Asphalt compatibility testing using the automated Heithaus titration test

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

Pauli, A.T.

1996-12-31

The Heithaus titration test or variations of the test have been used for over 35 years to predict compatibilities of blends of asphalts from different crude sources. Asphalt compatibility is determined from three calculated parameters that measure the state of peptization of an asphalt or asphalt blend. The parameter p{sub a} is a measure of the peptizability of the asphaltenes. The parameter p{sub a} is a measure of the peptizing power of the maltenes, and the parameter P, derived from p{sub a} and p{sub o} values, is a measure of the overall state of peptization of the asphalt or asphaltmore » blend. In Heithaus original procedure, samples of asphalt were dissolved in toluene and titrated with n-heptane in order to initiate flocculation. The onset of flocculation was detected either by photography or by spotting a filter paper with a small amount of the titrated solution. Recently, an {open_quotes}automated{close_quotes} procedure, after Hotier and Robin, has been developed for use with asphalt. In the automated method UV-visible spectrophotometric detection measures the onset of flocculation as a peak with the percent transmittance plotted as a function of the volume of titrating solvent added to a solution of asphalt. The automated procedure has proven to be less operator dependent and much faster than the original Heithaus procedure. Results from the automated procedure show the data to be consistent with results from the original, {open_quotes}classical{close_quotes} Heithaus procedure.« less

Determination of sulphite in wine by coulometric titration.

PubMed

Lowinsohn, D; Bertotti, M

2001-09-01

A method for the determination of both free and bound S(IV) in white wine samples by coulometric titration with electrogenerated iodine is described, the S(IV) speciation being performed by extracting SO2 from samples acidified wiith hydrochloric acid. Titrations of samples treated with NaOH led to the total S(IV) concentration, the results being in agreement with the ones obtained by the distillation procedure as well as by using the classical Monier-Williams method. An average recovery of 97% was obtained for samples spiked with S(IV) in the range 0.4-1.2 mM, which demonstrated the validity of the proposed procedure. The repeatability was 1.3% and the limit of detection was estimated as 0.01 mM. Results from direct titrations of wine added to the electrochemical cell are reported, which give indications of the stability of adducts towards the reaction with iodine.

The CCD Photometric Calibration Cookbook

NASA Astrophysics Data System (ADS)

Palmer, J.; Davenhall, A. C.

This cookbook presents simple recipes for the photometric calibration of CCD frames. Using these recipes you can calibrate the brightness of objects measured in CCD frames into magnitudes in standard photometric systems, such as the Johnson-Morgan UBV, system. The recipes use standard software available at all Starlink sites. The topics covered include: selecting standard stars, measuring instrumental magnitudes and calibrating instrumental magnitudes into a standard system. The recipes are appropriate for use with data acquired with optical CCDs and filters, operated in standard ways, and describe the usual calibration technique of observing standard stars. The software is robust and reliable, but the techniques are usually not suitable where very high accuracy is required. In addition to the recipes and scripts, sufficient background material is presented to explain the procedures and techniques used. The treatment is deliberately practical rather than theoretical, in keeping with the aim of providing advice on the actual calibration of observations. This cookbook is aimed firmly at people who are new to astronomical photometry. Typical readers might have a set of photometric observations to reduce (perhaps observed by a colleague) or be planning a programme of photometric observations, perhaps for the first time. No prior knowledge of astronomical photometry is assumed. The cookbook is not aimed at experts in astronomical photometry. Many finer points are omitted for clarity and brevity. Also, in order to make the most accurate possible calibration of high-precision photometry, it is usually necessary to use bespoke software tailored to the observing programme and photometric system you are using.

Photometric microdetermination of malathion

USGS Publications Warehouse

Kallman, B.J.

1962-01-01

Carboxylic esters and lactones react with alkaline hydroxylamine to yield hydroxamates; these in acidic solution form colored iron(III) complexes. A photometric determination of such esters and lactones is thus permitted and has been extensively applied ( I-6). Hestrin ( 3) utilized this method for the microdetermination of acetylcholine and his procedure is much used for the in vitro study of cholinesterase activity and inhibition (4-6).

Effects of Acute and Chronic Cocaine Administration on Titrating-Delay Matching-to-Sample Performance

ERIC Educational Resources Information Center

Kangas, Brian D.; Branch, Marc N.

2012-01-01

The effects of cocaine were examined under a titrating-delay matching-to-sample procedure. In this procedure, the delay between sample stimulus offset and comparison stimuli onset adjusts as a function of the subject's performance. Specifically, matches increase the delay and mismatches decrease the delay. Titrated delay values served as the…

On the Photometric Calibration of FORS2 and the Sloan Digital Sky Survey

NASA Astrophysics Data System (ADS)

Bramich, D.; Moehler, S.; Coccato, L.; Freudling, W.; Garcia-Dabó, C. E.; Müller, P.; Saviane, I.

2012-09-01

An accurate absolute calibration of photometric data to place them on a standard magnitude scale is very important for many science goals. Absolute calibration requires the observation of photometric standard stars and analysis of the observations with an appropriate photometric model including all relevant effects. In the FORS Absolute Photometry (FAP) project, we have developed a standard star observing strategy and modelling procedure that enables calibration of science target photometry to better than 3% accuracy on photometrically stable nights given sufficient signal-to-noise. In the application of this photometric modelling to large photometric databases, we have investigated the Sloan Digital Sky Survey (SDSS) and found systematic trends in the published photometric data. The amplitudes of these trends are similar to the reported typical precision (˜1% and ˜2%) of the SDSS photometry in the griz- and u-bands, respectively.

Titration Techniques

NASA Astrophysics Data System (ADS)

Jacobsen, Jerrold J.; Houston Jetzer, Kelly; Patani, Néha; Zimmerman, John; Zweerink, Gerald

1995-07-01

Significant attention is paid to the proper technique for reading a meniscus. Video shows meniscus-viewing techniques for colorless and dark liquids and the consequences of not reading a meniscus at eye level. Lessons are provided on approaching the end point, focusing on end point colors produced via different commonly used indicators. The concept of a titration curve is illustrated by means of a pH meter. Carefully recorded images of the entire range of meniscus values in a buret, pipet, and graduated cylinder are included so that you can show your students, in lecture or pre-lab discussion, any meniscus and discuss how to read the buret properly. These buret meniscus values are very carefully recorded at the rate of one video frame per hundredth of a milliliter, so that an image showing any given meniscus value can be obtained. These images can be easily incorporated into a computer-based multimedia environment for testing or meniscus-reading exercises. Two of the authors have used this technique and found the exercise to be very well received by their students. Video on side two shows nearly 100 "bloopers", demonstrating both the right way and wrong ways to do tasks associated with titration. This material can be used in a variety of situations: to show students the correct way to do something; to test students by asking them "What is this person doing wrong?"; or to develop multimedia, computer-based lessons. The contents of Titration Techniques are listed below: Side 1 Titration: what it is. A simple titration; Acid-base titration animation; A brief redox titration; Redox titration animation; A complete acid-base titration. Titration techniques. Hand technique variations; Stopcock; Using a buret to measure liquid volumes; Wait before reading meniscus; Dirty and clean burets; Read meniscus at eye level (see Fig. 1); Meniscus viewing techniques--light colored liquids; Meniscus viewing techniques--dark liquids; Using a magnetic stirrer; Rough titration

End-point detection in potentiometric titration by continuous wavelet transform.

PubMed

Jakubowska, Małgorzata; Baś, Bogusław; Kubiak, Władysław W

2009-10-15

The aim of this work was construction of the new wavelet function and verification that a continuous wavelet transform with a specially defined dedicated mother wavelet is a useful tool for precise detection of end-point in a potentiometric titration. The proposed algorithm does not require any initial information about the nature or the type of analyte and/or the shape of the titration curve. The signal imperfection, as well as random noise or spikes has no influence on the operation of the procedure. The optimization of the new algorithm was done using simulated curves and next experimental data were considered. In the case of well-shaped and noise-free titration data, the proposed method gives the same accuracy and precision as commonly used algorithms. But, in the case of noisy or badly shaped curves, the presented approach works good (relative error mainly below 2% and coefficients of variability below 5%) while traditional procedures fail. Therefore, the proposed algorithm may be useful in interpretation of the experimental data and also in automation of the typical titration analysis, specially in the case when random noise interfere with analytical signal.

Estimation of uncertainty in pKa values determined by potentiometric titration.

PubMed

Koort, Eve; Herodes, Koit; Pihl, Viljar; Leito, Ivo

2004-06-01

A procedure is presented for estimation of uncertainty in measurement of the pK(a) of a weak acid by potentiometric titration. The procedure is based on the ISO GUM. The core of the procedure is a mathematical model that involves 40 input parameters. A novel approach is used for taking into account the purity of the acid, the impurities are not treated as inert compounds only, their possible acidic dissociation is also taken into account. Application to an example of practical pK(a) determination is presented. Altogether 67 different sources of uncertainty are identified and quantified within the example. The relative importance of different uncertainty sources is discussed. The most important source of uncertainty (with the experimental set-up of the example) is the uncertainty of pH measurement followed by the accuracy of the burette and the uncertainty of weighing. The procedure gives uncertainty separately for each point of the titration curve. The uncertainty depends on the amount of titrant added, being lowest in the central part of the titration curve. The possibilities of reducing the uncertainty and interpreting the drift of the pK(a) values obtained from the same curve are discussed.

Improving Photometric Calibration of Meteor Video Camera Systems

NASA Technical Reports Server (NTRS)

Ehlert, Steven; Kingery, Aaron; Cooke, William

2016-01-01

Current optical observations of meteors are commonly limited by systematic uncertainties in photometric calibration at the level of approximately 0.5 mag or higher. Future improvements to meteor ablation models, luminous efficiency models, or emission spectra will hinge on new camera systems and techniques that significantly reduce calibration uncertainties and can reliably perform absolute photometric measurements of meteors. In this talk we discuss the algorithms and tests that NASA's Meteoroid Environment Office (MEO) has developed to better calibrate photometric measurements for the existing All-Sky and Wide-Field video camera networks as well as for a newly deployed four-camera system for measuring meteor colors in Johnson-Cousins BV RI filters. In particular we will emphasize how the MEO has been able to address two long-standing concerns with the traditional procedure, discussed in more detail below.

Photometric method for determination of acidity constants through integral spectra analysis

NASA Astrophysics Data System (ADS)

Zevatskiy, Yuriy Eduardovich; Ruzanov, Daniil Olegovich; Samoylov, Denis Vladimirovich

2015-04-01

An express method for determination of acidity constants of organic acids, based on the analysis of the integral transmittance vs. pH dependence is developed. The integral value is registered as a photocurrent of photometric device simultaneously with potentiometric titration. The proposed method allows to obtain pKa using only simple and low-cost instrumentation. The optical part of the experimental setup has been optimized through the exclusion of the monochromator device. Thus it only takes 10-15 min to obtain one pKa value with the absolute error of less than 0.15 pH units. Application limitations and reliability of the method have been tested for a series of organic acids of various nature.

Determination of quaternary ammonium compounds by potentiometric titration with an ionic surfactant electrode: single-laboratory validation.

PubMed

Price, Randi; Wan, Ping

2010-01-01

A potentiometric titration for determining the quaternary ammonium compounds (QAC) commonly found in antimicrobial products was validated by a single laboratory. Traditionally, QACs were determined by using a biphasic (chloroform and water) manual titration procedure. Because of safety considerations regarding chloroform, as well as the subjectivity of color indicator-based manual titration determinations, an automatic potentiometric titration procedure was tested with quaternary nitrogen product formulations. By using the Metrohm Titrando system coupled with an ionic surfactant electrode and an Ag/AgCl reference electrode, titrations were performed with various QAC-containing formulation products/matrixes; a standard sodium lauryl sulfate solution was used as the titrant. Results for the products tested are sufficiently reproducible and accurate for the purpose of regulatory product enforcement. The robustness of the method was measured by varying pH levels, as well as by comparing buffered versus unbuffered titration systems. A quantitation range of 1-1000 ppm quaternary nitrogen was established. Eight commercially available antimicrobial products covering a variety of matrixes were assayed; the results obtained were comparable to those obtained by the manual titration method. Recoveries of 94 to 104% were obtained for spiked samples.

Thermometric titration of sulphate.

PubMed

Williams, M B; Janata, J

1970-06-01

Direct thermometric titration of sulphate with a solution of barium perchlorate is proposed. The stoichiometry of the titration is shown to be critically dependent on the concentration of ethanol in the titration medium. The titration is rapid and suffers from only a few interferences.

Acid Rain Analysis by Standard Addition Titration.

ERIC Educational Resources Information Center

Ophardt, Charles E.

1985-01-01

The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

Photometric method for determination of acidity constants through integral spectra analysis.

PubMed

Zevatskiy, Yuriy Eduardovich; Ruzanov, Daniil Olegovich; Samoylov, Denis Vladimirovich

2015-04-15

An express method for determination of acidity constants of organic acids, based on the analysis of the integral transmittance vs. pH dependence is developed. The integral value is registered as a photocurrent of photometric device simultaneously with potentiometric titration. The proposed method allows to obtain pKa using only simple and low-cost instrumentation. The optical part of the experimental setup has been optimized through the exclusion of the monochromator device. Thus it only takes 10-15 min to obtain one pKa value with the absolute error of less than 0.15 pH units. Application limitations and reliability of the method have been tested for a series of organic acids of various nature. Copyright © 2015 Elsevier B.V. All rights reserved.

Photometric properties of Mars soils analogs

USGS Publications Warehouse

Pommerol, A.; Thomas, N.; Jost, B.; Beck, P.; Okubo, C.; McEwen, A.S.

2013-01-01

We have measured the bidirectional reflectance of analogs of dry, wet, and frozen Martian soils over a wide range of phase angles in the visible spectral range. All samples were produced from two geologic samples: the standard JSC Mars-1 soil simulant and Hawaiian basaltic sand. In a first step, experiments were conducted with the dry samples to investigate the effects of surface texture. Comparisons with results independently obtained by different teams with similar samples showed a satisfying reproducibility of the photometric measurements as well as a noticeable influence of surface textures resulting from different sample preparation procedures. In a second step, water was introduced to produce wet and frozen samples and their photometry investigated. Optical microscope images of the samples provided information about their microtexture. Liquid water, even in relatively low amount, resulted in the disappearance of the backscattering peak and the appearance of a forward-scattering peak whose intensity increases with the amount of water. Specular reflections only appeared when water was present in an amount large enough to allow water to form a film at the surface of the sample. Icy samples showed a wide variability of photometric properties depending on the physical properties of the water ice. We discuss the implications of these measurements in terms of the expected photometric behavior of the Martian surface, from equatorial to circum-polar regions. In particular, we propose some simple photometric criteria to improve the identification of wet and/or icy soils from multiple observations under different geometries.

The effect of photometric and geometric context on photometric and geometric lightness effects.

PubMed

Lee, Thomas Y; Brainard, David H

2014-01-24

We measured the lightness of probe tabs embedded at different orientations in various contextual images presented on a computer-controlled stereo display. Two background context planes met along a horizontal roof-like ridge. Each plane was a graphic rendering of a set of achromatic surfaces with the simulated illumination for each plane controlled independently. Photometric context was varied by changing the difference in simulated illumination intensity between the two background planes. Geometric context was varied by changing the angle between them. We parsed the data into separate photometric effects and geometric effects. For fixed geometry, varying photometric context led to linear changes in both the photometric and geometric effects. Varying geometric context did not produce a statistically reliable change in either the photometric or geometric effects.

LIGHT TITRATIONS

PubMed Central

Field, John; Baas-Becking, Lourens G. M.

1926-01-01

1. The usefulness of the radiomicrometer in titration work has been pointed out. The authors suggest that light titration may also be used where a reaction mixture changes its absorption in the (near) infra-red. 2. The applicability of this method to the starch-iodine reaction has been demonstrated. PMID:19872266

The effect of photometric and geometric context on photometric and geometric lightness effects

PubMed Central

Lee, Thomas Y.; Brainard, David H.

2014-01-01

We measured the lightness of probe tabs embedded at different orientations in various contextual images presented on a computer-controlled stereo display. Two background context planes met along a horizontal roof-like ridge. Each plane was a graphic rendering of a set of achromatic surfaces with the simulated illumination for each plane controlled independently. Photometric context was varied by changing the difference in simulated illumination intensity between the two background planes. Geometric context was varied by changing the angle between them. We parsed the data into separate photometric effects and geometric effects. For fixed geometry, varying photometric context led to linear changes in both the photometric and geometric effects. Varying geometric context did not produce a statistically reliable change in either the photometric or geometric effects. PMID:24464163

A new titration system of a novel split-type superconducting magnet NMR spectrometer.

PubMed

Kitagawa, Isao; Tanaka, Hideki; Okada, Michiya; Kitaguchi, Hitoshi; Kohzuma, Takamitsu

2008-12-01

A new titration system for studying protein-ligand interactions has been developed. In this system, the sample solution is circulated in the route formed by an access path in a split superconducting magnet to maintain a constant protein concentration during the titration experiments. A concentration-control procedure for the ligand/protein ratio is devised, and the ligand/protein ratio is well controlled by this apparatus.

Optimal level of continuous positive airway pressure: auto-adjusting titration versus titration with a predictive equation.

PubMed

Choi, Ji Ho; Jun, Young Joon; Oh, Jeong In; Jung, Jong Yoon; Hwang, Gyu Ho; Kwon, Soon Young; Lee, Heung Man; Kim, Tae Hoon; Lee, Sang Hag; Lee, Seung Hoon

2013-05-01

The aims of the present study were twofold. We sought to compare two methods of titrating the level of continuous positive airway pressure (CPAP) - auto-adjusting titration and titration using a predictive equation - with full-night manual titration used as the benchmark. We also investigated the reliability of the two methods in patients with obstructive sleep apnea syndrome (OSAS). Twenty consecutive adult patients with OSAS who had successful, full-night manual and auto-adjusting CPAP titration participated in this study. The titration pressure level was calculated with a previously developed predictive equation based on body mass index and apnea-hypopnea index. The mean titration pressure levels obtained with the manual, auto-adjusting, and predictive equation methods were 9.0 +/- 3.6, 9.4 +/- 3.0, and 8.1 +/- 1.6 cm H2O,respectively. There was a significant difference in the concordance within the range of +/- 2 cm H2O (p = 0.019) between both the auto-adjusting titration and the titration using the predictive equation compared to the full-night manual titration. However, there was no significant difference in the concordance within the range of +/- 1 cm H2O (p > 0.999). When compared to full-night manual titration as the standard method, auto-adjusting titration appears to be more reliable than using a predictive equation for determining the optimal CPAP level in patients with OSAS.

Determination of Acidity Constants by Gradient Flow-Injection Titration

ERIC Educational Resources Information Center

Conceicao, Antonio C. L.; Minas da Piedade, Manuel E.

2006-01-01

A three-hour laboratory experiment, designed for an advanced undergraduate course in instrumental analysis that illustrates the application of the gradient chamber flow-injection titration (GCFIT) method with spectrophotometric detection to determine acidity constants is presented. The procedure involves the use of an acid-base indicator to obtain…

Going Beyond, Going Further: The Preparation of Acid-Base Titration Curves.

ERIC Educational Resources Information Center

McClendon, Michael

1984-01-01

Background information, list of materials needed, and procedures used are provided for a simple technique for generating mechanically plotted acid-base titration curves. The method is suitable for second-year high school chemistry students. (JN)

Potentiometric/turbidometric titration of antiperspirant actives.

