Applications of Computational Methods for Dynamic Stability and Control Derivatives
NASA Technical Reports Server (NTRS)
Green, Lawrence L.; Spence, Angela M.
2004-01-01
Initial steps in the application o f a low-order panel method computational fluid dynamic (CFD) code to the calculation of aircraft dynamic stability and control (S&C) derivatives are documented. Several capabilities, unique to CFD but not unique to this particular demonstration, are identified and demonstrated in this paper. These unique capabilities complement conventional S&C techniques and they include the ability to: 1) perform maneuvers without the flow-kinematic restrictions and support interference commonly associated with experimental S&C facilities, 2) easily simulate advanced S&C testing techniques, 3) compute exact S&C derivatives with uncertainty propagation bounds, and 4) alter the flow physics associated with a particular testing technique from those observed in a wind or water tunnel test in order to isolate effects. Also presented are discussions about some computational issues associated with the simulation of S&C tests and selected results from numerous surface grid resolution studies performed during the course of the study.
Application of the Bootstrap Statistical Method in Deriving Vibroacoustic Specifications
NASA Technical Reports Server (NTRS)
Hughes, William O.; Paez, Thomas L.
2006-01-01
This paper discusses the Bootstrap Method for specification of vibroacoustic test specifications. Vibroacoustic test specifications are necessary to properly accept or qualify a spacecraft and its components for the expected acoustic, random vibration and shock environments seen on an expendable launch vehicle. Traditionally, NASA and the U.S. Air Force have employed methods of Normal Tolerance Limits to derive these test levels based upon the amount of data available, and the probability and confidence levels desired. The Normal Tolerance Limit method contains inherent assumptions about the distribution of the data. The Bootstrap is a distribution-free statistical subsampling method which uses the measured data themselves to establish estimates of statistical measures of random sources. This is achieved through the computation of large numbers of Bootstrap replicates of a data measure of interest and the use of these replicates to derive test levels consistent with the probability and confidence desired. The comparison of the results of these two methods is illustrated via an example utilizing actual spacecraft vibroacoustic data.
Multidimensional quantum trajectories: Applications of the derivative propagation method
Trahan, Corey J.; Wyatt, Robert E.; Poirier, Bill
2005-04-22
In a previous publication [J. Chem. Phys. 118, 9911 (2003)], the derivative propagation method (DPM) was introduced as a novel numerical scheme for solving the quantum hydrodynamic equations of motion (QHEM) and computing the time evolution of quantum mechanical wave packets. These equations are a set of coupled, nonlinear partial differential equations governing the time evolution of the real-valued functions C and S in the complex action, S=C(r,t)+iS(r,t)/({Dirac_h}/2{pi}), where {psi}(r,t)=exp(S). Past numerical solutions to the QHEM were obtained via ensemble trajectory propagation, where the required first- and second-order spatial derivatives were evaluated using fitting techniques such as moving least squares. In the DPM, however, equations of motion are developed for the derivatives themselves, and a truncated set of these are integrated along quantum trajectories concurrently with the original QHEM equations for C and S. Using the DPM quantum effects can be included at various orders of approximation; no spatial fitting is involved; there is no basis set expansion; and single, uncoupled quantum trajectories can be propagated (in parallel) rather than in correlated ensembles. In this study, the DPM is extended from previous one-dimensional (1D) results to calculate transmission probabilities for 2D and 3D wave packet evolution on coupled Eckart barrier/harmonic oscillator surfaces. In the 2D problem, the DPM results are compared to standard numerical integration of the time-dependent Schroedinger equation. Also in this study, the practicality of implementing the DPM for systems with many more degrees of freedom is discussed.
Multidimensional quantum trajectories: applications of the derivative propagation method.
Trahan, Corey J; Wyatt, Robert E; Poirier, Bill
2005-04-22
In a previous publication [J. Chem. Phys. 118, 9911 (2003)], the derivative propagation method (DPM) was introduced as a novel numerical scheme for solving the quantum hydrodynamic equations of motion (QHEM) and computing the time evolution of quantum mechanical wave packets. These equations are a set of coupled, nonlinear partial differential equations governing the time evolution of the real-valued functions C and S in the complex action, S=C(r,t) + iS(r,t)/Planck's over 2pi, where Psi(r,t)=exp(S). Past numerical solutions to the QHEM were obtained via ensemble trajectory propagation, where the required first- and second-order spatial derivatives were evaluated using fitting techniques such as moving least squares. In the DPM, however, equations of motion are developed for the derivatives themselves, and a truncated set of these are integrated along quantum trajectories concurrently with the original QHEM equations for C and S. Using the DPM quantum effects can be included at various orders of approximation; no spatial fitting is involved; there is no basis set expansion; and single, uncoupled quantum trajectories can be propagated (in parallel) rather than in correlated ensembles. In this study, the DPM is extended from previous one-dimensional (1D) results to calculate transmission probabilities for 2D and 3D wave packet evolution on coupled Eckart barrier/harmonic oscillator surfaces. In the 2D problem, the DPM results are compared to standard numerical integration of the time-dependent Schrodinger equation. Also in this study, the practicality of implementing the DPM for systems with many more degrees of freedom is discussed. PMID:15945669
A Standardized Method of Isolating Adipose-Derived Stem Cells for Clinical Applications.
Raposio, Edoardo; Caruana, Giorgia; Petrella, Maira; Bonomini, Sabrina; Grieco, Michele P
2016-01-01
White adipose tissue is the most abundant and accessible source of stem cells in the adult human body. In this paper, we present a standardised and safe method of isolating and maximizing the number of adipose-derived stem cells (ASCs) from conventional liposuction for clinical applications, which was carried out through both mechanical (centrifuge) and enzymatic (collagenase) means. Isolated cells were characterized through flow cytometry assay. Gathered data showed a greater amount (9.06 × 10(5) ASCs from 100 mL of adipose tissue) of isolated ASCs compared to previous protocol, also with high (99%) cell vitality; the procedure we presented is easy and fast (80 minutes), allowing collecting a significative number of mesenchymal stem cells, which can be used for clinical purposes, such as wound healing. PMID:26418805
Technology Transfer Automated Retrieval System (TEKTRAN)
Conventional pad-dry-cure (non-scCO2) and supercritical carbon dioxide (scCO2) application methods were investigated to study the effectiveness of a phosphazene derivative as a flame retardant on cotton fabric. 1,1',4,5-tetrahydrotrispiro[1,3,2-diazaphosphole-2,2'-[1,3,5,2,4,6]triazatriphosphinine-4...
Induced Pluripotent Stem Cell-derived Vascular Smooth Muscle Cells: Methods and Application
Dash, Biraja C.; Jiang, Zhengxin; Suh, Carol; Qyang, Yibing
2015-01-01
Vascular smooth muscle cells (VSMCs) play a major role in the pathophysiology of cardiovascular diseases. The advent of induced pluripotent stem cell (iPSC) technology and their capability to differentiation into virtually every cell type in the human body make this field a ray of hope for vascular regenerative therapy and for understanding disease mechanism. In this review, we first discuss the recent iPSC technology and vascular smooth muscle development from embryo and then examine different methodology to derive VSMCs from iPSCs and their applications in regenerative therapy and disease modeling. PMID:25559088
Houssaini, Allal; Assoumou, Lambert; Miller, Veronica; Calvez, Vincent; Marcelin, Anne-Geneviève; Flandre, Philippe
2013-01-01
Background Several attempts have been made to determine HIV-1 resistance from genotype resistance testing. We compare scoring methods for building weighted genotyping scores and commonly used systems to determine whether the virus of a HIV-infected patient is resistant. Methods and Principal Findings Three statistical methods (linear discriminant analysis, support vector machine and logistic regression) are used to determine the weight of mutations involved in HIV resistance. We compared these weighted scores with known interpretation systems (ANRS, REGA and Stanford HIV-db) to classify patients as resistant or not. Our methodology is illustrated on the Forum for Collaborative HIV Research didanosine database (N = 1453). The database was divided into four samples according to the country of enrolment (France, USA/Canada, Italy and Spain/UK/Switzerland). The total sample and the four country-based samples allow external validation (one sample is used to estimate a score and the other samples are used to validate it). We used the observed precision to compare the performance of newly derived scores with other interpretation systems. Our results show that newly derived scores performed better than or similar to existing interpretation systems, even with external validation sets. No difference was found between the three methods investigated. Our analysis identified four new mutations associated with didanosine resistance: D123S, Q207K, H208Y and K223Q. Conclusions We explored the potential of three statistical methods to construct weighted scores for didanosine resistance. Our proposed scores performed at least as well as already existing interpretation systems and previously unrecognized didanosine-resistance associated mutations were identified. This approach could be used for building scores of genotypic resistance to other antiretroviral drugs. PMID:23555613
Bayesian methods for uncertainty factor application for derivation of reference values.
Simon, Ted W; Zhu, Yiliang; Dourson, Michael L; Beck, Nancy B
2016-10-01
In 2014, the National Research Council (NRC) published Review of EPA's Integrated Risk Information System (IRIS) Process that considers methods EPA uses for developing toxicity criteria for non-carcinogens. These criteria are the Reference Dose (RfD) for oral exposure and Reference Concentration (RfC) for inhalation exposure. The NRC Review suggested using Bayesian methods for application of uncertainty factors (UFs) to adjust the point of departure dose or concentration to a level considered to be without adverse effects for the human population. The NRC foresaw Bayesian methods would be potentially useful for combining toxicity data from disparate sources-high throughput assays, animal testing, and observational epidemiology. UFs represent five distinct areas for which both adjustment and consideration of uncertainty may be needed. NRC suggested UFs could be represented as Bayesian prior distributions, illustrated the use of a log-normal distribution to represent the composite UF, and combined this distribution with a log-normal distribution representing uncertainty in the point of departure (POD) to reflect the overall uncertainty. Here, we explore these suggestions and present a refinement of the methodology suggested by NRC that considers each individual UF as a distribution. From an examination of 24 evaluations from EPA's IRIS program, when individual UFs were represented using this approach, the geometric mean fold change in the value of the RfD or RfC increased from 3 to over 30, depending on the number of individual UFs used and the sophistication of the assessment. We present example calculations and recommendations for implementing the refined NRC methodology. PMID:27211295
Jameson, Donald L; Field, Thomas; Schmidt, Monica R; DeStefano, Alyson K; Stiteler, Christopher J; Venditto, Vincent J; Krovic, Brooke; Hoffman, Christopher M; Ondisco, Matthew T; Belowich, Matthew E
2013-11-15
A general method for the gram scale resolution of 2-substituted and 2,8-disubstituted Tröger's base (TB) derivatives in 63-91% yield has been achieved through the application of crystallization-induced asymmetric transformation (CIAT). Enantiomeric ratios of the resolved TB derivatives range from 99.1:0.9 to >99.5:0.5. Among the Tröger's base compounds resolved are four synthetically valuable bromo and iodo derivatives. PMID:24116701
Fullerene Derivatives for Medical Applications
NASA Astrophysics Data System (ADS)
Hirsch, Andreas
2005-09-01
Water-soluble fullerene derivatives have a potential for a variety of medical applications. This is due to the unique structural-, electronic and chemical properties of the fullerene core. The biological properties of suitably functionalized fullerenes range from enzyme inhibition/receptor binding, anticancer and antiviral activity, cell signalling, DNA- and genomic applications, photodynamic activation and most importantly antioxidant properties. This review focusses on the anti-HIV and antioxidant properties of a couple of water soluble fullerene derivatives.
NASA Astrophysics Data System (ADS)
Duan, Beiping; Zheng, Zhoushun; Cao, Wen
2016-08-01
In this paper, we revisit two spectral approximations, including truncated approximation and interpolation for Caputo fractional derivative. The two approaches have been studied to approximate Riemann-Liouville (R-L) fractional derivative by Chen et al. and Zayernouri et al. respectively in their most recent work. For truncated approximation the reconsideration partly arises from the difference between fractional derivative in R-L sense and Caputo sense: Caputo fractional derivative requires higher regularity of the unknown than R-L version. Another reason for the reconsideration is that we distinguish the differential order of the unknown with the index of Jacobi polynomials, which is not presented in the previous work. Also we provide a way to choose the index when facing multi-order problems. By using generalized Hardy's inequality, the gap between the weighted Sobolev space involving Caputo fractional derivative and the classical weighted space is bridged, then the optimal projection error is derived in the non-uniformly Jacobi-weighted Sobolev space and the maximum absolute error is presented as well. For the interpolation, analysis of interpolation error was not given in their work. In this paper we build the interpolation error in non-uniformly Jacobi-weighted Sobolev space by constructing fractional inverse inequality. With combining collocation method, the approximation technique is applied to solve fractional initial-value problems (FIVPs). Numerical examples are also provided to illustrate the effectiveness of this algorithm.
Elevation Derivatives for National Applications
U.S. Geological Survey
2005-01-01
The Elevation Derivatives for National Applications (EDNA) project is a multi-agency effort to develop standard topographically derived layers for use in hydrologic and environmental modeling. The EDNA takes advantage of the seamless and filtered characteristics for the National Elevation Dataset (NED) to create a hydrologically conditioned Digital Elevation Model (DEM) useful for modeling applications. The goals of the project are to create a hydrologically conditioned DEM and systematically extract a set of standard derivatives that can be used to facilitate data integration with other U.S. Geological Survey (USGS) framework data sets such as the National Hydrography Dataset (NHD) and the Watershed Boundaries Dataset (WBD).
NASA Technical Reports Server (NTRS)
Chahine, M.; Barnet, C.; Olsen, E. T.; Chen, L.; Maddy, E.
2005-01-01
We present a general method for the determination of minor gases in the troposphere from high spectral resolution observations. In this method, we make use of a general property of the total differential of multi-variable functions to separate the contributions of each individual minor gas. We have applied this method to derive the mixing ratio of carbon dioxide in the mid-troposphere using data from the Atmospheric Infrared Sounder (AIRS) currently flying on the NASA Aqua Mission. We compare our results to the aircraft flask CO2 measurements obtained by H. Matsueda et al. over the western Pacific and demonstrate skill in tracking the measured 5 ppmv seasonal variation with an accuracy of 0.43 +/- 1.20 ppmv.
Inostroza, Pedro A; Wicht, Anna-Jorina; Huber, Thomas; Nagy, Claudia; Brack, Werner; Krauss, Martin
2016-07-01
While environmental risk assessment is typically based on toxicant concentrations in water and/or sediment, awareness is increasing that internal concentrations or body burdens are the key to understand adverse effects in organisms. In order to link environmental micropollutants as causes of observed effects, there is an increasing demand for methods to analyse these chemicals in organisms. Here, a multi-target screening method based on pulverised liquid extraction (PuLE) and a modified QuEChERS approach with an additional hexane phase was developed. It is capable to extract and quantify organic micropollutants of diverse chemical classes in freshwater invertebrates. The method was tested on gammarids from the Danube River (within the Joint Danube Survey 3) and target compounds were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Furthermore, a non-target screening using high resolution-tandem mass spectrometry (LC-HRMS/MS) was conducted. A total of 17 pollutants were detected and/or quantified in gammarids at low concentrations. Pesticide concentrations ranged from 0.1 to 6.52 ng g(-1) (wet weight), those of wastewater-derived pollutants from 0.1 to 2.83 ng g(-1) (wet weight). The presence of wastewater-derived pollutants was prominent at all spots sampled. Using non-target screening, we could successfully identify several chlorinated compounds. These results demonstrate for the first time the presence of pesticides and wastewater-derived pollutants in invertebrates of the Danube River. PMID:27064613
Brandes, S.D.
1993-06-01
This literature survey was conducted to address an important question: What are the methods available in the realm of analytical chemistry that may have potential usefulness to the development of coal liquefaction technology? In an attempt to answer to that question, the emphasis of this survey was directed at analytical techniques which would be applicable to the high molecular weight, non-distillable residue of coal-derived liquids. It is this material which is most problematic to the analytical investigator and the developer of direct coal liquefaction processes. A number of comprehensive analytical reviews of literature dealing with coal and other fossil fuels are available. This literature survey will (1) be limited to articles published between 1980--1991, with some exceptions; (2) be limited to the use of analytical methods for high molecular weight, primarily nondistillable, fossil fuel-derived materials, except where the application of an analytical method to coals or distillates may show promise for application to non-distillable coal-derived materials; and (3) demonstrate the potential usefulness of an analytical method by showing how the method has been applied to high molecular weight, non-distillable materials, if not specifically to coal liquids. The text is divided by type of methodology, i.e. spectroscopy, microscopy, etc. Each section will be essentially free-standing. An historical background is provided.
Application of EOF/PCA-based methods in the post-processing of GRACE derived water variations
NASA Astrophysics Data System (ADS)
Forootan, Ehsan; Kusche, Jürgen
2010-05-01
Two problems that users of monthly GRACE gravity field solutions face are 1) the presence of correlated noise in the Stokes coefficients that increases with harmonic degree and causes ‘striping', and 2) the fact that different physical signals are overlaid and difficult to separate from each other in the data. These problems are termed the signal-noise separation problem and the signal-signal separation problem. Methods that are based on principal component analysis and empirical orthogonal functions (PCA/EOF) have been frequently proposed to deal with these problems for GRACE. However, different strategies have been applied to different (spatial: global/regional, spectral: global/order-wise, geoid/equivalent water height) representations of the GRACE level 2 data products, leading to differing results and a general feeling that PCA/EOF-based methods are to be applied ‘with care'. In addition, it is known that conventional EOF/PCA methods force separated modes to be orthogonal, and that, on the other hand, to either EOFs or PCs an arbitrary orthogonal rotation can be applied. The aim of this paper is to provide a common theoretical framework and to study the application of PCA/EOF-based methods as a signal separation tool due to post-process GRACE data products. In order to investigate and illustrate the applicability of PCA/EOF-based methods, we have employed them on GRACE level 2 monthly solutions based on the Center for Space Research, University of Texas (CSR/UT) RL04 products and on the ITG-GRACE03 solutions from the University of Bonn, and on various representations of them. Our results show that EOF modes do reveal the dominating annual, semiannual and also long-periodic signals in the global water storage variations, but they also show how choosing different strategies changes the outcome and may lead to unexpected results.
Lev, S.M.; Landa, E.R.; Szlavecz, K.; Casey, R.; Snodgrass, J.
2008-01-01
The impact of human activities on biogeochemical cycles in terrestrial environments is nowhere more apparent than in urban landscapes. Trace metals, collected on roadways and transported by storm water, may contaminate soils and sediments associated with storm water management systems. These systems will accumulate metals and associated sediments may reach toxic levels for terrestrial and aquatic organisms using the retention basins as habitat. The fate and bioavailability of these metals once deposited is poorly understood. Here we present results from a dose-response experiment that examines the application of synchrotron X-ray fluorescence methods (??-SXRF) to test the hypothesis that earthworms will bio-accumulate Zn in a roadway-dust contaminated soil system providing a potential pathway for roadway contaminants into the terrestrial food web, and that the storage and distribution of Zn will change with the level of exposure reflecting the micronutrient status of Zn. Lumbricus friendi was exposed to Zn-bearing roadway dust amended to a field soil at six target concentrations ranging from background levels (45 mg/kg Zn) to highly contaminated levels (460 mg/kg Zn) designed to replicate the observed concentration range in storm-water retention basin soils. After a 30 day exposure, Zn storage in the intestine is positively correlated with dose and there is a change in the pattern of Zn storage within the intestine. This relationship is only clear when ??-SXRF Zn map data is coupled with a traditional toxicological approach, and suggests that the gut concentration in L. friendi is a better indicator of Zn bioaccumulation and storage than the total body burden. ?? 2008 The Mineralogical Society.
Lev,S.; Landa, E.; Szlavecz, K.; Casey, R.; Snodgrass, J.
2008-01-01
The impact of human activities on biogeochemical cycles in terrestrial environments is nowhere more apparent than in urban landscapes. Trace metals, collected on roadways and transported by storm water, may contaminate soils and sediments associated with storm water management systems. These systems will accumulate metals and associated sediments may reach toxic levels for terrestrial and aquatic organisms using the retention basins as habitat. The fate and bioavailability of these metals once deposited is poorly understood. Here we present results from a dose-response experiment that examines the application of synchrotron X-ray fluorescence methods ({mu}-SXRF) to test the hypothesis that earthworms will bio-accumulate Zn in a roadway-dust contaminated soil system providing a potential pathway for roadway contaminants into the terrestrial food web, and that the storage and distribution of Zn will change with the level of exposure reflecting the micronutrient status of Zn. Lumbricus friendi was exposed to Zn-bearing roadway dust amended to a field soil at six target concentrations ranging from background levels (45 mg/kg Zn) to highly contaminated levels (460 mg/kg Zn) designed to replicate the observed concentration range in storm-water retention basin soils. After a 30 day exposure, Zn storage in the intestine is positively correlated with dose and there is a change in the pattern of Zn storage within the intestine. This relationship is only clear when {mu}-SXRF Zn map data is coupled with a traditional toxicological approach, and suggests that the gut concentration in L. friendi is a better indicator of Zn bioaccumulation and storage than the total body burden.
ERIC Educational Resources Information Center
Green, Francis; Vignoles, Anna
2012-01-01
We present a method to compare different qualifications for entry to higher education by studying students' subsequent performance. Using this method for students holding either the International Baccalaureate (IB) or A-levels gaining their degrees in 2010, we estimate an "empirical" equivalence scale between IB grade points and UCAS points…
Rittgen, Jan; Pütz, Michael; Zimmermann, Ralf
2012-06-01
The identification of fentanyl derivatives at trace levels employing capillary electrophoresis coupled to electrospray ionization tandem mass spectrometry (CE-ESI-MS(n) , n = 2, 3) is presented. The studied synthetic opioid fentanyl and its derivatives have an exceeding analgesic potency which can be up to 8000 times higher that of morphine. Apart from their therapeutical applications, there is an abuse of them in the drug scene as a heroin substitute. The identification of these opioids at trace levels is of further significant forensic interest with respect to recent seizures of clandestine fentanyl laboratories in Germany. In this work, a nonaqueous capillary electrophoresis (NACE)-ESI-MS(n) procedure was developed for the separation and identification of six fentanyl derivatives including fentanyl, cis- and trans-methylfentanyl, sufentanil, alfentanil, and carfentanil. Their fragmentation pattern in MS(n) experiments were investigated as well as the influence of the sheath-liquid mixture and the influence of the inside diameter of the fused silica capillary on the peak shape and the signal to noise ratio. Method validation included determination of the detection limits (about 1-2 nmol/L) and the repeatability of migration time (at most 0.07% relative standard deviation). The NACE-MS procedure was successfully applied for the analysis of real samples from seizures in illegal fentanyl laboratories. PMID:22736362
NASA Astrophysics Data System (ADS)
Gruber, C.; Auer, I.
2009-09-01
The demand for climate extreme studies is getting more and more important. As a consequence reliable data of (at least) daily resolution are required. The examination of the data according to inhomogeneities is indispensable for these questions. The main objective of the "homogenization of daily data” is to remove inhomogeneities not only in mean (e.g. temperature) data, but to account for inhomogeneities in higher order moments as well, thus that inhomogeneities that affect climate extremes are removed. Within the last years several methods for the homogenization of daily (temperature) time series have been developed (e.g. Della-Marta and Wanner, 2006; Mestre et al., submitted; Vincent et al., 2002; Trewin and Trevitt, 1996). However, a general comparison of their advantages and disadvantages has not been performed yet. Based on the experience of the homogenization of Austrian daily temperature data, the benefit of such methods is discussed. The method used for the homogenization of the Austrian data is a combination of the methods Mestre et al. (submitted) and Vincent et al. (2002). The results show that temperature dependent adjustments are beneficial for a minor fraction of inhomogeneities only: Either inhomogeneities affect just the temperature mean or the data availability it too sparse for adjusting higher order moments. However, these methods can be valuable in specific cases and they are even more helpful for the assessment of the time series reliability with respect to climate extremes.
Träber, S C; Li, W B; Höllriegl, V; Nebelung, K; Michalke, B; Rühm, W; Oeh, U
2015-08-01
The aim of the present study was to determine the internal dose in humans after the ingestion of soil highly contaminated with uranium. Therefore, an in vitro solubility assay was performed to estimate the bioaccessibility of uranium for two types of soil. Based on the results, the corresponding bioavailabilities were assessed by using a recently published method. Finally, these bioavailability data were used together with the biokinetic model of uranium to assess the internal doses for a hypothetical but realistic scenario characterized by a daily ingestion of 10 mg of soil over 1 year. The investigated soil samples were from two former uranium mining sites of Germany with (238)U concentrations of about 460 and 550 mg/kg. For these soils, the bioavailabilities of (238)U were quantified as 0.18 and 0.28 % (geometric mean) with 2.5th percentiles of 0.02 and 0.03 % and 97.5th percentiles of 1.48 and 2.34 %, respectively. The corresponding calculated annual committed effective doses for the assumed scenario were 0.4 and 0.6 µSv (GM) with 2.5th percentiles of 0.2 and 0.3 µSv and 97.5th percentiles of 1.6 and 3.0 µSv, respectively. These annual committed effective doses are similar to those from natural uranium intake by food and drinking water, which is estimated to be 0.5 µSv. Based on the present experimental data and the selected ingestion scenario, the investigated soils-although highly contaminated with uranium-are not expected to pose any major health risk to humans related to radiation. PMID:25980738
Alves, Tiago Vinicius; Simón-Carballido, Luis; Ornellas, Fernando Rei; Fernández-Ramos, Antonio
2016-04-01
In this work we present a novel application of the two-dimensional non-separable (2D-NS) method to the calculation of torsional tunneling splittings in systems with two hindered internal rotors. This method could be considered an extension of one-dimensional methods for the case of compounds with two tops. The 2D-NS method includes coupling between torsions in the kinetic and potential energy. Specifically, it has been applied to benzyl alcohol (BA) and two of its fluorine derivatives: 3-fluorobenzyl alcohol (3FBA) and 4-fluorobenzyl alcohol (4FBA). These molecules present two torsions, i.e., about the -CH2OH (ϕ1) and -OH (ϕ2) groups. The electronic structure calculations to build the two-dimensional torsional potential energy surface were performed at the DF-LMP2-F12//DF-LMP2/cc-pVQZ level of theory. For BA and 4FBA the calculated ground-state vibrational level splittings are 429 and 453 MHz, respectively, in good agreement with the experimental values of 337.10 and 492.82 MHz, respectively. In these two cases there are four equivalent wells and the tunneling splitting is the result of transitions between the two closer minima along ϕ1. The analysis of the wavefunctions, as well as the previous experimental work on the system, supports this conclusion. For 3FBA the observed ground-state splitting is 0.82 MHz, whereas in this case the calculated value amounts only to 0.02 MHz. The 2D-NS method, through the analysis of the wavefunctions, shows that this tiny tunneling splitting occurs between the two most stable minima of the potential energy surface. Additionally, we predict that the first vibrationally excited tunneling splitting will also be small and exclusively due to the interconversion between the second lowest minima. PMID:26960818
Choudhari, Vishnu P.; Ingale, Snehal; Gite, Sacchidanand R.; Tajane, Dipali D.; Modak, Vikram G.; Ambekar, Archana
2011-01-01
Three simple, economical, precise, and accurate methods are described for the simultaneous determination of Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM) in combined tablet dosage form. The first method is ratio derivative spectra, second is first-order derivative spectrophotometry and third is absorption corrected method. The amplitudes at 271.07 and 302.17 nm in the ratio derivative method, 224.38 and 306.88 nm in the first order derivative method were selected to determine Tenofovir disoproxil fumarate (TE) and Emtricitabine (EM), respectively, in combined formulation. Beer's law is obeyed in the concentration range of 3-21 μg/ml for TE and 2-14 μg/ml for EM for first two methods and range for third method was 6-30 μg/ml of TE and 4-20 μg/ml of EM. The percent assay for commercial formulation was found to be in the range 98.91%–101.72% for both the analytes by the proposed three methods. Absorption corrected method was successfully applied to carry out dissolution study of commercial tablet formulation by using USP II dissolution test apparatus. The methods were validated with respect to linearity, precision, and accuracy. Recoveries by proposed methods were found in the range of 99.06 %-101.34 % for both the analytes. PMID:23781430
Plant-derived nanostructures: types and applications
Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...
Two-derivative Runge-Kutta methods for differential equations
NASA Astrophysics Data System (ADS)
Chan, Robert P. K.; Wang, Shixiao; Tsai, Angela Y. J.
2012-09-01
Two-derivative Runge-Kutta (TDRK) methods are a special case of multi-derivative Runge-Kutta methods first studied by Kastlunger and Wanner [1, 2]. These methods incorporate derivatives of order higher than the first in their formulation but we consider only the first and second derivatives. In this paper we first present our study of both explicit [3] and implicit TDRK methods on stiff ODE problems. We then extend the applications of these TDRK methods to various partial differential equations [4]. In particular, we show how a 2-stage implicit TDRK method of order 4 and stage order 4 can be adapted to solve diffusion equations more efficiently than the popular Crank-Nicolson method.
Sun, Jing; Cao, Ling; Feng, Youlong; Tan, Li
2014-11-01
The compounds with similar structure often have similar pharmacological activities. So it is a trend for illegal addition that new derivatives of effective drugs are synthesized to avoid the statutory test. This bring challenges to crack down on illegal addition behavior, however, modified derivatives usually have similar product ions, which allow for precursor ion scanning. In this work, precursor ion scanning mode of a triple quadrupole mass spectrometer was first applied to screen illegally added drugs in complex matrix such as Chinese traditional patent medicines and healthy foods. Phosphodiesterase-5 inhibitors were used as experimental examples. Through the analysis of the structure and mass spectrum characteristics of the compounds, phosphodiesterase-5 inhibitors were classified, and their common product ions were screened by full scan of product ions of typical compounds. Then high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with precursor ion scanning mode was established based on the optimization of MS parameters. The effect of mass parameters and the choice of fragment ions were also studied. The method was applied to determine actual samples and further refined. The results demonstrated that this method can meet the need of rapid screening of unknown derivatives of phosphodiesterase-5 inhibitors in complex matrix, and prevent unknown derivatives undetected. This method shows advantages in sensitivity, specificity and efficiency, and is worth to be further investigated. PMID:25764652
Shih, Yuan-Ta; Cheng, Hao-Min; Sung, Shih-Hsien; Hu, Wei-Chih; Chen, Chen-Huan
2014-04-01
The N-point moving average (NPMA) is a mathematical low-pass filter that can smooth peaked noninvasively acquired radial pressure waveforms to estimate central aortic systolic pressure using a common denominator of N/4 (where N=the acquisition sampling frequency). The present study investigated whether the NPMA method can be applied to brachial pressure waveforms. In the derivation group, simultaneously recorded invasive high-fidelity brachial and central aortic pressure waveforms from 40 subjects were analyzed to identify the best common denominator. In the validation group, the NPMA method with the obtained common denominator was applied on noninvasive brachial pressure waveforms of 100 subjects. Validity was tested by comparing the noninvasive with the simultaneously recorded invasive central aortic systolic pressure. Noninvasive brachial pressure waveforms were calibrated to the cuff systolic and diastolic blood pressures. In the derivation study, an optimal denominator of N/6 was identified for NPMA to derive central aortic systolic pressure. The mean difference between the invasively/noninvasively estimated (N/6) and invasively measured central aortic systolic pressure was 0.1±3.5 and -0.6±7.6 mm Hg in the derivation and validation study, respectively. It satisfied the Association for the Advancement of Medical Instrumentation standard of 5±8 mm Hg. In conclusion, this method for estimating central aortic systolic pressure using either invasive or noninvasive brachial pressure waves requires a common denominator of N/6. By integrating the NPMA method into the ordinary oscillometric blood pressure determining process, convenient noninvasive central aortic systolic pressure values could be obtained with acceptable accuracy. PMID:24420554
Second derivatives for approximate spin projection methods
Thompson, Lee M.; Hratchian, Hrant P.
2015-02-07
The use of broken-symmetry electronic structure methods is required in order to obtain correct behavior of electronically strained open-shell systems, such as transition states, biradicals, and transition metals. This approach often has issues with spin contamination, which can lead to significant errors in predicted energies, geometries, and properties. Approximate projection schemes are able to correct for spin contamination and can often yield improved results. To fully make use of these methods and to carry out exploration of the potential energy surface, it is desirable to develop an efficient second energy derivative theory. In this paper, we formulate the analytical second derivatives for the Yamaguchi approximate projection scheme, building on recent work that has yielded an efficient implementation of the analytical first derivatives.
Computing Airplane Stopping Distance: Applications of Derivatives.
ERIC Educational Resources Information Center
Tylee, J. Louis
1997-01-01
Presents two real world applications that use derivatives and are related to computing the distance required to stop an airplane. Examines the curve-fitting techniques used to develop an equation for braking force and develops equations for the deceleration and speed. (DDR)
Charlesworth, Paul; Thomas, Christopher W.; Paulsen, Ole
2016-01-01
Accurate identification of bursting activity is an essential element in the characterization of neuronal network activity. Despite this, no one technique for identifying bursts in spike trains has been widely adopted. Instead, many methods have been developed for the analysis of bursting activity, often on an ad hoc basis. Here we provide an unbiased assessment of the effectiveness of eight of these methods at detecting bursts in a range of spike trains. We suggest a list of features that an ideal burst detection technique should possess and use synthetic data to assess each method in regard to these properties. We further employ each of the methods to reanalyze microelectrode array (MEA) recordings from mouse retinal ganglion cells and examine their coherence with bursts detected by a human observer. We show that several common burst detection techniques perform poorly at analyzing spike trains with a variety of properties. We identify four promising burst detection techniques, which are then applied to MEA recordings of networks of human induced pluripotent stem cell-derived neurons and used to describe the ontogeny of bursting activity in these networks over several months of development. We conclude that no current method can provide “perfect” burst detection results across a range of spike trains; however, two burst detection techniques, the MaxInterval and logISI methods, outperform compared with others. We provide recommendations for the robust analysis of bursting activity in experimental recordings using current techniques. PMID:27098024
Cotterill, Ellese; Charlesworth, Paul; Thomas, Christopher W; Paulsen, Ole; Eglen, Stephen J
2016-08-01
Accurate identification of bursting activity is an essential element in the characterization of neuronal network activity. Despite this, no one technique for identifying bursts in spike trains has been widely adopted. Instead, many methods have been developed for the analysis of bursting activity, often on an ad hoc basis. Here we provide an unbiased assessment of the effectiveness of eight of these methods at detecting bursts in a range of spike trains. We suggest a list of features that an ideal burst detection technique should possess and use synthetic data to assess each method in regard to these properties. We further employ each of the methods to reanalyze microelectrode array (MEA) recordings from mouse retinal ganglion cells and examine their coherence with bursts detected by a human observer. We show that several common burst detection techniques perform poorly at analyzing spike trains with a variety of properties. We identify four promising burst detection techniques, which are then applied to MEA recordings of networks of human induced pluripotent stem cell-derived neurons and used to describe the ontogeny of bursting activity in these networks over several months of development. We conclude that no current method can provide "perfect" burst detection results across a range of spike trains; however, two burst detection techniques, the MaxInterval and logISI methods, outperform compared with others. We provide recommendations for the robust analysis of bursting activity in experimental recordings using current techniques. PMID:27098024
On the Exploitation of Sensitivity Derivatives for Improving Sampling Methods
NASA Technical Reports Server (NTRS)
Cao, Yanzhao; Hussaini, M. Yousuff; Zang, Thomas A.
2003-01-01
Many application codes, such as finite-element structural analyses and computational fluid dynamics codes, are capable of producing many sensitivity derivatives at a small fraction of the cost of the underlying analysis. This paper describes a simple variance reduction method that exploits such inexpensive sensitivity derivatives to increase the accuracy of sampling methods. Three examples, including a finite-element structural analysis of an aircraft wing, are provided that illustrate an order of magnitude improvement in accuracy for both Monte Carlo and stratified sampling schemes.
Shelley, Brandon C.; Gowing, Geneviève; Svendsen, Clive N.
2014-01-01
A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as “chopping” that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products. PMID:24962813
Shelley, Brandon C; Gowing, Geneviève; Svendsen, Clive N
2014-01-01
A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as "chopping" that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products. PMID:24962813
Computational Methods for Dynamic Stability and Control Derivatives
NASA Technical Reports Server (NTRS)
Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.
2003-01-01
Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.
Computational Methods for Dynamic Stability and Control Derivatives
NASA Technical Reports Server (NTRS)
Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.
2004-01-01
Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.
A Discretized Method for Deriving Vortex Impulse from Volumetric Datasets
NASA Astrophysics Data System (ADS)
Buckman, Noam; Mendelson, Leah; Techet, Alexandra
2015-11-01
Many biological and mechanical systems transfer momentum through a fluid by creating vortical structures. To study this mechanism, we derive a method for extracting impulse and its time derivative from flow fields observed in experiments and simulations. We begin by discretizing a thin-cored vortex filament, and extend the model to account for finite vortex core thickness and asymmetric distributions of vorticity. By solely using velocity fields to extract vortex cores and calculate circulation, this method is applicable to 3D PIV datasets, even with low spatial resolution flow fields and measurement noise. To assess the performance of this analysis method, we simulate vortex rings and arbitrary vortex structures using OpenFOAM computational fluid dynamics software and analyze the wake momentum using this model in order to validate this method. We further examine a piston-vortex experiment, using 3D synthetic particle image velocimetry (SAPIV) to capture velocity fields. Strengths, limitations, and improvements to the framework are discussed.
Ansari, Fatemeh; Ghaedi, Mehrorang; Taghdiri, Mehdi; Asfaram, Arash
2016-11-01
A method based on application of ZnO nanorods loaded on activated carbon (ZnO-NRs-AC) for adsorption of Bromocresol Green (BCG) and Eosin Y (EY) accelerated by ultrasound was described. The present material was synthesized under ultrasound assisted wet-chemical method and subsequently was characterized by FE-SEM, TEM, BET and XRD analysis. The extent of contribution of conventional variables like pH (2.0-10.0), BCG concentration (4-20mgL(-1)), EY concentration (3-23mgL(-1)), adsorbent dosage (0.01-0.03g), sonication time (1-5min) and centrifuge time (2-6min) as main and interaction part were investigated by central composite design under response surface methodology. Analysis of variance (ANOVA) was adapted to experimental data and guide the best operational conditions mass by set at 6.0, 9mgL(-1), 10mgL(-1), 0.02g, 4 and 4min for pH, BCG concentration, EY concentration, adsorbent dosage, sonication and centrifuge time, respectively. At these specified conditions dye adsorption efficiency was higher than 99.5%. The suitability and well prediction of optimum point was tested by conducting five experiments and respective results revel that RSD% was lower than 3% and high quality of fitting was confirmed by t-test. The experimental data were best fitted in Langmuir isotherm equation and the removal followed pseudo second order kinetics. The experimentally obtained maximum adsorption capacities were estimated as 57.80 and 61.73mgg(-1) of ZnO-NRs-AC for BCG and EY respectively from binary dye solutions. The mechanism of removal was explained by boundary layer diffusion via intraparticle diffusion. PMID:27245971
System and method for deriving a process-based specification
NASA Technical Reports Server (NTRS)
Hinchey, Michael Gerard (Inventor); Rash, James Larry (Inventor); Rouff, Christopher A. (Inventor)
2009-01-01
A system and method for deriving a process-based specification for a system is disclosed. The process-based specification is mathematically inferred from a trace-based specification. The trace-based specification is derived from a non-empty set of traces or natural language scenarios. The process-based specification is mathematically equivalent to the trace-based specification. Code is generated, if applicable, from the process-based specification. A process, or phases of a process, using the features disclosed can be reversed and repeated to allow for an interactive development and modification of legacy systems. The process is applicable to any class of system, including, but not limited to, biological and physical systems, electrical and electro-mechanical systems in addition to software, hardware and hybrid hardware-software systems.
Empirical Distributional Semantics: Methods and Biomedical Applications
Cohen, Trevor; Widdows, Dominic
2009-01-01
Over the past fifteen years, a range of methods have been developed that are able to learn human-like estimates of the semantic relatedness between terms from the way in which these terms are distributed in a corpus of unannotated natural language text. These methods have also been evaluated in a number of applications in the cognitive science, computational linguistics and the information retrieval literatures. In this paper, we review the available methodologies for derivation of semantic relatedness from free text, as well as their evaluation in a variety of biomedical and other applications. Recent methodological developments, and their applicability to several existing applications are also discussed. PMID:19232399
Advancing MODFLOW Applying the Derived Vector Space Method
NASA Astrophysics Data System (ADS)
Herrera, G. S.; Herrera, I.; Lemus-García, M.; Hernandez-Garcia, G. D.
2015-12-01
The most effective domain decomposition methods (DDM) are non-overlapping DDMs. Recently a new approach, the DVS-framework, based on an innovative discretization method that uses a non-overlapping system of nodes (the derived-nodes), was introduced and developed by I. Herrera et al. [1, 2]. Using the DVS-approach a group of four algorithms, referred to as the 'DVS-algorithms', which fulfill the DDM-paradigm (i.e. the solution of global problems is obtained by resolution of local problems exclusively) has been derived. Such procedures are applicable to any boundary-value problem, or system of such equations, for which a standard discretization method is available and then software with a high degree of parallelization can be constructed. In a parallel talk, in this AGU Fall Meeting, Ismael Herrera will introduce the general DVS methodology. The application of the DVS-algorithms has been demonstrated in the solution of several boundary values problems of interest in Geophysics. Numerical examples for a single-equation, for the cases of symmetric, non-symmetric and indefinite problems were demonstrated before [1,2]. For these problems DVS-algorithms exhibited significantly improved numerical performance with respect to standard versions of DDM algorithms. In view of these results our research group is in the process of applying the DVS method to a widely used simulator for the first time, here we present the advances of the application of this method for the parallelization of MODFLOW. Efficiency results for a group of tests will be presented. References [1] I. Herrera, L.M. de la Cruz and A. Rosas-Medina. Non overlapping discretization methods for partial differential equations, Numer Meth Part D E, (2013). [2] Herrera, I., & Contreras Iván "An Innovative Tool for Effectively Applying Highly Parallelized Software To Problems of Elasticity". Geofísica Internacional, 2015 (In press)
Environmental applications of chitosan and its derivatives.
Yong, Soon Kong; Shrivastava, Manoj; Srivastava, Prashant; Kunhikrishnan, Anitha; Bolan, Nanthi
2015-01-01
Chitosan originates from the seafood processing industry and is one of the most abundant of bio-waste materials. Chitosan is a by-product of the alkaline deacetylation process of chitin. Chemically, chitosan is a polysaccharide that is soluble in acidic solution and precipitates at higher pHs. It has great potential for certain environmental applications, such as remediation of organic and inorganic contaminants, including toxic metals and dyes in soil, sediment and water, and development of contaminant sensors. Traditionally, seafood waste has been the primary source of chitin. More recently, alternative sources have emerged such as fungal mycelium, mushroom and krill wastes, and these new sources of chitin and chitosan may overcome seasonal supply limitations that have existed. The production of chitosan from the above-mentioned waste streams not only reduces waste volume, but alleviates pressure on landfills to which the waste would otherwise go. Chitosan production involves four major steps, viz., deproteination, demineralization, bleaching and deacetylation. These four processes require excessive usage of strong alkali at different stages, and drives chitosan's production cost up, potentially making the application of high-grade chitosan for commercial remediation untenable. Alternate chitosan processing techniques, such as microbial or enzymatic processes, may become more cost-effective due to lower energy consumption and waste generation. Chitosan has proved to be versatile for so many environmental applications, because it possesses certain key functional groups, including - OH and -NH2 . However, the efficacy of chitosan is diminished at low pH because of its increased solubility and instability. These deficiencies can be overcome by modifying chitosan's structure via crosslinking. Such modification not only enhances the structural stability of chitosan under low pH conditions, but also improves its physicochemical characteristics, such as porosity
NASA Astrophysics Data System (ADS)
Dias, B.; Barbuy, B.; Saviane, I.; Held, E. V.; Da Costa, G. S.; Ortolani, S.; Vasquez, S.; Gullieuszik, M.; Katz, D.
2015-01-01
Context. We have observed almost one third of the globular clusters in the Milky Way, targeting distant and/or highly reddened objects, as well as a few reference clusters. A large sample of red giant stars was observed with FORS2 at VLT/ESO at R ~ 2000. The method for deriving stellar parameters is presented with application to six reference clusters. Aims: We aim at deriving the stellar parameters effective temperature, gravity, metallicity, and alpha-element enhancement as well as the radial velocity to confirm the membership of individual stars in each cluster. We analyse the spectra collected for the reference globular clusters NGC 6528 ([Fe/H] ~-0.1), NGC 6553 ([Fe/H] ~-0.2), M 71 ([Fe/H] ~-0.8), NGC 6558 ([Fe/H] ~-1.0), NGC 6426 ([Fe/H] ~-2.1), and Terzan 8 ([Fe/H] ~-2.2). They cover the full range of globular cluster metallicities, and are located in the bulge, disc, and halo. Methods: Full spectrum-fitting techniques were applied by comparing each target spectrum with a stellar library in the optical region at 4560-5860 Å. We employed the library of observed spectra MILES, and the Coelho synthetic library. We validated the method by recovering the known atmospheric parameters for 49 well-studied stars that cover a wide range in the parameter space. We adopted as final stellar parameters (effective temperatures, gravities, metallicities) the average of results using the observed and synthetic spectral libraries. Results: We identified 4 member stars in NGC 6528, 13 in NGC 6553, 10 in M 71, 5 in NGC 6558, 5 in NGC 6426, and 12 in Terzan 8. Radial velocities, Teff, log(g), [Fe/H], and alpha-element enhancements were derived. We derived ⟨ vhelio ⟩ = -242 ± 11 km s-1, [Fe/H] = - 2.39 ± 0.04, [Mg/Fe] = 0.38 ± 0.06 for NGC 6426 from spectroscopy for the first time. Conclusions: The method proved to be reliable for red giant stars observed with resolution R ~ 2000, yielding results compatible with high-resolution spectroscopy. The derived
An Adaptive Derivative-based Method for Function Approximation
Tong, C
2008-10-22
To alleviate the high computational cost of large-scale multi-physics simulations to study the relationships between the model parameters and the outputs of interest, response surfaces are often used in place of the exact functional relationships. This report explores a method for response surface construction using adaptive sampling guided by derivative information at each selected sample point. This method is especially suitable for applications that can readily provide added information such as gradients and Hessian with respect to the input parameters under study. When higher order terms (third and above) in the Taylor series are negligible, the approximation error for this method can be controlled. We present details of the adaptive algorithm and numerical results on a few test problems.
The discrete variational derivative method based on discrete differential forms
NASA Astrophysics Data System (ADS)
Yaguchi, Takaharu; Matsuo, Takayasu; Sugihara, Masaaki
2012-05-01
As is well known, for PDEs that enjoy a conservation or dissipation property, numerical schemes that inherit this property are often advantageous in that the schemes are fairly stable and give qualitatively better numerical solutions in practice. Lately, Furihata and Matsuo have developed the so-called “discrete variational derivative method” that automatically constructs energy preserving or dissipative finite difference schemes. Although this method was originally developed on uniform meshes, the use of non-uniform meshes is of importance for multi-dimensional problems. On the other hand, the theories of discrete differential forms have received much attention recently. These theories provide a discrete analogue of the vector calculus on general meshes. In this paper, we show that the discrete variational derivative method and the discrete differential forms by Bochev and Hyman can be combined. Applications to the Cahn-Hilliard equation and the Klein-Gordon equation on triangular meshes are provided as demonstrations. We also show that the schemes for these equations are H1-stable under some assumptions. In particular, one for the nonlinear Klein-Gordon equation is obtained by combination of the energy conservation property and the discrete Poincaré inequality, which are the temporal and spacial structures that are preserved by the above methods.
Methods for synthesis of olefins and derivatives
Burk, Mark J.; Pharkya, Priti; Van Dien, Stephen J.; Burgard, Anthony P.; Schilling, Christophe H.
2016-06-14
The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.
Methods for deoxygenating biomass-derived pyrolysis oil
Brandvold, Timothy A.
2015-07-14
Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method comprising the steps of diluting the biomass-derived pyrolysis oil with a phenolic-containing diluent to form a diluted pyoil-phenolic feed is provided. The diluted pyoil-phenolic feed is contacted with a deoxygenating catalyst in the presence of hydrogen at hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.
Bacteriophages and Phage-Derived Proteins – Application Approaches
Drulis-Kawa, Zuzanna; Majkowska-Skrobek, Grazyna; Maciejewska, Barbara
2015-01-01
Currently, the bacterial resistance, especially to most commonly used antibiotics has proved to be a severe therapeutic problem. Nosocomial and community-acquired infections are usually caused by multidrug resistant strains. Therefore, we are forced to develop an alternative or supportive treatment for successful cure of life-threatening infections. The idea of using natural bacterial pathogens such as bacteriophages is already well known. Many papers have been published proving the high antibacterial efficacy of lytic phages tested in animal models as well as in the clinic. Researchers have also investigated the application of non-lytic phages and temperate phages, with promising results. Moreover, the development of molecular biology and novel generation methods of sequencing has opened up new possibilities in the design of engineered phages and recombinant phage-derived proteins. Encouraging performances were noted especially for phage enzymes involved in the first step of viral infection responsible for bacterial envelope degradation, named depolymerases. There are at least five major groups of such enzymes – peptidoglycan hydrolases, endosialidases, endorhamnosidases, alginate lyases and hyaluronate lyases – that have application potential. There is also much interest in proteins encoded by lysis cassette genes (holins, endolysins, spanins) responsible for progeny release during the phage lytic cycle. In this review, we discuss several issues of phage and phage-derived protein application approaches in therapy, diagnostics and biotechnology in general. PMID:25666799
Bacteriophages and phage-derived proteins--application approaches.
Drulis-Kawa, Zuzanna; Majkowska-Skrobek, Grazyna; Maciejewska, Barbara
2015-01-01
Currently, the bacterial resistance, especially to most commonly used antibiotics has proved to be a severe therapeutic problem. Nosocomial and community-acquired infections are usually caused by multidrug resistant strains. Therefore, we are forced to develop an alternative or supportive treatment for successful cure of life-threatening infections. The idea of using natural bacterial pathogens such as bacteriophages is already well known. Many papers have been published proving the high antibacterial efficacy of lytic phages tested in animal models as well as in the clinic. Researchers have also investigated the application of non-lytic phages and temperate phages, with promising results. Moreover, the development of molecular biology and novel generation methods of sequencing has opened up new possibilities in the design of engineered phages and recombinant phage-derived proteins. Encouraging performances were noted especially for phage enzymes involved in the first step of viral infection responsible for bacterial envelope degradation, named depolymerases. There are at least five major groups of such enzymes - peptidoglycan hydrolases, endosialidases, endorhamnosidases, alginate lyases and hyaluronate lyases - that have application potential. There is also much interest in proteins encoded by lysis cassette genes (holins, endolysins, spanins) responsible for progeny release during the phage lytic cycle. In this review, we discuss several issues of phage and phage-derived protein application approaches in therapy, diagnostics and biotechnology in general. PMID:25666799
Methods for deoxygenating biomass-derived pyrolysis oil
Baird, Lance Awender; Brandvold, Timothy A.
2015-06-30
Methods for deoxygenating a biomass-derived pyrolysis oil are provided. A method for deoxygenating a biomass-derived pyrolysis oil comprising the steps of combining a biomass-derived pyrolysis oil stream with a heated low-oxygen-pyoil diluent recycle stream to form a heated diluted pyoil feed stream is provided. The heated diluted pyoil feed stream has a feed temperature of about 150.degree. C. or greater. The heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen at first hydroprocessing conditions effective to form a low-oxygen biomass-derived pyrolysis oil effluent.
Deriving and applying generally applicable safety principles
Spray, S.D.
1998-08-01
The nuclear detonation safety of modern nuclear weapons depends on a coordinated safety theme incorporating three general safety principles: isolation, inoperability, and incompatibility. The success of this approach has encouraged them to study whether these and/or other principles might be useful in other applications. Not surprisingly, no additional first-principles (based on physical laws) have been identified. However, a more widely applicable definition and application of the principle-based approach has been developed, resulting in a selection of strategies that are basically subsets and varied combinations of the more general principles above. However, identification of principles to be relied on is only one step in providing a safe design. As one other important example, coordinating overall architecture and strategy is essential: the authors term this a safety theme.
Strigolactone derivatives for potential crop enhancement applications.
Screpanti, Claudio; Fonné-Pfister, Raymonde; Lumbroso, Alexandre; Rendine, Stefano; Lachia, Mathilde; De Mesmaeker, Alain
2016-05-15
New technologies able to mitigate the main abiotic stresses (i.e., drought, salinity, cold and heat) represent a substantial opportunity to contribute to a sustainable increase of agricultural production. In this context, the recently discovered phytohormone strigolactone is an important area of study which can underpin the quest for new anti-stress technologies. The pleiotropic roles played by strigolactones in plant growth/development and in plant adaptation to environmental changes can pave the way for new innovative crop enhancement applications. Although a significant scientific effort has been dedicated to the strigolactone subject, an updated review with emphasis on the crop protection perspective was missing. This paper aims to analyze the advancement in different areas of the strigolactone domain and the implications for agronomical applications. PMID:27036522
Logarithmic derivative method and system for capacitance measurement.
Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao
2015-08-01
A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10(-8) s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes. PMID:26329235
Logarithmic derivative method and system for capacitance measurement
NASA Astrophysics Data System (ADS)
Wu, Yichun; Wang, Lingzhi; Cai, Yuanfeng; Wu, Cunqiao
2015-08-01
A novel method based on logarithmic derivative is introduced to analyze multi-lifetime decay. As the discharge voltage signal of a RC circuit is a special kind of multi-lifetime exponential decay, the logarithmic derivative method can be used to measure single capacitance and multiple capacitances. With the logarithmic derivative method, a log(t) curve strongly peaked at precisely log(τ) is obtained, where the lifetime τ equals to RC. In a measurement system, if the resistance R is known, then the capacitance under test can be calculated. A logarithmic derivative curve fitting method is also presented, which has better anti-noise capability than the method that simply finds the maximum data on the peak. The curve fitting method can also be used for multiple capacitors measurement. To measure small capacitances, a large enough time window of the measuring instrument is required. Based on a field programmable gate array and a high speed analog-to-digital converter, a measurement system is developed. This system can provide the 16-bit resolution with sampling rate up to 250 MHz, which has a large enough time window for measuring lifetime shorter than 10-8 s. To reduce the amount of data needed to be stored and the noise due to the derivative treatment of transient data, the interpolation and noise-filter algorithms are employed. Experiments indicate that the logarithmic derivative method and system are suitable for the measurement of capacitances discharge and other exponential decay processes.
Review of methods to derive a Polar Cap (PC) index.
NASA Astrophysics Data System (ADS)
Stauning, Peter
2016-07-01
Since a Polar Cap (PC) index was introduced in 1985, several different methods have been used to derive index values. Basically, the northern (PCN) and southern (PCS) are based on geomagnetic recordings at Qaanaaq (Thule) and Vostok, respectively. However, different derivation methods can give index values differing by more than a factor 2. The PC indices are used, among other, in scientific analyses to link solar wind conditions to relevant geophysical effects and in forecast efforts to establish numerical criteria for imminent risk of geomagnetic storms and substorms. Thus, it is unfortunate that several different versions of the PC index have been in use, often without specifically mentioning the index version being used or without ensuring that proper documention and specification of the derivation method is available. The presentation shall briefly describe the basic calculation of a Polar Cap index and point specifically to the differences between the different derivation methods and to the consequences for the index values
ERIC Educational Resources Information Center
Kleppinger, E. W.; And Others
1984-01-01
Although determination of phosphorus is important in biology, physiology, and environmental science, traditional gravimetric and colorimetric methods are cumbersome and lack the requisite sensitivity. Therefore, a derivative activation analysis method is suggested. Background information, procedures, and results are provided. (JN)
An improved method to derive periods of cyclic phenomena
NASA Astrophysics Data System (ADS)
Marraco, H. G.; Muzzio, J. C.
1980-10-01
Two simple improvements are presented to Jurkevich's method (1971) for deriving periods of variable stars; the method is particularly useful when large numbers of observations are available. An example (the case of HD 217792) of the results of both the original and improved methods is presented.
Comparison of several methods for estimating low speed stability derivatives
NASA Technical Reports Server (NTRS)
Fletcher, H. S.
