Not All Biofluids Are Created Equal: Chewing Over Salivary Diagnostics and the Epigenome

PubMed Central

Wren, M.E.; Shirtcliff, E.A.; Drury, Stacy S.

2015-01-01

Purpose This article describes progress to date in the characterization of the salivary epigenome and considers the importance of previous work in the salivary microbiome, proteome, endocrine analytes, genome, and transcriptome. Methods PubMed and Web of Science were used to extensively search the existing literature (original research and reviews) related to salivary diagnostics and bio-marker development, of which 125 studies were examined. This article was derived from the most relevant 73 sources highlighting the recent state of the evolving field of salivary epigenomics and contributing significantly to the foundational work in saliva-based research. Findings Validation of any new saliva-based diagnostic or analyte will require comparison to previously accepted standards established in blood. Careful attention to the collection, processing, and analysis of salivary analytes is critical for the development and implementation of newer applications that include genomic, transcriptomic, and epigenomic markers. All these factors must be integrated into initial study design. Implications This commentary highlights the appeal of the salivary epigenome for translational applications and its utility in future studies of development and the interface among environment, disease, and health. PMID:25778408

A single factor underlies the metabolic syndrome: a confirmatory factor analysis.

PubMed

Pladevall, Manel; Singal, Bonita; Williams, L Keoki; Brotons, Carlos; Guyer, Heidi; Sadurni, Josep; Falces, Carles; Serrano-Rios, Manuel; Gabriel, Rafael; Shaw, Jonathan E; Zimmet, Paul Z; Haffner, Steven

2006-01-01

Confirmatory factor analysis (CFA) was used to test the hypothesis that the components of the metabolic syndrome are manifestations of a single common factor. Three different datasets were used to test and validate the model. The Spanish and Mauritian studies included 207 men and 203 women and 1,411 men and 1,650 women, respectively. A third analytical dataset including 847 men was obtained from a previously published CFA of a U.S. population. The one-factor model included the metabolic syndrome core components (central obesity, insulin resistance, blood pressure, and lipid measurements). We also tested an expanded one-factor model that included uric acid and leptin levels. Finally, we used CFA to compare the goodness of fit of one-factor models with the fit of two previously published four-factor models. The simplest one-factor model showed the best goodness-of-fit indexes (comparative fit index 1, root mean-square error of approximation 0.00). Comparisons of one-factor with four-factor models in the three datasets favored the one-factor model structure. The selection of variables to represent the different metabolic syndrome components and model specification explained why previous exploratory and confirmatory factor analysis, respectively, failed to identify a single factor for the metabolic syndrome. These analyses support the current clinical definition of the metabolic syndrome, as well as the existence of a single factor that links all of the core components.

Single-Cell Detection of Secreted Aβ and sAPPα from Human IPSC-Derived Neurons and Astrocytes.

PubMed

Liao, Mei-Chen; Muratore, Christina R; Gierahn, Todd M; Sullivan, Sarah E; Srikanth, Priya; De Jager, Philip L; Love, J Christopher; Young-Pearse, Tracy L

2016-02-03

Secreted factors play a central role in normal and pathological processes in every tissue in the body. The brain is composed of a highly complex milieu of different cell types and few methods exist that can identify which individual cells in a complex mixture are secreting specific analytes. By identifying which cells are responsible, we can better understand neural physiology and pathophysiology, more readily identify the underlying pathways responsible for analyte production, and ultimately use this information to guide the development of novel therapeutic strategies that target the cell types of relevance. We present here a method for detecting analytes secreted from single human induced pluripotent stem cell (iPSC)-derived neural cells and have applied the method to measure amyloid β (Aβ) and soluble amyloid precursor protein-alpha (sAPPα), analytes central to Alzheimer's disease pathogenesis. Through these studies, we have uncovered the dynamic range of secretion profiles of these analytes from single iPSC-derived neuronal and glial cells and have molecularly characterized subpopulations of these cells through immunostaining and gene expression analyses. In examining Aβ and sAPPα secretion from single cells, we were able to identify previously unappreciated complexities in the biology of APP cleavage that could not otherwise have been found by studying averaged responses over pools of cells. This technique can be readily adapted to the detection of other analytes secreted by neural cells, which would have the potential to open new perspectives into human CNS development and dysfunction. We have established a technology that, for the first time, detects secreted analytes from single human neurons and astrocytes. We examine secretion of the Alzheimer's disease-relevant factors amyloid β (Aβ) and soluble amyloid precursor protein-alpha (sAPPα) and present novel findings that could not have been observed without a single-cell analytical platform. First, we identify a previously unappreciated subpopulation that secretes high levels of Aβ in the absence of detectable sAPPα. Further, we show that multiple cell types secrete high levels of Aβ and sAPPα, but cells expressing GABAergic neuronal markers are overrepresented. Finally, we show that astrocytes are competent to secrete high levels of Aβ and therefore may be a significant contributor to Aβ accumulation in the brain. Copyright © 2016 the authors 0270-6474/16/361730-17$15.00/0.

Determination of immersion factors for radiance sensors in marine and inland waters: a semi-analytical approach using refractive index approximation

NASA Astrophysics Data System (ADS)

Dev, Pravin J.; Shanmugam, P.

2016-05-01

Underwater radiometers are generally calibrated in air using a standard source. The immersion factors are required for these radiometers to account for the change in the in-water measurements with respect to in-air due to the different refractive index of the medium. The immersion factors previously determined for RAMSES series of commercial radiometers manufactured by TriOS are applicable to clear oceanic waters. In typical inland and turbid productive coastal waters, these experimentally determined immersion factors yield significantly large errors in water-leaving radiances (Lw) and hence remote sensing reflectances (Rrs). To overcome this limitation, a semi-analytical method with based on the refractive index approximation is proposed in this study, with the aim of obtaining reliable Lw and Rrs from RAMSES radiometers for turbid and productive waters within coastal and inland water environments. We also briefly show the variation of pure water immersion factors (Ifw) and newly derived If on Lw and Rrs for clear and turbid waters. The remnant problems other than the immersion factor coefficients such as transmission, air-water and water-air Fresnel's reflectances are also discussed.

Soft materials with recoverable shape factors from extreme distortion states

DOE PAGES

Goff, Jonathan; Sulaiman, Santy; Arkles, Barry; ...

2016-01-20

We present elastomeric polysiloxane nanocomposites with elongations of >5000% (more than 3× greater than any previously reported material) with excellent shape recovery. Highly deformable materials are desirable for the fabrication of stretchable implants and microfluidic devices. No crosslinking or domain formation is observed by a variety of analytical techniques, suggesting that their elastomeric behavior is caused by polymer chain entanglements.

Testing alternative factor models of PTSD and the robustness of the dysphoria factor.

PubMed

Elklit, Ask; Armour, Cherie; Shevlin, Mark

2010-01-01

This study first aimed to examine the structure of self-reported posttraumatic stress disorder (PTSD) symptoms using three different samples. The second aim of the paper was to test the robustness of the factor analytic model when depression scores were controlled for. Based on previous factor analytic findings and the DSM-IV formulation, six confirmatory factor models were specified and estimated that reflected different symptom clusters. The best fitting model was subsequently re-fitted to the data after including a depression variable. The analyses were based on responses from 973 participants across three samples. Sample 1 consisted of 633 parents who were members of 'The National Association of Infant Death' and who had lost a child. Sample 2 consisted of 227 victims of rape, who completed a questionnaire within 4 weeks of the rape. Each respondent had been in contact with the Centre for Rape Victims (CRV) at the Aarhus University Hospital, Denmark. Sample 3 consisted of 113 refugees resident in Denmark. All participants had been referred to a treatment centre which focused on rehabilitating refugees through treatment for psychosocial integration problems (RRCF: Rehabliterings og Revliderings Centre for Flygtninge). In total 500 participants received a diagnosis of PTSD/sub-clinical PTSD (Sample 1, N=214; 2, N=176; 3, N=110). A correlated four-factor model with re-experiencing, avoidance, dysphoria, and arousal factors provided the best fit to the sample data. The average attenuation in the factor loadings was highest for the dysphoria factor (M=-.26, SD=.11) compared to the re-experiencing (M=-.14, SD=.18), avoidance (M=-.10, SD=.21), and arousal (M=-.09, SD=.13) factors. With regards to the best fitting factor model these results concur with previous research findings using different trauma populations but do not reflect the current DSM-IV symptom groupings. The attenuation of dysphoria factor loadings suggests that dysphoria is a non-specific component of PTSD.

Dispersive analysis of the pion transition form factor

NASA Astrophysics Data System (ADS)

Hoferichter, M.; Kubis, B.; Leupold, S.; Niecknig, F.; Schneider, S. P.

2014-11-01

We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the cross section, generalizing previous studies on decays and scattering, and verify our result by comparing to data. We perform the analytic continuation to the space-like region, predicting the poorly-constrained space-like transition form factor below , and extract the slope of the form factor at vanishing momentum transfer . We derive the dispersive formalism necessary for the extension of these results to the doubly-virtual case, as required for the pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.

Analyzing the factors that influencing the success of post graduates in achieving graduate on time (GOT) using analytic hierarchy process (AHP)

NASA Astrophysics Data System (ADS)

Chin, Wan Yung; Ch'ng, Chee Keong; Jamil, Jastini Mohd.; Shaharanee, Izwan Nizal Mohd.

2017-11-01

In the globalization era, education plays an important role in educating and preparing individuals to face the demands and challenges of 21st century. Thus, this contributes to the increase of the number of individuals pursuing their studies in Doctor of Philosophy (Ph.D) program. However, the ability of Ph.D students in heading to the four years Graduate on Time (GOT) mission that is stipulated by University has become a major concern of students, institution and government. Therefore, the main objective of this study is to investigate the factors that influence the Ph.D students in Universiti Utara Malaysia (UUM) to achieve GOT. Through the reviewing of previous research, six factors which are student factor, financial factor, supervisor factor, skills factor, project factors and institution factor had been identified as the domain factors that influence the Ph.D students in achieving GOT. The level of importance for each factor will be ranked by the experts from three graduate schools using Analytic Hierarchy Process (AHP) technique. This study will bring a significant contribution to the understanding of factors that affecting the Ph.D students in UUM to achieve GOT. In Addition, this study can also succor the university in planning and assisting the Ph.D students to accomplish the GOT in future.

Headspace versus direct immersion solid phase microextraction in complex matrixes: investigation of analyte behavior in multicomponent mixtures.

PubMed

Gionfriddo, Emanuela; Souza-Silva, Érica A; Pawliszyn, Janusz

2015-08-18

This work aims to investigate the behavior of analytes in complex mixtures and matrixes with the use of solid-phase microextraction (SPME). Various factors that influence analyte uptake such as coating chemistry, extraction mode, the physicochemical properties of analytes, and matrix complexity were considered. At first, an aqueous system containing analytes bearing different hydrophobicities, molecular weights, and chemical functionalities was investigated by using commercially available liquid and solid porous coatings. The differences in the mass transfer mechanisms resulted in a more pronounced occurrence of coating saturation in headspace mode. Contrariwise, direct immersion extraction minimizes the occurrence of artifacts related to coating saturation and provides enhanced extraction of polar compounds. In addition, matrix-compatible PDMS-modified solid coatings, characterized by a new morphology that avoids coating fouling, were compared to their nonmodified analogues. The obtained results indicate that PDMS-modified coatings reduce artifacts associated with coating saturation, even in headspace mode. This factor, coupled to their matrix compatibility, make the use of direct SPME very practical as a quantification approach and the best choice for metabolomics studies where wide coverage is intended. To further understand the influence on analyte uptake on a system where additional interactions occur due to matrix components, ex vivo and in vivo sampling conditions were simulated using a starch matrix model, with the aim of mimicking plant-derived materials. Our results corroborate the fact that matrix handling can affect analyte/matrix equilibria, with consequent release of high concentrations of previously bound hydrophobic compounds, potentially leading to coating saturation. Direct immersion SPME limited the occurrence of the artifacts, which confirms the suitability of SPME for in vivo applications. These findings shed light into the implementation of in vivo SPME strategies in quantitative metabolomics studies of complex plant-based systems.

Not all biofluids are created equal: chewing over salivary diagnostics and the epigenome.

PubMed

Wren, Michael E; Shirtcliff, Elizabeth A; Drury, Stacy S

2015-03-01

This article describes progress to date in the characterization of the salivary epigenome and considers the importance of previous work in the salivary microbiome, proteome, endocrine analytes, genome, and transcriptome. PubMed and Web of Science were used to extensively search the existing literature (original research and reviews) related to salivary diagnostics and biomarker development, of which 125 studies were examined. This article was derived from the most relevant 74 sources highlighting the recent state of the evolving field of salivary epigenomics and contributing significantly to the foundational work in saliva-based research. Validation of any new saliva-based diagnostic or analyte will require comparison to previously accepted standards established in blood. Careful attention to the collection, processing, and analysis of salivary analytes is critical for the development and implementation of newer applications that include genomic, transcriptomic, and epigenomic markers. All these factors must be integrated into initial study design. This commentary highlights the appeal of the salivary epigenome for translational applications and its utility in future studies of development and the interface among environment, disease, and health. Copyright © 2015 Elsevier HS Journals, Inc. All rights reserved.

Construct validity of the Beck Hopelessness Scale (BHS) among university students: A multitrait-multimethod approach.

PubMed

Boduszek, Daniel; Dhingra, Katie

2016-10-01

There is considerable debate about the underlying factor structure of the Beck Hopelessness Scale (BHS) in the literature. An established view is that it reflects a unitary or bidimensional construct in nonclinical samples. There are, however, reasons to reconsider this conceptualization. Based on previous factor analytic findings from both clinical and nonclinical studies, the aim of the present study was to compare 16 competing models of the BHS in a large university student sample (N = 1, 733). Sixteen distinct factor models were specified and tested using conventional confirmatory factor analytic techniques, along with confirmatory bifactor modeling. A 3-factor solution with 2 method effects (i.e., a multitrait-multimethod model) provided the best fit to the data. The reliability of this conceptualization was supported by McDonald's coefficient omega and the differential relationships exhibited between the 3 hopelessness factors ("feelings about the future," "loss of motivation," and "future expectations") and measures of goal disengagement, brooding rumination, suicide ideation, and suicide attempt history. The results provide statistical support for a 3-trait and 2-method factor model, and hence the 3 dimensions of hopelessness theorized by Beck. The theoretical and methodological implications of these findings are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Prediction of light aircraft interior noise

NASA Technical Reports Server (NTRS)

Howlett, J. T.; Morales, D. A.

1976-01-01

At the present time, predictions of aircraft interior noise depend heavily on empirical correction factors derived from previous flight measurements. However, to design for acceptable interior noise levels and to optimize acoustic treatments, analytical techniques which do not depend on empirical data are needed. This paper describes a computerized interior noise prediction method for light aircraft. An existing analytical program (developed for commercial jets by Cockburn and Jolly in 1968) forms the basis of some modal analysis work which is described. The accuracy of this modal analysis technique for predicting low-frequency coupled acoustic-structural natural frequencies is discussed along with trends indicating the effects of varying parameters such as fuselage length and diameter, structural stiffness, and interior acoustic absorption.

Dust ring formation due to sublimation of dust grains drifting radially inward by the Poynting-Robertson drag: An analytical model

NASA Astrophysics Data System (ADS)

Kobayashi, Hiroshi; Watanabe, Sei-ichiro; Kimura, Hiroshi; Yamamoto, Tetsuo

2009-05-01

Dust particles exposed to the stellar radiation and wind drift radially inward by the Poynting-Robertson (P-R) drag and pile up at the zone where they begin to sublime substantially. The reason they pile up or form a ring is that their inward drifts due to the P-R drag are suppressed by stellar radiation pressure when the ratio of radiation pressure to stellar gravity on them increases during their sublimation phases. We present analytic solutions to the orbital and mass evolution of such subliming dust particles, and find their drift velocities at the pileup zone are almost independent of their initial semimajor axes and masses. We derive analytically an enhancement factor of the number density of the particles at the outer edge of the sublimation zone from the solutions. We show that the formula of the enhancement factor reproduces well numerical simulations in the previous studies. The enhancement factor for spherical dust particles of silicate and carbon extends from 3 to more than 20 at stellar luminosities L=0.8-500L, where L is solar luminosity. Although the enhancement factor for fluffy dust particles is smaller than that for spherical particles, sublimating particles inevitably form a dust ring as long as their masses decrease faster than their surface areas during sublimation. The formulation is applicable to dust ring formation for arbitrary shape and material of dust in dust-debris disks as well as in the Solar System.

Parametrizations of three-body hadronic B - and D -decay amplitudes in terms of analytic and unitary meson-meson form factors

NASA Astrophysics Data System (ADS)

Boito, D.; Dedonder, J.-P.; El-Bennich, B.; Escribano, R.; Kamiński, R.; Leśniak, L.; Loiseau, B.

2017-12-01

We introduce parametrizations of hadronic three-body B and D weak decay amplitudes that can be readily implemented in experimental analyses and are a sound alternative to the simplistic and widely used sum of Breit-Wigner type amplitudes, also known as the isobar model. These parametrizations can be particularly useful in the interpretation of C P asymmetries in the Dalitz plots. They are derived from previous calculations based on a quasi-two-body factorization approach in which two-body hadronic final-state interactions are fully taken into account in terms of unitary S - and P -wave π π , π K , and K K ¯ form factors. These form factors can be determined rigorously, fulfilling fundamental properties of quantum field-theory amplitudes such as analyticity and unitarity, and are in agreement with the low-energy behavior predicted by effective theories of QCD. They are derived from sets of coupled-channel equations using T -matrix elements constrained by experimental meson-meson phase shifts and inelasticities, chiral symmetry, and asymptotic QCD. We provide explicit amplitude expressions for the decays B±→π+π-π±, B →K π+π-, B±→K+K-K±, D+→π-π+π+, D+→K-π+π+, and D0→KS0π+π-, for which we have shown in previous studies that this approach is phenomenologically successful; in addition, we provide expressions for the D0→KS0K+K- decay. Other three-body hadronic channels can be parametrized likewise.

Stability and change of personality traits, self-esteem, and well-being: Introducing the meta-analytic stability and change model of retest correlations.

PubMed

Anusic, Ivana; Schimmack, Ulrich

2016-05-01

The stability of individual differences is a fundamental issue in personality psychology. Although accumulating evidence suggests that many psychological attributes are both stable and change over time, existing research rarely takes advantage of theoretical models that capture both stability and change. In this article, we present the Meta-Analytic Stability and Change model (MASC), a novel meta-analytic model for synthesizing data from longitudinal studies. MASC is based on trait-state models that can separate influences of stable and changing factors from unreliable variance (Kenny & Zautra, 1995). We used MASC to evaluate the extent to which personality traits, life satisfaction, affect, and self-esteem are influenced by these different factors. The results showed that the majority of reliable variance in personality traits is attributable to stable influences (83%). Changing factors had a greater influence on reliable variance in life satisfaction, self-esteem, and affect than in personality (42%-56% vs. 17%). In addition, changing influences on well-being were more stable than changing influences on personality traits, suggesting that different changing factors contribute to personality and well-being. Measures of affect were less reliable than measures of the other 3 constructs, reflecting influences of transient factors, such as mood on affective judgments. After accounting for differences in reliability, stability of affect did not differ from other well-being variables. Consistent with previous research, we found that stability of individual differences increases with age. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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

Xia, T. Y.; Zhang, Y.

We present an analytical calculation of the spectra of CMB anisotropies and polarizations generated by relic gravitational waves (RGWs). As a substantial extension to the previous studies, three new ingredients are included in this work. First, the analytic C{sub l}{sup TT} and C{sub l}{sup TE} are given; especially the latter can be useful to extract signal of RGWs from the observed data in the zero-multipole method. Second, a fitting formula of the decaying factor on small scales is given, coming from the visibility function around the photon decoupling. Third, the impacts by the neutrino free-streaming (NFS) is examined, a processmore » that occurred in the early universe and leaves observable imprints on CMB via RGWs. It is found that the analytic C{sub l}{sup TT} and C{sub l}{sup TE} have profiles agreeing with the numeric ones, except that C{sub l}{sup TT} in a range l{<=}10 and the first trough of C{sub l}{sup TE} around l{approx}75 have some deviations. With the new damping factor, the analytic C{sub l}{sup EE} and C{sub l}{sup BB} match with the numeric ones with the maximum errors only {approx}3% up to the first three peaks for l{<=}600, improving the previous studies substantially. The correspondence of the positions of peaks of C{sub l}{sup XX} and those of RGWs are also demonstrated explicitly. We also find that NFS reduces the amplitudes of C{sub l}{sup XX} by (20%{approx}35%) for l{approx_equal}(100{approx}600) and shifts slightly their peaks to smaller angles. Detailed analyses show that the zero multipoles l{sub 0}, where C{sub l}{sup TE} crosses 0, are shifted to larger values by NFS. This shifting effect is as important as those caused by different inflation models and different baryon fractions.« less

[Clinical and analytical findings in patients with toxic oil syndrome. Study of a cohort of 758 patients].

PubMed

Martín Alvarez, H; Plaza Cano, M; Estirado de Cabo, E; García de Aguinaga, M; Izquierdo Martínez, M; Posada de la Paz, M

2000-06-01

To report the symptoms and analytical findings observed in the collective of patients affected with the toxic oil syndrome (TOS) 18 years after the poisoning. At the Centro de Investigación sobre el Síndrome del Aceite Tóxico (CISAT) we followed the clinical and analytical course of 758 patients affected with the TOS since December 1997 up to May 1999. Patients were evaluated by means of a previously standardized questionnaire in which a clinical review and a battery of complementary tests (thyroid hormones, spirometry with diffusion test and arterial gasometry) were included. One hundred and sixty-two patients underwent also echocardiogram because of presumptive pulmonary hypertension and/or heart disease. Out of the 758 patients, 516 were females and 242 males (M:F ratio 2:1), with ages ranging from 17 to 84 years (mean age 47 years). One of the most remarkable findings was the increased prevalence of cardiovascular risk factors: arterial hypertension (34%), dyslipemias (44%), overweight (40%), obesity (27%), carbohydrate intolerance (9%) and diabetes mellitus (9.4%). The most common reported symptoms were: cramps (78%), arthralgias (78%), and paresthesias (70%). Only 2.8% of patients reported to be asymptomatic. The analytical results most commonly changed were: changes in lipidic and carbohydrate metabolism (already reported), overt or subclinical hypothyroidism (6.6%) and respiratory changes in patients with no previous pulmonary disease: changes in spirometry (6%), diffusion test (8%) and hypoxemia (18%). Echocardiographic findings suggestive of PHT were obtained in 3.1% of cases. Although TOS occurred in 1981, this syndrome still has a relevant morbidity in a portion of the spanish population. To remark the high prevalence of cardiovascular risk factors with changes in lipidic and carbohydrate metabolism and subclinical hypothyroidism observed in our series. Further studies are necessary to evaluate the actual dimension of this poisoning.

Simplex optimization of headspace factors for headspace gas chromatography determination of residual solvents in pharmaceutical products.

PubMed

Grodowska, Katarzyna; Parczewski, Andrzej

2013-01-01

The purpose of the present work was to find optimum conditions of headspace gas chromatography (HS-GC) determination of residual solvents which usually appear in pharmaceutical products. Two groups of solvents were taken into account in the present examination. Group I consisted of isopropanol, n-propanol, isobutanol, n-butanol and 1,4-dioxane and group II included cyclohexane, n-hexane and n-heptane. The members of the groups were selected in previous investigations in which experimental design and chemometric methods were applied. Four factors were taken into consideration in optimization which describe HS conditions: sample volume, equilibration time, equilibrium temperature and NaCl concentration in a sample. The relative GC peak area served as an optimization criterion which was considered separately for each analyte. Sequential variable size simplex optimization strategy was used and the progress of optimization was traced and visualized in various ways simultaneously. The optimum HS conditions appeared different for the groups of solvents tested, which proves that influence of experimental conditions (factors) depends on analyte properties. The optimization resulted in significant signal increase (from seven to fifteen times).

The QCD form factor of heavy quarks at NNLO

NASA Astrophysics Data System (ADS)

Gluza, J.; Mitov, A.; Moch, S.; Riemann, T.

2009-07-01

We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are computed through higher orders in the parameter of dimensional regularization epsilon = (4-D)/2. Our result includes all terms of order epsilon at two loops and extends the previous literature. We apply the exponentiation of the heavy-quark form factor to derive new improved three-loop expansions in the high-energy limit. We also discuss the implications for predictions of massive n-parton amplitudes based on massless results in the limit, where the quark mass is small compared to all kinematical invariants.

Dispersive analysis of the pion transition form factor.

PubMed

Hoferichter, M; Kubis, B; Leupold, S; Niecknig, F; Schneider, S P

We analyze the pion transition form factor using dispersion theory. We calculate the singly-virtual form factor in the time-like region based on data for the [Formula: see text] cross section, generalizing previous studies on [Formula: see text] decays and [Formula: see text] scattering, and verify our result by comparing to [Formula: see text] data. We perform the analytic continuation to the space-like region, predicting the poorly-constrained space-like transition form factor below [Formula: see text], and extract the slope of the form factor at vanishing momentum transfer [Formula: see text]. We derive the dispersive formalism necessary for the extension of these results to the doubly-virtual case, as required for the pion-pole contribution to hadronic light-by-light scattering in the anomalous magnetic moment of the muon.

Consideration of some factors affecting low-frequency fuselage noise transmission for propeller aircraft

NASA Technical Reports Server (NTRS)

Mixson, J. S.; Roussos, L. A.

1986-01-01

Possible reasons for disagreement between measured and predicted trends of sidewall noise transmission at low frequency are investigated using simplified analysis methods. An analytical model combining incident plane acoustic waves with an infinite flat panel is used to study the effects of sound incidence angle, plate structural properties, frequency, absorption, and the difference between noise reduction and transmission loss. Analysis shows that these factors have significant effects on noise transmission but they do not account for the differences between measured and predicted trends at low frequencies. An analytical model combining an infinite flat plate with a normally incident acoustic wave having exponentially decaying magnitude along one coordinate is used to study the effect of a localized source distribution such as is associated with propeller noise. Results show that the localization brings the predicted low-frequency trend of noise transmission into better agreement with measured propeller results. This effect is independent of low-frequency stiffness effects that have been previously reported to be associated with boundary conditions.

Relationships among abilities in elderly adults: a time lag analysis.

PubMed

Hayslip, B; Brookshire, R G

1985-11-01

Previous research has suggested that relationships among primary abilities said to measure crystallized (Gc) and fluid (Gf) intelligences remain the same across cohorts if age is held constant, despite generational changes in the levels of abilities. The present study assessed differences in relationship among several components of Gf/Gc in two independent samples of elderly adults, tested in 1975 and 1979 by the same investigator. The 1975 sample consisted of 54 elderly adults aged 59 to 76 years (M = 67.7); the 1979 sample of 50 elderly adults was aged 55 to 82 (M = 69.4). Time-lagged differences in relationships among abilities measuring Gf and Gc (induction, figural relations, and verbal comprehension) were investigated using confirmatory factor analytic procedures. Although a two factor (Gf, Gc) model was common to both the 1975 and 1979 samples, significant differences in unique variances were observed across samples. Some, albeit weaker, evidence was found suggesting time-lagged differences in factor covariances. These data, for the most part, support previous research with younger individuals, suggesting consistency in factor structure across time and cohort.

Confirmatory Factor Analysis of the Minnesota Nicotine Withdrawal Scale

PubMed Central

Toll, Benjamin A.; O’Malley, Stephanie S.; McKee, Sherry A.; Salovey, Peter; Krishnan-Sarin, Suchitra

2008-01-01

The authors examined the factor structure of the Minnesota Nicotine Withdrawal Scale (MNWS) using confirmatory factor analysis in clinical research samples of smokers trying to quit (n = 723). Three confirmatory factor analytic models, based on previous research, were tested with each of the 3 study samples at multiple points in time. A unidimensional model including all 8 MNWS items was found to be the best explanation of the data. This model produced fair to good internal consistency estimates. Additionally, these data revealed that craving should be included in the total score of the MNWS. Factor scores derived from this single-factor, 8-item model showed that increases in withdrawal were associated with poor smoking outcome for 2 of the clinical studies. Confirmatory factor analyses of change scores showed that the MNWS symptoms cohere as a syndrome over time. Future investigators should report a total score using all of the items from the MNWS. PMID:17563141

Social cognition in schizophrenia: cognitive and affective factors.

PubMed

Ziv, Ido; Leiser, David; Levine, Joseph

2011-01-01

Social cognition refers to how people conceive, perceive, and draw inferences about mental and emotional states of others in the social world. Previous studies suggest that the concept of social cognition involves several abilities, including those related to affect and cognition. The present study analyses the deficits of individuals with schizophrenia in two areas of social cognition: Theory of Mind (ToM) and emotion recognition and processing. Examining the impairment of these abilities in patients with schizophrenia has the potential to elucidate the neurophysiological regions involved in social cognition and may also have the potential to aid rehabilitation. Two experiments were conducted. Both included the same five tasks: first- and second-level false-belief ToM tasks, emotion inferencing, understanding of irony, and matrix reasoning (a WAIS-R subtest). The matrix reasoning task was administered to evaluate and control for the association of the other tasks with analytic reasoning skills. Experiment 1 involved factor analysis of the task performance of 75 healthy participants. Experiment 2 compared 30 patients with schizophrenia to an equal number of matched controls. Results. (1) The five tasks were clearly divided into two factors corresponding to the two areas of social cognition, ToM and emotion recognition and processing. (2) Schizophrenics' performance was impaired on all tasks, particularly on those loading heavily on the analytic component (matrix reasoning and second-order ToM). (3) Matrix reasoning, second-level ToM (ToM2), and irony were found to distinguish patients from controls, even when all other tasks that revealed significant impairment in the patients' performance were taken into account. The two areas of social cognition examined are related to distinct factors. The mechanism for answering ToM questions (especially ToM2) depends on analytic reasoning capabilities, but the difficulties they present to individuals with schizophrenia are due to other components as well. The impairment in social cognition in schizophrenia stems from deficiencies in several mechanisms, including the ability to think analytically and to process emotion information and cues.

Environmental and human monitoring of Americium-241 utilizing extraction chromatography and alpha-spectrometry.

PubMed

Goldstein, S J; Hensley, C A; Armenta, C E; Peters, R J

1997-03-01

Recent developments in extraction chromatography have simplified the separation of americium from complex matrices in preparation for alpha-spectroscopy relative to traditional methods. Here we present results of procedures developed/adapted for water, air, and bioassay samples with less than 1 g of inorganic residue. Prior analytical methods required the use of a complex, multistage procedure for separation of americium from these matrices. The newer, simplified procedure requires only a single 2 mL extraction chromatographic separation for isolation of Am and lanthanides from other components of the sample. This method has been implemented on an extensive variety of "real" environmental and bioassay samples from the Los Alamos area, and consistently reliable and accurate results with appropriate detection limits have been obtained. The new method increases analytical throughput by a factor of approximately 2 and decreases environmental hazards from acid and mixed-waste generation relative to the prior technique. Analytical accuracy, reproducibility, and reliability are also significantly improved over the more complex and laborious method used previously.

Extraction of fullerenes from environmental matrices as affected by solvent characteristics and analyte concentration.

PubMed

Place, Benjamin J; Kleber, Markus; Field, Jennifer A

2013-03-01

Fullerenes possess unique chemical properties that make the isolation of these compounds from heterogeneous environmental matrices difficult. For example, previous reports indicate that toluene-based extraction techniques vary in their ability to extract C60, especially from highly carbonaceous solid matrices. Here, we examined the effects of (i) solvent type (toluene alone versus an 80:20 v/v mixture of toluene and 1-methylnaphthalene) and (ii) analyte concentration on the extraction efficiency of an isotopically labeled surrogate compound, (13)C60. The toluene/1-methylnaphthalene mixture increased fullerene extraction efficiency from carbon lampblack by a factor of five, but was not significantly different from 100% toluene when applied to wood stove soot or montmorillonite. Recovery of the (13)C60 surrogate declined with decreasing analyte concentration. The usefulness of isotopically labeled surrogate is demonstrated and the study provides a quantitative assessment regarding the dependence of fullerene extraction efficiencies on the geochemical characteristics of solid matrices. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

An investigation of the open-loop amplification of Reynolds number dependent processes by wave distortion

NASA Technical Reports Server (NTRS)

Purdy, K. R.; Ventrice, M. B.; Fang, J.

1972-01-01

Analytical and experimental studies were initiated to determine if the response of a constant temperature hot wire anemometer to acoustic oscillations could serve as an analog to the response of the drop vaporization burning rate process to acoustic oscillations, and, perhaps, also as an analog to any Reynolds number dependent process. The motivation behind this study was a recent analytical study which showed that distorted acoustic oscillations could amplify the open-loop response of vaporization limited combustion. This type of amplification may be the cause of unstable combustion in liquid propellant rocket engines. The analytical results obtained for the constant temperature anemometer are similar in nature to those previously obtained for vaporization limited combustion and indicate that the response is dependent on the amount and type of distortion as well as other factors, such as sound pressure level, Mach number and hot wire temperature. Preliminary results indicate qualitative agreement between theory and experiment.

Is age kinder to the initially more able?: Yes, and no

PubMed Central

Gow, Alan J.; Johnson, Wendy; Mishra, Gita; Richards, Marcus; Kuh, Diana; Deary, Ian J.

2012-01-01

Although a number of analyses have addressed whether initial cognitive ability level is associated with age-related cognitive decline, results have been inconsistent. Latent growth curve modeling was applied to two aging cohorts, extending previous analyses with a further wave of data collection, or as a more appropriate analytical methodology than used previously. In the Lothian Birth Cohort 1921, cognitive ability at age 11 was not associated with cognitive change from age 79 to 87, either in general cognitive ability, or in tests of reasoning, memory and executive function. However, data from the MRC National Survey of Health and Development suggested that higher cognitive ability at age 15 predicted less decline between ages 43 and 53 years in a latent cognitive factor from tests of verbal memory and search speed, and in search speed when considered separately. The results are discussed in terms of the differences between the cohorts and the interpretability of the analytical approach. Suggestions are made about when initial ability might be cognitively protective, and study requirements to bring about a clearer resolution. PMID:23690652

Periodic Orbits and Semiclassical Form Factor in Barrier Billiards

NASA Astrophysics Data System (ADS)

Giraud, O.

2005-11-01

Using heuristic arguments based on the trace formulas, we analytically calculate the semiclassical two-point correlation form factor for a family of rectangular billiards with a barrier of height irrational with respect to the side of the billiard and located at any rational position p/q from the side. To do this, we first obtain the asymptotic density of lengths for each family of periodic orbits by a Siegel-Veech formula. The result obtained for these pseudo-integrable, non-Veech billiards is different but not far from the value of 1/2 expected for semi-Poisson statistics and from values of obtained previously in the case of Veech billiards.

A factor analytic investigation of the Mercy Evaluation of Multiple Sclerosis.

PubMed

Merz, Zachary C; Wright, John D; Vander Wal, Jillon S; Gfeller, Jeffrey D

2018-01-23

Neurocognitive deficits commonly are an accompanying feature of Multiple Sclerosis (MS). A brief, yet comprehensive neuropsychological battery is desirable for assessing the extent of these deficits. Therefore, the present study examined the validity of the Mercy Evaluation of Multiple Sclerosis (MEMS) for use with the MS population. Archival data from individuals diagnosed with MS (N = 378) by independent neurologists was examined. Cognitive domains assessed included processing speed and attention, learning, and memory, visuospatial, language, and executive functioning. A mean battery index was calculated to provide a general indicator of cognitive impairment within the current sample. Overall performance across participants was found to be in the lower limits of the average range. Results of factor analytic statistical procedures yielded a four-factor solution, accounting for 67% of total variance within the MEMS. Four neurocognitive measures exhibited the highest sensitivity in detecting cognitive impairment, constituting a psychometrically established brief cognitive screening battery, which accounted for 83% of total variance within the mean battery index score. Overall, the results of the current study suggest appropriate construct validity of the MEMS for use with individuals with MS, as well as provide support for previously established cognitive batteries.

A confirmatory factor analytic validation of the Tinnitus Handicap Inventory.

PubMed

Kleinstäuber, Maria; Frank, Ina; Weise, Cornelia

2015-03-01

Because the postulated three-factor structure of the internationally widely used Tinnitus Handicap Inventory (THI) has not been confirmed yet by a confirmatory factor analytic approach this was the central aim of the current study. From a clinical setting, N=373 patients with chronic tinnitus completed the THI and further questionnaires assessing tinnitus-related and psychological variables. In order to analyze the psychometric properties of the THI, confirmatory factor analysis (CFA) and correlational analyses were conducted. CFA provided a statistically significant support for a better fit of the data to the hypothesized three-factor structure (RMSEA=.049, WRMR=1.062, CFI=.965, TLI=.961) than to a general factor model (RMSEA=.062, WRMR=1.258, CFI=.942, TLI=.937). The calculation of Cronbach's alpha as indicator of internal consistency revealed satisfactory values (.80-.91) with the exception of the catastrophic subscale (.65). High positive correlations of the THI and its subscales with other measures of tinnitus distress, anxiety, and depression, high negative correlations with tinnitus acceptance, moderate positive correlations with anxiety sensitivity, sleeping difficulties, tinnitus loudness, and small correlations with the Big Five personality dimensions confirmed construct validity. Results show that the THI is a highly reliable and valid measure of tinnitus-related handicap. In contrast to results of previous exploratory analyses the current findings speak for a three-factor in contrast to a unifactorial structure. Future research is needed to replicate this result in different tinnitus populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Exploring the Different Trajectories of Analytical Thinking Ability Factors: An Application of the Second-Order Growth Curve Factor Model

ERIC Educational Resources Information Center

Saengprom, Narumon; Erawan, Waraporn; Damrongpanit, Suntonrapot; Sakulku, Jaruwan

2015-01-01

The purposes of this study were 1) Compare analytical thinking ability by testing the same sets of students 5 times 2) Develop and verify whether analytical thinking ability of students corresponds to second-order growth curve factors model. Samples were 1,093 eighth-grade students. The results revealed that 1) Analytical thinking ability scores…

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

Safari, L., E-mail: laleh.safari@ist.ac.at; Department of Physics, University of Oulu, Box 3000, FI-90014 Oulu; Santos, J. P.

Atomic form factors are widely used for the characterization of targets and specimens, from crystallography to biology. By using recent mathematical results, here we derive an analytical expression for the atomic form factor within the independent particle model constructed from nonrelativistic screened hydrogenic wave functions. The range of validity of this analytical expression is checked by comparing the analytically obtained form factors with the ones obtained within the Hartee-Fock method. As an example, we apply our analytical expression for the atomic form factor to evaluate the differential cross section for Rayleigh scattering off neutral atoms.

Critical Factors in Data Governance for Learning Analytics

ERIC Educational Resources Information Center

Elouazizi, Noureddine

2014-01-01

This paper identifies some of the main challenges of data governance modelling in the context of learning analytics for higher education institutions, and discusses the critical factors for designing data governance models for learning analytics. It identifies three fundamental common challenges that cut across any learning analytics data…

Advantages of using tetrahydrofuran-water as mobile phases in the quantitation of cyclosporin A in monkey and rat plasma by liquid chromatography-tandem mass spectrometry.

PubMed

Li, Austin C; Li, Yinghe; Guirguis, Micheal S; Caldwell, Robert G; Shou, Wilson Z

2007-01-04

A new analytical method is described here for the quantitation of anti-inflammatory drug cyclosporin A (CyA) in monkey and rat plasma. The method used tetrahydrofuran (THF)-water mobile phases to elute the analyte and internal standard, cyclosporin C (CyC). The gradient mobile phase program successfully eluted CyA into a sharp peak and therefore improved resolution between the analyte and possible interfering materials compared with previously reported analytical approaches, where CyA was eluted as a broad peak due to the rapid conversion between different conformers. The sharp peak resulted from this method facilitated the quantitative calculation as multiple smoothing and large number of bunching factors were not necessary. The chromatography in the new method was performed at 30 degrees C instead of 65-70 degrees C as reported previously. Other advantages of the method included simple and fast sample extraction-protein precipitation, direct injection of the extraction supernatant to column for analysis, and elimination of evaporation and reconstitution steps, which were needed in solid phase extraction or liquid-liquid extraction reported before. This method is amenable to high-throughput analysis with a total chromatographic run time of 3 min. This approach has been verified as sensitive, linear (0.977-4000 ng/mL), accurate and precise for the quantitation of CyA in monkey and rat plasma. However, compared with the usage of conventional mobile phases, the only drawback of this approach was the reduced detection response from the mass spectrometer that was possibly caused by poor desolvation in the ionization source. This is the first report to demonstrate the advantages of using THF-water mobile phases to elute CyA in liquid chromatography.

Optimal study design with identical power: an application of power equivalence to latent growth curve models.

PubMed

von Oertzen, Timo; Brandmaier, Andreas M

2013-06-01

Structural equation models have become a broadly applied data-analytic framework. Among them, latent growth curve models have become a standard method in longitudinal research. However, researchers often rely solely on rules of thumb about statistical power in their study designs. The theory of power equivalence provides an analytical answer to the question of how design factors, for example, the number of observed indicators and the number of time points assessed in repeated measures, trade off against each other while holding the power for likelihood-ratio tests on the latent structure constant. In this article, we present applications of power-equivalent transformations on a model with data from a previously published study on cognitive aging, and highlight consequences of participant attrition on power. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Evaluation of generalized degrees of freedom for sparse estimation by replica method

NASA Astrophysics Data System (ADS)

Sakata, A.

2016-12-01

We develop a method to evaluate the generalized degrees of freedom (GDF) for linear regression with sparse regularization. The GDF is a key factor in model selection, and thus its evaluation is useful in many modelling applications. An analytical expression for the GDF is derived using the replica method in the large-system-size limit with random Gaussian predictors. The resulting formula has a universal form that is independent of the type of regularization, providing us with a simple interpretation. Within the framework of replica symmetric (RS) analysis, GDF has a physical meaning as the effective fraction of non-zero components. The validity of our method in the RS phase is supported by the consistency of our results with previous mathematical results. The analytical results in the RS phase are calculated numerically using the belief propagation algorithm.

Analytical solutions for solute transport in groundwater and riverine flow using Green's Function Method and pertinent coordinate transformation method

NASA Astrophysics Data System (ADS)

Sanskrityayn, Abhishek; Suk, Heejun; Kumar, Naveen

2017-04-01

In this study, analytical solutions of one-dimensional pollutant transport originating from instantaneous and continuous point sources were developed in groundwater and riverine flow using both Green's Function Method (GFM) and pertinent coordinate transformation method. Dispersion coefficient and flow velocity are considered spatially and temporally dependent. The spatial dependence of the velocity is linear, non-homogeneous and that of dispersion coefficient is square of that of velocity, while the temporal dependence is considered linear, exponentially and asymptotically decelerating and accelerating. Our proposed analytical solutions are derived for three different situations depending on variations of dispersion coefficient and velocity, respectively which can represent real physical processes occurring in groundwater and riverine systems. First case refers to steady solute transport situation in steady flow in which dispersion coefficient and velocity are only spatially dependent. The second case represents transient solute transport in steady flow in which dispersion coefficient is spatially and temporally dependent while the velocity is spatially dependent. Finally, the third case indicates transient solute transport in unsteady flow in which both dispersion coefficient and velocity are spatially and temporally dependent. The present paper demonstrates the concentration distribution behavior from a point source in realistically occurring flow domains of hydrological systems including groundwater and riverine water in which the dispersivity of pollutant's mass is affected by heterogeneity of the medium as well as by other factors like velocity fluctuations, while velocity is influenced by water table slope and recharge rate. Such capabilities give the proposed method's superiority about application of various hydrological problems to be solved over other previously existing analytical solutions. Especially, to author's knowledge, any other solution doesn't exist for both spatially and temporally variations of dispersion coefficient and velocity. In this study, the existing analytical solutions from previous widely known studies are used for comparison as validation tools to verify the proposed analytical solution as well as the numerical code of the Two-Dimensional Subsurface Flow, Fate and Transport of Microbes and Chemicals (2DFATMIC) code and the developed 1D finite difference code (FDM). All such solutions show perfect match with the respective proposed solutions.

Egoistic, altruistic, and biospheric environmental concerns: a path analytic investigation of their determinants.

PubMed

Swami, Viren; Chamorro-Premuzic, Tomas; Snelgar, Rosemary; Furnham, Adrian

2010-04-01

Previous studies have shown that environmental concerns (ECs) can be reduced to a three-factor model - comprising altruistic, biospheric, and egoistic concerns - but there have been few studies examining individual difference predictors of ECs. In this study with 203 individuals from a British community sample, we show that biospheric concern was significantly associated with participants' age, political orientation, Machiavellianism, and the Big Five personality traits of Agreeableness, Emotional Stability, and Conscientiousness. Altruistic concern was significantly associated with sex, age, political orientation, and Machiavellianism, but not the Big Five traits, whereas egoistic concern was not significantly associated with any of these predictors except sex. These results are discussed in relation to previous work on ECs and pro-environmental behavior.

A predictive analytic model for the solar modulation of cosmic rays

DOE PAGES

Cholis, Ilias; Hooper, Dan; Linden, Tim

2016-02-23

An important factor limiting our ability to understand the production and propagation of cosmic rays pertains to the effects of heliospheric forces, commonly known as solar modulation. The solar wind is capable of generating time- and charge-dependent effects on the spectrum and intensity of low-energy (≲10 GeV) cosmic rays reaching Earth. Previous analytic treatments of solar modulation have utilized the force-field approximation, in which a simple potential is adopted whose amplitude is selected to best fit the cosmic-ray data taken over a given period of time. Making use of recently available cosmic-ray data from the Voyager 1 spacecraft, along withmore » measurements of the heliospheric magnetic field and solar wind, we construct a time-, charge- and rigidity-dependent model of solar modulation that can be directly compared to data from a variety of cosmic-ray experiments. Here, we provide a simple analytic formula that can be easily utilized in a variety of applications, allowing us to better predict the effects of solar modulation and reduce the number of free parameters involved in cosmic-ray propagation models.« less

Environmental and human monitoring of Americium-241 utilizing extraction chromatography and {alpha}-Spectrometry

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

Goldstein, S.J.; Hensley, C.A.; Armenta, C.E.

1997-03-01

Recent developments in extraction chromatography have simplified the separation of americium from complex matrices in preparation for {alpha}-spectroscopy relative to traditional methods. Here we present results of procedures developed/adapted for water, air, and bioassay samples with less than 1 g of inorganic residue. Prior analytical methods required the use of a complex, multistage procedure for separation of americium from these matrices. The newer, simplified procedure requires only a single 2 mL extraction chromatographic separation for isolation of Am and lanthanides from other components of the sample. This method has been implemented on an extensive variety of `real` environmental and bioassaymore » samples from the Los Alamos area, and consistently reliable and accurate results with appropriate detection limits have been obtained. The new method increases analytical throughput by a factor of {approx}2 and decreases environmental hazards from acid and mixed-waste generation relative to the prior technique. Analytical accuracy, reproducibility, and reliability are also significantly improved over the more complex and laborious method used previously. 24 refs., 2 figs., 2 tabs.« less

Package-X 2.0: A Mathematica package for the analytic calculation of one-loop integrals

NASA Astrophysics Data System (ADS)

Patel, Hiren H.

2017-09-01

This article summarizes new features and enhancements of the first major update of Package-X. Package-X 2.0 can now generate analytic expressions for arbitrarily high rank dimensionally regulated tensor integrals with up to four distinct propagators, each with arbitrary integer weight, near an arbitrary even number of spacetime dimensions, giving UV divergent, IR divergent, and finite parts at (almost) any real-valued kinematic point. Additionally, it can generate multivariable Taylor series expansions of these integrals around any non-singular kinematic point to arbitrary order. All special functions and abbreviations output by Package-X 2.0 support Mathematica's arbitrary precision evaluation capabilities to deal with issues of numerical stability. Finally, tensor algebraic routines of Package-X have been polished and extended to support open fermion chains both on and off shell. The documentation (equivalent to over 100 printed pages) is accessed through Mathematica's Wolfram Documentation Center and contains information on all Package-X symbols, with over 300 basic usage examples, 3 project-scale tutorials, and instructions on linking to FEYNCALC and LOOPTOOLS. Program files doi:http://dx.doi.org/10.17632/yfkwrd4d5t.1 Licensing provisions: CC by 4.0 Programming language: Mathematica (Wolfram Language) Journal reference of previous version: H. H. Patel, Comput. Phys. Commun 197, 276 (2015) Does the new version supersede the previous version?: Yes Summary of revisions: Extension to four point one-loop integrals with higher powers of denominator factors, separate extraction of UV and IR divergent parts, testing for power IR divergences, construction of Taylor series expansions of one-loop integrals, numerical evaluation with arbitrary precision arithmetic, manipulation of fermion chains, improved tensor algebraic routines, and much expanded documentation. Nature of problem: Analytic calculation of one-loop integrals in relativistic quantum field theory. Solution method: Passarino-Veltman reduction formula, Denner-Dittmaier reduction formulae, and additional algorithms described in the manuscript. Restrictions: One-loop integrals are limited to those involving no more than four denominator factors.

Impact of exchanges and client-therapist alliance in online-text psychotherapy.

PubMed

Reynolds, D'Arcy J; Stiles, William B; Bailer, A John; Hughes, Michael R

2013-05-01

The impact of exchanges and client-therapist alliance of online therapy text exchanges were compared to previously published results in face-to-face therapy, and the moderating effects of four participant factors found significant in previously published face-to-face studies were investigated using statistical mixed-effect modeling analytic techniques. Therapists (N=30) and clients (N=30) engaged in online therapy were recruited from private practitioner sites, e-clinics, online counseling centers, and mental-health-related discussion boards. In a naturalistic design, they each visited an online site weekly and completed the standard impact and alliance questionnaires for at least 6 weeks. Results indicated that the impact of exchanges and client-therapist alliance in text therapy was similar to, but in some respects more positive than, previous evaluations of face-to-face therapy. The significance of participant factors previously found to influence impact and alliance in face-to-face therapy (client symptom severity, social support, therapist theoretical orientation, and therapist experience) was not replicated, except that therapists with the more symptomatic clients rated their text exchanges as less smooth and comfortable. Although its small size and naturalistic design impose limitations on sensitivity and generalizability, this study provides some insights into treatment impact and the alliance in online therapy.

An enhanced beam model for constrained layer damping and a parameter study of damping contribution

NASA Astrophysics Data System (ADS)

Xie, Zhengchao; Shepard, W. Steve, Jr.

2009-01-01

An enhanced analytical model is presented based on an extension of previous models for constrained layer damping (CLD) in beam-like structures. Most existing CLD models are based on the assumption that shear deformation in the core layer is the only source of damping in the structure. However, previous research has shown that other types of deformation in the core layer, such as deformations from longitudinal extension and transverse compression, can also be important. In the enhanced analytical model developed here, shear, extension, and compression deformations are all included. This model can be used to predict the natural frequencies and modal loss factors. The numerical study shows that compared to other models, this enhanced model is accurate in predicting the dynamic characteristics. As a result, the model can be accepted as a general computation model. With all three types of damping included and the formulation used here, it is possible to study the impact of the structure's geometry and boundary conditions on the relative contribution of each type of damping. To that end, the relative contributions in the frequency domain for a few sample cases are presented.

Gradient retention prediction of acid-base analytes in reversed phase liquid chromatography: a simplified approach for acetonitrile-water mobile phases.

PubMed

Andrés, Axel; Rosés, Martí; Bosch, Elisabeth

2014-11-28

In previous work, a two-parameter model to predict chromatographic retention of ionizable analytes in gradient mode was proposed. However, the procedure required some previous experimental work to get a suitable description of the pKa change with the mobile phase composition. In the present study this previous experimental work has been simplified. The analyte pKa values have been calculated through equations whose coefficients vary depending on their functional group. Forced by this new approach, other simplifications regarding the retention of the totally neutral and totally ionized species also had to be performed. After the simplifications were applied, new prediction values were obtained and compared with the previously acquired experimental data. The simplified model gave pretty good predictions while saving a significant amount of time and resources. Copyright © 2014 Elsevier B.V. All rights reserved.

Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes

NASA Astrophysics Data System (ADS)

Lifton, Nathaniel; Sato, Tatsuhiko; Dunai, Tibor J.

2014-01-01

Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling factors based on recently updated neutron and proton excitation functions (probability of nuclide production in a given nuclear reaction as a function of energy) for commonly measured in situ cosmogenic nuclides. Such scaling factors reflect the influence of the energy distribution of the flux folded with the relevant excitation functions. Resulting scaling factors indicate 3He shows the strongest positive deviation from the flux-based scaling, while 14C exhibits a negative deviation. These results are consistent with a recent Monte Carlo-based study using a different cosmic-ray physics code package but the same excitation functions.

An approach to get thermodynamic properties from speed of sound

NASA Astrophysics Data System (ADS)

Núñez, M. A.; Medina, L. A.

2017-01-01

An approach for estimating thermodynamic properties of gases from the speed of sound u, is proposed. The square u2, the compression factor Z and the molar heat capacity at constant volume C V are connected by two coupled nonlinear partial differential equations. Previous approaches to solving this system differ in the conditions used on the range of temperature values [Tmin,Tmax]. In this work we propose the use of Dirichlet boundary conditions at Tmin, Tmax. The virial series of the compression factor Z = 1+Bρ+Cρ2+… and other properties leads the problem to the solution of a recursive set of linear ordinary differential equations for the B, C. Analytic solutions of the B equation for Argon are used to study the stability of our approach and previous ones under perturbation errors of the input data. The results show that the approach yields B with a relative error bounded basically by that of the boundary values and the error of other approaches can be some orders of magnitude lager.

Geographic Profiling to Assess the Risk of Rare Plant Poaching in Natural Areas

NASA Astrophysics Data System (ADS)

Young, John A.; van Manen, Frank T.; Thatcher, Cindy A.

2011-09-01

We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities.

Methods for Estimating Uncertainty in Factor Analytic Solutions

EPA Science Inventory

The EPA PMF (Environmental Protection Agency positive matrix factorization) version 5.0 and the underlying multilinear engine-executable ME-2 contain three methods for estimating uncertainty in factor analytic models: classical bootstrap (BS), displacement of factor elements (DI...

Analysis of environmental factors impacting the life cycle cost analysis of conventional and fuel cell/battery-powered passenger vehicles. Final report

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

NONE

This report presents the results of the further developments and testing of the Life Cycle Cost (LCC) Model previously developed by Engineering Systems Management, Inc. (ESM) on behalf of the U.S. Department of Energy (DOE) under contract No. DE-AC02-91CH10491. The Model incorporates specific analytical relationships and cost/performance data relevant to internal combustion engine (ICE) powered vehicles, battery powered electric vehicles (BPEVs), and fuel cell/battery-powered electric vehicles (FCEVs).

Transfer function concept for ultrasonic characterization of material microstructures

NASA Technical Reports Server (NTRS)

Vary, A.; Kautz, H. E.

1986-01-01

The approach given depends on treating material microstructures as elastomechanical filters that have analytically definable transfer functions. These transfer functions can be defined in terms of the frequency dependence of the ultrasonic attenuation coefficient. The transfer function concept provides a basis for synthesizing expressions that characterize polycrystalline materials relative to microstructural factors such as mean grain size, grain-size distribution functions, and grain boundary energy transmission. Although the approach is nonrigorous, it leads to a rational basis for combining the previously mentioned diverse and fragmented equations for ultrasonic attenuation coefficients.

Uncertainty of relative sensitivity factors in glow discharge mass spectrometry

NASA Astrophysics Data System (ADS)

Meija, Juris; Methven, Brad; Sturgeon, Ralph E.

2017-10-01

The concept of the relative sensitivity factors required for the correction of the measured ion beam ratios in pin-cell glow discharge mass spectrometry is examined in detail. We propose a data-driven model for predicting the relative response factors, which relies on a non-linear least squares adjustment and analyte/matrix interchangeability phenomena. The model provides a self-consistent set of response factors for any analyte/matrix combination of any element that appears as either an analyte or matrix in at least one known response factor.

Enantioselective determination of representative profens in wastewater by a single-step sample treatment and chiral liquid chromatography-tandem mass spectrometry.

PubMed

Caballo, C; Sicilia, M D; Rubio, S

2015-03-01

This manuscript describes, for the first time, the simultaneous enantioselective determination of ibuprofen, naproxen and ketoprofen in wastewater based on liquid chromatography tandem mass spectrometry (LC-MS/MS). The method uses a single-step sample treatment based on microextraction with a supramolecular solvent made up of hexagonal inverted aggregates of decanoic acid, formed in situ in the wastewater sample through a spontaneous self-assembly process. Microextraction of profens was optimized and the analytical method validated. Isotopically labeled internal standards were used to compensate for both matrix interferences and recoveries. Apparent recoveries for the six enantiomers in influent and effluent wastewater samples were in the interval 97-103%. Low method detection limits (MDLs) were obtained (0.5-1.2 ng L(-1)) as a result of the high concentration factors achieved in the microextraction process (i.e. actual concentration factors 469-736). No analyte derivatization or evaporation of extracts, as it is required with GC-MS, was necessary. Relative standard deviations for enantiomers in wastewater were always below 8%. The method was applied to the determination of the concentrations and enantiomeric fractions of the targeted analytes in influents and effluents from three wastewater treatment plants. All the values found for profen enantiomers were consistent with those previously reported and confirmed again the suitability of using the enantiomeric fraction of ibuprofen as an indicator of the discharge of untreated or poorly treated wastewaters. Both the analytical and operational features of this method make it applicable to the assessment of the enantiomeric fate of profens in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Conceptual framework for outcomes research studies of hepatitis C: an analytical review

PubMed Central

Sbarigia, Urbano; Denee, Tom R; Turner, Norris G; Wan, George J; Morrison, Alan; Kaufman, Anna S; Rice, Gary; Dusheiko, Geoffrey M

2016-01-01

Hepatitis C virus infection is one of the main causes of chronic liver disease worldwide. Until recently, the standard antiviral regimen for hepatitis C was a combination of an interferon derivative and ribavirin, but a plethora of new antiviral drugs is becoming available. While these new drugs have shown great efficacy in clinical trials, observational studies are needed to determine their effectiveness in clinical practice. Previous observational studies have shown that multiple factors, besides the drug regimen, affect patient outcomes in clinical practice. Here, we provide an analytical review of published outcomes studies of the management of hepatitis C virus infection. A conceptual framework defines the relationships between four categories of variables: health care system structure, patient characteristics, process-of-care, and patient outcomes. This framework can provide a starting point for outcomes studies addressing the use and effectiveness of new antiviral drug treatments. PMID:27313473

Theoretical optimum of implant positional index design.

PubMed

Semper, W; Kraft, S; Krüger, T; Nelson, K

2009-08-01

Rotational freedom of the implant-abutment connection influences its screw joint stability; for optimization, influential factors need to be evaluated based on a previously developed closed formula. The underlying hypothesis is that the manufacturing tolerances, geometric pattern, and dimensions of the index do not influence positional stability. We used the dimensions of 5 commonly used implant systems with a clearance of 20 microm to calculate the extent of rotational freedom; a 3D simulation (SolidWorks) validated the analytical findings. Polygonal positional indices showed the highest degrees of rotational freedom. The polygonal profile displayed higher positional stability than the polygons, but less positional accuracy than the cam-groove connection. Features of a maximal rotation-safe positional index were determined. The analytical calculation of rotational freedom of implant positional indices is possible. Rotational freedom is dependent on the geometric design of the index and may be decreased by incorporating specific aspects into the positional index design.

Recent meta-analyses neglect previous systematic reviews and meta-analyses about the same topic: a systematic examination.

PubMed

Helfer, Bartosz; Prosser, Aaron; Samara, Myrto T; Geddes, John R; Cipriani, Andrea; Davis, John M; Mavridis, Dimitris; Salanti, Georgia; Leucht, Stefan

2015-04-14

As the number of systematic reviews is growing rapidly, we systematically investigate whether meta-analyses published in leading medical journals present an outline of available evidence by referring to previous meta-analyses and systematic reviews. We searched PubMed for recent meta-analyses of pharmacological treatments published in high impact factor journals. Previous systematic reviews and meta-analyses were identified with electronic searches of keywords and by searching reference sections. We analyzed the number of meta-analyses and systematic reviews that were cited, described and discussed in each recent meta-analysis. Moreover, we investigated publication characteristics that potentially influence the referencing practices. We identified 52 recent meta-analyses and 242 previous meta-analyses on the same topics. Of these, 66% of identified previous meta-analyses were cited, 36% described, and only 20% discussed by recent meta-analyses. The probability of citing a previous meta-analysis was positively associated with its publication in a journal with a higher impact factor (odds ratio, 1.49; 95% confidence interval, 1.06 to 2.10) and more recent publication year (odds ratio, 1.19; 95% confidence interval 1.03 to 1.37). Additionally, the probability of a previous study being described by the recent meta-analysis was inversely associated with the concordance of results (odds ratio, 0.38; 95% confidence interval, 0.17 to 0.88), and the probability of being discussed was increased for previous studies that employed meta-analytic methods (odds ratio, 32.36; 95% confidence interval, 2.00 to 522.85). Meta-analyses on pharmacological treatments do not consistently refer to and discuss findings of previous meta-analyses on the same topic. Such neglect can lead to research waste and be confusing for readers. Journals should make the discussion of related meta-analyses mandatory.