PubMed

Johnston, Clifford T; Hem, Stanley L; Guenin, Eric; Mattai, Jairajh; Afflito, John

2003-01-01

A titration procedure that simultaneously monitors the pH and turbidity of an antiperspirant solution during neutralization with sodium hydroxide was developed to characterize antiperspirant actives. Aluminum chloride, aluminum chlorohydrate (ACH), and aluminum zirconium glycine complex (AZG) gave distinctive pH/turbidity profiles. The activated forms of aluminum chlorohydrate (ACH') and aluminum zirconium glycine complex (AZG') produced more turbidity than the non-activated forms. On an equimolar basis, AZG' produced more turbidity than any of the antiperspirant actives tested.

Photometric Characterization of the Dark Energy Camera

DOE PAGES

Bernstein, G. M.; Abbott, T. M. C.; Armstrong, R.; ...

2018-04-02

We characterize the variation in photometric response of the Dark Energy Camera (DECam) across its 520 Mpix science array during 4 years of operation. These variations are measured using high signal-to-noise aperture photometry of >10 7 stellar images in thousands of exposures of a few selected fields, with the telescope dithered to move the sources around the array. A calibration procedure based on these results brings the rms variation in aperture magnitudes of bright stars on cloudless nights down to 2–3 mmag, with <1 mmag of correlated photometric errors for stars separated by ≥20''. On cloudless nights, any departures ofmore » the exposure zeropoints from a secant airmass law exceeding 1 mmag are plausibly attributable to spatial/temporal variations in aperture corrections. These variations can be inferred and corrected by measuring the fraction of stellar light in an annulus between 6'' and 8'' diameter. Key elements of this calibration include: correction of amplifier nonlinearities; distinguishing pixel-area variations and stray light from quantum-efficiency variations in the flat fields; field-dependent color corrections; and the use of an aperture-correction proxy. The DECam response pattern across the 2° field drifts over months by up to ±9 mmag, in a nearly wavelength-independent low-order pattern. Here, we find no fundamental barriers to pushing global photometric calibrations toward mmag accuracy.« less

Photometric Characterization of the Dark Energy Camera

NASA Astrophysics Data System (ADS)

Bernstein, G. M.; Abbott, T. M. C.; Armstrong, R.; Burke, D. L.; Diehl, H. T.; Gruendl, R. A.; Johnson, M. D.; Li, T. S.; Rykoff, E. S.; Walker, A. R.; Wester, W.; Yanny, B.

2018-05-01

We characterize the variation in photometric response of the Dark Energy Camera (DECam) across its 520 Mpix science array during 4 years of operation. These variations are measured using high signal-to-noise aperture photometry of >107 stellar images in thousands of exposures of a few selected fields, with the telescope dithered to move the sources around the array. A calibration procedure based on these results brings the rms variation in aperture magnitudes of bright stars on cloudless nights down to 2–3 mmag, with <1 mmag of correlated photometric errors for stars separated by ≥20″. On cloudless nights, any departures of the exposure zeropoints from a secant airmass law exceeding 1 mmag are plausibly attributable to spatial/temporal variations in aperture corrections. These variations can be inferred and corrected by measuring the fraction of stellar light in an annulus between 6″ and 8″ diameter. Key elements of this calibration include: correction of amplifier nonlinearities; distinguishing pixel-area variations and stray light from quantum-efficiency variations in the flat fields; field-dependent color corrections; and the use of an aperture-correction proxy. The DECam response pattern across the 2° field drifts over months by up to ±9 mmag, in a nearly wavelength-independent low-order pattern. We find no fundamental barriers to pushing global photometric calibrations toward mmag accuracy.

Photometric Characterization of the Dark Energy Camera

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

Bernstein, G. M.; Abbott, T. M. C.; Armstrong, R.

We characterize the variation in photometric response of the Dark Energy Camera (DECam) across its 520 Mpix science array during 4 years of operation. These variations are measured using high signal-to-noise aperture photometry of >10 7 stellar images in thousands of exposures of a few selected fields, with the telescope dithered to move the sources around the array. A calibration procedure based on these results brings the rms variation in aperture magnitudes of bright stars on cloudless nights down to 2–3 mmag, with <1 mmag of correlated photometric errors for stars separated by ≥20''. On cloudless nights, any departures ofmore » the exposure zeropoints from a secant airmass law exceeding 1 mmag are plausibly attributable to spatial/temporal variations in aperture corrections. These variations can be inferred and corrected by measuring the fraction of stellar light in an annulus between 6'' and 8'' diameter. Key elements of this calibration include: correction of amplifier nonlinearities; distinguishing pixel-area variations and stray light from quantum-efficiency variations in the flat fields; field-dependent color corrections; and the use of an aperture-correction proxy. The DECam response pattern across the 2° field drifts over months by up to ±9 mmag, in a nearly wavelength-independent low-order pattern. Here, we find no fundamental barriers to pushing global photometric calibrations toward mmag accuracy.« less

Calibrating photometric redshifts of luminous red galaxies

DOE PAGES

Padmanabhan, Nikhil; Budavari, Tamas; Schlegel, David J.; ...

2005-05-01

We discuss the construction of a photometric redshift catalogue of luminous red galaxies (LRGs) from the Sloan Digital Sky Survey (SDSS), emphasizing the principal steps necessary for constructing such a catalogue: (i) photometrically selecting the sample, (ii) measuring photometric redshifts and their error distributions, and (iii) estimating the true redshift distribution. We compare two photometric redshift algorithms for these data and find that they give comparable results. Calibrating against the SDSS and SDSS–2dF (Two Degree Field) spectroscopic surveys, we find that the photometric redshift accuracy is σ~ 0.03 for redshifts less than 0.55 and worsens at higher redshift (~ 0.06more » for z < 0.7). These errors are caused by photometric scatter, as well as systematic errors in the templates, filter curves and photometric zero-points. We also parametrize the photometric redshift error distribution with a sum of Gaussians and use this model to deconvolve the errors from the measured photometric redshift distribution to estimate the true redshift distribution. We pay special attention to the stability of this deconvolution, regularizing the method with a prior on the smoothness of the true redshift distribution. The methods that we develop are applicable to general photometric redshift surveys.« less

NICOLAU: compact unit for photometric characterization of automotive lighting from near-field measurements

NASA Astrophysics Data System (ADS)

Royo, Santiago; Arranz, Maria J.; Arasa, Josep; Cattoen, Michel; Bosch, Thierry

2005-02-01

The present works depicts a measurement technique intended to enhance the characterization procedures of the photometric emissions of automotive headlamps, with potential applications to any light source emission, either automotive or non-automotive. A CCD array with a precisely characterized optical system is used for sampling the luminance field of the headlamp just a few centimetres in front of it, by combining deflectometric techniques (yielding the direction of the light beams) and photometric techniques (yielding the energy travelling in each direction). The CCD array scans the measurement plane using a self-developed mechanical unit and electronics, and then image-processing techniques are used for obtaining the photometric behaviour of the headlamp in any given plane, in particular in the plane and positions required by current normative, but also on the road, on traffic signs, etc. An overview of the construction of the system, of the considered principle of measurement, and of the main calibrations performed on the unit is presented. First results concerning relative measurements are presented compared both to reference data from a photometric tunnel and from a plane placed 5m away from the source. Preliminary results for the absolute photometric calibration of the system are also presented for different illumination beams of different headlamps (driving and passing beam).

Titration Curves: Fact and Fiction.

ERIC Educational Resources Information Center

Chamberlain, John

1997-01-01

Discusses ways in which datalogging equipment can enable titration curves to be measured accurately and how computing power can be used to predict the shape of curves. Highlights include sources of error, use of spreadsheets to generate titration curves, titration of a weak acid with a strong alkali, dibasic acids, weak acid and weak base, and…

Novel approaches to analysis by flow injection gradient titration.

PubMed

Wójtowicz, Marzena; Kozak, Joanna; Kościelniak, Paweł

2007-09-26

Two novel procedures for flow injection gradient titration with the use of a single stock standard solution are proposed. In the multi-point single-line (MP-SL) method the calibration graph is constructed on the basis of a set of standard solutions, which are generated in a standard reservoir and subsequently injected into the titrant. According to the single-point multi-line (SP-ML) procedure the standard solution and a sample are injected into the titrant stream from four loops of different capacities, hence four calibration graphs are able to be constructed and the analytical result is calculated on the basis of a generalized slope of these graphs. Both approaches have been tested on the example of spectrophotometric acid-base titration of hydrochloric and acetic acids with using bromothymol blue and phenolphthalein as indicators, respectively, and sodium hydroxide as a titrant. Under optimized experimental conditions the analytical results of precision less than 1.8 and 2.5% (RSD) and of accuracy less than 3.0 and 5.4% (relative error (RE)) were obtained for MP-SL and SP-ML procedures, respectively, in ranges of 0.0031-0.0631 mol L(-1) for samples of hydrochloric acid and of 0.1680-1.7600 mol L(-1) for samples of acetic acid. The feasibility of both methods was illustrated by applying them to the total acidity determination in vinegar samples with precision lower than 0.5 and 2.9% (RSD) for MP-SL and SP-ML procedures, respectively.

Ionization behavior of polyphosphoinositides determined via the preparation of pH titration curves using solid-state 31P NMR.

PubMed

Graber, Zachary T; Kooijman, Edgar E

2013-01-01

Detailed knowledge of the degree of ionization of lipid titratable groups is important for the evaluation of protein-lipid and lipid-lipid interactions. The degree of ionization is commonly evaluated by acid-base titration, but for lipids localized in a multicomponent membrane interface this is not a suitable technique. For phosphomonoester-containing lipids such as the polyphosphoinositides, phosphatidic acid, and ceramide-1-phosphate, this is more conveniently accomplished by (31)P NMR. Here, we describe a solid-state (31)P NMR procedure to construct pH titration curves to determine the degree of ionization of phosphomonoester groups in polyphosphoinositides. This procedure can also be used, with suitable sample preparation conditions, for other important signaling lipids. Access to a solid-state, i.e., magic angle spinning, capable NMR spectrometer is assumed. The procedures described here are valid for a Bruker instrument, but can be adapted for other spectrometers as needed.

Development and validation of a simplified titration method for monitoring volatile fatty acids in anaerobic digestion.

PubMed

Sun, Hao; Guo, Jianbin; Wu, Shubiao; Liu, Fang; Dong, Renjie

2017-09-01

The volatile fatty acids (VFAs) concentration has been considered as one of the most sensitive process performance indicators in anaerobic digestion (AD) process. However, the accurate determination of VFAs concentration in AD processes normally requires advanced equipment and complex pretreatment procedures. A simplified method with fewer sample pretreatment procedures and improved accuracy is greatly needed, particularly for on-site application. This report outlines improvements to the Nordmann method, one of the most popular titrations used for VFA monitoring. The influence of ion and solid interfering subsystems in titrated samples on results accuracy was discussed. The total solid content in titrated samples was the main factor affecting accuracy in VFA monitoring. Moreover, a high linear correlation was established between the total solids contents and VFA measurement differences between the traditional Nordmann equation and gas chromatography (GC). Accordingly, a simplified titration method was developed and validated using a semi-continuous experiment of chicken manure anaerobic digestion with various organic loading rates. The good fitting of the results obtained by this method in comparison with GC results strongly supported the potential application of this method to VFA monitoring. Copyright © 2017. Published by Elsevier Ltd.

Photometric Flux in EXONEST

NASA Astrophysics Data System (ADS)

Young, Steven K.

As a planet orbits its parent star, the amount of light that reaches Earth from that system is dependent on the dynamics of that star system. Known as photometric variations, these slight changes in light flux are detectable by the Kepler Space Telescope and must be fully understood in order to properly model the system. There are four main factors that contribute to the photometric flux: reflected light from the planet, thermal emissions from the planet, doppler boosting in the light being emitted by the star, and ellipsoidal variations in the star. The total observed flux from each contribution then determines how much light will be seen from the star system to be used for analysis. Previous studies have normalized the photometric variation fluxes by the observed flux emitted from the star. However, normalizing data inherently and unphysically skews the result which must then be taken into account. Additionally, when the stellar flux is an unknown it is impossible to normalize the photometric variation fluxes with respect to it. This paper will preliminarily attempt to improve upon the existing studies by removing the source of the deviation for the flux results, i.e. the stellar flux. The fluxes found from each photometric variation factor will then be incorporated into EXONEST, an algorithm using Bayesian inference, that will be implemented for characterizing extrasolar systems.

The many flavours of photometric redshifts

NASA Astrophysics Data System (ADS)

Salvato, Mara; Ilbert, Olivier; Hoyle, Ben

2018-06-01

Since more than 70 years ago, the colours of galaxies derived from flux measurements at different wavelengths have been used to estimate their cosmological distances. Such distance measurements, called photometric redshifts, are necessary for many scientific projects, ranging from investigations of the formation and evolution of galaxies and active galactic nuclei to precision cosmology. The primary benefit of photometric redshifts is that distance estimates can be obtained relatively cheaply for all sources detected in photometric images. The drawback is that these cheap estimates have low precision compared with resource-expensive spectroscopic ones. The methodology for estimating redshifts has been through several revolutions in recent decades, triggered by increasingly stringent requirements on the photometric redshift accuracy. Here, we review the various techniques for obtaining photometric redshifts, from template-fitting to machine learning and hybrid schemes. We also describe state-of-the-art results on current extragalactic samples and explain how survey strategy choices affect redshift accuracy. We close with a description of the photometric redshift efforts planned for upcoming wide-field surveys, which will collect data on billions of galaxies, aiming to investigate, among other matters, the stellar mass assembly and the nature of dark energy.

CALiPER Report 23: Photometric Testing of White Tunable LED Luminaires

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

None, None

2016-01-01

This report documents an initial investigation of photometric testing procedures for white-tunable LED luminaires and summarizes the key features of those products. Goals of the study include understanding the amount of testing required to characterize a white-tunable product, and documenting the performance of available color-tunable luminaires that are intended for architectural lighting.

Determining a Solubility Product Constant by Potentiometric Titration to Increase Students' Conceptual Understanding of Potentiometry and Titrations

ERIC Educational Resources Information Center

Grabowski, Lauren E.; Goode, Scott R.

2017-01-01

Potentiometric titrations are widely taught in first-year undergraduate courses to connect electrochemistry, stoichiometry, and equilibria and to reinforce acid-base titrations. Students perform a potentiometric titration that is then analyzed to determine analyte concentrations and the solubility product constant of the solid species.

GKI chloride in water, analysis method. GKI boron in water, analysis method

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

Morriss, L.L.

1979-05-01

Procedures for the chemical analysis of chlorides and boron in water are presented. Chlorides can be titrated with mercuric nitrate to form mercuric chloride. At pH 2.3 to 2.8, diphenylcarbazone indicates the end point of this titration by formation of a purple complex with mercury ions. When a sample of water containing boron is acidified and evaporated in the presence of curcumin, a red colored product called rosocyanine is formed. This is dissolved and can be measured photometrically or visually. (DMC)

Titration Calorimetry Standards and the Precision of Isothermal Titration Calorimetry Data

PubMed Central

Baranauskienė, Lina; Petrikaitė, Vilma; Matulienė, Jurgita; Matulis, Daumantas

2009-01-01

Current Isothermal Titration Calorimetry (ITC) data in the literature have relatively high errors in the measured enthalpies of protein-ligand binding reactions. There is a need for universal validation standards for titration calorimeters. Several inorganic salt co-precipitation and buffer protonation reactions have been suggested as possible enthalpy standards. The performances of several commercial calorimeters, including the VP-ITC, ITC200, and Nano ITC-III, were validated using these suggested standard reactions. PMID:19582227

Robust photometric invariant features from the color tensor.

PubMed

van de Weijer, Joost; Gevers, Theo; Smeulders, Arnold W M

2006-01-01

Luminance-based features are widely used as low-level input for computer vision applications, even when color data is available. The extension of feature detection to the color domain prevents information loss due to isoluminance and allows us to exploit the photometric information. To fully exploit the extra information in the color data, the vector nature of color data has to be taken into account and a sound framework is needed to combine feature and photometric invariance theory. In this paper, we focus on the structure tensor, or color tensor, which adequately handles the vector nature of color images. Further, we combine the features based on the color tensor with photometric invariant derivatives to arrive at photometric invariant features. We circumvent the drawback of unstable photometric invariants by deriving an uncertainty measure to accompany the photometric invariant derivatives. The uncertainty is incorporated in the color tensor, hereby allowing the computation of robust photometric invariant features. The combination of the photometric invariance theory and tensor-based features allows for detection of a variety of features such as photometric invariant edges, corners, optical flow, and curvature. The proposed features are tested for noise characteristics and robustness to photometric changes. Experiments show that the proposed features are robust to scene incidental events and that the proposed uncertainty measure improves the applicability of full invariants.

Improving medication titration in heart failure by embedding a structured medication titration plan.

PubMed

Hickey, Annabel; Suna, Jessica; Marquart, Louise; Denaro, Charles; Javorsky, George; Munns, Andrew; Mudge, Alison; Atherton, John J

2016-12-01

To improve up-titration of medications to target dose in heart failure patients by improving communication from hospital to primary care. This quality improvement project was undertaken within three heart failure disease management (HFDM) services in Queensland, Australia. A structured medication plan was collaboratively designed and implemented in an iterative manner, using methods including awareness raising and education, audit and feedback, integration into existing work practice, and incentive payments. Evaluation was undertaken using sequential audits, and included process measures (use of the titration plan, assignment of responsibility) and outcome measures (proportion of patients achieving target dose) in HFDM service patients with reduced left ventricular ejection fraction. Comparison of the three patient cohorts (pre-intervention cohort A n=96, intervention cohort B n=95, intervention cohort C n=89) showed increase use of the titration plan, a shift to greater primary care responsibility for titration, and an increase in the proportion of patients achieving target doses of angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) (A 37% vs B 48% vs C 55%, p=0.051) and beta-blockers (A 38% vs B 33% vs C 51%, p=0.045). Combining all three cohorts, patients not on target doses when discharged from hospital were more likely to achieve target doses of ACEI/ARB (p<0.0001) and beta blockers (p<0.0001) within six months if they received a medication titration plan. A medication titration plan was successfully implemented in three HFDM services and improved transitional communication and achievement of target doses of evidence-based therapies within six months of hospital discharge. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

A photometric study of the Orion OB 1 association. 2: Photometric analysis

NASA Technical Reports Server (NTRS)

Warren, W. H., Jr.; Hesser, J. E.

1976-01-01

The procedures adopted for analysis of photometric data in terms of color excesses, intrinsic color indexes, absolute visual magnitudes, and rotational-velocity effects are discussed in detail for Orion association B-, intermediate (I)-, and AF-type stars. The effects of the nebular environment and a comparison of various calibrations of Balmer-line and four-color indexes are considered for the determination of individual absolute magnitudes for B-type stars. When absolute magnitudes of stars in the region of the Orion Nebula are determined from the beta index, emission mechanisms appear to spuriously brighten them. A detailed comparison of absolute magnitudes derived from Balmer-line indexes and MK spectral-type calibrations is presented. The data are also examined with regard to the effects of polarization and infrared excesses. The results suggest a complex combination of intracluster and circumstellar origins for these processes.

A Sensitive Photometric Procedure for Cobalt Determination in Water Employing a Compact Multicommuted Flow Analysis System.