1971-01-01
Methods presented in five different publications have been used to estimate the low-speed stability derivatives of two unpowered airplane configurations. One configuration had unswept lifting surfaces, the other configuration was the D-558-II swept-wing research airplane. The results of the computations were compared with each other, with existing wind-tunnel data, and with flight-test data for the D-558-II configuration to assess the relative merits of the methods for estimating derivatives. The results of the study indicated that, in general, for low subsonic speeds, no one text appeared consistently better for estimating all derivatives.
Chitooligosaccharide and Its Derivatives: Preparation and Biological Applications
Lodhi, Gaurav; Hwang, Jin-Woo; Kim, Se-Kwon; Jeon, You-Jin; Je, Jae-Young; Ahn, Chang-Bum; Moon, Sang-Ho; Jeon, Byong-Tae; Park, Pyo-Jam
2014-01-01
Chitin is a natural polysaccharide of major importance. This biopolymer is synthesized by an enormous number of living organisms; considering the amount of chitin produced annually in the world, it is the most abundant polymer after cellulose. The most important derivative of chitin is chitosan, obtained by partial deacetylation of chitin under alkaline conditions or by enzymatic hydrolysis. Chitin and chitosan are known to have important functional activities but poor solubility makes them difficult to use in food and biomedicinal applications. Chitooligosaccharides (COS) are the degraded products of chitosan or chitin prepared by enzymatic or chemical hydrolysis of chitosan. The greater solubility and low viscosity of COS have attracted the interest of many researchers to utilize COS and their derivatives for various biomedical applications. In light of the recent interest in the biomedical applications of chitin, chitosan, and their derivatives, this review focuses on the preparation and biological activities of chitin, chitosan, COS, and their derivatives. PMID:24724091
Application of Statistically Derived CPAS Parachute Parameters
NASA Technical Reports Server (NTRS)
Romero, Leah M.; Ray, Eric S.
2013-01-01
The Capsule Parachute Assembly System (CPAS) Analysis Team is responsible for determining parachute inflation parameters and dispersions that are ultimately used in verifying system requirements. A model memo is internally released semi-annually documenting parachute inflation and other key parameters reconstructed from flight test data. Dispersion probability distributions published in previous versions of the model memo were uniform because insufficient data were available for determination of statistical based distributions. Uniform distributions do not accurately represent the expected distributions since extreme parameter values are just as likely to occur as the nominal value. CPAS has taken incremental steps to move away from uniform distributions. Model Memo version 9 (MMv9) made the first use of non-uniform dispersions, but only for the reefing cutter timing, for which a large number of sample was available. In order to maximize the utility of the available flight test data, clusters of parachutes were reconstructed individually starting with Model Memo version 10. This allowed for statistical assessment for steady-state drag area (CDS) and parachute inflation parameters such as the canopy fill distance (n), profile shape exponent (expopen), over-inflation factor (C(sub k)), and ramp-down time (t(sub k)) distributions. Built-in MATLAB distributions were applied to the histograms, and parameters such as scale (sigma) and location (mu) were output. Engineering judgment was used to determine the "best fit" distribution based on the test data. Results include normal, log normal, and uniform (where available data remains insufficient) fits of nominal and failure (loss of parachute and skipped stage) cases for all CPAS parachutes. This paper discusses the uniform methodology that was previously used, the process and result of the statistical assessment, how the dispersions were incorporated into Monte Carlo analyses, and the application of the distributions in
Deriving average soliton equations with a perturbative method
Ballantyne, G.J.; Gough, P.T.; Taylor, D.P. )
1995-01-01
The method of multiple scales is applied to periodically amplified, lossy media described by either the nonlinear Schroedinger (NLS) equation or the Korteweg--de Vries (KdV) equation. An existing result for the NLS equation, derived in the context of nonlinear optical communications, is confirmed. The method is then applied to the KdV equation and the result is confirmed numerically.
Advanced composite applications for sub-micron biologically derived microstructures
NASA Technical Reports Server (NTRS)
Schnur, J. M.; Price, R. R.; Schoen, P. E.; Bonanventura, Joseph; Kirkpatrick, Douglas
1991-01-01
A major thrust of advanced material development is in the area of self-assembled ultra-fine particulate based composites (micro-composites). The application of biologically derived, self-assembled microstructures to form advanced composite materials is discussed. Hollow 0.5 micron diameter cylindrical shaped microcylinders self-assemble from diacetylenic lipids. These microstructures have a multiplicity of potential applications in the material sciences. Exploratory development is proceeding in application areas such as controlled release for drug delivery, wound repair, and biofouling as well as composites for electronic and magnetic applications, and high power microwave cathodes.
NASA Astrophysics Data System (ADS)
Hoffman, Adam J.; Lee, John C.
2016-02-01
A new time-dependent Method of Characteristics (MOC) formulation for nuclear reactor kinetics was developed utilizing angular flux time-derivative propagation. This method avoids the requirement of storing the angular flux at previous points in time to represent a discretized time derivative; instead, an equation for the angular flux time derivative along 1D spatial characteristics is derived and solved concurrently with the 1D transport characteristic equation. This approach allows the angular flux time derivative to be recast principally in terms of the neutron source time derivatives, which are approximated to high-order accuracy using the backward differentiation formula (BDF). This approach, called Source Derivative Propagation (SDP), drastically reduces the memory requirements of time-dependent MOC relative to methods that require storing the angular flux. An SDP method was developed for 2D and 3D applications and implemented in the computer code DeCART in 2D. DeCART was used to model two reactor transient benchmarks: a modified TWIGL problem and a C5G7 transient. The SDP method accurately and efficiently replicated the solution of the conventional time-dependent MOC method using two orders of magnitude less memory.
Hemon, Mathilde C; Phillips, Justin P
2016-04-01
The suitability of different methods of finding the foot point of a pulse as measured using earlobe photoplethysmography during stationary conditions was investigated. Instantaneous pulse period (PP) values from PPG signals recorded from the ear in healthy volunteer subjects were compared with simultaneous ECG-derived cardiac periods (RR interval). Six methods of deriving pulse period were used, each based on a different method of finding specific landmark points on the PPG waveform. These methods included maximum and minimum value, maximum first and second derivative, 'intersecting tangents' and 'diastole patching' methods. Selected time domain HRV variables were also calculated from the PPG signals obtained using multiple methods and compared with ECG-derived HRV variables. The correlation between PPG and ECG was greatest for the intersecting tangents method compared to the other methods (RMSE = 5.69 ms, r (2) = 0.997). No significant differences between PP and RR were seen for all PPG methods, however the PRV variables derived using all methods showed significant differences to HRV, attributable to the sensitivity of PRV parameters to pulse transients and artifacts. The results suggest that the intersecting tangents method shows the most promise for extracting accurate pulse rate variability data from PPG datasets. This work has applications in other areas where pulse arrival time is a key measurement including pulse wave velocity assessment. PMID:25902897
Methods and apparatuses for deoxygenating biomass-derived pyrolysis oil
Baird, Lance Awender; Brandvold, Timothy A.
2015-10-20
Embodiments of methods and apparatuses for deoxygenating a biomass-derived pyrolysis oil are provided. In one example, a method comprises the steps of separating a low-oxygen biomass-derived pyrolysis oil effluent into a low-oxygen-pyoil organic phase stream and an aqueous phase stream. Phenolic compounds are removed from the aqueous phase stream to form a phenolic-rich diluent recycle stream. A biomass-derived pyrolysis oil stream is diluted and heated with the phenolic-rich diluent recycle stream to form a heated diluted pyoil feed stream. The heated diluted pyoil feed stream is contacted with a deoxygenating catalyst in the presence of hydrogen to deoxygenate the heated diluted pyoil feed stream.
A method for deriving leading causes of death.
Becker, Roberto; Silvi, John; Ma Fat, Doris; L'Hours, André; Laurenti, Ruy
2006-01-01
OBJECTIVE: A standard list for ranking leading causes of death worldwide does not exist. WHO headquarters, regional offices and Member States all use different lists that have varying levels of detail. We sought to derive a standard list to enable countries to identify their leading causes of death and to permit comparison between countries. Our aim is to share the criteria and methodology we used to bring some order to the construction of such a list, to provide a consistent procedure that can be used by others, and to give researchers and data owners an opportunity to utilize the list at national and subnational levels. METHODS: Results were primarily data-driven. Data from individual countries representing different regions of the world were extracted from the WHO Mortality Database. Supplementary information from WHO estimates on mortality was used for regions where data were scarce. In addition, a set of criteria was used to group the candidate causes and to determine other causes that should be included on the list. FINDINGS: A ranking list of the leading causes of death that contains broad cause groupings (such as "all cancers", "all heart diseases" or "all accidents") is not effective and does not identify the leading individual causes within these broad groupings; thus it does not allow policy-makers to generate appropriate health advocacy and cost-effective interventions. Similarly, defining candidate causal groups too narrowly or including diseases that have a low frequency does not meet these objectives. CONCLUSION: For international comparisons, we recommend that countries use this list; it is based on extensive evidence and the application of public health disease-prevention criteria. It is not driven by political or financial motives. This list may be adapted for national statistical purposes. PMID:16628303
The Antibacterial Applications of Graphene and Its Derivatives.
Shi, Lin; Chen, Jiongrun; Teng, Lijing; Wang, Lin; Zhu, Guanglin; Liu, Sa; Luo, Zhengtang; Shi, Xuetao; Wang, Yingjun; Ren, Li
2016-08-01
Graphene materials have unique structures and outstanding thermal, optical, mechanical and electronic properties. In the last decade, these materials have attracted substantial interest in the field of nanomaterials, with applications ranging from biosensors to biomedicine. Among these applications, great advances have been made in the field of antibacterial agents. Here, recent advancements in the use of graphene and its derivatives as antibacterial agents are reviewed. Graphene is used in three forms: the pristine form; mixed with other antibacterial agents, such as Ag and chitosan; or with a base material, such as poly (N-vinylcarbazole) (PVK) and poly (lactic acid) (PLA). The main mechanisms proposed to explain the antibacterial behaviors of graphene and its derivatives are the membrane stress hypothesis, the oxidative stress hypothesis, the entrapment hypothesis, the electron transfer hypothesis and the photothermal hypothesis. This review describes contributions to improving these promising materials for antibacterial applications. PMID:27389848
Clabo, D.A. Jr.
1987-04-01
Inclusion of the anharmonicity normal mode vibrations (i.e., the third and fourth (and higher) derivatives of a molecular Born-Oppenheimer potential energy surface) is necessary in order to theoretically reproduce experimental fundamental vibrational frequencies of a molecule. Although ab initio determinations of harmonic vibrational frequencies may give errors of only a few percent by the inclusion of electron correlation within a large basis set for small molecules, in general, molecular fundamental vibrational frequencies are more often available from high resolution vibration-rotation spectra. Recently developed analytic third derivatives methods for self-consistent-field (SCF) wavefunctions have made it possible to examine with previously unavailable accuracy and computational efficiency the anharmonic force fields of small molecules.
NASA Astrophysics Data System (ADS)
Khabashesku, Valery N.
2011-08-01
Chemical methods for preparation of fluorinated carbon nanotubes and their functional derivatives published over the last 10-15 years are considered in detail and critically analyzed. Fluorinated carbon nanotube derivatives represent a new family of nanoscale fluorocarbon materials promising new applications in nanocomposites, sensors, nanoelectronic devices, nanoengineered drug delivery systems and lubricants. The bibliography includes 166 references. Dedicated to Academician O M Nefedov on occasion of his 80th birthday.
Potential applications of keratinocytes derived from human embryonic stem cells.
Movahednia, Mohammad M; Kidwai, Fahad K; Jokhun, Doorgesh S; Squier, Christopher A; Toh, Wei Seong; Cao, Tong
2016-01-01
Although skin grafting is one of the most advanced cell therapy technique, wide application of skin substitutes is hampered by the difficulty in securing sufficient amount of epidermal substitute. Additionally, in understanding the progression of skin aging and disease, and in screening the cosmetic and pharmaceutical products, there is lack of a satisfactory human skin-specific in vitro model. Recently, human embryonic stem cells (hESCs) have been proposed as an unlimited and reliable cell source to obtain almost all cell types present in the human body. This review focuses on the potential off-the-shelf use of hESC-derived keratinocytes for future clinical applications as well as a powerful in vitro skin model to study skin function and integrity, host-pathogen interactions and disease pathogenesis. Furthermore, we discuss the industrial applications of hESC-derived keratinized multi-layer epithelium which provides a human-like test platform for understanding disease pathogenesis, evaluation of new therapeutic modalities and assessment of the safety and efficacy of skin cosmetics and therapeutics. Overall, we conclude that the hESC-derived keratinocytes have great potential for clinical, research and industrial applications. PMID:26663861
Apparatuses and methods for deoxygenating biomass-derived pyrolysis oil
Kalnes, Tom N.
2015-12-29
Apparatuses and methods for deoxygenating a biomass-derived pyrolysis oil are provided herein. In one example, the method comprises of dividing a feedstock stream into first and second feedstock portions. The feedstock stream comprises the biomass-derived pyrolysis oil and has a temperature of about 60.degree. C. or less. The first feedstock portion is combined with a heated organic liquid stream to form a first heated diluted pyoil feed stream. The first heated diluted pyoil feed stream is contacted with a first deoxygenating catalyst in the presence of hydrogen to form an intermediate low-oxygen pyoil effluent. The second feedstock portion is combined with the intermediate low-oxygen pyoil effluent to form a second heated diluted pyoil feed stream. The second heated diluted pyoil feed stream is contacted with a second deoxygenating catalyst in the presence of hydrogen to form additional low-oxygen pyoil effluent.
METHOD FOR PRODUCING ISOTOPIC METHANES AND PARTIALLY HALOGENATED DERIVATIVES THEROF
Frazer, J.W.
1959-08-18
A method is given for producing isotopic methanes and/ or partially halogenated derivatives. Lithium hydride, deuteride, or tritide is reacted with a halogenated methane or with a halogenated methane in combination with free halogen. The process is conveniently carried out by passing a halogenated methane preferably at low pressures or in an admixture with an inert gas through a fixed bed of finely divided lithium hydride heated initially to temperatures of 100 to 200 deg C depending upon the halogenated methane used.
Amnion-derived stem cells: in quest of clinical applications
2011-01-01
In the promising field of regenerative medicine, human perinatal stem cells are of great interest as potential stem cells with clinical applications. Perinatal stem cells could be isolated from normally discarded human placentae, which are an ideal cell source in terms of availability, the fewer number of ethical concerns, less DNA damage, and so on. Numerous studies have demonstrated that some of the placenta-derived cells possess stem cell characteristics like pluripotent differentiation ability, particularly in amniotic epithelial (AE) cells. Term human amniotic epithelium contains a relatively large number of stem cell marker-positive cells as an adult stem cell source. In this review, we introduce a model theory of why so many AE cells possess stem cell characteristics. We also describe previous work concerning the therapeutic applications and discuss the pluripotency of the AE cells and potential pitfalls for amnion-derived stem cell research. PMID:21596003
Aguerssif, Nadia; Benamor, Mohamed; Kachbi, Malek; Draa, Mohamed Tahar
2008-01-01
Derivative spectrophotometry (graphical method) and partial least-squares regression (numerical method) methods were developed for the spectrophotometric multi-component analysis of post-haemodialysis fluids and synthetic mixtures containing Al(III) and Fe(III) without any chemical separation. The complexes of these metal ions with chrome azurol S were formed immediately at pH 5.5 and were stable for at least 3h. The graphical method is based on the use of first-derivative spectra for evaluation because working wavelength determination was more precise and spectral overlap was less than in the ordinary spectra. Two wavelengths at which the complexes exhibited maximum absorption values for Fe(III) and Al(III) were selected as analytical wavelengths, i.e., 675 and 623.5 nm, respectively. Lambert-Beer's law is obeyed between 0.0896-8.064 microg/mL Fe(III) and 0.054-0.486 microg/mL Al(III). Limits of detection for Fe(III) and Al(III) were 0.056 and 0.044 microg/mL, respectively. The reproducibility, expressed as variation coefficients, for two sets of 10 standard mixtures containing 3.584 microg/mL Fe(III) and 0.27 microg/mL Al(III) were 1.9% and 2% for iron and aluminium, respectively. In the numerical method, a training set was randomly prepared by using 14 samples. The concentration of each component has been varied in the linear range of the analytical signal. The spectral regions between 510 and 720 nm were selected for the analysis of the binary mixture of Fe(III)/Al(III). The proposed methods were validated by using synthetic binary mixtures and applied to the simultaneous determination of Fe(III) and Al(III) in post-haemodialysis samples. The obtained results were compared with each other; in general, both multi-component methods gave rise to similar recovery results for laboratory-prepared mixtures and real samples. PMID:18755392
The Enterprise Derivative Application: Flexible Software for Optimizing Manufacturing Processes
Ward, Richard C; Allgood, Glenn O; Knox, John R
2008-11-01
The Enterprise Derivative Application (EDA) implements the enterprise-derivative analysis for optimization of an industrial process (Allgood and Manges, 2001). It is a tool to help industry planners choose the most productive way of manufacturing their products while minimizing their cost. Developed in MS Access, the application allows users to input initial data ranging from raw material to variable costs and enables the tracking of specific information as material is passed from one process to another. Energy-derivative analysis is based on calculation of sensitivity parameters. For the specific application to a steel production process these include: the cost to product sensitivity, the product to energy sensitivity, the energy to efficiency sensitivity, and the efficiency to cost sensitivity. Using the EDA, for all processes the user can display a particular sensitivity or all sensitivities can be compared for all processes. Although energy-derivative analysis was originally designed for use by the steel industry, it is flexible enough to be applied to many other industrial processes. Examples of processes where energy-derivative analysis would prove useful are wireless monitoring of processes in the petroleum cracking industry and wireless monitoring of motor failure for determining the optimum time to replace motor parts. One advantage of the MS Access-based application is its flexibility in defining the process flow and establishing the relationships between parent and child process and products resulting from a process. Due to the general design of the program, a process can be anything that occurs over time with resulting output (products). So the application can be easily modified to many different industrial and organizational environments. Another advantage is the flexibility of defining sensitivity parameters. Sensitivities can be determined between all possible variables in the process flow as a function of time. Thus the dynamic development of the
Entrepreneur environment management behavior evaluation method derived from environmental economy.
Zhang, Lili; Hou, Xilin; Xi, Fengru
2013-12-01
Evaluation system can encourage and guide entrepreneurs, and impel them to perform well in environment management. An evaluation method based on advantage structure is established. It is used to analyze entrepreneur environment management behavior in China. Entrepreneur environment management behavior evaluation index system is constructed based on empirical research. Evaluation method of entrepreneurs is put forward, from the point of objective programming-theory to alert entrepreneurs concerned to think much of it, which means to take minimized objective function as comprehensive evaluation result and identify disadvantage structure pattern. Application research shows that overall behavior of Chinese entrepreneurs environmental management are good, specially, environment strategic behavior are best, environmental management behavior are second, cultural behavior ranks last. Application results show the efficiency and feasibility of this method. PMID:25078816
Electropolymerized phenol derivatives as permselective polymers for biosensor applications.
Calia, Giammario; Monti, Patrizia; Marceddu, Salvatore; Dettori, Maria A; Fabbri, Davide; Jaoua, Samir; O'Neill, Robert D; Serra, Pier A; Delogu, Giovanna; Migheli, Quirico
2015-05-21
Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interference by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized using either constant potential amperometry (CPA) or cyclic voltammetry (CV) from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related to the thickness and compactness of the polymer. The CV-derived films had a better permselectivity compared to the CPA-corresponding polymers. Based on these results, the permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly designed biosensors, coated with electropolymerized natural phenol derivatives, may represent promising analytical devices for different application fields. PMID:25857616
Kour, Gurleen; Chandan, Bal Krishan; Khullar, Mowkshi; Munagala, Gurunadham; Singh, Parvinder Pal; Bhagat, Asha; Gupta, Ajai Prakash; Vishwakarma, Ram A; Ahmed, Zabeer
2016-05-30
The study aims to illustrate an analytical validation of a rapid and sensitive liquid chromatography (LC) coupled to tandem mass spectrometry (MS-MS) and electrospray ionization (ESI) method for quantification of IIIM-019 (a novel nitroimidazole derivative with potential activity against Tuberculosis) in mice plasma. The extraction of the analyte and the internal standard (Tolbutamide) from the plasma samples involves protein precipitation using acetonitrile. The chromatographic separation was accomplished using a gradient mode and the mobile phase comprised of acetonitrile and 0.1% formic acid in water. The flow rate used was 0.7ml/min on a C18e high performance Chromolith column. IIIM-019 and Tolbutamide (IS) were analyzed by combined reversed-phase LC/MS-MS with positive ion electrospray ionization. The MS-MS ion transitions used were 533>170.1, 533>198 for IIIM-019 and 271>74, 271>155 for internal standard (IS) respectively. The method was linear over a concentration range of 0.5-1000ng/ml and the lower limit of quantification was 0.50ng/ml. The entire study was validated for accuracy, precision, linearity, range, selectivity, lower limit of quantification (LLOQ), recovery, and matrix effect in accordance with the FDA guidelines of method validation. Acceptable precision and accuracy were obtained for concentrations over the standard curve range. The intra and inter-day precisions were in the range of 0.51-11.18% and 0.51-7.55%. The pharmacokinetics was performed on male Balb/c mice by oral (2.5mg/kg), intraperitoneal (2.5mg/kg) and intravenous (1mg/kg) routes. The oral bioavailability of IIIM-019 was 51.6%. The method was also applied successfully in determining microsomal stability wherein the compound was found to be very slightly metabolized by rat liver microsomes. PMID:26922579
Incompressible spectral-element method: Derivation of equations
NASA Technical Reports Server (NTRS)
Deanna, Russell G.
1993-01-01
A fractional-step splitting scheme breaks the full Navier-Stokes equations into explicit and implicit portions amenable to the calculus of variations. Beginning with the functional forms of the Poisson and Helmholtz equations, we substitute finite expansion series for the dependent variables and derive the matrix equations for the unknown expansion coefficients. This method employs a new splitting scheme which differs from conventional three-step (nonlinear, pressure, viscous) schemes. The nonlinear step appears in the conventional, explicit manner, the difference occurs in the pressure step. Instead of solving for the pressure gradient using the nonlinear velocity, we add the viscous portion of the Navier-Stokes equation from the previous time step to the velocity before solving for the pressure gradient. By combining this 'predicted' pressure gradient with the nonlinear velocity in an explicit term, and the Crank-Nicholson method for the viscous terms, we develop a Helmholtz equation for the final velocity.
Numerical Method for Darcy Flow Derived Using Discrete Exterior Calculus
NASA Astrophysics Data System (ADS)
Hirani, A. N.; Nakshatrala, K. B.; Chaudhry, J. H.
2015-05-01
We derive a numerical method for Darcy flow, and also for Poisson's equation in mixed (first order) form, based on discrete exterior calculus (DEC). Exterior calculus is a generalization of vector calculus to smooth manifolds and DEC is one of its discretizations on simplicial complexes such as triangle and tetrahedral meshes. DEC is a coordinate invariant discretization, in that it does not depend on the embedding of the simplices or the whole mesh. We start by rewriting the governing equations of Darcy flow using the language of exterior calculus. This yields a formulation in terms of flux differential form and pressure. The numerical method is then derived by using the framework provided by DEC for discretizing differential forms and operators that act on forms. We also develop a discretization for a spatially dependent Hodge star that varies with the permeability of the medium. This also allows us to address discontinuous permeability. The matrix representation for our discrete non-homogeneous Hodge star is diagonal, with positive diagonal entries. The resulting linear system of equations for flux and pressure are saddle type, with a diagonal matrix as the top left block. The performance of the proposed numerical method is illustrated on many standard test problems. These include patch tests in two and three dimensions, comparison with analytically known solutions in two dimensions, layered medium with alternating permeability values, and a test with a change in permeability along the flow direction. We also show numerical evidence of convergence of the flux and the pressure. A convergence experiment is included for Darcy flow on a surface. A short introduction to the relevant parts of smooth and discrete exterior calculus is included in this article. We also include a discussion of the boundary condition in terms of exterior calculus.
Derivation of effectiveness-NTU method for heat exchangers with heat leak
William M. Soyars
2001-11-01
A powerful and useful method for heat exchanger analysis is the effectiveness-NTU method. The equations for this technique presented in textbooks, however, are limited to the case where all of the heat transfer occurs between the two fluid streams. In an application of interest to us, cryogenic heat exchangers, we wish to consider a heat leak term. Thus, we have derived equations for the {var_epsilon}-NTU method with heat leak involved. The cases to be studied include evaporators, condensers, and counter-flow, with heat leak both in and out.
Naval applications of a TAE-derived executive
NASA Technical Reports Server (NTRS)
Guberek, Michael; Borders, Stephen; Masse, Serge
1986-01-01
Global Imaging introduced an interactive image processing system in 1985, featuring the Global Applications Executive (GAE) which is a modified Transportable Applications Executive (TAE) environment. The executive plus a large variety of image processing functions, known commercially as the System 9000, are designed to operate on the Hewlett-Packard as its standard desktop computer (NSDTC), the System 9000 has found easy acceptance for Naval image processing applications. The Department of Oceanography at the Naval Academy, Annapolis, Maryland, has installed an NSDTC with an image processing upgrade. This interactive digital image processing workstation is used by the midshipmen and staff for training and research in remote sensing oceanography. The turn-key system provides the capability to process imagery from commonly used Earth observation spacecraft, in conjunction with in situ data sets. The Acoustic Group at the Naval Research Laboratory, Washington, D.C. has acquired its first System 9000 to interactively process ocean acoustic data gathered by shipboard sensors. Finally, the Naval Oceanographic Facility in Bay St. Louis, Mississippi has acquired a System 9000 to provide a second generation Tactical Environmental Support System (TESS 2) prototype with image processing capabilities. This will permit merging of conventional data with polar orbiting spacecraft imagery. A brief description of these applications and the TAE-derived system is presented.
Application of Argo-derived background diapycnal mixing in HYCOM
NASA Astrophysics Data System (ADS)
Deng, Zengan; Yu, Ting
2014-09-01
Internal wave-induced background diapycnal mixing (DM) in the upper 2000 m of the global ocean, which primarily depends on the local inertial frequency, is calculated based on Argo observations using the newly published Thermodynamic Equation of Seawater-2010 (IOC, SCOR and IAPSO, 2010). This spatially dependent background DM agrees well with previous theoretical and observational mixing estimates. More importantly, the DM data are gridded, which renders the data suitable for modeling applications. The implementation of these data in the HYbrid Coordinate Ocean Model (HYCOM) demonstrates the potential for their application in numerical ocean models. Three numerical experiments that are specifically designed with different DM settings reveal that the meridional overturning circulation (MOC), temperature and salinity in the Atlantic change substantially when the constant background DM is replaced with Argo-derived mixing. Tropical and high-latitude regions that are considered important for global climate are identified as the areas that are most sensitive to the magnitude of the background DM. Compared with constant background DM, the enhanced mid-latitude DM most likely contributes substantially to the MOC transport. Thus, although room remains for improvement, the spatially varying DM derived in the present study may facilitate global circulation and climate modeling.
NASA Astrophysics Data System (ADS)
Jia, Jinhong; Wang, Hong
2015-07-01
Numerical methods for space-fractional diffusion equations often generate dense or even full stiffness matrices. Traditionally, these methods were solved via Gaussian type direct solvers, which requires O (N3) of computational work per time step and O (N2) of memory to store where N is the number of spatial grid points in the discretization. In this paper we develop a preconditioned fast Krylov subspace iterative method for the efficient and faithful solution of finite difference methods (both steady-state and time-dependent) space-fractional diffusion equations with fractional derivative boundary conditions in one space dimension. The method requires O (N) of memory and O (Nlog N) of operations per iteration. Due to the application of effective preconditioners, significantly reduced numbers of iterations were achieved that further reduces the computational cost of the fast method. Numerical results are presented to show the utility of the method.
Two methods of computing molecular dipole and quadrupole derivatives
NASA Astrophysics Data System (ADS)
Lazzeretti, P.; Zanasi, R.; Fowler, P. W.
1988-01-01
Polarized basis sets are used to compute dipole and quadrupole derivatives of the hydrides LiH, CH4, NH3, H2O, and HF. Analytic calculation of derivatives is compared with calculation via the dipole and quadrupole electric shielding tensors. With these basis sets, violation of the Hellmann-Feynman theorem is only about 0.01 a.u. in dipole derivatives and 0.02 a.u. in quadrupole derivatives.
Illustrated structural application of universal first-order reliability method
NASA Technical Reports Server (NTRS)
Verderaime, V.
1994-01-01
The general application of the proposed first-order reliability method was achieved through the universal normalization of engineering probability distribution data. The method superimposes prevailing deterministic techniques and practices on the first-order reliability method to surmount deficiencies of the deterministic method and provide benefits of reliability techniques and predictions. A reliability design factor is derived from the reliability criterion to satisfy a specified reliability and is analogous to the deterministic safety factor. Its application is numerically illustrated on several practical structural design and verification cases with interesting results and insights. Two concepts of reliability selection criteria are suggested. Though the method was developed to support affordable structures for access to space, the method should also be applicable for most high-performance air and surface transportation systems.
A thermochemically derived global reaction mechanism for detonation application
NASA Astrophysics Data System (ADS)
Zhu, Y.; Yang, J.; Sun, M.
2012-07-01
A 4-species 4-step global reaction mechanism for detonation calculations is derived from detailed chemistry through thermochemical approach. Reaction species involved in the mechanism and their corresponding molecular weight and enthalpy data are derived from the real equilibrium properties. By substituting these global species into the results of constant volume explosion and examining the evolution process of these global species under varied conditions, reaction paths and corresponding rates are summarized and formulated. The proposed mechanism is first validated to the original chemistry through calculations of the CJ detonation wave, adiabatic constant volume explosion, and the steady reaction structure after a strong shock wave. Good agreement in both reaction scales and averaged thermodynamic properties has been achieved. Two sets of reaction rates based on different detailed chemistry are then examined and applied for numerical simulations of two-dimensional cellular detonations. Preliminary results and a brief comparison between the two mechanisms are presented. The proposed global mechanism is found to be economic in computation and also competent in description of the overall characteristics of detonation wave. Though only stoichiometric acetylene-oxygen mixture is investigated in this study, the method to derive such a global reaction mechanism possesses a certain generality for premixed reactions of most lean hydrocarbon mixtures.
Application of spectral derivative data in visible and near-infrared spectroscopy
Dehghani, Hamid; Leblond, Frederic; Pogue, Brian W; Chauchard, Fabien
2011-01-01
The use of the spectral derivative method in visible and near-infrared optical spectroscopy is presented, whereby instead of using discrete measurements around several wavelengths, the difference between nearest neighbouring spectral measurements is utilized. The proposed technique is shown to be insensitive to the unknown tissue and fibre contact coupling coefficients providing substantially increased accuracy as compared to more conventional techniques. The self-calibrating nature of the spectral derivative techniques increases its robustness for both clinical and industrial applications, as is demonstrated based on simulated results as well as experimental data. PMID:20505221
Methods for deriving pesticide aquatic life criteria for sediments.
Fojut, Tessa L; Vasquez, Martice E; Poulsen, Anita H; Tjeerdema, Ronald S
2013-01-01
In this review, we evaluated three main current approaches for deriving sediment quality guidelines: empirical, mechanistic (equilibrium partitioning), and spiked sediment toxicity testing approaches. Empirical approaches determine ranges of sediment concentrations that are likely or unlikely to cause toxicity, based on large datasets of matching sediment chemistry, field, and laboratory toxicity data. The empirical approaches are not suitable for determining SQC for specific pesticides because (I) direct cause-effect relationships between single sediment contaminants and toxicity cannot be discerned; (2) chemistry measurements have not accounted for bioavailability, which leads to numeric values with high uncertainty and low reliability; and (3) for many pesticides, little or no matching chemistry and toxicity data are available. In the EqP approach, SQC are derived by entering existing aquatic toxicity data into the equilibrium-partitioning model. This approach is practical for pesticides with water quality criteria in place, but the assumption of equilibrium in aquatic ecosystems is questionable, and the EqP approach neglects available sediment toxicity data. The SSTT approaches utilize sediment toxicity data, creating a scientifically defensible foundation for SQC, but experimental uncertainties regarding spiking technique and equilibration times are yet to be eliminated. The species sensitivity distribution approach generates criteria with confidence intervals, providing a measure of uncertainty, but requires relatively large datasets, whereas the assessment factor method lacks quantification of uncertainty but only requires few data to calculate conservative criteria. Several existing methodologies incorporate a combination of approaches that is dependent on data availability and the physicochemical properties of the compound of interest.A summary of the differences and similarities between key elements of the seven methodologies emphasized in this review is
Directional microwave applicator and methods
NASA Technical Reports Server (NTRS)
Fink, Patrick W. (Inventor); Lin, Greg Y. (Inventor); Chu, Andrew W. (Inventor); Dobbins, Justin A. (Inventor); Arndt, G. Dickey (Inventor); Ngo, Phong H. (Inventor)
2008-01-01
A miniature microwave antenna is disclosed which may be utilized for biomedical applications such as, for example, radiation induced hyperthermia through catheter systems. One feature of the antenna is that it possesses azimuthal directionality despite its small size. This directionality permits targeting of certain tissues while limiting thermal exposure of adjacent tissue. One embodiment has an outer diameter of about 0.095'' (2.4 mm) but the design permits for smaller diameters.
Analysis methods for photovoltaic applications
1980-01-01
Because photovoltaic power systems are being considered for an ever-widening range of applications, it is appropriate for system designers to have knowledge of and access to photovoltaic power systems simulation models and design tools. This brochure gives brief descriptions of a variety of such aids and was compiled after surveying both manufacturers and researchers. Services available through photovoltaic module manufacturers are outlined, and computer codes for systems analysis are briefly described. (WHK)
Biotechnological applications derived from microorganisms of the Atacama Desert.
Azua-Bustos, Armando; González-Silva, Carlos
2014-01-01
The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development. PMID:25147824
Biotechnological Applications Derived from Microorganisms of the Atacama Desert
González-Silva, Carlos
2014-01-01
The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development. PMID:25147824
Application of chitin and chitosan derivatives in the pharmaceutical field.
Kato, Yoshinori; Onishi, Hiraku; Machida, Yoshiharu
2003-10-01
Chitin and chitosan derivatives are used as excipients and drug carriers in the pharmaceutical field. Their derivatization contributed to expansion of application and decrease toxicity. Chitosan is used as an excipient in oral dosage form. Chitosan tablet can exhibit a sustained drug release compared to commercial products. Films prepared using chitin or chitosan have been developed as wound dressings, oral mucoadhesive and water-resisting adhesive by virtue of their release characteristics and adhesion. Intratumoral administration of gadopentetic acid-chitosan complex nanoparticles (approximately 430 nm in diameter) has been more effective for gadolinium neutron-capture therapy compared with a group treated with the solution. Compared to intragastrical feeding with diphtheria toxoid (DT) in PBS, a strong enhancement of the systemic (IgG) and local (IgA) immune responses against DT has been observed in mice fed with DT loaded chitosan microparticles (approximately 4.7 microm in size). When DNA-loaded chitosan microspheres (1.15 - 1.28 microm) were intramuscularly administrated into mice, high beta-galactosidase and luciferase productions were obtained even after a long post-transfection period (12 weeks). N-Succinyl-chitosan (Suc-Chi) has been studied for cancer chemotherapy as a drug carrier and the conjugates of mitomycin C with Suc-Chi exhibited good antitumor activities against various tumors. Furthermore, trimethyl-chitosan and monocarboxymethyl-chitosan has been shown to be effective as intestinal absorption enhancers due to their physiological properties. Chitosan-thioglycolic acid conjugates has been found to be a promising candidate as scaffold material in tissue engineering due to their physicochemical properties. This review summarizes the application of chitin and chitosan derivatives for hospital preparations and drug carriers. PMID:14529420
Sodium MRI: methods and applications.
Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R; Jerschow, Alexej
2014-05-01
Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges, limitations, and current and potential new applications of sodium MRI. PMID:24815363
Sodium MRI: Methods and applications
Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej
2014-01-01
Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363
Radiative Transfer: Methods and Applications
NASA Astrophysics Data System (ADS)
Mayer, Bernhard; Emde, Claudia; Buras, Robert; Kylling, Arve
Solar and terrestrial radiation is the driver of atmospheric dynamics and chemistry and can be exploited by remote sensing algorithms to determine atmospheric composition. For this purpose, accurate radiative transfer models are needed. Here, a modern radiative transfer tool developed over many years at the Institute of Atmospheric Physics is explained. As an application, the remote sensing of cloud microphysics using the angular distribution of reflected solar radiance in the rainbow and backscatter glory is shown, with special emphasis on the polarization of radiation.
Comparative genomics: methods and applications
NASA Astrophysics Data System (ADS)
Haubold, Bernhard; Wiehe, Thomas
2004-09-01
Interpreting the functional content of a given genomic sequence is one of the central challenges of biology today. Perhaps the most promising approach to this problem is based on the comparative method of classic biology in the modern guise of sequence comparison. For instance, protein-coding regions tend to be conserved between species. Hence, a simple method for distinguishing a functional exon from the chance absence of stop codons is to investigate its homologue from closely related species. Predicting regulatory elements is even more difficult than exon prediction, but again, comparisons pinpointing conserved sequence motifs upstream of translation start sites are helping to unravel gene regulatory networks. In addition to interspecific studies, intraspecific sequence comparison yields insights into the evolutionary forces that have acted on a species in the past. Of particular interest here is the identification of selection events such as selective sweeps. Both intra- and interspecific sequence comparisons are based on a variety of computational methods, including alignment, phylogenetic reconstruction, and coalescent theory. This article surveys the biology and the central computational ideas applied in recent comparative genomics projects. We argue that the most fruitful method of understanding the functional content of genomes is to study them in the context of related genomic sequences. In particular, such a study may reveal selection, a fundamental pointer to biological relevance.
Refining a model electron-density map via the Phantom Derivative method.
Burla, Maria Cristina; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Giacovazzo, Carmelo; Polidori, Giampiero
2015-09-01
The Phantom Derivative (PhD) method [Giacovazzo (2015), Acta Cryst. A71, 483-512] has recently been described for ab initio and non-ab initio phasing. It is based on the random generation of structures with the same unit cell and the same space group as the target structure (called ancil structures), which are used to create derivatives devoid of experimental diffraction amplitudes. In this paper, the non-ab initio variant of the method was checked using phase sets obtained by molecular-replacement techniques as a starting point for phase extension and refinement. It has been shown that application of PhD is able to extend and refine phases in a way that is competitive with other electron-density modification techniques. PMID:26327376
Phytosterols: applications and recovery methods.
Fernandes, P; Cabral, J M S
2007-09-01
Phytosterols, or plant sterols, are compounds that occur naturally and bear close structural resemblance to cholesterol, but have different side-chain configurations. Phytosterols are relevant in pharmaceuticals (production of therapeutic steroids), nutrition (anti-cholesterol additives in functional foods, anti-cancer properties), and cosmetics (creams, lipstick). Phytosterols can be obtained from vegetable oils or from industrial wastes, which gives an added value to the latter. Considerable efforts have been recently dedicated to the development of efficient processes for phytosterol isolation from natural sources. The present work aims to summarize information on the applications of phytosterols and to review recent approaches, mainly from the industry, for the large-scale recovery of phytosterols. PMID:17123816
NASA Technical Reports Server (NTRS)
Weil, J.
1981-01-01
Flight derived longitudinal and lateral-directional stability and control derivatives were compared to wind-tunnel derived values. As a result of these comparisons, boundaries representing the uncertainties that could be expected from wind-tunnel predictions were established. These boundaries provide a useful guide for control system sensitivity studies prior to flight. The primary application for this data was the space shuttle, and as a result the configurations included in the study were those most applicable to the space shuttle. The configurations included conventional delta wing aircraft as well as the X-15 and lifting body vehicles.
Method for Implementing Subsurface Solid Derived Concentration Guideline Levels (DCGL) - 12331
Lively, J.W.
2012-07-01
The U.S. Nuclear Regulatory Commission (NRC) and other federal agencies currently approve the Multi-Agency Radiation Site Survey and Investigation Manual (MARSSIM) as guidance for licensees who are conducting final radiological status surveys in support of decommissioning. MARSSIM provides a method to demonstrate compliance with the applicable regulation by comparing residual radioactivity in surface soils with derived concentration guideline levels (DCGLs), but specifically discounts its applicability to subsurface soils. Many sites and facilities undergoing decommissioning contain subsurface soils that are potentially impacted by radiological constituents. In the absence of specific guidance designed to address the derivation of subsurface soil DCGLs and compliance demonstration, decommissioning facilities have attempted to apply DCGLs and final status survey techniques designed specifically for surface soils to subsurface soils. The decision to apply surface soil limits and surface soil compliance metrics to subsurface soils typically results in significant over-excavation with associated cost escalation. MACTEC, Inc. has developed the overarching concepts and principles found in recent NRC decommissioning guidance in NUREG 1757 to establish a functional method to derive dose-based subsurface soil DCGLs. The subsurface soil method developed by MACTEC also establishes a rigorous set of criterion-based data evaluation metrics (with analogs to the MARSSIM methodology) that can be used to demonstrate compliance with the developed subsurface soil DCGLs. The method establishes a continuum of volume factors that relate the size and depth of a volume of subsurface soil having elevated concentrations of residual radioactivity with its ability to produce dose. The method integrates the subsurface soil sampling regime with the derivation of the subsurface soil DCGL such that a self-regulating optimization is naturally sought by both the responsible party and regulator
Quantum dots derived from two-dimensional materials and their applications for catalysis and energy.
Wang, Xuewan; Sun, Gengzhi; Li, Nan; Chen, Peng
2016-04-21
Quantum dots (QDs) derived from the atomically-thin two-dimensional (2D) sheets (graphene, transition metal dichalcogenide, graphitic carbon nitride, hexagonal boron nitride, and phosphorene) are emerging extraordinary zero-dimensional materials. Covering a broad spectrum of interesting optical, catalytic, electronic, chemical and electrochemical properties, these 2D-QDs promise a wide range of novel applications including imaging, sensing, cancer therapy, optoelectronics, display, catalysis, and energy. In this article, we discuss the synthesis methods and the properties of these 2D-QDs and emphasize their applications in electrocatalysis, photocatalysis, supercapacitors, batteries, and photovoltaics. PMID:26848039
Hybrid codes: Methods and applications
Winske, D. ); Omidi, N. )
1991-01-01
In this chapter we discuss hybrid'' algorithms used in the study of low frequency electromagnetic phenomena, where one or more ion species are treated kinetically via standard PIC methods used in particle codes and the electrons are treated as a single charge neutralizing massless fluid. Other types of hybrid models are possible, as discussed in Winske and Quest, but hybrid codes with particle ions and massless fluid electrons have become the most common for simulating space plasma physics phenomena in the last decade, as we discuss in this paper.
AMMOS software: method and application.
Pencheva, T; Lagorce, D; Pajeva, I; Villoutreix, B O; Miteva, M A
2012-01-01
Recent advances in computational sciences enabled extensive use of in silico methods in projects at the interface between chemistry and biology. Among them virtual ligand screening, a modern set of approaches, facilitates hit identification and lead optimization in drug discovery programs. Most of these approaches require the preparation of the libraries containing small organic molecules to be screened or a refinement of the virtual screening results. Here we present an overview of the open source AMMOS software, which is a platform performing an automatic procedure that allows for a structural generation and optimization of drug-like molecules in compound collections, as well as a structural refinement of protein-ligand complexes to assist in silico screening exercises. PMID:22183534
Adipose-Derived Stem Cells for Tissue Engineering and Regenerative Medicine Applications
Dai, Ru; Wang, Zongjie; Samanipour, Roya; Koo, Kyo-in; Kim, Keekyoung
2016-01-01
Adipose-derived stem cells (ASCs) are a mesenchymal stem cell source with properties of self-renewal and multipotential differentiation. Compared to bone marrow-derived stem cells (BMSCs), ASCs can be derived from more sources and are harvested more easily. Three-dimensional (3D) tissue engineering scaffolds are better able to mimic the in vivo cellular microenvironment, which benefits the localization, attachment, proliferation, and differentiation of ASCs. Therefore, tissue-engineered ASCs are recognized as an attractive substitute for tissue and organ transplantation. In this paper, we review the characteristics of ASCs, as well as the biomaterials and tissue engineering methods used to proliferate and differentiate ASCs in a 3D environment. Clinical applications of tissue-engineered ASCs are also discussed to reveal the potential and feasibility of using tissue-engineered ASCs in regenerative medicine. PMID:27057174
Application of 12S rRNA gene for the identification of animal-derived drugs.
Luo, Jiaoyang; Yan, Dan; Zhang, Da; Han, Yumei; Dong, Xiaoping; Yang, Yong; Deng, Kejun; Xiao, Xiaohe
2011-01-01
PURPOSE. Animal-derived drugs are the major source of biological products and traditional medicine, but they are often difficult to identify, causing confusion in the clinical application. Among these medicinal animals, a number of animal species are endangered, leading to the destruction of biodiversity. The identification of animal-derived drugs and their alternatives would be a first step toward biodiversity conservation and safe medication. Until now, no effective method for identifying animal-derived drugs has been demonstrated; DNA-based species identification presents a brand-new technique. METHODS. We designed primers to amplify a 523-bp fragment of 12S rRNA and generated sequences for 13 individuals within six medicinal animal species. We examined the efficiency of species recognition based on this sequence, and we also tested the taxonomic affiliations against the GenBank database. RESULTS. All the tested drugs were identified successfully, and a visible gap was found between the inter-specific and intra-specific variation. We further demonstrated the importance of data exploration in DNA-based species identification practice by examining the sequence characteristics of relative genera in GenBank. This region of the 12S rRNA gene had a 100% success rate of species recognition within the six medicinal animal species. CONCLUSIONS. We propose that the 12S rRNA locus might be universal for identifying animal-derived drugs and their adulterants. The development of 12S rRNA for indentifying animal-derived drugs that share a common gene target would contribute significantly to the clinical application of animal-derived drugs and the conservation of medicinal animal species. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page. PMID:21906480
A review on mathematical methods of conventional and Islamic derivatives
NASA Astrophysics Data System (ADS)
Hisham, Azie Farhani Badrol; Jaffar, Maheran Mohd
2014-12-01
Despite the impressive growth of risk management tools in financial institutions, Islamic finance remains miles away behind the conventional institutions. Islamic finance products need to comply with the syariah law and prohibitions, therefore they can use fewer of the available risk management tools compared to conventional. Derivatives have proven to be the effective hedging technique and instrument that broadly being used in the conventional institutions to manage their risks. However, derivatives are not generally accepted as the legitimate products in Islamic finance and they remain controversial issues among the Islamic scholars. This paper reviews the evolution of derivatives such as forwards, futures and options and then explores the mathematical models that being used to solve derivatives such as random walk model, asset pricing model that follows Brownian motion and Black-Scholes model. Other than that, this paper also critically discuss the perspective of derivatives from Islamic point of view. In conclusion, this paper delivers the traditional Islamic products such as salam, urbun and istijrar that can be used to create building blocks of Islamic derivatives.
Differential Monte Carlo method for computing seismogram envelopes and their partial derivatives
NASA Astrophysics Data System (ADS)
Takeuchi, Nozomu
2016-05-01
We present an efficient method that is applicable to waveform inversions of seismogram envelopes for structural parameters describing scattering properties in the Earth. We developed a differential Monte Carlo method that can simultaneously compute synthetic envelopes and their partial derivatives with respect to structural parameters, which greatly reduces the required CPU time. Our method has no theoretical limitations to apply to the problems with anisotropic scattering in a heterogeneous background medium. The effects of S wave polarity directions and phase differences between SH and SV components are taken into account. Several numerical examples are presented to show that the intrinsic and scattering attenuation at the depth range of the asthenosphere have different impacts on the observed seismogram envelopes, thus suggesting that our method can potentially be applied to inversions for scattering properties in the deep Earth.
Application of fractional derivative models in linear viscoelastic problems
NASA Astrophysics Data System (ADS)
Sasso, M.; Palmieri, G.; Amodio, D.
2011-11-01
Appropriate knowledge of viscoelastic properties of polymers and elastomers is of fundamental importance for a correct modelization and analysis of structures where such materials are present, especially when dealing with dynamic and vibration problems. In this paper experimental results of a series of compression and tension tests on specimens of styrene-butadiene rubber and polypropylene plastic are presented; tests consist of creep and relaxation tests, as well as cyclic loading at different frequencies. Experimental data are then used to calibrate some linear viscoelastic models; besides the classical approach based on a combination in series or parallel of standard mechanical elements as springs and dashpots, particular emphasis is given to the application of models whose constitutive equations are based on differential equations of fractional order (Fractional Derivative Model). The two approaches are compared analyzing their capability to reproduce all the experimental data for given materials; also, the main computational issues related with these models are addressed, and the advantage of using a limited number of parameters is demonstrated.
Systems and Methods for Derivative-Free Adaptive Control
NASA Technical Reports Server (NTRS)
Yucelen, Tansel (Inventor); Kim, Kilsoo (Inventor); Calise, Anthony J. (Inventor)
2015-01-01
An adaptive control system is disclosed. The control system can control uncertain dynamic systems. The control system can employ one or more derivative-free adaptive control architectures. The control system can further employ one or more derivative-free weight update laws. The derivative-free weight update laws can comprise a time-varying estimate of an ideal vector of weights. The control system of the present invention can therefore quickly stabilize systems that undergo sudden changes in dynamics, caused by, for example, sudden changes in weight. Embodiments of the present invention can also provide a less complex control system than existing adaptive control systems. The control system can control aircraft and other dynamic systems, such as, for example, those with non-minimum phase dynamics.
Zhu, Wei-Zhong; Filice, Dominic; Palpant, Nathan J.; Laflamme, Michael A.
2014-01-01
Cardiomyocytes derived from human pluripotent stem cells show tremendous promise for the replacement of myocardium and contractile function lost to infarction. However, until recently, no methods were available to directly determine whether these stem cell-derived grafts actually couple with host myocardium and fire synchronously following transplantation in either intact or injured hearts. To resolve this uncertainty, our group has developed techniques for the intravital imaging of hearts engrafted with stem cell-derived cardiomyocytes that have been modified to express the genetically encoded protein calcium sensor, GCaMP. When combined with the simultaneously recorded electrocardiogram, this protocol allows one to make quantitative assessments as to the presence and extent of host–graft electrical coupling as well as the timing and pattern of graft activation. As described here, this system has been employed to investigate the electromechanical integration of human embryonic stem cell-derived cardiomyocytes in a guinea pig model of cardiac injury, but analogous approaches should be applicable to other human graft cell types and animal models. PMID:25070341
METHODS FOR THE ANALYSIS OF ALKYLPHENOL ETHOXYLATES AND DERIVATIVES
Alkylphenol ethoxylates and their derivatives are well known for their harmful impact in wildlife. These compounds are being phased-out and banned in most European Countries. Their use has increased in the U.S. resulting in their addition to the Priority Testing List, TSCA (1...
Guan, Yongtao; Li, Yehua; Sinha, Rajita
2011-01-01
In a cocaine dependence treatment study, we use linear and nonlinear regression models to model posttreatment cocaine craving scores and first cocaine relapse time. A subset of the covariates are summary statistics derived from baseline daily cocaine use trajectories, such as baseline cocaine use frequency and average daily use amount. These summary statistics are subject to estimation error and can therefore cause biased estimators for the regression coefficients. Unlike classical measurement error problems, the error we encounter here is heteroscedastic with an unknown distribution, and there are no replicates for the error-prone variables or instrumental variables. We propose two robust methods to correct for the bias: a computationally efficient method-of-moments-based method for linear regression models and a subsampling extrapolation method that is generally applicable to both linear and nonlinear regression models. Simulations and an application to the cocaine dependence treatment data are used to illustrate the efficacy of the proposed methods. Asymptotic theory and variance estimation for the proposed subsampling extrapolation method and some additional simulation results are described in the online supplementary material. PMID:21984854
Discontinuous Galerkin Methods: Theory, Computation and Applications
Cockburn, B.; Karniadakis, G. E.; Shu, C-W
2000-12-31
This volume contains a survey article for Discontinuous Galerkin Methods (DGM) by the editors as well as 16 papers by invited speakers and 32 papers by contributed speakers of the First International Symposium on Discontinuous Galerkin Methods. It covers theory, applications, and implementation aspects of DGM.
Application of derivative matrices of skew rays to design of compound dispersion prisms.
Lin, Psang Dain
2016-09-01
Numerous optimization methods have been developed in recent decades for optical system design. However, these methods rely heavily on ray tracing and finite difference techniques to estimate the derivative matrices of the rays. Consequently, the accuracy of the results obtained from these methods is critically dependent on the incremental step size used in the tuning stage. To overcome this limitation, the present study proposes a comprehensive methodology for the design of compound dispersion prisms based on the first- and second-order derivative matrices of skew rays. The proposed method facilitates the analysis and design of prisms with respect to arbitrary system variables and provides an ideal basis for automatic prism design applications. Four illustrative examples are given. It is shown that the optical quantities required to evaluate the prism performance can be extracted directly from the proposed derivative matrices. In addition, it is shown in this study that the single-element 3D prism can have the same deviation angle and spectral dispersion as the 2D compound prism. PMID:27607509
The Typicality Ranking Task: A New Method to Derive Typicality Judgments from Children
Ameel, Eef; Storms, Gert
2016-01-01
An alternative method for deriving typicality judgments, applicable in young children that are not familiar with numerical values yet, is introduced, allowing researchers to study gradedness at younger ages in concept development. Contrary to the long tradition of using rating-based procedures to derive typicality judgments, we propose a method that is based on typicality ranking rather than rating, in which items are gradually sorted according to their typicality, and that requires a minimum of linguistic knowledge. The validity of the method is investigated and the method is compared to the traditional typicality rating measurement in a large empirical study with eight different semantic concepts. The results show that the typicality ranking task can be used to assess children’s category knowledge and to evaluate how this knowledge evolves over time. Contrary to earlier held assumptions in studies on typicality in young children, our results also show that preference is not so much a confounding variable to be avoided, but that both variables are often significantly correlated in older children and even in adults. PMID:27322371
New antimicrobial chitosan derivatives for wound dressing applications.
Dragostin, Oana Maria; Samal, Sangram Keshari; Dash, Mamoni; Lupascu, Florentina; Pânzariu, Andreea; Tuchilus, Cristina; Ghetu, Nicolae; Danciu, Mihai; Dubruel, Peter; Pieptu, Dragos; Vasile, Cornelia; Tatia, Rodica; Profire, Lenuta
2016-05-01
Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials. PMID:26876993
Error Bounds for Quadrature Methods Involving Lower Order Derivatives
ERIC Educational Resources Information Center
Engelbrecht, Johann; Fedotov, Igor; Fedotova, Tanya; Harding, Ansie
2003-01-01
Quadrature methods for approximating the definite integral of a function f(t) over an interval [a,b] are in common use. Examples of such methods are the Newton-Cotes formulas (midpoint, trapezoidal and Simpson methods etc.) and the Gauss-Legendre quadrature rules, to name two types of quadrature. Error bounds for these approximations involve…
Electromagnetic Imaging Methods for Nondestructive Evaluation Applications
Deng, Yiming; Liu, Xin
2011-01-01
Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions. PMID:22247693
NASA Technical Reports Server (NTRS)
Grillo, Vince
2016-01-01
The objective of this presentation is to give a brief overview of the theory behind the (DBA) method, an overview of the derivation and a practical application of the theory using the Python computer language. The Theory and Derivation will use both Acceleration and Pseudo Velocity methods to derive a series of equations for processing by Python. We will take the results and compare both Acceleration and Pseudo Velocity methods and discuss implementation of the Python functions. Also, we will discuss the efficiency of the methods and the amount of computer time required for the solution. In conclusion, (DBA) offers a powerful method to evaluate the amount of energy imparted into a system in the form of both Amplitude and Duration during qualification testing and flight environments. Many forms of steady state and transient vibratory motion can be characterized using this technique. (DBA) provides a more robust alternative to traditional methods such Power Spectral Density (PSD) using a Maximax approach.