ESTIMATING UNCERTAINITIES IN FACTOR ANALYTIC MODELS

EPA Science Inventory

When interpreting results from factor analytic models as used in receptor modeling, it is important to quantify the uncertainties in those results. For example, if the presence of a species on one of the factors is necessary to interpret the factor as originating from a certain ...

40 CFR 141.23 - Inorganic chemical sampling and analytical requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... highest analytical result. (e) All public water systems (community; non-transient, non-community; and... each subsequent sample during the quarter(s) which previously resulted in the highest analytical result...). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www...

Significance Testing in Confirmatory Factor Analytic Models.

ERIC Educational Resources Information Center

Khattab, Ali-Maher; Hocevar, Dennis

Traditionally, confirmatory factor analytic models are tested against a null model of total independence. Using randomly generated factors in a matrix of 46 aptitude tests, this approach is shown to be unlikely to reject even random factors. An alternative null model, based on a single general factor, is suggested. In addition, an index of model…

[Risk factors associated with preterm birth in a second level hospital].

PubMed

Escobar-Padilla, Beatriz; Gordillo-Lara, Limberg Darinel; Martínez-Puon, Horacio

2017-01-01

Preterm birth is one of the biggest problems in obstetrics and gynecology, given that it has an incidence of 10-11%. The objective was to identify the risk factors associated with a preterm birth. A retrospective, observational, transversal and analytic case-control study was made. All premature birth incidences were determined as study objects and controls were integrated with term deliveries. A sample size of 344 patients with a control per case was calculated. A total of 688 patients were studied. Statistical analysis was descriptive, univariate and bivariate and we used the Pearson chi square test, with a p < 0.05, odds ratios (OR) and 95% confidence intervals (95% CI). The risk factors associated with a preterm labor were placenta praevia: OR = 10.2 (p = 0.005); previous preterm delivery: OR = 10.2 (p = 0.005); preeclampsia: OR = 6.38 (p = 0.00); twin pregnancy: OR = 5.8 (p = 0.000); oligohydramnios: OR = 5.8 (p = 0.000); tobacco use: OR = 4.6 (p = 0.002); premature rupture of membranes (PROM): OR = 4.1 (p = 0.000); cervicovaginitis: OR = 3 (p = 0.000); urinary tract infections (UTI): OR = 1.5 (p = 0.010). Maternal history of prenatal care, preclampsia, PROM, twin pregnancy, placenta praevia, cervicovaginitis, previous preterm delivery and UTI are risk factors with statistical significance associated with preterm delivery.

The Big Five Factor Marker Adjectives Are Not Especially Popular Words. Are They Superior Descriptors?

PubMed

Roivainen, Eka

2015-12-01

Vocabularies of natural languages evolve over time. Useful words become more popular and useless concepts disappear. In this study, the frequency of the use of 295 English, 100 German, and 114 French personality adjectives in book texts and Twitter messages as qualifiers of the words person, woman, homme, femme, and Person was studied. Word frequency data were compared to factor loadings from previous factor analytic studies on personality terms. The correlation between the popularity of an adjective and its highest primary loading in five- and six-factor models was low (-0.12 to 0.17). The Big five (six) marker adjectives were not more popular than "blended" adjectives that had moderate loadings on several factors. This finding implies that laymen consider "blended" adjectives as equally useful descriptors compared to adjectives that represent core features of the five (six) factors. These results are compatible with three hypotheses: 1) laymen are not good at describing personality, 2) the five (six) factors are artifacts of research methods, 3) the interaction of the five (six) factors is not well understood.

Human performance modeling for system of systems analytics: combat performance-shaping factors.

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

Lawton, Craig R.; Miller, Dwight Peter

The US military has identified Human Performance Modeling (HPM) as a significant requirement and challenge of future systems modeling and analysis initiatives. To support this goal, Sandia National Laboratories (SNL) has undertaken a program of HPM as an integral augmentation to its system-of-system (SoS) analytics capabilities. The previous effort, reported in SAND2005-6569, evaluated the effects of soldier cognitive fatigue on SoS performance. The current effort began with a very broad survey of any performance-shaping factors (PSFs) that also might affect soldiers performance in combat situations. The work included consideration of three different approaches to cognition modeling and how appropriate theymore » would be for application to SoS analytics. This bulk of this report categorizes 47 PSFs into three groups (internal, external, and task-related) and provides brief descriptions of how each affects combat performance, according to the literature. The PSFs were then assembled into a matrix with 22 representative military tasks and assigned one of four levels of estimated negative impact on task performance, based on the literature. Blank versions of the matrix were then sent to two ex-military subject-matter experts to be filled out based on their personal experiences. Data analysis was performed to identify the consensus most influential PSFs. Results indicate that combat-related injury, cognitive fatigue, inadequate training, physical fatigue, thirst, stress, poor perceptual processing, and presence of chemical agents are among the PSFs with the most negative impact on combat performance.« less

Simple Numerical Modelling for Gasdynamic Design of Wave Rotors

NASA Astrophysics Data System (ADS)

Okamoto, Koji; Nagashima, Toshio

The precise estimation of pressure waves generated in the passages is a crucial factor in wave rotor design. However, it is difficult to estimate the pressure wave analytically, e.g. by the method of characteristics, because the mechanism of pressure-wave generation and propagation in the passages is extremely complicated as compared to that in a shock tube. In this study, a simple numerical modelling scheme was developed to facilitate the design procedure. This scheme considers the three dominant factors in the loss mechanism —gradual passage opening, wall friction and leakage— for simulating the pressure waves precisely. The numerical scheme itself is based on the one-dimensional Euler equations with appropriate source terms to reduce the calculation time. The modelling of these factors was verified by comparing the results with those of a two-dimensional numerical simulation, which were previously validated by the experimental data in our previous study. Regarding wave rotor miniaturization, the leakage flow effect, which involves the interaction between adjacent cells, was investigated extensively. A port configuration principle was also examined and analyzed in detail to verify the applicability of the present numerical modelling scheme to the wave rotor design.

On the Complexity of Item Response Theory Models.

PubMed

Bonifay, Wes; Cai, Li

2017-01-01

Complexity in item response theory (IRT) has traditionally been quantified by simply counting the number of freely estimated parameters in the model. However, complexity is also contingent upon the functional form of the model. We examined four popular IRT models-exploratory factor analytic, bifactor, DINA, and DINO-with different functional forms but the same number of free parameters. In comparison, a simpler (unidimensional 3PL) model was specified such that it had 1 more parameter than the previous models. All models were then evaluated according to the minimum description length principle. Specifically, each model was fit to 1,000 data sets that were randomly and uniformly sampled from the complete data space and then assessed using global and item-level fit and diagnostic measures. The findings revealed that the factor analytic and bifactor models possess a strong tendency to fit any possible data. The unidimensional 3PL model displayed minimal fitting propensity, despite the fact that it included an additional free parameter. The DINA and DINO models did not demonstrate a proclivity to fit any possible data, but they did fit well to distinct data patterns. Applied researchers and psychometricians should therefore consider functional form-and not goodness-of-fit alone-when selecting an IRT model.

A GRAPHICAL DIAGNOSTIC METHOD FOR ASSESSING THE ROTATION IN FACTOR ANALYTICAL MODELS OF ATMOSPHERIC POLLUTION. (R831078)

EPA Science Inventory

Factor analytic tools such as principal component analysis (PCA) and positive matrix factorization (PMF), suffer from rotational ambiguity in the results: different solutions (factors) provide equally good fits to the measured data. The PMF model imposes non-negativity of both...

Review of Research on Student-Facing Learning Analytics Dashboards and Educational Recommender Systems

ERIC Educational Resources Information Center

Bodily, Robert; Verbert, Katrien

2017-01-01

This article is a comprehensive literature review of student-facing learning analytics reporting systems that track learning analytics data and report it directly to students. This literature review builds on four previously conducted literature reviews in similar domains. Out of the 945 articles retrieved from databases and journals, 93 articles…

A Progressive Approach to Teaching Analytics in the Marketing Curriculum

ERIC Educational Resources Information Center

Liu, Yiyuan; Levin, Michael A.

2018-01-01

With the emerging use of analytics tools and methodologies in marketing, marketing educators have provided students training and experiences beyond the soft skills associated with understanding consumer behavior. Previous studies have only discussed how to apply analytics in course designs, tools, and related practices. However, there is a lack of…

Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

2007-01-01

Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

Mechanisms of chemical vapor generation by aqueous tetrahydridoborate. Recent developments toward the definition of a more general reaction model

NASA Astrophysics Data System (ADS)

D'Ulivo, Alessandro

2016-05-01

A reaction model describing the reactivity of metal and semimetal species with aqueous tetrahydridoborate (THB) has been drawn taking into account the mechanism of chemical vapor generation (CVG) of hydrides, recent evidences on the mechanism of interference and formation of byproducts in arsane generation, and other evidences in the field of the synthesis of nanoparticles and catalytic hydrolysis of THB by metal nanoparticles. The new "non-analytical" reaction model is of more general validity than the previously described "analytical" reaction model for CVG. The non-analytical model is valid for reaction of a single analyte with THB and for conditions approaching those typically encountered in the synthesis of nanoparticles and macroprecipitates. It reduces to the previously proposed analytical model under conditions typically employed in CVG for trace analysis (analyte below the μM level, borane/analyte ≫ 103 mol/mol, no interference). The non-analytical reaction model is not able to explain all the interference effects observed in CVG, which can be achieved only by assuming the interaction among the species of reaction pathways of different analytical substrates. The reunification of CVG, the synthesis of nanoparticles by aqueous THB and the catalytic hydrolysis of THB inside a common frame contribute to rationalization of the complex reactivity of aqueous THB with metal and semimetal species.

On geometric factors for neutral particle analyzers

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

Stagner, L.; Heidbrink, W. W.

2014-11-15

Neutral particle analyzers (NPA) detect neutralized energetic particles that escape from plasmas. Geometric factors relate the counting rate of the detectors to the intensity of the particle source. Accurate geometric factors enable quick simulation of geometric effects without the need to resort to slower Monte Carlo methods. Previously derived expressions [G. R. Thomas and D. M. Willis, “Analytical derivation of the geometric factor of a particle detector having circular or rectangular geometry,” J. Phys. E: Sci. Instrum. 5(3), 260 (1972); J. D. Sullivan, “Geometric factor and directional response of single and multi-element particle telescopes,” Nucl. Instrum. Methods 95(1), 5–11 (1971)]more » for the geometric factor implicitly assume that the particle source is very far away from the detector (far-field); this excludes applications close to the detector (near-field). The far-field assumption does not hold in most fusion applications of NPA detectors. We derive, from probability theory, a generalized framework for deriving geometric factors that are valid for both near and far-field applications as well as for non-isotropic sources and nonlinear particle trajectories.« less

Income inequality and mortality: a multilevel prospective study of 521 248 individuals in 50 US states.

PubMed

Backlund, Eric; Rowe, Geoff; Lynch, John; Wolfson, Michael C; Kaplan, George A; Sorlie, Paul D

2007-06-01

Some of the most consistent evidence in favour of an association between income inequality and health has been among US states. However, in multilevel studies of mortality, only two out of five studies have reported a positive relationship with income inequality after adjustment for the compositional characteristics of the state's inhabitants. In this study, we attempt to clarify these mixed results by analysing the relationship within age-sex groups and by applying a previously unused analytical method to a database that contains more deaths than any multilevel study to date. The US National Longitudinal Mortality Study (NLMS) was used to model the relationship between income inequality in US states and mortality using both a novel and previously used methodologies that fall into the general framework of multilevel regression. We adjust age-sex specific models for nine socioeconomic and demographic variables at the individual level and percentage black and region at the state level. The preponderance of evidence from this study suggests that 1990 state-level income inequality is associated with a 40% differential in state level mortality rates (95% CI = 26-56%) for men 25-64 years and a 14% (95% CI = 3-27%) differential for women 25-64 years after adjustment for compositional factors. No such relationship was found for men or women over 65. The relationship between income inequality and mortality is only robust to adjustment for compositional factors in men and women under 65. This explains why income inequality is not a major driver of mortality trends in the United States because most deaths occur at ages 65 and over. This analysis does suggest, however, the certain causes of death that occur primarily in the population under 65 may be associated with income inequality. Comparison of analytical techniques also suggests coefficients for income inequality in previous multilevel mortality studies may be biased, but further research is needed to provide a definitive answer.

Dimensions of Early Speech Sound Disorders: A Factor Analytic Study

ERIC Educational Resources Information Center

Lewis, Barbara A.; Freebairn, Lisa A.; Hansen, Amy J.; Stein, Catherine M.; Shriberg, Lawrence D.; Iyengar, Sudha K.; Taylor, H. Gerry

2006-01-01

The goal of this study was to classify children with speech sound disorders (SSD) empirically, using factor analytic techniques. Participants were 3-7-year olds enrolled in speech/language therapy (N=185). Factor analysis of an extensive battery of speech and language measures provided support for two distinct factors, representing the skill…

Microchip integrating magnetic nanoparticles for allergy diagnosis.

PubMed

Teste, Bruno; Malloggi, Florent; Siaugue, Jean-Michel; Varenne, Anne; Kanoufi, Frederic; Descroix, Stéphanie

2011-12-21

We report on the development of a simple and easy to use microchip dedicated to allergy diagnosis. This microchip combines both the advantages of homogeneous immunoassays i.e. species diffusion and heterogeneous immunoassays i.e. easy separation and preconcentration steps. In vitro allergy diagnosis is based on specific Immunoglobulin E (IgE) quantitation, in that way we have developed and integrated magnetic core-shell nanoparticles (MCSNPs) as an IgE capture nanoplatform in a microdevice taking benefit from both their magnetic and colloidal properties. Integrating such immunosupport allows to perform the target analyte (IgE) capture in the colloidal phase thus increasing the analyte capture kinetics since both immunological partners are diffusing during the immune reaction. This colloidal approach improves 1000 times the analyte capture kinetics compared to conventional methods. Moreover, based on the MCSNPs' magnetic properties and on the magnetic chamber we have previously developed the MCSNPs and therefore the target can be confined and preconcentrated within the microdevice prior to the detection step. The MCSNPs preconcentration factor achieved was about 35,000 and allows to reach high sensitivity thus avoiding catalytic amplification during the detection step. The developed microchip offers many advantages: the analytical procedure was fully integrated on-chip, analyses were performed in short assay time (20 min), the sample and reagents consumption was reduced to few microlitres (5 μL) while a low limit of detection can be achieved (about 1 ng mL(-1)).

[Quality Management and Quality Specifications of Laboratory Tests in Clinical Studies--Challenges in Pre-Analytical Processes in Clinical Laboratories].

PubMed

Ishibashi, Midori

2015-01-01

The cost, speed, and quality are the three important factors recently indicated by the Ministry of Health, Labour and Welfare (MHLW) for the purpose of accelerating clinical studies. Based on this background, the importance of laboratory tests is increasing, especially in the evaluation of clinical study participants' entry and safety, and drug efficacy. To assure the quality of laboratory tests, providing high-quality laboratory tests is mandatory. For providing adequate quality assurance in laboratory tests, quality control in the three fields of pre-analytical, analytical, and post-analytical processes is extremely important. There are, however, no detailed written requirements concerning specimen collection, handling, preparation, storage, and shipping. Most laboratory tests for clinical studies are performed onsite in a local laboratory; however, a part of laboratory tests is done in offsite central laboratories after specimen shipping. As factors affecting laboratory tests, individual and inter-individual variations are well-known. Besides these factors, standardizing the factors of specimen collection, handling, preparation, storage, and shipping, may improve and maintain the high quality of clinical studies in general. Furthermore, the analytical method, units, and reference interval are also important factors. It is concluded that, to overcome the problems derived from pre-analytical processes, it is necessary to standardize specimen handling in a broad sense.

THE IMPACT OF POINT-SOURCE SUBTRACTION RESIDUALS ON 21 cm EPOCH OF REIONIZATION ESTIMATION

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

Trott, Cathryn M.; Wayth, Randall B.; Tingay, Steven J., E-mail: cathryn.trott@curtin.edu.au

Precise subtraction of foreground sources is crucial for detecting and estimating 21 cm H I signals from the Epoch of Reionization (EoR). We quantify how imperfect point-source subtraction due to limitations of the measurement data set yields structured residual signal in the data set. We use the Cramer-Rao lower bound, as a metric for quantifying the precision with which a parameter may be measured, to estimate the residual signal in a visibility data set due to imperfect point-source subtraction. We then propagate these residuals into two metrics of interest for 21 cm EoR experiments-the angular power spectrum and two-dimensional powermore » spectrum-using a combination of full analytic covariant derivation, analytic variant derivation, and covariant Monte Carlo simulations. This methodology differs from previous work in two ways: (1) it uses information theory to set the point-source position error, rather than assuming a global rms error, and (2) it describes a method for propagating the errors analytically, thereby obtaining the full correlation structure of the power spectra. The methods are applied to two upcoming low-frequency instruments that are proposing to perform statistical EoR experiments: the Murchison Widefield Array and the Precision Array for Probing the Epoch of Reionization. In addition to the actual antenna configurations, we apply the methods to minimally redundant and maximally redundant configurations. We find that for peeling sources above 1 Jy, the amplitude of the residual signal, and its variance, will be smaller than the contribution from thermal noise for the observing parameters proposed for upcoming EoR experiments, and that optimal subtraction of bright point sources will not be a limiting factor for EoR parameter estimation. We then use the formalism to provide an ab initio analytic derivation motivating the 'wedge' feature in the two-dimensional power spectrum, complementing previous discussion in the literature.« less

Statically determined slip-line field solution for the axial forming force estimation in the radial-axial ring rolling process

NASA Astrophysics Data System (ADS)

Quagliato, Luca; Berti, Guido A.

2017-10-01

In this paper, a statically determined slip-line solution algorithm is proposed for the calculation of the axial forming force in the radial-axial ring rolling process of flat rings. The developed solution is implemented in an Excel spreadsheet for the construction of the slip-line field and the calculation of the pressure factor to be used in the force model. The comparison between analytical solution and authors' FE simulation allows stating that the developed model supersedes the previous literature ones and proves the reliability of the proposed approach.

A General Model for Performance Evaluation in DS-CDMA Systems with Variable Spreading Factors

NASA Astrophysics Data System (ADS)

Chiaraluce, Franco; Gambi, Ennio; Righi, Giorgia

This paper extends previous analytical approaches for the study of CDMA systems to the relevant case of multipath environments where users can operate at different bit rates. This scenario is of interest for the Wideband CDMA strategy employed in UMTS, and the model permits the performance comparison of classic and more innovative spreading signals. The method is based on the characteristic function approach, that allows to model accurately the various kinds of interferences. Some numerical examples are given with reference to the ITU-R M. 1225 Recommendations, but the analysis could be extended to different channel descriptions.

Stress analysis of ribbon parachutes

NASA Technical Reports Server (NTRS)

Reynolds, D. T.; Mullins, W. M.

1975-01-01

An analytical method has been developed for determining the internal load distribution for ribbon parachutes subjected to known riser and aerodynamic forces. Finite elements with non-linear elastic properties represent the parachute structure. This method is an extension of the analysis previously developed by the authors and implemented in the digital computer program CANO. The present analysis accounts for the effect of vertical ribbons in the solution for canopy shape and stress distribution. Parametric results are presented which relate the canopy stress distribution to such factors as vertical ribbon strength, number of gores, and gore shape in a ribbon parachute.

Analytical Description of Ascending Motion of Rockets in the Atmosphere

ERIC Educational Resources Information Center

Rodrigues, H.; de Pinho, M. O.; Portes, D., Jr.; Santiago, A.

2009-01-01

In continuation of a previous work, we present an analytic study of ascending vertical motion of a rocket subjected to a quadratic drag for the case where the mass-variation law is a linear function of time. We discuss the detailed analytical solution of the model differential equations in closed form. Examples of application are presented and…

Computing sensitivity and selectivity in parallel factor analysis and related multiway techniques: the need for further developments in net analyte signal theory.

PubMed

Olivieri, Alejandro C

2005-08-01

Sensitivity and selectivity are important figures of merit in multiway analysis, regularly employed for comparison of the analytical performance of methods and for experimental design and planning. They are especially interesting in the second-order advantage scenario, where the latter property allows for the analysis of samples with a complex background, permitting analyte determination even in the presence of unsuspected interferences. Since no general theory exists for estimating the multiway sensitivity, Monte Carlo numerical calculations have been developed for estimating variance inflation factors, as a convenient way of assessing both sensitivity and selectivity parameters for the popular parallel factor (PARAFAC) analysis and also for related multiway techniques. When the second-order advantage is achieved, the existing expressions derived from net analyte signal theory are only able to adequately cover cases where a single analyte is calibrated using second-order instrumental data. However, they fail for certain multianalyte cases, or when third-order data are employed, calling for an extension of net analyte theory. The results have strong implications in the planning of multiway analytical experiments.

Modified hollow Gaussian beam and its paraxial propagation

NASA Astrophysics Data System (ADS)

Cai, Yangjian; Chen, Chiyi; Wang, Fei

2007-10-01

A model named modified hollow Gaussian beam (HGB) is proposed to describe a dark hollow beam with adjustable beam spot size, central dark size and darkness factor. In this modified model, both the beam spot size and the central dark size will be convergent to finite constants as the beam order approaches infinity, which are much different from that of the previous unmodified model, where the beam spot size and the central dark size will not be convergent as the beam order approaches infinity. The dependences of the propagation factor of modified and unmodified HGBs on the beam order are found to be the same. Based on the Collins integral, analytical formulas for the modified HGB propagating through aligned and misaligned optical system are derived. Some numerical examples are given.

Experimental Design for a Macrofoam Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

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

Piepel, Gregory F.; Hutchison, Janine R.

2014-04-16

This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (plating/counting and polymerase chain reaction) will be used. Only one previous study has investigated false negative as a function of affecting test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completingmore » gaps in the available information on the performance of macrofoam swab sampling at low concentrations.« less

Experimental Design for a Macrofoam-Swab Study Relating the Recovery Efficiency and False Negative Rate to Low Concentrations of Two Bacillus anthracis Surrogates on Four Surface Materials

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

Piepel, Gregory F.; Hutchison, Janine R.

This report describes the experimental design for a laboratory study to quantify the recovery efficiencies and false negative rates of a validated, macrofoam-swab sampling method for low concentrations of Bacillus anthracis Sterne (BAS) and Bacillus atrophaeus (BG) spores on four surface materials (stainless steel, glass, vinyl tile, plastic light cover panel). Two analytical methods (culture and polymerase chain reaction) will be used. Only one previous study has investigated how the false negative rate depends on test factors. The surrogates BAS and BG have not been tested together in the same study previously. Hence, this study will provide for completing gapsmore » in the available information on the performance of macrofoam-swab sampling at low concentrations.« less

Factors Affecting Higher Order Thinking Skills of Students: A Meta-Analytic Structural Equation Modeling Study

ERIC Educational Resources Information Center

Budsankom, Prayoonsri; Sawangboon, Tatsirin; Damrongpanit, Suntorapot; Chuensirimongkol, Jariya

2015-01-01

The purpose of the research is to develop and identify the validity of factors affecting higher order thinking skills (HOTS) of students. The thinking skills can be divided into three types: analytical, critical, and creative thinking. This analysis is done by applying the meta-analytic structural equation modeling (MASEM) based on a database of…

Geographic profiling to assess the risk of rare plant poaching in natural areas

USGS Publications Warehouse

Young, J.A.; Van Manen, F.T.; Thatcher, C.A.

2011-01-01

We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities. ?? Springer Science+Business Media, LLC (outside the USA) 2011.

An analytical model of leakage neutron equivalent dose for passively-scattered proton radiotherapy and validation with measurements.

PubMed

Schneider, Christopher; Newhauser, Wayne; Farah, Jad

2015-05-18

Exposure to stray neutrons increases the risk of second cancer development after proton therapy. Previously reported analytical models of this exposure were difficult to configure and had not been investigated below 100 MeV proton energy. The purposes of this study were to test an analytical model of neutron equivalent dose per therapeutic absorbed dose  at 75 MeV and to improve the model by reducing the number of configuration parameters and making it continuous in proton energy from 100 to 250 MeV. To develop the analytical model, we used previously published H/D values in water from Monte Carlo simulations of a general-purpose beamline for proton energies from 100 to 250 MeV. We also configured and tested the model on in-air neutron equivalent doses measured for a 75 MeV ocular beamline. Predicted H/D values from the analytical model and Monte Carlo agreed well from 100 to 250 MeV (10% average difference). Predicted H/D values from the analytical model also agreed well with measurements at 75 MeV (15% average difference). The results indicate that analytical models can give fast, reliable calculations of neutron exposure after proton therapy. This ability is absent in treatment planning systems but vital to second cancer risk estimation.

Resilience: A Meta-Analytic Approach

ERIC Educational Resources Information Center

Lee, Ji Hee; Nam, Suk Kyung; Kim, A-Reum; Kim, Boram; Lee, Min Young; Lee, Sang Min

2013-01-01

This study investigated the relationship between psychological resilience and its relevant variables by using a meta-analytic method. The results indicated that the largest effect on resilience was found to stem from the protective factors, a medium effect from risk factors, and the smallest effect from demographic factors. (Contains 4 tables.)

Revisiting the Relationship between Individual Differences in Analytic Thinking and Religious Belief: Evidence That Measurement Order Moderates Their Inverse Correlation.

PubMed

Finley, Anna J; Tang, David; Schmeichel, Brandon J

2015-01-01

Prior research has found that persons who favor more analytic modes of thought are less religious. We propose that individual differences in analytic thought are associated with reduced religious beliefs particularly when analytic thought is measured (hence, primed) first. The current study provides a direct replication of prior evidence that individual differences in analytic thinking are negatively related to religious beliefs when analytic thought is measured before religious beliefs. When religious belief is measured before analytic thinking, however, the negative relationship is reduced to non-significance, suggesting that the link between analytic thought and religious belief is more tenuous than previously reported. The current study suggests that whereas inducing analytic processing may reduce religious belief, more analytic thinkers are not necessarily less religious. The potential for measurement order to inflate the inverse correlation between analytic thinking and religious beliefs deserves additional consideration.

Revisiting the Relationship between Individual Differences in Analytic Thinking and Religious Belief: Evidence That Measurement Order Moderates Their Inverse Correlation

PubMed Central

Finley, Anna J.; Tang, David; Schmeichel, Brandon J.

2015-01-01

Prior research has found that persons who favor more analytic modes of thought are less religious. We propose that individual differences in analytic thought are associated with reduced religious beliefs particularly when analytic thought is measured (hence, primed) first. The current study provides a direct replication of prior evidence that individual differences in analytic thinking are negatively related to religious beliefs when analytic thought is measured before religious beliefs. When religious belief is measured before analytic thinking, however, the negative relationship is reduced to non-significance, suggesting that the link between analytic thought and religious belief is more tenuous than previously reported. The current study suggests that whereas inducing analytic processing may reduce religious belief, more analytic thinkers are not necessarily less religious. The potential for measurement order to inflate the inverse correlation between analytic thinking and religious beliefs deserves additional consideration. PMID:26402334

Consistent Yokoya-Chen Approximation to Beamstrahlung(LCC-0010)

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

Peskin, M

2004-04-22

I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data.I reconsider the Yokoya-Chen approximate evolution equation for beamstrahlung and modify it slightly to generate simple, consistent analytical approximations for the electron and photon energy spectra. I compare these approximations to previous ones, and to simulation data.

An analytically based numerical method for computing view factors in real urban environments

NASA Astrophysics Data System (ADS)

Lee, Doo-Il; Woo, Ju-Wan; Lee, Sang-Hyun

2018-01-01

A view factor is an important morphological parameter used in parameterizing in-canyon radiative energy exchange process as well as in characterizing local climate over urban environments. For realistic representation of the in-canyon radiative processes, a complete set of view factors at the horizontal and vertical surfaces of urban facets is required. Various analytical and numerical methods have been suggested to determine the view factors for urban environments, but most of the methods provide only sky-view factor at the ground level of a specific location or assume simplified morphology of complex urban environments. In this study, a numerical method that can determine the sky-view factors ( ψ ga and ψ wa ) and wall-view factors ( ψ gw and ψ ww ) at the horizontal and vertical surfaces is presented for application to real urban morphology, which are derived from an analytical formulation of the view factor between two blackbody surfaces of arbitrary geometry. The established numerical method is validated against the analytical sky-view factor estimation for ideal street canyon geometries, showing a consolidate confidence in accuracy with errors of less than 0.2 %. Using a three-dimensional building database, the numerical method is also demonstrated to be applicable in determining the sky-view factors at the horizontal (roofs and roads) and vertical (walls) surfaces in real urban environments. The results suggest that the analytically based numerical method can be used for the radiative process parameterization of urban numerical models as well as for the characterization of local urban climate.

Community-Based Mental Health and Behavioral Programs for Low-Income Urban Youth: A Meta-Analytic Review

ERIC Educational Resources Information Center

Farahmand, Farahnaz K.; Duffy, Sophia N.; Tailor, Megha A.; Dubois, David L.; Lyon, Aaron L.; Grant, Kathryn E.; Zarlinski, Jennifer C.; Masini, Olivia; Zander, Keith J.; Nathanson, Alison M.

2012-01-01

A meta-analytic review of 33 studies and 41 independent samples was conducted of the effectiveness of community-based mental health and behavioral programs for low-income urban youth. Findings indicated positive effects, with an overall mean effect of 0.25 at post-test. While this is comparable to previous meta-analytic intervention research with…

Integration of gas chromatography mass spectrometry methods for differentiating ricin preparation methods.

PubMed

Wunschel, David S; Melville, Angela M; Ehrhardt, Christopher J; Colburn, Heather A; Victry, Kristin D; Antolick, Kathryn C; Wahl, Jon H; Wahl, Karen L

2012-05-07

The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of Ricinus communis, commonly known as the castor plant. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatography-mass spectrometry (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid, as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods, starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid, or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method, independent of the seed source. In particular, the abundance of mannose, arabinose, fucose, ricinoleic acid, and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation than would be possible using a single analytical method.

Demonstration/Validation of the Snap Sampler Passive Ground Water Sampling Device for Sampling Inorganic Analytes at the Former Pease Air Force Base

DTIC Science & Technology

2009-07-01

viii Unit Conversion Factors...sampler is also an economic alternative for sampling for inorganic analytes. ERDC/CRREL TR-09-12 xii Unit Conversion Factors Multiply By To Obtain...head- space and then covered with two layers of tightly fitting aluminum foil. To dissolve the analytes, the solutions were stirred for approximately

Heat transfer to and from vegetated surfaces - An analytical method for the bulk exchange coefficients

NASA Technical Reports Server (NTRS)

Massman, William J.

1987-01-01

The semianalytical model outlined in a previous study (Massman, 1987) to describe momentum exchange between the atmosphere and vegetated surfaces is extended to include the exchange of heat. The methods employed are based on one-dimensional turbulent diffusivities, and use analytical solutions to the steady-state diffusion equation. The model is used to assess the influence that the canopy foliage structure and density, the wind profile structure within the canopy, and the shelter factor can have upon the inverse surface Stanton number (kB exp -1), as well as to explore the consequences of introducing a scalar displacement height which can be different from the momentum displacement height. In general, the triangular foliage area density function gives results which agree more closely with observations than that for constant foliage area density. The intended application of this work is for parameterizing the bulk aerodynamic resistances for heat and momentum exchange for use within large-scale models of plant-atmosphere exchanges.

ANALYTICAL CHEMISTRY IN NUCLEAR REACTOR TECHNOLOGY. Analysis of Reactor Fuels, Fission-Product Mixtures and Related Materials: Analytical Chemistry of Plutonium and the Transplutonic Elements. Third Conference, Gatlinburg, Tennessee, October 26-29, 1959

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

None

1960-01-01

Thirty-one papers and 10 summaries of papers presented at the Third Conference on Analytical Chemistry in Nuclear Reactor Technology held at Gatlinburg, Tennessee, October 26 to 29, 1959, are given. The papers are grouped into four sections: general, analytical chemistry of fuels, analytical chemistry of plutonium and the transplutonic elements, and the analysis of fission-product mixtures. Twenty-seven of the papers are covered by separate abstracts. Four were previously abstracted for NSA. (M.C.G.)

Aspartame and Risk of Cancer: A Meta-analytic Review.

PubMed

Mallikarjun, Sreekanth; Sieburth, Rebecca McNeill

2015-01-01

Aspartame (APM) is the most commonly used artificial sweetener and flavor enhancer in the world. There is a rise in concern that APM is carcinogenic due to a variation in the findings of the previous APM carcinogenic bioassays. This article conducts a meta-analytic review of all previous APM carcinogenic bioassays on rodents that were conducted before 31 December 2012. The search yielded 10 original APM carcinogenic bioassays on rodents. The aggregate effect sizes suggest that APM consumption has no significant carcinogenic effect in rodents.

Spatio-Temporal Dimensions of Child Poverty in America, 1990-2010.

PubMed

Call, Maia A; Voss, Paul R

2016-01-01

The persistence of childhood poverty in the United States, a wealthy and developed country, continues to pose both an analytical dilemma and public policy challenge, despite many decades of research and remedial policy implementation. In this paper, our goals are twofold, though our primary focus is methodological. We attempt both to examine the relationship between space, time, and previously established factors correlated with childhood poverty at the county level in the continental United States as well as to provide an empirical case study to demonstrate an underutilized methodological approach. We analyze a spatially consistent dataset built from the 1990 and 2000 U.S. Censuses, and the 2006-2010 American Community Survey. Our analytic approach includes cross-sectional spatial models to estimate the reproduction of poverty for each of the reference years as well as a fixed effects panel data model, to analyze change in child poverty over time. In addition, we estimate a full space-time interaction model, which adjusts for spatial and temporal variation in these data. These models reinforce our understanding of the strong regional persistence of childhood poverty in the U.S. over time and suggest that the factors impacting childhood poverty remain much the same today as they have in past decades.

Big genomics and clinical data analytics strategies for precision cancer prognosis.

PubMed

Ow, Ghim Siong; Kuznetsov, Vladimir A

2016-11-07

The field of personalized and precise medicine in the era of big data analytics is growing rapidly. Previously, we proposed our model of patient classification termed Prognostic Signature Vector Matching (PSVM) and identified a 37 variable signature comprising 36 let-7b associated prognostic significant mRNAs and the age risk factor that stratified large high-grade serous ovarian cancer patient cohorts into three survival-significant risk groups. Here, we investigated the predictive performance of PSVM via optimization of the prognostic variable weights, which represent the relative importance of one prognostic variable over the others. In addition, we compared several multivariate prognostic models based on PSVM with classical machine learning techniques such as K-nearest-neighbor, support vector machine, random forest, neural networks and logistic regression. Our results revealed that negative log-rank p-values provides more robust weight values as opposed to the use of other quantities such as hazard ratios, fold change, or a combination of those factors. PSVM, together with the classical machine learning classifiers were combined in an ensemble (multi-test) voting system, which collectively provides a more precise and reproducible patient stratification. The use of the multi-test system approach, rather than the search for the ideal classification/prediction method, might help to address limitations of the individual classification algorithm in specific situation.

Preliminary Upper Estimate of Peak Currents in Transcranial Magnetic Stimulation at Distant Locations from a TMS Coil

PubMed Central

Makarov, Sergey N.; Yanamadala, Janakinadh; Piazza, Matthew W.; Helderman, Alex M.; Thang, Niang S.; Burnham, Edward H.; Pascual-Leone, Alvaro

2016-01-01

Goals Transcranial magnetic stimulation (TMS) is increasingly used as a diagnostic and therapeutic tool for numerous neuropsychiatric disorders. The use of TMS might cause whole-body exposure to undesired induced currents in patients and TMS operators. The aim of the present study is to test and justify a simple analytical model known previously, which may be helpful as an upper estimate of eddy current density at a particular distant observation point for any body composition and any coil setup. Methods We compare the analytical solution with comprehensive adaptive mesh refinement-based FEM simulations of a detailed full-body human model, two coil types, five coil positions, about 100,000 observation points, and two distinct pulse rise times, thus providing a representative number of different data sets for comparison, while also using other numerical data. Results Our simulations reveal that, after a certain modification, the analytical model provides an upper estimate for the eddy current density at any location within the body. In particular, it overestimates the peak eddy currents at distant locations from a TMS coil by a factor of 10 on average. Conclusion The simple analytical model tested in the present study may be valuable as a rapid method to safely estimate levels of TMS currents at different locations within a human body. Significance At present, safe limits of general exposure to TMS electric and magnetic fields are an open subject, including fetal exposure for pregnant women. PMID:26685221

Evaluation of the availability of bound analyte for passive sampling in the presence of mobile binding matrix.

PubMed

Xu, Jianqiao; Huang, Shuyao; Jiang, Ruifen; Cui, Shufen; Luan, Tiangang; Chen, Guosheng; Qiu, Junlang; Cao, Chenyang; Zhu, Fang; Ouyang, Gangfeng

2016-04-21

Elucidating the availability of the bound analytes for the mass transfer through the diffusion boundary layers (DBLs) adjacent to passive samplers is important for understanding the passive sampling kinetics in complex samples, in which the lability factor of the bound analyte in the DBL is an important parameter. In this study, the mathematical expression of lability factor was deduced by assuming a pseudo-steady state during passive sampling, and the equation indicated that the lability factor was equal to the ratio of normalized concentration gradients between the bound and free analytes. Through the introduction of the mathematical expression of lability factor, the modified effective average diffusion coefficient was proven to be more suitable for describing the passive sampling kinetics in the presence of mobile binding matrixes. Thereafter, the lability factors of the bound polycyclic aromatic hydrocarbons (PAHs) with sodium dodecylsulphate (SDS) micelles as the binding matrixes were figured out according to the improved theory. The lability factors were observed to decrease with larger binding ratios and smaller micelle sizes, and were successfully used to predict the mass transfer efficiencies of PAHs through DBLs. This study would promote the understanding of the availability of bound analytes for passive sampling based on the theoretical improvements and experimental assessments. Copyright © 2016 Elsevier B.V. All rights reserved.

Predictors of adherence to treatment by patients with coronary heart disease after percutaneous coronary intervention.

PubMed

Kähkönen, Outi; Saaranen, Terhi; Kankkunen, Päivi; Lamidi, Marja-Leena; Kyngäs, Helvi; Miettinen, Heikki

2018-03-01

To identify the predictors of adherence in patients with coronary heart disease after a percutaneous coronary intervention. Adherence is a key factor in preventing the progression of coronary heart disease. An analytical multihospital survey study. A survey of 416 postpercutaneous coronary intervention patients was conducted in 2013, using the Adherence of People with Chronic Disease Instrument. The instrument consists of 37 items measuring adherence and 18 items comprising sociodemographic, health behavioural and disease-specific factors. Adherence consisted of two mean sum variables: adherence to medication and a healthy lifestyle. Based on earlier studies, nine mean sum variables known to explain adherence were responsibility, cooperation, support from next of kin, sense of normality, motivation, results of care, support from nurses and physicians, and fear of complications. Frequencies and percentages were used to describe the data, cross-tabulation to find statistically significant background variables and multivariate logistic regression to confirm standardised predictors of adherence. Patients reported good adherence. However, there was inconsistency between adherence to a healthy lifestyle and health behaviours. Gender, close personal relationship, length of education, physical activity, vegetable and alcohol consumption, LDL cholesterol and duration of coronary heart disease without previous percutaneous coronary intervention were predictors of adherence. The predictive factors known to explain adherence to treatment were male gender, close personal relationship, longer education, lower LDL cholesterol and longer duration of coronary heart disease without previous percutaneous coronary intervention. Because a healthy lifestyle predicted factors known to explain adherence, these issues should be emphasised particularly for female patients not in a close personal relationship, with low education and a shorter coronary heart disease duration with previous coronary intervention. © 2017 John Wiley & Sons Ltd.

Stiffness of frictional contact of dissimilar elastic solids

DOE PAGES

Lee, Jin Haeng; Gao, Yanfei; Bower, Allan F.; ...

2017-12-22

The classic Sneddon relationship between the normal contact stiffness and the contact size is valid for axisymmetric, frictionless contact, in which the two contacting solids are approximated by elastic half-spaces. Deviation from this result critically affects the accuracy of the load and displacement sensing nanoindentation techniques. This study gives a thorough numerical and analytical investigation of corrections needed to the Sneddon solution when finite Coulomb friction exists between an elastic half-space and a flat-ended rigid punch with circular or noncircular shape. Because of linearity of the Coulomb friction, the correction factor is found to be a function of the frictionmore » coefficient, Poisson's ratio, and the contact shape, but independent of the contact size. Two issues are of primary concern in the finite element simulations – adequacy of the mesh near the contact edge and the friction implementation methodology. Although the stick or slip zone sizes are quite different from the penalty or Lagrangian methods, the calculated contact stiffnesses are almost the same and may be considerably larger than those in Sneddon's solution. For circular punch contact, the numerical solutions agree remarkably well with a previous analytical solution. For non-circular punch contact, the results can be represented using the equivalence between the contact problem and bi-material fracture mechanics. Finally, the correction factor is found to be a product of that for the circular contact and a multiplicative factor that depends only on the shape of the punch but not on the friction coefficient or Poisson's ratio.« less

Stiffness of frictional contact of dissimilar elastic solids

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

Lee, Jin Haeng; Gao, Yanfei; Bower, Allan F.

The classic Sneddon relationship between the normal contact stiffness and the contact size is valid for axisymmetric, frictionless contact, in which the two contacting solids are approximated by elastic half-spaces. Deviation from this result critically affects the accuracy of the load and displacement sensing nanoindentation techniques. This study gives a thorough numerical and analytical investigation of corrections needed to the Sneddon solution when finite Coulomb friction exists between an elastic half-space and a flat-ended rigid punch with circular or noncircular shape. Because of linearity of the Coulomb friction, the correction factor is found to be a function of the frictionmore » coefficient, Poisson's ratio, and the contact shape, but independent of the contact size. Two issues are of primary concern in the finite element simulations – adequacy of the mesh near the contact edge and the friction implementation methodology. Although the stick or slip zone sizes are quite different from the penalty or Lagrangian methods, the calculated contact stiffnesses are almost the same and may be considerably larger than those in Sneddon's solution. For circular punch contact, the numerical solutions agree remarkably well with a previous analytical solution. For non-circular punch contact, the results can be represented using the equivalence between the contact problem and bi-material fracture mechanics. Finally, the correction factor is found to be a product of that for the circular contact and a multiplicative factor that depends only on the shape of the punch but not on the friction coefficient or Poisson's ratio.« less

Stiffness of frictional contact of dissimilar elastic solids

NASA Astrophysics Data System (ADS)

Lee, Jin Haeng; Gao, Yanfei; Bower, Allan F.; Xu, Haitao; Pharr, George M.

2018-03-01

The classic Sneddon relationship between the normal contact stiffness and the contact size is valid for axisymmetric, frictionless contact, in which the two contacting solids are approximated by elastic half-spaces. Deviation from this result critically affects the accuracy of the load and displacement sensing nanoindentation techniques. This paper gives a thorough numerical and analytical investigation of corrections needed to the Sneddon solution when finite Coulomb friction exists between an elastic half-space and a flat-ended rigid punch with circular or noncircular shape. Because of linearity of the Coulomb friction, the correction factor is found to be a function of the friction coefficient, Poisson's ratio, and the contact shape, but independent of the contact size. Two issues are of primary concern in the finite element simulations - adequacy of the mesh near the contact edge and the friction implementation methodology. Although the stick or slip zone sizes are quite different from the penalty or Lagrangian methods, the calculated contact stiffnesses are almost the same and may be considerably larger than those in Sneddon's solution. For circular punch contact, the numerical solutions agree remarkably well with a previous analytical solution. For non-circular punch contact, the results can be represented using the equivalence between the contact problem and bi-material fracture mechanics. The correction factor is found to be a product of that for the circular contact and a multiplicative factor that depends only on the shape of the punch but not on the friction coefficient or Poisson's ratio.

Is a pre-analytical process for urinalysis required?

PubMed

Petit, Morgane; Beaudeux, Jean-Louis; Majoux, Sandrine; Hennequin, Carole

2017-10-01

For the reliable urinary measurement of calcium, phosphate and uric acid, a pre-analytical process by adding acid or base to urine samples at laboratory is recommended in order to dissolve precipitated solutes. Several studies on different kind of samples and analysers have previously shown that a such pre-analytical treatment is useless. The objective was to study the necessity of pre-analytical treatment of urine on samples collected using the V-Monovette ® (Sarstedt) system and measured on the analyser Architect C16000 (Abbott Diagnostics). Sixty urinary samples of hospitalized patients were selected (n=30 for calcium and phosphate, and n=30 for uric acid). After acidification of urine samples for measurement of calcium and phosphate, and alkalinisation for measurement of uric acid respectively, differences between results before and after the pre-analytical treatment were compared to acceptable limits recommended by the French society of clinical biology (SFBC). No difference in concentration between before and after pre-analytical treatment of urine samples exceeded acceptable limits from SFBC for measurement of calcium and uric acid. For phosphate, only one sample exceeded these acceptable limits, showing a result paradoxically lower after acidification. In conclusion, in agreement with previous study, our results show that acidification or alkalinisation of urine samples from 24 h urines or from urination is not a pre-analytical necessity for measurement of calcium, phosphate and uric acid.

A Meta-Analytic Review of Work-Family Conflict and Its Antecedents

ERIC Educational Resources Information Center

Byron, Kristin

2005-01-01

This meta-analytic review combines the results of more than 60 studies to help determine the relative effects of work, nonwork, and demographic and individual factors on work interference with family (WIF) and family interference with work (FIW). As expected, work factors related more strongly to WIF, and some nonwork factors were more strongly…

Taxometric and Factor Analytic Models of Anxiety Sensitivity among Youth: Exploring the Latent Structure of Anxiety Psychopathology Vulnerability

ERIC Educational Resources Information Center

Bernstein, Amit; Zvolensky, Michael J.; Stewart, Sherry; Comeau, Nancy

2007-01-01

This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), a well-established affect-sensitivity individual difference factor, among youth by employing taxometric and factor analytic approaches in an integrative manner. Taxometric analyses indicated that AS, as indexed by the Child Anxiety Sensitivity…

Orthogonal Higher Order Structure of the WISC-IV Spanish Using Hierarchical Exploratory Factor Analytic Procedures

ERIC Educational Resources Information Center

McGill, Ryan J.; Canivez, Gary L.

2016-01-01

As recommended by Carroll, the present study examined the factor structure of the Wechsler Intelligence Scale for Children-Fourth Edition Spanish (WISC-IV Spanish) normative sample using higher order exploratory factor analytic techniques not included in the WISC-IV Spanish Technical Manual. Results indicated that the WISC-IV Spanish subtests were…

Application of the epidemiological model in studying human error in aviation

NASA Technical Reports Server (NTRS)

Cheaney, E. S.; Billings, C. E.

1981-01-01

An epidemiological model is described in conjunction with the analytical process through which aviation occurrence reports are composed into the events and factors pertinent to it. The model represents a process in which disease, emanating from environmental conditions, manifests itself in symptoms that may lead to fatal illness, recoverable illness, or no illness depending on individual circumstances of patient vulnerability, preventive actions, and intervention. In the aviation system the analogy of the disease process is the predilection for error of human participants. This arises from factors in the operating or physical environment and results in errors of commission or omission that, again depending on the individual circumstances, may lead to accidents, system perturbations, or harmless corrections. A discussion of the previous investigations, each of which manifests the application of the epidemiological method, exemplifies its use and effectiveness.

The relevance of psychodynamic psychotherapy to understanding therapist-patient sexual abuse and treatment of survivors.

PubMed

Yahav, Rivka; Oz, Sheri

2006-01-01

Regardless of the therapy modality, research continues to point to the therapeutic relationship as a major salient factor in clinical success or failure. When a patient is sexually abused by his or her therapist, this therapeutic relationship is cynically exploited in a way that does not properly serve the essential needs of the patient. When this patient then seeks reparative therapy, the subsequent therapist needs to pay close attention to issues of the relationship which were breached by the previous clinician. In this article, two case studies showing very different dynamics will be presented in order to demonstrate: (1) relevant factors related to transference, countertransference, projective identification, and the analytic third pertaining to the former, abusive therapy; and (2) needs versus wishes, and issues related to boundaries and self-disclosure in the corrective therapy.

Investigating the two-moment characterisation of subcellular biochemical networks.

PubMed

Ullah, Mukhtar; Wolkenhauer, Olaf

2009-10-07

While ordinary differential equations (ODEs) form the conceptual framework for modelling many cellular processes, specific situations demand stochastic models to capture the influence of noise. The most common formulation of stochastic models for biochemical networks is the chemical master equation (CME). While stochastic simulations are a practical way to realise the CME, analytical approximations offer more insight into the influence of noise. Towards that end, the two-moment approximation (2MA) is a promising addition to the established analytical approaches including the chemical Langevin equation (CLE) and the related linear noise approximation (LNA). The 2MA approach directly tracks the mean and (co)variance which are coupled in general. This coupling is not obvious in CME and CLE and ignored by LNA and conventional ODE models. We extend previous derivations of 2MA by allowing (a) non-elementary reactions and (b) relative concentrations. Often, several elementary reactions are approximated by a single step. Furthermore, practical situations often require the use of relative concentrations. We investigate the applicability of the 2MA approach to the well-established fission yeast cell cycle model. Our analytical model reproduces the clustering of cycle times observed in experiments. This is explained through multiple resettings of M-phase promoting factor (MPF), caused by the coupling between mean and (co)variance, near the G2/M transition.

Analytic redundancy management for SCOLE

NASA Technical Reports Server (NTRS)

Montgomery, Raymond C.

1988-01-01

The objective of this work is to develop a practical sensor analytic redundancy management scheme for flexible spacecraft and to demonstrate it using the SCOLE experimental apparatus. The particular scheme to be used is taken from previous work on the Grid apparatus by Williams and Montgomery.

Survey Geometry and the Internal Consistency of Recent Cosmic Shear Measurements

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

Troxel, M.A.; et al.

We explore the impact of an update to the typical approximation for the shape noise term in the analytic covariance matrix for cosmic shear experiments that assumes the absence of survey boundary and mask effects. We present an exact expression for the number of galaxy pairs in this term based on the the survey mask, which leads to more than a factor of three increase in the shape noise on the largest measured scales for the Kilo-Degree Survey (KIDS-450) real-space cosmic shear data. We compare the result of this analytic expression to several alternative methods for measuring the shape noise from the data and find excellent agreement. This update to the covariance resolves any internal model tension evidenced by the previously large cosmological best-fitmore » $$\\chi^2$$ for the KiDS-450 cosmic shear data. The best-fit $$\\chi^2$$ is reduced from 161 to 121 for 118 degrees of freedom. We also apply a correction to how the multiplicative shear calibration uncertainty is included in the covariance. This change, along with a previously known update to the reported effective angular values of the data vector, jointly shift the inferred amplitude of the correlation function to higher values. We find that this improves agreement of the KiDS-450 cosmic shear results with Dark Energy Survey Year 1 and Planck results.« less

High-frequency phase shift measurement greatly enhances the sensitivity of QCM immunosensors.

PubMed

March, Carmen; García, José V; Sánchez, Ángel; Arnau, Antonio; Jiménez, Yolanda; García, Pablo; Manclús, Juan J; Montoya, Ángel

2015-03-15

In spite of being widely used for in liquid biosensing applications, sensitivity improvement of conventional (5-20MHz) quartz crystal microbalance (QCM) sensors remains an unsolved challenging task. With the help of a new electronic characterization approach based on phase change measurements at a constant fixed frequency, a highly sensitive and versatile high fundamental frequency (HFF) QCM immunosensor has successfully been developed and tested for its use in pesticide (carbaryl and thiabendazole) analysis. The analytical performance of several immunosensors was compared in competitive immunoassays taking carbaryl insecticide as the model analyte. The highest sensitivity was exhibited by the 100MHz HFF-QCM carbaryl immunosensor. When results were compared with those reported for 9MHz QCM, analytical parameters clearly showed an improvement of one order of magnitude for sensitivity (estimated as the I50 value) and two orders of magnitude for the limit of detection (LOD): 30μgl(-1) vs 0.66μgL(-1)I50 value and 11μgL(-1) vs 0.14μgL(-1) LOD, for 9 and 100MHz, respectively. For the fungicide thiabendazole, I50 value was roughly the same as that previously reported for SPR under the same biochemical conditions, whereas LOD improved by a factor of 2. The analytical performance achieved by high frequency QCM immunosensors surpassed those of conventional QCM and SPR, closely approaching the most sensitive ELISAs. The developed 100MHz QCM immunosensor strongly improves sensitivity in biosensing, and therefore can be considered as a very promising new analytical tool for in liquid applications where highly sensitive detection is required. Copyright © 2014 Elsevier B.V. All rights reserved.

Small-x asymptotics of the quark helicity distribution: Analytic results

DOE PAGES

Kovchegov, Yuri V.; Pitonyak, Daniel; Sievert, Matthew D.

2017-06-15

In this Letter, we analytically solve the evolution equations for the small-x asymptotic behavior of the (flavor singlet) quark helicity distribution in the large- N c limit. Here, these evolution equations form a set of coupled integro-differential equations, which previously could only be solved numerically. This approximate numerical solution, however, revealed simplifying properties of the small-x asymptotics, which we exploit here to obtain an analytic solution.

Pre-analytical and analytical factors influencing Alzheimer's disease cerebrospinal fluid biomarker variability.

PubMed

Fourier, Anthony; Portelius, Erik; Zetterberg, Henrik; Blennow, Kaj; Quadrio, Isabelle; Perret-Liaudet, Armand

2015-09-20

A panel of cerebrospinal fluid (CSF) biomarkers including total Tau (t-Tau), phosphorylated Tau protein at residue 181 (p-Tau) and β-amyloid peptides (Aβ42 and Aβ40), is frequently used as an aid in Alzheimer's disease (AD) diagnosis for young patients with cognitive impairment, for predicting prodromal AD in mild cognitive impairment (MCI) subjects, for AD discrimination in atypical clinical phenotypes and for inclusion/exclusion and stratification of patients in clinical trials. Due to variability in absolute levels between laboratories, there is no consensus on medical cut-off value for the CSF AD signature. Thus, for full implementation of this core AD biomarker panel in clinical routine, this issue has to be solved. Variability can be explained both by pre-analytical and analytical factors. For example, the plastic tubes used for CSF collection and storage, the lack of reference material and the variability of the analytical protocols were identified as important sources of variability. The aim of this review is to highlight these pre-analytical and analytical factors and describe efforts done to counteract them in order to establish cut-off values for core CSF AD biomarkers. This review will give the current state of recommendations. Copyright © 2015. Published by Elsevier B.V.

Comparison of three methods for wind turbine capacity factor estimation.

PubMed

Ditkovich, Y; Kuperman, A

2014-01-01

Three approaches to calculating capacity factor of fixed speed wind turbines are reviewed and compared using a case study. The first "quasiexact" approach utilizes discrete wind raw data (in the histogram form) and manufacturer-provided turbine power curve (also in discrete form) to numerically calculate the capacity factor. On the other hand, the second "analytic" approach employs a continuous probability distribution function, fitted to the wind data as well as continuous turbine power curve, resulting from double polynomial fitting of manufacturer-provided power curve data. The latter approach, while being an approximation, can be solved analytically thus providing a valuable insight into aspects, affecting the capacity factor. Moreover, several other merits of wind turbine performance may be derived based on the analytical approach. The third "approximate" approach, valid in case of Rayleigh winds only, employs a nonlinear approximation of the capacity factor versus average wind speed curve, only requiring rated power and rotor diameter of the turbine. It is shown that the results obtained by employing the three approaches are very close, enforcing the validity of the analytically derived approximations, which may be used for wind turbine performance evaluation.

Interobserver Agreement on First-Stage Conversation Analytic Transcription

ERIC Educational Resources Information Center

Roberts, Felicia; Robinson, Jeffrey D.

2004-01-01

This investigation assesses interobserver agreement on conversation analytic (CA) transcription. Four professional CA transcribers spent a maximum of 3 hours transcribing 2.5 minutes of a previously unknown, naturally occurring, mundane telephone call. Researchers unitized transcripts into words, sounds, silences, inbreaths, outbreaths, and laugh…

Chemical Sensors Based on IR Spectroscopy and Surface-Modified Waveguides

NASA Technical Reports Server (NTRS)

Lopez, Gabriel P.; Niemczyk, Thomas

1999-01-01

Sol-gel processing techniques have been used to apply thin porous films to the surfaces of planar infrared (IR) waveguides to produce widely useful chemical sensors. The thin- film coating serves to diminish the concentration of water and increase the concentration of the analyte in the region probed by the evanescent IR wave. These porous films are composed of silica, and therefore, conventional silica surface modification techniques can be used to give the surface a specific functional character. The sol-gel film was surface-modified to make the film highly hydrophobic. These sensors were shown to be capable of detecting non-polar organic analytes, such as benzonitrile, in aqueous solution with detection limits in the ppb range. Further, these porous sol-gel structures allow the analytes to diffuse into and out of the films rapidly, thus reaching equilibrium in less than ten seconds. These sensors are unique because of the fact that their operation is based on the measurement of an IR absorption spectrum. Thus, these sensors are able to identify the analytes as well as measure concentration with high sensitivity. These developments have been documented in previous reports and publications. Recently, we have also targeted detection of the polar organic molecules acetone and isopropanol in aqueous solution. Polar organics are widely used in industrial and chemical processes, hence it is of interest to monitor their presence in effluents or decontamination process flows. Although large improvements in detection limits were expected with non-polar organic molecules in aqueous solutions using very hydrophobic porous sol-gel films on silicon attenuated total reflectance (Si ATR) waveguides, it was not as clear what the detection enhancements might be for polar organic molecules. This report describes the use of modified sol-gel-coated Si ATR sensors for trace detection and quantitation of small polar organic molecules in aqueous solutions. The detection of both acetone and isopropanol molecules in aqueous solution has been previously reported for chalcogenide fiber optic sensors. The sol-gel film was produced using a mixture of ethyltriethoxysilane and tetraethoxysilane and the surface modification was carried out using trimethylchlorosilane. We have demonstrated that this film concentrates the target polar analytes from aqueous solution in the region probed by the evanescent wave to improve detection limits by as much as a factor of 450.

Factor-Analytic and Individualized Approaches to Constructing Brief Measures of ADHD Behaviors

ERIC Educational Resources Information Center

Volpe, Robert J.; Gadow, Kenneth D.; Blom-Hoffman, Jessica; Feinberg, Adam B.

2009-01-01

Two studies were performed to examine a factor-analytic and an individualized approach to creating short progress-monitoring measures from the longer "ADHD-Symptom Checklist-4" (ADHD-SC4). In Study 1, teacher ratings on items of the ADHD:Inattentive (IA) and ADHD:Hyperactive-Impulsive (HI) scales of the ADHD-SC4 were factor analyzed in a normative…

Analytical solution for vacuum preloading considering the nonlinear distribution of horizontal permeability within the smear zone.

PubMed

Peng, Jie; He, Xiang; Ye, Hanming

2015-01-01

The vacuum preloading is an effective method which is widely used in ground treatment. In consolidation analysis, the soil around prefabricated vertical drain (PVD) is traditionally divided into smear zone and undisturbed zone, both with constant permeability. In reality, the permeability of soil changes continuously within the smear zone. In this study, the horizontal permeability coefficient of soil within the smear zone is described by an exponential function of radial distance. A solution for vacuum preloading consolidation considers the nonlinear distribution of horizontal permeability within the smear zone is presented and compared with previous analytical results as well as a numerical solution, the results show that the presented solution correlates well with the numerical solution, and is more precise than previous analytical solution.

Analytical solution for vacuum preloading considering the nonlinear distribution of horizontal permeability within the smear zone

PubMed Central

Peng, Jie; He, Xiang; Ye, Hanming

2015-01-01

The vacuum preloading is an effective method which is widely used in ground treatment. In consolidation analysis, the soil around prefabricated vertical drain (PVD) is traditionally divided into smear zone and undisturbed zone, both with constant permeability. In reality, the permeability of soil changes continuously within the smear zone. In this study, the horizontal permeability coefficient of soil within the smear zone is described by an exponential function of radial distance. A solution for vacuum preloading consolidation considers the nonlinear distribution of horizontal permeability within the smear zone is presented and compared with previous analytical results as well as a numerical solution, the results show that the presented solution correlates well with the numerical solution, and is more precise than previous analytical solution. PMID:26447973

Influence of Pre-Analytical Factors on Thymus- and Activation-Regulated Chemokine Quantitation in Plasma

PubMed Central

Zhao, Xuemei; Delgado, Liliana; Weiner, Russell; Laterza, Omar F.

2015-01-01

Thymus- and activation-regulated chemokine (TARC) in serum/plasma associates with the disease activity of atopic dermatitis (AD), and is a promising tool for assessing the response to the treatment of the disease. TARC also exists within platelets, with elevated levels detectable in AD patients. We examined the effects of pre-analytical factors on the quantitation of TARC in human EDTA plasma. TARC levels in platelet-free plasma were significantly lower than those in platelet-containing plasma. After freeze-thaw, TARC levels increased in platelet-containing plasma, but remained unchanged in platelet-free plasma, suggesting TARC was released from the platelets during the freeze-thaw process. In contrast, TARC levels were stable in serum independent of freeze-thaw. These findings underscore the importance of pre-analytical factors to TARC quantitation. Plasma TARC levels should be measured in platelet-free plasma for accurate quantitation. Pre-analytical factors influence the quantitation, interpretation, and implementation of circulating TARC as a biomarker for the development of AD therapeutics. PMID:28936246

Exploring factors that influence work analysis data: A meta-analysis of design choices, purposes, and organizational context.