PubMed

da Silva Magalhães, Ticiane; Reis, Boaventura F

2017-09-01

In this work, a multicommuted flow analysis procedure is proposed for the spectrophotometric determination of cobalt in fresh water, employing an instrument setup of downsized dimension and improved cost-effectiveness. The method is based on the catalytic effect of Co(II) on the Tiron oxidation by hydrogen peroxide in alkaline medium, forming a complex that absorbs radiation at 425 nm. The photometric detection was accomplished using a homemade light-emitting-diode (LED)-based photometer designed to use a flow cell with an optical path-length of 100 mm to improve sensitivity. After selecting adequate values for the flow system variables, adherence to the Beer-Lambert-Bouguer law was observed for standard solution concentrations in the range of 0.13-1.5 µg L -1 Co(II). Other useful features including a relative standard deviation of 2.0% (n = 11) for a sample with 0.49 µg L -1 Co(II), a detection limit of 0.06 µg L -1 Co(II) (n = 20), an analytical frequency of 42 sample determinations per hour, and waste generation of 1.5 mL per determination were achieved.

Risks and Benefits of Rapid Clozapine Titration.

PubMed

Lochhead, Jeannie D; Nelson, Michele A; Schneider, Alan L

2016-05-18

Clozapine is often considered the gold standard for the treatment of schizophrenia. Clinical guidelines suggest a gradual titration over 2 weeks to reduce the risks of adverse events such as seizures, hypotension, agranulocytosis, and myocarditis. The slow titration often delays time to therapeutic response. This raises the question of whether, in some patients, it may be safe to use a more rapid clozapine titration. The following case illustrates the potential risks associated with the use of multiple antipsychotics and rapid clozapine titration. We present the case of a young man with schizophrenia who developed life threatening neuroleptic malignant syndrome (NMS) during rapid clozapine titration and treatment with multiple antipsychotics. We were unable to find another case in the literature of NMS associated with rapid clozapine titration. This case is meant to urge clinicians to carefully evaluate the risks and benefits of rapid clozapine titration, and to encourage researchers to further evaluate the safety of rapid clozapine titration. Rapid clozapine titration has implications for decreasing health care costs associated with prolonged hospitalizations, and decreasing the emotional suffering associated with uncontrolled symptoms of psychosis. Clozapine is considered the most effective antipsychotic available thus efforts should focus on developing strategies that would allow for safest and most efficient use of clozapine to encourage its utilization for treatment resistance schizophrenia.

Supernova Cosmology Inference with Probabilistic Photometric Redshifts (SCIPPR)

NASA Astrophysics Data System (ADS)

Peters, Christina; Malz, Alex; Hlozek, Renée

2018-01-01

The Bayesian Estimation Applied to Multiple Species (BEAMS) framework employs probabilistic supernova type classifications to do photometric SN cosmology. This work extends BEAMS to replace high-confidence spectroscopic redshifts with photometric redshift probability density functions, a capability that will be essential in the era the Large Synoptic Survey Telescope and other next-generation photometric surveys where it will not be possible to perform spectroscopic follow up on every SN. We present the Supernova Cosmology Inference with Probabilistic Photometric Redshifts (SCIPPR) Bayesian hierarchical model for constraining the cosmological parameters from photometric lightcurves and host galaxy photometry, which includes selection effects and is extensible to uncertainty in the redshift-dependent supernova type proportions. We create a pair of realistic mock catalogs of joint posteriors over supernova type, redshift, and distance modulus informed by photometric supernova lightcurves and over redshift from simulated host galaxy photometry. We perform inference under our model to obtain a joint posterior probability distribution over the cosmological parameters and compare our results with other methods, namely: a spectroscopic subset, a subset of high probability photometrically classified supernovae, and reducing the photometric redshift probability to a single measurement and error bar.

Potentiometric titration of metal ions in ethanol.

PubMed

Gibson, Graham T T; Mohamed, Mark F; Neverov, Alexei A; Brown, R S

2006-09-18

The potentiometric titrations of Zn2+, Cu2+ and 12 Ln3+ metal ions were obtained in ethanol to determine the titration constants (defined as the at which the [-OEt]/[Mx+]t ratios are 0.5, 1.5, and 2.5) and in two cases (La3+ and Zn2+) a complete speciation diagram. Several simple monobasic acids and aminium ions were also titrated to test the validity of experimental titration measurements and to establish new constants in this medium that will be useful for the preparation of buffers and standard solutions. The dependence of the titration constants on the concentration and type of metal ion and specific counterion effects is discussed. In selected cases, the titration profiles were analyzed using a commercially available fitting program to obtain information about the species present in solution, including La3+ for which a dimer model is proposed. The fitting provides the microscopic values for deprotonation of one to four metal-bound ethanol molecules. Kinetics for the La3+-catalyzed ethanolysis of paraoxon as a function of are presented and analyzed in terms of La3+ speciation as determined by the analysis of potentiometric titration curves. The stability constants for the formation of Zn2+ and Cu2+ complexes with 1,5,9-triazacyclododecane as determined by potentiometric titration are presented.

A new approach to flow-batch titration. A monosegmented flow titrator with coulometric reagent generation and potentiometric or biamperometric detection.

PubMed

de Aquino, Emerson Vidal; Rohwedder, Jarbas José Rodrigues; Pasquini, Celio

2006-11-01

Monosegmented flow analysis (MSFA) has been used as a flow-batch system to produce a simple, robust, and mechanized titrator that enables true titrations to be performed without the use of standards. This paper also introduces the use of coulometry with monosegmented titration by proposing a versatile flow cell. Coulometric generation of the titrand is attractive for titrations performed in monosegmented systems, because the reagent can be added without increasing the volume of sample injected. Also, biamperomeric and potentiometric detection of titration end-points can increase the versatility of the monosegmented titrator. The cell integrates coulometric generation of the titrand with detection of end-point by potentiometry or biamperometry. The resulting titrator is a flow-batch system in which the liquid monosegment, constrained by the interfaces of the gaseous carrier stream, plays the role of a sample of known volume to be titrated. The system has been used for determination of ascorbic acid, by coulometric generation of I2 with biamperometric detection, and for determination of Fe(II), by coulometric generation of Ce(IV) with potentiometric detection of the end-point, both in feed supplements.

UVIS Photometric Zero Points

NASA Astrophysics Data System (ADS)

Kalirai, Jason

2009-07-01

This proposal obtains the photometric zero points in 53 of the 62 UVIS/WFC3 filters: the 18 broad-band filters, 8 medium-band filters, 16 narrow-band filters, and 11 of the 20 quad filters {those being used in cycle 17}. The observations will be primary obtained by observing the hot DA white dwarf standards GD153 and G191-B2B. A redder secondary standard, P330E, will be observed in a subset of the filters to provide color corrections. Repeat observations in 16 of the most widely used cycle 17 filters will be obtained once per month for the first three months, and then once every second month for the duration of cycle 17, alternating and depending on target availability. These observations will enable monitoring of the stability of the photometric system. Photometric transformation equations will be calculated by comparing the photometry of stars in two globular clusters, 47 Tuc and NGC 2419, to previous measurements with other telescopes/instruments.

Developing a multipoint titration method with a variable dose implementation for anaerobic digestion monitoring.

PubMed

Salonen, K; Leisola, M; Eerikäinen, T

2009-01-01

Determination of metabolites from an anaerobic digester with an acid base titration is considered as superior method for many reasons. This paper describes a practical at line compatible multipoint titration method. The titration procedure was improved by speed and data quality. A simple and novel control algorithm for estimating a variable titrant dose was derived for this purpose. This non-linear PI-controller like algorithm does not require any preliminary information from sample. Performance of this controller is superior compared to traditional linear PI-controllers. In addition, simplification for presenting polyprotic acids as a sum of multiple monoprotic acids is introduced along with a mathematical error examination. A method for inclusion of the ionic strength effect with stepwise iteration is shown. The titration model is presented with matrix notations enabling simple computation of all concentration estimates. All methods and algorithms are illustrated in the experimental part. A linear correlation better than 0.999 was obtained for both acetate and phosphate used as model compounds with slopes of 0.98 and 1.00 and average standard deviations of 0.6% and 0.8%, respectively. Furthermore, insensitivity of the presented method for overlapping buffer capacity curves was shown.

Photometric theory for wide-angle phenomena

NASA Technical Reports Server (NTRS)

Usher, Peter D.

1990-01-01

An examination is made of the problem posed by wide-angle photographic photometry, in order to extract a photometric-morphological history of Comet P/Halley. Photometric solutions are presently achieved over wide angles through a generalization of an assumption-free moment-sum method. Standard stars in the field allow a complete solution to be obtained for extinction, sky brightness, and the characteristic curve. After formulating Newton's method for the solution of the general nonlinear least-square problem, an implementation is undertaken for a canonical data set. Attention is given to the problem of random and systematic photometric errors.

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

Code of Federal Regulations, 2011 CFR

2011-07-01

... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with a...

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

Code of Federal Regulations, 2010 CFR

2010-07-01

... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with a...

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

Code of Federal Regulations, 2012 CFR

2012-07-01

... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment... procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas Engineers Handbook, Fuel.... In principle, this method consists of titrating hydrogen sulfide in a gas sample directly with a...

Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

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

Taylor-Pashow, Kathryn M. L.; Jones, Daniel H.

A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration wasmore » determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.« less

Multiview photometric stereo.

PubMed

Hernández Esteban, Carlos; Vogiatzis, George; Cipolla, Roberto

2008-03-01

This paper addresses the problem of obtaining complete, detailed reconstructions of textureless shiny objects. We present an algorithm which uses silhouettes of the object, as well as images obtained under changing illumination conditions. In contrast with previous photometric stereo techniques, ours is not limited to a single viewpoint but produces accurate reconstructions in full 3D. A number of images of the object are obtained from multiple viewpoints, under varying lighting conditions. Starting from the silhouettes, the algorithm recovers camera motion and constructs the object's visual hull. This is then used to recover the illumination and initialise a multi-view photometric stereo scheme to obtain a closed surface reconstruction. There are two main contributions in this paper: Firstly we describe a robust technique to estimate light directions and intensities and secondly, we introduce a novel formulation of photometric stereo which combines multiple viewpoints and hence allows closed surface reconstructions. The algorithm has been implemented as a practical model acquisition system. Here, a quantitative evaluation of the algorithm on synthetic data is presented together with complete reconstructions of challenging real objects. Finally, we show experimentally how even in the case of highly textured objects, this technique can greatly improve on correspondence-based multi-view stereo results.

An Environmental Friendly Procedure for Photometric Determination of Hypochlorite in Tap Water Employing a Miniaturized Multicommuted Flow Analysis Setup

PubMed Central

Borges, Sivanildo S.; Reis, Boaventura F.

2011-01-01

A photometric procedure for the determination of ClO− in tap water employing a miniaturized multicommuted flow analysis setup and an LED-based photometer is described. The analytical procedure was implemented using leucocrystal violet (LCV; 4,4′,4′′-methylidynetris (N,N-dimethylaniline), C25H31N3) as a chromogenic reagent. Solenoid micropumps employed for solutions propelling were assembled together with the photometer in order to compose a compact unit of small dimensions. After control variables optimization, the system was applied for the determination of ClO− in samples of tap water, and aiming accuracy assessment samples were also analyzed using an independent method. Applying the paired t-test between results obtained using both methods, no significant difference at the 95% confidence level was observed. Other useful features include low reagent consumption, 2.4 μg of LCV per determination, a linear response ranging from 0.02 up to 2.0 mg L−1  ClO−, a relative standard deviation of 1.0% (n = 11) for samples containing 0.2 mg L−1  ClO−, a detection limit of 6.0 μg L−1  ClO−, a sampling throughput of 84 determinations per hour, and a waste generation of 432 μL per determination. PMID:21747732

Photo-z-SQL: Photometric redshift estimation framework

NASA Astrophysics Data System (ADS)

Beck, Róbert; Dobos, László; Budavári, Tamás; Szalay, Alexander S.; Csabai, István

2017-04-01

Photo-z-SQL is a flexible template-based photometric redshift estimation framework that can be seamlessly integrated into a SQL database (or DB) server and executed on demand in SQL. The DB integration eliminates the need to move large photometric datasets outside a database for redshift estimation, and uses the computational capabilities of DB hardware. Photo-z-SQL performs both maximum likelihood and Bayesian estimation and handles inputs of variable photometric filter sets and corresponding broad-band magnitudes.

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

Code of Federal Regulations, 2013 CFR

2013-07-01

... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment..., 2011 § 60.648 Optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a gas...

40 CFR 60.648 - Optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure. 1

Code of Federal Regulations, 2014 CFR

2014-07-01

... hydrogen sulfide in acid gas-Tutwiler Procedure. 1 60.648 Section 60.648 Protection of Environment..., 2011 § 60.648 Optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure. 1 1 Gas... dilute solutions are used. In principle, this method consists of titrating hydrogen sulfide in a gas...

Photometric requirements for portable changeable message signs.

DOT National Transportation Integrated Search

2001-09-01

This project reviewed the performance of pchangeable message signs (PCMSs) and developed photometric standards to establish performance requirements. In addition, researchers developed photometric test methods and recommended them for use in evaluati...

Photometric diversity of terrains on Triton

NASA Technical Reports Server (NTRS)

Hillier, J.; Veverka, J.; Helfenstein, P.; Lee, P.

1994-01-01

Voyager disk-resolved images of Triton in the violet (0.41 micrometers) and green (0.56 micrometer wavelengths have been analyzed to derive the photometric characteristics of terrains on Triton. Similar conclusions are found using two distinct but related definitions of photometric units, one based on color ratio and albedo properties (A. S. McEwen, 1990), the other on albedo and brightness ratios at different phase angles (P. Lee et al., 1992). A significant diversity of photometric behavior, much broader than that discovered so far on any other icy satellite, occurs among Triton's terrains. Remarkably, differences in photometric behavior do not correlate well with geologic terrain boundaries defined on the basis of surface morphology. This suggests that in most cases photometric properties on Triton are controlled by thin deposits superposed on underlying geologic units. Single scattering albedos are 0.98 or higher and asymmetry factors range from -0.35 to -0.45 for most units. The most distinct scattering behavior is exhibited by the reddish northern units already identified as the Anomalously Scattering Region (ASR), which scatters light almost isotropically with g = -0.04. In part due to the effects of Triton's clouds and haze, it is difficult to constrain the value of bar-theta, Hapke's macroscopic roughness parameter, precisely for Triton or to map differences in bar-theta among the different photometric terrains. However, our study shows that Triton must be relatively smooth, with bar-theta less than 15-20 degs and suggests that a value of 14 degs is appropriate. The differences in photometric characteristics lead to significantly different phase angle behavior for the various terrains. For example, a terrain (e.g., the ASR) that appears dark relative to another at low phase angles will reverse its contrast (become relatively brighter) at larger phase angles. The photometric parameters have been used to calculate hemispherical albedos for the units and to

PHOTOMETRIC REDSHIFTS OF SUBMILLIMETER GALAXIES

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

Chakrabarti, Sukanya; Magnelli, Benjamin; Lutz, Dieter

2013-08-20

We use the photometric redshift method of Chakrabarti and McKee to infer photometric redshifts of submillimeter galaxies with far-IR (FIR) Herschel data obtained as part of the PACS Evolutionary Probe program. For the sample with spectroscopic redshifts, we demonstrate the validity of this method over a large range of redshifts (4 {approx}> z {approx}> 0.3) and luminosities, finding an average accuracy in (1 + z{sub phot})/(1 + z{sub spec}) of 10%. Thus, this method is more accurate than other FIR photometric redshift methods. This method is different from typical FIR photometric methods in deriving redshifts from the light-to-gas mass (L/M)more » ratio of infrared-bright galaxies inferred from the FIR spectral energy distribution, rather than dust temperatures. To assess the dependence of our photometric redshift method on the data in this sample, we contrast the average accuracy of our method when we use PACS data, versus SPIRE data, versus both PACS and SPIRE data. We also discuss potential selection effects that may affect the Herschel sample. Once the redshift is derived, we can determine physical properties of infrared-bright galaxies, including the temperature variation within the dust envelope, luminosity, mass, and surface density. We use data from the GOODS-S field to calculate the star formation rate density (SFRD) of submillimeter bright sources detected by AzTEC and PACS. The AzTEC-PACS sources, which have a threshold 850 {mu}m flux {approx}> 5 mJy, contribute 15% of the SFRD from all ultraluminous infrared galaxies (L{sub IR} {approx}> 10{sup 12} L{sub Sun }), and 3% of the total SFRD at z {approx} 2.« less

Astronomical Research Institute Photometric Results

NASA Astrophysics Data System (ADS)

Linder, Tyler R.; Sampson, Ryan; Holmes, Robert

2013-01-01

The Astronomical Research Institute (ARI) conducts astrometric and photometric studies of asteroids with a concentration on near-Earth objects (NEOs). A 0.76-m autoscope was used for photometric studies of seven asteroids of which two were main-belt targets and five were NEOs, including one potentially hazardous asteroid (PHA). These objects are: 3122 Florence, 3960 Chaliubieju, 5143 Heracles, (6455) 1992 HE, (36284) 2000 DM8, (62128) 2000 SO1, and 2010 LF86.

Photometric Lunar Surface Reconstruction

NASA Technical Reports Server (NTRS)

Nefian, Ara V.; Alexandrov, Oleg; Morattlo, Zachary; Kim, Taemin; Beyer, Ross A.

2013-01-01

Accurate photometric reconstruction of the Lunar surface is important in the context of upcoming NASA robotic missions to the Moon and in giving a more accurate understanding of the Lunar soil composition. This paper describes a novel approach for joint estimation of Lunar albedo, camera exposure time, and photometric parameters that utilizes an accurate Lunar-Lambertian reflectance model and previously derived Lunar topography of the area visualized during the Apollo missions. The method introduced here is used in creating the largest Lunar albedo map (16% of the Lunar surface) at the resolution of 10 meters/pixel.

SCAMP: Automatic Astrometric and Photometric Calibration

NASA Astrophysics Data System (ADS)

Bertin, Emmanuel

2010-10-01

Astrometric and photometric calibrations have remained the most tiresome step in the reduction of large imaging surveys. SCAMP has been written to address this problem. The program efficiently computes accurate astrometric and photometric solutions for any arbitrary sequence of FITS images in a completely automatic way. SCAMP is released under the GNU General Public License.

Titration of individual strains in trivalent live-attenuated influenza vaccine without neutralization.

PubMed

Sirinonthanawech, Naraporn; Surichan, Somchaiya; Namsai, Aphinya; Puthavathana, Pilaipan; Auewarakul, Prasert; Kongchanagul, Alita

2016-11-01

Formulation and quality control of trivalent live-attenuated influenza vaccine requires titration of infectivity of individual strains in the trivalent mix. This is usually performed by selective neutralization of two of the three strains and titration of the un-neutralized strain in cell culture or embryonated eggs. This procedure requires standard sera with high neutralizing titer against each of the three strains. Obtaining standard sera, which can specifically neutralize only the corresponding strain of influenza viruses and is able to completely neutralize high concentration of virus in the vaccine samples, can be a problem for many vaccine manufacturers as vaccine stocks usually have very high viral titers and complete neutralization may not be obtained. Here an alternative approach for titration of individual strain in trivalent vaccine without the selective neutralization is presented. This was done by detecting individual strains with specific antibodies in an end-point titration of a trivalent vaccine in cell culture. Similar titers were observed in monovalent and trivalent vaccines for influenza A H3N2 and influenza B strains, whereas the influenza A H1N1 strain did not grow well in cell culture. Viral interference among the vaccine strains was not observed. Therefore, providing that vaccine strains grow well in cell culture, this assay can reliably determine the potency of individual strains in trivalent live-attenuated influenza vaccines. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

Code of Federal Regulations, 2013 CFR

2013-07-01

... measuring hydrogen sulfide in acid gas-Tutwiler Procedure? 60.5408 Section 60.5408 Protection of Environment... § 60.5408 What is an optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine. (b...