Variational Methods in Sensitivity Analysis and Optimization for Aerodynamic Applications
NASA Technical Reports Server (NTRS)
Ibrahim, A. H.; Hou, G. J.-W.; Tiwari, S. N. (Principal Investigator)
1996-01-01
Variational methods (VM) sensitivity analysis, which is the continuous alternative to the discrete sensitivity analysis, is employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function. The converged solution of the state equations together with the converged solution of the costate equations are integrated along the domain boundary to uniquely determine the functional sensitivity derivatives with respect to the design function. The determination of the sensitivity derivatives of the performance index or functional entails the coupled solutions of the state and costate equations. As the stable and converged numerical solution of the costate equations with their boundary conditions are a priori unknown, numerical stability analysis is performed on both the state and costate equations. Thereafter, based on the amplification factors obtained by solving the generalized eigenvalue equations, the stability behavior of the costate equations is discussed and compared with the state (Euler) equations. The stability analysis of the costate equations suggests that the converged and stable solution of the costate equation is possible only if the computational domain of the costate equations is transformed to take into account the reverse flow nature of the costate equations. The application of the variational methods to aerodynamic shape optimization problems is demonstrated for internal flow problems at supersonic Mach number range. The study shows, that while maintaining the accuracy of the functional sensitivity derivatives within the reasonable range for engineering prediction purposes, the variational methods show a substantial gain in computational efficiency, i.e., computer time and memory, when compared with the finite
Application of Derivative Spectrometry to the Analysis of Trace Gases
NASA Technical Reports Server (NTRS)
Hager, Robert N.
1971-01-01
A derivative spectrometer is sensitive to changes in spectral intensity over narrow wavelength internal. Specifically, a second derivative spectrometer senses the curvature of the incident spectral intensity, providing an output voltage signal proportional to the second derivative of intensity with respect to wavelength. When such an instrument is combined with multi-pass White cell, a unique trace gas analyzer results. The analyzer, operating within the middle ultraviolet spectral region, provides a highly amplified derivative spectrum of any molecular narrow band absorption which is used for trace gas identification. The intensity of any peak within a spectrum is proportional to the trace gas concentration. Such an analyzer, utilizing a 20 meter pathlength White cell, is presently being used to automatically monitor ambient air for SO2, NO, NO2, and O3 with minimum detectable concentration limits in the part per billion range.
Second derivative multistep method for solving first-order ordinary differential equations
NASA Astrophysics Data System (ADS)
Turki, Mohammed Yousif; Ismail, Fudziah; Senu, Norazak; Ibrahim, Zarina Bibi
2016-06-01
In this paper, a new second derivative multistep method was constructed to solve first order ordinary differential equations (ODEs). In particular, we used the new method as a corrector method and 5-steps Adam's Bashforth method as a predictor method to solve first order (ODEs). Numerical results were compared with the existing methods which clearly showed the efficiency of the new method.
40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.
Code of Federal Regulations, 2012 CFR
2012-07-01
... manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment... manufacture of rosin-based derivatives subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of rosin-based derivatives....
40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.
Code of Federal Regulations, 2014 CFR
2014-07-01
... manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment... manufacture of rosin-based derivatives subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of rosin-based derivatives....
40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.
Code of Federal Regulations, 2011 CFR
2011-07-01
... manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment... manufacture of rosin-based derivatives subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of rosin-based derivatives....
40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.
Code of Federal Regulations, 2013 CFR
2013-07-01
... manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment... manufacture of rosin-based derivatives subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of rosin-based derivatives....
40 CFR 454.60 - Applicability; description of manufacture of rosin-based derivatives subcategory.
Code of Federal Regulations, 2010 CFR
2010-07-01
... manufacture of rosin-based derivatives subcategory. 454.60 Section 454.60 Protection of Environment... manufacture of rosin-based derivatives subcategory. The provisions of this subpart are applicable to discharges resulting from the manufacture of rosin-based derivatives....
Extending the applicability of multigrid methods
Brannick, J; Brezina, M; Falgout, R; Manteuffel, T; McCormick, S; Ruge, J; Sheehan, B; Xu, J; Zikatanov, L
2006-09-25
Multigrid methods are ideal for solving the increasingly large-scale problems that arise in numerical simulations of physical phenomena because of their potential for computational costs and memory requirements that scale linearly with the degrees of freedom. Unfortunately, they have been historically limited by their applicability to elliptic-type problems and the need for special handling in their implementation. In this paper, we present an overview of several recent theoretical and algorithmic advances made by the TOPS multigrid partners and their collaborators in extending applicability of multigrid methods. Specific examples that are presented include quantum chromodynamics, radiation transport, and electromagnetics.
NASA Technical Reports Server (NTRS)
Donegan, James J
1954-01-01
Three matrice methods are developed and presented for determining the longitudinal-stability derivatives from transient flight data. In these methods the expressions for some of the stability derivatives are in the form generally used in stability calculations. The first method requires the combination of four measurements in time-history form, two of which must be incremental elevator deflection and incremental tail load and the other two measurements can be chosen from a possible three, namely incremental load factor, pitching velocity, and angle of attack. The method demonstrates the use of the tail load to separate the pitching-moment derivatives and to determine the downwash derivative. (author)
Some Recent Applications of Nuclear Methods
NASA Astrophysics Data System (ADS)
Csikai, J.; Dóczi, R.
2005-11-01
In this paper among the wide-ranging applications of nuclear methods the following topics were selected: a) Nuclear safeguards, illicit trafficking and demining; b) Bulk hydrogen analysis; c) Radiopharmaceuticals and related charged particle reactions; d) Accelerator transmutation of radioactive waste; e) Validation of nuclear data libraries by differential and integral measurements.
Engineering applications of heuristic multilevel optimization methods
NASA Technical Reports Server (NTRS)
Barthelemy, Jean-Francois M.
1989-01-01
Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.
Engineering applications of heuristic multilevel optimization methods
NASA Technical Reports Server (NTRS)
Barthelemy, Jean-Francois M.
1988-01-01
Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified.
Cell-derived matrices for tissue engineering and regenerative medicine applications1
Fitzpatrick, Lindsay E.; McDevitt, Todd C.
2014-01-01
The development and application of decellularized extracellular matrices (ECM) has grown rapidly in the fields of cell biology, tissue engineering and regenerative medicine in recent years. Similar to decellularized tissues and whole organs, cell-derived matrices (CDMs) represent bioactive, biocompatible materials consisting of a complex assembly of fibrillar proteins, matrix macromolecules and associated growth factors that often recapitulate, at least to some extent, the composition and organization of native ECM microenvironments. The unique ability to engineer CDMs de novo based on cell source and culture methods makes them an attractive alternative to conventional allogeneic and xenogeneic tissue-derived matrices that are currently harvested from cadaveric sources, suffer from inherent heterogeneity, and have limited ability for customization. Although CDMs have been investigated for a number of biomedical applications, including adhesive cell culture substrates, synthetic scaffold coatings, and tissue engineered products, such as heart valves and vascular grafts, the state of the field is still at a relatively nascent stage of development. In this review, we provide an overview of the various applications of CDM and discuss successes to date, current limitations and future directions. PMID:25530850
Signal processing using sparse derivatives with applications to chromatograms and ECG
NASA Astrophysics Data System (ADS)
Ning, Xiaoran
In this thesis, we investigate the sparsity exist in the derivative domain. Particularly, we focus on the type of signals which posses up to Mth (M > 0) order sparse derivatives. Efforts are put on formulating proper penalty functions and optimization problems to capture properties related to sparse derivatives, searching for fast, computationally efficient solvers. Also the effectiveness of these algorithms are applied to two real world applications. In the first application, we provide an algorithm which jointly addresses the problems of chromatogram baseline correction and noise reduction. The series of chromatogram peaks are modeled as sparse with sparse derivatives, and the baseline is modeled as a low-pass signal. A convex optimization problem is formulated so as to encapsulate these non-parametric models. To account for the positivity of chromatogram peaks, an asymmetric penalty function is also utilized with symmetric penalty functions. A robust, computationally efficient, iterative algorithm is developed that is guaranteed to converge to the unique optimal solution. The approach, termed Baseline Estimation And Denoising with Sparsity (BEADS), is evaluated and compared with two state-of-the-art methods using both simulated and real chromatogram data. Promising result is obtained. In the second application, a novel Electrocardiography (ECG) enhancement algorithm is designed also based on sparse derivatives. In the real medical environment, ECG signals are often contaminated by various kinds of noise or artifacts, for example, morphological changes due to motion artifact, non-stationary noise due to muscular contraction (EMG), etc. Some of these contaminations severely affect the usefulness of ECG signals, especially when computer aided algorithms are utilized. By solving the proposed convex l1 optimization problem, artifacts are reduced by modeling the clean ECG signal as a sum of two signals whose second and third-order derivatives (differences) are sparse
Methods for the synthesis of olefins and derivatives
Burk, Mark J.; Pharkya, Priti; Van Dien, Stephen J.; Burgard, Anthony P.; Schilling, Christophe H.
2011-09-27
The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.
Methods for the synthesis of olefins and derivatives
Burk, Mark J; Pharkya, Priti; Van Dien, Stephen J; Burgard, Anthony P; Schilling, Christophe H
2013-06-04
The invention provides a method of producing acrylic acid. The method includes contacting fumaric acid with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylic acid per mole of fumaric acid. Also provided is an acrylate ester. The method includes contacting fumarate diester with a sufficient amount of ethylene in the presence of a cross-metathesis transformation catalyst to produce about two moles of acrylate ester per mole of fumarate diester. An integrated process for process for producing acrylic acid or acrylate ester is provided which couples bioproduction of fumaric acid with metathesis transformation. An acrylic acid and an acrylate ester production also is provided.
Marine-derived fungi: diversity of enzymes and biotechnological applications
Bonugli-Santos, Rafaella C.; dos Santos Vasconcelos, Maria R.; Passarini, Michel R. Z.; Vieira, Gabriela A. L.; Lopes, Viviane C. P.; Mainardi, Pedro H.; dos Santos, Juliana A.; de Azevedo Duarte, Lidia; Otero, Igor V. R.; da Silva Yoshida, Aline M.; Feitosa, Valker A.; Pessoa, Adalberto; Sette, Lara D.
2015-01-01
The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. These enzymes present temperature and pH optima ranging from 35 to 70∘C, and 3.0 to 11.0, respectively. High-level production in bioreactors is mainly performed using submerged-state fermentation. Certain marine-derived fungal strains present enzymes with alkaline and cold-activity characteristics, and salinity is considered an important condition in screening and production processes. The adaptability of marine-derived fungi to oceanic conditions can be considered an attractive point in the field of fungal marine biotechnology. In this review, we focus on the advances in discovering enzymes from marine-derived fungi and their biotechnological relevance. PMID:25914680
Marine-derived fungi: diversity of enzymes and biotechnological applications.
Bonugli-Santos, Rafaella C; Dos Santos Vasconcelos, Maria R; Passarini, Michel R Z; Vieira, Gabriela A L; Lopes, Viviane C P; Mainardi, Pedro H; Dos Santos, Juliana A; de Azevedo Duarte, Lidia; Otero, Igor V R; da Silva Yoshida, Aline M; Feitosa, Valker A; Pessoa, Adalberto; Sette, Lara D
2015-01-01
The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. These enzymes present temperature and pH optima ranging from 35 to 70(∘)C, and 3.0 to 11.0, respectively. High-level production in bioreactors is mainly performed using submerged-state fermentation. Certain marine-derived fungal strains present enzymes with alkaline and cold-activity characteristics, and salinity is considered an important condition in screening and production processes. The adaptability of marine-derived fungi to oceanic conditions can be considered an attractive point in the field of fungal marine biotechnology. In this review, we focus on the advances in discovering enzymes from marine-derived fungi and their biotechnological relevance. PMID:25914680
Method of producing solution-derived metal oxide thin films
Boyle, Timothy J.; Ingersoll, David
2000-01-01
A method of preparing metal oxide thin films by a solution method. A .beta.-metal .beta.-diketonate or carboxylate compound, where the metal is selected from groups 8, 9, 10, 11, and 12 of the Periodic Table, is solubilized in a strong Lewis base to form a homogeneous solution. This precursor solution forms within minutes and can be deposited on a substrate in a single layer or a multiple layers to form a metal oxide thin film. The substrate with the deposited thin film is heated to change the film from an amorphous phase to a ceramic metal oxide and cooled.
Inactivation of viruses in labile blood derivatives. II. Physical methods
Horowitz, B.; Wiebe, M.E.; Lippin, A.; Vandersande, J.; Stryker, M.H.
1985-11-01
The thermal inactivation of viruses in labile blood derivatives was evaluated by addition of marker viruses (VSV, Sindbis, Sendai, EMC) to anti-hemophilic factor (AHF) concentrates. The rate of virus inactivation at 60 degrees C was decreased by at least 100- to 700-fold by inclusion of 2.75 M glycine and 50 percent sucrose, or 3.0 M potassium citrate, additives which contribute to retention of protein biologic activity. Nonetheless, at least 10(4) infectious units of each virus was inactivated within 10 hours. Increasing the temperature from 60 to 70 or 80 degrees C caused a 90 percent or greater loss in AHF activity. An even greater decline in the rate of virus inactivation was observed on heating AHF in the lyophilized state, although no loss in AHF activity was observed after 72 hours of heating at 60 degrees C. Several of the proteins present in lyophilized AHF concentrates displayed an altered electrophoretic mobility as a result of exposure to 60 degrees C for 24 hours. Exposure of lyophilized AHF to irradiation from a cobalt 60 source resulted in an acceptable yield of AHF at 1.0, but not at 2.0, megarads. At 1 megarad, greater than or equal to 6.0 logs of VSV and 3.3 logs of Sindbis virus were inactivated.
Extremal Optimization: Methods Derived from Co-Evolution
Boettcher, S.; Percus, A.G.
1999-07-13
We describe a general-purpose method for finding high-quality solutions to hard optimization problems, inspired by self-organized critical models of co-evolution such as the Bak-Sneppen model. The method, called Extremal Optimization, successively eliminates extremely undesirable components of sub-optimal solutions, rather than ''breeding'' better components. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, Extremal Optimization improves on a single candidate solution by treating each of its components as species co-evolving according to Darwinian principles. Unlike Simulated Annealing, its non-equilibrium approach effects an algorithm requiring few parameters to tune. With only one adjustable parameter, its performance proves competitive with, and often superior to, more elaborate stochastic optimization procedures. We demonstrate it here on two classic hard optimization problems: graph partitioning and the traveling salesman problem.
SYNTHESIS, APPLICATIONS, AND CHARACTERIZATION OF GUERBET COMPOUNDS AND THEIR DERIVATIVES
Technology Transfer Automated Retrieval System (TEKTRAN)
The Guerbet reaction and Guerbet compounds, particularly Guerbet alcohols, have been known for more than a century. Guerbet compounds are used in commercial applications such as lubricants, plasticizers, cosmetics, etc., due to their interesting properties. This article provides basic information ...
Derivation and application of a class of generalized boundary conditions
NASA Technical Reports Server (NTRS)
Senior, Thomas B. A.; Volakis, John L.
1989-01-01
Boundary conditions involving higher order derivatives are presented for simulating surfaces whose reflection coefficients are known analytically, numerically, or experimentally. Procedures for determining the coefficients of the derivatives are discussed, along with the effect of displacing the surface where the boundary conditions are applied. Provided the coefficients satisfy a duality relation, equivalent forms of the boundary conditions involving tangential field components are deduced, and these provide the natural extension to nonplanar surfaces. As an illustration, the simulation of metal-backed uniform and three-layer dielectric coatings is given. It is shown that fourth order conditions are capable of providing an accurate simulation for uniform coating at least a quarter of a wavelength in thickness.
Massive graviton on arbitrary background: derivation, syzygies, applications
Bernard, Laura; Deffayet, Cédric; Strauss, Mikael von
2015-06-23
We give the detailed derivation of the fully covariant form of the quadratic action and the derived linear equations of motion for a massive graviton in an arbitrary background metric (which were presented in arXiv:1410.8302 [hep-th]). Our starting point is the de Rham-Gabadadze-Tolley (dRGT) family of ghost free massive gravities and using a simple model of this family, we are able to express this action and these equations of motion in terms of a single metric in which the graviton propagates, hence removing in particular the need for a “reference metric' which is present in the non perturbative formulation. We show further how 5 covariant constraints can be obtained including one which leads to the tracelessness of the graviton on flat space-time and removes the Boulware-Deser ghost. This last constraint involves powers and combinations of the curvature of the background metric. The 5 constraints are obtained for a background metric which is unconstrained, i.e. which does not have to obey the background field equations. We then apply these results to the case of Einstein space-times, where we show that the 5 constraints become trivial, and Friedmann-Lemaître-Robertson-Walker space-times, for which we correct in particular some results that appeared elsewhere. To reach our results, we derive several non trivial identities, syzygies, involving the graviton fields, its derivatives and the background metric curvature. These identities have their own interest. We also discover that there exist backgrounds for which the dRGT equations cannot be unambiguously linearized.
Stability Characterization of Quinazoline Derivative BG1188 by Optical Methods
NASA Astrophysics Data System (ADS)
Militaru, Andra; Smarandache, Adriana; Mahamoud, Abdallah; Damian, Victor; Ganea, Paul; Alibert, Sandrine; Pagès, Jean-Marie; Pascu, Mihail-Lucian
2011-08-01
3-[2-(dimethylamino)ethyl]-6-nitroquinazolin-4(3H)-one, labeled BG1188, is a new synthesized compound, out of a series of quinazoline derivatives developed to fight the multidrug resistance of antibiotics acquired by bacteria. A characterization of the BG1188 powder was made using FTIR spectra in order to evidence the functional groups in the medicine's molecule. The ultraviolet-visible (UV-Vis) absorption spectra were used to study the stability of the BG1188 solutions in two solvents and at different temperatures. BG1188 concentration in ultrapure water was varied between 2×10-3 M (stock solution) and 10-6 M. The concentration recommended by higher activity on bacteria was 10-3 M. For the same reason, this was the utilized concentration of BG1188 in dimethyl sulfoxide (DMSO). Time stability was characterized by comparing the time evolution of the UV-Vis absorption spectra of the BG1188 solutions in ultrapure de-ionized water or in DMSO. The spectra were recorded daily for about 4 months after the preparation for the BG1188 solutions in ultrapure water. Generally, samples are stable within the experimental errors at concentrations higher than 10-5 M, but the stability time interval may vary from 119 days at 10-4 M to 34 days at 10-5 M. Time evolution of the absorption spectra at 10-3 M in ultrapure water shows reproducibility within the measuring errors (±1.045%) for time intervals up to 1032 hours (more than 40 days) after preparation. On the other hand, BG1188 solutions in DMSO may be considered unstable because the absorption spectra modify in terms of peak shapes and intensities, indicating that the samples exhibit modifications immediately after preparation. Regardless the solvent used, some aggregation phenomena took place and wire-like aggregates were observed in all the solutions with the naked eye. These aggregates were analyzed, tentatively, using optical microscopy and FTIR.
Cationic porphyrin derivatives for application in photodynamic therapy of cancer
NASA Astrophysics Data System (ADS)
Prack McCormick, Bárbara P.; Florencia Pansa, M.; Milla Sanabria, Laura N.; Carvalho, Carla M. B.; Faustino, M. Amparo F.; Neves, Maria Graça P. M. S.; Cavaleiro, José A. S.; Rumie Vittar, Natalia B.; Rivarola, Viviana A.
2014-04-01
Current studies in photodynamic therapy (PDT) against cancer are focused on the development of new photosensitizers (PSs), with higher phototoxic action. The aim of this study was to compare the therapeutic efficiency of tri-cationic meso-substituted porphyrin derivatives (Tri-Py+-Me-PF, Tri-Py+-Me-Ph, Tri-Py+-Me-CO2Me and Tri-Py+-Me-CO2H) with the well-known tetra-cationic T4PM. The phototoxic action of these derivatives was assessed in human colon adenocarcinoma cells by cell viability, intracellular localization and nuclear morphology analysis. In the experimental conditions used we determined that after light activation -PF, -Ph and -CO2Me cause a more significant decline of cell viability compared to -CO2H and T4PM. These results suggest that the nature of the peripheral substituent influences the extent of cell photodamage. Moreover, we have demonstrated that PS concentration, physicochemical properties and further light activation determine the PDT response. All porphyrins were clearly localized as a punctuated pattern in the cytoplasm of the cells, and the PDT scheme resulted in apoptotic cell death after 3 h post-PDT. The tri-cationic porphyrin derivatives Tri-Py+-Me-PF, Tri-Py+-Me-Ph and Tri-Py+-Me-CO2Me showed a promising ability, making them good photosensitizer candidates for oncological PDT.
González, Sheyla; Ibáñez, Elena
2010-01-01
Purpose The aim of the present study is to compare three previously described mouse embryonic stem cell derivation methods to evaluate the influence of culture conditions, number of isolated blastomeres and embryonic stage in the derivation process. Methods Three embryonic stem cell derivation methods: standard, pre-adhesion and defined culture medium method, were compared in the derivation from isolated blastomeres and whole embryos at 4- and 8-cell stages. Results A total of 200 embryonic stem cell lines were obtained with an efficiency ranging from 1.9% to 72%. Conclusions Using either isolated blastomeres or whole embryos, the highest rates of mouse embryonic stem cell establishment were achieved with the defined culture medium method and efficiencies increased as development progressed. Using isolated blastomeres, efficiencies increased in parallel to the proportion of the embryo volume used to start the derivation process. PMID:20862536
A New Method for Deriving Global Estimates of Maternal Mortality.
Wilmoth, John R; Mizoguchi, Nobuko; Oestergaard, Mikkel Z; Say, Lale; Mathers, Colin D; Zureick-Brown, Sarah; Inoue, Mie; Chou, Doris
2012-07-13
Maternal mortality is widely regarded as a key indicator of population health and of social and economic development. Its levels and trends are monitored closely by the United Nations and others, inspired in part by the UN's Millennium Development Goals (MDGs), which call for a three-fourths reduction in the maternal mortality ratio between 1990 and 2015. Unfortunately, the empirical basis for such monitoring remains quite weak, requiring the use of statistical models to obtain estimates for most countries. In this paper we describe a new method for estimating global levels and trends in maternal mortality. For countries lacking adequate data for direct calculation of estimates, we employed a parametric model that separates maternal deaths related to HIV/AIDS from all others. For maternal deaths unrelated to HIV/AIDS, the model consists of a hierarchical linear regression with three predictors and variable intercepts for both countries and regions. The uncertainty of estimates was assessed by simulating the estimation process, accounting for variability both in the data and in other model inputs. The method was used to obtain the most recent set of UN estimates, published in September 2010. Here, we provide a concise description and explanation of the approach, including a new analysis of the components of variability reflected in the uncertainty intervals. Final estimates provide evidence of a more rapid decline in the global maternal mortality ratio than suggested by previous work, including another study published in April 2010. We compare findings from the two recent studies and discuss topics for further research to help resolve differences. PMID:24416714
Computational methods for industrial radiation measurement applications
Gardner, R.P.; Guo, P.; Ao, Q.
1996-12-31
Computational methods have been used with considerable success to complement radiation measurements in solving a wide range of industrial problems. The almost exponential growth of computer capability and applications in the last few years leads to a {open_quotes}black box{close_quotes} mentality for radiation measurement applications. If a black box is defined as any radiation measurement device that is capable of measuring the parameters of interest when a wide range of operating and sample conditions may occur, then the development of computational methods for industrial radiation measurement applications should now be focused on the black box approach and the deduction of properties of interest from the response with acceptable accuracy and reasonable efficiency. Nowadays, increasingly better understanding of radiation physical processes, more accurate and complete fundamental physical data, and more advanced modeling and software/hardware techniques have made it possible to make giant strides in that direction with new ideas implemented with computer software. The Center for Engineering Applications of Radioisotopes (CEAR) at North Carolina State University has been working on a variety of projects in the area of radiation analyzers and gauges for accomplishing this for quite some time, and they are discussed here with emphasis on current accomplishments.
NASA Astrophysics Data System (ADS)
Yoshida, Kenichiro
2016-08-01
We derived the absorption coefficient ( μ a) and the reduced scattering coefficient ( μ s') using the edge-loss method (ELM) and the video reflectometry method (VRM), and compared the results. In a previous study, we developed the ELM to easily evaluate the lateral spread in the skin; the VRM is a conventional method. The ELM measures the translucency index, which is correlated with μ a and μ s'. To obtain a precise estimation of these parameters, we improved the treatment of a white standard and the surface reflection. For both skin phantoms and actual skin, the values for μ a and μ s' that we obtained using the ELM were similar to those obtained using the VRM, when μ a/ μ s' was less than or equal to 0.05 and the diffusion approximation was applicable. Under this condition, the spectral reflectivity is greater than 0.4. In this study, we considered wavelengths longer than 600 nm for Types III and IV of the Fitzpatrick scale. For skin, the repeatability errors of the parameters obtained with the ELM were smaller than those obtained with the VRM; this can be an advantage in field tests.
NASA Astrophysics Data System (ADS)
Yoshida, Kenichiro
2016-07-01
We derived the absorption coefficient (μ a) and the reduced scattering coefficient (μ s') using the edge-loss method (ELM) and the video reflectometry method (VRM), and compared the results. In a previous study, we developed the ELM to easily evaluate the lateral spread in the skin; the VRM is a conventional method. The ELM measures the translucency index, which is correlated with μ a and μ s'. To obtain a precise estimation of these parameters, we improved the treatment of a white standard and the surface reflection. For both skin phantoms and actual skin, the values for μ a and μ s' that we obtained using the ELM were similar to those obtained using the VRM, when μ a/μ s' was less than or equal to 0.05 and the diffusion approximation was applicable. Under this condition, the spectral reflectivity is greater than 0.4. In this study, we considered wavelengths longer than 600 nm for Types III and IV of the Fitzpatrick scale. For skin, the repeatability errors of the parameters obtained with the ELM were smaller than those obtained with the VRM; this can be an advantage in field tests.
Probabilistic structural analysis methods and applications
NASA Technical Reports Server (NTRS)
Cruse, T. A.; Wu, Y.-T.; Dias, B.; Rajagopal, K. R.
1988-01-01
An advanced algorithm for simulating the probabilistic distribution of structural responses due to statistical uncertainties in loads, geometry, material properties, and boundary conditions is reported. The method effectively combines an advanced algorithm for calculating probability levels for multivariate problems (fast probability integration) together with a general-purpose finite-element code for stress, vibration, and buckling analysis. Application is made to a space propulsion system turbine blade for which the geometry and material properties are treated as random variables.
Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.
Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing
2016-08-24
With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interesting morphology-a distinctly mesoporous structure. Moreover, the walls of fiber cells are composed of thousands of fibers (or macrofibrils) oriented in a similar angle. Nanofibrils and nanocrystals can be further liberated from macrofibrils by mechanical, chemical, and enzymatic methods. The obtained nanocellulose has unique optical, mechanical, and barrier properties and is an excellent candidate for chemical modification and reconfiguration. Wood is naturally a composite material, comprised of cellulose, hemicellulose, and lignin. Wood is sustainable, earth abundant, strong, biodegradable, biocompatible, and chemically accessible for modification; more importantly, multiscale natural fibers from wood have unique optical properties applicable to different kinds of optoelectronics and photonic devices. Today, the materials derived from wood are ready to be explored for applications in new technology areas, such as electronics, biomedical devices, and energy. The
Harmony Search Method: Theory and Applications
Gao, X. Z.; Govindasamy, V.; Xu, H.; Wang, X.; Zenger, K.
2015-01-01
The Harmony Search (HS) method is an emerging metaheuristic optimization algorithm, which has been employed to cope with numerous challenging tasks during the past decade. In this paper, the essential theory and applications of the HS algorithm are first described and reviewed. Several typical variants of the original HS are next briefly explained. As an example of case study, a modified HS method inspired by the idea of Pareto-dominance-based ranking is also presented. It is further applied to handle a practical wind generator optimal design problem. PMID:25945083
A Series of Imidazole Derivatives: Synthesis, Two-Photon Absorption, and Application for Bioimaging
Zhu, Yingzhong; Xiao, Lufei; Zhao, Meng; Zhou, Jiazheng; Zhang, Qiong; Wang, Hui; Li, Shengli; Zhou, Hongping; Wu, Jieying; Tian, Yupeng
2015-01-01
A new series of D-π-A type imidazole derivatives have been synthesized and characterized. Two corresponding imidazolium salts (iodine and hexafluorophosphate) were prepared from the imidazole compound. Their electron-withdrawing ability can be largely tunable by salt formation reaction or ion exchange. UV-vis absorption and single-photon fluorescence spectra have been systematically investigated in different solvents. The two-photon cross sections (δ2PA) of the imidazole derivatives are measured by two-photon excited fluorescence (2PEF) method. Compared with those of T-1 (107 GM) and T-3 (96 GM), T-2 (imidazolium iodine salt) has a large two-photon absorption (2PA) cross section value of 276 GM. Furthermore, the cytotoxicity and applications in bioimaging for the imidazole derivatives were carried out. The results showed that T-1 can be used as a lysosomal tracker with high stability and water solubility within pHs of 4–6, while T-2 and T-3 can be used as probes for cell cytoplasm. PMID:26579544
Ideal Diode Equation for Organic Heterojunctions. I. Derivation and Application
Giebink, Noel C; Wiederrecht, Gary P; Wasielewski, Michael R; Forrest, Stephen R.
2010-10-04
The current-voltage characteristics of organic heterojunctions (HJs) are often modeled using the generalized Shockley equation derived for inorganic diodes. However, since this description does not rigorously apply to organic semiconductor donor-acceptor (D-A) HJs, the extracted parameters lack a clear physical meaning. Here, we derive the current density-voltage (J-V) characteristic specifically for D-A HJ solar cells and show that it predicts the general dependence of dark current, open-circuit voltage (V_{oc}) , and short-circuit current (J_{oc}) on temperature and light intensity as well as the maximum V_{oc} for a given D-A material pair. We propose that trap-limited recombination due to disorder at the D-A interface leads to the introduction of two temperature-dependent ideality factors and show that this describes the dark current of copper phthalocyanine/C_{60} and boron subphthalocyanine/C_{60} cells at low temperature, where fits to the generalized Shockley equation break down. We identify the polaron pair recombination rate as a key factor that determines the J-V characteristics in the dark and under illumination and provide direct measurements of this process in our companion paper II [N. C. Giebink, B. E. Lassiter, G. P. Wiederrecht, M. R. Wasielewski, and S. R. Forrest, Phys. Rev. B 82, 155306 (2010)]. These results provide a general physical framework for interpreting the J-V characteristics
NASA Technical Reports Server (NTRS)
Yan, Jue; Shu, Chi-Wang; Bushnell, Dennis M. (Technical Monitor)
2002-01-01
In this paper we review the existing and develop new continuous Galerkin methods for solving time dependent partial differential equations with higher order derivatives in one and multiple space dimensions. We review local discontinuous Galerkin methods for convection diffusion equations involving second derivatives and for KdV type equations involving third derivatives. We then develop new local discontinuous Galerkin methods for the time dependent bi-harmonic type equations involving fourth derivatives, and partial differential equations involving fifth derivatives. For these new methods we present correct interface numerical fluxes and prove L(exp 2) stability for general nonlinear problems. Preliminary numerical examples are shown to illustrate these methods. Finally, we present new results on a post-processing technique, originally designed for methods with good negative-order error estimates, on the local discontinuous Galerkin methods applied to equations with higher derivatives. Numerical experiments show that this technique works as well for the new higher derivative cases, in effectively doubling the rate of convergence with negligible additional computational cost, for linear as well as some nonlinear problems, with a local uniform mesh.
Chemical reactivity and intracavitary application of alkylating sugar alcohol derivatives.
Kerpel-Fronius, S; Csetényi, J; Hegedüs, L; Horváth, I P; Ringwald, G; Töttössy, B; Eckhardt, S
1980-01-01
Lycurium [1,4-di-(methylsulfonyloxy-ethylamino)-1,4-didesoxy-erythrioldimethylsulfonate; R-74; NSC-122402] undergoes rapid hydrolysis in aqueous solutions. The concentration of the alkylating compound(s), demonstrated by the 4-(4'-nitrobenzyl)pyridine reaction, decreases approximately by 80% in 10 min following the dissolution of the drug in saline. In patients peak plasma concentration of radioactivity after the intracavitary injection of 14C-labelled Lycurim is observed between 4 and 6 h. It is assumed, therefore, that only a negligible amount of pharmacologically active alkylating compounds reaches the circulation after intracavitary application. This conclusion is supported by clinical experience showing that intracavitary administration of the same amount of Lycurim causes much milder systemic side-effects than intravenous injection. A dose escalation study was started to determine the applicability of Lycurim in the form of high volume intraperitoneal instillation ('belly bath') for the treatment of ovarian cancer. PMID:6893858
New Mathematical Derivations Applicable to Safety and Reliability Analysis
Cooper, J.A.; Ferson, S.
1999-04-19
Boolean logic expressions are often derived in safety and reliability analysis. Since the values of the operands are rarely exact, accounting for uncertainty with the tightest justifiable bounds is important. Accurate determination of result bounds is difficult when the inputs have constraints. One example of a constraint is that an uncertain variable that appears multiple times in a Boolean expression must always have the same value, although the value cannot be exactly specified. A solution for this repeated variable problem is demonstrated for two Boolean classes. The classes, termed functions with unate variables (including, but not limited to unate functions), and exclusive-or functions, frequently appear in Boolean equations for uncertain outcomes portrayed by logic trees (event trees and fault trees).
Deriving Hounsfield units using grey levels in cone beam CT: a clinical application
Reeves, TE; Mah, P; McDavid, WD
2012-01-01
Objective To present a clinical study demonstrating a method to derive Hounsfield units from grey levels in cone beam CT (CBCT). Methods An acrylic intraoral reference object with aluminium, outer bone equivalent material (cortical bone), inner bone equivalent material (trabecular bone), polymethlymethacrylate and water equivalent material was used. Patients were asked if they would be willing to have an acrylic bite plate with the reference object placed in their mouth during a routine CBCT scan. There were 31 scans taken on the Asahi Alphard 3030 (Belmont Takara, Kyoto, Japan) and 30 scans taken on the Planmeca ProMax 3D (Planmeca, Helsinki, Finland) CBCT. Linear regression between the grey levels of the reference materials and their linear attenuation coefficients was performed for various photon energies. The energy with the highest regression coefficient was chosen as the effective energy. The attenuation coefficients for the five materials at the effective energy were scaled as Hounsfield units using the standard Hounsfield units equation and compared to those derived from the measured grey levels of the materials using the regression equation. Results In general, there was a satisfactory linear relation between the grey levels and the attenuation coefficients. This made it possible to calculate Hounsfield units from the measured grey levels. Uncertainty in determining effective energies resulted in unrealistic effective energies and significant variability of calculated CT numbers. Linear regression from grey levels directly to Hounsfield units at specified energies resulted in greater consistency. Conclusions The clinical application of a method for deriving Hounsfield units from grey levels in CBCT was demonstrated. PMID:22752324
Cross-Linkable Fluorene-Diphenylamine Derivatives for Electrochromic Applications.
Abraham, Silja; Ganesh, Gayathri Prabhu T; Varughese, Sunil; Deb, Biswapriya; Joseph, Joshy
2015-11-18
Multicolor electrochromic systems based on heat cross-linkable arylamine-substituted fluorene derivatives, FD and FDOMe, are reported. These derivatives with pendant vinyl groups have been synthesized by the Buchwald-Hartwig amination reaction and were well-characterized using various analytical and spectroscopic techniques such as NMR, ESI-MS, and single-crystal X-ray diffraction analysis. FD and FDOMe exhibited thermally activated cross-linking above their melting temperatures, which was confirmed through absorption, differential scanning calorimetry (DSC), FT-IR, and wide-angle X-ray diffraction (WAXD) techniques. Cross-linked FD films (FD-X) on ITO showed two reversible redox peaks at 0.74 and 0.91 V (versus Ag/AgCl) that correspond to the formation of radical cations and dications, respectively. The corresponding redox peaks were observed at 0.6 and 0.8 V for cross-linked FDOMe films (FDOMe-X). Spectroelectrochemical studies of the electrochromic films on ITO revealed multicolor electrochromism of FD-X (colorless-yellow-dark cyan) and FDOMe-X (colorless-brick red-blue) with a color contrast of ∼44% at 485 nm for FD-X and ∼63% at 500 nm for FDOMe-X and good switching stability between the neutral and oxidized states (>300 cycles) with low switching voltages (<0.9 V for the first oxidation and <1.3 V for the second oxidation). Furthermore, fabrication of electrochromic devices using FD-X and FDOMe-X on FTO substrate with PMMA-based solid electrolyte was demonstrated, where the devices exhibited reasonably low switching time between the redox states (<30 s) with good optical contrast. PMID:26496020
Ideal diode equation for organic heterojunctions. I. Derivation and application
Giebink, Noel C; Wiederrecht, Gary P; Wasielewski, Michael R; Forrest, Stephen R.
2010-10-04
The current-voltage characteristics of organic heterojunctions (HJs) are often modeled using the generalized Shockley equation derived for inorganic diodes. However, since this description does not rigorously apply to organic semiconductor donor-acceptor (D-A) HJs, the extracted parameters lack a clear physical meaning. Here, we derive the current density-voltage (J-V) characteristic specifically for D-A HJ solar cells and show that it predicts the general dependence of dark current, open-circuit voltage (V{sub oc} ) , and short-circuit current (J{sub sc} ) on temperature and light intensity as well as the maximum V{sub oc} for a given D-A material pair. We propose that trap-limited recombination due to disorder at the D-A interface leads to the introduction of two temperature-dependent ideality factors and show that this describes the dark current of copper phthalocyanine/C{sub 60} and boron subphthalocyanine/C{sub 60} cells at low temperature, where fits to the generalized Shockley equation break down. We identify the polaron pair recombination rate as a key factor that determines the J-V characteristics in the dark and under illumination and provide direct measurements of this process in our companion paper II [N. C. Giebink, B. E. Lassiter, G. P. Wiederrecht, M. R. Wasielewski, and S. R. Forrest, Phys. Rev. B 82, 155306 (2010)]. These results provide a general physical framework for interpreting the J-V characteristics and understanding the efficiency of both small molecule and polymer organic, planar and bulk HJ solar cells.
The flame retardant properties of cyanuric chloride derivatives in cotton textile applications
Technology Transfer Automated Retrieval System (TEKTRAN)
Cyanuric chloride derivatives are promising flame retardants in cotton textile applications due to their ease of synthesis, high yield, and excellent flame retardant properties as measured by thermogravimetric analyses, limiting oxygen index, and vertical flame testing. Scanning electron microscopic...
NASA Astrophysics Data System (ADS)
Grima, C.; Schroeder, D. M.; Blankenship, D. D.; Young, D. A.
2013-12-01
Geological and climatic processes shaping the landscape of planetary bodies imprint the surface with particular textures, i.e. continuous topographic entities at meters to decameters scales where the surface elevation is dominated by a stochastic behavior. The so-called roughness is a proxy to get insights into the type of surface terrain and its ongoing evolution. It is also an important descriptor involved in landing site selection processes to ensure the safe delivery of a lander/rover over a stable work zone. Planetary surface roughnesses are usually derived from point-to-point elevation models acquired by laser altimetry or stereo-imagery. However, in the last decade, nadir-looking penetrating radars have become another remote-sensing technology commonly used for planetary surface and sub-surface characterization (e.g. MARSIS/SHARAD on Mars, LRS on the Moon, and Ice Penetrating Radars for future missions to Europa). Here, we present a statistical method to extract the reflected and scattered components embedded in the surface echoes of HF (3-30 MHz) and VHF (30-300 MHz) penetrating radars in order to derive significant roughness information. We demonstrate the reliability of the method with an application to a radar dataset acquired during the 2004-05 austral summer campaign of the Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica, (AGASEA) project with the High-Capability Radar Sounder (HiCARS, 60 MHz) system operated by the University of Texas Institute for Geophysics (UTIG). Results are thoroughly compared with simultaneously acquired laser altimetry and nadir imagery of the surface. We emphasize the possibilities and advantages of the method in light of the future exploration of the Europa and Ganymede icy moons by multi-frequency ice penetrating radars.
Welcome to Methods and Applications in Fluorescence
NASA Astrophysics Data System (ADS)
Birch, David; Mély, Yves; Wolfbeis, Otto S.
2013-03-01
On behalf of the Editorial Board of Methods and Applications in Fluorescence and IOP Publishing we are delighted to invite you to read the first articles in our new journal. Methods and Applications in Fluorescence is forged out of the renowned MAF conference series of the same name and we fully expect the natural synergy between the two to provide the ideal platform for moving the field of fluorescence forward. Our aim is for this new journal to reflect the truly global and diverse impact fluorescence is having across many disciplines and help fluorescence achieve its full potential. Just as MAF is the leading conference in fluorescence we are confident of the high impact of this new journal. Methods and Applications in Fluorescence has a distinguished Editorial Board that is drawn from the MAF conference Permanent Steering Committee. Together with the Editorial Board and the rest of the community, the journal will closely track the very latest developments in fluorescence while delivering a fair and constructive review process. We are very pleased that this journal is backed by the Institute of Physics, one of the world's premier learned societies. IOP Publishing has a wealth of experience in science publishing that dates back to 1874. It is a not-for-profit organization that publishes over 60 journals, many on multidisciplinary topics and many including seminal contributions from Nobel Laureates. Any funding surplus generated by IOP Publishing goes directly back into science through the Institute of Physics, thus helping to nurture science for future generations. We invite submissions as regular articles, review articles and technical notes within the scope of the journal, which includes all the major aspects of fluorescence. This covers both theory and experiment across spectroscopy, imaging, materials, labels, probes and sensors. The applications of fluorescence to emerging areas in bionanotechnology, nanotechnology and medicine are very much part of the
Park, Jeong-Ran; Kim, Eunjeong; Yang, Jungwon; Lee, Hanbyeol; Hong, Seok-Ho; Woo, Heung-Myong; Park, Sung-Min; Na, Sunghun; Yang, Se-Ran
2015-06-01
Recent studies have reported that stem cells can be isolated from a wide range of tissues including bone marrow, fatty tissue, adipose tissue and placenta. Moreover, several studies also suggest that skin dermis could serve as a source of stem cells, but are of unclear phenotype. Therefore, we isolated and investigated to determine the potential of stem cell within human skin dermis. We isolated cells from human dermis, termed here as human dermis-derived mesenchymal stem cells (hDMSCs) which is able to be isolated by using explants culture method. Our method has an advantage over the enzymatic method as it is easier, less expensive and less cell damage. hDMSCs were maintained in basal culture media and proliferation potential was measured. hDMSCs were highly proliferative and successfully expanded with no additional growth factor. In addition, hDMSCs revealed normal karyotype and expressed high levels of CD90, CD73 and CD105 while did not express the surface markers for CD34, CD45 and HLA-DR. Also, we confirmed that hDMSCs possess the capacity to differentiate into multiple lineage including adipocyte, osteocyte, chondrocyte and precursor of hepatocyte lineage. Considering these results, we suggest that hDMSCs might be a valuable source of stem cells and could potentially be a useful source of clinical application. PMID:25163610
Medical Application of Spirulina platensis Derived C-Phycocyanin
Liu, Qian; Huang, Yinghong; Zhang, Ronghua; Cai, Tiange; Cai, Yu
2016-01-01
Along with the development of marine biological pharmaceutical research, high-effective and low-toxic drugs and functional foods isolated from marine organisms have become a new field of pharmacy and bromatology. The pharmacological actions, such as anti-inflammation, antioxidation, antitumor, immunological enhancement, and hepatorenal protection of C-phycocyanin (C-PC) from Spirulina platensis, have been reported, and C-PC has important value of development and utilization either as drug or as functional food. There are many researches about the various pharmacological actions and mechanisms of C-PC, but related reports are only to some extent integrated deeply and accurately enough, which put some limitations to the further application of C-PC in medicine. Particularly, with the improvement of living standards and attention to health issues, C-PC being a functional food is preferred by more and more people. C-PC is easy to get, safe, and nontoxic; thus, it has a great potential of research and development as a drug or functional food. Here, the separation and purification, physicochemical properties, physiological and pharmacological activities, safety, and some applications are reviewed to provide relevant basis for the development of natural medicine and applied products. PMID:27293463
Medical Application of Spirulina platensis Derived C-Phycocyanin.
Liu, Qian; Huang, Yinghong; Zhang, Ronghua; Cai, Tiange; Cai, Yu
2016-01-01
Along with the development of marine biological pharmaceutical research, high-effective and low-toxic drugs and functional foods isolated from marine organisms have become a new field of pharmacy and bromatology. The pharmacological actions, such as anti-inflammation, antioxidation, antitumor, immunological enhancement, and hepatorenal protection of C-phycocyanin (C-PC) from Spirulina platensis, have been reported, and C-PC has important value of development and utilization either as drug or as functional food. There are many researches about the various pharmacological actions and mechanisms of C-PC, but related reports are only to some extent integrated deeply and accurately enough, which put some limitations to the further application of C-PC in medicine. Particularly, with the improvement of living standards and attention to health issues, C-PC being a functional food is preferred by more and more people. C-PC is easy to get, safe, and nontoxic; thus, it has a great potential of research and development as a drug or functional food. Here, the separation and purification, physicochemical properties, physiological and pharmacological activities, safety, and some applications are reviewed to provide relevant basis for the development of natural medicine and applied products. PMID:27293463
Antimicrobial bacteriophage-derived proteins and therapeutic applications
Roach, Dwayne R; Donovan, David M
2015-01-01
Antibiotics have the remarkable power to control bacterial infections. Unfortunately, widespread use, whether regarded as prudent or not, has favored the emergence and persistence of antibiotic resistant strains of human pathogenic bacteria, resulting in a global health threat. Bacteriophages (phages) are parasites that invade the cells of virtually all known bacteria. Phages reproduce by utilizing the host cell's machinery to replicate viral proteins and genomic material, generally damaging and killing the cell in the process. Thus, phage can be exploited therapeutically as bacteriolytic agents against bacteria. Furthermore, understanding of the molecular processes involved in the viral life cycle, particularly the entry and cell lysis steps, has led to the development of viral proteins as antibacterial agents. Here we review the current preclinical state of using phage-derived endolysins, virion-associated peptidoglycan hydrolases, polysaccharide depolymerases, and holins for the treatment of bacterial infection. The scope of this review is a focus on the viral proteins that have been assessed for protective effects against human pathogenic bacteria in animal models of infection and disease. PMID:26442196
A New Method for Deriving the Stellar Birth Function of Resolved Stellar Populations.
NASA Astrophysics Data System (ADS)
Gennaro, M.; Tchernyshyov, K.; Brown, T. M.; Gordon, K. D.
2015-07-01
We present a new method for deriving the stellar birth function (SBF) of resolved stellar populations. The SBF (stars born per unit mass, time, and metallicity) is the combination of the initial mass function (IMF), the star formation history (SFH), and the metallicity distribution function (MDF). The framework of our analysis is that of Poisson Point Processes (PPPs), a class of statistical models suitable when dealing with points (stars) in a multidimensional space (the measurement space of multiple photometric bands). The theory of PPPs easily accommodates the modeling of measurement errors as well as that of incompleteness. Our method avoids binning stars in the color–magnitude diagram and uses the whole likelihood function for each data point; combining the individual likelihoods allows the computation of the posterior probability for the population's SBF. Within the proposed framework it is possible to include nuisance parameters, such as distance and extinction, by specifying their prior distributions and marginalizing over them. The aim of this paper is to assess the validity of this new approach under a range of assumptions, using only simulated data. Forthcoming work will show applications to real data. Although it has a broad scope of possible applications, we have developed this method to study multi-band Hubble Space Telescope observations of the Milky Way Bulge. Therefore we will focus on simulations with characteristics similar to those of the Galactic Bulge. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by AURA, Inc., under NASA contract NAS 5-26555.
Synthesis and Applications of Ionic Liquids Derived from Natural Sugars
NASA Astrophysics Data System (ADS)
Chiappe, Cinzia; Marra, Alberto; Mele, Andrea
Aiming to develop environmentally compatible chemical syntheses, the replacement of traditional organic solvents with ionic liquids (ILs) has attracted considerable attention. ILs are special molten salts with melting points below 100°C that are typically constituted of organic cations (imidazolium, pyridinium, sulfonium, phosphonium, etc.) and inorganic anions. Due to their ionic nature, they are endowed with high chemical and thermal stability, good solvent properties, and non-measurable vapor pressure. Although the recovery of unaltered ILs and recycling partly compensate their rather high cost, it is important to develop new synthetic approaches to less expensive and environmentally sustainable ILs based on renewable raw materials. In fact, most of these alternative solvents are still prepared starting from fossil feedstocks. Until now, only a limited number of ILs have been prepared from renewable sources. Surprisingly, the most available and inexpensive raw material, i.e., carbohydrates, has been hardly exploited in the synthesis of ILs. In 2003 imidazolium-based ILs were prepared from d-fructose and used as solvents in Mizoroki-Heck and Diels-Alder reactions. Later on, the first chiral ILs derived from sugars were prepared from methyl d-glucopyranoside. In the same year, a family of new chiral ILs, obtained from commercial isosorbide (dianhydro-d-glucitol), was described. A closely related approach was followed by other researchers to synthesize mono- and bis-ammonium ILs from isomannide (dianhydro-d-mannitol). Finally, a few ILs bearing a pentofuranose unit as the chiral moiety were prepared using sugar phosphates as glycosyl donors and 1-methylimidazole as the acceptor.
Application of cow milk-derived carbon dots/Ag NPs composite as the antibacterial agent
NASA Astrophysics Data System (ADS)
Han, Shuai; Zhang, He; Xie, Yujie; Liu, Liangliang; Shan, Changfu; Li, Xiangkai; Liu, Weisheng; Tang, Yu
2015-02-01
Cow milk-derived carbon dots (CMCDs) were prepared by hydrothermal treatment of cow milk, and the as-prepared CMCDs were further extracted by ethyl acetate to obtain amphiphilic CMCDs (ACMCDs). Using the ACMCDs both as a reducing agent and a template, the ACMCDs-supported silver nanoparticles (ACMCD-Ag nanocomposites) were prepared, which showed good biocidal effect on both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacterias. After that, a novel ACMCD-Ag/polymethylmethacrylate nanocomposite antibacterial film was fabricated by solvent casting method. Due to the excellent antibacterial, light admitting, and flexible properties, the nanocomposite antibacterial film is considered to be of great potential in applications.
On the applications of algebraic grid generation methods based on transfinite interpolation
NASA Technical Reports Server (NTRS)
Nguyen, Hung Lee
1989-01-01
Algebraic grid generation methods based on transfinite interpolation called the two-boundary and four-boundary methods are applied for generating grids with highly complex boundaries. These methods yield grid point distributions that allow for accurate application to regions of sharp gradients in the physical domain or time-dependent problems with small length scale phenomena. Algebraic grids are derived using the two-boundary and four-boundary methods for applications in both two- and three-dimensional domains. Grids are developed for distinctly different geometrical problems and the two-boundary and four-boundary methods are demonstrated to be applicable to a wide class of geometries.
Gabel, D.
1991-06-04
The present invention pertains to boron containing thiouracil derivatives, their method of preparations, and their use in the therapy of malignant melanoma using boron neutron capture therapy. No Drawings
Development of Mass Spectrometric Ionization Methods for Fullerenes and Fullerene Derivatives
Currently investigations into the environmental behavior of fullerenes and fullerene derivatives is hampered by the lack of well characterized standards and by the lack of readily available quantitative analytical methods. Reported herein are investigations into the utility of ma...
Global Precipitation Measurement: Methods, Datasets and Applications
NASA Technical Reports Server (NTRS)
Tapiador, Francisco; Turk, Francis J.; Petersen, Walt; Hou, Arthur Y.; Garcia-Ortega, Eduardo; Machado, Luiz, A. T.; Angelis, Carlos F.; Salio, Paola; Kidd, Chris; Huffman, George J.; De Castro, Manuel
2011-01-01
This paper reviews the many aspects of precipitation measurement that are relevant to providing an accurate global assessment of this important environmental parameter. Methods discussed include ground data, satellite estimates and numerical models. First, the methods for measuring, estimating, and modeling precipitation are discussed. Then, the most relevant datasets gathering precipitation information from those three sources are presented. The third part of the paper illustrates a number of the many applications of those measurements and databases. The aim of the paper is to organize the many links and feedbacks between precipitation measurement, estimation and modeling, indicating the uncertainties and limitations of each technique in order to identify areas requiring further attention, and to show the limits within which datasets can be used.
Application of multifocusing method for subsurface imaging
NASA Astrophysics Data System (ADS)
Landa, Evgeny; Gurevich, Boris; Keydar, Shemer; Trachtman, Pinchas
1999-12-01
The multifocusing method consists of stacking seismic data with arbitrary source-receiver distribution according to a new paraxial moveout correction. This multifocusing moveout correction is based on a local spherical approximation of the reflection wave fronts in the vicinity of an observation surface. The multifocusing method does not require any knowledge of the subsurface model and can produce an accurate zero offset section, even in cases of a complex geological structure and/or low signal-to-noise ratio. The moveout correction parameters are the emergence angle and the wavefront curvatures for the normal wave and normal-incidence-point wave. The estimated sets of these parameters can be looked upon as new wavefield attributes containing important information regarding the subsurface model. Application of the multifocusing algorithm to synthetic and real data examples demonstrates its advantages in comparison with conventional CMP processing.
Coordinate-Free Methods with Applications
NASA Astrophysics Data System (ADS)
Rolf, Steven R.
A formalism for the coordinate-free description of the vector properties of a physical system has been developed. A concise definition of coordinate-free vectors, dyadics and their algebraic properties are presented. It is demonstrated that a finite number of independent vectors in a system leads to a complete set of dyadic operators based upon these vectors. These operators are shown to obey a closed, associative algebra. Several sets of operators are demonstrated for one and two vectors in two and three dimensions, including a dyadic representation of the Pauli matrices. The algebra for these operators is exploited to reduce an arbitrary function of the dyadics to a linear combination of them. This result is used to find the inverse of a linear combination of the dyadic operators and to define a generalized rotation operator. Applications to electrodynamics include the derivation of optical rotation in gyrotropic media and the general solution for the dispersion relations and polarization states of a wave propagating in a conductive medium. This last result has been applied to a cold, magnetized plasma. It is demonstrated that Faraday rotation results for an arbitrarily directed wave in such a plasma.
Boundary Value Technique for Initial Value Problems Based on Adams-Type Second Derivative Methods
ERIC Educational Resources Information Center
Jator, S. N.; Sahi, R. K.
2010-01-01
In this article, we propose a family of second derivative Adams-type methods (SDAMs) of order up to 2k + 2 ("k" is the step number) for initial value problems. The methods are constructed through a continuous approximation of the SDAM which is obtained by multistep collocation. The continuous approximation is used to obtain initial value methods,…
Novel applications of fast neutron interrogation methods
NASA Astrophysics Data System (ADS)
Gozani, Tsahi
1994-12-01
The development of non-intrusive inspection methods for contraband consisting primarily of carbon, nitrogen, oxygen, and hydrogen requires the use of fast neutrons. While most elements can be sufficiently well detected by the thermal neutron capture process, some important ones, e.g., carbon and in particular oxygen, cannot be detected by this process. Fortunately, fast neutrons, with energies above the threshold for inelastic scattering, stimulate relatively strong and specific gamma ray lines from these elements. The main lines are: 6.13 for O, 4.43 for C, and 5.11, 2.31 and 1.64 MeV for N. Accelerator-generated neutrons in the energy range of 7 to 15 MeV are being considered as interrogating radiations in a variety of non-intrusive inspection systems for contraband, from explosives to drugs and from coal to smuggled, dutiable goods. In some applications, mostly for inspection of small items such as luggage, the decision process involves a rudimentary imaging, akin to emission tomography, to obtain the localized concentration of various elements. This technique is called FNA — Fast Neutron Analysis. While this approach offers improvements over the TNA (Thermal Neutron Analysis), it is not applicable to large objects such as shipping containers and trucks. For these challenging applications, a collimated beam of neutrons is rastered along the height of the moving object. In addition, the neutrons are generated in very narrow nanosecond pulses. The point of their interaction inside the object is determined by the time of flight (TOF) method, that is measuring the time elapsed from the neutron generation to the time of detection of the stimulated gamma rays. This technique, called PFNA (Pulsed Fast Neutron Analysis), thus directly provides the elemental, and by inference, the chemical composition of the material at every volume element (voxel) of the object. The various neutron-based techniques are briefly described below.
