν¯ and the determination of the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vub|. The analysis is based on a sample of 467×106 Υ(4S)→BB¯ decays recorded with the BABAR detector at the PEP-II e+e- storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions ΔB in several restricted regions of phase space and determine the CKM element |Vub| based on different QCD predictions. For decays with a charged lepton momentum pℓ*>1.0GeV in the B meson rest frame, we obtain ΔB=(1.80±0.13stat±0.15sys±0.02theo)×10-3 from a fit to the two-dimensional MX-q2 distribution. Here, MX refers to the invariant mass of the final state hadron X and q2 is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |Vub|=(4.33±0.24exp⁡±0.15theo)×10-3 as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B¯0 and B- decays and derive a limit on the isospin breaking in B¯→Xuℓν¯ decays.

Partial Derivatives, the Energy Crisis, and Urban Transportation: Calculus for Concerned Citizens

ERIC Educational Resources Information Center

Bent, Henry A.

1976-01-01

Presented is a method utilizing partial derivatives for determining the energy saved per dollar by substituting bicycling for driving a car while not reducing jobs dependent upon the auto industry. (SL)

Vertical Diffusivities of Active and Passive Tracers

NASA Technical Reports Server (NTRS)

Canuto, V. M.; Cheng, Y.; Howard, A. M.

2010-01-01

The climate models that include a carbon-cycle need the vertical diffusivity of a passive tracer. Since an expression for the latter is not available, it has been common practice to identify it with that of salt. The identification is questionable since T, S are active, not passive tracers. We present the first derivation of the diffusivity of a passive tracer in terms of Ri (Richardson number) and Rq (density ratio, ratio of salinity over temperature z-gradients). The following results have emerged: (a) The passive tracer diffusivity is an algebraic function of Ri, Rq. (b) In doubly stable regimes (DS, partial derivative of T with respect to z > 0, partial derivative of S with respect to z < 0), the passive scalar diffusivity is nearly the same as that of salt/heat for any values of Rq < 0 and Ri > 0. (c) In DC regimes (diffusive convection, partial derivative of T with respect to z < 0, partial derivative of S with respect to z < 0, Rq > 1), the passive scalar diffusivity is larger than that of salt. At Ri = O(1), it can be more than twice as large. (d) In SF regimes (salt fingers, partial derivative of T with respect to z > 0, partial derivative of S with respect to z > 0, Rq < 1), the passive scalar diffusivity is smaller than that of salt. At Ri = O(1), it can be less than half of it. (e) The passive tracer diffusivity predicted at the location of NATRE (North Atlantic Tracer Release Experiment) is discussed. (f) Perhaps the most relevant conclusion is that the common identification of the tracer diffusivity with that of salt is valid only in DS regimes. In the Southern Ocean, where there is the largest CO2 absorption, the dominant regime is diffusive convection discussed in (c) above.

Fabrication of a metal-ceramic crown to fit an existing partial removable dental prosthesis using ceramic pressed to metal technique: a clinical report

PubMed Central

Seo, Jae-Min

2014-01-01

Fabricating a crown to retrofit an existing abutment tooth for a partial removable dental prosthesis (PRDP) is one of the most time-consuming and labor-intensive clinical procedures. In particular, when the patient is concerned with esthetic aspects of restoration, the task of fabricating becomes more daunting. Many techniques for the fabrication of all-metallic or metal-ceramic crowns have been discussed in the literature. This article was aimed to describe a simple fabrication method in which a retrofitting crown was fabricated for a precise fit using a ceramic-pressed-to-metal system. PMID:25006389

Improved methods for the measurement and analysis of stellar magnetic fields

NASA Technical Reports Server (NTRS)

Saar, Steven H.

1988-01-01

The paper presents several improved methods for the measurement of magnetic fields on cool stars which take into account simple radiative transfer effects and the exact Zeeman patterns. Using these methods, high-resolution, low-noise data can be fitted with theoretical line profiles to determine the mean magnetic field strength in stellar active regions and a model-dependent fraction of the stellar surface (filling factor) covered by these regions. Random errors in the derived field strength and filling factor are parameterized in terms of signal-to-noise ratio, wavelength, spectral resolution, stellar rotation rate, and the magnetic parameters themselves. Weak line blends, if left uncorrected, can have significant systematic effects on the derived magnetic parameters, and thus several methods are developed to compensate partially for them. The magnetic parameters determined by previous methods likely have systematic errors because of such line blends and because of line saturation effects. Other sources of systematic error are explored in detail. These sources of error currently make it difficult to determine the magnetic parameters of individual stars to better than about + or - 20 percent.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Filinov, A.V.; Golubnychiy, V.O.; Bonitz, M.

Extending our previous work [A.V. Filinov et al., J. Phys. A 36, 5957 (2003)], we present a detailed discussion of accuracy and practical applications of finite-temperature pseudopotentials for two-component Coulomb systems. Different pseudopotentials are discussed: (i) the diagonal Kelbg potential, (ii) the off-diagonal Kelbg potential, (iii) the improved diagonal Kelbg potential, (iv) an effective potential obtained with the Feynman-Kleinert variational principle, and (v) the 'exact' quantum pair potential derived from the two-particle density matrix. For the improved diagonal Kelbg potential, a simple temperature-dependent fit is derived which accurately reproduces the 'exact' pair potential in the whole temperature range. The derivedmore » pseudopotentials are then used in path integral Monte Carlo and molecular-dynamics (MD) simulations to obtain thermodynamical properties of strongly coupled hydrogen. It is demonstrated that classical MD simulations with spin-dependent interaction potentials for the electrons allow for an accurate description of the internal energy of hydrogen in the difficult regime of partial ionization down to the temperatures of about 60 000 K. Finally, we point out an interesting relationship between the quantum potentials and the effective potentials used in density-functional theory.« less

Dependence of Impedance of Embedded Single Cells on Cellular Behaviour

PubMed Central

Cho, Sungbo; Castellarnau, Marc; Samitier, Josep; Thielecke, Hagen

2008-01-01

Non-invasive single cell analyses are increasingly required for the medical diagnostics of test substances or the development of drugs and therapies on the single cell level. For the non-invasive characterisation of cells, impedance spectroscopy which provides the frequency dependent electrical properties has been used. Recently, microfludic systems have been investigated to manipulate the single cells and to characterise the electrical properties of embedded cells. In this article, the impedance of partially embedded single cells dependent on the cellular behaviour was investigated by using the microcapillary. An analytical equation was derived to relate the impedance of embedded cells with respect to the morphological and physiological change of extracellular interface. The capillary system with impedance measurement showed a feasibility to monitor the impedance change of embedded single cells caused by morphological and physiological change of cell during the addition of DMSO. By fitting the derived equation to the measured impedance of cell embedded at different negative pressure levels, it was able to extrapolate the equivalent gap and gap conductivity between the cell and capillary wall representing the cellular behaviour. PMID:27879760

Processes for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil, and apparatuses for treating biomass-derived pyrolysis oil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baird, Lance Awender; Brandvold, Timothy A.

Processes and apparatuses for washing a spent ion exchange bed and for treating biomass-derived pyrolysis oil are provided herein. An exemplary process for washing a spent ion exchange bed employed in purification of biomass-derived pyrolysis oil includes the step of providing a ion-depleted pyrolysis oil stream having an original oxygen content. The ion-depleted pyrolysis oil stream is partially hydrotreated to reduce the oxygen content thereof, thereby producing a partially hydrotreated pyrolysis oil stream having a residual oxygen content that is less than the original oxygen content. At least a portion of the partially hydrotreated pyrolysis oil stream is passed throughmore » the spent ion exchange bed. Water is passed through the spent ion exchange bed after passing at least the portion of the partially hydrotreated pyrolysis oil stream therethrough.« less

Associations between physical activity, screen time, and fitness among 6- to 10-year-old children living in Edmonton, Canada.

PubMed

Potter, Morgan; Spence, John C; Boulé, Normand G; Stearns, Jodie A; Carson, Valerie

2017-05-01

The objectives of this study were to describe fitness levels; examine associations between physical activity (PA), screen time (ST), and fitness; and examine sex-moderating effects in a sample of children. Participants were 649 children (age, 7.8 ± 0.6 years; 52.4% female) from Edmonton, Canada. Hours/week of PA and ST were parent-reported. PA was also objectively measured with pedometers and expressed in increments of 1000 steps/day. Fitness components (i.e., vertical jump, sit-and-reach, waist circumference, grip strength, predicted maximal oxygen consumption, push-ups, partial curl-ups, overall fitness) were measured according to the Canadian Physical Activity, Fitness, and Lifestyle Approach protocols and expressed as z scores or low/high fitness. Positive associations were observed between PA and overall fitness for both the complete (subjective: β = 0.009, 95% confidence interval (CI): 0.001-0.017) and partial (≥3 available fitness measures; subjective: β = 0.006, 95% CI: 0.000-0.011; objective: β = 0.025, 95% CI: 0.007-0.042) fitness scores. Subjective (β = 0.011, 95% CI: 0.000-0.022) and objective (β = 0.043, 95% CI: 0.008-0.078) PAs were positively associated with vertical jump. Children with higher objective PA were more likely to be in the high push-ups group (odds ratio = 1.156, 95% CI: 1.054-1.267). PA was positively associated with predicted maximal oxygen uptake (subjective: β = 0.040, 95% CI: 0.018-0.063; objective: β = 0.084, 95% CI: 0.012-0.157) and grip strength (subjective: β = 0.025, 95% CI: 0.011-0.040) in boys only. ST was negatively associated with grip strength (β = -0.016, 95% CI: -0.028 to -0.004) in boys. PA was associated with several components of fitness, especially in boys. However, few associations were observed between ST and fitness. Promoting regular PA in young children may address declining fitness levels.

The association of health-related fitness with indicators of academic performance in Texas schools.

PubMed

Welk, Gregory J; Jackson, Allen W; Morrow, James R; Haskell, William H; Meredith, Marilu D; Cooper, Kenneth H

2010-09-01

This study examined the associations between indicators of health-related physical fitness (cardiovascular fitness and body mass index) and academic performance (Texas Assessment of Knowledge and Skills). Partial correlations were generally stronger for cardiovascular fitness than body mass index and consistently stronger in the middle school grades. Mixed-model regression analyses revealed modest associations between fitness and academic achievement after controlling for potentially confounding variables. The effects of fitness on academic achievement were positive but small. A separate logistic regression analysis indicated that higher fitness rates increased the odds of schools achieving exemplary/recognized school status within the state. School fitness attainment is an indicator of higher performing schools. Direction of causality cannot be inferred due to the cross-sectional nature of the data.

Partial molar volumes of proteins: amino acid side-chain contributions derived from the partial molar volumes of some tripeptides over the temperature range 10-90 degrees C.

PubMed

Häckel, M; Hinz, H J; Hedwig, G R

1999-11-15

The partial molar volumes of tripeptides of sequence glycyl-X-glycine, where X is one of the amino acids alanine, leucine, threonine, glutamine, phenylalanine, histidine, cysteine, proline, glutamic acid, and arginine, have been determined in aqueous solution over the temperature range 10-90 degrees C using differential scanning densitometry . These data, together with those reported previously, have been used to derive the partial molar volumes of the side-chains of all 20 amino acids. The side-chain volumes are critically compared with literature values derived using partial molar volumes for alternative model compounds. The new amino acid side-chain volumes, along with that for the backbone glycyl group, were used to calculate the partial specific volumes of several proteins in aqueous solution. The results obtained are compared with those observed experimentally. The new side-chain volumes have also been used to re-determine residue volume changes upon protein folding.

Sarcoptic mange breaks up bottom-up regulation of body condition in a large herbivore population.

PubMed

Carvalho, João; Granados, José E; López-Olvera, Jorge R; Cano-Manuel, Francisco Javier; Pérez, Jesús M; Fandos, Paulino; Soriguer, Ramón C; Velarde, Roser; Fonseca, Carlos; Ráez, Arian; Espinosa, José; Pettorelli, Nathalie; Serrano, Emmanuel

2015-11-06

Both parasitic load and resource availability can impact individual fitness, yet little is known about the interplay between these parameters in shaping body condition, a key determinant of fitness in wild mammals inhabiting seasonal environments. Using partial least square regressions (PLSR), we explored how temporal variation in climatic conditions, vegetation dynamics and sarcoptic mange (Sarcoptes scabiei) severity impacted body condition of 473 Iberian ibexes (Capra pyrenaica) harvested between 1995 and 2008 in the highly seasonal Alpine ecosystem of Sierra Nevada Natural Space (SNNS), southern Spain. Bottom-up regulation was found to only occur in healthy ibexes; the condition of infected ibexes was independent of primary productivity and snow cover. No link between ibex abundance and ibex body condition could be established when only considering infected individuals. The pernicious effects of mange on Iberian ibexes overcome the benefits of favorable environmental conditions. Even though the increase in primary production exerts a positive effect on the body condition of healthy ibexes, the scabietic individuals do not derive any advantage from increased resource availability. Further applied research coupled with continuous sanitary surveillance are needed to address remaining knowledge gaps associated with the transmission dynamics and management of sarcoptic mange in free-living populations.

Publisher's Note: Branching ratio of the electromagnetic decay of the Σ+(1385) Phys. Rev. D 85, 052004 (2012)

NASA Astrophysics Data System (ADS)

Keller, D.; Hicks, K.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bookwalter, C.; Boiarinov, S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Doughty, D.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Vernarsky, B.; Vineyard, M. F.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhao, B.; Zhao, Z. W.

2012-03-01

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the $\\Sigma^{*+}(1385)$ from the reaction $\\gamma p \\to K^0 \\Sigma^{*+}(1385)$. A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and $\\Sigma^*$ hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the partial width measurement of $250.0\\pm56.9(stat)^{+34.3}_{-41.2}(sys)$ keV. A U-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the $\\Sigma^{*+}(1385)\\to\\Sigma^{+}\\gamma$ and $\\Sigma^{*0}(1385)\\to\\Lambda\\gamma$ partial widths that agree with the experimental measurements.

Branching Ratio of the Electromagnetic Decay of the Σ +(1385)

DOE PAGES

Keller, D.; Hicks, K.; Adhikari, K. P.; ...

2012-03-01

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the Σ* +(1385) from the reaction γp → K 0 Σ* +(1385). A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and Σ* hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the partial width measurement of 250.0 ± 56.9(stat) -41.2 +34.3(sys) keV. A U-spin symmetry testmore » using the SU(3) flavor-multiplet representation yields predictions for the Σ* +(1385) → Σ +γ and Σ* 0(1385) → Λγ partial widths that agree with the experimental measurements.« less

N* resonances from K $$\\Lambda$$ Λ amplitudes in sliced bins in energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.

The two reactionsmore » $$\\gamma p\\to K^+\\Lambda$$ and $$\\pi^-p\\to K^0\\Lambda$$ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9\\,GeV with quantum numbers $J^P = 1/2^+$, $3/2^+, 1/2^-, 3/2^-, 5/2^-$.« less

Branching Ratio of the Electromagnetic Decay of the Σ +(1385)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, D.; Hicks, K.; Adhikari, K. P.

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the Σ* +(1385) from the reaction γp → K 0 Σ* +(1385). A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and Σ* hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the partial width measurement of 250.0 ± 56.9(stat) -41.2 +34.3(sys) keV. A U-spin symmetry testmore » using the SU(3) flavor-multiplet representation yields predictions for the Σ* +(1385) → Σ +γ and Σ* 0(1385) → Λγ partial widths that agree with the experimental measurements.« less

N* resonances from K $$\\Lambda$$ Λ amplitudes in sliced bins in energy

DOE PAGES

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.; ...

2017-12-22

The two reactionsmore » $$\\gamma p\\to K^+\\Lambda$$ and $$\\pi^-p\\to K^0\\Lambda$$ are analyzed to determine the leading photoproduction multipoles and the pion-induced partial wave amplitudes in slices of the invariant mass. The multipoles and the partial-wave amplitudes are simultaneously fitted in a multichannel Laurent+Pietarinen model (L+P model), which determines the poles in the complex energy plane on the second Riemann sheet close to the physical axes. The results from the L+P fit are compared with the results of an energy-dependent fit based on the Bonn-Gatchina (BnGa) approach. The study confirms the existence of several poles due to nucleon resonances in the region at about 1.9\\,GeV with quantum numbers $J^P = 1/2^+$, $3/2^+, 1/2^-, 3/2^-, 5/2^-$.« less

Microstructure selection in thin-sample directional solidification of an Al-Cu alloy: In situ X-ray imaging and phase-field simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarke, A. J.; Tourret, D.; Song, Y.

We study microstructure selection during directional solidification of a thin metallic sample. We combine in situ X-ray radiography of a dilute Al-Cu alloy solidification experiments with three-dimensional phase-field simulations. We explore a range of temperature gradient G and growth velocity V and build a microstructure selection map for this alloy. We investigate the selection of the primary dendritic spacing Lambda and tip radius rho. While rho shows a good agreement between experimental measurements and dendrite growth theory, with rho similar to V-1/2, Lambda is observed to increase with V (partial derivative Lambda/partial derivative V > 0), in apparent disagreement withmore » classical scaling laws for primary dendritic spacing, which predict that partial derivative Lambda/partial derivative V <0. We show through simulations that this trend inversion for Lambda(V) is due to liquid convection in our experiments, despite the thin sample configuration. We use a classical diffusion boundary-layer approximation to semi-quantitatively incorporate the effect of liquid convection into phase-field simulations. This approximation is implemented by assuming complete solute mixing outside a purely diffusive zone of constant thickness that surrounds the solid-liquid interface. This simple method enables us to quantitatively match experimental measurements of the planar morphological instability threshold and primary spacings over an order of magnitude in V. We explain the observed inversion of partial derivative Lambda/partial derivative V by a combination of slow transient dynamics of microstructural homogenization and the influence of the sample thickness.« less

Single-component and binary CO2 and H2O adsorption of amine-functionalized cellulose.

PubMed

Gebald, Christoph; Wurzbacher, Jan A; Borgschulte, Andreas; Zimmermann, Tanja; Steinfeld, Aldo

2014-02-18

A fundamental analysis of single-component and binary CO2 and H2O adsorption of amine-functionalized nanofibrillated cellulose is carried out in the temperature range of 283-353 K and at CO2 partial pressures in the range of 0.02-105 kPa, where the ultralow partial pressure range is relevant for the direct capture of CO2 from atmospheric air. Single-component CO2 and H2O adsorption experimental data are fitted to the Toth and Guggenheim-Anderson-de Boer models, respectively. Corresponding heats of adsorption, derived from explicit solutions of the van't Hoff equation, are -50 kJ/mol CO2 and -48.8 kJ/mol H2O. Binary CO2/H2O adsorption measurements for humid air reveal that the presence of H2O at 2.55 kPa enhances CO2 adsorption, while the presence of CO2 at 0.045 kPa does not influence H2O adsorption. The energy demand of the temperature-vacuum-swing adsorption/desorption cycle for delivering pure CO2 from air increases significantly with H2O adsorption and indicates the need to reduce the hygroscopicity of the adsorbent.

Coherent and partially coherent dark hollow beams with rectangular symmetry and paraxial propagation properties

NASA Astrophysics Data System (ADS)

Cai, Yangjian; Zhang, Lei

2006-07-01

A theoretical model is proposed to describe coherent dark hollow beams (DHBs) with rectangular symmetry. The electric field of a coherent rectangular DHB is expressed as a superposition of a series of the electric field of a finite series of fundamental Gaussian beams. Analytical propagation formulas for a coherent rectangular DHB passing through paraxial optical systems are derived in a tensor form. Furthermore, for the more general case, we propose a theoretical model to describe a partially coherent rectangular DHB. Analytical propagation formulas for a partially coherent rectangular DHB passing through paraxial optical systems are derived. The beam propagation factor (M2 factor) for both coherent and partially coherent rectangular DHBs are studied. Numerical examples are given by using the derived formulas. Our models and method provide an effective way to describe and treat the propagation of coherent and partially coherent rectangular DHBs.

A Model Fit Statistic for Generalized Partial Credit Model

ERIC Educational Resources Information Center

Liang, Tie; Wells, Craig S.

2009-01-01

Investigating the fit of a parametric model is an important part of the measurement process when implementing item response theory (IRT), but research examining it is limited. A general nonparametric approach for detecting model misfit, introduced by J. Douglas and A. S. Cohen (2001), has exhibited promising results for the two-parameter logistic…

46 CFR 42.20-9 - Initial conditions of loading.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following: (i) Each tank and space fitted to... only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full. (3) If the...

46 CFR 42.20-9 - Initial conditions of loading.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following: (i) Each tank and space fitted to... only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full. (3) If the...

46 CFR 42.20-9 - Initial conditions of loading.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following: (i) Each tank and space fitted to... only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full. (3) If the...

46 CFR 42.20-9 - Initial conditions of loading.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following: (i) Each tank and space fitted to... only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full. (3) If the...

46 CFR 42.20-9 - Initial conditions of loading.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Fifty percent of the total capacity of all tanks and spaces fitted to contain consumable liquids or stores must be assumed to be distributed to accomplish the following: (i) Each tank and space fitted to... only partially filled. In the case of liquid cargoes, fully loaded means 98 percent full. (3) If the...

Assessment of the fit of removable partial denture fabricated by computer-aided designing/computer aided manufacturing technology.

PubMed

Arafa, Khalid A O

2018-01-01

To assess the level of evidence that supports the quality of fit for removable partial denture (RPD) fabricated by computer-aided designing/computer aided manufacturing (CAD/CAM) and rapid prototyping (RP) technology. Methods: An electronic search was performed in Google Scholar, PubMed, and Cochrane library search engines, using Boolean operators. All articles published in English and published in the period from 1950 until April 2017 were eligible to be included in this review. The total number of articles contained the search terms in any part of the article (including titles, abstracts, or article texts) were screened, which resulted in 214 articles. After exclusion of irrelevant and duplicated articles, 12 papers were included in this systematic review.  Results: All the included studies were case reports, except one study, which was a case series that recruited 10 study participants. The visual and tactile examination in the cast or clinically in the patient's mouth was the most-used method for assessment of the fit of RPDs. From all included studies, only one has assessed the internal fit between RPDs and oral tissues using silicone registration material. The vast majority of included studies found that the fit of RPDs ranged from satisfactory to excellent fit. Conclusion: Despite the lack of clinical trials that provide strong evidence, the available evidence supported the claim of good fit of RPDs fabricated by new technologies using CAD/CAM.

The evolution of sex is favoured during adaptation to new environments.

PubMed

Becks, Lutz; Agrawal, Aneil F

2012-01-01

Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., "short-" or "long-term" effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This "long-term advantage" builds over multiple generations, eventually resulting in higher fitness of sexual types.

The Evolution of Sex Is Favoured During Adaptation to New Environments

PubMed Central

Becks, Lutz; Agrawal, Aneil F.

2012-01-01

Both theory and experiments have demonstrated that sex can facilitate adaptation, potentially yielding a group-level advantage to sex. However, it is unclear whether this process can help solve the more difficult problem of the maintenance of sex within populations. Using experimental populations of the facultatively sexual rotifer Brachionus calyciflorus, we show that rates of sex evolve to higher levels during adaptation but then decline as fitness plateaus. To assess the fitness consequences of genetic mixing, we directly compare the fitnesses of sexually and asexually derived genotypes that naturally occur in our experimental populations. Sexually derived genotypes are more fit than asexually derived genotypes when adaptive pressures are strong, but this pattern reverses as the pace of adaptation slows, matching the pattern of evolutionary change in the rate of sex. These fitness assays test the net effect of sex but cannot be used to disentangle whether selection on sex arises because highly sexual lineages become associated with different allele combinations or with different allele frequencies than less sexual lineages (i.e., “short-” or “long-term” effects, respectively). We infer which of these mechanisms provides an advantage to sex by performing additional manipulations to obtain fitness distributions of sexual and asexual progeny arrays from unbiased parents (rather than from naturally occurring, and thereby evolutionarily biased, parents). We find evidence that sex breaks down adaptive gene combinations, resulting in lower average fitness of sexual progeny (i.e., a short-term disadvantage to sex). As predicted by theory, the advantage to sex arises because sexually derived progeny are more variable in fitness, allowing for faster adaptation. This “long-term advantage” builds over multiple generations, eventually resulting in higher fitness of sexual types. PMID:22563299

Singularities in the lineshape of a second-order perturbed quadrupolar nucleus and their use in data fitting.

PubMed

Field, Timothy R; Bain, Alex D

2014-01-01

Even for large quadrupolar interactions, the powder spectrum of the central transition for a half-integral spin is relatively narrow, because it is unperturbed to first order. However, the second-order perturbation is still orientation dependent, so it generates a characteristic lineshape. This lineshape has both finite step discontinuities and singularities where the spectrum is infinite, in theory. The relative positions of these features are well-known and they play an important role in fitting experimental data. However, there has been relatively little discussion of how high the steps are, so we present explicit formulae for these heights. This gives a full characterization of the features in this lineshape which can lead to an analysis of the spectrum without the usual laborious powder average. The transition frequency, as a function of the orientation angles, shows critical points: maxima, minima and saddle points. The maxima and minima correspond to the step discontinuities and the saddle points generate the singularities. Near a maximum, the contours are ellipses, whose dimensions are determined by the second derivatives of the frequency with respect to the polar and azimuthal angles. The density of points is smooth as the contour levels move up and down, but then drops to zero when a maximum is passed, giving a step. The height of the step is determined by the Hessian matrix-the matrix of all partial second derivatives. The points near the poles and the saddle points require a more detailed analysis, but this can still be done analytically. The resulting formulae are then compared to numerical simulations of the lineshape. We expand this calculation to include a relatively simple case where there is chemical shielding anisotropy and use this to fit experimental (139)La spectra of La2O3. Copyright © 2014 Elsevier Inc. All rights reserved.

Multi-species sensing using multi-mode absorption spectroscopy with mid-infrared interband cascade lasers

NASA Astrophysics Data System (ADS)

O'Hagan, S.; Northern, J. H.; Gras, B.; Ewart, P.; Kim, C. S.; Kim, M.; Merritt, C. D.; Bewley, W. W.; Canedy, C. L.; Vurgaftman, I.; Meyer, J. R.

2016-06-01

The application of an interband cascade laser, ICL, to multi-mode absorption spectroscopy, MUMAS, in the mid-infrared region is reported. Measurements of individual mode linewidths of the ICL, derived from the pressure dependence of lineshapes in MUMAS signatures of single, isolated, lines in the spectrum of HCl, were found to be in the range 10-80 MHz. Multi-line spectra of methane were recorded using spectrally limited bandwidths, of approximate width 27 cm-1, defined by an interference filter, and consist of approximately 80 modes at spectral locations spanning the 100 cm-1 bandwidth of the ICL output. Calibration of the methane pressures derived from MUMAS data using a capacitance manometer provided measurements with an uncertainty of 1.1 %. Multi-species sensing is demonstrated by the simultaneous detection of methane, acetylene and formaldehyde in a gas mixture. Individual partial pressures of the three gases are derived from best fits of model MUMAS signatures to the data with an experimental error of 10 %. Using an ICL, with an inter-mode interval of ~10 GHz, MUMAS spectra were recorded at pressures in the range 1-10 mbar, and, based on the data, a potential minimum detection limit of the order of 100 ppmv is estimated for MUMAS at atmospheric pressure using an inter-mode interval of 80 GHz.

Analyzing Bleriot's propeller gaps in Cassini NAC images

NASA Astrophysics Data System (ADS)

Hoffmann, Holger; Chen, Cheng; Seiß, Martin; Albers, Nicole; Spahn, Frank; Nic

2016-10-01

Among the great discoveries of the Cassini mission are the propeller-shaped structures created by small moonlets embedded in Saturn's dense rings. These moonlets are not massive enough to counteract the viscous ring diffusion to open and maintain circumferential gaps, distinguishing them from ring-moons like Pan and Daphnis.Although one of the defining features of propeller structures, well-formed partial gaps have been resolved by the Imaging Science Subsystem Narrow Angle Camera onboard the Cassini spacecraft only for the largest known propeller named Bleriot. We analyze images of the sunlit side of Saturn's outer A ring showing the propeller Bleriot with clearly visible gaps. By fitting a Gaussian to radial brightness profiles at different azimuthal locations, we obtain the evolution of gap minimum and gap width downstream of the moonlet.We report two findings:1) Numerical simulations indicate that the radial separation of the partial propeller gaps is expected to be 4 Hill radii (Spahn and Sremcevic, 2000, A&A). We infer Bleriot's Hill radius to be a few hundred meters, consistent with values given by Sremcevic et al. (2014, DPS) and Hoffmann et al. (2015, Icarus).2) In order to estimate the ring viscosity in the region of Saturn's outer A ring, where Bleriot orbits, we fit several model functions (one example being the analytic solution derived by Sremcevic, Spahn and Duschl, 2002, MNRAS) describing the azimuthal evolution of the surface density in the propeller gap region to the data obtained from the image analysis. We find viscosity values consistent with the parameterization of ring viscosity by Daisaka et al. (2001, Icarus), but significantly lower than the upper limit given by Esposito et al. (1983, Icarus)

Spectral and Temporal Characteristics of LS PEG and TW PIC Using XMM-NEWTON Data

NASA Astrophysics Data System (ADS)

Talebpour Sheshvan, Nasrin; Balman, Solen

2016-07-01

We report the analysis of archival XMM-Newton X-ray observations of LS Peg and TW Pic. These are Cataclysmic Variables (CVs) suggested as Intermediate Polars (IPs), but unconfirmed in the X-rays. Identification of several periodic oscillations in the optical band hint them as IPs. Unlike the previous spectral analysis on the EPIC-MOS data by fitting a hot optically thin plasma emission model with a single temperature for LS Peg, we simultaneously fitted all EPIC spectrum (pn+MOS) using a composite model of absorption for interstellar medium (tbabs) with two different partial covering absorbers (pcfabs) including a multitemperature plasma emission component (cevmkl) and a Gaussian emission line at 6.4 keV. TW Pic is best modeled in a similar manner with only one partial covering absorber and an extra Gaussian emission line at 6.7 keV. LS Peg has a maximum plasma temperature of ˜14.8 keV with an X-ray luminosity of ˜5×10^{32}ergs ^{-1} translating to an accretion rate of ˜1.27×10^{-10}M _{⊙}yr ^{-1}. TW Pic shows kT _{max} ˜38.7 keV with an X-ray luminosity around 1.6×10^{33}ergs ^{-1} at an accretion rate of ˜4×10^{-10}M _{⊙}yr ^{-1}. In addition, we discuss orbital modulations in the X-rays and power spectral analysis, and derive the EPIC pn spectra for orbital minimum and orbital maximum phases for both sources. We elaborate on the geometry of accretion and absorption in the X-ray emitting regions of both sources with articulation on the magnetic nature.

Fitting Prony Series To Data On Viscoelastic Materials

NASA Technical Reports Server (NTRS)

Hill, S. A.

1995-01-01

Improved method of fitting Prony series to data on viscoelastic materials involves use of least-squares optimization techniques. Based on optimization techniques yields closer correlation with data than traditional method. Involves no assumptions regarding the gamma'(sub i)s and higher-order terms, and provides for as many Prony terms as needed to represent higher-order subtleties in data. Curve-fitting problem treated as design-optimization problem and solved by use of partially-constrained-optimization techniques.

Performance of Transit Model Fitting in Processing Four Years of Kepler Science Data

NASA Astrophysics Data System (ADS)

Li, Jie; Burke, Christopher J.; Jenkins, Jon Michael; Quintana, Elisa V.; Rowe, Jason; Seader, Shawn; Tenenbaum, Peter; Twicken, Joseph D.

2014-06-01

We present transit model fitting performance of the Kepler Science Operations Center (SOC) Pipeline in processing four years of science data, which were collected by the Kepler spacecraft from May 13, 2009 to May 12, 2013. Threshold Crossing Events (TCEs), which represent transiting planet detections, are generated by the Transiting Planet Search (TPS) component of the pipeline and subsequently processed in the Data Validation (DV) component. The transit model is used in DV to fit TCEs and derive parameters that are used in various diagnostic tests to validate planetary candidates. The standard transit model includes five fit parameters: transit epoch time (i.e. central time of first transit), orbital period, impact parameter, ratio of planet radius to star radius and ratio of semi-major axis to star radius. In the latest Kepler SOC pipeline codebase, the light curve of the target for which a TCE is generated is initially fitted by a trapezoidal model with four parameters: transit epoch time, depth, duration and ingress time. The trapezoidal model fit, implemented with repeated Levenberg-Marquardt minimization, provides a quick and high fidelity assessment of the transit signal. The fit parameters of the trapezoidal model with the minimum chi-square metric are converted to set initial values of the fit parameters of the standard transit model. Additional parameters, such as the equilibrium temperature and effective stellar flux of the planet candidate, are derived from the fit parameters of the standard transit model to characterize pipeline candidates for the search of Earth-size planets in the Habitable Zone. The uncertainties of all derived parameters are updated in the latest codebase to take into account for the propagated errors of the fit parameters as well as the uncertainties in stellar parameters. The results of the transit model fitting of the TCEs identified by the Kepler SOC Pipeline, including fitted and derived parameters, fit goodness metrics and diagnostic figures, are included in the DV report and one-page report summary, which are accessible by the science community at NASA Exoplanet Archive. Funding for the Kepler Mission has been provided by the NASA Science Mission Directorate.

Development of ground-water vulnerability database for the U.S. Environmental protection agency's hazard ranking system using a geographic information system

USGS Publications Warehouse

Clarke, John S.; Sorensen, Jerry W.; Strickland, Henry G.; Collins, George

1992-01-01

Geographic information system (GIS) methods were applied to the U.S. Environmental Protection Agency's (EPA) hazard ranking system (HRS) to evaluate the vulnerability of ground water to contamination from actual or potential releases of hazardous materials from waste-disposal sites. Computerized maps of four factors influencing ground-water vulnerability - hydraulic conductivity, sorptive capacity, depth to water, and net precipitation - were derived for the Southeastern United States from digitized copies of published maps and from computerized databases, including the U.S. Geological Survey's (USGS) national water information system. To test the accuracy of the derived data coverages used to assess ground-water vulnerability, GIS-derived values for hydraulic conductivity, depth to water, and net precipitation were compared to corresponding values assigned by EPA's field investigation teams (FIT) at 28 hazardous waste sites. For each factor, site data were divided into three physiographic groupings: (1) Coastal Plain, (2) Valley and Ridge-Interior Low Plateaus, and (3) Piedmont-Blue Ridge. The best correlation between the paired data sets was for the net precipitation factor, where most GIS-derived values were within 0 to 40% of the FIT data, and 79% were within the same HRS scoring range. For the hydraulic conductivity factor, the best correlation between GIS and FIT data was for values derived from a published surficial deposits map, where most of the values were within one order of magnitude of the FIT data, and on the average were within 1.24 orders of magnitude of the FIT data. For this map, the best match between data sets was in the Coastal Plain province, where the difference in order to magnitude averaged 0.92. For the depth-to-water factor, most of the GIS derived values were within 51 to 100% of the FIT data, and only 44 to 50% of the sites were within a common scoring range. The best correlation for depth to water was in the Coastal Plain where GIS derived values were within 8 to 100% of the FIT data.

The Partial Molar Volume and Compressibility of the FeO Component in Model Basalts (Mixed CaAl2Si2O8-CaMgSi2O6-CaFeSi2O6 Liquids) at 0 GPa: evidence of Fe2+ in 6-fold coordination

NASA Astrophysics Data System (ADS)

Guo, X.; Lange, R. A.; Ai, Y.

2010-12-01

FeO is an important component in magmatic liquids and yet its partial molar volume at one bar is not as well known as that for Fe2O3 because of the difficulty of performing double-bob density measurements under reducing conditions. Moreover, there is growing evidence from spectroscopic studies that Fe2+ occurs in 4, 5, and 6-fold coordination in silicate melts, and it is expected that the partial molar volume and compressibility of the FeO component will vary accordingly. We have conducted both density and relaxed sound speed measurements on four liquids in the An-Di-Hd (CaAl2Si2O8-CaMgSi2O6-CaFeSi2O6) system: (1) Di-Hd (50:50), (2) An-Hd (50:50), (3) An-Di-Hd (33:33:33) and (4) Hd (100). Densities were measured between 1573 and 1838 K at one bar with the double-bob Archimedean method using molybdenum bobs and crucibles in a reducing gas (1%CO-99%Ar) environment. The sound speeds were measured under similar conditions with a frequency-sweep acoustic interferometer, and used to calculate isothermal compressibility. All the density data for the three multi-component (model basalt) liquids were combined with density data on SiO2-Al2O3-CaO-MgO-K2O-Na2O liquids (Lange, 1997) in a fit to a linear volume equation; the results lead to a partial molar volume (±1σ) for FeO =11.7 ± 0.3(±1σ) cm3/mol at 1723 K. This value is similar to that for crystalline FeO at 298 K (halite structure; 12.06 cm3/mol), which suggests an average Fe2+ coordination of ~6 in these model basalt compositions. In contrast, the fitted partial molar volume of FeO in pure hedenbergite liquid is 14.6 ± 0.3 at 1723 K, which is consistent with an average Fe2+ coordination of 4.3 derived from EXAFS spectroscopy (Rossano, 2000). Similarly, all the compressibility data for the three multi-component liquids were combined with compressibility data on SiO2-Al2O3-CaO-MgO liquids (Ai and Lange, 2008) in a fit to an ideal mixing model for melt compressibility; the results lead to a partial molar compressibility (±1σ) for FeO = 2.4 (± 0.3) 10-2 GPa-1 at 1723 K. In contrast, the compressibility of FeO in pure hedenbergite liquid is more than twice as large: 6.3 (± 0.2) 10-2 GPa-1. When these results are combined with density and sound speed data on CaO-FeO-SiO2 liquids at one bar (Guo et al., 2009), a systematic and linear variation between the partial molar volume and compressibility of the FeO component is obtained, which appears to track changes in the average Fe2+ coordination in these liquids. Therefore, the three most important conclusions of this study are: (1) ideal mixing of volume and compressibility does not occur for all FeO-bearing magmatic liquids, owing to changes in Fe2+ coordination, (2) the partial molar volume and compressibility of FeO varies linearly and systematically with Fe2+ coordination, and (3) ideal mixing of volume and compressibility does occur among the three mixed An-Di-Hd liquids, presumably because of a common, average Fe2+ coordination of ~6.

Different fits satisfy different needs: linking person-environment fit to employee commitment and performance using self-determination theory.

PubMed

Greguras, Gary J; Diefendorff, James M

2009-03-01

Integrating and expanding upon the person-environment fit (PE fit) and the self-determination theory literatures, the authors hypothesized and tested a model in which the satisfaction of the psychological needs for autonomy, relatedness, and competence partially mediated the relations between different types of perceived PE fit (i.e., person-organization fit, person-group fit, and job demands-abilities fit) with employee affective organizational commitment and overall job performance. Data from 163 full-time working employees and their supervisors were collected across 3 time periods. Results indicate that different types of PE fit predicted different types of psychological need satisfaction and that psychological need satisfaction predicted affective commitment and performance. Further, person-organization fit and demands-abilities fit also evidenced direct effects on employee affective commitment. These results begin to explicate the processes through which different types of PE fit relate to employee attitudes and behaviors. (c) 2009 APA, all rights reserved.

Modeling of the morphological change of cellulose microfibrils caused with aqueous NaOH solution: the longitudinal contraction and laterally swelling during decrystallization.

PubMed

Nakano, Takato

2017-04-01

The conformation of cellulose microfibrils treated with aqueous NaOH was modeled as partially decrystallized cellulose chains before completing conversion to cellulose II, in order to elucidate the change in morphology of ramie fiber caused by NaOH treatment. Equations for the relative length and width of the microfibrils were derived on the basis of partially decrystallized microfibrils modeling. Each equation contains four parameters, n, β, w c , and c r , which correspond to the number of glucose residues between periodic defects along the untreated ramie cellulose microfibrils, the extension ratio of amorphous cellulose chain along length, the cross-section crystallinity, and the correction term of crystallinity, respectively. The validity of the derived equations was confirmed by two types of simulations. One is performed using experimental data L/L 0 and W/W 0 as a function of crystallinity, while the other is done using the relationship between the relative length and width obtained from the experimental data, which is independent of crystallinity, was performed. The best-fit simulation was obtained under n = 277, β = 2.813, and c r w c  = 0.671 for the former and under n = 301 and β = 2.792 for the latter. These values of n and β correspond closely to the values reported in references for ramie microfibrils. Both simulation results show that macroscopic changes in the morphology of ramie fibers is attributable to the changes in cellulose chain conformation in the decrystallized regions created along the microfibrils upon NaOH treatment.

Local Discontinuous Galerkin Methods for Partial Differential Equations with Higher Order Derivatives

NASA Technical Reports Server (NTRS)

Yan, Jue; Shu, Chi-Wang; Bushnell, Dennis M. (Technical Monitor)

2002-01-01

In this paper we review the existing and develop new continuous Galerkin methods for solving time dependent partial differential equations with higher order derivatives in one and multiple space dimensions. We review local discontinuous Galerkin methods for convection diffusion equations involving second derivatives and for KdV type equations involving third derivatives. We then develop new local discontinuous Galerkin methods for the time dependent bi-harmonic type equations involving fourth derivatives, and partial differential equations involving fifth derivatives. For these new methods we present correct interface numerical fluxes and prove L(exp 2) stability for general nonlinear problems. Preliminary numerical examples are shown to illustrate these methods. Finally, we present new results on a post-processing technique, originally designed for methods with good negative-order error estimates, on the local discontinuous Galerkin methods applied to equations with higher derivatives. Numerical experiments show that this technique works as well for the new higher derivative cases, in effectively doubling the rate of convergence with negligible additional computational cost, for linear as well as some nonlinear problems, with a local uniform mesh.

Spin models inferred from patient-derived viral sequence data faithfully describe HIV fitness landscapes

NASA Astrophysics Data System (ADS)

Shekhar, Karthik; Ruberman, Claire F.; Ferguson, Andrew L.; Barton, John P.; Kardar, Mehran; Chakraborty, Arup K.

2013-12-01

Mutational escape from vaccine-induced immune responses has thwarted the development of a successful vaccine against AIDS, whose causative agent is HIV, a highly mutable virus. Knowing the virus' fitness as a function of its proteomic sequence can enable rational design of potent vaccines, as this information can focus vaccine-induced immune responses to target mutational vulnerabilities of the virus. Spin models have been proposed as a means to infer intrinsic fitness landscapes of HIV proteins from patient-derived viral protein sequences. These sequences are the product of nonequilibrium viral evolution driven by patient-specific immune responses and are subject to phylogenetic constraints. How can such sequence data allow inference of intrinsic fitness landscapes? We combined computer simulations and variational theory á la Feynman to show that, in most circumstances, spin models inferred from patient-derived viral sequences reflect the correct rank order of the fitness of mutant viral strains. Our findings are relevant for diverse viruses.

Evidence of the Role of Physical Activity and Cardiorespiratory Fitness in the Prevention of Coronary Heart Disease.

ERIC Educational Resources Information Center

Leon, Arthur S.; Norstrom, Jane

1995-01-01

This paper presents epidemiologic evidence on the contributions of physical inactivity and reduced cardiorespiratory fitness to risk of coronary heart disease (CHD). The types and dose of physical activity to reduce risk of CHD and plausible biologic mechanisms for the partial protective effect are reviewed. (Author/SM)

A Person Fit Test for IRT Models for Polytomous Items

ERIC Educational Resources Information Center

Glas, C. A. W.; Dagohoy, Anna Villa T.

2007-01-01

A person fit test based on the Lagrange multiplier test is presented for three item response theory models for polytomous items: the generalized partial credit model, the sequential model, and the graded response model. The test can also be used in the framework of multidimensional ability parameters. It is shown that the Lagrange multiplier…

Understanding the transmission dynamics of respiratory syncytial virus using multiple time series and nested models.

PubMed

White, L J; Mandl, J N; Gomes, M G M; Bodley-Tickell, A T; Cane, P A; Perez-Brena, P; Aguilar, J C; Siqueira, M M; Portes, S A; Straliotto, S M; Waris, M; Nokes, D J; Medley, G F

2007-09-01

The nature and role of re-infection and partial immunity are likely to be important determinants of the transmission dynamics of human respiratory syncytial virus (hRSV). We propose a single model structure that captures four possible host responses to infection and subsequent reinfection: partial susceptibility, altered infection duration, reduced infectiousness and temporary immunity (which might be partial). The magnitude of these responses is determined by four homotopy parameters, and by setting some of these parameters to extreme values we generate a set of eight nested, deterministic transmission models. In order to investigate hRSV transmission dynamics, we applied these models to incidence data from eight international locations. Seasonality is included as cyclic variation in transmission. Parameters associated with the natural history of the infection were assumed to be independent of geographic location, while others, such as those associated with seasonality, were assumed location specific. Models incorporating either of the two extreme assumptions for immunity (none or solid and lifelong) were unable to reproduce the observed dynamics. Model fits with either waning or partial immunity to disease or both were visually comparable. The best fitting structure was a lifelong partial immunity to both disease and infection. Observed patterns were reproduced by stochastic simulations using the parameter values estimated from the deterministic models.

A direct potential fitting RKR method: Semiclassical vs. quantal comparisons

NASA Astrophysics Data System (ADS)

Tellinghuisen, Joel

2016-12-01

Quantal and semiclassical (SC) eigenvalues are compared for three diatomic molecular potential curves: the X state of CO, the X state of Rb2, and the A state of I2. The comparisons show higher levels of agreement than generally recognized, when the SC calculations incorporate a quantum defect correction to the vibrational quantum number, in keeping with the Kaiser modification. One particular aspect of this is better agreement between quantal and SC estimates of the zero-point vibrational energy, supporting the need for the Y00 correction in this context. The pursuit of a direct-potential-fitting (DPF) RKR method is motivated by the notion that some of the limitations of RKR potentials may be innate, from their generation by an exact inversion of approximate quantities: the vibrational energy Gυ and rotational constant Bυ from least-squares analysis of spectroscopic data. In contrast, the DPF RKR method resembles the quantal DPF methods now increasingly used to analyze diatomic spectral data, but with the eigenvalues obtained from SC phase integrals. Application of this method to the analysis of 9500 assigned lines in the I2A ← X spectrum fails to alter the quantal-SC disparities found for the A-state RKR curve from a previous analysis. On the other hand, the SC method can be much faster than the quantal method in exploratory work with different potential functions, where it is convenient to use finite-difference methods to evaluate the partial derivatives required in nonlinear fitting.

Partial Return Yoke for MICE Step IV and Final Step

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witte, Holger; Plate, Stephen; Berg, J.Scott

2015-06-01

This paper reports on the progress of the design and construction of a retro-fitted return yoke for the international Muon Ionization Cooling Experiment (MICE). MICE is a proof-of-principle experiment aiming to demonstrate ionization cooling experimentally. In earlier studies we outlined how a partial return yoke can be used to mitigate stray magnetic field in the experimental hall; we report on the progress of the construction of the partial return yoke for MICE Step IV. We also discuss an extension of the Partial Return Yoke for the final step of MICE; we show simulation results of the expected performance.

Partial return yoke for MICE step IV and final step

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witte, H.; Plate, S.; Berg, J. S.

2015-05-03

This paper reports on the progress of the design and construction of a retro-fitted return yoke for the international Muon Ionization Cooling Experiment (MICE). MICE is a proof-of-principle experiment aiming to demonstrate ionization cooling experimentally. In earlier studies we outlined how a partial return yoke can be used to mitigate stray magnetic field in the experimental hall; we report on the progress of the construction of the partial return yoke for MICE Step IV. We also discuss an extension of the Partial Return Yoke for the final step of MICE; we show simulation results of the expected performance.

A Comparison of Graded Response and Rasch Partial Credit Models with Subjective Well-Being.

ERIC Educational Resources Information Center

Baker, John G.; Rounds, James B.; Zevon, Michael A.

2000-01-01

Compared two multiple category item response theory models using a data set of 52 mood terms with 713 undergraduate psychology students. Comparative model fit for the Samejima (F. Samejima, 1966) logistic model for graded responses and the Masters (G. Masters, 1982) partial credit model favored the former model for this data set. (SLD)

A Fifth-order Symplectic Trigonometrically Fitted Partitioned Runge-Kutta Method

NASA Astrophysics Data System (ADS)

Kalogiratou, Z.; Monovasilis, Th.; Simos, T. E.

2007-09-01

Trigonometrically fitted symplectic Partitioned Runge Kutta (EFSPRK) methods for the numerical integration of Hamoltonian systems with oscillatory solutions are derived. These methods integrate exactly differential systems whose solutions can be expressed as linear combinations of the set of functions sin(wx),cos(wx), w∈R. We modify a fifth order symplectic PRK method with six stages so to derive an exponentially fitted SPRK method. The methods are tested on the numerical integration of the two body problem.

Study of B̄→X ulν̄ decays in BB̄ events tagged by a fully reconstructed B-meson decay and determination of |V ub|

DOE PAGES

Lees, J. P.; Poireau, V.; Tisserand, V.; ...

2012-08-07

We report measurements of partial branching fractions for inclusive charmless semileptonic B decays B¯¯¯→X ulν¯ and the determination of the Cabibbo–Kobayashi–Maskawa (CKM) matrix element |V ub|. The analysis is based on a sample of 467×10⁶ Υ(4S)→BB¯¯¯ decays recorded with the BABAR detector at the PEP-II e⁺e⁻ storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions ΔB in several restricted regions of phase space and determine the CKM element |V ub| basedmore » on different QCD predictions. For decays with a charged lepton momentum p * l>1.0 GeV in the B meson rest frame, we obtain ΔB=(1.80±0.13stat±0.15sys±0.02theo)×10⁻³ from a fit to the two-dimensional M X-q² distribution. Here, M X refers to the invariant mass of the final state hadron X and q² is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V ub|=(4.33±0.24 exp±0.15 theo)×10⁻³ as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for B¯¯¯0 and B⁻ decays and derive a limit on the isospin breaking in B¯¯¯→X ulν¯ decays.« less

Partial Fractions via Calculus

ERIC Educational Resources Information Center

Bauldry, William C.

2018-01-01

The standard technique taught in calculus courses for partial fraction expansions uses undetermined coefficients to generate a system of linear equations; we present a derivative-based technique that calculus and differential equations instructors can use to reinforce connections to calculus. Simple algebra shows that we can use the derivative to…

Efficient automatic OCR word validation using word partial format derivation and language model

NASA Astrophysics Data System (ADS)

Chen, Siyuan; Misra, Dharitri; Thoma, George R.

2010-01-01

In this paper we present an OCR validation module, implemented for the System for Preservation of Electronic Resources (SPER) developed at the U.S. National Library of Medicine.1 The module detects and corrects suspicious words in the OCR output of scanned textual documents through a procedure of deriving partial formats for each suspicious word, retrieving candidate words by partial-match search from lexicons, and comparing the joint probabilities of N-gram and OCR edit transformation corresponding to the candidates. The partial format derivation, based on OCR error analysis, efficiently and accurately generates candidate words from lexicons represented by ternary search trees. In our test case comprising a historic medico-legal document collection, this OCR validation module yielded the correct words with 87% accuracy and reduced the overall OCR word errors by around 60%.

The use of type 1 collagen scaffold containing stromal cell-derived factor-1 to create a matrix environment conducive to partial-thickness cartilage defects repair.

PubMed

Zhang, Wei; Chen, Jialin; Tao, Jiadong; Jiang, Yangzi; Hu, Changchang; Huang, Lu; Ji, Junfeng; Ouyang, Hong Wei

2013-01-01

Despite the presence of cartilage-derived mesenchymal stem cells (C-MSCs) and synovial membrane-derived mesenchymal stem cells (SM-MSCs) populations, partial-thickness cartilage defects, in contrast to the full-thickness defects, are devoid of spontaneous repair capacity. This study aims to create an in situ matrix environment conducive to C-MSCs and SM-MSCs to promote cartilage self-repair. Spontaneous repair with MSCs migration into the defect area was observed in full-thickness defects, but not in partial-thickness defects in rabbit model. Ex vivo and in vitro studies showed that subchondral bone or type 1 collagen (col1) scaffold was more permissive for MSCs adhesion than cartilage or type 2 collagen (col2) scaffold and induced robust stromal cell-derived factors-1 (SDF-1) dependent migration of MSCs. Furthermore, creating a matrix environment with col1 scaffold containing SDF-1 enhanced in situ self-repair of partial-thickness defects in rabbit 6 weeks post-injury. Hence, the inferior self-repair capacity in partial-thickness defects is partially owing to the non-permissive matrix environment. Creating an in situ matrix environment conducive to C-MSCs and SM-MSCs migration and adhesion with col1 scaffold containing SDF-1 can be exploited to improve self-repair capacity of cartilage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Zernike expansion of derivatives and Laplacians of the Zernike circle polynomials.

PubMed

Janssen, A J E M

2014-07-01

The partial derivatives and Laplacians of the Zernike circle polynomials occur in various places in the literature on computational optics. In a number of cases, the expansion of these derivatives and Laplacians in the circle polynomials are required. For the first-order partial derivatives, analytic results are scattered in the literature. Results start as early as 1942 in Nijboer's thesis and continue until present day, with some emphasis on recursive computation schemes. A brief historic account of these results is given in the present paper. By choosing the unnormalized version of the circle polynomials, with exponential rather than trigonometric azimuthal dependence, and by a proper combination of the two partial derivatives, a concise form of the expressions emerges. This form is appropriate for the formulation and solution of a model wavefront sensing problem of reconstructing a wavefront on the level of its expansion coefficients from (measurements of the expansion coefficients of) the partial derivatives. It turns out that the least-squares estimation problem arising here decouples per azimuthal order m, and per m the generalized inverse solution assumes a concise analytic form so that singular value decompositions are avoided. The preferred version of the circle polynomials, with proper combination of the partial derivatives, also leads to a concise analytic result for the Zernike expansion of the Laplacian of the circle polynomials. From these expansions, the properties of the Laplacian as a mapping from the space of circle polynomials of maximal degree N, as required in the study of the Neumann problem associated with the transport-of-intensity equation, can be read off within a single glance. Furthermore, the inverse of the Laplacian on this space is shown to have a concise analytic form.