40 CFR 60.5408 - What is an optional procedure for measuring hydrogen sulfide in acid gas-Tutwiler Procedure?

Code of Federal Regulations, 2014 CFR

2014-07-01

... measuring hydrogen sulfide in acid gas-Tutwiler Procedure? 60.5408 Section 60.5408 Protection of Environment... § 60.5408 What is an optional procedure for measuring hydrogen sulfide in acid gas—Tutwiler Procedure... of titrating hydrogen sulfide in a gas sample directly with a standard solution of iodine. (b...

Symmetry Properties of Potentiometric Titration Curves.

ERIC Educational Resources Information Center

Macca, Carlo; Bombi, G. Giorgio

1983-01-01

Demonstrates how the symmetry properties of titration curves can be efficiently and rigorously treated by means of a simple method, assisted by the use of logarithmic diagrams. Discusses the symmetry properties of several typical titration curves, comparing the graphical approach and an explicit mathematical treatment. (Author/JM)

A Tabular Approach to Titration Calculations

ERIC Educational Resources Information Center

Lim, Kieran F.

2012-01-01

Titrations are common laboratory exercises in high school and university chemistry courses, because they are easy, relatively inexpensive, and they illustrate a number of fundamental chemical principles. While students have little difficulty with calculations involving a single titration step, there is a significant leap in conceptual difficulty…

Rapid Clozapine Titration in Patients with Treatment Refractory Schizophrenia.

PubMed

Poyraz, Cana Aksoy; Özdemir, Armağan; Sağlam, Nazife Gamze Usta; Turan, Şenol; Poyraz, Burç Çağrı; Tomruk, Nesrin; Duran, Alaattin

2016-06-01

The aim of this study is to evaluate the safety and effectiveness of rapid clozapine titration in patients with schizophrenia in hospital settings. We conducted a retrospective two-center cohort study to compare the safety and effectiveness of clozapine with different titration rates in treatment-refractory patients with schizophrenia. In the first center, clozapine was started at 25-50 mg followed by 50-100 mg as needed every 6 h on day 1, followed by increases of 50-100 mg/day. In the second center, titration was slower; clozapine initiated with 12.5-50 mg on day 1 followed by increases of 25-50 mg/day. The number of days between starting of clozapine until discharge was shorter in the rapid titration group (22.4 ± 8.72 vs 27.0 ± 10.5, p = 0.1). Number of days of total hospital stay were significantly shorter in the rapid titration group (29.6 ± 10.6 vs 41.2 ± 14.8, p = 0.002). Hypotension was more common in the rapid titration group and one patient had suspected myocarditis. Rapid clozapine titration appeared safe and effective. The length of stay following initiation of clozapine was shorter in the rapid-titration group, although this was not statistically significant. However starting clozapine earlier together with rapid titration has significantly shortened the length of hospital stay in patients with treatment refractory schizophrenia.

Photometric Uncertainties

NASA Astrophysics Data System (ADS)

Zou, Xiao-Duan; Li, Jian-Yang; Clark, Beth Ellen; Golish, Dathon

2018-01-01

The OSIRIS-REx spacecraft, launched in September, 2016, will study the asteroid Bennu and return a sample from its surface to Earth in 2023. Bennu is a near-Earth carbonaceous asteroid which will provide insight into the formation and evolution of the solar system. OSIRIS-REx will first approach Bennu in August 2018 and will study the asteroid for approximately two years before sampling. OSIRIS-REx will develop its photometric model (including Lommel-Seelinger, ROLO, McEwen, Minnaert and Akimov) of Bennu with OCAM and OVIRS during the Detailed Survey mission phase. The model developed during this phase will be used to photometrically correct the OCAM and OVIRS data.Here we present the analysis of the error for the photometric corrections. Based on our testing data sets, we find:1. The model uncertainties is only correct when we use the covariance matrix to calculate, because the parameters are highly correlated.2. No evidence of domination of any parameter in each model.3. And both model error and the data error contribute to the final correction error comparably.4. We tested the uncertainty module on fake and real data sets, and find that model performance depends on the data coverage and data quality. These tests gave us a better understanding of how different model behave in different case.5. L-S model is more reliable than others. Maybe because the simulated data are based on L-S model. However, the test on real data (SPDIF) does show slight advantage of L-S, too. ROLO is not reliable to use when calculating bond albedo. The uncertainty of McEwen model is big in most cases. Akimov performs unphysical on SOPIE 1 data.6. Better use L-S as our default choice, this conclusion is based mainly on our test on SOPIE data and IPDIF.

Determination of nitrites in water by in-electrode coulometric titration in reticulated vitreous carbon electrode.

PubMed

Lenghartova, Katarina; Lauko, Lukas; Cachob, Frantisek; Beinrohr, Ernest

2015-01-01

Nitrite in water samples was determined by in-electrode coulometric titration in a reticulated vitreous carbon (RVC) electrode of 100 ppi porosity. The sample was mixed with dilute sulphuric acid and sodium sulphate, filled into a flow cell with the porous electrode and nitrite was oxidised to nitrate by constant current of 5 µA at which the potential of the electrode was monitored. The limits of detection and quantification were found to be 0.4 and 1.2 µg/L, respectively. The repeatability and reproducibility were 2.2 % and 2.6 %, respectively. The bias at 100 µg/L were found to be 0.3 %. The duration of the measurement is 2-3 min depending on the nitrite concentration. There were few interferences only, neutral and cationic surfactants decreased and increased slightly the signal, respectively. Humic acids above 30 mg/L increased the signal by 10 %. Drinking and surface water samples were analysed and the results matched well those from the photometric method.

Up-titration of allopurinol in patients with gout.

PubMed

Jennings, Claudine G; Mackenzie, Isla S; Flynn, Rob; Ford, Ian; Nuki, George; De Caterina, Raffaele; Riches, Philip L; Ralston, Stuart H; MacDonald, Thomas M

2014-08-01

European League against Rheumatism (EULAR) gout management guidelines recommend achieving a target urate level <6.0 mg/dL (<357 µmol/L). Allopurinol is the most widely used urate-lowering therapy; however, many gout patients who are prescribed allopurinol do not have urate levels optimally controlled. The objective of this analysis was to review the efficacy and tolerability of allopurinol up-titration in achieving the EULAR target levels. The Febuxostat versus Allopurinol Streamlined Trial (FAST) is an ongoing multi-centre study comparing the cardiovascular safety of febuxostat and allopurinol (target recruitment: 5706 patients). Recruited patients were already taking allopurinol and the protocol required up-titration of daily allopurinol dose, in 100 mg increments, to achieve the EULAR urate target level prior to randomisation. We reviewed pre-randomisation data from the first 400 recruited and subsequently randomised FAST patients. Of 400 patients, 144 (36%) had urate levels ≥357 µmol/L at screening and required allopurinol up-titration. Higher urate levels were significantly associated with lower allopurinol dose, male sex, increased BMI, increased alcohol intake and diuretic use. Mean fall in urate levels after a single 100-mg dose increase was 71 µmol/L. The number of up-titrations required ranged from one to five (median = 1) with 65% of patients controlled after one 100-mg up-titration. Overall, 97% of up-titrated patients achieved target urate levels with median final allopurinol dose of 300 mg daily. Side effects and complications of up-titration were minimal. Overall, 36% of FAST patients were not at target urate levels and required up-titration. Allopurinol up-titration was effective in achieving urate target levels and was generally well tolerated by patients. Copyright © 2014 Elsevier Inc. All rights reserved.

Monosodium glutamate for simple photometric iron analysis

NASA Astrophysics Data System (ADS)

Prasetyo, E.

2018-01-01

Simple photometric method for iron analysis using monosodium glutamate (MSG) was proposed. The method could be used as an alternative method, which was technically simple, economic, quantitative, readily available, scientifically sound and environmental friendly. Rapid reaction of iron (III) with glutamate in sodium chloride-hydrochloric acid buffer (pH 2) to form red-brown complex was served as a basis in the photometric determination, which obeyed the range of iron (III) concentration 1.6 - 80 µg/ml. This method could be applied to determine iron concentration in soil with satisfactory results (accuracy and precision) compared to other photometric and atomic absorption spectrometry results.

Aquaporin-4 antibody titration in NMO patients treated with rituximab: A retrospective study.

PubMed

Valentino, Paola; Marnetto, Fabiana; Granieri, Letizia; Capobianco, Marco; Bertolotto, Antonio

2017-03-01

We undertook an observational retrospective study to investigate the usefulness of aquaporin-4 (AQP4) antibodies (Ab) titration in the management of patients with neuromyelitis optica (NMO) treated with rituximab (RTX) by studying (1) the correlation between AQP4-Ab titer and disease activity, (2) the influence of RTX on antibody levels, and (3) the association between AQP4-Ab levels and responsiveness to RTX. A cell-based assay was used for AQP4-Ab titration in 322 serum samples from 7 patients with NMO treated with RTX (median follow-up 65 months), according to a treatment-to-target approach. Serum samples were collected every month following standardized procedures. (1) In group analysis, AQP4-Ab titers correlated with the disease activity, showing higher titers during and preceding relapses than during remission. However, in individual analysis, an increase in AQP4-Ab titers and CD19+ B cells did not always precede a relapse. (2) A reduction of AQP4-Ab titers in the short-term and long-term period was observed during RTX treatment. (3) Reduction of AQP4-Ab titers was observed in responder patients both 3 months after RTX infusion and in the long-term follow-up. In one nonresponder patient, AQP4-Ab levels never decreased during the treatment period. Titration of AQP4-Abs could be useful in the clinical management of patients with NMO treated with RTX: titration before each reinfusion and 3 months after each reinfusion may provide information about responsiveness to RTX. Although a relationship among AQP4-Ab levels, disease activity, and response to RTX was observed, the usefulness of AQP4-Ab titration to predict relapses is limited.

Coulometric Titration of Ethylenediaminetetraacetate (EDTA) with Spectrophotometric Endpoint Detection: An Experiment for the Instrumental Analysis Laboratory

ERIC Educational Resources Information Center

Williams, Kathryn R.; Young, Vaneica Y.; Killian, Benjamin J.

2011-01-01

Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

New insights on the accuracy of photometric redshift measurements

NASA Astrophysics Data System (ADS)

Massarotti, M.; Iovino, A.; Buzzoni, A.; Valls-Gabaud, D.

2001-12-01

We use the deepest and most complete redshift catalog currently available (the Hubble Deep Field (HDF) North supplemented by new HDF South redshift data) to minimize residuals between photometric and spectroscopic redshift estimates. The good agreement at zspec < 1.5 shows that model libraries provide a good description of the galaxy population. At zspec >= 2.0, the systematic shift between photometric and spectroscopic redshifts decreases when the modeling of the absorption by the interstellar and intergalactic media is refined. As a result, in the entire redshift range z in [0, 6], residuals between photometric and spectroscopic redshifts are roughly halved. For objects fainter than the spectroscopic limit, the main source of uncertainty in photometric redshifts is related to photometric errors, and can be assessed with Monte Carlo simulations.

Photometric Modeling of Simulated Surace-Resolved Bennu Images

NASA Astrophysics Data System (ADS)

Golish, D.; DellaGiustina, D. N.; Clark, B.; Li, J. Y.; Zou, X. D.; Bennett, C. A.; Lauretta, D. S.

2017-12-01

The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) is a NASA mission to study and return a sample of asteroid (101955) Bennu. Imaging data from the mission will be used to develop empirical surface-resolved photometric models of Bennu at a series of wavelengths. These models will be used to photometrically correct panchromatic and color base maps of Bennu, compensating for variations due to shadows and photometric angle differences, thereby minimizing seams in mosaicked images. Well-corrected mosaics are critical to the generation of a global hazard map and a global 1064-nm reflectance map which predicts LIDAR response. These data products directly feed into the selection of a site from which to safely acquire a sample. We also require photometric correction for the creation of color ratio maps of Bennu. Color ratios maps provide insight into the composition and geological history of the surface and allow for comparison to other Solar System small bodies. In advance of OSIRIS-REx's arrival at Bennu, we use simulated images to judge the efficacy of both the photometric modeling software and the mission observation plan. Our simulation software is based on USGS's Integrated Software for Imagers and Spectrometers (ISIS) and uses a synthetic shape model, a camera model, and an empirical photometric model to generate simulated images. This approach gives us the flexibility to create simulated images of Bennu based on analog surfaces from other small Solar System bodies and to test our modeling software under those conditions. Our photometric modeling software fits image data to several conventional empirical photometric models and produces the best fit model parameters. The process is largely automated, which is crucial to the efficient production of data products during proximity operations. The software also produces several metrics on the quality of the observations themselves, such as surface coverage and the

Time-to-isolation guided titration of freeze duration in 3rd generation short-tip cryoballoon pulmonary vein isolation - Comparable clinical outcome and shorter procedure duration.

PubMed

Pott, Alexander; Kraft, Christoph; Stephan, Tilman; Petscher, Kerstin; Rottbauer, Wolfgang; Dahme, Tillman

2018-03-15

The optimal freeze duration in cryoballoon pulmonary vein isolation (PVI) is unknown. The 3rd generation cryoballoon facilitates observation of the time-to-isolation (TTI) and thereby enables individualized cryoenergy titration. To evaluate the efficacy of an individualized freeze duration we compared the clinical outcome of patients treated with a TTI-guided ablation protocol to the outcome of patients treated with a fixed ablation protocol. We compared 100 patients treated with the 3rd generation cryoballoon applying a TTI-based protocol (TTI group) to 100 patients treated by a fixed freeze protocol (fixed group). In the fixed group a 240s freeze cycle was followed by a 240s bonus freeze after acute PV isolation. In the TTI group freeze duration was 180s if TTI was ≥30s and reduced to only 120s, if TTI was <30s. In case of a TTI >60s a 180s bonus freeze was applied. Freedom from atrial arrhythmia recurrence off class I/III antiarrhythmic drugs after one year was not different between the TTI group (73.6%) and the fixed group (75.7%; p=0.75). Mean procedure duration was 85.8±27.3min in the TTI group compared to 115.7±27.1min in the fixed group (p<0.001). Mean fluoroscopy time was 17.5±6.6min in the TTI group and 22.5±9.8min in the fixed group (p<0.001). TTI-guided cryoenergy titration leads to reduced procedure duration and fluoroscopy time and appears to be as effective as a fixed ablation strategy. A single 2-minute freeze seems to be sufficient in case of short TTI. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Toward an efficient Photometric Supernova Classifier

NASA Astrophysics Data System (ADS)

McClain, Bradley

2018-01-01

The Sloan Digital Sky Survey Supernova Survey (SDSS) discovered more than 1,000 Type Ia Supernovae, yet less than half of these have spectroscopic measurements. As wide-field imaging telescopes such as The Dark Energy Survey (DES) and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS) discover more supernovae, the need for accurate and computationally cheap photometric classifiers increases. My goal is to use a photometric classification algorithm based on Sncosmo, a python library for supernova cosmology analysis, to reclassify previously identified Hubble SN and other non-spectroscopically confirmed surveys. My results will be compared to other photometric classifiers such as PSNID and STARDUST. In the near future, I expect to have the algorithm validated with simulated data, optimized for efficiency, and applied with high performance computing to real data.

An Olfactory Indicator for Acid-Base Titrations.

ERIC Educational Resources Information Center

Flair, Mark N.; Setzer, William N.

1990-01-01

The use of an olfactory acid-base indicator in titrations for visually impaired students is discussed. Potential olfactory indicators include eugenol, thymol, vanillin, and thiophenol. Titrations performed with each indicator with eugenol proved to be successful. (KR)

Philosophy and updating of the asteroid photometric catalogue

NASA Technical Reports Server (NTRS)

Magnusson, Per; Barucci, M. Antonietta; Capria, M. T.; Dahlgren, Mats; Fulchignoni, Marcello; Lagerkvist, C. I.

1992-01-01

The Asteroid Photometric Catalogue now contains photometric lightcurves for 584 asteroids. We discuss some of the guiding principles behind it. This concerns both observers who offer input to it and users of the product.

Linear Titration Curves of Acids and Bases.

PubMed

Joseph, N R

1959-05-29

The Henderson-Hasselbalch equation, by a simple transformation, becomes pH - pK = pA - pB, where pA and pB are the negative logarithms of acid and base concentrations. Sigmoid titration curves then reduce to straight lines; titration curves of polyelectrolytes, to families of straight lines. The method is applied to the titration of the dipeptide glycyl aminotricarballylic acid, with four titrable groups. Results are expressed as Cartesian and d'Ocagne nomograms. The latter is of a general form applicable to polyelectrolytes of any degree of complexity.

System for clinical photometric stereo endoscopy

NASA Astrophysics Data System (ADS)

Durr, Nicholas J.; González, Germán.; Lim, Daryl; Traverso, Giovanni; Nishioka, Norman S.; Vakoc, Benjamin J.; Parot, Vicente

2014-02-01

Photometric stereo endoscopy is a technique that captures information about the high-spatial-frequency topography of the field of view simultaneously with a conventional color image. Here we describe a system that will enable photometric stereo endoscopy to be clinically evaluated in the large intestine of human patients. The clinical photometric stereo endoscopy system consists of a commercial gastroscope, a commercial video processor, an image capturing and processing unit, custom synchronization electronics, white light LEDs, a set of four fibers with diffusing tips, and an alignment cap. The custom pieces that come into contact with the patient are composed of biocompatible materials that can be sterilized before use. The components can then be assembled in the endoscopy suite before use. The resulting endoscope has the same outer diameter as a conventional colonoscope (14 mm), plugs into a commercial video processor, captures topography and color images at 15 Hz, and displays the conventional color image to the gastroenterologist in real-time. We show that this system can capture a color and topographical video in a tubular colon phantom, demonstrating robustness to complex geometries and motion. The reported system is suitable for in vivo evaluation of photometric stereo endoscopy in the human large intestine.

Potentiometric titration and equivalent weight of humic acid

USGS Publications Warehouse

Pommer, A.M.; Breger, I.A.

1960-01-01

The "acid nature" of humic acid has been controversial for many years. Some investigators claim that humic acid is a true weak acid, while others feel that its behaviour during potentiometric titration can be accounted for by colloidal adsorption of hydrogen ions. The acid character of humic acid has been reinvestigated using newly-derived relationships for the titration of weak acids with strong base. Re-interpreting the potentiometric titration data published by Thiele and Kettner in 1953, it was found that Merck humic acid behaves as a weak polyelectrolytic acid having an equivalent weight of 150, a pKa of 6.8 to 7.0, and a titration exponent of about 4.8. Interdretation of similar data pertaining to the titration of phenol-formaldehyde and pyrogallol-formaldehyde resins, considered to be analogs for humic acid by Thiele and Kettner, leads to the conclusion that it is not possible to differentiate between adsorption and acid-base reaction for these substances. ?? 1960.

Titrating Oxygen Requirements During Exercise: Evaluation of a Standardized Single Walk Test Protocol.