Engineering derivatives from biological systems for advanced aerospace applications
NASA Technical Reports Server (NTRS)
Winfield, Daniel L.; Hering, Dean H.; Cole, David
1991-01-01
The present study consisted of a literature survey, a survey of researchers, and a workshop on bionics. These tasks produced an extensive annotated bibliography of bionics research (282 citations), a directory of bionics researchers, and a workshop report on specific bionics research topics applicable to space technology. These deliverables are included as Appendix A, Appendix B, and Section 5.0, respectively. To provide organization to this highly interdisciplinary field and to serve as a guide for interested researchers, we have also prepared a taxonomy or classification of the various subelements of natural engineering systems. Finally, we have synthesized the results of the various components of this study into a discussion of the most promising opportunities for accelerated research, seeking solutions which apply engineering principles from natural systems to advanced aerospace problems. A discussion of opportunities within the areas of materials, structures, sensors, information processing, robotics, autonomous systems, life support systems, and aeronautics is given. Following the conclusions are six discipline summaries that highlight the potential benefits of research in these areas for NASA's space technology programs.
A Multi-Modal Face Recognition Method Using Complete Local Derivative Patterns and Depth Maps
Yin, Shouyi; Dai, Xu; Ouyang, Peng; Liu, Leibo; Wei, Shaojun
2014-01-01
In this paper, we propose a multi-modal 2D + 3D face recognition method for a smart city application based on a Wireless Sensor Network (WSN) and various kinds of sensors. Depth maps are exploited for the 3D face representation. As for feature extraction, we propose a new feature called Complete Local Derivative Pattern (CLDP). It adopts the idea of layering and has four layers. In the whole system, we apply CLDP separately on Gabor features extracted from a 2D image and depth map. Then, we obtain two features: CLDP-Gabor and CLDP-Depth. The two features weighted by the corresponding coefficients are combined together in the decision level to compute the total classification distance. At last, the probe face is assigned the identity with the smallest classification distance. Extensive experiments are conducted on three different databases. The results demonstrate the robustness and superiority of the new approach. The experimental results also prove that the proposed multi-modal 2D + 3D method is superior to other multi-modal ones and CLDP performs better than other Local Binary Pattern (LBP) based features. PMID:25333290
A multi-modal face recognition method using complete local derivative patterns and depth maps.
Yin, Shouyi; Dai, Xu; Ouyang, Peng; Liu, Leibo; Wei, Shaojun
2014-01-01
In this paper, we propose a multi-modal 2D + 3D face recognition method for a smart city application based on a Wireless Sensor Network (WSN) and various kinds of sensors. Depth maps are exploited for the 3D face representation. As for feature extraction, we propose a new feature called Complete Local Derivative Pattern (CLDP). It adopts the idea of layering and has four layers. In the whole system, we apply CLDP separately on Gabor features extracted from a 2D image and depth map. Then, we obtain two features: CLDP-Gabor and CLDP-Depth. The two features weighted by the corresponding coefficients are combined together in the decision level to compute the total classification distance. At last, the probe face is assigned the identity with the smallest classification distance. Extensive experiments are conducted on three different databases. The results demonstrate the robustness and superiority of the new approach. The experimental results also prove that the proposed multi-modal 2D + 3D method is superior to other multi-modal ones and CLDP performs better than other Local Binary Pattern (LBP) based features. PMID:25333290
Mihailova, A; Pedentchouk, N; Kelly, S D
2014-07-01
The lack of reliable markers for the discrimination between organic and conventional products makes the organic food market susceptible to attempted fraud. Robust analytical methodologies for organic food authentication are urgently needed. In this study a new approach, compound-specific nitrogen and oxygen isotope analysis of plant-derived nitrate, has been applied alongside bulk nitrogen isotope analysis for discrimination between organically and conventionally greenhouse-grown lettuce and retail potatoes and tomatoes. The method revealed significant differences between conventional and organic fertilisation. An intra-plant isotopic variation as well as significant impact of the fertiliser application rate on the nitrogen and oxygen isotope values of plant-derived nitrate has been observed. Nitrogen and oxygen isotope analysis of nitrate has a potential for differentiation between organic and conventional crops. Further analysis is needed to improve our understanding of the scope of application and robustness of this compound-specific approach. PMID:24518338
Methods of geodiversity assessment and theirs application
NASA Astrophysics Data System (ADS)
Zwoliński, Zbigniew; Najwer, Alicja; Giardino, Marco
2016-04-01
The concept of geodiversity has rapidly gained the approval of scientists around the world (Wiedenbein 1993, Sharples 1993, Kiernan 1995, 1996, Dixon 1996, Eberhard 1997, Kostrzewski 1998, 2011, Gray 2004, 2008, 2013, Zwoliński 2004, Serrano, Ruiz- Flano 2007, Gordon et al. 2012). However, the problem recognition is still at an early stage, and in effect not explicitly understood and defined (Najwer, Zwoliński 2014). Nevertheless, despite widespread use of the concept, little progress has been made in its assessment and mapping. Less than the last decade can be observing investigation of methods for geodiversity assessment and its visualisation. Though, many have acknowledged the importance of geodiversity evaluation (Kozłowski 2004, Gray 2004, Reynard, Panizza 2005, Zouros 2007, Pereira et al. 2007, Hjort et al. 2015). Hitherto, only a few authors have undertaken that kind of methodological issues. Geodiversity maps are being created for a variety of purposes and therefore their methods are quite manifold. In the literature exists some examples of the geodiversity maps applications for the geotourism purpose, basing mainly on the geological diversity, in order to point the scale of the area's tourist attractiveness (Zwoliński 2010, Serrano and Gonzalez Trueba 2011, Zwoliński and Stachowiak 2012). In some studies, geodiversity maps were created and applied to investigate the spatial or genetic relationships with the richness of particular natural environmental components (Burnett et al. 1998, Silva 2004, Jačková, Romportl 2008, Hjort et al. 2012, 2015, Mazurek et al. 2015, Najwer et al. 2014). There are also a few examples of geodiversity assessment in order to geoconservation and efficient management and planning of the natural protected areas (Serrano and Gonzalez Trueba 2011, Pellitero et al. 2011, 2014, Jaskulska et al. 2013, Melelli 2014, Martinez-Grana et al. 2015). The most popular method of assessing the diversity of abiotic components of the natural
Zunjarrao, Suraj C.; Singh, Abhishek K.; Singh, Raman P.
2006-07-01
Silicon carbide (SiC) is a promising candidate for several applications in nuclear reactors owing to its high thermal conductivity, high melting temperature, good chemical stability, and resistance to swelling under heavy ion bombardment. However, fabricating SiC by traditional powder processing route generally requires very high temperatures for pressureless sintering. Polymer derived ceramic materials offer unique advantages such as ability to fabricate net shaped components, incorporate reinforcements and relatively low processing temperatures. Furthermore, for SiC based ceramics fabricated using polymer infiltration process (PIP), the microstructure can be tailored by controlling the processing parameters, to get an amorphous, nanocrystalline or crystalline SiC. In this work, fabrication of polymer derived amorphous and nano-grained SiC is presented and its application as an in-core material is explored. Monolithic SiC samples are fabricated by controlled pyrolysis of allyl-hydrido-poly-carbo-silane (AHPCS) under inert atmosphere. Chemical changes, phase transformations and microstructural changes occurring during the pyrolysis process are studied as a function of the processing temperature. Polymer cross-linking and polymer to ceramic conversion is studied using infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) are performed to monitor the mass loss and phase change as a function of temperature. X-ray diffraction studies are done to study the intermediate phases and microstructural changes. Variation in density is carefully monitored as a function of processing temperature. Owing to shrinkage and gas evolution during pyrolysis, precursor derived ceramics are inherently porous and composite fabrication typically involves repeated cycles of polymer re-infiltration and pyrolysis. However, there is a limit to the densification that can be achieved by this method and porosity in the final materials presents
Formal methods demonstration project for space applications
NASA Technical Reports Server (NTRS)
Divito, Ben L.
1995-01-01
The Space Shuttle program is cooperating in a pilot project to apply formal methods to live requirements analysis activities. As one of the larger ongoing shuttle Change Requests (CR's), the Global Positioning System (GPS) CR involves a significant upgrade to the Shuttle's navigation capability. Shuttles are to be outfitted with GPS receivers and the primary avionics software will be enhanced to accept GPS-provided positions and integrate them into navigation calculations. Prior to implementing the CR, requirements analysts at Loral Space Information Systems, the Shuttle software contractor, must scrutinize the CR to identify and resolve any requirements issues. We describe an ongoing task of the Formal Methods Demonstration Project for Space Applications whose goal is to find an effective way to use formal methods in the GPS CR requirements analysis phase. This phase is currently under way and a small team from NASA Langley, ViGYAN Inc. and Loral is now engaged in this task. Background on the GPS CR is provided and an overview of the hardware/software architecture is presented. We outline the approach being taken to formalize the requirements, only a subset of which is being attempted. The approach features the use of the PVS specification language to model 'principal functions', which are major units of Shuttle software. Conventional state machine techniques form the basis of our approach. Given this background, we present interim results based on a snapshot of work in progress. Samples of requirements specifications rendered in PVS are offered to illustration. We walk through a specification sketch for the principal function known as GPS Receiver State processing. Results to date are summarized and feedback from Loral requirements analysts is highlighted. Preliminary data is shown comparing issues detected by the formal methods team versus those detected using existing requirements analysis methods. We conclude by discussing our plan to complete the remaining
NASA Astrophysics Data System (ADS)
Ivanyshyn Yaman, Olha; Le Louër, Frédérique
2016-09-01
This paper deals with the material derivative analysis of the boundary integral operators arising from the scattering theory of time-harmonic electromagnetic waves and its application to inverse problems. We present new results using the Piola transform of the boundary parametrisation to transport the integral operators on a fixed reference boundary. The transported integral operators are infinitely differentiable with respect to the parametrisations and simplified expressions of the material derivatives are obtained. Using these results, we extend a nonlinear integral equations approach developed for solving acoustic inverse obstacle scattering problems to electromagnetism. The inverse problem is formulated as a pair of nonlinear and ill-posed integral equations for the unknown boundary representing the boundary condition and the measurements, for which the iteratively regularized Gauss-Newton method can be applied. The algorithm has the interesting feature that it avoids the numerous numerical solution of boundary value problems at each iteration step. Numerical experiments are presented in the special case of star-shaped obstacles.
Potential Biological Applications of Bio-Based Anacardic Acids and Their Derivatives
Hamad, Fatma B.; Mubofu, Egid B.
2015-01-01
Cashew nut shells (CNS), which are agro wastes from cashew nut processing factories, have proven to be among the most versatile bio-based renewable materials in the search for functional materials and chemicals from renewable resources. CNS are produced in the cashew nut processing process as waste, but they contain cashew nut shell liquid (CNSL) up to about 30–35 wt. % of the nut shell weight depending on the method of extraction. CNSL is a mixture of anacardic acid, cardanol, cardol, and methyl cardol, and the structures of these phenols offer opportunities for the development of diverse products. For anacardic acid, the combination of phenolic, carboxylic, and a 15-carbon alkyl side chain functional group makes it attractive in biological applications or as a synthon for the synthesis of a multitude of bioactive compounds. Anacardic acid, which is about 65% of a CNSL mixture, can be extracted from the agro waste. This shows that CNS waste can be used to extract useful chemicals and thus provide alternative green sources of chemicals, apart from relying only on the otherwise declining petroleum based sources. This paper reviews the potential of anacardic acids and their semi-synthetic derivatives for antibacterial, antitumor, and antioxidant activities. The review focuses on natural anacardic acids from CNS and other plants and their semi-synthetic derivatives as possible lead compounds in medicine. In addition, the use of anacardic acid as a starting material for the synthesis of various biologically active compounds and complexes is reported. PMID:25894225
Potential biological applications of bio-based anacardic acids and their derivatives.
Hamad, Fatma B; Mubofu, Egid B
2015-01-01
Cashew nut shells (CNS), which are agro wastes from cashew nut processing factories, have proven to be among the most versatile bio-based renewable materials in the search for functional materials and chemicals from renewable resources. CNS are produced in the cashew nut processing process as waste, but they contain cashew nut shell liquid (CNSL) up to about 30-35 wt. % of the nut shell weight depending on the method of extraction. CNSL is a mixture of anacardic acid, cardanol, cardol, and methyl cardol, and the structures of these phenols offer opportunities for the development of diverse products. For anacardic acid, the combination of phenolic, carboxylic, and a 15-carbon alkyl side chain functional group makes it attractive in biological applications or as a synthon for the synthesis of a multitude of bioactive compounds. Anacardic acid, which is about 65% of a CNSL mixture, can be extracted from the agro waste. This shows that CNS waste can be used to extract useful chemicals and thus provide alternative green sources of chemicals, apart from relying only on the otherwise declining petroleum based sources. This paper reviews the potential of anacardic acids and their semi-synthetic derivatives for antibacterial, antitumor, and antioxidant activities. The review focuses on natural anacardic acids from CNS and other plants and their semi-synthetic derivatives as possible lead compounds in medicine. In addition, the use of anacardic acid as a starting material for the synthesis of various biologically active compounds and complexes is reported. PMID:25894225
Mora, Leticia; Hayes, Maria
2015-02-11
The primary function of dietary protein is to provide amino acids for protein synthesis. However, protein is also a source of latent bioactive peptides or cryptides with potential health benefits including the control and regulation of blood pressure. Hypertension or high blood pressure is one of the major, controllable risk factors in the development of cardiovascular disease (CVD), and it is also implicated in the development of myocardial infarction, heart failure, and end-stage diabetes. Cryptides can act on various systems of the body including the circulatory, gastrointestinal (GI), nervous, skeletal, and respiratory systems. A number of studies carried out to date have examined the health benefits of food protein isolates and hydrolysates. This review provides an overview of existing blood pressure regulating peptides and products derived from fish and other protein sources and hydrolysates. It discusses the methods used currently to generate and identify cryptides from these sources and their application in food and pharmaceutical products. It also looks at the current market for protein-derived peptides and peptide-containing products, legislation governing their use, and the future development of research in this area. PMID:25597264
Accuracy of the domain method for the material derivative approach to shape design sensitivities
NASA Technical Reports Server (NTRS)
Yang, R. J.; Botkin, M. E.
1987-01-01
Numerical accuracy for the boundary and domain methods of the material derivative approach to shape design sensitivities is investigated through the use of mesh refinement. The results show that the domain method is generally more accurate than the boundary method, using the finite element technique. It is also shown that the domain method is equivalent, under certain assumptions, to the implicit differentiation approach not only theoretically but also numerically.
Biological applications of hydrophilic C60 derivatives (hC60s)- a structural perspective.
Zhu, Xiaolei; Sollogoub, Matthieu; Zhang, Yongmin
2016-06-10
Reactive oxygen species (ROS) generation and radical scavenging are dual properties of hydrophilic C60 derivatives (hC60s). hC60s eliminate radicals in dark, while they produce reactive oxygen species (ROS) in the presence of irradiation and oxygen. Compared to the pristine C60 suspension, the aqueous solution of hC60s is easier to handle in vivo. hC60s are diverse and could be placed into two general categories: covalently modified C60 derivatives and pristine C60 solubilized non-covalently by macromolecules. In order to present in detail, the above categories are broken down into 8 parts: C60(OH)n, C60 with carboxylic acid, C60 with quaternary ammonium salts, C60 with peptide, C60 containing sugar, C60 modified covalently or non-covalently solubilized by cyclodextrins (CDs), pristine C60 delivered by liposomes, functionalized C60-polymer and pristine C60 solubilized by polymer. Each hC60 shows the propensity to be ROS producer or radical scavenger. This preference is dependent on hC60s structures. For example, major application of C60(OH)n is radical scavenger, while pristine C60/γ-CD complex usually serves as ROS producer. In addition, the electron acceptability and innate hydrophobic surface confer hC60s with O2 uptake inhibition, HIV inhibition and membrane permeability. In this review, we summarize the preparation methods and biological applications of hC60s according to the structures. PMID:27049677
Kubec, Roman; Dadáková, Eva
2009-10-01
A novel HPLC method for determination of a wide variety of S-substituted cysteine derivatives in Allium species has been developed and validated. This method allows simultaneous separation and quantification of S-alk(en)ylcysteine S-oxides, gamma-glutamyl-S-alk(en)ylcysteines and gamma-glutamyl-S-alk(en)ylcysteine S-oxides in a single run. The procedure is based on extraction of these amino acids and dipeptides by methanol, their derivatization by dansyl chloride and subsequent separation by reversed phase HPLC. The main advantages of the new method are simplicity, excellent stability of derivatives, high sensitivity, specificity and the ability to simultaneously analyze the whole range of S-substituted cysteine derivatives. This method was critically compared with other chromatographic procedures used for quantification of S-substituted cysteine derivatives, namely with two other HPLC methods (derivatization by o-phthaldialdehyde/tert-butylthiol and fluorenylmethyl chloroformate), and with determination by gas chromatography or capillary electrophoresis. Major advantages and drawbacks of these analytical procedures are discussed. Employing these various chromatographic methods, the content and relative proportions of individual S-substituted cysteine derivatives were determined in four most frequently consumed alliaceous vegetables (garlic, onion, shallot, and leek). PMID:19733357
NASA Astrophysics Data System (ADS)
Chou, Chia-Chun
2015-08-01
The complex quantum Hamilton-Jacobi equation for the complex action is approximately solved by propagating individual Bohmian trajectories in real space. Equations of motion for the complex action and its spatial derivatives are derived through use of the derivative propagation method. We transform these equations into the arbitrary Lagrangian-Eulerian version with the grid velocity matching the flow velocity of the probability fluid. Setting higher-order derivatives equal to zero, we obtain a truncated system of equations of motion describing the rate of change in the complex action and its spatial derivatives transported along approximate Bohmian trajectories. A set of test trajectories is propagated to determine appropriate initial positions for transmitted trajectories. Computational results for transmitted wave packets and transmission probabilities are presented and analyzed for a one-dimensional Eckart barrier and a two-dimensional system involving either a thick or thin Eckart barrier along the reaction coordinate coupled to a harmonic oscillator.
The ONIOM molecular dynamics method for biochemical applications: cytidine deaminase
Matsubara, Toshiaki; Dupuis, Michel; Aida, Misako
2007-03-22
Abstract We derived and implemented the ONIOM-molecular dynamics (MD) method for biochemical applications. The implementation allows the characterization of the functions of the real enzymes taking account of their thermal motion. In this method, the direct MD is performed by calculating the ONIOM energy and gradients of the system on the fly. We describe the first application of this ONOM-MD method to cytidine deaminase. The environmental effects on the substrate in the active site are examined. The ONIOM-MD simulations show that the product uridine is strongly perturbed by the thermal motion of the environment and dissociates easily from the active site. TM and MA were supported in part by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan. MD was supported by the Division of Chemical Sciences, Office of Basic Energy Sciences, and by the Office of Biological and Environmental Research of the U.S. Department of Energy DOE. Battelle operates Pacific Northwest National Laboratory for DOE.
NASA Technical Reports Server (NTRS)
Campbell, John P; Mckinney, Marion O
1952-01-01
A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Detailed estimation methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic and supersonic speed conditions.
Optimized methods for preparation of 6I-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives
Bednářová, Eva; Hybelbauerová, Simona
2016-01-01
Summary A general high-yielding method for the preparation of monosubstituted β-cyclodextrin derivatives which have attached a thiol group in position 6 is described. The thiol group is attached through linkers of different lengths and repeating units (ethylene glycol or methylene). The target compounds were characterized by IR, MS and NMR spectra. A simple method for their complete conversion to the corresponding disulfides as well as a method for the reduction of the disulfides back to the thiols is presented. Both, thiols and disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces. PMID:26977195
Optimized methods for preparation of 6(I)-(ω-sulfanyl-alkylene-sulfanyl)-β-cyclodextrin derivatives.
Bednářová, Eva; Hybelbauerová, Simona; Jindřich, Jindřich
2016-01-01
A general high-yielding method for the preparation of monosubstituted β-cyclodextrin derivatives which have attached a thiol group in position 6 is described. The thiol group is attached through linkers of different lengths and repeating units (ethylene glycol or methylene). The target compounds were characterized by IR, MS and NMR spectra. A simple method for their complete conversion to the corresponding disulfides as well as a method for the reduction of the disulfides back to the thiols is presented. Both, thiols and disulfides are derivatives usable for well-defined covalent attachment of cyclodextrin to gold or polydopamine-coated solid surfaces. PMID:26977195
CSM research: Methods and application studies
NASA Technical Reports Server (NTRS)
Knight, Norman F., Jr.
1989-01-01
Computational mechanics is that discipline of applied science and engineering devoted to the study of physical phenomena by means of computational methods based on mathematical modeling and simulation, utilizing digital computers. The discipline combines theoretical and applied mechanics, approximation theory, numerical analysis, and computer science. Computational mechanics has had a major impact on engineering analysis and design. When applied to structural mechanics, the discipline is referred to herein as computational structural mechanics. Complex structures being considered by NASA for the 1990's include composite primary aircraft structures and the space station. These structures will be much more difficult to analyze than today's structures and necessitate a major upgrade in computerized structural analysis technology. NASA has initiated a research activity in structural analysis called Computational Structural Mechanics (CSM). The broad objective of the CSM activity is to develop advanced structural analysis technology that will exploit modern and emerging computers, such as those with vector and/or parallel processing capabilities. Here, the current research directions for the Methods and Application Studies Team of the Langley CSM activity are described.
Application of numerical methods to elasticity imaging.
Castaneda, Benjamin; Ormachea, Juvenal; Rodríguez, Paul; Parker, Kevin J
2013-03-01
Elasticity imaging can be understood as the intersection of the study of biomechanical properties, imaging sciences, and physics. It was mainly motivated by the fact that pathological tissue presents an increased stiffness when compared to surrounding normal tissue. In the last two decades, research on elasticity imaging has been an international and interdisciplinary pursuit aiming to map the viscoelastic properties of tissue in order to provide clinically useful information. As a result, several modalities of elasticity imaging, mostly based on ultrasound but also on magnetic resonance imaging and optical coherence tomography, have been proposed and applied to a number of clinical applications: cancer diagnosis (prostate, breast, liver), hepatic cirrhosis, renal disease, thyroiditis, arterial plaque evaluation, wall stiffness in arteries, evaluation of thrombosis in veins, and many others. In this context, numerical methods are applied to solve forward and inverse problems implicit in the algorithms in order to estimate viscoelastic linear and nonlinear parameters, especially for quantitative elasticity imaging modalities. In this work, an introduction to elasticity imaging modalities is presented. The working principle of qualitative modalities (sonoelasticity, strain elastography, acoustic radiation force impulse) and quantitative modalities (Crawling Waves Sonoelastography, Spatially Modulated Ultrasound Radiation Force (SMURF), Supersonic Imaging) will be explained. Subsequently, the areas in which numerical methods can be applied to elasticity imaging are highlighted and discussed. Finally, we present a detailed example of applying total variation and AM-FM techniques to the estimation of elasticity. PMID:24010245
Chen, Zhaoxia; Li, Juan; Zhang, Ruqiang; You, Xiong
2015-01-01
Oscillation is one of the most important phenomena in the chemical reaction systems in living cells. The general purpose simulation algorithms fail to take into account this special character and produce unsatisfying results. In order to enhance the accuracy of the integrator, the second-order derivative is incorporated in the scheme. The oscillatory feature of the solution is captured by the integrators with an exponential fitting property. Three practical exponentially fitted TDRK (EFTDRK) methods are derived. To test the effectiveness of the new EFTDRK methods, the two-gene system with cross-regulation and the circadian oscillation of the period protein in Drosophila are simulated. Each EFTDRK method has the best fitting frequency which minimizes the global error. The numerical results show that the new EFTDRK methods are more accurate and more efficient than their prototype TDRK methods or RK methods of the same order and the traditional exponentially fitted RK method in the literature. PMID:26633991
Chen, Zhaoxia; Li, Juan; Zhang, Ruqiang; You, Xiong
2015-01-01
Oscillation is one of the most important phenomena in the chemical reaction systems in living cells. The general purpose simulation algorithms fail to take into account this special character and produce unsatisfying results. In order to enhance the accuracy of the integrator, the second-order derivative is incorporated in the scheme. The oscillatory feature of the solution is captured by the integrators with an exponential fitting property. Three practical exponentially fitted TDRK (EFTDRK) methods are derived. To test the effectiveness of the new EFTDRK methods, the two-gene system with cross-regulation and the circadian oscillation of the period protein in Drosophila are simulated. Each EFTDRK method has the best fitting frequency which minimizes the global error. The numerical results show that the new EFTDRK methods are more accurate and more efficient than their prototype TDRK methods or RK methods of the same order and the traditional exponentially fitted RK method in the literature. PMID:26633991
Applicability of adipose-derived stem cells in type 1 diabetes mellitus.
Lin, Hui-Ping; Chan, Tzu-Min; Fu, Ru-Huei; Chuu, Chih-Pin; Chiu, Shao-Chih; Tseng, Yu-Hsiung; Liu, Shih-Ping; Lai, Kuang-Chi; Shih, Mu-Chin; Lin, Zung-Sheng; Chen, Hsin-Shui; Yeh, Da-Chuan; Lin, Shinn-Zong
2015-01-01
Type 1 diabetes mellitus (T1DM) is a form of early onset diabetes mellitus characterized by the autoimmune destruction of insulin-producing cells (IPCs), resulting in hyperglycemia and abnormal glucose metabolism. There are currently no treatments available capable of completely curing the symptoms associated with the loss or functional defects of IPCs. Nonetheless, stem cell therapy has demonstrated considerable promise in the replacement of IPCs with immunomodulatory functions to overcome the defects caused by T1DM. Adipose-derived stem cells (ADSCs) are particularly suitable for use in cell transplantation therapy, especially when seeking to avoid the ethical issues and tumorigenic complications commonly associated with embryos or induced pluripotent stem cells. Cell-based treatments have demonstrated therapeutic advantages and clinical applicability of ADSCs in T1DM, ensuring their suitability for transplantation therapy. This manuscript focuses on the benefits and possible mechanisms in a T1DM-relevant model and displays positive results from finished or ongoing human clinical trials. We also discuss and hypothesize potential methods to further enhance the therapeutic efficacy of these efforts, such as a humanized rodent model and gene therapies for IPC clusters, to meet the clinical applicability of the standard. PMID:25621468
Ryabinkin, Ilya G; Nagesh, Jayashree; Izmaylov, Artur F
2015-11-01
We have developed a numerical differentiation scheme that eliminates evaluation of overlap determinants in calculating the time-derivative nonadiabatic couplings (TDNACs). Evaluation of these determinants was the bottleneck in previous implementations of mixed quantum-classical methods using numerical differentiation of electronic wave functions in the Slater determinant representation. The central idea of our approach is, first, to reduce the analytic time derivatives of Slater determinants to time derivatives of molecular orbitals and then to apply a finite-difference formula. Benchmark calculations prove the efficiency of the proposed scheme showing impressive several-order-of-magnitude speedups of the TDNAC calculation step for midsize molecules. PMID:26538034
Methods of geodiversity assessment and theirs application
NASA Astrophysics Data System (ADS)
Zwoliński, Zbigniew; Najwer, Alicja; Giardino, Marco
2016-04-01
The concept of geodiversity has rapidly gained the approval of scientists around the world (Wiedenbein 1993, Sharples 1993, Kiernan 1995, 1996, Dixon 1996, Eberhard 1997, Kostrzewski 1998, 2011, Gray 2004, 2008, 2013, Zwoliński 2004, Serrano, Ruiz- Flano 2007, Gordon et al. 2012). However, the problem recognition is still at an early stage, and in effect not explicitly understood and defined (Najwer, Zwoliński 2014). Nevertheless, despite widespread use of the concept, little progress has been made in its assessment and mapping. Less than the last decade can be observing investigation of methods for geodiversity assessment and its visualisation. Though, many have acknowledged the importance of geodiversity evaluation (Kozłowski 2004, Gray 2004, Reynard, Panizza 2005, Zouros 2007, Pereira et al. 2007, Hjort et al. 2015). Hitherto, only a few authors have undertaken that kind of methodological issues. Geodiversity maps are being created for a variety of purposes and therefore their methods are quite manifold. In the literature exists some examples of the geodiversity maps applications for the geotourism purpose, basing mainly on the geological diversity, in order to point the scale of the area's tourist attractiveness (Zwoliński 2010, Serrano and Gonzalez Trueba 2011, Zwoliński and Stachowiak 2012). In some studies, geodiversity maps were created and applied to investigate the spatial or genetic relationships with the richness of particular natural environmental components (Burnett et al. 1998, Silva 2004, Jačková, Romportl 2008, Hjort et al. 2012, 2015, Mazurek et al. 2015, Najwer et al. 2014). There are also a few examples of geodiversity assessment in order to geoconservation and efficient management and planning of the natural protected areas (Serrano and Gonzalez Trueba 2011, Pellitero et al. 2011, 2014, Jaskulska et al. 2013, Melelli 2014, Martinez-Grana et al. 2015). The most popular method of assessing the diversity of abiotic components of the natural
Turbulent heat transfer prediction method for application to scramjet engines
NASA Technical Reports Server (NTRS)
Pinckney, S. Z.
1974-01-01
An integral method for predicting boundary layer development in turbulent flow regions on two-dimensional or axisymmetric bodies was developed. The method has the capability of approximating nonequilibrium velocity profiles as well as the local surface friction in the presence of a pressure gradient. An approach was developed for the problem of predicting the heat transfer in a turbulent boundary layer in the presence of a high pressure gradient. The solution was derived with particular emphasis on its applicability to supersonic combustion; thus, the effects of real gas flows were included. The resulting integrodifferential boundary layer method permits the estimation of cooling reguirements for scramjet engines. Theoretical heat transfer results are compared with experimental combustor and noncombustor heat transfer data. The heat transfer method was used in the development of engine design concepts which will produce an engine with reduced cooling requirements. The Langley scramjet engine module was designed by utilizing these design concepts and this engine design is discussed along with its corresponding cooling requirements. The heat transfer method was also used to develop a combustor cooling correlation for a combustor whose local properties are computed one dimensionally by assuming a linear area variation and a given heat release schedule.
NASA Astrophysics Data System (ADS)
He, Zhihong; Yang, Xiangbo; Wang, Zhenyu
2010-05-01
In this Letter, in order to overcome the disadvantages of controlling the second-harmonic-generation (SHG) light derived from the traditional one-dimensional (1D) periodic ferroelectric domains we propose a kind of so-called complex periodic ferroelectric structure (CPFS), which unit cell is composed of even layers of positive and negative domains arranged alternatively following aperiodic sequence. It is found that comparing with the traditional periodic structure, CPFS cannot offer more reciprocal vector compensations for the mismatching phase, but CPFS may provide larger effective nonlinear coefficients (ENCs) in high-order quasi-phase-matching (QPM) and possesses advantages of the amplitude modulation for SHG peaks. In this Letter we study CPFS by use of vector method (VM), where the contribution to ENC for each domain or each unit cell will be treated as a vector and the QPM condition for CPFS and the modulation effect of aperiodic unit cells have been obtained. Without any Fourier transformation VM treats the grating function in real space and will be very convenient and intuitive. Both VM and CPFS would possess potential applications in the field of SHG investigations.
40 CFR 425.03 - Sulfide analytical methods and applicability.
Code of Federal Regulations, 2013 CFR
2013-07-01
... Provisions § 425.03 Sulfide analytical methods and applicability. (a) The potassium ferricyanide titration... the potassium ferricyanide titration method for the determination of sulfide in wastewaters...
25 CFR 700.461 - Method for soliciting applications.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 25 Indians 2 2014-04-01 2014-04-01 false Method for soliciting applications. 700.461 Section 700.461 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Discretionary Funds § 700.461 Method for soliciting applications. (a) The Commission shall utilize two methods to solicit applications...
25 CFR 700.461 - Method for soliciting applications.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 25 Indians 2 2011-04-01 2011-04-01 false Method for soliciting applications. 700.461 Section 700.461 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Discretionary Funds § 700.461 Method for soliciting applications. (a) The Commission shall utilize two methods to solicit applications...
25 CFR 700.461 - Method for soliciting applications.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 25 Indians 2 2012-04-01 2012-04-01 false Method for soliciting applications. 700.461 Section 700.461 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Discretionary Funds § 700.461 Method for soliciting applications. (a) The Commission shall utilize two methods to solicit applications...
25 CFR 700.461 - Method for soliciting applications.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 25 Indians 2 2013-04-01 2013-04-01 false Method for soliciting applications. 700.461 Section 700.461 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES Discretionary Funds § 700.461 Method for soliciting applications. (a) The Commission shall utilize two methods to solicit applications...
Aggregative Learning Method and Its Application for Communication Quality Evaluation
NASA Astrophysics Data System (ADS)
Akhmetov, Dauren F.; Kotaki, Minoru
2007-12-01
In this paper, so-called Aggregative Learning Method (ALM) is proposed to improve and simplify the learning and classification abilities of different data processing systems. It provides a universal basis for design and analysis of mathematical models of wide class. A procedure was elaborated for time series model reconstruction and analysis for linear and nonlinear cases. Data approximation accuracy (during learning phase) and data classification quality (during recall phase) are estimated from introduced statistic parameters. The validity and efficiency of the proposed approach have been demonstrated through its application for monitoring of wireless communication quality, namely, for Fixed Wireless Access (FWA) system. Low memory and computation resources were shown to be needed for the procedure realization, especially for data classification (recall) stage. Characterized with high computational efficiency and simple decision making procedure, the derived approaches can be useful for simple and reliable real-time surveillance and control system design.
NASA Technical Reports Server (NTRS)
Campbell, John P; Mckinney, Marion O
1951-01-01
A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Reference is also made to reports presenting experimental data that should be useful in making estimates of the derivatives. Detailed estimating methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic- and supersonic-speed conditions.
Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.
2010-01-01
Digital elevation data commonly are used to extract surface flow features. One source for high-resolution elevation data is light detection and ranging (lidar). Lidar can capture a vast amount of topographic detail because of its fine-scale ability to digitally capture the surface of the earth. Because elevation is a key factor in extracting surface flow features, high-resolution lidar-derived digital elevation models (DEMs) provide the detail needed to consistently integrate hydrography with elevation, land cover, structures, and other geospatial features. The U.S. Geological Survey has developed selective drainage methods to extract continuous surface flow from high-resolution lidar-derived digital elevation data. The lidar-derived continuous surface flow network contains valuable information for water resource management involving flood hazard mapping, flood inundation, and coastal erosion. DEMs used in hydrologic applications typically are processed to remove depressions by filling them. High-resolution DEMs derived from lidar can capture much more detail of the land surface than courser elevation data. Therefore, high-resolution DEMs contain more depressions because of obstructions such as roads, railroads, and other elevated structures. The filling of these depressions can significantly affect the DEM-derived surface flow routing and terrain characteristics in an adverse way. In this report, selective draining methods that modify the elevation surface to drain a depression through an obstruction are presented. If such obstructions are not removed from the elevation data, the filling of depressions to create continuous surface flow can cause the flow to spill over an obstruction in the wrong location. Using this modified elevation surface improves the quality of derived surface flow and retains more of the true surface characteristics by correcting large filled depressions. A reliable flow surface is necessary for deriving a consistently connected drainage
Park, Yun-Jong; Cha, Seunghee; Park, Young-Seok
2016-01-01
Tooth derived stem cells or dental stem cells are categorized according to the location from which they are isolated and represent a promising source of cells for regenerative medicine. Originally, as one kind of mesenchymal stem cells, they are considered an alternative of bone marrow stromal cells. They share many commonalties but maintain differences. Considering their original function in development and the homeostasis of tooth structures, many applications of these cells in dentistry have aimed at tooth structure regeneration; however, the application in other than tooth structures has been attempted extensively. The availability from discarded or removed teeth can be an innate benefit as a source of autologous cells. Their origin from the neural crest results in exploitation of neurological and numerous other applications. This review briefly highlights current and future perspectives of the regenerative applications of tooth derived stem cells in areas beyond tooth regeneration. PMID:26798366
Zhang, Weixiang; Zhu, Yun; Li, Jia; Guo, Quanyi; Peng, Jiang; Liu, Shichen; Yang, Jianhua; Wang, Yu
2016-06-01
The extracellular matrix (ECM) is a dynamic and intricate microenvironment with excellent biophysical, biomechanical, and biochemical properties, which can directly or indirectly regulate cell proliferation, adhesion, migration, and differentiation, as well as plays key roles in homeostasis and regeneration of tissues and organs. The ECM has attracted a great deal of attention with the rapid development of tissue engineering in the field of regenerative medicine. Tissue-derived ECM scaffolds (also referred to as decellularized tissues and whole organs) are considered a promising therapy for the repair of musculoskeletal defects, including those that are widely used in orthopedics, although there are a few shortcomings. Similar to tissue-derived ECM scaffolds, cell-derived ECM scaffolds also have highly advantageous biophysical and biochemical properties, in particular their ability to be produced in vitro from a number of different cell types. Furthermore, cell-derived ECM scaffolds more closely resemble native ECM microenvironments. The products of cell-derived ECM have a wide range of biomedical applications; these include reagents for cell culture substrates and biomaterials for scaffolds, hybrid scaffolds, and living cell sheet coculture systems. Although cell-derived ECM has only just begun to be investigated, it has great potential as a novel approach for cell-based tissue repair in orthopedic tissue engineering. This review summarizes and analyzes the various types of cell-derived ECM products applied in cartilage, bone, and nerve tissue engineering in vitro or in vivo and discusses future directions for investigation of cell-derived ECM. PMID:26671674
Fluorescent protein methods: strategies and applications.
Hutter, Harald
2012-01-01
Fluorescent proteins such as the "green fluorescent protein" (GFP) are popular tools in Caenorhabditis elegans, because as genetically encoded markers they are easy to introduce. Furthermore, they can be used in a living animal without the need for extensive sample preparation, because C. elegans is transparent and small enough so that entire animals can be imaged directly. Consequently, fluorescent proteins have emerged as the method of choice to study gene expression in C. elegans and reporter constructs for thousands of genes are currently available. When fused to a protein of interest, fluorescent proteins allow the imaging of its subcellular localization in vivo, offering a powerful alternative to antibody staining techniques. Fluorescent proteins can be employed to label cellular and subcellular structures and as indicators for cell physiological parameters like calcium concentration. Genetic screens relying on fluorescent proteins to visualize anatomical structures and recent progress in automation techniques have tremendously expanded their potential uses. This chapter presents tools and techniques related to the use of fluorescent proteins, discusses their advantages and shortcomings, and provides practical considerations for various applications. PMID:22226521
Subjective evidence based ethnography: method and applications.
Lahlou, Saadi; Le Bellu, Sophie; Boesen-Mariani, Sabine
2015-06-01
Subjective Evidence Based Ethnography (SEBE) is a method designed to access subjective experience. It uses First Person Perspective (FPP) digital recordings as a basis for analytic Replay Interviews (RIW) with the participants. This triggers their memory and enables a detailed step by step understanding of activity: goals, subgoals, determinants of actions, decision-making processes, etc. This paper describes the technique and two applications. First, the analysis of professional practices for know-how transferring purposes in industry is illustrated with the analysis of nuclear power-plant operators' gestures. This shows how SEBE enables modelling activity, describing good and bad practices, risky situations, and expert tacit knowledge. Second, the analysis of full days lived by Polish mothers taking care of their children is described, with a specific focus on how they manage their eating and drinking. This research has been done on a sub-sample of a large scale intervention designed to increase plain water drinking vs sweet beverages. It illustrates the interest of SEBE as an exploratory technique in complement to other more classic approaches such as questionnaires and behavioural diaries. It provides the detailed "how" of the effects that are measured at aggregate level by other techniques. PMID:25579747
Synthetic Bioluminescent Coelenterazine Derivatives.
Nishihara, Ryo; Citterio, Daniel; Suzuki, Koji
2016-01-01
The development of coelenterazine (CTZ) derivatives resulting in superior optical characteristics is an efficient method to extend the range of its possible applications. Here, we describe the synthesis of three C-6 substituted CTZ derivatives retaining the recognition by Renilla luciferase (RLuc) and its derivatives. The novel derivatives are useful as bright blue-shifted CTZ derivatives, which can be used as an alternative to hitherto reported compound DeepBlueC™. PMID:27424892
Space-time adaptive numerical methods for geophysical applications.
Castro, C E; Käser, M; Toro, E F
2009-11-28
In this paper we present high-order formulations of the finite volume and discontinuous Galerkin finite-element methods for wave propagation problems with a space-time adaptation technique using unstructured meshes in order to reduce computational cost without reducing accuracy. Both methods can be derived in a similar mathematical framework and are identical in their first-order version. In their extension to higher order accuracy in space and time, both methods use spatial polynomials of higher degree inside each element, a high-order solution of the generalized Riemann problem and a high-order time integration method based on the Taylor series expansion. The static adaptation strategy uses locally refined high-resolution meshes in areas with low wave speeds to improve the approximation quality. Furthermore, the time step length is chosen locally adaptive such that the solution is evolved explicitly in time by an optimal time step determined by a local stability criterion. After validating the numerical approach, both schemes are applied to geophysical wave propagation problems such as tsunami waves and seismic waves comparing the new approach with the classical global time-stepping technique. The problem of mesh partitioning for large-scale applications on multi-processor architectures is discussed and a new mesh partition approach is proposed and tested to further reduce computational cost. PMID:19840984
NASA Astrophysics Data System (ADS)
Eidsvig, Unni; Vidar Vangelsten, Bjørn; Geiss, Christian; Klotz, Martin; Ekseth, Kristine; Taubenböck, Hannes
2014-05-01
The choice and the development of methods for risk assessment of landslides depends on several factors. Important factors are the type of landslide and the elements at risk, the choice of spatial and temporal scale, the purpose of the analysis and the needs of the end-users. In addition, data availability is a major constraint, which greatly affects the type of methods and models that can be developed. Remote sensing is a promising tool for an economical and up-to-date data collection, which also could be applied to monitor the dynamic development of risk. The spatial and temporal distribution of the risk for landslides can be assessed by monitoring hazard indicators (e.g. slope height and slope angle), exposure indicators (e.g. number of houses and the total population) and vulnerability indicators (e.g. population density, settlement structures or indicators related to structural vulnerability). Several of the indicators applicable for landslide risk and vulnerability can be obtained by remote sensing techniques. However, for better results, indicators from remote sensing should be combined with other type of data. In this work, a review on the application of indicators for landslide risk assessment in explicit models as well as an assessment of end user needs was conducted in order to determine the most relevant indicators for landslide hazard and vulnerability. Lists of recommended indicators, mainly derivable from remote sensing, have been developed. These indicators are supposed to be used in risk assessment, e.g. by combining hazard, vulnerability and exposure indicators to produce risk indices. Moreover schemes for ranking, weighting and aggregation of the indicators into hazard- and vulnerability indices are provided. The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7-SPACE-2012-1] under Grant agreement No 312972 Framework to integrate Space-based and in-situ sENSing for dynamic v
Three dimethoxy-substituted luminol derivatives: A comparative study using theoretical method
NASA Astrophysics Data System (ADS)
Xue, Bingchun; Liu, Cuilan; Liu, Yanhong; Liu, Erbao
2015-02-01
In this research, geometrical optimisation, Mulliken charge, molecular electrostatic potential, and the frontier molecular orbitals of three dimethoxy-substituted luminol derivatives were investigated by ab initio, density functional, and Møller-Plesset perturbation theory with a 6-311G (d, p) basis set in gas phase, water, and dimethylsulphoxide solution. The UV-vis spectra were calculated by time dependent density functional theory method. The properties of derivatives were compared with luminol at a molecular level to investigate the change induced by the methoxy group. The three derivatives were also compared with the aim of predicting the order of chemiluminescent efficiency. The results showed that methoxy substitution significantly changed the electronic and spectral properties of luminol. Among three derivatives, structure 2 was suggested to have the highest chemiluminescent efficiency. The results may shed some light on the design and selection of chemiluminescent reagents.
Deniz, Furkan Nur; Alagoz, Baris Baykant; Tan, Nusret; Atherton, Derek P
2016-05-01
This paper introduces an integer order approximation method for numerical implementation of fractional order derivative/integrator operators in control systems. The proposed method is based on fitting the stability boundary locus (SBL) of fractional order derivative/integrator operators and SBL of integer order transfer functions. SBL defines a boundary in the parametric design plane of controller, which separates stable and unstable regions of a feedback control system and SBL analysis is mainly employed to graphically indicate the choice of controller parameters which result in stable operation of the feedback systems. This study reveals that the SBL curves of fractional order operators can be matched with integer order models in a limited frequency range. SBL fitting method provides straightforward solutions to obtain an integer order model approximation of fractional order operators and systems according to matching points from SBL of fractional order systems in desired frequency ranges. Thus, the proposed method can effectively deal with stability preservation problems of approximate models. Illustrative examples are given to show performance of the proposed method and results are compared with the well-known approximation methods developed for fractional order systems. The integer-order approximate modeling of fractional order PID controllers is also illustrated for control applications. PMID:26876378
Method and apparatus for collaborative use of application program
Dean, Craig D.
1994-01-01
Method and apparatus permitting the collaborative use of a computer application program simultaneously by multiple users at different stations. The method is useful with communication protocols having client/server control structures. The method of the invention requires only a sole executing copy of the application program and a sole executing copy of software comprising the invention. Users may collaboratively use a set of application programs by invoking for each desired application program one copy of software comprising the invention.
Applicability of optical scanner method for fine root dynamics
NASA Astrophysics Data System (ADS)
Kume, Tomonori; Ohashi, Mizue; Makita, Naoki; Khoon Kho, Lip; Katayama, Ayumi; Matsumoto, Kazuho; Ikeno, Hidetoshi
2016-04-01
Fine root dynamics is one of the important components in forest carbon cycling, as ~60 % of tree photosynthetic production can be allocated to root growth and metabolic activities. Various techniques have been developed for monitoring fine root biomass, production, mortality in order to understand carbon pools and fluxes resulting from fine roots dynamics. The minirhizotron method is now a widely used technique, in which a transparent tube is inserted into the soil and researchers count an increase and decrease of roots along the tube using images taken by a minirhizotron camera or minirhizotron video camera inside the tube. This method allows us to observe root behavior directly without destruction, but has several weaknesses; e.g., the difficulty of scaling up the results to stand level because of the small observation windows. Also, most of the image analysis are performed manually, which may yield insufficient quantitative and objective data. Recently, scanner method has been proposed, which can produce much bigger-size images (A4-size) with lower cost than those of the minirhizotron methods. However, laborious and time-consuming image analysis still limits the applicability of this method. In this study, therefore, we aimed to develop a new protocol for scanner image analysis to extract root behavior in soil. We evaluated applicability of this method in two ways; 1) the impact of different observers including root-study professionals, semi- and non-professionals on the detected results of root dynamics such as abundance, growth, and decomposition, and 2) the impact of window size on the results using a random sampling basis exercise. We applied our new protocol to analyze temporal changes of root behavior from sequential scanner images derived from a Bornean tropical forests. The results detected by the six observers showed considerable concordance in temporal changes in the abundance and the growth of fine roots but less in the decomposition. We also examined
Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications
Luo, Xuan; Su, Peng; Zhang, Wei
2015-01-01
Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry. PMID:26184233
NASA Astrophysics Data System (ADS)
Koroleva, Elena V.; Gusak, K. N.; Ignatovich, Zh V.
2010-10-01
Published data on the main approaches to the formation of the heterocyclic 2-aminopyrimidine system, which is one of important pharmacophores responsible for the biological properties of its derivatives, are described systematically. Main chemical transformations of functionalized 2-aminopyrimidines and their application in the synthesis of modern pharmaceuticals are considered.
ERIC Educational Resources Information Center
Kelter, Paul B.; Carr, James D.
1983-01-01
Describes an experiment designed to teach temperature programed gas chromatography (TPGC) techniques and importance of derivatizing many classes of substrated to be separated. Includes equipment needed, procedures for making trimethylsilyl derivatives, applications, sample calculations, and typical results. Procedure required one, three-hour…
Nanobody-derived nanobiotechnology tool kits for diverse biomedical and biotechnology applications.
Wang, Yongzhong; Fan, Zhen; Shao, Lei; Kong, Xiaowei; Hou, Xianjuan; Tian, Dongrui; Sun, Ying; Xiao, Yazhong; Yu, Li
2016-01-01
Owing to peculiar properties of nanobody, including nanoscale size, robust structure, stable and soluble behaviors in aqueous solution, reversible refolding, high affinity and specificity for only one cognate target, superior cryptic cleft accessibility, and deep tissue penetration, as well as a sustainable source, it has been an ideal research tool for the development of sophisticated nanobiotechnologies. Currently, the nanobody has been evolved into versatile research and application tool kits for diverse biomedical and biotechnology applications. Various nanobody-derived formats, including the nanobody itself, the radionuclide or fluorescent-labeled nanobodies, nanobody homo- or heteromultimers, nanobody-coated nanoparticles, and nanobody-displayed bacteriophages, have been successfully demonstrated as powerful nanobiotechnological tool kits for basic biomedical research, targeting drug delivery and therapy, disease diagnosis, bioimaging, and agricultural and plant protection. These applications indicate a special advantage of these nanobody-derived technologies, already surpassing the "me-too" products of other equivalent binders, such as the full-length antibodies, single-chain variable fragments, antigen-binding fragments, targeting peptides, and DNA-based aptamers. In this review, we summarize the current state of the art in nanobody research, focusing on the nanobody structural features, nanobody production approach, nanobody-derived nanobiotechnology tool kits, and the potentially diverse applications in biomedicine and biotechnology. The future trends, challenges, and limitations of the nanobody-derived nanobiotechnology tool kits are also discussed. PMID:27499623
Nanobody-derived nanobiotechnology tool kits for diverse biomedical and biotechnology applications
Wang, Yongzhong; Fan, Zhen; Shao, Lei; Kong, Xiaowei; Hou, Xianjuan; Tian, Dongrui; Sun, Ying; Xiao, Yazhong; Yu, Li
2016-01-01
Owing to peculiar properties of nanobody, including nanoscale size, robust structure, stable and soluble behaviors in aqueous solution, reversible refolding, high affinity and specificity for only one cognate target, superior cryptic cleft accessibility, and deep tissue penetration, as well as a sustainable source, it has been an ideal research tool for the development of sophisticated nanobiotechnologies. Currently, the nanobody has been evolved into versatile research and application tool kits for diverse biomedical and biotechnology applications. Various nanobody-derived formats, including the nanobody itself, the radionuclide or fluorescent-labeled nanobodies, nanobody homo- or heteromultimers, nanobody-coated nanoparticles, and nanobody-displayed bacteriophages, have been successfully demonstrated as powerful nanobiotechnological tool kits for basic biomedical research, targeting drug delivery and therapy, disease diagnosis, bioimaging, and agricultural and plant protection. These applications indicate a special advantage of these nanobody-derived technologies, already surpassing the “me-too” products of other equivalent binders, such as the full-length antibodies, single-chain variable fragments, antigen-binding fragments, targeting peptides, and DNA-based aptamers. In this review, we summarize the current state of the art in nanobody research, focusing on the nanobody structural features, nanobody production approach, nanobody-derived nanobiotechnology tool kits, and the potentially diverse applications in biomedicine and biotechnology. The future trends, challenges, and limitations of the nanobody-derived nanobiotechnology tool kits are also discussed. PMID:27499623
Sol-gel-derived silicate nano-hybrids for biomedical applications.
Tsuru, Kanji; Shirosaki, Yuki; Hayakawa, Satoshi; Osaka, Akiyoshi
2013-01-01
Organic-inorganic hybrids of poly(dimethyl siloxane), gelatin, and chitosan with such silanes as tetraethoxysilane and 3-glycidoxytriethoxysilane are derived via the sol-gel routes. Their biomedical applications are discussed from biomimetic deposition of bone-like apatite, cell culture, and in vivo behavior. PMID:24189412
Doktorov, A. B.
2014-09-14
In the framework of unified many-particle approach the familiar problem of fluorescence concentration quenching in the presence of pumping (light pulse) of arbitrary intensity is considered. This process is a vivid and the simplest example of multistage bulk reaction including bimolecular irreversible quenching reaction and reversible monomolecular transformation as elementary stages. General relation between the kinetics of multistage bulk reaction and that of the elementary stage of quenching has been established. This allows one to derive general kinetic equations (of two types) for the multistage reaction in question on the basis of general kinetic equations (differential and integro-differential) of elementary stage of quenching. Relying on the same unified many-particle approach we have developed binary approximations with the use of two (frequently employed in the literature) many-particle methods (such as simple superposition approximation and the method of extracting pair channels in three-particle correlation evolution) to the derivation of non-Markovian binary kinetic equations. The possibility of reducing the obtained binary equations to the Markovian equations of formal chemical kinetics has been considered. As an example the exact solution of the problem (for the specific case) is examined, and the applicability of two many particle methods of derivation of binary equations is analyzed.
Imagery-derived modulation transfer function and its applications for underwater imaging
NASA Astrophysics Data System (ADS)
Hou, Weilin; Weidemann, Alan D.; Gray, Deric J.; Fournier, Georges R.
2007-09-01
The main challenge working with underwater imagery results from both rapid decay of signals due to absorption, which leads to poor signal to noise returns, and the blurring caused by strong scattering by the water itself and constituents within, especially particulates. The modulation transfer function (MTF) of an optical system gives the detailed and precise information regarding the system behavior. Underwater imageries can be better restored with the knowledge of the system MTF or the point spread function (PSF), the Fourier transformed equivalent, extending the performance range as well as the information retrieval from underwater electro-optical system. This is critical in many civilian and military applications, including target and especially mine detection, search and rescue, and diver visibility. This effort utilizes test imageries obtained by the Laser Underwater Camera Imaging Enhancer (LUCIE) from Defense Research and Development Canada (DRDC), during an April-May 2006 trial experiment in Panama City, Florida. Imaging of a standard resolution chart with various spatial frequencies were taken underwater in a controlled optical environment, at varying distances. In-water optical properties during the experiment were measured, which included the absorption and attenuation coefficients, particle size distribution, and volume scattering function. Resulting images were preprocessed to enhance signal to noise ratio by averaging multiple frames, and to remove uneven illumination at target plane. The MTF of the medium was then derived from measurement of above imageries, subtracting the effect of the camera system. PSFs converted from the measured MTF were then used to restore the blurred imageries by different deconvolution methods. The effects of polarization from source to receiver on resulting MTFs were examined and we demonstrate that matching polarizations do enhance system transfer functions. This approach also shows promise in deriving medium optical
NASA Astrophysics Data System (ADS)
Ali, Omnia I. M.; Ismail, Nahla S.; Elgohary, Rasha M.
2016-01-01
Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method (1D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry (2D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL- 1 for LCD and 4.0-20.0 μg mL- 1 for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form.
Ali, Omnia I M; Ismail, Nahla S; Elgohary, Rasha M
2016-01-15
Three simple, precise, accurate and validated derivative spectrophotometric methods have been developed for the simultaneous determination of levocetirizine dihydrochloride (LCD) and ambroxol hydrochloride (ABH) in bulk powder and in pharmaceutical formulations. The first method is a first derivative spectrophotometric method ((1)D) using a zero-crossing technique of measurement at 210.4 nm for LCD and at 220.0 nm for ABH. The second method employs a second derivative spectrophotometry ((2)D) where the measurements were carried out at 242.0 and 224.4 nm for LCD and ABH, respectively. In the third method, the first derivative of the ratio spectra was calculated and the first derivative of the ratio amplitudes at 222.8 and 247.2 nm was selected for the determination of LCD and ABH, respectively. Calibration graphs were established in the ranges of 1.0-20.0 μg mL(-1) for LCD and 4.0-20.0 μg mL(-1) for ABH using derivative and ratio first derivative spectrophotometric methods with good correlation coefficients. The developed methods have been successfully applied to the simultaneous determination of both drugs in commercial tablet dosage form. PMID:26439526
An assessment of GLOBOCAN methods for deriving national estimates of cancer incidence
Soerjomataram, Isabelle; Møller, Bjørn; Bray, Freddie; Ferlay, Jacques
2016-01-01
Abstract Objective To assess the validity of the GLOBOCAN methods for deriving national estimates of cancer incidence. Methods We obtained incidence and mortality data from Norway by region, year of diagnosis, cancer site, sex and 5-year age group for the period 1983–2012 from the NORDCAN database. Estimates for the year 2010 were derived using nine different methods from GLOBOCAN. These included the projection of national historical rates, the use of regional proxies and the combination of national mortality data with mortality to incidence ratios or relative survival proportions. We then compared the national estimates with recorded cancer incidence data. Findings Differences between the estimates derived using different methods varied by cancer site and sex. Methods based on projections performed better where major changes in recent trends were absent. Methods based on mortality data performed less well for cancers associated with small numbers of deaths and for cancers detectable by screening. In countries with longstanding cancer registries of high quality, regional-based, or trends-based incidence estimates perform reasonably well in comparison with recorded incidence. Conclusion Although the performance of the GLOBOCAN methods varies by cancer site and sex in this study, the results emphasize a need for more high-quality population-based cancer registries – either regional or, where practical and feasible, national registries – to describe cancer patterns and trends for planning cancer control priorities. PMID:26966328
Calculation Methods and Conversions for Pesticide Application.