PubMed

DuVernet, Amy M; Dierdorff, Erich C; Wilson, Mark A

2015-09-01

Work analysis is fundamental to designing effective human resource systems. The current investigation extends previous research by identifying the differential effects of common design decisions, purposes, and organizational contexts on the data generated by work analyses. The effects of 19 distinct factors that span choices of descriptor, collection method, rating scale, and data source, as well as project purpose and organizational features, are explored. Meta-analytic results cumulated from 205 articles indicate that many of these variables hold significant consequences for work analysis data. Factors pertaining to descriptor choice, collection method, rating scale, and the purpose for conducting the work analysis each showed strong associations with work analysis data. The source of the work analysis information and organizational context in which it was conducted displayed fewer relationships. Findings can be used to inform choices work analysts make about methodology and postcollection evaluations of work analysis information. (c) 2015 APA, all rights reserved).

Experimental verification of a gain reduction model for the space charge effect in a wire chamber

NASA Astrophysics Data System (ADS)

Nagakura, Naoki; Fujii, Kazuki; Harayama, Isao; Kato, Yu; Sekiba, Daiichiro; Watahiki, Yumi; Yamashita, Satoru

2018-01-01

A wire chamber often suffers significant saturation of the multiplication factor when the electric field around its wires is strong. An analytical model of this effect has previously been proposed [Y. Arimoto et al., Nucl. Instrum. Meth. Phys. Res. A 799, 187 (2015)], in which the saturation was described by the multiplication factor, energy deposit density per wire length, and one constant parameter. In order to confirm the validity of this model, a multi-wire drift chamber was developed and irradiated by a MeV-range proton beam at the University of Tsukuba. The saturation effect was compared for energy deposits ranging from 70 keV/cm to 180 keV/cm and multiplication factors 3× 103 to 3× 104. The chamber was rotated with respect to the proton beam in order to vary the space charge density around the wires. The energy deposit distribution corrected for the effect was consistent with the result of a Monte Carlo simulation, thus validating the proposed model.

Sexual Violence Among Male Inmates.

PubMed

Hilinski-Rosick, Carly M; Freiburger, Tina L

2018-04-01

Inmate misconduct has been a widely studied topic for many decades. General studies of misconduct have found that there are certain factors that contribute to misconduct, including age, gender, sentence length, and facility type. Few studies, however, have examined the factors predicting sexual offenses in a prison conduct. Although many studies of victims of sexual offenses in prison have been conducted, there is a lack of studies examining the perpetrators of prison sexual violence. The current study attempted to expand this body of literature by examining the correlates of sexual misconduct among a sample of male inmates incarcerated in the state of North Carolina during 2010. Deprivation and importation theories of inmate behavior were used to guide the analysis, and measures of deprivation and importation factors were both included in the analytical models. Findings indicate that Black, nonmarried, younger inmates, who had more previous incarcerations and had been incarcerated longer, had greater odds of having a sexual infraction. Additional findings, as well as policy implications, are discussed.

A Genome-Wide Association Study of the Human Metabolome in a Community-Based Cohort

PubMed Central

Rhee, Eugene P.; Ho, Jennifer E.; Chen, Ming-Huei; Shen, Dongxiao; Cheng, Susan; Larson, Martin G.; Ghorbani, Anahita; Shi, Xu; Helenius, Iiro T.; O’Donnell, Christopher J.; Souza, Amanda L.; Deik, Amy; Pierce, Kerry A.; Bullock, Kevin; Walford, Geoffrey A.; Vasan, Ramachandran S.; Florez, Jose C.; Clish, Clary; Yeh, J.-R. Joanna; Wang, Thomas J.; Gerszten, Robert E.

2014-01-01

SUMMARY Because metabolites are hypothesized to play key roles as markers and effectors of cardio-metabolic diseases, recent studies have sought to annotate the genetic determinants of circulating metabolite levels. We report a genome-wide association study (GWAS) of 217 plasma metabolites, including >100 not measured in prior GWAS, in 2,076 participants of the Framingham Heart Study. For the majority of analytes, we find that estimated heritability explains >20% of inter-individual variation, and that variation attributable to heritable factors is greater than that attributable to clinical factors. Further, we identify 31 genetic loci associated with plasma metabolites, including 23 that have not previously been reported. Importantly, we include GWAS results for all surveyed metabolites, and demonstrate how this information highlights a role for AGXT2 in cholesterol ester and triacylglycerol metabolism. Thus, our study outlines the relative contributions of inherited and clinical factors on the plasma metabolome and provides a resource for metabolism research. PMID:23823483

Aerosol hygroscopic growth parameterization based on a solute specific coefficient

NASA Astrophysics Data System (ADS)

Metzger, S.; Steil, B.; Xu, L.; Penner, J. E.; Lelieveld, J.

2011-09-01

Water is a main component of atmospheric aerosols and its amount depends on the particle chemical composition. We introduce a new parameterization for the aerosol hygroscopic growth factor (HGF), based on an empirical relation between water activity (aw) and solute molality (μs) through a single solute specific coefficient νi. Three main advantages are: (1) wide applicability, (2) simplicity and (3) analytical nature. (1) Our approach considers the Kelvin effect and covers ideal solutions at large relative humidity (RH), including CCN activation, as well as concentrated solutions with high ionic strength at low RH such as the relative humidity of deliquescence (RHD). (2) A single νi coefficient suffices to parameterize the HGF for a wide range of particle sizes, from nanometer nucleation mode to micrometer coarse mode particles. (3) In contrast to previous methods, our analytical aw parameterization depends not only on a linear correction factor for the solute molality, instead νi also appears in the exponent in form x · ax. According to our findings, νi can be assumed constant for the entire aw range (0-1). Thus, the νi based method is computationally efficient. In this work we focus on single solute solutions, where νi is pre-determined with the bisection method from our analytical equations using RHD measurements and the saturation molality μssat. The computed aerosol HGF and supersaturation (Köhler-theory) compare well with the results of the thermodynamic reference model E-AIM for the key compounds NaCl and (NH4)2SO4 relevant for CCN modeling and calibration studies. The equations introduced here provide the basis of our revised gas-liquid-solid partitioning model, i.e. version 4 of the EQuilibrium Simplified Aerosol Model (EQSAM4), described in a companion paper.

Performance of Orbital Neutron Instruments for Spatially Resolved Hydrogen Measurements of Airless Planetary Bodies

PubMed Central

Elphic, Richard C.; Feldman, William C.; Funsten, Herbert O.; Prettyman, Thomas H.

2010-01-01

Abstract Orbital neutron spectroscopy has become a standard technique for measuring planetary surface compositions from orbit. While this technique has led to important discoveries, such as the deposits of hydrogen at the Moon and Mars, a limitation is its poor spatial resolution. For omni-directional neutron sensors, spatial resolutions are 1–1.5 times the spacecraft's altitude above the planetary surface (or 40–600 km for typical orbital altitudes). Neutron sensors with enhanced spatial resolution have been proposed, and one with a collimated field of view is scheduled to fly on a mission to measure lunar polar hydrogen. No quantitative studies or analyses have been published that evaluate in detail the detection and sensitivity limits of spatially resolved neutron measurements. Here, we describe two complementary techniques for evaluating the hydrogen sensitivity of spatially resolved neutron sensors: an analytic, closed-form expression that has been validated with Lunar Prospector neutron data, and a three-dimensional modeling technique. The analytic technique, called the Spatially resolved Neutron Analytic Sensitivity Approximation (SNASA), provides a straightforward method to evaluate spatially resolved neutron data from existing instruments as well as to plan for future mission scenarios. We conclude that the existing detector—the Lunar Exploration Neutron Detector (LEND)—scheduled to launch on the Lunar Reconnaissance Orbiter will have hydrogen sensitivities that are over an order of magnitude poorer than previously estimated. We further conclude that a sensor with a geometric factor of ∼ 100 cm2 Sr (compared to the LEND geometric factor of ∼ 10.9 cm2 Sr) could make substantially improved measurements of the lunar polar hydrogen spatial distribution. Key Words: Planetary instrumentation—Planetary science—Moon—Spacecraft experiments—Hydrogen. Astrobiology 10, 183–200. PMID:20298147

Finding high-order analytic post-Newtonian parameters from a high-precision numerical self-force calculation

NASA Astrophysics Data System (ADS)

Shah, Abhay G.; Friedman, John L.; Whiting, Bernard F.

2014-03-01

We present a novel analytic extraction of high-order post-Newtonian (pN) parameters that govern quasicircular binary systems. Coefficients in the pN expansion of the energy of a binary system can be found from corresponding coefficients in an extreme-mass-ratio inspiral computation of the change ΔU in the redshift factor of a circular orbit at fixed angular velocity. Remarkably, by computing this essentially gauge-invariant quantity to accuracy greater than one part in 10225, and by assuming that a subset of pN coefficients are rational numbers or products of π and a rational, we obtain the exact analytic coefficients. We find the previously unexpected result that the post-Newtonian expansion of ΔU (and of the change ΔΩ in the angular velocity at fixed redshift factor) have conservative terms at half-integral pN order beginning with a 5.5 pN term. This implies the existence of a corresponding 5.5 pN term in the expansion of the energy of a binary system. Coefficients in the pN series that do not belong to the subset just described are obtained to accuracy better than 1 part in 10265-23n at nth pN order. We work in a radiation gauge, finding the radiative part of the metric perturbation from the gauge-invariant Weyl scalar ψ0 via a Hertz potential. We use mode-sum renormalization, and find high-order renormalization coefficients by matching a series in L=ℓ+1/2 to the large-L behavior of the expression for ΔU. The nonradiative parts of the perturbed metric associated with changes in mass and angular momentum are calculated in the Schwarzschild gauge.

A Big Data Analytics Methodology Program in the Health Sector

ERIC Educational Resources Information Center

Lawler, James; Joseph, Anthony; Howell-Barber, H.

2016-01-01

The benefits of Big Data Analytics are cited frequently in the literature. However, the difficulties of implementing Big Data Analytics can limit the number of organizational projects. In this study, the authors evaluate business, procedural and technical factors in the implementation of Big Data Analytics, applying a methodology program. Focusing…

ANALYTICAL METHODS AND QUALITY ASSURANCE CRITERIA FOR LC/ES/MS DETERMINATION OF PFOS IN FISH

EPA Science Inventory

PFOS, perfluorooctanesulfonate, has recently received much attention from environmental researchers. Previous analytical methods were based upon complexing with a strong ion-pairing reagent and extraction into MTBE. Detection was done on a concentrate using negative ion LC/ES/MS/...

Analytical and Numerical Results for an Adhesively Bonded Joint Subjected to Pure Bending

NASA Technical Reports Server (NTRS)

Smeltzer, Stanley S., III; Lundgren, Eric

2006-01-01

A one-dimensional, semi-analytical methodology that was previously developed for evaluating adhesively bonded joints composed of anisotropic adherends and adhesives that exhibit inelastic material behavior is further verified in the present paper. A summary of the first-order differential equations and applied joint loading used to determine the adhesive response from the methodology are also presented. The method was previously verified against a variety of single-lap joint configurations from the literature that subjected the joints to cases of axial tension and pure bending. Using the same joint configuration and applied bending load presented in a study by Yang, the finite element analysis software ABAQUS was used to further verify the semi-analytical method. Linear static ABAQUS results are presented for two models, one with a coarse and one with a fine element meshing, that were used to verify convergence of the finite element analyses. Close agreement between the finite element results and the semi-analytical methodology were determined for both the shear and normal stress responses of the adhesive bondline. Thus, the semi-analytical methodology was successfully verified using the ABAQUS finite element software and a single-lap joint configuration subjected to pure bending.

Holistic rubric vs. analytic rubric for measuring clinical performance levels in medical students.

PubMed

Yune, So Jung; Lee, Sang Yeoup; Im, Sun Ju; Kam, Bee Sung; Baek, Sun Yong

2018-06-05

Task-specific checklists, holistic rubrics, and analytic rubrics are often used for performance assessments. We examined what factors evaluators consider important in holistic scoring of clinical performance assessment, and compared the usefulness of applying holistic and analytic rubrics respectively, and analytic rubrics in addition to task-specific checklists based on traditional standards. We compared the usefulness of a holistic rubric versus an analytic rubric in effectively measuring the clinical skill performances of 126 third-year medical students who participated in a clinical performance assessment conducted by Pusan National University School of Medicine. We conducted a questionnaire survey of 37 evaluators who used all three evaluation methods-holistic rubric, analytic rubric, and task-specific checklist-for each student. The relationship between the scores on the three evaluation methods was analyzed using Pearson's correlation. Inter-rater agreement was analyzed by Kappa index. The effect of holistic and analytic rubric scores on the task-specific checklist score was analyzed using multiple regression analysis. Evaluators perceived accuracy and proficiency to be major factors in objective structured clinical examinations evaluation, and history taking and physical examination to be major factors in clinical performance examinations evaluation. Holistic rubric scores were highly related to the scores of the task-specific checklist and analytic rubric. Relatively low agreement was found in clinical performance examinations compared to objective structured clinical examinations. Meanwhile, the holistic and analytic rubric scores explained 59.1% of the task-specific checklist score in objective structured clinical examinations and 51.6% in clinical performance examinations. The results show the usefulness of holistic and analytic rubrics in clinical performance assessment, which can be used in conjunction with task-specific checklists for more efficient evaluation.

FACTOR ANALYTIC MODELS OF CLUSTERED MULTIVARIATE DATA WITH INFORMATIVE CENSORING

EPA Science Inventory

This paper describes a general class of factor analytic models for the analysis of clustered multivariate data in the presence of informative missingness. We assume that there are distinct sets of cluster-level latent variables related to the primary outcomes and to the censorin...

Analytic thinking promotes religious disbelief.

PubMed

Gervais, Will M; Norenzayan, Ara

2012-04-27

Scientific interest in the cognitive underpinnings of religious belief has grown in recent years. However, to date, little experimental research has focused on the cognitive processes that may promote religious disbelief. The present studies apply a dual-process model of cognitive processing to this problem, testing the hypothesis that analytic processing promotes religious disbelief. Individual differences in the tendency to analytically override initially flawed intuitions in reasoning were associated with increased religious disbelief. Four additional experiments provided evidence of causation, as subtle manipulations known to trigger analytic processing also encouraged religious disbelief. Combined, these studies indicate that analytic processing is one factor (presumably among several) that promotes religious disbelief. Although these findings do not speak directly to conversations about the inherent rationality, value, or truth of religious beliefs, they illuminate one cognitive factor that may influence such discussions.

Universal analytical scattering form factor for shell-, core-shell, or homogeneous particles with continuously variable density profile shape.

PubMed

Foster, Tobias

2011-09-01

A novel analytical and continuous density distribution function with a widely variable shape is reported and used to derive an analytical scattering form factor that allows us to universally describe the scattering from particles with the radial density profile of homogeneous spheres, shells, or core-shell particles. Composed by the sum of two Fermi-Dirac distribution functions, the shape of the density profile can be altered continuously from step-like via Gaussian-like or parabolic to asymptotically hyperbolic by varying a single "shape parameter", d. Using this density profile, the scattering form factor can be calculated numerically. An analytical form factor can be derived using an approximate expression for the original Fermi-Dirac distribution function. This approximation is accurate for sufficiently small rescaled shape parameters, d/R (R being the particle radius), up to values of d/R ≈ 0.1, and thus captures step-like, Gaussian-like, and parabolic as well as asymptotically hyperbolic profile shapes. It is expected that this form factor is particularly useful in a model-dependent analysis of small-angle scattering data since the applied continuous and analytical function for the particle density profile can be compared directly with the density profile extracted from the data by model-free approaches like the generalized inverse Fourier transform method. © 2011 American Chemical Society

Aqueous Mesocosm Techniques Enabling the Real-Time Measurement of the Chemical and Isotopic Kinetics of Dissolved Methane and Carbon Dioxide.

PubMed

Chan, Eric W; Kessler, John D; Shiller, Alan M; Joung, DongJoo; Colombo, Frank

2016-03-15

Previous studies of microbially mediated methane oxidation in oceanic environments have examined the many different factors that control the rates of oxidation. However, there is debate on what factor(s) are limiting in these types of environments. These factors include the availability of methane, O2, trace metals, nutrients, the density of cell population, and the influence that CO2 production may have on pH. To look at this process in its entirety, we developed an automated mesocosm incubation system with a Dissolved Gas Analysis System (DGAS) coupled to a myriad of analytical tools to monitor chemical changes during methane oxidation. Here, we present new high temporal resolution techniques for investigating dissolved methane and carbon dioxide concentrations and stable isotopic dynamics during aqueous mesocosm and pure culture incubations. These techniques enable us to analyze the gases dissolved in solution and are nondestructive to both the liquid media and the analyzed gases enabling the investigation of a mesocosm or pure culture experiment in a completely closed system, if so desired.

Comprehensive quantification of signal-to-noise ratio and g-factor for image-based and k-space-based parallel imaging reconstructions.

PubMed

Robson, Philip M; Grant, Aaron K; Madhuranthakam, Ananth J; Lattanzi, Riccardo; Sodickson, Daniel K; McKenzie, Charles A

2008-10-01

Parallel imaging reconstructions result in spatially varying noise amplification characterized by the g-factor, precluding conventional measurements of noise from the final image. A simple Monte Carlo based method is proposed for all linear image reconstruction algorithms, which allows measurement of signal-to-noise ratio and g-factor and is demonstrated for SENSE and GRAPPA reconstructions for accelerated acquisitions that have not previously been amenable to such assessment. Only a simple "prescan" measurement of noise amplitude and correlation in the phased-array receiver, and a single accelerated image acquisition are required, allowing robust assessment of signal-to-noise ratio and g-factor. The "pseudo multiple replica" method has been rigorously validated in phantoms and in vivo, showing excellent agreement with true multiple replica and analytical methods. This method is universally applicable to the parallel imaging reconstruction techniques used in clinical applications and will allow pixel-by-pixel image noise measurements for all parallel imaging strategies, allowing quantitative comparison between arbitrary k-space trajectories, image reconstruction, or noise conditioning techniques. (c) 2008 Wiley-Liss, Inc.

New analytical solutions to the two-phase water faucet problem

DOE PAGES

Zou, Ling; Zhao, Haihua; Zhang, Hongbin

2016-06-17

Here, the one-dimensional water faucet problem is one of the classical benchmark problems originally proposed by Ransom to study the two-fluid two-phase flow model. With certain simplifications, such as massless gas phase and no wall and interfacial frictions, analytical solutions had been previously obtained for the transient liquid velocity and void fraction distribution. The water faucet problem and its analytical solutions have been widely used for the purposes of code assessment, benchmark and numerical verifications. In our previous study, the Ransom’s solutions were used for the mesh convergence study of a high-resolution spatial discretization scheme. It was found that, atmore » the steady state, an anticipated second-order spatial accuracy could not be achieved, when compared to the existing Ransom’s analytical solutions. A further investigation showed that the existing analytical solutions do not actually satisfy the commonly used two-fluid single-pressure two-phase flow equations. In this work, we present a new set of analytical solutions of the water faucet problem at the steady state, considering the gas phase density’s effect on pressure distribution. This new set of analytical solutions are used for mesh convergence studies, from which anticipated second-order of accuracy is achieved for the 2nd order spatial discretization scheme. In addition, extended Ransom’s transient solutions for the gas phase velocity and pressure are derived, with the assumption of decoupled liquid and gas pressures. Numerical verifications on the extended Ransom’s solutions are also presented.« less

Understanding patient participation behaviour in studies of COPD support programmes such as pulmonary rehabilitation and self-management: a qualitative synthesis with application of theory.

PubMed

Sohanpal, Ratna; Steed, Liz; Mars, Thomas; Taylor, Stephanie J C

2015-09-17

In chronic obstructive pulmonary disease (COPD), the problem of poor patient participation in studies of self-management (SM) and pulmonary rehabilitation (PR) programmes (together referred to as COPD support programmes) is established. Understanding this problem beyond the previously reported socio-demographics and clinical factors is critical. The aim of this study was to explore factors that explain patient participation in studies of COPD support programmes. Thematic 'framework' synthesis was conducted on literature published from 1984 to 1 February 2015. Emergent themes and subthemes were mapped onto the adapted 'attitude-social influence-external barriers' and the 'self-regulation' models to produce analytical themes. Ten out of 12 studies were included: PR (n=9) and SM (n=1). Three descriptive themes with 38 subthemes were mapped onto the models' constructs, and it generated four analytical themes: 'attitude', 'social influences' and 'illness' and 'intervention representations'. The following factors influenced (1) attendance-helping oneself through health improvements, perceived control of worsening condition, perceived benefits and positive past experience of the programme, as well as perceived positive influence of professionals; (2) non-attendance-perceived negative effects and negative past experience of the programme, perceived physical/practical concerns related to attendance, perceived severity of condition/symptoms and perceived negative influence of professionals/friends; (3) dropout-no health improvements perceived after attending a few sessions of the programme, perceived severity of the condition and perceived physical/practical concerns related to attendance. Psychosocial factors including perceived practical/physical concerns related to attendance influenced patients' participation in COPD support programmes. Addressing the negative beliefs/perceptions via behaviour change interventions may help improve participation in COPD support programmes and, ultimately, patient outcomes.

Prediction of Success in External Cephalic Version under Tocolysis: Still a Challenge.

PubMed

Vaz de Macedo, Carolina; Clode, Nuno; Mendes da Graça, Luís

2015-01-01

External cephalic version is a procedure of fetal rotation to a cephalic presentation through manoeuvres applied to the maternal abdomen. There are several prognostic factors described in literature for external cephalic version success and prediction scores have been proposed, but their true implication in clinical practice is controversial. We aim to identify possible factors that could contribute to the success of an external cephalic version attempt in our population. We retrospectively examined 207 consecutive external cephalic version attempts under tocolysis conducted between January 1997 and July 2012. We consulted the department's database for the following variables: race, age, parity, maternal body mass index, gestational age, estimated fetal weight, breech category, placental location and amniotic fluid index. We performed descriptive and analytical statistics for each variable and binary logistic regression. External cephalic version was successful in 46.9% of cases (97/207). None of the included variables was associated with the outcome of external cephalic version attempts after adjustment for confounding factors. We present a success rate similar to what has been previously described in literature. However, in contrast to previous authors, we could not associate any of the analysed variables with success of the external cephalic version attempt. We believe this discrepancy is partly related to the type of statistical analysis performed. Even though there are numerous prognostic factors identified for the success in external cephalic version, care must be taken when counselling and selecting patients for this procedure. The data obtained suggests that external cephalic version should continue being offered to all eligible patients regardless of prognostic factors for success.

Selective binding and oligomerization of the murine granulocyte colony-stimulating factor receptor by a low molecular weight, nonpeptidyl ligand.

PubMed

Doyle, Michael L; Tian, Shin-Shay; Miller, Stephen G; Kessler, Linda; Baker, Audrey E; Brigham-Burke, Michael R; Dillon, Susan B; Duffy, Kevin J; Keenan, Richard M; Lehr, Ruth; Rosen, Jon; Schneeweis, Lumelle A; Trill, John; Young, Peter R; Luengo, Juan I; Lamb, Peter

2003-03-14

Granulocyte colony-stimulating factor regulates neutrophil production by binding to a specific receptor, the granulocyte colony-stimulating factor receptor, expressed on cells of the granulocytic lineage. Recombinant forms of granulocyte colony-stimulating factor are used clinically to treat neutropenias. As part of an effort to develop granulocyte colony-stimulating factor mimics with the potential for oral bioavailability, we previously identified a nonpeptidyl small molecule (SB-247464) that selectively activates murine granulocyte colony-stimulating factor signal transduction pathways and promotes neutrophil formation in vivo. To elucidate the mechanism of action of SB-247464, a series of cell-based and biochemical assays were performed. The activity of SB-247464 is strictly dependent on the presence of zinc ions. Titration microcalorimetry experiments using a soluble murine granulocyte colony-stimulating factor receptor construct show that SB-247464 binds to the extracellular domain of the receptor in a zinc ion-dependent manner. Analytical ultracentrifugation studies demonstrate that SB-247464 induces self-association of the N-terminal three-domain fragment in a manner that is consistent with dimerization. SB-247464 induces internalization of granulocyte colony-stimulating factor receptor on intact cells, consistent with a mechanism involving receptor oligomerization. These data show that small nonpeptidyl compounds are capable of selectively binding and inducing productive oligomerization of cytokine receptors.

How Dispositional Learning Analytics Helps Understanding the Worked-Example Principle

ERIC Educational Resources Information Center

Tempelaar, Dirk

2017-01-01

This empirical study aims to demonstrate how Dispositional Learning Analytics can contribute in the investigation of the effectiveness of didactical scenarios in authentic settings, where previous research has mostly been laboratory based. Using a showcase based on learning processes of 1080 students in a blended introductory quantitative course,…

Quantitative Analysis of Nail Polish Remover Using Nuclear Magnetic Resonance Spectroscopy Revisited

ERIC Educational Resources Information Center

Hoffmann, Markus M.; Caccamis, Joshua T.; Heitz, Mark P.; Schlecht, Kenneth D.

2008-01-01

Substantial modifications are presented for a previously described experiment using nuclear magnetic resonance (NMR) spectroscopy to quantitatively determine analytes in commercial nail polish remover. The revised experiment is intended for a second- or third-year laboratory course in analytical chemistry and can be conducted for larger laboratory…

Hemispheric Activation Differences in Novice and Expert Clinicians during Clinical Decision Making

ERIC Educational Resources Information Center

Hruska, Pam; Hecker, Kent G.; Coderre, Sylvain; McLaughlin, Kevin; Cortese, Filomeno; Doig, Christopher; Beran, Tanya; Wright, Bruce; Krigolson, Olav

2016-01-01

Clinical decision making requires knowledge, experience and analytical/non-analytical types of decision processes. As clinicians progress from novice to expert, research indicates decision-making becomes less reliant on foundational biomedical knowledge and more on previous experience. In this study, we investigated how knowledge and experience…

Instrumentation: Photodiode Array Detectors in UV-VIS Spectroscopy. Part II.

ERIC Educational Resources Information Center

Jones, Dianna G.

1985-01-01

A previous part (Analytical Chemistry; v57 n9 p1057A) discussed the theoretical aspects of diode ultraviolet-visual (UV-VIS) spectroscopy. This part describes the applications of diode arrays in analytical chemistry, also considering spectroelectrochemistry, high performance liquid chromatography (HPLC), HPLC data processing, stopped flow, and…

Functional Analytic Psychotherapy with Juveniles Who Have Committed Sexual Offenses

ERIC Educational Resources Information Center

Newring, Kirk A. B.; Wheeler, Jennifer G.

2012-01-01

We have previously discussed the application of Functional Analytic Psychotherapy (FAP) with adults who have committed sexual offense behaviors (Newring & Wheeler, 2010). The present entry borrows heavily from the foundation presented in that chapter, and extends this approach to working with adolescents, youth, and juveniles with sexual offense…

Correlation of ground tests and analyses of a dynamically scaled Space Station model configuration

NASA Technical Reports Server (NTRS)

Javeed, Mehzad; Edighoffer, Harold H.; Mcgowan, Paul E.

1993-01-01

Verification of analytical models through correlation with ground test results of a complex space truss structure is demonstrated. A multi-component, dynamically scaled space station model configuration is the focus structure for this work. Previously established test/analysis correlation procedures are used to develop improved component analytical models. Integrated system analytical models, consisting of updated component analytical models, are compared with modal test results to establish the accuracy of system-level dynamic predictions. Design sensitivity model updating methods are shown to be effective for providing improved component analytical models. Also, the effects of component model accuracy and interface modeling fidelity on the accuracy of integrated model predictions is examined.

Psychometric Structure of a Comprehensive Objective Structured Clinical Examination: A Factor Analytic Approach

ERIC Educational Resources Information Center

Volkan, Kevin; Simon, Steven R.; Baker, Harley; Todres, I. David

2004-01-01

Problem Statement and Background: While the psychometric properties of Objective Structured Clinical Examinations (OSCEs) have been studied, their latent structures have not been well characterized. This study examines a factor analytic model of a comprehensive OSCE and addresses implications for measurement of clinical performance. Methods: An…

Big Data Analytics Methodology in the Financial Industry

ERIC Educational Resources Information Center

Lawler, James; Joseph, Anthony

2017-01-01

Firms in industry continue to be attracted by the benefits of Big Data Analytics. The benefits of Big Data Analytics projects may not be as evident as frequently indicated in the literature. The authors of the study evaluate factors in a customized methodology that may increase the benefits of Big Data Analytics projects. Evaluating firms in the…

A guide for measurement of circulating metabolic hormones in rodents: Pitfalls during the pre-analytical phase

PubMed Central

Bielohuby, Maximilian; Popp, Sarah; Bidlingmaier, Martin

2012-01-01

Researchers analyse hormones to draw conclusions from changes in hormone concentrations observed under specific physiological conditions and to elucidate mechanisms underlying their biological variability. It is, however, frequently overlooked that also circumstances occurring after collection of biological samples can significantly affect the hormone concentrations measured, owing to analytical and pre-analytical variability. Whereas the awareness for such potential confounders is increasing in human laboratory medicine, there is sometimes limited consensus about the control of these factors in rodent studies. In this guide, we demonstrate how such factors can affect reliability and consequent interpretation of the data from immunoassay measurements of circulating metabolic hormones in rodent studies. We also compare the knowledge about such factors in rodent studies to recent recommendations established for biomarker studies in humans and give specific practical recommendations for the control of pre-analytical conditions in metabolic studies in rodents. PMID:24024118

Moderating factors of video-modeling with other as model: a meta-analysis of single-case studies.

PubMed

Mason, Rose A; Ganz, Jennifer B; Parker, Richard I; Burke, Mack D; Camargo, Siglia P

2012-01-01

Video modeling with other as model (VMO) is a more practical method for implementing video-based modeling techniques, such as video self-modeling, which requires significantly more editing. Despite this, identification of contextual factors such as participant characteristics and targeted outcomes that moderate the effectiveness of VMO has not previously been explored. The purpose of this study was to meta-analytically evaluate the evidence base of VMO with individuals with disabilities to determine if participant characteristics and targeted outcomes moderate the effectiveness of the intervention. Findings indicate that VMO is highly effective for participants with autism spectrum disorder (IRD=.83) and moderately effective for participants with developmental disabilities (IRD=.68). However, differential effects are indicated across levels of moderators for diagnoses and targeted outcomes. Implications for practice and future research are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

Lashuel, Hilal A.; Aljabari, Bayan; Sigurdsson, Einar M.

We demonstrate herein that human macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine expressed in the brain and not previously considered to be amyloidogenic, forms amyloid fibrils similar to those derived from the disease associated amyloidogenic proteins {beta}-amyloid and {alpha}-synuclein. Acid denaturing conditions were found to readily induce MIF to undergo amyloid fibril formation. MIF aggregates to form amyloid-like structures with a morphology that is highly dependent on pH. The mechanism of MIF amyloid formation was probed by electron microscopy, turbidity, Thioflavin T binding, circular dichroism spectroscopy, and analytical ultracentrifugation. The fibrillar structures formed by MIF bind Congo red andmore » exhibit the characteristic green birefringence under polarized light. These results are consistent with the notion that amyloid fibril formation is not an exclusive property of a select group of amyloidogenic proteins, and contribute to a better understanding of the factors which govern protein conformational changes and amyloid fibril formation in vivo.« less

Energy thresholds of discrete breathers in thermal equilibrium and relaxation processes.

PubMed

Ming, Yi; Ling, Dong-Bo; Li, Hui-Min; Ding, Ze-Jun

2017-06-01

So far, only the energy thresholds of single discrete breathers in nonlinear Hamiltonian systems have been analytically obtained. In this work, the energy thresholds of discrete breathers in thermal equilibrium and the energy thresholds of long-lived discrete breathers which can remain after a long time relaxation are analytically estimated for nonlinear chains. These energy thresholds are size dependent. The energy thresholds of discrete breathers in thermal equilibrium are the same as the previous analytical results for single discrete breathers. The energy thresholds of long-lived discrete breathers in relaxation processes are different from the previous results for single discrete breathers but agree well with the published numerical results known to us. Because real systems are either in thermal equilibrium or in relaxation processes, the obtained results could be important for experimental detection of discrete breathers.

Implementation of serial amplifying fluorescent polymer arrays for enhanced chemical vapor sensing of landmines

NASA Astrophysics Data System (ADS)

Fisher, Mark E.; la Grone, Marcus; Sikes, John

2003-09-01

A sensor (known as Fido) that utilizes amplification of fluorescence quenching as the transduction mechanism for ultra-trace detection of nitroaromatic compounds associated with landmines has been described previously. Previous sensor prototypes utilized a single band of amplifying polymer deployed inside a capillary waveguide to form the sensing element of the detector. A new prototype has been developed that incorporates multiple, discrete bands of different amplifying polymers deployed in a linear array inside the capillary. Vapor-phase samples are introduced into the sensor as a sharp pulse via a gated inlet. As the vapor pulse is swept through the capillary by flow of a carrier gas, the pulse of analyte encounters the bands of polymer sequentially. If the sample contains nitroaromatic explosives, the bands of polymer will respond with a reduction in emission intensity proportional to the mass of analyte in the sample. Because the polymer bands are deployed serially, the analyte pulse does not reach the bands of polymer simultaneously. Hence, a temporal response pattern will be observed as the analyte pulse traverses the length of the capillary. In addition, the intensity of response for each band will vary, producing a ratiometric response. The temporal and ratiometric responses are characteristic of a given analyte, enhancing discrimination of target analytes from potential interferents. This should translate into a reduction in sensor false alarm rates.

Body fluid matrix evaluation on a Roche cobas 8000 system.

PubMed

Owen, William E; Thatcher, Mindy L; Crabtree, Karolyn J; Greer, Ryan W; Strathmann, Frederick G; Straseski, Joely A; Genzen, Jonathan R

2015-09-01

Chemical analysis of body fluids is commonly requested by physicians. Because most commercial FDA-cleared clinical laboratory assays are not validated by diagnostic manufacturers for "non-serum" and "non-plasma" specimens, laboratories may need to complete additional validation studies to comply with regulatory requirements regarding body fluid testing. The objective of this report is to perform recovery studies to evaluate potential body fluid matrix interferences for commonly requested chemistry analytes. Using an IRB-approved protocol, previously collected clinical body fluid specimens (biliary/hepatic, cerebrospinal, dialysate, drain, pancreatic, pericardial, peritoneal, pleural, synovial, and vitreous) were de-identified and frozen (-20°C) until experiments were performed. Recovery studies (spiking with high concentration serum, control, and/or calibrator) were conducted using 10% spiking solution by volume; n=5 specimens per analyte/body fluid investigated. Specimens were tested on a Roche cobas 8000 system (c502, c702, e602, and ISE modules). In all 80 analyte/body fluid combinations investigated (including amylase, total bilirubin, urea nitrogen, carbohydrate antigen 19-9, carcinoembryonic antigen, cholesterol, chloride, creatinine, glucose, potassium, lactate dehydrogenase, lipase, rheumatoid factor, sodium, total protein, triglycerides, and uric acid), the average percent recovery was within predefined acceptable limits (less than ±10% from the calculated ideal recovery). The present study provides evidence against the presence of any systematic matrix interference in the analyte/body fluid combinations investigated on the Roche cobas 8000 system. Such findings support the utility of ongoing body fluid validation initiatives conducted to maintain compliance with regulatory requirements. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Theoretical reflections on governance in health regions.

PubMed

Bretas, Nilo; Shimizu, Helena Eri

2017-04-01

This article analyzes governance in health regions, through the contributions of two studies: one on a governance model and the other on duties in the management of public policies networks. The former conducted a meta-analysis of 137 case studies in the literature on collaborative governance aimed at preparing an explanatory and analytical model. Authors identified critical variables that will influence the results: a previous history of conflict or cooperation, incentives for participation, power imbalances, leadership and institutional design. They also identified key factors: face-to-face dialogue, trust building and development of commitment and shared vision. The latter study examined networks of public policies in the analytic tradition and the perspective of governance, incorporating concepts from the field of political science, economics and interorganizational relations, in order to support the management of public policies networks. The study identified network management as equivalent to a strategic game involving functions: network activation, framework of relations, intermediation, facilitation and consensus building and mediation and arbitration. The combination of the two reflections provides a conceptual reference for better understanding of governance in health regions.

Diffuse interstellar clouds as a chemical laboratory - The chemistry of diatomic carbon species

NASA Technical Reports Server (NTRS)

Federman, S. R.; Huntress, W. T., Jr.

1989-01-01

The chemistry of C2, CH, and CO in diffuse interstellar clouds is analyzed and compared to absorption line measurements toward background stars. Analytical expressions in terms of column densities are derived for the rate equations. The results indicate that in clouds with 4 mag of visual extinction, the abundance of C+ has to decrease by a factor of about 15 from the value traditionally used for clouds with 1 mag of extinction. The rate coefficients for the reactions C+ + CH - C2+ + H and C+ + H2 - CH2+ + h-nu need to be reduced from previous estimates. Chemical arguments are presented for the revised rate coefficients.

Assessing the Sustainable Development of Coastal Reclamation: A Case of Makassar Using GIS Application

NASA Astrophysics Data System (ADS)

Yurnita, A.; Trisutomo, S.; Ali, M.

2017-07-01

Reclamation has been made in many areas in Indonesia including Makassar, as a response to the present needs of land as the impact of human activity in urban area. This research aims to assess the sustainable development of coastal reclamation and focus on environmental dimension of sustainable urban development. Assessment will be done by reclamation sustainability index (RSI) and analysis by GIS as the tools. RSI was built from previous research that has simplified from many researches and analysis by Structure of Analytic Hierarchy Process (AHP) and expert choice. RSI uses 9 indices from three indicators of environment factor which are coastal resources, building and infrastructure.

A Structural and Correlational Analysis of Two Common Measures of Personal Epistemology

ERIC Educational Resources Information Center

Laster, Bonnie Bost

2010-01-01

Scope and Method of Study: The current inquiry is a factor analytic study which utilizes first and second order factor analytic methods to examine the internal structures of two measurements of personal epistemological beliefs: the Schommer Epistemological Questionnaire (SEQ) and Epistemic Belief Inventory (EBI). The study also examines the…

A Bayesian Multi-Level Factor Analytic Model of Consumer Price Sensitivities across Categories

ERIC Educational Resources Information Center

Duvvuri, Sri Devi; Gruca, Thomas S.

2010-01-01

Identifying price sensitive consumers is an important problem in marketing. We develop a Bayesian multi-level factor analytic model of the covariation among household-level price sensitivities across product categories that are substitutes. Based on a multivariate probit model of category incidence, this framework also allows the researcher to…

Recently published analytical methods for determining alcohol in body materials : alcohol countermeasures literature review

DOT National Transportation Integrated Search

1974-10-01

The author has brought the review of published analytical methods for determining alcohol in body materials up-to- date. The review deals with analytical methods for alcohol in blood and other body fluids and tissues; breath alcohol methods; factors ...

An Analysis of Machine- and Human-Analytics in Classification.

PubMed

Tam, Gary K L; Kothari, Vivek; Chen, Min

2017-01-01

In this work, we present a study that traces the technical and cognitive processes in two visual analytics applications to a common theoretic model of soft knowledge that may be added into a visual analytics process for constructing a decision-tree model. Both case studies involved the development of classification models based on the "bag of features" approach. Both compared a visual analytics approach using parallel coordinates with a machine-learning approach using information theory. Both found that the visual analytics approach had some advantages over the machine learning approach, especially when sparse datasets were used as the ground truth. We examine various possible factors that may have contributed to such advantages, and collect empirical evidence for supporting the observation and reasoning of these factors. We propose an information-theoretic model as a common theoretic basis to explain the phenomena exhibited in these two case studies. Together we provide interconnected empirical and theoretical evidence to support the usefulness of visual analytics.

Social Cognitive Predictors of College Students' Academic Performance and Persistence: A Meta-Analytic Path Analysis

ERIC Educational Resources Information Center

Brown, Steven D.; Tramayne, Selena; Hoxha, Denada; Telander, Kyle; Fan, Xiaoyan; Lent, Robert W.

2008-01-01

This study tested Social Cognitive Career Theory's (SCCT) academic performance model using a two-stage approach that combined meta-analytic and structural equation modeling methodologies. Unbiased correlations obtained from a previously published meta-analysis [Robbins, S. B., Lauver, K., Le, H., Davis, D., & Langley, R. (2004). Do psychosocial…

Do Premarital Education Programs Really Work? A Meta-Analytic Study

ERIC Educational Resources Information Center

Fawcett, Elizabeth B.; Hawkins, Alan J.; Blanchard, Victoria L.; Carroll, Jason S.

2010-01-01

Previous studies (J. S. Carroll & W. J. Doherty, 2003) have asserted that premarital education programs have a positive effect on program participants. Using meta-analytic methods of current best practices to look across the entire body of published and unpublished evaluation research on premarital education, we found a more complex pattern of…

Analytic Solutions of the Vector Burgers Equation

NASA Technical Reports Server (NTRS)

Nerney, Steven; Schmahl, Edward J.; Musielak, Z. E.

1996-01-01

The well-known analytical solution of Burgers' equation is extended to curvilinear coordinate systems in three dimensions by a method that is much simpler and more suitable to practical applications than that previously used. The results obtained are applied to incompressible flow with cylindrical symmetry, and also to the decay of an initially linearly increasing wind.

Unraveling Students' Interaction around a Tangible Interface Using Multimodal Learning Analytics

ERIC Educational Resources Information Center

Schneider, Bertrand; Blikstein, Paulo

2015-01-01

In this paper, we describe multimodal learning analytics (MMLA) techniques to analyze data collected around an interactive learning environment. In a previous study (Schneider & Blikstein, submitted), we designed and evaluated a Tangible User Interface (TUI) where dyads of students were asked to learn about the human hearing system by…

Community standards for genomic resources, genetic conservation, and data integration

Treesearch

Jill Wegrzyn; Meg Staton; Emily Grau; Richard Cronn; C. Dana Nelson

2017-01-01

Genetics and genomics are increasingly important in forestry management and conservation. Next generation sequencing can increase analytical power, but still relies on building on the structure of previously acquired data. Data standards and data sharing allow the community to maximize the analytical power of high throughput genomics data. The landscape of incomplete...

Using Photocatalytic Oxidation and Analytic Techniques to Remediate Lab Wastewater Containing Methanol

ERIC Educational Resources Information Center

Xiong, Qing; Luo, Mingliang; Bao, Xiaoming; Deng, Yurong; Qin, Song; Pu, Xuemei

2018-01-01

This experiment is dedicated to second-year and above undergraduates who are in their experimental session of the analytical chemistry course. Grouped students are required to use a TiO[subscript 2] photocatalytic oxidation process to treat the methanol-containing wastewater that resulted from their previous HPLC experiments. Students learn to…

The Challenge of Developing a Universal Case Conceptualization for Functional Analytic Psychotherapy

ERIC Educational Resources Information Center

Bonow, Jordan T.; Maragakis, Alexandros; Follette, William C.

2012-01-01

Functional Analytic Psychotherapy (FAP) targets a client's interpersonal behavior for change with the goal of improving his or her quality of life. One question guiding FAP case conceptualization is, "What interpersonal behavioral repertoires will allow a specific client to function optimally?" Previous FAP writings have suggested that a therapist…

Comparison of adjoint and analytical Bayesian inversion methods for constraining Asian sources of carbon monoxide using satellite (MOPITT) measurements of CO columns

NASA Astrophysics Data System (ADS)

Kopacz, Monika; Jacob, Daniel J.; Henze, Daven K.; Heald, Colette L.; Streets, David G.; Zhang, Qiang

2009-02-01

We apply the adjoint of an atmospheric chemical transport model (GEOS-Chem CTM) to constrain Asian sources of carbon monoxide (CO) with 2° × 2.5° spatial resolution using Measurement of Pollution in the Troposphere (MOPITT) satellite observations of CO columns in February-April 2001. Results are compared to the more common analytical method for solving the same Bayesian inverse problem and applied to the same data set. The analytical method is more exact but because of computational limitations it can only constrain emissions over coarse regions. We find that the correction factors to the a priori CO emission inventory from the adjoint inversion are generally consistent with those of the analytical inversion when averaged over the large regions of the latter. The adjoint solution reveals fine-scale variability (cities, political boundaries) that the analytical inversion cannot resolve, for example, in the Indian subcontinent or between Korea and Japan, and some of that variability is of opposite sign which points to large aggregation errors in the analytical solution. Upward correction factors to Chinese emissions from the prior inventory are largest in central and eastern China, consistent with a recent bottom-up revision of that inventory, although the revised inventory also sees the need for upward corrections in southern China where the adjoint and analytical inversions call for downward correction. Correction factors for biomass burning emissions derived from the adjoint and analytical inversions are consistent with a recent bottom-up inventory on the basis of MODIS satellite fire data.

Analytical Study of 90Sr Betavoltaic Nuclear Battery Performance Based on p-n Junction Silicon

NASA Astrophysics Data System (ADS)

Rahastama, Swastya; Waris, Abdul

2016-08-01

Previously, an analytical calculation of 63Ni p-n junction betavoltaic battery has been published. As the basic approach, we reproduced the analytical simulation of 63Ni betavoltaic battery and then compared it to previous results using the same design of the battery. Furthermore, we calculated its maximum power output and radiation- electricity conversion efficiency using semiconductor analysis method.Then, the same method were applied to calculate and analyse the performance of 90Sr betavoltaic battery. The aim of this project is to compare the analytical perfomance results of 90Sr betavoltaic battery to 63Ni betavoltaic battery and the source activity influences to performance. Since it has a higher power density, 90Sr betavoltaic battery yields more power than 63Ni betavoltaic battery but less radiation-electricity conversion efficiency. However, beta particles emitted from 90Sr source could travel further inside the silicon corresponding to stopping range of beta particles, thus the 90Sr betavoltaic battery could be designed thicker than 63Ni betavoltaic battery to achieve higher conversion efficiency.

A multi-analyte serum test for the detection of non-small cell lung cancer

PubMed Central

Farlow, E C; Vercillo, M S; Coon, J S; Basu, S; Kim, A W; Faber, L P; Warren, W H; Bonomi, P; Liptay, M J; Borgia, J A

2010-01-01

Background: In this study, we appraised a wide assortment of biomarkers previously shown to have diagnostic or prognostic value for non-small cell lung cancer (NSCLC) with the intent of establishing a multi-analyte serum test capable of identifying patients with lung cancer. Methods: Circulating levels of 47 biomarkers were evaluated against patient cohorts consisting of 90 NSCLC and 43 non-cancer controls using commercial immunoassays. Multivariate statistical methods were used on all biomarkers achieving statistical relevance to define an optimised panel of diagnostic biomarkers for NSCLC. The resulting biomarkers were fashioned into a classification algorithm and validated against serum from a second patient cohort. Results: A total of 14 analytes achieved statistical relevance upon evaluation. Multivariate statistical methods then identified a panel of six biomarkers (tumour necrosis factor-α, CYFRA 21-1, interleukin-1ra, matrix metalloproteinase-2, monocyte chemotactic protein-1 and sE-selectin) as being the most efficacious for diagnosing early stage NSCLC. When tested against a second patient cohort, the panel successfully classified 75 of 88 patients. Conclusions: Here, we report the development of a serum algorithm with high specificity for classifying patients with NSCLC against cohorts of various ‘high-risk' individuals. A high rate of false positives was observed within the cohort in which patients had non-neoplastic lung nodules, possibly as a consequence of the inflammatory nature of these conditions. PMID:20859284

Complete characterization of fourth-order symplectic integrators with extended-linear coefficients.

PubMed

Chin, Siu A

2006-02-01

The structure of symplectic integrators up to fourth order can be completely and analytically understood when the factorization (split) coefficients are related linearly but with a uniform nonlinear proportional factor. The analytic form of these extended-linear symplectic integrators greatly simplified proofs of their general properties and allowed easy construction of both forward and nonforward fourth-order algorithms with an arbitrary number of operators. Most fourth-order forward integrators can now be derived analytically from this extended-linear formulation without the use of symbolic algebra.

Structure of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Criteria for Obsessive–Compulsive Personality Disorder in Patients With Binge Eating Disorder

PubMed Central

Ansell, Emily B; Pinto, Anthony; Edelen, Maria Orlando; Grilo, Carlos M

2013-01-01

Objective To examine 1-, 2-, and 3-factor model structures through confirmatory analytic procedures for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) obsessive–compulsive personality disorder (OCPD) criteria in patients with binge eating disorder (BED). Method Participants were consecutive outpatients (n = 263) with binge eating disorder and were assessed with semi-structured interviews. The 8 OCPD criteria were submitted to confirmatory factor analyses in Mplus Version 4.2 (Los Angeles, CA) in which previously identified factor models of OCPD were compared for fit, theoretical relevance, and parsimony. Nested models were compared for significant improvements in model fit. Results Evaluation of indices of fit in combination with theoretical considerations suggest a multifactorial model is a significant improvement in fit over the current DSM-IV single-factor model of OCPD. Though the data support both 2- and 3-factor models, the 3-factor model is hindered by an underspecified third factor. Conclusion A multifactorial model of OCPD incorporating the factors perfectionism and rigidity represents the best compromise of fit and theory in modelling the structure of OCPD in patients with BED. A third factor representing miserliness may be relevant in BED populations but needs further development. The perfectionism and rigidity factors may represent distinct intrapersonal and interpersonal attempts at control and may have implications for the assessment of OCPD. PMID:19087485

Structure of diagnostic and statistical manual of mental disorders, fourth edition criteria for obsessive-compulsive personality disorder in patients with binge eating disorder.

PubMed

Ansell, Emily B; Pinto, Anthony; Edelen, Maria Orlando; Grilo, Carlos M

2008-12-01

To examine 1-, 2-, and 3-factor model structures through confirmatory analytic procedures for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) obsessive-compulsive personality disorder (OCPD) criteria in patients with binge eating disorder (BED). Participants were consecutive outpatients (n = 263) with binge eating disorder and were assessed with semi-structured interviews. The 8 OCPD criteria were submitted to confirmatory factor analyses in Mplus Version 4.2 (Los Angeles, CA) in which previously identified factor models of OCPD were compared for fit, theoretical relevance, and parsimony. Nested models were compared for significant improvements in model fit. Evaluation of indices of fit in combination with theoretical considerations suggest a multifactorial model is a significant improvement in fit over the current DSM-IV single- factor model of OCPD. Though the data support both 2- and 3-factor models, the 3-factor model is hindered by an underspecified third factor. A multifactorial model of OCPD incorporating the factors perfectionism and rigidity represents the best compromise of fit and theory in modelling the structure of OCPD in patients with BED. A third factor representing miserliness may be relevant in BED populations but needs further development. The perfectionism and rigidity factors may represent distinct intrapersonal and interpersonal attempts at control and may have implications for the assessment of OCPD.

Composite Repairs of Cracked Metallic Airframe Structures

DTIC Science & Technology

1993-05-01

painting of the surface of composites. Therefore, repairs on external surfaces of aircraft should be painted prior to service. 30 2. ANALITICAL AND...tends to decrease the ’apparent’ stress intensity factor. These factors have to be taken into account when comparing the analytical predictions with the...analytical predictions . The fatigue crack growth data for one of the specimens appears in Figure 2-46Zhe ’Inferred’ stress-intensity factor [from the

Quantitative and Qualitative Relations between Motivation and Critical-Analytic Thinking

ERIC Educational Resources Information Center

Miele, David B.; Wigfield, Allan

2014-01-01

The authors examine two kinds of factors that affect students' motivation to engage in critical-analytic thinking. The first, which includes ability beliefs, achievement values, and achievement goal orientations, influences the "quantitative" relation between motivation and critical-analytic thinking; that is, whether students are…

Cancel and rethink in the Wason selection task: further evidence for the heuristic-analytic dual process theory.

PubMed

Wada, Kazushige; Nittono, Hiroshi

2004-06-01

The reasoning process in the Wason selection task was examined by measuring card inspection times in the letter-number and drinking-age problems. 24 students were asked to solve the problems presented on a computer screen. Only the card touched with a mouse pointer was visible, and the total exposure time of each card was measured. Participants were allowed to cancel their previous selections at any time. Although rethinking was encouraged, the cards once selected were rarely cancelled (10% of the total selections). Moreover, most of the cancelled cards were reselected (89% of the total cancellations). Consistent with previous findings, inspection times were longer for selected cards than for nonselected cards. These results suggest that card selections are determined largely by initial heuristic processes and rarely reversed by subsequent analytic processes. The present study gives further support for the heuristic-analytic dual process theory.

NASTRAN analysis of the 1/8-scale space shuttle dynamic model

NASA Technical Reports Server (NTRS)

Bernstein, M.; Mason, P. W.; Zalesak, J.; Gregory, D. J.; Levy, A.

1973-01-01

The space shuttle configuration has more complex structural dynamic characteristics than previous launch vehicles primarily because of the high model density at low frequencies and the high degree of coupling between the lateral and longitudinal motions. An accurate analytical representation of these characteristics is a primary means for treating structural dynamics problems during the design phase of the shuttle program. The 1/8-scale model program was developed to explore the adequacy of available analytical modeling technology and to provide the means for investigating problems which are more readily treated experimentally. The basic objectives of the 1/8-scale model program are: (1) to provide early verification of analytical modeling procedures on a shuttle-like structure, (2) to demonstrate important vehicle dynamic characteristics of a typical shuttle design, (3) to disclose any previously unanticipated structural dynamic characteristics, and (4) to provide for development and demonstration of cost effective prototype testing procedures.

Event-by-Event Simulations of Early Gluon Fields in High Energy Nuclear Collisions

NASA Astrophysics Data System (ADS)

Nickel, Matthew; Rose, Steven; Fries, Rainer

2017-09-01

Collisions of heavy ions are carried out at ultra relativistic speeds at the Relativistic Heavy Ion Collider and the Large Hadron Collider to create Quark Gluon Plasma. The earliest stages of such collisions are dominated by the dynamics of classical gluon fields. The McLerran-Venugopalan (MV) model of color glass condensate provides a model for this process. Previous research has provided an analytic solution for event averaged observables in the MV model. Using the High Performance Research Computing Center (HPRC) at Texas A&M, we have developed a C++ code to explicitly calculate the initial gluon fields and energy momentum tensor event by event using the analytic recursive solution. The code has been tested against previously known analytic results up to fourth order. We have also have been able to test the convergence of the recursive solution at high orders in time and studied the time evolution of color glass condensate.

Analytic theory for the selection of 2-D needle crystal at arbitrary Peclet number

NASA Technical Reports Server (NTRS)

Tanveer, Saleh

1989-01-01

An accurate analytic theory is presented for the velocity selection of a two-dimensional needle crystal for arbitrary Peclet number for small values of the surface tension parameter. The velocity selection is caused by the effect of transcendentally small terms which are determined by analytic continuation to the complex plane and analysis of nonlinear equations. The work supports the general conclusion of previous small Peclet number analytical results of other investigators, though there are some discrepancies in details. It also addresses questions raised on the validity of selection theory owing to assumptions made on shape corrections at large distances from the tip.

Beyond Engagement Analytics: Which Online Mixed-Data Factors Predict Student Learning Outcomes?

ERIC Educational Resources Information Center

Strang, Kenneth David

2017-01-01

This mixed-method study focuses on online learning analytics, a research area of importance. Several important student attributes and their online activities are examined to identify what seems to work best to predict higher grades. The purpose is to explore the relationships between student grade and key learning engagement factors using a large…

Multiplexed bovine milk oligosaccharide analysis with aminoxy tandem mass tags

PubMed Central

Poulsen, Nina Aagaard; Barile, Daniela

2018-01-01

Milk oligosaccharides (OS) are a key factor that influences the infant gut microbial composition, and their importance in promoting healthy infant development and disease prevention is becoming increasingly apparent. Investigating the structures, properties, and sources of these compounds requires a host of complementary analytical techniques. Relative compound quantification by mass spectral analysis of isobarically labeled samples is a relatively new technique that has been used mainly in the proteomics field. Glycomics applications have so far focused on analysis of protein-linked glycans, while analysis of free milk OS has previously been conducted only on analytical standards. In this paper, we extend the use of isobaric glycan tags to the analysis of bovine milk OS by presenting a method for separation of labeled OS on a porous graphitized carbon liquid chromatographic column with subsequent analysis by quadrupole time-of-flight tandem mass spectrometry. Abundances for 15 OS extracted from mature bovine milk were measured, with replicate injections providing coefficients of variation below 15% for most OS. Isobaric labeling improved ionization efficiency for low-abundance, high-molecular weight fucosylated OS, which are known to exist in bovine milk but have been only sporadically reported in the literature. We compared the abundances of four fucosylated OS in milk from Holstein and Jersey cattle and found that three of the compounds were more abundant in Jersey milk, which is in general agreement with a previous study. This novel method represents an advancement in our ability to characterize milk OS and provides the advantages associated with isobaric labeling, including reduced instrumental analysis time and increased analyte ionization efficiency. This improved ability to measure differences in bioactive OS abundances in large datasets will facilitate exploration of OS from all food sources for the purpose of developing health-guiding products for infants, immune-compromised elderly, and the population at large. PMID:29698512

Mathematical models of solute retention in gas chromatography as sources of thermodynamic data. Part IV. Aliphatic alcohols as the test analytes.

PubMed

Ciazyńska-Halarewicz, Katarzyna; Helbin, Monika; Korzenecki, Paweł; Kowalska, Teresa

2007-09-01

This study is the fourth consecutive part belonging to the cycle devoted to an alternative approach to deriving certain thermodynamic magnitudes. The previous three papers were dedicated, respectively, to ketones, aldehydes, and alkylbenzenes. In our present study (similar to the previous ones) the following working procedure is adopted. With the aid of capillary gas chromatography, the retention times are obtained for a wide variety of the aliphatic alcohols. The analyses are carried out isothermally on stationary phases of different polarity and at five different measuring temperatures. These data constitute an experimental basis for further processing with the aid of the specially devised mathematical equations. The fitting parameters of these equations, due to their physicochemical meaning, enable determination of certain thermodynamic data. Nine equations used in this study are the relationships coupling the selected retention data [relative retention (r), non-reduced relative retention (rG), the retention factor (k), or the Kováts retention index (I)] and a variety of the physical magnitudes [the boiling point of the analyte (T(B)), its molar volume (Vm), or its molar refraction (Rm)]. These relationships are tested with respect to their performance to predict the molar enthalpy of vaporization (deltaHvap) of the analytes of interest (i.e., of aliphatic alcohols). Evaluation of the equations' performance is carried out through a comparison of the numerical values generated from this approach with those originating from the other methods, and a very good agreement was found between these two series of the data. The best molar enthalpy vaporization values (deltaHvap) are obtained from the retention data originating from the most polar of the three investigated stationary phases (i.e., DB-Wax). Models V and VIII proved the best performing ones among the nine models tested in this study.

Penetrating the Fog: Analytics in Learning and Education

ERIC Educational Resources Information Center

Siemens, George; Long, Phil

2011-01-01

Attempts to imagine the future of education often emphasize new technologies--ubiquitous computing devices, flexible classroom designs, and innovative visual displays. But the most dramatic factor shaping the future of higher education is something that people cannot actually touch or see: "big data and analytics." Learning analytics is still in…

Analytic model for academic research productivity having factors, interactions and implications

PubMed Central

2011-01-01

Financial support is dear in academia and will tighten further. How can the research mission be accomplished within new restraints? A model is presented for evaluating source components of academic research productivity. It comprises six factors: funding; investigator quality; efficiency of the research institution; the research mix of novelty, incremental advancement, and confirmatory studies; analytic accuracy; and passion. Their interactions produce output and patterned influences between factors. Strategies for optimizing output are enabled. PMID:22130145

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

Zou, Ling; Zhao, Haihua; Zhang, Hongbin

Here, the one-dimensional water faucet problem is one of the classical benchmark problems originally proposed by Ransom to study the two-fluid two-phase flow model. With certain simplifications, such as massless gas phase and no wall and interfacial frictions, analytical solutions had been previously obtained for the transient liquid velocity and void fraction distribution. The water faucet problem and its analytical solutions have been widely used for the purposes of code assessment, benchmark and numerical verifications. In our previous study, the Ransom’s solutions were used for the mesh convergence study of a high-resolution spatial discretization scheme. It was found that, atmore » the steady state, an anticipated second-order spatial accuracy could not be achieved, when compared to the existing Ransom’s analytical solutions. A further investigation showed that the existing analytical solutions do not actually satisfy the commonly used two-fluid single-pressure two-phase flow equations. In this work, we present a new set of analytical solutions of the water faucet problem at the steady state, considering the gas phase density’s effect on pressure distribution. This new set of analytical solutions are used for mesh convergence studies, from which anticipated second-order of accuracy is achieved for the 2nd order spatial discretization scheme. In addition, extended Ransom’s transient solutions for the gas phase velocity and pressure are derived, with the assumption of decoupled liquid and gas pressures. Numerical verifications on the extended Ransom’s solutions are also presented.« less

Human Resources for Treating HIV/AIDS: Are the Preventive Effects of Antiretroviral Treatment a Game Changer?