PubMed

Giovacchini, Coral X; Mathews, Anne M; Lawlor, Brian R; MacIntyre, Neil R

2018-04-01

Oxygen supplementation for exercise-induced hypoxemia is a common clinical practice that improves exercise tolerance. However, we know of no standardized exercise oxygen titration protocol using a single walk test. We report our experience with a protocol developed in our laboratory. Our protocol is based on the 6-min walk test (6MWT). Pulse oximetry readings (oxygen saturation [Spo 2 ]) are monitored, and supplemental oxygen is added in 2 L/min increments to keep Spo 2 > 88%. This continues for at least 6 min of walking with the Spo 2 remaining > 88% for at least 3 min. The records of consecutive patients over 4 months undergoing this procedure were reviewed for test performance, oxygen titration results, and adverse events. Two hundred twenty-two patients were tested; only two prematurely terminated the protocol because of intractable dyspnea. One hundred fifty-six patients (38%) required oxygen supplementation, with the first titration most commonly occurring between 1 and 2 min of walking. Nine of the patients had the first titration after 5 min of walking. The average test duration was 7 min (maximum, 15 min). The average number of titrations was 2.2 (maximum six). Sixteen patients could not maintain Spo 2 > 88% for 3 min despite administration of 15 L/min of supplemental oxygen (maximal dose). Our protocol was easily performed as a modification of a standard 6MWT with no serious adverse events. Because it is based on a widely accepted measurement of functional capabilities, and because it determined a stable final oxygen dose for ≥ 3 min of walking in most patients, we believe this protocol can be easily adapted for clinical use. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Photometric Study of Fourteen Low-mass Binaries

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

Korda, D.; Zasche, P.; Wolf, M.

2017-07-01

New CCD photometric observations of fourteen short-period low-mass eclipsing binaries (LMBs) in the photometric filters I, R, and V were used for a light curve analysis. A discrepancy remains between observed radii and those derived from the theoretical modeling for LMBs, in general. Mass calibration of all observed LMBs was performed using only the photometric indices. The light curve modeling of these selected systems was completed, yielding the new derived masses and radii for both components. We compared these systems with the compilation of other known double-lined LMB systems with uncertainties of masses and radii less then 5%, which includesmore » 66 components of binaries where both spectroscopy and photometry were combined together. All of our systems are circular short-period binaries, and for some of them, the photospheric spots were also used. A purely photometric study of the light curves without spectroscopy seems unable to achieve high enough precision and accuracy in the masses and radii to act as meaningful test of the M–R relation for low-mass stars.« less

Probabilistic Photometric Redshifts in the Era of Petascale Astronomy

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

Carrasco Kind, Matias

2014-01-01

With the growth of large photometric surveys, accurately estimating photometric redshifts, preferably as a probability density function (PDF), and fully understanding the implicit systematic uncertainties in this process has become increasingly important. These surveys are expected to obtain images of billions of distinct galaxies. As a result, storing and analyzing all of these photometric redshift PDFs will be non-trivial, and this challenge becomes even more severe if a survey plans to compute and store multiple different PDFs. In this thesis, we have developed an end-to-end framework that will compute accurate and robust photometric redshift PDFs for massive data sets bymore » using two new, state-of-the-art machine learning techniques that are based on a random forest and a random atlas, respectively. By using data from several photometric surveys, we demonstrate the applicability of these new techniques, and we demonstrate that our new approach is among the best techniques currently available. We also show how different techniques can be combined by using novel Bayesian techniques to improve the photometric redshift precision to unprecedented levels while also presenting new approaches to better identify outliers. In addition, our framework provides supplementary information regarding the data being analyzed, including unbiased estimates of the accuracy of the technique without resorting to a validation data set, identification of poor photometric redshift areas within the parameter space occupied by the spectroscopic training data, and a quantification of the relative importance of the variables used during the estimation process. Furthermore, we present a new approach to represent and store photometric redshift PDFs by using a sparse representation with outstanding compression and reconstruction capabilities. We also demonstrate how this framework can also be directly incorporated into cosmological analyses. The new techniques presented in this thesis are

Assessment of two theoretical methods to estimate potentiometric titration curves of peptides: comparison with experiment.

PubMed

Makowska, Joanna; Bagiñska, Katarzyna; Makowski, Mariusz; Jagielska, Anna; Liwo, Adam; Kasprzykowski, Franciszek; Chmurzyñski, Lech; Scheraga, Harold A

2006-03-09

We compared the ability of two theoretical methods of pH-dependent conformational calculations to reproduce experimental potentiometric titration curves of two models of peptides: Ac-K5-NHMe in 95% methanol (MeOH)/5% water mixture and Ac-XX(A)7OO-NH2 (XAO) (where X is diaminobutyric acid, A is alanine, and O is ornithine) in water, methanol (MeOH), and dimethyl sulfoxide (DMSO), respectively. The titration curve of the former was taken from the literature, and the curve of the latter was determined in this work. The first theoretical method involves a conformational search using the electrostatically driven Monte Carlo (EDMC) method with a low-cost energy function (ECEPP/3 plus the SRFOPT surface-solvation model, assumming that all titratable groups are uncharged) and subsequent reevaluation of the free energy at a given pH with the Poisson-Boltzmann equation, considering variable protonation states. In the second procedure, molecular dynamics (MD) simulations are run with the AMBER force field and the generalized Born model of electrostatic solvation, and the protonation states are sampled during constant-pH MD runs. In all three solvents, the first pKa of XAO is strongly downshifted compared to the value for the reference compounds (ethylamine and propylamine, respectively); the water and methanol curves have one, and the DMSO curve has two jumps characteristic of remarkable differences in the dissociation constants of acidic groups. The predicted titration curves of Ac-K5-NHMe are in good agreement with the experimental ones; better agreement is achieved with the MD-based method. The titration curves of XAO in methanol and DMSO, calculated using the MD-based approach, trace the shape of the experimental curves, reproducing the pH jump, while those calculated with the EDMC-based approach and the titration curve in water calculated using the MD-based approach have smooth shapes characteristic of the titration of weak multifunctional acids with small differences

Thermometric titration in investigation of the formation of polyanions of molybdenum(VI), tungsten(VI), vanadium(V), and chromium (VI)-I: comparison of thermometric and potentiometric titration curves.

PubMed

Kiba, N; Takeuchi, T

1973-09-01

A new twin-cell thermometric titrator has been devised and used for thermometric titration of solutions of sodium molybdate, sodium tungstate, sodium orthovanadate, ammonium metavanadate, and potassium chromate with perchloric acid. The thermometric titration curves were compared with corresponding pH-titration curves for elucidation of the reactions occurring in the titrations. Thermometric titrimetric methods have been developed for the determination of tungsten, vanadium and chromium.

Photometric followup investigations on LAMOST survey target Ly And

NASA Astrophysics Data System (ADS)

Lu, Hong-peng; Zhang, Li-yun; Han, Xianming L.; Pi, Qing-feng; Wang, Dai-mei

2017-02-01

We present a low-dispersion spectrum and two sets of CCD photometric light curves of the eclipsing binary LY And for the first time. The spectrum of LY And was classified as G2. We derived an updated ephemeris based on all previously available and our newly acquired minimum light times. Our analyses of LY And light curve minimum times reveals that the differences between calculated and observed minimum times for LY And can be represented by an upward parabolic curve, which means its orbital period is increasing with a rate of 1.88 (± 0.13) × 10-7 days/year. This increase in orbital period may be interpreted as mass transfer from the primary component to the secondary component, with a rate of dM1/dt = -4.54 × 10-8M⊙/year. By analyzing our CCD photometric light curves obtained in 2015, we obtained its photometric solution with the Wilson-Devinney program. This photometric solution also fits very well our light curves obtained in 2014. Our photometric solution shows that LY And is a contact eclipsing binary and its contact factor is f = (17.8 ± 1.9)%. Furthermore, both our spectroscopic and photometric data show no obvious chromospheric activity of LY And.

Charge characteristics of humic and fulvic acids: comparative analysis by colloid titration and potentiometric titration with continuous pK-distribution function model.

PubMed

Bratskaya, S; Golikov, A; Lutsenko, T; Nesterova, O; Dudarchik, V

2008-09-01

Charge characteristics of humic and fulvic acids of a different origin (inshore soils, peat, marine sediments, and soil (lysimetric) waters) were evaluated by means of two alternative methods - colloid titration and potentiometric titration. In order to elucidate possible limitations of the colloid titration as an express method of analysis of low content of humic substances we monitored changes in acid-base properties and charge densities of humic substances with soil depth, fractionation, and origin. We have shown that both factors - strength of acidic groups and molecular weight distribution in humic and fulvic acids - can affect the reliability of colloid titration. Due to deviations from 1:1 stoichiometry in interactions of humic substances with polymeric cationic titrant, the colloid titration can underestimate total acidity (charge density) of humic substances with domination of weak acidic functional groups (pK>6) and high content of the fractions with molecular weight below 1kDa.

Automated potentiometric titrations in KCl/water-saturated octanol: method for quantifying factors influencing ion-pair partitioning.

PubMed

Scherrer, Robert A; Donovan, Stephen F

2009-04-01

The knowledge base of factors influencing ion pair partitioning is very sparse, primarily because of the difficulty in determining accurate log P(I) values of desirable low molecular weight (MW) reference compounds. We have developed a potentiometric titration procedure in KCl/water-saturated octanol that provides a link to log P(I) through the thermodynamic cycle of ionization and partitioning. These titrations have the advantage of being independent of the magnitude of log P, while maintaining a reproducibility of a few hundredths of a log P in the calculated difference between log P neutral and log P ion pair (diff (log P(N - I))). Simple model compounds can be used. The titration procedure is described in detail, along with a program for calculating pK(a)'' values incorporating the ionization of water in octanol. Hydrogen bonding and steric factors have a greater influence on ion pairs than they do on neutral species, yet these factors are missing from current programs used to calculate log P(I) and log D. In contrast to the common assumption that diff (log P(N - I)) is the same for all amines, they can actually vary more than 3 log units, as in our examples. A major factor affecting log P(I) is the ability of water and the counterion to approach the charge center. Bulky substituents near the charge center have a negative influence on log P(I). On the other hand, hydrogen bonding groups near the charge center have the opposite effect by lowering the free energy of the ion pair. The use of this titration method to determine substituent ion pair stabilization values (IPS) should bring about more accurate log D calculations and encourage species-specific QSAR involving log D(N) and log D(I). This work also brings attention to the fascinating world of nature's highly stabilized ion pairs.

Automated Potentiometric Titrations in KCl/Water-Saturated Octanol: Method for Quantifying Factors Influencing Ion-Pair Partitioning

PubMed Central

2009-01-01

The knowledge base of factors influencing ion pair partitioning is very sparse, primarily because of the difficulty in determining accurate log PI values of desirable low molecular weight (MW) reference compounds. We have developed a potentiometric titration procedure in KCl/water-saturated octanol that provides a link to log PI through the thermodynamic cycle of ionization and partitioning. These titrations have the advantage of being independent of the magnitude of log P, while maintaining a reproducibility of a few hundredths of a log P in the calculated difference between log P neutral and log P ion pair (diff (log PN − I)). Simple model compounds can be used. The titration procedure is described in detail, along with a program for calculating pKa′′ values incorporating the ionization of water in octanol. Hydrogen bonding and steric factors have a greater influence on ion pairs than they do on neutral species, yet these factors are missing from current programs used to calculate log PI and log D. In contrast to the common assumption that diff (log PN − I) is the same for all amines, they can actually vary more than 3 log units, as in our examples. A major factor affecting log PI is the ability of water and the counterion to approach the charge center. Bulky substituents near the charge center have a negative influence on log PI. On the other hand, hydrogen bonding groups near the charge center have the opposite effect by lowering the free energy of the ion pair. The use of this titration method to determine substituent ion pair stabilization values (IPS) should bring about more accurate log D calculations and encourage species-specific QSAR involving log DN and log DI. This work also brings attention to the fascinating world of nature’s highly stabilized ion pairs. PMID:19265385

Sensitivity of the acid-base properties of clays to the methods of preparation and measurement. 2. Evidence from continuous potentiometric titrations.

PubMed

Duc, Myriam; Gaboriaud, Fabien; Thomas, Fabien

2005-09-01

The effects of experimental procedures on the acid-base consumption titration curves of montmorillonite suspension were studied using continuous potentiometric titration. For that purpose, the hysteresis amplitudes between the acid and base branches were found to be useful to systematically evaluate the impacts of storage conditions (wet or dried), the atmosphere in titration reactor, the solid-liquid ratio, the time interval between successive increments, and the ionic strength. In the case of storage conditions, the increase of the hysteresis was significantly higher for longer storage of clay in suspension and drying procedures compared to "fresh" clay suspension. The titration carried out under air demonstrated carbonate contamination that could only be cancelled by performing experiments under inert gas. Interestingly, the increase of the time intervals between successive increments of titrant strongly emphasized the amplitude of hysteresis, which could be correlated with the slow kinetic process specifically observed for acid addition in acid media. Thus, such kinetic behavior is probably associated with dissolution processes of clay particles. However, the resulting curves recorded at different ionic strengths under optimized conditions did not show the common intersection point required to define point of zero charge. Nevertheless, the ionic strength dependence of the point of zero net proton charge suggested that the point of zero charge of sodic montmorillonite could be estimated as lower than 5.

Students' integration of multiple representations in a titration experiment

NASA Astrophysics Data System (ADS)

Kunze, Nicole M.

A complete understanding of a chemical concept is dependent upon a student's ability to understand the microscopic or particulate nature of the phenomenon and integrate the microscopic, symbolic, and macroscopic representations of the phenomenon. Acid-base chemistry is a general chemistry topic requiring students to understand the topics of chemical reactions, solutions, and equilibrium presented earlier in the course. In this study, twenty-five student volunteers from a second semester general chemistry course completed two interviews. The first interview was completed prior to any classroom instruction on acids and bases. The second interview took place after classroom instruction, a prelab activity consisting of a titration calculation worksheet, a titration computer simulation, or a microscopic level animation of a titration, and two microcomputer-based laboratory (MBL) titration experiments. During the interviews, participants were asked to define and describe acid-base concepts and in the second interview they also drew the microscopic representations of four stages in an acid-base titration. An analysis of the data showed that participants had integrated the three representations of an acid-base titration to varying degrees. While some participants showed complete understanding of acids, bases, titrations, and solution chemistry, other participants showed several alternative conceptions concerning strong acid and base dissociation, the formation of titration products, and the dissociation of soluble salts. Before instruction, participants' definitions of acid, base, and pH were brief and consisted of descriptive terms. After instruction, the definitions were more scientific and reflected the definitions presented during classroom instruction.

Automatic Astrometric and Photometric Calibration with SCAMP

NASA Astrophysics Data System (ADS)

Bertin, E.

2006-07-01

Astrometric and photometric calibrations have remained the most tiresome step in the reduction of large imaging surveys. I present a new software package, SCAMP which has been written to address this problem. SCAMP efficiently computes accurate astrometric and photometric solutions for any arbitrary sequence of FITS images in a completely automatic way. SCAMP is released under the GNU General Public Licence.

Galaxy Tagging: photometric redshift refinement and group richness enhancement

NASA Astrophysics Data System (ADS)

Kafle, P. R.; Robotham, A. S. G.; Driver, S. P.; Deeley, S.; Norberg, P.; Drinkwater, M. J.; Davies, L. J.

2018-06-01

We present a new scheme, galtag, for refining the photometric redshift measurements of faint galaxies by probabilistically tagging them to observed galaxy groups constructed from a brighter, magnitude-limited spectroscopy survey. First, this method is tested on the DESI light-cone data constructed on the GALFORM galaxy formation model to tests its validity. We then apply it to the photometric observations of galaxies in the Kilo-Degree Imaging Survey (KiDS) over a 1 deg2 region centred at 15h. This region contains Galaxy and Mass Assembly (GAMA) deep spectroscopic observations (i-band<22) and an accompanying group catalogue to r-band<19.8. We demonstrate that even with some trade-off in sample size, an order of magnitude improvement on the accuracy of photometric redshifts is achievable when using galtag. This approach provides both refined photometric redshift measurements and group richness enhancement. In combination these products will hugely improve the scientific potential of both photometric and spectroscopic datasets. The galtag software will be made publicly available at https://github.com/pkaf/galtag.git.

Photometric Variability of the Be Star Population

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

Labadie-Bartz, Jonathan; Pepper, Joshua; McSwain, M. Virginia

2017-06-01

Be stars have generally been characterized by the emission lines in their spectra, and especially the time variability of those spectroscopic features. They are known to also exhibit photometric variability at multiple timescales, but have not been broadly compared and analyzed by that behavior. We have taken advantage of the advent of wide-field, long-baseline, and high-cadence photometric surveys that search for transiting exoplanets to perform a comprehensive analysis of brightness variations among a large number of known Be stars. The photometric data comes from the KELT transit survey, with a typical cadence of 30 minutes, a baseline of up to 10more » years, photometric precision of about 1%, and coverage of about 60% of the sky. We analyze KELT light curves of 610 known Be stars in both the northern and southern hemispheres in an effort to study their variability. Consistent with other studies of Be star variability, we find most of the stars to be photometrically variable. We derive lower limits on the fraction of stars in our sample that exhibit features consistent with non-radial pulsations (25%), outbursts (36%), and long-term trends in the circumstellar disk (37%), and show how these are correlated with spectral sub-types. Other types of variability, such as those owing to binarity, are also explored. Simultaneous spectroscopy for some of these systems from the Be Star Spectra database allow us to better understand the physical causes for the observed variability, especially in cases of outbursts and changes in the disk.« less

Data-driven, Interpretable Photometric Redshifts Trained on Heterogeneous and Unrepresentative Data

NASA Astrophysics Data System (ADS)

Leistedt, Boris; Hogg, David W.

2017-03-01

We present a new method for inferring photometric redshifts in deep galaxy and quasar surveys, based on a data-driven model of latent spectral energy distributions (SEDs) and a physical model of photometric fluxes as a function of redshift. This conceptually novel approach combines the advantages of both machine learning methods and template fitting methods by building template SEDs directly from the spectroscopic training data. This is made computationally tractable with Gaussian processes operating in flux-redshift space, encoding the physics of redshifts and the projection of galaxy SEDs onto photometric bandpasses. This method alleviates the need to acquire representative training data or to construct detailed galaxy SED models; it requires only that the photometric bandpasses and calibrations be known or have parameterized unknowns. The training data can consist of a combination of spectroscopic and deep many-band photometric data with reliable redshifts, which do not need to entirely spatially overlap with the target survey of interest or even involve the same photometric bands. We showcase the method on the I-magnitude-selected, spectroscopically confirmed galaxies in the COSMOS field. The model is trained on the deepest bands (from SUBARU and HST) and photometric redshifts are derived using the shallower SDSS optical bands only. We demonstrate that we obtain accurate redshift point estimates and probability distributions despite the training and target sets having very different redshift distributions, noise properties, and even photometric bands. Our model can also be used to predict missing photometric fluxes or to simulate populations of galaxies with realistic fluxes and redshifts, for example.

Implementation of a pharmacist-managed heart failure medication titration clinic.

PubMed

Martinez, Amanda S; Saef, Jerold; Paszczuk, Anna; Bhatt-Chugani, Hetal

2013-06-15

The development, implementation, and initial results of a pharmacist-managed heart failure (HF) medication titration clinic are described. In a quality-improvement initiative at a Veterans Affairs health care system, clinical pharmacists were incorporated into the hospital system's interprofessional outpatient HF clinic. In addition, a separate pharmacist-managed HF medication titration clinic was established, in which pharmacists were granted an advanced scope of practice and prescribing privileges, enabling them to initiate and adjust medication dosages under specific protocols jointly established by cardiology and pharmacy staff. Pharmacists involved in the titration clinic tracked patients' daily body weight, vital signs, and volume status using telephone-monitoring technology and via patient interviews. A retrospective chart review comparing achievement of target doses of angiotensin-converting enzyme inhibitor (ACEI), angiotensin-receptor blocker (ARB), and β-blocker therapies in a group of patients (n = 28) whose dosage titrations were carried out by nurses or physicians prior to implementation of the pharmacist-managed HF medication titration clinic and a group of patients (n = 27) enrolled in the medication titration clinic during its first six months of operation indicated that target ACEI and ARB doses were achieved in a significantly higher percentage of pharmacist-managed titration clinic enrollees (52.9% versus 31%, p = 0.007). Patients enrolled in the pharmacist-managed HF medication titration clinic also had a significantly higher rate of attainment of optimal β-blocker doses (49% versus 24.7%, p = 0.012). Implementation of a pharmacist-managed HF medication titration clinic increased the percentage of patients achieving optimal ACEI, ARB, and β-blocker dosages.