Person Fit Analysis in Computerized Adaptive Testing Using Tests for a Change Point

ERIC Educational Resources Information Center

Sinharay, Sandip

2016-01-01

Meijer and van Krimpen-Stoop noted that the number of person-fit statistics (PFSs) that have been designed for computerized adaptive tests (CATs) is relatively modest. This article partially addresses that concern by suggesting three new PFSs for CATs. The statistics are based on tests for a change point and can be used to detect an abrupt change…

Branching ratio of the electromagnetic decay of the Σ+(1385)

NASA Astrophysics Data System (ADS)

Keller, D.; Hicks, K.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Bedlinskiy, I.; Biselli, A. S.; Bookwalter, C.; Boiarinov, S.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Cole, P. L.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; de Vita, R.; de Sanctis, E.; Djalali, C.; Doughty, D.; Dupre, R.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Gabrielyan, M. Y.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hakobyan, H.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, A.; Kubarovsky, V.; Kuleshov, S. V.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Anefalos Pereira, S.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seraydaryan, H.; Sharabian, Y. G.; Smith, E. S.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Vernarsky, B.; Vineyard, M. F.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Watts, D. P.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhao, B.; Zhao, Z. W.

2012-03-01

The CLAS detector was used to obtain the first ever measurement of the electromagnetic decay of the Σ*+(1385) from the reaction γp→K0Σ*+(1385). A real photon beam with a maximum energy of 3.8 GeV was incident on a liquid-hydrogen target, resulting in the photoproduction of the kaon and Σ* hyperon. Kinematic fitting was used to separate the reaction channel from the background processes. The fitting algorithm exploited a new method to kinematically fit neutrons in the CLAS detector, leading to the measured decay widths ratio Σ+(1385)→Σ+γ/Σ+(1385)→Σ+π0=11.95±2.21(stat)-1.21+0.53(sys)% and a deduced partial width of 250.0±56.9(stat)-41.2+34.3(sys)keV. A U-spin symmetry test using the SU(3) flavor-multiplet representation yields predictions for the Σ*+(1385)→Σ+γ and Σ*0(1385)→Λγ partial widths that agree with the experimental measurements.

Estimating errors in least-squares fitting

NASA Technical Reports Server (NTRS)

Richter, P. H.

1995-01-01

While least-squares fitting procedures are commonly used in data analysis and are extensively discussed in the literature devoted to this subject, the proper assessment of errors resulting from such fits has received relatively little attention. The present work considers statistical errors in the fitted parameters, as well as in the values of the fitted function itself, resulting from random errors in the data. Expressions are derived for the standard error of the fit, as a function of the independent variable, for the general nonlinear and linear fitting problems. Additionally, closed-form expressions are derived for some examples commonly encountered in the scientific and engineering fields, namely ordinary polynomial and Gaussian fitting functions. These results have direct application to the assessment of the antenna gain and system temperature characteristics, in addition to a broad range of problems in data analysis. The effects of the nature of the data and the choice of fitting function on the ability to accurately model the system under study are discussed, and some general rules are deduced to assist workers intent on maximizing the amount of information obtained form a given set of measurements.

Low energy constants of S U ( 2 ) partially quenched chiral perturbation theory from N f = 2 + 1 domain wall QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyle, P. A.; Christ, N. H.; Garron, N.

2016-03-09

Here, we have performed fits of the pseudoscalar masses and decay constants, from a variety of the RBC-UKQCD Collaboration’s domain wall fermion ensembles, to SU(2) partially quenched chiral perturbation theory at next-to-leading order (NLO) and next-to-next-to-leading order (NNLO). We report values for 9 NLO and 8 linearly independent combinations of NNLO partially quenched low-energy constants, which we compare to other lattice and phenomenological determinations. We discuss the size of successive terms in the chiral expansion and use our large set of low-energy constants to make predictions for mass splittings due to QCD isospin-breaking effects and the S-wave ππ scattering lengths.more » Lastly, we conclude that, for the range of pseudoscalar masses explored in this work, 115 MeV≲mPS≲430 MeV, the NNLO SU(2) expansion is quite robust and can fit lattice data with percent-scale accuracy.« less

Evaluation of the best fit distribution for partial duration series of daily rainfall in Madinah, western Saudi Arabia

NASA Astrophysics Data System (ADS)

Alahmadi, F.; Rahman, N. A.; Abdulrazzak, M.

2014-09-01

Rainfall frequency analysis is an essential tool for the design of water related infrastructure. It can be used to predict future flood magnitudes for a given magnitude and frequency of extreme rainfall events. This study analyses the application of rainfall partial duration series (PDS) in the vast growing urban Madinah city located in the western part of Saudi Arabia. Different statistical distributions were applied (i.e. Normal, Log Normal, Extreme Value type I, Generalized Extreme Value, Pearson Type III, Log Pearson Type III) and their distribution parameters were estimated using L-moments methods. Also, different selection criteria models are applied, e.g. Akaike Information Criterion (AIC), Corrected Akaike Information Criterion (AICc), Bayesian Information Criterion (BIC) and Anderson-Darling Criterion (ADC). The analysis indicated the advantage of Generalized Extreme Value as the best fit statistical distribution for Madinah partial duration daily rainfall series. The outcome of such an evaluation can contribute toward better design criteria for flood management, especially flood protection measures.

Random Fields and Collective Effects in Molecular Magnets

DTIC Science & Technology

2018-01-29

longitudinal fields the final state consists of only partially reversed spins. Further, we measured the front speed as a function of applied magnetic...field. The theory of magnetic deflagration, together with a modification that takes into account the partial spin reversal, fits the transverse field...Conference Paper or Presentation Conference Name: APS March Meeting 2016 Conference Location: Baltimore, Paper Title: Time-resolved Measurements

Strong Evidence for Nucleon Resonances near 1900 MeV

DOE PAGES

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.; ...

2017-08-11

Data on the reaction yp→K +A from the CLAS experiments are used to derive the leading multipoles, E 0+, M 1-, E 1+, and M 1+, from the production threshold to 2180 MeV in 24 slices of the invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L+P model that allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion andmore » photoinduced reactions within the Bonn-Gatchina partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin parity J P=1/2 -, 1/2 +, and 3/2 + in the region at about 1.9 GeV.« less

Strong Evidence for Nucleon Resonances near 1900 MeV

NASA Astrophysics Data System (ADS)

Anisovich, A. V.; Burkert, V.; Hadžimehmedović, M.; Ireland, D. G.; Klempt, E.; Nikonov, V. A.; Omerović, R.; Osmanović, H.; Sarantsev, A. V.; Stahov, J.; Švarc, A.; Thoma, U.

2017-08-01

Data on the reaction γ p →K+Λ from the CLAS experiments are used to derive the leading multipoles, E0 +, M1 -, E1 +, and M1 +, from the production threshold to 2180 MeV in 24 slices of the invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L +P model that allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion and photoinduced reactions within the Bonn-Gatchina partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin parity JP=1 /2- , 1 /2+ , and 3 /2+ in the region at about 1.9 GeV.

Spatial diffusion of raccoon rabies in Pennsylvania, USA.

PubMed

Moore, D A

1999-05-14

Identification of the geographic pattern of diffusion of a wildlife disease could lead to information regarding its control. The objective of this study was to model raccoon-rabies diffusion in Pennsylvania to identify geographic constraints on the diffusion pattern for potential use in bait-vaccination strategies. A trend-surface analysis (TSA) was used as a spatial filter for month to first report by county location. A cubic polynomial model was fitted (R2 = 0.80). Velocity vectors were calculated from the partial derivatives of the model and mapped to demonstrate the instantaneous speed of diffusion at each location. A main corridor of diffusion through the ridge and valley section of the state was evident early in the outbreak. Once the disease reached the northern counties, the disease moved west toward Ohio. I believe that TSA was useful in identifying the pattern of raccoon-rabies diffusion across the stage from the inherent noise of disease-reporting data.

CO2-broadening and shift coefficients in the ν3 and ν2 + (ν4 +ν5)+0 bands of acetylene

NASA Astrophysics Data System (ADS)

Lyulin, O. M.; Petrova, T. M.; Solodov, A. M.; Solodov, A. A.; Perevalov, V. I.

2018-03-01

The absorption spectra of the mixture of C2H2 and CO2 at different partial pressures of both gases have been recorded at room temperature in the 3 μm region using the Bruker IFS 125 HR FTIR spectrometer. The multispectrum fitting procedure has been applied to these spectra to recover the broadening and shift parameters of the acetylene spectral lines. The CO2 broadening and pressure induced shift coefficients for 119 lines of the ν3 and ν2 + (ν4 +ν5)+0 bands of acetylene have been derived. The rotational dependence of the values of these coefficients is discussed. The comparison of the obtained coefficients to those published by other authors for the ν1 + ν3 and (ν4 +ν5)+0 bands is performed.

Polydiacetylene as an all-optical picosecond Switch

NASA Technical Reports Server (NTRS)

Abdeldayem, Hossin A.; Frazier, D. O.; Paley, M. S.; Whitaker, Ann F. (Technical Monitor)

2001-01-01

Polydiacetylene derivative of 2-methyl-4-nitroaniline (PDAMNA) shows a picosecond switching property, which illustrated a partial all-optical picosecond NAND logic gate. The switching phenomenon was demonstrated by waveguiding two collinear beams at 633 nm and 532 nm through a hollow fiber of 50 micrometers diameter, coated from inside with a thin film of PDAMNA. A Z-scan investigations of a PDAMNA thin film on quartz substrate revealed that the switching effect was attributed to an excited state absorption in the systems. The studies also showed that the polymer suffers a photo-oxidation beyond an intensity level of 2.9 x 10(exp 6) w/square cm. The photo-oxidized film has different physical properties that are different from the original film before oxidation. The life time of both excited states before and after oxidation as well as their absorption coefficients were estimated by fitting a three level system model to the experimental results.

Eldercare responsibilities, interrole conflict, and employee absence: a daily study.

PubMed

Hepburn, C G; Barling, J

1996-07-01

A model was developed specifying that the number of hours employees spend providing care to or interacting with elderly parents predicts conflict between the roles of employee and caregiver. Interrole conflict was subsequently expected to predict partial absence from work (e.g., arriving late). Seventeen employed eldercare providers completed a daily questionnaire for 20 work days. The data were standardized and pooled, and the proposed model was tested by using structural equation modeling. The proposed model provided a good fit to the data. A competing model that added the direct effects of hours of interacting with and hours of providing care to parents on partial absence provided a significantly better fit. The potential impact of the findings on employees and organizations is discussed.

An improved 3D MoF method based on analytical partial derivatives

NASA Astrophysics Data System (ADS)

Chen, Xiang; Zhang, Xiong

2016-12-01

MoF (Moment of Fluid) method is one of the most accurate approaches among various surface reconstruction algorithms. As other second order methods, MoF method needs to solve an implicit optimization problem to obtain the optimal approximate surface. Therefore, the partial derivatives of the objective function have to be involved during the iteration for efficiency and accuracy. However, to the best of our knowledge, the derivatives are currently estimated numerically by finite difference approximation because it is very difficult to obtain the analytical derivatives of the object function for an implicit optimization problem. Employing numerical derivatives in an iteration not only increase the computational cost, but also deteriorate the convergence rate and robustness of the iteration due to their numerical error. In this paper, the analytical first order partial derivatives of the objective function are deduced for 3D problems. The analytical derivatives can be calculated accurately, so they are incorporated into the MoF method to improve its accuracy, efficiency and robustness. Numerical studies show that by using the analytical derivatives the iterations are converged in all mixed cells with the efficiency improvement of 3 to 4 times.

Series expansion solutions for the multi-term time and space fractional partial differential equations in two- and three-dimensions

NASA Astrophysics Data System (ADS)

Ye, H.; Liu, F.; Turner, I.; Anh, V.; Burrage, K.

2013-09-01

Fractional partial differential equations with more than one fractional derivative in time describe some important physical phenomena, such as the telegraph equation, the power law wave equation, or the Szabo wave equation. In this paper, we consider two- and three-dimensional multi-term time and space fractional partial differential equations. The multi-term time-fractional derivative is defined in the Caputo sense, whose order belongs to the interval (1,2],(2,3],(3,4] or (0, m], and the space-fractional derivative is referred to as the fractional Laplacian form. We derive series expansion solutions based on a spectral representation of the Laplacian operator on a bounded region. Some applications are given for the two- and three-dimensional telegraph equation, power law wave equation and Szabo wave equation.

[A correction method of baseline drift of discrete spectrum of NIR].

PubMed

Hu, Ai-Qin; Yuan, Hong-Fu; Song, Chun-Feng; Li, Xiao-Yu

2014-10-01

In the present paper, a new correction method of baseline drift of discrete spectrum is proposed by combination of cubic spline interpolation and first order derivative. A fitting spectrum is constructed by cubic spline interpolation, using the datum in discrete spectrum as interpolation nodes. The fitting spectrum is differentiable. First order derivative is applied to the fitting spectrum to calculate derivative spectrum. The spectral wavelengths which are the same as the original discrete spectrum were taken out from the derivative spectrum to constitute the first derivative spectra of the discrete spectra, thereby to correct the baseline drift of the discrete spectra. The effects of the new method were demonstrated by comparison of the performances of multivariate models built using original spectra, direct differential spectra and the spectra pretreated by the new method. The results show that negative effects on the performance of multivariate model caused by baseline drift of discrete spectra can be effectively eliminated by the new method.

Quantitative photoplethysmography: Lambert-Beer law or inverse function incorporating light scatter.

PubMed

Cejnar, M; Kobler, H; Hunyor, S N

1993-03-01

Finger blood volume is commonly determined from measurement of infra-red (IR) light transmittance using the Lambert-Beer law of light absorption derived for use in non-scattering media, even when such transmission involves light scatter around the phalangeal bone. Simultaneous IR transmittance and finger volume were measured over the full dynamic range of vascular volumes in seven subjects and outcomes compared with data fitted according to the Lambert-Beer exponential function and an inverse function derived for light attenuation by scattering materials. Curves were fitted by the least-squares method and goodness of fit was compared using standard errors of estimate (SEE). The inverse function gave a better data fit in six of the subjects: mean SEE 1.9 (SD 0.7, range 0.7-2.8) and 4.6 (2.2, 2.0-8.0) respectively (p < 0.02, paired t-test). Thus, when relating IR transmittance to blood volume, as occurs in the finger during measurements of arterial compliance, an inverse function derived from a model of light attenuation by scattering media gives more accurate results than the traditional exponential fit.

A curve-fitting approach to estimate the arterial plasma input function for the assessment of glucose metabolic rate and response to treatment.

PubMed

Vriens, Dennis; de Geus-Oei, Lioe-Fee; Oyen, Wim J G; Visser, Eric P

2009-12-01

For the quantification of dynamic (18)F-FDG PET studies, the arterial plasma time-activity concentration curve (APTAC) needs to be available. This can be obtained using serial sampling of arterial blood or an image-derived input function (IDIF). Arterial sampling is invasive and often not feasible in practice; IDIFs are biased because of partial-volume effects and cannot be used when no large arterial blood pool is in the field of view. We propose a mathematic function, consisting of an initial linear rising activity concentration followed by a triexponential decay, to describe the APTAC. This function was fitted to 80 oncologic patients and verified for 40 different oncologic patients by area-under-the-curve (AUC) comparison, Patlak glucose metabolic rate (MR(glc)) estimation, and therapy response monitoring (Delta MR(glc)). The proposed function was compared with the gold standard (serial arterial sampling) and the IDIF. To determine the free parameters of the function, plasma time-activity curves based on arterial samples in 80 patients were fitted after normalization for administered activity (AA) and initial distribution volume (iDV) of (18)F-FDG. The medians of these free parameters were used for the model. In 40 other patients (20 baseline and 20 follow-up dynamic (18)F-FDG PET scans), this model was validated. The population-based curve, individually calibrated by AA and iDV (APTAC(AA/iDV)), by 1 late arterial sample (APTAC(1 sample)), and by the individual IDIF (APTAC(IDIF)), was compared with the gold standard of serial arterial sampling (APTAC(sampled)) using the AUC. Additionally, these 3 methods of APTAC determination were evaluated with Patlak MR(glc) estimation and with Delta MR(glc) for therapy effects using serial sampling as the gold standard. Excellent individual fits to the function were derived with significantly different decay constants (P < 0.001). Correlations between AUC from APTAC(AA/iDV), APTAC(1 sample), and APTAC(IDIF) with the gold standard (APTAC(sampled)) were 0.880, 0.994, and 0.856, respectively. For MR(glc), these correlations were 0.963, 0.994, and 0.966, respectively. In response monitoring, these correlations were 0.947, 0.982, and 0.949, respectively. Additional scaling by 1 late arterial sample showed a significant improvement (P < 0.001). The fitted input function calibrated for AA and iDV performed similarly to IDIF. Performance improved significantly using 1 late arterial sample. The proposed model can be used when an IDIF is not available or when serial arterial sampling is not feasible.

Selective photooxidation of hydrocarbons in zeolites by oxygen

DOEpatents

Frei, Heinz; Blatter, Fritz; Sun, Hai

1998-01-01

A selective photooxidation process for the conversion of hydrocarbon molecules to partially oxygenated derivatives, which comprises the steps of adsorbing a hydrocarbon and oxygen onto a dehydrated zeolite support matrix to form a hydrocarbon-oxygen contact pair, and subsequently exposing the hydrocarbon-oxygen contact pair to visible light, thereby forming a partially oxygenated derivative.

A Holocene paleosecular variation from 14C-dated volcanic rocks in Western North America

USGS Publications Warehouse

Hagstrum, J.T.; Champion, D.E.

2002-01-01

A paleosecular variation (PSV) curve for western North America is presented on the basis of 94 virtual geomagnetic poles (VGPs) from dated volcanic rocks sampled at 446 sites. Approximately 60% of the paleomagnetic database has been previously published. A curve defined by "spherical smoothed splines" is fitted to the VGPs, ranked by the quality of the age determinations, where the data density is highest between 3690 and -30 years before present (B.P.) (A.D. 1950), between 7800 and 7050 years B.P., and between 14,060 and 12,700 years B.P. The younger segments of the curve derived from volcanic rocks are similar but less complex than other high-resolution PSV curves derived from lacustrine sediments, particularly the record at Fish Lake, Oregon. The PSV record from lava flows (PSVL), however, is perhaps more reliable in its general shape and chronology because of the higher fidelity of volcanic rocks as magnetic field recorders and because of the greater density of 14C dates. The new PSVL record provides a partial Holocene master curve for western North America and will be of particular value in dating geological and archeological materials using paleomagnetic directions.

Gas adsorption in Mg-porphyrin-based porous organic frameworks: A computational simulation by first-principles derived force field.

PubMed

Pang, Yujia; Li, Wenliang; Zhang, Jingping

2017-09-15

A novel type of porous organic frameworks, based on Mg-porphyrin, with diamond-like topology, named POF-Mgs is computationally designed, and the gas uptakes of CO 2 , H 2 , N 2 , and H 2 O in POF-Mgs are investigated by Grand canonical Monte Carlo simulations based on first-principles derived force fields (FF). The FF, which describes the interactions between POF-Mgs and gases, are fitted by dispersion corrected double-hybrid density functional theory, B2PLYP-D3. The good agreement between the obtained FF and the first-principle energies data confirms the reliability of the FF. Furthermore our simulation shows the presence of a small amount of H 2 O (≤ 0.01 kPa) does not much affect the adsorption quantity of CO 2 , but the presence of higher partial pressure of H 2 O (≥ 0.1 kPa) results in the CO 2 adsorption decrease significantly. The good performance of POF-Mgs in the simulation inspires us to design novel porous materials experimentally for gas adsorption and purification. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The evolution of sexes: A specific test of the disruptive selection theory.

PubMed

da Silva, Jack

2018-01-01

The disruptive selection theory of the evolution of anisogamy posits that the evolution of a larger body or greater organismal complexity selects for a larger zygote, which in turn selects for larger gametes. This may provide the opportunity for one mating type to produce more numerous, small gametes, forcing the other mating type to produce fewer, large gametes. Predictions common to this and related theories have been partially upheld. Here, a prediction specific to the disruptive selection theory is derived from a previously published game-theoretic model that represents the most complete description of the theory. The prediction, that the ratio of macrogamete to microgamete size should be above three for anisogamous species, is supported for the volvocine algae. A fully population genetic implementation of the model, involving mutation, genetic drift, and selection, is used to verify the game-theoretic approach and accurately simulates the evolution of gamete sizes in anisogamous species. This model was extended to include a locus for gamete motility and shows that oogamy should evolve whenever there is costly motility. The classic twofold cost of sex may be derived from the fitness functions of these models, showing that this cost is ultimately due to genetic conflict.

Gröbner Bases and Generation of Difference Schemes for Partial Differential Equations

NASA Astrophysics Data System (ADS)

Gerdt, Vladimir P.; Blinkov, Yuri A.; Mozzhilkin, Vladimir V.

2006-05-01

In this paper we present an algorithmic approach to the generation of fully conservative difference schemes for linear partial differential equations. The approach is based on enlargement of the equations in their integral conservation law form by extra integral relations between unknown functions and their derivatives, and on discretization of the obtained system. The structure of the discrete system depends on numerical approximation methods for the integrals occurring in the enlarged system. As a result of the discretization, a system of linear polynomial difference equations is derived for the unknown functions and their partial derivatives. A difference scheme is constructed by elimination of all the partial derivatives. The elimination can be achieved by selecting a proper elimination ranking and by computing a Gröbner basis of the linear difference ideal generated by the polynomials in the discrete system. For these purposes we use the difference form of Janet-like Gröbner bases and their implementation in Maple. As illustration of the described methods and algorithms, we construct a number of difference schemes for Burgers and Falkowich-Karman equations and discuss their numerical properties.

Reduced Physical Fitness in Patients With Heart Failure as a Possible Risk Factor for Impaired Driving Performance

PubMed Central

Alosco, Michael L.; Penn, Marc S.; Spitznagel, Mary Beth; Cleveland, Mary Jo; Ott, Brian R.

2015-01-01

OBJECTIVE. Reduced physical fitness secondary to heart failure (HF) may contribute to poor driving; reduced physical fitness is a known correlate of cognitive impairment and has been associated with decreased independence in driving. No study has examined the associations among physical fitness, cognition, and driving performance in people with HF. METHOD. Eighteen people with HF completed a physical fitness assessment, a cognitive test battery, and a validated driving simulator scenario. RESULTS. Partial correlations showed that poorer physical fitness was correlated with more collisions and stop signs missed and lower scores on a composite score of attention, executive function, and psychomotor speed. Cognitive dysfunction predicted reduced driving simulation performance. CONCLUSION. Reduced physical fitness in participants with HF was associated with worse simulated driving, possibly because of cognitive dysfunction. Larger studies using on-road testing are needed to confirm our findings and identify clinical interventions to maximize safe driving. PMID:26122681

Inferring genetic interactions from comparative fitness data

PubMed Central

2017-01-01

Darwinian fitness is a central concept in evolutionary biology. In practice, however, it is hardly possible to measure fitness for all genotypes in a natural population. Here, we present quantitative tools to make inferences about epistatic gene interactions when the fitness landscape is only incompletely determined due to imprecise measurements or missing observations. We demonstrate that genetic interactions can often be inferred from fitness rank orders, where all genotypes are ordered according to fitness, and even from partial fitness orders. We provide a complete characterization of rank orders that imply higher order epistasis. Our theory applies to all common types of gene interactions and facilitates comprehensive investigations of diverse genetic interactions. We analyzed various genetic systems comprising HIV-1, the malaria-causing parasite Plasmodium vivax, the fungus Aspergillus niger, and the TEM-family of β-lactamase associated with antibiotic resistance. For all systems, our approach revealed higher order interactions among mutations. PMID:29260711

Inferring genetic interactions from comparative fitness data.

PubMed

Crona, Kristina; Gavryushkin, Alex; Greene, Devin; Beerenwinkel, Niko

2017-12-20

Darwinian fitness is a central concept in evolutionary biology. In practice, however, it is hardly possible to measure fitness for all genotypes in a natural population. Here, we present quantitative tools to make inferences about epistatic gene interactions when the fitness landscape is only incompletely determined due to imprecise measurements or missing observations. We demonstrate that genetic interactions can often be inferred from fitness rank orders, where all genotypes are ordered according to fitness, and even from partial fitness orders. We provide a complete characterization of rank orders that imply higher order epistasis. Our theory applies to all common types of gene interactions and facilitates comprehensive investigations of diverse genetic interactions. We analyzed various genetic systems comprising HIV-1, the malaria-causing parasite Plasmodium vivax , the fungus Aspergillus niger , and the TEM-family of β-lactamase associated with antibiotic resistance. For all systems, our approach revealed higher order interactions among mutations.

The derivation of vector magnetic fields from Stokes profiles - Integral versus least squares fitting techniques

NASA Technical Reports Server (NTRS)

Ronan, R. S.; Mickey, D. L.; Orrall, F. Q.

1987-01-01

The results of two methods for deriving photospheric vector magnetic fields from the Zeeman effect, as observed in the Fe I line at 6302.5 A at high spectral resolution (45 mA), are compared. The first method does not take magnetooptical effects into account, but determines the vector magnetic field from the integral properties of the Stokes profiles. The second method is an iterative least-squares fitting technique which fits the observed Stokes profiles to the profiles predicted by the Unno-Rachkovsky solution to the radiative transfer equation. For sunspot fields above about 1500 gauss, the two methods are found to agree in derived azimuthal and inclination angles to within about + or - 20 deg.

A Posteriori Finite Element Bounds for Sensitivity Derivatives of Partial-Differential-Equation Outputs. Revised

NASA Technical Reports Server (NTRS)

Lewis, Robert Michael; Patera, Anthony T.; Peraire, Jaume

1998-01-01

We present a Neumann-subproblem a posteriori finite element procedure for the efficient and accurate calculation of rigorous, 'constant-free' upper and lower bounds for sensitivity derivatives of functionals of the solutions of partial differential equations. The design motivation for sensitivity derivative error control is discussed; the a posteriori finite element procedure is described; the asymptotic bounding properties and computational complexity of the method are summarized; and illustrative numerical results are presented.

Subatmospheric vapor pressures for fluoromethane (R41), 1,1-difluoroethane (R152a), and 1,1,1-trifluoroethane (R143a) evaluated from internal-energy measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duarte-Garza, H.A.; Magee, J.W.

1999-09-01

Vapor pressures were evaluated from measured internal-energy changes {Delta}U{sup (2)} in the vapor + liquid two-phase region. The method employed a thermodynamic relationship between the derivative quantity ({partial_derivative}U{sup (2)}/{partial_derivative}V){sub T}, the vapor pressure p{sub {sigma}}, and its temperature derivative ({partial_derivative}p/{partial_derivative}T){sub {sigma}}. This method was applied at temperatures between the triple point and the normal boiling point of three substances: fluoromethane (R41), 1,1-difluoroethane (R152a), and 1,1,1-trifluoroethane (R143a). In the case of R41, vapor pressures up to 1 MPa were calculated to validate the technique at higher pressures. For R152a, the calculated vapor pressure at the triple-point temperature differed from a directmore » experimental measurement by less than the claimed uncertainty (5 Pa) of the measurement. The calculated vapor pressures for R41 helped to resolve discrepancies in several published vapor pressure sources. Agreement with experimentally measured vapor pressures for R152a and for R143a near the normal boiling point (101.325 kPa) was within the experimental uncertainty of approximately 0.04 kPa (0.04%) for the published measurements.« less

The 630 nm MIG and the vertical neutral wind in the low latitude nighttime thermosphere

NASA Technical Reports Server (NTRS)

Herrero, F. A.; Meriwether, J. W., Jr.

1994-01-01

It is shown that large negative divergences (gradients) in the horizontal neutral wind in the equatorial thermosphere can support downward neutral winds in excess of 20 m/s. With attention to the meridional and vertical winds only, the pressure tendency equation is used to derive the expression U(sub z0) approximately equals (Partial derivative U(sub y)/Partial derivative y)H for the vertical wind U(sub z0) at the reference altitude for the pressure tendency equation; H is the atmospheric density scale height, and (Partial derivative U(sub y)/Partial derivative y) is the meridional wind gradient. The velocity gradient associated with the Meridional Intensity Gradient (MIG) of the O((sup 1)D) emission (630 nm) at low latitudes is used to estimate the vertical neutral wind in the MIG region. Velocity gradients derived from MIG data are about 0.5 (m/s)/km) or more, indicating that the MIG region may contain downward neutral winds in excess of 20 m/s. Though direct measurements of the vertical wind are scarce, Fabry-Perot interferometer data of the equatorial F-region above Natal, Brazil, showed downward winds of 30 m/s occurring during a strong meridional wind convergence in 1982. In-situ measurements with the WATS instrument on the DE-2 satellite also show large vertical neutral winds in the equatorial region.

What Is Fitness Training? Definitions and Implications: A Systematic Review Article

PubMed Central

PAOLI, Antonio; BIANCO, Antonino

2015-01-01

Background: This review based upon studies searched from the major scientific libraries has the objective of clarifying what is fitness training in modern days, the implications that it has on health in both youth and elderly and finally discuss fitness training practical implications. Methods: The PRISMA statement was partially adopted and a number of 92 items were selected, according to the inclusion criteria. Results were discussed in 4 main sections: 1. Children and adolescents fitness levels; 2. Fitness training in the elderly; 3. Pathology prevention through fitness training; 4. Training through Fitness activities. Results: This review pointed out the fact that nowadays there is a large variety of fitness activities available within gyms and fitness centers. Even though they significantly differ with each other, the common aim they have is the wellbeing of the people through the improvement of the physical fitness components and the psychological balance. Conclusion: Fitness instructors’ recommendations should be followed in gym context and should be contingent upon an individual’s objectives, physical capacity, physical characteristics and experience. PMID:26284201

Deriving an Abstraction Network to Support Quality Assurance in OCRe

PubMed Central

Ochs, Christopher; Agrawal, Ankur; Perl, Yehoshua; Halper, Michael; Tu, Samson W.; Carini, Simona; Sim, Ida; Noy, Natasha; Musen, Mark; Geller, James

2012-01-01

An abstraction network is an auxiliary network of nodes and links that provides a compact, high-level view of an ontology. Such a view lends support to ontology orientation, comprehension, and quality-assurance efforts. A methodology is presented for deriving a kind of abstraction network, called a partial-area taxonomy, for the Ontology of Clinical Research (OCRe). OCRe was selected as a representative of ontologies implemented using the Web Ontology Language (OWL) based on shared domains. The derivation of the partial-area taxonomy for the Entity hierarchy of OCRe is described. Utilizing the visualization of the content and structure of the hierarchy provided by the taxonomy, the Entity hierarchy is audited, and several errors and inconsistencies in OCRe’s modeling of its domain are exposed. After appropriate corrections are made to OCRe, a new partial-area taxonomy is derived. The generalizability of the paradigm of the derivation methodology to various families of biomedical ontologies is discussed. PMID:23304341

Auto-Bäcklund transformations for a matrix partial differential equation

NASA Astrophysics Data System (ADS)

Gordoa, P. R.; Pickering, A.

2018-07-01

We derive auto-Bäcklund transformations, analogous to those of the matrix second Painlevé equation, for a matrix partial differential equation. We also then use these auto-Bäcklund transformations to derive matrix equations involving shifts in a discrete variable, a process analogous to the use of the auto-Bäcklund transformations of the matrix second Painlevé equation to derive a discrete matrix first Painlevé equation. The equations thus derived then include amongst other examples a semidiscrete matrix equation which can be considered to be an extension of this discrete matrix first Painlevé equation. The application of this technique to the auto-Bäcklund transformations of the scalar case of our partial differential equation has not been considered before, and so the results obtained here in this scalar case are also new. Other equations obtained here using this technique include a scalar semidiscrete equation which arises in the case of the second Painlevé equation, and which does not seem to have been thus derived previously.

Yoga Is as Good as Stretching–Strengthening Exercises in Improving Functional Fitness Outcomes: Results From a Randomized Controlled Trial

PubMed Central

McAuley, Edward

2016-01-01

Abstract Background. Despite yoga’s popularity, few clinical trials have employed rigorous methodology to systematically explore its functional benefits compared with more established forms of exercise. The objective of this study was to compare the functional benefits of yoga with the conventional stretching–strengthening exercises recommended for adults. Methods. Sedentary healthy adults ( N = 118; Mage = 62.0) participated in an 8-week (three times a week for 1 hour) randomized controlled trial, which consisted of a Hatha yoga group ( n = 61) and a stretching–strengthening exercise group ( n = 57). Standardized functional fitness tests assessing balance, strength, flexibility, and mobility were administered at baseline and postintervention. Results. A repeated measures multivariate analysis of variance showed a significant time effect for measures of balance [ F (3,18) = 4.88, p < .01, partial η 2 = .45], strength [ F (2,19) = 15.37, p < .001, partial η 2 = .62], flexibility [ F (4,17) = 8.86, p < .001, partial η 2 = .68], and mobility [ F (2,19) = 8.54, p < .002, partial η 2 = .47]. Both groups showed significant improvements on measures of balance (left–right leg and four square step); strength (chair stands and arm curls); flexibility (back scratch and sit-and-reach); and mobility (gait speed and 8-feet up and go), with partial η 2 ranging from .05 to .47. Conclusions. These data suggest that regular yoga practice is just as effective as stretching–strengthening exercises in improving functional fitness. To our knowledge, this is the first study to examine functional benefits of yoga in comparison with stretching–strengthening exercises in sedentary, healthy, community-dwelling older adults. These findings have clinical implications as yoga is a more amenable form of exercise than strengthening exercises as it requires minimal equipment and can be adapted for individuals with lower levels of functioning or disabilities. PMID:26297940

Yoga Is as Good as Stretching-Strengthening Exercises in Improving Functional Fitness Outcomes: Results From a Randomized Controlled Trial.

PubMed

Gothe, Neha P; McAuley, Edward

2016-03-01

Despite yoga's popularity, few clinical trials have employed rigorous methodology to systematically explore its functional benefits compared with more established forms of exercise. The objective of this study was to compare the functional benefits of yoga with the conventional stretching-strengthening exercises recommended for adults. Sedentary healthy adults (N = 118; M age = 62.0) participated in an 8-week (three times a week for 1 hour) randomized controlled trial, which consisted of a Hatha yoga group (n = 61) and a stretching-strengthening exercise group (n = 57). Standardized functional fitness tests assessing balance, strength, flexibility, and mobility were administered at baseline and postintervention. A repeated measures multivariate analysis of variance showed a significant time effect for measures of balance [F(3,18) = 4.88, p < .01, partial η(2) = .45], strength [F(2,19) = 15.37, p < .001, partial η(2) = .62], flexibility [F(4,17) = 8.86, p < .001, partial η(2) = .68], and mobility [F(2,19) = 8.54, p < .002, partial η(2) = .47]. Both groups showed significant improvements on measures of balance (left-right leg and four square step); strength (chair stands and arm curls); flexibility (back scratch and sit-and-reach); and mobility (gait speed and 8-feet up and go), with partial η(2) ranging from .05 to .47. These data suggest that regular yoga practice is just as effective as stretching-strengthening exercises in improving functional fitness. To our knowledge, this is the first study to examine functional benefits of yoga in comparison with stretching-strengthening exercises in sedentary, healthy, community-dwelling older adults. These findings have clinical implications as yoga is a more amenable form of exercise than strengthening exercises as it requires minimal equipment and can be adapted for individuals with lower levels of functioning or disabilities. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of variation in self-incompatibility on pollen limitation and inbreeding depression in Flourensia cernua (Asteraceae) scrubs of contrasting density

PubMed Central

Ferrer, Miriam M.; Good-Avila, Sara V.; Montaña, Carlos; Domínguez, César A.; Eguiarte, Luis E.

2009-01-01

Background and Aims Selection may favour a partial or complete loss of self-incompatibility (SI) if it increases the reproductive output of individuals in the presence of low mate availability. The reproductive output of individuals varying in their strength of SI may also be affected by population density via its affect on the spatial structuring and number of S-alleles in populations. Modifiers increasing levels of self-compatibility can be selected when self-compatible individuals receive reproductive compensation by, for example, increasing seed set and/or when they become associated with high fitness genotypes. Methods The effect of variation in the strength of SI and scrub density (low versus high) on seed set, seed germination and inbreeding depression in seed germination (δgerm) was investigated in the partially self-incompatible species Flourensia cernua by analysing data from self-, cross- and open-pollinated florets. Key Results Examination of 100 plants in both high and low scrub densities revealed that 51% of plants were strongly self-incompatible and 49 % varied from being self-incompatible to self-compatible. Seed set after hand cross-pollination was higher than after open-pollination for self-incompatible, partially self-incompatible and self-compatible plants but was uniformly low for strongly self-incompatible plants. Strongly self-incompatible and self-incompatible plants exhibited lower seed set, seed germination and multiplicative female fitness (floral display × seed set × seed germination) in open-pollinated florets compared with partially self-incompatible and self-compatible plants. Scrub density also had an effect on seed set and inbreeding depression: in low-density scrubs seed set was higher after open-pollination and δgerm was lower. Conclusions These data suggest that (a) plants suffered outcross pollen limitation, (b) female fitness in partially self-incompatible and self-compatible plants is enhanced by increased mate-compatibility and (c) plants in low-density scrubs received higher quality pollen via open-pollination than plants in high-density scrubs. PMID:19218580

A new approach to aid the characterisation and identification of metabolites of a model drug; partial isotope enrichment combined with novel formula elucidation software.

PubMed

Hobby, Kirsten; Gallagher, Richard T; Caldwell, Patrick; Wilson, Ian D

2009-01-01

This work describes the identification of 'isotopically enriched' metabolites of 4-cyanoaniline using the unique features of the software package 'Spectral Simplicity'. The software is capable of creating the theoretical mass spectra for partially isotope-enriched compounds, and subsequently performing an elemental composition analysis to give the elemental formula for the 'isotopically enriched' metabolite. A novel mass spectral correlation method, called 'FuzzyFit', was employed. 'FuzzyFit' utilises the expected experimental distribution of errors in both mass accuracy and isotope pattern and enables discrimination between statistically probable and improbable candidate formulae. The software correctly determined the molecular formulae of ten previously described metabolites of 4-cyanoaniline confirming the technique of partial isotope enrichment can produce results analogous to standard methodologies. Six previously unknown species were also identified, based on the presence of the unique 'designer' isotope ratio. Three of the unknowns were tentatively identified as N-acetylglutamine, O-methyl-N acetylglucuronide and a putative fatty acid conjugate. The discovery of a significant number of unknown species of a model drug with a comprehensive history of investigation highlights the potential for enhancement to the analytical process by the use of 'designer' isotope ratio compounds. The 'FuzzyFit' methodology significantly aided the elucidation of candidate formulae, by provision of a vastly simplified candidate formula data set. Copyright (c) 2008 John Wiley & Sons, Ltd.

Toward lattice fractional vector calculus

NASA Astrophysics Data System (ADS)

Tarasov, Vasily E.

2014-09-01

An analog of fractional vector calculus for physical lattice models is suggested. We use an approach based on the models of three-dimensional lattices with long-range inter-particle interactions. The lattice analogs of fractional partial derivatives are represented by kernels of lattice long-range interactions, where the Fourier series transformations of these kernels have a power-law form with respect to wave vector components. In the continuum limit, these lattice partial derivatives give derivatives of non-integer order with respect to coordinates. In the three-dimensional description of the non-local continuum, the fractional differential operators have the form of fractional partial derivatives of the Riesz type. As examples of the applications of the suggested lattice fractional vector calculus, we give lattice models with long-range interactions for the fractional Maxwell equations of non-local continuous media and for the fractional generalization of the Mindlin and Aifantis continuum models of gradient elasticity.

Extending compile-time reverse mode and exploiting partial separability in ADIFOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bischof, C.H.; El-Khadiri, M.

1992-10-01

The numerical methods employed in the solution of many scientific computing problems require the computation of the gradient of a function f: R[sup n] [yields] R. ADIFOR is a source translator that, given a collection of subroutines to compute f, generates Fortran 77 code for computing the derivative of this function. Using the so-called torsion problem from the MINPACK-2 test collection as an example, this paper explores two issues in automatic differentiation: the efficient computation of derivatives for partial separable functions and the use of the compile-time reverse mode for the generation of derivatives. We show that orders of magnitudesmore » of improvement are possible when exploiting partial separability and maximizing use of the reverse mode.« less

Theoretical Investigation of Thermo-Mechanical Behavior of Carbon Nanotube-Based Composites Using the Integral Transform Method

NASA Technical Reports Server (NTRS)

Pawloski, Janice S.

2001-01-01

This project uses the integral transform technique to model the problem of nanotube behavior as an axially symmetric system of shells. Assuming that the nanotube behavior can be described by the equations of elasticity, we seek a stress function x which satisfies the biharmonic equation: del(exp 4) chi = [partial deriv(r(exp 2)) + partial deriv(r) + partial deriv(z(exp 2))] chi = 0. The method of integral transformations is used to transform the differential equation. The symmetry with respect to the z-axis indicates that we only need to consider the sine transform of the stress function: X(bar)(r,zeta) = integral(from 0 to infinity) chi(r,z)sin(zeta,z) dz.

Validation of Improved Broadband Shortwave and Longwave Fluxes Derived From GOES

NASA Technical Reports Server (NTRS)

Khaiyer, Mandana M.; Nordeen, Michele L.; Palikonda, Rabindra; Yi, Yuhong; Minnis, Patrick; Doelling, David R.

2009-01-01

Broadband (BB) shortwave (SW) and longwave (LW) fluxes at TOA (Top of Atmosphere) are crucial parameters in the study of climate and can be monitored over large portions of the Earth's surface using satellites. The VISST (Visible Infrared Solar Split-Window Technique) satellite retrieval algorithm facilitates derivation of these parameters from the Geostationery Operational Environmental Satellites (GOES). However, only narrowband (NB) fluxes are available from GOES, so this derivation requires use of narrowband-to-broadband (NB-BB) conversion coefficients. The accuracy of these coefficients affects the validity of the derived broadband (BB) fluxes. Most recently, NB-BB fits were re-derived using the NB fluxes from VISST/GOES data with BB fluxes observed by the CERES (Clouds and the Earth's Radiant Energy Budget) instrument aboard Terra, a sun-synchronous polar-orbiting satellite that crosses the equator at 10:30 LT. Subsequent comparison with ARM's (Atmospheric Radiation Measurement) BBHRP (Broadband Heating Rate Profile) BB fluxes revealed that while the derived broadband fluxes agreed well with CERES near the Terra overpass times, the accuracy of both LW and SW fluxes decreased farther away from the overpass times. Terra's orbit hampers the ability of the NB-BB fits to capture diurnal variability. To account for this in the LW, seasonal NB-BB fits are derived separately for day and night. Information from hourly SW BB fluxes from the Meteosat-8 Geostationary Earth Radiation Budget (GERB) is employed to include samples over the complete solar zenith angle (SZA) range sampled by Terra. The BB fluxes derived from these improved NB-BB fits are compared to BB fluxes computed with a radiative transfer model.

Walking performance in people with diabetic neuropathy: benefits and threats.

PubMed

Kanade, R V; van Deursen, R W M; Harding, K; Price, P

2006-08-01

Walking is recommended as an adjunct therapy to diet and medication in diabetic patients, with the aim of improving physical fitness, glycaemic control and body weight reduction. Therefore we evaluated walking activity on the basis of capacity, performance and potential risk of plantar injury in the diabetic population before it can be prescribed safely. Twenty-three subjects with diabetic neuropathy (DMPN) were compared with 23 patients with current diabetic foot ulcers, 16 patients with partial foot amputations and 22 patients with trans-tibial amputations. The capacity for walking was measured using a total heart beat index (THBI). Gait velocity and average daily strides were measured to assess the performance of walking, and its impact on weight-bearing was studied using maximum peak pressure. THBI increased (p<0.01) and gait velocity and daily stride count fell (p<0.001 for both) with progression of foot complications. The maximum peak pressures over the affected foot of patients with diabetic foot ulcers (p<0.05) and partial foot amputations (p<0.01) were higher than in the group with DMPN. On the contralateral side, the diabetic foot ulcer group showed higher maximum peak pressure over the total foot (p<0.05), and patients with partial foot amputations (p<0.01) and trans-tibial amputations (p<0.05) showed higher maximum peak pressure over the heel. Walking capacity and performance decrease with progression of foot complications. Although walking is recommended to improve fitness, it cannot be prescribed in isolation, considering the increased risk of plantar injury. For essential walking we therefore recommend the use of protective footwear. Walking exercise should be supplemented by partial or non-weight-bearing exercises to improve physical fitness in diabetic populations.

Comparison of yellow poplar growth models on the basis of derived growth analysis variables

Treesearch

Keith F. Jensen; Daniel A. Yaussy

1986-01-01

Quadratic and cubic polynomials, and Gompertz and Richards asymptotic models were fitted to yellow poplar growth data. These data included height, leaf area, leaf weight and new shoot height for 23 weeks. Seven growth analysis variables were estimated from each function. The Gompertz and Richards models fitted the data best and provided the most accurate derived...

Ligand-based virtual screening under partial shape constraints.

PubMed

von Behren, Mathias M; Rarey, Matthias

2017-04-01

Ligand-based virtual screening has proven to be a viable technology during the search for new lead structures in drug discovery. Despite the rapidly increasing number of published methods, meaningful shape matching as well as ligand and target flexibility still remain open challenges. In this work, we analyze the influence of knowledge-based sterical constraints on the performance of the recently published ligand-based virtual screening method mRAISE. We introduce the concept of partial shape matching enabling a more differentiated view on chemical structure. The new method is integrated into the LBVS tool mRAISE providing multiple options for such constraints. The applied constraints can either be derived automatically from a protein-ligand complex structure or by manual selection of ligand atoms. In this way, the descriptor directly encodes the fit of a ligand into the binding site. Furthermore, the conservation of close contacts between the binding site surface and the query ligand can be enforced. We validated our new method on the DUD and DUD-E datasets. Although the statistical performance remains on the same level, detailed analysis reveal that for certain and especially very flexible targets a significant improvement can be achieved. This is further highlighted looking at the quality of calculated molecular alignments using the recently introduced mRAISE dataset. The new partial shape constraints improved the overall quality of molecular alignments especially for difficult targets with highly flexible or different sized molecules. The software tool mRAISE is freely available on Linux operating systems for evaluation purposes and academic use (see http://www.zbh.uni-hamburg.de/raise ).

Ligand-based virtual screening under partial shape constraints

NASA Astrophysics Data System (ADS)

von Behren, Mathias M.; Rarey, Matthias

2017-04-01

Ligand-based virtual screening has proven to be a viable technology during the search for new lead structures in drug discovery. Despite the rapidly increasing number of published methods, meaningful shape matching as well as ligand and target flexibility still remain open challenges. In this work, we analyze the influence of knowledge-based sterical constraints on the performance of the recently published ligand-based virtual screening method mRAISE. We introduce the concept of partial shape matching enabling a more differentiated view on chemical structure. The new method is integrated into the LBVS tool mRAISE providing multiple options for such constraints. The applied constraints can either be derived automatically from a protein-ligand complex structure or by manual selection of ligand atoms. In this way, the descriptor directly encodes the fit of a ligand into the binding site. Furthermore, the conservation of close contacts between the binding site surface and the query ligand can be enforced. We validated our new method on the DUD and DUD-E datasets. Although the statistical performance remains on the same level, detailed analysis reveal that for certain and especially very flexible targets a significant improvement can be achieved. This is further highlighted looking at the quality of calculated molecular alignments using the recently introduced mRAISE dataset. The new partial shape constraints improved the overall quality of molecular alignments especially for difficult targets with highly flexible or different sized molecules. The software tool mRAISE is freely available on Linux operating systems for evaluation purposes and academic use (see http://www.zbh.uni-hamburg.de/raise).

Reversing Period-Doubling Bifurcations in Models of Population Interactions Using Constant Stocking or Harvesting

Treesearch

James F. Selgrade; James H. Roberds

1998-01-01

This study considers a general class of two-dimensional, discrete population models where each per capita transition function (fitness) depends on a linear combination of the densities of the interacting populations. The fitness functions are either monotone decreasing functions (pioneer fitnesses) or one-humped functions (climax fitnesses). Conditions are derived...

The Air Force Fitness Test: Creating New Fitness Assessment Charts Using Waist to Height Ratios

DTIC Science & Technology

2017-03-23

concurrence with their schedule, and the memo gave more direction to physical training leaders (PTLs). The memorandum provided training expectations for...van Leer, Seidell, and Lean (1995) concluded an increased cardiovascular disease risk is positively associated with waist circumference (Han, van...Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of

Does a Fitness Factor Contribute to the Association between Intelligence and Health Outcomes? Evidence from Medical Abnormality Counts among 3654 US Veterans

ERIC Educational Resources Information Center

Arden, Rosalind; Gottfredson, Linda S.; Miller, Geoffrey

2009-01-01

We suggest that an over-arching "fitness factor" (an index of general genetic quality that predicts survival and reproductive success) partially explains the observed associations between health outcomes and intelligence. As a proof of concept, we tested this idea in a sample of 3654 US Vietnam veterans aged 31-49 who completed five cognitive…

Phase equilibria constraints on models of subduction zone magmatism

NASA Astrophysics Data System (ADS)

Myers, James D.; Johnston, Dana A.

Petrologic models of subduction zone magmatism can be grouped into three broad classes: (1) predominantly slab-derived, (2) mainly mantle-derived, and (3) multi-source. Slab-derived models assume high-alumina basalt (HAB) approximates primary magma and is derived by partial fusion of the subducting slab. Such melts must, therefore, be saturated with some combination of eclogite phases, e.g. cpx, garnet, qtz, at the pressures, temperatures and water contents of magma generation. In contrast, mantle-dominated models suggest partial melting of the mantle wedge produces primary high-magnesia basalts (HMB) which fractionate to yield derivative HAB magmas. In this context, HMB melts should be saturated with a combination of peridotite phases, i.e. ol, cpx and opx, and have liquid-lines-of-descent that produce high-alumina basalts. HAB generated in this manner must be saturated with a mafic phase assemblage at the intensive conditions of fractionation. Multi-source models combine slab and mantle components in varying proportions to generate the four main lava types (HMB, HAB, high-magnesia andesites (HMA) and evolved lavas) characteristic of subduction zones. The mechanism of mass transfer from slab to wedge as well as the nature and fate of primary magmas vary considerably among these models. Because of their complexity, these models imply a wide range of phase equilibria. Although the experiments conducted on calc-alkaline lavas are limited, they place the following limitations on arc petrologic models: (1) HAB cannot be derived from HMB by crystal fractionation at the intensive conditions thus far investigated, (2) HAB could be produced by anhydrous partial fusion of eclogite at high pressure, (3) HMB liquids can be produced by peridotite partial fusion 50-60 km above the slab-mantle interface, (4) HMA cannot be primary magmas derived by partial melting of the subducted slab, but could have formed by slab melt-peridotite interaction, and (5) many evolved calc-alkaline lavas could have been formed by crystal fractionation at a range of crustal pressures.

Navy Fuel Composition and Screening Tool (FCAST) v2.8

DTIC Science & Technology

2016-05-10

allowed us to develop partial least squares (PLS) models based on gas chromatography–mass spectrometry (GC-MS) data that predict fuel properties. The...Chemometric property modeling Partial least squares PLS Compositional profiler Naval Air Systems Command Air-4.4.5 Patuxent River Naval Air Station Patuxent...Cumulative predicted residual error sum of squares DiEGME Diethylene glycol monomethyl ether FCAST Fuel Composition and Screening Tool FFP Fit for

5 CFR 353.102 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... performed. Partially recovered means an injured employee, though not ready to resume the full range of his... for the purpose of examination to determine fitness to perform such duty. Status means the particular...

5 CFR 353.102 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... performed. Partially recovered means an injured employee, though not ready to resume the full range of his... for the purpose of examination to determine fitness to perform such duty. Status means the particular...

A unified software framework for deriving, visualizing, and exploring abstraction networks for ontologies

PubMed Central

Ochs, Christopher; Geller, James; Perl, Yehoshua; Musen, Mark A.

2016-01-01

Software tools play a critical role in the development and maintenance of biomedical ontologies. One important task that is difficult without software tools is ontology quality assurance. In previous work, we have introduced different kinds of abstraction networks to provide a theoretical foundation for ontology quality assurance tools. Abstraction networks summarize the structure and content of ontologies. One kind of abstraction network that we have used repeatedly to support ontology quality assurance is the partial-area taxonomy. It summarizes structurally and semantically similar concepts within an ontology. However, the use of partial-area taxonomies was ad hoc and not generalizable. In this paper, we describe the Ontology Abstraction Framework (OAF), a unified framework and software system for deriving, visualizing, and exploring partial-area taxonomy abstraction networks. The OAF includes support for various ontology representations (e.g., OWL and SNOMED CT's relational format). A Protégé plugin for deriving “live partial-area taxonomies” is demonstrated. PMID:27345947

A unified software framework for deriving, visualizing, and exploring abstraction networks for ontologies.