PubMed

Bärnighausen, Till; Bloom, David E; Humair, Salal

2016-01-01

Shortages of human resources for treating HIV/AIDS (HRHA) are a fundamental barrier to reaching universal antiretroviral treatment (ART) coverage in developing countries. Previous studies suggest that recruiting HRHA to attain universal ART coverage poses an insurmountable challenge as ART significantly increases survival among HIV-infected individuals. While new evidence about ART's prevention benefits suggests fewer infections may mitigate the challenge, new policies such as treatment-as-prevention (TasP) will exacerbate it. We develop a mathematical model to analytically study the net effects of these countervailing factors. Using South Africa as a case study, we find that contrary to previous results, universal ART coverage is achievable even with current HRHA numbers. However, larger health gains are possible through a surge-capacity policy that aggressively recruits HRHA to reach universal ART coverage quickly. Without such a policy, TasP roll-out can increase health losses by crowding out sicker patients from treatment, unless a surge capacity exclusively for TasP is also created.

Dendritic growth model of multilevel marketing

NASA Astrophysics Data System (ADS)

Pang, James Christopher S.; Monterola, Christopher P.

2017-02-01

Biologically inspired dendritic network growth is utilized to model the evolving connections of a multilevel marketing (MLM) enterprise. Starting from agents at random spatial locations, a network is formed by minimizing a distance cost function controlled by a parameter, termed the balancing factor bf, that weighs the wiring and the path length costs of connection. The paradigm is compared to an actual MLM membership data and is shown to be successful in statistically capturing the membership distribution, better than the previously reported agent based preferential attachment or analytic branching process models. Moreover, it recovers the known empirical statistics of previously studied MLM, specifically: (i) a membership distribution characterized by the existence of peak levels indicating limited growth, and (ii) an income distribution obeying the 80 - 20 Pareto principle. Extensive types of income distributions from uniform to Pareto to a "winner-take-all" kind are also modeled by varying bf. Finally, the robustness of our dendritic growth paradigm to random agent removals is explored and its implications to MLM income distributions are discussed.

Clinical and epidemiological aspects of cornea transplant patients of a reference hospital 1

PubMed Central

Cruz, Giovanna Karinny Pereira; de Azevedo, Isabelle Campos; Carvalho, Diana Paula de Souza Rego Pinto; Vitor, Allyne Fortes; Santos, Viviane Euzébia Pereira; Ferreira, Marcos Antonio

2017-01-01

ABSTRACT Objective: clinically characterizing cornea transplant patients and their distribution according to indicated and post-operative conditions of cornea transplantation, as well as estimating the average waiting time. Method: a cross-sectional, descriptive and analytical study performed for all cornea transplants performed at a reference service (n=258). Data were analyzed using Statistical Package for the Social Sciences, version 20.0. Results: the main indicator for cornea transplant was keratoconus. The mean waiting time for the transplant was approximately 5 months and 3 weeks for elective transplants and 9 days for urgent cases. An association between the type of corneal disorder with gender, age, previous surgery, eye classification, glaucoma and anterior graft failure were found. Conclusion: keratoconus was the main indicator for cornea transplant. Factors such as age, previous corneal graft failure (retransplantation), glaucoma, cases of surgeries prior to cornea transplant (especially cataract surgery) may be related to the onset corneal endothelium disorders. PMID:28614429

Human Resources for Treating HIV/AIDS: Are the Preventive Effects of Antiretroviral Treatment a Game Changer?

PubMed Central

2016-01-01

Shortages of human resources for treating HIV/AIDS (HRHA) are a fundamental barrier to reaching universal antiretroviral treatment (ART) coverage in developing countries. Previous studies suggest that recruiting HRHA to attain universal ART coverage poses an insurmountable challenge as ART significantly increases survival among HIV-infected individuals. While new evidence about ART’s prevention benefits suggests fewer infections may mitigate the challenge, new policies such as treatment-as-prevention (TasP) will exacerbate it. We develop a mathematical model to analytically study the net effects of these countervailing factors. Using South Africa as a case study, we find that contrary to previous results, universal ART coverage is achievable even with current HRHA numbers. However, larger health gains are possible through a surge-capacity policy that aggressively recruits HRHA to reach universal ART coverage quickly. Without such a policy, TasP roll-out can increase health losses by crowding out sicker patients from treatment, unless a surge capacity exclusively for TasP is also created. PMID:27716813

The Pneumonia Etiology Research for Child Health Project: A 21st Century Childhood Pneumonia Etiology Study

PubMed Central

O’Brien, Katherine L.; Deloria-Knoll, Maria; Murdoch, David R.; Feikin, Daniel R.; DeLuca, Andrea N.; Driscoll, Amanda J.; Baggett, Henry C.; Brooks, W. Abdullah; Howie, Stephen R. C.; Kotloff, Karen L.; Madhi, Shabir A.; Maloney, Susan A.; Sow, Samba; Thea, Donald M.; Scott, J. Anthony

2012-01-01

The Pneumonia Etiology Research for Child Health (PERCH) project is a 7-country, standardized, comprehensive evaluation of the etiologic agents causing severe pneumonia in children from developing countries. During previous etiology studies, between one-quarter and one-third of patients failed to yield an obvious etiology; PERCH will employ and evaluate previously unavailable innovative, more sensitive diagnostic techniques. Innovative and rigorous epidemiologic and analytic methods will be used to establish the causal association between presence of potential pathogens and pneumonia. By strategic selection of study sites that are broadly representative of regions with the greatest burden of childhood pneumonia, PERCH aims to provide data that reflect the epidemiologic situation in developing countries in 2015, using pneumococcal and Haemophilus influenzae type b vaccines. PERCH will also address differences in host, environmental, and/or geographic factors that might determine pneumonia etiology and, by preserving specimens, will generate a resource for future research and pathogen discovery. PMID:22403238

The Pneumonia Etiology Research for Child Health Project: a 21st century childhood pneumonia etiology study.

PubMed

Levine, Orin S; O'Brien, Katherine L; Deloria-Knoll, Maria; Murdoch, David R; Feikin, Daniel R; DeLuca, Andrea N; Driscoll, Amanda J; Baggett, Henry C; Brooks, W Abdullah; Howie, Stephen R C; Kotloff, Karen L; Madhi, Shabir A; Maloney, Susan A; Sow, Samba; Thea, Donald M; Scott, J Anthony

2012-04-01

The Pneumonia Etiology Research for Child Health (PERCH) project is a 7-country, standardized, comprehensive evaluation of the etiologic agents causing severe pneumonia in children from developing countries. During previous etiology studies, between one-quarter and one-third of patients failed to yield an obvious etiology; PERCH will employ and evaluate previously unavailable innovative, more sensitive diagnostic techniques. Innovative and rigorous epidemiologic and analytic methods will be used to establish the causal association between presence of potential pathogens and pneumonia. By strategic selection of study sites that are broadly representative of regions with the greatest burden of childhood pneumonia, PERCH aims to provide data that reflect the epidemiologic situation in developing countries in 2015, using pneumococcal and Haemophilus influenzae type b vaccines. PERCH will also address differences in host, environmental, and/or geographic factors that might determine pneumonia etiology and, by preserving specimens, will generate a resource for future research and pathogen discovery.

Analytical method development of nifedipine and its degradants binary mixture using high performance liquid chromatography through a quality by design approach

NASA Astrophysics Data System (ADS)

Choiri, S.; Ainurofiq, A.; Ratri, R.; Zulmi, M. U.

2018-03-01

Nifedipin (NIF) is a photo-labile drug that easily degrades when it exposures a sunlight. This research aimed to develop of an analytical method using a high-performance liquid chromatography and implemented a quality by design approach to obtain effective, efficient, and validated analytical methods of NIF and its degradants. A 22 full factorial design approach with a curvature as a center point was applied to optimize of the analytical condition of NIF and its degradants. Mobile phase composition (MPC) and flow rate (FR) as factors determined on the system suitability parameters. The selected condition was validated by cross-validation using a leave one out technique. Alteration of MPC affected on time retention significantly. Furthermore, an increase of FR reduced the tailing factor. In addition, the interaction of both factors affected on an increase of the theoretical plates and resolution of NIF and its degradants. The selected analytical condition of NIF and its degradants has been validated at range 1 – 16 µg/mL that had good linearity, precision, accuration and efficient due to an analysis time within 10 min.

The detection of problem analytes in a single proficiency test challenge in the absence of the Health Care Financing Administration rule violations.

PubMed

Cembrowski, G S; Hackney, J R; Carey, N

1993-04-01

The Clinical Laboratory Improvement Act of 1988 (CLIA 88) has dramatically changed proficiency testing (PT) practices having mandated (1) satisfactory PT for certain analytes as a condition of laboratory operation, (2) fixed PT limits for many of these "regulated" analytes, and (3) an increased number of PT specimens (n = 5) for each testing cycle. For many of these analytes, the fixed limits are much broader than the previously employed Standard Deviation Index (SDI) criteria. Paradoxically, there may be less incentive to identify and evaluate analytically significant outliers to improve the analytical process. Previously described "control rules" to evaluate these PT results are unworkable as they consider only two or three results. We used Monte Carlo simulations of Kodak Ektachem analyzers participating in PT to determine optimal control rules for the identification of PT results that are inconsistent with those from other laboratories using the same methods. The analysis of three representative analytes, potassium, creatine kinase, and iron was simulated with varying intrainstrument and interinstrument standard deviations (si and sg, respectively) obtained from the College of American Pathologists (Northfield, Ill) Quality Assurance Services data and Proficiency Test data, respectively. Analytical errors were simulated in each of the analytes and evaluated in terms of multiples of the interlaboratory SDI. Simple control rules for detecting systematic and random error were evaluated with power function graphs, graphs of probability of error detected vs magnitude of error. Based on the simulation results, we recommend screening all analytes for the occurrence of two or more observations exceeding the same +/- 1 SDI limit. For any analyte satisfying this condition, the mean of the observations should be calculated. For analytes with sg/si ratios between 1.0 and 1.5, a significant systematic error is signaled by the mean exceeding 1.0 SDI. Significant random error is signaled by one observation exceeding the +/- 3-SDI limit or the range of the observations exceeding 4 SDIs. For analytes with higher sg/si, significant systematic or random error is signaled by violation of the screening rule (having at least two observations exceeding the same +/- 1 SDI limit). Random error can also be signaled by one observation exceeding the +/- 1.5-SDI limit or the range of the observations exceeding 3 SDIs. We present a practical approach to the workup of apparent PT errors.

An analytical model for scanning electron microscope Type I magnetic contrast with energy filtering

NASA Astrophysics Data System (ADS)

Chim, W. K.

1994-02-01

In this article, a theoretical model for type I magnetic contrast calculations in the scanning electron microscope with energy filtering is presented. This model uses an approximate form of the secondary electron (SE) energy distribution by Chung and Everhart [M. S. Chung and T. E. Everhart, J. Appl. Phys. 45, 707 (1974). Closed form analytical expressions for the contrast and quality factors, which take into consideration the work function and field-distance integral of the material being studied, are obtained. This analytical model is compared with that of a more accurate numerical model. Results showed that the contrast and quality factors for the analytical model differed by not more than 20% from the numerical model, with the actual difference depending on the range of filtered SE energies considered. This model has also been extended to the situation of a two-detector (i.e., detector A and B) configuration, in which enhanced magnetic contrast and quality factor can be obtained by operating in the ``A-B'' mode.

Exploring the Efficacy of Behavioral Skills Training to Teach Basic Behavior Analytic Techniques to Oral Care Providers

ERIC Educational Resources Information Center

Graudins, Maija M.; Rehfeldt, Ruth Anne; DeMattei, Ronda; Baker, Jonathan C.; Scaglia, Fiorella

2012-01-01

Performing oral care procedures with children with autism who exhibit noncompliance can be challenging for oral care professionals. Previous research has elucidated a number of effective behavior analytic procedures for increasing compliance, but some procedures are likely to be too time consuming and expensive for community-based oral care…

The Use of Academic Words in the Analytical Writing of Secondary English Learners and Native English Speakers

ERIC Educational Resources Information Center

Cons, Andrea M.

2013-01-01

This study explores the following research question: How do secondary English learners (ELs) and Re-designated fluent English proficient students (RFEPs) use academic words in analytical writing in comparison to native English speakers (NESs)? It highlights previously overlooked differences in academic word use in the writing of students who are…

A Conversation-Analytic Perspective on the Organization of Teacher-Led Clarification and Its Implications for L2 Teacher Training

ERIC Educational Resources Information Center

Atar, Cihat; Seedhouse, Paul

2018-01-01

This study analyses teacher-led clarification sequences in a university second language classroom setting from a conversation-analytic perspective. In the literature, there are many studies of clarification requests, but the focus is on individual categories and quantification. No previous study has examined clarification, as reconceptualised in…

A Meta-Analysis of Factors Influencing the Development of Trust in Automation: Implications for Understanding Autonomy in Future Systems.

PubMed

Schaefer, Kristin E; Chen, Jessie Y C; Szalma, James L; Hancock, P A

2016-05-01

We used meta-analysis to assess research concerning human trust in automation to understand the foundation upon which future autonomous systems can be built. Trust is increasingly important in the growing need for synergistic human-machine teaming. Thus, we expand on our previous meta-analytic foundation in the field of human-robot interaction to include all of automation interaction. We used meta-analysis to assess trust in automation. Thirty studies provided 164 pairwise effect sizes, and 16 studies provided 63 correlational effect sizes. The overall effect size of all factors on trust development was ḡ = +0.48, and the correlational effect was [Formula: see text]  = +0.34, each of which represented medium effects. Moderator effects were observed for the human-related (ḡ  = +0.49; [Formula: see text] = +0.16) and automation-related (ḡ = +0.53; [Formula: see text] = +0.41) factors. Moderator effects specific to environmental factors proved insufficient in number to calculate at this time. Findings provide a quantitative representation of factors influencing the development of trust in automation as well as identify additional areas of needed empirical research. This work has important implications to the enhancement of current and future human-automation interaction, especially in high-risk or extreme performance environments. © 2016, Human Factors and Ergonomics Society.

A model of self-directed learning in internal medicine residency: a qualitative study using grounded theory.

PubMed

Sawatsky, Adam P; Ratelle, John T; Bonnes, Sara L; Egginton, Jason S; Beckman, Thomas J

2017-02-02

Existing theories of self-directed learning (SDL) have emphasized the importance of process, personal, and contextual factors. Previous medical education research has largely focused on the process of SDL. We explored the experience with and perception of SDL among internal medicine residents to gain understanding of the personal and contextual factors of SDL in graduate medical education. Using a constructivist grounded theory approach, we conducted 7 focus group interviews with 46 internal medicine residents at an academic medical center. We processed the data by using open coding and writing analytic memos. Team members organized open codes to create axial codes, which were applied to all transcripts. Guided by a previous model of SDL, we developed a theoretical model that was revised through constant comparison with new data as they were collected, and we refined the theory until it had adequate explanatory power and was appropriately grounded in the experiences of residents. We developed a theoretical model of SDL to explain the process, personal, and contextual factors affecting SDL during residency training. The process of SDL began with a trigger that uncovered a knowledge gap. Residents progressed to formulating learning objectives, using resources, applying knowledge, and evaluating learning. Personal factors included motivations, individual characteristics, and the change in approach to SDL over time. Contextual factors included the need for external guidance, the influence of residency program structure and culture, and the presence of contextual barriers. We developed a theoretical model of SDL in medical education that can be used to promote and assess resident SDL through understanding the process, person, and context of SDL.

Bayes Factors Unmask Highly Variable Information Content, Bias, and Extreme Influence in Phylogenomic Analyses.

PubMed

Brown, Jeremy M; Thomson, Robert C

2017-07-01

As the application of genomic data in phylogenetics has become routine, a number of cases have arisen where alternative data sets strongly support conflicting conclusions. This sensitivity to analytical decisions has prevented firm resolution of some of the most recalcitrant nodes in the tree of life. To better understand the causes and nature of this sensitivity, we analyzed several phylogenomic data sets using an alternative measure of topological support (the Bayes factor) that both demonstrates and averts several limitations of more frequently employed support measures (such as Markov chain Monte Carlo estimates of posterior probabilities). Bayes factors reveal important, previously hidden, differences across six "phylogenomic" data sets collected to resolve the phylogenetic placement of turtles within Amniota. These data sets vary substantially in their support for well-established amniote relationships, particularly in the proportion of genes that contain extreme amounts of information as well as the proportion that strongly reject these uncontroversial relationships. All six data sets contain little information to resolve the phylogenetic placement of turtles relative to other amniotes. Bayes factors also reveal that a very small number of extremely influential genes (less than 1% of genes in a data set) can fundamentally change significant phylogenetic conclusions. In one example, these genes are shown to contain previously unrecognized paralogs. This study demonstrates both that the resolution of difficult phylogenomic problems remains sensitive to seemingly minor analysis details and that Bayes factors are a valuable tool for identifying and solving these challenges. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Exact mode volume and Purcell factor of open optical systems

NASA Astrophysics Data System (ADS)

Muljarov, E. A.; Langbein, W.

2016-12-01

The Purcell factor quantifies the change of the radiative decay of a dipole in an electromagnetic environment relative to free space. Designing this factor is at the heart of photonics technology, striving to develop ever smaller or less lossy optical resonators. The Purcell factor can be expressed using the electromagnetic eigenmodes of the resonators, introducing the notion of a mode volume for each mode. This approach allows an analytic treatment, reducing the Purcell factor and other observables to sums over eigenmode resonances. Calculating the mode volumes requires a correct normalization of the modes. We introduce an exact normalization of modes, not relying on perfectly matched layers. We present an analytic theory of the Purcell effect based on this exact mode normalization and the resulting effective mode volume. We use a homogeneous dielectric sphere in vacuum, which is analytically solvable, to exemplify these findings. We furthermore verify the applicability of the normalization to numerically determined modes of a finite dielectric cylinder.

Sinking bubbles in stout beers

NASA Astrophysics Data System (ADS)

Lee, W. T.; Kaar, S.; O'Brien, S. B. G.

2018-04-01

A surprising phenomenon witnessed by many is the sinking bubbles seen in a settling pint of stout beer. Bubbles are less dense than the surrounding fluid so how does this happen? Previous work has shown that the explanation lies in a circulation of fluid promoted by the tilted sides of the glass. However, this work has relied heavily on computational fluid dynamics (CFD) simulations. Here, we show that the phenomenon of sinking bubbles can be predicted using a simple analytic model. To make the model analytically tractable, we work in the limit of small bubbles and consider a simplified geometry. The model confirms both the existence of sinking bubbles and the previously proposed mechanism.

DREAMING THE ANALYTIC SESSION: A CLINICAL ESSAY.

PubMed

Ogden, Thomas H

2017-01-01

This is a clinical paper in which the author describes analytic work in which he dreams the analytic session with three of his patients. He begins with a brief discussion of aspects of analytic theory that make up a good deal of the context for his clinical work. Central among these concepts are (1) the idea that the role of the analyst is to help the patient dream his previously "undreamt" and "interrupted" dreams; and (2) dreaming the analytic session involves engaging in the experience of dreaming the session with the patient and, at the same time, unconsciously (and at times consciously) understanding the dream. The author offers no "technique" for dreaming the analytic session. Each analyst must find his or her own way of dreaming each session with each patient. Dreaming the session is not something one works at; rather, one tries not to get in its way. © 2017 The Psychoanalytic Quarterly, Inc.

Taxometric and Factor Analytic Models of Anxiety Sensitivity: Integrating Approaches to Latent Structural Research

ERIC Educational Resources Information Center

Bernstein, Amit; Zvolensky, Michael J.; Norton, Peter J.; Schmidt, Norman B.; Taylor, Steven; Forsyth, John P.; Lewis, Sarah F.; Feldner, Matthew T.; Leen-Feldner, Ellen W.; Stewart, Sherry H.; Cox, Brian

2007-01-01

This study represents an effort to better understand the latent structure of anxiety sensitivity (AS), as indexed by the 16-item Anxiety Sensitivity Index (ASI; S. Reiss, R. A. Peterson, M. Gursky, & R. J. McNally, 1986), by using taxometric and factor-analytic approaches in an integrative manner. Taxometric analyses indicated that AS has a…

Separation of very hydrophobic analytes by micellar electrokinetic chromatography IV. Modeling of the effective electrophoretic mobility from carbon number equivalents and octanol-water partition coefficients.

PubMed

Huhn, Carolin; Pyell, Ute

2008-07-11

It is investigated whether those relationships derived within an optimization scheme developed previously to optimize separations in micellar electrokinetic chromatography can be used to model effective electrophoretic mobilities of analytes strongly differing in their properties (polarity and type of interaction with the pseudostationary phase). The modeling is based on two parameter sets: (i) carbon number equivalents or octanol-water partition coefficients as analyte descriptors and (ii) four coefficients describing properties of the separation electrolyte (based on retention data for a homologous series of alkyl phenyl ketones used as reference analytes). The applicability of the proposed model is validated comparing experimental and calculated effective electrophoretic mobilities. The results demonstrate that the model can effectively be used to predict effective electrophoretic mobilities of neutral analytes from the determined carbon number equivalents or from octanol-water partition coefficients provided that the solvation parameters of the analytes of interest are similar to those of the reference analytes.

Detour factors in water and plastic phantoms and their use for range and depth scaling in electron-beam dosimetry.

PubMed

Fernández-Varea, J M; Andreo, P; Tabata, T

1996-07-01

Average penetration depths and detour factors of 1-50 MeV electrons in water and plastic materials have been computed by means of analytical calculation, within the continuous-slowing-down approximation and including multiple scattering, and using the Monte Carlo codes ITS and PENELOPE. Results are compared to detour factors from alternative definitions previously proposed in the literature. Different procedures used in low-energy electron-beam dosimetry to convert ranges and depths measured in plastic phantoms into water-equivalent ranges and depths are analysed. A new simple and accurate scaling method, based on Monte Carlo-derived ratios of average electron penetration depths and thus incorporating the effect of multiple scattering, is presented. Data are given for most plastics used in electron-beam dosimetry together with a fit which extends the method to any other low-Z plastic material. A study of scaled depth-dose curves and mean energies as a function of depth for some plastics of common usage shows that the method improves the consistency and results of other scaling procedures in dosimetry with electron beams at therapeutic energies.

Factors Influencing Beliefs for Adoption of a Learning Analytics Tool: An Empirical Study

ERIC Educational Resources Information Center

Ali, Liaqat; Asadi, Mohsen; Gasevic, Dragan; Jovanovic, Jelena; Hatala, Marek

2013-01-01

Present research and development offer various learning analytics tools providing insights into different aspects of learning processes. Adoption of a specific tool for practice is based on how its learning analytics are perceived by educators to support their pedagogical and organizational goals. In this paper, we propose and empirically validate…

Development of a dynamic headspace gas chromatography-mass spectrometry method for on-site analysis of sulfur mustard degradation products in sediments.

PubMed

Magnusson, R; Nordlander, T; Östin, A

2016-01-15

Sampling teams performing work at sea in areas where chemical munitions may have been dumped require rapid and reliable analytical methods for verifying sulfur mustard leakage from suspected objects. Here we present such an on-site analysis method based on dynamic headspace GC-MS for analysis of five cyclic sulfur mustard degradation products that have previously been detected in sediments from chemical weapon dumping sites: 1,4-oxathiane, 1,3-dithiolane, 1,4-dithiane, 1,4,5-oxadithiephane, and 1,2,5-trithiephane. An experimental design involving authentic Baltic Sea sediments spiked with the target analytes was used to develop an optimized protocol for sample preparation, headspace extraction and analysis that afforded recoveries of up to 60-90%. The optimized method needs no organic solvents, uses only two grams of sediment on a dry weight basis and involves a unique sample presentation whereby sediment is spread uniformly as a thin layer inside the walls of a glass headspace vial. The method showed good linearity for analyte concentrations of 5-200 ng/g dw, good repeatability, and acceptable carry-over. The method's limits of detection for spiked sediment samples ranged from 2.5 to 11 μg/kg dw, with matrix interference being the main limiting factor. The instrumental detection limits were one to two orders of magnitude lower. Full-scan GC-MS analysis enabled the use of automated mass spectral deconvolution for rapid identification of target analytes. Using this approach, analytes could be identified in spiked sediment samples at concentrations down to 13-65 μg/kg dw. On-site validation experiments conducted aboard the research vessel R/V Oceania demonstrated the method's practical applicability, enabling the successful identification of four cyclic sulfur mustard degradation products at concentrations of 15-308μg/kg in sediments immediately after being collected near a wreck at the Bornholm Deep dumpsite in the Baltic Sea. Copyright © 2015 Elsevier B.V. All rights reserved.

Comprehensive analytical strategy for biomonitoring of pesticides in urine by liquid chromatography–orbitrap high resolution masss pectrometry.

PubMed

Roca, M; Leon, N; Pastor, A; Yusà, V

2014-12-29

In this study we propose an analytical strategy that combines a target approach for the quantitative analysis of contemporary pesticide metabolites with a comprehensive post-target screening for the identification of biomarkers of exposure to environmental contaminants in urine using liquid chromatography coupled to high-resolution mass spectrometry (LC–HRMS). The quantitative method for the target analysis of 29 urinary metabolites of organophosphate (OP) insecticides, synthetic pyrethroids, herbicides and fungicides was validated after a previous statistical optimization of the main factors governing the ion source ionization and a fragmentation study using the high energy collision dissociation (HCD) cell. The full scan accurate mass data were acquired with a resolving power of 50,000 FWHM (scan speed, 2 Hz), in both ESI+ and ESI− modes, and with and without HCD-fragmentation. The method – LOQ was lower than 3.2 μg L−1 for the majority of the analytes. For post-target screening a customized theoretical database was built, for the identification of 60 metabolites including pesticides, PAHs, phenols, and other metabolites of environmental pollutants. For identification purposes, accurate exact mass with less than 5 ppm, and diagnostic ions including isotopes and/or fragments were used. The analytical strategy was applied to 20 urine sample collected from children living in Valencia Region. Eleven target metabolites were detected with concentrations ranging from 1.18 to 131 μg L−1. Likewise, several compounds were tentatively identified in the post-target analysis belonging to the families of phthalates, phenols and parabenes. The proposed strategy is suitable for the determination of target pesticide biomarkers in urine in the framework of biomonitoring studies, and appropriate for the identification of other non-target metabolites.

Exact analytic solution for non-linear density fluctuation in a ΛCDM universe

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

Yoo, Jaiyul; Gong, Jinn-Ouk, E-mail: jyoo@physik.uzh.ch, E-mail: jinn-ouk.gong@apctp.org

We derive the exact third-order analytic solution of the matter density fluctuation in the proper-time hypersurface in a ΛCDM universe, accounting for the explicit time-dependence and clarifying the relation to the initial condition. Furthermore, we compare our analytic solution to the previous calculation in the comoving gauge, and to the standard Newtonian perturbation theory by providing Fourier kernels for the relativistic effects. Our results provide an essential ingredient for a complete description of galaxy bias in the relativistic context.

One- and two-center ETF-integrals of first order in relativistic calculation of NMR parameters

NASA Astrophysics Data System (ADS)

Slevinsky, R. M.; Temga, T.; Mouattamid, M.; Safouhi, H.

2010-06-01

The present work focuses on the analytical and numerical developments of first-order integrals involved in the relativistic calculation of the shielding tensor using exponential-type functions as a basis set of atomic orbitals. For the analytical development, we use the Fourier integral transformation and practical properties of spherical harmonics and the Rayleigh expansion of the plane wavefunctions. The Fourier transforms of the operators were derived in previous work and they are used for analytical development. In both the one- and two-center integrals, Cauchy's residue theorem is used in the final developments of the analytical expressions, which are shown to be accurate to machine precision.

Latent structure of the Wisconsin Card Sorting Test: a confirmatory factor analytic study.

PubMed

Greve, Kevin W; Stickle, Timothy R; Love, Jeffrey M; Bianchini, Kevin J; Stanford, Matthew S

2005-05-01

The present study represents the first large scale confirmatory factor analysis of the Wisconsin Card Sorting Test (WCST). The results generally support the three factor solutions reported in the exploratory factor analysis literature. However, only the first factor, which reflects general executive functioning, is statistically sound. The secondary factors, while likely reflecting meaningful cognitive abilities, are less stable except when all subjects complete all 128 cards. It is likely that having two discontinuation rules for the WCST has contributed to the varied factor analytic solutions reported in the literature and early discontinuation may result in some loss of useful information. Continued multivariate research will be necessary to better clarify the processes underlying WCST performance and their relationships to one another.

Differential change in integrative psychotherapy: a re-analysis of a change-factor based RCT in a naturalistic setting.

PubMed

Holtforth, Martin Grosse; Wilm, Katharina; Beyermann, Stefanie; Rhode, Annemarie; Trost, Stephanie; Steyer, Rolf

2011-11-01

General Psychotherapy (GPT; Grawe, 1997) is a research-informed psychotherapy that combines cognitive-behavioral and process-experiential techniques and that assumes motivational clarification and problem mastery as central mechanisms of change. To isolate the effect of motivational clarification, GPT was compared to a treatment that proscribed motivational clarification (General Psychotherapy Minus Clarification, GPT-C) in a randomized-controlled trial with 67 diagnostically heterogeneous outpatients. Previous analyses demonstrated equal outcomes and some superiority for highly avoidant patients in GPT. Re-analyses using causal-analytic methods confirmed equal changes, but also showed superior effects for GPT in highly symptomatic patients. Results are discussed regarding theory, methodological limitations, and implications for research and practice.

Adatom lifetime in film growth at solid surfaces in the framework of the Johnson Mehl Avrami Kolmogorov model

NASA Astrophysics Data System (ADS)

Tomellini, M.; Fanfoni, M.

1999-10-01

On the basis of the quasi-static approximation and for simultaneous nucleation the adatom lifetime, τ, during film growth at solid surfaces has been computed by Monte Carlo (MC) simulation. The quantity DN0τ, N0 and D being respectively the cluster density and the adatom diffusion coefficient, is found to depend upon the portion of surface covered by clusters and, very weakly, on N0. Moreover, a stochastic approach based on the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory has been developed to obtain the analytical expression of the MC curve. The collision factor of the mean island has been calculated and compared with those previously obtained from the uniform depletion approximation and the lattice approximation.

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

Peters, T. B.

Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the “microbatches” of Integrated Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 9 have been analyzed for 238Pu, 90Sr, 137Cs, cations (Inductively Coupled Plasma Emission Spectroscopy - ICPES), and anions (Ion Chromatography Anions - IC-A). The analytical results from the current microbatch samples are similar to those from previous macrobatch samples. The Cs removal continues to be acceptable, with decontamination factors (DF) averaging 25700 (107% RSD). The bulk chemistry of the DSSHT and SEHT samples do not show any signs of unusual behavior, other thanmore » lacking the anticipated degree of dilution that is calculated to occur during Modular Caustic-Side Solvent Extraction Unit (MCU) processing.« less

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

Peters, T. B.

Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the “microbatches” of Integrated Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 8B have been analyzed for 238Pu, 90Sr, 137Cs, cations (Inductively Coupled Plasma Emission Spectroscopy - ICPES), and anions (Ion Chromatography Anions - IC-A). The analytical results from the current microbatch samples are similar to those from previous macrobatch samples. The Cs removal continues to be excellent, with decontamination factors (DF) averaging 22,100 (114% RSD). The bulk chemistry of the DSSHT and SEHT samples does not show any signs of unusual behavior, other thanmore » lacking the anticipated degree of dilution that is calculated to occur during Modular Caustic-Side Solvent Extraction Unit (MCU) processing.« less

Pre-analytical issues in the haemostasis laboratory: guidance for the clinical laboratories.

PubMed

Magnette, A; Chatelain, M; Chatelain, B; Ten Cate, H; Mullier, F

2016-01-01

Ensuring quality has become a daily requirement in laboratories. In haemostasis, even more than in other disciplines of biology, quality is determined by a pre-analytical step that encompasses all procedures, starting with the formulation of the medical question, and includes patient preparation, sample collection, handling, transportation, processing, and storage until time of analysis. This step, based on a variety of manual activities, is the most vulnerable part of the total testing process and is a major component of the reliability and validity of results in haemostasis and constitutes the most important source of erroneous or un-interpretable results. Pre-analytical errors may occur throughout the testing process and arise from unsuitable, inappropriate or wrongly handled procedures. Problems may arise during the collection of blood specimens such as misidentification of the sample, use of inadequate devices or needles, incorrect order of draw, prolonged tourniquet placing, unsuccessful attempts to locate the vein, incorrect use of additive tubes, collection of unsuitable samples for quality or quantity, inappropriate mixing of a sample, etc. Some factors can alter the result of a sample constituent after collection during transportation, preparation and storage. Laboratory errors can often have serious adverse consequences. Lack of standardized procedures for sample collection accounts for most of the errors encountered within the total testing process. They can also have clinical consequences as well as a significant impact on patient care, especially those related to specialized tests as these are often considered as "diagnostic". Controlling pre-analytical variables is critical since this has a direct influence on the quality of results and on their clinical reliability. The accurate standardization of the pre-analytical phase is of pivotal importance for achieving reliable results of coagulation tests and should reduce the side effects of the influence factors. This review is a summary of the most important recommendations regarding the importance of pre-analytical factors for coagulation testing and should be a tool to increase awareness about the importance of pre-analytical factors for coagulation testing.

Improved partition equilibrium model for predicting analyte response in electrospray ionization mass spectrometry.

PubMed

Du, Lihong; White, Robert L

2009-02-01

A previously proposed partition equilibrium model for quantitative prediction of analyte response in electrospray ionization mass spectrometry is modified to yield an improved linear relationship. Analyte mass spectrometer response is modeled by a competition mechanism between analyte and background electrolytes that is based on partition equilibrium considerations. The correlation between analyte response and solution composition is described by the linear model over a wide concentration range and the improved model is shown to be valid for a wide range of experimental conditions. The behavior of an analyte in a salt solution, which could not be explained by the original model, is correctly predicted. The ion suppression effects of 16:0 lysophosphatidylcholine (LPC) on analyte signals are attributed to a combination of competition for excess charge and reduction of total charge due to surface tension effects. In contrast to the complicated mathematical forms that comprise the original model, the simplified model described here can more easily be employed to predict analyte mass spectrometer responses for solutions containing multiple components. Copyright (c) 2008 John Wiley & Sons, Ltd.

Determining a carbohydrate profile for Hansenula polymorpha

NASA Technical Reports Server (NTRS)

Petersen, G. R.

1985-01-01

The determination of the levels of carbohydrates in the yeast Hansenula polymorpha required the development of new analytical procedures. Existing fractionation and analytical methods were adapted to deal with the problems involved with the lysis of whole cells. Using these new procedures, the complete carbohydrate profiles of H. polymorpha and selected mutant strains were determined and shown to correlate favourably with previously published results.

Ethical Oversight of Student Data in Learning Analytics: A Typology Derived from a Cross-Continental, Cross-Institutional Perspective

ERIC Educational Resources Information Center

Willis, James E.; Slade, Sharon; Prinsloo, Paul

2016-01-01

The growth of learning analytics as a means to improve student learning outcomes means that student data is being collected, analyzed, and applied in previously unforeseen ways. As the use of this data continues to shape academic and support interventions, there is increasing need for ethical reflection on "operational" approvals for…

Analyte species and concentration identification using differentially functionalized microcantilever arrays and artificial neural networks

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

Senesac, Larry R; Datskos, Panos G; Sepaniak, Michael J

2006-01-01

In the present work, we have performed analyte species and concentration identification using an array of ten differentially functionalized microcantilevers coupled with a back-propagation artificial neural network pattern recognition algorithm. The array consists of ten nanostructured silicon microcantilevers functionalized by polymeric and gas chromatography phases and macrocyclic receptors as spatially dense, differentially responding sensing layers for identification and quantitation of individual analyte(s) and their binary mixtures. The array response (i.e. cantilever bending) to analyte vapor was measured by an optical readout scheme and the responses were recorded for a selection of individual analytes as well as several binary mixtures. Anmore » artificial neural network (ANN) was designed and trained to recognize not only the individual analytes and binary mixtures, but also to determine the concentration of individual components in a mixture. To the best of our knowledge, ANNs have not been applied to microcantilever array responses previously to determine concentrations of individual analytes. The trained ANN correctly identified the eleven test analyte(s) as individual components, most with probabilities greater than 97%, whereas it did not misidentify an unknown (untrained) analyte. Demonstrated unique aspects of this work include an ability to measure binary mixtures and provide both qualitative (identification) and quantitative (concentration) information with array-ANN-based sensor methodologies.« less

R-mode constraints from neutron star equation of state

NASA Astrophysics Data System (ADS)

Papazoglou, M. C.; Moustakidis, C. C.

2016-03-01

The gravitational radiation has been proposed a long time before, as an explanation for the observed relatively low spin frequencies of young neutron stars and of accreting neutron stars in low-mass X-ray binaries as well. In the present work we studied the effects of the neutron star equation of state on the r-mode instability window of rotating neutron stars. Firstly, we employed a set of analytical solution of the Tolman-Oppenheimer-Volkoff equations with special emphasis on the Tolman VII solution. In particular, we tried to clarify the effects of the bulk neutron star properties (mass, radius, density distribution, crust size and elasticity) on the r-mode instability window. We found that the critical angular velocity \\varOmegac depends mainly on the neutron star radius. The effects of the gravitational mass and the mass distribution are almost negligible. Secondly, we studied the effect of the elasticity of the crust, via to the slippage factor S and also the effect of the nuclear equation of state, via the slope parameter L, on the instability window. We found that the crust effects are more pronounced, compared to those originated from the equation of state. Moreover, we proposed simple analytical expressions which relate the macroscopic quantity \\varOmegac to the radius, the parameter L and the factor {S}. We also investigated the possibility to measure the radius of a neutron star and the factor {S} with the help of accurate measures of \\varOmegac and the neutron star temperature. Finally, we studied the effects of the mutual friction on the instability window and discussed the results in comparison with previous similar studies.

Integration of Gas Chromatography Mass Spectrometry Methods for Differentiating Ricin Preparation Methods

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

Wunschel, David S.; Melville, Angela M.; Ehrhardt, Christopher J.

2012-05-17

The investigation of crimes involving chemical or biological agents is infrequent, but presents unique analytical challenges. The protein toxin ricin is encountered more frequently than other agents and is found in the seeds of the castor plant Ricinus communis. Typically, the toxin is extracted from castor seeds utilizing a variety of different recipes that result in varying purity of the toxin. Moreover, these various purification steps can also leave or differentially remove a variety of exogenous and endogenous residual components with the toxin that may indicate the type and number of purification steps involved. We have applied three gas chromatographicmore » - mass spectrometric (GC-MS) based analytical methods to measure the variation in seed carbohydrates and castor oil ricinoleic acid as well as the presence of solvents used for purification. These methods were applied to the same samples prepared using four previously identified toxin preparation methods starting from four varieties of castor seeds. The individual data sets for seed carbohydrate profiles, ricinoleic acid or acetone amount each provided information capable of differentiating different types of toxin preparations across seed types. However, the integration of the data sets using multivariate factor analysis provided a clear distinction of all samples based on the preparation method and independent of the seed source. In particular the abundance of mannose, arabinose, fucose, ricinoleic acid and acetone were shown to be important differentiating factors. These complementary tools provide a more confident determination of the method of toxin preparation.« less

Liquid chromatography of hydrocarbonaeous quaternary amines on cyclodextrin bonded silica

USGS Publications Warehouse

Abidi, S.L.

1986-01-01

Mixtures of n-alkylbenzyldimethylammonium chloride (ABDAC) were resolved into homologous components by high-performance liquid chromatography (HPLC) with a cyclodextrin-bonded silica stationary phase. With a few exceptions, results from this study are similar to those obtained from traditional reversed-phase HPLC. It was found that the presence of electrolytes in aqueous mobile phases is not a critical factor in determining the success of HPLC separation. Under normal HPLC conditions, a mobile phase consisting of either methanol–water (50:50) or acetonitrile–water (30:70) was employed for obtaining adequate resolution of the quaternary ammonium mixtures. Although the percent organic modifier–water profiles were similar to those in previous studies with these compounds, resolution (R) and selectivity (α) parameters were found to be quite susceptible to changes in the mobile phase solvent composition. The retention behavior of the cationic analytes in the homologous series is consistent with the hydrophobic-interaction concept proposed for the retention mechanism via dominant inclusion complex formation. Several electrolytes were chosen for a study of the counter ion effect on the chromatographic characteristics of ABDAC components. Among the electrolytes examined, the perchlorate ion was found most likely to act as an ion-pairing counter ion for ammonium cations in the HPLC system studied. A correlation study established linear relationships between the chain length of ABDAC and the logarithmic capacity factor (k2). The analytical utility of the HPLC method was demonstrated by the analysis of various unknown mixtures.

Background Signal as an in Situ Predictor of Dopamine Oxidation Potential: Improving Interpretation of Fast-Scan Cyclic Voltammetry Data.

PubMed

Meunier, Carl J; Roberts, James G; McCarty, Gregory S; Sombers, Leslie A

2017-02-15

Background-subtracted fast-scan cyclic voltammetry (FSCV) has emerged as a powerful analytical technique for monitoring subsecond molecular fluctuations in live brain tissue. Despite increasing utilization of FSCV, efforts to improve the accuracy of quantification have been limited due to the complexity of the technique and the dynamic recording environment. It is clear that variable electrode performance renders calibration necessary for accurate quantification; however, the nature of in vivo measurements can make conventional postcalibration difficult, or even impossible. Analyte-specific voltammograms and scaling factors that are critical for quantification can shift or fluctuate in vivo. This is largely due to impedance changes, and the effects of impedance on these measurements have not been characterized. We have previously reported that the background current can be used to predict electrode-specific scaling factors in situ. In this work, we employ model circuits to investigate the impact of impedance on FSCV measurements. Additionally, we take another step toward in situ electrode calibration by using the oxidation potential of quinones on the electrode surface to accurately predict the oxidation potential for dopamine at any point in an electrochemical experiment, as both are dependent on impedance. The model, validated both in adrenal slice and live brain tissue, enables information encoded in the shape of the background voltammogram to determine electrochemical parameters that are critical for accurate quantification. This improves data interpretation and provides a significant next step toward more automated methods for in vivo data analysis.

Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays. Applications, fundamentals, and optimization

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

Driskell, Jeremy Daniel

2006-08-09

Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitivemore » immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments of SPR and SERS. Chapter 4 introduces a novel method of reducing sample incubation time via capture substrate rotation. Moreover, this work led to a method of virus quantification without the use of standards. Chapter 5 extends the methodology developed in Chapter 4 to both the antigen and ERL labeling step to perform assays with improved analytical performance in less time than can be accomplished in diffusion controlled assays. This dissertation concludes with a general summary and speculates on the future of this exciting approach to carrying out immunoassays.« less

40 CFR 63.786 - Test methods and procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... level of sample dilution must be factored in. (2) Repeatability. First, at the 0.1-5 percent analyte... percent analyte range the results would be suspect if duplicates vary by more than 5 percent relative and...) Reproducibility. First, at the 0.1-5 percent analyte range the results would be suspect if lab to lab variation...

40 CFR 63.786 - Test methods and procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... level of sample dilution must be factored in. (2) Repeatability. First, at the 0.1-5 percent analyte... percent analyte range the results would be suspect if duplicates vary by more than 5 percent relative and...) Reproducibility. First, at the 0.1-5 percent analyte range the results would be suspect if lab to lab variation...

Factors influencing unsafe behaviors and accidents on construction sites: a review.

PubMed

Khosravi, Yahya; Asilian-Mahabadi, Hassan; Hajizadeh, Ebrahim; Hassanzadeh-Rangi, Narmin; Bastani, Hamid; Behzadan, Amir H

2014-01-01

Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations.

Relation between diagnosis of atheromatous plaque from orthopantomographs and cardiovascular risk factors. A study of cases and control subjects

PubMed Central

Gutierrez-Bonet, Carmen; Leco-Berrocal, Isabel; Fernández-Cáliz, Fernando; Martínez-González, José-María

2016-01-01

Background In recent years the use of orthopantomography has been proposed as a low-cost, reliable and non-invasive diagnostic medium for detecting atheromatous plaque. The purpose of this study was to correlate the presence of carotid calcifications (atheroma) in orthopantomographs with specific risk factors for cerebrovascular accidents (previous cerebrovascular accidents, arterial hypertension, and diabetes). Material and Methods The methods used in this observational study of cases and control subjects followed STROBE (Strengthening the Reporting of Observational studies in Epidemiology) recommendations. The study analyzed a total of 1,602 panoramic radiographs taken for dental diagnostic purposes between January 2010 and February 2014. The main variables analyzed were the incidence of atheromatous plaque and other cardiovascular risk factors. Epidat 3.1 statistical software was used to determine minimum sample sizes and the results were analyzed using PASW (Predictive Analytics Software) Statistics 10.0.0. Results For all the variables analyzed, the correlation between radiographic detection of atheromatous plaque and the presence of cardiovascular disease risk factors was found to be statistically significant (RR>1.5). Conclusions The presence of cardiovascular risk factors is related to the incidence of radiopaque lesions at the carotid artery bifurcation, indicating the presence of atheromatous plaque. Key words:Orthopantomography, atheromatous plaque, cerebrovascular accident, diabetes, arterial hypertension. PMID:26595828

Factors affecting the results of comprehensive pre-internship exam among medical students of Kermanshah University of Medical Sciences.

PubMed

Khazaei, Mohammad Rasool; Zarin, Afshin; Rezaei, Mansuor; Khazaei, Mozafar

2018-06-01

This study was aimed to evaluate the factors affecting the results of comprehensive pre-internship exam (CPIE) among medicals students of Kermanshah University of Medical Sciences. In this descriptive-analytical study, all students (n=240) participating in CPIE over a 3-year period (2012-2014) were selected. Data were gathered by a questionnaire, including the CPIE results and educational and demographic data. Spearman correlation coefficient, Mann-Whitney U-test, and analysis of variance were used to analyze the association of students' success with study variables. Also, regression analysis was applied to determine the role of independent variables in students' success. The frequency of the failed units in apprenticeship course was one of the most important risk factors associated with failure in CPIE. Average scores of pre-internship course were the most important factors of success in CPIE. The CPIE score had the highest direct relationship with grade point average (GPA) of apprenticeship course, total GPA of all three courses, GPAs of physiopathology and basic sciences courses, and score of comprehensive basic sciences examination, respectively. CPIE showed the highest inverse correlation with the number of failed units in apprenticeship course. The most important factors influencing this exam were failure in apprenticeship course and GPA of previous educational stages.

An analytical approach for the calculation of stress-intensity factors in transformation-toughened ceramics

NASA Astrophysics Data System (ADS)

Müller, W. H.

1990-12-01

Stress-induced transformation toughening in Zirconia-containing ceramics is described analytically by means of a quantitative model: A Griffith crack which interacts with a transformed, circular Zirconia inclusion. Due to its volume expansion, a ZrO2-particle compresses its flanks, whereas a particle in front of the crack opens the flanks such that the crack will be attracted and finally absorbed. Erdogan's integral equation technique is applied to calculate the dislocation functions and the stress-intensity-factors which correspond to these situations. In order to derive analytical expressions, the elastic constants of the inclusion and the matrix are assumed to be equal.

An Analytical Quantum Model to Calculate Fluorescence Enhancement of a Molecule in Vicinity of a Sub-10 nm Metal Nanoparticle.

PubMed

Bagheri, Zahra; Massudi, Reza

2017-05-01

An analytical quantum model is used to calculate electrical permittivity of a metal nanoparticle located in an adjacent molecule. Different parameters, such as radiative and non-radiative decay rates, quantum yield, electrical field enhancement factor, and fluorescence enhancement are calculated by such a model and they are compared with those obtained by using the classical Drude model. It is observed that using an analytical quantum model presents a higher enhancement factor, up to 30%, as compared to classical model for nanoparticles smaller than 10 nm. Furthermore, the results are in better agreement with those experimentally realized.

Sweeping as a multistep enrichment process in micellar electrokinetic chromatography: the retention factor gradient effect.

PubMed

El-Awady, Mohamed; Pyell, Ute

2013-07-05

The application of a new method developed for the assessment of sweeping efficiency in MEKC under homogeneous and inhomogeneous electric field conditions is extended to the general case, in which the distribution coefficient and the electric conductivity of the analyte in the sample zone and in the separation compartment are varied. As test analytes p-hydroxybenzoates (parabens), benzamide and some aromatic amines are studied under MEKC conditions with SDS as anionic surfactant. We show that in the general case - in contrast to the classical description - the obtainable enrichment factor is not only dependent on the retention factor of the analyte in the sample zone but also dependent on the retention factor in the background electrolyte (BGE). It is shown that in the general case sweeping is inherently a multistep focusing process. We describe an additional focusing/defocusing step (the retention factor gradient effect, RFGE) quantitatively by extending the classical equation employed for the description of the sweeping process with an additional focusing/defocusing factor. The validity of this equation is demonstrated experimentally (and theoretically) under variation of the organic solvent content (in the sample and/or the BGE), the type of organic solvent (in the sample and/or the BGE), the electric conductivity (in the sample), the pH (in the sample), and the concentration of surfactant (in the BGE). It is shown that very high enrichment factors can be obtained, if the pH in the sample zone makes possible to convert the analyte into a charged species that has a high distribution coefficient with respect to an oppositely charged micellar phase, while the pH in the BGE enables separation of the neutral species under moderate retention factor conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of the risk factors associated with rectal neuroendocrine tumors: a big data analytic study from a health screening center.

PubMed

Pyo, Jeung Hui; Hong, Sung Noh; Min, Byung-Hoon; Lee, Jun Haeng; Chang, Dong Kyung; Rhee, Poong-Lyul; Kim, Jae Jun; Choi, Sun Kyu; Jung, Sin-Ho; Son, Hee Jung; Kim, Young-Ho

2016-12-01

Rectal neuroendocrine tumor (NET) is the most common NET in Asia. The risk factors associated with rectal NETs are unclear because of the overall low incidence rate of these tumors and the associated difficulty in conducting large epidemiological studies on rare cases. The aim of this study was to exploit the benefits of big data analytics to assess the risk factors associated with rectal NET. A retrospective case-control study was conducted, including 102 patients with histologically confirmed rectal NETs and 52,583 healthy controls who underwent screening colonoscopy at the Center for Health Promotion of the Samsung Medical Center in Korea between January 2002 and December 2012. Information on different risk factors was collected and logistic regression analysis applied to identify predictive factors. Four factors were significantly associated with rectal NET: higher levels of cholesterol [odds ratio (OR) = 1.007, 95 % confidence interval (CI), 1.001-1.013, p = 0.016] and ferritin (OR = 1.502, 95 % CI, 1.167-1.935, p = 0.002), presence of metabolic syndrome (OR = 1.768, 95 % CI, 1.071-2.918, p = 0.026), and family history of cancer among first-degree relatives (OR = 1.664, 95 % CI, 1.019-2.718, p = 0.042). The findings of our study demonstrate the benefits of using big data analytics for research and clinical risk factor studies. Specifically, in this study, this analytical method was applied to identify higher levels of serum cholesterol and ferritin, metabolic syndrome, and family history of cancer as factors that may explain the increasing incidence and prevalence of rectal NET.

Pre-analytical Factors Influence Accuracy of Urine Spot Iodine Assessment in Epidemiological Surveys.

PubMed

Doggui, Radhouene; El Ati-Hellal, Myriam; Traissac, Pierre; El Ati, Jalila

2018-03-26

Urinary iodine concentration (UIC) is commonly used to assess iodine status of subjects in epidemiological surveys. As pre-analytical factors are an important source of measurement error and studies about this phase are scarce, our objective was to assess the influence of urine sampling conditions on UIC, i.e., whether the child ate breakfast or not, urine void rank of the day, and time span between last meal and urine collection. A nationwide, two-stage, stratified, cross-sectional study including 1560 children (6-12 years) was performed in 2012. UIC was determined by the Sandell-Kolthoff method. Pre-analytical factors were assessed from children's mothers by using a questionnaire. Association between iodine status and pre-analytical factors were adjusted for one another and socio-economic characteristics by multivariate linear and multinomial regression models (RPR: relative prevalence ratios). Skipping breakfast prior to morning urine sampling decreased UIC by 40 to 50 μg/L and the proportion of UIC < 100 μg/L was higher among children having those skipped breakfast (RPR = 3.2[1.0-10.4]). In unadjusted analyses, UIC was less among children sampled more than 5 h from their last meal. UIC decreased with rank of urine void (e.g., first vs. second, P < 0.001); also, the proportion of UIC < 100 μg/L was greater among 4th rank samples (vs. second RPR = 2.1[1.1-4.0]). Subjects' breakfast status and urine void rank should be accounted for when assessing iodine status. Providing recommendations to standardize pre-analytical factors is a key step toward improving accuracy and comparability of survey results for assessing iodine status from spot urine samples. These recommendations have to be evaluated by future research.

PCB congener analysis with Hall electrolytic conductivity detection

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

Edstrom, R.D.

1989-01-01

This work reports the development of an analytical methodology for the analysis of PCB congeners based on integrating relative retention data provided by other researchers. The retention data were transposed into a multiple retention marker system which provided good precision in the calculation of relative retention indices for PCB congener analysis. Analytical run times for the developed methodology were approximately one hour using a commercially available GC capillary column. A Tracor Model 700A Hall Electrolytic Conductivity Detector (HECD) was employed in the GC detection of Aroclor standards and environmental samples. Responses by the HECD provided good sensitivity and were reasonablymore » predictable. Ten response factors were calculated based on the molar chlorine content of each homolog group. Homolog distributions were determined for Aroclors 1016, 1221, 1232, 1242, 1248, 1254, 1260, 1262 along with binary and ternary mixtures of the same. These distributions were compared with distributions reported by other researchers using electron capture detection as well as chemical ionization mass spectrometric methodologies. Homolog distributions acquired by the HECD methodology showed good correlation with the previously mentioned methodologies. The developed analytical methodology was used in the analysis of bluefish (Pomatomas saltatrix) and weakfish (Cynoscion regalis) collected from the York River, lower James River and lower Chesapeake Bay in Virginia. Total PCB concentrations were calculated and homolog distributions were constructed from the acquired data. Increases in total PCB concentrations were found in the analyzed fish samples during the fall of 1985 collected from the lower James River and lower Chesapeake Bay.« less

Detecting a wide range of environmental contaminants in human blood samples--combining QuEChERS with LC-MS and GC-MS methods.

PubMed

Plassmann, Merle M; Schmidt, Magdalena; Brack, Werner; Krauss, Martin

2015-09-01

Exposure to environmental pollution and consumer products may result in an uptake of chemicals into human tissues. Several studies have reported the presence of diverse environmental contaminants in human blood samples. However, previously developed multi-target methods for the analysis of human blood include a fairly limited amount of compounds stemming from one or two related compound groups. Thus, the sample preparation method QuEChERS (quick easy cheap effective rugged and safe) was tested for the extraction of 64 analytes covering a broad compound domain followed by detection using liquid and gas chromatography coupled to mass spectrometry (LC- and GC-MS). Forty-seven analytes showed absolute recoveries above 70% in the first QuEChERS step, being a simple liquid-liquid extraction (LLE) using acetonitrile and salt. The second QuEChERS step, being a dispersive solid phase extraction, did not result in an overall improvement of recoveries or removal of background signals. Using solely the LLE step, eight analytes could subsequently be detected in human blood samples from the German Environmental Specimen Bank. Using a LC-multiple reaction monitoring (MRM) method with a triple quadrupole instrument, better recoveries were achieved than with an older LC-high-resolution (HR) MS full scan orbitrap instrument, which required a higher concentration factor of the extracts. However, the application of HRMS full scan methods could be used for the detection of additional compounds retrospectively.

What is the best strategy for investigating abnormal liver function tests in primary care? Implications from a prospective study.

PubMed

Lilford, Richard J; Bentham, Louise M; Armstrong, Matthew J; Neuberger, James; Girling, Alan J

2013-06-20

Evaluation of predictive value of liver function tests (LFTs) for the detection of liver-related disease in primary care. A prospective observational study. 11 UK primary care practices. Patients (n=1290) with an abnormal eight-panel LFT (but no previously diagnosed liver disease). Patients were investigated by recording clinical features, and repeating LFTs, specific tests for individual liver diseases, and abdominal ultrasound scan. Patients were characterised as having: hepatocellular disease; biliary disease; tumours of the hepato-biliary system and none of the above. The relationship between LFT results and disease categories was evaluated by stepwise regression and logistic discrimination, with adjustment for demographic and clinical factors. True and False Positives generated by all possible LFT combinations were compared with a view towards optimising the choice of analytes in the routine LFT panel. Regression methods showed that alanine aminotransferase (ALT) was associated with hepatocellular disease (32 patients), while alkaline phosphatase (ALP) was associated with biliary disease (12 patients) and tumours of the hepatobiliary system (9 patients). A restricted panel of ALT and ALP was an efficient choice of analytes, comparing favourably with the complete panel of eight analytes, provided that 48 False Positives can be tolerated to obtain one additional True Positive. Repeating a complete panel in response to an abnormal reading is not the optimal strategy. The LFT panel can be restricted to ALT and ALP when the purpose of testing is to exclude liver disease in primary care.

Determination of Slope Safety Factor with Analytical Solution and Searching Critical Slip Surface with Genetic-Traversal Random Method

PubMed Central

2014-01-01

In the current practice, to determine the safety factor of a slope with two-dimensional circular potential failure surface, one of the searching methods for the critical slip surface is Genetic Algorithm (GA), while the method to calculate the slope safety factor is Fellenius' slices method. However GA needs to be validated with more numeric tests, while Fellenius' slices method is just an approximate method like finite element method. This paper proposed a new method to determine the minimum slope safety factor which is the determination of slope safety factor with analytical solution and searching critical slip surface with Genetic-Traversal Random Method. The analytical solution is more accurate than Fellenius' slices method. The Genetic-Traversal Random Method uses random pick to utilize mutation. A computer automatic search program is developed for the Genetic-Traversal Random Method. After comparison with other methods like slope/w software, results indicate that the Genetic-Traversal Random Search Method can give very low safety factor which is about half of the other methods. However the obtained minimum safety factor with Genetic-Traversal Random Search Method is very close to the lower bound solutions of slope safety factor given by the Ansys software. PMID:24782679

High Z neoclassical transport: Application and limitation of analytical formulae for modelling JET experimental parameters

NASA Astrophysics Data System (ADS)

Breton, S.; Casson, F. J.; Bourdelle, C.; Angioni, C.; Belli, E.; Camenen, Y.; Citrin, J.; Garbet, X.; Sarazin, Y.; Sertoli, M.; JET Contributors

2018-01-01

Heavy impurities, such as tungsten (W), can exhibit strongly poloidally asymmetric density profiles in rotating or radio frequency heated plasmas. In the metallic environment of JET, the poloidal asymmetry of tungsten enhances its neoclassical transport up to an order of magnitude, so that neoclassical convection dominates over turbulent transport in the core. Accounting for asymmetries in neoclassical transport is hence necessary in the integrated modeling framework. The neoclassical drift kinetic code, NEO [E. Belli and J. Candy, Plasma Phys. Controlled Fusion P50, 095010 (2008)], includes the impact of poloidal asymmetries on W transport. However, the computational cost required to run NEO slows down significantly integrated modeling. A previous analytical formulation to describe heavy impurity neoclassical transport in the presence of poloidal asymmetries in specific collisional regimes [C. Angioni and P. Helander, Plasma Phys. Controlled Fusion 56, 124001 (2014)] is compared in this work to numerical results from NEO. Within the domain of validity of the formula, the factor for reducing the temperature screening due to poloidal asymmetries had to be empirically adjusted. After adjustment, the modified formula can reproduce NEO results outside of its definition domain, with some limitations: When main ions are in the banana regime, the formula reproduces NEO results whatever the collisionality regime of impurities, provided that the poloidal asymmetry is not too large. However, for very strong poloidal asymmetries, agreement requires impurities in the Pfirsch-Schlüter regime. Within the JETTO integrated transport code, the analytical formula combined with the poloidally symmetric neoclassical code NCLASS [W. A. Houlberg et al., Phys. Plasmas 4, 3230 (1997)] predicts the same tungsten profile as NEO in certain cases, while saving a factor of one thousand in computer time, which can be useful in scoping studies. The parametric dependencies of the temperature screening reduction due to poloidal asymmetries would need to be better characterised for this faster model to be extended to a more general applicability.

A RECONNECTION-DRIVEN MODEL OF THE HARD X-RAY LOOP-TOP SOURCE FROM FLARE 2004 FEBRUARY 26

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

Longcope, Dana; Qiu, Jiong; Brewer, Jasmine

A compact X-class flare on 2004 February 26 showed a concentrated source of hard X-rays at the tops of the flare’s loops. This was analyzed in previous work and interpreted as plasma heated and compressed by slow magnetosonic shocks (SMSs) generated during post-reconnection retraction of the flux. That work used analytic expressions from a thin flux tube (TFT) model, which neglected many potentially important factors such as thermal conduction and chromospheric evaporation. Here we use a numerical solution of the TFT equations to produce a more comprehensive and accurate model of the same flare, including those effects previously omitted. Thesemore » simulations corroborate the prior hypothesis that slow-mode shocks persist well after the retraction has ended, thus producing a compact, loop-top source instead of an elongated jet, as steady reconnection models predict. Thermal conduction leads to densities higher than analytic estimates had predicted, and evaporation enhances the density still higher, but at lower temperatures. X-ray light curves and spectra are synthesized by convolving the results from a single TFT simulation with the rate at which flux is reconnected, as measured through motion of flare ribbons, for example. These agree well with light curves observed by RHESSI and GOES and spectra from RHESSI . An image created from a superposition of TFT model runs resembles one produced from RHESSI observations. This suggests that the HXR loop-top source, at least the one observed in this flare, could be the result of SMSs produced in fast reconnection models like Petschek’s.« less

A transient laboratory method for determining the hydraulic properties of 'tight' rocks-I. Theory

USGS Publications Warehouse

Hsieh, P.A.; Tracy, J.V.; Neuzil, C.E.; Bredehoeft, J.D.; Silliman, Stephen E.