ERIC Educational Resources Information Center
Cole, Herbert, Jr.
This agriculture extension service publication from Pennsylvania State University consists of conversion tables and formulas for determining concentration and rate of application of pesticides. Contents include: (1) Area and volume conversions; (2) Important conversion formulae; (3) Conversions for rates of application; (4) Quantities of pesticide…
Three Dimensional Atmospheric Radiative Transfer-Applications and Methods Comparison
NASA Technical Reports Server (NTRS)
Cahalan, Robert F.; Einaudi, Franco (Technical Monitor)
2001-01-01
We review applications of 3D radiative transfer in the atmosphere, emphasizing the wide spectrum of scales important to remote sensing and modeling of cloud fields, and the characteristic scales introduced into observed radiances and fluxes by the distribution of photon pathlengths at conservative and absorbing wavelengths. We define the "plane-parallel bias", which is a measure of the importance of 3D cloud structure in large-scale models, and the "independent pixel errors" that quantify the significance of 3D effects in remote sensing, and emphasize their relative magnitude and scale dependence. A variety of approaches in current use in 3D radiative transfer, and issues of speed, accuracy, and flexibility are summarized. We also describe a recently initiated "International Intercomparison of 3-Dimensional Radiation Codes", or I3RC. I3RC is a 3-phase effort that has as its goals to: (1) understand the errors and limits of 3D methods; (2) provide "baseline" cases for future 3D code development; (3) promote sharing of 3D tools; (4) derive guidelines for 3D tool selection; and (5) improve atmospheric science education in 3D radiative transfer. Selected results from Phases 1 and 2 of I3RC are discussed. These are taken from five cloud fields: a 1D field of bar clouds, a 2D radar-derived field, a 3D Landsat-derived field, a stratiform cloud from the model of C. Moeng, and a convective cloud from the model of B. Stevens. Computations have been carried out for three monochromatic wavelengths (one conservative, one absorptive, and one thermal) and two solar zenith angles (0, 60 degrees).
Non-intrusive hybrid interval method for uncertain nonlinear systems using derivative information
NASA Astrophysics Data System (ADS)
Liu, Zhuang-Zhuang; Wang, Tian-Shu; Li, Jun-Feng
2016-02-01
This paper proposes a new non-intrusive hybrid interval method using derivative information for the dynamic response analysis of nonlinear systems with uncertain-but-bounded parameters and/or initial conditions. This method provides tighter solution ranges compared to the existing polynomial approximation interval methods. Interval arithmetic using the Chebyshev basis and interval arithmetic using the general form modified affine basis for polynomials are developed to obtain tighter bounds for interval computation. To further reduce the overestimation caused by the "wrapping effect" of interval arithmetic, the derivative information of dynamic responses is used to achieve exact solutions when the dynamic responses are monotonic with respect to all the uncertain variables. Finally, two typical numerical examples with nonlinearity are applied to demonstrate the effectiveness of the proposed hybrid interval method, in particular, its ability to effectively control the overestimation for specific timepoints.
ERIC Educational Resources Information Center
Stone, David H.
1987-01-01
Definitions of specific medical competencies to be acquired by medical students in the course of their studies may be derived from the juxtaposition of a list of generic competencies with a list of appropriate subject areas. The operation of the method is demonstrated in relation to the curriculum of The Beer Sheva Medical School, Israel.…
Image method for the derivation of point sources in elastostatic problems with plane interfaces
NASA Technical Reports Server (NTRS)
Fares, Nabil; Li, Victor C.
1986-01-01
An image method algorithm is presented for the derivation of point sources of elastostatics in multilayered media assuming the infinite space point source is known. Specific cases were worked out and shown to coincide with well known solutions in the literature.
Ejection time by ear densitogram and its derivative - Clinical and physiologic applications.
NASA Technical Reports Server (NTRS)
Quarry-Pigott, V.; Chirife, R.; Spodick, D. H.
1973-01-01
Ear densitographic ejection times (EDET) and first derivative ear densitogram ejection times (dEDET) were studied to determine whether their reliability and validity justify their substitution for ejection times derived from the far less stable carotid pulse tracing. Inter- and intra-subject comparisons were made on thirty individuals under a wide variety of disease and challenge states. Statistical analysis of the data - which had been obtained through a blinded procedure - showed an overall correlation (r) of .98 for carotid vs EDET and .99 for carotid vs dEDET. The t-test demonstrated no significant differences among ejection times derived from the three methods. Moreover, the close tracking at rest and during challenges of ejection times derived from these curves with those from the carotid indicate that either method may be substituted for standard carotid curves without sacrificing reliability or validity of the measure.
Novel scanner characterization method for color measurement and diagnostics applications
NASA Astrophysics Data System (ADS)
Lee, Bong-Sun; Bala, Raja; Sharma, Gaurav
2006-02-01
We propose a novel scanner characterization approach for applications requiring color measurement of hardcopy output in printer calibration, characterization, and diagnostic applications. It is assumed that a typical printed medium comprises the three basic colorants C, M, Y. The proposed method is particularly advantageous when additional colorants are used in the print (e.g. black (K)). A family of scanner characterization targets is constructed, each varying in C, M, Y and at a fixed level of K. A corresponding family of 3-D scanner characterizations is derived, one for each level of K. Each characterization maps scanner RGB to a colorimetric representation such as CIELAB, using standard characterization techniques. These are then combined into a single 4-D characterization mapping RGBK to CIELAB. A refinement of the technique improves performance significantly by using a function of the scanned values for K (e.g. the scanner's green channel response to printed K) instead of the digital K value directly. This makes this new approach more robust with respect to variations in printed K over time. Secondly it enables, with a single scanner characterization, accurate color measurement of prints from different printers within the same family. Results show that the 4-D characterization technique can significantly outperform standard 3-D approaches especially in cases where the image being scanned is a patch target made up of unconstrained CMYK combinations. Thus the algorithm finds particular use in printer characterization and diagnostic applications. The method readily generalizes to printed media containing other (e.g "hi-fi") colorants, and also to other image capture devices such as digital cameras.
42 CFR 61.35 - Method of application.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 42 Public Health 1 2013-10-01 2013-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...
42 CFR 61.6 - Method of application.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 42 Public Health 1 2013-10-01 2013-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...
42 CFR 61.6 - Method of application.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 42 Public Health 1 2014-10-01 2014-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...
42 CFR 61.6 - Method of application.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 42 Public Health 1 2012-10-01 2012-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...
42 CFR 61.6 - Method of application.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...
42 CFR 61.35 - Method of application.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 42 Public Health 1 2012-10-01 2012-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...
42 CFR 61.6 - Method of application.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false Method of application. 61.6 Section 61.6 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Regular Fellowships § 61.6 Method of application. Application for a regular fellowship shall...
42 CFR 61.35 - Method of application.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 42 Public Health 1 2011-10-01 2011-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...
42 CFR 61.35 - Method of application.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 42 Public Health 1 2014-10-01 2014-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...
42 CFR 61.35 - Method of application.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false Method of application. 61.35 Section 61.35 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES FELLOWSHIPS, INTERNSHIPS, TRAINING FELLOWSHIPS Service Fellowships § 61.35 Method of application. Application for a service fellowship shall...
40 CFR 18.6 - Method of Application.
Code of Federal Regulations, 2010 CFR
2010-07-01
... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Method of Application. 18.6 Section...
40 CFR 18.6 - Method of Application.
Code of Federal Regulations, 2012 CFR
2012-07-01
... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Method of Application. 18.6 Section...
40 CFR 18.6 - Method of Application.
Code of Federal Regulations, 2014 CFR
2014-07-01
... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Method of Application. 18.6 Section...
40 CFR 18.6 - Method of Application.
Code of Federal Regulations, 2013 CFR
2013-07-01
... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Method of Application. 18.6 Section...
7 CFR 760.804 - Time and method of application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 7 2010-01-01 2010-01-01 false Time and method of application. 760.804 Section 760.804 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY....804 Time and method of application. (a) The 2005, 2006, 2007 Crop Disaster Program application must...
7 CFR 786.103 - Time and method of application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 7 2010-01-01 2010-01-01 false Time and method of application. 786.103 Section 786.103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY... Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...
The Immersed Structural Potential Method for haemodynamic applications
NASA Astrophysics Data System (ADS)
Gil, A. J.; Arranz Carreño, A.; Bonet, J.; Hassan, O.
2010-11-01
In this paper, a new fluid-structure interaction immersed computational methodology, based upon the original Immersed Boundary Method (IBM) [1] is outlined with the final aim of modelling cardiovascular phenomena, specifically, heart valve related problems. The principal characteristic of such immersed techniques is the representation of any deformable or rigid body immersed within an incompressible viscous flow field as a momentum forcing source in the Navier-Stokes equations. A number of shortcomings within the immersed formulation still require further investigation and improvement, including the excessive numerical diffusion caused by the interpolation/spreading process, the need to include realistic viscoelastic composite constitutive models describing more accurately the nature of cardiovascular tissues and also the need to capture more effectively stresses developed at the fluid-structure interface. By following the same philosophy as the original IBM, a more sophisticated formulation is derived in this paper, the "Immersed Structural Potential Method (ISPM)". The method introduced presents an alternative approach to compute the equivalent fluid-structure interaction forces at the fluid mesh, accounts for a sophisticated viscoelastic fibre-reinforced constitutive model to better describe the mechanics of cardiovascular tissues and utilises a novel time-integration methodology for the computation of the deformation gradient tensor which ensures compliance with the incompressibility constraint. A series of numerical examples will be presented in order to demonstrate the robustness and applicability of this new methodology.
Application of throughfall methods to estimate dry deposition of mercury
Lindberg, S.E.; Owens, J.G.; Stratton, W.
1992-12-31
Several dry deposition methods for Mercury (Hg) are being developed and tested in our laboratory. These include big-leaf and multilayer resistance models, micrometeorological methods such as Bowen ratio gradient approaches, laboratory controlled plant chambers, and throughfall. We have previously described our initial results using modeling and gradient methods. Throughfall may be used to estimate Hg dry deposition if some simplifying assumptions are met. We describe here the application and initial results of throughfull studies at the Walker Branch Watershed forest, and discuss the influence of certain assumptions on interpretation of the data. Throughfall appears useful in that it can place a lower bound to dry deposition under field conditions. Our preliminary throughfall data indicate net dry deposition rates to a pine canopy which increase significantly from winter to summer, as previously predicted by our resistance model. Atmospheric data suggest that rainfall washoff of fine aerosol dry deposition at this site is not sufficient to account for all of the Hg in net throughfall. Potential additional sources include dry deposited gas-phase compounds, soil-derived coarse aerosols, and oxidation reactions at the leaf surface.
7 CFR 1776.8 - Methods for submitting applications.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 12 2010-01-01 2010-01-01 false Methods for submitting applications. 1776.8 Section... for submitting applications. (a) Applications may be filed in either paper or electronic format. RUS... by the U.S. Postal Service (USPS) or courier delivery services. Applications submitted by mail...
Biomedical Application of Dental Tissue-Derived Induced Pluripotent Stem Cells
Lee, Jung-Hwan; Seo, Seog-Jin
2016-01-01
The academic researches and clinical applications in recent years found interest in induced pluripotent stem cells (iPSCs-) based regenerative medicine due to their pluripotency able to differentiate into any cell types in the body without using embryo. However, it is limited in generating iPSCs from adult somatic cells and use of these cells due to the low stem cell potency and donor site morbidity. In biomedical applications, particularly, dental tissue-derived iPSCs have been getting attention as a type of alternative sources for regenerating damaged tissues due to high potential of stem cell characteristics, easy accessibility and attainment, and their ectomesenchymal origin, which allow them to have potential for nerve, vessel, and dental tissue regeneration. This paper will cover the overview of dental tissue-derived iPSCs and their application with their advantages and drawbacks. PMID:26989423
Zhao, H-Y; Jiang, J-G
2010-11-01
Chromatography technology has been widely applied in various aspects of the pharmacy research on traditional Chinese medicine (TCM). This paper reviews literatures, published in the past decades, on the separation of active component from TCM using chromatography technology. Ultra-performance liquid chromatography (UPLC), high-speed counter-current chromatography (HSCCC), rapid resolution liquid chromatography (RRLC), supercritical fluid chromatography (SFC), affinity chromatography (AC), and bio-chromatography (BC) are introduced in detail. Compared to high performance of high-performance liquid chromatography (HPLC), analysis time and solvent loss are significantly reduced by UPLC with increase in resolution and sensitivity. Some ingredients from nature derived drugs can be separated more completely by HSCCC, which has remarkable characteristics such as low cost, simple operation and no pollution. Trace components from complex systems can be selectively and efficiently separated and purified by AC, This feature makes it effective in isolation and identification of active components of Chinese herbs. Interference of some impurities could be excluded by BC. Active ingredients that are difficult to be separated by normal method can be acquired by SFC. Currently, application of novel chromatography techniques in TCM is still in the exploratory stage and many problems, such as preparation of stationary phase and detection, need to be solved. PMID:20701587
NASA Astrophysics Data System (ADS)
Zhang, Qinyuan; Pita, Kantisara; Xu, Chang-Qing; Que, Wenxiu; Hinooda, S.; Thilakan, Periyasamy
2001-10-01
A single layer sol-gel derived TiO2 thin films and 6 periods SiO2/TiO2 multilayer coating were designed and prepared on GaAs substrates as anti-reflection coating or near-IR-reflective coating for high power semiconductor laser applications. Crack free TiO2 thin films having thickness of 80-150 nm, and refractive indices of 1.8-2.1 have been obtained by simply sol-gel method upon heating at different temperatures. The obtained TiO2 thin films on GaAs substrates have shown reflectance of
Monosodium glutamate derived tricolor fluorescent carbon nanoparticles for cell-imaging application.
Zheng, Nannan; Ding, Sha; Zhou, Xingping
2016-06-01
Fluorescent carbon nanoparticle (FCN) is a new type of carbon-based materials. Because of its wide raw material sources, excellent optical properties and good biocompatibility, FCN is getting more and more attentions. However, its synthesis from resources at low cost under mild conditions is still a challenge. Here we report a novel and simple method derived from monosodium glutamate carbonization to make tricolor fluorescent carbon nanoparticles with an average size below 10nm, a high yield up to 35.2% based on the carbon content in the resource, a long life-time of 3.71ns, and a high fluorescence quantum yield up to 51.5% by using quinine sulfate as the standard substance. We discovered that the fluorescent stability of the FCNs was very excellent under UV irradiation for hours in aqueous solutions of pH ranged from 2.0 to 9.0. The cell viability tested under a pretty high concentration of FCNs indicated their safety for biological applications. Based on their high fluorescence quantum efficiency and the advantages mentioned above, these FCNs were then used for cell imaging and exhibited a perfect performance under 3 kinds of excitation bands (UV, blue, and green lights). Thus, they can be practically applied to immune labeling and imaging in vivo in the near future. PMID:26945164
Amniotic Fluid-Derived Stem Cells for Cardiovascular Tissue Engineering Applications
Petsche Connell, Jennifer; Camci-Unal, Gulden; Khademhosseini, Ali
2013-01-01
Recent research has demonstrated that a population of stem cells can be isolated from amniotic fluid removed by amniocentesis that are broadly multipotent and nontumorogenic. These amniotic fluid-derived stem cells (AFSC) could potentially provide an autologous cell source for treatment of congenital defects identified during gestation, particularly cardiovascular defects. In this review, the various methods of isolating, sorting, and culturing AFSC are compared, along with techniques for inducing differentiation into cardiac myocytes and endothelial cells. Although research has not demonstrated complete and high-yield cardiac differentiation, AFSC have been shown to effectively differentiate into endothelial cells and can effectively support cardiac tissue. Additionally, several tissue engineering and regenerative therapeutic approaches for the use of these cells in heart patches, injection after myocardial infarction, heart valves, vascularized scaffolds, and blood vessels are summarized. These applications show great promise in the treatment of congenital cardiovascular defects, and further studies of isolation, culture, and differentiation of AFSC will help to develop their use for tissue engineering, regenerative medicine, and cardiovascular therapies. PMID:23350771
Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh
2016-01-01
Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment. PMID:27168748
Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh
2016-01-01
Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment. PMID:27168748
Gupta-Ostermann, Disha; Hirose, Yoichiro; Odagami, Takenao; Kouji, Hiroyuki; Bajorath, Jürgen
2015-01-01
In a previous Method Article, we have presented the 'Structure-Activity Relationship (SAR) Matrix' (SARM) approach. The SARM methodology is designed to systematically extract structurally related compound series from screening or chemical optimization data and organize these series and associated SAR information in matrices reminiscent of R-group tables. SARM calculations also yield many virtual candidate compounds that form a "chemical space envelope" around related series. To further extend the SARM approach, different methods are developed to predict the activity of virtual compounds. In this follow-up contribution, we describe an activity prediction method that derives conditional probabilities of activity from SARMs and report representative results of first prospective applications of this approach. PMID:25949808
Low oxygen biomass-derived pyrolysis oils and methods for producing the same
Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A
2013-08-27
Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.
A Parallel Multigrid Method for Neutronics Applications
Alcouffe, Raymond E.
2001-01-01
The multigrid method has been shown to be the most effective general method for solving the multi-dimensional diffusion equation encountered in neutronics. This being the method of choice, we develop a strategy for implementing the multigrid method on computers of massively parallel architecture. This leads us to strategies for parallelizing the relaxation, contraction (interpolation), and prolongation operators involved in the method. We then compare the efficiency of our parallel multigrid with other parallel methods for solving the diffusion equation on selected problems encountered in reactor physics.
A Fast Method of Deriving the Kirchhoff Formula for Moving Surfaces
NASA Technical Reports Server (NTRS)
Farassat, F.; Posey, Joe W.
2007-01-01
The Kirchhoff formula for a moving surface is very useful in many wave propagation problems, particularly in the prediction of noise from rotating machinery. Several publications in the last two decades have presented derivations of the Kirchhoff formula for moving surfaces in both time and frequency domains. Here we present a method originally developed by Farassat and Myers in time domain that is both simple and direct. It is based on generalized function theory and the useful concept of imbedding the problem in the unbounded three-dimensional space. We derive an inhomogeneous wave equation with the source terms that involve Dirac delta functions with their supports on the moving data surface. This wave equation is then solved using the simple free space Green's function of the wave equation resulting in the Kirchhoff formula. The algebraic manipulations are minimal and simple. We do not need the Green's theorem in four dimensions and there is no ambiguity in the interpretation of any terms in the final formulas. Furthermore, this method also gives the simplest derivation of the classical Kirchhoff formula which has a fairly lengthy derivation in physics and applied mathematics books. The Farassat-Myers method can be used easily in frequency domain.
Fuzzy Set Methods for Object Recognition in Space Applications
NASA Technical Reports Server (NTRS)
Keller, James M. (Editor)
1992-01-01
Progress on the following four tasks is described: (1) fuzzy set based decision methodologies; (2) membership calculation; (3) clustering methods (including derivation of pose estimation parameters), and (4) acquisition of images and testing of algorithms.
Pałasz, Aleksandra; Cież, Dariusz
2015-06-01
This review article is an effort to summarize recent developments in researches providing uracil derivatives with promising biological potential. This article also aims to discuss potential future directions on the development of more potent and specific uracil analogues for various biological targets. Uracils are considered as privileged structures in drug discovery with a wide array of biological activities and synthetic accessibility. Antiviral and anti-tumour are the two most widely reported activities of uracil analogues however they also possess herbicidal, insecticidal and bactericidal activities. Their antiviral potential is based on the inhibition of key step in viral replication pathway resulting in potent activities against HIV, hepatitis B and C, the herpes viruses etc. Uracil derivatives such as 5-fluorouracil or 5-chlorouracil were the first pharmacological active derivatives to be generated. Poor selectivity limits its therapeutic application, resulting in high incidences of gastrointestinal tract or central nervous toxicity. Numerous modifications of uracil structure have been performed to tackle these problems resulting in the development of derivatives exhibiting better pharmacological and pharmacokinetic properties including increased bioactivity, selectivity, metabolic stability, absorption and lower toxicity. Researches of new uracils and fused uracil derivatives as bioactive agents are related with modifications of substituents at N(1), N(3), C(5) and C(6) positions of pyrimidine ring. This review is an endeavour to highlight the progress in the chemistry and biological activity of the uracils, predominately after the year 2000. In particular are presented synthetic methods and biological study for such analogues as: 5-fluorouracil or 5-chlorouracil derivatives, tegafur analogues, arabinopyranonucleosides of uracil, glucopyranonucleosides of uracil, liposidomycins, caprazamycins or tunicamycins, tritylated uridine analogues, nitro or cyano
An acoustic intensity-based method and its aeroacoustic applications
NASA Astrophysics Data System (ADS)
Yu, Chao
Aircraft noise prediction and control is one of the most urgent and challenging tasks worldwide. A hybrid approach is usually considered for predicting the aerodynamic noise. The approach separates the field into aerodynamic source and acoustic propagation regions. Conventional CFD solvers are typically used to evaluate the flow field in the source region. Once the sound source is predicted, the linearized Euler Equations (LEE) can be used to extend the near-field CFD solution to the mid-field acoustic radiation. However, the far-field extension is very time consuming and always prohibited by the excessive computer memory requirements. The FW-H method, instead, predicts the far-field radiation using the flow-field quantities on a closed control surface (that encloses the entire aerodynamic source region) if the wave equation is assumed outside. The surface integration, however, has to be carried out for each far-field location. This would be still computationally intensive for a practical 3D problem even though the intensity in terms of the CPU time has been much decreased compared with that required by the LEE methods. For an accurate far-field prediction, the other difficulty of using the FW-H method is that the complete control surface may be infeasible to accomplish for most practical applications. Motivated by the need for the accurate and efficient far-field prediction techniques, an Acoustic Intensity-Based Method (AIBM) has been developed based on an acoustic input from an OPEN control surface. The AIBM assumes that the sound propagation is governed by the modified Helmholtz equation on and outside a control surface that encloses all the nonlinear effects and noise sources. The prediction of the acoustic radiation field is carried out by the inverse method with an input of acoustic pressure derivative and its simultaneous, co-located acoustic pressure. The reconstructed acoustic radiation field using the AIBM is unique due to the unique continuation theory
Hybrid method for designing digital FIR filters based on fractional derivative constraints.
Baderia, Kuldeep; Kumar, Anil; Kumar Singh, Girish
2015-09-01
In this manuscript, a hybrid approach based on Lagrange multiplier method and cuckoo search (CS) optimization technique is proposed for the design of linear phase finite impulse response (FIR) filters using fractional derivative constraints. In the proposed method, FIR filter is designed by optimizing the integral squares in passband and stopband from ideal response such that the fractional derivatives of designed filter response become zero at a given frequency point. Lagrange multiplier method is exploited for finding the optimized filter coefficients. Optimal value of fractional derivative constraints for optimized filter coefficients are determined by minimizing the objective function constructed using a sum of maximum passband ripple and maximum stopband ripple in frequency domain using CS algorithm. Performance of the proposed method is evaluated by passband error (ϕ(p)), stopband error (ϕ(s)), stopband attenuation (A(s)), maximum passband ripple (MPR), maximum stopband ripple (MSR) and CPU time. A comparative study of the performance of particle swarm optimization (PSO) and artificial bee colony (ABC) for designing FIR filters using the proposed method is also made. PMID:26142984
Sherman, L.L.; Taylor, A.C. III; Hou, G.W.; Korivi, V.M.
1996-12-01
The straightforward automatic-differentiation and the hand-differentiated incremental iterative methods are interwoven to produce a hybrid scheme that captures some of the strengths of each strategy. With this compromise, discrete aerodynamic sensitivity derivatives are calculated with the efficient incremental iterative solution algorithm of the original flow code. Moreover, the principal advantage of automatic differentiation is retained. The basic equations for second-order sensitivity derivatives are presented, which results in a comparison of four different methods. Each of these four schemes for second-order derivatives requires that large systems are solved first for the first-order adjoint variables. Of these latter three schemes, two require no solutions of large systems thereafter. For the other two for which additional systems are solved, the equations and solution procedures are analogous to those for the first-order derivatives. From a practical viewpoint, implementation of the second-order methods is feasible only with software tools such as automatic differentiation, because of the extreme complexity and large number of terms. First- and second-order sensitivities are calculated accurately for two airfoil problems, including a turbulent-flow example. In each of these two sample problems, three dependent variables (coefficients of lift, drag, and pitching-moment) and six independent variables (three geometric-shape and three flow-condition design variables) are considered. Several different procedures are tested, and results are compared on the basis of accuracy, computational time, and computer memory. For first-order derivatives, the hybrid incremental iterative scheme obtained with automatic differentiation is competitive with the best hand-differentiated method. Furthermore, it is at least two to four times faster than central finite differences, without an overwhelming penalty in computer memory. 23 refs., 14 tabs.
Demeke, Tigst; Jenkins, G Ronald
2010-03-01
Biotechnology-derived varieties of canola, cotton, corn and soybean are being grown in the USA, Canada and other predominantly grain exporting countries. Although the amount of farmland devoted to production of biotechnology-derived crops continues to increase, lingering concerns that unintended consequences may occur provide the EU and most grain-importing countries with justification to regulate these crops. Legislation in the EU requires traceability of grains/oilseeds, food and feed products, and labelling, when a threshold level of 0.9% w/w of genetically engineered trait is demonstrated to be present in an analytical sample. The GE content is routinely determined by quantitative PCR (qPCR) and plant genomic DNA provides the template for the initial steps in this process. A plethora of DNA extraction methods exist for qPCR applications. Implementing standardized methods for detection of genetically engineered traits is necessary to facilitate grain marketing. The International Organization for Standardization draft standard 21571 identifies detergent-based methods and commercially available kits that are widely used for DNA extraction, but also indicates that adaptations may be necessary depending upon the sample matrix. This review assesses advantages and disadvantages of various commercially available DNA extraction kits, as well as modifications to published cetyltrimethylammonium bromide methods. Inhibitors are a major obstacle for efficient amplification in qPCR. The types of PCR inhibitors and techniques to minimize inhibition are discussed. Finally, accurate quantification of DNA for applications in qPCR is not trivial. Many confounders contribute to differences in analytical measurements when a particular DNA quantification method is applied and different methods do not always provide concordant results on the same DNA sample. How these differences impact measurement uncertainty in qPCR is considered. PMID:19789856
HNO 3 fluxes to a deciduous forest derived using gradient and REA methods
NASA Astrophysics Data System (ADS)
Pryor, S. C.; Barthelmie, R. J.; Jensen, B.; Jensen, N. O.; Sørensen, L. L.
Summertime nitric acid concentrations over a deciduous forest in the midwestern United States are reported, which range between 0.36 and 3.3 μg m -3. Fluxes to the forest are computed using the relaxed eddy accumulation technique and gradient methods. In accord with previous studies, the results indicate substantial uncertainties in the gradient-based calculations. The relaxed eddy accumulation (REA) derived fluxes are physically reasonable and are shown to be of similar magnitude to dry deposition estimates from gradient sampling. The REA derived mean deposition velocity is approximately 3 cm s -1, which is also comparable to growing season estimates derived by Meyers et al. for a similar deciduous forest. Occasional inverted concentration gradients and fluxes are observed but most are not statistically significant. Data are also presented that indicate substantial through canopy penetration of nitric acid.
Higher-order numerical methods derived from three-point polynomial interpolation
NASA Technical Reports Server (NTRS)
Rubin, S. G.; Khosla, P. K.
1976-01-01
Higher-order collocation procedures resulting in tridiagonal matrix systems are derived from polynomial spline interpolation and Hermitian finite-difference discretization. The equations generally apply for both uniform and variable meshes. Hybrid schemes resulting from different polynomial approximations for first and second derivatives lead to the nonuniform mesh extension of the so-called compact or Pade difference techniques. A variety of fourth-order methods are described and this concept is extended to sixth-order. Solutions with these procedures are presented for the similar and non-similar boundary layer equations with and without mass transfer, the Burgers equation, and the incompressible viscous flow in a driven cavity. Finally, the interpolation procedure is used to derive higher-order temporal integration schemes and results are shown for the diffusion equation.
NASA Astrophysics Data System (ADS)
Loehnert, U.; Feingold, G.; Frisch, S.; Shupe, M.; Uttal, T.
During the summer months (May-August) of the SHEBA (Surface HEat Budget of the Artic ocean) project, combined two-channel microwave radiometer/cloud radar mea- surements detected numerous events of low level, non-drizzling liquid stratus clouds. An algorithm according to Frisch et al. (1995, 1998) used to derive profiles of liq- uid water density (LWC) was applied to these cases assuming constant cloud number density and cloud drop distribution width with height. A second algorithm according to Löhnert (2001) was developed specifically for the SHEBA site, using a priori data from a three-dimensional LES model and its two-dimensional counterpart, initialized with summer time SHEBA radiosondes. The underlying assumption in this approach is that the model data describes mean and variance of physical quantities in a realistic way. About 50 soundings during non-drizzling, low-level liquid water cloud events were chosen. The model was run for at least five hours. For the purpose of algorithm development, profiles of the liquid water distribution were analyzed in five-minute time steps on a vertical grid of 45 m. The horizontal grid of the model was set to 50 m. A relationship between simulated radar reflectivity (Z) and model LWC was derived together with an a priori LWC profile. Once the theoretical error covariance matrix of the Z-LWC relation was derived, and the covariance of the LWC profile calculated, an optimal estimation method was applied, constraining the LWC profile to the liquid water path within its assumed error (measured by the microwave radiometer). Both the Frisch et al. method and the one described above were applied to the LES model data set. In this presentation we will show the error characteristics, as well as the feasibilty of deriving LWC from this combination of measurments during arctic, low-level stra- tus conditions. Additionally, the application of both algorithms to the SHEBA data set will show possible systematic errors between both
Two non-parametric methods for derivation of constraints from radiotherapy dose-histogram data
NASA Astrophysics Data System (ADS)
Ebert, M. A.; Gulliford, S. L.; Buettner, F.; Foo, K.; Haworth, A.; Kennedy, A.; Joseph, D. J.; Denham, J. W.
2014-07-01
Dose constraints based on histograms provide a convenient and widely-used method for informing and guiding radiotherapy treatment planning. Methods of derivation of such constraints are often poorly described. Two non-parametric methods for derivation of constraints are described and investigated in the context of determination of dose-specific cut-points—values of the free parameter (e.g., percentage volume of the irradiated organ) which best reflect resulting changes in complication incidence. A method based on receiver operating characteristic (ROC) analysis and one based on a maximally-selected standardized rank sum are described and compared using rectal toxicity data from a prostate radiotherapy trial. Multiple test corrections are applied using a free step-down resampling algorithm, which accounts for the large number of tests undertaken to search for optimal cut-points and the inherent correlation between dose-histogram points. Both methods provide consistent significant cut-point values, with the rank sum method displaying some sensitivity to the underlying data. The ROC method is simple to implement and can utilize a complication atlas, though an advantage of the rank sum method is the ability to incorporate all complication grades without the need for grade dichotomization.
Low-derivative operators of the Standard Model effective field theory via Hilbert series methods
NASA Astrophysics Data System (ADS)
Lehman, Landon; Martin, Adam
2016-02-01
In this work, we explore an extension of Hilbert series techniques to count operators that include derivatives. For sufficiently low-derivative operators, we conjecture an algorithm that gives the number of invariant operators, properly accounting for redundancies due to the equations of motion and integration by parts. Specifically, the conjectured technique can be applied whenever there is only one Lorentz invariant for a given partitioning of derivatives among the fields. At higher numbers of derivatives, equation of motion redundancies can be removed, but the increased number of Lorentz contractions spoils the subtraction of integration by parts redundancies. While restricted, this technique is sufficient to automatically recreate the complete set of invariant operators of the Standard Model effective field theory for dimensions 6 and 7 (for arbitrary numbers of flavors). At dimension 8, the algorithm does not automatically generate the complete operator set; however, it suffices for all but five classes of operators. For these remaining classes, there is a well defined procedure to manually determine the number of invariants. Assuming our method is correct, we derive a set of 535 dimension-8 N f = 1 operators.
Applications of graphene and its derivatives in intracellular biosensing and bioimaging.
Zhu, Xiaohua; Liu, Yang; Li, Pei; Nie, Zhou; Li, Jinghong
2016-08-01
Graphene has a unique planar structure, as well as excellent electronic properties, and has attracted a great deal of interest from scientists. Graphene and its derivatives display advantageous characteristics as a biosensing platform due to their high surface area, good biocompatibility and ease of functionalization. Moreover, graphene and its derivatives exhibit excellent optical properties; thus they are considered to be promising and attractive candidates for bioimaging, mainly of cells and tissues. Following an introduction and a discussion of the optical properties of graphene, this review assesses the methods for engineering the functions of graphene and its derivatives. Specific examples are given on the use of graphene and its derivatives in fluorescence bioimaging, surface-enhanced Raman scattering (SERS) imaging, and magnetic resonance imaging (MRI). Finally, the prospects and further developments in this exciting field of graphene-based materials are suggested. PMID:27373227
NASA Technical Reports Server (NTRS)
Slemp, Wesley C. H.; Kapania, Rakesh K.; Tessler, Alexander
2010-01-01
Computation of interlaminar stresses from the higher-order shear and normal deformable beam theory and the refined zigzag theory was performed using the Sinc method based on Interpolation of Highest Derivative. The Sinc method based on Interpolation of Highest Derivative was proposed as an efficient method for determining through-the-thickness variations of interlaminar stresses from one- and two-dimensional analysis by integration of the equilibrium equations of three-dimensional elasticity. However, the use of traditional equivalent single layer theories often results in inaccuracies near the boundaries and when the lamina have extremely large differences in material properties. Interlaminar stresses in symmetric cross-ply laminated beams were obtained by solving the higher-order shear and normal deformable beam theory and the refined zigzag theory with the Sinc method based on Interpolation of Highest Derivative. Interlaminar stresses and bending stresses from the present approach were compared with a detailed finite element solution obtained by ABAQUS/Standard. The results illustrate the ease with which the Sinc method based on Interpolation of Highest Derivative can be used to obtain the through-the-thickness distributions of interlaminar stresses from the beam theories. Moreover, the results indicate that the refined zigzag theory is a substantial improvement over the Timoshenko beam theory due to the piecewise continuous displacement field which more accurately represents interlaminar discontinuities in the strain field. The higher-order shear and normal deformable beam theory more accurately captures the interlaminar stresses at the ends of the beam because it allows transverse normal strain. However, the continuous nature of the displacement field requires a large number of monomial terms before the interlaminar stresses are computed as accurately as the refined zigzag theory.
Problems of applicability of statistical methods in cosmology
Levin, S. F.
2015-12-15
The problems arising from the incorrect formulation of measuring problems of identification for cosmological models and violations of conditions of applicability of statistical methods are considered.
An application of oil vaporization evaluation methods
Fleckenstein, W.W.; Bouck, L.S.; Hudgens, D.; Querin, M.; Williams, L.
1992-02-01
This paper describes and quantifies the benefits of residual oil vaporization in an enhanced recovery gas injection project. Vaporized oil is recovered as natural gas liquid (NGL) when the injected gas is produced. In the reservoir application studied, 20% of the liquid hydrocarbons produced were being recovered as NGL. (VC)
French, Anna; Bravery, Christopher; Smith, James; Chandra, Amit; Archibald, Peter; Gold, Joseph D; Artzi, Natalie; Kim, Hae-Won; Barker, Richard W; Meissner, Alexander; Wu, Joseph C; Knowles, Jonathan C; Williams, David; García-Cardeña, Guillermo; Sipp, Doug; Oh, Steve; Loring, Jeanne F; Rao, Mahendra S; Reeve, Brock; Wall, Ivan; Carr, Andrew J; Bure, Kim; Stacey, Glyn; Karp, Jeffrey M; Snyder, Evan Y; Brindley, David A
2015-03-01
There is a need for physical standards (reference materials) to ensure both reproducibility and consistency in the production of somatic cell types from human pluripotent stem cell (hPSC) sources. We have outlined the need for reference materials (RMs) in relation to the unique properties and concerns surrounding hPSC-derived products and suggest in-house approaches to RM generation relevant to basic research, drug screening, and therapeutic applications. hPSCs have an unparalleled potential as a source of somatic cells for drug screening, disease modeling, and therapeutic application. Undefined variation and product variability after differentiation to the lineage or cell type of interest impede efficient translation and can obscure the evaluation of clinical safety and efficacy. Moreover, in the absence of a consistent population, data generated from in vitro studies could be unreliable and irreproducible. Efforts to devise approaches and tools that facilitate improved consistency of hPSC-derived products, both as development tools and therapeutic products, will aid translation. Standards exist in both written and physical form; however, because many unknown factors persist in the field, premature written standards could inhibit rather than promote innovation and translation. We focused on the derivation of physical standard RMs. We outline the need for RMs and assess the approaches to in-house RM generation for hPSC-derived products, a critical tool for the analysis and control of product variation that can be applied by researchers and developers. We then explore potential routes for the generation of RMs, including both cellular and noncellular materials and novel methods that might provide valuable tools to measure and account for variation. Multiparametric techniques to identify "signatures" for therapeutically relevant cell types, such as neurons and cardiomyocytes that can be derived from hPSCs, would be of significant utility, although physical RMs will
Bravery, Christopher; Smith, James; Chandra, Amit; Archibald, Peter; Gold, Joseph D.; Artzi, Natalie; Kim, Hae-Won; Barker, Richard W.; Meissner, Alexander; Wu, Joseph C.; Knowles, Jonathan C.; Williams, David; García-Cardeña, Guillermo; Sipp, Doug; Oh, Steve; Loring, Jeanne F.; Rao, Mahendra S.; Reeve, Brock; Wall, Ivan; Carr, Andrew J.; Bure, Kim; Stacey, Glyn; Karp, Jeffrey M.
2015-01-01
Summary There is a need for physical standards (reference materials) to ensure both reproducibility and consistency in the production of somatic cell types from human pluripotent stem cell (hPSC) sources. We have outlined the need for reference materials (RMs) in relation to the unique properties and concerns surrounding hPSC-derived products and suggest in-house approaches to RM generation relevant to basic research, drug screening, and therapeutic applications. hPSCs have an unparalleled potential as a source of somatic cells for drug screening, disease modeling, and therapeutic application. Undefined variation and product variability after differentiation to the lineage or cell type of interest impede efficient translation and can obscure the evaluation of clinical safety and efficacy. Moreover, in the absence of a consistent population, data generated from in vitro studies could be unreliable and irreproducible. Efforts to devise approaches and tools that facilitate improved consistency of hPSC-derived products, both as development tools and therapeutic products, will aid translation. Standards exist in both written and physical form; however, because many unknown factors persist in the field, premature written standards could inhibit rather than promote innovation and translation. We focused on the derivation of physical standard RMs. We outline the need for RMs and assess the approaches to in-house RM generation for hPSC-derived products, a critical tool for the analysis and control of product variation that can be applied by researchers and developers. We then explore potential routes for the generation of RMs, including both cellular and noncellular materials and novel methods that might provide valuable tools to measure and account for variation. Multiparametric techniques to identify “signatures” for therapeutically relevant cell types, such as neurons and cardiomyocytes that can be derived from hPSCs, would be of significant utility, although
Carbide derived carbon from MAX-phases and their separation applications
NASA Astrophysics Data System (ADS)
Hoffman, Elizabeth N.
Improved sorbents with increased selectivity and permeability are needed to meet growing energy and environmental needs. New forms of carbon based sorbents have been discovered recently, including carbons produced by etching metals from metal carbides, known as carbide derived carbons (CDCs). A common method for the synthesis of CDC is by chlorination at elevated temperatures. The goal of this work is to synthesize CDC from ternary carbides and to explore the links between the initial carbide chemistry and structure with the resulting CDCs properties, including porosity. CDC was produced from MAX-phase carbides, in particular Ti3SiC 2, Ti3AlC2, Ti2AlC, and Ta2AlC. Additionally, CDC was produced from Ta-based binary carbides, TaC and Ta 2C, and one carbo-nitride Ti2AlC0.5N0.5. The CDC structure was characterized using XRD, Raman microspectroscopy, and HRTEM. Porosity characterization was performed using sorption analysis with both Ar and N2 as adsorbates. It was determined the microporosity of CDC is related to the density of the initial carbide. The layered structure of the MAX-phase carbides lent toward the formation of larger mesopores within the resulting CDCs, while the amount of mesopores was dependent on the chemistry of the carbide. Furthermore, CDC produced from carbides with extremely high theoretical porosity resulted in small specific surface areas due to a collapse of the carbon structure. To expand the potential applications for CDC beyond powder and bulk forms, CDC membranes were produced from a thin film of TiC deposited by magnetron sputtering onto porous ceramic substrates. The TiC thin film was subsequently chlorinated to produce a bilayer membrane with CDC as the active layer. Both gases and liquids are capable of passing the membrane. The membrane separates based on selective adsorption, rather than a size separation molecular sieving effect. Two applications for CDC produced from MAX-phases were investigated: protein adsorption and gas
Scenistic Methods for Training: Applications and Practice
ERIC Educational Resources Information Center
Lyons, Paul R.
2011-01-01
Purpose: This paper aims to complement an earlier article (2010) in "Journal of European Industrial Training" in which the description and theory bases of scenistic methods were presented. This paper also offers a description of scenistic methods and information on theory bases. However, the main thrust of this paper is to describe, give suggested…
Bajwa, Dilpreet S; Wang, Xinnan; Sitz, Evan; Loll, Tyler; Bhattacharjee, Sujal
2016-08-01
Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite(®)LY 8601/Aradur(®) 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes. PMID:27131732
Abdelwahab, Nada S; Abdelrahman, Maha M
2014-01-01
Methocarbamol is formulated with Ibuprofen for treatment of alleviated pain associated with muscle spasm. This manuscript describes a sensitive and selective first derivative synchronous spectrofluorimetric method for simultaneous determination of both drugs. Factors affecting method selectivity were studied where best results were obtained upon using Δ λ = 20 and water as a solvent. Methocartbamol was determined at 283 nm while Ibuprofen at 285.5 nm in the concentration ranges of 0.4-5 and 0.2-4.8 μg/mL, respectively. The applicability of the proposed method was ascertained by application to different laboratory prepared mixtures and marketed formulation. The high sensitivity achieved by the proposed method permitted its application for determination of the drugs in human plasma spiked with pure drugs and their combined tablets. The proposed method showed no significant difference when compared with the reported HPLC method using student's t-test and F-ratio test. PMID:23912962
Kernel-Correlated Levy Field Driven Forward Rate and Application to Derivative Pricing
Bo Lijun; Wang Yongjin; Yang Xuewei
2013-08-01
We propose a term structure of forward rates driven by a kernel-correlated Levy random field under the HJM framework. The kernel-correlated Levy random field is composed of a kernel-correlated Gaussian random field and a centered Poisson random measure. We shall give a criterion to preclude arbitrage under the risk-neutral pricing measure. As applications, an interest rate derivative with general payoff functional is priced under this pricing measure.
Ravat, D.; Kirkham, K.; Hildenbrand, T.G.
2002-01-01
An overview is given on the benefits of applying the Euler method on derivatives of anomalies to enhance the location of shallow and deep sources. Used properly, the method is suitable for characterizing sources from all potential-field data and/or their derivative, as long as the data can be regarded mathematically as "continuous". Furthermore, the reasons why the use of the Euler method on derivatives of anomalies is particularly helpful in the analysis and interpretation of shallow features are explained.
Power Measurement Methods for Energy Efficient Applications
Calandrini, Guilherme; Gardel, Alfredo; Bravo, Ignacio; Revenga, Pedro; Lázaro, José L.; Toledo-Moreo, F. Javier
2013-01-01
Energy consumption constraints on computing systems are more important than ever. Maintenance costs for high performance systems are limiting the applicability of processing devices with large dissipation power. New solutions are needed to increase both the computation capability and the power efficiency. Moreover, energy efficient applications should balance performance vs. consumption. Therefore power data of components are important. This work presents the most remarkable alternatives to measure the power consumption of different types of computing systems, describing the advantages and limitations of available power measurement systems. Finally, a methodology is proposed to select the right power consumption measurement system taking into account precision of the measure, scalability and controllability of the acquisition system. PMID:23778191
A General Symbolic Method with Physical Applications
NASA Astrophysics Data System (ADS)
Smith, Gregory M.
2000-06-01
A solution to the problem of unifying the General Relativistic and Quantum Theoretical formalisms is given which introduces a new non-axiomatic symbolic method and an algebraic generalization of the Calculus to non-finite symbolisms without reference to the concept of a limit. An essential feature of the non-axiomatic method is the inadequacy of any (finite) statements: Identifying this aspect of the theory with the "existence of an external physical reality" both allows for the consistency of the method with the results of experiments and avoids the so-called "measurement problem" of quantum theory.
Development of a rapid HRM genotyping method for detection of dog-derived Giardia lamblia.
Tan, Liping; Yu, Xingang; Abdullahi, Auwalu Yusuf; Wu, Sheng; Zheng, Guochao; Hu, Wei; Song, Meiran; Wang, Zhen; Jiang, Biao; Li, Guoqing
2015-11-01
Giardia lamblia is a zoonotic flagellate protozoan in the intestine of human and many mammals including dogs. To assess a threat of dog-derived G. lamblia to humans, the common dog-derived G. lamblia assemblages A, C, and D were genotyped by high-resolution melting (HRM) technology. According to β-giardin gene sequence, the qPCR-HRM primers BG5 and BG7 were designed. A series of experiments on the stability, sensitivity, and accuracy of the HRM method were also tested. Results showed that the primers BG5 and BG7 could distinguish among three assemblages A, C, and D, which Tm value differences were about 1 °C to each other. The melting curves of intra-assay reproducibility were almost coincided, and those of inter-assay reproducibility were much the same shape. The lowest detection concentration was about 5 × 10(-6)-ng/μL sample. The genotyping results from 21 G. lamblia samples by the HRM method were in complete accordance with sequencing results. It is concluded that the HRM genotyping method is rapid, stable, specific, highly sensitive, and suitable for clinical detection and molecular epidemiological survey of dog-derived G. lamblia. PMID:26212101
Liu, Wangta; Shiue, Yow-Ling; Lin, Yi-Reng; Lin, Hugo You-Hsien; Liang, Shih-Shin
2015-01-01
In this study, we demonstrated an oxidative method with free radical to generate 3,5,4′-trihydroxy-trans-stilbene (trans-resveratrol) metabolites and detect sequentially by an autosampler coupling with liquid chromatography electrospray ionization tandem mass spectrometer (LC-ESI–MS/MS). In this oxidative method, the free radical initiator, ammonium persulfate (APS), was placed in a sample bottle containing resveratrol to produce oxidative derivatives, and the reaction progress was tracked by autosampler sequencing. Resveratrol, a natural product with purported cancer preventative qualities, produces metabolites including dihydroresveratrol, 3,4′-dihydroxy-trans-stilbene, lunularin, resveratrol monosulfate, and dihydroresveratrol monosulfate by free radical oxidation. Using APS free radical, the concentrations of resveratrol derivatives differ as a function of time. Besides simple, convenient and time- and labor saving, the advantages of free radical oxidative method of its in situ generation of oxidative derivatives followed by LC-ESI–MS/MS can be utilized to evaluate different metabolites in various conditions.
Krylov subspace methods - Theory, algorithms, and applications
NASA Technical Reports Server (NTRS)
Sad, Youcef
1990-01-01
Projection methods based on Krylov subspaces for solving various types of scientific problems are reviewed. The main idea of this class of methods when applied to a linear system Ax = b, is to generate in some manner an approximate solution to the original problem from the so-called Krylov subspace span. Thus, the original problem of size N is approximated by one of dimension m, typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now becoming popular for solving nonlinear equations. The main ideas in Krylov subspace methods are shown and their use in solving linear systems, eigenvalue problems, parabolic partial differential equations, Liapunov matrix equations, and nonlinear system of equations are discussed.
Application of geophysical methods for fracture characterization
Lee, K.H.; Majer, E.L.; McEvilly, T.V. |; Morrison, H.F. |
1990-01-01
One of the most crucial needs in the design and implementation of an underground waste isolation facility is a reliable method for the detection and characterization of fractures in zones away from boreholes or subsurface workings. Geophysical methods may represent a solution to this problem. If fractures represent anomalies in the elastic properties or conductive properties of the rocks, then the seismic and electrical techniques may be useful in detecting and characterizing fracture properties. 7 refs., 3 figs.
Yarmukhamedov, R.
2014-05-09
The basic methods of the determination of asymptotic normalization coefficient for A+a→B of astrophysical interest are briefly presented. The results of the application of the specific asymptotic normalization coefficients derived within these methods for the extrapolation of the astrophysical S factors to experimentally inaccessible energy regions (E ≤ 25 keV) for the some specific radiative capture A(a,γ)B reactions of the pp-chain and the CNO cycle are presented.
NASA Technical Reports Server (NTRS)
Chapman, G.; Kirk, D.
1974-01-01
The parameter identification scheme being used is a differential correction least squares procedure (Gauss-Newton method). The position, orientation, and derivatives of these quantities with respect to the parameters of interest (i.e., sensitivity coefficients) are determined by digital integration of the equations of motion and the parametric differential equations. The application of this technique to three vastly different sets of data is used to illustrate the versatility of the method and to indicate some of the problems that still remain.
Minteer, Danielle Marie; Young, Matthew T; Lin, Yen-Chih; Over, Patrick J; Rubin, J Peter; Gerlach, Jorg C; Marra, Kacey G
2015-01-01
To address the functionality of diabetic adipose-derived stem cells in tissue engineering applications, adipose-derived stem cells isolated from patients with and without type II diabetes mellitus were cultured in bioreactor culture systems. The adipose-derived stem cells were differentiated into adipocytes and maintained as functional adipocytes. The bioreactor system utilizes a hollow fiber-based technology for three-dimensional perfusion of tissues in vitro, creating a model in which long-term culture of adipocytes is feasible, and providing a potential tool useful for drug discovery. Daily metabolic activity of the adipose-derived stem cells was analyzed within the medium recirculating throughout the bioreactor system. At experiment termination, tissues were extracted from bioreactors for immunohistological analyses in addition to gene and protein expression. Type II diabetic adipose-derived stem cells did not exhibit significantly different glucose consumption compared to adipose-derived stem cells from patients without type II diabetes (p > 0.05, N = 3). Expression of mature adipocyte genes was not significantly different between diabetic/non-diabetic groups (p > 0.05, N = 3). Protein expression of adipose tissue grown within all bioreactors was verified by Western blotting.The results from this small-scale study reveal adipose-derived stem cells from patients with type II diabetes when removed from diabetic environments behave metabolically similar to the same cells of non-diabetic patients when cultured in a three-dimensional perfusion bioreactor, suggesting that glucose transport across the adipocyte cell membrane, the hindrance of which being characteristic of type II diabetes, is dependent on environment. The presented observation describes a tissue-engineered tool for long-term cell culture and, following future adjustments to the culture environment and increased sample sizes, potentially for anti-diabetic drug testing. PMID:26090087
Björnstad, Kristian; Beck, Olof; Helander, Anders
2009-04-15
A sensitive and specific LC-MS/MS method for simultaneous detection of 10 plant-derived psychoactive substances (atropine, N,N-dimethyltryptamine, ephedrine, harmaline, harmine, ibogaine, lysergic acid amide, psilocin, scopolamine and yohimbine) in urine was developed. Direct injection of urine diluted with 3 deuterated internal standards allowed for a readily accessible method suitable for application in clinical intoxication cases. Separation was achieved using reversed phase chromatography and gradient elution with a total analysis time of 14 min. Electrospray ionization was used and ions were monitored in the positive selected reaction monitoring mode. The calibration curves were linear (r(2)>0.999) and the total imprecision at high (1000 microg/L) and low (50 microg/L) substance concentrations were 4.9-13.8% and 8.3-26%, respectively. Infusing the analytes post column and injecting matrix samples showed limited influence by ion suppression. The multi-component method proved to be useful for investigation of authentic cases of intoxication with plant-derived psychoactive drugs and was indicated to cover the clinically relevant concentration ranges. PMID:19332394
Multigrid methods with applications to reservoir simulation
Xiao, Shengyou
1994-05-01
Multigrid methods are studied for solving elliptic partial differential equations. Focus is on parallel multigrid methods and their use for reservoir simulation. Multicolor Fourier analysis is used to analyze the behavior of standard multigrid methods for problems in one and two dimensions. Relation between multicolor and standard Fourier analysis is established. Multiple coarse grid methods for solving model problems in 1 and 2 dimensions are considered; at each coarse grid level we use more than one coarse grid to improve convergence. For a given Dirichlet problem, a related extended problem is first constructed; a purification procedure can be used to obtain Moore-Penrose solutions of the singular systems encountered. For solving anisotropic equations, semicoarsening and line smoothing techniques are used with multiple coarse grid methods to improve convergence. Two-level convergence factors are estimated using multicolor. In the case where each operator has the same stencil on each grid point on one level, exact multilevel convergence factors can be obtained. For solving partial differential equations with discontinuous coefficients, interpolation and restriction operators should include information about the equation coefficients. Matrix-dependent interpolation and restriction operators based on the Schur complement can be used in nonsymmetric cases. A semicoarsening multigrid solver with these operators is used in UTCOMP, a 3-D, multiphase, multicomponent, compositional reservoir simulator. The numerical experiments are carried out on different computing systems. Results indicate that the multigrid methods are promising.
7 CFR 1430.503 - Time and method for application.
Code of Federal Regulations, 2012 CFR
2012-01-01
... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS Dairy Market Loss Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an application, Form CCC-1040 (Dairy Market Loss Assistance Program Payment Application), in person, by mail,...
7 CFR 1430.503 - Time and method for application.
Code of Federal Regulations, 2011 CFR
2011-01-01
... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS Dairy Market Loss Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an application, Form CCC-1040 (Dairy Market Loss Assistance Program Payment Application), in person, by mail,...
7 CFR 1430.503 - Time and method for application.
Code of Federal Regulations, 2013 CFR
2013-01-01
... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS Dairy Market Loss Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an application, Form CCC-1040 (Dairy Market Loss Assistance Program Payment Application), in person, by mail,...
7 CFR 1430.503 - Time and method for application.
Code of Federal Regulations, 2014 CFR
2014-01-01
... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS Dairy Market Loss Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an application, Form CCC-1040 (Dairy Market Loss Assistance Program Payment Application), in person, by mail,...
Minnick, L. John
1981-01-01
Method for the production of cementitious compositions and aggregate derivatives of said compositions, and cementitious compositions and aggregates produced by said method, wherein fluidized bed combustion residue and pozzolanic material, such as pulverized coal combustion system fly ash, are incorporated in a cementitious mix. The mix is cast into desired shape and cured. If desired, the shape may then be crushed so as to result in a fluidized bed combustion residue-fly ash aggregate material or the shape may be used by itself.
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.
Applications of a transonic wing design method
NASA Technical Reports Server (NTRS)
Campbell, Richard L.; Smith, Leigh A.
1989-01-01
A method for designing wings and airfoils at transonic speeds using a predictor/corrector approach was developed. The procedure iterates between an aerodynamic code, which predicts the flow about a given geometry, and the design module, which compares the calculated and target pressure distributions and modifies the geometry using an algorithm that relates differences in pressure to a change in surface curvature. The modular nature of the design method makes it relatively simple to couple it to any analysis method. The iterative approach allows the design process and aerodynamic analysis to converge in parallel, significantly reducing the time required to reach a final design. Viscous and static aeroelastic effects can also be accounted for during the design or as a post-design correction. Results from several pilot design codes indicated that the method accurately reproduced pressure distributions as well as the coordinates of a given airfoil or wing by modifying an initial contour. The codes were applied to supercritical as well as conventional airfoils, forward- and aft-swept transport wings, and moderate-to-highly swept fighter wings. The design method was found to be robust and efficient, even for cases having fairly strong shocks.
Silver nanoparticles: Synthesis methods, bio-applications and properties.