PubMed

Ochs, Christopher; Geller, James; Perl, Yehoshua; Musen, Mark A

2016-08-01

Software tools play a critical role in the development and maintenance of biomedical ontologies. One important task that is difficult without software tools is ontology quality assurance. In previous work, we have introduced different kinds of abstraction networks to provide a theoretical foundation for ontology quality assurance tools. Abstraction networks summarize the structure and content of ontologies. One kind of abstraction network that we have used repeatedly to support ontology quality assurance is the partial-area taxonomy. It summarizes structurally and semantically similar concepts within an ontology. However, the use of partial-area taxonomies was ad hoc and not generalizable. In this paper, we describe the Ontology Abstraction Framework (OAF), a unified framework and software system for deriving, visualizing, and exploring partial-area taxonomy abstraction networks. The OAF includes support for various ontology representations (e.g., OWL and SNOMED CT's relational format). A Protégé plugin for deriving "live partial-area taxonomies" is demonstrated. Copyright © 2016 Elsevier Inc. All rights reserved.

Determining the dominant partial wave contributions from angular distributions of single- and double-polarization observables in pseudoscalar meson photoproduction

NASA Astrophysics Data System (ADS)

Wunderlich, Y.; Afzal, F.; Thiel, A.; Beck, R.

2017-05-01

This work presents a simple method to determine the significant partial wave contributions to experimentally determined observables in pseudoscalar meson photoproduction. First, fits to angular distributions are presented and the maximum orbital angular momentum Lmax needed to achieve a good fit is determined. Then, recent polarization measurements for γ p → π0 p from ELSA, GRAAL, JLab and MAMI are investigated according to the proposed method. This method allows us to project high-spin partial wave contributions to any observable as long as the measurement has the necessary statistical accuracy. We show, that high precision and large angular coverage in the polarization data are needed in order to be sensitive to high-spin resonance states and thereby also for the finding of small resonance contributions. This task can be achieved via interference of these resonances with the well-known states. For the channel γ p → π0 p, those are the N(1680)5/2+ and Δ(1950)7/2+, contributing to the F-waves.

Trigonometric Integrals via Partial Fractions

ERIC Educational Resources Information Center

Chen, H.; Fulford, M.

2005-01-01

Parametric differentiation is used to derive the partial fractions decompositions of certain rational functions. Those decompositions enable us to integrate some new combinations of trigonometric functions.

Accuracy of six elastic impression materials used for complete-arch fixed partial dentures.

PubMed

Stauffer, J P; Meyer, J M; Nally, J N

1976-04-01

1. The accuracy of four types of impression materials used to make a complete-arch fixed partial denture was evaluated by visual comparison and indirect measurement methods. 2. None of the tested materials allows safe finishing of a complete-arch fixed partial denture on a cast poured from one single master impression. 3. All of the tested materials can be used for impressions for a complete-arch fixed partial denture provided it is not finished on one single cast. Errors can be avoided by making a new impression with the fitted castings in place. Assembly and soldering should be done on the second cast. 4. In making the master fixed partial denture for this study, inaccurate soldering was a problem that was overcome with the use of epoxy glue. Hence, soldering seems to be a major source of inaccuracy for every fixed partial denture.

Extending compile-time reverse mode and exploiting partial separability in ADIFOR. ADIFOR Working Note No. 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bischof, C.H.; El-Khadiri, M.

1992-10-01

The numerical methods employed in the solution of many scientific computing problems require the computation of the gradient of a function f: R{sup n} {yields} R. ADIFOR is a source translator that, given a collection of subroutines to compute f, generates Fortran 77 code for computing the derivative of this function. Using the so-called torsion problem from the MINPACK-2 test collection as an example, this paper explores two issues in automatic differentiation: the efficient computation of derivatives for partial separable functions and the use of the compile-time reverse mode for the generation of derivatives. We show that orders of magnitudesmore » of improvement are possible when exploiting partial separability and maximizing use of the reverse mode.« less

Pricing timer options and variance derivatives with closed-form partial transform under the 3/2 model

PubMed Central

Zheng, Wendong; Zeng, Pingping

2016-01-01

ABSTRACT Most of the empirical studies on stochastic volatility dynamics favour the 3/2 specification over the square-root (CIR) process in the Heston model. In the context of option pricing, the 3/2 stochastic volatility model (SVM) is reported to be able to capture the volatility skew evolution better than the Heston model. In this article, we make a thorough investigation on the analytic tractability of the 3/2 SVM by proposing a closed-form formula for the partial transform of the triple joint transition density which stand for the log asset price, the quadratic variation (continuous realized variance) and the instantaneous variance, respectively. Two distinct formulations are provided for deriving the main result. The closed-form partial transform enables us to deduce a variety of marginal partial transforms and characteristic functions and plays a crucial role in pricing discretely sampled variance derivatives and exotic options that depend on both the asset price and quadratic variation. Various applications and numerical examples on pricing moment swaps and timer options with discrete monitoring feature are given to demonstrate the versatility of the partial transform under the 3/2 model. PMID:28706460

Fast and exact Newton and Bidirectional fitting of Active Appearance Models.

PubMed

Kossaifi, Jean; Tzimiropoulos, Yorgos; Pantic, Maja

2016-12-21

Active Appearance Models (AAMs) are generative models of shape and appearance that have proven very attractive for their ability to handle wide changes in illumination, pose and occlusion when trained in the wild, while not requiring large training dataset like regression-based or deep learning methods. The problem of fitting an AAM is usually formulated as a non-linear least squares one and the main way of solving it is a standard Gauss-Newton algorithm. In this paper we extend Active Appearance Models in two ways: we first extend the Gauss-Newton framework by formulating a bidirectional fitting method that deforms both the image and the template to fit a new instance. We then formulate a second order method by deriving an efficient Newton method for AAMs fitting. We derive both methods in a unified framework for two types of Active Appearance Models, holistic and part-based, and additionally show how to exploit the structure in the problem to derive fast yet exact solutions. We perform a thorough evaluation of all algorithms on three challenging and recently annotated inthe- wild datasets, and investigate fitting accuracy, convergence properties and the influence of noise in the initialisation. We compare our proposed methods to other algorithms and show that they yield state-of-the-art results, out-performing other methods while having superior convergence properties.

Using a second‐order differential model to fit data without baselines in protein isothermal chemical denaturation

PubMed Central

Tang, Chuanning; Lew, Scott

2016-01-01

Abstract In vitro protein stability studies are commonly conducted via thermal or chemical denaturation/renaturation of protein. Conventional data analyses on the protein unfolding/(re)folding require well‐defined pre‐ and post‐transition baselines to evaluate Gibbs free‐energy change associated with the protein unfolding/(re)folding. This evaluation becomes problematic when there is insufficient data for determining the pre‐ or post‐transition baselines. In this study, fitting on such partial data obtained in protein chemical denaturation is established by introducing second‐order differential (SOD) analysis to overcome the limitations that the conventional fitting method has. By reducing numbers of the baseline‐related fitting parameters, the SOD analysis can successfully fit incomplete chemical denaturation data sets with high agreement to the conventional evaluation on the equivalent completed data, where the conventional fitting fails in analyzing them. This SOD fitting for the abbreviated isothermal chemical denaturation further fulfills data analysis methods on the insufficient data sets conducted in the two prevalent protein stability studies. PMID:26757366

On contribution of known atomic partial charges of protein backbone in electrostatic potential density maps.

PubMed

Wang, Jimin

2017-06-01

Partial charges of atoms in a molecule and electrostatic potential (ESP) density for that molecule are known to bear a strong correlation. In order to generate a set of point-field force field parameters for molecular dynamics, Kollman and coworkers have extracted atomic partial charges for each of all 20 amino acids using restrained partial charge-fitting procedures from theoretical ESP density obtained from condensed-state quantum mechanics. The magnitude of atomic partial charges for neutral peptide backbone they have obtained is similar to that of partial atomic charges for ionized carboxylate side chain atoms. In this study, the effect of these known atomic partial charges on ESP is examined using computer simulations and compared with the experimental ESP density recently obtained for proteins using electron microscopy. It is found that the observed ESP density maps are most consistent with the simulations that include atomic partial charges of protein backbone. Therefore, atomic partial charges are integral part of atomic properties in protein molecules and should be included in model refinement. © 2017 The Protein Society.

On contribution of known atomic partial charges of protein backbone in electrostatic potential density maps

PubMed Central

2017-01-01

Abstract Partial charges of atoms in a molecule and electrostatic potential (ESP) density for that molecule are known to bear a strong correlation. In order to generate a set of point‐field force field parameters for molecular dynamics, Kollman and coworkers have extracted atomic partial charges for each of all 20 amino acids using restrained partial charge‐fitting procedures from theoretical ESP density obtained from condensed‐state quantum mechanics. The magnitude of atomic partial charges for neutral peptide backbone they have obtained is similar to that of partial atomic charges for ionized carboxylate side chain atoms. In this study, the effect of these known atomic partial charges on ESP is examined using computer simulations and compared with the experimental ESP density recently obtained for proteins using electron microscopy. It is found that the observed ESP density maps are most consistent with the simulations that include atomic partial charges of protein backbone. Therefore, atomic partial charges are integral part of atomic properties in protein molecules and should be included in model refinement. PMID:28370507

Topics in spectral methods

NASA Technical Reports Server (NTRS)

Gottlieb, D.; Turkel, E.

1985-01-01

After detailing the construction of spectral approximations to time-dependent mixed initial boundary value problems, a study is conducted of differential equations of the form 'partial derivative of u/partial derivative of t = Lu + f', where for each t, u(t) belongs to a Hilbert space such that u satisfies homogeneous boundary conditions. For the sake of simplicity, it is assumed that L is an unbounded, time-independent linear operator. Attention is given to Fourier methods of both Galerkin and pseudospectral method types, the Galerkin method, the pseudospectral Chebyshev and Legendre methods, the error equation, hyperbolic partial differentiation equations, and time discretization and iterative methods.

A Proposed Mediation Model of the Effects of Motivation for a Healthy Lifestyle: Impacts on Emotional Exhaustion, Medication Regimens, and Low-Density Lipoprotein

DTIC Science & Technology

2012-03-01

possible roles of motivation/goal setting education in addition to nutrition and fitness for making positive lifestyle changes for decreasing the...ofbehavioral change support ( education ) increases participation of healthy lifestyle changes, in addition to participation in nutrition and fitness classes...Engineering and Management Air Force Institute of Technology Air University Air Education and Training Command In Partial Fulfillment of the

rSalvador: An R Package for the Fluctuation Experiment

PubMed Central

Zheng, Qi

2017-01-01

The past few years have seen a surge of novel applications of the Luria-Delbrück fluctuation assay protocol in bacterial research. Appropriate analysis of fluctuation assay data often requires computational methods that are unavailable in the popular web tool FALCOR. This paper introduces an R package named rSalvador to bring improvements to the field. The paper focuses on rSalvador’s capabilities to alleviate three kinds of problems found in recent investigations: (i) resorting to partial plating without properly accounting for the effects of partial plating; (ii) conducting attendant fitness assays without incorporating mutants’ relative fitness in subsequent data analysis; and (iii) comparing mutation rates using methods that are in general inapplicable to fluctuation assay data. In addition, the paper touches on rSalvador’s capabilities to estimate sample size and the difficulties related to parameter nonidentifiability. PMID:29084818

A partial exponential lumped parameter model to evaluate groundwater age distributions and nitrate trends in long-screened wells

USGS Publications Warehouse

Jurgens, Bryant; Böhlke, John Karl; Kauffman, Leon J.; Belitz, Kenneth; Esser, Bradley K.

2016-01-01

A partial exponential lumped parameter model (PEM) was derived to determine age distributions and nitrate trends in long-screened production wells. The PEM can simulate age distributions for wells screened over any finite interval of an aquifer that has an exponential distribution of age with depth. The PEM has 3 parameters – the ratio of saturated thickness to the top and bottom of the screen and mean age, but these can be reduced to 1 parameter (mean age) by using well construction information and estimates of the saturated thickness. The PEM was tested with data from 30 production wells in a heterogeneous alluvial fan aquifer in California, USA. Well construction data were used to guide parameterization of a PEM for each well and mean age was calibrated to measured environmental tracer data (3H, 3He, CFC-113, and 14C). Results were compared to age distributions generated for individual wells using advective particle tracking models (PTMs). Age distributions from PTMs were more complex than PEM distributions, but PEMs provided better fits to tracer data, partly because the PTMs did not simulate 14C accurately in wells that captured varying amounts of old groundwater recharged at lower rates prior to groundwater development and irrigation. Nitrate trends were simulated independently of the calibration process and the PEM provided good fits for at least 11 of 24 wells. This work shows that the PEM, and lumped parameter models (LPMs) in general, can often identify critical features of the age distributions in wells that are needed to explain observed tracer data and nonpoint source contaminant trends, even in systems where aquifer heterogeneity and water-use complicate distributions of age. While accurate PTMs are preferable for understanding and predicting aquifer-scale responses to water use and contaminant transport, LPMs can be sensitive to local conditions near individual wells that may be inaccurately represented or missing in an aquifer-scale flow model.

SMALL-ANGLE NEUTRON SCATTERING CHARACTERIZATION OF THE STRUCTURE OF NANOPOROUS CARBONS FOR ENERGY-RELATED APPLICATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Lilin; Mavila Chathoth, Suresh; Melnichenko, Yuri B

2011-01-01

We used small-angle neutron scattering (SANS) and neutron contrast variation to study the structure of four nanoporouscarbons prepared by thermo-chemical etching of titanium carbide TiC in chlorine at 300, 400, 600, and 800 C with pore diameters ranging between -4 and -11 {angstrom}. SANS patterns were obtained from dry samples and samples saturated with deuterium oxide (D{sub 2}O) in order to delineate origin of the power law scattering in the low Q domain as well as to evaluate pore accessibility for D{sub 2}O molecules. SANS cross section of all samples was fitted to Debye-Anderson-Brumberger (DAB), DAB-Kirste-Porod models as well asmore » to the Guinier and modified Guinier formulae for cylindrical objects, which allowed for evaluating the radii of gyration as well as the radii and lengths of the pores under cylindrical shape approximation. SANS data from D{sub 2}O-saturated samples indicate that strong upturn in the low Q limit usually observed in the scattering patterns from microporous carbon powders is due to the scattering from outer surface of the powder particles. Micropores are only partially filled with D{sub 2}O molecules due to geometrical constraints and or partial hydrophobicity of the carbon matrix. Structural parameters of the dry carbons obtained using SANS are compared with the results of the gas sorption measurements and the values agree for carbide-derived carbons (CDCs) obtained at high chlorination temperatures (>600 C). For lower chlorination temperatures, pore radii obtained from gas sorption overestimate the actual pore size as calculated from SANS for two reasons: inaccessible small pores are present and the model-dependent fitting based on density functional theory models assumes non-spherical pores, whereas SANS clearly indicates that the pore shape in microporous CDC obtained at low chlorination temperatures is nearly spherical.« less

Genetic background in partitioning of metabolizable energy efficiency in dairy cows.

PubMed

Mehtiö, T; Negussie, E; Mäntysaari, P; Mäntysaari, E A; Lidauer, M H

2018-05-01

The main objective of this study was to assess the genetic differences in metabolizable energy efficiency and efficiency in partitioning metabolizable energy in different pathways: maintenance, milk production, and growth in primiparous dairy cows. Repeatability models for residual energy intake (REI) and metabolizable energy intake (MEI) were compared and the genetic and permanent environmental variations in MEI were partitioned into its energy sinks using random regression models. We proposed 2 new feed efficiency traits: metabolizable energy efficiency (MEE), which is formed by modeling MEI fitting regressions on energy sinks [metabolic body weight (BW 0.75 ), energy-corrected milk, body weight gain, and body weight loss] directly; and partial MEE (pMEE), where the model for MEE is extended with regressions on energy sinks nested within additive genetic and permanent environmental effects. The data used were collected from Luke's experimental farms Rehtijärvi and Minkiö between 1998 and 2014. There were altogether 12,350 weekly MEI records on 495 primiparous Nordic Red dairy cows from wk 2 to 40 of lactation. Heritability estimates for REI and MEE were moderate, 0.33 and 0.26, respectively. The estimate of the residual variance was smaller for MEE than for REI, indicating that analyzing weekly MEI observations simultaneously with energy sinks is preferable. Model validation based on Akaike's information criterion showed that pMEE models fitted the data even better and also resulted in smaller residual variance estimates. However, models that included random regression on BW 0.75 converged slowly. The resulting genetic standard deviation estimate from the pMEE coefficient for milk production was 0.75 MJ of MEI/kg of energy-corrected milk. The derived partial heritabilities for energy efficiency in maintenance, milk production, and growth were 0.02, 0.06, and 0.04, respectively, indicating that some genetic variation may exist in the efficiency of using metabolizable energy for different pathways in dairy cows. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

76 FR 722 - Governance Requirements for Derivatives Clearing Organizations, Designated Contract Markets, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-06

... regulations to implement core principles concerning governance fitness standards and the composition of...(c) of the CEA to include new DCO Core Principle O (Governance Fitness Standards), P (Conflicts of... owners and participants; (ii) appropriate fitness standards for directors, members, and others; (iii...

Correlating multispectral imaging and compositional data from the Mars Exploration Rovers and implications for Mars Science Laboratory

NASA Astrophysics Data System (ADS)

Anderson, Ryan B.; Bell, James F.

2013-03-01

In an effort to infer compositional information about distant targets based on multispectral imaging data, we investigated methods of relating Mars Exploration Rover (MER) Pancam multispectral remote sensing observations to in situ alpha particle X-ray spectrometer (APXS)-derived elemental abundances and Mössbauer (MB)-derived abundances of Fe-bearing phases at the MER field sites in Gusev crater and Meridiani Planum. The majority of the partial correlation coefficients between these data sets were not statistically significant. Restricting the targets to those that were abraded by the rock abrasion tool (RAT) led to improved Pearson’s correlations, most notably between the red-blue ratio (673 nm/434 nm) and Fe3+-bearing phases, but partial correlations were not statistically significant. Partial Least Squares (PLS) calculations relating Pancam 11-color visible to near-IR (VNIR; ∼400-1000 nm) “spectra” to APXS and Mössbauer element or mineral abundances showed generally poor performance, although the presence of compositional outliers led to improved PLS results for data from Meridiani. When the Meridiani PLS model for pyroxene was tested by predicting the pyroxene content of Gusev targets, the results were poor, indicating that the PLS models for Meridiani are not applicable to data from other sites. Soft Independent Modeling of Class Analogy (SIMCA) classification of Gusev crater data showed mixed results. Of the 24 Gusev test regions of interest (ROIs) with known classes, 11 had >30% of the pixels in the ROI classified correctly, while others were mis-classified or unclassified. k-Means clustering of APXS and Mössbauer data was used to assign Meridiani targets to compositional classes. The clustering-derived classes corresponded to meaningful geologic and/or color unit differences, and SIMCA classification using these classes was somewhat successful, with >30% of pixels correctly classified in 9 of the 11 ROIs with known classes. This work shows that the relationship between SWIR multispectral imaging data and APXS- and Mössbauer-derived composition/mineralogy is often weak, a perhaps not entirely unexpected result given the different surface sampling depths of SWIR imaging (uppermost few microns) vs. APXS (tens of μm) and MB measurements (hundreds of μm). Results from the upcoming Mars Science Laboratory (MSL) rover’s ChemCam Laser Induced Breakdown Spectroscopy (LIBS) instrument may show a closer relationship to Mastcam SWIR multispectral observations, however, because the initial laser shots onto a target will analyze only the upper few micrometers of the surface. The clustering and classification methods used in this study can be applied to any data set to formalize the definition of classes and identify targets that do not fit in previously defined classes.

Correlating multispectral imaging and compositional data from the Mars Exploration Rovers and implications for Mars Science Laboratory

USGS Publications Warehouse

Anderson, Ryan B.; Bell, James F.

2013-01-01

In an effort to infer compositional information about distant targets based on multispectral imaging data, we investigated methods of relating Mars Exploration Rover (MER) Pancam multispectral remote sensing observations to in situ alpha particle X-ray spectrometer (APXS)-derived elemental abundances and Mössbauer (MB)-derived abundances of Fe-bearing phases at the MER field sites in Gusev crater and Meridiani Planum. The majority of the partial correlation coefficients between these data sets were not statistically significant. Restricting the targets to those that were abraded by the rock abrasion tool (RAT) led to improved Pearson’s correlations, most notably between the red–blue ratio (673 nm/434 nm) and Fe3+-bearing phases, but partial correlations were not statistically significant. Partial Least Squares (PLS) calculations relating Pancam 11-color visible to near-IR (VNIR; ∼400–1000 nm) “spectra” to APXS and Mössbauer element or mineral abundances showed generally poor performance, although the presence of compositional outliers led to improved PLS results for data from Meridiani. When the Meridiani PLS model for pyroxene was tested by predicting the pyroxene content of Gusev targets, the results were poor, indicating that the PLS models for Meridiani are not applicable to data from other sites. Soft Independent Modeling of Class Analogy (SIMCA) classification of Gusev crater data showed mixed results. Of the 24 Gusev test regions of interest (ROIs) with known classes, 11 had >30% of the pixels in the ROI classified correctly, while others were mis-classified or unclassified. k-Means clustering of APXS and Mössbauer data was used to assign Meridiani targets to compositional classes. The clustering-derived classes corresponded to meaningful geologic and/or color unit differences, and SIMCA classification using these classes was somewhat successful, with >30% of pixels correctly classified in 9 of the 11 ROIs with known classes. This work shows that the relationship between SWIR multispectral imaging data and APXS- and Mössbauer-derived composition/mineralogy is often weak, a perhaps not entirely unexpected result given the different surface sampling depths of SWIR imaging (uppermost few microns) vs. APXS (tens of μm) and MB measurements (hundreds of μm). Results from the upcoming Mars Science Laboratory (MSL) rover’s ChemCam Laser Induced Breakdown Spectroscopy (LIBS) instrument may show a closer relationship to Mastcam SWIR multispectral observations, however, because the initial laser shots onto a target will analyze only the upper few micrometers of the surface. The clustering and classification methods used in this study can be applied to any data set to formalize the definition of classes and identify targets that do not fit in previously defined classes.

Partial Pressures of Te2 and Thermodynamic Properties of Ga-Te System

NASA Technical Reports Server (NTRS)

Su, Ching-Hua; Curreri, Peter A. (Technical Monitor)

2001-01-01

The partial pressures of Te2 in equilibrium with Ga(1-x)Te(x) samples were measured by optical absorption technique from 450 to 1100 C for compositions, x, between 0.333 and 0.612. To establish the relationship between the partial pressure of Te, and the measured optical absorbance, the calibration runs of a pure Te sample were also conducted to determine the Beer's Law constants. The partial pressures of Te2 in equilibrium with the GaTe(s) and Ga2Te3(s)compounds, or the so-called three-phase curves, were established. These partial pressure data imply the existence of the Ga3Te4(s) compound. From the partial pressures of Te2 over the Ga-Te melts, partial molar enthalpy and entropy of mixing for Te were derived and they agree reasonable well with the published data. The activities of Te in the Ga-Te melts were also derived from the measured partial pressures of Te2. These data agree well with most of the previous results. The possible reason for the high activity of Te measured for x less than 0.60 is discussed.

Implications of New Methane Absorption Coefficients on Uranus Vertical Structure Derived from Near-IR Spectra

NASA Astrophysics Data System (ADS)

Fry, Patrick M.; Sromovsky, L. A.

2009-09-01

Using new methane absorption coefficients from Karkoschka and Tomasko (2009, submitted to Icarus, "Methane Absorption Coefficients for the Jovian Planets from Laboratory, Huygens, and HST Data"), we fit Uranus near-IR spectra previously analyzed in Sromovsky et al. (2006, Icarus 182, 577-593, Fink and Larson, 1979 J- and H-band), Sromovsky and Fry (2008, Icarus 193, 252-266, 2006 NIRC2 J- and H-band, 2006 SpeX) using Irwin et al. (2006, Icarus 181, 309-319) methane absorption coefficients. Because the new absorption coefficients usually result in higher opacities at the low temperatures seen in Uranus' upper troposphere, our previously derived cloud altitudes are expected to generally rise to higher altitudes. For example, using Lindal et al. (1987, JGR 92, 14987-15001) model D temperature and methane abundance profiles, we are better able to fit the J-band 43-deg. south bright band with the new coefficients (chi-square=205, vs. 315 for Irwin), with the pressure of the upper tropospheric cloud decreasing to 1.6 bars (from 2.4 bars using Irwin coefficients). Improvements in fitting H-band spectra from the same latitude are not as readily obtained. Derived upper tropospheric cloud pressures are very similar using the two absorption datasets (1.6-1.7 bars), but the character of the fits differs. New Karkoschka and Tomasko coefficients better fit some details in the 1.5-1.58 micron region, but Irwin fits the broad absorption band wing at 1.61-1.62 microns better, and the fit chi-square values are similar (K&T: 243, Irwin: 220). Results for a higher methane concentration (Lindal et al. model F) were similar. Whether the new coefficients will simply raise derived altitudes across the planet or will result in fundamental changes in structure is as yet unclear. This work was suported by NASA planetary astronomy and planetary atmospheres programs.

Derivation of error sources for experimentally derived heliostat shapes

NASA Astrophysics Data System (ADS)

Cumpston, Jeff; Coventry, Joe

2017-06-01

Data gathered using photogrammetry that represents the surface and structure of a heliostat mirror panel is investigated in detail. A curve-fitting approach that allows the retrieval of four distinct mirror error components, while prioritizing the best fit possible to paraboloidal terms in the curve fitting equation, is presented. The angular errors associated with each of the four surfaces are calculated, and the relative magnitude for each of them is given. It is found that in this case, the mirror had a significant structural twist, and an estimate of the improvement to the mirror surface quality in the case of no twist was made.

On mixed derivatives type high dimensional multi-term fractional partial differential equations approximate solutions

NASA Astrophysics Data System (ADS)

Talib, Imran; Belgacem, Fethi Bin Muhammad; Asif, Naseer Ahmad; Khalil, Hammad

2017-01-01

In this research article, we derive and analyze an efficient spectral method based on the operational matrices of three dimensional orthogonal Jacobi polynomials to solve numerically the mixed partial derivatives type multi-terms high dimensions generalized class of fractional order partial differential equations. We transform the considered fractional order problem to an easily solvable algebraic equations with the aid of the operational matrices. Being easily solvable, the associated algebraic system leads to finding the solution of the problem. Some test problems are considered to confirm the accuracy and validity of the proposed numerical method. The convergence of the method is ensured by comparing our Matlab software simulations based obtained results with the exact solutions in the literature, yielding negligible errors. Moreover, comparative results discussed in the literature are extended and improved in this study.

Air pollution and case fatality of SARS in the People's Republic of China: an ecologic study

PubMed Central

Cui, Yan; Zhang, Zuo-Feng; Froines, John; Zhao, Jinkou; Wang, Hua; Yu, Shun-Zhang; Detels, Roger

2003-01-01

Background Severe acute respiratory syndrome (SARS) has claimed 349 lives with 5,327 probable cases reported in mainland China since November 2002. SARS case fatality has varied across geographical areas, which might be partially explained by air pollution level. Methods Publicly accessible data on SARS morbidity and mortality were utilized in the data analysis. Air pollution was evaluated by air pollution index (API) derived from the concentrations of particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide and ground-level ozone. Ecologic analysis was conducted to explore the association and correlation between air pollution and SARS case fatality via model fitting. Partially ecologic studies were performed to assess the effects of long-term and short-term exposures on the risk of dying from SARS. Results Ecologic analysis conducted among 5 regions with 100 or more SARS cases showed that case fatality rate increased with the increment of API (case fatality = - 0.063 + 0.001 * API). Partially ecologic study based on short-term exposure demonstrated that SARS patients from regions with moderate APIs had an 84% increased risk of dying from SARS compared to those from regions with low APIs (RR = 1.84, 95% CI: 1.41–2.40). Similarly, SARS patients from regions with high APIs were twice as likely to die from SARS compared to those from regions with low APIs. (RR = 2.18, 95% CI: 1.31–3.65). Partially ecologic analysis based on long-term exposure to ambient air pollution showed the similar association. Conclusion Our studies demonstrated a positive association between air pollution and SARS case fatality in Chinese population by utilizing publicly accessible data on SARS statistics and air pollution indices. Although ecologic fallacy and uncontrolled confounding effect might have biased the results, the possibility of a detrimental effect of air pollution on the prognosis of SARS patients deserves further investigation. PMID:14629774

Using Patient Health Questionnaire-9 item parameters of a common metric resulted in similar depression scores compared to independent item response theory model reestimation.

PubMed

Liegl, Gregor; Wahl, Inka; Berghöfer, Anne; Nolte, Sandra; Pieh, Christoph; Rose, Matthias; Fischer, Felix

2016-03-01

To investigate the validity of a common depression metric in independent samples. We applied a common metrics approach based on item-response theory for measuring depression to four German-speaking samples that completed the Patient Health Questionnaire (PHQ-9). We compared the PHQ item parameters reported for this common metric to reestimated item parameters that derived from fitting a generalized partial credit model solely to the PHQ-9 items. We calibrated the new model on the same scale as the common metric using two approaches (estimation with shifted prior and Stocking-Lord linking). By fitting a mixed-effects model and using Bland-Altman plots, we investigated the agreement between latent depression scores resulting from the different estimation models. We found different item parameters across samples and estimation methods. Although differences in latent depression scores between different estimation methods were statistically significant, these were clinically irrelevant. Our findings provide evidence that it is possible to estimate latent depression scores by using the item parameters from a common metric instead of reestimating and linking a model. The use of common metric parameters is simple, for example, using a Web application (http://www.common-metrics.org) and offers a long-term perspective to improve the comparability of patient-reported outcome measures. Copyright © 2016 Elsevier Inc. All rights reserved.

Determining plasma parameters in cold, multi-species plasmas using Maxwell and Kappa distribution functions.

NASA Astrophysics Data System (ADS)

Jahn, J. M.; Denton, R. E.; Nose, M.; Bonnell, J. W.; Kurth, W. S.; Livadiotis, G.; Larsen, B.; Goldstein, J.

2016-12-01

Determining the total plasma density from ion data is essentially an impossible task for particle instruments. The lowest instrument energy threshold never includes the coldest particles (i.e., Emin> 0 eV), and any positive spacecraft charging—which is normal for a sunlit spacecraft—exacerbates the problem by shifting the detectable minimum energy to higher values. For ion data, traditionally field line resonance measurements of ULF waves in the magnetosphere have been used to determine the mass loading of magnetic field lines in this case. This approach delivers a reduced ion mass M that represents the mass ratio of all ions on a magnetic field line. For multi-species plasmas like the plasmasphere this bounds the problem, but it does not provide a unique solution. To at least estimate partial densities using particle instruments, one traditionally performs fits to the measured particle distribution functions under the assumption that the underlying particle distributions are Maxwellian. Uncertainties performing a fit aside, there is usually no possibility to detect a possible bi-Maxwellian distribution where one of the Maxwellians is very cold. The tail of such a distribution may fall completely below the low energy threshold of the measurement. In this paper we present a different approach to determining the fractional temperatures Ti and densities ni in a multi-species plasma. First, we describe and demonstrate an approach to determine Ti and ni that does not require fitting but relies more on the mathematical properties of the distribution functions. We apply our approach to Van Allen Probes measurements of the plasmaspheric H+, He+, and O+ distribution functions under the assumption that the particle distributions are Maxwellian. We compare our results to mass loading results from the Van Allen Probes field line resonance analyses (for composition) and to the total (electron) plasma density derived from the EFW and EMFISIS experiments. Then we expand our approach to allow for kappa distributions instead. While this introduces an additional degree of freedom and therefore requires fitting, our approach is still better constrained than the traditional Maxwell fitting and may hold the key to a better understanding of the true nature of plasmaspheric particle distributions.

Space Shuttle propulsion parameter estimation using optimal estimation techniques

NASA Technical Reports Server (NTRS)

1983-01-01

This fourth monthly progress report again contains corrections and additions to the previously submitted reports. The additions include a simplified SRB model that is directly incorporated into the estimation algorithm and provides the required partial derivatives. The resulting partial derivatives are analytical rather than numerical as would be the case using the SOBER routines. The filter and smoother routine developments have continued. These routines are being checked out.

Nutrient Patterns and Their Association with Socio-Demographic, Lifestyle Factors and Obesity Risk in Rural South African Adolescents

PubMed Central

Pisa, Pedro T.; Pedro, Titilola M.; Kahn, Kathleen; Tollman, Stephen M.; Pettifor, John M.; Norris, Shane A.

2015-01-01

The aim of this study was to identify and describe the diversity of nutrient patterns and how they associate with socio-demographic and lifestyle factors including body mass index in rural black South African adolescents. Nutrient patterns were identified from quantified food frequency questionnaires (QFFQ) in 388 rural South African adolescents between the ages of 11–15 years from the Agincourt Health and Socio-demographic Surveillance System (AHDSS). Principle Component Analysis (PCA) was applied to 25 nutrients derived from QFFQs. Multiple linear regression and partial R2 models were fitted and computed respectively for each of the retained principal component (PC) scores on socio-demographic and lifestyle characteristics including body mass index (BMI) for age Z scores. Four nutrient patterns explaining 79% of the total variance were identified: PCI (26%) was characterized by animal derived nutrients; PC2 (21%) by vitamins, fibre and vegetable oil nutrients; PC3 (19%) by both animal and plant derived nutrients (mixed diet driven nutrients); and PC4 (13%) by starch and folate. A positive and significant association was observed with BMI for age Z scores per 1 standard deviation (SD) increase in PC1 (0.13 (0.02; 0.24); p = 0.02) and PC4 (0.10 (−0.01; 0.21); p = 0.05) scores only. We confirmed variability in nutrient patterns that were significantly associated with various lifestyle factors including obesity. PMID:25984738

An Empirical Fitting Method for Type Ia Supernova Light Curves: A Case Study of SN 2011fe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, WeiKang; Filippenko, Alexei V., E-mail: zwk@astro.berkeley.edu

We present a new empirical fitting method for the optical light curves of Type Ia supernovae (SNe Ia). We find that a variant broken-power-law function provides a good fit, with the simple assumption that the optical emission is approximately the blackbody emission of the expanding fireball. This function is mathematically analytic and is derived directly from the photospheric velocity evolution. When deriving the function, we assume that both the blackbody temperature and photospheric velocity are constant, but the final function is able to accommodate these changes during the fitting procedure. Applying it to the case study of SN 2011fe givesmore » a surprisingly good fit that can describe the light curves from the first-light time to a few weeks after peak brightness, as well as over a large range of fluxes (∼5 mag, and even ∼7 mag in the g band). Since SNe Ia share similar light-curve shapes, this fitting method has the potential to fit most other SNe Ia and characterize their properties in large statistical samples such as those already gathered and in the near future as new facilities become available.« less

Model-based approach to partial tracking for musical transcription

NASA Astrophysics Data System (ADS)

Sterian, Andrew; Wakefield, Gregory H.

1998-10-01

We present a new method for musical partial tracking in the context of musical transcription using a time-frequency Kalman filter structure. The filter is based upon a model for the evolution of a partial behavior across a wide range of pitch from four brass instruments. Statistics are computed independently for the partial attributes of frequency and log-power first differences. We present observed power spectral density shapes, total powers, and histograms, as well as least-squares approximations to these. We demonstrate that a Kalman filter tracker using this partial model is capable of tracking partials in music. We discuss how the filter structure naturally provides quality-of-fit information about the data for use in further processing and how this information can be used to perform partial track initiation and termination within a common framework. We propose that a model-based approach to partial tracking is preferable to existing approaches which generally use heuristic rules or birth/death notions over a small time neighborhood. The advantages include better performance in the presence of cluttered data and simplified tracking over missed observations.

Exercisers' perceptions of their fitness instructor's interacting style, perceived competence, and autonomy as a function of self-determined regulation to exercise, enjoyment, affect, and exercise frequency.

PubMed

Puente, Rogelio; Anshel, Mark H

2010-02-01

The primary purpose of the present investigation was to test the hypothesis, derived from Self-Determination Theory (SDT), that an individual's perceived competence and autonomy mediate the relationship between the exercisers' perception of their instructor's interaction style and the exercisers' motivation to exercise. A secondary purpose was to identify the affective and behavioral outcomes derived from self-determined regulation. It was hypothesized that SDT would significantly explain and predict exercise behavior. Participants consisted of 238 college students, 103 males and 135 females (M age = 20.4 years, SD = 2.16), who volunteered to participate in the study. They were asked to complete a battery of questionnaires measuring instructor's interacting style, self-regulation to exercise, perceived autonomy and competence, enjoyment, positive and negative affect, and exercise frequency. Using structural equation modeling with observed variables, the results showed that perceived competence and autonomy mediated the relationship between perceived instructor's interacting style and self-determined regulation. It was also found that self-determined regulation was significantly related to exercise enjoyment, positive affect, and exercise frequency. It was concluded that understanding the motivational factors and emotional and behavioral consequences of physical activity will partially explain an individual's motives to engage regularly in exercise.

Alchemical prediction of hydration free energies for SAMPL

PubMed Central

Mobley, David L.; Liu, Shaui; Cerutti, David S.; Swope, William C.; Rice, Julia E.

2013-01-01

Hydration free energy calculations have become important tests of force fields. Alchemical free energy calculations based on molecular dynamics simulations provide a rigorous way to calculate these free energies for a particular force field, given sufficient sampling. Here, we report results of alchemical hydration free energy calculations for the set of small molecules comprising the 2011 Statistical Assessment of Modeling of Proteins and Ligands (SAMPL) challenge. Our calculations are largely based on the Generalized Amber Force Field (GAFF) with several different charge models, and we achieved RMS errors in the 1.4-2.2 kcal/mol range depending on charge model, marginally higher than what we typically observed in previous studies1-5. The test set consists of ethane, biphenyl, and a dibenzyl dioxin, as well as a series of chlorinated derivatives of each. We found that, for this set, using high-quality partial charges from MP2/cc-PVTZ SCRF RESP fits provided marginally improved agreement with experiment over using AM1-BCC partial charges as we have more typically done, in keeping with our recent findings5. Switching to OPLS Lennard-Jones parameters with AM1-BCC charges also improves agreement with experiment. We also find a number of chemical trends within each molecular series which we can explain, but there are also some surprises, including some that are captured by the calculations and some that are not. PMID:22198475

Removable partial dentures vs overdentures in children with ectodermal dysplasia: two case reports.

PubMed

Maroulakos, G; Artopoulou, I I; Angelopoulou, M V; Emmanouil, D

2016-06-01

Ectodermal dysplasia (ED) represents a disorder group characterised by abnormal development of the ectodermal derivatives. Removable partial dentures (RPD), complete dentures (CD) or overdentures (OD) are most often the treatment of choice for young affected patients. Prosthetic intervention is of utmost importance in the management of ED patients, as it resolves problems associated with functional, aesthetic, and psychological issues, and improves a patient's quality of life. However, few studies present the principles and guidelines that can assist in the decision-making process of the most appropriate removable prosthesis. The purpose of this study was to suggest a simple treatment decision-making algorithm for selecting an effective and individualised rehabilitative treatment plan, considering different parameters. The cases and treatment of two young ED patients are described and each one was treated with either RPDs or ODs. Periodic recalls were employed to manage problems, and monitor the changes associated with occlusion and fit of the prostheses in relation to each patient's growth. Both patients were followed up for more than 2 years and reported significant improvement in their appearance, masticatory function, and social behaviour as a result of the prosthetic rehabilitation. The main factors guiding the decision process towards the choice of an RPD or an OD are the presence of posterior natural teeth, facial aesthetics, lip support, number and size of existing natural teeth, and the occlusal vertical dimension.

Sensitivity test of derivative matrix isopotential synchronous fluorimetry and least squares fitting methods.

PubMed

Makkai, Géza; Buzády, Andrea; Erostyák, János

2010-01-01

Determination of concentrations of spectrally overlapping compounds has special difficulties. Several methods are available to calculate the constituents' concentrations in moderately complex mixtures. A method which can provide information about spectrally hidden components in mixtures is very useful. Two methods powerful in resolving spectral components are compared in this paper. The first method tested is the Derivative Matrix Isopotential Synchronous Fluorimetry (DMISF). It is based on derivative analysis of MISF spectra, which are constructed using isopotential trajectories in the Excitation-Emission Matrix (EEM) of background solution. For DMISF method, a mathematical routine fitting the 3D data of EEMs was developed. The other method tested uses classical Least Squares Fitting (LSF) algorithm, wherein Rayleigh- and Raman-scattering bands may lead to complications. Both methods give excellent sensitivity and have advantages against each other. Detection limits of DMISF and LSF have been determined at very different concentration and noise levels.

A combined analysis of the hadronic and leptonic decays of the Z 0

NASA Astrophysics Data System (ADS)

Akrawy, M. Z.; Alexander, G.; Allison, J.; Allport, P. P.; Anderson, K. J.; Armitage, J. C.; Arnison, G. T. J.; Ashton, P.; Azuelos, G.; Baines, J. T. M.; Ball, A. H.; Banks, J.; Barker, G. J.; Barlow, R. J.; Batley, J. R.; Becker, J.; Behnke, T.; Bell, K. W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I. J.; Bock, P.; Breuker, H.; Brown, R. M.; Brun, R.; Buijs, A.; Burckhart, H. J.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Chrin, J. T. M.; Cohen, I.; Collins, W. J.; Conboy, J. E.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G. M.; Deninno, M. M.; Dieckmann, A.; Dittmar, M.; Dixit, M. S.; Duchovni, E.; Duerdoth, I. P.; Dumas, D.; El Mamouni, H.; Elcombe, P. A.; Estabrooks, P. G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fischer, H. M.; Fong, D. G.; French, M. T.; Fukunaga, C.; Gandois, B.; Ganel, O.; Gary, J. W.; Gascon, J.; Geddes, N. I.; Gee, C. N. P.; Geich-Gimbel, C.; Gensler, S. W.; Gentit, F. X.; Giacomelli, G.; Gibson, V.; Gibson, W. R.; Gillies, J. D.; Goldberg, J.; Goodrick, M. J.; Gorn, W.; Granite, D.; Gross, E.; Grosse-Wiesmann, P.; Grunhaus, J.; Hagedorn, H.; Hagemann, J.; Hansroul, M.; Hargrove, C. K.; Hart, J.; Hattersley, P. M.; Hauschild, M.; Hawkes, C. M.; Heflin, E.; Hemingway, R. J.; Heuer, R. D.; Hill, J. C.; Hillier, S. J.; Ho, C.; Hobbs, J. D.; Hobson, P. R.; Hochman, D.; Holl, B.; Homer, R. J.; Hou, S. R.; Howarth, C. P.; Hughes-Jones, R. E.; Igo-Kemenes, P.; Ihssen, H.; Imrie, D. C.; Jawahery, A.; Jeffreys, P. W.; Jeremie, H.; Jimack, M.; Jobes, M.; Jones, R. W. L.; Jovanovic, P.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Kellogg, R. G.; Kennedy, B. W.; Kleinwort, C.; Klem, D. E.; Knop, G.; Kobayashi, T.; Kokott, T. P.; Köpke, L.; Kowalewski, R.; Kreutzmann, H.; Von Krogh, J.; Kroll, J.; Kuwano, M.; Kyberd, P.; Lafferty, G. D.; Lamarche, F.; Larson, W. J.; Lasota, M. M. B.; Layter, J. G.; Le Du, P.; Leblanc, P.; Lee, A. M.; Lellouch, D.; Lennert, P.; Lessard, L.; Levinson, L.; Lloyd, S. L.; Loebinger, F. K.; Lorah, J. M.; Lorazo, B.; Losty, M. J.; Ludwig, J.; Lupu, N.; Ma, J.; Macbeth, A. A.; Mannelli, M.; Marcellini, S.; Maringer, G.; Martin, A. J.; Martin, J. P.; Mashimo, T.; Mättig, P.; Maur, U.; McMahon, T. J.; McPherson, A. C.; Meijers, F.; Menszner, D.; Merritt, F. S.; Mes, H.; Michelini, A.; Middleton, R. P.; Mikenberg, G.; Miller, D. J.; Milstene, C.; Minowa, M.; Mohr, W.; Montanari, A.; Mori, T.; Moss, M. W.; Muller, A.; Murphy, P. G.; Murray, W. J.; Nellen, B.; Nguyen, H. H.; Nozaki, M.; O'Dowd, A. J. P.; O'Neale, S. W.; O'Neill, B. P.; Oakham, F. G.; Odorici, F.; Ogg, M.; Oh, H.; Oreglia, M. J.; Orito, S.; Patrick, G. N.; Pawley, S. J.; Pfister, P.; Pilcher, J. E.; Pinfold, J. L.; Plane, D. E.; Poli, B.; Pouladdej, A.; Pritchard, T. W.; Quast, G.; Raab, J.; Redmond, M. W.; Rees, D. L.; Regimbald, M.; Riles, K.; Roach, C. M.; Robins, S. A.; Rollnik, A.; Roney, J. M.; Rossberg, S.; Rossi, A. M.; Routenburg, P.; Runge, K.; Runolfsson, O.; Sanghera, S.; Sansum, R. A.; Sasaki, M.; Saunders, B. J.; Schaile, A. D.; Schaile, O.; Schappert, W.; Scharff-Hansen, P.; Von der Schmitt, H.; Schreiber, S.; Schwarz, J.; Shapira, A.; Shen, B. C.; Sherwood, P.; Simon, A.; Siroli, G. P.; Skuja, A.; Smith, A. M.; Smith, T. J.; Snow, G. A.; Spreadbury, E. J.; Springer, R. W.; Sproston, M.; Stephens, K.; Stier, H. E.; Ströhmer, R.; Strom, D.; Takeda, H.; Takeshita, T.; Tsukamoto, T.; Turner, M. F.; Tysarczyk-Niemeyer, G.; Van den Plas, D.; Vandalen, G. J.; Virtue, C. J.; Wagner, A.; Wahl, C.; Ward, C. P.; Ward, D. R.; Waterhouse, J.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Weber, M.; Weisz, S.; Wermes, N.; Weymann, M.; Wilson, G. W.; Wilson, J. A.; Wingerter, I.; Winterer, V.-H.; Wood, N. C.; Wotton, S.; Wuensch, B.; Wyatt, T. R.; Yaari, R.; Yang, Y.; Yekutieli, G.; Yoshida, T.; Zeuner, W.; Zorn, G. T.; Zylberajch, S.; OPAL Collaboration

1990-04-01

We report on a measurement of the mass of the Z 0 boson, its total width, and its partial decay widths into hadrons and leptons. On the basis of 25 801 hadronic decays and 1999 decays into electrons, muons or taus, selected over eleven energy points between 88.28 GeV and 95.04 GeV, we obtain from a combined fit to hadrons and leptons a mass of Mz=91.154±0.021 (exp)±0.030 (LEP) GeV, and a total width of Γz=2.536±0.045 GeV. The errors on Mz have been separated into the experimental error and the uncertainty due to the LEP beam energy. The measured leptonic partial widths are Γee=81.2±2.6 MeV, Γμμ=82.6± 5.8 MeV, and Γττ=85.7±7.1 MeV, consistent with lepton universality. From a fit assuming lepton universality we obtain Γℓ + ℓ - = 81.9±2.0 MeV. The hadronic partial width is Γhad=1838±46 MeV. From the measured total and partial widths a model independent value for the invisible width is calculated to be Γinv=453±44 MeV. The errors quoted include both the statistical and the systematic uncertainties.

An evolutionary strategy based on partial imitation for solving optimization problems

NASA Astrophysics Data System (ADS)

Javarone, Marco Alberto

2016-12-01

In this work we introduce an evolutionary strategy to solve combinatorial optimization tasks, i.e. problems characterized by a discrete search space. In particular, we focus on the Traveling Salesman Problem (TSP), i.e. a famous problem whose search space grows exponentially, increasing the number of cities, up to becoming NP-hard. The solutions of the TSP can be codified by arrays of cities, and can be evaluated by fitness, computed according to a cost function (e.g. the length of a path). Our method is based on the evolution of an agent population by means of an imitative mechanism, we define 'partial imitation'. In particular, agents receive a random solution and then, interacting among themselves, may imitate the solutions of agents with a higher fitness. Since the imitation mechanism is only partial, agents copy only one entry (randomly chosen) of another array (i.e. solution). In doing so, the population converges towards a shared solution, behaving like a spin system undergoing a cooling process, i.e. driven towards an ordered phase. We highlight that the adopted 'partial imitation' mechanism allows the population to generate solutions over time, before reaching the final equilibrium. Results of numerical simulations show that our method is able to find, in a finite time, both optimal and suboptimal solutions, depending on the size of the considered search space.

Sources of genetic and phenotypic variance in fertilization rates and larval traits in a sea urchin.

PubMed

Evans, Jonathan P; García-González, Francisco; Marshall, Dustin J

2007-12-01

In nonresource based mating systems females are thought to derive indirect genetic benefits by mating with high-quality males. Such benefits can be due either to the intrinsic genetic quality of sires or to beneficial interactions between maternal and paternal haplotypes. Animals with external fertilization and no parental care offer unrivaled opportunities to address these hypotheses. With these systems, cross-classified breeding designs and in vitro fertilization can be used to disentangle sources of genetic and environmental variance in offspring fitness. Here, we employ these approaches in the Australian sea urchin Heliocidaris erythrogramma and explore how sire-dam identities influence fertilization rates, embryo viability (survival to hatching), and metamorphosis, as well as the interrelationships between these potential fitness traits. We show that fertilization is influenced by a combination of strong maternal effects and intrinsic male effects. Our subsequent analysis of embryo viability, however, revealed a highly significant interaction between parental genotypes, indicating that partial incompatibilities can severely limit offspring survival at this life-history stage. Importantly, we detected no significant relationship between fertilization rates and embryo viability. This finding suggests that fertilization rates should not be inferred from hatching rates, which is commonly practiced in species in which it is not possible to estimate fertilization at conception. Finally, we detected significant additive genetic variance due to sires in rates of juvenile metamorphosis, and a positive correlation between fertilization rates and metamorphosis. This latter finding indicates that the performance of a male's ejaculate in noncompetitive IVF trials predicts heritable offspring traits, although the fitness implications of variance in rates of spontaneous juvenile metamorphosis have yet to be determined.

Gaussian intrinsic entanglement for states with partial minimum uncertainty

NASA Astrophysics Data System (ADS)

Mišta, Ladislav; Baksová, Klára

2018-01-01

We develop a recently proposed theory of a quantifier of bipartite Gaussian entanglement called Gaussian intrinsic entanglement (GIE) [L. Mišta, Jr. and R. Tatham, Phys. Rev. Lett. 117, 240505 (2016), 10.1103/PhysRevLett.117.240505]. Gaussian intrinsic entanglement provides a compromise between computable and physically meaningful entanglement quantifiers and so far it has been calculated for two-mode Gaussian states including all symmetric partial minimum-uncertainty states, weakly mixed asymmetric squeezed thermal states with partial minimum uncertainty, and weakly mixed symmetric squeezed thermal states. We improve the method of derivation of GIE and show that all previously derived formulas for GIE of weakly mixed states in fact hold for states with higher mixedness. In addition, we derive analytical formulas for GIE for several other classes of two-mode Gaussian states with partial minimum uncertainty. Finally, we show that, like for all previously known states, also for all currently considered states the GIE is equal to Gaussian Rényi-2 entanglement of formation. This finding strengthens a conjecture about the equivalence of GIE and Gaussian Rényi-2 entanglement of formation for all bipartite Gaussian states.

Measured, modeled, and causal conceptions of fitness

PubMed Central

Abrams, Marshall

2012-01-01

This paper proposes partial answers to the following questions: in what senses can fitness differences plausibly be considered causes of evolution?What relationships are there between fitness concepts used in empirical research, modeling, and abstract theoretical proposals? How does the relevance of different fitness concepts depend on research questions and methodological constraints? The paper develops a novel taxonomy of fitness concepts, beginning with type fitness (a property of a genotype or phenotype), token fitness (a property of a particular individual), and purely mathematical fitness. Type fitness includes statistical type fitness, which can be measured from population data, and parametric type fitness, which is an underlying property estimated by statistical type fitnesses. Token fitness includes measurable token fitness, which can be measured on an individual, and tendential token fitness, which is assumed to be an underlying property of the individual in its environmental circumstances. Some of the paper's conclusions can be outlined as follows: claims that fitness differences do not cause evolution are reasonable when fitness is treated as statistical type fitness, measurable token fitness, or purely mathematical fitness. Some of the ways in which statistical methods are used in population genetics suggest that what natural selection involves are differences in parametric type fitnesses. Further, it's reasonable to think that differences in parametric type fitness can cause evolution. Tendential token fitnesses, however, are not themselves sufficient for natural selection. Though parametric type fitnesses are typically not directly measurable, they can be modeled with purely mathematical fitnesses and estimated by statistical type fitnesses, which in turn are defined in terms of measurable token fitnesses. The paper clarifies the ways in which fitnesses depend on pragmatic choices made by researchers. PMID:23112804

The positive cognitive impact of aerobic fitness is associated with peripheral inflammatory and brain-derived neurotrophic biomarkers in young adults.