1981-01-01

Transient pulse testing has been employed increasingly in the laboratory to measure the hydraulic properties of rock samples with low permeability. Several investigators have proposed a mathematical model in terms of an initial-boundary value problem to describe fluid flow in a transient pulse test. However, the solution of this problem has not been available. In analyzing data from the transient pulse test, previous investigators have either employed analytical solutions that are derived with the use of additional, restrictive assumptions, or have resorted to numerical methods. In Part I of this paper, a general, analytical solution for the transient pulse test is presented. This solution is graphically illustrated by plots of dimensionless variables for several cases of interest. The solution is shown to contain, as limiting cases, the more restrictive analytical solutions that the previous investigators have derived. A method of computing both the permeability and specific storage of the test sample from experimental data will be presented in Part II. ?? 1981.

Comparison of functional group selective ion-molecule reactions of trimethyl borate in different ion trap mass spectrometers

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

Habicht, S C; Vinueza, Nelson R; Amundson, Lucas M

2011-02-01

We report here a comparison of the use of diagnostic ion–molecule reactions for the identification of oxygen-containing functional groups in Fourier-transform ion cyclotron resonance (FTICR) and linear quadrupole ion trap (LQIT) mass spectrometers. The ultimate goal of this research is to be able to identify functionalities in previously unknown analytes by using many different types of mass spectrometers. Previous work has focused on the reactions of various boron reagents with protonated oxygen-containing analytes in FTICR mass spectrometers. By using a LQIT modified to allow the introduction of neutral reagents into the helium buffer gas, this methodology has been successfully implementedmore » to this type of an ion trap instrument. The products obtained from the reactions of trimethyl borate (TMB) with various protonated analytes are compared for the two instruments. Finally, the ability to integrate these reactions into LC-MS experiments on the LQIT is demonstrated.« less

An accelerated photo-magnetic imaging reconstruction algorithm based on an analytical forward solution and a fast Jacobian assembly method

NASA Astrophysics Data System (ADS)

Nouizi, F.; Erkol, H.; Luk, A.; Marks, M.; Unlu, M. B.; Gulsen, G.

2016-10-01

We previously introduced photo-magnetic imaging (PMI), an imaging technique that illuminates the medium under investigation with near-infrared light and measures the induced temperature increase using magnetic resonance thermometry (MRT). Using a multiphysics solver combining photon migration and heat diffusion, PMI models the spatiotemporal distribution of temperature variation and recovers high resolution optical absorption images using these temperature maps. In this paper, we present a new fast non-iterative reconstruction algorithm for PMI. This new algorithm uses analytic methods during the resolution of the forward problem and the assembly of the sensitivity matrix. We validate our new analytic-based algorithm with the first generation finite element method (FEM) based reconstruction algorithm previously developed by our team. The validation is performed using, first synthetic data and afterwards, real MRT measured temperature maps. Our new method accelerates the reconstruction process 30-fold when compared to a single iteration of the FEM-based algorithm.

Experimental and theoretical analysis of defocused CO2 laser microchanneling on PMMA for enhanced surface finish

NASA Astrophysics Data System (ADS)

Prakash, Shashi; Kumar, Subrata

2017-02-01

The poor surface finish of CO2 laser-micromachined microchannel walls is a major limitation of its utilization despite several key advantages, like low fabrication cost and low time consumption. Defocused CO2 laser beam machining is an effective solution for fabricating smooth microchannel walls on polymer and glass substrates. In this research work, the CO2 laser microchanneling process on PMMA has been analyzed at different beam defocus positions. Defocused processing has been investigated both theoretically and experimentally, and the depth of focus and beam diameter have been determined experimentally. The effect of beam defocusing on the microchannel width, depth, surface roughness, heat affected zone and microchannel profile were examined. A previously developed analytical model for microchannel depth prediction has been improved by incorporating the threshold energy density factor. A semi-analytical model for predicting the microchannel width at different defocus positions has been developed. A semi-empirical model has also been developed for predicting microchannel widths at different defocusing conditions for lower depth values. The developed models were compared and verified by performing actual experiments. Multi-objective optimization was performed to select the best optimum set of input parameters for achieving the desired surface roughness.

Low-frequency analogue Hawking radiation: The Korteweg-de Vries model

NASA Astrophysics Data System (ADS)

Coutant, Antonin; Weinfurtner, Silke

2018-01-01

We derive analytic expressions for the low-frequency properties of the analogue Hawking radiation in a general weak-dispersive medium. A thermal low-frequency part of the spectrum is expected even when dispersive effects become significant. We consider the two most common class of weak-dispersive media and investigate all possible anomalous scattering processes due inhomogeneous background flows. We first argue that under minimal assumptions, the scattering processes in near-critical flows are well described by a linearized Korteweg-de Vries equation. Within our theoretical model grey-body factors are neglected, that is, the mode comoving with the flow decouples from the other ones. We also exhibit a flow example with an exact expression for the effective temperature. We see that this temperature coincides with the Hawking one only when the dispersive length scale is much smaller than the flow gradient scale. We apply the same method in inhomogeneous flows without an analogue horizon. In this case, the spectrum coefficients decrease with decreasing frequencies. Our findings are in agreement with previous numerical works, generalizing their findings to arbitrary flow profiles. Our analytical expressions provide estimates to guide ongoing experimental efforts.

Analytical Results from Routine DSSHT and SEHT Monthly Samples

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

Peters, T. B.

2016-08-17

Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the “microbatches” of Integrated Salt Disposition Project (ISDP) Salt Batch (“Macrobatch”) 8B have been analyzed for 238Pu, 90Sr, 137Cs, cations (Inductively Coupled Plasma Emission Spectroscopy - ICPES), and anions (Ion Chromatography Anions - IC-A). The analytical results from the current microbatch samples are similar to those from previous macrobatch samples. The Actinide Removal Process (ARP) and the Modular Caustic-Side Solvent Extraction Unit (MCU) continue to show more than adequate Pu and Sr removal for times when monosodium titanate (MST) is used. Even with nomore » MST strike being performed there exists some small Pu and Sr removal, likely from filtration of fines containing these elements. The Cs removal continues to be excellent, with decontamination factors (DF) averaging 16,400. The bulk chemistry of the DSSHT and SEHT samples do not show any signs of unusual behavior. SRNL recommends that a sample of the strip feed be analyzed for cation and anion content if a further decline in boron concentration is noted in future SEHT samples.« less

Extracting p Λ scattering lengths from heavy ion collisions

NASA Astrophysics Data System (ADS)

Shapoval, V. M.; Erazmus, B.; Lednicky, R.; Sinyukov, Yu. M.

2015-09-01

The source radii previously extracted by the STAR Collaboration from the p -Λ ⊕p ¯-Λ ¯ and p ¯-Λ ⊕p -Λ ¯ correlation functions measured in 10% most central Au+Au collisions at top Relativistic Heavy Ion Collider (RHIC) energy, √{sN N}=200 GeV, differ by a factor of 2. The probable reason for this is the neglect of residual correlation effect in the STAR analysis. In the present paper we analyze baryon correlation functions within the Lednický and Lyuboshitz analytical model, extended to effectively account for the residual correlation contribution. Different analytical approximations for such a contribution are considered. We also use the averaged source radii extracted from hydrokinetic model (HKM) simulations to fit the experimental data. In contrast to the STAR experimental study, the calculations in HKM show both p Λ and p Λ ¯ radii to be quite close, as expected from theoretical considerations. Using the effective Gaussian parametrization of residual correlations we obtain a satisfactory fit to the measured baryon-antibaryon correlation function with the HKM source radius value 3.28 fm. The baryon-antibaryon spin-averaged strong interaction scattering length is also extracted from the fit to the experimental correlation function.

A new modeling strategy for third-order fast high-performance liquid chromatographic data with fluorescence detection. Quantitation of fluoroquinolones in water samples.

PubMed

Alcaráz, Mirta R; Bortolato, Santiago A; Goicoechea, Héctor C; Olivieri, Alejandro C

2015-03-01

Matrix augmentation is regularly employed in extended multivariate curve resolution-alternating least-squares (MCR-ALS), as applied to analytical calibration based on second- and third-order data. However, this highly useful concept has almost no correspondence in parallel factor analysis (PARAFAC) of third-order data. In the present work, we propose a strategy to process third-order chromatographic data with matrix fluorescence detection, based on an Augmented PARAFAC model. The latter involves decomposition of a three-way data array augmented along the elution time mode with data for the calibration samples and for each of the test samples. A set of excitation-emission fluorescence matrices, measured at different chromatographic elution times for drinking water samples, containing three fluoroquinolones and uncalibrated interferences, were evaluated using this approach. Augmented PARAFAC exploits the second-order advantage, even in the presence of significant changes in chromatographic profiles from run to run. The obtained relative errors of prediction were ca. 10 % for ofloxacin, ciprofloxacin, and danofloxacin, with a significant enhancement in analytical figures of merit in comparison with previous reports. The results are compared with those furnished by MCR-ALS.

Analytic model for washout of HCl(g) from dispersing rocket exhaust clouds

NASA Technical Reports Server (NTRS)

Pellett, G. L.

1981-01-01

The potential is investigated that precipitation scavenging of HCl from large solid rocket exhaust clouds may result in unacceptably acidic rain in the Cape Canaveral, Florida, area before atmospheric dispersion reduces HCl concentrations to safe limits. Several analytic expressions for HCl(g) and HCl(g + aq) washout are derived; a geometric mean washout coefficient is recommended. A previous HCl washout model is refined and applied to a space shuttle case (70 t HCl exhausted up to 4 km) and eight Titan 3 (60 percent less exhaust) dispersion cases. The vertical column density (sigma) decays were deduced by application of a multilayer Gaussian diffusion model to seven standard meteorological regimes for overland advection. The Titan 3 decays of sigma and initial rain pH differed greatly among regimes; e.g., a range of 2 pH units was spanned at x 100 km downwind and t = 2 hr. Environmentally significant pH's .5 for infrequent exposures were shown possible at X = 50 km and t 5 hr for the two least dispersive Titan 3 cases. Representative examples of downwind rainwater pH and G(X) are analyzed. Factors affecting the validity of the results are discussed.

An analytical model for solute transport in an infiltration tracer test in soil with a shallow groundwater table

NASA Astrophysics Data System (ADS)

Liang, Ching-Ping; Hsu, Shao-Yiu; Chen, Jui-Sheng

2016-09-01

It is recommended that an in-situ infiltration tracer test is considered for simultaneously determining the longitudinal and transverse dispersion coefficients in soil. Analytical solutions have been derived for two-dimensional advective-dispersive transport in a radial geometry in the literature which can be used for interpreting the result of such a tracer test. However, these solutions were developed for a transport domain with an unbounded-radial extent and an infinite thickness of vadose zone which might not be realistically manifested in the actual solute transport during a field infiltration tracer test. Especially, the assumption of infinite thickness of vadose zone should be invalid for infiltration tracer tests conducted in soil with a shallow groundwater table. This paper describes an analytical model for interpreting the results of an infiltration tracer test based on improving the transport domain with a bounded-radial extent and a finite thickness of vadose zone. The analytical model is obtained with the successive application of appropriate integral transforms and their corresponding inverse transforms. A comparison of the newly derived analytical solution against the previous analytical solutions in which two distinct sets of radial extent and thickness of vadose zone are considered is conducted to determine the influence of the radial and exit boundary conditions on the solute transport. The results shows that both the radial and exit boundary conditions substantially affect the trailing segment of the breakthrough curves for a soil medium with large dispersion coefficients. Previous solutions derived for a transport domain with an unbounded-radial and an infinite thickness of vadose zone boundary conditions give lower concentration predictions compared with the proposed solution at late times. Moreover, the differences between two solutions are amplified when the observation positions are near the groundwater table. In addition, we compare our solution against the approximate solutions that derived from the previous analytical solution and has been suggested to serve as fast tools for simultaneously estimating the longitudinal and transverse dispersion coefficients. The results indicate that the approximate solutions offer predictions that are markedly distinct from our solution for the entire range of dispersion coefficient values. Thus, it is not appropriate to use the approximate solution for interpreting the results of an infiltration tracer test.

An analysis of scientific self-efficacy as a benefit of summer research participation for underrepresented minorities in science, technology, engineering, and mathematics (STEM) fields

NASA Astrophysics Data System (ADS)

Carter, Frances D.

2011-12-01

Low participation and performance in science, technology, engineering, and mathematics (STEM) fields by U.S. citizens are widely recognized as major problems with substantial economic, political, and social ramifications. Studies of collegiate interventions designed to broaden participation in STEM fields suggest that participation in undergraduate research is a key program component that enhances such student outcomes as undergraduate GPA, graduation, persistence in a STEM major, and graduate school enrollment. However, little is known about the mechanisms that are responsible for these positive effects. The current study hypothesizes that undergraduate research participation increases scientific self-efficacy and scientific research proficiency. This hypothesis was tested using data obtained from a survey of minority students from several STEM intervention programs that offer undergraduate research opportunities. Students were surveyed both prior to and following the summer of 2010. Factor analysis was used to examine the factor structure of participants' responses on scientific self-efficacy and scientific research proficiency scales. Difference-in-difference analysis was then applied to the resulting factor score differences to estimate the relationship of summer research participation with scientific self-efficacy and scientific research proficiency. Factor analytic results replicate and further validate previous findings of a general scientific self-efficacy construct (Schultz, 2008). While the factor analytic results for the exploratory scientific research proficiency scale suggest that it was also a measureable construct, the factor structure was not generalizable over time. Potential reasons for the lack of generalizability validity for the scientific research proficiency scale are explored and recommendations for emerging scales are provided. Recent restructuring attempts within federal science agencies threaten the future of STEM intervention programs. Causal estimates of the effect of undergraduate research participation on specific and measurable benefits can play an important role in ensuring the sustainability of STEM intervention programs. Obtaining such estimates requires additional studies that, inter alia, incorporate adequate sample sizes, valid measurement scales, and the ability to account for unobserved variables. Political strategies, such as compromise, can also play an important role in ensuring the sustainability of STEM intervention programs.

Bayesian analysis of multimethod ego-depletion studies favours the null hypothesis.

PubMed

Etherton, Joseph L; Osborne, Randall; Stephenson, Katelyn; Grace, Morgan; Jones, Chas; De Nadai, Alessandro S

2018-04-01

Ego-depletion refers to the purported decrease in performance on a task requiring self-control after engaging in a previous task involving self-control, with self-control proposed to be a limited resource. Despite many published studies consistent with this hypothesis, recurrent null findings within our laboratory and indications of publication bias have called into question the validity of the depletion effect. This project used three depletion protocols involved three different depleting initial tasks followed by three different self-control tasks as dependent measures (total n = 840). For each method, effect sizes were not significantly different from zero When data were aggregated across the three different methods and examined meta-analytically, the pooled effect size was not significantly different from zero (for all priors evaluated, Hedges' g = 0.10 with 95% credibility interval of [-0.05, 0.24]) and Bayes factors reflected strong support for the null hypothesis (Bayes factor > 25 for all priors evaluated). © 2018 The British Psychological Society.

History of the preanalytical phase: a personal view

PubMed Central

Guder, Walter G.

2014-01-01

In the 70ies of the last century, ther term “preanalytical phase” was introduced in the literature. This term describes all actions and aspects of the “brain to brain circle” of the medical laboratory diagnostic procedure happening before the analytical phase. The author describes his personal experiences in the early seventies and the following history of increasing awareness of this phase as the main cause of “laboratory errors”. This includes the definitions of influence and interference factors as well as the first publications in book, internet, CD-Rom and recent App form over the past 40 years. In addition, a short summary of previous developments as prerequesits of laboratory diagnostic actions is described from the middle age matula for urine collection to the blood collection tubes, anticoagulants and centrifuges. The short review gives a personal view on the possible causes of missing awareness of preanalytical causes of error and future aspects of new techniques in regulation of requests to introduction of quality assurance programs for preanalytical factors. PMID:24627712

Analytical study of shimmy of airplane wheels

NASA Technical Reports Server (NTRS)

Bourcier De Carbon, Christian

1952-01-01

The problem of shimmy of a castering wheel, such as the nose wheel of a tricycle gear airplane, is treated analytically. The flexibility of the tire is considered to be the primary cause of shimmy. The rather simple theory developed agrees rather well with previous experimental results. The author suggests that shimmy may be eliminated through a suitable choice of landing gear dimensions in lieu of a damper.

Analytic theory of photoacoustic wave generation from a spheroidal droplet.

PubMed

Li, Yong; Fang, Hui; Min, Changjun; Yuan, Xiaocong

2014-08-25

In this paper, we develop an analytic theory for describing the photoacoustic wave generation from a spheroidal droplet and derive the first complete analytic solution. Our derivation is based on solving the photoacoustic Helmholtz equation in spheroidal coordinates with the separation-of-variables method. As the verification, besides carrying out the asymptotic analyses which recover the standard solutions for a sphere, an infinite cylinder and an infinite layer, we also confirm that the partial transmission and reflection model previously demonstrated for these three geometries still stands. We expect that this analytic solution will find broad practical uses in interpreting experiment results, considering that its building blocks, the spheroidal wave functions (SWFs), can be numerically calculated by the existing computer programs.

Towards an analytical framework for tailoring supercontinuum generation.

PubMed

Castelló-Lurbe, David; Vermeulen, Nathalie; Silvestre, Enrique

2016-11-14

A fully analytical toolbox for supercontinuum generation relying on scenarios without pulse splitting is presented. Furthermore, starting from the new insights provided by this formalism about the physical nature of direct and cascaded dispersive wave emission, a unified description of this radiation in both normal and anomalous dispersion regimes is derived. Previously unidentified physics of broadband spectra reported in earlier works is successfully explained on this basis. Finally, a foundry-compatible few-millimeters-long silicon waveguide allowing octave-spanning supercontinuum generation pumped at telecom wavelengths in the normal dispersion regime is designed, hence showcasing the potential of this new analytical approach.

Analytic theory of alternate multilayer gratings operating in single-order regime.

PubMed

Yang, Xiaowei; Kozhevnikov, Igor V; Huang, Qiushi; Wang, Hongchang; Hand, Matthew; Sawhney, Kawal; Wang, Zhanshan

2017-07-10

Using the coupled wave approach (CWA), we introduce the analytical theory for alternate multilayer grating (AMG) operating in the single-order regime, in which only one diffraction order is excited. Differing from previous study analogizing AMG to crystals, we conclude that symmetrical structure, or equal thickness of the two multilayer materials, is not the optimal design for AMG and may result in significant reduction in diffraction efficiency. The peculiarities of AMG compared with other multilayer gratings are analyzed. An influence of multilayer structure materials on diffraction efficiency is considered. The validity conditions of analytical theory are also discussed.

Analytical collisionless damping rate of geodesic acoustic mode

NASA Astrophysics Data System (ADS)

Ren, H.; Xu, X. Q.

2016-10-01

Collisionless damping of geodesic acoustic mode (GAM) is analytically investigated by considering the finite-orbit-width (FOW) resonance effect to the 3rd order in the gyro-kinetic equations. A concise and transparent expression for the damping rate is presented for the first time. Good agreement is found between the analytical damping rate and the previous TEMPEST simulation result (Xu 2008 et al Phys. Rev. Lett. 100 215001) for systematic q scans. Our result also shows that it is of sufficient accuracy and has to take into account the FOW effect to the 3rd order.

Generalized M-factor of hollow Gaussian beams through a hard-edge circular aperture

NASA Astrophysics Data System (ADS)

Deng, Dongmei

2005-06-01

Based on the generalized truncated second-order moments, the generalized M-factor (MG2-factor) of three-dimensional hollow Gaussian beams (HGBs) through a hard-edge circular aperture is studied in cylindrical coordinate system analytically and numerically. The closed-form expression for the MG2-factor of the truncated HGBs, which is dependent on the truncation parameter β and the beam order n, can be simplified to that of the truncated, the untruncated Gaussian beams and the untruncated HGBs. Also, the power fraction is demonstrated analytically and numerically, which shows that the area of the dark region across the HGBs increases as n increasing.

Field-scale effective matrix diffusion coefficient for fractured rock: results from literature survey.

PubMed

Zhou, Quanlin; Liu, Hui-Hai; Molz, Fred J; Zhang, Yingqi; Bodvarsson, Gudmundur S

2007-08-15

Matrix diffusion is an important mechanism for solute transport in fractured rock. We recently conducted a literature survey on the effective matrix diffusion coefficient, D(m)(e), a key parameter for describing matrix diffusion processes at the field scale. Forty field tracer tests at 15 fractured geologic sites were surveyed and selected for the study, based on data availability and quality. Field-scale D(m)(e) values were calculated, either directly using data reported in the literature, or by reanalyzing the corresponding field tracer tests. The reanalysis was conducted for the selected tracer tests using analytic or semi-analytic solutions for tracer transport in linear, radial, or interwell flow fields. Surveyed data show that the scale factor of the effective matrix diffusion coefficient (defined as the ratio of D(m)(e) to the lab-scale matrix diffusion coefficient, D(m), of the same tracer) is generally larger than one, indicating that the effective matrix diffusion coefficient in the field is comparatively larger than the matrix diffusion coefficient at the rock-core scale. This larger value can be attributed to the many mass-transfer processes at different scales in naturally heterogeneous, fractured rock systems. Furthermore, we observed a moderate, on average trend toward systematic increase in the scale factor with observation scale. This trend suggests that the effective matrix diffusion coefficient is likely to be statistically scale-dependent. The scale-factor value ranges from 0.5 to 884 for observation scales from 5 to 2000 m. At a given scale, the scale factor varies by two orders of magnitude, reflecting the influence of differing degrees of fractured rock heterogeneity at different geologic sites. In addition, the surveyed data indicate that field-scale longitudinal dispersivity generally increases with observation scale, which is consistent with previous studies. The scale-dependent field-scale matrix diffusion coefficient (and dispersivity) may have significant implications for assessing long-term, large-scale radionuclide and contaminant transport events in fractured rock, both for nuclear waste disposal and contaminant remediation.

[Cutaneous melanoma associated with previous nevus].

PubMed

Gutiérrez, María P; Barengo, Mónica; Mainardi, Claudio; Garay, Iliana; Kurpis, María; Ruiz Lascano, Alejandro

2009-01-01

The malignant melanoma is a neoplasia originated from the melanocytes located in the skin and other locations. Even though there is not information regarding its incidence and prevalence in our country, its most important risk factors are known. The melanoma can originate de novo or from previous melanocytic lesions. The concept that a melanocytic nevus can serve as a precursor lesion is supported by clinical and histological evidence. An observational, retrospective and analytical study was carried out in the Hospital Privado de Córdoba. The objective was to determine which is the frequency of association of malignant melanomas that develop on previous nevus. A total of 134 melanomas were analyzed. In 32 cases (24%), the melanomas were histologically associated with nevus, in individuals with Breslow's depth bigger than 1 mm the percentage of association was 16.3% while in those exhibiting Breslow smaller than 1 mm the percentage of association was 38.1%. Having evaluated the melanomas in relation to the Breslow and Clark classification, we observed that the nevus associated melanoma group showed less Breslow thickness and low Clark levels, which, by statistical analysis were shown to be significant predictors of the probabilty of finding this association (p < 0.027). This study demonstrates that the tumor thickness by itself is an independent predictive factor of the association melanoma-nevus. However, the rest of the variables studied did not throw significant results from the statistical point of view. In conclusion, patients must be educated for the control of new pigmented injuries as well as for the modification of preexisting nevi.

Nonlinear Analyte Concentration Gradients for One-Step Kinetic Analysis Employing Optical Microring Resonators

PubMed Central

Marty, Michael T.; Kuhnline Sloan, Courtney D.; Bailey, Ryan C.; Sligar, Stephen G.

2012-01-01

Conventional methods to probe the binding kinetics of macromolecules at biosensor surfaces employ a stepwise titration of analyte concentrations and measure the association and dissociation to the immobilized ligand at each concentration level. It has previously been shown that kinetic rates can be measured in a single step by monitoring binding as the analyte concentration increases over time in a linear gradient. We report here the application of nonlinear analyte concentration gradients for determining kinetic rates and equilibrium binding affinities in a single experiment. A versatile nonlinear gradient maker is presented, which is easily applied to microfluidic systems. Simulations validate that accurate kinetic rates can be extracted for a wide range of association and dissociation rates, gradient slopes and curvatures, and with models for mass transport. The nonlinear analyte gradient method is demonstrated with a silicon photonic microring resonator platform to measure prostate specific antigen-antibody binding kinetics. PMID:22686186

Nonlinear analyte concentration gradients for one-step kinetic analysis employing optical microring resonators.

PubMed

Marty, Michael T; Sloan, Courtney D Kuhnline; Bailey, Ryan C; Sligar, Stephen G

2012-07-03

Conventional methods to probe the binding kinetics of macromolecules at biosensor surfaces employ a stepwise titration of analyte concentrations and measure the association and dissociation to the immobilized ligand at each concentration level. It has previously been shown that kinetic rates can be measured in a single step by monitoring binding as the analyte concentration increases over time in a linear gradient. We report here the application of nonlinear analyte concentration gradients for determining kinetic rates and equilibrium binding affinities in a single experiment. A versatile nonlinear gradient maker is presented, which is easily applied to microfluidic systems. Simulations validate that accurate kinetic rates can be extracted for a wide range of association and dissociation rates, gradient slopes, and curvatures, and with models for mass transport. The nonlinear analyte gradient method is demonstrated with a silicon photonic microring resonator platform to measure prostate specific antigen-antibody binding kinetics.

Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework

PubMed Central

Matej, Samuel; Daube-Witherspoon, Margaret E.; Karp, Joel S.

2016-01-01

Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of TOF scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (Direct Image Reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias vs. variance performance to iterative TOF reconstruction with a matched resolution model. PMID:27032968

Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework

NASA Astrophysics Data System (ADS)

Matej, Samuel; Daube-Witherspoon, Margaret E.; Karp, Joel S.

2016-05-01

Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of time-of-flight (TOF) scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (DIRECT: direct image reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias versus variance performance to iterative TOF reconstruction with a matched resolution model.

Analytical Model and Optimized Design of Power Transmitting Coil for Inductively Coupled Endoscope Robot.

PubMed

Ke, Quan; Luo, Weijie; Yan, Guozheng; Yang, Kai

2016-04-01

A wireless power transfer system based on the weakly inductive coupling makes it possible to provide the endoscope microrobot (EMR) with infinite power. To facilitate the patients' inspection with the EMR system, the diameter of the transmitting coil is enlarged to 69 cm. Due to the large transmitting range, a high quality factor of the Litz-wire transmitting coil is a necessity to ensure the intensity of magnetic field generated efficiently. Thus, this paper builds an analytical model of the transmitting coil, and then, optimizes the parameters of the coil by enlarging the quality factor. The lumped model of the transmitting coil includes three parameters: ac resistance, self-inductance, and stray capacitance. Based on the exact two-dimension solution, the accurate analytical expression of ac resistance is derived. Several transmitting coils of different specifications are utilized to verify this analytical expression, being in good agreements with the measured results except the coils with a large number of strands. Then, the quality factor of transmitting coils can be well predicted with the available analytical expressions of self- inductance and stray capacitance. Owing to the exact estimation of quality factor, the appropriate coil turns of the transmitting coil is set to 18-40 within the restrictions of transmitting circuit and human tissue issues. To supply enough energy for the next generation of the EMR equipped with a Ø9.5×10.1 mm receiving coil, the coil turns of the transmitting coil is optimally set to 28, which can transfer a maximum power of 750 mW with the remarkable delivering efficiency of 3.55%.

Evaluation of spacecraft toxic gas removal agents

NASA Technical Reports Server (NTRS)

1972-01-01

A study of the decomposition of various compounds adsorbed on charcoal was made, with a view toward providing a critical appraisal of previous data from charcoal adsorption studies. It was found that thermal decomposition occurs at temperature lower than previously suspected during the charcoal stripping process. A discussion is presented dealing with the various types of reactions found. A rough, quantitative scheme for correcting previous analytical results is developed and presented.

Factor Analysis and Counseling Research

ERIC Educational Resources Information Center

Weiss, David J.

1970-01-01

Topics discussed include factor analysis versus cluster analysis, analysis of Q correlation matrices, ipsativity and factor analysis, and tests for the significance of a correlation matrix prior to application of factor analytic techniques. Techniques for factor extraction discussed include principal components, canonical factor analysis, alpha…

An all-purpose metric for the exterior of any kind of rotating neutron star

NASA Astrophysics Data System (ADS)

Pappas, George; Apostolatos, Theocharis A.

2013-03-01

We have tested the appropriateness of two-soliton analytic metric to describe the exterior of all types of neutron stars, no matter what their equation of state or rotation rate is. The particular analytic solution of the vacuum Einstein equations proved quite adjustable to mimic the metric functions of all numerically constructed neutron star models that we used as a testbed. The neutron star models covered a wide range of stiffness, with regard to the equation of state of their interior, and all rotation rates up to the maximum possible rotation rate allowed for each such star. Apart from the metric functions themselves, we have compared the radius of the innermost stable circular orbit RISCO, the orbital frequency Ω equiv dφ /dt of circular geodesics, and their epicyclic frequencies Ωρ, Ωz, as well as the change of the energy of circular orbits per logarithmic change of orbital frequency Δ tilde{E}. All these quantities, calculated by means of the two-soliton analytic metric, fitted with good accuracy the corresponding numerical ones as in previous analogous comparisons (although previous attempts were restricted to neutron star models with either high or low rotation rates). We believe that this particular analytic solution could be considered as an analytic faithful representation of the gravitation field of any rotating neutron star with such accuracy, that one could explore the interior structure of a neutron star by using this space-time to interpret observations of astrophysical processes that take place around it.

Overview of mycotoxin methods, present status and future needs.

PubMed

Gilbert, J

1999-01-01

This article reviews current requirements for the analysis for mycotoxins in foods and identifies legislative as well as other factors that are driving development and validation of new methods. New regulatory limits for mycotoxins and analytical quality assurance requirements for laboratories to only use validated methods are seen as major factors driving developments. Three major classes of methods are identified which serve different purposes and can be categorized as screening, official and research. In each case the present status and future needs are assessed. In addition to an overview of trends in analytical methods, some other areas of analytical quality assurance such as participation in proficiency testing and reference materials are identified.

Enhancement in the sensitivity of microfluidic enzyme-linked immunosorbent assays through analyte preconcentration.

PubMed

Yanagisawa, Naoki; Dutta, Debashis

2012-08-21

In this Article, we describe a microfluidic enzyme-linked immunosorbent assay (ELISA) method whose sensitivity can be substantially enhanced through preconcentration of the target analyte around a semipermeable membrane. The reported preconcentration has been accomplished in our current work via electrokinetic means allowing a significant increase in the amount of captured analyte relative to nonspecific binding in the trapping/detection zone. Upon introduction of an enzyme substrate into this region, the rate of generation of the ELISA reaction product (resorufin) was observed to increase by over a factor of 200 for the sample and 2 for the corresponding blank compared to similar assays without analyte trapping. Interestingly, in spite of nonuniformities in the amount of captured analyte along the surface of our analysis channel, the measured fluorescence signal in the preconcentration zone increased linearly with time over an enzyme reaction period of 30 min and at a rate that was proportional to the analyte concentration in the bulk sample. In our current study, the reported technique has been shown to reduce the smallest detectable concentration of the tumor marker CA 19-9 and Blue Tongue Viral antibody by over 2 orders of magnitude compared to immunoassays without analyte preconcentration. When compared to microwell based ELISAs, the reported microfluidic approach not only yielded a similar improvement in the smallest detectable analyte concentration but also reduced the sample consumption in the assay by a factor of 20 (5 μL versus 100 μL).

Temperature dependence of single-event burnout in n-channel power MOSFET's

NASA Astrophysics Data System (ADS)

Johnson, G. H.; Schrimpf, R. D.; Galloway, K. F.; Koga, R.

1994-03-01

The temperature dependence of single-event burnout (SEB) in n-channel power metal-oxide-semiconductor field effect transistors (MOSFET's) is investigated experimentally and analytically. Experimental data are presented which indicate that the SEB susceptibility of the power MOSFET decreases with increasing temperature. A previously reported analytical model that describes the SEB mechanism is updated to include temperature variations. This model is shown to agree with the experimental trends.

SOMFlow: Guided Exploratory Cluster Analysis with Self-Organizing Maps and Analytic Provenance.

PubMed

Sacha, Dominik; Kraus, Matthias; Bernard, Jurgen; Behrisch, Michael; Schreck, Tobias; Asano, Yuki; Keim, Daniel A

2018-01-01

Clustering is a core building block for data analysis, aiming to extract otherwise hidden structures and relations from raw datasets, such as particular groups that can be effectively related, compared, and interpreted. A plethora of visual-interactive cluster analysis techniques has been proposed to date, however, arriving at useful clusterings often requires several rounds of user interactions to fine-tune the data preprocessing and algorithms. We present a multi-stage Visual Analytics (VA) approach for iterative cluster refinement together with an implementation (SOMFlow) that uses Self-Organizing Maps (SOM) to analyze time series data. It supports exploration by offering the analyst a visual platform to analyze intermediate results, adapt the underlying computations, iteratively partition the data, and to reflect previous analytical activities. The history of previous decisions is explicitly visualized within a flow graph, allowing to compare earlier cluster refinements and to explore relations. We further leverage quality and interestingness measures to guide the analyst in the discovery of useful patterns, relations, and data partitions. We conducted two pair analytics experiments together with a subject matter expert in speech intonation research to demonstrate that the approach is effective for interactive data analysis, supporting enhanced understanding of clustering results as well as the interactive process itself.

76 FR 26363 - Medicare Program; Prospective Payment System and Consolidated Billing for Skilled Nursing...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-06

... previous case-mix classification system. It also includes a discussion of a Non-Therapy Ancillary component... facilities. Finally, it proposes certain changes relating to the payment of group therapy services and... Payment for SNF Non-Therapy Ancillary Costs 1. Previous Research 2. Conceptual Analysis 3. Analytic Sample...

Using Similarities and Differences: A Meta-Analysis of Its Effects and Emergent Patterns

ERIC Educational Resources Information Center

Apthorp, Helen S.; Igel, Charles; Dean, Ceri

2012-01-01

The purpose of the study was to update previous meta-analytic findings on the effectiveness of using similarities and differences as an instructional strategy. The strategy includes facilitating student comparison, classification, use of analogies, and use of metaphors. Previously, Marzano, Pickering, and Pollock reported a mean effect size of…

A development of logistics management models for the Space Transportation System

NASA Technical Reports Server (NTRS)

Carrillo, M. J.; Jacobsen, S. E.; Abell, J. B.; Lippiatt, T. F.

1983-01-01

A new analytic queueing approach was described which relates stockage levels, repair level decisions, and the project network schedule of prelaunch operations directly to the probability distribution of the space transportation system launch delay. Finite source population and limited repair capability were additional factors included in this logistics management model developed specifically for STS maintenance requirements. Data presently available to support logistics decisions were based on a comparability study of heavy aircraft components. A two-phase program is recommended by which NASA would implement an integrated data collection system, assemble logistics data from previous STS flights, revise extant logistics planning and resource requirement parameters using Bayes-Lin techniques, and adjust for uncertainty surrounding logistics systems performance parameters. The implementation of these recommendations can be expected to deliver more cost-effective logistics support.

The shape parameter and its modification for defining coastal profiles

NASA Astrophysics Data System (ADS)

Türker, Umut; Kabdaşli, M. Sedat

2009-03-01

The shape parameter is important for the theoretical description of the sandy coastal profiles. This parameter has previously been defined as a function of the sediment-settling velocity. However, the settling velocity cannot be characterized over a wide range of sediment grains. This, in turn, limits the calculation of the shape parameter over a wide range. This paper provides a simpler and faster analytical equation to describe the shape parameter. The validity of the equation has been tested and compared with the previously estimated values given in both graphical and tabular forms. The results of this study indicate that the analytical solutions of the shape parameter improved the usability of profile better than graphical solutions, predicting better results both at the surf zone and offshore.

Theoretical Assessment of Compressibility Factor of Gases by Using Second Virial Coefficient

NASA Astrophysics Data System (ADS)

Mamedov, Bahtiyar A.; Somuncu, Elif; Askerov, Iskender M.

2018-01-01

We present a new analytical approximation for determining the compressibility factor of real gases at various temperature values. This algorithm is suitable for the accurate evaluation of the compressibility factor using the second virial coefficient with a Lennard-Jones (12-6) potential. Numerical examples are presented for the gases H2, N2, He, CO2, CH4 and air, and the results are compared with other studies in the literature. Our results showed good agreement with the data in the literature. The consistency of the results demonstrates the effectiveness of our analytical approximation for real gases.

Selected field and analytical methods and analytical results in the Dutch Flats area, western Nebraska, 1995-99

USGS Publications Warehouse

Verstraeten, Ingrid M.; Steele, G.V.; Cannia, J.C.; Bohlke, J.K.; Kraemer, T.E.; Hitch, D.E.; Wilson, K.E.; Carnes, A.E.

2001-01-01

A study of the water resources of the Dutch Flats area in the western part of the North Platte Natural Resources District, western Nebraska, was conducted from 1995 through 1999 to describe the surface water and hydrogeology, the spatial distribution of selected water-quality constituents in surface and ground water, and the surface-water/ground-water interaction in selected areas. This report describes the selected field and analytical methods used in the study and selected analytical results from the study not previously published. Specifically, dissolved gases, age-dating data, and other isotopes collected as part of an intensive sampling effort in August and November 1998 and all uranium and uranium isotope data collected through the course of this study are included in the report.

An economic analysis of pregnancy resolution in Virginia: specific as to race and residence.

PubMed

Liu, G G

1995-01-01

This study analyses an economic model of pregnancy resolution; that is, a model of the choice by a pregnant woman to abort her fetus or carry it to term. This analysis, using an analytical model derived from the household utility framework, adds to previous research by presenting race- and residence-specific estimates of how individual characteristics, history of abortion, and the community-based factors determine women's choices of giving birth vs. aborting. The main data for estimating the model were drawn from the 1984 vital statistics of all induced abortions and live births in the Commonwealth of Virginia. The major findings indicate that low parental education, high maternal age, previous early abortions, and the availability of abortion providers all significantly reduce the probability of choosing the live birth option. Married status and the availability of family planning clinics significantly increase the probability of the live birth option. The findings also suggest that women's choices between abortion and live birth vary substantially with race (White vs. Black) and residential (urban vs. rural) location.

The Structure of Temperament in Preschoolers: A Two-Stage Factor Analytic Approach

PubMed Central

Dyson, Margaret W.; Olino, Thomas M.; Durbin, C. Emily; Goldsmith, H. Hill; Klein, Daniel N.

2012-01-01

The structure of temperament traits in young children has been the subject of extensive debate, with separate models proposing different trait dimensions. This research has relied almost exclusively on parent-report measures. The present study used an alternative approach, a laboratory observational measure, to explore the structure of temperament in preschoolers. A 2-stage factor analytic approach, exploratory factor analyses (n = 274) followed by confirmatory factor analyses (n = 276), was used. We retrieved an adequately fitting model that consisted of 5 dimensions: Sociability, Positive Affect/Interest, Dysphoria, Fear/Inhibition, and Constraint versus Impulsivity. This solution overlaps with, but is also distinct from, the major models derived from parent-report measures. PMID:21859196

[Determining factors in the sedation of geriatric and oncology patients treated at home].

PubMed

Zamora-Mur, A; García-Foncillas, R; Zamora-Catevilla, A; Nabal-Vicuña, M; Calderero-Aragón, V; Lostalé-Latorre, F

2017-04-01

Sedation, used as a therapeutic measure in the field of Palliative Care, continues to present difficulties for many professionals in its management and indications. Is varied existing literature in this regard, often exclusive cancer patients. Our objective is to analyse the characteristics of patients attended by a Home Care Support Team who required sedation compared to non-sedated patients, for possible determining factors for its use that could help in decision-making. A prospective analytical study conducted in Barbastro (Huesca) from September 2007 to February 2011. The study population are patients referred to the Home Care Support Team of Barbastro. Age, sex, medical history, symptoms, previous and current Barthel, Karnofsky, primary caregiver, previous drugs, drugs after intervention, sedation yes/no. Required sedation 16.6% (n=106) of the cases (N=638). Sedated patients were younger, with no differences in sex, and the large majority (83%) were oncology patients. The presence of metastases showed no differences in need for sedation. Sedated patients have an increased functional impairment, determined by Barthel index decreased and a worse Karnofsky. Sedated patients showed increased frequency of uncontrolled symptoms, except psychomotor agitation, a fact determined by the medications used pre- and post-intervention. The presence of neoplastic disease, marked with existence of functional decline, and uncontrolled clinical need for certain medications to control symptoms may determine the need for sedation at the end of the process, above other factors such as patient comorbidity. Copyright © 2016 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

The Effects of Added Hydrogen on Noble Gas Discharges Used as Ambient Desorption/Ionization Sources for Mass Spectrometry

NASA Astrophysics Data System (ADS)

Ellis, Wade C.; Lewis, Charlotte R.; Openshaw, Anna P.; Farnsworth, Paul B.

2016-09-01

We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration.

The pitfalls of hair analysis for toxicants in clinical practice: three case reports.

PubMed Central

Frisch, Melissa; Schwartz, Brian S

2002-01-01

Hair analysis is used to assess exposure to heavy metals in patients presenting with nonspecific symptoms and is a commonly used procedure in patients referred to our clinic. We are frequently called on to evaluate patients who have health-related concerns as a result of hair analysis. Three patients first presented to outside physicians with nonspecific, multisystemic symptoms. A panel of analytes was measured in hair, and one or more values were interpreted as elevated. As a result of the hair analysis and other unconventional diagnostic tests, the patients presented to us believing they suffered from metal toxicity. In this paper we review the clinical efficacy of this procedure within the context of a patient population with somatic disorders and no clear risk factors for metal intoxication. We also review limitations of hair analysis in this setting; these limitations include patient factors such as low pretest probability of disease and test factors such as the lack of validation of analytic techniques, the inability to discern between exogenous contaminants and endogenous toxicants in hair, the variability of analytic procedures, low interlaboratory reliability, and the increased likelihood of false positive test results in the measurement of panels of analytes. PMID:11940463

Rapid analysis of aminoglycoside antibiotics in bovine tissues using disposable pipette extraction and ultrahigh performance liquid chromatography-tandem mass spectrometry.

PubMed

Lehotay, Steven J; Mastovska, Katerina; Lightfield, Alan R; Nuñez, Alberto; Dutko, Terry; Ng, Chilton; Bluhm, Louis

2013-10-25

A high-throughput qualitative screening and identification method for 9 aminoglycosides of regulatory interest has been developed, validated, and implemented for bovine kidney, liver, and muscle tissues. The method involves extraction at previously validated conditions, cleanup using disposable pipette extraction, and analysis by a 3 min ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method. The drug analytes include neomycin, streptomycin, dihydrosptreptomycin, and spectinomycin, which have residue tolerances in bovine in the US, and kanamicin, gentamicin, apramycin, amikacin, and hygromycin, which do not have US tolerances established in bovine tissues. Tobramycin was used as an internal standard. An additional drug, paromomycin also was validated in the method, but it was dropped during implementation due to conversion of neomycin into paromomycin. Proposed fragmentation patterns for the monitored ions of each analyte were elucidated with the aid of high resolution MS using a quadrupole-time-of-flight instrument. Recoveries from spiking experiments at regulatory levels of concern showed that all analytes averaged 70-120% recoveries in all tissues, except hygromycin averaged 61% recovery. Lowest calibrated levels were as low as 0.005 μg/g in matrix extracts, which approximately corresponded to the limit of detection for screening purposes. Drug identifications at levels <0.05 μg/g were made in spiked and/or real samples for all analytes and tissues tested. Analyses of 60 samples from 20 slaughtered cattle previously screened positive for aminoglycosides showed that this method worked well in practice. The UHPLC-MS/MS method has several advantages compared to the previous microbial inhibition screening assay, especially for distinguishing individual drugs from a mixture and improving identification of gentamicin in tissue samples. Published by Elsevier B.V.

Semi-analytical integration of the Earth's precession-nutation based on the GCRS coordinates of the CIP unit vector

NASA Astrophysics Data System (ADS)

Capitaine, N.; Folgueira, M.

2012-12-01

In a previous paper (Capitaine et al. 2006), referred here as Paper I, we demonstrated the possibility of integrating the Earth's rotational motion in terms of the coordinates (X, Y ) of the celestial intermediate pole (CIP) unit vector in the Geocentric celestial reference system (GCRS). Here, we report on the approach that has been followed for solving the equations in the case of an axially symmetric rigid Earth and the semi-analytical (X, Y ) solution obtained from the expression of the external torque acting on the Earth derived from the most complete semi-analytical solutions for the Earth, Moon and planets.

Quantifying risks with exact analytical solutions of derivative pricing distribution

NASA Astrophysics Data System (ADS)

Zhang, Kun; Liu, Jing; Wang, Erkang; Wang, Jin

2017-04-01

Derivative (i.e. option) pricing is essential for modern financial instrumentations. Despite of the previous efforts, the exact analytical forms of the derivative pricing distributions are still challenging to obtain. In this study, we established a quantitative framework using path integrals to obtain the exact analytical solutions of the statistical distribution for bond and bond option pricing for the Vasicek model. We discuss the importance of statistical fluctuations away from the expected option pricing characterized by the distribution tail and their associations to value at risk (VaR). The framework established here is general and can be applied to other financial derivatives for quantifying the underlying statistical distributions.

Analytical theory of coherent synchrotron radiation wakefield of short bunches shielded by conducting parallel plates

NASA Astrophysics Data System (ADS)

Stupakov, Gennady; Zhou, Demin

2016-04-01

We develop a general model of coherent synchrotron radiation (CSR) impedance with shielding provided by two parallel conducting plates. This model allows us to easily reproduce all previously known analytical CSR wakes and to expand the analysis to situations not explored before. It reduces calculations of the impedance to taking integrals along the trajectory of the beam. New analytical results are derived for the radiation impedance with shielding for the following orbits: a kink, a bending magnet, a wiggler of finite length, and an infinitely long wiggler. All our formulas are benchmarked against numerical simulations with the CSRZ computer code.

Analytical electron microscopy of Mg-SiO smokes - A comparison with infrared and XRD studies

NASA Technical Reports Server (NTRS)

Rietmeijer, F. J. M.; Nuth, J. A.; Mackinnon, I. D. R.

1986-01-01

Analytical electron microscopy conducted for Mg-SiO smokes (experimentally obtained from samples previously characterized by IR spectroscopy) indicates that the microcrystallinity content of unannealed smokes increases with increased annealing for up to 30 hr. The growth of forsterite microcrystallites in the initially nonstoichiometric smokes may give rise to the contemporaneous growth of the SiO polymorph tridymite and MgO; after 4 hr of annealing, these react to form enstatite. It is suggested that XRD analysis and IR spectroscopy should be conducted in conjunction with detailed analytical electron microscopy for the detection of emerging crystallinity in vapor-phase condensates.

Analytical theory of coherent synchrotron radiation wakefield of short bunches shielded by conducting parallel plates

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

Stupakov, Gennady; Zhou, Demin

2016-04-21

We develop a general model of coherent synchrotron radiation (CSR) impedance with shielding provided by two parallel conducting plates. This model allows us to easily reproduce all previously known analytical CSR wakes and to expand the analysis to situations not explored before. It reduces calculations of the impedance to taking integrals along the trajectory of the beam. New analytical results are derived for the radiation impedance with shielding for the following orbits: a kink, a bending magnet, a wiggler of finite length, and an infinitely long wiggler. All our formulas are benchmarked against numerical simulations with the CSRZ computer code.

Comparison of Three Methods for Wind Turbine Capacity Factor Estimation

PubMed Central

Ditkovich, Y.; Kuperman, A.

2014-01-01

Three approaches to calculating capacity factor of fixed speed wind turbines are reviewed and compared using a case study. The first “quasiexact” approach utilizes discrete wind raw data (in the histogram form) and manufacturer-provided turbine power curve (also in discrete form) to numerically calculate the capacity factor. On the other hand, the second “analytic” approach employs a continuous probability distribution function, fitted to the wind data as well as continuous turbine power curve, resulting from double polynomial fitting of manufacturer-provided power curve data. The latter approach, while being an approximation, can be solved analytically thus providing a valuable insight into aspects, affecting the capacity factor. Moreover, several other merits of wind turbine performance may be derived based on the analytical approach. The third “approximate” approach, valid in case of Rayleigh winds only, employs a nonlinear approximation of the capacity factor versus average wind speed curve, only requiring rated power and rotor diameter of the turbine. It is shown that the results obtained by employing the three approaches are very close, enforcing the validity of the analytically derived approximations, which may be used for wind turbine performance evaluation. PMID:24587755

Child development: analysis of a new concept.

PubMed

de Souza, Juliana Martins; Veríssimo, Maria de La Ó Ramallo

2015-01-01

To perform concept analysis of the term child development (CD) and submit it to review by experts. Analysis of concept according to the hybrid model, in three phases: theoretical phase, with literature review; field phase of qualitative research with professionals who care for children; and analytical phase, of articulation of data from previous steps, based on the bioecological theory of development. The new definition was analyzed by experts in a focus group. Project approved by the Research Ethics Committee. We reviewed 256 articles, from 12 databases and books, and interviewed 10 professionals, identifying that: The CD concept has as antecedents aspects of pregnancy, factors of the child, factors of context, highlighting the relationships and child care, and social aspects; its consequences can be positive or negative, impacting on society; its attributes are behaviors and abilities of the child; its definitions are based on maturation, contextual perspectives or both. The new definition elaborated in concept analysis was validated by nine experts in focus group. It expresses the magnitude of the phenomenon and factors not presented in other definitions. The research produced a new definition of CD that can improve nursing classifications for the comprehensive care of the child.

Calibration of neutron detectors on the Joint European Torus.

PubMed

Batistoni, Paola; Popovichev, S; Conroy, S; Lengar, I; Čufar, A; Abhangi, M; Snoj, L; Horton, L

2017-10-01

The present paper describes the findings of the calibration of the neutron yield monitors on the Joint European Torus (JET) performed in 2013 using a 252 Cf source deployed inside the torus by the remote handling system, with particular regard to the calibration of fission chambers which provide the time resolved neutron yield from JET plasmas. The experimental data obtained in toroidal, radial, and vertical scans are presented. These data are first analysed following an analytical approach adopted in the previous neutron calibrations at JET. In this way, a calibration function for the volumetric plasma source is derived which allows us to understand the importance of the different plasma regions and of different spatial profiles of neutron emissivity on fission chamber response. Neutronics analyses have also been performed to calculate the correction factors needed to derive the plasma calibration factors taking into account the different energy spectrum and angular emission distribution of the calibrating (point) 252 Cf source, the discrete positions compared to the plasma volumetric source, and the calibration circumstances. All correction factors are presented and discussed. We discuss also the lessons learnt which are the basis for the on-going 14 MeV neutron calibration at JET and for ITER.

Child development: analysis of a new concept1

PubMed Central

de Souza, Juliana Martins; Veríssimo, Maria de La Ó Ramallo

2015-01-01

Objectives: to perform concept analysis of the term child development (CD) and submit it to review by experts. Method: analysis of concept according to the hybrid model, in three phases: theoretical phase, with literature review; field phase of qualitative research with professionals who care for children; and analytical phase, of articulation of data from previous steps, based on the bioecological theory of development. The new definition was analyzed by experts in a focus group. Project approved by the Research Ethics Committee. Results: we reviewed 256 articles, from 12 databases and books, and interviewed 10 professionals, identifying that: The CD concept has as antecedents aspects of pregnancy, factors of the child, factors of context, highlighting the relationships and child care, and social aspects; its consequences can be positive or negative, impacting on society; its attributes are behaviors and abilities of the child; its definitions are based on maturation, contextual perspectives or both. The new definition elaborated in concept analysis was validated by nine experts in focus group. It expresses the magnitude of the phenomenon and factors not presented in other definitions. Conclusion: the research produced a new definition of CD that can improve nursing classifications for the comprehensive care of the child. PMID:26626001

Changes in prescribed doses for the Seattle neutron therapy system

NASA Astrophysics Data System (ADS)

Popescu, A.

2008-06-01

From the beginning of the neutron therapy program at the University of Washington Medical Center, the neutron dose distribution in tissue has been calculated using an in-house treatment planning system called PRISM. In order to increase the accuracy of the absorbed dose calculations, two main improvements were made to the PRISM treatment planning system: (a) the algorithm was changed by the addition of an analytical expression of the central axis wedge factor dependence with field size and depth developed at UWMC. Older versions of the treatment-planning algorithm used a constant central axis wedge factor; (b) a complete newly commissioned set of measured data was introduced in the latest version of PRISM. The new version of the PRISM algorithm allowed for the use of the wedge profiles measured at different depths instead of one wedge profile measured at one depth. The comparison of the absorbed dose calculations using the old and the improved algorithm showed discrepancies mainly due to the missing central axis wedge factor dependence with field size and depth and due to the absence of the wedge profiles at depths different from 10 cm. This study concludes that the previously reported prescribed doses for neutron therapy should be changed.

A novel scale for measuring mixed states in bipolar disorder.

PubMed

Cavanagh, Jonathan; Schwannauer, Matthias; Power, Mick; Goodwin, Guy M

2009-01-01

Conventional descriptions of bipolar disorder tend to treat the mixed state as something of an afterthought. There is no scale that specifically measures the phenomena of the mixed state. This study aimed to test a novel scale for mixed state in a clinical and community population of bipolar patients. The scale included clinically relevant symptoms of both mania and depression in a bivariate scale. Recovered respondents were asked to recall their last manic episode. The scale allowed endorsement of one or more of the manic and depressive symptoms. Internal consistency analyses were carried out using Cronbach alpha. Factor analysis was carried out using a standard Principal Components Analysis followed by Varimax Rotation. A confirmatory factor analytic method was used to validate the scale structure in a representative clinical sample. The reliability analysis gave a Cronbach alpha value of 0.950, with a range of corrected-item-total-scale correlations from 0.546 (weight change) to 0.830 (mood). The factor analysis revealed a two-factor solution for the manic and depressed items which accounted for 61.2% of the variance in the data. Factor 1 represented physical activity, verbal activity, thought processes and mood. Factor 2 represented eating habits, weight change, passage of time and pain sensitivity. This novel scale appears to capture the key features of mixed states. The two-factor solution fits well with previous models of bipolar disorder and concurs with the view that mixed states may be more than the sum of their parts.

Heat Loads Due to Small Penetrations in Multilayer Insulation Blankets

NASA Technical Reports Server (NTRS)

Johnson, W. L.; Heckle, K. W.; Fesmire, J. E.

2017-01-01

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to each the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fouriers Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at 76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Contact variables for exposure to avian influenza H5N1 virus at the human-animal interface.

PubMed

Rabinowitz, P; Perdue, M; Mumford, E

2010-06-01

Although the highly pathogenic avian influenza H5N1 virus continues to cause infections in both avian and human populations, the specific zoonotic risk factors remain poorly understood. This review summarizes available evidence regarding types of contact associated with transmission of H5N1 virus at the human-animal interface. A systematic search of the published literature revealed five analytical studies and 15 case reports describing avian influenza transmission from animals to humans for further review. Risk factors identified in analytical studies were compared, and World Health Organization-confirmed cases, identified in case reports, were classified according to type of contact reported using a standardized algorithm. Although cases were primarily associated with direct contact with sick/unexpectedly dead birds, some cases reported only indirect contact with birds or contaminated environments or contact with apparently healthy birds. Specific types of contacts or activities leading to exposure could not be determined from data available in the publications reviewed. These results support previous reports that direct contact with sick birds is not the only means of human exposure to avian influenza H5N1 virus. To target public health measures and disease awareness messaging for reducing the risk of zoonotic infection with avian influenza H5N1 virus, the specific types of contacts and activities leading to transmission need to be further understood. The role of environmental virus persistence, shedding of virus by asymptomatic poultry and disease pathophysiology in different avian species relative to human zoonotic risk, as well as specific modes of zoonotic transmission, should be determined.

Heat Loads Due To Small Penetrations In Multilayer Insulation Blankets

NASA Astrophysics Data System (ADS)

Johnson, W. L.; Heckle, K. W.; E Fesmire, J.

2017-12-01

The main penetrations (supports and piping) through multilayer insulation systems for cryogenic tanks have been previously addressed by heat flow measurements. Smaller penetrations due to fasteners and attachments are now experimentally investigated. The use of small pins or plastic garment tag fasteners to ease the handling and construction of multilayer insulation (MLI) blankets goes back many years. While it has long been understood that penetrations and other discontinuities degrade the performance of the MLI blanket, quantification of this degradation has generally been lumped into gross performance multipliers (often called degradation factors or scale factors). Small penetrations contribute both solid conduction and radiation heat transfer paths through the blanket. The conduction is down the stem of the structural element itself while the radiation is through the hole formed during installation of the pin or fastener. Analytical models were developed in conjunction with MLI perforation theory and Fourier’s Law. Results of the analytical models are compared to experimental testing performed on a 10 layer MLI blanket with approximately 50 small plastic pins penetrating the test specimen. The pins were installed at ∼76-mm spacing inches in both directions to minimize the compounding of thermal effects due to localized compression or lateral heat transfer. The testing was performed using a liquid nitrogen boil-off calorimeter (Cryostat-100) with the standard boundary temperatures of 293 K and 78 K. Results show that the added radiation through the holes is much more significant than the conduction down the fastener. The results are shown to be in agreement with radiation theory for perforated films.

Analytical approximate solutions for a general class of nonlinear delay differential equations.

PubMed

Căruntu, Bogdan; Bota, Constantin

2014-01-01

We use the polynomial least squares method (PLSM), which allows us to compute analytical approximate polynomial solutions for a very general class of strongly nonlinear delay differential equations. The method is tested by computing approximate solutions for several applications including the pantograph equations and a nonlinear time-delay model from biology. The accuracy of the method is illustrated by a comparison with approximate solutions previously computed using other methods.

Moderate severity heart failure does not involve a downregulation of myocardial fatty acid oxidation

DTIC Science & Technology

2004-10-01

malonyl-CoA-sensitive form of carnitine palmitoyltransferase is not local - ized exclusively in the outer membrane of rat liver mitochondria . J Biol...for the isolation of fresh mitochondria , both subsarcolemmal and interfibrillar. Analytic methods. Detailed analytic methods have been previously cited...populations of mitochondria , the subsarcolemmal and inter- fibrillar, were isolated from hearts of normal and HF dogs using the procedure of Palmer et al

Design of Structurally Efficient Tapered Struts

NASA Technical Reports Server (NTRS)

Messinger, Ross

2010-01-01

This report describes the analytical study of two full-scale tapered composite struts. The analytical study resulted in the design of two structurally efficient carbon/epoxy struts in accordance with NASA-specified geometries and loading conditions. Detailed stress analysis was performed of the insert, end fitting, and strut body to obtain an optimized weight with positive margins. Two demonstration struts were fabricated based on a well-established design from a previous Space Shuttle strut development program.

Analytic, High-beta Solutions of the Helical Grad-Shafranov Equation

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

D.R. Smith; A.H. Reiman

We present analytic, high-beta ({beta} {approx} O(1)), helical equilibrium solutions for a class of helical axis configurations having large helical aspect ratio, with the helix assumed to be tightly wound. The solutions develop a narrow boundary layer of strongly compressed flux, similar to that previously found in high beta tokamak equilibrium solutions. The boundary layer is associated with a strong localized current which prevents the equilibrium from having zero net current.

Comparisons of Exploratory and Confirmatory Factor Analysis.

ERIC Educational Resources Information Center

Daniel, Larry G.

Historically, most researchers conducting factor analysis have used exploratory methods. However, more recently, confirmatory factor analytic methods have been developed that can directly test theory either during factor rotation using "best fit" rotation methods or during factor extraction, as with the LISREL computer programs developed…

Effect of vibration on retention characteristics of screen acquisition systems. [for surface tension propellant acquisition

NASA Technical Reports Server (NTRS)

Tegart, J. R.; Aydelott, J. C.

1978-01-01

The design of surface tension propellant acquisition systems using fine-mesh screen must take into account all factors that influence the liquid pressure differentials within the system. One of those factors is spacecraft vibration. Analytical models to predict the effects of vibration have been developed. A test program to verify the analytical models and to allow a comparative evaluation of the parameters influencing the response to vibration was performed. Screen specimens were tested under conditions simulating the operation of an acquisition system, considering the effects of such parameters as screen orientation and configuration, screen support method, screen mesh, liquid flow and liquid properties. An analytical model, based on empirical coefficients, was most successful in predicting the effects of vibration.

Thermoelastic damping in thin microrings with two-dimensional heat conduction

NASA Astrophysics Data System (ADS)

Fang, Yuming; Li, Pu

2015-05-01

Accurate determination of thermoelastic damping (TED) is very challenging in the design of micro-resonators. Microrings are widely used in many micro-resonators. In the past, to model the TED effect on the microrings, some analytical models have been developed. However, in the previous works, the heat conduction within the microring is modeled by using the one-dimensional approach. The governing equation for heat conduction is solved only for the one-dimensional heat conduction along the radial thickness of the microring. This paper presents a simple analytical model for TED in microrings. The two-dimensional heat conduction over the thermoelastic temperature gradients along the radial thickness and the circumferential direction are considered in the present model. A two-dimensional heat conduction equation is developed. The solution of the equation is represented by the product of an assumed sine series along the radial thickness and an assumed trigonometric series along the circumferential direction. The analytical results obtained by the present 2-D model show a good agreement with the numerical (FEM) results. The limitations of the previous 1-D model are assessed.