Computer controlled titration with piston burette or peristaltic pump - a comparison.

PubMed

Hoffmann, W

1996-09-01

The advantages and problems of the use of piston burettes and peristaltic pumps for dosage of titrant solutions in automatic titrations are shown. For comparison, only the dosing devices were exchanged and all other components and conditions remained unchanged. The results of continuous acid base titration show good agreement and comparable reproducibility. Potentiometric sensors (glass electrodes) with different equilibration behaviour influence the results. The capability of such electrodes was tested. Conductometric measurements allow a much faster detection because there is no equilibration of electrodes. Piston burettes should be used for titration with very high precision, titration with organic solvents and slow titrations. Peristaltic pumps seem to be more suitable for continuous titrations and long time operation without service.

Titration in the treatment of the more troubled patient.

PubMed

Winer, J A; Ornstein, E D

2001-01-01

This article defines and discusses a modification of technique recommended by the authors in the psychoanalytic treatment of more troubled patients--a modification they call titration. Titration is defined as a conscious decision by the analyst to increase or decrease assistance (or gratification) gradually, in order to facilitate the analytic process. The authors emphasize the complexity of decisions in treatment by focusing on the decision-making processes that titration requires. Guidelines and a case vignette are presented. The authors conclude by considering some of the politics involved in the introduction of technique modifications, the salience of the titration concept, and directions for further exploration.

Rapid clozapine titration in treatment-refractory bipolar disorder.

PubMed

Ifteni, Petru; Correll, Christoph U; Nielsen, Jimmi; Burtea, Victoria; Kane, John M; Manu, Peter

2014-09-01

Clozapine is effective in treatment-refractory bipolar disorder (BD). Guidelines recommend slow titration to prevent seizures, hypotension and myocarditis, but this stance is not supported by comparative data. To evaluate the safety and effectiveness of rapid clozapine titration in BD. Analysis of a consecutive cohort of treatment-refractory BD patients with mixed/manic episode admitted on alternate days to one of two units of a psychiatric hospital. On one unit, clozapine was started at 25mg followed by 25-50mg as needed every 6h (maximum=100mg/day) on day 1, followed by increases of 25-100mg/day. On the other unit, clozapine was initiated with 25mg in day 1, followed by increases of 25-50mg/day. The primary outcome was the number of days from starting clozapine until readiness for discharge, adjusted in logistic regression for the number of antipsychotics tried during the hospitalization, psychotropic co-treatments and presence of psychotic features. Patients subject to rapid (N=44) and standard (N=23) titration were similar in age, gender, smoking status, body mass index, illness severity at baseline and discharge, and highest clozapine dose. Clozapine was discontinued due to hypotension (N=1) and pneumonia (N=1) during rapid titration, and for excessive sedation (N=1) in each titration group. The number of hospital days from starting clozapine until readiness for discharge was 3.8 days shorter in the rapid titration group (12.7±6.3 vs. 16.5±5.8, p=0.0077). Rapid clozapine titration appeared safe and effective for treatment-refractory BD. The potential for shorter hospital stays justifies prospective trials of this method. Copyright © 2014 Elsevier B.V. All rights reserved.

21 CFR 862.2160 - Discrete photometric chemistry analyzer for clinical use.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Discrete photometric chemistry analyzer for... Clinical Laboratory Instruments § 862.2160 Discrete photometric chemistry analyzer for clinical use. (a) Identification. A discrete photometric chemistry analyzer for clinical use is a device intended to duplicate...

Endpoint titration and immunotherapy.

PubMed

King, H C

1985-11-01

Inhalant allergy, or "atopy" as it is now termed, is the best understood form of allergy today. In some circles, it is the only recognized form of allergy. While an overall picture of its effects on the body and a reasonable approach to its treatment now exist, many problems remain to be solved and much improvement in its treatment will probably occur within the next several years. Many new approaches to treatment of aeroallergens are now available; however, all are compared with the skin test, which is and has been the baseline for testing and treatment. Endpoint titration provides a quantitative means for undertaking treatment of aeroallergen sensitivity. In no other way does it differ from the forms of skin testing that have been widely used for generations. The practitioners of endpoint titration feel that this difference is highly significant in simplifying, validating, and shortening the necessary period of therapy. While the concept of endpoint titration is not difficult, it is by definition a quantitative form of testing and requires a degree of expertise in performing it correctly. While a good understanding of the method may be gained from the literature, adequate hands-on experience should be obtained by any physician prior to instituting the technique as a treatment modality. Once mastered, it becomes a reliable baseline for all forms of inhalant allergy care.

The wavelength dependence and an interpretation of the photometric parameters of Mars

NASA Technical Reports Server (NTRS)

Weaver, W. R.; Meador, W. E.

1976-01-01

The photometric function developed by Meador and Weaver has been used with photometric data from the bright desert areas of Mars to determine the wavelength dependence of the three photometric parameters of that function and to provide some predictions about the physical properties of the surface. Knowledge of the parameters permits the brightness of these areas of Mars to be determined for scattering geometry over the wavelength range of 0.45 to 0.70 micrometer. The changes in the photometric parameters with wavelength are shown to be consistent with qualitative theoretical predictions, and the predictions of surface properties are shown to be consistent with conditions that might exist in these regions of Mars. The photometric function is shown to have good potential as a diagnostic tool for the determination of surface properties, and the consistency of the behavior of the photometric parameters is shown to be good support for the validity of the photometric function.

Semi-supervised learning for photometric supernova classification

NASA Astrophysics Data System (ADS)

Richards, Joseph W.; Homrighausen, Darren; Freeman, Peter E.; Schafer, Chad M.; Poznanski, Dovi

2012-01-01

We present a semi-supervised method for photometric supernova typing. Our approach is to first use the non-linear dimension reduction technique diffusion map to detect structure in a data base of supernova light curves and subsequently employ random forest classification on a spectroscopically confirmed training set to learn a model that can predict the type of each newly observed supernova. We demonstrate that this is an effective method for supernova typing. As supernova numbers increase, our semi-supervised method efficiently utilizes this information to improve classification, a property not enjoyed by template-based methods. Applied to supernova data simulated by Kessler et al. to mimic those of the Dark Energy Survey, our methods achieve (cross-validated) 95 per cent Type Ia purity and 87 per cent Type Ia efficiency on the spectroscopic sample, but only 50 per cent Type Ia purity and 50 per cent efficiency on the photometric sample due to their spectroscopic follow-up strategy. To improve the performance on the photometric sample, we search for better spectroscopic follow-up procedures by studying the sensitivity of our machine-learned supernova classification on the specific strategy used to obtain training sets. With a fixed amount of spectroscopic follow-up time, we find that, despite collecting data on a smaller number of supernovae, deeper magnitude-limited spectroscopic surveys are better for producing training sets. For supernova Ia (II-P) typing, we obtain a 44 per cent (1 per cent) increase in purity to 72 per cent (87 per cent) and 30 per cent (162 per cent) increase in efficiency to 65 per cent (84 per cent) of the sample using a 25th (24.5th) magnitude-limited survey instead of the shallower spectroscopic sample used in the original simulations. When redshift information is available, we incorporate it into our analysis using a novel method of altering the diffusion map representation of the supernovae. Incorporating host redshifts leads to a 5

Surfactant titration of nanoparticle-protein corona.

PubMed

Maiolo, Daniele; Bergese, Paolo; Mahon, Eugene; Dawson, Kenneth A; Monopoli, Marco P

2014-12-16

Nanoparticles (NP), when exposed to biological fluids, are coated by specific proteins that form the so-called protein corona. While some adsorbing proteins exchange with the surroundings on a short time scale, described as a "dynamic" corona, others with higher affinity and long-lived interaction with the NP surface form a "hard" corona (HC), which is believed to mediate NP interaction with cellular machineries. In-depth NP protein corona characterization is therefore a necessary step in understanding the relationship between surface layer structure and biological outcomes. In the present work, we evaluate the protein composition and stability over time and we systematically challenge the formed complexes with surfactants. Each challenge is characterized through different physicochemical measurements (dynamic light scattering, ζ-potential, and differential centrifugal sedimentation) alongside proteomic evaluation in titration type experiments (surfactant titration). 100 nm silicon oxide (Si) and 100 nm carboxylated polystyrene (PS-COOH) NPs cloaked by human plasma HC were titrated with 3-[(3-Cholamidopropyl) dimethylammonio]-1-propanesulfonate (CHAPS, zwitterionic), Triton X-100 (nonionic), sodium dodecyl sulfate (SDS, anionic), and dodecyltrimethylammonium bromide (DTAB, cationic) surfactants. Composition and density of HC together with size and ζ-potential of NP-HC complexes were tracked at each step after surfactant titration. Results on Si NP-HC complexes showed that SDS removes most of the HC, while DTAB induces NP agglomeration. Analogous results were obtained for PS NP-HC complexes. Interestingly, CHAPS and Triton X-100, thanks to similar surface binding preferences, enable selective extraction of apolipoprotein AI (ApoAI) from Si NP hard coronas, leaving unaltered the dispersion physicochemical properties. These findings indicate that surfactant titration can enable the study of NP-HC stability through surfactant variation and also selective separation

Toward Millimagnitude Photometric Calibration (Abstract)

NASA Astrophysics Data System (ADS)

Dose, E.

2014-12-01

(Abstract only) Asteroid roation, exoplanet transits, and similar measurements will increasingly call for photometric precisions better than about 10 millimagnitudes, often between nights and ideally between distant observers. The present work applies detailed spectral simulations to test popular photometric calibration practices, and to test new extensions of these practices. Using 107 synthetic spectra of stars of diverse colors, detailed atmospheric transmission spectra computed by solar-energy software, realistic spectra of popular astronomy gear, and the option of three sources of noise added at realistic millimagnitude levels, we find that certain adjustments to current calibration practices can help remove small systematic errors, especially for imperfect filters, high airmasses, and possibly passing thin cirrus clouds.

Differential Binding Models for Direct and Reverse Isothermal Titration Calorimetry.

PubMed

Herrera, Isaac; Winnik, Mitchell A

2016-03-10

Isothermal titration calorimetry (ITC) is a technique to measure the stoichiometry and thermodynamics from binding experiments. Identifying an appropriate mathematical model to evaluate titration curves of receptors with multiple sites is challenging, particularly when the stoichiometry or binding mechanism is not available. In a recent theoretical study, we presented a differential binding model (DBM) to study calorimetry titrations independently of the interaction among the binding sites (Herrera, I.; Winnik, M. A. J. Phys. Chem. B 2013, 117, 8659-8672). Here, we build upon our DBM and show its practical application to evaluate calorimetry titrations of receptors with multiple sites independently of the titration direction. Specifically, we present a set of ordinary differential equations (ODEs) with the general form d[S]/dV that can be integrated numerically to calculate the equilibrium concentrations of free and bound species S at every injection step and, subsequently, to evaluate the volume-normalized heat signal (δQ(V) = δq/dV) of direct and reverse calorimetry titrations. Additionally, we identify factors that influence the shape of the titration curve and can be used to optimize the initial concentrations of titrant and analyte. We demonstrate the flexibility of our updated DBM by applying these differentials and a global regression analysis to direct and reverse calorimetric titrations of gadolinium ions with multidentate ligands of increasing denticity, namely, diglycolic acid (DGA), citric acid (CIT), and nitrilotriacetic acid (NTA), and use statistical tests to validate the stoichiometries for the metal-ligand pairs studied.

Signal processing with a summing operational amplifier in multicomponent potentiometric titrations.

PubMed

Parczewski, A

1987-06-01

It has been proved that application of two indicator electrodes connected to the ordinary titration apparatus through an auxiliary electronic device (a summing operational amplifier) significantly extends the scope of multicomponent potentiometric titrations in which the analytes are determined simultaneously from a single titration curve. For each analyte there is a corresponding potential jump on the titration curve. By application of the proposed auxiliary device, the sum of the electrode potentials is measured. The device also enables the relative sizes of the potential jumps at the end-points on the titration curve to be varied. The advantages of the proposed signal processing are exemplified by complexometric potentiometric titrations of Fe(III) and Cu(II) in mixtures, with a platinum electrode and a copper ion-selective electrode as the indicator electrodes.

Simple and Automated Coulometric Titration of Acid Using Nonisolated Electrodes

ERIC Educational Resources Information Center

Kuntzleman, Thomas S.; Kenney, Joshua B.; Hasbrouck, Scott; Collins, Michael J.; Amend, John R.

2011-01-01

Coulometric titrations involve the quantification of analyte by measurements of current and time. In most coulometric titrations, the anode and cathode are placed in isolated cells that are connected by a salt bridge. By contrast, the experiments described here involve coulometric titrations (of acidic protons in solution) using a silver anode and…

Systemic errors in quantitative polymerase chain reaction titration of self-complementary adeno-associated viral vectors and improved alternative methods.

PubMed

Fagone, Paolo; Wright, J Fraser; Nathwani, Amit C; Nienhuis, Arthur W; Davidoff, Andrew M; Gray, John T

2012-02-01

Self-complementary AAV (scAAV) vector genomes contain a covalently closed hairpin derived from a mutated inverted terminal repeat that connects the two monomer single-stranded genomes into a head-to-head or tail-to-tail dimer. We found that during quantitative PCR (qPCR) this structure inhibits the amplification of proximal amplicons and causes the systemic underreporting of copy number by as much as 10-fold. We show that cleavage of scAAV vector genomes with restriction endonuclease to liberate amplicons from the covalently closed terminal hairpin restores quantitative amplification, and we implement this procedure in a simple, modified qPCR titration method for scAAV vectors. In addition, we developed and present an AAV genome titration procedure based on gel electrophoresis that requires minimal sample processing and has low interassay variability, and as such is well suited for the rigorous quality control demands of clinical vector production facilities.

A Closer Look at Acid-Base Olfactory Titrations

ERIC Educational Resources Information Center

Neppel, Kerry; Oliver-Hoyo, Maria T.; Queen, Connie; Reed, Nicole

2005-01-01

Olfactory titrations using raw onions and eugenol as acid-base indicators are reported. An in-depth investigation on olfactory titrations is presented to include requirements for potential olfactory indicators and protocols for using garlic, onions, and vanillin as acid-base olfactory indicators are tested.

Determination of carbonate carbon in geological materials by coulometric titration

USGS Publications Warehouse

Engleman, E.E.; Jackson, L.L.; Norton, D.R.

1985-01-01

A coulometric titration is used for the determination of carbonate carbon in geological materials. Carbon dioxide is evolved from the sample by the addition of 2 M perchloric acid, with heating, and is determined by automated coulometric titration. The coulometric titration showed improved speed and precision with comparable accuracy to gravimetric and gasometric techniques. ?? 1985.

On differential photometric reconstruction for unknown, isotropic BRDFs.

PubMed

Chandraker, Manmohan; Bai, Jiamin; Ramamoorthi, Ravi

2013-12-01

This paper presents a comprehensive theory of photometric surface reconstruction from image derivatives in the presence of a general, unknown isotropic BRDF. We derive precise topological classes up to which the surface may be determined and specify exact priors for a full geometric reconstruction. These results are the culmination of a series of fundamental observations. First, we exploit the linearity of chain rule differentiation to discover photometric invariants that relate image derivatives to the surface geometry, regardless of the form of isotropic BRDF. For the problem of shape-from-shading, we show that a reconstruction may be performed up to isocontours of constant magnitude of the gradient. For the problem of photometric stereo, we show that just two measurements of spatial and temporal image derivatives, from unknown light directions on a circle, suffice to recover surface information from the photometric invariant. Surprisingly, the form of the invariant bears a striking resemblance to optical flow; however, it does not suffer from the aperture problem. This photometric flow is shown to determine the surface up to isocontours of constant magnitude of the surface gradient, as well as isocontours of constant depth. Further, we prove that specification of the surface normal at a single point completely determines the surface depth from these isocontours. In addition, we propose practical algorithms that require additional initial or boundary information, but recover depth from lower order derivatives. Our theoretical results are illustrated with several examples on synthetic and real data.

Detoxification with titration and tapering in gamma-hydroxybutyrate (GHB) dependent patients: The Dutch GHB monitor project.

PubMed

Dijkstra, Boukje A G; Kamal, Rama; van Noorden, Martijn S; de Haan, Hein; Loonen, Anton J M; De Jong, Cor A J

2017-01-01

Gamma-hydroxybutyrate (GHB) detoxification procedures have been insufficiently studied for effectiveness and safety. Based on case reports, benzodiazepines are generally regarded as first-choice agents in GHB detoxification. Detoxification by titration and tapering (DeTiTap) with pharmaceutical GHB in an open-label consecutive case series of 23 GHB-dependent patients showed to be feasible, effective and safe. This study further explored the feasibility, effectiveness and safety of this detoxification procedure in a large group of patients. A large observational multicenter study was carried out in six addiction treatment centers in the Netherlands. GHB-dependent inpatients (229 unique patients, 274 admissions) were titrated on and tapered off with pharmaceutical GHB. Successful detoxification was achieved in 85% of cases. Detoxification was carried out in 12.5days in most patients. The DeTiTap procedure proved to be feasible and significantly reduced the experienced withdrawal symptoms and craving (p≤0.001). Several symptoms were found to influence the course of subjective withdrawal symptoms. During detoxification, psychological symptoms such as depression, anxiety, and stress decreased (p≤0.05). The main complications were hypertension and anxiety. Six patients were sent to the general hospital for observation, but all six were able to continue detoxification in the addiction treatment centers. Most patients (69%) relapsed within three months after detoxification. The DeTiTap procedure using pharmaceutical GHB seems a safe alternative to benzodiazepines as a GHB detoxification procedure. However, the high relapse rates warrant further investigation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Comparative study of titrated oral misoprostol solution and vaginal dinoprostone for labor induction at term pregnancy.

PubMed

Wang, Xiu; Yang, Aijun; Ma, Qingyong; Li, Xuelan; Qin, Li; He, Tongqiang

2016-09-01

To evaluate effectiveness and safety of titrated oral misoprostol solution (OMS) in comparison with vaginal dinoprostone for cervix ripening and labor induction in term pregnant women. A multicenter randomized controlled trial of women with term singleton pregnancy with indications for labor induction; 481 participants were allocated to receive titrated OMS with different doses by hourly administration according to the procedure or insert vaginal dinoprostone for cervix ripening and labor induction to compare maternal outcomes including indication of labor induction, mode of outcome of delivery, maternal morbidity, and neonatal outcomes between two groups for evaluating the efficacy and safety of titrated oral misoprostol induction. Proportion of delivery within 12 h of titrated oral misoprostol is significantly less than vaginal dinoprostone (p = 0.03), but no difference of total vaginal delivery rate (p = 0.93); the mean time of first treatment to vaginal delivery was longer in OMS group (21.3 ± 14.5 h) compared with the vaginal dinoprostone group (15.7 ± 9.6 h). Although the proportion of cesarean section between the two groups showed no statistically significant difference, OMS group showed significantly lower frequency of uterine hyperstimulation, hypertonus, partus precipitatus and non-reassuring fetal heart rate than dinoprostone group. Neonatal outcomes were similar evaluating from Apgar score and NICU admission. Our study also showed that labor induction of women with cervix Bishop score ≤3 needed increased dosage of misoprostol solution. Titrated OMS is as effective as vaginal dinoprostone in labor induction for term pregnant women, with safer effect for its lower rate of adverse effect for women.