PubMed

Hwang, Jungyun; Castelli, Darla M; Gonzalez-Lima, F

2017-10-01

There is ample evidence for supporting the positive impact of aerobic fitness on cognitive function, but little is known about the physiological mechanisms. The objective of this study was to investigate whether the positive cognitive impact of aerobic fitness is associated with inflammatory and neurotrophic peripheral biomarkers in young adults aged 18 to 29years (n=87). For the objective assessment of aerobic fitness, we measured maximal oxygen uptake (VO 2 max) as a parametric measure of cardiorespiratory capacity. We demonstrated that young adults with the higher levels of VO 2 max performed better on computerized cognitive tasks assessing sustained attention and working memory. This positive VO 2 max-cognitive performance association existed independently of confounders (e.g., years of education, intelligence scores) but was significantly dependent on resting peripheral blood levels of inflammatory (C-reactive protein, CRP) and neurotrophic (brain-derived neurotrophic factor, BDNF) biomarkers. Statistical models showed that CRP was a mediator of the effect of VO 2 max on working memory. Further, BDNF was a moderator of the effect of VO 2 max on working memory. These mediating and moderating effects occurred in individuals with higher levels of aerobic fitness. The results suggest that higher aerobic fitness, as measured by VO 2 max, is associated with enhanced cognitive functioning and favorable resting peripheral levels of inflammatory and brain-derived neurotrophic biomarkers in young adults. Copyright © 2017 Elsevier Inc. All rights reserved.

QTL affecting fitness of hybrids between wild and cultivated soybeans in experimental fields

PubMed Central

Kuroda, Yosuke; Kaga, Akito; Tomooka, Norihiko; Yano, Hiroshi; Takada, Yoshitake; Kato, Shin; Vaughan, Duncan

2013-01-01

The objective of this study was to identify quantitative trait loci (QTL) affecting fitness of hybrids between wild soybean (Glycine soja) and cultivated soybean (Glycine max). Seed dormancy and seed number, both of which are important for fitness, were evaluated by testing artificial hybrids of G. soja × G. max in a multiple-site field trial. Generally, the fitness of the F1 hybrids and hybrid derivatives from self-pollination was lower than that of G. soja due to loss of seed dormancy, whereas the fitness of hybrid derivatives with higher proportions of G. soja genetic background was comparable with that of G. soja. These differences were genetically dissected into QTL for each population. Three QTLs for seed dormancy and one QTL for total seed number were detected in the F2 progenies of two diverse cross combinations. At those four QTLs, the G. max alleles reduced seed number and severely reduced seed survival during the winter, suggesting that major genes acquired during soybean adaptation to cultivation have a selective disadvantage in natural habitats. In progenies with a higher proportion of G. soja genetic background, the genetic effects of the G. max alleles were not expressed as phenotypes because the G. soja alleles were dominant over the G. max alleles. Considering the highly inbreeding nature of these species, most hybrid derivatives would disappear quickly in early self-pollinating generations in natural habitats because of the low fitness of plants carrying G. max alleles. PMID:23919159

ACCELERATED FITTING OF STELLAR SPECTRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ting, Yuan-Sen; Conroy, Charlie; Rix, Hans-Walter

2016-07-20

Stellar spectra are often modeled and fitted by interpolating within a rectilinear grid of synthetic spectra to derive the stars’ labels: stellar parameters and elemental abundances. However, the number of synthetic spectra needed for a rectilinear grid grows exponentially with the label space dimensions, precluding the simultaneous and self-consistent fitting of more than a few elemental abundances. Shortcuts such as fitting subsets of labels separately can introduce unknown systematics and do not produce correct error covariances in the derived labels. In this paper we present a new approach—Convex Hull Adaptive Tessellation (chat)—which includes several new ideas for inexpensively generating amore » sufficient stellar synthetic library, using linear algebra and the concept of an adaptive, data-driven grid. A convex hull approximates the region where the data lie in the label space. A variety of tests with mock data sets demonstrate that chat can reduce the number of required synthetic model calculations by three orders of magnitude in an eight-dimensional label space. The reduction will be even larger for higher dimensional label spaces. In chat the computational effort increases only linearly with the number of labels that are fit simultaneously. Around each of these grid points in the label space an approximate synthetic spectrum can be generated through linear expansion using a set of “gradient spectra” that represent flux derivatives at every wavelength point with respect to all labels. These techniques provide new opportunities to fit the full stellar spectra from large surveys with 15–30 labels simultaneously.« less

Bayesian parameter estimation for chiral effective field theory

NASA Astrophysics Data System (ADS)

Wesolowski, Sarah; Furnstahl, Richard; Phillips, Daniel; Klco, Natalie

2016-09-01

The low-energy constants (LECs) of a chiral effective field theory (EFT) interaction in the two-body sector are fit to observable data using a Bayesian parameter estimation framework. By using Bayesian prior probability distributions (pdfs), we quantify relevant physical expectations such as LEC naturalness and include them in the parameter estimation procedure. The final result is a posterior pdf for the LECs, which can be used to propagate uncertainty resulting from the fit to data to the final observable predictions. The posterior pdf also allows an empirical test of operator redundancy and other features of the potential. We compare results of our framework with other fitting procedures, interpreting the underlying assumptions in Bayesian probabilistic language. We also compare results from fitting all partial waves of the interaction simultaneously to cross section data compared to fitting to extracted phase shifts, appropriately accounting for correlations in the data. Supported in part by the NSF and DOE.

Work, family and life-course fit

PubMed Central

Moen, Phyllis; Kelly, Erin; Huang, Qinlei

2008-01-01

This study moves from “work-family” to a multi-dimensional “life-course fit” construct (employees’ cognitive assessments of resources, resource deficits, and resource demands), using a combined work-family, demands-control and ecology of the life course framing. It examined (1) impacts of job and home ecological systems on fit dimensions, and (2) whether control over work time predicted and mediated life-course fit outcomes. Using cluster analysis of survey data on a sample of 917 white-collar employees from Best Buy headquarters, we identified four job ecologies (corresponding to the job demands-job control model) and five home ecologies (theorizing an analogous home demands-home control model). Job and home ecologies predicted fit dimensions in an additive, not interactive, fashion. Employees’ work-time control predicted every life-course fit dimension and partially mediated effects of job ecologies, organizational tenure, and job category. PMID:19430546

CrossFit-related cervical internal carotid artery dissection.

PubMed

Lu, Albert; Shen, Peter; Lee, Paul; Dahlin, Brian; Waldau, Ben; Nidecker, Anna E; Nundkumar, Anoop; Bobinski, Matthew

2015-08-01

CrossFit is a high-intensity strength and conditioning program that has gained popularity over the past decade. Potential injuries associated with CrossFit training have been suggested in past reports. We report three cases of cervical carotid dissection that are associated with CrossFit workouts. Patient 1 suffered a distal cervical internal carotid artery (ICA) dissection near the skull base and a small infarct in Wernicke's area. He was placed on anticoagulation and on follow-up has near complete recovery. Patient 2 suffered a proximal cervical ICA dissection that led to arterial occlusion and recurrent middle cerebral artery territory infarcts and significant neurological sequelae. Patient 3 had a skull base ICA dissection that led to a partial Horner's syndrome but no cerebral infarct. While direct causality cannot be proven, intense CrossFit workouts may have led to the ICA dissections in these patients.

TaylUR 3, a multivariate arbitrary-order automatic differentiation package for Fortran 95

NASA Astrophysics Data System (ADS)

von Hippel, G. M.

2010-03-01

This new version of TaylUR is based on a completely new core, which now is able to compute the numerical values of all of a complex-valued function's partial derivatives up to an arbitrary order, including mixed partial derivatives. New version program summaryProgram title: TaylUR Catalogue identifier: ADXR_v3_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADXR_v3_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPLv2 No. of lines in distributed program, including test data, etc.: 6750 No. of bytes in distributed program, including test data, etc.: 19 162 Distribution format: tar.gz Programming language: Fortran 95 Computer: Any computer with a conforming Fortran 95 compiler Operating system: Any system with a conforming Fortran 95 compiler Classification: 4.12, 4.14 Catalogue identifier of previous version: ADXR_v2_0 Journal reference of previous version: Comput. Phys. Comm. 176 (2007) 710 Does the new version supersede the previous version?: Yes Nature of problem: Problems that require potentially high orders of partial derivatives with respect to several variables or derivatives of complex-valued functions, such as e.g. momentum or mass expansions of Feynman diagrams in perturbative QFT, and which previous versions of this TaylUR [1,2] cannot handle due to their lack of support for mixed partial derivatives. Solution method: Arithmetic operators and Fortran intrinsics are overloaded to act correctly on objects of a defined type taylor, which encodes a function along with its first few partial derivatives with respect to the user-defined independent variables. Derivatives of products and composite functions are computed using multivariate forms [3] of Leibniz's rule D(fg)=∑{ν!}/{μ!(μ-ν)!}DfDg where ν=(ν,…,ν), |ν|=∑j=1dν, ν!=∏j=1dν!, Df=∂f/(∂x⋯∂x), and μ<ν iff either |μ|<|ν| or |μ|=|ν|,μ=ν,…,μ=ν,μ<ν for some k∈{0,…,d-1}, and of Fàa di Bruno's formula D(f○g)=∑p=1|ν|(f○g)∑s=1|ν|∑,…,k;λ,…,λ)}ν!/(∏j=1sk!λ!)(g)k where the sum is over {(k,…,k;λ,…,λ)∈Z:k>0,0<λ<⋯<λ, ∑i=1sk=p,∑i=1skλ=ν}. An indexed storage system is used to store the higher-order derivative tensors in a one-dimensional array. The relevant indices (k,…,k;λ,…,λ) and the weights occurring in the sums in Leibniz's and Fàa di Bruno's formula are precomputed at startup and stored in static arrays for later use. Reasons for new version: The earlier version lacked support for mixed partial derivatives, but a number of projects of interest required them. Summary of revisions: The internal representation of a taylor object has changed to a one-dimensional array which contains the partial derivatives in ascending order, and in lexicographic order of the corresponding multiindex within the same order. The necessary mappings between multiindices and indices into the taylor objects' internal array are computed at startup. To support the change to a genuinely multivariate taylor type, the DERIVATIVE function is now implemented via an interface that accepts both the older format derivative(f,mu,n)=∂μnf and also a new format derivative(f,mu(:))=Df that allows access to mixed partial derivatives. Another related extension to the functionality of the module is the HESSIAN function that returns the Hessian matrix of second derivatives of its argument. Since the calculation of all mixed partial derivatives can be very costly, and in many cases only some subset is actually needed, a masking facility has been added. Calling the subroutine DEACTIVATE_DERIVATIVE with a multiindex as an argument will deactivate the calculation of the partial derivative belonging to that multiindex, and of all partial derivatives it can feed into. Similarly, calling the subroutine ACTIVATE_DERIVATIVE will activate the calculation of the partial derivative belonging to its argument, and of all partial derivatives that can feed into it. Moreover, it is possible to turn off the computation of mixed derivatives altogether by setting Diagonal_taylors to .TRUE.. It should be noted that any change of Diagonal_taylors or Taylor_order invalidates all existing taylor objects. To aid the better integration of TaylUR into the HPSrc library [4], routines SET_DERIVATIVE and SET_ALL_DERIVATIVES are provided as a means of manually constructing a taylor object with given derivatives. Restrictions: Memory and CPU time constraints may restrict the number of variables and Taylor expansion order that can be achieved. Loss of numerical accuracy due to cancellation may become an issue at very high orders. Unusual features: These are the same as in previous versions, but are enumerated again here for clarity. The complex conjugation operation assumes all independent variables to be real. The functions REAL and AIMAG do not convert to real type, but return a result of type taylor (with the real/imaginary part of each derivative taken) instead. The user-defined functions VALUE, REALVALUE and IMAGVALUE, which return the value of a taylor object as a complex number, and the real and imaginary part of this value, respectively, as a real number are also provided. Fortran 95 intrinsics that are defined only for arguments of real type ( ACOS, AINT, ANINT, ASIN, ATAN, ATAN2, CEILING, DIM, FLOOR, INT, LOG10, MAX, MAXLOC, MAXVAL, MIN, MINLOC, MINVAL, MOD, MODULO, NINT, SIGN) will silently take the real part of taylor-valued arguments unless the module variable Real_args_warn is set to .TRUE., in which case they will return a quiet NaN value (if supported by the compiler) when called with a taylor argument whose imaginary part exceeds the module variable Real_args_tol. In those cases where the derivative of a function becomes undefined at certain points (as for ABS, AINT, ANINT, MAX, MIN, MOD, and MODULO), while the value is well defined, the derivative fields will be filled with quiet NaN values (if supported by the compiler). Additional comments: This version of TaylUR is released under the second version of the GNU General Public License (GPLv2). Therefore anyone is free to use or modify the code for their own calculations. As part of the licensing, it is requested that any publications including results from the use of TaylUR or any modification derived from it cite Refs. [1,2] as well as this paper. Finally, users are also requested to communicate to the author details of such publications, as well as of any bugs found or of required or useful modifications made or desired by them. Running time: The running time of TaylUR operations grows rapidly with both the number of variables and the Taylor expansion order. Judicious use of the masking facility to drop unneeded higher derivatives can lead to significant accelerations, as can activation of the Diagonal_taylors variable whenever mixed partial derivatives are not needed. Acknowledgments: The author thanks Alistair Hart for helpful comments and suggestions. This work is supported by the Deutsche Forschungsgemeinschaft in the SFB/TR 09. References:G.M. von Hippel, TaylUR, an arbitrary-order diagonal automatic differentiation package for Fortran 95, Comput. Phys. Comm. 174 (2006) 569. G.M. von Hippel, New version announcement for TaylUR, an arbitrary-order diagonal automatic differentiation package for Fortran 95, Comput. Phys. Comm. 176 (2007) 710. G.M. Constantine, T.H. Savits, A multivariate Faa di Bruno formula with applications, Trans. Amer. Math. Soc. 348 (2) (1996) 503. A. Hart, G.M. von Hippel, R.R. Horgan, E.H. Müller, Automated generation of lattice QCD Feynman rules, Comput. Phys. Comm. 180 (2009) 2698, doi:10.1016/j.cpc.2009.04.021, arXiv:0904.0375.

WAVELET-DOMAIN REGRESSION AND PREDICTIVE INFERENCE IN PSYCHIATRIC NEUROIMAGING

PubMed Central

Reiss, Philip T.; Huo, Lan; Zhao, Yihong; Kelly, Clare; Ogden, R. Todd

2016-01-01

An increasingly important goal of psychiatry is the use of brain imaging data to develop predictive models. Here we present two contributions to statistical methodology for this purpose. First, we propose and compare a set of wavelet-domain procedures for fitting generalized linear models with scalar responses and image predictors: sparse variants of principal component regression and of partial least squares, and the elastic net. Second, we consider assessing the contribution of image predictors over and above available scalar predictors, in particular via permutation tests and an extension of the idea of confounding to the case of functional or image predictors. Using the proposed methods, we assess whether maps of a spontaneous brain activity measure, derived from functional magnetic resonance imaging, can meaningfully predict presence or absence of attention deficit/hyperactivity disorder (ADHD). Our results shed light on the role of confounding in the surprising outcome of the recent ADHD-200 Global Competition, which challenged researchers to develop algorithms for automated image-based diagnosis of the disorder. PMID:27330652

Removal of the 2-mercaptobenotiazole from model wastewater by ozonation.

PubMed

Derco, Jan; Kassai, Angelika; Melicher, Michal; Dudas, Jozef

2014-01-01

The feasibility of ozonation process for 2-mercaptobenzothiazole (2-MBT) removal follows from results of ozonation of the model wastewater. Total removal of 2-MBT was observed after 20 minutes of ozonation. Very good reproducibility of repeated ozonation trials including sampling and analysis was observed. However, the majority of dissolved organic carbon (DOC) and chemical oxygen demand (COD) remained in the reaction mixture. Benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) intermediates were identified during degradation of 2-MBT with ozone. In addition to the above benzothiazole derivatives, the creation of some other organic compounds follows from results of mass balance. The best fits of experimental data were obtained using the first kinetic model for 2-MBT and zero-order kinetic model for COD and DOC. The reaction time of 60 minutes can be considered as effective with regard to controlled oxidation in order to increase a portion of partially oxidized substances. Higher biodegradability and lower toxicity of ozonation products on respiration activity of activated sludge microorganisms was observed at higher ozonation time.

Removal of the 2-Mercaptobenotiazole from Model Wastewater by Ozonation

PubMed Central

Kassai, Angelika

2014-01-01

The feasibility of ozonation process for 2-mercaptobenzothiazole (2-MBT) removal follows from results of ozonation of the model wastewater. Total removal of 2-MBT was observed after 20 minutes of ozonation. Very good reproducibility of repeated ozonation trials including sampling and analysis was observed. However, the majority of dissolved organic carbon (DOC) and chemical oxygen demand (COD) remained in the reaction mixture. Benzothiazole (BT) and 2-hydroxybenzothiazole (OBT) intermediates were identified during degradation of 2-MBT with ozone. In addition to the above benzothiazole derivatives, the creation of some other organic compounds follows from results of mass balance. The best fits of experimental data were obtained using the first kinetic model for 2-MBT and zero-order kinetic model for COD and DOC. The reaction time of 60 minutes can be considered as effective with regard to controlled oxidation in order to increase a portion of partially oxidized substances. Higher biodegradability and lower toxicity of ozonation products on respiration activity of activated sludge microorganisms was observed at higher ozonation time. PMID:24578619

Three-dimensional boundary layer calculation by a characteristic method

NASA Technical Reports Server (NTRS)

Houdeville, R.

1992-01-01

A numerical method for solving the three-dimensional boundary layer equations for bodies of arbitrary shape is presented. In laminar flows, the application domain extends from incompressible to hypersonic flows with the assumption of chemical equilibrium. For turbulent boundary layers, the application domain is limited by the validity of the mixing length model used. In order to respect the hyperbolic nature of the equations reduced to first order partial derivative terms, the momentum equations are discretized along the local streamlines using of the osculator tangent plane at each node of the body fitted coordinate system. With this original approach, it is possible to overcome the use of the generalized coordinates, and therefore, it is not necessary to impose an extra hypothesis about the regularity of the mesh in which the boundary conditions are given. By doing so, it is possible to limit, and sometimes to suppress, the pre-treatment of the data coming from an inviscid calculation. Although the proposed scheme is only semi-implicit, the method remains numerically very efficient.

Multiscale Modeling of Angiogenesis and Predictive Capacity

NASA Astrophysics Data System (ADS)

Pillay, Samara; Byrne, Helen; Maini, Philip

Tumors induce the growth of new blood vessels from existing vasculature through angiogenesis. Using an agent-based approach, we model the behavior of individual endothelial cells during angiogenesis. We incorporate crowding effects through volume exclusion, motility of cells through biased random walks, and include birth and death-like processes. We use the transition probabilities associated with the discrete model and a discrete conservation equation for cell occupancy to determine collective cell behavior, in terms of partial differential equations (PDEs). We derive three PDE models incorporating single, multi-species and no volume exclusion. By fitting the parameters in our PDE models and other well-established continuum models to agent-based simulations during a specific time period, and then comparing the outputs from the PDE models and agent-based model at later times, we aim to determine how well the PDE models predict the future behavior of the agent-based model. We also determine whether predictions differ across PDE models and the significance of those differences. This may impact drug development strategies based on PDE models.

Bayesian inference of radiation belt loss timescales.

NASA Astrophysics Data System (ADS)

Camporeale, E.; Chandorkar, M.

2017-12-01

Electron fluxes in the Earth's radiation belts are routinely studied using the classical quasi-linear radial diffusion model. Although this simplified linear equation has proven to be an indispensable tool in understanding the dynamics of the radiation belt, it requires specification of quantities such as the diffusion coefficient and electron loss timescales that are never directly measured. Researchers have so far assumed a-priori parameterisations for radiation belt quantities and derived the best fit using satellite data. The state of the art in this domain lacks a coherent formulation of this problem in a probabilistic framework. We present some recent progress that we have made in performing Bayesian inference of radial diffusion parameters. We achieve this by making extensive use of the theory connecting Gaussian Processes and linear partial differential equations, and performing Markov Chain Monte Carlo sampling of radial diffusion parameters. These results are important for understanding the role and the propagation of uncertainties in radiation belt simulations and, eventually, for providing a probabilistic forecast of energetic electron fluxes in a Space Weather context.

Kinematic sensitivity of robot manipulators

NASA Technical Reports Server (NTRS)

Vuskovic, Marko I.

1989-01-01

Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors.

OPEN CLUSTERS AS PROBES OF THE GALACTIC MAGNETIC FIELD. I. CLUSTER PROPERTIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoq, Sadia; Clemens, D. P., E-mail: shoq@bu.edu, E-mail: clemens@bu.edu

2015-10-15

Stars in open clusters are powerful probes of the intervening Galactic magnetic field via background starlight polarimetry because they provide constraints on the magnetic field distances. We use 2MASS photometric data for a sample of 31 clusters in the outer Galaxy for which near-IR polarimetric data were obtained to determine the cluster distances, ages, and reddenings via fitting theoretical isochrones to cluster color–magnitude diagrams. The fitting approach uses an objective χ{sup 2} minimization technique to derive the cluster properties and their uncertainties. We found the ages, distances, and reddenings for 24 of the clusters, and the distances and reddenings formore » 6 additional clusters that were either sparse or faint in the near-IR. The derived ranges of log(age), distance, and E(B−V) were 7.25–9.63, ∼670–6160 pc, and 0.02–1.46 mag, respectively. The distance uncertainties ranged from ∼8% to 20%. The derived parameters were compared to previous studies, and most cluster parameters agree within our uncertainties. To test the accuracy of the fitting technique, synthetic clusters with 50, 100, or 200 cluster members and a wide range of ages were fit. These tests recovered the input parameters within their uncertainties for more than 90% of the individual synthetic cluster parameters. These results indicate that the fitting technique likely provides reliable estimates of cluster properties. The distances derived will be used in an upcoming study of the Galactic magnetic field in the outer Galaxy.« less

Maximal exercise testing variables and 10-year survival: fitness risk score derivation from the FIT Project.

PubMed

Ahmed, Haitham M; Al-Mallah, Mouaz H; McEvoy, John W; Nasir, Khurram; Blumenthal, Roger S; Jones, Steven R; Brawner, Clinton A; Keteyian, Steven J; Blaha, Michael J

2015-03-01

To determine which routinely collected exercise test variables most strongly correlate with survival and to derive a fitness risk score that can be used to predict 10-year survival. This was a retrospective cohort study of 58,020 adults aged 18 to 96 years who were free of established heart disease and were referred for an exercise stress test from January 1, 1991, through May 31, 2009. Demographic, clinical, exercise, and mortality data were collected on all patients as part of the Henry Ford ExercIse Testing (FIT) Project. Cox proportional hazards models were used to identify exercise test variables most predictive of survival. A "FIT Treadmill Score" was then derived from the β coefficients of the model with the highest survival discrimination. The median age of the 58,020 participants was 53 years (interquartile range, 45-62 years), and 28,201 (49%) were female. Over a median of 10 years (interquartile range, 8-14 years), 6456 patients (11%) died. After age and sex, peak metabolic equivalents of task and percentage of maximum predicted heart rate achieved were most highly predictive of survival (P<.001). Subsequent addition of baseline blood pressure and heart rate, change in vital signs, double product, and risk factor data did not further improve survival discrimination. The FIT Treadmill Score, calculated as [percentage of maximum predicted heart rate + 12(metabolic equivalents of task) - 4(age) + 43 if female], ranged from -200 to 200 across the cohort, was near normally distributed, and was found to be highly predictive of 10-year survival (Harrell C statistic, 0.811). The FIT Treadmill Score is easily attainable from any standard exercise test and translates basic treadmill performance measures into a fitness-related mortality risk score. The FIT Treadmill Score should be validated in external populations. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Constructing general partial differential equations using polynomial and neural networks.

PubMed

Zjavka, Ladislav; Pedrycz, Witold

2016-01-01

Sum fraction terms can approximate multi-variable functions on the basis of discrete observations, replacing a partial differential equation definition with polynomial elementary data relation descriptions. Artificial neural networks commonly transform the weighted sum of inputs to describe overall similarity relationships of trained and new testing input patterns. Differential polynomial neural networks form a new class of neural networks, which construct and solve an unknown general partial differential equation of a function of interest with selected substitution relative terms using non-linear multi-variable composite polynomials. The layers of the network generate simple and composite relative substitution terms whose convergent series combinations can describe partial dependent derivative changes of the input variables. This regression is based on trained generalized partial derivative data relations, decomposed into a multi-layer polynomial network structure. The sigmoidal function, commonly used as a nonlinear activation of artificial neurons, may transform some polynomial items together with the parameters with the aim to improve the polynomial derivative term series ability to approximate complicated periodic functions, as simple low order polynomials are not able to fully make up for the complete cycles. The similarity analysis facilitates substitutions for differential equations or can form dimensional units from data samples to describe real-world problems. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Quest for the Largest Depleted Galaxy Core: Supermassive Black Hole Binaries and Stalled Infalling Satellites

NASA Astrophysics Data System (ADS)

Bonfini, Paolo; Graham, Alister W.

2016-10-01

Partially depleted cores are practically ubiquitous in luminous early-type galaxies (M B ≲ -20.5 mag) and are typically smaller than 1 kpc. In one popular scenario, supermassive black hole (SMBH) binaries—established during dry (I.e., gas-poor) galaxy mergers—kick out the stars from a galaxy’s central region via three-body interactions. Here, this “binary black hole scouring scenario” is probed at its extremes by investigating the two galaxies reported to have the largest partially depleted cores found to date: 2MASX J09194427+5622012 and 2MASX J17222717+3207571 (the brightest galaxy in Abell 2261). We have fit these galaxy’s two-dimensional light distribution using the core-Sérsic model and found that the former galaxy has a core-Sérsic break radius {R}b,{cS}=0.55 {{kpc}}, which is three times smaller than the published value. We use this galaxy to caution that other reportedly large break radii may too have been overestimated if they were derived using the “sharp-transition” (inner core)-to-(outer Sérsic) model. In the case of 2MASX J17222717+3207571, we obtain R b,cS = 3.6 kpc. While we confirm that this is the biggest known partially depleted core of any galaxy, we stress that it is larger than expected from the evolution of SMBH binaries—unless one invokes substantial gravitational-wave-induced (black hole-)recoil events. Given the presence of multiple nuclei located (in projection) within the core radius of this galaxy, we explored and found support for the alternative “stalled infalling perturber” core-formation scenario, in which this galaxy’s core could have been excavated by the action of an infalling massive perturber.

Investigation on the Reference Evapotranspiration Distribution at Regional Scale By Alternative Methods to Compute the FAO Penman-Monteith Equation

NASA Astrophysics Data System (ADS)

Snyder, R. L.; Mancosu, N.; Spano, D.

2014-12-01

This study derived the summer (June-August) reference evapotranspiration distribution map for Sardinia (Italy) based on weather station data and use of the geographic information system (GIS). A modified daily Penman-Monteith equation from the Food and Agriculture Organization of the United Nations (UN-FAO) and the American Society of Civil Engineers Environmental and Water Resources Institute (ASCE-EWRI) was used to calculate the Standardized Reference Evapotranspiration (ETos) for all weather stations having a "full" set of required data for the calculations. For stations having only temperature data (partial stations), the Hargreaves-Samani equation was used to estimate the reference evapotranspiration for a grass surface (ETo). The ETos and ETo results were different depending on the local climate, so two methods to estimate ETos from the ETo were tested. Substitution of missing solar radiation, wind speed, and humidity data from a nearby station within a similar microclimate was found to give better results than using a calibration factor that related ETos and ETo. Therefore, the substitution method was used to estimate ETos at "partial" stations having only temperature data. The combination of 63 full and partial stations was sufficient to use GIS to map ETos for Sardinia. Three interpolation methods were studied, and the ordinary kriging model fitted the observed data better than a radial basis function or the inverse distance weighting method. Using station data points to create a regional map simplified the zonation of ETos when large scale computations were needed. Making a distinction based on ETos classes allows the simulation of crop water requirements for large areas and it can potentially lead to improved irrigation management and water savings. It also provides a baseline to investigate possible impact of climate change.

Applications of hybrid genetic algorithms in seismic tomography

NASA Astrophysics Data System (ADS)

Soupios, Pantelis; Akca, Irfan; Mpogiatzis, Petros; Basokur, Ahmet T.; Papazachos, Constantinos

2011-11-01

Almost all earth sciences inverse problems are nonlinear and involve a large number of unknown parameters, making the application of analytical inversion methods quite restrictive. In practice, most analytical methods are local in nature and rely on a linearized form of the problem equations, adopting an iterative procedure which typically employs partial derivatives in order to optimize the starting (initial) model by minimizing a misfit (penalty) function. Unfortunately, especially for highly non-linear cases, the final model strongly depends on the initial model, hence it is prone to solution-entrapment in local minima of the misfit function, while the derivative calculation is often computationally inefficient and creates instabilities when numerical approximations are used. An alternative is to employ global techniques which do not rely on partial derivatives, are independent of the misfit form and are computationally robust. Such methods employ pseudo-randomly generated models (sampling an appropriately selected section of the model space) which are assessed in terms of their data-fit. A typical example is the class of methods known as genetic algorithms (GA), which achieves the aforementioned approximation through model representation and manipulations, and has attracted the attention of the earth sciences community during the last decade, with several applications already presented for several geophysical problems. In this paper, we examine the efficiency of the combination of the typical regularized least-squares and genetic methods for a typical seismic tomography problem. The proposed approach combines a local (LOM) and a global (GOM) optimization method, in an attempt to overcome the limitations of each individual approach, such as local minima and slow convergence, respectively. The potential of both optimization methods is tested and compared, both independently and jointly, using the several test models and synthetic refraction travel-time date sets that employ the same experimental geometry, wavelength and geometrical characteristics of the model anomalies. Moreover, real data from a crosswell tomographic project for the subsurface mapping of an ancient wall foundation are used for testing the efficiency of the proposed algorithm. The results show that the combined use of both methods can exploit the benefits of each approach, leading to improved final models and producing realistic velocity models, without significantly increasing the required computation time.

Migration confers winter survival benefits in a partially migratory songbird

PubMed Central

Zúñiga, Daniel; Gager, Yann; Kokko, Hanna; Fudickar, Adam Michael; Schmidt, Andreas; Naef-Daenzer, Beat; Wikelski, Martin

2017-01-01

To evolve and to be maintained, seasonal migration, despite its risks, has to yield fitness benefits compared with year-round residency. Empirical data supporting this prediction have remained elusive in the bird literature. To test fitness related benefits of migration, we studied a partial migratory population of European blackbirds (Turdus merula) over 7 years. Using a combination of capture-mark-recapture and radio telemetry, we compared survival probabilities between migrants and residents estimated by multi-event survival models, showing that migrant blackbirds had 16% higher probability to survive the winter compared to residents. A subsequent modelling exercise revealed that residents should have 61.25% higher breeding success than migrants, to outweigh the survival costs of residency. Our results support theoretical models that migration should confer survival benefits to evolve, and thus provide empirical evidence to understand the evolution and maintenance of migration. PMID:29157357

A modified moment-fitted integration scheme for X-FEM applications with history-dependent material data

NASA Astrophysics Data System (ADS)

Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.

2018-01-01

We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.

Removable partial denture on osseointegrated implants and natural teeth.

PubMed

Chang, Li-Ching; Wang, Jen-Chyan; Tasi, Chi-Cheng

2007-01-01

Implants have been designed to provide edentulous patients with fixed prostheses or overdentures. Recently, implant-supported fixed partial prostheses and single crowns have become successful treatment alternatives to removable and fixed partial dentures. However, few researchers have examined "removable partial dentures on implants and natural teeth". In this article, we report two patients fitted with "removable partial dentures on implants and natural teeth". The patients were satisfied with their dentures in terms of function and aesthetics. Regular follow-up visits revealed that the periodontal and peri-implant conditions were stable. There was no evidence of excessive intrusion or mobility of the teeth, nor were any visible changes in the bone levels of the natural teeth or implants noted on radiographs. Since the average duration of observation was about 38 months, further follow-up examinations are necessary to determine whether these dentures remain stable long-term.

Genomic regions with a history of divergent selection affect fitness of hybrids between two butterfly species.

PubMed

Gompert, Zachariah; Lucas, Lauren K; Nice, Chris C; Fordyce, James A; Forister, Matthew L; Buerkle, C Alex

2012-07-01

Speciation is the process by which reproductively isolated lineages arise, and is one of the fundamental means by which the diversity of life increases. Whereas numerous studies have documented an association between ecological divergence and reproductive isolation, relatively little is known about the role of natural selection in genome divergence during the process of speciation. Here, we use genome-wide DNA sequences and Bayesian models to test the hypothesis that loci under divergent selection between two butterfly species (Lycaeides idas and L. melissa) also affect fitness in an admixed population. Locus-specific measures of genetic differentiation between L. idas and L. melissa and genomic introgression in hybrids varied across the genome. The most differentiated genetic regions were characterized by elevated L. idas ancestry in the admixed population, which occurs in L. idas-like habitat, consistent with the hypothesis that local adaptation contributes to speciation. Moreover, locus-specific measures of genetic differentiation (a metric of divergent selection) were positively associated with extreme genomic introgression (a metric of hybrid fitness). Interestingly, concordance of differentiation and introgression was only partial. We discuss multiple, complementary explanations for this partial concordance. © 2012 The Author(s).

Improving Measures via Examining the Behavior of Distractors in Multiple-Choice Tests

PubMed Central

Sideridis, Georgios; Tsaousis, Ioannis; Al Harbi, Khaleel

2017-01-01

The purpose of the present article was to illustrate, using an example from a national assessment, the value from analyzing the behavior of distractors in measures that engage the multiple-choice format. A secondary purpose of the present article was to illustrate four remedial actions that can potentially improve the measurement of the construct(s) under study. Participants were 2,248 individuals who took a national examination of chemistry. The behavior of the distractors was analyzed by modeling their behavior within the Rasch model. Potentially informative distractors were (a) further modeled using the partial credit model, (b) split onto separate items and retested for model fit and parsimony, (c) combined to form a “super” item or testlet, and (d) reexamined after deleting low-ability individuals who likely guessed on those informative, albeit erroneous, distractors. Results indicated that all but the item split strategies were associated with better model fit compared with the original model. The best fitted model, however, involved modeling and crediting informative distractors via the partial credit model or eliminating the responses of low-ability individuals who likely guessed on informative distractors. The implications, advantages, and disadvantages of modeling informative distractors for measurement purposes are discussed. PMID:29795904

Activated partial thromboplastin time derivative curves: helpful diagnostic tool in mixing test interpretation.

PubMed

Esmedere Eren, Sevim; Karakukcu, Cigdem; Ciraci, Mehmet Z; Ustundag, Yasemin; Karakukcu, Musa

2018-06-01

: The mixing test is used to evaluate whether prolonged activated partial thromboplastin time (APTT) is due to an inhibitor or a factor deficiency. The coagulation reaction is demonstrated with APTT derivative curves on the ACL TOP series. We aimed to determine the utility of APTT derivative curves in the mixing test process. The plasma of a patient was mixed with normal plasma in a 1 : 1 ratio and APTT assay was performed with SynthASil reagent. We observed roughness, biphasic and shoulder patterns in derivative curves during the mixing test. An extended laboratory investigation revealed a positive lupus anticoagulant, low factors XI and IX activities. Along with mixing test cut-off limits, we recommend analysing changes in APTT derivative curves to minimize erroneous interpretations of the mixing test. Derivative curves display either a normalizing pattern in factor deficiencies or an atypical pattern in the presence of lupus anticoagulant.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenau, Philip

A wide variety of propagating disturbances in physical systems are described by equations whose solutions lack a sharp propagating front. We demonstrate that presence of particular nonlinearities may induce such fronts. To exemplify this idea, we study both dissipative u{sub t}+{partial_derivative}{sub x}f(u)=u{sub xx} and dispersive u{sub t}+{partial_derivative}{sub x}f(u)+u{sub xxx}=0 patterns, and show that a weakly singular convection f(u)=-u{sup {alpha}}+u{sup m}, 0<{alpha}<1

Measuring the degradation level of polymer films subjected to partial discharges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bozzo, R.; Gemme, C.; Guastavino, F.

1996-12-31

Polymer films have been subjected to partial discharge (PD) aging. It is shown that statistical quantities derived from partial discharges patterns can be related to test conditions, film characteristics and degradation level. PDs have been measured by means of a digital system. Several resulting PD patterns have been elaborated and about 50 derived and statistical quantities have been obtained for each pattern. The effects of the test conditions on the derived quantities has been studied with relevance to the following items: To recognize the kind of film under test; to correlate the value of quantities with the degradation level ofmore » the film (i.e., to focus at the quantities which change with time); to find a link between the quantities values and the test ambient conditions (i.e., relative humidity); to determine the influence of the film thickness; and to evidence the effect of the voltage level.« less

Fitness, adiposopathy, and adiposity are independent predictors of insulin sensitivity in middle-aged men without diabetes.

PubMed

Huth, Claire; Pigeon, Étienne; Riou, Marie-Ève; St-Onge, Josée; Arguin, Hélène; Couillard, Erick; Dubois, Marie-Julie; Marette, André; Tremblay, Angelo; Weisnagel, S John; Lacaille, Michel; Mauriège, Pascale; Joanisse, Denis R

2016-09-01

Adiposopathy, or sick fat, refers to adipose tissue dysfunction that can lead to several complications such as dyslipidemia, insulin resistance, and hyperglycemia. The relative contribution of adiposopathy in predicting insulin resistance remains unclear. We investigated the relationship between adiposopathy, as assessed as a low plasma adiponectin/leptin ratio, with anthropometry, body composition (hydrostatic weighing), insulin sensitivity (hyperinsulinemic-euglycemic clamp), inflammation, and fitness level (ergocycle VO2max, mL/kgFFM/min) in 53 men (aged 34-53 years) from four groups: sedentary controls without obesity (body mass index [BMI] <25 kg/m(2)), sedentary with obesity (BMI > 30 kg/m(2)), sedentary with obesity and glucose intolerance, and endurance trained active without obesity. The adiponectin/leptin ratio was the highest in trained men (4.75 ± 0.82) and the lowest in glucose intolerant subjects with obesity (0.27 ± 0.06; ANOVA p < 0.0001) indicating increased adiposopathy in those with obesity. The ratio was negatively associated with adiposity (e.g., waist circumference, r = -0.59, p < 0.01) and positively associated with VO2max (r = 0.67, p < 0.01) and insulin sensitivity (M/I, r = 0.73, p < 0.01). Multiple regression analysis revealed fitness as the strongest independent predictor of insulin sensitivity (partial R (2) = 0.61). While adiposopathy was also an independent and significant contributor (partial R (2) = 0.10), waist circumference added little power to the model (partial R (2) = 0.024). All three variables remained significant independent predictors when trained subjects were excluded from the model. Plasma lipids were not retained in the model. We conclude that low fitness, adiposopathy, as well as adiposity (and in particular abdominal obesity) are independent contributors to insulin resistance in men without diabetes.

Masking Misfit in Confirmatory Factor Analysis by Increasing Unique Variances: A Cautionary Note on the Usefulness of Cutoff Values of Fit Indices

ERIC Educational Resources Information Center

Heene, Moritz; Hilbert, Sven; Draxler, Clemens; Ziegler, Matthias; Buhner, Markus

2011-01-01

Fit indices are widely used in order to test the model fit for structural equation models. In a highly influential study, Hu and Bentler (1999) showed that certain cutoff values for these indices could be derived, which, over time, has led to the reification of these suggested thresholds as "golden rules" for establishing the fit or other aspects…

Construction and accuracy of partial differential equation approximations to the chemical master equation.

PubMed

Grima, Ramon

2011-11-01

The mesoscopic description of chemical kinetics, the chemical master equation, can be exactly solved in only a few simple cases. The analytical intractability stems from the discrete character of the equation, and hence considerable effort has been invested in the development of Fokker-Planck equations, second-order partial differential equation approximations to the master equation. We here consider two different types of higher-order partial differential approximations, one derived from the system-size expansion and the other from the Kramers-Moyal expansion, and derive the accuracy of their predictions for chemical reactive networks composed of arbitrary numbers of unimolecular and bimolecular reactions. In particular, we show that the partial differential equation approximation of order Q from the Kramers-Moyal expansion leads to estimates of the mean number of molecules accurate to order Ω(-(2Q-3)/2), of the variance of the fluctuations in the number of molecules accurate to order Ω(-(2Q-5)/2), and of skewness accurate to order Ω(-(Q-2)). We also show that for large Q, the accuracy in the estimates can be matched only by a partial differential equation approximation from the system-size expansion of approximate order 2Q. Hence, we conclude that partial differential approximations based on the Kramers-Moyal expansion generally lead to considerably more accurate estimates in the mean, variance, and skewness than approximations of the same order derived from the system-size expansion.

Auditory processing disorders and problems with hearing-aid fitting in old age.

PubMed

Antonelli, A R

1978-01-01

The hearing handicap experienced by elderly subjects depends only partially on end-organ impairment. Not only the neural unit loss along the central auditory pathways contributes to decreased speech discrimination, but also learning processes are slowed down. Diotic listening in elderly people seems to fasten learning of discrimination in critical conditions, as in the case of sensitized speech. This fact, and the binaural gain through the binaural release from masking, stress the superiority, on theoretical grounds, of binaural over monaural hearing-aid fitting.

Transient Dupuit Interface Flow with partially penetrating features

NASA Astrophysics Data System (ADS)

Bakker, Mark

1998-11-01

A comprehensive potential is presented for Dupuit interface flow in coastal aquifers where both the fresh water and salt water are moving. The resulting potential flow problem may be solved, for incompressible confined aquifers, using analytic functions. The vertical velocity of the interface may then be computed analytically and the change of the position of the interface may be simulated by numerical integration through time, starting with a known (or estimated) initial position. The upconing of the interface below a partially penetrating ditch or well may be studied if Dupuit solutions for such features are available. A new Dupuit solution is derived for a ditch that penetrates the aquifer partially from above; a Dupuit solution for a partially penetrating well may be obtained following a similar derivation. The new Dupuit solution is combined with the interface solution to simulate the upconing of an initially horizontal interface below a series of partially penetrating ditches; the interface converges to the known steady state position.

INFOS: spectrum fitting software for NMR analysis.

PubMed

Smith, Albert A

2017-02-01

Software for fitting of NMR spectra in MATLAB is presented. Spectra are fitted in the frequency domain, using Fourier transformed lineshapes, which are derived using the experimental acquisition and processing parameters. This yields more accurate fits compared to common fitting methods that use Lorentzian or Gaussian functions. Furthermore, a very time-efficient algorithm for calculating and fitting spectra has been developed. The software also performs initial peak picking, followed by subsequent fitting and refinement of the peak list, by iteratively adding and removing peaks to improve the overall fit. Estimation of error on fitting parameters is performed using a Monte-Carlo approach. Many fitting options allow the software to be flexible enough for a wide array of applications, while still being straightforward to set up with minimal user input.

Final report, Portland State University intelligent transportation research initiative.

DOT National Transportation Integrated Search

2006-07-01

This FY 2004 ITS Integration grant has provided partial funding for design, outfitting, and interior fit up for the new regional Intelligent Transportation Systems (ITS) Laboratory suite located in the new $60 million Northwest Center for Engin...

Use of hyperbolic partial differential equations to generate body fitted coordinates

NASA Technical Reports Server (NTRS)

Steger, J. L.; Sorenson, R. L.

1980-01-01

The hyperbolic scheme is used to efficiently generate smoothly varying grids with good step size control near the body. Although only two dimensional applications are presented, the basic concepts are shown to extend to three dimensions.

Glass Transition Temperature- and Specific Volume- Composition Models for Tellurite Glasses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riley, Brian J.; Vienna, John D.

This report provides models for predicting composition-properties for tellurite glasses, namely specific gravity and glass transition temperature. Included are the partial specific coefficients for each model, the component validity ranges, and model fit parameters.

The partial-reinforcement extinction effect and the contingent-sampling hypothesis.

PubMed

Hochman, Guy; Erev, Ido

2013-12-01

The partial-reinforcement extinction effect (PREE) implies that learning under partial reinforcements is more robust than learning under full reinforcements. While the advantages of partial reinforcements have been well-documented in laboratory studies, field research has failed to support this prediction. In the present study, we aimed to clarify this pattern. Experiment 1 showed that partial reinforcements increase the tendency to select the promoted option during extinction; however, this effect is much smaller than the negative effect of partial reinforcements on the tendency to select the promoted option during the training phase. Experiment 2 demonstrated that the overall effect of partial reinforcements varies inversely with the attractiveness of the alternative to the promoted behavior: The overall effect is negative when the alternative is relatively attractive, and positive when the alternative is relatively unattractive. These results can be captured with a contingent-sampling model assuming that people select options that provided the best payoff in similar past experiences. The best fit was obtained under the assumption that similarity is defined by the sequence of the last four outcomes.

Temperature responses of individual soil organic matter components

NASA Astrophysics Data System (ADS)

Feng, Xiaojuan; Simpson, Myrna J.

2008-09-01

Temperature responses of soil organic matter (SOM) remain unclear partly due to its chemical and compositional heterogeneity. In this study, the decomposition of SOM from two grassland soils was investigated in a 1-year laboratory incubation at six different temperatures. SOM was separated into solvent extractable compounds, suberin- and cutin-derived compounds, and lignin-derived monomers by solvent extraction, base hydrolysis, and CuO oxidation, respectively. These SOM components have distinct chemical structures and stabilities and their decomposition patterns over the course of the experiment were fitted with a two-pool exponential decay model. The stability of SOM components was also assessed using geochemical parameters and kinetic parameters derived from model fitting. Compared with the solvent extractable compounds, a low percentage of lignin monomers partitioned into the labile SOM pool. Suberin- and cutin-derived compounds were poorly fitted by the decay model, and their recalcitrance was shown by the geochemical degradation parameter (ω - C16/∑C16), which was observed to stabilize during the incubation. The temperature sensitivity of decomposition, expressed as Q10, was derived from the relationship between temperature and SOM decay rates. SOM components exhibited varying temperature responses and the decomposition of lignin monomers exhibited higher Q10 values than the decomposition of solvent extractable compounds. Our study shows that Q10 values derived from soil respiration measurements may not be reliable indicators of temperature responses of individual SOM components.

Alterations to the relativistic Love-Franey model and their application to inelastic scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeile, J.R.

The fictitious axial-vector and tensor mesons for the real part of the relativistic Love-Franey interaction are removed. In an attempt to make up for this loss, derivative couplings are used for the {pi} and {rho} mesons. Such derivative couplings require the introduction of axial-vector and tensor contact term corrections. Meson parameters are then fit to free nucleon-nucleon scattering data. The resulting fits are comparable to those of the relativistic Love-Franey model provided that the contact term corrections are included and the fits are weighted over the physically significant quantity of twice the tensor minus the axial-vector Lorentz invariants. Failure tomore » include contact term corrections leads to poor fits at higher energies. The off-shell behavior of this model is then examined by looking at several applications from inelastic proton-nucleus scattering.« less

Correlation singularities in a partially coherent electromagnetic beam with initially radial polarization.

PubMed

Zhang, Yongtao; Cui, Yan; Wang, Fei; Cai, Yangjian

2015-05-04

We have investigated the correlation singularities, coherence vortices of two-point correlation function in a partially coherent vector beam with initially radial polarization, i.e., partially coherent radially polarized (PCRP) beam. It is found that these singularities generally occur during free space propagation. Analytical formulae for characterizing the dynamics of the correlation singularities on propagation are derived. The influence of the spatial coherence length of the beam on the evolution properties of the correlation singularities and the conditions for creation and annihilation of the correlation singularities during propagation have been studied in detail based on the derived formulae. Some interesting results are illustrated. These correlation singularities have implication for interference experiments with a PCRP beam.

FIREFLY (Fitting IteRativEly For Likelihood analYsis): a full spectral fitting code

NASA Astrophysics Data System (ADS)

Wilkinson, David M.; Maraston, Claudia; Goddard, Daniel; Thomas, Daniel; Parikh, Taniya

2017-12-01

We present a new spectral fitting code, FIREFLY, for deriving the stellar population properties of stellar systems. FIREFLY is a chi-squared minimization fitting code that fits combinations of single-burst stellar population models to spectroscopic data, following an iterative best-fitting process controlled by the Bayesian information criterion. No priors are applied, rather all solutions within a statistical cut are retained with their weight. Moreover, no additive or multiplicative polynomials are employed to adjust the spectral shape. This fitting freedom is envisaged in order to map out the effect of intrinsic spectral energy distribution degeneracies, such as age, metallicity, dust reddening on galaxy properties, and to quantify the effect of varying input model components on such properties. Dust attenuation is included using a new procedure, which was tested on Integral Field Spectroscopic data in a previous paper. The fitting method is extensively tested with a comprehensive suite of mock galaxies, real galaxies from the Sloan Digital Sky Survey and Milky Way globular clusters. We also assess the robustness of the derived properties as a function of signal-to-noise ratio (S/N) and adopted wavelength range. We show that FIREFLY is able to recover age, metallicity, stellar mass, and even the star formation history remarkably well down to an S/N ∼ 5, for moderately dusty systems. Code and results are publicly available.1

Trial-dependent psychometric functions accounting for perceptual learning in 2-AFC discrimination tasks.

PubMed

Kattner, Florian; Cochrane, Aaron; Green, C Shawn

2017-09-01

The majority of theoretical models of learning consider learning to be a continuous function of experience. However, most perceptual learning studies use thresholds estimated by fitting psychometric functions to independent blocks, sometimes then fitting a parametric function to these block-wise estimated thresholds. Critically, such approaches tend to violate the basic principle that learning is continuous through time (e.g., by aggregating trials into large "blocks" for analysis that each assume stationarity, then fitting learning functions to these aggregated blocks). To address this discrepancy between base theory and analysis practice, here we instead propose fitting a parametric function to thresholds from each individual trial. In particular, we implemented a dynamic psychometric function whose parameters were allowed to change continuously with each trial, thus parameterizing nonstationarity. We fit the resulting continuous time parametric model to data from two different perceptual learning tasks. In nearly every case, the quality of the fits derived from the continuous time parametric model outperformed the fits derived from a nonparametric approach wherein separate psychometric functions were fit to blocks of trials. Because such a continuous trial-dependent model of perceptual learning also offers a number of additional advantages (e.g., the ability to extrapolate beyond the observed data; the ability to estimate performance on individual critical trials), we suggest that this technique would be a useful addition to each psychophysicist's analysis toolkit.

Plasma distributions in meteor head echoes and implications for radar cross section interpretation

NASA Astrophysics Data System (ADS)

Marshall, Robert A.; Brown, Peter; Close, Sigrid

2017-09-01

The derivation of meteoroid masses from radar measurements requires conversion of the measured radar cross section (RCS) to meteoroid mass. Typically, this conversion passes first through an estimate of the meteor plasma density derived from the RCS. However, the conversion from RCS to meteor plasma density requires assumptions on the radial electron density distribution. We use simultaneous triple-frequency measurements of the RCS for 63 large meteor head echoes to derive estimates of the meteor plasma size and density using five different possible radial electron density distributions. By fitting these distributions to the observed meteor RCS values and estimating the goodness-of-fit, we determine that the best fit to the data is a 1 /r2 plasma distribution, i.e. the electron density decays as 1 /r2 from the center of the meteor plasma. Next, we use the derived plasma distributions to estimate the electron line density q for each meteor using each of the five distributions. We show that depending on the choice of distribution, the line density can vary by a factor of three or more. We thus argue that a best estimate for the radial plasma distribution in a meteor head echo is necessary in order to have any confidence in derived meteoroid masses.

Fit accuracy of metal partial removable dental prosthesis frameworks fabricated by traditional or light curing modeling material technique: An in vitro study

PubMed Central

Anan, Mohammad Tarek M.; Al-Saadi, Mohannad H.

2015-01-01

Objective The aim of this study was to compare the fit accuracies of metal partial removable dental prosthesis (PRDP) frameworks fabricated by the traditional technique (TT) or the light-curing modeling material technique (LCMT). Materials and methods A metal model of a Kennedy class III modification 1 mandibular dental arch with two edentulous spaces of different spans, short and long, was used for the study. Thirty identical working casts were used to produce 15 PRDP frameworks each by TT and by LCMT. Every framework was transferred to a metal master cast to measure the gap between the metal base of the framework and the crest of the alveolar ridge of the cast. Gaps were measured at three points on each side by a USB digital intraoral camera at ×16.5 magnification. Images were transferred to a graphics editing program. A single examiner performed all measurements. The two-tailed t-test was performed at the 5% significance level. Results The mean gap value was significantly smaller in the LCMT group compared to the TT group. The mean value of the short edentulous span was significantly smaller than that of the long edentulous span in the LCMT group, whereas the opposite result was obtained in the TT group. Conclusion Within the limitations of this study, it can be concluded that the fit of the LCMT-fabricated frameworks was better than the fit of the TT-fabricated frameworks. The framework fit can differ according to the span of the edentate ridge and the fabrication technique for the metal framework. PMID:26236129

Anomalous diffusion associated with nonlinear fractional derivative fokker-planck-like equation: exact time-dependent solutions

PubMed

Bologna; Tsallis; Grigolini

2000-08-01

We consider the d=1 nonlinear Fokker-Planck-like equation with fractional derivatives ( partial differential/ partial differentialt)P(x,t)=D( partial differential(gamma)/ partial differentialx(gamma))[P(x,t)](nu). Exact time-dependent solutions are found for nu=(2-gamma)/(1+gamma)(-infinity

Generation of various partially coherent beams and their propagation properties in turbulent atmosphere: a review

NASA Astrophysics Data System (ADS)

Cai, Yangjian

2011-03-01

Partially coherent beams, such as Gaussian Schell-model beam, partially coherent dark hollow beam, partially coherent flat-topped beam and electromagnetic Gaussian Schell-model beam, have important applications in free space optical communications, optical imaging, optical trapping, inertial confinement fusion and nonlinear optics. In this paper, experimental generations of various partially coherent beams are introduced. Furthermore, with the help of a tensor method, analytical formulae for such beams propagating in turbulent atmosphere are derived, and the propagation properties of such beams in turbulent atmosphere are reviewed.