Multicentric Comparative Analytical Performance Study for Molecular Detection of Low Amounts of Toxoplasma gondii from Simulated Specimens▿ †

PubMed Central

Sterkers, Yvon; Varlet-Marie, Emmanuelle; Cassaing, Sophie; Brenier-Pinchart, Marie-Pierre; Brun, Sophie; Dalle, Frédéric; Delhaes, Laurence; Filisetti, Denis; Pelloux, Hervé; Yera, Hélène; Bastien, Patrick

2010-01-01

Although screening for maternal toxoplasmic seroconversion during pregnancy is based on immunodiagnostic assays, the diagnosis of clinically relevant toxoplasmosis greatly relies upon molecular methods. A problem is that this molecular diagnosis is subject to variation of performances, mainly due to a large diversity of PCR methods and primers and the lack of standardization. The present multicentric prospective study, involving eight laboratories proficient in the molecular prenatal diagnosis of toxoplasmosis, was a first step toward the harmonization of this diagnosis among university hospitals in France. Its aim was to compare the analytical performances of different PCR protocols used for Toxoplasma detection. Each center extracted the same concentrated Toxoplasma gondii suspension and tested serial dilutions of the DNA using its own assays. Differences in analytical sensitivities were observed between assays, particularly at low parasite concentrations (≤2 T. gondii genomes per reaction tube), with “performance scores” differing by a 20-fold factor among laboratories. Our data stress the fact that differences do exist in the performances of molecular assays in spite of expertise in the matter; we propose that laboratories work toward a detection threshold defined for a best sensitivity of this diagnosis. Moreover, on the one hand, intralaboratory comparisons confirmed previous studies showing that rep529 is a more adequate DNA target for this diagnosis than the widely used B1 gene. But, on the other hand, interlaboratory comparisons showed differences that appear independent of the target, primers, or technology and that hence rely essentially on proficiency and care in the optimization of PCR conditions. PMID:20610670

Determination of endocrine disrupting compounds and their metabolites in fish bile.

PubMed

Ros, Oihana; Izaguirre, Jon Kepa; Olivares, Maitane; Bizarro, Cristina; Ortiz-Zarragoitia, Maren; Cajaraville, Miren Pilar; Etxebarria, Nestor; Prieto, Ailette; Vallejo, Asier

2015-12-01

This work describes a new methodology for the simultaneous determination of a large variety of emerging and persistent organic compounds and some of their metabolites in fish bile samples. The target compounds were musk fragrances, alkyl phenols, hormones, pesticides, phthalate esters and bisphenol-A, all of them with a known endocrine disrupting effect. To achieve the determination these three steps were optimized: i) an enzymatic hydrolysis of the metabolites to render the unconjugated compounds; ii) the solid phase extraction of the target analytes (Plexa cartridges 200-mg); and, iii) a clean-up of the extracts (Florisil cartridges 1-g). The samples were analyzed by gas-chromatography-mass spectrometry (GC-MS), though the polar fraction required a previous derivatization with O-bis (trimethylsilyl) trifluoroacetamide. Good apparent recoveries (63-122%), repeatability (<20%) and limits of detection (LODs) ranging between 0.04 and 459 ng/mL were obtained. This method was applied to the analysis of the target analytes in bile samples of thicklip grey mullets (Chelon labrosus) from five different populations of the Basque Coast (South East Bay of Biscay) during the period of May-June 2012. The target analytes were found at concentrations ranging from

The Influence of Judgment Calls on Meta-Analytic Findings.

PubMed

Tarrahi, Farid; Eisend, Martin

2016-01-01

Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions.

The politics of insight

PubMed Central

Salvi, Carola; Cristofori, Irene; Grafman, Jordan; Beeman, Mark

2016-01-01

Previous studies showed that liberals and conservatives differ in cognitive style. Liberals are more flexible, and tolerant of complexity and novelty, whereas conservatives are more rigid, are more resistant to change, and prefer clear answers. We administered a set of compound remote associate problems, a task extensively used to differentiate problem-solving styles (via insight or analysis). Using this task, several researches have proven that self-reports, which differentiate between insight and analytic problem-solving, are reliable and are associated with two different neural circuits. In our research we found that participants self-identifying with distinct political orientations demonstrated differences in problem-solving strategy. Liberals solved significantly more problems via insight instead of in a step-by-step analytic fashion. Our findings extend previous observations that self-identified political orientations reflect differences in cognitive styles. More specifically, we show that type of political orientation is associated with problem-solving strategy. The data converge with previous neurobehavioural and cognitive studies indicating a link between cognitive style and the psychological mechanisms that mediate political beliefs. PMID:26810954

The politics of insight.

PubMed

Salvi, Carola; Cristofori, Irene; Grafman, Jordan; Beeman, Mark

2016-01-01

Previous studies showed that liberals and conservatives differ in cognitive style. Liberals are more flexible, and tolerant of complexity and novelty, whereas conservatives are more rigid, are more resistant to change, and prefer clear answers. We administered a set of compound remote associate problems, a task extensively used to differentiate problem-solving styles (via insight or analysis). Using this task, several researches have proven that self-reports, which differentiate between insight and analytic problem-solving, are reliable and are associated with two different neural circuits. In our research we found that participants self-identifying with distinct political orientations demonstrated differences in problem-solving strategy. Liberals solved significantly more problems via insight instead of in a step-by-step analytic fashion. Our findings extend previous observations that self-identified political orientations reflect differences in cognitive styles. More specifically, we show that type of political orientation is associated with problem-solving strategy. The data converge with previous neurobehavioural and cognitive studies indicating a link between cognitive style and the psychological mechanisms that mediate political beliefs.

Mitigating Sports Injury Risks Using Internet of Things and Analytics Approaches.

PubMed

Wilkerson, Gary B; Gupta, Ashish; Colston, Marisa A

2018-03-12

Sport injuries restrict participation, impose a substantial economic burden, and can have persisting adverse effects on health-related quality of life. The effective use of Internet of Things (IoT), when combined with analytics approaches, can improve player safety through identification of injury risk factors that can be addressed by targeted risk reduction training activities. Use of IoT devices can facilitate highly efficient quantification of relevant functional capabilities prior to sport participation, which could substantially advance the prevailing sport injury management paradigm. This study introduces a framework for using sensor-derived IoT data to supplement other data for objective estimation of each individual college football player's level of injury risk, which is an approach to injury prevention that has not been previously reported. A cohort of 45 NCAA Division I-FCS college players provided data in the form of self-ratings of persisting effects of previous injuries and single-leg postural stability test. Instantaneous change in body mass acceleration (jerk) during the test was quantified by a smartphone accelerometer, with data wirelessly transmitted to a secure cloud server. Injuries sustained from the beginning of practice sessions until the end of the 13-game season were documented, along with the number of games played by each athlete over the course of a 13-game season. Results demonstrate a strong prediction model. Our approach may have strong relevance to the estimation of injury risk for other physically demanding activities. Clearly, there is great potential for improvement of injury prevention initiatives through identification of individual athletes who possess elevated injury risk and targeted interventions. © 2018 Society for Risk Analysis.

Dimensional structure of DSM-5 posttraumatic stress symptoms in Spanish trauma victims.

PubMed

Soberón, Carmen; Crespo, María; Del Mar Gómez-Gutiérrez, María; Fernández-Lansac, Violeta; Armour, Cherie

2016-01-01

Confirmatory factor analytic studies have shown that posttraumatic stress disorder (PTSD) symptoms included in the fifth edition of the Diagnostic and Statistical Manual Disorders (DSM-5) may be better explained by two 6-factor models (the Externalizing Behaviours model and the Anhedonia model) and a 7-factor Hybrid model. The latter model comprises the symptom clusters of intrusion, avoidance, negative affect, anhedonia, externalizing behaviours, and anxious and dysphoric arousal. This model has received empirical support mainly in American samples. Of note, there have been a limited number of studies conducted on samples from other countries. This study aimed to examine the underlying dimensionality of DSM-5 PTSD symptoms in a Spanish clinical sample exposed to a range of traumatic events. Participants included 165 adults (78.8% females) seeking treatment in trauma services in the Madrid area (Spain). PTSD was assessed using the Global Assessment of Posttraumatic Stress Scale 5, a Spanish self-report instrument assessing posttraumatic symptoms according to the DSM-5 criteria. Confirmatory factor analyses were conducted in Mplus. Both the 7-factor Hybrid model and the 6-factor Anhedonia model demonstrated good and equivalent fit to the data. The findings of this study replicate and extend previous research by providing support for both the 7-factor Hybrid model and the 6-factor Anhedonia model in a clinical sample of Spanish trauma survivors. Given equivalent fit for these two models and the fewer number of latent factors in the Anhedonia model, it was selected as optimal in a traumatized Spanish sample. Implications and future research directions are discussed.

Standardization and optimization of fluorescence in situ hybridization (FISH) for HER-2 assessment in breast cancer: A single center experience.

PubMed

Bogdanovska-Todorovska, Magdalena; Petrushevska, Gordana; Janevska, Vesna; Spasevska, Liljana; Kostadinova-Kunovska, Slavica

2018-05-20

Accurate assessment of human epidermal growth factor receptor 2 (HER-2) is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE) tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples) and DAKO Histology FISH Accessory Kit (30 samples). The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing) affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70); the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p < 0.0001). The greatest discordance (82%) between IHC and FISH was observed in IHC 2+ group. A standardized FISH protocol for HER-2 assessment, with high hybridization efficiency, is necessary due to variability in tissue processing and individual tissue characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.

Improvement in the stability of serum samples stored in an automated refrigerated module.

PubMed

Parra-Robert, Marina; Rico-Santana, Naira; Alcaraz-Quiles, José; Sandalinas, Silvia; Fernández, Esther; Falcón, Isabel; Pérez-Riedweg, Margarita; Bedini, Josep Lluís

2016-12-01

In clinical laboratories it is necessary to know for how long the analytes are stable in the samples with specific storage conditions. Our laboratory has implemented the new Aptio Automation System (AAS) (Siemens Healthcare Diagnostics) where the analyzed samples are stored in a refrigerated storage module (RSM) after being sealed. The aim of the study was to evaluate the stability of serum samples with the AAS and comparing the results with a previous study using a conventional refrigerated system. Serum samples from a total of 50 patients were collected and for each of them 27 biochemical analytes were analyzed. The samples were divided in 5 sets of 10 samples. Each set was re-analyzed at one of the following times: 24, 48, 72, 96 and 120h. Stability was evaluated according to the Total Limit of Change (TLC) criteria, which combine both analytical and biologic variation. A total of 26 out of 27 analytes were stable at the end of the study according to TLC criteria. Lactate dehydrogenase was not stable at 48h observing a decrease in its concentration until the end of the study. In the previous study (conventional storage system) 9 biochemical analytes were not stable with an increase of their levels due to the evaporation process. The RSM connected to the AAS improves the stability of serum samples. This system avoids the evaporation process due to the sealing of samples and allows better control of the samples during their storage. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Compliance measurements of chevron notched four point bend specimen

NASA Technical Reports Server (NTRS)

Calomino, Anthony; Bubsey, Raymond; Ghosn, Louis J.

1994-01-01

The experimental stress intensity factors for various chevron notched four point bend specimens are presented. The experimental compliance is verified using the analytical solution for a straight through crack four point bend specimen and the boundary integral equation method for one chevron geometry. Excellent agreement is obtained between the experimental and analytical results. In this report, stress intensity factors, loading displacements and crack mouth opening displacements are reported for different crack lengths and different chevron geometries, under four point bend loading condition.

Complex formation of vanadium(V) with resorcylalhydrazides of carboxylic acids

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

Dudarev, V.I.; Dolgorev, V.A.; Volkov, A.N.

1986-08-01

In this work, a previous investigation of hydrazine derivatives as analytical reagents for vanadium(V) was continued. The authors studied arylalhydrazones -- derivatives of resorcylalhydrazides of anisic (RHASA), anthranilic (RHANA), and benzoic (RHBA) acids. The reagents presented differ from those studied previously by the presence of a second hydroxy group in the para-position of the benzene ring -the resorcinol fragment -- and substituents in the benzoin fragment. Such changes made it possible to increase the solubility of the reagents in aqueous medium and to estimate the change in the main spectrophotometric parameters of the analytical reaction. A rapid method was developedmore » for the determination of vanadium in steels with the resorcylalhydrazide of anthranilic acid. The minimum determinable vanadium content is 0.18 micrograms/ml.« less

Sensitive analytical method for simultaneous analysis of some vasoconstrictors with highly overlapped analytical signals

NASA Astrophysics Data System (ADS)

Nikolić, G. S.; Žerajić, S.; Cakić, M.

2011-10-01

Multivariate calibration method is a powerful mathematical tool that can be applied in analytical chemistry when the analytical signals are highly overlapped. The method with regression by partial least squares is proposed for the simultaneous spectrophotometric determination of adrenergic vasoconstrictors in decongestive solution containing two active components: phenyleprine hydrochloride and trimazoline hydrochloride. These sympathomimetic agents are that frequently associated in pharmaceutical formulations against the common cold. The proposed method, which is, simple and rapid, offers the advantages of sensitivity and wide range of determinations without the need for extraction of the vasoconstrictors. In order to minimize the optimal factors necessary to obtain the calibration matrix by multivariate calibration, different parameters were evaluated. The adequate selection of the spectral regions proved to be important on the number of factors. In order to simultaneously quantify both hydrochlorides among excipients, the spectral region between 250 and 290 nm was selected. A recovery for the vasoconstrictor was 98-101%. The developed method was applied to assay of two decongestive pharmaceutical preparations.

Noise-immune cavity-enhanced analytical atomic spectrometry - NICE-AAS - A technique for detection of elements down to zeptogram amounts

NASA Astrophysics Data System (ADS)

Axner, Ove; Ehlers, Patrick; Hausmaninger, Thomas; Silander, Isak; Ma, Weiguang

2014-10-01

Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is a powerful technique for detection of molecular compounds in gas phase that is based on a combination of two important concepts: frequency modulation spectroscopy (FMS) for reduction of noise, and cavity enhancement, for prolongation of the interaction length between the light and the sample. Due to its unique properties, it has demonstrated unparalleled detection sensitivity when it comes to detection of molecular constituents in the gas phase. However, despite these, it has so far not been used for detection of atoms, i.e. for elemental analysis. The present work presents an assessment of the expected performance of Doppler-broadened (Db) NICE-OHMS for analytical atomic spectrometry, then referred to as noise-immune cavity-enhanced analytical atomic spectrometry (NICE-AAS). After a description of the basic principles of Db-NICE-OHMS, the modulation and detection conditions for optimum performance are identified. Based on a previous demonstrated detection sensitivity of Db-NICE-OHMS of 5 × 10- 12 cm- 1 Hz- 1/2 (corresponding to a single-pass absorbance of 7 × 10- 11 over 10 s), the expected limits of detection (LODs) of Hg and Na by NICE-AAS are estimated. Hg is assumed to be detected in gas phase directly while Na is considered to be atomized in a graphite furnace (GF) prior to detection. It is shown that in the absence of spectral interferences, contaminated sample compartments, and optical saturation, it should be feasible to detect Hg down to 10 zg/cm3 (10 fg/m3 or 10- 5 ng/m3), which corresponds to 25 atoms/cm3, and Na down to 0.5 zg (zg = zeptogram = 10- 21 g), representing 50 zg/mL (parts-per-sextillion, pps, 1:1021) in liquid solution (assuming a sample of 10 μL) or solely 15 atoms injected into the GF, respectively. These LODs are several orders of magnitude lower (better) than any previous laser-based absorption technique previously demonstrated under atmospheric pressure conditions. It is prophesied that NICE-AAS could provide such high detection sensitivity that the instrumentation should not, by itself, be the limiting factor of an assessment of elemental abundance; the accuracy of an assessment would then instead be limited by concomitant species, e.g. originating from the handling procedures of the sample or the environment.

An Analytical-Numerical Model for Two-Phase Slug Flow through a Sudden Area Change in Microchannels

DOE PAGES

Momen, A. Mehdizadeh; Sherif, S. A.; Lear, W. E.

2016-01-01

In this article, two new analytical models have been developed to calculate two-phase slug flow pressure drop in microchannels through a sudden contraction. Even though many studies have been reported on two-phase flow in microchannels, considerable discrepancies still exist, mainly due to the difficulties in experimental setup and measurements. Numerical simulations were performed to support the new analytical models and to explore in more detail the physics of the flow in microchannels with a sudden contraction. Both analytical and numerical results were compared to the available experimental data and other empirical correlations. Results show that models, which were developed basedmore » on the slug and semi-slug assumptions, agree well with experiments in microchannels. Moreover, in contrast to the previous empirical correlations which were tuned for a specific geometry, the new analytical models are capable of taking geometrical parameters as well as flow conditions into account.« less

Analytical Ultrasonics in Materials Research and Testing

NASA Technical Reports Server (NTRS)

Vary, A.

1986-01-01

Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

A theoretical analysis of the free vibrations of ring- and/or stringer-stiffened elliptical cylinders with arbitrary end conditions. Volume 1: Analytical derivation and applications

NASA Technical Reports Server (NTRS)

Boyd, D. E.; Rao, C. K. P.

1973-01-01

The derivation and application of a Rayleigh-Ritz modal vibration analysis are presented for ring and/or stringer stiffened noncircular cylindrical shells with arbitrary end conditions. Comparisons with previous results from experimental and analytical studies showed this method of analysis to be accurate for a variety of end conditions. Results indicate a greater effect of rings on natural frequencies than of stringers.

An Exploratory Investigation of the Factor Structure of the Reynolds Intellectual Assessment Scales (RIAS)

ERIC Educational Resources Information Center

Dombrowski, Stefan C.; Watkins, Marley W.; Brogan, Michael J.

2009-01-01

This study investigated the factor structure of the Reynolds Intellectual Assessment Scales (RIAS) using rigorous exploratory factor analytic and factor extraction procedures. The results of this study indicate that the RIAS is a single factor test. Despite these results, higher order factor analysis using the Schmid-Leiman procedure indicates…

The rate of bubble growth in a superheated liquid in pool boiling

NASA Astrophysics Data System (ADS)

Abdollahi, Mohammad Reza; Jafarian, Mehdi; Jamialahmadi, Mohammad

2017-12-01

A semi-empirical model for the estimation of the rate of bubble growth in nucleate pool boiling is presented, considering a new equation to estimate the temperature history of the bubble in the bulk of liquid. The conservation equations of energy, mass and momentum have been firstly derived and solved analytically. The present analytical model of the bubble growth predicts that the radius of the bubble grows as a function of √{t}.{\\operatorname{erf}}( N√{t}) , while so far the bubble growth rate has been mainly correlated to √{t} in the previous studies. In the next step, the analytical solutions were used to develop a new semi-empirical equation. To achieve this, firstly the analytical solution were non-dimensionalised and then the experimental data, available in the literature, were applied to tune the dimensionless coefficients appeared in the dimensionless equation. Finally, the reliability of the proposed semi-empirical model was assessed through comparison of the model predictions with the available experimental data in the literature, which were not applied in the tuning of the dimensionless parameters of the model. The comparison of the model predictions with other proposed models in the literature was also performed. These comparisons show that this model enables more accurate predictions than previously proposed models with a deviation of less than 10% in a wide range of operating conditions.

Hematology and serum biochemistry of Sumatran rhinoceroses (Dicerorhinus sumatrensis) in a rainforest sanctuary in Way Kambas National Park, Indonesia.

PubMed

Andriansyah; Candra, Dedi; Riyanto, Marcellus A C T; Barry, Jason; Radcliffe, Robin W

2013-06-01

There is a paucity of basic biological information for the Sumatran rhinoceros (Dicerorhinus sumatrensis). This information is fundamental to husbandry and management practices for captive animals and for support of in situ conservation efforts. Serial blood samples were collected over an 8-yr period to evaluate patterns in hematology and serum biochemistry values among five Sumatran rhinoceroses housed at the Sumatran Rhino Sanctuary in Way Kambas National Park, Lampung, Indonesia. Understanding the basis for variance in analytes both within and between subjects can allow use of more sensitive subject-based reference values, and is particularly suitable for small populations of endangered animals. Both intra- and intersubject variability was computed for each analyte and the associated index of individuality was determined. Previously published cutoff points for index of individuality indicate where population-based reference intervals can be used with confidence (index > 1.4) or with caution (0.6 < index < 1.4). Interrhino variability was small for the majority of analytes, with 12 of 19 analytes having an index of individuality greater than 1.4 and none having an index of individuality less than 0.6. With the high within-individual variability of most anayltes in the Sumatran rhinoceroses at the sanctuary, subject-based reference intervals offer little advantage over standard population-based reference intervals for monitoring the health of these endangered animals. Differences were noted (but not tested for statistical significance) in serum urea, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and cholesterol between young and old rhinoceroses, and in hematocrit, AST, alanine aminotransferase (ALT), LDH, and glucose between male and female rhinoceroses. Husbandry practices, animal management, nutrition and habitat factors may also impact hematology and biochemistry results, and these relationships deserve more careful investigation. This study represents the most comprehensive hematology and serum biochemistry comparison of Sumatran rhinoceroses held in natural rainforest conditions outside a traditional zoological setting.

Interactive Visual Analytics Approch for Exploration of Geochemical Model Simulations with Different Parameter Sets

NASA Astrophysics Data System (ADS)

Jatnieks, Janis; De Lucia, Marco; Sips, Mike; Dransch, Doris

2015-04-01

Many geoscience applications can benefit from testing many combinations of input parameters for geochemical simulation models. It is, however, a challenge to screen the input and output data from the model to identify the significant relationships between input parameters and output variables. For addressing this problem we propose a Visual Analytics approach that has been developed in an ongoing collaboration between computer science and geoscience researchers. Our Visual Analytics approach uses visualization methods of hierarchical horizontal axis, multi-factor stacked bar charts and interactive semi-automated filtering for input and output data together with automatic sensitivity analysis. This guides the users towards significant relationships. We implement our approach as an interactive data exploration tool. It is designed with flexibility in mind, so that a diverse set of tasks such as inverse modeling, sensitivity analysis and model parameter refinement can be supported. Here we demonstrate the capabilities of our approach by two examples for gas storage applications. For the first example our Visual Analytics approach enabled the analyst to observe how the element concentrations change around previously established baselines in response to thousands of different combinations of mineral phases. This supported combinatorial inverse modeling for interpreting observations about the chemical composition of the formation fluids at the Ketzin pilot site for CO2 storage. The results indicate that, within the experimental error range, the formation fluid cannot be considered at local thermodynamical equilibrium with the mineral assemblage of the reservoir rock. This is a valuable insight from the predictive geochemical modeling for the Ketzin site. For the second example our approach supports sensitivity analysis for a reaction involving the reductive dissolution of pyrite with formation of pyrrothite in presence of gaseous hydrogen. We determine that this reaction is thermodynamically favorable under a broad range of conditions. This includes low temperatures and absence of microbial catalysators. Our approach has potential for use in other applications that involve exploration of relationships in geochemical simulation model data.

Two-factor theory – at the intersection of health care management and patient satisfaction

PubMed Central

Bohm, Josef

2012-01-01

Using data obtained from the 2004 Joint Canadian/United States Survey of Health, an analytic model using principles derived from Herzberg’s motivational hygiene theory was developed for evaluating patient satisfaction with health care. The analysis sought to determine whether survey variables associated with consumer satisfaction act as Hertzberg factors and contribute to survey participants’ self-reported levels of health care satisfaction. To validate the technique, data from the survey were analyzed using logistic regression methods and then compared with results obtained from the two-factor model. The findings indicate a high degree of correlation between the two methods. The two-factor analytical methodology offers advantages due to its ability to identify whether a factor assumes a motivational or hygienic role and assesses the influence of a factor within select populations. Its ease of use makes this methodology well suited for assessment of multidimensional variables. PMID:23055755

Two-factor theory - at the intersection of health care management and patient satisfaction.

PubMed

Bohm, Josef

2012-01-01

Using data obtained from the 2004 Joint Canadian/United States Survey of Health, an analytic model using principles derived from Herzberg's motivational hygiene theory was developed for evaluating patient satisfaction with health care. The analysis sought to determine whether survey variables associated with consumer satisfaction act as Hertzberg factors and contribute to survey participants' self-reported levels of health care satisfaction. To validate the technique, data from the survey were analyzed using logistic regression methods and then compared with results obtained from the two-factor model. The findings indicate a high degree of correlation between the two methods. The two-factor analytical methodology offers advantages due to its ability to identify whether a factor assumes a motivational or hygienic role and assesses the influence of a factor within select populations. Its ease of use makes this methodology well suited for assessment of multidimensional variables.

Determinants of judgment and decision making quality: the interplay between information processing style and situational factors

PubMed Central

Ayal, Shahar; Rusou, Zohar; Zakay, Dan; Hochman, Guy

2015-01-01

A framework is presented to better characterize the role of individual differences in information processing style and their interplay with contextual factors in determining decision making quality. In Experiment 1, we show that individual differences in information processing style are flexible and can be modified by situational factors. Specifically, a situational manipulation that induced an analytical mode of thought improved decision quality. In Experiment 2, we show that this improvement in decision quality is highly contingent on the compatibility between the dominant thinking mode and the nature of the task. That is, encouraging an intuitive mode of thought led to better performance on an intuitive task but hampered performance on an analytical task. The reverse pattern was obtained when an analytical mode of thought was encouraged. We discuss the implications of these results for the assessment of decision making competence, and suggest practical directions to help individuals better adjust their information processing style to the situation at hand and make optimal decisions. PMID:26284011

An analytical model for pressure of volume fractured tight oil reservoir with horizontal well

NASA Astrophysics Data System (ADS)

Feng, Qihong; Dou, Kaiwen; Zhang, Xianmin; Xing, Xiangdong; Xia, Tian

2017-05-01

The property of tight oil reservoir is worse than common reservoir that we usually seen before, the porosity and permeability is low, the diffusion is very complex. Therefore, the ordinary depletion method is useless here. The volume fracture breaks through the conventional EOR mechanism, which set the target by amplifying the contact area of fracture and reservoir so as to improving the production of every single well. In order to forecast the production effectively, we use the traditional dual-porosity model, build an analytical model for production of volume fractured tight oil reservoir with horizontal well, and get the analytical solution in Laplace domain. Then we construct the log-log plot of dimensionless pressure and time by stiffest conversion. After that, we discuss the influential factors of pressure. Several factors like cross flow, skin factors and threshold pressure gradient was analyzed in the article. This model provides a useful method for tight oil production forecast and it has certain guiding significance for the production capacity prediction and dynamic analysis.

Determinants of judgment and decision making quality: the interplay between information processing style and situational factors.

PubMed

Ayal, Shahar; Rusou, Zohar; Zakay, Dan; Hochman, Guy

2015-01-01

A framework is presented to better characterize the role of individual differences in information processing style and their interplay with contextual factors in determining decision making quality. In Experiment 1, we show that individual differences in information processing style are flexible and can be modified by situational factors. Specifically, a situational manipulation that induced an analytical mode of thought improved decision quality. In Experiment 2, we show that this improvement in decision quality is highly contingent on the compatibility between the dominant thinking mode and the nature of the task. That is, encouraging an intuitive mode of thought led to better performance on an intuitive task but hampered performance on an analytical task. The reverse pattern was obtained when an analytical mode of thought was encouraged. We discuss the implications of these results for the assessment of decision making competence, and suggest practical directions to help individuals better adjust their information processing style to the situation at hand and make optimal decisions.

Analytic study of orbiter landing profiles

NASA Technical Reports Server (NTRS)

Walker, H. J.

1981-01-01

A broad survey of possible orbiter landing configurations was made with specific goals of defining boundaries for the landing task. The results suggest that the center of the corridors between marginal and routine represents a more or less optimal preflare condition for regular operations. Various constraints used to define the boundaries are based largely on qualitative judgements from earlier flight experience with the X-15 and lifting body research aircraft. The results should serve as useful background for expanding and validating landing simulation programs. The analytic approach offers a particular advantage in identifying trends due to the systematic variation of factors such as vehicle weight, load factor, approach speed, and aim point. Limitations such as a constant load factor during the flare and using a fixed gear deployment time interval, can be removed by increasing the flexibility of the computer program. This analytic definition of landing profiles of the orbiter may suggest additional studies, includin more configurations or more comparisons of landing profiles within and beyond the corridor boundaries.

An analytic modeling and system identification study of rotor/fuselage dynamics at hover

NASA Technical Reports Server (NTRS)

Hong, Steven W.; Curtiss, H. C., Jr.

1993-01-01

A combination of analytic modeling and system identification methods have been used to develop an improved dynamic model describing the response of articulated rotor helicopters to control inputs. A high-order linearized model of coupled rotor/body dynamics including flap and lag degrees of freedom and inflow dynamics with literal coefficients is compared to flight test data from single rotor helicopters in the near hover trim condition. The identification problem was formulated using the maximum likelihood function in the time domain. The dynamic model with literal coefficients was used to generate the model states, and the model was parametrized in terms of physical constants of the aircraft rather than the stability derivatives resulting in a significant reduction in the number of quantities to be identified. The likelihood function was optimized using the genetic algorithm approach. This method proved highly effective in producing an estimated model from flight test data which included coupled fuselage/rotor dynamics. Using this approach it has been shown that blade flexibility is a significant contributing factor to the discrepancies between theory and experiment shown in previous studies. Addition of flexible modes, properly incorporating the constraint due to the lag dampers, results in excellent agreement between flight test and theory, especially in the high frequency range.

Survey geometry and the internal consistency of recent cosmic shear measurements

NASA Astrophysics Data System (ADS)

Troxel, M. A.; Krause, E.; Chang, C.; Eifler, T. F.; Friedrich, O.; Gruen, D.; MacCrann, N.; Chen, A.; Davis, C.; DeRose, J.; Dodelson, S.; Gatti, M.; Hoyle, B.; Huterer, D.; Jarvis, M.; Lacasa, F.; Lemos, P.; Peiris, H. V.; Prat, J.; Samuroff, S.; Sánchez, C.; Sheldon, E.; Vielzeuf, P.; Wang, M.; Zuntz, J.; Lahav, O.; Abdalla, F. B.; Allam, S.; Annis, J.; Avila, S.; Bertin, E.; Brooks, D.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; da Costa, L. N.; De Vicente, J.; Diehl, H. T.; Doel, P.; Evrard, A. E.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Hollowood, D. L.; Honscheid, K.; James, D. J.; Kirk, D.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; March, M.; Menanteau, F.; Miquel, R.; Mohr, J. J.; Ogando, R. L. C.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Sevilla-Noarbe, I.; Smith, M.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Swanson, M. E. C.; Thomas, D.; Walker, A. R.; Wechsler, R. H.

2018-06-01

We explore the impact of an update to the typical approximation for the shape noise term in the analytic covariance matrix for cosmic shear experiments that assumes the absence of survey boundary and mask effects. We present an exact expression for the number of galaxy pairs in this term based on the survey mask, which leads to more than a factor of three increase in the shape noise on the largest measured scales for the Kilo-Degree Survey (KIDS-450) real-space cosmic shear data. We compare the result of this analytic expression to several alternative methods for measuring the shape noise from the data and find excellent agreement. This update to the covariance resolves any internal model tension evidenced by the previously large cosmological best-fit χ2 for the KiDS-450 cosmic shear data. The best-fit χ2 is reduced from 161 to 121 for 118 degrees of freedom. We also apply a correction to how the multiplicative shear calibration uncertainty is included in the covariance. This change shifts the inferred amplitude of the correlation function to higher values. We find that this improves agreement of the KiDS-450 cosmic shear results with Dark Energy Survey Year 1 and Planck results.

An analytic modeling and system identification study of rotor/fuselage dynamics at hover

NASA Technical Reports Server (NTRS)

Hong, Steven W.; Curtiss, H. C., Jr.

1993-01-01

A combination of analytic modeling and system identification methods have been used to develop an improved dynamic model describing the response of articulated rotor helicopters to control inputs. A high-order linearized model of coupled rotor/body dynamics including flap and lag degrees of freedom and inflow dynamics with literal coefficients is compared to flight test data from single rotor helicopters in the near hover trim condition. The identification problem was formulated using the maximum likelihood function in the time domain. The dynamic model with literal coefficients was used to generate the model states, and the model was parametrized in terms of physical constants of the aircraft rather than the stability derivatives, resulting in a significant reduction in the number of quantities to be identified. The likelihood function was optimized using the genetic algorithm approach. This method proved highly effective in producing an estimated model from flight test data which included coupled fuselage/rotor dynamics. Using this approach it has been shown that blade flexibility is a significant contributing factor to the discrepancies between theory and experiment shown in previous studies. Addition of flexible modes, properly incorporating the constraint due to the lag dampers, results in excellent agreement between flight test and theory, especially in the high frequency range.

Factors affecting the oral uptake and translocation of polystyrene nanoparticles: histological and analytical evidence.

PubMed

Florence, A T; Hillery, A M; Hussain, N; Jani, P U

1995-01-01

Quantitative and qualitative evidence from our laboratories on the absorption and translocation of polystyrene latex nanoparticles both by histological (qualitative) and analytical measurement of levels of polystyrene (quantitative) is briefly reviewed in this paper. We have previously compared the uptake of nonionized polystyrene latex ranging in size from 50nm to 3 microns, and made some comparisons of uptake between carboxylated microspheres and nonionic systems, showing the lower uptake of the former through the lymphoid tissue of the gastrointestinal tract. Size is a key parameter, uptake increasing with decreasing particle diameter. Early evidence suggested that uptake is by way of the Peyer's patches and other elements of the gut associated lymphoid tissue (GALT). Adsorption of hydrophilic block-copolymers onto polystyrene markedly reduces the uptake by intestinal GALT. Modification of the surface with specific ligands such as by covalent attachment of tomato lectin molecules has indicated widespread uptake by non-GALT tissues, following their binding to and internalisation by enterocytes. The ability to decrease and increase uptake is clear evidence of a phenomenon which has the potential for further control to allow it to be exploited fully for drug or vaccine delivery. The evidence to date with nanoparticles as carriers systems for labile drugs such as proteins by the oral route remains to be substantiated.

Tryptophan oxidation catabolite, N-formylkynurenine, in photo degraded cell culture medium results in reduced cell culture performance.

PubMed

McElearney, Kyle; Ali, Amr; Gilbert, Alan; Kshirsagar, Rashmi; Zang, Li

2016-01-01

Chemically defined media have been widely used in the biopharmaceutical industry to enhance cell culture productivities and ensure process robustness. These media, which are quite complex, often contain a mixture of many components such as vitamins, amino acids, metals and other chemicals. Some of these components are known to be sensitive to various stress factors including photodegradation. Previous work has shown that small changes in impurity concentrations induced by these potential stresses can have a large impact on the cell culture process including growth and product quality attributes. Furthermore, it has been shown to be difficult to detect these modifications analytically due to the complexity of the cell culture media and the trace level of the degradant products. Here, we describe work performed to identify the specific chemical(s) in photodegraded medium that affect cell culture performance. First, we developed a model system capable of detecting changes in cell culture performance. Second, we used these data and applied an LC-MS analytical technique to characterize the cell culture media and identify degradant products which affect cell culture performance. Riboflavin limitation and N-formylkynurenine (NFK), a tryptophan oxidation catabolite, were identified as chemicals which results in a reduction in cell culture performance. © 2015 American Institute of Chemical Engineers.

An integrative computational approach for prioritization of genomic variants

DOE PAGES

Dubchak, Inna; Balasubramanian, Sandhya; Wang, Sheng; ...

2014-12-15

An essential step in the discovery of molecular mechanisms contributing to disease phenotypes and efficient experimental planning is the development of weighted hypotheses that estimate the functional effects of sequence variants discovered by high-throughput genomics. With the increasing specialization of the bioinformatics resources, creating analytical workflows that seamlessly integrate data and bioinformatics tools developed by multiple groups becomes inevitable. Here we present a case study of a use of the distributed analytical environment integrating four complementary specialized resources, namely the Lynx platform, VISTA RViewer, the Developmental Brain Disorders Database (DBDB), and the RaptorX server, for the identification of high-confidence candidatemore » genes contributing to pathogenesis of spina bifida. The analysis resulted in prediction and validation of deleterious mutations in the SLC19A placental transporter in mothers of the affected children that causes narrowing of the outlet channel and therefore leads to the reduced folate permeation rate. The described approach also enabled correct identification of several genes, previously shown to contribute to pathogenesis of spina bifida, and suggestion of additional genes for experimental validations. This study demonstrates that the seamless integration of bioinformatics resources enables fast and efficient prioritization and characterization of genomic factors and molecular networks contributing to the phenotypes of interest.« less

Deep and wide gaps by super Earths in low-viscosity discs

NASA Astrophysics Data System (ADS)

Ginzburg, Sivan; Sari, Re'em

2018-06-01

Planets can open cavities (gaps) in the protoplanetary gaseous discs in which they are born by exerting gravitational torques. Viscosity counters these torques and limits the depletion of the gaps. We present a simple one-dimensional scheme to calculate the gas density profile inside gaps by balancing the gravitational and viscous torques. By generalizing the results of Goodman & Rafikov (2001), our scheme properly accounts for the propagation of angular momentum by density waves. This method allows us to easily study low-viscosity discs, which are challenging for full hydrodynamical simulations. We complement our numerical integration by analytical equations for the gap's steady-state depth and width as a function of the planet's to star's mass ratio μ, the gas disc's aspect ratio h, and its Shakura & Sunyaev viscosity parameter α. Specifically, we focus on low-mass planets (μ < μth ≡ h3) and identify a new low-viscosity regime, α < h(μ/μth)5, in which the classical analytical scaling relations are invalid. Equivalently, this low-viscosity regime applies to every gap that is depleted by more than a factor of (μth/μ)3 relative to the unperturbed density. We show that such gaps are significantly deeper and wider than previously thought, and consequently take a longer time to reach equilibrium.

14 CFR 25.723 - Shock absorption tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... absorption tests. (a) The analytical representation of the landing gear dynamic characteristics that is used... previous tests conducted on the same basic landing gear system that has similar energy absorption...

Examining the Efficacy of Self-Regulated Strategy Development for Students with Emotional or Behavioral Disorders: A Meta-Analysis

ERIC Educational Resources Information Center

Losinski, Mickey; Cuenca-Carlino, Yojanna; Zablocki, Mark; Teagarden, James

2014-01-01

Two previous reviews have indicated that self-regulated strategy instruction (SRSD) is an evidence-based practice that can improve the writing skills of students with emotional and behavioral disorders. The purpose of this meta-analysis is to extend the findings and analytic methods of previous reviews by examining published studies regarding…

SU-F-T-610: Comparison of Output Factors for Small Radiation Fields Used in SBRT Treatment

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

Gupta, R; Eldib, A; Li, J

2016-06-15

Purpose: In order to fundamentally understand our previous dose verification results between measurements and calculations from treatment planning system (TPS) for SBRT plans for different sized targets, the goal of the present work was to compare output factors for small fields measured using EDR2 films with TPS and Monet Carlo (MC) simulations. Methods: 6MV beam was delivered to EDR2 films for each of the following field sizes; 1×1 cm{sup 2}, 1.5×1.5 cm{sup 2}, 2×2 cm{sup 2}, 3×3 cm{sup 2}, 4×4 cm{sup 2}, 5×5 cm{sup 2} and 10×10 cm{sup 2}. The films were developed in a film processer, then scanned withmore » a Vidar VXR-16 scanner and analyzed using RIT113 version 6.1. A standard calibration curve was obtained with the 6MV beam and was used to get absolute dose for measured field sizes. Similar plans for all fields sizes mentioned above were generated using Eclipse with the Analytical Anisotropic Algorithm. Similarly, MC simulations were carried out using the MCSIM, an in-house MC code for different field sizes. Output factors normalized to 10×10 cm{sup 2} reference field were calculated for different field sizes in all the three cases and compared. Results: For field sizes ranging from 1×1 cm{sup 2} to 2×2 cm{sup 2}, the differences in output factors between measurements (films), TPS and MC simulations were within 0.22%. For field sizes ranging from 3×3cm{sup 2} to 5×5cm{sup 2}, differences in output factors were within 0.10%. Conclusion: No clinically significant difference was obtained in output factors for different field sizes acquired from films, TPS and MC simulations. Our results showed that the output factors are predicted accurately from TPS when compared to the actual measurements and superior dose calculation Monte Carlo method. This study would help us in understanding our previously obtained dose verification results for small fields used in the SBRT treatment.« less

Analytical solutions by squeezing to the anisotropic Rabi model in the nonperturbative deep-strong-coupling regime

NASA Astrophysics Data System (ADS)

Zhang, Yu-Yu; Chen, Xiang-You

2017-12-01

An unexplored nonperturbative deep strong coupling (npDSC) achieved in superconducting circuits has been studied in the anisotropic Rabi model by the generalized squeezing rotating-wave approximation. Energy levels are evaluated analytically from the reformulated Hamiltonian and agree well with numerical ones in a wide range of coupling strength. Such improvement ascribes to deformation effects in the displaced-squeezed state presented by the squeezed momentum variance, which are omitted in previous displaced states. The atom population dynamics confirms the validity of our approach for the npDSC strength. Our approach offers the possibility to explore interesting phenomena analytically in the npDSC regime in qubit-oscillator experiments.

Analytical mass formula and nuclear surface properties in the ETF approximation. Part I: symmetric nuclei

NASA Astrophysics Data System (ADS)

Aymard, François; Gulminelli, Francesca; Margueron, Jérôme

2016-08-01

The problem of determination of nuclear surface energy is addressed within the framework of the extended Thomas Fermi (ETF) approximation using Skyrme functionals. We propose an analytical model for the density profiles with variationally determined diffuseness parameters. In this first paper, we consider the case of symmetric nuclei. In this situation, the ETF functional can be exactly integrated, leading to an analytical formula expressing the surface energy as a function of the couplings of the energy functional. The importance of non-local terms is stressed and it is shown that they cannot be deduced simply from the local part of the functional, as it was suggested in previous works.

Analytic model for ultrasound energy receivers and their optimal electric loads II: Experimental validation

NASA Astrophysics Data System (ADS)

Gorostiaga, M.; Wapler, M. C.; Wallrabe, U.

2017-10-01

In this paper, we verify the two optimal electric load concepts based on the zero reflection condition and on the power maximization approach for ultrasound energy receivers. We test a high loss 1-3 composite transducer, and find that the measurements agree very well with the predictions of the analytic model for plate transducers that we have developed previously. Additionally, we also confirm that the power maximization and zero reflection loads are very different when the losses in the receiver are high. Finally, we compare the optimal load predictions by the KLM and the analytic models with frequency dependent attenuation to evaluate the influence of the viscosity.

Analytic Quasi-Perodic Cocycles with Singularities and the Lyapunov Exponent of Extended Harper's Model

NASA Astrophysics Data System (ADS)

Jitomirskaya, S.; Marx, C. A.

2012-11-01

We show how to extend (and with what limitations) Avila's global theory of analytic SL(2,C) cocycles to families of cocycles with singularities. This allows us to develop a strategy to determine the Lyapunov exponent for the extended Harper's model, for all values of parameters and all irrational frequencies. In particular, this includes the self-dual regime for which even heuristic results did not previously exist in physics literature. The extension of Avila's global theory is also shown to imply continuous behavior of the LE on the space of analytic {M_2({C})}-cocycles. This includes rational approximation of the frequency, which so far has not been available.

Analytic calculation of 1-jettiness in DIS at O (α s)

DOE PAGES

Kang, Daekyoung; Lee, Christopher; Stewart, Iain W.

2014-11-01

We present an analytic O(α s) calculation of cross sections in deep inelastic scattering (DIS) dependent on an event shape, 1-jettiness, that probes final states with one jet plus initial state radiation. This is the first entirely analytic calculation for a DIS event shape cross section at this order. We present results for the differential and cumulative 1-jettiness cross sections, and express both in terms of structure functions dependent not only on the usual DIS variables x, Q 2 but also on the 1-jettiness τ. Combined with previous results for log resummation, predictions are obtained over the entire range ofmore » the 1-jettiness distribution.« less

Analytical theory of coherent synchrotron radiation wakefield of short bunches shielded by conducting parallel plates

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

Stupakov, Gennady; Zhou, Demin

2016-04-21

We develop a general model of coherent synchrotron radiation (CSR) impedance with shielding provided by two parallel conducting plates. This model allows us to easily reproduce all previously known analytical CSR wakes and to expand the analysis to situations not explored before. It reduces calculations of the impedance to taking integrals along the trajectory of the beam. New analytical results are derived for the radiation impedance with shielding for the following orbits: a kink, a bending magnet, a wiggler of finite length, and an infinitely long wiggler. Furthermore, all our formulas are benchmarked against numerical simulations with the CSRZ computermore » code.« less

ASVCP quality assurance guidelines: control of general analytical factors in veterinary laboratories.

PubMed

Flatland, Bente; Freeman, Kathy P; Friedrichs, Kristen R; Vap, Linda M; Getzy, Karen M; Evans, Ellen W; Harr, Kendal E

2010-09-01

Owing to lack of governmental regulation of veterinary laboratory performance, veterinarians ideally should demonstrate a commitment to self-monitoring and regulation of laboratory performance from within the profession. In response to member concerns about quality management in veterinary laboratories, the American Society for Veterinary Clinical Pathology (ASVCP) formed a Quality Assurance and Laboratory Standards (QAS) committee in 1996. This committee recently published updated and peer-reviewed Quality Assurance Guidelines on the ASVCP website. The Quality Assurance Guidelines are intended for use by veterinary diagnostic laboratories and veterinary research laboratories that are not covered by the US Food and Drug Administration Good Laboratory Practice standards (Code of Federal Regulations Title 21, Chapter 58). The guidelines have been divided into 3 reports on 1) general analytic factors for veterinary laboratory performance and comparisons, 2) hematology and hemostasis, and 3) clinical chemistry, endocrine assessment, and urinalysis. This report documents recommendations for control of general analytical factors within veterinary clinical laboratories and is based on section 2.1 (Analytical Factors Important In Veterinary Clinical Pathology, General) of the newly revised ASVCP QAS Guidelines. These guidelines are not intended to be all-inclusive; rather, they provide minimum guidelines for quality assurance and quality control for veterinary laboratory testing. It is hoped that these guidelines will provide a basis for laboratories to assess their current practices, determine areas for improvement, and guide continuing professional development and education efforts. ©2010 American Society for Veterinary Clinical Pathology.

Factors associated with anemia in children under three years of age in Perú: analysis of the Encuesta Demográfica y de Salud Familiar, ENDES, 2007-2013.

PubMed

Velásquez-Hurtado, José Enrique; Rodríguez, Yuleika; Gonzáles, Marco; Astete-Robilliard, Laura; Loyola-Romaní, Jessica; Vigo, Walter Eduardo; Rosas-Aguirre, Ángel Martín

2016-06-03

Despite the reduction of poverty in Perú, the prevalence of anemia in the country remains high.  To identify socio-demographic, child and maternal-child care factors associated with anemia in children between 6 and 35 months in Perú.  We conducted an analytical and descriptive study that included registered data from the national survey on demography and family health, 2007-2013, on children between 6 and 35 months old, including the measurement of blood hemoglobin. Anemia was confirmed by hemoglobin-altitude corrected values below 11 mg/dl. We used multivariate logistic regression models to assess potential associated factors for anemia.  Anemia prevalence was high (47.9%). Twelve factors were independently associated with anemia in children: Socio-demographic factors such as living outside Lima and Callao, in a low socioeconomic household, and having an adolescent mother with low education level; child-related factors as being male, younger than 24 months of age, and having fever in the previous two weeks, and maternal-child care factors such as lack of prenatal control in the first trimester of pregnancy, lack or short period of iron supplementation during pregnancy, house delivery, anemia detection at the moment of the survey, and lack of intestinal anti-parasite preventive treatment in the child.  The analysis of survey data provided valuable information about factors associated with anemia in children between 6 and 35 months, which can be used to increase the coverage and effectiveness of maternal-child care practices.

On non-homogeneous tachyon condensation in closed string theory

NASA Astrophysics Data System (ADS)

Giribet, Gaston; Rado, Laura

2017-08-01

Lorentzian continuation of the Sine-Liouville model describes non-homogeneous rolling closed string tachyon. Via T-duality, this relates to the gauged H + 3 Wess-Zumino-Witten model at subcritical level. This model is exactly solvable. We give a closed formula for the 3-point correlation functions for the model at level k within the range 0 < k < 2, which relates to the analogous quantity for k > 2 in a similar way as how the Harlow-Maltz-Witten 3-point function of timelike Liouville field theory relates to the analytic continuation of the Dorn-Otto-Zamolodchikov-Zamolodchikov structure constants: we find that the ratio between both 3-point functions can be written in terms of quotients of Jacobi's θ-functions, while their product exhibits remarkable cancellations and eventually factorizes. Our formula is consistent with previous proposals made in the literature.

Efficient visualization of urban spaces

NASA Astrophysics Data System (ADS)

Stamps, A. E.

2012-10-01

This chapter presents a new method for calculating efficiency and applies that method to the issues of selecting simulation media and evaluating the contextual fit of new buildings in urban spaces. The new method is called "meta-analysis". A meta-analytic review of 967 environments indicated that static color simulations are the most efficient media for visualizing urban spaces. For contextual fit, four original experiments are reported on how strongly five factors influence visual appeal of a street: architectural style, trees, height of a new building relative to the heights of existing buildings, setting back a third story, and distance. A meta-analysis of these four experiments and previous findings, covering 461 environments, indicated that architectural style, trees, and height had effects strong enough to warrant implementation, but the effects of setting back third stories and distance were too small to warrant implementation.

Inverse Scattering and Local Observable Algebras in Integrable Quantum Field Theories

NASA Astrophysics Data System (ADS)

Alazzawi, Sabina; Lechner, Gandalf

2017-09-01

We present a solution method for the inverse scattering problem for integrable two-dimensional relativistic quantum field theories, specified in terms of a given massive single particle spectrum and a factorizing S-matrix. An arbitrary number of massive particles transforming under an arbitrary compact global gauge group is allowed, thereby generalizing previous constructions of scalar theories. The two-particle S-matrix S is assumed to be an analytic solution of the Yang-Baxter equation with standard properties, including unitarity, TCP invariance, and crossing symmetry. Using methods from operator algebras and complex analysis, we identify sufficient criteria on S that imply the solution of the inverse scattering problem. These conditions are shown to be satisfied in particular by so-called diagonal S-matrices, but presumably also in other cases such as the O( N)-invariant nonlinear {σ}-models.

Tides and tidal stress: Applications to Europa

NASA Astrophysics Data System (ADS)

Hurford, Terry Anthony, Jr.

A review of analytical techniques and documentation of previously inaccessible mathematical formulations is applied to study of Jupiter's satellite Europa. Compared with numerical codes that are commonly used to model global tidal effects, analytical models of tidal deformation give deeper insight into the mechanics of tides, and can better reveal the nature of the dependence of observable effects on key parameters. I develop analytical models for tidal deformation of multi-layered bodies. Previous studies of Europa, based on numerical computation, only to show isolated examples from parameter space. My results show a systematic dependence of tidal response on the thicknesses and material parameters of Europa's core, rocky mantle, liquid water ocean, and outer layer of ice. As in the earlier work, I restrict these studies to incompressible materials. Any set of Love numbers h 2 and k 2 which describe a planet's tidal deformation, could be fit by a range of ice thickness values, by adjusting other parameters such as mantle rigidity or core size, an important result for mission planning. Inclusion of compression into multilayer models has been addressed analytically, uncovering several issues that are not explicit in the literature. Full evaluation with compression is here restricted to a uniform sphere. A set of singularities in the classical solution, which correspond to instabilities due to self-gravity has been identified and mapped in parameter space. The analytical models of tidal response yield the stresses anywhere within the body, including on its surface. Crack patterns (such as cycloids) on Europa are probably controlled by these stresses. However, in contrast to previous studies which used a thin shell approximation of the tidal stress, I consider how other tidal models compare with the observed tectonic features. In this way the relationship between Europa's surface tectonics and the global tidal distortion can be constrained. While large-scale tidal deformations probe internal structure deep within a body, small-scale deformations can probe internal structure at shallower depths. I have used photoclinometry to obtain topographic profiles across terrain adjacent to Europan ridges to detect the effects of loading on the lithosphere. Lithospheric thicknesses have been determined and correlated with types and ages of terrain.

General Relativistic Precession in Small Solar System Bodies

NASA Astrophysics Data System (ADS)

Sekhar, Aswin; Werner, Stephanie; Hoffmann, Volker; Asher, David; Vaubaillon, Jeremie; Hajdukova, Maria; Li, Gongjie

2016-10-01

Introduction: One of the greatest successes of the Einstein's General Theory of Relativity (GR) was the correct prediction of the precession of perihelion of Mercury. The closed form expression to compute this precession tells us that substantial GR precession would occur only if the bodies have a combination of both moderately small perihelion distance and semi-major axis. Minimum Orbit Intersection Distance (MOID) is a quantity which helps us to understand the closest proximity of two orbits in space. Hence evaluating MOID is crucial to understand close encounters and collision scenarios better. In this work, we look at the possible scenarios where a small GR precession in argument of pericentre (ω) can create substantial changes in MOID for small bodies ranging from meteoroids to comets and asteroids.Analytical Approach and Numerical Integrations: Previous works have looked into neat analytical techniques to understand different collision scenarios and we use those standard expressions to compute MOID analytically. We find the nature of this mathematical function is such that a relatively small GR precession can lead to drastic changes in MOID values depending on the initial value of ω. Numerical integrations were done with package MERCURY incorporating the GR code to test the same effects. Numerical approach showed the same interesting relationship (as shown by analytical theory) between values of ω and the peaks/dips in MOID values. Previous works have shown that GR precession suppresses Kozai oscillations and this aspect was verified using our integrations. There is an overall agreement between both analytical and numerical methods.Summary and Discussion: We find that GR precession could play an important role in the calculations pertaining to MOID and close encounter scenarios in the case of certain small solar system bodies (depending on their initial orbital elements). Previous works have looked into impact probabilities and collision scenarios on planets from different small body populations. This work aims to find certain sub-sets of orbits where GR could play an interesting role. Certain parallels are drawn between the cases of asteroids, comets and small perihelion distance meteoroid streams.

Analytic strategies to evaluate the association of time-varying exposures to HIV-related outcomes: Alcohol consumption as an example.

PubMed

Cook, Robert L; Kelso, Natalie E; Brumback, Babette A; Chen, Xinguang

2016-01-01

As persons with HIV are living longer, there is a growing need to investigate factors associated with chronic disease, rate of disease progression and survivorship. Many risk factors for this high-risk population change over time, such as participation in treatment, alcohol consumption and drug abuse. Longitudinal datasets are increasingly available, particularly clinical data that contain multiple observations of health exposures and outcomes over time. Several analytic options are available for assessment of longitudinal data; however, it can be challenging to choose the appropriate analytic method for specific combinations of research questions and types of data. The purpose of this review is to help researchers choose the appropriate methods to analyze longitudinal data, using alcohol consumption as an example of a time-varying exposure variable. When selecting the optimal analytic method, one must consider aspects of exposure (e.g. timing, pattern, and amount) and outcome (fixed or time-varying), while also addressing minimizing bias. In this article, we will describe several analytic approaches for longitudinal data, including developmental trajectory analysis, generalized estimating equations, and mixed effect models. For each analytic strategy, we describe appropriate situations to use the method and provide an example that demonstrates the use of the method. Clinical data related to alcohol consumption and HIV are used to illustrate these methods.

Influence of a strong sample solvent on analyte dispersion in chromatographic columns.

PubMed

Mishra, Manoranjan; Rana, Chinar; De Wit, A; Martin, Michel

2013-07-05

In chromatographic columns, when the eluting strength of the sample solvent is larger than that of the carrier liquid, a deformation of the analyte zone occurs because its frontal part moves at a relatively high velocity due to a low retention factor in the sample solvent while the rear part of the analyte zone is more retained in the carrier liquid and hence moves at a lower velocity. The influence of this solvent strength effect on the separation of analytes is studied here theoretically using a mass balance model describing the spatio-temporal evolution of the eluent, the sample solvent and the analyte. The viscosity of the sample solvent and carrier fluid is supposed to be the same (i.e. no viscous fingering effects are taken into account). A linear isotherm adsorption with a retention factor depending upon the local concentration of the liquid phase is considered. The governing equations are numerically solved by using a Fourier spectral method and parametric studies are performed to analyze the effect of various governing parameters on the dispersion and skewness of the analyte zone. The distortion of this zone is found to depend strongly on the difference in eluting strength between the mobile phase and the sample solvent as well as on the sample volume. Copyright © 2013 Elsevier B.V. All rights reserved.

Exploratory Bifactor Analysis: The Schmid-Leiman Orthogonalization and Jennrich-Bentler Analytic Rotations

PubMed Central

Mansolf, Maxwell; Reise, Steven P.

2017-01-01

Analytic bifactor rotations (Jennrich & Bentler, 2011, 2012) have been recently developed and made generally available, but are not well understood. The Jennrich-Bentler analytic bifactor rotations (bi-quartimin and bi-geomin) are an alternative to, and arguably an improvement upon, the less technically sophisticated Schmid-Leiman orthogonalization (Schmid & Leiman, 1957). We review the technical details that underlie the Schmid-Leiman and Jennrich-Bentler bifactor rotations, using simulated data structures to illustrate important features and limitations. For the Schmid-Leiman, we review the problem of inaccurate parameter estimates caused by the linear dependencies, sometimes called “proportionality constraints,” that are required to expand a p correlated factors solution into a (p+1) (bi)factor space. We also review the complexities involved when the data depart from perfect cluster structure (e.g., item cross-loading on group factors). For the Jennrich-Bentler rotations, we describe problems in parameter estimation caused by departures from perfect cluster structure. In addition, we illustrate the related problems of: (a) solutions that are not invariant under different starting values (i.e., local minima problems); and, (b) group factors collapsing onto the general factor. Recommendations are made for substantive researchers including examining all local minima and applying multiple exploratory techniques in an effort to identify an accurate model. PMID:27612521

Group virtue: the importance of morality (vs. competence and sociability) in the positive evaluation of in-groups.

PubMed

Leach, Colin Wayne; Ellemers, Naomi; Barreto, Manuela

2007-08-01

Although previous research has focused on competence and sociability as the characteristics most important to positive group evaluation, the authors suggest that morality is more important. Studies with preexisting and experimentally created in-groups showed that a set of positive traits constituted distinct factors of morality, competence, and sociability. When asked directly, Study 1 participants reported that their in-group's morality was more important than its competence or sociability. An unobtrusive factor analytic method also showed morality to be a more important explanation of positive in-group evaluation than competence or sociability. Experimental manipulations of morality and competence (Study 4) and morality and sociability (Study 5) showed that only in-group morality affected aspects of the group-level self-concept related to positive evaluation (i.e., pride in, or distancing from, the in-group). Consistent with this finding, identification with experimentally created (Study 2b) and preexisting (Studies 4 and 5) in-groups predicted the ascription of morality, but not competence or sociability, to the in-group.

Improving the analyte ion signal in matrix-assisted laser desorption/ionization imaging mass spectrometry via electrospray deposition by enhancing incorporation of the analyte in the matrix.

PubMed

Malys, Brian J; Owens, Kevin G

2017-05-15

Matrix-assisted laser desorption/ionization (MALDI) is widely used as the ionization method in high-resolution chemical imaging studies that seek to visualize the distribution of analytes within sectioned biological tissues. This work extends the use of electrospray deposition (ESD) to apply matrix with an additional solvent spray to incorporate and homogenize analyte within the matrix overlayer. Analytes and matrix are sequentially and independently applied by ESD to create a sample from which spectra are collected, mimicking a MALDI imaging mass spectrometry (IMS) experiment. Subsequently, an incorporation spray consisting of methanol is applied by ESD to the sample and another set of spectra are collected. The spectra prior to and after the incorporation spray are compared to evaluate the improvement in the analyte signal. Prior to the incorporation spray, samples prepared using α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) as the matrix showed low signal while the sample using sinapinic acid (SA) initially exhibited good signal. Following the incorporation spray, the sample using SA did not show an increase in signal; the sample using DHB showed moderate gain factors of 2-5 (full ablation spectra) and 12-336 (raster spectra), while CHCA samples saw large increases in signal, with gain factors of 14-172 (full ablation spectra) and 148-1139 (raster spectra). The use of an incorporation spray to apply solvent by ESD to a matrix layer already deposited by ESD provides an increase in signal by both promoting incorporation of the analyte within and homogenizing the distribution of the incorporated analyte throughout the matrix layer. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Analytic and Heuristic Processing Influences on Adolescent Reasoning and Decision-Making.

ERIC Educational Resources Information Center

Klaczynski, Paul A.

2001-01-01

Examined the relationship between age and the normative/descriptive gap--the discrepancy between actual reasoning and traditional standards for reasoning. Found that middle adolescents performed closer to normative ideals than early adolescents. Factor analyses suggested that performance was based on two processing systems, analytic and heuristic…

A Cluster Analytic Study of Osteoprotective Behavior in Undergraduates

ERIC Educational Resources Information Center

Sharp, Katherine; Thombs, Dennis L.