A Photometric redshift galaxy catalog from the Red-Sequence Cluster Survey

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

Hsieh, Bau-Ching; /Taiwan, Natl. Central U. /Taipei, Inst. Astron. Astrophys.; Yee, H.K.C.

2005-02-01

The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the z' and R{sub c} bands for 90 square degrees of sky, and supplemental V and B data have been obtained for 33.6 deg{sup 2}. They compile a photometric redshift catalog from these 4-band data by utilizing the empirical quadratic polynomial photometric redshift fitting technique in combination with CNOC2 and GOODS/HDF-N redshift data. The training set includes 4924 spectral redshifts. The resulting catalog contains more than one million galaxies with photometric redshifts < 1.5 and R{sub c} < 24, giving an rms scatter {delta}({Delta}z) photometric redshift fitting technique which they use to determine the relation between red-shift and photometry. A kd-tree algorithm is used to divide up the sample to improve the accuracy of the catalog. They also present a method for estimating the photometric redshift error for individual galaxies. They show that the redshift distribution of the sample is in excellent agreement with smaller and much deeper photometric and spectroscopic redshift surveys.« less

The Potentiometric Titration of Filtrates from the Bachmann Process

DTIC Science & Technology

1942-06-23

SCIENTIFIC RESEARCH AND DEVELOP11ENT The Potentiometric Titration of Filtrates from the Bachmann Process (OD-12) by F. C. Whitmore OSRD No. 654... Potentiometric Titration of Synthetic Mixtures. A? Nitric Acid-Acetic Acid. A sample of 60 ml. glacial acetic acid war diluted to 200 ml. with distilled...i4flinflr?fj3 TADLE 1 CO) |S?lDBnTl» POTENTIOMETRIC TITRATION OF SYNTHETIC t’.IXTURES WITH CONCENTRATED AJKDNIUM HYDROXIDE A; unonium HNO-j- AcOfi Ky

A novel approach for high precision rapid potentiometric titrations: application to hydrazine assay.

PubMed

Sahoo, P; Malathi, N; Ananthanarayanan, R; Praveen, K; Murali, N

2011-11-01

We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ~2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO(3) in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors. © 2011 American Institute of Physics

A novel approach for high precision rapid potentiometric titrations: Application to hydrazine assay

NASA Astrophysics Data System (ADS)

Sahoo, P.; Malathi, N.; Ananthanarayanan, R.; Praveen, K.; Murali, N.

2011-11-01

We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ˜2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO3 in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

3-D Surface Visualization of pH Titration "Topos": Equivalence Point Cliffs, Dilution Ramps, and Buffer Plateaus

ERIC Educational Resources Information Center

Smith, Garon C.; Hossain, Md Mainul; MacCarthy, Patrick

2014-01-01

3-D topographic surfaces ("topos") can be generated to visualize how pH behaves during titration and dilution procedures. The surfaces are constructed by plotting computed pH values above a composition grid with volume of base added in one direction and overall system dilution on the other. What emerge are surface features that…

DIFFERENTIAL THERMOMETRIC TITRATIONS AND THE DETERMINATION OF HEATS OF REACTION,

DTIC Science & Technology

TITRATION , THERMISTORS), (*HEAT OF REACTION, TITRATION ), SILVER COMPOUNDS, NITRATES, AMMONIA, PYRIDINES, ETHYLENEDIAMINE, AMINES, ALCOHOLS, BUTANOLS, PROPANOLS, SODIUM COMPOUNDS, HYDROXIDES, TEST METHODS

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Potassium Ferricyanide Titration..., App. A Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium... buffered sulfide solution is titrated with standard potassium ferricyanide solution in the presence of a...

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Potassium Ferricyanide Titration..., App. A Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium... buffered sulfide solution is titrated with standard potassium ferricyanide solution in the presence of a...

HFF-DeepSpace Photometric Catalogs of the 12 Hubble Frontier Fields, Clusters, and Parallels: Photometry, Photometric Redshifts, and Stellar Masses

NASA Astrophysics Data System (ADS)

Shipley, Heath V.; Lange-Vagle, Daniel; Marchesini, Danilo; Brammer, Gabriel B.; Ferrarese, Laura; Stefanon, Mauro; Kado-Fong, Erin; Whitaker, Katherine E.; Oesch, Pascal A.; Feinstein, Adina D.; Labbé, Ivo; Lundgren, Britt; Martis, Nicholas; Muzzin, Adam; Nedkova, Kalina; Skelton, Rosalind; van der Wel, Arjen

2018-03-01

We present Hubble multi-wavelength photometric catalogs, including (up to) 17 filters with the Advanced Camera for Surveys and Wide Field Camera 3 from the ultra-violet to near-infrared for the Hubble Frontier Fields and associated parallels. We have constructed homogeneous photometric catalogs for all six clusters and their parallels. To further expand these data catalogs, we have added ultra-deep K S -band imaging at 2.2 μm from the Very Large Telescope HAWK-I and Keck-I MOSFIRE instruments. We also add post-cryogenic Spitzer imaging at 3.6 and 4.5 μm with the Infrared Array Camera (IRAC), as well as archival IRAC 5.8 and 8.0 μm imaging when available. We introduce the public release of the multi-wavelength (0.2–8 μm) photometric catalogs, and we describe the unique steps applied for the construction of these catalogs. Particular emphasis is given to the source detection band, the contamination of light from the bright cluster galaxies (bCGs), and intra-cluster light (ICL). In addition to the photometric catalogs, we provide catalogs of photometric redshifts and stellar population properties. Furthermore, this includes all the images used in the construction of the catalogs, including the combined models of bCGs and ICL, the residual images, segmentation maps, and more. These catalogs are a robust data set of the Hubble Frontier Fields and will be an important aid in designing future surveys, as well as planning follow-up programs with current and future observatories to answer key questions remaining about first light, reionization, the assembly of galaxies, and many more topics, most notably by identifying high-redshift sources to target.

A Blind Test of Hapke's Photometric Model

NASA Technical Reports Server (NTRS)

Helfenstein, P.; Shepard, M. K.

2003-01-01

Hapke's bidirectional reflectance equation is a versatile analytical tool for predicting (i.e. forward modeling) the photometric behavior of a particulate surface from the observed optical and structural properties of its constituents. Remote sensing applications of Hapke s model, however, generally seek to predict the optical and structural properties of particulate soil constituents from the observed photometric behavior of a planetary surface (i.e. inverse-modeling). Our confidence in the latter approach can be established only if we ruthlessly test and optimize it. Here, we summarize preliminary results from a blind-test of the Hapke model using laboratory measurements obtained with the Bloomsburg University Goniometer (B.U.G.). The first author selected eleven well-characterized powder samples and measured the spectrophotometric behavior of each. A subset of twenty undisclosed examples of the photometric measurement sets were sent to the second author who fit the data using the Hapke model and attempted to interpret their optical and mechanical properties from photometry alone.

The Candela and Photometric and Radiometric Measurements

PubMed Central

Parr, Albert C.

2001-01-01

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements. PMID:27500020

DES Science Portal: Computing Photometric Redshifts

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

Gschwend, Julia

An important challenge facing photometric surveys for cosmological purposes, such as the Dark Energy Survey (DES), is the need to produce reliable photometric redshifts (photo-z). The choice of adequate algorithms and configurations and the maintenance of an up-to-date spectroscopic database to build training sets, for example, are challenging tasks when dealing with large amounts of data that are regularly updated and constantly growing. In this paper, we present the first of a series of tools developed by DES, provided as part of the DES Science Portal, an integrated web-based data portal developed to facilitate the scientific analysis of the data,more » while ensuring the reproducibility of the analysis. We present the DES Science Portal photometric redshift tools, starting from the creation of a spectroscopic sample to training the neural network photo-z codes, to the final estimation of photo-zs for a large photometric catalog. We illustrate this operation by calculating well calibrated photo-zs for a galaxy sample extracted from the DES first year (Y1A1) data. The series of processes mentioned above is run entirely within the Portal environment, which automatically produces validation metrics, and maintains the provenance between the different steps. This system allows us to fine tune the many steps involved in the process of calculating photo-zs, making sure that we do not lose the information on the configurations and inputs of the previous processes. By matching the DES Y1A1 photometry to a spectroscopic sample, we define different training sets that we use to feed the photo-z algorithms already installed at the Portal. Finally, we validate the results under several conditions, including the case of a sample limited to i<22.5 with the color properties close to the full DES Y1A1 photometric data. This way we compare the performance of multiple methods and training configurations. The infrastructure presented here is an effcient way to test several methods

Photometric Redshifts with the LSST: Evaluating Survey Observing Strategies

NASA Astrophysics Data System (ADS)

Graham, Melissa L.; Connolly, Andrew J.; Ivezić, Željko; Schmidt, Samuel J.; Jones, R. Lynne; Jurić, Mario; Daniel, Scott F.; Yoachim, Peter

2018-01-01

In this paper we present and characterize a nearest-neighbors color-matching photometric redshift estimator that features a direct relationship between the precision and accuracy of the input magnitudes and the output photometric redshifts. This aspect makes our estimator an ideal tool for evaluating the impact of changes to LSST survey parameters that affect the measurement errors of the photometry, which is the main motivation of our work (i.e., it is not intended to provide the “best” photometric redshifts for LSST data). We show how the photometric redshifts will improve with time over the 10 year LSST survey and confirm that the nominal distribution of visits per filter provides the most accurate photo-z results. The LSST survey strategy naturally produces observations over a range of airmass, which offers the opportunity of using an SED- and z-dependent atmospheric affect on the observed photometry as a color-independent redshift indicator. We show that measuring this airmass effect and including it as a prior has the potential to improve the photometric redshifts and can ameliorate extreme outliers, but that it will only be adequately measured for the brightest galaxies, which limits its overall impact on LSST photometric redshifts. We furthermore demonstrate how this airmass effect can induce a bias in the photo-z results, and caution against survey strategies that prioritize high-airmass observations for the purpose of improving this prior. Ultimately, we intend for this work to serve as a guide for the expectations and preparations of the LSST science community with regard to the minimum quality of photo-z as the survey progresses.

Leveraging 3D-HST Grism Redshifts to Quantify Photometric Redshift Performance

NASA Astrophysics Data System (ADS)

Bezanson, Rachel; Wake, David A.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Franx, Marijn; Labbé, Ivo; Leja, Joel; Momcheva, Ivelina G.; Nelson, Erica J.; Quadri, Ryan F.; Skelton, Rosalind E.; Weiner, Benjamin J.; Whitaker, Katherine E.

2016-05-01

We present a study of photometric redshift accuracy in the 3D-HST photometric catalogs, using 3D-HST grism redshifts to quantify and dissect trends in redshift accuracy for galaxies brighter than JH IR > 24 with an unprecedented and representative high-redshift galaxy sample. We find an average scatter of 0.0197 ± 0.0003(1 + z) in the Skelton et al. photometric redshifts. Photometric redshift accuracy decreases with magnitude and redshift, but does not vary monotonically with color or stellar mass. The 1σ scatter lies between 0.01 and 0.03 (1 + z) for galaxies of all masses and colors below z < 2.5 (for JH IR < 24), with the exception of a population of very red (U - V > 2), dusty star-forming galaxies for which the scatter increases to ˜0.1 (1 + z). We find that photometric redshifts depend significantly on galaxy size; the largest galaxies at fixed magnitude have photo-zs with up to ˜30% more scatter and ˜5 times the outlier rate. Although the overall photometric redshift accuracy for quiescent galaxies is better than that for star-forming galaxies, scatter depends more strongly on magnitude and redshift than on galaxy type. We verify these trends using the redshift distributions of close pairs and extend the analysis to fainter objects, where photometric redshift errors further increase to ˜0.046 (1 + z) at {H}F160W=26. We demonstrate that photometric redshift accuracy is strongly filter dependent and quantify the contribution of multiple filter combinations. We evaluate the widths of redshift probability distribution functions and find that error estimates are underestimated by a factor of ˜1.1-1.6, but that uniformly broadening the distribution does not adequately account for fitting outliers. Finally, we suggest possible applications of these data in planning for current and future surveys and simulate photometric redshift performance in the Large Synoptic Survey Telescope, Dark Energy Survey (DES), and combined DES and Vista Hemisphere surveys.

Photometric Repeatability of Scanned Imagery: UVIS

NASA Astrophysics Data System (ADS)

Shanahan, Clare E.; McCullough, Peter; Baggett, Sylvia

2017-08-01

We provide the preliminary results of a study on the photometric repeatability of spatial scans of bright, isolated white dwarf stars with the UVIS channel of the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We analyze straight-line scans from the first pair of identical orbits of HST program 14878 to assess if sub 0.1% repeatability can be attained with WFC3/UVIS. This study is motivated by the desire to achieve better signal-to-noise in the UVIS contamination and stability monitor, in which observations of standard stars in staring mode have been taken from the installation of WFC3 in 2009 to the present to assess temporal photometric stability. Higher signal to noise in this program would greatly benefit the sensitivity to detect contamination, and to better characterize the observed small throughput drifts over time. We find excellent repeatability between identical visits of program 14878, with sub 0.1% repeatability achieved in most filters. These! results support the initiative to transition the staring mode UVIS contamination and photometric stability monitor from staring mode images to spatial scans.

A new sensor for thermometric titrations.

PubMed

Najib, Fadhil M; Zewar, Sardir; Abdulla, Ahmad M

2007-01-15

A new thermometric sensor, which is a transistor (OC71), has been introduced to follow thermometric titrations successfully to clear end points. The sensor was suitable in both normal and differential modes of titration. It is possible to titrate down to 1.32micromol of HCl and 26.4micromol of H(3)BO(3)in a final 20ml solution with accuracy and precision of 1%, 2.2% and 1.4%, 2.2%, respectively. The sensor, in association with a pH glass electrode, was used for the determination of pK values of some well established weak acids such as, acetic acid (4.77), phosphoric acid (pK(1)=2.18, pK(2)=7.20 and pK(3)=12.32) as well as for a very weak acid of uncertain pK values H(3)BO(3) (pK(1)=9.20, pK(2)=12.7 and pK(3)=13.80). The sensor was also examined for kinetic catalytic determination of iron(III) in water, milk and pharmaceuticals.

Predicting prolonged dose titration in patients starting warfarin.

PubMed

Finkelman, Brian S; French, Benjamin; Bershaw, Luanne; Brensinger, Colleen M; Streiff, Michael B; Epstein, Andrew E; Kimmel, Stephen E

2016-11-01

Patients initiating warfarin therapy generally experience a dose-titration period of weeks to months, during which time they are at higher risk of both thromboembolic and bleeding events. Accurate prediction of prolonged dose titration could help clinicians determine which patients might be better treated by alternative anticoagulants that, while more costly, do not require dose titration. A prediction model was derived in a prospective cohort of patients starting warfarin (n = 390), using Cox regression, and validated in an external cohort (n = 663) from a later time period. Prolonged dose titration was defined as a dose-titration period >12 weeks. Predictor variables were selected using a modified best subsets algorithm, using leave-one-out cross-validation to reduce overfitting. The final model had five variables: warfarin indication, insurance status, number of doctor's visits in the previous year, smoking status, and heart failure. The area under the ROC curve (AUC) in the derivation cohort was 0.66 (95%CI 0.60, 0.74) using leave-one-out cross-validation, but only 0.59 (95%CI 0.54, 0.64) in the external validation cohort, and varied across clinics. Including genetic factors in the model did not improve the area under the ROC curve (0.59; 95%CI 0.54, 0.65). Relative utility curves indicated that the model was unlikely to provide a clinically meaningful benefit compared with no prediction. Our results suggest that prolonged dose titration cannot be accurately predicted in warfarin patients using traditional clinical, social, and genetic predictors, and that accurate prediction will need to accommodate heterogeneities across clinical sites and over time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Photometric Detection of Extra-Solar Planets

NASA Technical Reports Server (NTRS)

Hatzes, Artie P.; Cochran, William D.

2004-01-01

This NASA Origins Program grant supported the TEMPEST Texas McDonald Photometric Extrasolar Search for Transits) program at McDonald Observatory, which searches for transits of extrasolar planets across the disks of their parent stars. The basic approach is to use a wide-field ground-based telescope (in our case the McDonald Observatory 0.76m telescope and it s Prime Focus Corrector) to search for transits of short period (1-15 day orbits) of close-in hot-Jupiter planets in orbit around a large sample of field stars. The next task is to search these data streams for possible transit events. We collected our first set of test data for this program using the 0.76 m PFC in the summer of 1998. From those data, we developed the optimal observing procedures, including tailoring the stellar density, exposure times, and filters to best-suit the instrument and project. In the summer of 1999, we obtained the first partial season of data on a dedicated field in the constellation Cygnus. These data were used to develop and refine the reduction and analysis procedures to produce high-precision photometry and search for transits in the resulting light curves. The TeMPEST project subsequently obtained three full seasons of data on six different fields using the McDonald Observatory 0.76m PFC.

Microscale pH Titrations Using an Automatic Pipet.

ERIC Educational Resources Information Center

Flint, Edward B.; Kortz, Carrie L.; Taylor, Max A.

2002-01-01

Presents a microscale pH titration technique that utilizes an automatic pipet. A small aliquot (1-5 mL) of the analyte solution is titrated with repeated additions of titrant, and the pH is determined after each delivery. The equivalence point is determined graphically by either the second derivative method or a Gran plot. The pipet can be…

Simultaneous Photometric and Spectroscopic Solution for AW Cam

NASA Astrophysics Data System (ADS)

Frey, J. R.; Angione, R. J.; Sievers, J. R.

2010-07-01

We present the first four color Stromgren uvby photometric observations of the eclipsing binary system AW Cam along with the first simultaneous photometric and spectroscopic solution. This solution produced a detached system with a mass ratio of 0.45 consisting of an A1 primary and an F8 secondary, both in the main sequence band. The Hipparcos/Tycho Catalogue gives V = 8.24 and a parallax = 2.17 mas.

[Photometric determination of butyl "aeroflot" flotation agent (sodium dibutyl dithiophosphate) in the air of work zone and skin washings].

PubMed

Dorogova, V B; Kucheriavykh, E I; Sokolova, T V

1989-01-01

Photometric procedure of butyl "aeroflot" identification in the work zone air and in wash-out from workers' integument was developed, The procedure was based on the formation of yellow- and orange-dyed copper dibutyl dithiophosphate under butyl "aeroflot" interaction with copper sulphate with the subsequent photometry of dyed solutions for the wavelength of 420 nm in the 10-mm cell. Buffer solution with pH-9.2 was used as an absorbing solution for the workplace air sampling and integument wash-out.