Physical fitness and shapes of subcortical brain structures in children.

PubMed

Ortega, Francisco B; Campos, Daniel; Cadenas-Sanchez, Cristina; Altmäe, Signe; Martínez-Zaldívar, Cristina; Martín-Matillas, Miguel; Catena, Andrés; Campoy, Cristina

2017-03-27

A few studies have recently reported that higher cardiorespiratory fitness is associated with higher volumes of subcortical brain structures in children. It is, however, unknown how different fitness measures relate to shapes of subcortical brain nuclei. We aimed to examine the association of the main health-related physical fitness components with shapes of subcortical brain structures in a sample of forty-four Spanish children aged 9·7 (sd 0·2) years from the NUtraceuticals for a HEALthier life project. Cardiorespiratory fitness, muscular strength and speed agility were assessed using valid and reliable tests (ALPHA-fitness test battery). Shape of the subcortical brain structures was assessed by MRI, and its relationship with fitness was examined after controlling for a set of potential confounders using a partial correlation permutation approach. Our results showed that all physical fitness components studied were significantly related to the shapes of subcortical brain nuclei. These associations were both positive and negative, indicating that a higher level of fitness in childhood is related to both expansions and contractions in certain regions of the accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus. Cardiorespiratory fitness was mainly associated with expansions, whereas handgrip was mostly associated with contractions in the structures studied. Future randomised-controlled trials will confirm or contrast our findings, demonstrating whether changes in fitness modify the shapes of brain structures and the extent to which those changes influence cognitive function.

Connection between angle-dependent phase ambiguities and the uniqueness of the partial-wave decomposition

NASA Astrophysics Data System (ADS)

Švarc, A.; Wunderlich, Y.; Osmanović, H.; Hadžimehmedović, M.; Omerović, R.; Stahov, J.; Kashevarov, V.; Nikonov, K.; Ostrick, M.; Tiator, L.; Workman, R.

2018-05-01

Unconstrained partial -wave amplitudes, obtained at discrete energies from fits to complete sets of eight independent observables, may be used to reconstruct reaction amplitudes. These partial-wave amplitudes do not vary smoothly with energy and are in principle nonunique. We demonstrate how this behavior can be ascribed to the continuum ambiguity. Starting from the spinless scattering case, we show how an unknown overall phase, depending on energy and angle, mixes the structures seen in the associated partial-wave amplitudes. This process is illustrated using a simple toy model. We then apply these principles to pseudoscalar meson photoproduction, showing how the above effect can be removed through a phase rotation, allowing a consistent comparison with model amplitudes. The effect of this phase ambiguity is also considered for Legendre expansions of experimental observables.

Empirical calibration of the near-infrared Ca II triplet - III. Fitting functions

NASA Astrophysics Data System (ADS)

Cenarro, A. J.; Gorgas, J.; Cardiel, N.; Vazdekis, A.; Peletier, R. F.

2002-02-01

Using a near-infrared stellar library of 706 stars with a wide coverage of atmospheric parameters, we study the behaviour of the CaII triplet strength in terms of effective temperature, surface gravity and metallicity. Empirical fitting functions for recently defined line-strength indices, namely CaT*, CaT and PaT, are provided. These functions can be easily implemented into stellar population models to provide accurate predictions for integrated CaII strengths. We also present a thorough study of the various error sources and their relation to the residuals of the derived fitting functions. Finally, the derived functional forms and the behaviour of the predicted CaII are compared with those of previous works in the field.

A new analytical method for estimating lumped parameter constants of linear viscoelastic models from strain rate tests

NASA Astrophysics Data System (ADS)

Mattei, G.; Ahluwalia, A.

2018-04-01

We introduce a new function, the apparent elastic modulus strain-rate spectrum, E_{app} ( \\dot{ɛ} ), for the derivation of lumped parameter constants for Generalized Maxwell (GM) linear viscoelastic models from stress-strain data obtained at various compressive strain rates ( \\dot{ɛ}). The E_{app} ( \\dot{ɛ} ) function was derived using the tangent modulus function obtained from the GM model stress-strain response to a constant \\dot{ɛ} input. Material viscoelastic parameters can be rapidly derived by fitting experimental E_{app} data obtained at different strain rates to the E_{app} ( \\dot{ɛ} ) function. This single-curve fitting returns similar viscoelastic constants as the original epsilon dot method based on a multi-curve global fitting procedure with shared parameters. Its low computational cost permits quick and robust identification of viscoelastic constants even when a large number of strain rates or replicates per strain rate are considered. This method is particularly suited for the analysis of bulk compression and nano-indentation data of soft (bio)materials.

Dynamics of Tumor Heterogeneity Derived from Clonal Karyotypic Evolution.

PubMed

Laughney, Ashley M; Elizalde, Sergi; Genovese, Giulio; Bakhoum, Samuel F

2015-08-04

Numerical chromosomal instability is a ubiquitous feature of human neoplasms. Due to experimental limitations, fundamental characteristics of karyotypic changes in cancer are poorly understood. Using an experimentally inspired stochastic model, based on the potency and chromosomal distribution of oncogenes and tumor suppressor genes, we show that cancer cells have evolved to exist within a narrow range of chromosome missegregation rates that optimizes phenotypic heterogeneity and clonal survival. Departure from this range reduces clonal fitness and limits subclonal diversity. Mapping of the aneuploid fitness landscape reveals a highly favorable, commonly observed, near-triploid state onto which evolving diploid- and tetraploid-derived populations spontaneously converge, albeit at a much lower fitness cost for the latter. Finally, by analyzing 1,368 chromosomal translocation events in five human cancers, we find that karyotypic evolution also shapes chromosomal translocation patterns by selecting for more oncogenic derivative chromosomes. Thus, chromosomal instability can generate the heterogeneity required for Darwinian tumor evolution. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Fitness, fatness, cognition, behavior, and academic achievement among overweight children: Do cross-sectional associations correspond to exercise trial outcomes?

PubMed Central

Davis, Catherine L.; Cooper, Stephanie

2011-01-01

Background This study examined associations of fitness and fatness with cognitive processes, academic achievement, and behavior, independent of demographic factors, at the baseline of an exercise trial. Methods Overweight, sedentary but otherwise healthy 7–11 year olds (N=170) participated in a study of health, cognition and achievement in the Augusta, GA area from 2003–2006. Children underwent evaluations of fatness and fitness, psychological assessments of cognition and academic achievement, and behavior ratings by parents and teachers. Partial correlations examined associations of fitness and fatness with cognitive and achievement scores and behavior ratings, controlling for demographic factors. Results Fitness was associated with better cognition, achievement and behavior, and fatness with worse scores. Specifically, executive function, mathematics and reading achievement, and parent ratings of child behavior were related to fitness and fatness. Teacher ratings were related to fitness. Conclusion These results extend prior studies by providing reliable, standardized measures of cognitive processes, achievement, and behavior in relation to detailed measures of fitness and fatness. However, cross-sectional associations do not necessarily indicate that improving one factor, such as fatness or fitness, will result in improvements in factors that were associated with it. Thus, randomized clinical trials are necessary to determine the effects of interventions. PMID:21281668

Fitness, fatness, cognition, behavior, and academic achievement among overweight children: do cross-sectional associations correspond to exercise trial outcomes?

PubMed

Davis, Catherine L; Cooper, Stephanie

2011-06-01

This study examined associations of fitness and fatness with cognitive processes, academic achievement, and behavior, independent of demographic factors, at the baseline of an exercise trial. Overweight, sedentary but otherwise healthy 7-11 year olds (N=170) participated in a study of health, cognition and achievement in the Augusta, GA area from 2003-2006. Children underwent evaluations of fatness and fitness, psychological assessments of cognition and academic achievement, and behavior ratings by parents and teachers. Partial correlations examined associations of fitness and fatness with cognitive and achievement scores and behavior ratings, controlling for demographic factors. Fitness was associated with better cognition, achievement and behavior, and fatness with worse scores. Specifically, executive function, mathematics and reading achievement, and parent ratings of child behavior were related to fitness and fatness. Teacher ratings were related to fitness. These results extend prior studies by providing reliable, standardized measures of cognitive processes, achievement, and behavior in relation to detailed measures of fitness and fatness. However, cross-sectional associations do not necessarily indicate that improving one factor, such as fatness or fitness, will result in improvements in factors that were associated with it. Thus, randomized clinical trials are necessary to determine the effects of interventions. Copyright © 2011. Published by Elsevier Inc.

METHOD FOR PRODUCING ISOTOPIC METHANES AND PARTIALLY HALOGENATED DERIVATIVES THEROF

DOEpatents

Frazer, J.W.

1959-08-18

A method is given for producing isotopic methanes and/ or partially halogenated derivatives. Lithium hydride, deuteride, or tritide is reacted with a halogenated methane or with a halogenated methane in combination with free halogen. The process is conveniently carried out by passing a halogenated methane preferably at low pressures or in an admixture with an inert gas through a fixed bed of finely divided lithium hydride heated initially to temperatures of 100 to 200 deg C depending upon the halogenated methane used.

Modeling The Skeleton Weight of an Adult Caucasian Man.

PubMed

Avtandilashvili, Maia; Tolmachev, Sergei Y

2018-05-17

The reference value for the skeleton weight of an adult male (10.5 kg) recommended by the International Commission on Radiological Protection in Publication 70 is based on weights of dissected skeletons from 44 individuals, including two U.S. Transuranium and Uranium Registries whole-body donors. The International Commission on Radiological Protection analysis of anatomical data from 31 individuals with known values of body height demonstrated significant correlation between skeleton weight and body height. The corresponding regression equation, Wskel (kg) = -10.7 + 0.119 × H (cm), published in International Commission on Radiological Protection Publication 70 is typically used to estimate the skeleton weight from body height. Currently, the U.S. Transuranium and Uranium Registries holds data on individual bone weights from a total of 40 male whole-body donors, which has provided a unique opportunity to update the International Commission on Radiological Protection skeleton weight vs. body height equation. The original International Commission on Radiological Protection Publication 70 and the new U.S. Transuranium and Uranium Registries data were combined in a set of 69 data points representing a group of 33- to 95-y-old individuals with body heights and skeleton weights ranging from 155 to 188 cm and 6.5 to 13.4 kg, respectively. Data were fitted with a linear least-squares regression. A significant correlation between the two parameters was observed (r = 0.28), and an updated skeleton weight vs. body height equation was derived: Wskel (kg) = -6.5 + 0.093 × H (cm). In addition, a correlation of skeleton weight with multiple variables including body height, body weight, and age was evaluated using multiple regression analysis, and a corresponding fit equation was derived: Wskel (kg) = -0.25 + 0.046 × H (cm) + 0.036 × Wbody (kg) - 0.012 × A (y). These equations will be used to estimate skeleton weights and, ultimately, total skeletal actinide activities for biokinetic modeling of U.S. Transuranium and Uranium Registries partial-body donation cases.

Combining Gene Signatures Improves Prediction of Breast Cancer Survival

PubMed Central

Zhao, Xi; Naume, Bjørn; Langerød, Anita; Frigessi, Arnoldo; Kristensen, Vessela N.; Børresen-Dale, Anne-Lise; Lingjærde, Ole Christian

2011-01-01

Background Several gene sets for prediction of breast cancer survival have been derived from whole-genome mRNA expression profiles. Here, we develop a statistical framework to explore whether combination of the information from such sets may improve prediction of recurrence and breast cancer specific death in early-stage breast cancers. Microarray data from two clinically similar cohorts of breast cancer patients are used as training (n = 123) and test set (n = 81), respectively. Gene sets from eleven previously published gene signatures are included in the study. Principal Findings To investigate the relationship between breast cancer survival and gene expression on a particular gene set, a Cox proportional hazards model is applied using partial likelihood regression with an L2 penalty to avoid overfitting and using cross-validation to determine the penalty weight. The fitted models are applied to an independent test set to obtain a predicted risk for each individual and each gene set. Hierarchical clustering of the test individuals on the basis of the vector of predicted risks results in two clusters with distinct clinical characteristics in terms of the distribution of molecular subtypes, ER, PR status, TP53 mutation status and histological grade category, and associated with significantly different survival probabilities (recurrence: p = 0.005; breast cancer death: p = 0.014). Finally, principal components analysis of the gene signatures is used to derive combined predictors used to fit a new Cox model. This model classifies test individuals into two risk groups with distinct survival characteristics (recurrence: p = 0.003; breast cancer death: p = 0.001). The latter classifier outperforms all the individual gene signatures, as well as Cox models based on traditional clinical parameters and the Adjuvant! Online for survival prediction. Conclusion Combining the predictive strength of multiple gene signatures improves prediction of breast cancer survival. The presented methodology is broadly applicable to breast cancer risk assessment using any new identified gene set. PMID:21423775

A higher order numerical method for time fractional partial differential equations with nonsmooth data

NASA Astrophysics Data System (ADS)

Xing, Yanyuan; Yan, Yubin

2018-03-01

Gao et al. [11] (2014) introduced a numerical scheme to approximate the Caputo fractional derivative with the convergence rate O (k 3 - α), 0 < α < 1 by directly approximating the integer-order derivative with some finite difference quotients in the definition of the Caputo fractional derivative, see also Lv and Xu [20] (2016), where k is the time step size. Under the assumption that the solution of the time fractional partial differential equation is sufficiently smooth, Lv and Xu [20] (2016) proved by using energy method that the corresponding numerical method for solving time fractional partial differential equation has the convergence rate O (k 3 - α), 0 < α < 1 uniformly with respect to the time variable t. However, in general the solution of the time fractional partial differential equation has low regularity and in this case the numerical method fails to have the convergence rate O (k 3 - α), 0 < α < 1 uniformly with respect to the time variable t. In this paper, we first obtain a similar approximation scheme to the Riemann-Liouville fractional derivative with the convergence rate O (k 3 - α), 0 < α < 1 as in Gao et al. [11] (2014) by approximating the Hadamard finite-part integral with the piecewise quadratic interpolation polynomials. Based on this scheme, we introduce a time discretization scheme to approximate the time fractional partial differential equation and show by using Laplace transform methods that the time discretization scheme has the convergence rate O (k 3 - α), 0 < α < 1 for any fixed tn > 0 for smooth and nonsmooth data in both homogeneous and inhomogeneous cases. Numerical examples are given to show that the theoretical results are consistent with the numerical results.

Improving the fit of implant prosthetics: an in vitro study.

PubMed

Yannikakis, Stavros; Prombonas, Anthony

2013-01-01

Accurate and passive fit between a prosthesis and its supporting implants has been considered a prerequisite for successful long-term osseointegration. The objective of this in vitro study was to evaluate the strain development during tightening of a five-unit screw-retained superstructure constructed using five different methods. Five-unit screw-retained fixed partial prostheses (n = 25) were fabricated on three implants embedded in an epoxy resin block using five different methods: (1) cobalt-chromium (Co-Cr), plastic cylinders, one-piece cast; (2) Co-Cr, plastic cylinders, framework sectioned, preceramic laser-welding soldering; (3) gold-platinum (Au-Pt), gold cylinders, one-piece cast; (4) Au-Pt, gold cylinders, framework sectioned, preceramic laser-welding soldering; (5) Co-Cr, one-piece cast, and cementation to "passive abutments" (Southern Implants) after final finishing and polishing. Strain gauges (SG) were attached to the fixed partial prosthesis (FPP) and to the resin block to measure the stress created during screw tightening. The combination of Co-Cr alloy and plastic cylinders in a one-piece cast showed such an inadequate fit among the fabricated methods that this group was excluded from the remainder of the experiment. Specimens of Au-Pt cast on gold cylinders in one piece showed higher strain development than the other groups used in this study, with strains ranging from 223.1 to 2,198.1 Μm/m. Sectioning and soldering significantly improved the overall fit. FPPs of Co-Cr in a one-piece cast cemented to "passive abutments" produced the best level of fit, with the least strain development in the prosthesis and the resin block (59 to 204.6 Μm/m). Absolute fit of superstructures on implants is not possible using conventional laboratory procedures. Cementing FPPs onto prefabricated cylinders directly onto the implants significantly reduces strain development compared to the other fabrication methods.

The FORCE Fitness Profile--Adding a Measure of Health-Related Fitness to the Canadian Armed Forces Operational Fitness Evaluation.

PubMed

Gagnon, Patrick; Spivock, Michael; Reilly, Tara; Mattie, Paige; Stockbrugger, Barry

2015-11-01

In 2013, the Canadian Armed Forces (CAF) implemented the Fitness for Operational Requirements of Canadian Armed Forces Employment (FORCE), a field expedient fitness test designed to predict the physical requirements of completing common military tasks. Given that attaining this minimal physical fitness standard may not represent a challenge to some personnel, a fitness incentive program was requested by the chain of command to recognize and reward fitness over and above the minimal standard. At the same time, it was determined that the CAF would benefit from a measure of general health-related fitness, in addition to this measure of operational fitness. The resulting incentive program structure is based on gender and 8 age categories. The results on the 4 elements of the FORCE evaluation were converted to a point scale from which normative scores were derived, where the median score corresponds to the bronze level, and silver, gold, and platinum correspond to a score which is 1, 2, and 3 SDs above this median, respectively. A suite of rewards including merit board point toward promotions and recognition on the uniform and material rewards was developed. A separate group rewards program was also tabled, to recognize achievements in fitness at the unit level. For general fitness, oxygen capacity was derived from FORCE evaluation results and combined with a measure of abdominal circumference. Fitness categories were determined based on relative risks of mortality and morbidity for each age and gender group. Pilot testing of this entire program was performed with 624 participants to assess participants' reactions to the enhanced test, and also to verify logistical aspects of the electronic data capture, calculation, and transfer system. The newly dubbed fitness profile program was subsequently approved by the senior leadership of the CAF and is scheduled to begin a phased implementation in June 2015.

Infrared Spectroscopy and Born-Oppenheimer Molecular Dynamics Simulation Study on Deuterium Substitution in the Crystalline Benzoic Acid.

PubMed

Gług, Maciej; Brela, Mateusz Z; Boczar, Marek; Turek, Andrzej M; Boda, Łukasz; Wójcik, Marek J; Nakajima, Takahito; Ozaki, Yukihiro

2017-01-26

In this study we present complementary computational and experimental studies of hydrogen bond interaction in crystalline benzoic acid and its deuterated and partially deuterated derivatives. The experimental part of the presented work includes preparation of partially deuterated samples and measurement of attenuated total reflection (ATR)-FTIR spectra. Analysis of the geometrical parameters and time course of dipole moment of crystalline benzoic acid and its deuterated and partially deuterated derivatives by Born-Oppenheimer molecular dynamics (BOMD) enabled us to deeply analyze the IR spectra. Presented simulations based on BOMD gave us opportunity to investigate individual motion and its contribution to the IR spectra. The band contours calculated using Fourier transform of autocorrelation function are in quantitative agreement with the experimental spectra. Characterization of single bands was carried out by "normal coordinate analysis". The salient point of our study is a comparison of the spectra of the deuterated and partially deuterated crystalline benzoic acid with that of the nondeuterated one. Furthermore, we have applied the principal component analysis for analysis of the number of components in partially deuterated systems. In this study, we reveal that the arrangements of hydrogen and deuterium atoms in partially deuterated samples are random.

Special wrench for B-nuts reduces torque stress in tubing

NASA Technical Reports Server (NTRS)

Stein, J. A.

1970-01-01

Gear-driven torque wrench with bearing support is used to tighten B-nut connection of partially supported fluid line with minimum stress to adjacent tubing and fittings. Wrench is useful for working with weak or brittle lines such as glass tubing.

Construction of exponentially fitted symplectic Runge-Kutta-Nyström methods from partitioned Runge-Kutta methods

NASA Astrophysics Data System (ADS)

Monovasilis, Theodore; Kalogiratou, Zacharoula; Simos, T. E.

2014-10-01

In this work we derive exponentially fitted symplectic Runge-Kutta-Nyström (RKN) methods from symplectic exponentially fitted partitioned Runge-Kutta (PRK) methods methods (for the approximate solution of general problems of this category see [18] - [40] and references therein). We construct RKN methods from PRK methods with up to five stages and fourth algebraic order.

Non-singular spherical harmonic expressions of geomagnetic vector and gradient tensor fields in the local north-oriented reference frame

NASA Astrophysics Data System (ADS)

Du, J.; Chen, C.; Lesur, V.; Wang, L.

2015-07-01

General expressions of magnetic vector (MV) and magnetic gradient tensor (MGT) in terms of the first- and second-order derivatives of spherical harmonics at different degrees/orders are relatively complicated and singular at the poles. In this paper, we derived alternative non-singular expressions for the MV, the MGT and also the third-order partial derivatives of the magnetic potential field in the local north-oriented reference frame. Using our newly derived formulae, the magnetic potential, vector and gradient tensor fields and also the third-order partial derivatives of the magnetic potential field at an altitude of 300 km are calculated based on a global lithospheric magnetic field model GRIMM_L120 (GFZ Reference Internal Magnetic Model, version 0.0) with spherical harmonic degrees 16-90. The corresponding results at the poles are discussed and the validity of the derived formulas is verified using the Laplace equation of the magnetic potential field.

Experimentally testing the dependence of momentum transport on second derivatives using Gaussian process regression

NASA Astrophysics Data System (ADS)

Chilenski, M. A.; Greenwald, M. J.; Hubbard, A. E.; Hughes, J. W.; Lee, J. P.; Marzouk, Y. M.; Rice, J. E.; White, A. E.

2017-12-01

It remains an open question to explain the dramatic change in intrinsic rotation induced by slight changes in electron density (White et al 2013 Phys. Plasmas 20 056106). One proposed explanation is that momentum transport is sensitive to the second derivatives of the temperature and density profiles (Lee et al 2015 Plasma Phys. Control. Fusion 57 125006), but it is widely considered to be impossible to measure these higher derivatives. In this paper, we show that it is possible to estimate second derivatives of electron density and temperature using a nonparametric regression technique known as Gaussian process regression. This technique avoids over-constraining the fit by not assuming an explicit functional form for the fitted curve. The uncertainties, obtained rigorously using Markov chain Monte Carlo sampling, are small enough that it is reasonable to explore hypotheses which depend on second derivatives. It is found that the differences in the second derivatives of n{e} and T{e} between the peaked and hollow rotation cases are rather small, suggesting that changes in the second derivatives are not likely to explain the experimental results.

Sustainable breeding objectives and possible selection response: Finding the balance between economics and breeders' preferences.

PubMed

Fuerst-Waltl, Birgit; Fuerst, Christian; Obritzhauser, Walter; Egger-Danner, Christa

2016-12-01

To optimize breeding objectives of Fleckvieh and Brown Swiss cattle, economic values were re-estimated using updated prices, costs, and population parameters. Subsequently, the expected selection responses for the total merit index (TMI) were calculated using previous and newly derived economic values. The responses were compared for alternative scenarios that consider breeders' preferences. A dairy herd with milk production, bull fattening, and rearing of replacement stock was modeled. The economic value of a trait was derived by calculating the difference in herd profit before and after genetic improvement. Economic values for each trait were derived while keeping all other traits constant. The traits considered were dairy, beef, and fitness traits, the latter including direct health traits. The calculation of the TMI and the expected selection responses was done using selection index methodology with estimated breeding values instead of phenotypic deviations. For the scenario representing the situation up to 2016, all traits included in the TMI were considered with their respective economic values before the update. Selection response was also calculated for newly derived economic values and some alternative scenarios, including the new trait vitality index (subindex comprising stillbirth and rearing losses). For Fleckvieh, the relative economic value for the trait groups milk, beef, and fitness were 38, 16, and 46%, respectively, up to 2016, and 39, 13, and 48%, respectively, for the newly derived economic values. Approximately the same selection response may be expected for the milk trait group, whereas the new weightings resulted in a substantially decreased response in beef traits. Within the fitness block, all traits, with the exception of fertility, showed a positive selection response. For Brown Swiss, the relative economic values for the main trait groups milk, beef, and fitness were 48, 5, and 47% before 2016, respectively, whereas for the newly derived scenario they were 40, 14, and 39%. For both Brown Swiss and Fleckvieh, the fertility complex was expected to further deteriorate, whereas all other expected selection responses for fitness traits were positive. Several additional and alternative scenarios were calculated as a basis for discussion with breeders. A decision was made to implement TMI with relative economic values for milk, beef, and fitness with 38, 18, and 44% for Fleckvieh and 50, 5, and 45% for Brown Swiss, respectively. In both breeds, no positive expected selection response was predicted for fertility, although this trait complex received a markedly higher weight than that derived economically. An even higher weight for fertility could not be agreed on due to the effect on selection response of other traits. Hence, breeders decided to direct more attention toward the preselection of bulls with regard to fertility. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Observation model and parameter partials for the JPL VLBI parameter estimation software MASTERFIT-1987

NASA Technical Reports Server (NTRS)

Sovers, O. J.; Fanselow, J. L.

1987-01-01

This report is a revision of the document of the same title (1986), dated August 1, which it supersedes. Model changes during 1986 and 1987 included corrections for antenna feed rotation, refraction in modelling antenna axis offsets, and an option to employ improved values of the semiannual and annual nutation amplitudes. Partial derivatives of the observables with respect to an additional parameter (surface temperature) are now available. New versions of two figures representing the geometric delay are incorporated. The expressions for the partial derivatives with respect to the nutation parameters have been corrected to include contributions from the dependence of UTI on nutation. The authors hope to publish revisions of this document in the future, as modeling improvements warrant.

Observation model and parameter partials for the JPL VLBI parameter estimation software MASTERFIT-1987

NASA Astrophysics Data System (ADS)

Sovers, O. J.; Fanselow, J. L.

1987-12-01

This report is a revision of the document of the same title (1986), dated August 1, which it supersedes. Model changes during 1986 and 1987 included corrections for antenna feed rotation, refraction in modelling antenna axis offsets, and an option to employ improved values of the semiannual and annual nutation amplitudes. Partial derivatives of the observables with respect to an additional parameter (surface temperature) are now available. New versions of two figures representing the geometric delay are incorporated. The expressions for the partial derivatives with respect to the nutation parameters have been corrected to include contributions from the dependence of UTI on nutation. The authors hope to publish revisions of this document in the future, as modeling improvements warrant.

EDARV370A associated facial characteristics in Uyghur population revealing further pleiotropic effects.

PubMed

Peng, Qianqian; Li, Jinxi; Tan, Jingze; Yang, Yajun; Zhang, Manfei; Wu, Sijie; Liu, Yu; Zhang, Juan; Qin, Pengfei; Guan, Yaqun; Jiao, Yi; Zhang, Zhaoxia; Sabeti, Pardis C; Tang, Kun; Xu, Shuhua; Jin, Li; Wang, Sijia

2016-01-01

An adaptive variant of human Ectodysplasin receptor, EDARV370A, had undergone strong positive selection in East Asia. In mice and humans, EDARV370A was found to affect ectodermal-derived characteristics, including hair thickness, hair shape, active sweat gland density and teeth formation. Facial characteristics are also largely ectodermal derived. In this study, taking advantage of an admixed population of East Asian and European ancestry-the Uyghur, we aim to test whether EDARV370A is affecting facial characteristics and to investigate its pleiotropic nature and genetic model. In a sample of 1027 Uyghurs, we discover that EDARV370A is significantly associated with several facial characteristics, in particular shape of earlobe (P = 3.64 × 10 (-6) ) and type of chin (P = 9.23 × 10 (-5) ), with successful replication in other East Asian populations. Additionally, in this Uyghur population, we replicate previous association findings of incisors shoveling (P = 1.02 × 10 (-7) ), double incisors shoveling (P = 1.86 × 10 (-12) ) and hair straightness (P = 3.99 × 10 (-16) ), providing strong evidence supporting an additive model for the EDARV370A associations. Partial least square path model confirms EDARV370A systematically affect these weakly related ectodermal-derived characteristics, suggesting the pleiotropic effect of EDARV370A mainly plays roles in early embryo development. This study extends our knowledge about the pleiotropic nature of EDARV370A and provides potential clues to its adaptation fitness in human evolution.

Fit Minded College Edition Pilot Study: Can a Magazine-Based Discussion Group Improve Physical Activity in Female College Freshmen?

PubMed

Pellitteri, Katelyn; Huberty, Jennifer; Ehlers, Diane; Bruening, Meg

Initial efficacy of a magazine-based discussion group for improving physical activity (PA), self-worth, and eating behaviors in female college freshmen. Randomized control trial. A large university in southwestern United States. Thirty-seven female college freshmen were randomized to the intervention (n = 17) and control groups (n = 20) in September 2013. Participants completed an 8-week magazine-based discussion group program, Fit Minded College Edition, adapted from Fit Minded, a previously tested theory-based intervention. Education on PA, self-worth, and nutrition was provided using excerpts from women's health magazines. Participants also had access to a Web site with supplementary health and wellness material. The control group did not attend meetings or have access to the Web site but received the magazines. Interventions focusing on concepts of self-worth with less focus on weight and appearance may promote long term PA participation and healthy eating behaviors in college women. Self-reported PA, global self-worth, knowledge self-worth, self-efficacy, social support, eating behaviors (ie, fruit/veggie/junk food/sugar-sweetened beverage consumption), satisfaction, and Web site usage. Mean age of participants was 18.11 (SD = 0.32) years. Time × Intervention effects were observed for PA minutes per week (Partial η = 0.34), knowledge self-worth (Partial η = 0.02), and daily sugar-sweetened beverage consumption (Partial η = 0.17) (P < .05), with the intervention group reporting greater increases in PA and knowledge self-worth and greater decreases in sugar-sweetened beverage consumption. A magazine-based discussion group may provide a promising platform to improve health behaviors in female college freshmen.

Is HE 0436-4717 Anemic? A deep look at a bare Seyfert 1 galaxy

NASA Astrophysics Data System (ADS)

Bonson, K.; Gallo, L. C.; Vasudevan, R.

2015-06-01

A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436-4717 is conducted using optical to X-ray data from XMM-Newton and Swift (including the Burst Alert Telescope). Fitting of the UV-to-X-ray spectral energy distribution shows little evidence of extinction and the X-ray spectral analysis does not confirm previous reports of deep absorption edges from O VIII. HE 0436-4717 is a `bare' Seyfert with negligible line-of-sight absorption making it ideal to study the central X-ray emitting region. Three scenarios were considered to describe the X-ray data: partial covering absorption, blurred reflection, and soft Comptonization. All three interpretations describe the 0.5-10.0 keV spectra well. Extrapolating the models to 100 keV results in poorer fits for the partial covering model. When also considering the rapid variability during one of the XMM-Newton observations, the blurred reflection model appears to describe all the observations in the most self-consistent manner. If adopted, the blurred reflection model requires a very low iron abundance in HE 0436-4717. We consider the possibilities that this is an artefact of the fitting process, but it appears possible that it is intrinsic to the object.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yi, MinKyung; Tong, Xiao; Skelton, Angela

Drug resistance is a major issue in the development and use of specific antiviral therapies. Here we report the isolation and characterization of hepatitis C virus RNA replicons resistant to a novel ketoamide inhibitor of the NS3/4A protease, SCH6 (originally SCH446211). Resistant replicon RNAs were generated by G418 selection in the presence of SCH6 in a dose-dependent fashion, with the emergence of resistance reduced at higher SCH6 concentrations. Sequencing demonstrated remarkable consistency in the mutations conferring SCH6 resistance in genotype 1b replicons derived from two different strains of hepatitis C virus, A156T/A156V and R109K. R109K, a novel mutation not reportedmore » previously to cause resistance to NS3/4A inhibitors, conferred moderate resistance only to SCH6. Structural analysis indicated that this reflects unique interactions of SCH6 with P{prime}-side residues in the protease active site. In contrast, A156T conferred high level resistance to SCH6 and a related ketoamide, SCH503034, as well as BILN 2061 and VX-950. Unlike R109K, which had minimal impact on NS3/4A enzymatic function, A156T significantly reduced NS3/4A catalytic efficiency, polyprotein processing, and replicon fitness. However, three separate second-site mutations, P89L, Q86R, and G162R, were capable of partially reversing A156T-associated defects in polyprotein processing and/or replicon fitness, without significantly reducing resistance to the protease inhibitor.« less

Beyond Negative Affectivity: A Hierarchical Model of Global and Transdiagnostic Vulnerabilities for Emotional Disorders.

PubMed

Paulus, Daniel J; Talkovsky, Alexander M; Heggeness, Luke F; Norton, Peter J

2015-01-01

Negative affectivity (NA) has been linked to anxiety and depression (DEP). Identifying the common factors between anxiety and DEP is important when explaining their overlap and comorbidity. However, general factors such as NA tend to have differential relationships with different disorders, suggesting the need to identify mediators in order to explicate these relationships. The current study tests a theoretically and empirically derived hierarchical model of emotional disorders including both a general factor (NA) and transdiagnostic risk factors [anxiety sensitivity (AS) and intolerance of uncertainty (IoU)] using structural equation modeling. AS was tested as a mid-level factor between NA and panic disorder/agoraphobia, while IoU was tested as a mid-level factor between NA and social phobia, generalized anxiety disorder, obsessive-compulsive disorder, and DEP. Data from 642 clinical outpatients with a heterogeneous presentation of emotional disorders were available for analysis. The hierarchical model fits the data adequately. Moreover, while a simplified model removing AS and IoU fits the data well, it resulted in a significant loss of information for all latent disorder constructs. Data were unavailable to estimate post-traumatic stress disorder or specific phobias. Future work will need to extend to other emotional disorders. This study demonstrates the importance of both general factors that link disorders together and semi-specific transdiagnostic factors partially explaining their heterogeneity. Including these mid-level factors in hierarchical models of psychopathology can help account for additional variance and help to clarify the relationship between disorder constructs and NA.

The effect of various quantum mechanically derived partial atomic charges on the bulk properties of chloride-based ionic liquids

NASA Astrophysics Data System (ADS)

Zolghadr, Amin Reza; Ghatee, Mohammad Hadi; Moosavi, Fatemeh

2016-08-01

Partial atomic charges using various quantum mechanical calculations for [Cnmim]Cl (n = 1, 4) ionic liquids (ILs) are obtained and used for development of molecular dynamics simulation (MD) force fields. The isolated ion pairs are optimized using HF, B3LYP, and MP2 methods for electronic structure with 6-311++G(d,p) basis set. Partial atomic charges are assigned to the atomic center with CHELPG and NBO methods. The effect of these sets of partial charges on the static and dynamic properties of ILs is evaluated by performing a series of MD simulations and comparing the essential thermodynamic properties with the available experimental data and available molecular dynamics simulation results. In contrast to the general trends reported for ionic liquids with BF4, PF6, and iodide anions (in which restrained electrostatic potential (RESP) charges are preferred), partial charges derived by B3LYP-NBO method are relatively good in prediction of the structural, dynamical, and thermodynamic energetic properties of the chloride based ILs.

Influence of oxygen partial pressure on the microstructural and magnetic properties of Er-doped ZnO thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wei-Bin; Li, Fei; Chen, Hong-Ming

2015-06-15

Er-doped ZnO thin films have been prepared by using inductively coupled plasma enhanced physical vapor deposition at different O{sub 2}:Ar gas flow ratio (R = 0:30, 1:30, 1:15, 1:10 and 1:6). The influence of oxygen partial pressure on the structural, optical and magnetic properties was studied. It is found that an appropriate oxygen partial pressure (R=1:10) can produce the best crystalline quality with a maximum grain size. The internal strain, estimated by fitting the X-ray diffraction peaks, varied with oxygen partial pressure during growth. PL measurements show that plenty of defects, especially zinc vacancy, exist in Er-doped ZnO films. Allmore » the samples show room-temperature ferromagnetism. Importantly, the saturation magnetization exhibits similar dependency on oxygen partial pressure with the internal strain, which indicates that internal strain has an important effect on the magnetic properties of Er-doped ZnO thin films.« less

Low temperature heat capacities and thermodynamic functions described by Debye-Einstein integrals.

PubMed

Gamsjäger, Ernst; Wiessner, Manfred

2018-01-01

Thermodynamic data of various crystalline solids are assessed from low temperature heat capacity measurements, i.e., from almost absolute zero to 300 K by means of semi-empirical models. Previous studies frequently present fit functions with a large amount of coefficients resulting in almost perfect agreement with experimental data. It is, however, pointed out in this work that special care is required to avoid overfitting. Apart from anomalies like phase transformations, it is likely that data from calorimetric measurements can be fitted by a relatively simple Debye-Einstein integral with sufficient precision. Thereby, reliable values for the heat capacities, standard enthalpies, and standard entropies at T  = 298.15 K are obtained. Standard thermodynamic functions of various compounds strongly differing in the number of atoms in the formula unit can be derived from this fitting procedure and are compared to the results of previous fitting procedures. The residuals are of course larger when the Debye-Einstein integral is applied instead of using a high number of fit coefficients or connected splines, but the semi-empiric fit coefficients keep their meaning with respect to physics. It is suggested to use the Debye-Einstein integral fit as a standard method to describe heat capacities in the range between 0 and 300 K so that the derived thermodynamic functions are obtained on the same theory-related semi-empiric basis. Additional fitting is recommended when a precise description for data at ultra-low temperatures (0-20 K) is requested.

Quantification of Liver Proton-Density Fat Fraction in an 7.1 Tesla preclinical MR Systems: Impact of the Fitting Technique

PubMed Central

Mahlke, C; Hernando, D; Jahn, C; Cigliano, A; Ittermann, T; Mössler, A; Kromrey, ML; Domaska, G; Reeder, SB; Kühn, JP

2016-01-01

Purpose To investigate the feasibility of estimating the proton-density fat fraction (PDFF) using a 7.1 Tesla magnetic resonance imaging (MRI) system and to compare the accuracy of liver fat quantification using different fitting approaches. Materials and Methods Fourteen leptin-deficient ob/ob mice and eight intact controls were examined in a 7.1 Tesla animal scanner using a 3-dimensional six-echo chemical shift-encoded pulse sequence. Confounder-corrected PDFF was calculated using magnitude (magnitude data alone) and combined fitting (complex and magnitude data). Differences between fitting techniques were compared using Bland-Altman analysis. In addition, PDFFs derived with both reconstructions were correlated with histopathological fat content and triglyceride mass fraction using linear regression analysis. Results The PDFFs determined with use of both reconstructions correlated very strongly (r=0.91). However, small mean bias between reconstructions demonstrated divergent results (3.9%; CI 2.7%-5.1%). For both reconstructions, there was linear correlation with histopathology (combined fitting: r=0.61; magnitude fitting: r=0.64) and triglyceride content (combined fitting: r=0.79; magnitude fitting: r=0.70). Conclusion Liver fat quantification using the PDFF derived from MRI performed at 7.1 Tesla is feasible. PDFF has strong correlations with histopathologically determined fat and with triglyceride content. However, small differences between PDFF reconstruction techniques may impair the robustness and reliability of the biomarker at 7.1 Tesla. PMID:27197806

Generation of three-dimensional body-fitted grids by solving hyperbolic partial differential equations

NASA Technical Reports Server (NTRS)

Steger, Joseph L.

1989-01-01

Hyperbolic grid generation procedures are described which have been used in external flow simulations about complex configurations. For many practical applications a single well-ordered (i.e., structured) grid can be used to mesh an entire configuration, in other problems, composite or unstructured grid procedures are needed. Although the hyperbolic partial differential equation grid generation procedure has mainly been utilized to generate structured grids, an extension of the procedure to semiunstructured grids is briefly described. Extensions of the methodology are also described using two-dimensional equations.

Generation of three-dimensional body-fitted grids by solving hyperbolic and parabolic partial differential equations

NASA Technical Reports Server (NTRS)

Steger, Joseph L.

1989-01-01

Hyperbolic grid generation procedures are described which have been used in external flow simulations about complex configurations. For many practical applications a single well-ordered (i.e., structured) grid can be used to mesh an entire configuration, in other problems, composite or unstructured grid procedures are needed. Although the hyperbolic partial differential equation grid generation procedure has mainly been utilized to generate structured grids, extension of the procedure to semiunstructured grids is briefly described. Extensions of the methodology are also described using two-dimensional equations.

Extended optical model for fission

DOE PAGES

Sin, M.; Capote, R.; Herman, M. W.; ...

2016-03-07

A comprehensive formalism to calculate fission cross sections based on the extension of the optical model for fission is presented. It can be used for description of nuclear reactions on actinides featuring multi-humped fission barriers with partial absorption in the wells and direct transmission through discrete and continuum fission channels. The formalism describes the gross fluctuations observed in the fission probability due to vibrational resonances, and can be easily implemented in existing statistical reaction model codes. The extended optical model for fission is applied for neutron induced fission cross-section calculations on 234,235,238U and 239Pu targets. A triple-humped fission barrier ismore » used for 234,235U(n,f), while a double-humped fission barrier is used for 238U(n,f) and 239Pu(n,f) reactions as predicted by theoretical barrier calculations. The impact of partial damping of class-II/III states, and of direct transmission through discrete and continuum fission channels, is shown to be critical for a proper description of the measured fission cross sections for 234,235,238U(n,f) reactions. The 239Pu(n,f) reaction can be calculated in the complete damping approximation. Calculated cross sections for 235,238U(n,f) and 239Pu(n,f) reactions agree within 3% with the corresponding cross sections derived within the Neutron Standards least-squares fit of available experimental data. Lastly, the extended optical model for fission can be used for both theoretical fission studies and nuclear data evaluation.« less

Partial weight support differentially affects corticomotor excitability across muscles of the upper limb

PubMed Central

Runnalls, Keith D.; Anson, Greg; Wolf, Steven L.; Byblow, Winston D.

2014-01-01

Abstract Partial weight support may hold promise as a therapeutic adjuvant during rehabilitation after stroke by providing a permissive environment for reducing the expression of abnormal muscle synergies that cause upper limb impairment. We explored the neurophysiological effects of upper limb weight support in 13 healthy young adults by measuring motor‐evoked potentials (MEPs) from transcranial magnetic stimulation (TMS) of primary motor cortex and electromyography from anterior deltoid (AD), biceps brachii (BB), extensor carpi radialis (ECR), and first dorsal interosseous (FDI). Five levels of weight support, varying from none to full, were provided to the arm using a commercial device (Saebo Mobile Arm Support). For each level of support, stimulus–response (SR) curves were derived from MEPs across a range of TMS intensities. Weight support affected background EMG activity in each of the four muscles examined (P <0.0001 for each muscle). Tonic background activity was primarily reduced in the AD. Weight support had a differential effect on the size of MEPs across muscles. After curve fitting, the SR plateau for ECR increased at the lowest support level (P =0.004). For FDI, the SR plateau increased at the highest support level (P =0.0003). These results indicate that weight support of the proximal upper limb modulates corticomotor excitability across the forearm and hand. The findings support a model of integrated control of the upper limb and may inform the use of weight support in clinical settings. PMID:25501435

Predicting hydration Gibbs energies of alkyl-aromatics using molecular simulation: a comparison of current force fields and the development of a new parameter set for accurate solvation data.

PubMed

Garrido, Nuno M; Jorge, Miguel; Queimada, António J; Gomes, José R B; Economou, Ioannis G; Macedo, Eugénia A

2011-10-14

The Gibbs energy of hydration is an important quantity to understand the molecular behavior in aqueous systems at constant temperature and pressure. In this work we review the performance of some popular force fields, namely TraPPE, OPLS-AA and Gromos, in reproducing the experimental Gibbs energies of hydration of several alkyl-aromatic compounds--benzene, mono-, di- and tri-substituted alkylbenzenes--using molecular simulation techniques. In the second part of the paper, we report a new model that is able to improve such hydration energy predictions, based on Lennard Jones parameters from the recent TraPPE-EH force field and atomic partial charges obtained from natural population analysis of density functional theory calculations. We apply a scaling factor determined by fitting the experimental hydration energy of only two solutes, and then present a simple rule to generate atomic partial charges for different substituted alkyl-aromatics. This rule has the added advantages of eliminating the unnecessary assumption of fixed charge on every substituted carbon atom and providing a simple guideline for extrapolating the charge assignment to any multi-substituted alkyl-aromatic molecule. The point charges derived here yield excellent predictions of experimental Gibbs energies of hydration, with an overall absolute average deviation of less than 0.6 kJ mol(-1). This new parameter set can also give good predictive performance for other thermodynamic properties and liquid structural information.

A new fourth-order Fourier-Bessel split-step method for the extended nonlinear Schroedinger equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, Patrick L.

2008-01-10

Fourier split-step techniques are often used to compute soliton-like numerical solutions of the nonlinear Schroedinger equation. Here, a new fourth-order implementation of the Fourier split-step algorithm is described for problems possessing azimuthal symmetry in 3 + 1-dimensions. This implementation is based, in part, on a finite difference approximation {delta}{sub perpendicular} {sup FDA} of 1/r ({partial_derivative})/({partial_derivative}r) r({partial_derivative})/({partial_derivative}r) that possesses an associated exact unitary representation of e{sup i/2{lambda}}{sup {delta}{sub perpendicular}{sup FDA}}. The matrix elements of this unitary matrix are given by special functions known as the associated Bessel functions. Hence the attribute Fourier-Bessel for the method. The Fourier-Bessel algorithm is shown tomore » be unitary and unconditionally stable. The Fourier-Bessel algorithm is employed to simulate the propagation of a periodic series of short laser pulses through a nonlinear medium. This numerical simulation calculates waveform intensity profiles in a sequence of planes that are transverse to the general propagation direction, and labeled by the cylindrical coordinate z. These profiles exhibit a series of isolated pulses that are offset from the time origin by characteristic times, and provide evidence for a physical effect that may be loosely termed normal mode condensation. Normal mode condensation is consistent with experimentally observed pulse filamentation into a packet of short bursts, which may occur as a result of short, intense irradiation of a medium.« less

Estimating the Area Under ROC Curve When the Fitted Binormal Curves Demonstrate Improper Shape.

PubMed

Bandos, Andriy I; Guo, Ben; Gur, David

2017-02-01

The "binormal" model is the most frequently used tool for parametric receiver operating characteristic (ROC) analysis. The binormal ROC curves can have "improper" (non-concave) shapes that are unrealistic in many practical applications, and several tools (eg, PROPROC) have been developed to address this problem. However, due to the general robustness of binormal ROCs, the improperness of the fitted curves might carry little consequence for inferences about global summary indices, such as the area under the ROC curve (AUC). In this work, we investigate the effect of severe improperness of fitted binormal ROC curves on the reliability of AUC estimates when the data arise from an actually proper curve. We designed theoretically proper ROC scenarios that induce severely improper shape of fitted binormal curves in the presence of well-distributed empirical ROC points. The binormal curves were fitted using maximum likelihood approach. Using simulations, we estimated the frequency of severely improper fitted curves, bias of the estimated AUC, and coverage of 95% confidence intervals (CIs). In Appendix S1, we provide additional information on percentiles of the distribution of AUC estimates and bias when estimating partial AUCs. We also compared the results to a reference standard provided by empirical estimates obtained from continuous data. We observed up to 96% of severely improper curves depending on the scenario in question. The bias in the binormal AUC estimates was very small and the coverage of the CIs was close to nominal, whereas the estimates of partial AUC were biased upward in the high specificity range and downward in the low specificity range. Compared to a non-parametric approach, the binormal model led to slightly more variable AUC estimates, but at the same time to CIs with more appropriate coverage. The improper shape of the fitted binormal curve, by itself, ie, in the presence of a sufficient number of well-distributed points, does not imply unreliable AUC-based inferences. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Prediction of 30-year risk for cardiovascular mortality by fitness and risk factor levels: the Cooper Center Longitudinal Study.

PubMed

Wickramasinghe, Chanaka D; Ayers, Colby R; Das, Sandeep; de Lemos, James A; Willis, Benjamin L; Berry, Jarett D

2014-07-01

Fitness and traditional risk factors have well-known associations with cardiovascular disease (CVD) death in both short-term (10 years) and across the remaining lifespan. However, currently available short-term and long-term risk prediction tools do not incorporate measured fitness. We included 16 533 participants from the Cooper Center Longitudinal Study (CCLS) without prior CVD. Fitness was measured using the Balke protocol. Sex-specific fitness levels were derived from the Balke treadmill times and categorized into low, intermediate, and high fit according to age- and sex-specific treadmill times. Sex-specific 30-year risk estimates for CVD death adjusted for competing risk of non-CVD death were estimated using the cause-specific hazards model and included age, body mass index, systolic blood pressure, fitness, diabetes mellitus, total cholesterol, and smoking. During a median follow-up period of 28 years, there were 1123 CVD deaths. The 30-year risk estimates for CVD mortality derived from the cause-specific hazards model demonstrated overall good calibration (Nam-D'Agostino χ(2) [men, P=0.286; women, P=0.664] and discrimination (c statistic; men, 0.81 [0.80-0.82] and women, 0.86 [0.82-0.91]). Across all risk factor strata, the presence of low fitness was associated with a greater 30-year risk for CVD death. Fitness represents an important additional covariate in 30-year risk prediction functions that may serve as a useful tool in clinical practice. © 2014 American Heart Association, Inc.

Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

NASA Technical Reports Server (NTRS)

Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

2014-01-01

The safety-of-flight parameters for the Adaptive Compliant Trailing Edge (ACTE) flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces were monitored; each contained four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty-one applied test load cases were developed using the predicted in-flight loads. Pre-test predictions of strain gage responses were produced using finite element method models of the interface fittings. Predicted and measured test strains are presented. A load testing rig and three hydraulic jacks were used to apply combinations of shear, bending, and axial loads to the interface fittings. Hardware deflections under load were measured using photogrammetry and transducers. Due to deflections in the interface fitting hardware and test rig, finite element model techniques were used to calculate the reaction loads throughout the applied load range, taking into account the elastically-deformed geometry. The primary load equations were selected based on multiple calibration metrics. An independent set of validation cases was used to validate each derived equation. The 2-sigma residual errors for the shear loads were less than eight percent of the full-scale calibration load; the 2-sigma residual errors for the bending moment loads were less than three percent of the full-scale calibration load. The derived load equations for shear, bending, and axial loads are presented, with the calculated errors for both the calibration cases and the independent validation load cases.

Galaxy and mass assembly (GAMA): the consistency of GAMA and WISE derived mass-to-light ratios

NASA Astrophysics Data System (ADS)

Kettlety, T.; Hesling, J.; Phillipps, S.; Bremer, M. N.; Cluver, M. E.; Taylor, E. N.; Bland-Hawthorn, J.; Brough, S.; De Propris, R.; Driver, S. P.; Holwerda, B. W.; Kelvin, L. S.; Sutherland, W.; Wright, A. H.

2018-01-01

Recent work has suggested that mid-IR wavelengths are optimal for estimating the mass-to-light ratios of stellar populations and hence the stellar masses of galaxies. We compare stellar masses deduced from spectral energy distribution (SED) models, fitted to multiwavelength optical-NIR photometry, to luminosities derived from WISE photometry in the W1 and W2 bands at 3.6 and 4.5 μm for non-star forming galaxies. The SED-derived masses for a carefully selected sample of low-redshift (z ≤ 0.15) passive galaxies agree with the prediction from stellar population synthesis models such that M*/LW1 ≃ 0.6 for all such galaxies, independent of other stellar population parameters. The small scatter between masses predicted from the optical SED and from the WISE measurements implies that random errors (as opposed to systematic ones such as the use of different initial mass functions) are smaller than previous, deliberately conservative, estimates for the SED fits. This test is subtly different from simultaneously fitting at a wide range of optical and mid-IR wavelengths, which may just generate a compromised fit: we are directly checking that the best-fitting model to the optical data generates an SED whose M*/LW1 is also consistent with separate mid-IR data. We confirm that for passive low-redshift galaxies a fixed M*/LW1 = 0.65 can generate masses at least as accurate as those obtained from more complex methods. Going beyond the mean value, in agreement with expectations from the models, we see a modest change in M*/LW1 with SED fitted stellar population age but an insignificant one with metallicity.

Analytical solution of the nonlinear diffusion equation

NASA Astrophysics Data System (ADS)

Shanker Dubey, Ravi; Goswami, Pranay

2018-05-01

In the present paper, we derive the solution of the nonlinear fractional partial differential equations using an efficient approach based on the q -homotopy analysis transform method ( q -HATM). The fractional diffusion equations derivatives are considered in Caputo sense. The derived results are graphically demonstrated as well.

Physicochemical properties and ion-solvent interactions in aqueous sodium, ammonium, and lead acetate solution

NASA Astrophysics Data System (ADS)

Deosarkar, S. D.; Mendkudle, M. S.

2014-09-01

Densities (ρ), viscosities (η) and refractive indices ( n D) of aqueous sodium acetate (SA), ammonium acetate (AA), and lead acetate (LA) solutions have been measured for different concentrations of salts at 302.15 K. Apparent molar volumes (φv) for studied solutions were calculated from density data, and fitted to Masson's relation and partial molar volume (φ{v/o}) was determined. Viscosity data were fitted to Jones-Dole equation and viscosity A- and B-coefficients were determined. Refractive index and density data were fitted to Lorentz and Lorenz equation and specific refraction ( R D) were calculated. Behavior of various physicochemical properties indicated presence of strong ion-solvent interactions in present systems and the acetate salts structure maker in water.

Model-independent partial wave analysis using a massively-parallel fitting framework

NASA Astrophysics Data System (ADS)

Sun, L.; Aoude, R.; dos Reis, A. C.; Sokoloff, M.