Abbasi, Elham; Milani, Morteza; Fekri Aval, Sedigheh; Kouhi, Mohammad; Akbarzadeh, Abolfazl; Tayefi Nasrabadi, Hamid; Nikasa, Parisa; Joo, San Woo; Hanifehpour, Younes; Nejati-Koshki, Kazem; Samiei, Mohammad
2016-01-01
Silver nanoparticles size makes wide range of new applications in various fields of industry. Synthesis of noble metal nanoparticles for applications such as catalysis, electronics, optics, environmental and biotechnology is an area of constant interest. Two main methods for Silver nanoparticles are the physical and chemical methods. The problem with these methods is absorption of toxic substances onto them. Green synthesis approaches overcome this limitation. Silver nanoparticles size makes wide range of new applications in various fields of industry. This article summarizes exclusively scalable techniques and focuses on strengths, respectively, limitations with respect to the biomedical applicability and regulatory requirements concerning silver nanoparticles. PMID:24937409
25 CFR 700.461 - Method for soliciting applications.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 25 Indians 2 2010-04-01 2010-04-01 false Method for soliciting applications. 700.461 Section 700... PROCEDURES Discretionary Funds § 700.461 Method for soliciting applications. (a) The Commission shall utilize... of work required. (b) The annual announcements of the availability of funds and periodic requests...
7 CFR 1430.503 - Time and method for application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false Time and method for application. 1430.503 Section 1430.503 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT... Assistance Program § 1430.503 Time and method for application. (a) Dairy operations may obtain an...
7 CFR 1430.303 - Time and method of application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false Time and method of application. 1430.303 Section 1430.303 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION... Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain...
7 CFR 1430.603 - Time and method of application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false Time and method of application. 1430.603 Section 1430.603 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION... Assistance Payment Program II (DDAP-II) § 1430.603 Time and method of application. (a) Dairy producers...
Computational methods in the pricing and risk management of modern financial derivatives
NASA Astrophysics Data System (ADS)
Deutsch, Hans-Peter
1999-09-01
In the last 20 years modern finance has developed into a complex mathematically challenging field. Very complicated risks exist in financial markets which need very advanced methods to measure and/or model them. The financial instruments invented by the market participants to trade these risk, the so called derivatives are usually even more complicated than the risks themselves and also sometimes generate new riks. Topics like random walks, stochastic differential equations, martingale measures, time series analysis, implied correlations, etc. are of common use in the field. This is why more and more people with a science background, such as physicists, mathematicians, or computer scientists, are entering the field of finance. The measurement and management of all theses risks is the key to the continuing success of banks. This talk gives insight into today's common methods of modern market risk management such as variance-covariance, historical simulation, Monte Carlo, “Greek” ratios, etc., including the statistical concepts on which they are based. Derivatives are at the same time the main reason for and the most effective means of conducting risk management. As such, they stand at the beginning and end of risk management. The valuation of derivatives and structured financial instruments is therefore the prerequisite, the condition sine qua non, for all risk management. This talk introduces some of the important valuation methods used in modern derivatives pricing such as present value, Black-Scholes, binomial trees, Monte Carlo, etc. In summary this talk highlights an area outside physics where there is a lot of interesting work to do, especially for physicists. Or as one of our consultants said: The fascinating thing about this job is that Arthur Andersen hired me not ALTHOUGH I am a physicist but BECAUSE I am a physicist.
Therapeutic and cosmetic applications of Evodiamine and its derivatives--A patent review.
Gavaraskar, Kirti; Dhulap, Sivakami; Hirwani, R R
2015-10-01
Evodiamine, ((+)-(S)-8,13,13b,14-tetrahydro-14-methylindolo[2',3':3,4]pyrido[2,1-b]quinazolin-5(7H)-one) indoloquinazoline alkaloid, is the major component isolated from the fruits of Evodia rutaecarpa, family Rutaceae. Broad spectrum of pharmacological activities of Evodiamine suggests its imperative role in treating a variety of diseases influencing the function of diverse targets. A comprehensive search was carried out to collect patent information regarding Evodiamine and its derivatives using different patent databases covering priority years to till date. The patents claiming therapeutic as well as cosmetic applications of Evodiamine and its derivatives were analyzed in detail and were classified technically based on the its application such as treatment of metabolic disorders, cancer, neurological disorders, and cardiovascular disorders, etc. The analysis revealed that the use and the mode of actions of Evodiamine and its derivatives in weight management treatments are currently well established. For example the fat reducing property of this alkaloid is primarily due to its mode of actions such as prevention of muscle protein catabolism, enhancement of thermogenesis and lipid oxidation. Apart from its use for treating obesity, Evodiamine and its derivatives are also experimentally explored for their anti-cancer, anti-diabetic and anti-inflammatory properties. The possible mechanisms related to its anti-cancer activity as illustrated by different experimental studies include its potential action as modulator of specific receptors such as topoisomerase I, NF-kappa B and B-cell lymphoma 2 (Bcl2). The analysis hence highlights that, clinical studies pertaining to the anti-cancer, anti-diabetes as well as anti-inflammatory activities of the Evodiamine and its derivatives would possess important market potential for the development of Evodiamine based therapeutics. PMID:26255828
NASA Astrophysics Data System (ADS)
Wu, Chia-Yun
High speed Atomic Force Microscopy (AFM) has a wide variety of applications ranging from nanomanufacturing to biophysics. In order to have higher scanning speed of certain AFM modes, high resonant frequency cantilevers are needed; therefore, the goal of this research is to investigate using polymer derived ceramics for possible applications in making high resonant frequency AFM cantilevers using complex cross sections. The polymer derived ceramic that will be studied, is silicon carbide. Polymer derived ceramics offer a potentially more economic fabrication approach for MEMS due to their relatively low processing temperatures and ease of complex shape design. Photolithography was used to make the desired cantilever shapes with micron scale size followed by a wet etching process to release the cantilevers from the substrates. The whole manufacturing process we use borrow well-developed techniques from the semiconducting industry, and as such this project also could offer the opportunity to reduce the fabrication cost of AFM cantilevers and MEMS in general. The characteristics of silicon carbide made from the precursor polymer, SMP-10 (Starfire Systems), were studied. In order to produce high qualities of silicon carbide cantilevers, where the major concern is defects, proper process parameters needed to be determined. Films of polymer derived ceramics often have defects due to shrinkage during the conversion process. Thus control of defects was a central issue in this study. A second, related concern was preventing oxidation; the polymer derived ceramics we chose is easily oxidized during processing. Establishing an environment without oxygen in the whole process was a significant challenge in the project. The optimization of the parameters for using photolithography and wet etching process was the final and central goal of the project; well established techniques used in microfabrication were modified for use in making the cantilever in the project. The techniques
Translational bioinformatics in psychoneuroimmunology: methods and applications.
Yan, Qing
2012-01-01
Translational bioinformatics plays an indispensable role in transforming psychoneuroimmunology (PNI) into personalized medicine. It provides a powerful method to bridge the gaps between various knowledge domains in PNI and systems biology. Translational bioinformatics methods at various systems levels can facilitate pattern recognition, and expedite and validate the discovery of systemic biomarkers to allow their incorporation into clinical trials and outcome assessments. Analysis of the correlations between genotypes and phenotypes including the behavioral-based profiles will contribute to the transition from the disease-based medicine to human-centered medicine. Translational bioinformatics would also enable the establishment of predictive models for patient responses to diseases, vaccines, and drugs. In PNI research, the development of systems biology models such as those of the neurons would play a critical role. Methods based on data integration, data mining, and knowledge representation are essential elements in building health information systems such as electronic health records and computerized decision support systems. Data integration of genes, pathophysiology, and behaviors are needed for a broad range of PNI studies. Knowledge discovery approaches such as network-based systems biology methods are valuable in studying the cross-talks among pathways in various brain regions involved in disorders such as Alzheimer's disease. PMID:22933157
Direct Density Derivative Estimation.
Sasaki, Hiroaki; Noh, Yung-Kyun; Niu, Gang; Sugiyama, Masashi
2016-06-01
Estimating the derivatives of probability density functions is an essential step in statistical data analysis. A naive approach to estimate the derivatives is to first perform density estimation and then compute its derivatives. However, this approach can be unreliable because a good density estimator does not necessarily mean a good density derivative estimator. To cope with this problem, in this letter, we propose a novel method that directly estimates density derivatives without going through density estimation. The proposed method provides computationally efficient estimation for the derivatives of any order on multidimensional data with a hyperparameter tuning method and achieves the optimal parametric convergence rate. We further discuss an extension of the proposed method by applying regularized multitask learning and a general framework for density derivative estimation based on Bregman divergences. Applications of the proposed method to nonparametric Kullback-Leibler divergence approximation and bandwidth matrix selection in kernel density estimation are also explored. PMID:27140943
Mahoney, Noreen; Molyneux, Russell J
2010-04-14
Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as healthier alternatives to animal-based fats and oils. More recently, there has been increased interest in the use of alternative specialty plant-derived oils, including those from tree nuts (almonds, pistachios, and walnuts) and botanicals (borage, evening primrose, and perilla) both for direct human consumption (e.g., as salad dressings) and for the preparation of cosmetics, soaps, and fragrance oils. This has raised the issue as to whether or not exposure to aflatoxins can result from such oils. Although most crops are subject to analysis and control, it has generally been assumed that plant oils do not retain aflatoxins due to the high polarity and lipophobicity of these compounds. There is virtually no scientific evidence to support this supposition, and available information is conflicting. To improve the safety and consistency of botanicals and dietary supplements, research is needed to establish whether or not oils used directly, or in the formulation of products, contain aflatoxins. A validated analytical method for the analysis of aflatoxins in plant-derived oils is essential to establish the safety of dietary supplements for consumption or cosmetic use that contain such oils. The aim of this research was therefore to develop an HPLC method applicable to a wide variety of oils from different plant sources spiked with aflatoxins, thereby providing a basis for a comprehensive project to establish an intra- and interlaboratory validated analytical method for the analysis of aflatoxins in dietary supplements and cosmetics formulated with plant oils. PMID:20235534
Mahoney, Noreen; Molyneux, Russell J.
2010-01-01
Consumption of edible oils derived from conventional crop plants is increasing because they are generally regarded as more healthy alternatives to animal based fats and oils. More recently there has been increased interest in the use of alternative specialty plant-derived oils, including those from tree nuts (almonds, pistachios and walnuts) and botanicals (borage, evening primrose and perilla) both for direct human consumption (e.g. as salad dressings) but also for preparation of cosmetics, soaps, and fragrance oils. This has raised the issue as to whether or not exposure to aflatoxins can result from such oils. Although most crops are subject to analysis and control, it has generally been assumed that plant oils do not retain aflatoxins due to their high polarity and lipophobicity of these compounds. There is virtually no scientific evidence to support this supposition and available information is conflicting. To improve the safety and consistency of botanicals and dietary supplements, research is needed to establish whether or not oils used directly, or in the formulation of products, contain aflatoxins. A validated analytical method for the analysis of aflatoxins in plant-derived oils is essential, in order to establish the safety of dietary supplements for consumption or cosmetic use that contain such oils. The aim of this research was therefore to develop an HPLC method applicable to a wide variety of oils from different plant sources spiked with aflatoxins, thereby providing a basis for a comprehensive project to establish an intra- and inter-laboratory validated analytical method for analysis of aflatoxins in dietary supplements and cosmetics formulated with plant oils. PMID:20235534
The generalized log-derivative method for evaluation of second-order transition amplitudes
Mrugala, F.
1989-07-15
The log-derivative method of Johnson is generalized to calculate matrix elements of multichannel Green's functions---second-order transition amplitudes---which arise from description of a variety of physical processes involving weak interactions of initial and final (bound) states with a set of strongly coupled continuum and/or bound intermediate states. A purely approximate-solution algorithm and two hybrid approximate-solution approximate-potential versions, based on the use of piecewise constant reference potentials, are presented and tested on problems concerning investigations of nonadiabatic effects in the spectroscopy of H/sub 2/. A comparison with the renormalized Numerov method, extended to calculation of considered transition amplitudes, is made and superior efficiency of the hybrid log-derivative algorithms is demonstrated. It is shown both practically and theoretically that discretization errors of the hybrid algorithms grow linearly with increasing energy in calculations, whereas cubic growth of errors with energy is characteristic for the purely approximate-solution log-derivative and Numerov algorithms.
Identification of Baribis fault - West Java using second vertical derivative method of gravity
NASA Astrophysics Data System (ADS)
Sari, Endah Puspita; Subakti, Hendri
2015-04-01
Baribis fault is one of West Java fault zones which is an active fault. In modern era, the existence of fault zone can be observed by gravity anomaly. Baribis fault zone has not yet been measured by gravity directly. Based on this reason, satellite data supported this research. Data used on this research are GPS satellite data downloaded from TOPEX. The purpose of this research is to determine the type and strike of Baribis fault. The scope of this research is Baribis fault zone which lies on 6.50o - 7.50o S and 107.50o - 108.80o E. It consists of 5146 points which one point to another is separated by 1 minute meridian. The method used in this research is the Second Vertical Derivative (SVD) of gravity anomaly. The Second Vertical Derivative of gravity anomaly show as the amplitude of gravity anomaly caused by fault structure which appears as residual anomaly. The zero value of residual gravity anomaly indicates that the contact boundary of fault plane. Second Vertical Derivative method of gravity was applied for identifying Baribis fault. The result of this research shows that Baribis fault has a thrust mechanism. It has a lineament strike varies from 107o to 127o. This result agrees with focal mechanism data of earthquakes occurring on this region based on Global CMT catalogue.
Applications of the molecular dynamics flexible fitting method.
Trabuco, Leonardo G; Schreiner, Eduard; Gumbart, James; Hsin, Jen; Villa, Elizabeth; Schulten, Klaus
2011-03-01
In recent years, cryo-electron microscopy (cryo-EM) has established itself as a key method in structural biology, permitting the structural characterization of large biomolecular complexes in various functional states. The data obtained through single-particle cryo-EM has recently seen a leap in resolution thanks to landmark advances in experimental and computational techniques, resulting in sub-nanometer resolution structures being obtained routinely. The remaining gap between these data and revealing the mechanisms of molecular function can be closed through hybrid modeling tools that incorporate known atomic structures into the cryo-EM data. One such tool, molecular dynamics flexible fitting (MDFF), uses molecular dynamics simulations to combine structures from X-ray crystallography with cryo-EM density maps to derive atomic models of large biomolecular complexes. The structures furnished by MDFF can be used subsequently in computational investigations aimed at revealing the dynamics of the complexes under study. In the present work, recent applications of MDFF are presented, including the interpretation of cryo-EM data of the ribosome at different stages of translation and the structure of a membrane-curvature-inducing photosynthetic complex. PMID:20932910
Symmetries in nuclei: New methods and applications
NASA Astrophysics Data System (ADS)
Caprio, Mark A.
2011-04-01
When a symmetry is a ``good'' symmetry of the nuclear system, as in the dynamical symmetries of the shell model and interacting boson model, this symmetry can directly give the spectroscopic properties of the nucleus, without the need for involved calculations. However, even if a symmetry is strongly broken, it nonetheless provides a calculational tool, classifying the basis states used in a full computational treatment of the many-body problem and greatly simplifying the underlying computational machinery. The symmetry then serves as the foundation for a physically meaningful truncation scheme for the calculation. This talk will provide an introduction to new applications of symmetry approaches to the nuclear problem, including the required mathematical developments. Supported by the US DOE under grant DE-FG02-95ER-40934 and by the Research Corporation for Science Advancement under a Cottrell Scholar Award.
Numerical methods for time-domain and frequency-domain analysis: applications in engineering
NASA Astrophysics Data System (ADS)
Tamas, R. D.
2015-11-01
Numerical methods are widely used for modeling different physical phenomena in engineering, especially when an analytic approach is not possible. Time-domain or frequency- domain type variations are generally investigated, depending on the nature of the process under consideration. Some methods originate from mechanics, although most of their applications belong to other fields, such as electromagnetism. Conversely, other methods were firstly developed for electromagnetism, but their field of application was extended to other fields. This paper presents some results that we have obtained by using a general purpose method for solving linear equations, i.e., the method of moments (MoM), and a time-domain method derived for electromagnetism, i.e., the Transmission Line Matrix method (TLM).
NASA Astrophysics Data System (ADS)
Pauling, A.; Rotach, M. W.; Gehrig, R.; Clot, B.
2012-09-01
Detailed knowledge of the spatial distribution of sources is a crucial prerequisite for the application of pollen dispersion models such as, for example, COSMO-ART (COnsortium for Small-scale MOdeling - Aerosols and Reactive Trace gases). However, this input is not available for the allergy-relevant species such as hazel, alder, birch, grass or ragweed. Hence, plant distribution datasets need to be derived from suitable sources. We present an approach to produce such a dataset from existing sources using birch as an example. The basic idea is to construct a birch dataset using a region with good data coverage for calibration and then to extrapolate this relationship to a larger area by using land use classes. We use the Swiss forest inventory (1 km resolution) in combination with a 74-category land use dataset that covers the non-forested areas of Switzerland as well (resolution 100 m). Then we assign birch density categories of 0%, 0.1%, 0.5% and 2.5% to each of the 74 land use categories. The combination of this derived dataset with the birch distribution from the forest inventory yields a fairly accurate birch distribution encompassing entire Switzerland. The land use categories of the Global Land Cover 2000 (GLC2000; Global Land Cover 2000 database, 2003, European Commission, Joint Research Centre; resolution 1 km) are then calibrated with the Swiss dataset in order to derive a Europe-wide birch distribution dataset and aggregated onto the 7 km COSMO-ART grid. This procedure thus assumes that a certain GLC2000 land use category has the same birch density wherever it may occur in Europe. In order to reduce the strict application of this crucial assumption, the birch density distribution as obtained from the previous steps is weighted using the mean Seasonal Pollen Index (SPI; yearly sums of daily pollen concentrations). For future improvement, region-specific birch densities for the GLC2000 categories could be integrated into the mapping procedure.
Domain adaptive boosting method and its applications
NASA Astrophysics Data System (ADS)
Geng, Jie; Miao, Zhenjiang
2015-03-01
Differences of data distributions widely exist among datasets, i.e., domains. For many pattern recognition, nature language processing, and content-based analysis systems, a decrease in performance caused by the domain differences between the training and testing datasets is still a notable problem. We propose a domain adaptation method called domain adaptive boosting (DAB). It is based on the AdaBoost approach with extensions to cover the domain differences between the source and target domains. Two main stages are contained in this approach: source-domain clustering and source-domain sample selection. By iteratively adding the selected training samples from the source domain, the discrimination model is able to achieve better domain adaptation performance based on a small validation set. The DAB algorithm is suitable for the domains with large scale samples and easy to extend for multisource adaptation. We implement this method on three computer vision systems: the skin detection model in single images, the video concept detection model, and the object classification model. In the experiments, we compare the performances of several commonly used methods and the proposed DAB. Under most situations, the DAB is superior.
An empirical method for deriving RBE values associated with electrons, photons and radionuclides.
Bellamy, M; Puskin, J; Hertel, N; Eckerman, K
2015-12-01
There is substantial evidence to justify using relative biological effectiveness (RBE) values of >1 for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer has been assigned a radiation weighting factor wR of 1. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few kiloelectron volts. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions. PMID:25636403
Davies, Melari; Jung, Christophe; Wallis, Philipp; Schnitzler, Tobias; Li, Chen; Müllen, Klaus; Bräuchle, Christoph
2011-06-01
Three new photostable rylene dyes for applications in single molecule studies and membrane labelling have been synthesized and their photophysical properties were characterized. These dyes differ in the number of polyethylene glycol (PEG) chains attached to the core structure which is either a perylene derivate or a terrylene derivate. One perylene and one terrylene dye is modified with two PEG chains, and another terrylene derivate has four PEG chains. The results show that the terrylene dye with four PEG chains (4-PEG-TDI) forms soluble nonfluorescing H-aggregates in water, so that the absorption bands are blue-shifted with respect to those of the fluorescing monomeric form. The presence of a surfactant such as Pluronic P123 leads to the disruption of the aggregates due to the formation of monomers in micelles and a strong increase in fluorescence. Application for labelling cell membranes can be considered for this dye since it adsorbs in a similar way as monomer to a lipid bilayer. Furthermore a single-molecule study of all three rylene dyes in polymeric films of PMMA showed excellent photostability with respect to photobleaching, far above the photostability of other common water-soluble dyes, such as Oxazine-1, Atto647N, Cy5, Alexa647 and Rhodamin6G. Especially 4-PEG-TDI seems to be a promising dye for membrane labelling with its high photostability. PMID:21154947
Production and applications of carbohydrate-derived sugar acids as generic biobased chemicals.
Mehtiö, Tuomas; Toivari, Mervi; Wiebe, Marilyn G; Harlin, Ali; Penttilä, Merja; Koivula, Anu
2016-10-01
This review considers the chemical and biotechnological synthesis of acids that are obtained by direct oxidation of mono- or oligosaccharide, referred to as sugar acids. It focuses on sugar acids which can be readily derived from plant biomass sources and their current and future applications. The three main classes of sugar acids are aldonic, aldaric and uronic acids. Interest in organic acids derived from sugars has recently increased, as part of the interest to develop biorefineries which produce not only biofuels, but also chemicals to replace those currently derived from petroleum. More than half of the most desirable biologically produced platform chemicals are organic acids. Currently, the only sugar acid with high commercial production is d-gluconic acid. However, other sugar acids such as d-glucaric and meso-galactaric acids are being produced at a lower scale. The sugar acids have application as sequestering agents and binders, corrosion inhibitors, biodegradable chelators for pharmaceuticals and pH regulators. There is also considerable interest in the use of these molecules in the production of synthetic polymers, including polyamides, polyesters and hydrogels. Further development of these sugar acids will lead to higher volume production of the appropriate sugar acids and will help support the next generation of biorefineries. PMID:26177333
Liu, Yang; Zheng, Hua; Zhan, GuiHua; Qin, Wen; Tian, Li; Li, WenLi
2014-06-01
Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads. However, transformation of environmental strains is much more difficult than that of domesticated strains. Here, we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987, which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases. The transformation efficiency was greatly enhanced 10(3)-fold by using unmethylated plasmid to bypass modification-restriction barrier, and using glycine betaine to protect cells from electrical damages during electroporation. Addition of HEPES and 2 mmol L(-1) MgCl2 further improved the efficiency by additional 2-fold, with a maximum value of 7.1×10(4) cfu/μg pHT3101. To demonstrate the feasibility and efficiency of the protocol, a green fluorescent protein reporter system was constructed; furthermore, phosphopantetheinyl transferase gene sfp, which is essential to the biosynthesis of polyketides and nonribosomal peptides, was overexpressed in B-9987, leading to increased production of macrolactin A by about 1.6-fold. In addition, this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6, indicating it could be a reference for other undomesticated Bacillus strains. To our knowledge, this is the first report regarding the transformation of marine-derived Bacillus strain. PMID:24771061
Method and Application of Hadamard Transform Spectrometry
NASA Astrophysics Data System (ADS)
Jarvis, John Michael
A new electrooptic shutter based mask had been developed and characterized for Hadamard encoding spectrometric applications. The mask is based upon a radically new implementation of liquid crystal technology using liquid crystal materials dispersed in a polymer matrix. The mask has several advantages compared to the previous state of the art. The mask contains 255 electrically switchable encoding elements to roughly double the spatial resolution. It exhibits improved On -Off contrast and has increased optical throughput when compared to prior art. A simple and inexpensive spectrometer that used the mask was designed, constructed, and characterized. The spectrometer uses a linear variable spectral filter to form the spectrum. This innovation results in an extremely simple optical design that is suitable for high light level experiments such as absorption. Light leakage limits the design to absorption determinations on samples of optical density of one or less. A special nature of the Hadamard encoded spectrum was discovered. Quantitative spectral information can be extracted from the encoded spectrum directly. The necessity to use the Hadamard transform can be circumvented. Instead, factor based regression techniques are used to form calibrations using the encodement data directly. Examples are given for quantitation of a single component in a mixture by Raman spectrometry and for two components in a mixture by absorption spectrometry. This technique promises to provide a powerful tool for using Hadamard encoded spectrometers for quantitative analysis.
COMPLEX VARIABLE BOUNDARY ELEMENT METHOD: APPLICATIONS.
Hromadka, T.V., II; Yen, C.C.; Guymon, G.L.
1985-01-01
The complex variable boundary element method (CVBEM) is used to approximate several potential problems where analytical solutions are known. A modeling result produced from the CVBEM is a measure of relative error in matching the known boundary condition values of the problem. A CVBEM error-reduction algorithm is used to reduce the relative error of the approximation by adding nodal points in boundary regions where error is large. From the test problems, overall error is reduced significantly by utilizing the adaptive integration algorithm.
Optical and Transport Properties of Organic Molecules: Methods and Applications
NASA Astrophysics Data System (ADS)
Strubbe, David Alan
Organic molecules are versatile and tunable building blocks for technology, in nanoscale and bulk devices. In this dissertation, I will consider some important applications for organic molecules involving optical and transport properties, and develop methods and software appropriate for theoretical calculations of these properties. Specifically, we will consider second-harmonic generation, a nonlinear optical process; photoisomerization, in which absorption of light leads to mechanical motion; charge transport in junctions formed of single molecules; and optical excitations in pentacene, an organic semiconductor with applications in photovoltaics, optoelectronics, and flexible electronics. In the Introduction (Chapter 1), I will give an overview of some phenomenology about organic molecules and these application areas, and discuss the basics of the theoretical methodology I will use: density-functional theory (DFT), time-dependent density-functional theory (TDDFT), and many-body perturbation theory based on the GW approximation. In the subsequent chapters, I will further discuss, develop, and apply this methodology. 2. I will give a pedagogical derivation of the methods for calculating response properties in TDDFT, with particular focus on the Sternheimer equation, as will be used in subsequent chapters. I will review the many different response properties that can be calculated (dynamic and static) and the appropriate perturbations used to calculate them. 3. Standard techniques for calculating response use either integer occupations (as appropriate for a system with an energy gap) or fractional occupations due to a smearing function, used to improve convergence for metallic systems. I will present a generalization which can be used to compute response for a system with arbitrary fractional occupations. 4. Chloroform (CHCl3) is a small molecule commonly used as a solvent in measurements of nonlinear optics. I computed its hyperpolarizability for second
NASA Astrophysics Data System (ADS)
Chadha, R.; Bali, A.
2016-05-01
Rapid, sensitive, cost effective and reproducible stability-indicating derivative spectrophotometric methods have been developed for the estimation of dronedarone HCl employing peak-zero (P-0) and peak-peak (P-P) techniques, and their stability-indicating potential assessed in forced degraded solutions of the drug. The methods were validated with respect to linearity, accuracy, precision and robustness. Excellent linearity was observed in concentrations 2-40 μg/ml (r 2 = 0.9986). LOD and LOQ values for the proposed methods ranged from 0.42-0.46 μg/ml and 1.21-1.27 μg/ml, respectively, and excellent recovery of the drug was obtained in the tablet samples (99.70 ± 0.84%).
NASA Astrophysics Data System (ADS)
Chadha, R.; Bali, A.
2016-05-01
Rapid, sensitive, cost effective and reproducible stability-indicating derivative spectrophotometric methods have been developed for the estimation of dronedarone HCl employing peak-zero (P-0) and peak-peak (P-P) techniques, and their stability-indicating potential assessed in forced degraded solutions of the drug. The methods were validated with respect to linearity, accuracy, precision and robustness. Excellent linearity was observed in concentrations 2-40 μg/ml ( r 2 = 0.9986). LOD and LOQ values for the proposed methods ranged from 0.42-0.46 μg/ml and 1.21-1.27 μg/ml, respectively, and excellent recovery of the drug was obtained in the tablet samples (99.70 ± 0.84%).
Methods of synthesis of acrolein and its α-substituted derivatives
NASA Astrophysics Data System (ADS)
Keiko, Nataliya A.; Voronkov, Mikhail G.
1993-08-01
The methods of synthesis of acrolein and its α-alkyl-substituted derivatives are examined: (a) catalytic oxidation of propene, isobutene, propane, isobutane, propyl and tert-butyl alcohols, tert-butyl alkanoates, propionaldehyde, isobutyraldehyde, and allyl alcohol and its ethers: (b) condensation of formaldehyde with aliphatic aldehydes by the Mannich reactions and also in the vapour phase over heterogeneous catalysts. Both general methods (the Mannich reaction, ipso-substitution of a α-halogen in the acrylic system, and interaction of 1-brom-2-ethoxycyclopropyllithium with electrophiles) and various special methods are used in the synthesis of the α, β-unsaturated aldehydes with functional-group-substitutents. The bibliography includes 323 references.
Methods applicable to membrane nanodomain studies?
Ashrafzadeh, Parham; Parmryd, Ingela
2015-01-01
Membrane nanodomains are dynamic liquid entities surrounded by another type of dynamic liquid. Diffusion can take place inside, around and in and out of the domains, and membrane components therefore continuously shift between domains and their surroundings. In the plasma membrane, there is the further complexity of links between membrane lipids and proteins both to the extracellular matrix and to intracellular proteins such as actin filaments. In addition, new membrane components are continuously delivered and old ones removed. On top of this, cells move. Taking all of this into account imposes great methodological challenges, and in the present chapter we discuss some methods that are currently used for membrane nanodomain studies, what information they can provide and their weaknesses. PMID:25658344
Endothelial cell micropatterning: Methods, effects, and applications
Anderson, Deirdre E.J.; Hinds, Monica T.
2012-01-01
The effects of flow on endothelial cells have been widely examined for the ability of fluid shear stress to alter cell morphology and function; however, the effects of endothelial cell morphology without flow have only recently been observed. An increase in lithographic techniques in cell culture spurred a corresponding increase in research aiming to confine cell morphology. These studies lead to a better understanding of how morphology and cytoskeletal configuration affect the structure and function of the cells. This review examines endothelial cell micropatterning research by exploring both the many alternative methods used to alter endothelial cell morphology and the resulting changes in cellular shape and phenotype. Micropatterning induced changes in endothelial cell proliferation, apoptosis, cytoskeletal organization, mechanical properties, and cell functionality. Finally, the ways these cellular manipulation techniques have been applied to biomedical engineering research, including angiogenesis, cell migration, and tissue engineering, is discussed. PMID:21761242
Scheduled Relaxation Jacobi method: Improvements and applications
NASA Astrophysics Data System (ADS)
Adsuara, J. E.; Cordero-Carrión, I.; Cerdá-Durán, P.; Aloy, M. A.
2016-09-01
Elliptic partial differential equations (ePDEs) appear in a wide variety of areas of mathematics, physics and engineering. Typically, ePDEs must be solved numerically, which sets an ever growing demand for efficient and highly parallel algorithms to tackle their computational solution. The Scheduled Relaxation Jacobi (SRJ) is a promising class of methods, atypical for combining simplicity and efficiency, that has been recently introduced for solving linear Poisson-like ePDEs. The SRJ methodology relies on computing the appropriate parameters of a multilevel approach with the goal of minimizing the number of iterations needed to cut down the residuals below specified tolerances. The efficiency in the reduction of the residual increases with the number of levels employed in the algorithm. Applying the original methodology to compute the algorithm parameters with more than 5 levels notably hinders obtaining optimal SRJ schemes, as the mixed (non-linear) algebraic-differential system of equations from which they result becomes notably stiff. Here we present a new methodology for obtaining the parameters of SRJ schemes that overcomes the limitations of the original algorithm and provide parameters for SRJ schemes with up to 15 levels and resolutions of up to 215 points per dimension, allowing for acceleration factors larger than several hundreds with respect to the Jacobi method for typical resolutions and, in some high resolution cases, close to 1000. Most of the success in finding SRJ optimal schemes with more than 10 levels is based on an analytic reduction of the complexity of the previously mentioned system of equations. Furthermore, we extend the original algorithm to apply it to certain systems of non-linear ePDEs.
Reactive trityl derivatives: stabilised carbocation mass-tags for life sciences applications.
Ustinov, Alexey V; Shmanai, Vadim V; Patel, Kaajal; Stepanova, Irina A; Prokhorenko, Igor A; Astakhova, Irina V; Malakhov, Andrei D; Skorobogatyi, Mikhail V; Bernad, Pablo L; Khan, Safraz; Shahgholi, Mona; Southern, Edwin M; Korshun, Vladimir A; Shchepinov, Mikhail S
2008-12-21
The rational design of novel triarylmethyl (trityl)-based mass tags (MT) for mass-spectrometric (MS) applications is described. We propose a "pK(R+) rule" to correlate the stability of trityl carbocations with their MS performance: trityls with higher pK(R+) values ionise and desorb better. Trityl blocks were synthesised that have high pK(R+) values and are stable in conditions of MS analysis; these MTs can be ionised by matrix as well as irradiation with a 337 nm nitrogen laser. (13)C-Labelled tags were prepared for MS quantitation applications. Moreover, the tags were equipped with a variety of functional groups allowing conjugation with different functionalities within (bio)molecules to enhance the MS characteristics of the latter. The MS behaviour of model polycationic trityl compounds with and without the matrix was studied to reveal that poly-trityl clusters are always singly charged under the (MA)LDI-TOF conditions. Several peptide-trityl conjugates were prepared and comparisons revealed a beneficial effect of trityl tags on the conjugate detection in MS. Trityl compounds containing para-methoxy- and dimethylamine groups, as well as a xanthene fragment, showed considerable enhancement in MS detection of model peptides; thus they are promising tools for proteomic applications. Dimethoxytrityl derivatives allow one to distinguish between Arg- and Lys-containing peptides. Maleimido trityl derivatives are suitable for the efficient derivatisation of thiol-containing peptides in pyridine. PMID:19039369
The performance of selected semi-empirical and DFT methods in studying C60 fullerene derivatives
NASA Astrophysics Data System (ADS)
Sikorska, Celina; Puzyn, Tomasz
2015-11-01
The capability of reproducing the open circuit voltages (V oc) of 15 representative C60 fullerene derivatives was tested using the selected quantum mechanical methods (B3LYP, PM6, and PM7) together with the two one-electron basis sets. Certain theoretical treatments (e.g. PM6) were found to be satisfactory for preliminary estimates of the open circuit voltages (V oc), whereas the use of the B3LYP/6-31G(d) approach has been proven to assure highly accurate results. We also examined the structural similarity of 19 fullerene derivatives by employing principle component analysis (PCA). In order to express the structural features of the studied compounds we used molecular descriptors calculated with semi-empirical (PM6 and PM7) and density functional (B3LYP/6-31G(d)) methods separately. In performing PCA, we noticed that semi-empirical methods (i.e. PM6 and PM7) seem satisfactory for molecules, in which one can distinguish the aromatic and the aliphatic parts in the cyclopropane ring of PCBM (phenyl-C61-buteric acid methyl ester) and they significantly overestimate the energy of the highest occupied molecular orbital (E HOMO). The use of the B3LYP functional, however, is recommended for studying methanofullerenes, which closely resemble the structure of PCBM, and for their modifications.
Tellgren, Erik I; Reine, Simen S; Helgaker, Trygve
2012-07-14
Analytical integral evaluation is a central task of modern quantum chemistry. Here we present a general method for evaluating differentiated integrals over standard Gaussian and mixed Gaussian/plane-wave hybrid orbitals. The main idea is to have a representation of basis sets that is flexible enough to enable differentiated integrals to be reinterpreted as standard integrals over modified basis functions. As an illustration of the method, we report a very simple implementation of Hartree-Fock level geometrical derivatives in finite magnetic fields for gauge-origin independent atomic orbitals, within the London program. As a quantum-chemical application, we optimize the structure of helium clusters and some well-known covalently bound molecules (water, ammonia and benzene) subject to strong magnetic fields. PMID:22653039
Gunda, Venugopal; Verma, Raj K.; Pawar, Smita C.; Sudhakar, Yakkanti A.
2013-01-01
Collagen constitutes one of the vital components of the basement membrane scaffolds. Non-collagenous domains (NC1) derived from collagens exhibit potent anti-angiogenic properties, thus attaining significance in regulation of angiogenesis promoted diseases. Individual NC1 domains essential for anti-angiogenic evaluations are generally obtained through purification of individual non-collagenous domains, which have undergone steady developments for enhancing the yields, purpose of biological evaluations and solubility based on the nature of different NC1 domains. This review focuses on the method developments in obtaining biologically active NC1 domains and for specific evaluations in different scenarios. PMID:24215863
Coordinates Used in Derivation of Hawking Radiation via Hamilton-Jacobi Method
NASA Astrophysics Data System (ADS)
Liu, Bo; He, Xiaokai; Liu, Wenbiao
2009-05-01
Coordinates used in derivation of Hawking radiation via Hamilton-Jacobi method are investigated more deeply. In the case of a 4-dimensional Schwarzschild black hole, a direct computation leads to a wrong result. In the meantime, making use of the isotropic coordinate or invariant radial distance, we can get the correct conclusion. More coordinates including Painleve and Eddington-Finkelstein are tried to calculate the semi-classical Hawking emission rate. The reason of the discrepancy between naive coordinate and well-behaved coordinates is also discussed.
A Derivative-Free Riemannian Powell's Method, Minimizing Hartley-Entropy-Based ICA Contrast.
Chattopadhyay, Amit; Selvan, Suviseshamuthu Easter; Amato, Umberto
2016-09-01
Even though the Hartley-entropy-based contrast function guarantees an unmixing local minimum, the reported nonsmooth optimization techniques that minimize this nondifferentiable function encounter computational bottlenecks. Toward this, Powell's derivative-free optimization method has been extended to a Riemannian manifold, namely, oblique manifold, for the recovery of quasi-correlated sources by minimizing this contrast function. The proposed scheme has been demonstrated to converge faster than the related algorithms in the literature, besides the impressive source separation results in simulations involving synthetic sources having finite-support distributions and correlated images. PMID:26292347
NASA Astrophysics Data System (ADS)
Pluzhnik-Gladyr, S. M.
2016-02-01
Methods of synthesis of halogenated benzo- and dibenzocrown ether derivatives are surveyed: halogenation of benzo- and dibenzocrown ethers with molecular halogens, N-halosuccinimides in the solid phase and different media (water, ethanol, halohydrocarbons) and hypohalites in water, as well as the 'assembly' method. Reactions of these compounds are considered: synthesis of phosphorus-containing crown ethers, organometallic synthesis, the Heck and Sonogashira reactions, synthesis of acetylene derivatives and other reactions. Special attention is focused on the complexing properties of halogenated benzocrown ethers with respect to ionic guests and neutral organic molecules. The possibility of synthesis of complexes of such compounds in the solid phase is demonstrated. The extraction and sorption properties of halogenated benzo- and dibenzocrown ethers are considered. Examples of practical use of these compounds are presented. The bibliography includes 203 references.
Methods and applications of HPLC-AMS
NASA Astrophysics Data System (ADS)
Buchholz, Bruce A.; Dueker, Stephen R.; Lin, Yumei; Clifford, Andrew J.; Vogel, John S.
2000-10-01
Pharmacokinetics of physiologic doses of nutrients, pesticides, and herbicides can easily be traced in humans using a 14C-labeled compound. Basic kinetics can be monitored in blood or urine by measuring the elevation in the 14C content above the control predose tissue and converting to equivalents of the parent compound. High performance liquid chromatography (HPLC) is an excellent method for the chemical separation of complex mixtures whose profiles afford estimation of biochemical pathways of metabolism. Compounds elute from the HPLC systems with characteristic retention times and can be collected in fractions that can then be graphitized for AMS measurement. Unknowns are tentatively identified by co-elution with known standards and chemical tests that reveal functional groupings. Metabolites are quantified with the 14C signal. Thoroughly accounting for the carbon inventory in the LC solvents, ion-pairing agents, samples, and carriers adds some complexity to the analysis. In most cases the total carbon inventory is dominated by carrier. Baseline background and stability need to be carefully monitored. Limits of quantitation near 10 amol of 14C per HPLC fraction are typically achieved. Baselines are maintained by limiting injected 14C activity <0.17 Bq (4.5 pCi) on the HPLC column.
Nanoliposomes: Synthesis methods and applications in cosmetics.
Fakhravar, Zohreh; Ebrahimnejad, Pedram; Daraee, Hadis; Akbarzadeh, Abolfazl
2016-06-01
Nanotechnology is used frequently in marketing skin care goods, and whereas the word sounds as if it belongs in robotics and science fiction, it is rapidly becoming common in medicine and skin care. As few people actually recognize what the technology, benefits, or possible implications of its use are, we determined to outline them. The type of nanotechnology that is most significant in cosmetics, skin care and health products is the use of nanoparticles (or Bucky balls as they are known in manufacturing), and a particular kind of these nanoparticles have been touted as the next generation of liposomes. Nanoliposomes is one of the most recognized names for the nanoparticles used in skin care and cosmetic products, and we are also familiar with the term liposome, so this connection between the two is the perhaps the best way to clarify what nanoliposomes are. In this article, some of the techniques for their production are reviewed. Common methods of nanoliposome preparation are discussed. PMID:25968161
Formal Methods Applications in Air Transportation
NASA Technical Reports Server (NTRS)
Farley, Todd
2009-01-01
The U.S. air transportation system is the most productive in the world, moving far more people and goods than any other. It is also the safest system in the world, thanks in part to its venerable air traffic control system. But as demand for air travel continues to grow, the air traffic control system s aging infrastructure and labor-intensive procedures are impinging on its ability to keep pace with demand. And that impinges on the growth of our economy. Air traffic control modernization has long held the promise of a more efficient air transportation system. Part of NASA s current mission is to develop advanced automation and operational concepts that will expand the capacity of our national airspace system while still maintaining its excellent record for safety. It is a challenging mission, as efforts to modernize have, for decades, been hamstrung by the inability to assure safety to the satisfaction of system operators, system regulators, and/or the traveling public. In this talk, we ll provide a brief history of air traffic control, focusing on the tension between efficiency and safety assurance, and the promise of formal methods going forward.
Modern industrial and pharmacological applications of indigo dye and its derivatives--a review.
Stasiak, Natalia; Kukuła-Koch, Wirginia; Głowniak, Kazimierz
2014-01-01
Plant sources, chemical properties, bioactivities, as well as the synthesis of indigo dye and its derivatives, are reviewed in this paper. These compounds were chosen because of their significant benefits and scope of application as both coloring agents in the textile industry and as pharmacologically active natural products. Their use in traditional chinese medicine (TCM) has directed the attention of European researchers and medical doctors alike. The preparation of indigoferous plants--Indigo naturalis is currently about to be introduced into the European Pharmacopoeia. PMID:25272640
Acetylene-derived polymers and their applications in hair and skin care.
Petter, P J
1989-02-01
Synopsis Since the introduction over 30 years ago of polyvinylpyrrolidone (PVP) as the first synthetic hairspray resin, acetylene-derived polymers have found wide and increasing applications in the cosmetics and toiletries industry. This review covers the two main classes of acetylenic polymers. In the first class, in which the chemistry may be traced back to reaction of acetylene with formaldehyde, are included PVP homopolymers and copolymers of VP with vinyl acetate, dimethylaminoethyl methacrylate, vinylcaprolactam and styrene. In the second class, stemming from reaction of acetylene with methanol, are the poly (vinyl methyl ether/maleic acid) monoester resins. PMID:19456933
Analytical Derivation of the Inverse Moments of One-Sided Correlated Gram Matrices With Applications
NASA Astrophysics Data System (ADS)
Elkhalil, Khalil; Kammoun, Abla; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim
2016-05-01
This paper addresses the development of analytical tools for the computation of the moments of random Gram matrices with one side correlation. Such a question is mainly driven by applications in signal processing and wireless communications wherein such matrices naturally arise. In particular, we derive closed-form expressions for the inverse moments and show that the obtained results can help approximate several performance metrics such as the average estimation error corresponding to the Best Linear Unbiased Estimator (BLUE) and the Linear Minimum Mean Square Error LMMSE or also other loss functions used to measure the accuracy of covariance matrix estimates.
Application research on enhancing near-infrared micro-imaging quality by 2nd derivative
NASA Astrophysics Data System (ADS)
Wang, Dong; Ma, Zhi-hong; Zhao, Liu; Wang, Bei-hong; Han, Ping; Pan, Li-gang; Wang, Ji-hua
2013-08-01
Near-infrared micro-imaging will not only provide the sample's spatial distribution information, but also the spectroscopic information of each pixel. In this thesis, it took the artificial sample of wheat flour and formaldehyde sodium sulfoxylate distribution given for example to research the data processing method for enhancing the quality of near-infrared micro-imaging. Near-infrared spectroscopic feature of wheat flour and formaldehyde sodium sulfoxylate being studied on, compare correlation imaging and 2nd derivative imaging were applied in the imaging processing of the near-infrared micro-image of the artificial sample. Furthermore, the two methods were combined, i.e. 2nd derivative compare correlation imaging was acquired. The result indicated that the difference of the correlation coefficients between the two substances, i.e. wheat flour and formaldehyde sodium sulfoxylate, and the reference spectrum has been increased from 0.001 in compare correlation image to 0.796 in 2nd derivative compare correlation image respectively, which enhances the imaging quality efficiently. This study will, to some extent, be of important reference significance to near-infrared micro-imaging method research of agricultural products and foods.
Laser printing of azo-derivative thin films for non-linear optical applications
NASA Astrophysics Data System (ADS)
Matei, Andreea; Constantinescu, Catalin; Mitu, Bogdana; Filipescu, Mihaela; Ion, Valentin; Ionita, Iulian; Brajnicov, Simona; Alloncle, Anne-Patricia; Delaporte, Philippe; Emandi, Ana; Dinescu, Maria
2015-05-01
The use of laser-based processing is presented here for the transfer of azo-derivatives, for optoelectronics assembly applications. Laser-printing techniques are also adequate tools for rapid prototyping of diverse materials, since they avoid the usage of solutions, moulds, lithography masks, etc. Here, we present a study on the laser-induced forward transfer (LIFT) and printing of micrometric-sized pixels (350 μm × 350 μm), by using matrix-assisted pulsed laser evaporation (MAPLE) deposited thin film donors. Due to their particular optical properties, i.e. second harmonic generation, optical limiting and all-optical poling, and with applications in optoelectronics and sensor development, azo-dyes have been intensively studied in bulk or as thin films. The influence of a metallic dynamic release layer (DRL) during LIFT is investigated.
ATLID beam steering mechanism and derived new piezoelectric-based devices for optical applications
NASA Astrophysics Data System (ADS)
Bourgain, F.; Barillot, F.; Belly, C.; Claeyssen, F.
2015-09-01
In Space & Defence (as well as in many others fields), there is a trend for miniaturisation in active optics requiring new actuators. Applications also often require the ability to withstand high vibrations and shocks levels, as well as vacuum compatibility for space applications. A new generation of small and smart actuators such as piezoelectric (piezo) actuators, are resolving this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. This paper first presents the BSM mechanism and its requirements, the technologies involved in the design and the validation campaign results. Secondly, a derived XY piezoelectric positioning stage based on the same APA® and associated Strain Gage sensing technology is presented with its associated performances. Finally, a new piezoelectric motor based on the APA® technology, which allows the combination of long stroke while maintaining high resolution positioning of optical elements, is presented with experimental performances.
Failure mode analysis using state variables derived from fault trees with application
Bartholomew, R.J.
1981-01-01
Fault Tree Analysis (FTA) is used extensively to assess both the qualitative and quantitative reliability of engineered nuclear power systems employing many subsystems and components. FTA is very useful, but the method is limited by its inability to account for failure mode rate-of-change interdependencies (coupling) of statistically independent failure modes. The state variable approach (using FTA-derived failure modes as states) overcomes these difficulties and is applied to the determination of the lifetime distribution function for a heat pipe-thermoelectric nuclear power subsystem. Analyses are made using both Monte Carlo and deterministic methods and compared with a Markov model of the same subsystem.
Kupcewicz, Bogumiła; Małecka, Magdalena; Zapadka, Mariusz; Krajewska, Urszula; Rozalski, Marek; Budzisz, Elzbieta
2016-07-15
Quantitative relationships between the structure and cytotoxic activity of series flavonoid derivatives were examined. The first regression-based model, developed for 18 flavanone-2-pyrazoline hybrids, involved two interpretable descriptors: a Mor04v and partial atomic charge. The second model, developed for structurally diverse set of compounds, was based on descriptors derived from Hirshfeld surface analysis. This model suggests that cytotoxic activity of compounds can be successfully predicted based on a fraction of H⋯H contacts and a fraction of interactions involving a halogen atom. For non-halogen derivatives, the data reveal that cytotoxic activity is inversely proportional to the percentage of O⋯H and N⋯H close contacts to Hirshfeld surface, while directly proportional to the percentage of H⋯H interactions. Chlorine (1k) and bromine (1l) derivatives of compounds, containing flavanone fused with N-methyl-2-pyrazoline, exhibited high cytotoxic potential against HL-60 cancer cell line (IC50<10μM). The cytotoxicity of 1k and 1l towards normal cells (HUVEC) was 10 and 25-fold lower, respectively. PMID:27234147
NASA Astrophysics Data System (ADS)
Graczyk, Alfreda; Kwasny, Miroslaw; Ye, Shu; Milosz, Ewa; Kowalska, Agnieszka; Podhajska, Anna
2003-10-01
Observation and selective destruction of biological tissues, due to use of photochemical reaction sensitised with photosensitive dyes, are applied in modern method of tumor diagnosis and treatment as well as destruction of atheromatous plaques and restenosis prevention. This method, called photodynamic method (PDT), has been developed for recent 30 years in USA, Canada, Japan, and China and in majority of European countries. It has many advantages that distinguish it from among other currently used diagnostic and therapeutic methods. Both, the applied photosensitizers and photodynamic effect influence on active biological compounds present in an organism, mainly on enzymatic proteins, hormones, and particular elements of immunological system. The PDT method can be used not only for in situ tumor treatment but also for the treatment in metastasis state. It was thought previously that direct activity of cytotoxic radicals and singlet oxygen causes tissues necrosis. At present, additional investigations are performed on destruction mechanisms, i.e., occlusion of blood vessels and lymphatic vessels and PDT influence on immunological system revealing in cytokines release. In Poland, the technology of new class of photosensitizer - diaminoacid derivatives of protoporphyrin PP(AA)2Arg2 as well as the basic half-product - hemis of very high purity has been developed and activities for their industrial production have been performed. In vitro investigations on quantum luminescence yield and singlet oxygen quantum yield of the obtained preparations were made. These compounds do not show toxic properties and they are neither mutagenic nor teratogenic. Three aminoacid protoporphyrine derivatives were chosen for industrial scale production, i.e., PP(Ala)2Arg2, PP(Ser)2Arg2, PP(Plu)2Arg2 that were efficient for the largest number of tumors investigated on cell lines. A preparation being the mixture of these derivatives is called Sensyphyrine. In the first stage of Sensyphyrine
Sankaran, Sethuraman; Audet, Charles; Marsden, Alison L.
2010-06-20
Recent advances in coupling novel optimization methods to large-scale computing problems have opened the door to tackling a diverse set of physically realistic engineering design problems. A large computational overhead is associated with computing the cost function for most practical problems involving complex physical phenomena. Such problems are also plagued with uncertainties in a diverse set of parameters. We present a novel stochastic derivative-free optimization approach for tackling such problems. Our method extends the previously developed surrogate management framework (SMF) to allow for uncertainties in both simulation parameters and design variables. The stochastic collocation scheme is employed for stochastic variables whereas Kriging based surrogate functions are employed for the cost function. This approach is tested on four numerical optimization problems and is shown to have significant improvement in efficiency over traditional Monte-Carlo schemes. Problems with multiple probabilistic constraints are also discussed.
Using a derivative-free optimization method for multiple solutions of inverse transport problems
Armstrong, Jerawan C.; Favorite, Jeffrey A.
2016-01-14
Identifying unknown components of an object that emits radiation is an important problem for national and global security. Radiation signatures measured from an object of interest can be used to infer object parameter values that are not known. This problem is called an inverse transport problem. An inverse transport problem may have multiple solutions and the most widely used approach for its solution is an iterative optimization method. This paper proposes a stochastic derivative-free global optimization algorithm to find multiple solutions of inverse transport problems. The algorithm is an extension of a multilevel single linkage (MLSL) method where a meshmore » adaptive direct search (MADS) algorithm is incorporated into the local phase. Furthermore, numerical test cases using uncollided fluxes of discrete gamma-ray lines are presented to show the performance of this new algorithm.« less
Lima, Djalma S.; Zamboni, Dario S.
2010-01-01
The broad use of transgenic and gene-targeted mice has established bone marrow-derived macrophages (BMDM) as important mammalian host cells for investigation of the macrophages biology. Over the last decade, extensive research has been done to determine how to freeze and store viable hematopoietic human cells; however, there is no information regarding generation of BMDM from frozen murine bone marrow (BM) cells. Here, we establish a highly efficient protocol to freeze murine BM cells and further generate BMDM. Cryopreserved murine BM cells maintain their potential for BMDM differentiation for more than 6 years. We compared BMDM obtained from fresh and frozen BM cells and found that both are similarly able to trigger the expression of CD80 and CD86 in response to LPS or infection with the intracellular bacteria Legionella pneumophila. Additionally, BMDM obtained from fresh or frozen BM cells equally restrict or support the intracellular multiplication of pathogens such as L. pneumophila and the protozoan parasite Leishmania (L.) amazonensis. Although further investigation are required to support the use of the method for generation of dendritic cells, preliminary experiments indicate that bone marrow-derived dendritic cells can also be generated from cryopreserved BM cells. Overall, the method described and validated herein represents a technical advance as it allows ready and easy generation of BMDM from a stock of frozen BM cells. PMID:21179419
Remote sensing applications of the extended radiosity method
Gerstl, S.A.W.; Borel, C.C.
1992-01-01
In this paper we describe the progress made in the last three years on developing the radiosity method for remote sensing applications. The research covered canopy modeling, volumetric scattering and atmospheric corrections for future analysis of EOS imaging spectrometer data.
Remote sensing applications of the extended radiosity method
Gerstl, S.A.W.; Borel, C.C.
1992-05-01
In this paper we describe the progress made in the last three years on developing the radiosity method for remote sensing applications. The research covered canopy modeling, volumetric scattering and atmospheric corrections for future analysis of EOS imaging spectrometer data.
7 CFR 786.103 - Time and method of application.
Code of Federal Regulations, 2011 CFR
2011-01-01
....103 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS DAIRY DISASTER ASSISTANCE PAYMENT PROGRAM (DDAP-III) § 786.103 Time and method of application. (a) Dairy producers may obtain an application, in person, by mail,...
A greedy-based multiquadric method for LiDAR-derived ground data reduction
NASA Astrophysics Data System (ADS)
Chen, Chuanfa; Yan, Changqing; Cao, Xuewei; Guo, Jinyun; Dai, Honglei
2015-04-01
A new greedy-based multiquadric method (MQ-G) has been developed to perform LiDAR-derived ground data reduction by selecting a certain amount of significant terrain points from the raw dataset to keep the accuracy of the constructed DEMs as high as possible, while maximally retaining terrain features. In the process of MQ-G, the significant terrain points were selected with an iterative process. First, the points with the maximum and minimum elevations were selected as the initial significant points. Next, a smoothing MQ was employed to perform an interpolation with the selected critical points. Then, the importance of all candidate points was assessed by interpolation error (i.e. the absolute difference between the interpolated and actual elevations). Lastly, the most significant point in the current iteration was selected and used for point selection in the next iteration. The process was repeated until the number of selected points reached a pre-set level or no point was found to have the interpolation error exceeding a user-specified accuracy tolerance. In order to avoid the huge computing cost, a new technique was presented to quickly solve the systems of MQ equations in the global interpolation process, and then the global MQ was replaced with the local one when a certain amount of critical points were selected. Four study sites with different morphologies (i.e. flat, undulating, hilly and mountainous terrains) were respectively employed to comparatively analyze the performances of MQ-G and the classical data selection methods including maximum z-tolerance (Max-Z) and the random method for reducing LiDAR-derived ground datasets. Results show that irrespective of the number of selected critical points and terrain characteristics, MQ-G is always more accurate than the other methods for DEM construction. Moreover, MQ-G has a better ability of preserving terrain feature lines, especially for the undulating and hilly terrains.
NASA Astrophysics Data System (ADS)
Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Rybak, Wojciech; Krzek, Jan
2015-09-01
Fast, accurate and precise method for the determination of zofenopril and fluvastatin was developed using spectrophotometry of the first (D1), second (D2), and third (D3) order derivatives in two-component mixtures and in pharmaceutical preparations. It was shown, that the developed method allows for the determination of the tested components in a direct manner, despite the apparent interference of the absorption spectra in the UV range. For quantitative determinations, "zero-crossing" method was chosen, appropriate wavelengths for zofenopril were: D1 λ = 270.85 nm, D2 λ = 286.38 nm, D3 λ = 253.90 nm. Fluvastatin was determined at wavelengths: D1 λ = 339.03 nm, D2 λ = 252.57 nm, D3 λ = 258.50 nm, respectively. The method was characterized by high sensitivity and accuracy, for zofenopril LOD was in the range of 0.19-0.87 μg mL-1, for fluvastatin 0.51-1.18 μg mL-1, depending on the class of derivative, and for zofenopril and fluvastatin LOQ was 0.57-2.64 μg mL-1 and 1.56-3.57 μg mL-1, respectively. The recovery of individual components was within the range of 100 ± 5%. For zofenopril, the linearity range was estimated between 7.65 μg mL-1 and 22.94 μg mL-1, and for fluvastatin between 5.60 μg mL-1 and 28.00 μg mL-1.