2003-01-01

Objective: To derive an empirical taxonomy of osteoprotective stages using the Precaution Adoption Process Model (PAPM) and to identify the predisposing factors associated with each stage. Methods: An anonymous survey was completed by 504 undergraduates at a Midwestern public university. Results: Cluster analytic findings indicate that only 2…

Analysis and investigation of temperature and hydrostatic pressure effects on optical characteristics of multiple quantum well slow light devices.

PubMed

Abdolhosseini, Saeed; Kohandani, Reza; Kaatuzian, Hassan

2017-09-10

This paper represents the influences of temperature and hydrostatic pressure variations on GaAs/AlGaAs multiple quantum well slow light systems based on coherence population oscillations. An analytical model in non-integer dimension space is used to study the considerable effects of these parameters on optical properties of the slow light apparatus. Exciton oscillator strength and fractional dimension constants have special roles on the analytical model in fractional dimension. Hence, the impacts of hydrostatic pressure and temperature on exciton oscillator strength and fractional dimension quantity are investigated theoretically in this paper. Based on the achieved results, temperature and hydrostatic pressure play key roles on optical parameters of the slow light systems, such as the slow down factor and central energy of the device. It is found that the slope and value of the refractive index real part change with alterations of temperature and hydrostatic pressure in the range of 5-40 deg of Kelvin and 1 bar to 2 kbar, respectively. Thus, the peak value of the slow down factor can be adjusted by altering these parameters. Moreover, the central energy of the device shifts when the hydrostatic pressure is applied to the slow light device or temperature is varied. In comparison with previous reported experimental results, our simulations follow them successfully. It is shown that the maximum value of the slow down factor is estimated close to 5.5×10 4 with a fine adjustment of temperature and hydrostatic pressure. Meanwhile, the central energy shift of the slow light device rises up to 27 meV, which provides an appropriate basis for different optical devices in which multiple quantum well slow light is one of their essential subsections. This multiple quantum well slow light device has potential applications for use as a tunable optical buffer and pressure/temperature sensors.

On the three-dimensional instability of strained vortices

NASA Technical Reports Server (NTRS)

Waleffe, Fabian

1990-01-01

The three-dimensional (3-D) instability of a two-dimensional (2-D) flow with elliptical streamlines has been proposed as a generic mechanism for the breakdown of many 2-D flows. A physical interpretation for the mechanism is presented together with an analytical treatment of the problem. It is shown that the stability of an elliptical flow is governed by an Ince equation. An analytical representation for a localized solution is given and establishes a direct link with previous computations and experiments.

Leading multi-soft limits from scattering equations

NASA Astrophysics Data System (ADS)

Zlotnikov, Michael

2017-10-01

A Cachazo-He-Yuan (CHY) type formula is derived for the leading gluon, bi-adjoint scalar ϕ 3, Yang-Mills-scalar and non-linear sigma model m-soft factors S m in arbitrary dimension. The general formula is used to evaluate explicit examples for up to three soft legs analytically and up to four soft legs numerically via comparison with amplitude ratios under soft kinematics. A structural pattern for gluon m-soft factor is inferred and a simpler formula for its calculation is conjectured. In four dimensions, a Cachazo-Svrček-Witten (CSW) recursive procedure producing the leading m-soft gluon factor in spinor helicity formalism is developed as an alternative, and Britto-Cachazo-Feng-Witten (BCFW) recursion is used to obtain the leading four-soft gluon factor for all analytically distinct helicity configurations.

Longitudinal dielectric function and dispersion relation of electrostatic waves in relativistic plasmas

NASA Astrophysics Data System (ADS)

Touil, B.; Bendib, A.; Bendib-Kalache, K.

2017-02-01

The longitudinal dielectric function is derived analytically from the relativistic Vlasov equation for arbitrary values of the relevant parameters z = m c 2 / T , where m is the rest electron mass, c is the speed of light, and T is the electron temperature in energy units. A new analytical approach based on the Legendre polynomial expansion and continued fractions was used. Analytical expression of the electron distribution function was derived. The real part of the dispersion relation and the damping rate of electron plasma waves are calculated both analytically and numerically in the whole range of the parameter z . The results obtained improve significantly the previous results reported in the literature. For practical purposes, explicit expressions of the real part of the dispersion relation and the damping rate in the range z > 30 and strongly relativistic regime are also proposed.

RCRA Facility investigation report for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Volume 5, Technical Memorandums 06-09A, 06-10A, and 06-12A

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

None

This report provides a detailed summary of the activities carried out to sample groundwater at Waste Area Grouping (WAG) 6. The analytical results for samples collected during Phase 1, Activity 2 of the WAG 6 Resource Conservation and Recovery Act Facility Investigation (RFI) are also presented. In addition, analytical results for Phase 1, activity sampling events for which data were not previously reported are included in this TM. A summary of the groundwater sampling activities of WAG 6, to date, are given in the Introduction. The Methodology section describes the sampling procedures and analytical parameters. Six attachments are included. Attachmentsmore » 1 and 2 provide analytical results for selected RFI groundwater samples and ORNL sampling event. Attachment 3 provides a summary of the contaminants detected in each well sampled for all sampling events conducted at WAG 6. Bechtel National Inc. (BNI)/IT Corporation Contract Laboratory (IT) RFI analytical methods and detection limits are given in Attachment 4. Attachment 5 provides the Oak Ridge National Laboratory (ORNL)/Analytical Chemistry Division (ACD) analytical methods and detection limits and Resource Conservation and Recovery Act (RCRA) quarterly compliance monitoring (1988--1989). Attachment 6 provides ORNL/ACD groundwater analytical methods and detection limits (for the 1990 RCRA semi-annual compliance monitoring).« less

The effect on reliability and sensitivity to level of training of combining analytic and holistic rating scales for assessing communication skills in an internal medicine resident OSCE.

PubMed

Daniels, Vijay John; Harley, Dwight

2017-07-01

Although previous research has compared checklists to rating scales for assessing communication, the purpose of this study was to compare the effect on reliability and sensitivity to level of training of an analytic, a holistic, and a combined analytic-holistic rating scale in assessing communication skills. The University of Alberta Internal Medicine Residency runs OSCEs for postgraduate year (PGY) 1 and 2 residents and another for PGY-4 residents. Communication stations were scored with an analytic scale (empathy, non-verbal skills, verbal skills, and coherence subscales) and a holistic scale. Authors analyzed reliability of individual and combined scales using generalizability theory and evaluated each scale's sensitivity to level of training. For analytic, holistic, and combined scales, 12, 12, and 11 stations respectively yielded a Phi of 0.8 for the PGY-1,2 cohort, and 16, 16, and 14 stations yielded a Phi of 0.8 for the PGY-4 cohort. PGY-4 residents scored higher on the combined scale, the analytic rating scale, and the non-verbal and coherence subscales. A combined analytic-holistic rating scale increased score reliability and was sensitive to level of training. Given increased validity evidence, OSCE developers should consider combining analytic and holistic scales when assessing communication skills. Copyright © 2017 Elsevier B.V. All rights reserved.

Elements of analytic style: Bion's clinical seminars.

PubMed

Ogden, Thomas H

2007-10-01

The author finds that the idea of analytic style better describes significant aspects of the way he practices psychoanalysis than does the notion of analytic technique. The latter is comprised to a large extent of principles of practice developed by previous generations of analysts. By contrast, the concept of analytic style, though it presupposes the analyst's thorough knowledge of analytic theory and technique, emphasizes (1) the analyst's use of his unique personality as reflected in his individual ways of thinking, listening, and speaking, his own particular use of metaphor, humor, irony, and so on; (2) the analyst's drawing on his personal experience, for example, as an analyst, an analysand, a parent, a child, a spouse, a teacher, and a student; (3) the analyst's capacity to think in a way that draws on, but is independent of, the ideas of his colleagues, his teachers, his analyst, and his analytic ancestors; and (4) the responsibility of the analyst to invent psychoanalysis freshly for each patient. Close readings of three of Bion's 'Clinical seminars' are presented in order to articulate some of the elements of Bion's analytic style. Bion's style is not presented as a model for others to emulate or, worse yet, imitate; rather, it is described in an effort to help the reader consider from a different vantage point (provided by the concept of analytic style) the way in which he, the reader, practices psychoanalysis.

Correlation of the Capacity Factor in Vesicular Electrokinetic Chromatography with the Octanol:Water Partition Coefficient for Charged and Neutral Analytes

PubMed Central

Razak, J. L.; Cutak, B. J.; Larive, C. K.; Lunte, C. E.

2008-01-01

Purpose The aim of this study was to develop a method based upon electrokinetic chromatography (EKC) using oppositely charged surfactant vesicles as a buffer modifier to estimate hydrophobicity (log P) for a range of neutral and charged compounds. Methods Vesicles were formed from cetyltrimethylammonium bromide (CTAB) and sodium n-octyl sulfate (SOS). The size and polydispersity of the vesicles were characterized by electron microscopy, dynamic light scattering, and pulsed-field gradient NMR (PFG-NMR). PFG-NMR was also used to determine if ion-pairing between cationic analytes and free SOS monomer occurred. The CTAB/SOS vesicles were used as a buffer modifier in capillary electrophoresis (CE). The capacity factor (log k′) was calculated by determining the mobility of the analytes both in the presence and absence of vesicles. Log k′ was determined for 29 neutral and charged analytes. Results There was a linear relationship between the log of capacity factor (log k′) and octanol/water partition coefficient (log P) for both neutral and basic species at pH 6.0, 7.3, and 10.2. This indicated that interaction between the cation and vesicle was dominated by hydrophobic forces. At pH 4.3, the log k′ values for the least hydrophobic basic analytes were higher than expected, indicating that electrostatic attraction as well as hydrophobic forces contributed to the overall interaction between the cation and vesicle. Anionic compounds could not be evaluated using this system. Conclusion Vesicular electrokinetic chromatography (VEKC) using surfactant vesicles as buffer modifiers is a promising method for the estimation of hydrophobicity. PMID:11336344

Analytical solutions of one-dimensional multispecies reactive transport in a permeable reactive barrier-aquifer system

NASA Astrophysics Data System (ADS)

Mieles, John; Zhan, Hongbin

2012-06-01

The permeable reactive barrier (PRB) remediation technology has proven to be more cost-effective than conventional pump-and-treat systems, and has demonstrated the ability to rapidly reduce the concentrations of specific chemicals of concern (COCs) by up to several orders of magnitude in some scenarios. This study derives new steady-state analytical solutions to multispecies reactive transport in a PRB-aquifer (dual domain) system. The advantage of the dual domain model is that it can account for the potential existence of natural degradation in the aquifer, when designing the required PRB thickness. The study focuses primarily on the steady-state analytical solutions of the tetrachloroethene (PCE) serial degradation pathway and secondly on the analytical solutions of the parallel degradation pathway. The solutions in this study can also be applied to other types of dual domain systems with distinct flow and transport properties. The steady-state analytical solutions are shown to be accurate and the numerical program RT3D is selected for comparison. The results of this study are novel in that the solutions provide improved modeling flexibility including: 1) every species can have unique first-order reaction rates and unique retardation factors, and 2) daughter species can be modeled with their individual input concentrations or solely as byproducts of the parent species. The steady-state analytical solutions exhibit a limitation that occurs when interspecies reaction rate factors equal each other, which result in undefined solutions. Excel spreadsheet programs were created to facilitate prompt application of the steady-state analytical solutions, for both the serial and parallel degradation pathways.

Error-analysis and comparison to analytical models of numerical waveforms produced by the NRAR Collaboration

NASA Astrophysics Data System (ADS)

Hinder, Ian; Buonanno, Alessandra; Boyle, Michael; Etienne, Zachariah B.; Healy, James; Johnson-McDaniel, Nathan K.; Nagar, Alessandro; Nakano, Hiroyuki; Pan, Yi; Pfeiffer, Harald P.; Pürrer, Michael; Reisswig, Christian; Scheel, Mark A.; Schnetter, Erik; Sperhake, Ulrich; Szilágyi, Bela; Tichy, Wolfgang; Wardell, Barry; Zenginoğlu, Anıl; Alic, Daniela; Bernuzzi, Sebastiano; Bode, Tanja; Brügmann, Bernd; Buchman, Luisa T.; Campanelli, Manuela; Chu, Tony; Damour, Thibault; Grigsby, Jason D.; Hannam, Mark; Haas, Roland; Hemberger, Daniel A.; Husa, Sascha; Kidder, Lawrence E.; Laguna, Pablo; London, Lionel; Lovelace, Geoffrey; Lousto, Carlos O.; Marronetti, Pedro; Matzner, Richard A.; Mösta, Philipp; Mroué, Abdul; Müller, Doreen; Mundim, Bruno C.; Nerozzi, Andrea; Paschalidis, Vasileios; Pollney, Denis; Reifenberger, George; Rezzolla, Luciano; Shapiro, Stuart L.; Shoemaker, Deirdre; Taracchini, Andrea; Taylor, Nicholas W.; Teukolsky, Saul A.; Thierfelder, Marcus; Witek, Helvi; Zlochower, Yosef

2013-01-01

The Numerical-Relativity-Analytical-Relativity (NRAR) collaboration is a joint effort between members of the numerical relativity, analytical relativity and gravitational-wave data analysis communities. The goal of the NRAR collaboration is to produce numerical-relativity simulations of compact binaries and use them to develop accurate analytical templates for the LIGO/Virgo Collaboration to use in detecting gravitational-wave signals and extracting astrophysical information from them. We describe the results of the first stage of the NRAR project, which focused on producing an initial set of numerical waveforms from binary black holes with moderate mass ratios and spins, as well as one non-spinning binary configuration which has a mass ratio of 10. All of the numerical waveforms are analysed in a uniform and consistent manner, with numerical errors evaluated using an analysis code created by members of the NRAR collaboration. We compare previously-calibrated, non-precessing analytical waveforms, notably the effective-one-body (EOB) and phenomenological template families, to the newly-produced numerical waveforms. We find that when the binary's total mass is ˜100-200M⊙, current EOB and phenomenological models of spinning, non-precessing binary waveforms have overlaps above 99% (for advanced LIGO) with all of the non-precessing-binary numerical waveforms with mass ratios ⩽4, when maximizing over binary parameters. This implies that the loss of event rate due to modelling error is below 3%. Moreover, the non-spinning EOB waveforms previously calibrated to five non-spinning waveforms with mass ratio smaller than 6 have overlaps above 99.7% with the numerical waveform with a mass ratio of 10, without even maximizing on the binary parameters.

Fleet management performance monitoring.

DOT National Transportation Integrated Search

2013-05-01

The principle goal of this project was to enhance and expand the analytical modeling methodology previously developed as part of the Fleet Management Criteria: Disposal Points and Utilization Rates project completed in 2010. The enhanced and ex...

Cognitive Abilities as Expressions of Three "Ways of Knowing."

ERIC Educational Resources Information Center

Diamond, Stephen R.; Royce, Joseph R.

1980-01-01

Factor analytic studies suggest that there are six replicable second order cognitive factors. These six factors lend themselves to being interpreted as aspects of Royce's three ways of knowing: conceptual, perceptual, or symbolical. This view provides a unified explanation of the second and third order factors. (Author/CTM)

Portal scatter to primary dose ratio of 4 to 18 MV photon spectra incident on heterogeneous phantoms

NASA Astrophysics Data System (ADS)

Ozard, Siobhan R.

Electronic portal imagers designed and used to verify the positioning of a cancer patient undergoing radiation treatment can also be employed to measure the in vivo dose received by the patient. This thesis investigates the ratio of the dose from patient-scattered particles to the dose from primary (unscattered) photons at the imaging plane, called the scatter to primary dose ratio (SPR). The composition of the SPR according to the origin of scatter is analyzed more thoroughly than in previous studies. A new analytical method for calculating the SPR is developed and experimentally verified for heterogeneous phantoms. A novel technique that applies the analytical SPR method for in vivo dosimetry with a portal imager is evaluated. Monte Carlo simulation was used to determine the imager dose from patient-generated electrons and photons that scatter one or more times within the object. The database of SPRs reported from this investigation is new since the contribution from patient-generated electrons was neglected by previous Monte Carlo studies. The SPR from patient-generated electrons was found here to be as large as 0.03. The analytical SPR method relies on the established result that the scatter dose is uniform for an air gap between the patient and the imager that is greater than 50 cm. This method also applies the hypothesis that first-order Compton scatter only, is sufficient for scatter estimation. A comparison of analytical and measured SPRs for neck, thorax, and pelvis phantoms showed that the maximum difference was within +/-0.03, and the mean difference was less than +/-0.01 for most cases. This accuracy was comparable to similar analytical approaches that are limited to homogeneous phantoms. The analytical SPR method could replace lookup tables of measured scatter doses that can require significant time to measure. In vivo doses were calculated by combining our analytical SPR method and the convolution/superposition algorithm. Our calculated in vivo doses agreed within +/-3% with the doses measured in the phantom. The present in vivo method was faster compared to other techniques that use convolution/superposition. Our method is a feasible and satisfactory approach that contributes to on-line patient dose monitoring.

An analytical approach to γ-ray self-shielding effects for radioactive bodies encountered nuclear decommissioning scenarios.

PubMed

Gamage, K A A; Joyce, M J

2011-10-01

A novel analytical approach is described that accounts for self-shielding of γ radiation in decommissioning scenarios. The approach is developed with plutonium-239, cobalt-60 and caesium-137 as examples; stainless steel and concrete have been chosen as the media for cobalt-60 and caesium-137, respectively. The analytical methods have been compared MCNPX 2.6.0 simulations. A simple, linear correction factor relates the analytical results and the simulated estimates. This has the potential to greatly simplify the estimation of self-shielding effects in decommissioning activities. Copyright © 2011 Elsevier Ltd. All rights reserved.

Personality and academic performance of three cohorts of veterinary students in South Africa.

PubMed

van der Walt, H S; Pickworth, Glynis

2007-01-01

To aid in selecting students for admission to undergraduate veterinary training, admissions procedures often take into account students' previous academic performance as well as the results of an interview. The study reported here investigated the relationship between personality and academic success. Students from three entry cohorts to the second year of study of a six-year BVSc program at the University of Pretoria completed the 16 Personality Factor Questionnaire. A meta-analytic approach was used to estimate the relationship between academic performance in two major final-year subjects and academic performance on entry, an interview score, and the personality factors. The study confirmed the value of previous academic performance and the interview in selecting students for the veterinary degree program. The findings also indicate that the inclusion of a measure of intellectual ability could be of value. The value of various personality characteristics in predicting good study habits and examination performance is highlighted by the study results: students were more successful if they were conscientious, emotionally stable, socially adept, self-disciplined, practical rather than imaginative, and relaxed rather than anxious. It appears worthwhile to consider including an appropriate personality questionnaire in the selection process to improve the accuracy of predictions of students' success. A sound personality make-up will not only increase the likelihood of academic success but should also be beneficial in the successful management of a veterinary practice and in enjoying veterinary science as a career.

A Conceptual Analytics Model for an Outcome-Driven Quality Management Framework as Part of Professional Healthcare Education.

PubMed

Hervatis, Vasilis; Loe, Alan; Barman, Linda; O'Donoghue, John; Zary, Nabil

2015-10-06

Preparing the future health care professional workforce in a changing world is a significant undertaking. Educators and other decision makers look to evidence-based knowledge to improve quality of education. Analytics, the use of data to generate insights and support decisions, have been applied successfully across numerous application domains. Health care professional education is one area where great potential is yet to be realized. Previous research of Academic and Learning analytics has mainly focused on technical issues. The focus of this study relates to its practical implementation in the setting of health care education. The aim of this study is to create a conceptual model for a deeper understanding of the synthesizing process, and transforming data into information to support educators' decision making. A deductive case study approach was applied to develop the conceptual model. The analytics loop works both in theory and in practice. The conceptual model encompasses the underlying data, the quality indicators, and decision support for educators. The model illustrates how a theory can be applied to a traditional data-driven analytics approach, and alongside the context- or need-driven analytics approach.

A Conceptual Analytics Model for an Outcome-Driven Quality Management Framework as Part of Professional Healthcare Education

PubMed Central

Loe, Alan; Barman, Linda; O'Donoghue, John; Zary, Nabil

2015-01-01

Background Preparing the future health care professional workforce in a changing world is a significant undertaking. Educators and other decision makers look to evidence-based knowledge to improve quality of education. Analytics, the use of data to generate insights and support decisions, have been applied successfully across numerous application domains. Health care professional education is one area where great potential is yet to be realized. Previous research of Academic and Learning analytics has mainly focused on technical issues. The focus of this study relates to its practical implementation in the setting of health care education. Objective The aim of this study is to create a conceptual model for a deeper understanding of the synthesizing process, and transforming data into information to support educators’ decision making. Methods A deductive case study approach was applied to develop the conceptual model. Results The analytics loop works both in theory and in practice. The conceptual model encompasses the underlying data, the quality indicators, and decision support for educators. Conclusions The model illustrates how a theory can be applied to a traditional data-driven analytics approach, and alongside the context- or need-driven analytics approach. PMID:27731840

Prevalence and Factors Associated with the Utilization of Dental Care Services among Factory Workers in Nava Nakorn Industrial Estate, Pathumthani Province, Thailand.

PubMed

Jaidee, Jeeratip; Ratanasiri, Amornrat; Chatrchaiwiwatana, Supaporn; Soonthon, Surasak

2015-07-01

The present study aimed to find out the utilization prevalence of dental care services among factory workers over a period of one year and factors associated with utilization of dental care services. This was a cross-sectional analytic study. The study population was factory workers in Nava Nakorn Industrial Estate randomly sampled using Probability Proportion to Size Cluster Sampling Method. The tool was a questionnaire about utilization of dental care services. Among the sample group of 1,500 workers from 16 factories, almost 2/3 (63.9%) had never used any dental care services in the previous year while only 36.1% did. A multivariable logistic regression analysis showed that workplace, accommodation, tooth decay, toothache history, transportation, experience in using social security fund for dental care services, availability and accessibility of dental care services, brushing teeth regularly after meals, using dental care services regularly in a dental clinic, and agreement with the idea that a tooth extraction and medication by a dentist could reduce the risk of progression of disease, statistical significance (p-value < 0.05), were factors associated with the utilization of dental care services at R2 (The Nagelkerke R Square) 0.38. That the prevalence of the factory workers who did not use dental care services during the last one year was 63.9 percent. This study identified three groups of factors associated with the utilization of dental care services as: 1) Predisposing factors, 2) Enabling factors, and 3) Need factors.

Risk factors control for primary prevention of cardiovascular disease in men: Evidence from the Aragon Workers Health Study (AWHS).

PubMed

Aguilar-Palacio, Isabel; Malo, Sara; Feja, Cristina; Lallana, MªJesús; León-Latre, Montserrat; Casasnovas, José Antonio; Rabanaque, MªJosé; Guallar, Eliseo

2018-01-01

Benefits of cardiovascular disease (CVD) risk factors control are well known, but goals achievement remains low. The objective of this study is to evaluate the prevalence of CVD risk factors among men ina worker's cohort with no previous CVD, to study control variations across time and the factors associated with poor control. To this end, we conducted a cohort reexamination (2010-2014) within the context of the Aragon Workers Health Study (AWHS). Data from working characteristics, analytical values and pharmacological prescription were included in the analysis. Prevalences of risk factor diagnosis and control were calculated, as well as factors associated with poor control. The prevalence of CVD risk factors was high. In 2014dyslipidaemia was the most prevalent (85.2%) followed by Hypertension (HT) (42.0%). People under treatment increased for the period analysed (p<0.001). The proportion of people treated varied from 72.2% in Diabetes Mellitus to 31.1% in dyslipidaemia in 2014. 46.2% of the workers with HT were controlled, decreasing to 21.9% in Diabetes and 11.0% in dyslipidaemia (2014). Working in a turn different to central shift was associated with poor control, especially for those working at night with HT (Odds Ratio in 2010: 3.6; Confidence Interval 95% 1.8-7.4) and dyslipidaemia (Odds Ratio 2010: 4.7; Confidence Interval 95% 1.3-16.4). We conclude that, although CVD control has increased significantly for the period studied, there are still many people that do not receive any treatment, and control goals are normally not achieved.

Constraints on the [Formula: see text] form factor from analyticity and unitarity.

PubMed

Ananthanarayan, B; Caprini, I; Kubis, B

Motivated by the discrepancies noted recently between the theoretical calculations of the electromagnetic [Formula: see text] form factor and certain experimental data, we investigate this form factor using analyticity and unitarity in a framework known as the method of unitarity bounds. We use a QCD correlator computed on the spacelike axis by operator product expansion and perturbative QCD as input, and exploit unitarity and the positivity of its spectral function, including the two-pion contribution that can be reliably calculated using high-precision data on the pion form factor. From this information, we derive upper and lower bounds on the modulus of the [Formula: see text] form factor in the elastic region. The results provide a significant check on those obtained with standard dispersion relations, confirming the existence of a disagreement with experimental data in the region around [Formula: see text].

Information and complexity measures in the interface of a metal and a superconductor

NASA Astrophysics Data System (ADS)

Moustakidis, Ch. C.; Panos, C. P.

2018-06-01

Fisher information, Shannon information entropy and Statistical Complexity are calculated for the interface of a normal metal and a superconductor, as a function of the temperature for several materials. The order parameter Ψ (r) derived from the Ginzburg-Landau theory is used as an input together with experimental values of critical transition temperature Tc and the superconducting coherence length ξ0. Analytical expressions are obtained for information and complexity measures. Thus Tc is directly related in a simple way with disorder and complexity. An analytical relation is found of the Fisher Information with the energy profile of superconductivity i.e. the ratio of surface free energy and the bulk free energy. We verify that a simple relation holds between Shannon and Fisher information i.e. a decomposition of a global information quantity (Shannon) in terms of two local ones (Fisher information), previously derived and verified for atoms and molecules by Liu et al. Finally, we find analytical expressions for generalized information measures like the Tsallis entropy and Fisher information. We conclude that the proper value of the non-extensivity parameter q ≃ 1, in agreement with previous work using a different model, where q ≃ 1.005.

On Analytical Solutions of f(R) Modified Gravity Theories in FLRW Cosmologies

NASA Astrophysics Data System (ADS)

Domazet, Silvije; Radovanović, Voja; Simonović, Marko; Štefančić, Hrvoje

2013-02-01

A novel analytical method for f(R) modified theories without matter in Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetimes is introduced. The equation of motion for the scale factor in terms of cosmic time is reduced to the equation for the evolution of the Ricci scalar R with the Hubble parameter H. The solution of equation of motion for actions of the form of power law in Ricci scalar R is presented with a detailed elaboration of the action quadratic in R. The reverse use of the introduced method is exemplified in finding functional forms f(R), which leads to specified scale factor functions. The analytical solutions are corroborated by numerical calculations with excellent agreement. Possible further applications to the phases of inflationary expansion and late-time acceleration as well as f(R) theories with radiation are outlined.

Deconvoluting the effects of buffer salt concentration in hydrophilic interaction chromatography on a zwitterionic stationary phase.

PubMed

West, Caroline; Auroux, Emeline

2016-08-26

Quantitative structure-retention relationships (QSRRs) furnish a detailed and reliable description of the role and extent of different molecular interactions that can be established between the analytes and the chromatographic system. Among QSRRs, the solvation parameter model using Abraham descriptors has gained acceptance as a general tool to explore the factors affecting retention in chromatographic systems. We have previously shown how a modified version of the solvation parameter model, with two extra terms to take account of interactions occurring with ionic and ionizable species (with positive and/or negative charges), could be applied to the characterization of hydrophilic interaction chromatographic (HILIC) systems. In the present study, we will show how this methodology can be used to evaluate the effects of increasing buffer salt concentration on retention and separation in a HILIC system. A commercial stationary phase possessing a sulfobetaine zwitterionic bonded ligand (Nucleodur HILIC) was used with a mobile phase composed of 80% acetonitrile and 20% pwwH4 ammonium acetate buffer, with aqueous buffer concentrations varying from 10 to 100mM, resulting in overall concentrations ranging from 2 to 20mM in the mobile phase. Retention factors were measured for a selection of 76 probe analytes. The chosen compounds are small molecules presenting a wide diversity of molecular structures and are relevant to biomedical and pharmaceutical applications. The QSRR models obtained allow for a rationalization of the interactions contributing to retention and separation in the HILIC system considered and shed some light on the effect of varying buffer salt concentration, namely the progressive transition from ion-exchange and electrostatic-repulsion mechanisms to hydrophilic partitioning. Copyright © 2016 Elsevier B.V. All rights reserved.

Thermal Disk Winds in X-Ray Binaries: Realistic Heating and Cooling Rates Give Rise to Slow, but Massive, Outflows

NASA Astrophysics Data System (ADS)

Higginbottom, N.; Proga, D.; Knigge, C.; Long, K. S.

2017-02-01

A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer disk atmosphere. Higginbottom & Proga recently demonstrated that the properties of thermally driven winds depend critically on the shape of the thermal equilibrium curve, since this determines the thermal stability of the irradiated material. For a given spectral energy distribution, the thermal equilibrium curve depends on an exact balance between the various heating and cooling mechanisms at work. Most previous work on thermally driven disk winds relied on an analytical approximation to these rates. Here, we use the photoionization code cloudy to generate realistic heating and cooling rates which we then use in a 2.5D hydrodynamic model computed in ZEUS to simulate thermal winds in a typical black hole X-ray binary. We find that these heating and cooling rates produce a significantly more complex thermal equilibrium curve, with dramatically different stability properties. The resulting flow, calculated in the optically thin limit, is qualitatively different from flows calculated using approximate analytical rates. Specifically, our thermal disk wind is much denser and slower, with a mass-loss rate that is a factor of two higher and characteristic velocities that are a factor of three lower. The low velocity of the flow—{v}\\max ≃ 200 km s-1—may be difficult to reconcile with observations. However, the high mass-loss rate—15 × the accretion rate—is promising, since it has the potential to destabilize the disk. Thermally driven disk winds may therefore provide a mechanism for state changes.

Understanding consumer and clinician preferences and decision making for rehabilitation following arthroplasty in the private sector.

PubMed

Buhagiar, Mark A; Naylor, Justine M; Simpson, Grahame; Harris, Ian A; Kohler, Friedbert

2017-06-19

To understand private consumer and clinician preferences towards different rehabilitation modes following knee or hip arthroplasty, and identify factors which influence the chosen rehabilitation pathway. Mixed methods cross-sectional study involving 95 semi-structured interviews of consumers (patients and carers) and clinicians (arthroplasty surgeons, physiotherapists and rehabilitation physicians) in Sydney, Australia, during 2014-2015. Participants were asked about the acceptability of different modes of rehabilitation provision, and factors influencing their chosen rehabilitation pathway. Interviews were in person or via the telephone. Qualitative analysis software was used to electronically manage qualitative data. An analytical approach guided data analysis. Pre-operative preferences strongly influenced the type of rehabilitation chosen by consumers. Key factors that influenced this were both intrinsic and extrinsic, including; the previous experience of self or known others, the perceived benefits of the chosen mode, a sense of entitlement, the role of orthopaedic surgeons and influence of patient preference, a patient's clinical status post-surgery, the private hospital business model and insurance provider involvement. The acceptability of rehabilitation modes varied between clinician groups. No one rehabilitation mode provided following arthroplasty is singularly preferred by stakeholders. Factors other than the belief that a particular mode was more effective than another appear to dominate the pathway followed by private arthroplasty consumers, indicating evidence-based policies around rehabilitation provision may have limited appeal in the private sector.

Prenatal hazardous substance use and adverse birth outcomes

PubMed Central

Quesada, Odayme; Gotman, Nathan; Howell, Heather B.; Funai, Edmund F.; Rounsaville, Bruce J.; Yonkers, Kimberly A.

2012-01-01

Objective Assess the relative effects of a variety of illicit and licit drugs on risk for adverse birth outcomes. Methods We used data from two large prospective investigations, and a novel analytic method, recursive partitioning class analysis to identify risk factors associated with preterm birth and delivering a small for gestational age infant. Results Compared to cocaine and opiate non-users, cocaine users were 3.53 times as likely (95% Cl: 1.65–7.56; p=0.001) and opiate users 2.86 times as likely (95% Cl: 1.11–7.36; p=0.03) to deliver preterm. The odds of delivering a small for gestational age infant for women who smoked more than two cigarettes daily was 3.74, (95% Cl: 2.47–5.65; p<0.0001) compared to women who smoked two or less cigarettes daily and had one previous child. Similarly, less educated, nulliparous women who smoked two or fewer cigarettes daily were 4.12 times as likely (95% Cl: 2.04–8.34; p<0.0001) to have a small for gestational age infant. Conclusions Among our covariates, prenatal cocaine and opiate use are the predominant risk factors for preterm birth; while tobacco use was the primary risk factor predicting small for gestational age at delivery. Multi-substance use did not substantially increase risk of adverse birth outcomes over these risk factors. PMID:22489543

Consumer acceptance of insect-based foods in the Netherlands: Academic and commercial implications.

PubMed

House, Jonas

2016-12-01

Despite growing interest in the use of insects as food, uptake of insect-based foods in Europe is low. Existing research into Western consumer acceptance of insects as food tends to emphasise the role of individual cognition in food choice at the expense of social or contextual factors, and typically frames consumer acceptance as a general issue, rather than relevant only for relatively few early adopters. This paper outlines empirical work, theoretically and methodologically informed by a critical appraisal of previous research, with consumers of insect-based convenience foods in the Netherlands. Reported initial motivations for trying insect foods are shown to be substantially different from factors - such as price, taste, availability, and 'fit' with established eating practices - which affect repeat consumption. Such factors are congruent with those affecting routine consumption of more conventional foods, indicating that insect foods should be analysed according to similar criteria and should be designed with more practical considerations in mind. Further, a reorientation of consumer acceptance research is proposed. Research should shift from attempts to forecast acceptance and engage with 'actual' examples of insect consumption; social, practical and contextual factors affecting food consumption should be emphasised; and - following work on the establishment of other novel foods - early adopters, rather than general populations, should receive greater analytic attention. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Aberrant Production of Th1/Th2/Th17-Related Cytokines in Serum of C57BL/6 Mice after Short-Term Formaldehyde Exposure

PubMed Central

Wei, Haiyan; Tan, Kehong; Sun, Rongli; Yin, Lihong; Zhang, Juan; Pu, Yuepu

2014-01-01

Previous studies have shown that formaldehyde (FA) could cause immunotoxicity by changing the number of T lymphocytes and that cytokines play a pivotal role in the regulation of T lymphocytes. However, the previously used cytokine detection methods are difficult to use in the measurement of several cytokines in a small amount of sample for one test. Therefore, the cytometric bead array (CBA) technique was used. CBA showed better analytical efficiency and sensitivity than the previous methods. C57BL/6 mice were exposed to the control (normal saline), low FA concentration (0.5 mg/kg), and high FA concentration (2 mg/kg) for 1 week or 1 month. The contents of cytokines, including Th1-related cytokines (IL-2, IFN-γ, and tumor necrosis factor), Th2-related cytokines (IL-4, IL-6, and IL-10), and Th17-related cytokines (IL-17A), were measured by using the BD FACS Canto II Flow Cytometer and analyzed by FCAP ArrayTM Software. Th1/Th2/Th17-related cytokines showed a slightly decreasing trend after low FA exposure. Conversely, a significantly increasing trend was found after high FA exposure. Th1/Th2/Th17-related cytokines all serve important functions in the immune reactions in mice after FA exposure. PMID:25264680

Comparison of commercial analytical techniques for measuring chlorine dioxide in urban desalinated drinking water.

PubMed

Ammar, T A; Abid, K Y; El-Bindary, A A; El-Sonbati, A Z

2015-12-01

Most drinking water industries are closely examining options to maintain a certain level of disinfectant residual through the entire distribution system. Chlorine dioxide is one of the promising disinfectants that is usually used as a secondary disinfectant, whereas the selection of the proper monitoring analytical technique to ensure disinfection and regulatory compliance has been debated within the industry. This research endeavored to objectively compare the performance of commercially available analytical techniques used for chlorine dioxide measurements (namely, chronoamperometry, DPD (N,N-diethyl-p-phenylenediamine), Lissamine Green B (LGB WET) and amperometric titration), to determine the superior technique. The commonly available commercial analytical techniques were evaluated over a wide range of chlorine dioxide concentrations. In reference to pre-defined criteria, the superior analytical technique was determined. To discern the effectiveness of such superior technique, various factors, such as sample temperature, high ionic strength, and other interferences that might influence the performance were examined. Among the four techniques, chronoamperometry technique indicates a significant level of accuracy and precision. Furthermore, the various influencing factors studied did not diminish the technique's performance where it was fairly adequate in all matrices. This study is a step towards proper disinfection monitoring and it confidently assists engineers with chlorine dioxide disinfection system planning and management.

Quantitative Method for Simultaneous Analysis of Acetaminophen and 6 Metabolites.

PubMed

Lammers, Laureen A; Achterbergh, Roos; Pistorius, Marcel C M; Romijn, Johannes A; Mathôt, Ron A A

2017-04-01

Hepatotoxicity after ingestion of high-dose acetaminophen [N-acetyl-para-aminophenol (APAP)] is caused by the metabolites of the drug. To gain more insight into factors influencing susceptibility to APAP hepatotoxicity, quantification of APAP and metabolites is important. A few methods have been developed to simultaneously quantify APAP and its most important metabolites. However, these methods require a comprehensive sample preparation and long run times. The aim of this study was to develop and validate a simplified, but sensitive method for the simultaneous quantification of acetaminophen, the main metabolites acetaminophen glucuronide and acetaminophen sulfate, and 4 Cytochrome P450-mediated metabolites by using liquid chromatography with mass spectrometric (LC-MS) detection. The method was developed and validated for the human plasma, and it entailed a single method for sample preparation, enabling quick processing of the samples followed by an LC-MS method with a chromatographic run time of 9 minutes. The method was validated for selectivity, linearity, accuracy, imprecision, dilution integrity, recovery, process efficiency, ionization efficiency, and carryover effect. The method showed good selectivity without matrix interferences. For all analytes, the mean process efficiency was >86%, and the mean ionization efficiency was >94%. Furthermore, the accuracy was between 90.3% and 112% for all analytes, and the within- and between-run imprecision were <20% for the lower limit of quantification and <14.3% for the middle level and upper limit of quantification. The method presented here enables the simultaneous quantification of APAP and 6 of its metabolites. It is less time consuming than previously reported methods because it requires only a single and simple method for the sample preparation followed by an LC-MS method with a short run time. Therefore, this analytical method provides a useful method for both clinical and research purposes.

Development of Internal Controls for the Luminex Instrument as Part of a Multiplex Seven-Analyte Viral Respiratory Antibody Profile

PubMed Central

Martins, Thomas B.

2002-01-01

The ability of the Luminex system to simultaneously quantitate multiple analytes from a single sample source has proven to be a feasible and cost-effective technology for assay development. In previous studies, my colleagues and I introduced two multiplex profiles consisting of 20 individual assays into the clinical laboratory. With the Luminex instrument’s ability to classify up to 100 distinct microspheres, however, we have only begun to realize the enormous potential of this technology. By utilizing additional microspheres, it is now possible to add true internal controls to each individual sample. During the development of a seven-analyte serologic viral respiratory antibody profile, internal controls for detecting sample addition and interfering rheumatoid factor (RF) were investigated. To determine if the correct sample was added, distinct microspheres were developed for measuring the presence of sufficient quantities of immunoglobulin G (IgG) or IgM in the diluted patient sample. In a multiplex assay of 82 samples, the IgM verification control correctly identified 23 out of 23 samples with low levels (<20 mg/dl) of this antibody isotype. An internal control microsphere for RF detected 30 out of 30 samples with significant levels (>10 IU/ml) of IgM RF. Additionally, RF-positive samples causing false-positive adenovirus and influenza A virus IgM results were correctly identified. By exploiting the Luminex instrument’s multiplexing capabilities, I have developed true internal controls to ensure correct sample addition and identify interfering RF as part of a respiratory viral serologic profile that includes influenza A and B viruses, adenovirus, parainfluenza viruses 1, 2, and 3, and respiratory syncytial virus. Since these controls are not assay specific, they can be incorporated into any serologic multiplex assay. PMID:11777827

Development of internal controls for the Luminex instrument as part of a multiplex seven-analyte viral respiratory antibody profile.

PubMed

Martins, Thomas B

2002-01-01

The ability of the Luminex system to simultaneously quantitate multiple analytes from a single sample source has proven to be a feasible and cost-effective technology for assay development. In previous studies, my colleagues and I introduced two multiplex profiles consisting of 20 individual assays into the clinical laboratory. With the Luminex instrument's ability to classify up to 100 distinct microspheres, however, we have only begun to realize the enormous potential of this technology. By utilizing additional microspheres, it is now possible to add true internal controls to each individual sample. During the development of a seven-analyte serologic viral respiratory antibody profile, internal controls for detecting sample addition and interfering rheumatoid factor (RF) were investigated. To determine if the correct sample was added, distinct microspheres were developed for measuring the presence of sufficient quantities of immunoglobulin G (IgG) or IgM in the diluted patient sample. In a multiplex assay of 82 samples, the IgM verification control correctly identified 23 out of 23 samples with low levels (<20 mg/dl) of this antibody isotype. An internal control microsphere for RF detected 30 out of 30 samples with significant levels (>10 IU/ml) of IgM RF. Additionally, RF-positive samples causing false-positive adenovirus and influenza A virus IgM results were correctly identified. By exploiting the Luminex instrument's multiplexing capabilities, I have developed true internal controls to ensure correct sample addition and identify interfering RF as part of a respiratory viral serologic profile that includes influenza A and B viruses, adenovirus, parainfluenza viruses 1, 2, and 3, and respiratory syncytial virus. Since these controls are not assay specific, they can be incorporated into any serologic multiplex assay.

Matrix solid-phase dispersion on column clean-up/pre-concentration as a novel approach for fast isolation of abuse drugs from human hair.

PubMed

Míguez-Framil, Martha; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar; Alvarez-Freire, Iván; Tabernero, María Jesús; Bermejo, Ana María

2010-10-08

A simple and fast sample pre-treatment method based on matrix solid-phase dispersion (MSPD) for isolating cocaine, benzoylecgonine (BZE), codeine, morphine and 6-monoacethylmorphine (6-MAM) from human hair has been developed. The MSPD approach consisted of using alumina (1.80 g) as a dispersing agent and 0.6M hydrochloric acid (4 mL) as an extracting solvent. For a fixed hair sample mass of 0.050 g, the alumina mass to sample mass ratio obtained was 36. A previously conditioned Oasis HLB cartridge (2 mL methanol, plus 2 mL ultrapure water, plus 1 mL of 0.2M/0.2M sodium hydroxide/boric acid buffer solution at pH 9.2) was attached to the end of the MSPD syringe for on column clean-up of the hydrochloric acid extract and for transferring the target compounds to a suitable solvent for gas chromatography (GC) analysis. Therefore, the adsorbed analytes were directly eluted from the Oasis HLB cartridges with 2 mL of 2% acetic acid in methanol before concentration by N(2) stream evaporation and dry extract derivatization with N-methyl-tert-butylsilyltrifluoroacetamide (BSTFA) and chlorotrimethylsilane (TMCS). The optimization/evaluation of all the factors affecting the MSPD and on column clean-up procedures has led to a fast sample treatment, and analytes extraction and pre-concentration can be finished in approximately 30 min. The developed method has been applied to eight hair samples from poli-drug abusers and measured analyte concentrations have been found to be statistically similar (95% confidence interval) to those obtained after a conventional enzymatic hydrolysis method (Pronase E). Copyright © 2010. Published by Elsevier B.V.

Sequential Multiplex Analyte Capturing for Phosphoprotein Profiling*

PubMed Central

Poetz, Oliver; Henzler, Tanja; Hartmann, Michael; Kazmaier, Cornelia; Templin, Markus F.; Herget, Thomas; Joos, Thomas O.

2010-01-01

Microarray-based sandwich immunoassays can simultaneously detect dozens of proteins. However, their use in quantifying large numbers of proteins is hampered by cross-reactivity and incompatibilities caused by the immunoassays themselves. Sequential multiplex analyte capturing addresses these problems by repeatedly probing the same sample with different sets of antibody-coated, magnetic suspension bead arrays. As a miniaturized immunoassay format, suspension bead array-based assays fulfill the criteria of the ambient analyte theory, and our experiments reveal that the analyte concentrations are not significantly changed. The value of sequential multiplex analyte capturing was demonstrated by probing tumor cell line lysates for the abundance of seven different receptor tyrosine kinases and their degree of phosphorylation and by measuring the complex phosphorylation pattern of the epidermal growth factor receptor in the same sample from the same cavity. PMID:20682761

Analytical Approach to Large Deformation Problems of Frame Structures

NASA Astrophysics Data System (ADS)

Ohtsuki, Atsumi; Ellyin, Fernand

In elements used as flexible linking devices and structures, the main characteristic is a fairly large deformation without exceeding the elastic limit of the material. This property is of both analytical and technological interests. Previous studies of large deformation have been generally concerned with a single member (e.g. a cantilever beam, a simply supported beam, etc.). However, there are very few large deformation studies of assembled members such as frames. This paper deals with a square frame with rigid joints, loaded diagonally in either tension or compression by a pair of opposite forces. Analytical solutions for large deformation are obtained in terms of elliptic integrals, and are compared with the experimental data. The agreement is found to be fairly close.

Differential memory in the trilinear model magnetotail

NASA Technical Reports Server (NTRS)

Chen, James; Mitchell, Horage G.; Palmadesso, Peter J.

1990-01-01

The previously proposed concept of 'differential memory' is quantitatively demonstrated using an idealized analytical model of particle dynamics in the magnetotail geometry. In this model (the 'trilinear' tail model) the magnetotail is divided into three regions. The particle orbits are solved exactly in each region, thus reducing the orbit integration to an analytical mapping. It is shown that the trilinear model reproduces the essential phase space features of the earlier model (Chen and Palmadesso, 1986), possessing well-defined entry and exit regions, and stochastic, integrable (regular), and transient orbits, occupying disjoint phase space regions. Different regions have widely separated characteristic time scales corresponding to different types of particle motion. Using the analytical model, the evolution of single-particle distribution functions is calculated.

Quantitative 1H NMR: Development and Potential of an Analytical Method – an Update

PubMed Central

Pauli, Guido F.; Gödecke, Tanja; Jaki, Birgit U.; Lankin, David C.

2012-01-01

Covering the literature from mid-2004 until the end of 2011, this review continues a previous literature overview on quantitative 1H NMR (qHNMR) methodology and its applications in the analysis of natural products (NPs). Among the foremost advantages of qHNMR is its accurate function with external calibration, the lack of any requirement for identical reference materials, a high precision and accuracy when properly validated, and an ability to quantitate multiple analytes simultaneously. As a result of the inclusion of over 170 new references, this updated review summarizes a wealth of detailed experiential evidence and newly developed methodology that supports qHNMR as a valuable and unbiased analytical tool for natural product and other areas of research. PMID:22482996

An Improved Analytical Model of the Local Interstellar Magnetic Field: The Extension to Compressibility

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

Kleimann, Jens; Fichtner, Horst; Röken, Christian, E-mail: jk@tp4.rub.de, E-mail: hf@tp4.rub.de, E-mail: christian.roeken@mathematik.uni-regensburg.de

A previously published analytical magnetohydrodynamic model for the local interstellar magnetic field in the vicinity of the heliopause (Röken et al. 2015) is extended from incompressible to compressible, yet predominantly subsonic flow, considering both isothermal and adiabatic equations of state. Exact expressions and suitable approximations for the density and the flow velocity are derived and discussed. In addition to the stationary induction equation, these expressions also satisfy the momentum balance equation along stream lines. The practical usefulness of the corresponding, still exact, analytical magnetic field solution is assessed by comparing it quantitatively to results from a fully self-consistent magnetohydrodynamic simulationmore » of the interstellar magnetic field draping around the heliopause.« less

Gear Spline Coupling Program

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

Guo, Yi; Errichello, Robert

2013-08-29

An analytical model is developed to evaluate the design of a spline coupling. For a given torque and shaft misalignment, the model calculates the number of teeth in contact, tooth loads, stiffnesses, stresses, and safety factors. The analytic model provides essential spline coupling design and modeling information and could be easily integrated into gearbox design and simulation tools.

Do the Critical Success Factors from Learning Analytics Predict Student Outcomes?

ERIC Educational Resources Information Center

Strang, Kenneth David

2016-01-01

This article starts with a detailed literature review of recent studies that focused on using learning analytics software or learning management system data to determine the nature of any relationships between online student activity and their academic outcomes within university-level business courses. The article then describes how data was…

Disasters and Youth: A Meta-Analytic Examination of Posttraumatic Stress

ERIC Educational Resources Information Center

Furr, Jami M.; Comer, Jonathan S.; Edmunds, Julie M.; Kendall, Philip C.

2010-01-01

Objective: Meta-analyze the literature on posttraumatic stress (PTS) symptoms in youths post-disaster. Method: Meta-analytic synthesis of the literature (k = 96 studies; N[subscript total] = 74,154) summarizing the magnitude of associations between disasters and youth PTS, and key factors associated with variations in the magnitude of these…

Transcription factor-based biosensors enlightened by the analyte

PubMed Central

Fernandez-López, Raul; Ruiz, Raul; de la Cruz, Fernando; Moncalián, Gabriel

2015-01-01

Whole cell biosensors (WCBs) have multiple applications for environmental monitoring, detecting a wide range of pollutants. WCBs depend critically on the sensitivity and specificity of the transcription factor (TF) used to detect the analyte. We describe the mechanism of regulation and the structural and biochemical properties of TF families that are used, or could be used, for the development of environmental WCBs. Focusing on the chemical nature of the analyte, we review TFs that respond to aromatic compounds (XylS-AraC, XylR-NtrC, and LysR), metal ions (MerR, ArsR, DtxR, Fur, and NikR) or antibiotics (TetR and MarR). Analyzing the structural domains involved in DNA recognition, we highlight the similitudes in the DNA binding domains (DBDs) of these TF families. Opposite to DBDs, the wide range of analytes detected by TFs results in a diversity of structures at the effector binding domain. The modular architecture of TFs opens the possibility of engineering TFs with hybrid DNA and effector specificities. Yet, the lack of a crisp correlation between structural domains and specific functions makes this a challenging task. PMID:26191047

Transcription factor-based biosensors enlightened by the analyte.

PubMed

Fernandez-López, Raul; Ruiz, Raul; de la Cruz, Fernando; Moncalián, Gabriel

2015-01-01

Whole cell biosensors (WCBs) have multiple applications for environmental monitoring, detecting a wide range of pollutants. WCBs depend critically on the sensitivity and specificity of the transcription factor (TF) used to detect the analyte. We describe the mechanism of regulation and the structural and biochemical properties of TF families that are used, or could be used, for the development of environmental WCBs. Focusing on the chemical nature of the analyte, we review TFs that respond to aromatic compounds (XylS-AraC, XylR-NtrC, and LysR), metal ions (MerR, ArsR, DtxR, Fur, and NikR) or antibiotics (TetR and MarR). Analyzing the structural domains involved in DNA recognition, we highlight the similitudes in the DNA binding domains (DBDs) of these TF families. Opposite to DBDs, the wide range of analytes detected by TFs results in a diversity of structures at the effector binding domain. The modular architecture of TFs opens the possibility of engineering TFs with hybrid DNA and effector specificities. Yet, the lack of a crisp correlation between structural domains and specific functions makes this a challenging task.

Ionization Efficiency of Doubly Charged Ions Formed from Polyprotic Acids in Electrospray Negative Mode

NASA Astrophysics Data System (ADS)

Liigand, Piia; Kaupmees, Karl; Kruve, Anneli

2016-07-01

The ability of polyprotic acids to give doubly charged ions in negative mode electrospray was studied and related to physicochemical properties of the acids via linear discriminant analysis (LDA). It was discovered that the compound has to be strongly acidic (low p K a1 and p K a2) and to have high hydrophobicity (log P ow) to become multiply charged. Ability to give multiply charged ions in ESI/MS cannot be directly predicted from the solution phase acidities. Therefore, for the first time, a quantitative model to predict the charge state of the analyte in ESI/MS is proposed and validated for small anions. Also, a model to predict ionization efficiencies of these analytes was developed. Results indicate that acidity of the analyte, its octanol-water partition coefficient, and charge delocalization are important factors that influence ionization efficiencies as well as charge states of the analytes. The pH of the solvent was also found to be an important factor influencing the ionization efficiency of doubly charged ions.

Signal Enhancement in HPLC/Micro-Coil NMR Using Automated Column Trapping

PubMed Central

Djukovic, Danijel; Liu, Shuhui; Henry, Ian; Tobias, Brian; Raftery, Daniel

2008-01-01

A new HPLC-NMR system is described that performs analytical separation, pre-concentration, and NMR spectroscopy in rapid succession. The central component of our method is the online pre-concentration sequence that improves the match between post-column analyte peak volume and the micro-coil NMR detection volume. Separated samples are collected on to a C18 guard column with a mobile phase composed of 90% D2O/10% acetonitrile-D3, and back-flashed to the NMR micro-coil probe with 90% acetonitrile-D3/10% D2O. In order to assess the performance of our unit, we separated a standard mixture of 1 mM ibuprofen, naproxen, and phenylbutazone using a commercially available C18 analytical column. The S/N measurements from the NMR acquisitions indicated that we achieved signal enhancement factors up to 10.4 (±1.2)-fold. Furthermore, we observed that pre-concentration factors increased as the injected amount of analyte decreased. The highest concentration enrichment of 14.7 (±2.2)-fold was attained injecting 100 μL solution of 0.2 mM (~4 μg) ibuprofen. PMID:17037915

Notch Sensitivity of Woven Ceramic Matrix Composites Under Tensile Loading: An Experimental, Analytical, and Finite Element Study

NASA Technical Reports Server (NTRS)

Haque, A.; Ahmed, L.; Ware, T.; Jeelani, S.; Verrilli, Michael J. (Technical Monitor)

2001-01-01

The stress concentrations associated with circular notches and subjected to uniform tensile loading in woven ceramic matrix composites (CMCs) have been investigated for high-efficient turbine engine applications. The CMC's were composed of Nicalon silicon carbide woven fabric in SiNC matrix manufactured through polymer impregnation process (PIP). Several combinations of hole diameter/plate width ratios and ply orientations were considered in this study. In the first part, the stress concentrations were calculated measuring strain distributions surrounding the hole using strain gages at different locations of the specimens during the initial portion of the stress-strain curve before any microdamage developed. The stress concentration was also calculated analytically using Lekhnitskii's solution for orthotropic plates. A finite-width correction factor for anisotropic and orthotropic composite plate was considered. The stress distributions surrounding the circular hole of a CMC's plate were further studied using finite element analysis. Both solid and shell elements were considered. The experimental results were compared with both the analytical and finite element solutions. Extensive optical and scanning electron microscopic examinations were carried out for identifying the fracture behavior and failure mechanisms of both the notched and notched specimens. The stress concentration factors (SCF) determined by analytical method overpredicted the experimental results. But the numerical solution underpredicted the experimental SCF. Stress concentration factors are shown to increase with enlarged hole size and the effects of ply orientations on stress concentration factors are observed to be negligible. In all the cases, the crack initiated at the notch edge and propagated along the width towards the edge of the specimens.

In-house validation of a liquid chromatography-tandem mass spectrometry method for the determination of selective androgen receptor modulators (SARMS) in bovine urine.

PubMed

Schmidt, Kathrin S; Mankertz, Joachim

2018-06-01

A sensitive and robust LC-MS/MS method allowing the rapid screening and confirmation of selective androgen receptor modulators in bovine urine was developed and successfully validated according to Commission Decision 2002/657/EC, chapter 3.1.3 'alternative validation', by applying a matrix-comprehensive in-house validation concept. The confirmation of the analytes in the validation samples was achieved both on the basis of the MRM ion ratios as laid down in Commission Decision 2002/657/EC and by comparison of their enhanced product ion (EPI) spectra with a reference mass spectral library by making use of the QTRAP technology. Here, in addition to the MRM survey scan, EPI spectra were generated in a data-dependent way according to an information-dependent acquisition criterion. Moreover, stability studies of the analytes in solution and in matrix according to an isochronous approach proved the stability of the analytes in solution and in matrix for at least the duration of the validation study. To identify factors that have a significant influence on the test method in routine analysis, a factorial effect analysis was performed. To this end, factors considered to be relevant for the method in routine analysis (e.g. operator, storage duration of the extracts before measurement, different cartridge lots and different hydrolysis conditions) were systematically varied on two levels. The examination of the extent to which these factors influence the measurement results of the individual analytes showed that none of the validation factors exerts a significant influence on the measurement results.

Automobile tires--a potential source of highly carcinogenic dibenzopyrenes to the environment.

PubMed

Sadiktsis, Ioannis; Bergvall, Christoffer; Johansson, Christer; Westerholm, Roger

2012-03-20

Eight tires were analyzed for 15 high molecular weight (HMW) polycyclic aromatic hydrocarbons (PAH), using pressurized fluid extraction. The variability of the PAH concentrations determined between different tires was large; a factor of 22.6 between the lowest and the highest. The relative abundance of the analytes was quite similar regardless of tire. Almost all (92.3%) of the total extractable PAH content was attributed to five PAHs: benzo[ghi]perylene, coronene, indeno[1,2,3-cd]pyrene, benzo[e]pyrene, and benzo[a]pyrene. The difference in the measured PAH content between summer and winter tires varied substantially across manufacturers, making estimates of total vehicle fleet emissions very uncertain. However, when comparing different types of tires from the same manufacturer they had significantly (p = 0.05) different PAH content. Previously, there have been no data available for carcinogenic dibenzopyrene isomers in automobile tires. In this study, the four dibenzopyrene isomers dibenzo[a,l]pyrene, dibenzo[a,e]pyrene, dibenzo[a,i]pyrene, and dibenzo[a,h]pyrene constituted <2% of the sum of the 15 analyzed HMW PAHs. These findings show that automobile tires may be a potential previously unknown source of carcinogenic dibenzopyrenes to the environment.

Improving Estimation of Ground Casualty Risk From Reentering Space Objects

NASA Technical Reports Server (NTRS)

Ostrom, Chris L.

2017-01-01

A recent improvement to the long-term estimation of ground casualties from reentering space debris is the further refinement and update to the human population distribution. Previous human population distributions were based on global totals with simple scaling factors for future years, or a coarse grid of population counts in a subset of the world's countries, each cell having its own projected growth rate. The newest population model includes a 5-fold refinement in both latitude and longitude resolution. All areas along a single latitude are combined to form a global population distribution as a function of latitude, creating a more accurate population estimation based on non-uniform growth at the country and area levels. Previous risk probability calculations used simplifying assumptions that did not account for the ellipsoidal nature of the Earth. The new method uses first, a simple analytical method to estimate the amount of time spent above each latitude band for a debris object with a given orbit inclination and second, a more complex numerical method that incorporates the effects of a non-spherical Earth. These new results are compared with the prior models to assess the magnitude of the effects on reentry casualty risk.

Evaluation of partnership working in cities in phase IV of the WHO Healthy Cities Network.

PubMed

Lipp, Alistair; Winters, Tim; de Leeuw, Evelyne

2013-10-01

An intersectoral partnership for health improvement is a requirement of the WHO European Healthy Cities Network of municipalities. A review was undertaken in 59 cities based on responses to a structured questionnaire covering phase IV of the network (2003-2008). Cities usually combined formal and informal working partnerships in a pattern seen in previous phases. However, these encompassed more sectors than previously and achieved greater degrees of collaborative planning and implementation. Additional WHO technical support and networking in phase IV significantly enhanced collaboration with the urban planning sector. Critical success factors were high-level political commitment and a well-organized Healthy City office. Partnerships remain a successful component of Healthy City working. The core principles, purpose and intellectual rationale for intersectoral partnerships remain valid and fit for purpose. This applied to long-established phase III cities as well as newcomers to phase IV. The network, and in particular the WHO brand, is well regarded and encourages political and organizational engagement and is a source of support and technical expertise. A key challenge is to apply a more rigorous analytical framework and theory-informed approach to reviewing partnership and collaboration parameters.

Improving Estimation of Ground Casualty Risk from Reentering Space Objects

NASA Technical Reports Server (NTRS)

Ostrom, C.

2017-01-01

A recent improvement to the long-term estimation of ground casualties from reentering space debris is the further refinement and update to the human population distribution. Previous human population distributions were based on global totals with simple scaling factors for future years, or a coarse grid of population counts in a subset of the world's countries, each cell having its own projected growth rate. The newest population model includes a 5-fold refinement in both latitude and longitude resolution. All areas along a single latitude are combined to form a global population distribution as a function of latitude, creating a more accurate population estimation based on non-uniform growth at the country and area levels. Previous risk probability calculations used simplifying assumptions that did not account for the ellipsoidal nature of the earth. The new method uses first, a simple analytical method to estimate the amount of time spent above each latitude band for a debris object with a given orbit inclination, and second, a more complex numerical method that incorporates the effects of a non-spherical Earth. These new results are compared with the prior models to assess the magnitude of the effects on reentry casualty risk.

Extension of the general thermal field equation for nanosized emitters

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

Kyritsakis, A., E-mail: akyritsos1@gmail.com; Xanthakis, J. P.