2017-10-01

The functionality of GooFit, a GPU-friendly framework for doing maximum-likelihood fits, has been extended to extract model-independent {\\mathscr{S}}-wave amplitudes in three-body decays such as D + → h + h + h -. A full amplitude analysis is done where the magnitudes and phases of the {\\mathscr{S}}-wave amplitudes are anchored at a finite number of m 2(h + h -) control points, and a cubic spline is used to interpolate between these points. The amplitudes for {\\mathscr{P}}-wave and {\\mathscr{D}}-wave intermediate states are modeled as spin-dependent Breit-Wigner resonances. GooFit uses the Thrust library, with a CUDA backend for NVIDIA GPUs and an OpenMP backend for threads with conventional CPUs. Performance on a variety of platforms is compared. Executing on systems with GPUs is typically a few hundred times faster than executing the same algorithm on a single CPU.

Application of near-infrared spectroscopy for the rapid quality assessment of Radix Paeoniae Rubra

NASA Astrophysics Data System (ADS)

Zhan, Hao; Fang, Jing; Tang, Liying; Yang, Hongjun; Li, Hua; Wang, Zhuju; Yang, Bin; Wu, Hongwei; Fu, Meihong

2017-08-01

Near-infrared (NIR) spectroscopy with multivariate analysis was used to quantify gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra, and the feasibility to classify the samples originating from different areas was investigated. A new high-performance liquid chromatography method was developed and validated to analyze gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra as the reference. Partial least squares (PLS), principal component regression (PCR), and stepwise multivariate linear regression (SMLR) were performed to calibrate the regression model. Different data pretreatments such as derivatives (1st and 2nd), multiplicative scatter correction, standard normal variate, Savitzky-Golay filter, and Norris derivative filter were applied to remove the systematic errors. The performance of the model was evaluated according to the root mean square of calibration (RMSEC), root mean square error of prediction (RMSEP), root mean square error of cross-validation (RMSECV), and correlation coefficient (r). The results show that compared to PCR and SMLR, PLS had a lower RMSEC, RMSECV, and RMSEP and higher r for all the four analytes. PLS coupled with proper pretreatments showed good performance in both the fitting and predicting results. Furthermore, the original areas of Radix Paeoniae Rubra samples were partly distinguished by principal component analysis. This study shows that NIR with PLS is a reliable, inexpensive, and rapid tool for the quality assessment of Radix Paeoniae Rubra.

Kinetics of thermochemical gas-solid reactions important in the Venus sulfur cycle

NASA Technical Reports Server (NTRS)

Fegley, Bruce, Jr.

1988-01-01

The thermochemical net reaction CaCO3 + SO2 yields CaSO4 + CO is predicted to be an important sink for incorporation of SO2 into the Venus crust. The reaction rate law was established to understand the dependence of rate on experimental variables such as temperature and partial pressure of SO2, CO2, and O2. The experimental approach was a variant of the thermogravimetric method often employed to study the kinetics of thermochemical gas-solid reactions. Clear calcite crystals were heated at constant temperature in SO2-bearing gas streams for varying time periods. Reaction rate was determined by three independent methods. A weighted linear least squares fit to all rate data yielded a rate equation. Based on the Venera 13, 14 and Vega 2 observations of CaO content of the Venus atmosphere, SO2 at the calculated rate would be removed from the Venus atmosphere in about 1,900,00 years. The most plausible endogenic source of the sulfur needed to replenish atmospheric SO2 is volcanism. The annual amount of erupted material needed for the replenishment depends on sulfur content; three ratios are used to calculate rates ranging from 0.4 to 11 cu km/year. This geochemically derived volcanism rate can be used to test if geophysically derived rates are correct. The work also suggests that Venus is less volcanically active than the Earth.

Rasch model of a dynamic assessment: an investigation of the children's inferential thinking modifiability test.

PubMed

Rittner, Linda L; Pulos, Steven M

2014-01-01

The purpose of this study was to develop a general procedure for evaluation of a dynamic assessment and to demonstrate an analysis of a dynamic assessment, the CITM (Tzuriel, 1995b), as an objective measure for use as a group assessment. The techniques used to determine the fit of the CITM to a Rasch partial credit model are explicitly outlined. A modified format of the CITM was administered to 266 diverse second grade students in the USA; 58% of participants were identified as low SES. The participants (males n = 144) were White Anglo and Latino American students (55%), many of whom were first generation Mexican immigrants. The CITM was found to adequately fit a Rasch partial credit model (PCM) indicating that the CITM is a likely candidate for a group administered dynamic assessment that can be measured objectively. Data also supported that a model for objectively measuring change in learning ability for inferential thinking in the CITM was feasible.

Multivariate qualitative analysis of banned additives in food safety using surface enhanced Raman scattering spectroscopy

NASA Astrophysics Data System (ADS)

He, Shixuan; Xie, Wanyi; Zhang, Wei; Zhang, Liqun; Wang, Yunxia; Liu, Xiaoling; Liu, Yulong; Du, Chunlei

2015-02-01

A novel strategy which combines iteratively cubic spline fitting baseline correction method with discriminant partial least squares qualitative analysis is employed to analyze the surface enhanced Raman scattering (SERS) spectroscopy of banned food additives, such as Sudan I dye and Rhodamine B in food, Malachite green residues in aquaculture fish. Multivariate qualitative analysis methods, using the combination of spectra preprocessing iteratively cubic spline fitting (ICSF) baseline correction with principal component analysis (PCA) and discriminant partial least squares (DPLS) classification respectively, are applied to investigate the effectiveness of SERS spectroscopy for predicting the class assignments of unknown banned food additives. PCA cannot be used to predict the class assignments of unknown samples. However, the DPLS classification can discriminate the class assignment of unknown banned additives using the information of differences in relative intensities. The results demonstrate that SERS spectroscopy combined with ICSF baseline correction method and exploratory analysis methodology DPLS classification can be potentially used for distinguishing the banned food additives in field of food safety.

The fatigue of high office

NASA Astrophysics Data System (ADS)

Ramsden, Jeremy J.; Naran, Deven

2007-03-01

The word frequencies of the speeches of some contemporary politicians have been determined over a decade of office. By fitting Mandelbrot's simple canonical law (a development of Zipf 's law) to the data, the average cybernetic temperature θ was determined for each year of office. Two contrasting cases were examined. The first, that of the British Prime Minister Tony Blair, showed a steady decline of θ punctuated by partial recovery following certain key events such as re-election. The second, that of the Australian Prime Minister John Howard, showed a more uniform temperature. It is suggested that the first case is an example of the phenomenon of fatigue or habituation, inevitable in any complex system rich in equilibrium states, and the partial de-habituation observed is a consequence of a sharp disturbance to the system. Given the relative ease of carrying out the analysis, it could become a routine tool regularly applied to holders of high office to determine their continuing fitness to occupy the office.

Statistically Self-Consistent and Accurate Errors for SuperDARN Data

NASA Astrophysics Data System (ADS)

Reimer, A. S.; Hussey, G. C.; McWilliams, K. A.

2018-01-01

The Super Dual Auroral Radar Network (SuperDARN)-fitted data products (e.g., spectral width and velocity) are produced using weighted least squares fitting. We present a new First-Principles Fitting Methodology (FPFM) that utilizes the first-principles approach of Reimer et al. (2016) to estimate the variance of the real and imaginary components of the mean autocorrelation functions (ACFs) lags. SuperDARN ACFs fitted by the FPFM do not use ad hoc or empirical criteria. Currently, the weighting used to fit the ACF lags is derived from ad hoc estimates of the ACF lag variance. Additionally, an overcautious lag filtering criterion is used that sometimes discards data that contains useful information. In low signal-to-noise (SNR) and/or low signal-to-clutter regimes the ad hoc variance and empirical criterion lead to underestimated errors for the fitted parameter because the relative contributions of signal, noise, and clutter to the ACF variance is not taken into consideration. The FPFM variance expressions include contributions of signal, noise, and clutter. The clutter is estimated using the maximal power-based self-clutter estimator derived by Reimer and Hussey (2015). The FPFM was successfully implemented and tested using synthetic ACFs generated with the radar data simulator of Ribeiro, Ponomarenko, et al. (2013). The fitted parameters and the fitted-parameter errors produced by the FPFM are compared with the current SuperDARN fitting software, FITACF. Using self-consistent statistical analysis, the FPFM produces reliable or trustworthy quantitative measures of the errors of the fitted parameters. For an SNR in excess of 3 dB and velocity error below 100 m/s, the FPFM produces 52% more data points than FITACF.

Identification of biomarkers associated with partial epithelial to mesenchymal transition in the secretome of slug over-expressing hepatocellular carcinoma cells.

PubMed

Karaosmanoğlu, Oğuzhan; Banerjee, Sreeparna; Sivas, Hülya

2018-06-01

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Complete epithelial to mesenchymal transition (EMT) has long been considered as a crucial step for metastasis initiation. It has, however, become apparent that many carcinoma cells can metastasize without complete loss of epithelial traits or with incomplete gain of mesenchymal traits, i.e., partial EMT. Here, we aimed to determine the similarities and differences between complete and partial EMT through over-expression of the EMT-associated transcription factor Slug in different HCC-derived cell lines. Slug over-expressing HCC-derived HepG2 and Huh7 cells were assessed for their EMT, chemo-resistance and stemness features using Western blotting, qRT-PCR, neutral red uptake, doxorubicin accumulation and scratch wound healing assays. We also collected conditioned media from Slug over-expressing HCC cells and analyzed its exosomal protein content for the presence of chemo-resistance and partial EMT markers using MALDI-TOF/TOF and ELISA assays, respectively. We found that Slug over-expression resulted in the induction of both complete and partial EMT in the different HCC-derived cell lines tested. Complete EMT was characterized by downregulation of E-cadherin and upregulation of ZEB2. Partial EMT was characterized by upregulation of E-cadherin and downregulation of vimentin and ZEB2. Interestingly, we found that Slug induced chemo-resistance through downregulation of the ATP binding cassette (ABC) transporter ABCB1 and upregulation of the ABC transporter ABCG2, as well as through expression of CD133, a stemness marker that exhibited a similar expression pattern in cells with either a complete or a partial EMT phenotype. In addition, we found that Slug-mediated partial EMT was associated with enhanced exosomal secretion of post-translationally modified fibronectin 1 (FN1), collagen type II alpha 1 (COL2A1) and native fibrinogen gamma chain (FGG). From our data we conclude that the exosomal proteins identified may be considered as potential non-invasive biomarkers for chemo-resistance and partial EMT in HCC.

On the Accuracy of Atmospheric Parameter Determination in BAFGK Stars

NASA Astrophysics Data System (ADS)

Ryabchikova, T.; Piskunov, N.; Shulyak, D.

2015-04-01

During the past few years, many papers determining the atmospheric parameters in FGK stars appeared in the literature where the accuracy of effective temperatures is given as 20-40 K. For main sequence stars within the 5 000-13 000 K temperature range, we have performed a comparative analysis of the parameters derived from the spectra by using the SME (Spectroscopy Made Easy) package and those found in the literature. Our sample includes standard stars Sirius, Procyon, δ Eri, and the Sun. Combining different spectral regions in the fitting procedure, we investigated an effect different atomic species have on the derived atmospheric parameters. The temperature difference may exceed 100 K depending on the spectral regions used in the SME procedure. It is shown that the atmospheric parameters derived with the SME procedure which includes wings of hydrogen lines in fitting agrees better with the results derived by the other methods and tools across a large part of the main sequence. For three stars—π Cet, 21 Peg, and Procyon—the atmospheric parameters were also derived by fitting a calculated energy distribution to the observed one. We found a substantial difference in the parameters inferred from different sets and combinations of spectrophotometric observations. An intercomparison of our results and literature data shows that the average accuracy of effective temperature determination for cool stars and for the early B-stars is 70-85 K and 170-200 K, respectively.

Derivation of surface properties from Magellan altimetry data

NASA Astrophysics Data System (ADS)

Lovell, Amy J.; Schloerb, F. Peter; McGill, George E.

1992-12-01

The fit of the Hagfors model to the Magellan altimetry data provides a means to characterize the surface properties of Venus. However, the derived surface properties are only meaningful if the model provides a good representation of the data. The Hagfors model provides a good representation of the data. The Hagfors model is generally a realistic fit to surface scattering properties of a nadir-directed antenna such as the Magellan altimeter; however, some regions of the surface of Venus are poorly described by the existing model, according to the goodness of fit parameter provided on the ARCDR CD-ROMs. Poorly characterized regions need to be identified and fit to new models in order to derive more accurate surface properties for use in inferring the geological processes that affect the surface in those regions. We have compared the goodness of fit of the Hagfors model to the distribution of features across the planet, and preliminary results show a correlation between steep topographic slopes and poor fits to the standard model, as has been noticed by others. In this paper, we investigate possible relations between many classes of features and the ability of the Hagfors model to fit the observed echo profiles. In the regions that are not well characterized by existing models, we calculate new models that compensate for topographic relief in order to derive improved estimates of surface properties. Areas investigated to date span from longitude 315 through 45, at all latitudes covered by Magellan. A survey of those areas yields preliminary results that suggest that topographically high regions are well suited to the current implementation of the Hagfors model. Striking examples of such large-scale good fits are Alpha Regio, the northern edges of Lada Terra, and the southern edge of Ishtar Terra. Other features that are typically well fit are the rims of coronae such as Heng-O and the peaks of volcanos such as Gula Mons. Surprisingly, topographically low regions, such as the ubiquitous plains areas, are modeled poorly in comparison. However, this generalization has has exceptions: Lakshmi Planum is an elevated region that is not well fit compared to the rest of neighboring Ishtar, while the southern parts of topographically low Guinevere Planitia are characterized quite well by the Hagfors model. Features that are candidates for improved models are impact craters, coronae, ridges of significant scale, complex ridged terrains, moderate-sized mountains, and sharp terrain boundaries. These features are chosen because the goodness of fit is likely to be most affected either by departures from normal incidence angles or by sharp changes in terrain type within a single footprint. Most large features that are elevated with respect to their surroundings will suffer from steep slope effects, and smaller coronae and impact craters will probably suffer due to rapid changes in their appearance within a single footprint (10-20 km).

Derivation of surface properties from Magellan altimetry data

NASA Technical Reports Server (NTRS)

Lovell, Amy J.; Schloerb, F. Peter; Mcgill, George E.

1992-01-01

The fit of the Hagfors model to the Magellan altimetry data provides a means to characterize the surface properties of Venus. However, the derived surface properties are only meaningful if the model provides a good representation of the data. The Hagfors model provides a good representation of the data. The Hagfors model is generally a realistic fit to surface scattering properties of a nadir-directed antenna such as the Magellan altimeter; however, some regions of the surface of Venus are poorly described by the existing model, according to the goodness of fit parameter provided on the ARCDR CD-ROMs. Poorly characterized regions need to be identified and fit to new models in order to derive more accurate surface properties for use in inferring the geological processes that affect the surface in those regions. We have compared the goodness of fit of the Hagfors model to the distribution of features across the planet, and preliminary results show a correlation between steep topographic slopes and poor fits to the standard model, as has been noticed by others. In this paper, we investigate possible relations between many classes of features and the ability of the Hagfors model to fit the observed echo profiles. In the regions that are not well characterized by existing models, we calculate new models that compensate for topographic relief in order to derive improved estimates of surface properties. Areas investigated to date span from longitude 315 through 45, at all latitudes covered by Magellan. A survey of those areas yields preliminary results that suggest that topographically high regions are well suited to the current implementation of the Hagfors model. Striking examples of such large-scale good fits are Alpha Regio, the northern edges of Lada Terra, and the southern edge of Ishtar Terra. Other features that are typically well fit are the rims of coronae such as Heng-O and the peaks of volcanos such as Gula Mons. Surprisingly, topographically low regions, such as the ubiquitous plains areas, are modeled poorly in comparison. However, this generalization has has exceptions: Lakshmi Planum is an elevated region that is not well fit compared to the rest of neighboring Ishtar, while the southern parts of topographically low Guinevere Planitia are characterized quite well by the Hagfors model. Features that are candidates for improved models are impact craters, coronae, ridges of significant scale, complex ridged terrains, moderate-sized mountains, and sharp terrain boundaries. These features are chosen because the goodness of fit is likely to be most affected either by departures from normal incidence angles or by sharp changes in terrain type within a single footprint. Most large features that are elevated with respect to their surroundings will suffer from steep slope effects, and smaller coronae and impact craters will probably suffer due to rapid changes in their appearance within a single footprint (10-20 km).

Efficient scheme for parametric fitting of data in arbitrary dimensions.

PubMed

Pang, Ning-Ning; Tzeng, Wen-Jer; Kao, Hisen-Ching

2008-07-01

We propose an efficient scheme for parametric fitting expressed in terms of the Legendre polynomials. For continuous systems, our scheme is exact and the derived explicit expression is very helpful for further analytical studies. For discrete systems, our scheme is almost as accurate as the method of singular value decomposition. Through a few numerical examples, we show that our algorithm costs much less CPU time and memory space than the method of singular value decomposition. Thus, our algorithm is very suitable for a large amount of data fitting. In addition, the proposed scheme can also be used to extract the global structure of fluctuating systems. We then derive the exact relation between the correlation function and the detrended variance function of fluctuating systems in arbitrary dimensions and give a general scaling analysis.

Maxillary implant-retained partial overdenture with Dolder bar attachment: a clinical report.

PubMed

Kim, Hyeongil; Buhite, Robert J; Monaco, Edward A

2015-03-01

This article describes a technique for maintaining a maxillary Kennedy III partial removable dental prosthesis design in a patient who had non-restorable failing abutments by replacing the abutments with dental implants. Two implants were placed immediately after extraction of the abutment teeth in the anterior maxilla. After the implants were fully integrated, a Dolder bar attachment was fitted onto the implants. A new maxillary partial removable dental prosthesis was fabricated using the implants and the remaining natural teeth as abutments to restore function and esthetics. With the aid of dental implants, this Kennedy III maxillary removable dental prosthesis design could provide additional retention and support by promoting cross-arch stability and tissue, implant and tooth support. The patient's satisfaction was significantly increased.

Statistical evaluation of the metallurgical test data in the ORR-PSF-PVS irradiation experiment. [PWR; BWR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stallmann, F.W.

1984-08-01

A statistical analysis of Charpy test results of the two-year Pressure Vessel Simulation metallurgical irradiation experiment was performed. Determination of transition temperature and upper shelf energy derived from computer fits compare well with eyeball fits. Uncertainties for all results can be obtained with computer fits. The results were compared with predictions in Regulatory Guide 1.99 and other irradiation damage models.

Partial connectivity increases cultural accumulation within groups.

PubMed

Derex, Maxime; Boyd, Robert

2016-03-15

Complex technologies used in most human societies are beyond the inventive capacities of individuals. Instead, they result from a cumulative process in which innovations are gradually added to existing cultural traits across many generations. Recent work suggests that a population's ability to develop complex technologies is positively affected by its size and connectedness. Here, we present a simple computer-based experiment that compares the accumulation of innovations by fully and partially connected groups of the same size in a complex fitness landscape. We find that the propensity to learn from successful individuals drastically reduces cultural diversity within fully connected groups. In comparison, partially connected groups produce more diverse solutions, and this diversity allows them to develop complex solutions that are never produced in fully connected groups. These results suggest that explanations of ancestral patterns of cultural complexity may need to consider levels of population fragmentation and interaction patterns between partially isolated groups.

Partial connectivity increases cultural accumulation within groups

PubMed Central

Boyd, Robert

2016-01-01

Complex technologies used in most human societies are beyond the inventive capacities of individuals. Instead, they result from a cumulative process in which innovations are gradually added to existing cultural traits across many generations. Recent work suggests that a population’s ability to develop complex technologies is positively affected by its size and connectedness. Here, we present a simple computer-based experiment that compares the accumulation of innovations by fully and partially connected groups of the same size in a complex fitness landscape. We find that the propensity to learn from successful individuals drastically reduces cultural diversity within fully connected groups. In comparison, partially connected groups produce more diverse solutions, and this diversity allows them to develop complex solutions that are never produced in fully connected groups. These results suggest that explanations of ancestral patterns of cultural complexity may need to consider levels of population fragmentation and interaction patterns between partially isolated groups. PMID:26929364

Low temperature time resolved photoluminescence in ordered and disordered Cu2ZnSnS4 single crystals

NASA Astrophysics Data System (ADS)

Raadik, Taavi; Krustok, Jüri; Kauk-Kuusik, M.; Timmo, K.; Grossberg, M.; Ernits, K.; Bleuse, J.

2017-03-01

In this work we performed time-resolved micro-photoluminescence (TRPL) studies of Cu2ZnSnS4 (CZTS) single crystals grown in molten KI salt. The order/disorder degree of CZTS was varied by the thermal post treatment temperature. Photoluminescence spectra measured at T=8 K showed an asymmetric band with a peak position of 1.33 eV and 1.27 eV for partially ordered and disordered structures, respectively. Thermal activation energies were found to be ET (PO) =65±9 meV for partially ordered and ET (PD) =27±4 meV for partially disordered. These low activation energy values indicating to the defect cluster recombination model for both partially ordered and disordered structures. TRPL was measured for both crystals and their decay curves were fitted with a stretched exponential function, in order to describe the charge carriers' recombination dynamics at low temperature.

ppcor: An R Package for a Fast Calculation to Semi-partial Correlation Coefficients.

PubMed

Kim, Seongho

2015-11-01

Lack of a general matrix formula hampers implementation of the semi-partial correlation, also known as part correlation, to the higher-order coefficient. This is because the higher-order semi-partial correlation calculation using a recursive formula requires an enormous number of recursive calculations to obtain the correlation coefficients. To resolve this difficulty, we derive a general matrix formula of the semi-partial correlation for fast computation. The semi-partial correlations are then implemented on an R package ppcor along with the partial correlation. Owing to the general matrix formulas, users can readily calculate the coefficients of both partial and semi-partial correlations without computational burden. The package ppcor further provides users with the level of the statistical significance with its test statistic.

General formalism for partial spatial coherence in reflection Mueller matrix polarimetry.

PubMed

Ossikovski, Razvigor; Hingerl, Kurt

2016-09-01

Starting from the first principles, we derive the expressions governing partially coherent Mueller matrix reflection polarimetry on spatially inhomogeneous samples. These are reported both in their general form and in the practically important specific form for two juxtaposed media.

40 years of mineral elasticity: a critical review and a new parameterisation of equations of state for mantle olivines and diamond inclusions

NASA Astrophysics Data System (ADS)

Angel, Ross J.; Alvaro, Matteo; Nestola, Fabrizio

2018-02-01

Elasticity is a key property of materials, not only for predicting volumes and densities of minerals at the pressures and temperatures in the interior of the Earth, but also because it is a major factor in the energetics of structural phase transitions, surface energies, and defects within minerals. Over the 40 years of publication of Physics and Chemistry of Minerals, great progress has been made in the accuracy and precision of the measurements of both volumes and elastic tensors of minerals and in the pressures and temperatures at which the measurements are made. As an illustration of the state of the art, all available single-crystal data that constrain the elastic properties and pressure-volume-temperature equation of state (EoS) of mantle-composition olivine are reviewed. Single-crystal elasticity measurements clearly distinguish the Reuss and Voigt bulk moduli of olivine at all conditions. The consistency of volume and bulk modulus data is tested by fitting them simultaneously. Data collected at ambient pressure and data collected at ambient temperature up to 15 GPa are consistent with a Mie-Grünesien-Debye thermal-pressure EoS in combination with a third-order Birch-Murnaghan (BM) compressional EoS, the parameter V 0 = 43.89 cm3 mol-1, isothermal Reuss bulk modulus K_{TR,0} = 126.3(2){ GPa}, K^'_{TR,0} = 4.54(6), a Debye temperature θD = 644(9){K}, and a Grüneisen parameter γ 0 = 1.044(4), whose volume dependence is described by q = 1.9(2). High-pressure softening of the bulk modulus at room temperature, relative to this EoS, can be fit with a fourth-order BM EoS. However, recent high- P, T Brillouin measurements are incompatible with these EoS and the intrinsic physics implied by it, especially that ( {partial K^'_{TR} }/partial T )P > 0. We introduce a new parameterisation for isothermal-type EoS that scales both the Reuss isothermal bulk modulus and its pressure derivative at temperature by the volume, K_{TR} (T,P = 0) = K_{TR,0} [ {{V0 }/V(T)} ]^{{δT }} and K^'_{TR} (T,P = 0) = K^'_{TR,0} [ {V(T)/{V_{0 }}} ]^{{δ^', to ensure thermodynamic correctness at low temperatures. This allows the elastic softening implied by the high- P, T Brillouin data for mantle olivine to be fit simultaneously and consistently with the same bulk moduli and pressure derivatives (at room temperature) as the MGD EoS, and with the additional parameters of α V0 = 2.666(9) × 10-5 K-1, θE = 484(6), δT = 5.77(8), and δ^' = -3.5(1.1). The effects of the differences between the two EoS on the calculated density, volume, and elastic properties of olivine at mantle conditions and on the calculation of entrapment conditions of olivine inclusions in diamonds are discussed, and approaches to resolve the current uncertainties are proposed.

The impact of person-organization fit on innovative work behavior: the mediating effect of knowledge sharing behavior.

PubMed

Afsar, Bilal

2016-01-01

The direct relationship between person-organization (P-O) fit and employee's positive work attitudes and behaviours have been well researched. However, there has been no study on the impact of P-O fit on innovative work behaviour (IWB) of the nurses. The purpose of this paper is to fill this gap in the literature. In order to give a complete understanding of the psychology surrounding P-O fit, this study has longitudinally analysed the relationship between P-O fit and IWB along with the impact of a potential mediator, i.e. knowledge sharing behaviour (KSB) on this relationship. A total of 357 nurses and 71 doctors from three government hospitals of Thailand filled out the questionnaires. Structural equation modelling was used to analyse the relationships. Results of the study indicate that a nurse's P-O fit is positively associated with both self and doctor ratings of innovative behaviours; and KSB acts as a partial mediator between P-O fit and IWB at both Times 1 and 2. These results imply that a nurse's perceived fit in the hospital impacts his/her engagement into IWB. As nurses share knowledge with their co-workers frequently, it tends to strengthen the relationship between P-O fit and IWB. Study findings begin to explain how P-O fit impacts IWB of nurses. Specifically, the author find that KSB explains the relationship between P-O fit and IWB.

Geometerial description for a proposed aeroassist flight experiment vehicle

NASA Technical Reports Server (NTRS)

Cheatwood, F. M.; Dejarnette, F. J.; Hamilton, H. H., II

1986-01-01

One geometry currently under consideration for the Aeroassist Flight Experiment (AFE) vehicle is composed of several segments of simple general conics: an ellipsoidal nose tangent to an elliptical cone and a base skirt with the base plane raked relative to the body axis. An analytic representation for the body coordinates and first and second partial derivatives of this configuration has been developed. Equations are given which define the body radius and partial derivatives for a prescribed axial and circumferential position on the vehicle. The results for a sample case are tabulated and presented graphically.

Uncertainties in extracted parameters of a Gaussian emission line profile with continuum background.

PubMed

Minin, Serge; Kamalabadi, Farzad

2009-12-20

We derive analytical equations for uncertainties in parameters extracted by nonlinear least-squares fitting of a Gaussian emission function with an unknown continuum background component in the presence of additive white Gaussian noise. The derivation is based on the inversion of the full curvature matrix (equivalent to Fisher information matrix) of the least-squares error, chi(2), in a four-variable fitting parameter space. The derived uncertainty formulas (equivalent to Cramer-Rao error bounds) are found to be in good agreement with the numerically computed uncertainties from a large ensemble of simulated measurements. The derived formulas can be used for estimating minimum achievable errors for a given signal-to-noise ratio and for investigating some aspects of measurement setup trade-offs and optimization. While the intended application is Fabry-Perot spectroscopy for wind and temperature measurements in the upper atmosphere, the derivation is generic and applicable to other spectroscopy problems with a Gaussian line shape.

Fitness level and body composition indices: cross-sectional study among Malaysian adolescent

PubMed Central

2014-01-01

Background The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices. Methods 1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness. Results 43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p < 0.001) between body composition with fitness score (r = -0.360, -0.413 and -0.403 for body mass index for age, waist circumference and waist height ratio, respectively). Waist circumference was the strongest and significant predictor for fitness (ß = -0.318, p = 0.002). Conclusion Only 9.6% of the students were fit. There was also an inverse association between body composition and fitness score among apparently healthy adolescents, with waist circumference indicated as the strongest predictor. The low fitness level among the Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age. PMID:25436933

Fitness level and body composition indices: cross-sectional study among Malaysian adolescent.

PubMed

Hanifah, Redzal Abu; Majid, Hazreen Abdul; Jalaludin, Muhammad Yazid; Al-Sadat, Nabilla; Murray, Liam J; Cantwell, Marie; Su, Tin Tin; Nahar, Azmi Mohamed

2014-01-01

The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices. 1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness. 43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p < 0.001) between body composition with fitness score (r = -0.360, -0.413 and -0.403 for body mass index for age, waist circumference and waist height ratio, respectively). Waist circumference was the strongest and significant predictor for fitness (ß = -0.318, p = 0.002). Only 9.6% of the students were fit. There was also an inverse association between body composition and fitness score among apparently healthy adolescents, with waist circumference indicated as the strongest predictor. The low fitness level among the Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age.

Parenting Styles and Adjustment Outcomes among College Students

ERIC Educational Resources Information Center

Love, Keisha M.; Thomas, Deneia M.

2014-01-01

Research has demonstrated that parenting styles partially explain college students' academic adjustment. However, to account for academic adjustment more fully, additional contributors should be identified and tested. We examined the fit of a hypothesized model consisting of parenting styles, indicators of well-being, and academic adjustment…

Effect of turbulence on the beam quality of apertured partially coherent beams.

PubMed

Ji, Xiaoling; Ji, Guangming

2008-06-01

The effects of turbulence on the beam quality of apertured partially coherent beams have been studied both analytically and numerically. Taking the Gaussian Schell-model (GSM) beam as a typical example of partially coherent beams, closed-form expressions for the average intensity, mean-squared beam width, power in the bucket, beta parameter, and Strehl ratio of apertured partially coherent beams propagating through atmospheric turbulence are derived. It is shown that the smaller the beam truncation parameter is, the less affected by turbulence the apertured partially coherent beams are. Furthermore, the apertured partially coherent beams are less sensitive to the effects of turbulence than unapertured ones. The main results are interpreted physically.

Temperature Responses of Soil Organic Matter Components With Varying Recalcitrance

NASA Astrophysics Data System (ADS)

Simpson, M. J.; Feng, X.

2007-12-01

The response of soil organic matter (SOM) to global warming remains unclear partly due to the chemical heterogeneity of SOM composition. In this study, the decomposition of SOM from two grassland soils was investigated in a one-year laboratory incubation at six different temperatures. SOM was separated into solvent- extractable compounds, suberin- and cutin-derived compounds, and lignin monomers by solvent extraction, base hydrolysis, and CuO oxidation, respectively. These SOM components had distinct chemical structures and recalcitrance, and their decomposition was fitted by a two-pool exponential decay model. The stability of SOM components was assessed using geochemical parameters and kinetic parameters derived from model fitting. Lignin monomers exhibited much lower decay rates than solvent-extractable compounds and a relatively low percentage of lignin monomers partitioned into the labile SOM pool, which confirmed the generally accepted recalcitrance of lignin compounds. Suberin- and cutin-derived compounds had a poor fitting for the exponential decay model, and their recalcitrance was shown by the geochemical degradation parameter which stabilized during the incubation. The aliphatic components of suberin degraded faster than cutin-derived compounds, suggesting that cutin-derived compounds in the soil may be at a higher stage of degradation than suberin- derived compounds. The temperature sensitivity of decomposition, expressed as Q10, was derived from the relationship between temperature and SOM decay rates. SOM components exhibited varying temperature responses and the decomposition of the recalcitrant lignin monomers had much higher Q10 values than soil respiration or the solvent-extractable compounds decomposition. Our study shows that the decomposition of recalcitrant SOM is highly sensitive to temperature, more so than bulk soil mineralization. This observation suggests a potential acceleration in the degradation of the recalcitrant SOM pool with global warming.

Simultaneous processing of photographic and accelerator array data from sled impact experiment

NASA Astrophysics Data System (ADS)

Ash, M. E.

1982-12-01

A Quaternion-Kalman filter model is derived to simultaneously analyze accelerometer array and photographic data from sled impact experiments. Formulas are given for the quaternion representation of rotations, the propagation of dynamical states and their partial derivatives, the observables and their partial derivatives, and the Kalman filter update of the state given the observables. The observables are accelerometer and tachometer velocity data of the sled relative to the track, linear accelerometer array and photographic data of the subject relative to the sled, and ideal angular accelerometer data. The quaternion constraints enter through perfect constraint observations and normalization after a state update. Lateral and fore-aft impact tests are analyzed with FORTRAN IV software written using the formulas of this report.

A theoretical analysis of fluid flow and energy transport in hydrothermal systems

USGS Publications Warehouse

Faust, Charles R.; Mercer, James W.

1977-01-01

A mathematical derivation for fluid flow and energy transport in hydrothermal systems is presented. Specifically, the mathematical model describes the three-dimensional flow of both single- and two-phase, single-component water and the transport of heat in porous media. The derivation begins with the point balance equations for mass, momentum, and energy. These equations are then averaged over a finite volume to obtain the macroscopic balance equations for a porous medium. The macroscopic equations are combined by appropriate constitutive relationships to form two similified partial differential equations posed in terms of fluid pressure and enthalpy. A two-dimensional formulation of the simplified equations is also derived by partial integration in the vertical dimension. (Woodard-USGS)

Benefit finding in response to general life stress: measurement and correlates

PubMed Central

Cassidy, Tony; McLaughlin, Marian; Giles, Melanie

2014-01-01

Benefit finding herein defined as “the process of deriving positive growth from adversity” has become a key construct in the evolution of positive psychology, and research suggests that it may provide the basis for a resource model of stress and coping. However, measures of benefit finding have tended to be domain specific. The current study focused on developing a more generic multidimensional measure of benefit finding. A measure of benefit finding was developed and tested in 855 students (574 females and 281 males) aged between 18 and 40 years. A 28-item scale with six dimensions was produced and Confirmatory Factor Analysis (CFA) confirmed the scale structure. The model proposed that psychological and social resources would mediate the relationship between experienced stressors and benefit finding. Structural equation modelling with Analysis of Moment Structures (AMOS) shows that the model is a good fit for the data and psychological and social resources partially mediated the relationship. It is argued that psychological and social resources enable benefit finding in relation to life stress and provide a focus for the development of preventive interventions to improve positive health. PMID:25750781

Symplectic potentials and resolved Ricci-flat ACG metrics

NASA Astrophysics Data System (ADS)

Balasubramanian, Aswin K.; Govindarajan, Suresh; Gowdigere, Chethan N.

2007-12-01

We pursue the symplectic description of toric Kähler manifolds. There exists a general local classification of metrics on toric Kähler manifolds equipped with Hamiltonian 2-forms due to Apostolov, Calderbank and Gauduchon (ACG). We derive the symplectic potential for these metrics. Using a method due to Abreu, we relate the symplectic potential to the canonical potential written by Guillemin. This enables us to recover the moment polytope associated with metrics and we thus obtain global information about the metric. We illustrate these general considerations by focusing on six-dimensional Ricci-flat metrics and obtain Ricci-flat metrics associated with real cones over Lpqr and Ypq manifolds. The metrics associated with cones over Ypq manifolds turn out to be partially resolved with two blow-up parameters taking special (non-zero) values. For a fixed Ypq manifold, we find explicit metrics for several inequivalent blow-ups parametrized by a natural number k in the range 0 < k < p. We also show that all known examples of resolved metrics such as the resolved conifold and the resolution of {\\bb C}^3/{\\bb Z}_3 also fit the ACG classification.

Electropalatographic (EPG) assessment of tongue-to-palate contacts in dysarthric speakers following TBI.

PubMed

Kuruvilla, Mili S; Murdoch, Bruce E; Goozee, Justine V

2008-09-01

The aim of the investigation was to compare EPG-derived spatial and timing measures between a group of 11 dysarthric individuals post-severe TBI and 10 age- and sex-matched neurologically non-impaired individuals. Participants of the TBI group were diagnosed with dysarthria ranging from mild-to-moderate-severe dysarthria. Each participant from the TBI and comparison group was fitted with a custom-made artificial acrylic palate that recorded lingual palatal contact during target consonant production in sentence- and syllable-repetition tasks at a habitual rate and loudness level. Analysis of temporal parameters between the comparison and TBI groups revealed prolonged durations of the various phases of consonant production, which were attributed to articulatory slowness, impaired speech motor control, impaired accuracy, and impaired coordination of articulatory movements in the dysarthric speakers post-TBI. For the spatial measurements, quantitative analysis, as well as visual inspection of the tongue-to-palate contact diagrams, indicated spatial aberrations in dysarthric speech post-TBI. Both the spatial and temporal aberrations may have at least partially caused the perceptual judgement of articulatory impairments in the dysarthric speakers.

Analysis of diffusion and binding in cells using the RICS approach.

PubMed

Digman, Michelle A; Gratton, Enrico

2009-04-01

The movement of macromolecules in cells is assumed to occur either through active transport or by diffusion. However, the determination of the diffusion coefficients in cells using fluctuation methods or FRAP frequently give diffusion coefficient that are orders of magnitude smaller than the diffusion coefficients measured for the same macromolecule in solution. It is assumed that the cell internal viscosity is partially responsible for this decrease in the apparent diffusion. When the apparent diffusion is too slow to be due to cytoplasm viscosity, it is assumed that weak binding of the macromolecules to immobile or quasi immobile structures is taking place. In this article, we derive equations for fitting of the RICS (Raster-scan Image Correlations Spectroscopy) data in cells to a model that includes transient binding to immobile structures, and we show that under some conditions, the spatio-temporal correlation provided by the RICS approach can distinguish the process of diffusion and weak binding. We apply the method to determine the diffusion in the cytoplasm and binding of Focal Adhesion Kinase-EGFP to adhesions in MEF cells.

Helix-coil transition of a four-way DNA junction observed by multiple fluorescence parameters.

PubMed

Vámosi, György; Clegg, Robert M

2008-10-16

The thermal denaturation of immobile four-way DNA ("Holliday-") junctions with 17 base pair arms was studied via fluorescence spectroscopic measurements. Two arms of the molecule were labeled at the 5'-end with fluorescein and tetramethylrhodamine, respectively. Melting was monitored by the fluorescence intensity of the dyes, the fluorescence anisotropy of tetramethylrhodamine, and Forster resonance energy transfer (FRET) between fluorescein and rhodamine. To fit the thermal denaturation curves of the four-way junctions, two basic thermodynamic models were tested: (1) all-or-none transitions assuming a molecularity of one, two, or four and (2) a statistical "zipper" model. The all-or-none models correspond to reaction mechanisms assuming that the cooperative melting unit (that is, the structure changing from complete helix to complete coil) consists of (1) one arm, (2) two neighboring arms (which have one continuous strand common to the two arms), or (3) all four arms. In each case, the melting of the cooperative unit takes place in a single step. The tetramolecular reaction model (four-arm melting) yielded unrealistically low van't Hoff enthalpy and entropy values, whereas the monomolecular model (one-arm melting) resulted in a poor fit to the experimental data. The all-or-none bimolecular (two neighboring arm model) fit gave intermediate standard enthalpy change (Delta H) values between those expected for the melting of a duplex with a total length between the helix lengths of one and two arms (17 and 34 base pairs). Simulations according to the zipper model fit the experimental curves best when the length of the simulated duplex was assumed to be 34 base pairs, the length of a single strand. This suggests that the most important parameter determining the melting behavior of the molecule is the end-to-end distance of the strands (34 bases) rather than the length of the individual arms (17 base pairs) and that the equilibrium concentration of partially denatured intermediate states has to be taken into account. These findings are in good agreement with results obtained for three-way DNA junctions ( Stuhmeier, F. ; Lilley, D. M. ; Clegg, R. M. Biochemistry 1997, 36, 13539 ). An interesting result is that the extent-of-melting curves derived from the fluorescence intensity and anisotropy nearly agree, whereas the curve derived from the FRET data shows a change prior to the melting. This may be an indication of a conformational change leaving the double-stranded structure intact but changing the end-to-end distance of the different arms in a way consistent with the transition to the extended square configuration ( Clegg, R. M. ; Murchie, A. I. ; Lilley, D. M. Biophys. J. 1994, 66, 99 ) of this branched molecule.

Syndromes of Self-Reported Psychopathology for Ages 18-59 in 29 Societies.

PubMed

Ivanova, Masha Y; Achenbach, Thomas M; Rescorla, Leslie A; Tumer, Lori V; Ahmeti-Pronaj, Adelina; Au, Alma; Maese, Carmen Avila; Bellina, Monica; Caldas, J Carlos; Chen, Yi-Chuen; Csemy, Ladislav; da Rocha, Marina M; Decoster, Jeroen; Dobrean, Anca; Ezpeleta, Lourdes; Fontaine, Johnny R J; Funabiki, Yasuko; Guðmundsson, Halldór S; Harder, Valerie S; de la Cabada, Marie Leiner; Leung, Patrick; Liu, Jianghong; Mahr, Safia; Malykh, Sergey; Maras, Jelena Srdanovic; Markovic, Jasminka; Ndetei, David M; Oh, Kyung Ja; Petot, Jean-Michel; Riad, Geylan; Sakarya, Direnc; Samaniego, Virginia C; Sebre, Sandra; Shahini, Mimoza; Silvares, Edwiges; Simulioniene, Roma; Sokoli, Elvisa; Talcott, Joel B; Vazquez, Natalia; Zasepa, Ewa

2015-06-01

This study tested the multi-society generalizability of an eight-syndrome assessment model derived from factor analyses of American adults' self-ratings of 120 behavioral, emotional, and social problems. The Adult Self-Report (ASR; Achenbach and Rescorla 2003) was completed by 17,152 18-59-year-olds in 29 societies. Confirmatory factor analyses tested the fit of self-ratings in each sample to the eight-syndrome model. The primary model fit index (Root Mean Square Error of Approximation) showed good model fit for all samples, while secondary indices showed acceptable to good fit. Only 5 (0.06%) of the 8,598 estimated parameters were outside the admissible parameter space. Confidence intervals indicated that sampling fluctuations could account for the deviant parameters. Results thus supported the tested model in societies differing widely in social, political, and economic systems, languages, ethnicities, religions, and geographical regions. Although other items, societies, and analytic methods might yield different results, the findings indicate that adults in very diverse societies were willing and able to rate themselves on the same standardized set of 120 problem items. Moreover, their self-ratings fit an eight-syndrome model previously derived from self-ratings by American adults. The support for the statistically derived syndrome model is consistent with previous findings for parent, teacher, and self-ratings of 1½-18-year-olds in many societies. The ASR and its parallel collateral-report instrument, the Adult Behavior Checklist (ABCL), may offer mental health professionals practical tools for the multi-informant assessment of clinical constructs of adult psychopathology that appear to be meaningful across diverse societies.

Immersion freezing of water and aqueous ammonium sulfate droplets initiated by humic-like substances as a function of water activity

DOE PAGES

Rigg, Y. J.; Alpert, P. A.; Knopf, Daniel A.

2013-07-12

Immersion freezing of water and aqueous (NH 4) 2SO 4 droplets containing leonardite (LEO) and Pahokee peat (PP) serving as surrogates for humic-like substances (HULIS) has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere; however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215K and solution water activity, aw, from 0.85 to 1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5–15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of themore » ice melting curve as a function of solution aw by Δ aw = 0.2703 and 0.2466, respectively. Corresponding heterogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5) × 10 4 and (5.4 ± 1.4) × 10 4 cm -2 s -1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by Δ aw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and ice nuclei (IN) surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (α( T)-model) to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, α( T)-model, reproduce exactly experimentally derived frozen fractions without involving free-fit parameters. However, assigning the IN a single contact angle for the entire population (single-α model) is not suited to represent the frozen fractions. Application of α-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Furthermore, when using a single parameterization of α-PDF or active sites distribution to fit all individual aw immersion freezing data simultaneously, frozen fraction curves are not reproduced. This implies that these fitting formulations cannot be applied to immersion freezing of aqueous solutions, and suggests that derived fit parameters do not represent independent particle properties. Thus, from fitting frozen fractions only, the underlying ice nucleation mechanism and nature of the ice nucleating sites cannot be inferred. In contrast to using fitted functions obtained to represent experimental conditions only, we suggest to use experimentally derived Jhet as a function of temperature and aw that can be applied to conditions outside of those probed in laboratory. Finally, this is because Jhet(T) is independent of time and IN surface areas in contrast to the fit parameters obtained by representation of experimentally derived frozen fractions.« less

Chemical equilibrium. [maximizing entropy of gas system to derive relations between thermodynamic variables

NASA Technical Reports Server (NTRS)

1976-01-01

The entropy of a gas system with the number of particles subject to external control is maximized to derive relations between the thermodynamic variables that obtain at equilibrium. These relations are described in terms of the chemical potential, defined as equivalent partial derivatives of entropy, energy, enthalpy, free energy, or free enthalpy. At equilibrium, the change in total chemical potential must vanish. This fact is used to derive the equilibrium constants for chemical reactions in terms of the partition functions of the species involved in the reaction. Thus the equilibrium constants can be determined accurately, just as other thermodynamic properties, from a knowledge of the energy levels and degeneracies for the gas species involved. These equilibrium constants permit one to calculate the equilibrium concentrations or partial pressures of chemically reacting species that occur in gas mixtures at any given condition of pressure and temperature or volume and temperature.

Aerobic Fitness is Associated With Hippocampal Volume in Elderly Humans

PubMed Central

Erickson, Kirk I.; Prakash, Ruchika S.; Voss, Michelle W.; Chaddock, Laura; Hu, Liang; Morris, Katherine S.; White, Siobhan M.; Wójcicki, Thomas R.; McAuley, Edward; Kramer, Arthur F.

2010-01-01

Deterioration of the hippocampus occurs in elderly individuals with and without dementia, yet individual variation exists in the degree and rate of hippocampal decay. Determining the factors that influence individual variation in the magnitude and rate of hippocampal decay may help promote lifestyle changes that prevent such deterioration from taking place. Aerobic fitness and exercise are effective at preventing cortical decay and cognitive impairment in older adults and epidemiological studies suggest that physical activity can reduce the risk for developing dementia. However, the relationship between aerobic fitness and hippocampal volume in elderly humans is unknown. In this study, we investigated whether individuals with higher levels of aerobic fitness displayed greater volume of the hippocampus and better spatial memory performance than individuals with lower fitness levels. Furthermore, in exploratory analyses, we assessed whether hippocampal volume mediated the relationship between fitness and spatial memory. Using a region-of-interest analysis on magnetic resonance images in 165 nondemented older adults, we found a triple association such that higher fitness levels were associated with larger left and right hippocampi after controlling for age, sex, and years of education, and larger hippocampi and higher fitness levels were correlated with better spatial memory performance. Furthermore, we demonstrated that hippocampal volume partially mediated the relationship between higher fitness levels and enhanced spatial memory. Our results clearly indicate that higher levels of aerobic fitness are associated with increased hippocampal volume in older humans, which translates to better memory function. PMID:19123237

Propagation of partially coherent vector anomalous vortex beam in turbulent atmosphere

NASA Astrophysics Data System (ADS)

Zhang, Xu; Wang, Haiyan; Tang, Lei

2018-01-01

A theoretical model is proposed to describe a partially coherent vector anomalous vortex(AV) beam. Based on the extended Huygens-Fresnel principle, analytical propagation formula for the proposed beams in turbulent atmosphere is derived. The spectral properties of the partially coherent vector AV beam are explored by using the unified theory of coherence and polarization in detail. It is interesting to find that the turbulence of atmosphere and the source parameter of the partially coherent vector AV beam( order, topological charge, coherence length, beam waist size etc) have significantly impacted the propagation properties of the partially coherent vector AV beam in turbulent atmosphere.

Penetration and screening of perpendicularly launched electromagnetic waves through bounded supercritical plasma confined in multicusp magnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dey, Indranuj; Bhattacharjee, Sudeep

2011-02-15

The question of electromagnetic wave penetration and screening by a bounded supercritical ({omega}{sub p}>{omega} with {omega}{sub p} and {omega} being the electron-plasma and wave frequencies, respectively) plasma confined in a minimum B multicusp field, for waves launched in the k perpendicular B{sub o} mode, is addressed through experiments and numerical simulations. The scale length of radial plasma nonuniformity (|n{sub e}/({partial_derivative}n{sub e}/{partial_derivative}r)|) and magnetostatic field (B{sub o}) inhomogeneity (|B{sub o}/({partial_derivative}B{sub o}/{partial_derivative}r)|) are much smaller than the free space ({lambda}{sub o}) and guided wavelengths ({lambda}{sub g}). Contrary to predictions of plane wave dispersion theory and the Clemow-Mullaly-Allis (CMA) diagram, for a boundedmore » plasma a finite propagation occurs through the central plasma regions where {alpha}{sub p}{sup 2}={omega}{sub p}{sup 2}/{omega}{sup 2}{>=}1 and {beta}{sub c}{sup 2}={omega}{sub ce}{sup 2}/{omega}{sup 2}<<1({approx}10{sup -4}), with {omega}{sub ce} being the electron cyclotron frequency. Wave screening, as predicted by the plane wave model, does not remain valid due to phase mixing and superposition of reflected waves from the conducting boundary, leading to the formation of electromagnetic standing wave modes. The waves are found to satisfy a modified upper hybrid resonance (UHR) relation in the minimum B field and are damped at the local electron cyclotron resonance (ECR) location.« less

Persona-Based Journaling: Striving for Authenticity in Representing the Problem-Solving Process

ERIC Educational Resources Information Center

Liljedahl, Peter

2007-01-01

Students' mathematical problem-solving experiences are fraught with failed attempts, wrong turns, and partial successes that move in fits and jerks, oscillating between periods of inactivity, stalled progress, rapid advancement, and epiphanies. Students' problem-solving journals, however, do not always reflect this rather organic process. Without…

Empirically derived dimensional syndromes of self-reported psychopathology: Cross-cultural comparisons of Portuguese and US elders.

PubMed

Ivanova, Masha Y; Achenbach, Thomas; Leite, Manuela; Almeida, Vera; Caldas, Carlos; Turner, Lori; Dumas, Julie A

2018-05-01

As the world population ages, mental health professionals increasingly need empirically supported assessment instruments for older adult psychopathology. This study tested the degree to which syndromes derived from self-ratings of psychopathology by elders in the US would fit self-ratings by elders in Portugal. The Older Adult Self-Report (OASR) was completed by 352 60- to 102-year-olds in Portuguese community and residential settings. Confirmatory factor analyses tested the fit of the 7-syndrome OASR model to self-ratings by Portuguese elders. The primary fit index (Root Mean Square Error of Approximation) showed good fit, while secondary fit indices (the Comparative Fit Index and the Tucker-Lewis Index) showed acceptable fit. Loadings of 95 of the 97 items on their expected syndromes were statistically significant (mean = .63), indicating that the items measured the syndromes well. Correlations between latent factors, ie, between the hypothesized syndrome constructs measured by the items, averaged .66. The correlations between syndromes reflect varying degrees of comorbidity between problems comprising particular pairs of syndromes. The results support the syndrome structure of the OASR for Portuguese elders, offering Portuguese clinicians and researchers a useful instrument for assessing a broad spectrum of psychopathology. The results also offer a core of empirically supported taxonomic constructs of later life psychopathology as a basis for advancing clinical practice, training, and cross-cultural research. Copyright © 2017 John Wiley & Sons, Ltd.

Hamilton's rule, inclusive fitness maximization, and the goal of individual behaviour in symmetric two-player games.

PubMed

Okasha, S; Martens, J

2016-03-01

Hamilton's original work on inclusive fitness theory assumed additivity of costs and benefits. Recently, it has been argued that an exact version of Hamilton's rule for the spread of a pro-social allele (rb > c) holds under nonadditive pay-offs, so long as the cost and benefit terms are defined as partial regression coefficients rather than pay-off parameters. This article examines whether one of the key components of Hamilton's original theory can be preserved when the rule is generalized to the nonadditive case in this way, namely that evolved organisms will behave as if trying to maximize their inclusive fitness in social encounters. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Resilience as a mediator between cardiorespiratory fitness and mental health-related quality of life: A cross-sectional study.

PubMed

Pozuelo-Carrascosa, Diana P; Martínez-Vizcaíno, Vicente; Sánchez-López, Mairena; Bartolomé-Gutiérrez, Raquel; Rodríguez-Martín, Beatriz; Notario-Pacheco, Blanca

2017-09-01

In this cross-sectional study, we analyzed the relationship between resilience, cardiorespiratory fitness, and mental health-related quality of life, and examined whether resilience acts as a mediator between the latter two. The study included 770 university students, aged 18-30 years, from Cuenca, Spain. Anthropometric, sociodemographic, cardiorespiratory fitness (20 m shuttle run test), biochemical parameters, resilience, and mental health-related quality of life measurements were analyzed. The results showed that mental health-related quality-of-life values were significantly higher in students who had good cardiorespiratory fitness and a high level of resilience. Moreover, resilience acted as a partial mediator between cardiorespiratory fitness and mental health-related quality of life at 33.79%. Therefore, in young adults, resilience mediates the relationship between cardiorespiratory fitness and mental health-related quality of life. These findings should be taken into account by nurses and other public health professionals, because in addition to the development of physical activity interventions to improve mental health-related quality of life, it is necessary to implement measures that increase resilience to achieve mental wellness. © 2017 John Wiley & Sons Australia, Ltd.