NASA Technical Reports Server (NTRS)
Krishnamurthy, Thiagarajan
2005-01-01
Response construction methods using Moving Least Squares (MLS), Kriging and Radial Basis Functions (RBF) are compared with the Global Least Squares (GLS) method in three numerical examples for derivative generation capability. Also, a new Interpolating Moving Least Squares (IMLS) method adopted from the meshless method is presented. It is found that the response surface construction methods using the Kriging and RBF interpolation yields more accurate results compared with MLS and GLS methods. Several computational aspects of the response surface construction methods also discussed.
Optical scattering methods applicable to drops and bubbles
NASA Technical Reports Server (NTRS)
Marston, Philip L.
1990-01-01
An overview of optical scattering properties of drops and bubbles is presented. The properties lead to unconventional methods for optically monitoring the size or shape of a scatterer and are applicable to acoustically levitated objects. Several of the methods are applicable to the detection and measurement of small amplitude oscillations. Relevant optical phenomena include: (1) rainbows; (2) diffraction catastrophes from spheroids; (3) critical angle scattering; (4) effects of coatings; (5) glory scattering; and (6) optical levitation.
Application of biasing techniques to the contributon Monte Carlo method
Dubi, A.; Gerstl, S.A.W.
1980-01-01
Recently, a new Monte Carlo Method called the Contribution Monte Carlo Method was developed. The method is based on the theory of contributions, and uses a new receipe for estimating target responses by a volume integral over the contribution current. The analog features of the new method were discussed in previous publications. The application of some biasing methods to the new contribution scheme is examined here. A theoretical model is developed that enables an analytic prediction of the benefit to be expected when these biasing schemes are applied to both the contribution method and regular Monte Carlo. This model is verified by a variety of numerical experiments and is shown to yield satisfying results, especially for deep-penetration problems. Other considerations regarding the efficient use of the new method are also discussed, and remarks are made as to the application of other biasing methods. 14 figures, 1 tables.
The applications of buckminsterfullerene C60 and derivatives in orthopaedic research
Liu, Qihai; Cui, Quanjun; Li, Xudong Joshua; Jin, Li
2014-01-01
Buckminsterfullerene C60 and derivatives have been extensively explored in biomedical research due to their unique structure and unparalleled physicochemical properties. C60 is characterized as a “free radical sponge” with an anti-oxidant efficacy several hundred-fold higher than conventional anti-oxidants. Also, the C60 core has a strong electron-attracting ability and numerous functional compounds with widely different properties can be added to this fullerene cage. This review focused on the applications of C60 and derivatives in orthopaedic research, such as the treatment of cartilage degeneration, bone destruction, intervertebral disc degeneration (IVDD), vertebral bone marrow disorder, radiculopathy, etc., as well as their toxicity in vitro and in vivo. We suggest that C60 and derivatives, especially the C60 cores coupled with functional groups presenting new biological and pharmacological activities, are advantageous in orthopaedic research and will be promising in clinical performance for musculoskeletal disorders treatment; however, the pharmacokinetics and toxicology of these agents as local/systemic administration need to be carefully determined. PMID:24409811
NASA Technical Reports Server (NTRS)
Fares, Nabil; Li, Victor C.
1986-01-01
An image method algorithm is presented for the derivation of elastostatic solutions for point sources in bonded halfspaces assuming the infinite space point source is known. Specific cases were worked out and shown to coincide with well known solutions in the literature.
Application of a parallel DSMC method to hypersonic rarefied flows
Wilmoth, R.G. )
1991-01-01
This paper describes a method for doing direct simulation Monte Carlo (DSMC) calculations using parallel processing and presents some results of applying the method to several hypersonic, rarefied flow problems. The performance and efficiency of the parallel method are discussed. The applications described are the flow in a channel and the flow about a flat plate at incidence. The results show significant advantages of parallel processing over conventional scalar processing and demonstrate the scalability of the method to large problems. 8 refs.
Fairbanks, Benjamin D; Gunatillake, Pathiraja A; Meagher, Laurence
2015-08-30
RAFT- mediated polymerization, providing control over polymer length and architecture as well as facilitating post polymerization modification of end groups, has been applied to virtually every facet of biomedical materials research. RAFT polymers have seen particularly extensive use in drug delivery research. Facile generation of functional and telechelic polymers permits straightforward conjugation to many therapeutic compounds while synthesis of amphiphilic block copolymers via RAFT allows for the generation of self-assembled structures capable of carrying therapeutic payloads. With the large and growing body of literature employing RAFT polymers as drug delivery aids and vehicles, concern over the potential toxicity of RAFT derived polymers has been raised. While literature exploring this complication is relatively limited, the emerging consensus may be summed up in three parts: toxicity of polymers generated with dithiobenzoate RAFT agents is observed at high concentrations but not with polymers generated with trithiocarbonate RAFT agents; even for polymers generated with dithiobenzoate RAFT agents, most reported applications call for concentrations well below the toxicity threshold; and RAFT end-groups may be easily removed via any of a variety of techniques that leave the polymer with no intrinsic toxicity attributable to the mechanism of polymerization. The low toxicity of RAFT-derived polymers and the ability to remove end groups via straightforward and scalable processes make RAFT technology a valuable tool for practically any application in which a polymer of defined molecular weight and architecture is desired. PMID:26050529
Ali Tahir, Asif; Ullah, Habib; Sudhagar, Pitchaimuthu; Asri Mat Teridi, Mohd; Devadoss, Anitha; Sundaram, Senthilarasu
2016-06-01
Graphene (GR) and its derivatives are promising materials on the horizon of nanotechnology and material science and have attracted a tremendous amount of research interest in recent years. The unique atom-thick 2D structure with sp(2) hybridization and large specific surface area, high thermal conductivity, superior electron mobility, and chemical stability have made GR and its derivatives extremely attractive components for composite materials for solar energy conversion, energy storage, environmental purification, and biosensor applications. This review gives a brief introduction of GR's unique structure, band structure engineering, physical and chemical properties, and recent energy-related progress of GR-based materials in the fields of energy conversion (e.g., photocatalysis, photoelectrochemical water splitting, CO2 reduction, dye-sensitized and organic solar cells, and photosensitizers in photovoltaic devices) and energy storage (batteries, fuel cells, and supercapacitors). The vast coverage of advancements in environmental applications of GR-based materials for photocatalytic degradation of organic pollutants, gas sensing, and removal of heavy-metal ions is presented. Additionally, the use of graphene composites in the biosensing field is discussed. We conclude the review with remarks on the challenges, prospects, and further development of GR-based materials in the exciting fields of energy, environment, and bioscience. PMID:27230414
Synthesis and Characterization of a Chitosan Derivative for Electro-Optical Applications
NASA Technical Reports Server (NTRS)
Prastofer, Thomas
1996-01-01
Chitin is a naturally occurring polymer of alpha(1-4) poly N-acetylglucosamine found primarily in the shells of crustaceans and insects. This polymer is chemically and thermally stable and physically durable as a consequence of hydrogen bonding which causes the alignment and ordering of the polymer chains into microcrystals which aggregate into sheets with chiral nematic order. Industry has attempted to take advantage of chitin's properties and low cost (chitin is a waste product of the shellfish industry) to produce durable fibers and other products. This has been largely unsuccessful because of chitin's non reactivity and insolubility. Chitosan is the deacetylation product of chitin and retains many of the structural properties of chitin. Unlike chitin, chitosan is soluble in aqueous solution at reduced pH making it easier to be processed into fibers and films than chitin. Chitosan and its derivatives are now used in such commercial applications as wound dressings, waste water treatment, and in pharmaceuticals. In this study, we have synthesized a chitosan derivative, N-para-nitrophenyl chitosan (NPNPC), as a model material with potential applications in electro optics.
A Method for Deriving Accurate Gas-Phase Abundances for the Multiphase Interstellar Galactic Halo
NASA Astrophysics Data System (ADS)
Howk, J. Christopher; Sembach, Kenneth R.; Savage, Blair D.
2006-01-01
We describe a new method for accurately determining total gas-phase abundances for the Galactic halo interstellar medium with minimal ionization uncertainties. For sight lines toward globular clusters containing both ultraviolet-bright stars and radio pulsars, it is possible to measure column densities of H I and several ionization states of selected metals using ultraviolet absorption line measurements and of H II using radio dispersion measurements. By measuring the ionized hydrogen column, we minimize ionization uncertainties that plague abundance measurements of Galactic halo gas. We apply this method for the first time to the sight line toward the globular cluster Messier 3 [(l,b)=(42.2d,+78.7d), d=10.2 kpc, z=10.0 kpc] using Far Ultraviolet Spectroscopic Explorer and Hubble Space Telescope ultraviolet spectroscopy of the post-asymptotic giant branch star von Zeipel 1128 and radio observations by Ransom et al. of recently discovered millisecond pulsars. The fraction of hydrogen associated with ionized gas along this sight line is 45%+/-5%, with the warm (T~104 K) and hot (T>~105 K) ionized phases present in roughly a 5:1 ratio. This is the highest measured fraction of ionized hydrogen along a high-latitude pulsar sight line. We derive total gas-phase abundances logN(S)/N(H)=-4.87+/-0.03 and logN(Fe)/N(H)=-5.27+/-0.05. Our derived sulfur abundance is in excellent agreement with recent solar system determinations of Asplund, Grevesse, & Sauval. However, it is -0.14 dex below the solar system abundance typically adopted in studies of the interstellar medium. The iron abundance is ~-0.7 dex below the solar system abundance, consistent with the significant incorporation of iron into interstellar grains. Abundance estimates derived by simply comparing S II and Fe II to H I are +0.17 and +0.11 dex higher, respectively, than the abundance estimates derived from our refined approach. Ionization corrections to the gas-phase abundances measured in the standard way are
Mori, Yuka; Ohshimo, Jun; Shimazu, Takahisa; He, Haiping; Takahashi, Atsuko; Yamamoto, Yuki; Tsunoda, Hajime; Tojo, Arinobu; Nagamura-Inoue, Tokiko
2015-04-01
The umbilical cord (UC) has become one of the major sources of mesenchymal stem cells (MSCs). The common explant method of isolating UC-derived MSCs (UC-MSCs) involves mincing the UCs into small fragments, which are then attached to a culture dish bottom from which the MSCs migrate. However, the fragments frequently float up from the bottom of the dish, thereby reducing the cell recovery rate. To overcome this problem, we demonstrate an improved explant method for UC-MSC isolation, which involves the use of a stainless steel mesh (Cellamigo(®); Tsubakimoto Chain Co.), to protect the tissue from floating after the minced fragments are aligned at regular intervals in culture dishes. The culture medium was refreshed every 3 days and the adherent cells and tissue fragments were harvested using trypsin. The number of UC-MSCs isolated from 1 g of UC using the explant method with Cellamigo was 2.9 ± 1.4 × 10(6)/g, which was significantly higher than that obtained without Cellamigo (0.66 ± 0.53 × 10(6)/g) (n = 6, p < 0.01) when cells reached 80-90% confluence. In addition, the processing and incubation time required to reach 80-90% confluence was reduced in the improved explant method compared with the conventional method. The UC-MSCs isolated using the improved method were positive for CD105, CD73, CD90, and HLA class I expression and negative for CD45 and HLA class II expression. The isolated UC-MSCs efficiently inhibited the responder T cells induced by allogeneic dendritic cells in a mixed lymphocyte reaction. Conclusively, we demonstrated that the use of Cellamigo improves the explant method for isolating UC-MSCs. PMID:25220032
NASA Technical Reports Server (NTRS)
Taylor, Arthur C., III
2004-01-01
This final report will document the accomplishments of the work of this project. 1) The incremental-iterative (II) form of the reverse-mode (adjoint) method for computing first-order (FO) aerodynamic sensitivity derivatives (SDs) has been successfully implemented and tested in a 2D CFD code (called ANSERS) using the reverse-mode capability of ADIFOR 3.0. These preceding results compared very well with similar SDS computed via a black-box (BB) application of the reverse-mode capability of ADIFOR 3.0, and also with similar SDs calculated via the method of finite differences. 2) Second-order (SO) SDs have been implemented in the 2D ASNWERS code using the very efficient strategy that was originally proposed (but not previously tested) of Reference 3, Appendix A. Furthermore, these SO SOs have been validated for accuracy and computational efficiency. 3) Studies were conducted in Quasi-1D and 2D concerning the smoothness (or lack of smoothness) of the FO and SO SD's for flows with shock waves. The phenomenon is documented in the publications of this study (listed subsequently), however, the specific numerical mechanism which is responsible for this unsmoothness phenomenon was not discovered. 4) The FO and SO derivatives for Quasi-1D and 2D flows were applied to predict aerodynamic design uncertainties, and were also applied in robust design optimization studies.
NASA Astrophysics Data System (ADS)
Gulshani, P.
2016-07-01
We derive a microscopic version of the successful phenomenological hydrodynamic model of Bohr-Davydov-Faessler-Greiner for collective rotation-vibration motion of an axially symmetric deformed nucleus. The derivation is not limited to small oscillation amplitude. The nuclear Schrodinger equation is canonically transformed to collective co-ordinates, which is then linearized using a constrained variational method. The associated constraints are imposed on the wavefunction rather than on the particle co-ordinates. The approach yields three self-consistent, time-reversal invariant, cranking-type Schrodinger equations for the rotation-vibration and intrinsic motions, and a self-consistency equation. For harmonic oscillator mean-field potentials, these equations are solved in closed forms for excitation energy, cut-off angular momentum, and other nuclear properties for the ground-state rotational band in some deformed nuclei. The results are compared with measured data.
Fitting FFT-derived spectra: Theory, tool, and application to solar radio spike decomposition
Nita, Gelu M.; Fleishman, Gregory D.; Gary, Dale E.; Marin, William; Boone, Kristine
2014-07-10
Spectra derived from fast Fourier transform (FFT) analysis of time-domain data intrinsically contain statistical fluctuations whose distribution depends on the number of accumulated spectra contributing to a measurement. The tail of this distribution, which is essential for separating the true signal from the statistical fluctuations, deviates noticeably from the normal distribution for a finite number of accumulations. In this paper, we develop a theory to properly account for the statistical fluctuations when fitting a model to a given accumulated spectrum. The method is implemented in software for the purpose of automatically fitting a large body of such FFT-derived spectra. We apply this tool to analyze a portion of a dense cluster of spikes recorded by our FASR Subsystem Testbed instrument during a record-breaking event that occurred on 2006 December 6. The outcome of this analysis is briefly discussed.
Tena, R C; Delgado, M A; Sanchez, M; Montelongo, F G
1997-04-01
The application of the ratio spectra derivative and partial least-squares methods to the simultaneous determination of atrazine and its degradation product desethylatrazin-2-hydroxy is presented. When the different methods are applied to the determination of these products in ground waters, PLS method gives the best results due to the presence of interfering substances with overlapping spectra. PMID:18966789
Poppenga, Sandra; Worstell, Bruce; Stoker, Jason M.; Greenlee, Susan
2010-01-01
The methods to extract surface flow from coarse elevation data are well documented; however, the methods to extract surface flow from high-resolution, high-vertical accuracy digital elevation models (DEMs) derived from light detection and ranging (lidar) are less documented, but yet more complex. As lidar data are increasingly used to generate DEMS, the demand for lidar-derived surface flow escalates. Thus, the US Geological Survey has developed semi-automated selective drainage methods to extract continuous surface flow from lidar-derived DEMs. This integrated network is important in understanding surface water movement and runoff, flood inundation, and erosion.
Graphical method for deriving an effective interaction with a new vertex function
Suzuki, K.; Okamoto, R.; Kumagai, H.; Fujii, S.
2011-02-15
Introducing a new vertex function, Z(E), of an energy variable E, we derive a new equation for the effective interaction. The equation is obtained by replacing the Q box in the Krenciglowa-Kuo (KK) method with Z(E). This new approach can be viewed as an extension of the KK method. We show that this equation can be solved both in iterative and noniterative ways. We observe that the iteration procedure with Z(E) brings about fast convergence compared to the usual KK method. It is shown that, as in the KK approach, the procedure of calculating the effective interaction can be reduced to determining the true eigenvalues of the original Hamiltonian H and they can be obtained as the positions of intersections of graphs generated from Z(E). We find that this graphical method yields always precise results and reproduces any of the true eigenvalues of H. The calculation in the present approach can be made regardless of overlaps with the model space and energy differences between unperturbed energies and the eigenvalues of H. We find also that Z(E) is a well-behaved function of E and has no singularity. These characteristics of the present approach ensure stability in actual calculations and would be helpful to resolve some difficulties due to the presence of poles in the Q box. Performing test calculations, we verify numerically theoretical predictions made in the present approach.
An efficient and scalable extraction and quantification method for algal derived biofuel.
Lohman, Egan J; Gardner, Robert D; Halverson, Luke; Macur, Richard E; Peyton, Brent M; Gerlach, Robin
2013-09-01
Microalgae are capable of synthesizing a multitude of compounds including biofuel precursors and other high value products such as omega-3-fatty acids. However, accurate analysis of the specific compounds produced by microalgae is important since slight variations in saturation and carbon chain length can affect the quality, and thus the value, of the end product. We present a method that allows for fast and reliable extraction of lipids and similar compounds from a range of algae, followed by their characterization using gas chromatographic analysis with a focus on biodiesel-relevant compounds. This method determines which range of biologically synthesized compounds is likely responsible for each fatty acid methyl ester (FAME) produced; information that is fundamental for identifying preferred microalgae candidates as a biodiesel source. Traditional methods of analyzing these precursor molecules are time intensive and prone to high degrees of variation between species and experimental conditions. Here we detail a new method which uses microwave energy as a reliable, single-step cell disruption technique to extract lipids from live cultures of microalgae. After extractable lipid characterization (including lipid type (free fatty acids, mono-, di- or tri-acylglycerides) and carbon chain length determination) by GC-FID, the same lipid extracts are transesterified into FAMEs and directly compared to total biodiesel potential by GC-MS. This approach provides insight into the fraction of total FAMEs derived from extractable lipids compared to FAMEs derived from the residual fraction (i.e. membrane bound phospholipids, sterols, etc.). This approach can also indicate which extractable lipid compound, based on chain length and relative abundance, is responsible for each FAME. This method was tested on three species of microalgae; the marine diatom Phaeodactylum tricornutum, the model Chlorophyte Chlamydomonas reinhardtii, and the freshwater green alga Chlorella vulgaris
Application of Hybrid Method for Aerodynamic Noise Prediction
NASA Astrophysics Data System (ADS)
Yu, L.; Song, W. P.
2011-09-01
A hybrid prediction method for aerodynamic noise is performed using high order accuracy method in this paper. The method combines a two-dimensional Unsteady Reynolds-Averaged Navier-Stokes(URANS) solver with the acoustic analogy method using Ffowcs Williams-Hawkings equation with penetrable data surface (FW-Hpds). Tandem cylinders are chosen to validate the prediction method. The computations are conducted at a Reynolds number of 1.66 × 105 based on the cylinder diameter. Both the aerodynamic and acoustic results show good agreement with the experimental data, showing a successful application of the hybrid prediction method using two-dimensional URANS simulation.
Engineering applications of a dynamical state feedback chaotification method
NASA Astrophysics Data System (ADS)
Şahin, Savaş; Güzeliş, Cüneyt
2012-09-01
This paper presents two engineering applications of a chaotification method which can be applied to any inputstate linearizable (nonlinear) system including linear controllable ones as special cases. In the used chaotification method, a reference chaotic and linear system can be combined into a special form by a dynamical state feedback increasing the order of the open loop system to have the same chaotic dynamics with the reference chaotic system. Promising dc motor applications of the method are implemented by the proposed dynamical state feedback which is based on matching the closed loop dynamics to the well known Chua and also Lorenz chaotic systems. The first application, which is the chaotified dc motor used for mixing a corn syrup added acid-base mixture, is implemented via a personal computer and a microcontroller based circuit. As a second application, a chaotified dc motor with a taco-generator used in the feedback is realized by using fully analog circuit elements.
ZHANG, ZHUOYUAN; WANG, CHENXING; LI, TANG; LIU, ZHE; LI, LONGJIANG
2014-01-01
The aim of the present study was to compare the method of ultracentrifugation and density gradient separation for isolating Tca8113 human tongue squamous cell carcinoma cell line-derived exosomes. The exosomes were obtained from the culture supernatant of cultured Tca8113 cells, respectively, followed by identification with transmission electron microscopy observation and western blot analysis. The two different methods were then compared by the morphology, the distribution range of the particle size and the concentration of proteins of the extracted exosomes. In vitro, Tca8113 cells can secrete a large amount of vesicle-like structures, which are identified as exosomes by the presence of the surface markers, Hsp-70 and Alix. The protein profile of the two products are almost the same, however the particle size distribution of the exosomes extracted with density gradient centrifugation are more limited, between 40–120 nm, and these have a higher protein concentration. The results indicate that Tca8113 cells can secrete exosomes in vitro, and the density gradient separation methods for purifying exosomes is improved, which is helpful for future research and application of exosomes. PMID:25202395
Gao Jun; Wang, H.L.; Shreve, Andrew; Iyer, Rashi
2010-04-15
Engineered fullerenes (C{sub 60}) are extensively used for commercial and clinical applications based on their unique physicochemical properties. Such materials have also been recognized as byproducts of many industrial activities. Functionalization of C{sub 60} may significantly influence the nature of its interactions with biological systems, impacting its applications and raising uncertainties about its health effects. In the present study, we compared the bioimpact of two chemically modified fullerene derivatives, hexa carboxyl fullerene adduct (Hexa-C{sub 60}) and tris carboxyl fullerene adduct (tris-C{sub 60}) to pristine fullerene C{sub 60} encapsulated with gamma (gamma)-cyclodextrin C{sub 60} (CD-C{sub 60}), using human cutaneous epithelial cells (HEK) to simulate possible applications and occupational dermal exposure route. We report, for the first time, the discovery of premature senescence as a potential endpoint of nanomaterial elicited biological effects, providing a new paradigm for nanoparticle-induced toxicity in human cells. Moreover, this response appeared to be functionalization specific, in that, only tris-C{sub 60} induced senescence. We investigated key biological responses, such as cellular viability, intracellular ROS generation, cell proliferation and cell cycle responses. Our results indicate that the often observed 'anti-apoptotic' function of fullerene derivatives may be independent of their 'ROS scavenging' role as previously reported. We discovered that the tris-C{sub 60}-induced responses were associated with G{sub 0}/G{sub 1} cell cycle arrest and cellular senescence. On further evaluation of the molecular mechanisms underlying the senescent response, a significant decrease in the expression levels of HERC5 was noted. HERC5 is a ubiquitin ligase of the HERC family and is implicated to be involved in innate immune responses to viral and bacterial infections.
New method for deriving the topside ionospheric Vary-Chap scale height
NASA Astrophysics Data System (ADS)
Wang, Sicheng; Huang, Sixun; Fang, Hanxian
2015-09-01
An α-Chapman function with a continuously varying scale height H(h) can be used to describe the topside ionosphere electron density profile that seamlessly connects the ionosphere with the plasmasphere. Huang and Reinisch have derived the analytic expression of the scale height from the Vary-Chap function, which can be applied to the topside F2 region. However, the H(h) is still difficult to obtain because H(h) is a function of the unknown value H(h) at hmF2. In this paper, the maximum entropy method is introduced to solve this ill-posed problem, and the Vary-Chap scale height for each electron density profile is derived. Then the average percentage errors that defined as the differences between the measured electron density profiles and the Vary-Chap profiles obtained from the Vary-Chap scale heights are calculated with the Alouette/ISIS satellites topside sounder database. The results reveal that the average percentage errors are generally less than 5% and the Vary-Chap profiles can well represent the topside electron density profiles. What is more, the local time, seasonal, solar cycle, and latitudinal variations of the Vary-Chap scale height are preliminarily analyzed.
An Empirical Method for deriving RBE values associated with Electrons, Photons and Radionuclides
Bellamy, Michael B; Puskin, J.; Eckerman, Keith F.; Hertel, Nolan
2015-01-01
There is substantial evidence to justify using relative biological effectiveness (RBE) values greater than one for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer (LET) has been assigned a radiation weighting factor wR of one. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similarmore » low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few keV. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.« less
An Empirical Method for deriving RBE values associated with Electrons, Photons and Radionuclides
Bellamy, Michael B; Puskin, J.; Eckerman, Keith F.; Hertel, Nolan
2015-01-01
There is substantial evidence to justify using relative biological effectiveness (RBE) values greater than one for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer (LET) has been assigned a radiation weighting factor w_{R} of one. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few keV. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.
40 CFR 18.6 - Method of Application.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Method of Application. 18.6 Section 18.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method...
Project 6: Cumulative Risk Assessment (CRA) Methods and Applications
Project 6: CRA Methods and Applications addresses the need to move beyond traditional risk assessment practices by developing CRA methods to integrate and evaluate impacts of chemical and nonchemical stressors on the environment and human health. Project 6 has three specific obje...
7 CFR 1421.303 - Time and method for application.
Code of Federal Regulations, 2012 CFR
2012-01-01
... 7 Agriculture 10 2012-01-01 2012-01-01 false Time and method for application. 1421.303 Section... COMMODITIES-MARKETING ASSISTANCE LOANS AND LOAN DEFICIENCY PAYMENTS FOR 2008 THROUGH 2012 Grazing Payments for the 2008 Through 2012 Crop of Wheat, Barley, Oats, and Triticale § 1421.303 Time and method...
A process for application of ATHEANA - a new HRA method
Parry, G.W.; Bley, D.C.; Cooper, S.E.
1996-10-01
This paper describes the analytical process for the application of ATHEANA, a new approach to the performance of human reliability analysis as part of a PRA. This new method, unlike existing methods, is based upon an understanding of the reasons why people make errors, and was developed primarily to address the analysis of errors of commission.
Applications of Genetic Methods to NASA Design and Operations Problems
NASA Technical Reports Server (NTRS)
Laird, Philip D.
1996-01-01
We review four recent NASA-funded applications in which evolutionary/genetic methods are important. In the process we survey: the kinds of problems being solved today with these methods; techniques and tools used; problems encountered; and areas where research is needed. The presentation slides are annotated briefly at the top of each page.
7 CFR 1421.303 - Time and method for application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 10 2010-01-01 2010-01-01 false Time and method for application. 1421.303 Section 1421.303 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT... the 2008 Through 2012 Crop of Wheat, Barley, Oats, and Triticale § 1421.303 Time and method...
Ahmed, Tarek A; Aljaeid, Bader M
2016-01-01
Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768
Min, Geanna K; Bjerglund, Klaus; Kramer, Søren; Gøgsig, Thomas M; Lindhardt, Anders T; Skrydstrup, Troels
2013-12-16
Ethylene is one of the most important building blocks in industry for the production of polymers and commodity chemicals. (13)C- and D-isotope-labeled ethylenes are also valuable reagents with applications ranging from polymer-structure determination, reaction-mechanism elucidation to the preparation of more complex isotopically labeled compounds. However, these isotopic derivatives are expensive, and are flammable gases, which are difficult to handle. We have developed a method for the controlled generation of ethylene and its isotopic variants including, for the first time, fully isotopically labeled ethylene, from simple alkene precursors by using Ru catalysis. Applying a two-chamber reactor allows both the synthesis of ethylene and its immediate consumption in a chemical transformation permitting reactions to be performed with only stoichiometric amounts of this two carbon olefin. This was demonstrated in the Ni-catalyzed Heck reaction with aryl triflates and benzyl chlorides, as well as Ru-mediated enyne metathesis. PMID:24243666
Ahmed, Tarek A; Aljaeid, Bader M
2016-01-01
Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated. PMID:26869768
A new method for derivation of statistical weight of the Gentile Statistics
NASA Astrophysics Data System (ADS)
Selvi, Sevilay; Uncu, Haydar
2015-10-01
We present a new method for obtaining the statistical weight of the Gentile Statistics. In a recent paper, Perez and Tun presented an approximate combinatoric and an exact recursive formula for the statistical weight of Gentile Statistics, beginning from bosonic and fermionic cases, respectively Hernandez-Perez and Tun (2007). In this paper, we obtain two exact, one combinatoric and one recursive, formulae for the statistical weight of Gentile Statistics, by another approach. The combinatoric formula is valid only for special cases, whereas recursive formula is valid for all possible cases. Moreover, for a given q-maximum number of particles that can occupy a level for Gentile statistics-the recursive formula we have derived gives the result much faster than the recursive formula presented in Hernandez-Perez and Tun (2007), when one uses a computer program. Moreover we obtained the statistical weight for the distribution proposed by Dai and Xie (2009).
Processing methods, characteristics and adsorption behavior of tire derived carbons: a review.
Saleh, Tawfik A; Gupta, Vinod Kumar
2014-09-01
The remarkable increase in the number of vehicles worldwide; and the lack of both technical and economical mechanisms of disposal make waste tires to be a serious source of pollution. One potential recycling process is pyrolysis followed by chemical activation process to produce porous activated carbons. Many researchers have recently proved the capability of such carbons as adsorbents to remove various types of pollutants including organic and inorganic species. This review attempts to compile relevant knowledge about the production methods of carbon from waste rubber tires. The effects of various process parameters including temperature and heating rate, on the pyrolysis stage; activation temperature and time, activation agent and activating gas are reviewed. This review highlights the use of waste-tires derived carbon to remove various types of pollutants like heavy metals, dye, pesticides and others from aqueous media. PMID:25001042
Kulik, Anna; Białecka, Wanda; Podolska, Marzena; Kwiatkowska-Puchniarz, Barbara; Mazurek, Aleksander
2011-01-01
The subject of the study was to develop a versatile HPLC system for identification and determination of four benzimidazole derivatives in the antiparasitic drugs. The tests covered: Zentel, Panacur, Vermox tablets and Systamex suspension. A satisfactory separation was obtained using the Nucleosil C8 column in the gradient system composed of mobile phase A: 85% orthophosphoric acid / water / acetonitrile in 0.05:75:25, v/v/v ratio, and mobile phase B: 85% orthophosphoric acid / water / acetonitrile in 0.05:50:50, v/v/v ratio. Both phases were adjusted to pH = 4.5 with 15% sodium hydroxide solution. A detection at 288 nm for oxfendazole and 254 nm for albendazole, fenbendazole and mebendazole was applied. The correlation coefficients in the range 0,9997 - 0,9999 proved that the calibration curves were linear. The method was validated in terms of selectivity, accuracy and precision. PMID:22125945
Assessment of the derivative-moment transformation method for unsteady-load estimation
NASA Astrophysics Data System (ADS)
Mohebbian, Ali; Rival, David E.
2012-08-01
It is often difficult, if not impossible, to measure the aerodynamic or hydrodynamic forces on a moving body. For this reason, a classical control-volume technique is typically applied to extract the unsteady forces. However, measuring the acceleration term within the volume of interest using particle image velocimetry (PIV) can be limited by optical access, reflections, as well as shadows. Therefore, in this study, an alternative approach, termed the derivative-moment transformation (DMT) method, is introduced and tested on a synthetic data set produced using numerical simulations. The test case involves the unsteady loading of a flat plate in a two-dimensional, laminar periodic gust. The results suggest that the DMT method can accurately predict the acceleration term so long as appropriate spatial and temporal resolutions are maintained. The major deficiency, which is more dominant for the direction of drag, was found to be the determination of pressure and unsteady terms in the wake. The effect of control-volume size was investigated, suggesting that larger domains work best by minimizing the associated error in the determination of the pressure field. When decreasing the control-volume size, wake vortices, which produce high gradients across the control surfaces, are found to substantially increase the level of error. On the other hand, it was shown that for large control volumes, and with realistic spatial resolution, the accuracy of the DMT method would also suffer. Therefore, a delicate compromise is required when selecting control-volume size in future experiments.
Deriving Shape-Based Features for C. elegans Locomotion Using Dimensionality Reduction Methods
Gyenes, Bertalan; Brown, André E. X.
2016-01-01
High-throughput analysis of animal behavior is increasingly common following the advances of recording technology, leading to large high-dimensional data sets. This dimensionality can sometimes be reduced while still retaining relevant information. In the case of the nematode worm Caenorhabditis elegans, more than 90% of the shape variance can be captured using just four principal components. However, it remains unclear if other methods can achieve a more compact representation or contribute further biological insight to worm locomotion. Here we take a data-driven approach to worm shape analysis using independent component analysis (ICA), non-negative matrix factorization (NMF), a cosine series, and jPCA (a dynamic variant of principal component analysis [PCA]) and confirm that the dimensionality of worm shape space is close to four. Projecting worm shapes onto the bases derived using each method gives interpretable features ranging from head movements to tail oscillation. We use these as a comparison method to find differences between the wild type N2 worms and various mutants. For example, we find that the neuropeptide mutant nlp-1(ok1469) has an exaggerated head movement suggesting a mode of action for the previously described increased turning rate. The different bases provide complementary views of worm behavior and we expect that closer examination of the time series of projected amplitudes will lead to new results in the future. PMID:27582697
Deriving Shape-Based Features for C. elegans Locomotion Using Dimensionality Reduction Methods.
Gyenes, Bertalan; Brown, André E X
2016-01-01
High-throughput analysis of animal behavior is increasingly common following the advances of recording technology, leading to large high-dimensional data sets. This dimensionality can sometimes be reduced while still retaining relevant information. In the case of the nematode worm Caenorhabditis elegans, more than 90% of the shape variance can be captured using just four principal components. However, it remains unclear if other methods can achieve a more compact representation or contribute further biological insight to worm locomotion. Here we take a data-driven approach to worm shape analysis using independent component analysis (ICA), non-negative matrix factorization (NMF), a cosine series, and jPCA (a dynamic variant of principal component analysis [PCA]) and confirm that the dimensionality of worm shape space is close to four. Projecting worm shapes onto the bases derived using each method gives interpretable features ranging from head movements to tail oscillation. We use these as a comparison method to find differences between the wild type N2 worms and various mutants. For example, we find that the neuropeptide mutant nlp-1(ok1469) has an exaggerated head movement suggesting a mode of action for the previously described increased turning rate. The different bases provide complementary views of worm behavior and we expect that closer examination of the time series of projected amplitudes will lead to new results in the future. PMID:27582697
Van der Jeught, Margot; Taelman, Jasin; Duggal, Galbha; Ghimire, Sabitri; Lierman, Sylvie; Chuva de Sousa Lopes, Susana M.; Deforce, Dieter; Deroo, Tom; De Sutter, Petra
2015-01-01
Abstract In mice, inhibition of both the fibroblast growth factor (FGF) mitogen-activated protein kinase kinase/extracellular-signal regulated kinase (MEK/Erk) and the Wnt signaling inhibitor glycogen synthase-3β (GSK3β) enables the derivation of mouse embryonic stem cells (mESCs) from nonpermissive strains in the presence of leukemia inhibitory factor (LIF). Whereas mESCs are in an uncommitted naïve state, human embryonic stem cells (hESCs) represent a more advanced state, denoted as primed pluripotency. This burdens hESCs with a series of characteristics, which, in contrast to naïve ESCs, makes them not ideal for key applications such as cell-based clinical therapies and human disease modeling. In this study, different small molecule combinations were applied during human ESC derivation. Hereby, we aimed to sustain the naïve pluripotent state, by interfering with various key signaling pathways. First, we tested several combinations on existing, 2i (PD0325901 and CHIR99021)-derived mESCs. All combinations were shown to be equally adequate to sustain the expression of naïve pluripotency markers. Second, these conditions were tested during hESC derivation. Overall, the best results were observed in the presence of medium supplemented with 2i, LIF, and the noncanonical Wnt signaling agonist Wnt5A, alone and combined with epinephrine. In these conditions, outgrowths repeatedly showed an ESC progenitor-like morphology, starting from day 3. Culturing these “progenitor cells” did not result in stable, naïve hESC lines in the current conditions. Although Wnt5A could not promote naïve hESC derivation, we found that it was sustaining the conversion of established hESCs toward a more naïve state. Future work should aim to distinct the effects of the various culture formulations, including our Wnt5A-supplemented medium, reported to promote stable naïve pluripotency in hESCs. PMID:26053517
Van der Jeught, Margot; Taelman, Jasin; Duggal, Galbha; Ghimire, Sabitri; Lierman, Sylvie; Chuva de Sousa Lopes, Susana M; Deforce, Dieter; Deroo, Tom; De Sutter, Petra; Heindryckx, Björn
2015-06-01
In mice, inhibition of both the fibroblast growth factor (FGF) mitogen-activated protein kinase kinase/extracellular-signal regulated kinase (MEK/Erk) and the Wnt signaling inhibitor glycogen synthase-3β (GSK3β) enables the derivation of mouse embryonic stem cells (mESCs) from nonpermissive strains in the presence of leukemia inhibitory factor (LIF). Whereas mESCs are in an uncommitted naïve state, human embryonic stem cells (hESCs) represent a more advanced state, denoted as primed pluripotency. This burdens hESCs with a series of characteristics, which, in contrast to naïve ESCs, makes them not ideal for key applications such as cell-based clinical therapies and human disease modeling. In this study, different small molecule combinations were applied during human ESC derivation. Hereby, we aimed to sustain the naïve pluripotent state, by interfering with various key signaling pathways. First, we tested several combinations on existing, 2i (PD0325901 and CHIR99021)-derived mESCs. All combinations were shown to be equally adequate to sustain the expression of naïve pluripotency markers. Second, these conditions were tested during hESC derivation. Overall, the best results were observed in the presence of medium supplemented with 2i, LIF, and the noncanonical Wnt signaling agonist Wnt5A, alone and combined with epinephrine. In these conditions, outgrowths repeatedly showed an ESC progenitor-like morphology, starting from day 3. Culturing these "progenitor cells" did not result in stable, naïve hESC lines in the current conditions. Although Wnt5A could not promote naïve hESC derivation, we found that it was sustaining the conversion of established hESCs toward a more naïve state. Future work should aim to distinct the effects of the various culture formulations, including our Wnt5A-supplemented medium, reported to promote stable naïve pluripotency in hESCs. PMID:26053517
Advanced stress analysis methods applicable to turbine engine structures
NASA Technical Reports Server (NTRS)
Pian, T. H. H.
1985-01-01
Advanced stress analysis methods applicable to turbine engine structures are investigated. Constructions of special elements which containing traction-free circular boundaries are investigated. New versions of mixed variational principle and version of hybrid stress elements are formulated. A method is established for suppression of kinematic deformation modes. semiLoof plate and shell elements are constructed by assumed stress hybrid method. An elastic-plastic analysis is conducted by viscoplasticity theory using the mechanical subelement model.
Application of bifurcation methods to nonlinear flight dynamics problems
NASA Astrophysics Data System (ADS)
Goman, M. G.; Zagainov, G. I.; Khramtsovsky, A. V.
Applications of global stability and bifurcational analysis methods are presented for different nonlinear flight dynamics problems, such as roll-coupling, stall, spin, etc. Based on the results for different real aircraft, F-4, F-14, F-15, High Incidence Research Model, (HIRM), the general methods developed by many authors are presented. The outline of basic concepts and methods from dynamcal system theory are also introduced.
A robust general phase retrieval method for medical applications
Yan, A.; Liu, H.
2013-01-01
From medical imaging perspective the robustness of a phase retrieval method is of critical importance. In this presentation we compare the robustness of two general phase retrieval methods, namely the transport of intensity equation inversion (TIE-inversion) method and the attenuation partition based (AP-based) method. We showed that the TIE-inversion method, regardless if being assisted with the Tikhonov regularization, failed to retrieve the phase maps in two experimental studies. The failure exposes this method’s weakness as being unstable against the noise. In contrast, the sample phase maps are retrieved successfully by using the AP-based method. The stark performance differences of the two methods are rooted in their different techniques dealing with the singularity problem. This comparison shows that the robust AP-based phase retrieval method will be superior to the TIE-inversion method for medical imaging applications where radiation doses are stringently limited. PMID:23894250
ERIC Educational Resources Information Center
Akgün, Levent
2015-01-01
The aim of this study is to identify prospective secondary mathematics teachers' opinions about the mathematical modeling method and the applicability of this method in high schools. The case study design, which is among the qualitative research methods, was used in the study. The study was conducted with six prospective secondary mathematics…
Application of Hyperspectral Methods in Hydrothermal Mineral System Studies
NASA Astrophysics Data System (ADS)
Laukamp, Carsten; Cudahy, Thomas; Gessner, Klaus; Haest, Maarten; Cacetta, Mike; Rodger, Andrew; Jones, Mal; Thomas, Matilda
2010-05-01
Hyperspectral infrared reflectance spectra are used to identify abundances and compositional differences of mineral groups and single mineral phases. 3D mineral maps are derived from surface (airborne and satellite sensed) and sub-surface (drill core) mineralogical data and integrated with geological, geochemical and geophysical datasets, enabling a quantitative mineral systems analysis. The Western Australian Centre of Excellence for 3D Mineral Mapping is working on a variety of mineral deposits to showcase the emerging applications of hyperspectral techniques in mineral system studies. Applied remote sensing technologies comprise hyperspectral airborne surveys (HyMap) covering 126 bands in the visible and shortwave infrared, as well as satellite-based multispectral surveys (ASTER) featuring 14 bands from the visible to thermal infrared. Drill cores were scanned with CSIRO's HyLoggingTM systems, which allow a fast acquisition of mineralogical data in cm-spacing and thereby providing statistically significant datasets. Building on procedures developed for public Australian geosurvey data releases for north Queensland, Broken Hill and Kalgoorlie (http://c3dmm.csiro.au), the ultimate goal is to develop sensor-independent scalars based on the position, depth and shape of selected absorption features in the visible-near (VNIR), shortwave (SWIR) and thermal infrared (TIR), which can be applied to a wide range of mineral deposit types. In the Rocklea Dome Channel Iron Ore deposits of the Pilbara (Western Australia) for example, hyperspectral drill core data were processed into 3D mineral maps to delineate major ore zones by identifying various ore types and possible contaminants. Vitreous (silica-rich) iron ore was successfully separated from ochreous goethitic ore, with both of them requiring different metallurgical processing. The silicified vitreous iron ore as well as outlined carbonate-rich zones are presumably related to overprinting groundwater effects. The
NASA Astrophysics Data System (ADS)
Pham, H. V.; Elshall, A. S.; Tsai, F. T.; Yan, L.
2012-12-01
The inverse problem in groundwater modeling deals with a rugged (i.e. ill-conditioned and multimodal), nonseparable and noisy function since it involves solving second order nonlinear partial deferential equations with forcing terms. Derivative-based optimization algorithms may fail to reach a near global solution due to their stagnation at a local minimum solution. To avoid entrapment in a local optimum and enhance search efficiency, this study introduces the covariance matrix adaptation-evolution strategy (CMA-ES) as a local derivative-free optimization method. In the first part of the study, we compare CMA-ES with five commonly used heuristic methods and the traditional derivative-based Gauss-Newton method on a hypothetical problem. This problem involves four different cases to allow a rigorous assessment against ten criterions: ruggedness in terms of nonsmooth and multimodal, ruggedness in terms of ill-conditioning and high nonlinearity, nonseparablity, high dimensionality, noise, algorithm adaptation, algorithm tuning, performance, consistency, parallelization (scaling with number of cores) and invariance (solution vector and function values). The CMA-ES adapts a covariance matrix representing the pair-wise dependency between decision variables, which approximates the inverse of the Hessian matrix up to a certain factor. The solution is updated with the covariance matrix and an adaptable step size, which are adapted through two conjugates that implement heuristic control terms. The covariance matrix adaptation uses information from the current population of solutions and from the previous search path. Since such an elaborate search mechanism is not common in the other heuristic methods, CMA-ES proves to be more robust than other population-based heuristic methods in terms of reaching a near-optimal solution for a rugged, nonseparable and noisy inverse problem. Other favorable properties that the CMA-ES exhibits are the consistency of the solution for repeated
Shannon, Emer; Abu-Ghannam, Nissreen
2016-04-01
The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article. PMID:27110798
Study on iron oxide nanoparticles coated with glucose-derived polymers for biomedical applications
NASA Astrophysics Data System (ADS)
Herea, D. D.; Chiriac, H.; Lupu, N.; Grigoras, M.; Stoian, G.; Stoica, B. A.; Petreus, T.
2015-10-01
This study reports an approach for a facile one-step synthesis of magnetic nanoparticles (MNPs) coated with glucose-derived polymers (GDP) through a mechanochemical hydrothermal process for biomedical applications. Polymer-coated magnetic nanoparticles (Fe2O3/Fe3O4), with sizes below 10 nm, exhibited superparamagnetic behavior, with a specific magnetization saturation value of about 40 emu/g, and a maximum specific absorption rate (SAR) of 30 W/g in AC magnetic fields. Depending on the intensity of the applied AC magnetic field, a temperature of 42 °C can be achieved in 4-17 min. The surface polymerized layer affords functional hydroxyl groups for binding to biomolecules containing carboxyl, thiol, or amino groups, thereby making the coated nanoparticles feasible for bio-conjugation. In vitro cytotoxicity evaluation pointed out that a relatively high concentration of polymer-coated magnetic nanoparticles (GDP-MNPs) did not induce severe cell alteration, suggesting a good biocompatibility.
Shannon, Emer; Abu-Ghannam, Nissreen
2016-01-01
The marine environment is home to a taxonomically diverse ecosystem. Organisms such as algae, molluscs, sponges, corals, and tunicates have evolved to survive the high concentrations of infectious and surface-fouling bacteria that are indigenous to ocean waters. Both macroalgae (seaweeds) and microalgae (diatoms) contain pharmacologically active compounds such as phlorotannins, fatty acids, polysaccharides, peptides, and terpenes which combat bacterial invasion. The resistance of pathogenic bacteria to existing antibiotics has become a global epidemic. Marine algae derivatives have shown promise as candidates in novel, antibacterial drug discovery. The efficacy of these compounds, their mechanism of action, applications as antibiotics, disinfectants, and inhibitors of foodborne pathogenic and spoilage bacteria are reviewed in this article. PMID:27110798
Current applications of adipose-derived stem cells and their future perspectives
Kim, Eun-Hee; Heo, Chan Yeong
2014-01-01
Adult stem cells have a great potential to treat various diseases. For these cell-based therapies, adipose-derived stem cells (ADSCs) are one of the most promising stem cell types, including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs and iPSCs have taken center stage due to their pluripotency. However, ESCs and iPSCs have limitations in ethical issues and in identification of characteristics, respectively. Unlike ESCs and iPSCs, ADSCs do not have such limitations and are not only easily obtained but also uniquely expandable. ADSCs can differentiate into adipocytes, osteoblasts, chondrocytes, myocytes and neurons under specific differentiation conditions, and these kinds of differentiation potential of ADSCs could be applied in regenerative medicine e.g., skin reconstruction, bone and cartilage formation, etc. In this review, the current status of ADSC isolation, differentiation and their therapeutic applications are discussed. PMID:24567789
A Novel Human Adipocyte-derived Basement Membrane for Tissue Engineering Applications
NASA Astrophysics Data System (ADS)
Damm, Aaron
Tissue engineering strategies have traditionally focused on the use of synthetic polymers as support scaffolds for cell growth. Recently, strategies have shifted towards a natural biologically derived scaffold, with the main focus on decellularized organs. Here, we report the development and engineering of a scaffold naturally secreted by human preadipocytes during differentiation. During this differentiation process, the preadipocytes remodel the extracellular matrix by releasing new extracellular proteins. Finally, we investigated the viability of the new basement membrane as a scaffold for tissue engineering using human pancreatic islets, and as a scaffold for soft tissue repair. After identifying the original scaffold material, we sought to improve the yield of material, treating the cell as a bioreactor, through various nutritional and cytokine stimuli. The results suggest that adipocytes can be used as bioreactors to produce a designer-specified engineered human extracellular matrix scaffold for specific tissue engineering applications.
Bharadwaj, Shantaram; Liu, Guihua; Shi, Yingai; Wu, Rongpei; Yang, Bin; He, Tongchuan; Fan, Yuxin; Lu, Xinyan; Zhou, Xiaobo; Liu, Hong; Atala, Anthony; Rohozinski, Jan; Zhang, Yuanyuan
2013-09-01
We sought to biologically characterize and identify a subpopulation of urine-derived stem cells (USCs) with the capacity for multipotent differentiation. We demonstrated that single USCs can expand to a large population with 60-70 population doublings. Nine of 15 individual USC clones expressed detectable levels of telomerase and have long telomeres. These cells expressed pericyte and mesenchymal stem cell markers. Upon induction with appropriate media in vitro, USCs differentiated into bladder-associated cell types, including functional urothelial and smooth muscle cell lineages. When the differentiated USCs were seeded onto a scaffold and subcutaneously implanted into nude mice, multilayered tissue-like structures formed consisting of urothelium and smooth muscle. Additionally, USCs were able to differentiate into endothelial, osteogenic, chondrogenic, adipogenic, skeletal myogenic, and neurogenic lineages but did not form teratomas during the 1-month study despite telomerase activity. USCs may be useful in cell-based therapies and tissue engineering applications, including urogenital reconstruction. PMID:23666768
Underwater application of nasal decongestants: method for special operations.
Mutzbauer, T S; Mueller, P H; Sigg, O; Tetzlaff, K; Neubauer, B
2000-11-01
A simple method of emergency underwater application of a nasal decongestant in divers to prevent diving-related accidents or even fatalities attributable to sequelae of middle-ear and sinus barotrauma of ascent was evaluated. Eleven military divers had to inject 1 mL of 0.02% methylene blue into a central venous catheter after having inserted the tip between their upper lip and the mask at 1 m depth in a pool. After injection, the head had to be reclined. Blue liquid flowing from a diver's nostril and a "bitter" taste sensation reported immediately after surfacing indicated successful application. All divers were observed to have had blue liquid flowing from the nostril of application, and one diver could not describe the taste. This method of underwater application of nasal decongestants may be useful for emergency prevention in divers, especially during covert operations. Underwater availability of the system in a special kit carried by divers would be required. PMID:11143432
Aldrich, Jane V.; Kumar, Vivek; Dattachowdhury, Bhaswati; Peck, Angela M.; Wang, Xin; Murray, Thomas F.
2009-01-01
Solid phase synthetic methodology has been developed in our laboratory to incorporate an affinity label (a reactive functionality such as isothiocyanate or bromoacetamide) into peptides (Leelasvatanakij, L. and Aldrich, J. V. (2000) J. Peptide Res. 56, 80), and we have used this synthetic strategy to prepare affinity label derivatives of a variety of opioid peptides. To date side reactions have been detected only in two cases, both involving intramolecular cyclization. We have identified several peptide-based affinity labels for δ opioid receptors that exhibit wash-resistant inhibition of binding to these receptors and are valuable pharmacological tools to study opioid receptors. Even in cases where the peptide derivatives do not bind covalently to their target receptor, studying their binding has revealed subtle differences in receptor interactions with particular opioid peptide residues, especially Phe residues in the N-terminal “message” sequences. Solid phase synthetic methodology for the incorporation of other labels (e.g. biotin) into the C-terminus of peptides has also been developed in our laboratory (Kumar, V. and Aldrich, J. V. (2003) Org. Lett. 5, 613). These two synthetic approaches have been combined to prepare peptides containing multiple labels that can be used as tools to study peptide ligand-receptor interactions. These solid phase synthetic methodologies are versatile strategies that are applicable to the preparation of labeled peptides for a variety of targets in addition to opioid receptors. PMID:19956785
Adipose-derived stem cells in veterinary medicine: characterization and therapeutic applications.
Marx, Camila; Silveira, Maiele Dornelles; Beyer Nardi, Nance
2015-04-01
Mesenchymal stem cells, considered one of the most promising cell types for therapeutic applications due to their capacity to secrete regenerative bioactive molecules, are present in all tissues. Stem cells derived from the adipose tissue have been increasingly used for cell therapy in humans and animals, both as freshly isolated, stromal vascular fraction (SVF) cells, or as cultivated adipose-derived stem cells (ASCs). ASCs have been characterized in different animal species for proliferation, differentiation potential, immunophenotype, gene expression, and potential for tissue engineering. Whereas canine and equine ASCs are well studied, feline cells are still poorly known. Many companies around the world offer ASC therapy for dogs, cats, and horses, although in most countries these activities are not yet controlled by regulatory agencies. This is the first study to review the characterization and clinical use of SVF and ASCs in spontaneously occurring diseases in veterinary patients. Although a relatively large number of studies investigating ASC therapy in induced lesions are available in the literature, a surprisingly small number of reports describe ASC therapy for naturally affected dogs, cats, and horses. A total of seven studies were found with dogs, only two studies in cats, and four in horses. Taken as a whole, the results do not allow a conclusion on the effect of this therapy, due to the generally small number of patients included, diversity of cell populations used, and lack of adequate controls. Further controlled studies are clearly needed to establish the real potential of ASC in veterinary medicine. PMID:25556829
Activated carbons derived from oil palm empty-fruit bunches: application to environmental problems.
Alam, Md Zahangir; Muyibi, Suleyman A; Mansor, Mariatul F; Wahid, Radziah
2007-01-01
Activated carbons derived from oil palm empty fruit bunches (EFB) were investigated to find the suitability of its application for removal of phenol in aqueous solution through adsorption process. Two types of activation namely; thermal activation at 300, 500 and 800 degrees C and physical activation at 150 degrees C (boiling treatment) were used for the production of the activated carbons. A control (untreated EFB) was used to compare the adsorption capacity of the activated carbons produced from these processes. The results indicated that the activated carbon derived at the temperature of 800 degrees C showed maximum absorption capacity in the aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon at 800 degrees C. It was observed that the adsorption capacity was higher at lower values of pH (2-3) and higher value of initial concentration of phenol (200-300 mg/L). The equilibrium data fitted better with the Freundlich adsorption isotherm compared to the Langmuir. Kinetic studies of phenol adsorption onto activated carbons were also studied to evaluate the adsorption rate. The estimated cost for production of activated carbon from EFB was shown in lower price (USD 0.50/kg of activated carbon) compared the activated carbon from other sources and processes. PMID:17913162
Application of Spectroscopic Methods for Structural Analysis of Chitin and Chitosan
Kumirska, Jolanta; Czerwicka, Małgorzata; Kaczyński, Zbigniew; Bychowska, Anna; Brzozowski, Krzysztof; Thöming, Jorg; Stepnowski, Piotr
2010-01-01
Chitin, the second most important natural polymer in the world, and its N-deacetylated derivative chitosan, have been identified as versatile biopolymers for a broad range of applications in medicine, agriculture and the food industry. Two of the main reasons for this are firstly the unique chemical, physicochemical and biological properties of chitin and chitosan, and secondly the unlimited supply of raw materials for their production. These polymers exhibit widely differing physicochemical properties depending on the chitin source and the conditions of chitosan production. The presence of reactive functional groups as well as the polysaccharide nature of these biopolymers enables them to undergo diverse chemical modifications. A complete chemical and physicochemical characterization of chitin, chitosan and their derivatives is not possible without using spectroscopic techniques. This review focuses on the application of spectroscopic methods for the structural analysis of these compounds. PMID:20559489
The continuum discretized coupled-channels method and its applications
NASA Astrophysics Data System (ADS)
Yahiro, Masanobu; Ogata, Kazuyuki; Matsumoto, Takuma; Minomo, Kosho
2012-09-01
This is a review of recent developments in the continuum discretized coupled-channels method (CDCC) and its applications to nuclear physics, cosmology and astrophysics, and nuclear engineering. The theoretical foundation of CDCC is shown, and a microscopic reaction theory for nucleus-nucleus scattering is constructed as an underlying theory of CDCC. CDCC is then extended to treat Coulomb breakup and four-body breakup. We also propose a new theory that makes CDCC applicable to inclusive reactions.
Application of geo-information science methods in ecotourism exploitation
NASA Astrophysics Data System (ADS)
Dong, Suocheng; Hou, Xiaoli
2004-11-01
Application of geo-information science methods in ecotourism development was discussed in the article. Since 1990s, geo-information science methods, which take the 3S (Geographic Information System, Global Positioning System, and Remote Sensing) as core techniques, has played an important role in resources reconnaissance, data management, environment monitoring, and regional planning. Geo-information science methods can easily analyze and convert geographic spatial data. The application of 3S methods is helpful to sustainable development in tourism. Various assignments are involved in the development of ecotourism, such as reconnaissance of ecotourism resources, drawing of tourism maps, dealing with mass data, and also tourism information inquire, employee management, quality management of products. The utilization of geo-information methods in ecotourism can make the development more efficient by promoting the sustainable development of tourism and the protection of eco-environment.