2016-01-28

During the previous decade, Jensen et al. developed a general analytical model that successfully describes electron emission from metals both in the field and thermionic regimes, as well as in the transition region. In that development, the standard image corrected triangular potential barrier was used. This barrier model is valid only for planar surfaces and therefore cannot be used in general for modern nanometric emitters. In a recent publication, the authors showed that the standard Fowler-Nordheim theory can be generalized for highly curved emitters if a quadratic term is included to the potential model. In this paper, we extend thismore » generalization for high temperatures and include both the thermal and intermediate regimes. This is achieved by applying the general method developed by Jensen to the quadratic barrier model of our previous publication. We obtain results that are in good agreement with fully numerical calculations for radii R > 4 nm, while our calculated current density differs by a factor up to 27 from the one predicted by the Jensen's standard General-Thermal-Field (GTF) equation. Our extended GTF equation has application to modern sharp electron sources, beam simulation models, and vacuum breakdown theory.« less

An Economical Analytical Equation for the Integrated Vertical Overlap of Cumulus and Stratus

NASA Astrophysics Data System (ADS)

Park, Sungsu

2018-03-01

By extending the previously proposed heuristic parameterization, the author derived an analytical equation computing the overlap areas between the precipitation (or radiation) areas and the cloud areas in a cloud system consisting of cumulus and stratus. The new analytical equation is accurate and much more efficient than the previous heuristic equation, which suffers from the truncation error in association with the digitalization of the overlap areas. Global test simulations with the new analytical formula in an offline mode showed that the maximum cumulus overlap simulates more surface precipitation flux than the random cumulus overlap. On the other hand, the maximum stratus overlap simulates less surface precipitation flux than random stratus overlap, which is due to the increase in the evaporation rate of convective precipitation from the random to maximum stratus overlap. The independent precipitation approximation (IPA) marginally decreases the surface precipitation flux, implying that IPA works well with other parameterizations. In contrast to the net production rate of precipitation and surface precipitation flux that increase when the cumulus and stratus are maximally and randomly overlapped, respectively, the global mean net radiative cooling and longwave cloud radiative forcing (LWCF) increase when the cumulus and stratus are randomly overlapped. On the global average, the vertical cloud overlap exerts larger impacts on the precipitation flux than on the radiation flux. The radiation scheme taking the subgrid variability of water vapor between the cloud and clear portions into account substantially increases the global mean LWCF in tropical deep convection and midlatitude storm track regions.

Performance Analysis of ICA in Sensor Array

PubMed Central

Cai, Xin; Wang, Xiang; Huang, Zhitao; Wang, Fenghua

2016-01-01

As the best-known scheme in the field of Blind Source Separation (BSS), Independent Component Analysis (ICA) has been intensively used in various domains, including biomedical and acoustics applications, cooperative or non-cooperative communication, etc. While sensor arrays are involved in most of the applications, the influence on the performance of ICA of practical factors therein has not been sufficiently investigated yet. In this manuscript, the issue is researched by taking the typical antenna array as an illustrative example. Factors taken into consideration include the environment noise level, the properties of the array and that of the radiators. We analyze the analytic relationship between the noise variance, the source variance, the condition number of the mixing matrix and the optimal signal to interference-plus-noise ratio, as well as the relationship between the singularity of the mixing matrix and practical factors concerned. The situations where the mixing process turns (nearly) singular have been paid special attention to, since such circumstances are critical in applications. Results and conclusions obtained should be instructive when applying ICA algorithms on mixtures from sensor arrays. Moreover, an effective countermeasure against the cases of singular mixtures has been proposed, on the basis of previous analysis. Experiments validating the theoretical conclusions as well as the effectiveness of the proposed scheme have been included. PMID:27164100

Estimation of geopotential from satellite-to-satellite range rate data: Numerical results

NASA Technical Reports Server (NTRS)

Thobe, Glenn E.; Bose, Sam C.

1987-01-01

A technique for high-resolution geopotential field estimation by recovering the harmonic coefficients from satellite-to-satellite range rate data is presented and tested against both a controlled analytical simulation of a one-day satellite mission (maximum degree and order 8) and then against a Cowell method simulation of a 32-day mission (maximum degree and order 180). Innovations include: (1) a new frequency-domain observation equation based on kinetic energy perturbations which avoids much of the complication of the usual Keplerian element perturbation approaches; (2) a new method for computing the normalized inclination functions which unlike previous methods is both efficient and numerically stable even for large harmonic degrees and orders; (3) the application of a mass storage FFT to the entire mission range rate history; (4) the exploitation of newly discovered symmetries in the block diagonal observation matrix which reduce each block to the product of (a) a real diagonal matrix factor, (b) a real trapezoidal factor with half the number of rows as before, and (c) a complex diagonal factor; (5) a block-by-block least-squares solution of the observation equation by means of a custom-designed Givens orthogonal rotation method which is both numerically stable and tailored to the trapezoidal matrix structure for fast execution.

The seventh penis: towards effective psychoanalytic work with pre-surgical transsexuals.

PubMed

Withers, Robert

2015-06-01

The author reflects on his contrasting analytic work with two transsexual patients. He uses three previous psychoanalytic studies (Stoller, Morel and Lemma) to explore whether effective analytic work with the issues driving a person's determined wish for sex reassignment surgery (SRS) is possible. Particular consideration is given to how such work might navigate a path between traumatizing and pathologizing the patient on the one hand and avoiding important analytic material out of fear of so doing on the other. The author proceeds to ask whether it is possible to tell in advance, with any degree of reliability, who is and who is not likely to benefit from surgery. He considers certain diagnostic issues in relation to these questions. Illustrations are given of how, in practice, countertransference anxieties about psychopathologizing transsexual patients can contribute to significant difficulties in working clinically with them. It is argued that the understanding and containment of such anxieties could eventually lead to more effective analytic work, and that such work might be further facilitated by considering the contribution of mind-body dissociation to transsexualism. © 2015, The Society of Analytical Psychology.

The impact of capillary backpressure on spontaneous counter-current imbibition in porous media

NASA Astrophysics Data System (ADS)

Foley, Amir Y.; Nooruddin, Hasan A.; Blunt, Martin J.

2017-09-01

We investigate the impact of capillary backpressure on spontaneous counter-current imbibition. For such displacements in strongly water-wet systems, the non-wetting phase is forced out through the inlet boundary as the wetting phase imbibes into the rock, creating a finite capillary backpressure. Under the assumption that capillary backpressure depends on the water saturation applied at the inlet boundary of the porous medium, its impact is determined using the continuum modelling approach by varying the imposed inlet saturation in the analytical solution. We present analytical solutions for the one-dimensional incompressible horizontal displacement of a non-wetting phase by a wetting phase in a porous medium. There exists an inlet saturation value above which any change in capillary backpressure has a negligible impact on the solutions. Above this threshold value, imbibition rates and front positions are largely invariant. A method for identifying this inlet saturation is proposed using an analytical procedure and we explore how varying multiphase flow properties affects the analytical solutions and this threshold saturation. We show the value of this analytical approach through the analysis of previously published experimental data.

Thermoelastic damping in microrings with circular cross-section

NASA Astrophysics Data System (ADS)

Li, Pu; Fang, Yuming; Zhang, Jianrun

2016-01-01

Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

Fall Velocities of Hydrometeors in the Atmosphere: Refinements to a Continuous Analytical Power Law.

NASA Astrophysics Data System (ADS)

Khvorostyanov, Vitaly I.; Curry, Judith A.

2005-12-01

This paper extends the previous research of the authors on the unified representation of fall velocities for both liquid and crystalline particles as a power law over the entire size range of hydrometeors observed in the atmosphere. The power-law coefficients are determined as continuous analytical functions of the Best or Reynolds number or of the particle size. Here, analytical expressions are formulated for the turbulent corrections to the Reynolds number and to the power-law coefficients that describe the continuous transition from the laminar to the turbulent flow around a falling particle. A simple analytical expression is found for the correction of fall velocities for temperature and pressure. These expressions and the resulting fall velocities are compared with observations and other calculations for a range of ice crystal habits and sizes. This approach provides a continuous analytical power-law description of the terminal velocities of liquid and crystalline hydrometeors with sufficiently high accuracy and can be directly used in bin-resolving models or incorporated into parameterizations for cloud- and large-scale models and remote sensing techniques.

An analytical solution for Dean flow in curved ducts with rectangular cross section

NASA Astrophysics Data System (ADS)

Norouzi, M.; Biglari, N.

2013-05-01

In this paper, a full analytical solution for incompressible flow inside the curved ducts with rectangular cross-section is presented for the first time. The perturbation method is applied to solve the governing equations and curvature ratio is considered as the perturbation parameter. The previous perturbation solutions are usually restricted to the flow in curved circular or annular pipes related to the overly complex form of solutions or singularity situation for flow in curved ducts with non-circular shapes of cross section. This issue specifies the importance of analytical studies in the field of Dean flow inside the non-circular ducts. In this study, the main flow velocity, stream function of lateral velocities (secondary flows), and flow resistance ratio in rectangular curved ducts are obtained analytically. The effect of duct curvature and aspect ratio on flow field is investigated as well. Moreover, it is important to mention that the current analytical solution is able to simulate the Taylor-Görtler and Dean vortices (vortices in stable and unstable situations) in curved channels.

PubFocus: semantic MEDLINE/PubMed citations analytics through integration of controlled biomedical dictionaries and ranking algorithm

PubMed Central

Plikus, Maksim V; Zhang, Zina; Chuong, Cheng-Ming

2006-01-01

Background Understanding research activity within any given biomedical field is important. Search outputs generated by MEDLINE/PubMed are not well classified and require lengthy manual citation analysis. Automation of citation analytics can be very useful and timesaving for both novices and experts. Results PubFocus web server automates analysis of MEDLINE/PubMed search queries by enriching them with two widely used human factor-based bibliometric indicators of publication quality: journal impact factor and volume of forward references. In addition to providing basic volumetric statistics, PubFocus also prioritizes citations and evaluates authors' impact on the field of search. PubFocus also analyses presence and occurrence of biomedical key terms within citations by utilizing controlled vocabularies. Conclusion We have developed citations' prioritisation algorithm based on journal impact factor, forward referencing volume, referencing dynamics, and author's contribution level. It can be applied either to the primary set of PubMed search results or to the subsets of these results identified through key terms from controlled biomedical vocabularies and ontologies. NCI (National Cancer Institute) thesaurus and MGD (Mouse Genome Database) mammalian gene orthology have been implemented for key terms analytics. PubFocus provides a scalable platform for the integration of multiple available ontology databases. PubFocus analytics can be adapted for input sources of biomedical citations other than PubMed. PMID:17014720

Analytical modeling of demagnetizing effect in magnetoelectric ferrite/PZT/ferrite trilayers taking into account a mechanical coupling

NASA Astrophysics Data System (ADS)

Loyau, V.; Aubert, A.; LoBue, M.; Mazaleyrat, F.

2017-03-01

In this paper, we investigate the demagnetizing effect in ferrite/PZT/ferrite magnetoelectric (ME) trilayer composites consisting of commercial PZT discs bonded by epoxy layers to Ni-Co-Zn ferrite discs made by a reactive Spark Plasma Sintering (SPS) technique. ME voltage coefficients (transversal mode) were measured on ferrite/PZT/ferrite trilayer ME samples with different thicknesses or phase volume ratio in order to highlight the influence of the magnetic field penetration governed by these geometrical parameters. Experimental ME coefficients and voltages were compared to analytical calculations using a quasi-static model. Theoretical demagnetizing factors of two magnetic discs that interact together in parallel magnetic structures were derived from an analytical calculation based on a superposition method. These factors were introduced in ME voltage calculations which take account of the demagnetizing effect. To fit the experimental results, a mechanical coupling factor was also introduced in the theoretical formula. This reflects the differential strain that exists in the ferrite and PZT layers due to shear effects near the edge of the ME samples and within the bonding epoxy layers. From this study, an optimization in magnitude of the ME voltage is obtained. Lastly, an analytical calculation of demagnetizing effect was conducted for layered ME composites containing higher numbers of alternated layers (n ≥ 5). The advantage of such a structure is then discussed.

Analysis of Pre-Analytic Factors Affecting the Success of Clinical Next-Generation Sequencing of Solid Organ Malignancies.

PubMed

Chen, Hui; Luthra, Rajyalakshmi; Goswami, Rashmi S; Singh, Rajesh R; Roy-Chowdhuri, Sinchita

2015-08-28

Application of next-generation sequencing (NGS) technology to routine clinical practice has enabled characterization of personalized cancer genomes to identify patients likely to have a response to targeted therapy. The proper selection of tumor sample for downstream NGS based mutational analysis is critical to generate accurate results and to guide therapeutic intervention. However, multiple pre-analytic factors come into play in determining the success of NGS testing. In this review, we discuss pre-analytic requirements for AmpliSeq PCR-based sequencing using Ion Torrent Personal Genome Machine (PGM) (Life Technologies), a NGS sequencing platform that is often used by clinical laboratories for sequencing solid tumors because of its low input DNA requirement from formalin fixed and paraffin embedded tissue. The success of NGS mutational analysis is affected not only by the input DNA quantity but also by several other factors, including the specimen type, the DNA quality, and the tumor cellularity. Here, we review tissue requirements for solid tumor NGS based mutational analysis, including procedure types, tissue types, tumor volume and fraction, decalcification, and treatment effects.

Concurrent and Construct Validity of Three Counselor Social Influence Instruments.

ERIC Educational Resources Information Center

Wilson, F. Robert; Yager, Geoffrey G.

1990-01-01

Conducted factor analytic investigation of Counselor Rating Form, Counselor Rating Form-Short Form, and Counselor Effectiveness Rating Scale (CERS) using data from 160 undergraduate students. Analysis revealed two oblique factors (expertness and attractiveness-trustworthiness), whereas CERS produced single, global evaluative factor. Oblique…

Factor structure of the Halstead-Reitan Neuropsychological Battery for children: a brief report supplement.

PubMed

Ross, Sylvia An; Allen, Daniel N; Goldstein, Gerald

2014-01-01

The Halstead-Reitan Neuropsychological Battery (HRNB) is the first factor-analyzed neuropsychological battery and consists of three batteries for young children, older children, and adults. Halstead's original factor analysis extracted four factors from the adult version of the battery, which were the basis for his theory of biological intelligence. These factors were called Central Integrative Field, Abstraction, Power, and Directional. Since this original analysis, Reitan's additions to the battery, and the development of the child versions of the test, this factor-analytic research continued. An introduction and the adult literature are reviewed in Ross, Allen, and Goldstein ( in press ). In this supplemental article, factor-analytic studies of the HRNB with children are reviewed. It is concluded that factor analysis of the HRNB or Reitan-Indiana Neuropsychological Battery with children does not replicate the extensiveness of the adult literature, although there is some evidence that when the traditional battery for older children is used, the factor structure is similar to what is found in adult studies. Reitan's changes to the battery appear to have added factors including language and sensory-perceptual factors. When other tests and scoring methods are used in addition to the core battery, differing solutions are produced.

Women's Career Success: A Factor Analytic Study of Contributing Factors.

ERIC Educational Resources Information Center

Gaskill, LuAnn Ricketts

1991-01-01

A survey of 466 women employed in retailing received 205 responses identifying (1) factors influencing the success and advancement of women in retailing and (2) how those factors differ for women in upper versus middle positions. Upper-level executives placed more importance on ambition and abilities; midlevel executives credited opportunity and…

Humanism Factors and Islam Viewpoint from Motahri's Point of View

ERIC Educational Resources Information Center

Yousefi, Zargham; Yousefy, Alireza; Keshtiaray, Narges

2015-01-01

The aim of this research is to criticize liberal humanism based on Islam viewpoint emphasizing Motahri's point of view. In this paper, the researchers tried to identify liberalism humanism factors with analytical look in order to present a new categorization called "main factor of liberal humanism". Then, each factor was studied and…

Power and Precision in Confirmatory Factor Analytic Tests of Measurement Invariance

ERIC Educational Resources Information Center

Meade, Adam W.; Bauer, Daniel J.

2007-01-01

This study investigates the effects of sample size, factor overdetermination, and communality on the precision of factor loading estimates and the power of the likelihood ratio test of factorial invariance in multigroup confirmatory factor analysis. Although sample sizes are typically thought to be the primary determinant of precision and power,…

An Examination of Sampling Characteristics of Some Analytic Factor Transformation Techniques.

ERIC Educational Resources Information Center

Skakun, Ernest N.; Hakstian, A. Ralph

Two population raw data matrices were constructed by computer simulation techniques. Each consisted of 10,000 subjects and 12 variables, and each was constructed according to an underlying factorial model consisting of four major common factors, eight minor common factors, and 12 unique factors. The computer simulation techniques were employed to…

Evidence for a General ADHD Factor from a Longitudinal General School Population Study

ERIC Educational Resources Information Center

Normand, Sebastien; Flora, David B.; Toplak, Maggie E.; Tannock, Rosemary

2012-01-01

Recent factor analytic studies in Attention-Deficit/Hyperactivity Disorder (ADHD) have shown that hierarchical models provide a better fit of ADHD symptoms than correlated models. A hierarchical model includes a general ADHD factor and specific factors for inattention, and hyperactivity/impulsivity. The aim of this 12-month longitudinal study was…

Analysis of uncertainties in turbine metal temperature predictions

NASA Technical Reports Server (NTRS)

Stepka, F. S.

1980-01-01

An analysis was conducted to examine the extent to which various factors influence the accuracy of analytically predicting turbine blade metal temperatures and to determine the uncertainties in these predictions for several accuracies of the influence factors. The advanced turbofan engine gas conditions of 1700 K and 40 atmospheres were considered along with those of a highly instrumented high temperature turbine test rig and a low temperature turbine rig that simulated the engine conditions. The analysis showed that the uncertainty in analytically predicting local blade temperature was as much as 98 K, or 7.6 percent of the metal absolute temperature, with current knowledge of the influence factors. The expected reductions in uncertainties in the influence factors with additional knowledge and tests should reduce the uncertainty in predicting blade metal temperature to 28 K, or 2.1 percent of the metal absolute temperature.

A flow resistance model for assessing the impact of vegetation on flood routing mechanics

NASA Astrophysics Data System (ADS)

Katul, Gabriel G.; Poggi, Davide; Ridolfi, Luca

2011-08-01

The specification of a flow resistance factor to account for vegetative effects in the Saint-Venant equation (SVE) remains uncertain and is a subject of active research in flood routing mechanics. Here, an analytical model for the flow resistance factor is proposed for submerged vegetation, where the water depth is commensurate with the canopy height and the roughness Reynolds number is sufficiently large so as to ignore viscous effects. The analytical model predicts that the resistance factor varies with three canonical length scales: the adjustment length scale that depends on the foliage drag and leaf area density, the canopy height, and the water level. These length scales can reasonably be inferred from a range of remote sensing products making the proposed flow resistance model eminently suitable for operational flood routing. Despite the numerous simplifications, agreement between measured and modeled resistance factors and bulk velocities is reasonable across a range of experimental and field studies. The proposed model asymptotically recovers the flow resistance formulation when the water depth greatly exceeds the canopy height. This analytical treatment provides a unifying framework that links the resistance factor to a number of concepts and length scales already in use to describe canopy turbulence. The implications of the coupling between the resistance factor and the water depth on solutions to the SVE are explored via a case study, which shows a reasonable match between empirical design standard and theoretical predictions.

Finite element and analytical solutions for van der Pauw and four-point probe correction factors when multiple non-ideal measurement conditions coexist

NASA Astrophysics Data System (ADS)

Reveil, Mardochee; Sorg, Victoria C.; Cheng, Emily R.; Ezzyat, Taha; Clancy, Paulette; Thompson, Michael O.

2017-09-01

This paper presents an extensive collection of calculated correction factors that account for the combined effects of a wide range of non-ideal conditions often encountered in realistic four-point probe and van der Pauw experiments. In this context, "non-ideal conditions" refer to conditions that deviate from the assumptions on sample and probe characteristics made in the development of these two techniques. We examine the combined effects of contact size and sample thickness on van der Pauw measurements. In the four-point probe configuration, we examine the combined effects of varying the sample's lateral dimensions, probe placement, and sample thickness. We derive an analytical expression to calculate correction factors that account, simultaneously, for finite sample size and asymmetric probe placement in four-point probe experiments. We provide experimental validation of the analytical solution via four-point probe measurements on a thin film rectangular sample with arbitrary probe placement. The finite sample size effect is very significant in four-point probe measurements (especially for a narrow sample) and asymmetric probe placement only worsens such effects. The contribution of conduction in multilayer samples is also studied and found to be substantial; hence, we provide a map of the necessary correction factors. This library of correction factors will enable the design of resistivity measurements with improved accuracy and reproducibility over a wide range of experimental conditions.

Finite element and analytical solutions for van der Pauw and four-point probe correction factors when multiple non-ideal measurement conditions coexist.

PubMed

Reveil, Mardochee; Sorg, Victoria C; Cheng, Emily R; Ezzyat, Taha; Clancy, Paulette; Thompson, Michael O

2017-09-01

This paper presents an extensive collection of calculated correction factors that account for the combined effects of a wide range of non-ideal conditions often encountered in realistic four-point probe and van der Pauw experiments. In this context, "non-ideal conditions" refer to conditions that deviate from the assumptions on sample and probe characteristics made in the development of these two techniques. We examine the combined effects of contact size and sample thickness on van der Pauw measurements. In the four-point probe configuration, we examine the combined effects of varying the sample's lateral dimensions, probe placement, and sample thickness. We derive an analytical expression to calculate correction factors that account, simultaneously, for finite sample size and asymmetric probe placement in four-point probe experiments. We provide experimental validation of the analytical solution via four-point probe measurements on a thin film rectangular sample with arbitrary probe placement. The finite sample size effect is very significant in four-point probe measurements (especially for a narrow sample) and asymmetric probe placement only worsens such effects. The contribution of conduction in multilayer samples is also studied and found to be substantial; hence, we provide a map of the necessary correction factors. This library of correction factors will enable the design of resistivity measurements with improved accuracy and reproducibility over a wide range of experimental conditions.

Vortex-assisted magnetic β-cyclodextrin/attapulgite-linked ionic liquid dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the fast determination of four fungicides in water samples.

PubMed

Yang, Miyi; Xi, Xuefei; Wu, Xiaoling; Lu, Runhua; Zhou, Wenfeng; Zhang, Sanbing; Gao, Haixiang

2015-02-13

A novel microextraction technique combining magnetic solid-phase microextraction (MSPME) with ionic liquid dispersive liquid-liquid microextraction (IL-DLLME) to determine four fungicides is presented in this work for the first time. The main factors affecting the extraction efficiency were optimized by the one-factor-at-a-time approach and the impacts of these factors were studied by an orthogonal design. Without tedious clean-up procedure, analytes were extracted from the sample to the adsorbent and organic solvent and then desorbed in acetonitrile prior to chromatographic analysis. Under the optimum conditions, good linearity and high enrichment factors were obtained for all analytes, with correlation coefficients ranging from 0.9998 to 1.0000 and enrichment factors ranging 135 and 159 folds. The recoveries for proposed approach were between 98% and 115%, the limits of detection were between 0.02 and 0.04 μg L(-1) and the RSDs changed from 2.96 to 4.16. The method was successfully applied in the analysis of four fungicides (azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin) in environmental water samples. The recoveries for the real water samples ranged between 81% and 109%. The procedure proved to be a time-saving, environmentally friendly, and efficient analytical technique. Copyright © 2015 Elsevier B.V. All rights reserved.

Utilization of medical services in the public health system in the Southern Brazil.

PubMed

Bastos, Gisele Alsina Nader; Duca, Giovâni Firpo Del; Hallal, Pedro Curi; Santos, Iná S

2011-06-01

To estimate the prevalence and analyze factors associated with the utilization of medical services in the public health system. Cross-sectional population-based study with 2,706 individuals aged 20-69 years carried out in Pelotas, Southern Brazil, in 2008. A systematic sampling with probability proportional to the number of households in each sector was adopted. The outcome was defined by the combination of the questions related to medical consultation in the previous three months and place. The exposure variables were: sex, age, marital status, level of schooling, family income, self-reported hospital admission in the previous year, having a regular physician, self-perception of health, and the main reason for the last consultation. Descriptive analysis was stratified by sex and the analytical statistics included the use of the Wald test for tendency and heterogeneity in the crude analysis and Poisson regression with robust variance in the adjusted analysis, taking into consideration cluster sampling. The prevalence of utilization of medical services in the three previous months was 60.6%, almost half of these (42.0%, 95%CI: 36.6;47.5) in public services. The most utilized public services were the primary care units (49.5%). In the adjusted analysis stratified by sex, men with advanced age and young women had higher probability of using the medical services in the public system. In both sexes, low level of schooling, low per capita family income, not having a regular physician and hospital admission in the previous year were associated with the outcome. Despite the expressive reduction in the utilization of medical health services in the public system in the last 15 years, the public services are now reaching a previously unassisted portion of the population (individuals with low income and schooling).

Understanding suicide risk within the Research Domain Criteria (RDoC) framework: A meta-analytic review.

PubMed

Glenn, Catherine R; Kleiman, Evan M; Cha, Christine B; Deming, Charlene A; Franklin, Joseph C; Nock, Matthew K

2018-01-01

The field is in need of novel and transdiagnostic risk factors for suicide. The National Institute of Mental Health's Research Domain Criteria (RDoC) provides a framework that may help advance research on suicidal behavior. We conducted a meta-analytic review of existing prospective risk and protective factors for suicidal thoughts and behaviors (ideation, attempts, and deaths) that fall within one of the five RDoC domains or relate to a prominent suicide theory. Predictors were selected from a database of 4,082 prospective risk and protective factors for suicide outcomes. A total of 460 predictors met inclusion criteria for this meta-analytic review and most examined risk (vs. protective) factors for suicidal thoughts and behaviors. The overall effect of risk factors was statistically significant, but relatively small, in predicting suicide ideation (weighted mean odds ratio: wOR = 1.72; 95% CI: 1.59-1.87), suicide attempt (wOR = 1.66 [1.57-1.76), and suicide death (wOR = 1.41 [1.24-1.60]). Across all suicide outcomes, most risk factors related to the Negative Valence Systems domain, although effect sizes were of similar magnitude across RDoC domains. This study demonstrated that the RDoC framework provides a novel and promising approach to suicide research; however, relatively few studies of suicidal behavior fit within this framework. Future studies must go beyond the "usual suspects" of suicide risk factors (e.g., mental disorders, sociodemographics) to understand the processes that combine to lead to this deadly outcome. © 2017 Wiley Periodicals, Inc.

New exponential synchronization criteria for time-varying delayed neural networks with discontinuous activations.

PubMed

Cai, Zuowei; Huang, Lihong; Zhang, Lingling

2015-05-01

This paper investigates the problem of exponential synchronization of time-varying delayed neural networks with discontinuous neuron activations. Under the extended Filippov differential inclusion framework, by designing discontinuous state-feedback controller and using some analytic techniques, new testable algebraic criteria are obtained to realize two different kinds of global exponential synchronization of the drive-response system. Moreover, we give the estimated rate of exponential synchronization which depends on the delays and system parameters. The obtained results extend some previous works on synchronization of delayed neural networks not only with continuous activations but also with discontinuous activations. Finally, numerical examples are provided to show the correctness of our analysis via computer simulations. Our method and theoretical results have a leading significance in the design of synchronized neural network circuits involving discontinuous factors and time-varying delays. Copyright © 2015 Elsevier Ltd. All rights reserved.

Homogenization of the lipid profile values.

PubMed

Pedro-Botet, Juan; Rodríguez-Padial, Luis; Brotons, Carlos; Esteban-Salán, Margarita; García-Lerín, Aurora; Pintó, Xavier; Lekuona, Iñaki; Ordóñez-Llanos, Jordi

Analytical reports from the clinical laboratory are essential to guide clinicians about what lipid profile values should be considered altered and, therefore, require intervention. Unfortunately, there is a great heterogeneity in the lipid values reported as "normal, desirable, recommended or referenced" by clinical laboratories. This can difficult clinical decisions and be a barrier to achieve the therapeutic goals for cardiovascular prevention. A recent international recommendation has added a new heterogeneity factor for the interpretation of lipid profile, such as the possibility of measuring it without previous fasting. All this justifies the need to develop a document that adapts the existing knowledge to the clinical practice of our health system. In this regard, professionals from different scientific societies involved in the measurement and use of lipid profile data have developed this document to establish recommendations that facilitate their homogenization. Copyright © 2017. Publicado por Elsevier España, S.L.U.

Next-to-leading-logarithmic power corrections for N -jettiness subtraction in color-singlet production

NASA Astrophysics Data System (ADS)

Boughezal, Radja; Isgrò, Andrea; Petriello, Frank

2018-04-01

We present a detailed derivation of the power corrections to the factorization theorem for the 0-jettiness event shape variable T . Our calculation is performed directly in QCD without using the formalism of effective field theory. We analytically calculate the next-to-leading logarithmic power corrections for small T at next-to-leading order in the strong coupling constant, extending previous computations which obtained only the leading-logarithmic power corrections. We address a discrepancy in the literature between results for the leading-logarithmic power corrections to a particular definition of 0-jettiness. We present a numerical study of the power corrections in the context of their application to the N -jettiness subtraction method for higher-order calculations, using gluon-fusion Higgs production as an example. The inclusion of the next-to-leading-logarithmic power corrections further improves the numerical efficiency of the approach beyond the improvement obtained from the leading-logarithmic power corrections.

Spectral reflectance of carbonate minerals and rocks in the visible and near infrared (0.35 - 2.55 microns) and its applications in carbonate petrology

NASA Technical Reports Server (NTRS)

Gaffey, S. J.

1984-01-01

Reflection spectroscopy in the visible and near infrared (0.35 to 2.55 micron) offers a rapid, inexpensive, nondestructive tool for determining the mineralogy and investigating the minor element chemistry of the hard-to-discriminate carbonate minerals, and can, in one step, provide information previously obtainable only by the combined application of two or more analytical techniques. When light interacts with a mineral certain wavelengths are preferentially absorbed. The number, positions, widths and relative intensities of these absorptions are diagnostic of the mineralogy and chemical composition of the sample. At least seven bands due to vibrations of the carbonate radical occur between 1.60 and 2.55 micron. Positions of these bands vary from one carbonae mineral to another and can be used for mineral identification. Cation mass is the primary factor controlling band position; cation radius plays a secondary role.

Lignin‐Derived Thioacidolysis Dimers: Reevaluation, New Products, Authentication, and Quantification

PubMed Central

Yue, Fengxia; Regner, Matt; Sun, Runcang

2017-01-01

Abstract Lignin structural studies play an essential role both in understanding the development of plant cell walls and for valorizing lignocellulosics as renewable biomaterials. Dimeric products released by selectively cleaving β–aryl ether linkages between lignin units reflect the distribution of recalcitrant lignin units, but have been neither absolutely defined nor quantitatively determined. Here, 12 guaiacyl‐type thioacidolysis dimers were identified and quantified using newly synthesized standards. One product previously attributed to deriving from β–1‐coupled units was established as resulting from β–5 units, correcting an analytical quandary. Another longstanding dilemma, that no β–β dimers were recognized in thioacidolysis products from gymnosperms, was resolved with the discovery of two such authenticated compounds. Individual GC response factors for each standard compound allowed rigorous quantification of dimeric products released from softwood lignins, affording insight into the various interunit‐linkage distributions in lignins and thereby guiding the valorization of lignocellulosics. PMID:28125766

Staggered Orbital Currents in the Half-Filled Two-Leg Ladder

NASA Astrophysics Data System (ADS)

Fjaerestad, J. O.; Marston, Brad; Sudbo, A.

2002-03-01

We present strong analytical and numerical evidence for the existence of a staggered flux (SF) phase in the half-filled two-leg ladder, with true long-range order in the counter-circulating currents. Using abelian bosonization with a careful treatment of the Klein factors, we show that a certain phase of the half-filled ladder, previously identified as having spin-Peierls order, instead exhibits staggered orbital currents with no dimerization.(J. O. Fjærestad and J. B. Marston, cond- mat/0107094.) This result, combined with a weak-coupling renormalization-group analysis, implies that the SF phase exists in a region of the phase diagram of the half-filled t-U-V-J ladder. Using the density-matrix renormalization-group (DMRG) approach generalized to complex-valued wavefunctions, we demonstrate that the SF phase exhibits robust currents at intermediate values of the interaction strengths.

Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

PubMed Central

Samak, M. Mosleh E. Abu; Bakar, A. Ashrif A.; Kashif, Muhammad; Zan, Mohd Saiful Dzulkifly

2016-01-01

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD)-FDTD method has similar numerical equation properties, which should be calculated as in the previous method. Generally, a small number of arithmetic processes, which result in a shorter simulation time, are desired. The alternating direction implicit technique can be considered a significant step forward for improving the efficiency of unconditionally stable FDTD schemes. This comparative study shows that the local one-dimensional method had minimum relative error ranges of less than 40% for analytical frequencies above 42.85 GHz, and the same accuracy was generated by both methods.

Happy software developers solve problems better: psychological measurements in empirical software engineering

PubMed Central

Wang, Xiaofeng; Abrahamsson, Pekka

2014-01-01

For more than thirty years, it has been claimed that a way to improve software developers’ productivity and software quality is to focus on people and to provide incentives to make developers satisfied and happy. This claim has rarely been verified in software engineering research, which faces an additional challenge in comparison to more traditional engineering fields: software development is an intellectual activity and is dominated by often-neglected human factors (called human aspects in software engineering research). Among the many skills required for software development, developers must possess high analytical problem-solving skills and creativity for the software construction process. According to psychology research, affective states—emotions and moods—deeply influence the cognitive processing abilities and performance of workers, including creativity and analytical problem solving. Nonetheless, little research has investigated the correlation between the affective states, creativity, and analytical problem-solving performance of programmers. This article echoes the call to employ psychological measurements in software engineering research. We report a study with 42 participants to investigate the relationship between the affective states, creativity, and analytical problem-solving skills of software developers. The results offer support for the claim that happy developers are indeed better problem solvers in terms of their analytical abilities. The following contributions are made by this study: (1) providing a better understanding of the impact of affective states on the creativity and analytical problem-solving capacities of developers, (2) introducing and validating psychological measurements, theories, and concepts of affective states, creativity, and analytical-problem-solving skills in empirical software engineering, and (3) raising the need for studying the human factors of software engineering by employing a multidisciplinary viewpoint. PMID:24688866

Happy software developers solve problems better: psychological measurements in empirical software engineering.

PubMed

Graziotin, Daniel; Wang, Xiaofeng; Abrahamsson, Pekka

2014-01-01

For more than thirty years, it has been claimed that a way to improve software developers' productivity and software quality is to focus on people and to provide incentives to make developers satisfied and happy. This claim has rarely been verified in software engineering research, which faces an additional challenge in comparison to more traditional engineering fields: software development is an intellectual activity and is dominated by often-neglected human factors (called human aspects in software engineering research). Among the many skills required for software development, developers must possess high analytical problem-solving skills and creativity for the software construction process. According to psychology research, affective states-emotions and moods-deeply influence the cognitive processing abilities and performance of workers, including creativity and analytical problem solving. Nonetheless, little research has investigated the correlation between the affective states, creativity, and analytical problem-solving performance of programmers. This article echoes the call to employ psychological measurements in software engineering research. We report a study with 42 participants to investigate the relationship between the affective states, creativity, and analytical problem-solving skills of software developers. The results offer support for the claim that happy developers are indeed better problem solvers in terms of their analytical abilities. The following contributions are made by this study: (1) providing a better understanding of the impact of affective states on the creativity and analytical problem-solving capacities of developers, (2) introducing and validating psychological measurements, theories, and concepts of affective states, creativity, and analytical-problem-solving skills in empirical software engineering, and (3) raising the need for studying the human factors of software engineering by employing a multidisciplinary viewpoint.

Single Particle-Inductively Coupled Plasma Mass Spectroscopy Analysis of Metallic Nanoparticles in Environmental Samples with Large Dissolved Analyte Fractions.

PubMed

Schwertfeger, D M; Velicogna, Jessica R; Jesmer, Alexander H; Scroggins, Richard P; Princz, Juliska I

2016-10-18

There is an increasing interest to use single particle-inductively coupled plasma mass spectroscopy (SP-ICPMS) to help quantify exposure to engineered nanoparticles, and their transformation products, released into the environment. Hindering the use of this analytical technique for environmental samples is the presence of high levels of dissolved analyte which impedes resolution of the particle signal from the dissolved. While sample dilution is often necessary to achieve the low analyte concentrations necessary for SP-ICPMS analysis, and to reduce the occurrence of matrix effects on the analyte signal, it is used here to also reduce the dissolved signal relative to the particulate, while maintaining a matrix chemistry that promotes particle stability. We propose a simple, systematic dilution series approach where by the first dilution is used to quantify the dissolved analyte, the second is used to optimize the particle signal, and the third is used as an analytical quality control. Using simple suspensions of well characterized Au and Ag nanoparticles spiked with the dissolved analyte form, as well as suspensions of complex environmental media (i.e., extracts from soils previously contaminated with engineered silver nanoparticles), we show how this dilution series technique improves resolution of the particle signal which in turn improves the accuracy of particle counts, quantification of particulate mass and determination of particle size. The technique proposed here is meant to offer a systematic and reproducible approach to the SP-ICPMS analysis of environmental samples and improve the quality and consistency of data generated from this relatively new analytical tool.

Stripping Voltammetry

NASA Astrophysics Data System (ADS)

Lovrić, Milivoj

Electrochemical stripping means the oxidative or reductive removal of atoms, ions, or compounds from an electrode surface (or from the electrode body, as in the case of liquid mercury electrodes with dissolved metals) [1-5]. In general, these atoms, ions, or compounds have been preliminarily immobilized on the surface of an inert electrode (or within it) as the result of a preconcentration step, while the products of the electrochemical stripping will dissolve in the electrolytic solution. Often the product of the electrochemical stripping is identical to the analyte before the preconcentration. However, there are exemptions to these rules. Electroanalytical stripping methods comprise two steps: first, the accumulation of a dissolved analyte onto, or in, the working electrode, and, second, the subsequent stripping of the accumulated substance by a voltammetric [3, 5], potentiometric [6, 7], or coulometric [8] technique. In stripping voltammetry, the condition is that there are two independent linear relationships: the first one between the activity of accumulated substance and the concentration of analyte in the sample, and the second between the maximum stripping current and the accumulated substance activity. Hence, a cumulative linear relationship between the maximum response and the analyte concentration exists. However, the electrode capacity for the analyte accumulation is limited and the condition of linearity is satisfied only well below the electrode saturation. For this reason, stripping voltammetry is used mainly in trace analysis. The limit of detection depends on the factor of proportionality between the activity of the accumulated substance and the bulk concentration of the analyte. This factor is a constant in the case of a chemical accumulation, but for electrochemical accumulation it depends on the electrode potential. The factor of proportionality between the maximum stripping current and the analyte concentration is rarely known exactly. In fact, it is frequently ignored. For the analysis it suffices to establish the linear relationship empirically. The slope of this relationship may vary from one sample to another because of different influences of the matrix. In this case the concentration of the analyte is determined by the method of standard additions [1]. After measuring the response of the sample, the concentration of the analyte is deliberately increased by adding a certain volume of its standard solution. The response is measured again, and this procedure is repeated three or four times. The unknown concentration is determined by extrapolation of the regression line to the concentration axis [9]. However, in many analytical methods, the final measurement is performed in a standard matrix that allows the construction of a calibration plot. Still, the slope of this plot depends on the active area of the working electrode surface. Each solid electrode needs a separate calibration plot, and that plot must be checked from time to time because of possible deterioration of the electrode surface [2].

Bias and precision of selected analytes reported by the National Atmospheric Deposition Program and National Trends Network, 1984

USGS Publications Warehouse

Brooks, M.H.; Schroder, L.J.; Willoughby, T.C.

1987-01-01

The U.S. Geological Survey operated a blind audit sample program during 1974 to test the effects of the sample handling and shipping procedures used by the National Atmospheric Deposition Program and National Trends Network on the quality of wet deposition data produced by the combined networks. Blind audit samples, which were dilutions of standard reference water samples, were submitted by network site operators to the central analytical laboratory disguised as actual wet deposition samples. Results from the analyses of blind audit samples were used to calculate estimates of analyte bias associated with all network wet deposition samples analyzed in 1984 and to estimate analyte precision. Concentration differences between double blind samples that were submitted to the central analytical laboratory and separate analyses of aliquots of those blind audit samples that had not undergone network sample handling and shipping were used to calculate analyte masses that apparently were added to each blind audit sample by routine network handling and shipping procedures. These calculated masses indicated statistically significant biases for magnesium, sodium , potassium, chloride, and sulfate. Median calculated masses were 41.4 micrograms (ug) for calcium, 14.9 ug for magnesium, 23.3 ug for sodium, 0.7 ug for potassium, 16.5 ug for chloride and 55.3 ug for sulfate. Analyte precision was estimated using two different sets of replicate measures performed by the central analytical laboratory. Estimated standard deviations were similar to those previously reported. (Author 's abstract)

Quantifying the contributions of behavioral and biological risk factors to socioeconomic disparities in coronary heart disease incidence: The MORGEN study

PubMed Central

Kershaw, Kiarri N.; Droomers, Mariël; Robinson, Whitney R.; Carnethon, Mercedes R.; Daviglus, Martha L.; Verschuren, W.M. Monique

2013-01-01

Quantifying the impact of different modifiable behavioral and biological risk factors on socioeconomic disparities in coronary heart disease (CHD) may help inform targeted, population-specific strategies to reduce the unequal distribution of the disease. Previous studies have used analytic approaches that limit our ability to disentangle the relative contributions of these risk factors to CHD disparities. The goal of this study was to assess mediation of the effect of low education on incident CHD by multiple risk factors simultaneously. Analyses are based on 15,067 participants of the Dutch Monitoring Project on Risk Factors for Chronic Diseases aged 20–65 years examined 1994–1997 and followed for events until January 1, 2008. Path analysis was used to quantify and test mediation of the low education-CHD association by behavioral (current cigarette smoking, heavy alcohol use, poor diet, and physical inactivity) and biological (obesity, hypertension, diabetes, and hypercholesterolemia) risk factors. Behavioral and biological risk factors accounted for 56.6% (95% CI: 42.6%–70.8%) of the low education-incident CHD association. Smoking was the strongest mediator, accounting for 27.3% (95% CI: 17.7%–37.4%) of the association, followed by obesity (10.2%; 95% CI: 4.5%–16.1%), physical inactivity (6.3%; 95% CI: 2.7%–10.0%), and hypertension (5.3%; 95% CI: 2.8%–8.0%). In summary, in a Dutch cohort, the majority of the relationship between low education and incident CHD was mediated by traditional behavioral and biological risk factors. Addressing barriers to smoking cessation, blood pressure and weight management, and physical activity may be the most effective approaches to eliminating socioeconomic inequalities in CHD. PMID:24037117

Projected 1981 exposure estimates using iterative proportional fitting

DOT National Transportation Integrated Search

1985-10-01

1981 VMT estimates categorized by eight driver, vehicle, and environmental : variables are produced. These 1981 estimates are produced using analytical : methods developed in a previous report. The estimates are based on 1977 : NPTS data (the latest ...

Explicit analytical expression for the condition number of polynomials in power form

NASA Astrophysics Data System (ADS)

Rack, Heinz-Joachim

2017-07-01

In his influential papers [1-3] W. Gautschi has defined and reshaped the condition number κ∞ of polynomials Pn of degree ≤ n which are represented in power form on a zero-symmetric interval [-ω, ω]. Basically, κ∞ is expressed as the product of two operator norms: an explicit factor times an implicit one (the l∞-norm of the coefficient vector of the n-th Chebyshev polynomial of the first kind relative to [-ω, ω]). We provide a new proof, economize the second factor and express it by an explicit analytical formula.

An Analytical Thermal Model for Autonomous Soaring Research

NASA Technical Reports Server (NTRS)

Allen, Michael

2006-01-01

A viewgraph presentation describing an analytical thermal model used to enable research on autonomous soaring for a small UAV aircraft is given. The topics include: 1) Purpose; 2) Approach; 3) SURFRAD Data; 4) Convective Layer Thickness; 5) Surface Heat Budget; 6) Surface Virtual Potential Temperature Flux; 7) Convective Scaling Velocity; 8) Other Calculations; 9) Yearly trends; 10) Scale Factors; 11) Scale Factor Test Matrix; 12) Statistical Model; 13) Updraft Strength Calculation; 14) Updraft Diameter; 15) Updraft Shape; 16) Smoothed Updraft Shape; 17) Updraft Spacing; 18) Environment Sink; 19) Updraft Lifespan; 20) Autonomous Soaring Research; 21) Planned Flight Test; and 22) Mixing Ratio.

Replica Analysis for Portfolio Optimization with Single-Factor Model

NASA Astrophysics Data System (ADS)

Shinzato, Takashi

2017-06-01

In this paper, we use replica analysis to investigate the influence of correlation among the return rates of assets on the solution of the portfolio optimization problem. We consider the behavior of an optimal solution for the case where the return rate is described with a single-factor model and compare the findings obtained from our proposed methods with correlated return rates with those obtained with independent return rates. We then analytically assess the increase in the investment risk when correlation is included. Furthermore, we also compare our approach with analytical procedures for minimizing the investment risk from operations research.

On the vacuum Einstein equations along curves with a discrete local rotation and reflection symmetry

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

Korzyński, Mikołaj; Hinder, Ian; Bentivegna, Eloisa, E-mail: korzynski@cft.edu.pl, E-mail: ian.hinder@aei.mpg.de, E-mail: eloisa.bentivegna@ct.infn.it

We discuss the possibility of a dimensional reduction of the Einstein equations in S{sup 3} black-hole lattices. It was reported in previous literature that the evolution of spaces containing curves of local, discrete rotation and reflection symmetry (LDRRS) can be carried out via a system of ODEs along these curves. However, 3+1 Numerical Relativity computations demonstrate that this is not the case, and we show analytically that this is due to the presence of a tensorial quantity which is not suppressed by the symmetry. We calculate the term analytically, and verify numerically for an 8-black-hole lattice that it fully accountsmore » for the anomalous results, and thus quantify its magnitude in this specific case. The presence of this term prevents the exact evolution of these spaces via previously-reported methods which do not involve a full 3+1 integration of Einstein's equation.« less

Bayesian estimation of the discrete coefficient of determination.

PubMed

Chen, Ting; Braga-Neto, Ulisses M

2016-12-01

The discrete coefficient of determination (CoD) measures the nonlinear interaction between discrete predictor and target variables and has had far-reaching applications in Genomic Signal Processing. Previous work has addressed the inference of the discrete CoD using classical parametric and nonparametric approaches. In this paper, we introduce a Bayesian framework for the inference of the discrete CoD. We derive analytically the optimal minimum mean-square error (MMSE) CoD estimator, as well as a CoD estimator based on the Optimal Bayesian Predictor (OBP). For the latter estimator, exact expressions for its bias, variance, and root-mean-square (RMS) are given. The accuracy of both Bayesian CoD estimators with non-informative and informative priors, under fixed or random parameters, is studied via analytical and numerical approaches. We also demonstrate the application of the proposed Bayesian approach in the inference of gene regulatory networks, using gene-expression data from a previously published study on metastatic melanoma.

Analysis of modal behavior at frequency cross-over

NASA Astrophysics Data System (ADS)

Costa, Robert N., Jr.

1994-11-01

The existence of the mode crossing condition is detected and analyzed in the Active Control of Space Structures Model 4 (ACOSS4). The condition is studied for its contribution to the inability of previous algorithms to successfully optimize the structure and converge to a feasible solution. A new algorithm is developed to detect and correct for mode crossings. The existence of the mode crossing condition is verified in ACOSS4 and found not to have appreciably affected the solution. The structure is then successfully optimized using new analytic methods based on modal expansion. An unrelated error in the optimization algorithm previously used is verified and corrected, thereby equipping the optimization algorithm with a second analytic method for eigenvector differentiation based on Nelson's Method. The second structure is the Control of Flexible Structures (COFS). The COFS structure is successfully reproduced and an initial eigenanalysis completed.

Sixteen-Item Anxiety Sensitivity Index: Confirmatory Factor Analytic Evidence, Internal Consistency, and Construct Validity in a Young Adult Sample from the Netherlands

ERIC Educational Resources Information Center

Vujanovic, Anka A.; Arrindell, Willem A.; Bernstein, Amit; Norton, Peter J.; Zvolensky, Michael J.

2007-01-01

The present investigation examined the factor structure, internal consistency, and construct validity of the 16-item Anxiety Sensitivity Index (ASI; Reiss Peterson, Gursky, & McNally 1986) in a young adult sample (n = 420) from the Netherlands. Confirmatory factor analysis was used to comparatively evaluate two-factor, three-factor, and…

Virtual photon impact factors with exact gluon kinematics

NASA Astrophysics Data System (ADS)

Bialas, A.; Navelet, H.; Peschanski, R.

2001-06-01

An explicit analytic formula for the transverse and longitudinal impact factors ST, L( N, γ) of the photon using kT factorization with exact gluon kinematics is given. Applications to the QCD dipole model and the extraction of the unintegrated gluon structure function from data are proposed.

Structure and Measurement of Acculturation/Enculturation for Asian Americans Using the ARSMA-II

ERIC Educational Resources Information Center

Lee, Richard M.; Yoon, Eunju; Liu-Tom, Hsin-Tine Tina

2006-01-01

The structure and measurement of acculturation/enculturation was investigated on 2 Asian American samples. Factor analyses revealed similar 2-factor structures for both acculturation and enculturation. The factor-analytic-derived measure yielded scores with adequate reliability and marginal construct validity. Acculturation/enculturation…

How participants report their health status: cognitive interviews of self-rated health across race/ethnicity, gender, age, and educational attainment.

PubMed

Garbarski, Dana; Dykema, Jennifer; Croes, Kenneth D; Edwards, Dorothy F

2017-10-04

Self-rated health (SRH) is widely used to measure subjective health. Yet it is unclear what underlies health ratings, with implications for understanding the validity of SRH overall and across sociodemographic characteristics. We analyze participants' explanations of how they formulated their SRH answer in addition to which health factors they considered and examine group differences in these processes. Cognitive interviews were conducted with 64 participants in a convenience quota sample crossing dimensions of race/ethnicity (white, Latino, black, American Indian), gender, age, and education. Participants rated their health then described their thoughts when answering SRH. We coded participants' answers in an inductive, iterative, and systematic process from interview transcripts, developing analytic categories (i.e., themes) and subdimensions within. We examined whether the presence of each dimension of an analytic category varied across sociodemographic groups. Our qualitative analysis led to the identification and classification of various subdimensions of the following analytic categories: types of health factors mentioned, valence of health factors, temporality of health factors, conditional health statements, and descriptions and definitions of health. We found differences across groups in some types of health factors mentioned-corresponding, conflicting, or novel with respect to prior research. Furthermore, we also documented various processes through which respondents integrate seemingly disparate health factors to formulate an answer through valence and conditional health statements. Finally, we found some evidence of sociodemographic group differences with respect to types of health factors mentioned, valence of health factors, and conditional health statements, highlighting avenues for future research. This study provides a description of how participants rate their general health status and highlights potential differences in these processes across sociodemographic groups, helping to provide a more comprehensive understanding of how SRH functions as a measure of health.

Factors Affecting the Location of Road Emergency Bases in Iran Using Analytical Hierarchy Process (AHP).

PubMed

Bahadori, Mohammadkarim; Hajebrahimi, Ahmad; Alimohammadzadeh, Khalil; Ravangard, Ramin; Hosseini, Seyed Mojtaba

2017-10-01

To identify and prioritize factors affecting the location of road emergency bases in Iran using Analytical Hierarchy Process (AHP). This was a mixed method (quantitative-qualitative) study conducted in 2016. The participants in this study included the professionals and experts in the field of pre-hospital and road emergency services issues working in the Health Deputy of Iran Ministry of Health and Medical Education, which were selected using purposive sampling method. In this study at first, the factors affecting the location of road emergency bases in Iran were identified using literature review and conducting interviews with the experts. Then, the identified factors were scored and prioritized using the studied professionals and experts' viewpoints through using the analytic hierarchy process (AHP) technique and its related pair-wise questionnaire. The collected data were analyzed using MAXQDA 10.0 software to analyze the answers given to the open question and Expert Choice 10.0 software to determine the weights and priorities of the identified factors. The results showed that eight factors were effective in locating the road emergency bases in Iran from the viewpoints of the studied professionals and experts in the field of pre-hospital and road emergency services issues, including respectively distance from the next base, region population, topography and geographical situation of the region, the volume of road traffic, the existence of amenities such as water, electricity, gas, etc. and proximity to the village, accident-prone sites, University ownership of the base site, and proximity to toll-house. Among the eight factors which were effective in locating the road emergency bases from the studied professionals and experts' perspectives, "distance from the next base" and "region population" were respectively the most important ones which had great differences with other factors.

The predictive efficiency of school bullying versus later offending: a systematic/meta-analytic review of longitudinal studies.

PubMed

Ttofi, Maria M; Farrington, David P; Lösel, Friedrich; Loeber, Rolf

2011-04-01

Although bullying and delinquency share similar risk factors, no previous systematic review has ever been conducted to examine possible links between school bullying and criminal offending later in life. To investigate the extent to which bullying perpetration at school predicts offending later in life, and whether this relation holds after controlling for other major childhood risk factors. Results are based on a thorough systematic review and meta-analysis of studies measuring school bullying and later offending. Effect sizes are based on both published and unpublished studies; longitudinal investigators of 28 studies have conducted specific analyses for our review. The probability of offending up to 11 years later was much higher for school bullies than for non-involved students [odds ratio (OR) = 2.50; 95% confidence interval (CI): 2.03-3.08]. Bullying perpetration was a significant risk factor for later offending, even after controlling for major childhood risk factors (OR = 1.82, 95% CI: 1.55-2.14). Effect sizes were smaller when the follow-up period was longer and larger when bullying was assessed in older children. The age of participants when outcome measures were taken was negatively related with effect sizes. Finally, the summary effect size did not decrease much as the number of controlled risk factors increased. School bullying is a strong and specific risk factor for later offending. Effective anti-bullying programmes should be promoted, and could be viewed as a form of early crime prevention. Such programmes would have a high benefit : cost ratio. Copyright © 2011 John Wiley & Sons, Ltd.

Effects of pre-analytical variables on flow cytometric diagnosis of canine lymphoma: A retrospective study (2009-2015).

PubMed

Comazzi, S; Cozzi, M; Bernardi, S; Zanella, D R; Aresu, L; Stefanello, D; Marconato, L; Martini, V

2018-02-01

Flow cytometry (FC) is increasingly being used for immunophenotyping and staging of canine lymphoma. The aim of this retrospective study was to assess pre-analytical variables that might influence the diagnostic utility of FC of lymph node (LN) fine needle aspirate (FNA) specimens from dogs with lymphoproliferative diseases. The study included 987 cases with LN FNA specimens sent for immunophenotyping that were submitted to a diagnostic laboratory in Italy from 2009 to 2015. Cases were grouped into 'diagnostic' and 'non-diagnostic'. Pre-analytical factors analysed by univariate and multivariate analyses were animal-related factors (breed, age, sex, size), operator-related factors (year, season, shipping method, submitting veterinarian) and sample-related factors (type of sample material, cellular concentration, cytological smears, artefacts). The submitting veterinarian, sample material, sample cellularity and artefacts affected the likelihood of having a diagnostic sample. The availability of specimens from different sites and of cytological smears increased the odds of obtaining a diagnostic result. Major artefacts affecting diagnostic utility included poor cellularity and the presence of dead cells. Flow cytometry on LN FNA samples yielded conclusive results in more than 90% of cases with adequate sample quality and sampling conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sea-level rise impacts on seawater intrusion in coastal aquifers: Review and integration

NASA Astrophysics Data System (ADS)

Ketabchi, Hamed; Mahmoodzadeh, Davood; Ataie-Ashtiani, Behzad; Simmons, Craig T.

2016-04-01

Sea-level rise (SLR) influences groundwater hydraulics and in particular seawater intrusion (SWI) in many coastal aquifers. The quantification of the combined and relative impacts of influential factors on SWI has not previously been considered in coastal aquifers. In the present study, a systematic review of the available literature on this topic is first provided. Then, the potential remaining challenges are scrutinized. Open questions on the effects of more realistic complexities such as gradual SLR, parameter uncertainties, and the associated influences in decision-making models are issues requiring further investigation. We assess and quantify the seawater toe location under the impacts of SLR in combination with recharge rate variations, land-surface inundation (LSI) due to SLR, aquifer bed slope variation, and changing landward boundary conditions (LWBCs). This is the first study to include all of these factors in a single analysis framework. Both analytical and numerical models are used for these sensitivity assessments. It is demonstrated that (1) LSI caused by SLR has a significant incremental impact on the seawater toe location, especially in the flatter coasts and the flux-controlled (FC) LWBCs, however this impact is less than the reported orders of magnitude differences which were estimated using only analytical solutions; (2) LWBCs significantly influence the SLR impacts under almost all conditions considered in this study; (3) The main controlling factors of seawater toe location are the magnitudes of fresh groundwater discharge to sea and recharge rate. Regional freshwater flux entering from the landward boundary and the groundwater hydraulic gradient are the major contributors of fresh groundwater discharge to sea for both FC and head-controlled (HC) systems, respectively; (4) A larger response of the aquifer and larger seawater toe location changes are demonstrable for a larger ratio of the aquifer thickness to the aquifer length particularly in the HC systems; (5) The lowest sensitivity of seawater toe location is found for the density difference ratio of the seawater and freshwater, and also for the aquifer bed slope; (6) The early-time observations show seawater fingers below the inundated lands due to SLR which are diminished and ultimately extinguished; and (7) A less than 2% reversal effect on the seawater toe location after overshoot mechanism is observed in the transient simulations which suggests that this mechanism is an insignificant and impractical factor compared to other more significant factors.

Flight simulator fidelity assessment in a rotorcraft lateral translation maneuver

NASA Technical Reports Server (NTRS)

Hess, R. A.; Malsbury, T.; Atencio, A., Jr.

1992-01-01

A model-based methodology for assessing flight simulator fidelity in closed-loop fashion is exercised in analyzing a rotorcraft low-altitude maneuver for which flight test and simulation results were available. The addition of a handling qualities sensitivity function to a previously developed model-based assessment criteria allows an analytical comparison of both performance and handling qualities between simulation and flight test. Model predictions regarding the existence of simulator fidelity problems are corroborated by experiment. The modeling approach is used to assess analytically the effects of modifying simulator characteristics on simulator fidelity.

Sonic horizon formation for oscillating Bose-Einstein condensates in isotropic harmonic potential

PubMed Central

Wang, Ying; Zhou, Yu; Zhou, Shuyu

2016-01-01

We study the sonic horizon phenomena of the oscillating Bose-Einstein condensates in isotropic harmonic potential. Based on the Gross-Pitaevskii equation model and variational method, we derive the original analytical formula for the criteria and lifetime of the formation of the sonic horizon, demonstrating pictorially the interaction parameter dependence for the occur- rence of the sonic horizon and damping effect of the system distribution width. Our analytical results corroborate quantitatively the particular features of the sonic horizon reported in previous numerical study. PMID:27922129

Vibrational frequencies of transition metal chloride and oxo compounds using effective core potential analytic second derivatives

NASA Astrophysics Data System (ADS)

Russo, Thomas V.; Martin, Richard L.; Hay, P. Jeffrey; Rappé, Anthony K.

1995-06-01

The application of analytic second derivative techniques to quantum chemical calculations using effective core potentials is discussed. Using a recent implementation of these techniques, the vibrational frequencies of transition metal compounds are calculated including the chlorides TiCl4, ZrCl4, and HfCl4, the oxochlorides CrO2Cl2, MoO2Cl2, WO2Cl2, and VOCl3, and the oxide OsO4. Results are compared to previous calculations and with experimental results.

The analytical approach to optimization of active region structure of quantum dot laser

NASA Astrophysics Data System (ADS)

Korenev, V. V.; Savelyev, A. V.; Zhukov, A. E.; Omelchenko, A. V.; Maximov, M. V.

2014-10-01

Using the analytical approach introduced in our previous papers we analyse the possibilities of optimization of size and structure of active region of semiconductor quantum dot lasers emitting via ground-state optical transitions. It is shown that there are optimal length' dispersion and number of QD layers in laser active region which allow one to obtain lasing spectrum of a given width at minimum injection current. Laser efficiency corresponding to the injection current optimized by the cavity length is practically equal to its maximum value.

Nucleation and growth in one dimension. I. The generalized Kolmogorov-Johnson-Mehl-Avrami model

NASA Astrophysics Data System (ADS)

Jun, Suckjoon; Zhang, Haiyang; Bechhoefer, John

2005-01-01

Motivated by a recent application of the Kolmogorov-Johnson-Mehl-Avrami (KJMA) model to the study of DNA replication, we consider the one-dimensional (1D) version of this model. We generalize previous work to the case where the nucleation rate is an arbitrary function I(t) and obtain analytical results for the time-dependent distributions of various quantities (such as the island distribution). We also present improved computer simulation algorithms to study the 1D KJMA model. The analytical results and simulations are in excellent agreement.

High Rayleigh number convection in rectangular enclosures with differentially heated vertical walls and aspect ratios between zero and unity

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

Kassemi, S.A.

1988-04-01

High Rayleigh number convection in a rectangular cavity with insulated horizontal surfaces and differentially heated vertical walls was analyzed for an arbitrary aspect ratio smaller than or equal to unity. Unlike previous analytical studies, a systematic method of solution based on linearization technique and analytical iteration procedure was developed to obtain approximate closed-form solutions for a wide range of aspect ratios. The predicted velocity and temperature fields are shown to be in excellent agreement with available experimental and numerical data.