Inferring Boolean network states from partial information

PubMed Central

2013-01-01

Networks of molecular interactions regulate key processes in living cells. Therefore, understanding their functionality is a high priority in advancing biological knowledge. Boolean networks are often used to describe cellular networks mathematically and are fitted to experimental datasets. The fitting often results in ambiguities since the interpretation of the measurements is not straightforward and since the data contain noise. In order to facilitate a more reliable mapping between datasets and Boolean networks, we develop an algorithm that infers network trajectories from a dataset distorted by noise. We analyze our algorithm theoretically and demonstrate its accuracy using simulation and microarray expression data. PMID:24006954

Adherent Raindrop Modeling, Detectionand Removal in Video.

PubMed

You, Shaodi; Tan, Robby T; Kawakami, Rei; Mukaigawa, Yasuhiro; Ikeuchi, Katsushi

2016-09-01

Raindrops adhered to a windscreen or window glass can significantly degrade the visibility of a scene. Modeling, detecting and removing raindrops will, therefore, benefit many computer vision applications, particularly outdoor surveillance systems and intelligent vehicle systems. In this paper, a method that automatically detects and removes adherent raindrops is introduced. The core idea is to exploit the local spatio-temporal derivatives of raindrops. To accomplish the idea, we first model adherent raindrops using law of physics, and detect raindrops based on these models in combination with motion and intensity temporal derivatives of the input video. Having detected the raindrops, we remove them and restore the images based on an analysis that some areas of raindrops completely occludes the scene, and some other areas occlude only partially. For partially occluding areas, we restore them by retrieving as much as possible information of the scene, namely, by solving a blending function on the detected partially occluding areas using the temporal intensity derivative. For completely occluding areas, we recover them by using a video completion technique. Experimental results using various real videos show the effectiveness of our method.

PET-based compartmental modeling of (124)I-A33 antibody: quantitative characterization of patient-specific tumor targeting in colorectal cancer.

PubMed

Zanzonico, Pat; Carrasquillo, Jorge A; Pandit-Taskar, Neeta; O'Donoghue, Joseph A; Humm, John L; Smith-Jones, Peter; Ruan, Shutian; Divgi, Chaitanya; Scott, Andrew M; Kemeny, Nancy E; Fong, Yuman; Wong, Douglas; Scheinberg, David; Ritter, Gerd; Jungbluth, Achem; Old, Lloyd J; Larson, Steven M

2015-10-01

The molecular specificity of monoclonal antibodies (mAbs) directed against tumor antigens has proven effective for targeted therapy of human cancers, as shown by a growing list of successful antibody-based drug products. We describe a novel, nonlinear compartmental model using PET-derived data to determine the "best-fit" parameters and model-derived quantities for optimizing biodistribution of intravenously injected (124)I-labeled antitumor antibodies. As an example of this paradigm, quantitative image and kinetic analyses of anti-A33 humanized mAb (also known as "A33") were performed in 11 colorectal cancer patients. Serial whole-body PET scans of (124)I-labeled A33 and blood samples were acquired and the resulting tissue time-activity data for each patient were fit to a nonlinear compartmental model using the SAAM II computer code. Excellent agreement was observed between fitted and measured parameters of tumor uptake, "off-target" uptake in bowel mucosa, blood clearance, tumor antigen levels, and percent antigen occupancy. This approach should be generally applicable to antibody-antigen systems in human tumors for which the masses of antigen-expressing tumor and of normal tissues can be estimated and for which antibody kinetics can be measured with PET. Ultimately, based on each patient's resulting "best-fit" nonlinear model, a patient-specific optimum mAb dose (in micromoles, for example) may be derived.

Modulation transfer function of partial gating detector by liquid crystal auto-controlling light intensity

NASA Astrophysics Data System (ADS)

Yang, Xusan; Tang, Yuanhe; Liu, Kai; Liu, Hanchen; Gao, Haiyang; Li, Qing; Zhang, Ruixia; Ye, Na; Liang, Yuan; Zhao, Gaoxiang

2008-12-01

Based on the electro-optical properties of liquid crystal, we have designed a novel partial gating detector. Liquid crystal can be taken to change its own transmission according to the light intensity outside. Every single pixel of the image is real-time modulated by liquid crystal, thus the strong light is weakened and low light goes through the detector normally .The purpose of partial-gating strong light (>105lx) can be achieved by this detector. The modulation transfer function (MTF) equations of the main optical sub-systems are calculated in this paper, they are liquid crystal panels, linear fiber panel and CCD array detector. According to the relevant size, the MTF value of this system is fitted out. The result is MTF= 0.518 at Nyquist frequency.

Associations between different components of fitness and fatness with academic performance in Chilean youths.

PubMed

Olivares, Pedro R; García-Rubio, Javier

2016-01-01

To analyze the associations between different components of fitness and fatness with academic performance, adjusting the analysis by sex, age, socio-economic status, region and school type in a Chilean sample. Data of fitness, fatness and academic performance was obtained from the Chilean System for the Assessment of Educational Quality test for eighth grade in 2011 and includes a sample of 18,746 subjects (49% females). Partial correlations adjusted by confounders were done to explore association between fitness and fatness components, and between the academic scores. Three unadjusted and adjusted linear regression models were done in order to analyze the associations of variables. Fatness has a negative association with academic performance when Body Mass Index (BMI) and Waist to Height Ratio (WHR) are assessed independently. When BMI and WHR are assessed jointly and adjusted by cofounders, WHR is more associated with academic performance than BMI, and only the association of WHR is positive. For fitness components, strength was the variable most associated with the academic performance. Cardiorespiratory capacity was not associated with academic performance if fatness and other fitness components are included in the model. Fitness and fatness are associated with academic performance. WHR and strength are more related with academic performance than BMI and cardiorespiratory capacity.

Associations between different components of fitness and fatness with academic performance in Chilean youths

PubMed Central

2016-01-01

Objectives To analyze the associations between different components of fitness and fatness with academic performance, adjusting the analysis by sex, age, socio-economic status, region and school type in a Chilean sample. Methods Data of fitness, fatness and academic performance was obtained from the Chilean System for the Assessment of Educational Quality test for eighth grade in 2011 and includes a sample of 18,746 subjects (49% females). Partial correlations adjusted by confounders were done to explore association between fitness and fatness components, and between the academic scores. Three unadjusted and adjusted linear regression models were done in order to analyze the associations of variables. Results Fatness has a negative association with academic performance when Body Mass Index (BMI) and Waist to Height Ratio (WHR) are assessed independently. When BMI and WHR are assessed jointly and adjusted by cofounders, WHR is more associated with academic performance than BMI, and only the association of WHR is positive. For fitness components, strength was the variable most associated with the academic performance. Cardiorespiratory capacity was not associated with academic performance if fatness and other fitness components are included in the model. Conclusions Fitness and fatness are associated with academic performance. WHR and strength are more related with academic performance than BMI and cardiorespiratory capacity. PMID:27761345

S-Matrix to potential inversion of low-energy α-12C phase shifts

NASA Astrophysics Data System (ADS)

Cooper, S. G.; Mackintosh, R. S.

1990-10-01

The IP S-matrix to potential inversion procedure is applied to phase shifts for selected partial waves over a range of energies below the inelastic threshold for α-12C scattering. The phase shifts were determined by Plaga et al. Potentials found by Buck and Rubio to fit the low-energy alpha cluster resonances need only an increased attraction in the surface to accurately reproduce the phase-shift behaviour. Substantial differences between the potentials for odd and even partial waves are necessary. The surface tail of the potential is postulated to be a threshold effect.

Three-dimensional orbit and physical parameters of HD 6840

NASA Astrophysics Data System (ADS)

Wang, Xiao-Li; Ren, Shu-Lin; Fu, Yan-Ning

2016-02-01

HD 6840 is a double-lined visual binary with an orbital period of ˜7.5 years. By fitting the speckle interferometric measurements made by the 6 m BTA telescope and 3.5 m WIYN telescope, Balega et al. gave a preliminary astrometric orbital solution of the system in 2006. Recently, Griffin derived a precise spectroscopic orbital solution from radial velocities observed with OPH and Cambridge Coravel. However, due to the low precision of the determined orbital inclination, the derived component masses are not satisfying. By adding the newly collected astrometric data in the Fourth Catalog of Interferometric Measurements of Binary Stars, we give a three-dimensional orbit solution with high precision and derive the preliminary physical parameters of HD 6840 via a simultaneous fit including both astrometric and radial velocity measurements.

Coulomb Scattering in the Massless Nelson Model III: Ground State Wave Functions and Non-commutative Recurrence Relations

NASA Astrophysics Data System (ADS)

Dybalski, Wojciech; Pizzo, Alessandro

2018-02-01

Let $H_{P,\\sigma}$ be the single-electron fiber Hamiltonians of the massless Nelson model at total momentum $P$ and infrared cut-off $\\sigma>0$. We establish detailed regularity properties of the corresponding $n$-particle ground state wave functions $f^n_{P,\\sigma}$ as functions of $P$ and $\\sigma$. In particular, we show that \\[ |\\partial_{P^j}f^{n}_{P,\\sigma}(k_1,\\ldots, k_n)|, \\ \\ |\\partial_{P^j} \\partial_{P^{j'}} f^{n}_{P,\\sigma}(k_1,\\ldots, k_n)| \\leq \\frac{1}{\\sqrt{n!}} \\frac{(c\\lambda_0)^n}{\\sigma^{\\delta_{\\lambda_0}}} \\prod_{i=1}^n\\frac{ \\chi_{[\\sigma,\\kappa)}(k_i)}{|k_i|^{3/2}}, \\] where $c$ is a numerical constant, $\\lambda_0\\mapsto \\delta_{\\lambda_0}$ is a positive function of the maximal admissible coupling constant which satisfies $\\lim_{\\lambda_0\\to 0}\\delta_{\\lambda_0}=0$ and $\\chi_{[\\sigma,\\kappa)}$ is the (approximate) characteristic function of the energy region between the infrared cut-off $\\sigma$ and the ultraviolet cut-off $\\kappa$. While the analysis of the first derivative is relatively straightforward, the second derivative requires a new strategy. By solving a non-commutative recurrence relation we derive a novel formula for $f^n_{P,\\sigma}$ with improved infrared properties. In this representation $\\partial_{P^{j'}}\\partial_{P^{j}}f^n_{P,\\sigma}$ is amenable to sharp estimates obtained by iterative analytic perturbation theory in part II of this series of papers. The bounds stated above are instrumental for scattering theory of two electrons in the Nelson model, as explained in part I of this series.

[A preliminary study on the forming quality of titanium alloy removable partial denture frameworks fabricated by selective laser melting].

PubMed

Liu, Y F; Yu, H; Wang, W N; Gao, B

2017-06-09

Objective: To evaluate the processing accuracy, internal quality and suitability of the titanium alloy frameworks of removable partial denture (RPD) fabricated by selective laser melting (SLM) technique, and to provide reference for clinical application. Methods: The plaster model of one clinical patient was used as the working model, and was scanned and reconstructed into a digital working model. A RPD framework was designed on it. Then, eight corresponding RPD frameworks were fabricated using SLM technique. Three-dimensional (3D) optical scanner was used to scan and obtain the 3D data of the frameworks and the data was compared with the original computer aided design (CAD) model to evaluate their processing precision. The traditional casting pure titanium frameworks was used as the control group, and the internal quality was analyzed by X-ray examination. Finally, the fitness of the frameworks was examined on the plaster model. Results: The overall average deviation of the titanium alloy RPD framework fabricated by SLM technology was (0.089±0.076) mm, the root mean square error was 0.103 mm. No visible pores, cracks and other internal defects was detected in the frameworks. The framework fits on the plaster model completely, and its tissue surface fitted on the plaster model well. There was no obvious movement. Conclusions: The titanium alloy RPD framework fabricated by SLM technology is of good quality.

Thermodynamic properties, melting temperature and viscosity of the mantles of Super Earths

NASA Astrophysics Data System (ADS)

Stamenkovic, V.; Spohn, T.; Breuer, D.

2010-12-01

The recent dicscovery of extrasolar planets with radii of about twice the Earth radius and masses of several Earth masses such as e.g., Corot-7b (approx 5Mearth and 1.6Rearth, Queloz et al. 2009) has increased the interest in the properties of rock at extremely high pressures. While the pressure at the Earth’s core-mantle boundary is about 135GPa, pressures at the base of the mantles of extraterrestrial rocky planets - if these are at all differentiated into mantles and cores - may reach Tera Pascals. Although the properties and the mineralogy of rock at extremely high pressure is little known there have been speculations about mantle convection, plate tectonics and dynamo action in these “Super-Earths”. We assume that the mantles of these planets can be thought of as consisting of perovskite but we discuss the effects of the post-perovskite transition and of MgO. We use the Keane equation of state and the Slater relation (see e.g., Stacey and Davies 2004) to derive an infinite pressure value for the Grüneisen parameter of 1.035. To derive this value we adopted the infinite pressure limit for K’ (pressure derivative of the bulk modulus) of 2.41 as derived by Stacey and Davies (2004) by fitting PREM. We further use the Lindeman law to calculate the melting curve. We gauge the melting curve using the available experimental data for pressures up to 120GPa. The melting temperature profile reaches 6000K at 135GPa and increases to temperatures between 12,000K and 24,000K at 1.1TPa with a preferred value of 21,000K. We find the adiabatic temperature increase to reach 2,500K at 135GPa and 5,400K at 1.1TPa. To calculate the pressure dependence of the viscosity we assume that the rheology is diffusion controlled and calculate the partial derivative with respect to pressure of the activation enthalpy. We cast the partial derivative in terms of an activation volume and use the semi-empirical homologous temperature scaling (e.g., Karato 2008). We find that the activation volume decreases from 2.4cm^3/mol at 135GPa to 1.6cm^3/mol at 1.1TPa. An estimate of the viscosity increase across the mantle to a pressure of 1.1TPa using the adiabat calculated above results in an increase of the viscosity of 19 orders of magnitude. This value raises questions about the differentiation of these planets, heat transfer in their deep interiors, and magnetic field generation.(Ref.: Karato, S. 2008. Deformation of Earth Materials, Cambridge University Press.; Stacey, F.D., Davies, P.M. 2004. PEPI 142: 137; Queloz, D. et al., 2009. Astronomy and Astrophysics 506: 303.)

Canonical coordinates for partial differential equations

NASA Technical Reports Server (NTRS)

Hunt, L. R.; Villarreal, Ramiro

1988-01-01

Necessary and sufficient conditions are found under which operators of the form Sigma (m, j=1) x (2) sub j + X sub O can be made constant coefficient. In addition, necessary and sufficient conditions are derived which classify those linear partial differential operators that can be moved to the Kolmogorov type.

Canonical coordinates for partial differential equations

NASA Technical Reports Server (NTRS)

Hunt, L. R.; Villarreal, Ramiro

1987-01-01

Necessary and sufficient conditions are found under which operators of the form Sigma(m, j=1) X(2)sub j + X sub 0 can be made constant coefficient. In addition, necessary and sufficient conditions are derived which classify those linear partial differential operators that can be moved to the Kolmogorov type.

Viscoelastic modeling of the fusion of multicellular tumor spheroids in growth phase.

PubMed

Dechristé, Guillaume; Fehrenbach, Jérôme; Griseti, Elena; Lobjois, Valérie; Poignard, Clair

2018-06-08

Since several decades, the experiments have highlighted the analogy of fusing cell aggregates with liquid droplets. The physical macroscopic models have been derived under incompressible assumptions. The aim of this paper is to provide a 3D model of growing spheroids, which is more relevant regarding embryo cell aggregates or tumor cell spheroids. We extend the past approach to a compressible 3D framework in order to account for the tumor spheroid growth. We exhibit the crucial importance of the effective surface tension, and of the inner pressure of the spheroid to describe precisely the fusion. The experimental data were obtained on spheroids of colon carcinoma human cells (HCT116 cell line). After 3 or 6 days of culture, two identical spheroids were transferred in one well and their fusion was monitored by live videomicroscopy acquisition each 2 h during 72 h. From these images the neck radius and the diameter of the assembly of the fusing spheroids are extracted. The numerical model is fitted with the experiments. It is worth noting that the time evolution of both neck radius and spheroid diameter are quantitatively obtained. The interesting feature lies in the fact that such measurements characterise the macroscopic rheological properties of the tumor spheroids. The experimental determination of the kinetics of neck radius and overall diameter during spheroids fusion characterises the rheological properties of the spheroids. The consistency of the model is shown by fitting the model with two different experiments, enhancing the importance of both surface tension and cell proliferation. The paper sheds new light on the macroscopic rheological properties of tumor spheroids. It emphasizes the role of the surface tension and the inner pressure in the fusion of growing spheroid. Under geometrical assumptions, the model reduces to a 2-parameter differential equation fit with experimental measurements. The 3-D partial differential system makes it possible to study the fusion of spheroids in non-symmetrical or more general frameworks. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of spatial coherence on the scintillation properties of a dark hollow beam in turbulent atmosphere

NASA Astrophysics Data System (ADS)

Yuan, Yangsheng; Chen, Yahong; Liang, Chunhao; Cai, Yangjian; Baykal, Yahya

2013-03-01

With the help of a tensor method, we derive an explicit expression for the on-axis scintillation index of a circular partially coherent dark hollow (DH) beam in weakly turbulent atmosphere. The derived formula can be applied to study the scintillation properties of a partially coherent Gaussian beam and a partially coherent flat-topped (FT) beam. The effect of spatial coherence on the scintillation properties of DH beam, FT beam and Gaussian beam is studied numerically and comparatively. Our results show that the advantage of a DH beam over a FT beam and a Gaussian beam for reducing turbulence-induced scintillation increases particularly at long propagation distances with the decrease of spatial coherence or the increase of the atmospheric turbulence, which will be useful for long-distance free-space optical communications.

A generalized framework unifying image registration and respiratory motion models and incorporating image reconstruction, for partial image data or full images.

PubMed

McClelland, Jamie R; Modat, Marc; Arridge, Simon; Grimes, Helen; D'Souza, Derek; Thomas, David; Connell, Dylan O'; Low, Daniel A; Kaza, Evangelia; Collins, David J; Leach, Martin O; Hawkes, David J

2017-06-07

Surrogate-driven respiratory motion models relate the motion of the internal anatomy to easily acquired respiratory surrogate signals, such as the motion of the skin surface. They are usually built by first using image registration to determine the motion from a number of dynamic images, and then fitting a correspondence model relating the motion to the surrogate signals. In this paper we present a generalized framework that unifies the image registration and correspondence model fitting into a single optimization. This allows the use of 'partial' imaging data, such as individual slices, projections, or k-space data, where it would not be possible to determine the motion from an individual frame of data. Motion compensated image reconstruction can also be incorporated using an iterative approach, so that both the motion and a motion-free image can be estimated from the partial image data. The framework has been applied to real 4DCT, Cine CT, multi-slice CT, and multi-slice MR data, as well as simulated datasets from a computer phantom. This includes the use of a super-resolution reconstruction method for the multi-slice MR data. Good results were obtained for all datasets, including quantitative results for the 4DCT and phantom datasets where the ground truth motion was known or could be estimated.

Physical Fitness Is Longitudinally Associated With Academic Performance During Childhood and Adolescence, and Waist Circumference Mediated the Relationship.

PubMed

Lima, Rodrigo Antunes; Larsen, Lisbeth Runge; Bugge, Anna; Andersen, Lars Bo

2018-03-10

The current investigation aimed to investigate the longitudinal association between physical fitness and academic performance over 3 years in adolescents. A secondary aim was to determine to what extent waist circumference mediated the association between physical fitness and academic performance. For the current study, 1020 students from first grade [mean age: 7.87 (0.34) y] to fifth grade [mean age: 11.87 (0.37) y] were monitored annually for 3 years (2010-2013). Physical fitness was assessed using the Andersen test, 5 × 5-m shuttle run, jump height, and grip strength tests and by constructing a composite score combining all 4 fitness tests. Academic performance was assessed by national standardized tests in Danish language and math. Generalized structural equation modeling was used to evaluate the relationships between these variables. The Andersen test (standardized β = 0.15 SD), shuttle run (β = -0.18 SD), jump height (β = 0.10 SD), and the fitness composite score (β = 0.23 SD) were positively associated with academic performance over 3 years. In addition, waist circumference partially mediated the association between physical fitness and academic performance. Thus, physical fitness abilities should be stimulated during childhood and early adolescence because of their positive association with academic performance.

On the classification of scalar evolution equations with non-constant separant

NASA Astrophysics Data System (ADS)

Hümeyra Bilge, Ayşe; Mizrahi, Eti

2017-01-01

The ‘separant’ of the evolution equation u t   =  F, where F is some differentiable function of the derivatives of u up to order m, is the partial derivative \\partial F/\\partial {{u}m}, where {{u}m}={{\\partial}m}u/\\partial {{x}m} . As an integrability test, we use the formal symmetry method of Mikhailov-Shabat-Sokolov, which is based on the existence of a recursion operator as a formal series. The solvability of its coefficients in the class of local functions gives a sequence of conservation laws, called the ‘conserved densities’ {ρ(i)}, i=-1,1,2,3,\\ldots . We apply this method to the classification of scalar evolution equations of orders 3≤slant m≤slant 15 , for which {ρ(-1)}={≤ft[\\partial F/\\partial {{u}m}\\right]}-1/m} and {{ρ(1)} are non-trivial, i.e. they are not total derivatives and {ρ(-1)} is not linear in its highest order derivative. We obtain the ‘top level’ parts of these equations and their ‘top dependencies’ with respect to the ‘level grading’, that we defined in a previous paper, as a grading on the algebra of polynomials generated by the derivatives u b+i , over the ring of {{C}∞} functions of u,{{u}1},\\ldots,{{u}b} . In this setting b and i are called ‘base’ and ‘level’, respectively. We solve the conserved density conditions to show that if {ρ(-1)} depends on u,{{u}1},\\ldots,{{u}b}, then, these equations are level homogeneous polynomials in {{u}b+i},\\ldots,{{u}m} , i≥slant 1 . Furthermore, we prove that if {ρ(3)} is non-trivial, then {ρ(-1)}={≤ft(α ub2+β {{u}b}+γ \\right)}1/2} , with b≤slant 3 while if {{ρ(3)} is trivial, then {ρ(-1)}={≤ft(λ {{u}b}+μ \\right)}1/3} , where b≤slant 5 and α, β, γ, λ and μ are functions of u,\\ldots,{{u}b-1} . We show that the equations that we obtain form commuting flows and we construct their recursion operators that are respectively of orders 2 and 6 for non-trivial and trivial {{ρ(3)} respectively. Omitting lower order dependencies, we show that equations with non-trivial {ρ(3)} and b  =  3 are symmetries of the ‘essentially non-linear third order equation’ for trivial {ρ(3)} , the equations with b  =  5 are symmetries of a non-quasilinear fifth order equation obtained in previous work, while for b  =  3, 4 they are symmetries of quasilinear fifth order equations.

Calibration data Analysis Package (CAP): An IDL based widget application for analysis of X-ray calibration data

NASA Astrophysics Data System (ADS)

Vaishali, S.; Narendranath, S.; Sreekumar, P.

An IDL (interactive data language) based widget application developed for the calibration of C1XS (Narendranath et al., 2010) instrument on Chandrayaan-1 is modified to provide a generic package for the analysis of data from x-ray detectors. The package supports files in ascii as well as FITS format. Data can be fitted with a list of inbuilt functions to derive the spectral redistribution function (SRF). We have incorporated functions such as `HYPERMET' (Philips & Marlow 1976) including non Gaussian components in the SRF such as low energy tail, low energy shelf and escape peak. In addition users can incorporate additional models which may be required to model detector specific features. Spectral fits use a routine `mpfit' which uses Leven-Marquardt least squares fitting method. The SRF derived from this tool can be fed into an accompanying program to generate a redistribution matrix file (RMF) compatible with the X-ray spectral analysis package XSPEC. The tool provides a user friendly interface of help to beginners and also provides transparency and advanced features for experts.

The ν8 band of C2HD3 by high-resolution synchrotron FTIR spectroscopy: Coriolis interactions between the v8 = 1 and v6 = 1 states

NASA Astrophysics Data System (ADS)

Ng, L. L.; Tan, T. L.; Akasyah, Luqman; Wong, Andy; Appadoo, Dominique R. T.; McNaughton, Don

2017-10-01

The synchrotron Fourier transform infrared (FTIR) spectrum of the ν8 band of ethylene-d3 (C2HD3) was measured at an unapodized resolution of 0.00096 cm-1 from 830 to 1010 cm-1. Rovibrational constants up to five quartic terms were derived with improved precision for the v8 = 1 state through the fitting of 1566 unperturbed infrared transitions using the Watson's A-reduced Hamiltonian in the Ir representation with a root-mean-square (rms) deviation of 0.00044 cm-1. For the first time, 446 perturbed IR transitions of the ν8 band were fitted together with the 1566 unperturbed infrared transitions to obtain the a- and b-Coriolis resonance parameters from its interaction with the v6 = 1 state, with an rms deviation of 0.00039 cm-1. The IR lines of the ν6 band were too weak for detection. Three rotational constants, a quartic constant and band center of the v6 = 1 state were also derived for the first time in this work. Ground state rovibrational constants of C2HD3 up to five quartic constants were also derived from a fit of 906 ground state combination differences with an rms deviation of 0.00030 cm-1 from infrared transitions of the present analysis. The ground state rotational constants are in close agreement with theoretically calculated values using the cc-pVTZ basis set at CCSD(T), MP2 and B3LYP levels of theory. Alpha constants determined from the rotational constants of the v8 = 1 state derived from the perturbed IR fit compared favourably with those from anharmonic calculations.

Analytic expressions for perturbations and partial derivatives of range and range rate of a spacecraft with respect to the coefficient of the second harmonic

NASA Technical Reports Server (NTRS)

Georgevic, R. M.

1973-01-01

Closed-form analytic expressions for the time variations of instantaneous orbital parameters and of the topocentric range and range rate of a spacecraft moving in the gravitational field of an oblate large body are derived using a first-order variation of parameters technique. In addition, the closed-form analytic expressions for the partial derivatives of the topocentric range and range rate are obtained, with respect to the coefficient of the second harmonic of the potential of the central body (J sub 2). The results are applied to the motion of a point-mass spacecraft moving in the orbit around the equatorially elliptic, oblate sun, with J sub 2 approximately equal to .000027.

Stable multi-domain spectral penalty methods for fractional partial differential equations

NASA Astrophysics Data System (ADS)

Xu, Qinwu; Hesthaven, Jan S.

2014-01-01

We propose stable multi-domain spectral penalty methods suitable for solving fractional partial differential equations with fractional derivatives of any order. First, a high order discretization is proposed to approximate fractional derivatives of any order on any given grids based on orthogonal polynomials. The approximation order is analyzed and verified through numerical examples. Based on the discrete fractional derivative, we introduce stable multi-domain spectral penalty methods for solving fractional advection and diffusion equations. The equations are discretized in each sub-domain separately and the global schemes are obtained by weakly imposed boundary and interface conditions through a penalty term. Stability of the schemes are analyzed and numerical examples based on both uniform and nonuniform grids are considered to highlight the flexibility and high accuracy of the proposed schemes.

When 'fit' leads to fit, and when 'fit' leads to fat: how message framing and intrinsic vs. extrinsic exercise outcomes interact in promoting physical activity.

PubMed

Gallagher, Kristel M; Updegraff, John A

2011-07-01

A unique aspect of exercise is that people may choose to engage in it to achieve a variety of outcomes, ranging from extrinsic (appearance, health) to intrinsic (satisfaction, enjoyment). We examined how the impact of gain- vs. loss-framed messages depends on the type of outcome emphasised. Drawing from regulatory focus theory (Higgins, E.T. (1997). Beyond pleasure and pain. American Psychologist, 52, 1280-1300; Higgins, E.T. (2000). Making a good decision: Value from fit. American Psychologist, 55, 1217-1230), we predicted that gain-framed messages would 'fit' with intrinsic outcomes and loss-framed messages would 'fit' with extrinsic outcomes, but the effect of such fit on physical activity would depend on the participants' need for cognition (NC). We tested these hypotheses with a sample of 176 sedentary young adults who read an exercise message with randomly assigned frame (gain/loss) and outcome (intrinsic/extrinsic). Participants provided daily reports of exercise over the following week. The predicted interaction between frame, outcome and NC was found (p=0.001) such that a 'fit' message promoted somewhat, but not significantly, greater exercise for those with high NC, but a 'non-fit' message promoted significantly greater exercise for those with low NC. Furthermore, differences in physical activity were partially mediated by attitudes towards exercise. Findings shed light on how the outcomes and motivations associated with physical activity shape people's behavioural responses to framed health communications. © 2011 Taylor & Francis

Errors in finite-difference computations on curvilinear coordinate systems

NASA Technical Reports Server (NTRS)

Mastin, C. W.; Thompson, J. F.

1980-01-01

Curvilinear coordinate systems were used extensively to solve partial differential equations on arbitrary regions. An analysis of truncation error in the computation of derivatives revealed why numerical results may be erroneous. A more accurate method of computing derivatives is presented.

Searching for the right fit: development of applicant person-organization fit perceptions during the recruitment process.

PubMed

Swider, Brian W; Zimmerman, Ryan D; Barrick, Murray R

2015-05-01

Numerous studies link applicant fit perceptions measured at a single point in time to recruitment outcomes. Expanding upon this prior research by incorporating decision-making theory, this study examines how applicants develop these fit perceptions over the duration of the recruitment process, showing meaningful changes in fit perceptions across and within organizations overtime. To assess the development of applicant fit perceptions, eight assessments of person-organization (PO) fit with up to four different organizations across 169 applicants for 403 job choice decisions were analyzed. Results showed the presence of initial levels and changes in differentiation of applicant PO fit perceptions across organizations, which significantly predicted future job choice. In addition, changes in within-organizational PO fit perceptions across two stages of recruitment predicted applicant job choices among multiple employers. The implications of these results for accurately understanding the development of fit perceptions, relationships between fit perceptions and key recruiting outcomes, and possible limitations of past meta-analytically derived estimates of these relationships are discussed. (c) 2015 APA, all rights reserved.

Hyper-Fit: Fitting Linear Models to Multidimensional Data with Multivariate Gaussian Uncertainties

NASA Astrophysics Data System (ADS)

Robotham, A. S. G.; Obreschkow, D.

2015-09-01

Astronomical data is often uncertain with errors that are heteroscedastic (different for each data point) and covariant between different dimensions. Assuming that a set of D-dimensional data points can be described by a (D - 1)-dimensional plane with intrinsic scatter, we derive the general likelihood function to be maximised to recover the best fitting model. Alongside the mathematical description, we also release the hyper-fit package for the R statistical language (http://github.com/asgr/hyper.fit) and a user-friendly web interface for online fitting (http://hyperfit.icrar.org). The hyper-fit package offers access to a large number of fitting routines, includes visualisation tools, and is fully documented in an extensive user manual. Most of the hyper-fit functionality is accessible via the web interface. In this paper, we include applications to toy examples and to real astronomical data from the literature: the mass-size, Tully-Fisher, Fundamental Plane, and mass-spin-morphology relations. In most cases, the hyper-fit solutions are in good agreement with published values, but uncover more information regarding the fitted model.

Extracting Fitness Relationships and Oncogenic Patterns among Driver Genes in Cancer.

PubMed

Zhang, Xindong; Gao, Lin; Jia, Songwei

2017-12-25

Driver mutation provides fitness advantage to cancer cells, the accumulation of which increases the fitness of cancer cells and accelerates cancer progression. This work seeks to extract patterns accumulated by driver genes ("fitness relationships") in tumorigenesis. We introduce a network-based method for extracting the fitness relationships of driver genes by modeling the network properties of the "fitness" of cancer cells. Colon adenocarcinoma (COAD) and skin cutaneous malignant melanoma (SKCM) are employed as case studies. Consistent results derived from different background networks suggest the reliability of the identified fitness relationships. Additionally co-occurrence analysis and pathway analysis reveal the functional significance of the fitness relationships with signaling transduction. In addition, a subset of driver genes called the "fitness core" is recognized for each case. Further analyses indicate the functional importance of the fitness core in carcinogenesis, and provide potential therapeutic opportunities in medicinal intervention. Fitness relationships characterize the functional continuity among driver genes in carcinogenesis, and suggest new insights in understanding the oncogenic mechanisms of cancers, as well as providing guiding information for medicinal intervention.

Improving the developability profile of pyrrolidine progesterone receptor partial agonists

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kallander, Lara S.; Washburn, David G.; Hoang, Tram H.

2010-09-17

The previously reported pyrrolidine class of progesterone receptor partial agonists demonstrated excellent potency but suffered from serious liabilities including hERG blockade and high volume of distribution in the rat. The basic pyrrolidine amine was intentionally converted to a sulfonamide, carbamate, or amide to address these liabilities. The evaluation of the degree of partial agonism for these non-basic pyrrolidine derivatives and demonstration of their efficacy in an in vivo model of endometriosis is disclosed herein.

Statistical distributions of extreme dry spell in Peninsular Malaysia

NASA Astrophysics Data System (ADS)

Zin, Wan Zawiah Wan; Jemain, Abdul Aziz

2010-11-01

Statistical distributions of annual extreme (AE) series and partial duration (PD) series for dry-spell event are analyzed for a database of daily rainfall records of 50 rain-gauge stations in Peninsular Malaysia, with recording period extending from 1975 to 2004. The three-parameter generalized extreme value (GEV) and generalized Pareto (GP) distributions are considered to model both series. In both cases, the parameters of these two distributions are fitted by means of the L-moments method, which provides a robust estimation of them. The goodness-of-fit (GOF) between empirical data and theoretical distributions are then evaluated by means of the L-moment ratio diagram and several goodness-of-fit tests for each of the 50 stations. It is found that for the majority of stations, the AE and PD series are well fitted by the GEV and GP models, respectively. Based on the models that have been identified, we can reasonably predict the risks associated with extreme dry spells for various return periods.

A comparison of fit of CNC-milled titanium and zirconia frameworks to implants.

PubMed

Abduo, Jaafar; Lyons, Karl; Waddell, Neil; Bennani, Vincent; Swain, Michael

2012-05-01

Computer numeric controlled (CNC) milling was proven to be predictable method to fabricate accurately fitting implant titanium frameworks. However, no data are available regarding the fit of CNC-milled implant zirconia frameworks. To compare the precision of fit of implant frameworks milled from titanium and zirconia and relate it to peri-implant strain development after framework fixation. A partially edentulous epoxy resin models received two Branemark implants in the areas of the lower left second premolar and second molar. From this model, 10 identical frameworks were fabricated by mean of CNC milling. Half of them were made from titanium and the other half from zirconia. Strain gauges were mounted close to the implants to qualitatively and quantitatively assess strain development as a result of framework fitting. In addition, the fit of the framework implant interface was measured using an optical microscope, when only one screw was tightened (passive fit) and when all screws were tightened (vertical fit). The data was statistically analyzed using the Mann-Whitney test. All frameworks produced measurable amounts of peri-implant strain. The zirconia frameworks produced significantly less strain than titanium. Combining the qualitative and quantitative information indicates that the implants were under vertical displacement rather than horizontal. The vertical fit was similar for zirconia (3.7 µm) and titanium (3.6 µm) frameworks; however, the zirconia frameworks exhibited a significantly finer passive fit (5.5 µm) than titanium frameworks (13.6 µm). CNC milling produced zirconia and titanium frameworks with high accuracy. The difference between the two materials in terms of fit is expected to be of minimal clinical significance. The strain developed around the implants was more related to the framework fit rather than framework material. © 2011 Wiley Periodicals, Inc.

Model fit evaluation in multilevel structural equation models

PubMed Central

Ryu, Ehri

2014-01-01

Assessing goodness of model fit is one of the key questions in structural equation modeling (SEM). Goodness of fit is the extent to which the hypothesized model reproduces the multivariate structure underlying the set of variables. During the earlier development of multilevel structural equation models, the “standard” approach was to evaluate the goodness of fit for the entire model across all levels simultaneously. The model fit statistics produced by the standard approach have a potential problem in detecting lack of fit in the higher-level model for which the effective sample size is much smaller. Also when the standard approach results in poor model fit, it is not clear at which level the model does not fit well. This article reviews two alternative approaches that have been proposed to overcome the limitations of the standard approach. One is a two-step procedure which first produces estimates of saturated covariance matrices at each level and then performs single-level analysis at each level with the estimated covariance matrices as input (Yuan and Bentler, 2007). The other level-specific approach utilizes partially saturated models to obtain test statistics and fit indices for each level separately (Ryu and West, 2009). Simulation studies (e.g., Yuan and Bentler, 2007; Ryu and West, 2009) have consistently shown that both alternative approaches performed well in detecting lack of fit at any level, whereas the standard approach failed to detect lack of fit at the higher level. It is recommended that the alternative approaches are used to assess the model fit in multilevel structural equation model. Advantages and disadvantages of the two alternative approaches are discussed. The alternative approaches are demonstrated in an empirical example. PMID:24550882

Protein Dynamics from NMR: The Slowly Relaxing Local Structure Analysis Compared with Model-Free Analysis

PubMed Central

Meirovitch, Eva; Shapiro, Yury E.; Polimeno, Antonino; Freed, Jack H.

2009-01-01

15N-1H spin relaxation is a powerful method for deriving information on protein dynamics. The traditional method of data analysis is model-free (MF), where the global and local N-H motions are independent and the local geometry is simplified. The common MF analysis consists of fitting single-field data. The results are typically field-dependent, and multi-field data cannot be fit with standard fitting schemes. Cases where known functional dynamics has not been detected by MF were identified by us and others. Recently we applied to spin relaxation in proteins the Slowly Relaxing Local Structure (SRLS) approach which accounts rigorously for mode-mixing and general features of local geometry. SRLS was shown to yield MF in appropriate asymptotic limits. We found that the experimental spectral density corresponds quite well to the SRLS spectral density. The MF formulae are often used outside of their validity ranges, allowing small data sets to be force-fitted with good statistics but inaccurate best-fit parameters. This paper focuses on the mechanism of force-fitting and its implications. It is shown that MF force-fits the experimental data because mode-mixing, the rhombic symmetry of the local ordering and general features of local geometry are not accounted for. Combined multi-field multi-temperature data analyzed by MF may lead to the detection of incorrect phenomena, while conformational entropy derived from MF order parameters may be highly inaccurate. On the other hand, fitting to more appropriate models can yield consistent physically insightful information. This requires that the complexity of the theoretical spectral densities matches the integrity of the experimental data. As shown herein, the SRLS densities comply with this requirement. PMID:16821820

Propagation of partially coherent Lorentz-Gauss vortex beam through oceanic turbulence.

PubMed

Liu, Dajun; Yin, Hongming; Wang, Guiqiu; Wang, Yaochuan

2017-11-01

The partially coherent Lorentz-Gauss vortex beam generated by a Schell-model source has been introduced. Based on the extended Huygens-Fresnel principle, the cross-spectral density function of a partially coherent Lorentz-Gauss vortex beam propagating in oceanic turbulence is derived. The influences of coherence length, topological charge M, and oceanic turbulence on the spreading properties and position of the coherence vortex for a partially coherent Lorentz-Gauss vortex beam are analyzed in detail. The results show that a partially coherent Lorentz-Gauss vortex beam propagating in stronger oceanic turbulence will evolve into a Gaussian-like beam more rapidly as the propagation distance increases, and the number of coherent vortices will change.

The R.E.D. tools: advances in RESP and ESP charge derivation and force field library building.

PubMed

Dupradeau, François-Yves; Pigache, Adrien; Zaffran, Thomas; Savineau, Corentin; Lelong, Rodolphe; Grivel, Nicolas; Lelong, Dimitri; Rosanski, Wilfried; Cieplak, Piotr

2010-07-28

Deriving atomic charges and building a force field library for a new molecule are key steps when developing a force field required for conducting structural and energy-based analysis using molecular mechanics. Derivation of popular RESP charges for a set of residues is a complex and error prone procedure because it depends on numerous input parameters. To overcome these problems, the R.E.D. Tools (RESP and ESP charge Derive, ) have been developed to perform charge derivation in an automatic and straightforward way. The R.E.D. program handles chemical elements up to bromine in the periodic table. It interfaces different quantum mechanical programs employed for geometry optimization and computing molecular electrostatic potential(s), and performs charge fitting using the RESP program. By defining tight optimization criteria and by controlling the molecular orientation of each optimized geometry, charge values are reproduced at any computer platform with an accuracy of 0.0001 e. The charges can be fitted using multiple conformations, making them suitable for molecular dynamics simulations. R.E.D. allows also for defining charge constraints during multiple molecule charge fitting, which are used to derive charges for molecular fragments. Finally, R.E.D. incorporates charges into a force field library, readily usable in molecular dynamics computer packages. For complex cases, such as a set of homologous molecules belonging to a common family, an entire force field topology database is generated. Currently, the atomic charges and force field libraries have been developed for more than fifty model systems and stored in the RESP ESP charge DDataBase. Selected results related to non-polarizable charge models are presented and discussed.

Effects of the Use of Millimeter Waves on the Statistics of Writer-to-Reader Delays in Military Communications Systems,

DTIC Science & Technology

1980-12-01

distributions of Figs. 3 and 4 may be fitted quit, accurately by broken straight lines. If we had plotted the differential distributions directly...collection process. These fluctuations are smoothed by replacing the actual differential distribution by the derivative of the fitted broken-line lognormal...for each interval T. The constants in the distribution for each broken section of the lognormal approximations are found by fitting lines to the curve

Syndromes of Self-Reported Psychopathology for Ages 18–59 in 29 Societies

PubMed Central

Achenbach, Thomas M.; Rescorla, Leslie A.; Tumer, Lori V.; Ahmeti-Pronaj, Adelina; Au, Alma; Maese, Carmen Avila; Bellina, Monica; Caldas, J. Carlos; Chen, Yi-Chuen; Csemy, Ladislav; da Rocha, Marina M.; Decoster, Jeroen; Dobrean, Anca; Ezpeleta, Lourdes; Fontaine, Johnny R. J.; Funabiki, Yasuko; Guðmundsson, Halldór S.; Harder, Valerie s; de la Cabada, Marie Leiner; Leung, Patrick; Liu, Jianghong; Mahr, Safia; Malykh, Sergey; Maras, Jelena Srdanovic; Markovic, Jasminka; Ndetei, David M.; Oh, Kyung Ja; Petot, Jean-Michel; Riad, Geylan; Sakarya, Direnc; Samaniego, Virginia C.; Sebre, Sandra; Shahini, Mimoza; Silvares, Edwiges; Simulioniene, Roma; Sokoli, Elvisa; Talcott, Joel B.; Vazquez, Natalia; Zasepa, Ewa

2017-01-01

This study tested the multi-society generalizability of an eight-syndrome assessment model derived from factor analyses of American adults’ self-ratings of 120 behavioral, emotional, and social problems. The Adult Self-Report (ASR; Achenbach and Rescorla 2003) was completed by 17,152 18–59-year-olds in 29 societies. Confirmatory factor analyses tested the fit of self-ratings in each sample to the eight-syndrome model. The primary model fit index (Root Mean Square Error of Approximation) showed good model fit for all samples, while secondary indices showed acceptable to good fit. Only 5 (0.06%) of the 8,598 estimated parameters were outside the admissible parameter space. Confidence intervals indicated that sampling fluctuations could account for the deviant parameters. Results thus supported the tested model in societies differing widely in social, political, and economic systems, languages, ethnicities, religions, and geographical regions. Although other items, societies, and analytic methods might yield different results, the findings indicate that adults in very diverse societies were willing and able to rate themselves on the same standardized set of 120 problem items. Moreover, their self-ratings fit an eight-syndrome model previously derived from self-ratings by American adults. The support for the statistically derived syndrome model is consistent with previous findings for parent, teacher, and self-ratings of 1½–18-year-olds in many societies. The ASR and its parallel collateral-report instrument, the Adult Behavior Checklist (ABCL), may offer mental health professionals practical tools for the multi-informant assessment of clinical constructs of adult psychopathology that appear to be meaningful across diverse societies. PMID:29805197

Interventions for Students with Attention-Deficit/Hyperactivity Disorder: One Size Does Not Fit All.

ERIC Educational Resources Information Center

DuPaul, George J.; Eckert, Tanya L.; McGoey, Kara E.

1997-01-01

Article dispels the following myths about attention-deficit/hyperactivity disorder (ADHD): it has neurobiological base that can only be treated with medication; it must be treated with contingency management procedures; the children do not perform well under partial reinforcement schedules; and students must receive special-education services.…

Task-Technology Fit Assessment of an Expertise Transfer System

DTIC Science & Technology

2009-03-01

Air Education and Training Command In Partial Fulfillment of the Requirements for the Degree of Master of Science in Information Resource Management...Transfer Forum (ETF) developed by the Oklahoma State University for the Defense Ammunition Center’s quality assurance personnel. The preliminary findings...Technology-to-Performance Chain (TPC) ....................................................................13 Expertise Transfer Forum (ETF

Fuel utilization during exercise after 7 days of bed rest

NASA Technical Reports Server (NTRS)

Barrows, Linda H.; Harris, Bernard A.; Moore, Alan D.; Siconolfi, Steven F.

1992-01-01

Energy yield from carbohydrate, fat, and protein during physical activity is partially dependent on an individual's fitness level. Prolonged exposure to microgravity causes musculoskeletal and cardiovascular deconditioning; these adaptations may alter fuel utilization during space flight. Carbohydrate and fat metabolism during exercise were analyzed before and after 7 days of horizontal bed rest.

On the incorporation of the geometric phase in general single potential energy surface dynamics: A removable approximation to ab initio data.

PubMed

Malbon, Christopher L; Zhu, Xiaolei; Guo, Hua; Yarkony, David R

2016-12-21

For two electronic states coupled by conical intersections, the line integral of the derivative coupling can be used to construct a complex-valued multiplicative phase factor that makes the real-valued adiabatic electronic wave function single-valued, provided that the curl of the derivative coupling is zero. Unfortunately for ab initio determined wave functions, the curl is never rigorously zero. However, when the wave functions are determined from a coupled two diabatic state Hamiltonian H d (fit to ab initio data), the resulting derivative couplings are by construction curl free, except at points of conical intersection. In this work we focus on a recently introduced diabatization scheme that produces the H d by fitting ab initio determined energies, energy gradients, and derivative couplings to the corresponding H d determined quantities in a least squares sense, producing a removable approximation to the ab initio determined derivative coupling. This approach and related numerical issues associated with the nonremovable ab initio derivative couplings are illustrated using a full 33-dimensional representation of phenol photodissociation. The use of this approach to provide a general framework for treating the molecular Aharonov Bohm effect is demonstrated.

JUPITER’S PHASE VARIATIONS FROM CASSINI : A TESTBED FOR FUTURE DIRECT-IMAGING MISSIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayorga, L. C.; Jackiewicz, J.; Rages, K.

We present empirical phase curves of Jupiter from ∼0° to 140° as measured in multiple optical bandpasses by Cassini /Imaging Science Subsystem (ISS) during the Millennium flyby of Jupiter in late 2000 to early 2001. Phase curves are of interest for studying the energy balance of Jupiter and understanding the scattering behavior of the planet as an exoplanet analog. We find that Jupiter is significantly darker at partial phases than an idealized Lambertian planet by roughly 25% and is not well fit by Jupiter-like exoplanet atmospheric models across all wavelengths. We provide analytic fits to Jupiter’s phase function in severalmore » Cassini /ISS imaging filter bandpasses. In addition, these observations show that Jupiter’s color is more variable with phase angle than predicted by models. Therefore, the color of even a near Jupiter-twin planet observed at a partial phase cannot be assumed to be comparable to that of Jupiter at full phase. We discuss how the Wide-Field Infrared Survey Telescope and other future direct-imaging missions can enhance the study of cool giants.« less

Multivariate qualitative analysis of banned additives in food safety using surface enhanced Raman scattering spectroscopy.

PubMed

He, Shixuan; Xie, Wanyi; Zhang, Wei; Zhang, Liqun; Wang, Yunxia; Liu, Xiaoling; Liu, Yulong; Du, Chunlei

2015-02-25

A novel strategy which combines iteratively cubic spline fitting baseline correction method with discriminant partial least squares qualitative analysis is employed to analyze the surface enhanced Raman scattering (SERS) spectroscopy of banned food additives, such as Sudan I dye and Rhodamine B in food, Malachite green residues in aquaculture fish. Multivariate qualitative analysis methods, using the combination of spectra preprocessing iteratively cubic spline fitting (ICSF) baseline correction with principal component analysis (PCA) and discriminant partial least squares (DPLS) classification respectively, are applied to investigate the effectiveness of SERS spectroscopy for predicting the class assignments of unknown banned food additives. PCA cannot be used to predict the class assignments of unknown samples. However, the DPLS classification can discriminate the class assignment of unknown banned additives using the information of differences in relative intensities. The results demonstrate that SERS spectroscopy combined with ICSF baseline correction method and exploratory analysis methodology DPLS classification can be potentially used for distinguishing the banned food additives in field of food safety. Copyright © 2014 Elsevier B.V. All rights reserved.

Structure solution of network materials by solid-state NMR without knowledge of the crystallographic space group.

PubMed

Brouwer, Darren H

2013-01-01

An algorithm is presented for solving the structures of silicate network materials such as zeolites or layered silicates from solid-state (29)Si double-quantum NMR data for situations in which the crystallographic space group is not known. The algorithm is explained and illustrated in detail using a hypothetical two-dimensional network structure as a working example. The algorithm involves an atom-by-atom structure building process in which candidate partial structures are evaluated according to their agreement with Si-O-Si connectivity information, symmetry restraints, and fits to (29)Si double quantum NMR curves followed by minimization of a cost function that incorporates connectivity, symmetry, and quality of fit to the double quantum curves. The two-dimensional network material is successfully reconstructed from hypothetical NMR data that can be reasonably expected to be obtained for real samples. This advance in "NMR crystallography" is expected to be important for structure determination of partially ordered silicate materials for which diffraction provides very limited structural information. Copyright © 2013 Elsevier Inc. All rights reserved.

Breakup fusion theory of nuclear reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mastroleo, R.C.

1987-01-01

Continuum spectra of particles emitted in incomplete fusion reactions are one of the major interests in current nuclear reaction studies. Based on an idea of the so-called breakup fusion (BF) reaction, several authors derived closed formulas for the singles cross section of the particles that are emitted. There have been presented, however, two conflicting cross section formulas for the same BF reaction. For convenience, we shall call one of them the IAV (Ichimura, Austern and Vincent) and the other UT (Udagawa and Tamura) cross section formulas. In this work, the formulation of the UT cross section formula (prior-form) is presented,more » and the post-form version of the IAV cross section formula is evaluted for a few {alpha}- and d-induced reactions based on the exact finite range method. It is shown that the values thus calculated are larger by an order of magnitude as compared with the experimental cross sections for the {alpha}-induced reactions, while they are comparable with the experimental cross sections for the d-induced reactions. A possible origin of why such a large cross section is resulted in the case of {alpha}-induced reactions is also discussed. Polarization of the residual compound nucleus produced in breakup fusion reactions are calculated and compared with experiments. It is shown that the polarization is rather sensitive to the deflection angles of the strongly absortive partial waves and to obtain a good fit with the experimental data a l-dependent potential in the incident channel is needed in order to stress the lower partial waves.« less

4D-Fingerprint Categorical QSAR Models for Skin Sensitization Based on Classification Local Lymph Node Assay Measures

PubMed Central

Li, Yi; Tseng, Yufeng J.; Pan, Dahua; Liu, Jianzhong; Kern, Petra S.; Gerberick, G. Frank; Hopfinger, Anton J.

2008-01-01

Currently, the only validated methods to identify skin sensitization effects are in vivo models, such as the Local Lymph Node Assay (LLNA) and guinea pig studies. There is a tremendous need, in particular due to novel legislation, to develop animal alternatives, eg. Quantitative Structure-Activity Relationship (QSAR) models. Here, QSAR models for skin sensitization using LLNA data have been constructed. The descriptors used to generate these models are derived from the 4D-molecular similarity paradigm and are referred to as universal 4D-fingerprints. A training set of 132 structurally diverse compounds and a test set of 15 structurally diverse compounds were used in this study. The statistical methodologies used to build the models are logistic regression (LR), and partial least square coupled logistic regression (PLS-LR), which prove to be effective tools for studying skin sensitization measures expressed in the two categorical terms of sensitizer and non-sensitizer. QSAR models with low values of the Hosmer-Lemeshow goodness-of-fit statistic, χHL2, are significant and predictive. For the training set, the cross-validated prediction accuracy of the logistic regression models ranges from 77.3% to 78.0%, while that of PLS-logistic regression models ranges from 87.1% to 89.4%. For the test set, the prediction accuracy of logistic regression models ranges from 80.0%-86.7%, while that of PLS-logistic regression models ranges from 73.3%-80.0%. The QSAR models are made up of 4D-fingerprints related to aromatic atoms, hydrogen bond acceptors and negatively partially charged atoms. PMID:17226934

Fractional flow in fractured chalk; a flow and tracer test revisited.