NASA Astrophysics Data System (ADS)
Villeneuve-Faure, C.; Boudou, L.; Makasheva, K.; Teyssedre, G.
2014-11-01
Charges injection and accumulation in the dielectric remains a critical issue, mainly because these phenomena are involved in a great number of failure mechanisms in cables or electronic components. Achieving a better understanding of the mechanisms leading to charge injection, transport and trapping under electrical stress and of the relevant interface phenomena is a high priority. The classical methods used for space charge density profile measurements have a limited spatial resolution, which prevents them being used for investigating thin dielectric layers or interface processes. Thus, techniques derived from atomic force microscopy (AFM) have been investigated more and more for this kind of application, but so far they have been limited by their lack of in-depth sensitivity. In this paper a new method for space charge probing is described, the electrostatic force distance curve (EFDC), which is based on electrostatic force measurements using AFM. A comparison with the results obtained using kelvin force microscopy (KFM) allowed us to highlight the fact that EFDC is sensitive to charges localized in the third-dimension.
Comparison of formant detection methods used in speech processing applications
NASA Astrophysics Data System (ADS)
Belean, Bogdan
2013-11-01
The paper describes time frequency representations of speech signal together with the formant significance in speech processing applications. Speech formants can be used in emotion recognition, sex discrimination or diagnosing different neurological diseases. Taking into account the various applications of formant detection in speech signal, two methods for detecting formants are presented. First, the poles resulted after a complex analysis of LPC coefficients are used for formants detection. The second approach uses the Kalman filter for formant prediction along the speech signal. Results are presented for both approaches on real life speech spectrograms. A comparison regarding the features of the proposed methods is also performed, in order to establish which method is more suitable in case of different speech processing applications.
Kittrell, Frances; Valdez, Kelli; Elsarraj, Hanan; Hong, Yan; Medina, Daniel; Behbod, Fariba
2016-01-01
The MIND method involves intraductal injection of patient derived ductal carcinoma in situ (DCIS) cells and DCIS cell lines (MCF10DCIS.COM and SUM225) inside the mouse mammary ducts [Video 1 and Figure 1 in Behbod et al. (2009)]. This method mimics the normal environment of DCIS and facilitates study of the natural progression of human DCIS, i.e., their initial growth as carcinoma in situ within the ducts, followed by invasion into the stroma through the myoepithelial cell layer and basement membrane (Behbod et al., 2009; Valdez et al., 2011). In order to demonstrate that transplantation procedure is successful, the transplanted mammary glands may be excised as early as two weeks following intraductal injection of cells followed by Hematoxylin and Eosin (H&E) staining and/or immunofluorescence staining using human specific cytokeratin 5 and/or 19 [please see Figures 2–4 in Behbod et al. (2009)]. Additionally, the presence of trypan blue inside the mouse mammary ducts immediately following intraductal injection is the best indicator that the injection was successful (Video 1 starting at 4:33 sec).
A new method to derive electronegativity from resonant inelastic x-ray scattering
Carniato, S.; Journel, L.; Guillemin, R.; Piancastelli, M. N.; Simon, M.; Stolte, W. C.; Lindle, D. W.
2012-10-14
Electronegativity is a well-known property of atoms and substituent groups. Because there is no direct way to measure it, establishing a useful scale for electronegativity often entails correlating it to another chemical parameter; a wide variety of methods have been proposed over the past 80 years to do just that. This work reports a new approach that connects electronegativity to a spectroscopic parameter derived from resonant inelastic x-ray scattering. The new method is demonstrated using a series of chlorine-containing compounds, focusing on the Cl 2p{sup -1}LUMO{sup 1} electronic states reached after Cl 1s{yields} LUMO core excitation and subsequent KL radiative decay. Based on an electron-density analysis of the LUMOs, the relative weights of the Cl 2p{sub z} atomic orbital contributing to the Cl 2p{sub 3/2} molecular spin-orbit components are shown to yield a linear electronegativity scale consistent with previous approaches.
Moreta, Cristina; Tena, María-Teresa; Kannan, Kurunthachalam
2015-10-01
Exposure of humans to parabens is a concern due to the estrogenic activity of these compounds. Parabens are widely used as preservatives in some personal care products, foodstuffs and pharmaceuticals owing to their low cost, high water solubility and broad spectrum antimicrobial properties. Despite this, little is known on the occurrence of parabens in pharmaceutical products. In this study, a method based on solid-liquid or liquid-liquid extraction (SLE or LLE), and high performance liquid chromatography (HPLC) coupled with triple quadrupole tandem mass spectrometry (QqQ or MS/MS) was developed for the determination of six most frequently used parabens and four paraben derivatives (methyl- and ethyl-protocatechuates, and mono- and di-hydroxybenzoic acids) in pharmaceuticals. A sample-purification step involving solid phase extraction (SPE) was optimized for the analysis of solid and lipid-rich pharmaceuticals. To our knowledge, this is the first comprehensive report on the occurrence of parabens in pharmaceuticals. The developed method was applied for the analysis of 128 liquid/syrup, cream, solid, prescription or over-the counter (OTC) drugs collected from the USA and a few other countries in Europe and Asia. Although majority of the drugs analyzed in the study did not contain parabens, concentrations as high as 2 mg/g were found in some drugs. Methyl- and propyl- parabens were the frequently detected compounds. 4-Hydroxybenzoic acid was the major metabolite found in pharmaceutical products. PMID:26252961
Bajek, Anna; Gurtowska, Natalia; Gackowska, Lidia; Kubiszewska, Izabela; Bodnar, Magdalena; Marszałek, Andrzej; Januszewski, Rafał; Michalkiewicz, Jacek; Drewa, Tomasz
2015-01-01
Adipose-derived stem cells (ASCs) possess a high differentiation and proliferation potential. However, the phenotypic characterization of ASCs is still difficult. Until now, there is no extensive analysis of ASCs markers depending on different liposuction methods. Therefore, the aim of the present study was to analyse 242 surface markers and determine the differences in the phenotypic pattern between ASCs obtained during mechanical and ultrasound-assisted liposuction. ASCs were isolated from healthy donors, due to mechanical and ultrasound-assisted liposuction and cultured in standard medium to the second passage. Differentiation potential and markers expression was evaluated to confirm the mesenchymal nature of cells. Then, the BD LyoplateTM Human Cell Surface Marker Screening Panel was used. Results shown that both population of ASCs are characterized by high expression of markers specific for ASCs: cluster of differentiation (CD)9, CD10, CD34, CD44, CD49d, CD54, CD55, CD59, CD71 and low expression of CD11a, CD11c and CD144. Moreover, we have noticed significant differences in antigen expression in 58 markers from the 242 studied. Presented study shows for the first time that different liposuction methods are not a significant factor which can influence the expression of human ASCs surface markers. PMID:26182374
Different isolation methods alter the gene expression profiling of adipose derived stem cells.
Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu
2014-01-01
Human adipose stem cells (ASCs) has been in the limelight since its discovery as a suitable source of mesenchymal stem cells (MSCs) in regenerative medicine. Currently, two major techniques are used to isolate ASCs, namely liposuction and tissue biopsy. These two methods are relatively risk-free but the question as to which method could give a more efficient output remains unclear. Thus, this study was carried out to compare and contrast the output generated in regards to growth kinetics, differentiation capabilities in vitro, and gene expression profiling. It was found that ASCs from both isolation methods were comparable in terms of growth kinetics and tri-lineage differentiation. Furthermore, ASCs from both populations were reported as CD44(+), CD73(+), CD90(+), CD166(+), CD34(-), CD45(-) and HLA-DR(-). However, in regards to gene expression, a group of overlapping genes as well as distinct genes were observed. Distinct gene expressions indicated that ASCs (liposuction) has endoderm lineage propensity whereas ASCs (biopsy) has a tendency towards mesoderm/ectoderm lineage. This information suggests involvement in different functional activity in accordance to isolation method. In conclusion, future studies to better understand these gene functions should be carried out in order to contribute in the applicability of each respective cells in regenerative therapy. PMID:24669199
Chen, Guang; Yang, Ping; Kattawar, George W
2008-03-01
The pseudospectral time-domain (PSTD) method is a powerful approach for computing the single-scattering properties of arbitrarily shaped particles with small-to-moderate-sized parameters. In the PSTD method, the spatial derivative approximation based on the spectral method is more accurate than its counterpart based on the finite-difference technique. Additionally, the PSTD method can substantially diminish accumulated errors that increase with the spatial scale and temporal duration of simulation. We report on the application of the PSTD method to the scattering of light by nonspherical ice particles. The applicability of the PSTD method is validated against the Lorenz-Mie theory and the T-matrix method. The phase functions computed from the PSTD method and the Lorenz-Mie theory agree well for size parameters as large as 80. Furthermore, the PSTD code is also applied to the scattering of light by nonspherical ice crystals, namely, hollow hexagonal columns and aggregates, which are frequently observed in cirrus clouds. The phase functions computed from the PSTD method are compared with the counterparts computed from the finite-difference time-domain (FDTD) method for a size parameter of 20 and an incident wavelength of 3.7 microm. The comparisons show good agreement between the two methods. PMID:18311250
Li Xiantao Yang, Jerry Z. E, Weinan
2010-05-20
We present a multiscale model for numerical simulations of dynamics of crystalline solids. The method combines the continuum nonlinear elasto-dynamics model, which models the stress waves and physical loading conditions, and molecular dynamics model, which provides the nonlinear constitutive relation and resolves the atomic structures near local defects. The coupling of the two models is achieved based on a general framework for multiscale modeling - the heterogeneous multiscale method (HMM). We derive an explicit coupling condition at the atomistic/continuum interface. Application to the dynamics of brittle cracks under various loading conditions is presented as test examples.
Applications of the layer-KKR method to photonic crystals.
Modinos, A; Stefanou, N; Yannopapas, V
2001-01-29
A brief introduction of the layer-Korringa-Kohn-Rostoker method for calculations of the frequency band structure of photonic crystals and of the transmission and reflection coefficients of light incident on slabs of such crystals is followed by two applications of the method. The first relates to the frequency band structure of metallodielectric composites and demonstrates the essential difference between cermet and network topology of such composites at low frequencies. The second application is an analysis of recent measurements of the reflection of light from a slab of a colloidal system consisting of latex spheres in air. PMID:19417804
NASA Astrophysics Data System (ADS)
Doungmo Goufo, Emile Franc; Atangana, Abdon
2016-08-01
There have been numbers of conflicting and confusing situations, but also uniformity, in the application of the two most popular fractional derivatives, namely the classic Riemann-Liouville and Caputo fractional derivatives. The range of these issues is wide, including the initialization with the Caputo derivative and its observed difficulties compared to the Riemann-Liouville initialization conditions. In this paper, being aware of these issues and reacting to the newly introduced Caputo-Fabrizio fractional derivative (CFFD) without singular kernel, we introduce a new definition of fractional derivative called the new Riemann-Liouville fractional derivative (NRLFD) without singular kernel. The filtering property of the NRLFD is pointed out by showing it as the derivative of a convolution and contrary to the CFFD, it matches with the function when the order is zero. We also explore various scientific situations that may be conflicting and confusing in the applicability of both new derivatives. In particular, we show that both definitions still have some basic similarities, like not obeying the traditional chain rule. Furthermore, we provide the explicit formula for the Laplace transform of the NRLFD and we prove that, contrary to the CFFD, the NRLFD requires non-constant initial conditions and does not require the function f to be continuous or differentiable. Some simulations for the NRLFD are presented for different values of the derivative order. In the second part of this work, numerical approximations for the first- and second-order NRLFD are developped followed by a concrete application to diffusion. The stability of the numerical scheme is proved and numerical simulations are performed for different values of the derivative order α. They exhibit similar behavior for closed values of α.
Development and applications of Krotov method of global control improvement
NASA Astrophysics Data System (ADS)
Rasina, Irina V.; Trushkova, Ekaterina A.; Baturina, Olga V.; Bulatov, Alexander V.; Guseva, Irina S.
2016-06-01
This is a survey of works on main properties, application and development of the Krotov method of global control improvement very popular among researchers of modern problems in quantum physics and quantum chemistry, applying actively optimal control methods. The survey includes a brief description of the method in comparison with well known gradient method demonstrating such its serious advantage as absence of tuning parameters; investigations aimed to make its special version for the quantum system well defined and more effective; and generalization for wide classes of control systems, including the systems of heterogeneous structure.
Application of Vacuum Deposition Methods to Solid Oxide Fuel Cells
Pederson, Larry R.; Singh, Prabhakar; Zhou, Xiao Dong
2006-07-01
The application of vacuum deposition techniques to the fabrication of solid oxide fuel cell materials and structures are reviewed, focusing on magnetron sputtering, vacuum plasma methods, laser ablation, and electrochemical vapor deposition. A description of each method and examples of use to produce electrolyte, electrode, and/or electrical interconnects are given. Generally high equipment costs and relatively low deposition rates have limited the use of vacuum deposition methods in solid oxide fuel cell manufacture, with a few notable exceptions. Vacuum methods are particularly promising in the fabrication of micro fuel cells, where thin films of high quality and unusual configuration are desired.
Fernández, Estibalitz; Rodríguez, Gelen; Hostachy, Sarah; Clède, Sylvain; Cócera, Mercedes; Sandt, Christophe; Lambert, François; de la Maza, Alfonso; Policar, Clotilde; López, Olga
2015-07-01
A rhenium tris-carbonyl derivative (fac-[Re(CO)3Cl(2-(1-dodecyl-1H-1,2,3,triazol-4-yl)-pyridine)]) was incorporated into phospholipid assemblies, called bicosomes, and the penetration of this molecule into skin was monitored using Fourier-transform infrared microspectroscopy (FTIR). To evaluate the capacity of bicosomes to promote the penetration of this derivative, the skin penetration of the Re(CO)3 derivative dissolved in dimethyl sulfoxide (DMSO), a typical enhancer, was also studied. Dynamic light scattering results (DLS) showed an increase in the size of the bicosomes with the incorporation of the Re(CO)3 derivative, and the FTIR microspectroscopy showed that the Re(CO)3 derivative incorporated in bicosomes penetrated deeper into the skin than when dissolved in DMSO. When this molecule was applied on the skin using the bicosomes, 60% of the Re(CO)3 derivative was retained in the stratum corneum (SC) and 40% reached the epidermis (Epi). Otherwise, the application of this molecule via DMSO resulted in 95% of the Re(CO)3 derivative being in the SC and only 5% reaching the Epi. Using a Re(CO)3 derivative with a dodecyl-chain as a model molecule, it was possible to determine the distribution of molecules with similar physicochemical characteristics in the skin using bicosomes. This fact makes these nanostructures promising vehicles for the application of lipophilic molecules inside the skin. PMID:25969419
Biogenesis, Function, and Applications of Virus-Derived Small RNAs in Plants
Zhang, Chao; Wu, Zujian; Li, Yi; Wu, Jianguo
2015-01-01
RNA silencing, an evolutionarily conserved and sequence-specific gene-inactivation system, has a pivotal role in antiviral defense in most eukaryotic organisms. In plants, a class of exogenous small RNAs (sRNAs) originating from the infecting virus called virus-derived small interfering RNAs (vsiRNAs) are predominantly responsible for RNA silencing-mediated antiviral immunity. Nowadays, the process of vsiRNA formation and the role of vsiRNAs in plant viral defense have been revealed through deep sequencing of sRNAs and diverse genetic analysis. The biogenesis of vsiRNAs is analogous to that of endogenous sRNAs, which require diverse essential components including dicer-like (DCL), argonaute (AGO), and RNA-dependent RNA polymerase (RDR) proteins. vsiRNAs trigger antiviral defense through post-transcriptional gene silencing (PTGS) or transcriptional gene silencing (TGS) of viral RNA, and they hijack the host RNA silencing system to target complementary host transcripts. Additionally, several applications that take advantage of the current knowledge of vsiRNAs research are being used, such as breeding antiviral plants through genetic engineering technology, reconstructing of viral genomes, and surveying viral ecology and populations. Here, we will provide an overview of vsiRNA pathways, with a primary focus on the advances in vsiRNA biogenesis and function, and discuss their potential applications as well as the future challenges in vsiRNAs research. PMID:26617580
Jamnik, Veronica K; Thomas, Scott G; Burr, Jamie F; Gledhill, Norman
2010-02-01
The purpose of this investigation was to develop and validate a fitness test for correctional officer (CO) applicants (FITCO) and to establish associated standards of acceptability. The FITCO incorporated the most important, physically demanding, and frequently occurring tasks of a CO. It consists of (i) a simulated cell search; (ii) an emergency response circuit (ERC), involving a 60-m run while scaling 4 sets of stairs, followed by simulations of an inmate control, wrist restraint, arm retraction, and 40-m mannequin drag; and (iii) a test of aerobic fitness. The validity of the FITCO was established by very high congruence between the oxygen consumption, heart rate, and rating of perceived exertion of incumbent COs while performing the ERC with the same measurements while COs were performing the on-the-job tasks on which the ERC was based. The content validity of the FITCO was confirmed by very high Likert ratings (>6 on a 7-point scale) by both male and female incumbent COs of all ages concerning the importance, relatedness, physical demands, and overall appropriateness of the FITCO for evaluating CO applicants. We conclude that because the forces built into the ERC and the FITCO standards were both derived from the performance of safe and efficient incumbent female COs of all ages, and both the validity and test-retest reliability (intraclass correllation coefficient = 0.977) of the FITCO are very high, the FITCO was properly constructed to meet the requirements of the Supreme Court of Canada's Meiorin Decision. PMID:20130667
Application Scope and Limitations of TADDOL-Derived Chiral Ammonium Salt Phase-Transfer Catalysts
Gururaja, Guddeangadi N.; Herchl, Richard; Pichler, Antonia; Gratzer, Katharina; Waser, Mario
2014-01-01
We have recently introduced a new class of chiral ammonium salt catalysts derived from easily available TADDOLs. To get a full picture of the scope of application and limitations of our catalysts we tested them in a variety of different important transformations. We found that, although these compounds have recently shown their good potential in the asymmetric α-alkylation of glycine Schiff bases, they clearly failed when we attempted to control more reactive nucleophiles like β-keto esters. On the other hand, when using them to catalyse the addition of glycine Schiff bases to different Michael acceptors it was found necessary to carefully optimize the reaction conditions for every single substrate class, as seemingly small structural changes sometimes required the use of totally different reaction conditions. Under carefully optimized conditions enantiomeric ratios up to 91:9 could be achieved in the addition of glycine Schiff bases to acrylates, whereas acrylamides and methyl vinyl ketone gave slightly lower selectivities (up to e.r. 77:23 in these cases). Thus, together with additional studies towards the syntheses of these catalysts we have now a very detailed understanding about the scope and limitations of the synthesis sequence to access our PTCs and about the application scope of these catalysts in asymmetric transformations. PMID:23584056
Accumulation of uranium derived from long-term fertilizer applications in a cultivated Andisol.
Takeda, Akira; Tsukada, Hirofumi; Takaku, Yuichi; Hisamatsu, Shun'ichi; Nanzyo, Masami
2006-08-31
The U concentrations in the soils of experimental fields with continuous fertilizer applications and in neighboring non-agricultural soils were determined. The surface soils in the three experimental fields with fertilizer applications contained higher amounts of U compared with the non-agricultural surface soils. The amount of U elevated in the soil was estimated by the vertical profile of U concentration, and an increase of about 200 mg m-2 of U was found in the soils at 0-35 cm depth during a 61-year cultivation period. The estimated value was almost the same as the amount of U added through the fertilizers as calculated from U concentrations in the applied fertilizers. Therefore, almost all the U from the fertilizers would still remain in the upper part of the soils. Chemical extraction results suggested that organic substances and noncrystalline clay minerals in the surface soil should play an important role for accumulation of U derived from the fertilizers. PMID:16487995
Biogenesis, Function, and Applications of Virus-Derived Small RNAs in Plants.
Zhang, Chao; Wu, Zujian; Li, Yi; Wu, Jianguo
2015-01-01
RNA silencing, an evolutionarily conserved and sequence-specific gene-inactivation system, has a pivotal role in antiviral defense in most eukaryotic organisms. In plants, a class of exogenous small RNAs (sRNAs) originating from the infecting virus called virus-derived small interfering RNAs (vsiRNAs) are predominantly responsible for RNA silencing-mediated antiviral immunity. Nowadays, the process of vsiRNA formation and the role of vsiRNAs in plant viral defense have been revealed through deep sequencing of sRNAs and diverse genetic analysis. The biogenesis of vsiRNAs is analogous to that of endogenous sRNAs, which require diverse essential components including dicer-like (DCL), argonaute (AGO), and RNA-dependent RNA polymerase (RDR) proteins. vsiRNAs trigger antiviral defense through post-transcriptional gene silencing (PTGS) or transcriptional gene silencing (TGS) of viral RNA, and they hijack the host RNA silencing system to target complementary host transcripts. Additionally, several applications that take advantage of the current knowledge of vsiRNAs research are being used, such as breeding antiviral plants through genetic engineering technology, reconstructing of viral genomes, and surveying viral ecology and populations. Here, we will provide an overview of vsiRNA pathways, with a primary focus on the advances in vsiRNA biogenesis and function, and discuss their potential applications as well as the future challenges in vsiRNAs research. PMID:26617580
Luo, Yuehao; Yuan, Lu; Li, Jianhua; Wang, Jianshe
2015-12-01
Nature has supplied the inexhaustible resources for mankind, and at the same time, it has also progressively developed into the school for scientists and engineers. Through more than four billions years of rigorous and stringent evolution, different creatures in nature gradually exhibit their own special and fascinating biological functional surfaces. For example, sharkskin has the potential drag-reducing effect in turbulence, lotus leaf possesses the self-cleaning and anti-foiling function, gecko feet have the controllable super-adhesion surfaces, the flexible skin of dolphin can accelerate its swimming velocity. Great profits of applying biological functional surfaces in daily life, industry, transportation and agriculture have been achieved so far, and much attention from all over the world has been attracted and focused on this field. In this overview, the bio-inspired drag-reducing mechanism derived from sharkskin is explained and explored comprehensively from different aspects, and then the main applications in different fluid engineering are demonstrated in brief. This overview will inevitably improve the comprehension of the drag reduction mechanism of sharkskin surface and better understand the recent applications in fluid engineering. PMID:26348428
NASA Astrophysics Data System (ADS)
Soltanmohammadi, Hossein; Osanloo, Morteza; Aghajani Bazzazi, Abbas
2009-08-01
This study intends to take advantage of a previously developed framework for mined land suitability analysis (MLSA) consisted of economical, social, technical and mine site factors to achieve a partial and also a complete pre-order of feasible post-mining land-uses. Analysis by an outranking multi-attribute decision-making (MADM) technique, called PROMETHEE (preference ranking organization method for enrichment evaluation), was taken into consideration because of its clear advantages on the field of MLSA as compared with MADM ranking techniques. Application of the proposed approach on a mined land can be completed through some successive steps. First, performance of the MLSA attributes is scored locally by each individual decision maker (DM). Then the assigned performance scores are normalized and the deviation amplitudes of non-dominated alternatives are calculated. Weights of the attributes are calculated by another MADM technique namely, analytical hierarchy process (AHP) in a separate procedure. Using the Gaussian preference function beside the weights, the preference indexes of the land-use alternatives are obtained. Calculation of the outgoing and entering flows of the alternatives and one by one comparison of these values will lead to partial pre-order of them and calculation of the net flows, will lead to a ranked preference for each land-use. At the final step, utilizing the PROMETHEE group decision support system which incorporates judgments of all the DMs, a consensual ranking can be derived. In this paper, preference order of post-mining land-uses for a hypothetical mined land has been derived according to judgments of one DM to reveal applicability of the proposed approach.
NASA Astrophysics Data System (ADS)
Delbridge, Brent G.; Bürgmann, Roland; Fielding, Eric; Hensley, Scott; Schulz, William H.
2016-05-01
In order to provide surface geodetic measurements with "landslide-wide" spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide, which is 3.9 km long and moves persistently at rates up to ˜2 cm/day. A comparison with concurrent GPS measurements validates this method and shows that it provides reliable and accurate 3-D surface deformation measurements. The UAVSAR-derived vector velocity field measurements accurately capture the sharp boundaries defining previously identified kinematic units and geomorphic domains within the landslide. We acquired data across the landslide during spring and summer and identify that the landslide moves more slowly during summer except at its head, presumably in response to spatiotemporal variations in snowmelt infiltration. In order to constrain the mechanics controlling landslide motion from surface velocity measurements, we present an inversion framework for the extraction of slide thickness and basal geometry from dense 3-D surface velocity fields. We find that the average depth of the Slumgullion Landslide is 7.5 m, several meters less than previous depth estimates. We show that by considering a viscoplastic rheology, we can derive tighter theoretical bounds on the rheological parameter relating mean horizontal flow rate to surface velocity. Using inclinometer data for slow-moving, clay-rich landslides across the globe, we find a consistent value for the rheological parameter of 0.85 ± 0.08.
Application of the {gamma}SF method to palladium
Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Iwamoto, C.; Kamata, M.; Itoh, O.; Goriely, S.; Daoutidis, I.; Arteaga, D. P.; Harada, H.; Kitatani, F.; Goko, S.; Toyokawa, H.; Yamada, K.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.
2011-10-28
Photoneutron cross sections were measured for {sup 108}Pd, {sup 106}Pd, and {sup 105}Pd with laser-Compton scattering {gamma}-ray beams in an application of the {gamma}SF method to a radioactive nucleus {sup 107}Pd. We present radiative neutron cross sections for {sup 107}Pd[6.5x10{sup 6} y] obtained with the {gamma}SF method.
Monte Carlo methods and applications in nuclear physics
Carlson, J.
1990-01-01
Monte Carlo methods for studying few- and many-body quantum systems are introduced, with special emphasis given to their applications in nuclear physics. Variational and Green's function Monte Carlo methods are presented in some detail. The status of calculations of light nuclei is reviewed, including discussions of the three-nucleon-interaction, charge and magnetic form factors, the coulomb sum rule, and studies of low-energy radiative transitions. 58 refs., 12 figs.
Zhao, Qian; Jia, Xiaobo; Xia, Rui; Lin, Jianing; Zhang, Yuan
2016-09-01
Ionic mixtures, measured as specific conductivity, have been increasingly concerned because of their toxicities to aquatic organisms. However, identifying protective values of specific conductivity for aquatic organisms is challenging given that laboratory test systems cannot examine more salt-intolerant species nor effects occurring in streams. Large data sets used for deriving field-based benchmarks are rarely available. In this study, a field-based method for small data sets was used to derive specific conductivity benchmark, which is expected to prevent the extirpation of 95% of local taxa from circum-neutral to alkaline waters dominated by a mixture of SO4(2-) and HCO3(-) anions and other dissolved ions. To compensate for the smaller sample size, species level analyses were combined with genus level analyses. The benchmark is based on extirpation concentration (XC95) values of specific conductivity for 60 macroinvertebrate genera estimated from 296 sampling sites in the Hun-Tai River Basin. We derived the specific conductivity benchmark by using a 2-point interpolation method, which yielded the benchmark of 249 μS/cm. Our study tailored the method that was developed by USEPA to derive aquatic life benchmark for specific conductivity for basin scale application, and may provide useful information for water pollution control and management. PMID:27389551
NASA Astrophysics Data System (ADS)
Wise, Stephen
2000-07-01
Digital elevation models (DEMs) are becoming increasingly important tools in hydrological research and in water resources management. The quality of DEMs, however, normally is reported simply as the root mean square error of elevation, a statistic that fails to capture the numerous sources of error in DEMs or to predict their effect on the result of using the DEM. This paper presents a review of other approaches to assessing DEM quality, and argues that a full assessment of DEM quality must focus on the accuracy and reliability of the final product of the DEM analysis. A number of DEMs for the Slapton Ley catchments in Devon derived from digitized contour data are compared in an initial assessment of their sustainability for use in hydrological work. Two are available for purchase from data suppliers, and five more were created using a variety of interpolation techniques in widely available geographical information system software. The different interpretation methods produce DEMs with different artefacts, although analyses of the distribution of elevation values, and visual techniques, suggested that none of these were of a particularly pronounced nature. The results of using the DEMs to derive drainage networks and catchment areas showed that at the broad scale there was a high level of agreement between the DEMs. There were, however, important differences of detail. For example, some DEMs predicted drainage lines that occasionally crossed the original contours. The results of calculating the TOPMODEL topographic index showed far more variation, because the index is calculated for each pixel in the area, rather than being an aggregate result derived from numerous pixels. The main conclusion was that care should always be taken to assess the quality of a DEM before attempting to use it, and that results should always be checked to ensure that they appear to be reasonable.
Method for deriving information regarding stress from a stressed ferromagnetic material
Jiles, David C.
1991-04-30
A non-destructive evaluation technique for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.
Method for deriving information regarding stress from a stressed ferromagnetic material
Jiles, D.C.
1991-04-30
A nondestructive evaluation technique is disclosed for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.
7 CFR 1430.603 - Time and method of application.
Code of Federal Regulations, 2012 CFR
2012-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2005 Dairy Disaster Assistance Payment Program II (DDAP-II) § 1430.603 Time and method of application. (a) Dairy producers may... county where the dairy operation is located but, in any case, must be received by the FSA county...
7 CFR 1430.603 - Time and method of application.
Code of Federal Regulations, 2011 CFR
2011-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2005 Dairy Disaster Assistance Payment Program II (DDAP-II) § 1430.603 Time and method of application. (a) Dairy producers may... county where the dairy operation is located but, in any case, must be received by the FSA county...
7 CFR 1430.303 - Time and method of application.
Code of Federal Regulations, 2013 CFR
2013-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2004 Dairy Disaster Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain an... where the dairy operation is located but, in any case, must be received by the FSA county office by...
7 CFR 1430.303 - Time and method of application.
Code of Federal Regulations, 2014 CFR
2014-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2004 Dairy Disaster Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain an... where the dairy operation is located but, in any case, must be received by the FSA county office by...
7 CFR 1430.303 - Time and method of application.
Code of Federal Regulations, 2011 CFR
2011-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2004 Dairy Disaster Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain an... where the dairy operation is located but, in any case, must be received by the FSA county office by...
7 CFR 1430.303 - Time and method of application.
Code of Federal Regulations, 2012 CFR
2012-01-01
..., DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS DAIRY PRODUCTS 2004 Dairy Disaster Assistance Payment Program § 1430.303 Time and method of application. (a) Dairy producers may obtain an... where the dairy operation is located but, in any case, must be received by the FSA county office by...
How to save water by choice of irrigation application method
Technology Transfer Automated Retrieval System (TEKTRAN)
It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield de...
The ReaxFF method - new applications and developments
NASA Astrophysics Data System (ADS)
van Duin, Adri
The ReaxFF method provides a highly transferable simulation method for atomistic scale simulations on chemical reactions at the nanosecond and nanometer scale. It combines concepts of bond-order based potentials with a polarizable charge distribution. Since it initial development for hydrocarbons in 2001, we have found that this concept is transferable to applications to elements all across the periodic table, including all first row elements, metals, ceramics and ionic materials. For all these elements and associated materials we have demonstrated that ReaxFF can reproduce quantum mechanics-based structures, reaction energies and reaction barriers with reasonable accuracy, enabling the method to predict reaction kinetics in complicated, multi-material environments at a relatively modest computational expense. This presentation will describe the current concepts of the ReaxFF method, the current status of the various ReaxFF codes, including parallel implementations and recently developed hybrid Grand Canonical Monte Carlo options - which significantly increase its application areas. Also, we will present and overview of recent applications to a range of materials of increasing complexity, with a focus on applications to combustion, biomaterials, batteries, tribology and catalysis.
Application of geophysical methods to agriculture: An overview
Technology Transfer Automated Retrieval System (TEKTRAN)
Geophysical methods are becoming an increasingly valuable tool for agricultural applications. Agricultural geophysics investigations are commonly (although certainly not always) focused on delineating small- and/or large-scale objects/features within the soil profile (~ 0 to 2 m depth) over very lar...
7 CFR 784.4 - Time and method of application.
Code of Federal Regulations, 2010 CFR
2010-01-01
... 7 Agriculture 7 2010-01-01 2010-01-01 false Time and method of application. 784.4 Section 784.4 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS 2004 EWE LAMB REPLACEMENT AND RETENTION PAYMENT PROGRAM § 784.4 Time and...
Liu, Mei; Li, Baoxin; Cui, Xiang
2013-10-15
In this paper, we discovered that the anionic polythiophenes derivative, poly[2-(3-thienyl)ethyloxy-4-butylsulfonate] (PTEBS), possesses intrinsic peroxidase-like activity that can catalyze the reaction of peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2 to produce a blue color reaction, which provides colorimetric detection of H2O2. PTEBS exhibits several advantages such as high catalytic efficiency, good stability, and rapid response over horseradish peroxidase (HRP). By coupling the oxidation of glucose catalyzed by glucose oxidase, a simple, inexpensive, highly sensitive and selective colorimetric method for glucose detection has been developed. The absorbance was proportional to the concentration of glucose in the range from 0.01 to 0.5mM with a detection limit of 0.004 mM. This work is not only of importance for a better understanding of the unique properties of polythiophenes derivative but also of great potential for medical diagnostics and biotechnology. PMID:24054671
Morral-Ruíz, Genoveva; Melgar-Lesmes, Pedro; García, María Luísa; Solans, Conxita; García-Celma, María José
2014-01-30
The design of new, safe and effective nanotherapeutic systems is an important challenge for the researchers in the nanotechnology area. This study describes the formation of biocompatible polyurethane and polyurea nanoparticles based on polyoxyethylene castor oil derivative surfactant formed from O/W nano-emulsions by polymerization at the droplet interfaces in systems composed by aqueous solution/Kolliphor(®) ELP/medium chain triglyceride suitable for intravenous administration. Initial nano-emulsions incorporating highly hydrophilic materials were prepared by the phase inversion composition (PIC) method. After polymerization, nanoparticles with a small particle diameter (25-55 nm) and low polydispersity index were obtained. Parameters such as concentration of monomer, O/S weight ratio as well as the polymerization temperature were crucial to achieve a correct formation of these nanoparticles. Moreover, FT-IR studies showed the full conversion of the monomer to polyurethane and polyurea polymers. Likewise the involvement of the surfactant in the polymerization process through their nucleophilic groups to form the polymeric matrix was demonstrated. This could mean a first step in the development of biocompatible systems formulated with polyoxyethylene castor oil derivative surfactants. In addition, haemolysis and cell viability assays evidenced the good biocompatibility of KELP polyurethane and polyurea nanoparticles thus indicating the potential of these nanosystems as promising drug carriers. PMID:24275445
Xiao, Ni; Deng, Jian; Huang, Kaihui; Ju, Saiqin; Hu, Canhui; Liang, Jun
2014-07-15
Two novel methods, first derivative spectrophotometric method ((1)D) and first derivative ratio spectrophotometric method ((1)DR), have been developed for the simultaneous trace determination of rhodamine B (RhB) and rhodamine 6G (Rh6G) in food samples after dispersive liquid-liquid microextraction (DLLME). The combination of derivative spectrophotometric techniques and DLLME procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimum conditions, the linear calibration curves ranged from 5 to 450 ng mL(-1), with the correlation coefficients (r) of 0.9997 for RhB and 0.9977 for Rh6G by (1)D method, and 0.9987 for RhB and 0.9958 for Rh6G by (1)DR method, respectively. The calculated limits of detection (LODs) based on the variability of the blank solutions (S/N = 3 criterion) for 11 measurements were in the range of 0.48-1.93 ng mL(-1). The recoveries ranged from 88.1% to 111.6% (with RSD less than 4.4%) and 91.5-110.5% (with RSD less than 4.7%) for (1)D and (1)DR method, respectively. The influence of interfering substances such as foreign ions and food colorants which might be present in the food samples on the signals of RhB and Rh6G was examined. The developed methods have been successfully applied to the determination of RhB and Rh6G in black tea, red wine and chilli powder samples with the characteristics of simplicity, cost-effectiveness, environmental friendliness, and could be valuable for routine analysis. PMID:24691361
NASA Astrophysics Data System (ADS)
Xiao, Ni; Deng, Jian; Huang, Kaihui; Ju, Saiqin; Hu, Canhui; Liang, Jun
2014-07-01
Two novel methods, first derivative spectrophotometric method (1D) and first derivative ratio spectrophotometric method (1DR), have been developed for the simultaneous trace determination of rhodamine B (RhB) and rhodamine 6G (Rh6G) in food samples after dispersive liquid-liquid microextraction (DLLME). The combination of derivative spectrophotometric techniques and DLLME procedure endows the presented methods with enhanced sensitivity and selectivity. Under optimum conditions, the linear calibration curves ranged from 5 to 450 ng mL-1, with the correlation coefficients (r) of 0.9997 for RhB and 0.9977 for Rh6G by 1D method, and 0.9987 for RhB and 0.9958 for Rh6G by 1DR method, respectively. The calculated limits of detection (LODs) based on the variability of the blank solutions (S/N = 3 criterion) for 11 measurements were in the range of 0.48-1.93 ng mL-1. The recoveries ranged from 88.1% to 111.6% (with RSD less than 4.4%) and 91.5-110.5% (with RSD less than 4.7%) for 1D and 1DR method, respectively. The influence of interfering substances such as foreign ions and food colorants which might be present in the food samples on the signals of RhB and Rh6G was examined. The developed methods have been successfully applied to the determination of RhB and Rh6G in black tea, red wine and chilli powder samples with the characteristics of simplicity, cost-effectiveness, environmental friendliness, and could be valuable for routine analysis.
Khantasup, Kannika; Chantima, Warangkana; Sangma, Chak; Poomputsa, Kanokwan; Dharakul, Tararaj
2015-12-01
Single-chain variable antibody fragments (scFvs) are attractive candidates for targeted immunotherapy in several human diseases. In this study, a concise humanization strategy combined with an optimized production method for humanizing scFvs was successfully employed. Two antibody clones, one directed against the hemagglutinin of H5N1 influenza virus, the other against EpCAM, a cancer biomarker, were used to demonstrate the validity of the method. Heavy chain (VH) and light chain (VL) variable regions of immunoglobulin genes from mouse hybridoma cells were sequenced and subjected to the construction of mouse scFv 3-D structure. Based on in silico modeling, the humanized version of the scFv was designed via complementarity-determining region (CDR) grafting with the retention of mouse framework region (FR) residues identified by primary sequence analysis. Root-mean-square deviation (RMSD) value between mouse and humanized scFv structures was calculated to evaluate the preservation of CDR conformation. Mouse and humanized scFv genes were then constructed and expressed in Escherichia coli. Using this method, we successfully generated humanized scFvs that retained the targeting activity of their respective mouse scFv counterparts. In addition, the humanized scFvs were engineered with a C-terminal cysteine residue (hscFv-C) for site-directed conjugation for use in future targeting applications. The hscFv-C expression was extensively optimized to improve protein production yield. The protocol yielded a 20-fold increase in production of hscFv-Cs in E. coli periplasm. The strategy described in this study may be applicable in the humanization of other antibodies derived from mouse hybridoma. PMID:26683180
Czubak, Paweł; Putowski, Lechosław
2014-01-01
Type 1 diabetes mellitus is a result of autoimmune destruction of pancreatic insulin producing β-cells and so far it can be cured only by insulin injection, by pancreas transplantation, or by pancreatic islet cells' transplantation. The methods are, however, imperfect and have a lot of disadvantages. Therefore new solutions are needed. The best one would be the use of differentiated mesenchymal stem cells (MSCs). In the present study, we investigated the potential of the bone marrow-derived MSCs line for in vitro differentiation into insulin producing cells (IPSs). We applied an 18-day protocol to differentiate MSCs. Differentiating cells formed cell clusters some of which resembled pancreatic islet-like cells. Using dithizone we confirmed the presence of insulin in the cells. What is more, the expression of proinsulin C-peptide in differentiated IPCs was analyzed by flow cytometry. For the first time, we investigated the influence of growth factors' concentration on IPCs differentiation efficiency. We have found that an increase in the concentration of growth factors up to 60 ng/mL of β-FGF/EGF and 30 ng/mL of activin A/β-cellulin increases the percentage of IPCs. Further increase of growth factors does not show any increase of the percentage of differentiated cells. Our findings suggest that the presented protocol can be adapted for differentiation of insulin producing cells from stem cells. PMID:25405207
Czubak, Paweł; Bojarska-Junak, Agnieszka; Tabarkiewicz, Jacek; Putowski, Lechosław
2014-01-01
Type 1 diabetes mellitus is a result of autoimmune destruction of pancreatic insulin producing β-cells and so far it can be cured only by insulin injection, by pancreas transplantation, or by pancreatic islet cells' transplantation. The methods are, however, imperfect and have a lot of disadvantages. Therefore new solutions are needed. The best one would be the use of differentiated mesenchymal stem cells (MSCs). In the present study, we investigated the potential of the bone marrow-derived MSCs line for in vitro differentiation into insulin producing cells (IPSs). We applied an 18-day protocol to differentiate MSCs. Differentiating cells formed cell clusters some of which resembled pancreatic islet-like cells. Using dithizone we confirmed the presence of insulin in the cells. What is more, the expression of proinsulin C-peptide in differentiated IPCs was analyzed by flow cytometry. For the first time, we investigated the influence of growth factors' concentration on IPCs differentiation efficiency. We have found that an increase in the concentration of growth factors up to 60 ng/mL of β-FGF/EGF and 30 ng/mL of activin A/β-cellulin increases the percentage of IPCs. Further increase of growth factors does not show any increase of the percentage of differentiated cells. Our findings suggest that the presented protocol can be adapted for differentiation of insulin producing cells from stem cells. PMID:25405207
NASA Astrophysics Data System (ADS)
Stevenazzi, Stefania; Masetti, Marco; Nghiem, Son V.; Sorichetta, Alessandro
2015-03-01
Introducing the time variable in groundwater vulnerability assessment is an innovative approach to study the evolution of contamination by non-point sources and to forecast future trends. This requires a determination of the relationship between temporal changes in groundwater contamination and in land use. Such effort will enable breakthrough advances in mapping hazardous areas, and in assessing the efficacy of land-use planning for groundwater protection. Through a Bayesian spatial statistical approach, time-dependent vulnerability maps are derived by using hydrogeological variables together with three different time-dependent datasets: population density, high-resolution urban survey, and satellite QuikSCAT (QSCAT) data processed with the innovative dense sampling method (DSM). This approach is demonstrated extensively over the Po Plain in Lombardy region (northern Italy). Calibrated and validated maps show physically consistent relations between the hydrogeological variables and nitrate trends. The results indicate that changes of urban nitrate sources are strongly related to groundwater deterioration. Among the different datasets, QSCAT-DSM is proven to be the most efficient dataset to represent urban nitrate sources of contamination, with major advantages: a worldwide coverage, a continuous decadal data collection, and an adequate resolution without spatial gaps. This study presents a successful approach that, for the first time, allows the inclusion of the time dimension in groundwater vulnerability assessment by using innovative satellite remote sensing data for quantitative statistical analyses of groundwater quality changes.
ROS evaluation for a series of CNTs and their derivatives using an ESR method with DMPO
NASA Astrophysics Data System (ADS)
Tsuruoka, S.; Takeuchi, K.; Koyama, K.; Noguchi, T.; Endo, M.; Tristan, F.; Terrones, M.; Matsumoto, H.; Saito, N.; Usui, Y.; Porter, D. W.; Castranova, V.
2013-04-01
Carbon nanotubes (CNTs) are important materials in advanced industries. It is a concern that pulmonary exposure to CNTs may induce carcinogenic responses. It has been recently reported that CNTs scavenge ROS though non-carbon fibers generate ROS. A comprehensive evaluation of ROS scavenging using various kinds of CNTs has not been demonstrated well. The present work specifically investigates ROS scavenging capabilities with a series of CNTs and their derivatives that were physically treated, and with the number of commercially available CNTs. CNT concentrations were controlled at 0.2 through 0.6 wt%. The ROS scavenging rate was measured by ESR with DMPO. Interestingly, the ROS scavenging rate was not only influenced by physical treatments, but was also dependent on individual manufacturing methods. Ratio of CNTs to DMPO/ hydrogen peroxide is a key parameter to obtain appropriate ROS quenching results for comparison of CNTs. The present results suggest that dangling bonds are not a sole factor for scavenging, and electron transfer on the CNT surface is not clearly determined to be the sole mechanism to explain ROS scavenging.
ROS evaluation for a series of CNTs and their derivatives using an ESR method with DMPO
Tsuruoka, S; Takeuchi, K; Koyama, K; Noguchi, T; Endo, M; Tristan, F; Terrones, M; Matsumoto, H; Saito, N; Usui, Y; Porter, D W; Castranova, V
2015-01-01
Carbon nanotubes (CNTs) are important materials in advanced industries. It is a concern that pulmonary exposure to CNTs may induce carcinogenic responses. It has been recently reported that CNTs scavenge ROS though non-carbon fibers generate ROS. A comprehensive evaluation of ROS scavenging using various kinds of CNTs has not been demonstrated well. The present work specifically investigates ROS scavenging capabilities with a series of CNTs and their derivatives that were physically treated, and with the number of commercially available CNTs. CNT concentrations were controlled at 0.2 through 0.6 wt%. The ROS scavenging rate was measured by ESR with DMPO. Interestingly, the ROS scavenging rate was not only influenced by physical treatments, but was also dependent on individual manufacturing methods. Ratio of CNTs to DMPO/ hydrogen peroxide is a key parameter to obtain appropriate ROS quenching results for comparison of CNTs. The present results suggest that dangling bonds are not a sole factor for scavenging, and electron transfer on the CNT surface is not clearly determined to be the sole mechanism to explain ROS scavenging. PMID:26300949
NASA Astrophysics Data System (ADS)
El-Yazbi, Fawzi A.; Hammud, Hassan H.; Assi, Sulaf A.
2007-10-01
A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.
A novel feature selection method and its application
Li, Bing; Chow, Tommy W. S.; Huang, Di
2014-01-01
In this paper, a novel feature selection method based on rough sets and mutual information is proposed. The dependency of each feature guides the selection, and mutual information is employed to reduce the features which do not favor addition of dependency significantly. So the dependency of the subset found by our method reaches maximum with small number of features. Since our method evaluates both definitive relevance and uncertain relevance by a combined selection criterion of dependency and class-based distance metric, the feature subset is more relevant than other rough sets based methods. As a result, the subset is near optimal solution. In order to verify the contribution, eight different classification applications are employed. Our method is also employed on a real Alzheimer's disease dataset, and finds a feature subset where classification accuracy arrives at 81.3%. Those present results verify the contribution of our method. PMID:25530672
A novel broadband impedance method for detection of cell-derived microparticles
Lvovich, Vadim; Srikanthan, Sowmya; Silverstein, Roy L.
2010-01-01
A novel label-free method is presented to detect and quantify cell-derived microparticles (MPs) by the electrochemical potential-modulated electrochemical impedance spectroscopy (EIS). MPs are present in elevated concentrations during pathological conditions and play a major role in the establishment and pathogenesis of many diseases. Considering this, accurate detection and quantification of MPs is very important in clinical diagnostics and therapeutics. A combination of bulk solution electrokinetic sorting and interfacial impedance responses allows achieving detection limits as low as several MPs per µL. By fitting resulting EIS spectra with an equivalent electrical circuit, the bulk solution electrokinetic and interfacial impedance responses were characterized. In the bulk solution two major relaxations were prominent - β-relaxation in low MHz region due to the MP capacitive membrane bridging, and α-relaxation at ∼ 10 kHz due to counter ions diffusion. At low frequencies (10-0.1 Hz) at electrochemical potentials exceeding −100 mV, a facile interfacial Faradaic process of oxidation in MPs coupled with diffusion and non Faradaic double layer charging dominate, probably due to oxidation of phospholipids and/or proteins on the MP surface and MP lysis. Buffer influence on the MP detection demonstrated that that a relatively low conductivity Tyrode’s buffer background solution is preferential for the MP electrokinetic separation and characterization. This study also demonstrated that standard laboratory methods such as flow cytometry underestimate MP concentrations, especially those with smaller average sizes, by as much as a factor of 2 to 40. PMID:20729061
Ground-based GPS-derived Precipitable Water Vapour Estimates for Climate Application in Australia
NASA Astrophysics Data System (ADS)
Choy, Suelynn; Dawson, John; Jia, Minghai; Kuleshov, Yuriy
2013-04-01
Atmospheric water vapour is a critical component of the greenhouse effect and plays a significant role in the global climate system. The knowledge of the long-term spatial and temporal variability of water vapour is vital for understanding climate change. The Global Positioning System (GPS) has long offered the prospect of retrieving column integrated Precipitable Water Vapour (PWV) profiles from the time-varying tropospheric Zenith Path Delay (ZPD), which can be retrieved by stochastic filtering of the GPS measurements. However, observing GPS-PWV for climate studies requires a homogenous and long-term time series of GPS data. We present a regional reanalysis of GPS data focussing on the Australian Regional GPS Network stations from 1997 to 2012 (15 years). These stations are selectively chosen to provide a representative regional distribution of GPS sites on the Australian continent while ensuring conventional meteorological observations (surface-based data) are available for PWV conversion and other PWV sensors (e.g. upper-air data from radiosondes) for validation purposes. The research work is divided into three components: 1) estimation of homogenous long-term tropospheric ZPD from GPS measurements that are accurate, stable and consistent; 2) conversion of tropospheric ZPD to PWV estimates given surface temperature and pressure readings, and 3) intertechnique comparison and validation of the GPS-derived PWV. The derived data will be used to investigate the secular trend and seasonal variation PWV time series and its implications for climate application. This research represents the first attempt to utilise the Australian regional network of GPS stations to study the climate processes and variations from the long-term time series of GPS-PWV.
Bebawy, Lories I; Abbas, Samah S; Fattah, Laila A; Refaat, Heba H
2005-10-01
Four sensitive methods are described for the direct determination of telmisartan (TELM) and hydrochlorothiazide (HCT) in combined dosage forms without prior separation. The first method is a first derivative spectophotometry (1D) using a zero- crossing technique of measurement at 241.6 and 227.6 nm for TELM and HCT, respectively. The second method is the first derivative of ratio spectrophotometry (1DD) where the amplitudes were measured at 242.7 nm for TELM and 274.9 nm for HCT. The third method is based on TLC separation of the two drugs followed by the densitometric measurements of their spots at 295 and 225 nm for TELM and HCT, respectively. The separation was carried out on silica gel 60 F254 using butanol: ammonia 25% (8:2 v/v) as mobile phase. The fourth method is spectrofluorimetric determination of TELM, depending on measuring the native fluorescence of the drug in 1 M sodium hydroxide at lambda excitation 230 nm and emission at 365 nm. The proposed methods were applied successfully for the determination of the two drugs in bulk powder and in pharmaceutical formulations. The spectrofluorimetric method was utilized for the analysis of TELM in human plasma. PMID:16129437
Hart, Vern P; Doyle, Timothy E
2013-09-01
A Monte Carlo method was derived from the optical scattering properties of spheroidal particles and used for modeling diffuse photon migration in biological tissue. The spheroidal scattering solution used a separation of variables approach and numerical calculation of the light intensity as a function of the scattering angle. A Monte Carlo algorithm was then developed which utilized the scattering solution to determine successive photon trajectories in a three-dimensional simulation of optical diffusion and resultant scattering intensities in virtual tissue. Monte Carlo simulations using isotropic randomization, Henyey-Greenstein phase functions, and spherical Mie scattering were additionally developed and used for comparison to the spheroidal method. Intensity profiles extracted from diffusion simulations showed that the four models differed significantly. The depth of scattering extinction varied widely among the four models, with the isotropic, spherical, spheroidal, and phase function models displaying total extinction at depths of 3.62, 2.83, 3.28, and 1.95 cm, respectively. The results suggest that advanced scattering simulations could be used as a diagnostic tool by distinguishing specific cellular structures in the diffused signal. For example, simulations could be used to detect large concentrations of deformed cell nuclei indicative of early stage cancer. The presented technique is proposed to be a more physical description of photon migration than existing phase function methods. This is attributed to the spheroidal structure of highly scattering mitochondria and elongation of the cell nucleus, which occurs in the initial phases of certain cancers. The potential applications of the model and its importance to diffusive imaging techniques are discussed. PMID:24085080
NASA Technical Reports Server (NTRS)
Lan, C. E.
1981-01-01
The nonplanar quasi-vortex-lattice method is applied to the calculation of lateral-directional stability derivatives of wings with and without vortex-lift effect. Results for conventional configurations and those with winglets, V-tail, etc. are compared with available data. All rolling moment derivatives are found to be accurately predicted. The prediction of side force and yawing moment derivatives for some configurations is not as accurate. Causes of the discrepancy are discussed. A user's manual for the program and the program listing are also included.
Management applications of lidar-derived mean high water shorelines in North Carolina
Limber, Patrick W.; List, Jeffrey H.; Warren, Jeffrey D.
2007-01-01
The accuracy of shoreline change analysis is dependent on how the shoreline is defined and the consistency of the techniques(s) used to define it. Using the concurrent lidar (light detection and ranging) and orthophotography dataset from August and September of 2004 covering North Carolina's 516 kilometers of barrier island oceanfront, Limber et al. (2007) examined the spatial relationship between two common shoreline definitions used in shoreline change analysis, mean high water [MHW] derived from lidar data and the wet/dry line digitized from orthophotography. Here, we summarize this work and extend the analysis with a comparison between two different methods of MHW shoreline extraction from liar data: a profile-based method (Stockdon et al., 2002) and a method based on correction of the lidar data to a MHW datum (Hess et al., 2005). Potential bias generated by using these different shoreline types together can affect not only the accuracy of shoreline change analysis, but also the coastal management policies and decision that rely on it. Therefore, the implications of this study potential extend far beyond North Carolina and Atlantic Coast of the United States.
Application of integrated fluid-thermal-structural analysis methods
NASA Technical Reports Server (NTRS)
Wieting, Allan R.; Dechaumphai, Pramote; Bey, Kim S.; Thornton, Earl A.; Morgan, Ken
1988-01-01
Hypersonic vehicles operate in a hostile aerothermal environment which has a significant impact on their aerothermostructural performance. Significant coupling occurs between the aerodynamic flow field, structural heat transfer, and structural response creating a multidisciplinary interaction. Interfacing state-of-the-art disciplinary analysis methods is not efficient, hence interdisciplinary analysis methods integrated into a single aerothermostructural analyzer are needed. The NASA Langley Research Center is developing such methods in an analyzer called LIFTS (Langley Integrated Fluid-Thermal-Structural) analyzer. The evolution and status of LIFTS is reviewed and illustrated through applications.
Advanced stress analysis methods applicable to turbine engine structures
NASA Technical Reports Server (NTRS)
Pian, Theodore H. H.
1991-01-01
The following tasks on the study of advanced stress analysis methods applicable to turbine engine structures are described: (1) constructions of special elements which contain traction-free circular boundaries; (2) formulation of new version of mixed variational principles and new version of hybrid stress elements; (3) establishment of methods for suppression of kinematic deformation modes; (4) construction of semiLoof plate and shell elements by assumed stress hybrid method; and (5) elastic-plastic analysis by viscoplasticity theory using the mechanical subelement model.
Applications of alignment-free methods in epigenomics
Pinello, Luca
2014-01-01
Epigenetic mechanisms play an important role in the regulation of cell type-specific gene activities, yet how epigenetic patterns are established and maintained remains poorly understood. Recent studies have supported a role of DNA sequences in recruitment of epigenetic regulators. Alignment-free methods have been applied to identify distinct sequence features that are associated with epigenetic patterns and to predict epigenomic profiles. Here, we review recent advances in such applications, including the methods to map DNA sequence to feature space, sequence comparison and prediction models. Computational studies using these methods have provided important insights into the epigenetic regulatory mechanisms. PMID:24197932
Analytical study to define a helicoper stability derivative extraction method, volume 2
NASA Technical Reports Server (NTRS)
Molusis, J. A.
1973-01-01
The data generated during tests to determine helicopter stability derivatives are presented in the form of graphs. The data are based on CH-53A helicopters and CH-54B helicopters with various digital filters operating at various airspeeds. Curves are plotted for a time history comparison of identified derivative models against flight data for the helicopters at specific airspeeds and maneuvers.