PubMed

Odling, N E; West, L J; Hartmann, S; Kilpatrick, A

2013-04-01

A multi-borehole pumping and tracer test in fractured chalk is revisited and reinterpreted in the light of fractional flow. Pumping test data analyzed using a fractional flow model gives sub-spherical flow dimensions of 2.2-2.4 which are interpreted as due to the partially penetrating nature of the pumped borehole. The fractional flow model offers greater versatility than classical methods for interpreting pumping tests in fractured aquifers but its use has been hampered because the hydraulic parameters derived are hard to interpret. A method is developed to convert apparent transmissivity and storativity (L(4-n)/T and S(2-n)) to conventional transmissivity and storativity (L2/T and dimensionless) for the case where flow dimension, 2

Enhancement of partial robust M-regression (PRM) performance using Bisquare weight function

NASA Astrophysics Data System (ADS)

Mohamad, Mazni; Ramli, Norazan Mohamed; Ghani@Mamat, Nor Azura Md; Ahmad, Sanizah

2014-09-01

Partial Least Squares (PLS) regression is a popular regression technique for handling multicollinearity in low and high dimensional data which fits a linear relationship between sets of explanatory and response variables. Several robust PLS methods are proposed to accommodate the classical PLS algorithms which are easily affected with the presence of outliers. The recent one was called partial robust M-regression (PRM). Unfortunately, the use of monotonous weighting function in the PRM algorithm fails to assign appropriate and proper weights to large outliers according to their severity. Thus, in this paper, a modified partial robust M-regression is introduced to enhance the performance of the original PRM. A re-descending weight function, known as Bisquare weight function is recommended to replace the fair function in the PRM. A simulation study is done to assess the performance of the modified PRM and its efficiency is also tested in both contaminated and uncontaminated simulated data under various percentages of outliers, sample sizes and number of predictors.

Testing spectral models for stellar populations with star clusters - II. Results

NASA Astrophysics Data System (ADS)

González Delgado, Rosa M.; Cid Fernandes, Roberto

2010-04-01

High spectral resolution evolutionary synthesis models have become a routinely used ingredient in extragalactic work, and as such deserve thorough testing. Star clusters are ideal laboratories for such tests. This paper applies the spectral fitting methodology outlined in Paper I to a sample of clusters, mainly from the Magellanic Clouds and spanning a wide range in age and metallicity, fitting their integrated light spectra with a suite of modern evolutionary synthesis models for single stellar populations. The combinations of model plus spectral library employed in this investigation are Galaxev/STELIB, Vazdekis/MILES, SED@/GRANADA and Galaxev/MILES+GRANADA, which provide a representative sample of models currently available for spectral fitting work. A series of empirical tests are performed with these models, comparing the quality of the spectral fits and the values of age, metallicity and extinction obtained with each of them. A comparison is also made between the properties derived from these spectral fits and literature data on these nearby, well studied clusters. These comparisons are done with the general goal of providing useful feedback for model makers, as well as guidance to the users of such models. We find the following. (i) All models are able to derive ages that are in good agreement both with each other and with literature data, although ages derived from spectral fits are on average slightly older than those based on the S-colour-magnitude diagram (S-CMD) method as calibrated by Girardi et al. (ii) There is less agreement between the models for the metallicity and extinction. In particular, Galaxev/STELIB models underestimate the metallicity by ~0.6 dex, and the extinction is overestimated by 0.1 mag. (iii) New generations of models using the GRANADA and MILES libraries are superior to STELIB-based models both in terms of spectral fit quality and regarding the accuracy with which age and metallicity are retrieved. Accuracies of about 0.1 dex in age and 0.3 dex in metallicity can be achieved as long as the models are not extrapolated beyond their expected range of validity.

Paroxetine exposure skews litter sex ratios in mice suggesting a Trivers–Willard process

PubMed Central

Gaukler, Shannon Marie; Ruff, James Steven; Potts, Wayne K.

2016-01-01

While conducting a toxicity assessment of the antidepressant paroxetine (Paxil®), in wild-derived mice (Mus musculus), we observed that exposed dams (P0) produced female biased litters (32:68 M:F). Though numerous experimental manipulations have induced sex ratio bias in mice, none have assessed the fitness of the offspring from these litters relative to controls. Here, we retrospectively analyze experimentally derived fitness data gathered for the purpose of toxicological assessment in light of 2 leading hypothesis (Trivers–Willard hypothesis [TWH] and cost of reproduction hypothesis [CRH]), seeking to test if this facultative sex ratio adjustment fits into an adaptive framework. Control F1 males were heavier than F1 females, but no differences in mass were detected between exposed F1 males and females, suggesting that exposed dams did not save energy by producing fewer males, despite producing 29.2% lighter litters relative to controls. F1 offspring of both treatments were released into seminatural enclosures where fitness was quantified. In enclosures, the relative reproductive success of F1-exposed males (compared with controls) was reduced by ~20% compared with the relative reproductive success of F1-exposed females. Thus, exposed dams increased their fitness by adjusting litters toward females who were less negatively affected by the exposure than males. Collectively, these data provide less support that the observed sex ratio bias results in energetic savings (CRH), and more support for the TWH because fitness was increased by biasing litters toward female offspring. These mammalian data are unique in their ability to support the TWH through the use of relevant fitness data. PMID:27418753

Evaluation of anonymous and expressed sequence tag derived polymorphic microsatellite markers in the tobacco budworm Heliothis virescens (Lepidoptera: noctuidae)

USDA-ARS?s Scientific Manuscript database

Polymorphic genetic markers were identified and characterized using a partial genomic library of Heliothis virescens enriched for simple sequence repeats (SSR) and nucleotide sequences of expressed sequence tags (EST). Nucleotide sequences of 192 clones from the partial genomic library yielded 147 u...

Classifying Acute Respiratory Distress Syndrome Severity: Correcting the Arterial Oxygen Partial Pressure to Fractional Inspired Oxygen at Altitude.

PubMed

Pérez-Padilla, Rogelio; Hernández-Cárdenas, Carmen Margarita; Lugo-Goytia, Gustavo

2016-01-01

In the well-known Berlin definition of acute respiratory distress syndrome (ARDS), there is a recommended adjustment for arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FIO2) at altitude, but without a reference as to how it was derived.

THREE-POINT BACKWARD FINITE DIFFERENCE METHOD FOR SOLVING A SYSTEM OF MIXED HYPERBOLIC-PARABOLIC PARTIAL DIFFERENTIAL EQUATIONS. (R825549C019)

EPA Science Inventory

A three-point backward finite-difference method has been derived for a system of mixed hyperbolic_¯¯parabolic (convection_¯¯diffusion) partial differential equations (mixed PDEs). The method resorts to the three-point backward differenci...

Fitted Fourier-pseudospectral methods for solving a delayed reaction-diffusion partial differential equation in biology

NASA Astrophysics Data System (ADS)

Adam, A. M. A.; Bashier, E. B. M.; Hashim, M. H. A.; Patidar, K. C.

2017-07-01

In this work, we design and analyze a fitted numerical method to solve a reaction-diffusion model with time delay, namely, a delayed version of a population model which is an extension of the logistic growth (LG) equation for a food-limited population proposed by Smith [F.E. Smith, Population dynamics in Daphnia magna and a new model for population growth, Ecology 44 (1963) 651-663]. Seeing that the analytical solution (in closed form) is hard to obtain, we seek for a robust numerical method. The method consists of a Fourier-pseudospectral semi-discretization in space and a fitted operator implicit-explicit scheme in temporal direction. The proposed method is analyzed for convergence and we found that it is unconditionally stable. Illustrative numerical results will be presented at the conference.

Fitting the Incidence Data from the City of Campinas, Brazil, Based on Dengue Transmission Modellings Considering Time-Dependent Entomological Parameters

PubMed Central

Yang, Hyun Mo; Boldrini, José Luiz; Fassoni, Artur César; Freitas, Luiz Fernando Souza; Gomez, Miller Ceron; de Lima, Karla Katerine Barboza; Andrade, Valmir Roberto; Freitas, André Ricardo Ribas

2016-01-01

Four time-dependent dengue transmission models are considered in order to fit the incidence data from the City of Campinas, Brazil, recorded from October 1st 1995 to September 30th 2012. The entomological parameters are allowed to depend on temperature and precipitation, while the carrying capacity and the hatching of eggs depend only on precipitation. The whole period of incidence of dengue is split into four periods, due to the fact that the model is formulated considering the circulation of only one serotype. Dengue transmission parameters from human to mosquito and mosquito to human are fitted for each one of the periods. The time varying partial and overall effective reproduction numbers are obtained to explain the incidence of dengue provided by the models. PMID:27010654

Blood flow problem in the presence of magnetic particles through a circular cylinder using Caputo-Fabrizio fractional derivative

NASA Astrophysics Data System (ADS)

Uddin, Salah; Mohamad, Mahathir; Khalid, Kamil; Abdulhammed, Mohammed; Saifullah Rusiman, Mohd; Che – Him, Norziha; Roslan, Rozaini

2018-04-01

In this paper, the flow of blood mixed with magnetic particles subjected to uniform transverse magnetic field and pressure gradient in an axisymmetric circular cylinder is studied by using a new trend of fractional derivative without singular kernel. The governing equations are fractional partial differential equations derived based on the Caputo-Fabrizio time-fractional derivatives NFDt. The current result agrees considerably well with that of the previous Caputo fractional derivatives UFDt.

Modeling Evolution on Nearly Neutral Network Fitness Landscapes

NASA Astrophysics Data System (ADS)

Yakushkina, Tatiana; Saakian, David B.

2017-08-01

To describe virus evolution, it is necessary to define a fitness landscape. In this article, we consider the microscopic models with the advanced version of neutral network fitness landscapes. In this problem setting, we suppose a fitness difference between one-point mutation neighbors to be small. We construct a modification of the Wright-Fisher model, which is related to ordinary infinite population models with nearly neutral network fitness landscape at the large population limit. From the microscopic models in the realistic sequence space, we derive two versions of nearly neutral network models: with sinks and without sinks. We claim that the suggested model describes the evolutionary dynamics of RNA viruses better than the traditional Wright-Fisher model with few sequences.

From crater functions to partial differential equations: a new approach to ion bombardment induced nonequilibrium pattern formation.

PubMed

Norris, Scott A; Brenner, Michael P; Aziz, Michael J

2009-06-03

We develop a methodology for deriving continuum partial differential equations for the evolution of large-scale surface morphology directly from molecular dynamics simulations of the craters formed from individual ion impacts. Our formalism relies on the separation between the length scale of ion impact and the characteristic scale of pattern formation, and expresses the surface evolution in terms of the moments of the crater function. We demonstrate that the formalism reproduces the classical Bradley-Harper results, as well as ballistic atomic drift, under the appropriate simplifying assumptions. Given an actual set of converged molecular dynamics moments and their derivatives with respect to the incidence angle, our approach can be applied directly to predict the presence and absence of surface morphological instabilities. This analysis represents the first work systematically connecting molecular dynamics simulations of ion bombardment to partial differential equations that govern topographic pattern-forming instabilities.

PARTIAL REPRODUCTIVE ISOLATION OF A RECENTLY DERIVED RESIDENT-FRESHWATER POPULATION OF THREESPINE STICKLEBACK (GASTEROSTEUS ACULEATUS) FROM ITS PUTATIVE ANADROMOUS ANCESTOR

PubMed Central

Furin, Christoff G.; Von Hippel, Frank A.; Bell, Michael A.

2012-01-01

We used no-choice mating trials to test for assortative mating between a newly derived resident-freshwater population (8 – 22 generations since founding) of threespine stickleback (Gasterosteus aculeatus) in Loberg Lake, Alaska and its putative anadromous ancestor as well as a morphologically convergent but distantly related resident-freshwater population. Partial reproductive isolation has evolved between the Loberg Lake population and its ancestor within a remarkably short time period. However, Loberg stickleback readily mate with morphologically similar, but distantly related resident-freshwater stickleback. Partial pre-mating isolation is asymmetrical; anadromous females and smaller, resident-freshwater males from Loberg Lake readily mate, but the anadromous males and smaller Loberg females do not. Our results indicate that pre-mating isolation can begin to evolve in allopatry within a few generations after isolation as a correlated effect of evolution of reduced body size. PMID:23025615

Boundary-fitted coordinate systems for numerical solution of partial differential equations - A review

NASA Technical Reports Server (NTRS)

Thompson, J. F.; Warsi, Z. U. A.; Mastin, C. W.

1982-01-01

A comprehensive review of methods of numerically generating curvilinear coordinate systems with coordinate lines coincident with all boundary segments is given. Some general mathematical framework and error analysis common to such coordinate systems is also included. The general categories of generating systems are those based on conformal mapping, orthogonal systems, nearly orthogonal systems, systems produced as the solution of elliptic and hyperbolic partial differential equations, and systems generated algebraically by interpolation among the boundaries. Also covered are the control of coordinate line spacing by functions embedded in the partial differential operators of the generating system and by subsequent stretching transformation. Dynamically adaptive coordinate systems, coupled with the physical solution, and time-dependent systems that follow moving boundaries are treated. References reporting experience using such coordinate systems are reviewed as well as those covering the system development.

Partial polarization: a comprehensive student exercise

NASA Astrophysics Data System (ADS)

Topasna, Gregory A.; Topasna, Daniela M.

2015-10-01

We present a comprehensive student exercise in partial polarization. Students are first introduced to the concept of partial polarization using Fresnel Equations. Next, MATHCAD is used to compute and graph the reflectance for dielectrics materials. The students then design and construct a simple, easy to use collimated light source for their experiment, which is performed on an optical breadboard using optical components typically found in an optics lab above the introductory level. The students obtain reflection data that is compared with their model by a nonlinear least square fit using EXCEL. Sources of error and uncertainty are discussed and students present a final written report. In this one exercise students learn how an experiment is constructed "from the ground up". They gain practical experience on data modeling and analysis, working with optical equipment, machining and construction, and preparing a final presentation.

The X-ray spectrum and spectral energy distribution of FIRST J155633.8+351758: a LoBAL quasar with a probable polar outflow

NASA Astrophysics Data System (ADS)

Berrington, Robert C.; Brotherton, Michael S.; Gallagher, Sarah C.; Ganguly, Rajib; Shang, Zhaohui; DiPompeo, Michael; Chatterjee, Ritaban; Lacy, Mark; Gregg, Michael D.; Hall, Patrick B.; Laurent-Muehleisen, S. A.

2013-12-01

We report the results of a new 60 ks Chandra X-ray Observatory Advanced CCD Imaging Spectrometer S-array (ACIS-S) observation of the reddened, radio-selected, highly polarized `FeLoBAL' quasar FIRST J1556+3517. We investigated a number of models of varied sophistication to fit the 531-photon spectrum. These models ranged from simple power laws to power laws absorbed by hydrogen gas in differing ionization states and degrees of partial covering. Preferred fits indicate that the intrinsic X-ray flux is consistent with that expected for quasars of similarly high luminosity, i.e. an intrinsic, dereddened and unabsorbed optical to X-ray spectral index of -1.7. We cannot tightly constrain the intrinsic X-ray power-law slope, but find indications that it is flat (photon index Γ = 1.7 or flatter at a >99 per cent confidence for a neutral hydrogen absorber model). Absorption is present, with a column density a few times 1023 cm-2, with both partially ionized models and partially covering neutral hydrogen models providing good fits. We present several lines of argument that suggest the fraction of X-ray emissions associated with the radio jet is not large. We combine our Chandra data with observations from the literature to construct the spectral energy distribution of FIRST J1556+3517 from radio to X-ray energies. We make corrections for Doppler beaming for the pole-on radio jet, optical dust reddening and X-ray absorption, in order to recover a probable intrinsic spectrum. The quasar FIRST J1556+3517 seems to be an intrinsically normal radio-quiet quasar with a reddened optical/UV spectrum, a Doppler-boosted but intrinsically weak radio jet and an X-ray absorber not dissimilar from that of other broad absorption line quasars.

A quantitative life history of endangered humpback chub that spawn in the Little Colorado River: variation in movement, growth, and survival

USGS Publications Warehouse

Yackulic, Charles B.; Yard, Michael D.; Korman, Josh; Van Haverbeke, David R.

2014-01-01

While the ecology and evolution of partial migratory systems (defined broadly to include skip spawning) have been well studied, we are only beginning to understand how partial migratory populations are responding to ongoing environmental change. Environmental change can lead to differences in the fitness of residents and migrants, which could eventually lead to changes in the frequency of the strategies in the overall population. Here, we address questions concerning the life history of the endangered Gila cypha (humpback chub) in the regulated Colorado River and the unregulated tributary and primary spawning area, the Little Colorado River. We develop eight multistate models for the population based on three movement hypotheses, in which states are defined in terms of fish size classes and river locations. We fit these models to mark–recapture data collected in 2009–2012. We compare survival and growth estimates between the Colorado River and Little Colorado River and calculate abundances for all size classes. The best model supports the hypotheses that larger adults spawn more frequently than smaller adults, that there are residents in the spawning grounds, and that juveniles move out of the Little Colorado River in large numbers during the monsoon season (July–September). Monthly survival rates for G. cypha in the Colorado River are higher than in the Little Colorado River in all size classes; however, growth is slower. While the hypothetical life histories of life-long residents in the Little Colorado River and partial migrants spending most of its time in the Colorado River are very different, they lead to roughly similar fitness expectations when we used expected number of spawns as a proxy. However, more research is needed because our study period covers a period of years when conditions in the Colorado River for G. cypha are likely to have been better than has been typical over the last few decades.

Is the effect of person-organisation fit on turnover intention mediated by job satisfaction? A survey of community health workers in China

PubMed Central

Yan, Fei; Wang, Wei; Li, Guohong

2017-01-01

Objectives Person-organisation fit (P-O fit) is a predictor of work attitude. However, in the area of human resource for health, the literature of P-O fit is quite limited. It is unclear whether P-O fit directly or indirectly affects turnover intention. This study aims to examine the mediation effect of job satisfaction on the relationship between P-O fit and turnover intention based on data from China. Design and methods This is a cross-sectional survey of community health workers (CHWs) in China in 2013. A questionnaire of P-O fit, job satisfaction and turnover intention was developed, and its validity and reliability were assessed. Multiple regression and structural equation modelling were used to examine the relationship among P-O fit, job satisfaction and turnover intention. Setting and participants Multistage sampling was applied. In total, 656 valid questionnaire responses were collected from CHWs in four provincial regions in China, namely Shanghai, Shaanxi, Shandong and Anhui. Results P-O fit was directly related to job satisfaction (standardised β 0.246) and inversely related to turnover intention (standardised β −0.186). In the mediation model, the total effect of P-O fit on turnover intention was −0.186 (p<0.001); the direct effect of P-O fit on turnover intention was −0.094 (p<0.01); the indirect effect of job satisfaction on the relationship between P-O fit and turnover intention was −0.092 (p<0.001). Conclusions The effect of P-O fit on turnover intention was partially mediated through job satisfaction. It is suggested that more work attitude variables and different dimensions of P-O fit be taken into account to examine the complete mechanism of person-organisation interaction. Indirect measures of P-O fit should be encouraged in practice to enhance work attitudes of health workers. PMID:28399513

Real-Time Exponential Curve Fits Using Discrete Calculus

NASA Technical Reports Server (NTRS)

Rowe, Geoffrey

2010-01-01

An improved solution for curve fitting data to an exponential equation (y = Ae(exp Bt) + C) has been developed. This improvement is in four areas -- speed, stability, determinant processing time, and the removal of limits. The solution presented avoids iterative techniques and their stability errors by using three mathematical ideas: discrete calculus, a special relationship (be tween exponential curves and the Mean Value Theorem for Derivatives), and a simple linear curve fit algorithm. This method can also be applied to fitting data to the general power law equation y = Ax(exp B) + C and the general geometric growth equation y = Ak(exp Bt) + C.

Deriving the Regression Equation without Using Calculus

ERIC Educational Resources Information Center

Gordon, Sheldon P.; Gordon, Florence S.

2004-01-01

Probably the one "new" mathematical topic that is most responsible for modernizing courses in college algebra and precalculus over the last few years is the idea of fitting a function to a set of data in the sense of a least squares fit. Whether it be simple linear regression or nonlinear regression, this topic opens the door to applying the…

Effect of polarization on the evolution of electromagnetic hollow Gaussian Schell-model beam

NASA Astrophysics Data System (ADS)

Long, Xuewen; Lu, Keqing; Zhang, Yuhong; Guo, Jianbang; Li, Kehao

2011-02-01

Based on the theory of coherence, an analytical propagation formula for partially polarized and partially coherent hollow Gaussian Schell-model beams (HGSMBs) passing through a paraxial optical system is derived. Furthermore, we show that the degree of polarization of source may affect the evolution of HGSMBs and a tunable dark region may exist. For two special cases of fully coherent and partially coherent δxx = δyy, normalized intensity distributions are independent of the polarization of source.

The method of A-harmonic approximation and optimal interior partial regularity for nonlinear elliptic systems under the controllable growth condition

NASA Astrophysics Data System (ADS)

Chen, Shuhong; Tan, Zhong

2007-11-01

In this paper, we consider the nonlinear elliptic systems under controllable growth condition. We use a new method introduced by Duzaar and Grotowski, for proving partial regularity for weak solutions, based on a generalization of the technique of harmonic approximation. We extend previous partial regularity results under the natural growth condition to the case of the controllable growth condition, and directly establishing the optimal Hölder exponent for the derivative of a weak solution.

Partially Coherent Scattering in Stellar Chromospheres. Part 4; Analytic Wing Approximations

NASA Technical Reports Server (NTRS)

Gayley, K. G.

1993-01-01

Simple analytic expressions are derived to understand resonance-line wings in stellar chromospheres and similar astrophysical plasmas. The results are approximate, but compare well with accurate numerical simulations. The redistribution is modeled using an extension of the partially coherent scattering approximation (PCS) which we term the comoving-frame partially coherent scattering approximation (CPCS). The distinction is made here because Doppler diffusion is included in the coherent/noncoherent decomposition, in a form slightly improved from the earlier papers in this series.

The modified extended Hansen method to determine partial solubility parameters of drugs containing a single hydrogen bonding group and their sodium derivatives: benzoic acid/Na and ibuprofen/Na.

PubMed

Bustamante, P; Pena, M A; Barra, J

2000-01-20

Sodium salts are often used in drug formulation but their partial solubility parameters are not available. Sodium alters the physical properties of the drug and the knowledge of these parameters would help to predict adhesion properties that cannot be estimated using the solubility parameters of the parent acid. This work tests the applicability of the modified extended Hansen method to determine partial solubility parameters of sodium salts of acidic drugs containing a single hydrogen bonding group (ibuprofen, sodium ibuprofen, benzoic acid and sodium benzoate). The method uses a regression analysis of the logarithm of the experimental mole fraction solubility of the drug against the partial solubility parameters of the solvents, using models with three and four parameters. The solubility of the drugs was determined in a set of solvents representative of several chemical classes, ranging from low to high solubility parameter values. The best results were obtained with the four parameter model for the acidic drugs and with the three parameter model for the sodium derivatives. The four parameter model includes both a Lewis-acid and a Lewis-base term. Since the Lewis acid properties of the sodium derivatives are blocked by sodium, the three parameter model is recommended for these kind of compounds. Comparison of the parameters obtained shows that sodium greatly changes the polar parameters whereas the dispersion parameter is not much affected. Consequently the total solubility parameters of the salts are larger than for the parent acids in good agreement with the larger hydrophilicity expected from the introduction of sodium. The results indicate that the modified extended Hansen method can be applied to determine the partial solubility parameters of acidic drugs and their sodium salts.

Fitness attenuates the prevalence of increased coronary artery calcium in individuals with metabolic syndrome.

PubMed

Ekblom-Bak, Elin; Ekblom, Örjan; Fagman, Erika; Angerås, Oskar; Schmidt, Caroline; Rosengren, Annika; Börjesson, Mats; Bergström, Göran

2018-02-01

Background The association between cardiorespiratory fitness, physical activity and coronary artery calcium (CAC) is unclear, and whether higher levels of fitness attenuate CAC prevalence in subjects with metabolic syndrome is not fully elucidated. The present study aims to: a) investigate the independent association of fitness on the prevalence of CAC, after adjustment for moderate-to-vigorous physical activity and sedentary time, and b) study the possible attenuation of increased CAC by higher fitness, in participants with metabolic syndrome. Design Cross-sectional. Methods In total 678 participants (52% women), 50-65 years old, from the SCAPIS pilot study were included. Fitness (VO 2 max) was estimated by submaximal cycle ergometer test and moderate-to-vigorous physical activity and sedentary time were assessed using hip-worn accelerometers. CAC score (CACS) was quantified using the Agatston score. Results The odds of having a significant CACS (≥100) was half in participants with moderate/high fitness compared with their low fitness counterparts. Further consideration of moderate-to-vigorous physical activity, sedentary time and number of components of the metabolic syndrome did only slightly alter the effect size. Those with metabolic syndrome had 47% higher odds for significant CAC compared with those without metabolic syndrome. However, moderate/high fitness seems to partially attenuate this risk, as further joint analysis indicated an increased odds for having significant CAC only in the unfit metabolic syndrome participants. Conclusions Being fit is associated with a reduced risk of having significant CAC in individuals with metabolic syndrome. While still very much underutilized, fitness should be taken into consideration in everyday clinical risk prediction in addition to the traditional risk factors of the metabolic syndrome.

Generalized Lie symmetry approach for fractional order systems of differential equations. III

NASA Astrophysics Data System (ADS)

Singla, Komal; Gupta, R. K.

2017-06-01

The generalized Lie symmetry technique is proposed for the derivation of point symmetries for systems of fractional differential equations with an arbitrary number of independent as well as dependent variables. The efficiency of the method is illustrated by its application to three higher dimensional nonlinear systems of fractional order partial differential equations consisting of the (2 + 1)-dimensional asymmetric Nizhnik-Novikov-Veselov system, (3 + 1)-dimensional Burgers system, and (3 + 1)-dimensional Navier-Stokes equations. With the help of derived Lie point symmetries, the corresponding invariant solutions transform each of the considered systems into a system of lower-dimensional fractional partial differential equations.

Solution of some types of differential equations: operational calculus and inverse differential operators.

PubMed

Zhukovsky, K

2014-01-01

We present a general method of operational nature to analyze and obtain solutions for a variety of equations of mathematical physics and related mathematical problems. We construct inverse differential operators and produce operational identities, involving inverse derivatives and families of generalised orthogonal polynomials, such as Hermite and Laguerre polynomial families. We develop the methodology of inverse and exponential operators, employing them for the study of partial differential equations. Advantages of the operational technique, combined with the use of integral transforms, generating functions with exponentials and their integrals, for solving a wide class of partial derivative equations, related to heat, wave, and transport problems, are demonstrated.

LOGISTIC FUNCTION PROFILE FIT: A least-squares program for fitting interface profiles to an extended logistic function

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirchhoff, William H.

2012-09-15

The extended logistic function provides a physically reasonable description of interfaces such as depth profiles or line scans of surface topological or compositional features. It describes these interfaces with the minimum number of parameters, namely, position, width, and asymmetry. Logistic Function Profile Fit (LFPF) is a robust, least-squares fitting program in which the nonlinear extended logistic function is linearized by a Taylor series expansion (equivalent to a Newton-Raphson approach) with no apparent introduction of bias in the analysis. The program provides reliable confidence limits for the parameters when systematic errors are minimal and provides a display of the residuals frommore » the fit for the detection of systematic errors. The program will aid researchers in applying ASTM E1636-10, 'Standard practice for analytically describing sputter-depth-profile and linescan-profile data by an extended logistic function,' and may also prove useful in applying ISO 18516: 2006, 'Surface chemical analysis-Auger electron spectroscopy and x-ray photoelectron spectroscopy-determination of lateral resolution.' Examples are given of LFPF fits to a secondary ion mass spectrometry depth profile, an Auger surface line scan, and synthetic data generated to exhibit known systematic errors for examining the significance of such errors to the extrapolation of partial profiles.« less

Thresholding functional connectomes by means of mixture modeling.

PubMed

Bielczyk, Natalia Z; Walocha, Fabian; Ebel, Patrick W; Haak, Koen V; Llera, Alberto; Buitelaar, Jan K; Glennon, Jeffrey C; Beckmann, Christian F

2018-05-01

Functional connectivity has been shown to be a very promising tool for studying the large-scale functional architecture of the human brain. In network research in fMRI, functional connectivity is considered as a set of pair-wise interactions between the nodes of the network. These interactions are typically operationalized through the full or partial correlation between all pairs of regional time series. Estimating the structure of the latent underlying functional connectome from the set of pair-wise partial correlations remains an open research problem though. Typically, this thresholding problem is approached by proportional thresholding, or by means of parametric or non-parametric permutation testing across a cohort of subjects at each possible connection. As an alternative, we propose a data-driven thresholding approach for network matrices on the basis of mixture modeling. This approach allows for creating subject-specific sparse connectomes by modeling the full set of partial correlations as a mixture of low correlation values associated with weak or unreliable edges in the connectome and a sparse set of reliable connections. Consequently, we propose to use alternative thresholding strategy based on the model fit using pseudo-False Discovery Rates derived on the basis of the empirical null estimated as part of the mixture distribution. We evaluate the method on synthetic benchmark fMRI datasets where the underlying network structure is known, and demonstrate that it gives improved performance with respect to the alternative methods for thresholding connectomes, given the canonical thresholding levels. We also demonstrate that mixture modeling gives highly reproducible results when applied to the functional connectomes of the visual system derived from the n-back Working Memory task in the Human Connectome Project. The sparse connectomes obtained from mixture modeling are further discussed in the light of the previous knowledge of the functional architecture of the visual system in humans. We also demonstrate that with use of our method, we are able to extract similar information on the group level as can be achieved with permutation testing even though these two methods are not equivalent. We demonstrate that with both of these methods, we obtain functional decoupling between the two hemispheres in the higher order areas of the visual cortex during visual stimulation as compared to the resting state, which is in line with previous studies suggesting lateralization in the visual processing. However, as opposed to permutation testing, our approach does not require inference at the cohort level and can be used for creating sparse connectomes at the level of a single subject. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Topics in two-body hadronic decays of D mesons

NASA Astrophysics Data System (ADS)

El Aaoud, El Hassan

We have carried out an analysis of helicity and partial- wave amplitudes for the decay of D mesons to two vector mesons V 1V2, D --> V1V2. In particular we have studied the Cabibbo-favored decays D+s --> ρφ and D --> K*ρ in the factorization approximation using several models for the form factors. All the models, with the exception of one, generate partial-wave amplitudes with the hierarchy |S| > |P| > | D|. Even though in most models the D-wave amplitude is an order of magnitude smaller than the S-wave amplitude, its effect on the longitudinal polarization could be as large as 30%. Due to a misidentification of the partial-wave amplitudes in terms of the Lorentz structures in the relevant literature, we cast doubt on the veracity of the listed data for the decay D --> K*ρ, particularly the partial-wave branching ratios. We have also investigated the effect of the isospin ½, JP = 0+ resonant state K*0 (1950) on the decays D0 --> K¯0η and D0 --> K¯0η' as a function of the branching ratio sum r = Br( K*0 (1950) --> K¯0η) + Br( K*0 (1950) --> K¯0η ') and the coupling constants gK*0 K0h , and gK*0 K0h' . We have used a factorized input for the D 0 --> K*0 (1950) weak transition through a πK loop. We estimated both on- and off-shell contributions from the loop. Our calculation shows that the off-shell effects are significant. For r >= 30% a fit to the decay amplitude |A(D 0 --> K¯0η' )| was possible, but the amplitude A(D 0 --> K¯0η) remained at its factorized value and hence a branching ratio too low compared to data. For small values of r, r <= 18%, we were able to fit |A(D0 --> K¯0η)|, and despite the fact that | A(D0 --> K¯ 0η') | could be raised by almost 100% over its factorized value, it still falls short of its experimental value. A simultaneous fit to both amplitudes |(A(D0 --> K¯0η')| and | A(D0 --> K¯ 0η| was not possible. We have also determined the strong phase of the resonant amplitudes for both decays.

Quantitative trait loci from two genotypes of oat (Avena sativa L.) conditioning resistance to Puccinia coronata

USDA-ARS?s Scientific Manuscript database

Developing oat cultivars with partial resistance to crown rust would be beneficial for disease management. Two recombinant inbred line (RIL) populations were derived by crossing the susceptible cultivar ‘Provena’ with two partially resistant sources, ‘CDC Boyer’ and breeding line 94197A1-9-2-2-2-5. ...

Partial-fraction expansion and inverse Laplace transform of a rational function with real coefficients

NASA Technical Reports Server (NTRS)

Chang, F.-C.; Mott, H.

1974-01-01

This paper presents a technique for the partial-fraction expansion of functions which are ratios of polynomials with real coefficients. The expansion coefficients are determined by writing the polynomials as Taylor's series and obtaining the Laurent series expansion of the function. The general formula for the inverse Laplace transform is also derived.

The use (or misuse) of microsatellite allelic distances in the context of inbreeding and conservation genetics.

PubMed

Hansson, Bengt

2010-03-01

In line with inbreeding theory, genetic diversity at a set of molecular markers may explain variation in fitness-associated traits in partially inbred populations, and such associations will appear as 'genotype-fitness correlations'. An individual genetic diversity index specifically used for microsatellites is 'mean d(2)', i.e. the mean squared distance between alleles. The original hypothesis for mean d(2)-fitness correlations assumes that mean d(2) captures fitness effects at both ends of the inbreeding-outbreeding spectrum. This hypothesis received strong criticism from work showing that even a plain diversity estimate such as multi-locus heterozygosity (MLH) outperforms mean d(2) as a predictor of the inbreeding coefficient and fitness in most realistic situations. Despite this critique, the mean d(2)-approach is still used frequently in ecological and evolutionary research, producing results suggesting that mean d(2) sometimes provides a stronger prediction of fitness than does MLH. In light of the critique, such results are unexpected, but potential explanations for them may exist (at least hypothetically), including scenarios based on close linkage and recent admixture. Nevertheless, a major caveat is that it is very difficult to predict a priori if mean d(2) will improve the genotype-fitness correlation, which in turn makes objective interpretations difficult. Mean d(2)-fitness associations are potentially interesting, but the fact that we cannot easily understand them is problematic and should be thoroughly addressed in each study. Therefore, instead of hastily reached interpretations of mean d(2)-fitness correlations, conclusions need support from complementary analyses, e.g. verifying admixture of genetically structured populations.

Fitness consequences of sex-specific selection.

PubMed

Connallon, Tim; Cox, Robert M; Calsbeek, Ryan

2010-06-01

Theory suggests that sex-specific selection can facilitate adaptation in sexually reproducing populations. However, sexual conflict theory and recent experiments indicate that sex-specific selection is potentially costly due to sexual antagonism: alleles harmful to one sex can accumulate within a population because they are favored in the other sex. Whether sex-specific selection provides a net fitness benefit or cost depends, in part, on the relative frequency and strength of sexually concordant versus sexually antagonistic selection throughout a species' genome. Here, we model the net fitness consequences of sex-specific selection while explicitly considering both sexually concordant and sexually antagonistic selection. The model shows that, even when sexual antagonism is rare, the fitness costs that it imposes will generally overwhelm fitness benefits of sexually concordant selection. Furthermore, the cost of sexual antagonism is, at best, only partially resolved by the evolution of sex-limited gene expression. To evaluate the key parameters of the model, we analyze an extensive dataset of sex-specific selection gradients from wild populations, along with data from the experimental evolution literature. The model and data imply that sex-specific selection may likely impose a net cost on sexually reproducing species, although additional research will be required to confirm this conclusion.

The Rasch Rating Model and the Disordered Threshold Controversy

ERIC Educational Resources Information Center

Adams, Raymond J.; Wu, Margaret L.; Wilson, Mark

2012-01-01

The Rasch rating (or partial credit) model is a widely applied item response model that is used to model ordinal observed variables that are assumed to collectively reflect a common latent variable. In the application of the model there is considerable controversy surrounding the assessment of fit. This controversy is most notable when the set of…

Open-path FTIR data reduction algorithm with atmospheric absorption corrections: the NONLIN code

NASA Astrophysics Data System (ADS)

Phillips, William; Russwurm, George M.

1999-02-01

This paper describes the progress made to date in developing, testing, and refining a data reduction computer code, NONLIN, that alleviates many of the difficulties experienced in the analysis of open path FTIR data. Among the problems that currently effect FTIR open path data quality are: the inability to obtain a true I degree or background, spectral interferences of atmospheric gases such as water vapor and carbon dioxide, and matching the spectral resolution and shift of the reference spectra to a particular field instrument. This algorithm is based on a non-linear fitting scheme and is therefore not constrained by many of the assumptions required for the application of linear methods such as classical least squares (CLS). As a result, a more realistic mathematical model of the spectral absorption measurement process can be employed in the curve fitting process. Applications of the algorithm have proven successful in circumventing open path data reduction problems. However, recent studies, by one of the authors, of the temperature and pressure effects on atmospheric absorption indicate there exist temperature and water partial pressure effects that should be incorporated into the NONLIN algorithm for accurate quantification of gas concentrations. This paper investigates the sources of these phenomena. As a result of this study a partial pressure correction has been employed in NONLIN computer code. Two typical field spectra are examined to determine what effect the partial pressure correction has on gas quantification.

Evaluation of the National Research Council (2001) dairy model and derivation of new prediction equations. 1. Digestibility of fiber, fat, protein, and nonfiber carbohydrate.

PubMed

White, R R; Roman-Garcia, Y; Firkins, J L; VandeHaar, M J; Armentano, L E; Weiss, W P; McGill, T; Garnett, R; Hanigan, M D

2017-05-01

Evaluation of ration balancing systems such as the National Research Council (NRC) Nutrient Requirements series is important for improving predictions of animal nutrient requirements and advancing feeding strategies. This work used a literature data set (n = 550) to evaluate predictions of total-tract digested neutral detergent fiber (NDF), fatty acid (FA), crude protein (CP), and nonfiber carbohydrate (NFC) estimated by the NRC (2001) dairy model. Mean biases suggested that the NRC (2001) lactating cow model overestimated true FA and CP digestibility by 26 and 7%, respectively, and under-predicted NDF digestibility by 16%. All NRC (2001) estimates had notable mean and slope biases and large root mean squared prediction error (RMSPE), and concordance (CCC) ranged from poor to good. Predicting NDF digestibility with independent equations for legumes, corn silage, other forages, and nonforage feeds improved CCC (0.85 vs. 0.76) compared with the re-derived NRC (2001) equation form (NRC equation with parameter estimates re-derived against this data set). Separate FA digestion coefficients were derived for different fat supplements (animal fats, oils, and other fat types) and for the basal diet. This equation returned improved (from 0.76 to 0.94) CCC compared with the re-derived NRC (2001) equation form. Unique CP digestibility equations were derived for forages, animal protein feeds, plant protein feeds, and other feeds, which improved CCC compared with the re-derived NRC (2001) equation form (0.74 to 0.85). New NFC digestibility coefficients were derived for grain-specific starch digestibilities, with residual organic matter assumed to be 98% digestible. A Monte Carlo cross-validation was performed to evaluate repeatability of model fit. In this procedure, data were randomly subsetted 500 times into derivation (60%) and evaluation (40%) data sets, and equations were derived using the derivation data and then evaluated against the independent evaluation data. Models derived with random study effects demonstrated poor repeatability of fit in independent evaluation. Similar equations derived without random study effects showed improved fit against independent data and little evidence of biased parameter estimates associated with failure to include study effects. The equations derived in this analysis provide interesting insight into how NDF, starch, FA, and CP digestibilities are affected by intake, feed type, and diet composition. The Authors. Published by the Federation of Animal Science Societies and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Jackknife variance of the partial area under the empirical receiver operating characteristic curve.

PubMed

Bandos, Andriy I; Guo, Ben; Gur, David

2017-04-01

Receiver operating characteristic analysis provides an important methodology for assessing traditional (e.g., imaging technologies and clinical practices) and new (e.g., genomic studies, biomarker development) diagnostic problems. The area under the clinically/practically relevant part of the receiver operating characteristic curve (partial area or partial area under the receiver operating characteristic curve) is an important performance index summarizing diagnostic accuracy at multiple operating points (decision thresholds) that are relevant to actual clinical practice. A robust estimate of the partial area under the receiver operating characteristic curve is provided by the area under the corresponding part of the empirical receiver operating characteristic curve. We derive a closed-form expression for the jackknife variance of the partial area under the empirical receiver operating characteristic curve. Using the derived analytical expression, we investigate the differences between the jackknife variance and a conventional variance estimator. The relative properties in finite samples are demonstrated in a simulation study. The developed formula enables an easy way to estimate the variance of the empirical partial area under the receiver operating characteristic curve, thereby substantially reducing the computation burden, and provides important insight into the structure of the variability. We demonstrate that when compared with the conventional approach, the jackknife variance has substantially smaller bias, and leads to a more appropriate type I error rate of the Wald-type test. The use of the jackknife variance is illustrated in the analysis of a data set from a diagnostic imaging study.

Filtering coal-derived oil through a filter media precoated with particles partially solubilized by said oil

DOEpatents

Rodgers, Billy R.; Edwards, Michael S.

1977-01-01

Solids such as char, ash, and refractory organic compounds are removed from coal-derived liquids from coal liquefaction processes by the pressure precoat filtration method using particles of 85-350 mesh material selected from the group of bituminous coal, anthracite coal, lignite, and devolatilized coals as precoat materials and as body feed to the unfiltered coal-derived liquid.

Engineering and Design: Precipitation/Coagulation/Flocculation

DTIC Science & Technology

2001-11-15

Flocculation 7-3 7-3 Jar Test Analysis 10-1 10-3 Alternating Flow Diversion Equalization System 11-1 11-1 Intermittent Flow Diversion System...EM 1110-1-4012 15 NOV 01 (2) Polyaluminum chloride (PAC), another aluminum derivative, is a partially hydrolyzed aluminum chloride solution...derived from natural products include starch, starch derivatives, proteins, and tannins (EPA, 1987). Of these, starch is the most widely used. The

The Price Equation, Gradient Dynamics, and Continuous Trait Game Theory.

PubMed

Lehtonen, Jussi

2018-01-01

A recent article convincingly nominated the Price equation as the fundamental theorem of evolution and used it as a foundation to derive several other theorems. A major section of evolutionary theory that was not addressed is that of game theory and gradient dynamics of continuous traits with frequency-dependent fitness. Deriving fundamental results in these fields under the unifying framework of the Price equation illuminates similarities and differences between approaches and allows a simple, unified view of game-theoretical and dynamic concepts. Using Taylor polynomials and the Price equation, I derive a dynamic measure of evolutionary change, a condition for singular points, the convergence stability criterion, and an alternative interpretation of evolutionary stability. Furthermore, by applying the Price equation to a multivariable Taylor polynomial, the direct fitness approach to kin selection emerges. Finally, I compare these results to the mean gradient equation of quantitative genetics and the canonical equation of adaptive dynamics.

Gray Matter Correlates of Fluid, Crystallized, and Spatial Intelligence: Testing the P-FIT Model

ERIC Educational Resources Information Center

Colom, Roberto; Haier, Richard J.; Head, Kevin; Alvarez-Linera, Juan; Quiroga, Maria Angeles; Shih, Pei Chun; Jung, Rex E.

2009-01-01

The parieto-frontal integration theory (P-FIT) nominates several areas distributed throughout the brain as relevant for intelligence. This theory was derived from previously published studies using a variety of both imaging methods and tests of cognitive ability. Here we test this theory in a new sample of young healthy adults (N = 100) using a…

Examining the "WorkFORCE"™ Assessment for Job Fit and Core Capabilities of "FACETS"™. Research Report. ETS RR-14-32

ERIC Educational Resources Information Center

Naemi, Bobby; Seybert, Jacob; Robbins, Steven; Kyllonen, Patrick

2014-01-01

This report introduces the "WorkFORCE"™ Assessment for Job Fit, a personality assessment utilizing the "FACETS"™ core capability, which is based on innovations in forced-choice assessment and computer adaptive testing. The instrument is derived from the fivefactor model (FFM) of personality and encompasses a broad spectrum of…

Women, disability, and sport and physical fitness activity: the intersection of gender and disability dynamics.

PubMed

Blinde, E M; McCallister, S G

1999-09-01

This study explores the often overlooked experiences of women with physical disabilities in the sport and physical fitness activity domain. Interviews with 16 women with a physical disability (age range of 19-54 years) revealed the following major themes: (a) participation in fitness-related as opposed to sport-related activities, (b) participation to maintain the functional level of the body and preserve existing capabilities, (c) intrinsic nature of gains derived from participation (perceived competence, enhanced view of body, motivational outlet, control in life), and (d) perceived differences in the sport and physical fitness activity experiences of men and women with disabilities. Findings support the notion that gender and disability interact in the sport and physical fitness context for women with physical disabilities.

Perceived versus used workplace flexibility in Singapore: predicting work-family fit.

PubMed

Jones, Blake L; Scoville, D Phillip; Hill, E Jeffrey; Childs, Geniel; Leishman, Joan M; Nally, Kathryn S

2008-10-01

This study examined the relationship of 2 types of workplace flexibility to work-family fit and work, personal, and marriage-family outcomes using data (N = 1,601) representative of employed persons in Singapore. We hypothesized that perceived and used workplace flexibility would be positively related to the study variables. Results derived from structural equation modeling revealed that perceived flexibility predicted work-family fit; however, used flexibility did not. Work-family fit related positively to each work, personal, and marriage-family outcome; however, workplace flexibility only predicted work and personal outcomes. Findings suggest work-family fit may be an important facilitating factor in the interface between work and family life, relating directly to marital satisfaction and satisfaction in other family relationships. Implications of these findings are discussed. Copyright 2008 APA, all rights reserved.

Persistence of transmitted HIV-1 drug resistance mutations associated with fitness costs and viral genetic backgrounds.

PubMed

Yang, Wan-Lin; Kouyos, Roger D; Böni, Jürg; Yerly, Sabine; Klimkait, Thomas; Aubert, Vincent; Scherrer, Alexandra U; Shilaih, Mohaned; Hinkley, Trevor; Petropoulos, Christos; Bonhoeffer, Sebastian; Günthard, Huldrych F

2015-03-01

Transmission of drug-resistant pathogens presents an almost-universal challenge for fighting infectious diseases. Transmitted drug resistance mutations (TDRM) can persist in the absence of drugs for considerable time. It is generally believed that differential TDRM-persistence is caused, at least partially, by variations in TDRM-fitness-costs. However, in vivo epidemiological evidence for the impact of fitness costs on TDRM-persistence is rare. Here, we studied the persistence of TDRM in HIV-1 using longitudinally-sampled nucleotide sequences from the Swiss-HIV-Cohort-Study (SHCS). All treatment-naïve individuals with TDRM at baseline were included. Persistence of TDRM was quantified via reversion rates (RR) determined with interval-censored survival models. Fitness costs of TDRM were estimated in the genetic background in which they occurred using a previously published and validated machine-learning algorithm (based on in vitro replicative capacities) and were included in the survival models as explanatory variables. In 857 sequential samples from 168 treatment-naïve patients, 17 TDRM were analyzed. RR varied substantially and ranged from 174.0/100-person-years;CI=[51.4, 588.8] (for 184V) to 2.7/100-person-years;[0.7, 10.9] (for 215D). RR increased significantly with fitness cost (increase by 1.6[1.3,2.0] per standard deviation of fitness costs). When subdividing fitness costs into the average fitness cost of a given mutation and the deviation from the average fitness cost of a mutation in a given genetic background, we found that both components were significantly associated with reversion-rates. Our results show that the substantial variations of TDRM persistence in the absence of drugs are associated with fitness-cost differences both among mutations and among different genetic backgrounds for the same mutation.

Towards a mechanistic foundation of evolutionary theory.

PubMed

Doebeli, Michael; Ispolatov, Yaroslav; Simon, Burt

2017-02-15

Most evolutionary thinking is based on the notion of fitness and related ideas such as fitness landscapes and evolutionary optima. Nevertheless, it is often unclear what fitness actually is, and its meaning often depends on the context. Here we argue that fitness should not be a basal ingredient in verbal or mathematical descriptions of evolution. Instead, we propose that evolutionary birth-death processes, in which individuals give birth and die at ever-changing rates, should be the basis of evolutionary theory, because such processes capture the fundamental events that generate evolutionary dynamics. In evolutionary birth-death processes, fitness is at best a derived quantity, and owing to the potential complexity of such processes, there is no guarantee that there is a simple scalar, such as fitness, that would describe long-term evolutionary outcomes. We discuss how evolutionary birth-death processes can provide useful perspectives on a number of central issues in evolution.

The influence of social anxiety on the body checking behaviors of female college students.

PubMed

White, Emily K; Warren, Cortney S

2014-09-01

Social anxiety and eating pathology frequently co-occur. However, there is limited research examining the relationship between anxiety and body checking, aside from one study in which social physique anxiety partially mediated the relationship between body checking cognitions and body checking behavior (Haase, Mountford, & Waller, 2007). In an independent sample of 567 college women, we tested the fit of Haase and colleagues' foundational model but did not find evidence of mediation. Thus we tested the fit of an expanded path model that included eating pathology and clinical impairment. In the best-fitting path model (CFI=.991; RMSEA=.083) eating pathology and social physique anxiety positively predicted body checking, and body checking positively predicted clinical impairment. Therefore, women who endorse social physique anxiety may be more likely to engage in body checking behaviors and experience impaired psychosocial functioning. Published by Elsevier Ltd.

Local climatic adaptation in a widespread microorganism.

PubMed

Leducq, Jean-Baptiste; Charron, Guillaume; Samani, Pedram; Dubé, Alexandre K; Sylvester, Kayla; James, Brielle; Almeida, Pedro; Sampaio, José Paulo; Hittinger, Chris Todd; Bell, Graham; Landry, Christian R

2014-02-22

Exploring the ability of organisms to locally adapt is critical for determining the outcome of rapid climate changes, yet few studies have addressed this question in microorganisms. We investigated the role of a heterogeneous climate on adaptation of North American populations of the wild yeast Saccharomyces paradoxus. We found abundant among-strain variation for fitness components across a range of temperatures, but this variation was only partially explained by climatic variation in the distribution area. Most of fitness variation was explained by the divergence of genetically distinct groups, distributed along a north-south cline, suggesting that these groups have adapted to distinct climatic conditions. Within-group fitness components were correlated with climatic conditions, illustrating that even ubiquitous microorganisms locally adapt and harbour standing genetic variation for climate-related traits. Our results suggest that global climatic changes could lead to adaptation to new conditions within groups, or changes in their geographical distributions.

Atmospheric Soundings from AIRS/AMSU in Partial Cloud Cover

NASA Technical Reports Server (NTRS)

Susskind, Joel; Atlas, Robert

2005-01-01

Simultaneous use of AIRS/AMSU-A observations allow for the determination of accurate atmospheric soundings under partial cloud cover conditions. The methodology involves the determination of the radiances AIRS would have seen if the AIRS fields of view were clear, called clear column radiances, and use of these radiances to infer the atmospheric and surface conditions giving rise to these clear column radiances. Susskind et al. demonstrate via simulation that accurate temperature soundings and clear column radiances can be derived from AIRS/AMSU-A observations in cases of up to 80% partial cloud cover, with only a small degradation in accuracy compared to that obtained in clear scenes. Susskind and Atlas show that these findings hold for real AIRS/AMSU-A soundings as well. For data assimilation purposes, this small degradation in accuracy is more than offset by a significant increase in spatial coverage (roughly 50% of global cases were accepted, compared to 3.6% of the global cases being diagnosed as clear), and assimilation of AIRS temperature soundings in partially cloudy conditions resulted in a larger improvement in forecast skill than when AIRS soundings were assimilated only under clear conditions. Alternatively, derived AIRS clear column radiances under partial cloud cover could also be used for data assimilation purposes. Further improvements in AIRS sounding methodology have been made since the results shown in Susskind and Atlas . A new version of the AIRS/AMSU-A retrieval algorithm, Version 4.0, was delivered to the Goddard DAAC in February 2005 for production of AIRS derived products, including clear column radiances. The major improvement in the Version 4.0 retrieval algorithm is with regard to a more flexible, parameter dependent, quality control. Results are shown of the accuracy and spatial distribution of temperature-moisture profiles and clear column radiances derived from AIRS/AMSU-A as a function of fractional cloud cover using the Version 4.0 algorithm. Use of the Version 4.0 AIRS temperature profiles increased the positive forecast impact arising from AIRS retrievals relative to what was shown in Susskind and Atlas .

Molecular dynamics force-field refinement against quasi-elastic neutron scattering data

DOE PAGES

Borreguero Calvo, Jose M.; Lynch, Vickie E.

2015-11-23

Quasi-elastic neutron scattering (QENS) is one of the experimental techniques of choice for probing the dynamics at length and time scales that are also in the realm of full-atom molecular dynamics (MD) simulations. This overlap enables extension of current fitting methods that use time-independent equilibrium measurements to new methods fitting against dynamics data. We present an algorithm that fits simulation-derived incoherent dynamical structure factors against QENS data probing the diffusive dynamics of the system. We showcase the difficulties inherent to this type of fitting problem, namely, the disparity between simulation and experiment environment, as well as limitations in the simulationmore » due to incomplete sampling of phase space. We discuss a methodology to overcome these difficulties and apply it to a set of full-atom MD simulations for the purpose of refining the force-field parameter governing the activation energy of methyl rotation in the octa-methyl polyhedral oligomeric silsesquioxane molecule. Our optimal simulated activation energy agrees with the experimentally derived value up to a 5% difference, well within experimental error. We believe the method will find applicability to other types of diffusive motions and other representation of the systems such as coarse-grain models where empirical fitting is essential. In addition, the refinement method can be extended to the coherent dynamic structure factor with no additional effort.« less

Punctuated equilibrium and shock waves in molecular models of biological evolution.

PubMed

Saakian, David B; Ghazaryan, Makar H; Hu, Chin-Kun

2014-08-01

We consider the dynamics in infinite population evolution models with a general symmetric fitness landscape. We find shock waves, i.e., discontinuous transitions in the mean fitness, in evolution dynamics even with smooth fitness landscapes, which means that the search for the optimal evolution trajectory is more complicated. These shock waves appear in the case of positive epistasis and can be used to represent punctuated equilibria in biological evolution during long geological time scales. We find exact analytical solutions for discontinuous dynamics at the large-genome-length limit and derive optimal mutation rates for a fixed fitness landscape to send the population from the initial configuration to some final configuration in the fastest way.