Simulation analysis of photometric data for attitude estimation of unresolved space objects

NASA Astrophysics Data System (ADS)

Du, Xiaoping; Gou, Ruixin; Liu, Hao; Hu, Heng; Wang, Yang

2017-10-01

The attitude information acquisition of unresolved space objects, such as micro-nano satellites and GEO objects under the way of ground-based optical observations, is a challenge to space surveillance. In this paper, a useful method is proposed to estimate the SO attitude state according to the simulation analysis of photometric data in different attitude states. The object shape model was established and the parameters of the BRDF model were determined, then the space object photometric model was established. Furthermore, the photometric data of space objects in different states are analyzed by simulation and the regular characteristics of the photometric curves are summarized. The simulation results show that the photometric characteristics are useful for attitude inversion in a unique way. Thus, a new idea is provided for space object identification in this paper.

ASSESSMENT OF ATTENTION THRESHOLD IN RATS BY TITRATION OF VISUAL CUE DURATION DURING THE FIVE CHOICE SERIAL REACTION TIME TASK

PubMed Central

Martin, Thomas J.; Grigg, Amanda; Kim, Susy A.; Ririe, Douglas G.; Eisenach, James C.

2014-01-01

Background The 5 choice serial reaction time task (5CSRTT) is commonly used to assess attention in rodents. We sought to develop a variant of the 5CSRTT that would speed training to objective success criteria, and to test whether this variant could determine attention capability in each subject. New Method Fisher 344 rats were trained to perform a variant of the 5CSRTT in which the duration of visual cue presentation (cue duration) was titrated between trials based upon performance. The cue duration was decreased when the subject made a correct response, or increased with incorrect responses or omissions. Additionally, test day challenges were provided consisting of lengthening the intertrial interval and inclusion of a visual distracting stimulus. Results Rats readily titrated the cue duration to less than 1 sec in 25 training sessions or less (mean ± SEM, 22.9 ± 0.7), and the median cue duration (MCD) was calculated as a measure of attention threshold. Increasing the intertrial interval increased premature responses, decreased the number of trials completed, and increased the MCD. Decreasing the intertrial interval and time allotted for consuming the food reward demonstrated that a minimum of 3.5 sec is required for rats to consume two food pellets and successfully attend to the next trial. Visual distraction in the form of a 3 Hz flashing light increased the MCD and both premature and time out responses. Comparison with existing method The titration variant of the 5CSRTT is a useful method that dynamically measures attention threshold across a wide range of subject performance, and significantly decreases the time required for training. Task challenges produce similar effects in the titration method as reported for the classical procedure. Conclusions The titration 5CSRTT method is an efficient training procedure for assessing attention and can be utilized to assess the limit in performance ability across subjects and various schedule manipulations. PMID

Thermometric titrations of amines with nitrosyl perchlorate in acetonitrile solvent.

PubMed

Gündüz, T; Kiliç, E; Cakirer, O

1996-05-01

Thirteen aliphatic and four aromatic amines, namely diethylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-butylamine, isopropylamine, di-isopropylamine, n-butylamine, di-n-butylamine, tri-n-butylamine, isobutylamine, sec-butylamine, tert-butylamine, aniline, N,N-dimethylaniline, 2-nitroaniline and 4-nitroaniline were titrated thermometrically with nitrosyl perchlorate in acetonitrile solvent. All the aliphatic amines gave very well-shaped thermometric titration curves. The calculated recovery values of the amines were very good. In comparison, the aromatic amines, aniline and N,N-dimethylaniline gave rather well-shaped titration curves, but the recovery values were fairly low. 2-Nitro- and 4-nitro anilines gave no thermometric response at all. The heats of reaction of the amines with nitrosyl perchlorate are rather high. However, the average heat of reaction of the aromatic amines is approximately two-thirds that of the average heat of the aliphatic amines. To support this method all the amines were also titrated potentiometrically and very similar results to those obtained with the thermometric method are seen. The nitrosyl ion is a Lewis acid, strong enough to titrate quantitatively aliphatic amines in acetonitrile solvent, but not strong enough to titrate aromatic amines at the required level in the same solvent.

Concentration-related response potentiometric titrations to study the interaction of small molecules with large biomolecules.

PubMed

Hamidi-Asl, Ezat; Daems, Devin; De Wael, Karolien; Van Camp, Guy; Nagels, Luc J

2014-12-16

In the present paper, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small-molecule interactions is reported. This approach is fast, sensitive, reproducible, and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small-molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed into a concentration-related signal over the entire concentration interval, also at low concentrations, where the millivolt (y-axis) versus log canalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anticocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis(4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using surface plasmon resonance. The potentiometric titration approach called "concentration-related response potentiometry" is used to study molecular interaction for seven macromolecular target molecules and four small-molecule ligands.

The photometric functions of Phobos and Deimos. II - Surface photometry of Deimos

NASA Technical Reports Server (NTRS)

Noland, M.; Veverka, J.

1977-01-01

Mariner 9 television pictures of Deimos are used to study the uniformity of a certain photometric scattering parameter over the surface of the satellite. It is shown that the photometric data considered satisfy the reciprocity principle and that the Hapke-Irvine scattering law is adequate for describing the surface. Phase functions for Deimos are obtained from scans along the photometric equator, and the photometric behavior of the brightest and darkest areas on the satellite's disk is examined. The results indicate that the surface of Deimos is covered uniformly by a dark and texturally complex material whose photometric behavior is well-represented by the Hapke-Irvine law, that the intrinsic phase coefficient of this material is about 0.017 mag/deg over the phase-angle range from 20 to 80 deg, and that slightly brighter material is present near some craters. Since enhanced brightening was not observed at the specular point of the photometric equator in any of the pictures studied, it is concluded that large exposures of solid rock are absent from the Mars-facing side of Deimos.

Filtrates & Residues: Olfactory Titration.

ERIC Educational Resources Information Center

Wood, John T.; Eddy, Roberta M.

1996-01-01

Presents an experiment that uses a unique acid-base indicator--the odor of raw onion--to indicate the end point of the titration of sodium hydroxide with hydrochloric acid. Allows the student to detect the completion of the neutralization reaction by olfaction rather than sight. (JRH)

Spectral reflectance and photometric properties of selected rocks

USGS Publications Warehouse

Watson, Robert D.

1971-01-01

Studies of the spectral reflectance and photometric properties of selected rocks at the USGS Mill Creek, Oklahoma, remote sensing test site demonstrate that discrimination of rock types is possible through reflection measurements, but that the discrimination is complicated by surface conditions, such as weathering and lichen growth. Comparisons between fresh-broken, weathered, and lichen-covered granite show that whereas both degree of weathering and amount of lichen cover change the reflectance quality of the granite, lichen cover also considerably changes the photometric properties of the granite. Measurements of the spectral reflectance normal to the surface of both limestone and dolomite show limestone to be more reflective than dolomite in the wavelength range from 380 to 1550 nanometers. The reflectance difference decreases at view angles greater than 40° owing to the difference in the photometric properties of dolomite and limestone.

An imaging-based photometric and colorimetric measurement method for characterizing OLED panels for lighting applications

NASA Astrophysics Data System (ADS)

Zhu, Yiting; Narendran, Nadarajah; Tan, Jianchuan; Mou, Xi

2014-09-01

The organic light-emitting diode (OLED) has demonstrated its novelty in displays and certain lighting applications. Similar to white light-emitting diode (LED) technology, it also holds the promise of saving energy. Even though the luminous efficacy values of OLED products have been steadily growing, their longevity is still not well understood. Furthermore, currently there is no industry standard for photometric and colorimetric testing, short and long term, of OLEDs. Each OLED manufacturer tests its OLED panels under different electrical and thermal conditions using different measurement methods. In this study, an imaging-based photometric and colorimetric measurement method for OLED panels was investigated. Unlike an LED that can be considered as a point source, the OLED is a large form area source. Therefore, for an area source to satisfy lighting application needs, it is important that it maintains uniform light level and color properties across the emitting surface of the panel over a long period. This study intended to develop a measurement procedure that can be used to test long-term photometric and colorimetric properties of OLED panels. The objective was to better understand how test parameters such as drive current or luminance and temperature affect the degradation rate. In addition, this study investigated whether data interpolation could allow for determination of degradation and lifetime, L70, at application conditions based on the degradation rates measured at different operating conditions.

A cooperative approach among methods for photometric redshifts estimation: an application to KiDS data

NASA Astrophysics Data System (ADS)

Cavuoti, S.; Tortora, C.; Brescia, M.; Longo, G.; Radovich, M.; Napolitano, N. R.; Amaro, V.; Vellucci, C.; La Barbera, F.; Getman, F.; Grado, A.

2017-04-01

Photometric redshifts (photo-z) are fundamental in galaxy surveys to address different topics, from gravitational lensing and dark matter distribution to galaxy evolution. The Kilo Degree Survey (KiDS), I.e. the European Southern Observatory (ESO) public survey on the VLT Survey Telescope (VST), provides the unprecedented opportunity to exploit a large galaxy data set with an exceptional image quality and depth in the optical wavebands. Using a KiDS subset of about 25000 galaxies with measured spectroscopic redshifts, we have derived photo-z using (I) three different empirical methods based on supervised machine learning; (II) the Bayesian photometric redshift model (or BPZ); and (III) a classical spectral energy distribution (SED) template fitting procedure (LE PHARE). We confirm that, in the regions of the photometric parameter space properly sampled by the spectroscopic templates, machine learning methods provide better redshift estimates, with a lower scatter and a smaller fraction of outliers. SED fitting techniques, however, provide useful information on the galaxy spectral type, which can be effectively used to constrain systematic errors and to better characterize potential catastrophic outliers. Such classification is then used to specialize the training of regression machine learning models, by demonstrating that a hybrid approach, involving SED fitting and machine learning in a single collaborative framework, can be effectively used to improve the accuracy of photo-z estimates.

The Acid-Base Titration of a Very Weak Acid: Boric Acid

ERIC Educational Resources Information Center

Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

2012-01-01

A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

Photometric variability in earthshine observations.

PubMed

Langford, Sally V; Wyithe, J Stuart B; Turner, Edwin L

2009-04-01

The identification of an extrasolar planet as Earth-like will depend on the detection of atmospheric signatures or surface non-uniformities. In this paper we present spatially unresolved flux light curves of Earth for the purpose of studying a prototype extrasolar terrestrial planet. Our monitoring of the photometric variability of earthshine revealed changes of up to 23% per hour in the brightness of Earth's scattered light at around 600 nm, due to the removal of specular reflection from the view of the Moon. This variability is accompanied by reddening of the spectrum and results from a change in surface properties across the continental boundary between the Indian Ocean and Africa's east coast. Our results based on earthshine monitoring indicate that specular reflection should provide a useful tool in determining the presence of liquid water on extrasolar planets via photometric observations.

A potentiometric titration method for the crystallization of drug-like organic molecules.

PubMed

Du-Cuny, Lei; Huwyler, Jörg; Fischer, Holger; Kansy, Manfred

2007-09-05

It is generally accepted, that crystalline solids representing a low energy polymorph should be selected for development of oral dosage forms. As a consequence, efficient and robust procedures are needed at an early stage during drug discovery to prepare crystals from drug-like organic molecules. In contrast to the use of supersaturated solutions, we present a potentiometric crystallization procedure where saturated solutions are prepared in a controlled manner by pH-titration. Crystallization is carried out under defined conditions using the sample concentration and experimental pK(a) values as input parameters. Crystals of high quality were obtained for 11 drugs selected to demonstrate the efficiency and applicability of the new method. Technical improvements are suggested to overcome practical limitations and to enhance the possibility of obtaining crystals from molecules in their uncharged form.

Amperometric, Bipotentiometric, and Coulometric Titration.

ERIC Educational Resources Information Center

Stock, John T.

1980-01-01

Discusses recent review articles in various kinds of titration. Also discusses new research in apparatus and methodology, acid-base reactions, precipitation and complexing reactions, oxidation-reduction reactions, and nomenclature. Cites 338 references. (CS)

CALIBRATION OF THE MEARTH PHOTOMETRIC SYSTEM: OPTICAL MAGNITUDES AND PHOTOMETRIC METALLICITY ESTIMATES FOR 1802 NEARBY M-DWARFS

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

Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David

The MEarth Project is a photometric survey systematically searching the smallest stars near the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late M dwarfs. We have augmented this survey by taking nightly exposures of photometric standard stars and have utilized this data to photometrically calibrate the MEarth system, identify photometric nights, and obtain an optical magnitude with 1.5% precision for each M dwarf system. Each optical magnitude is an average over many years of data, and therefore should be largely immune to stellar variability and flaring. Wemore » combine this with trigonometric distance measurements, spectroscopic metallicity measurements, and 2MASS infrared magnitude measurements in order to derive a color–magnitude–metallicity relation across the mid-to-late M dwarf spectral sequence that can reproduce spectroscopic metallicity determinations to a precision of 0.1 dex. We release optical magnitudes and metallicity estimates for 1567 M dwarfs, many of which did not have an accurate determination of either prior to this work. For an additional 277 stars without a trigonometric parallax, we provide an estimate of the distance, assuming solar neighborhood metallicity. We find that the median metallicity for a volume-limited sample of stars within 20 pc of the Sun is [Fe/H] = −0.03 ± 0.008, and that 29/565 of these stars have a metallicity of [Fe/H] = −0.5 or lower, similar to the low-metallicity distribution of nearby G dwarfs. When combined with the results of ongoing and future planet surveys targeting these objects, the metallicity estimates presented here will be important for assessing the significance of any putative planet–metallicity correlation.« less

Calibration of the MEarth Photometric System: Optical Magnitudes and Photometric Metallicity Estimates for 1802 Nearby M-Dwarfs

NASA Astrophysics Data System (ADS)

Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Newton, Elisabeth R.

2016-02-01

The MEarth Project is a photometric survey systematically searching the smallest stars near the Sun for transiting rocky planets. Since 2008, MEarth has taken approximately two million images of 1844 stars suspected to be mid-to-late M dwarfs. We have augmented this survey by taking nightly exposures of photometric standard stars and have utilized this data to photometrically calibrate the MEarth system, identify photometric nights, and obtain an optical magnitude with 1.5% precision for each M dwarf system. Each optical magnitude is an average over many years of data, and therefore should be largely immune to stellar variability and flaring. We combine this with trigonometric distance measurements, spectroscopic metallicity measurements, and 2MASS infrared magnitude measurements in order to derive a color-magnitude-metallicity relation across the mid-to-late M dwarf spectral sequence that can reproduce spectroscopic metallicity determinations to a precision of 0.1 dex. We release optical magnitudes and metallicity estimates for 1567 M dwarfs, many of which did not have an accurate determination of either prior to this work. For an additional 277 stars without a trigonometric parallax, we provide an estimate of the distance, assuming solar neighborhood metallicity. We find that the median metallicity for a volume-limited sample of stars within 20 pc of the Sun is [Fe/H] = -0.03 ± 0.008, and that 29/565 of these stars have a metallicity of [Fe/H] = -0.5 or lower, similar to the low-metallicity distribution of nearby G dwarfs. When combined with the results of ongoing and future planet surveys targeting these objects, the metallicity estimates presented here will be important for assessing the significance of any putative planet-metallicity correlation.

Supernova Photometric Lightcurve Classification

NASA Astrophysics Data System (ADS)

Zaidi, Tayeb; Narayan, Gautham

2016-01-01

This is a preliminary report on photometric supernova classification. We first explore the properties of supernova light curves, and attempt to restructure the unevenly sampled and sparse data from assorted datasets to allow for processing and classification. The data was primarily drawn from the Dark Energy Survey (DES) simulated data, created for the Supernova Photometric Classification Challenge. This poster shows a method for producing a non-parametric representation of the light curve data, and applying a Random Forest classifier algorithm to distinguish between supernovae types. We examine the impact of Principal Component Analysis to reduce the dimensionality of the dataset, for future classification work. The classification code will be used in a stage of the ANTARES pipeline, created for use on the Large Synoptic Survey Telescope alert data and other wide-field surveys. The final figure-of-merit for the DES data in the r band was 60% for binary classification (Type I vs II).Zaidi was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

Digital movie-based on automatic titrations.

PubMed

Lima, Ricardo Alexandre C; Almeida, Luciano F; Lyra, Wellington S; Siqueira, Lucas A; Gaião, Edvaldo N; Paiva Junior, Sérgio S L; Lima, Rafaela L F C

2016-01-15

This study proposes the use of digital movies (DMs) in a flow-batch analyzer (FBA) to perform automatic, fast and accurate titrations. The term used for this process is "Digital movie-based on automatic titrations" (DMB-AT). A webcam records the DM during the addition of the titrant to the mixing chamber (MC). While the DM is recorded, it is decompiled into frames ordered sequentially at a constant rate of 26 frames per second (FPS). The first frame is used as a reference to define the region of interest (ROI) of 28×13pixels and the R, G and B values, which are used to calculate the Hue (H) values for each frame. The Pearson's correlation coefficient (r) is calculated between the H values of the initial frame and each subsequent frame. The titration curves are plotted in real time using the r values and the opening time of the titrant valve. The end point is estimated by the second derivative method. A software written in C language manages all analytical steps and data treatment in real time. The feasibility of the method was attested by application in acid/base test samples and edible oils. Results were compared with classical titration and did not present statistically significant differences when the paired t-test at the 95% confidence level was applied. The proposed method is able to process about 117-128 samples per hour for the test and edible oil samples, respectively, and its precision was confirmed by overall relative standard deviation (RSD) values, always less than 1.0%. Copyright © 2015 Elsevier B.V. All rights reserved.

Antiepileptic Drug Titration and Related Health Care Resource Use and Costs.

PubMed

Fishman, Jesse; Kalilani, Linda; Song, Yan; Swallow, Elyse; Wild, Imane

2018-02-27

Unexpected breakthrough seizures resulting from suboptimal antiepileptic drug (AED) dosing during the titration period, as well as adverse events resulting from rapid AED titration, may influence the titration schedule and significantly increase health care resource use (HRU) and health care costs. To assess the relationship between AEDs, HRU, and costs during AED titration and maintenance. Practicing neurologists were recruited from a nationwide panel to provide up to 3 patient records each for this retrospective medical chart review. Patients with epilepsy who were aged ≥ 18 years and had initiated an AED between January 1, 2014, and January 1, 2016, were followed for 6 months from AED initiation. Titration duration was the time from AED initiation to the beginning of treatment maintenance as determined by the physician. Outcomes were epilepsy-specific HRU (hospitalizations, emergency department visits, outpatient visits, physician referral, laboratory testing/diagnostic imaging, and phone calls) and related costs that occurred during the titration or maintenance treatment periods. Of 811 patients, 156, 128, 125, 120, 114, 107, and 61 initiated the following AEDs: levetiracetam, lamotrigine, lacosamide, valproate, topiramate, carbamazepine, and phenytoin, respectively. Most patients (619/803 [77.1%] with complete AED data) received monotherapy. Baseline characteristics were similar across AEDs (mean [SD] age, 36.6 [14.4] years; 59.0% male). Kaplan-Meier estimates of titration duration ranged from 3.3 weeks (phenytoin) to 8.1 weeks (lamotrigine). From titration to maintenance, the overall incidence of HRU per person-month decreased 54.5%-89.3% for each HRU measure except outpatient visits (24.6% decrease). Total epilepsy-related costs decreased from $80.48 to $42.77 per person-month, or 46.9% from titration to maintenance. AED titration periods had higher HRU rates and costs than AED maintenance, suggesting that use of AEDs with shorter titration requirements

Photometric imaging in particle size measurement and surface visualization.

PubMed

Sandler, Niklas

2011-09-30

The aim of this paper is to give an insight into photometric particle sizing approaches, which differ from the typical particle size measurement of dispersed particles. These approaches can often be advantageous especially for samples that are moist or cohesive, when dispersion of particles is difficult or sometimes impossible. The main focus of this paper is in the use of photometric stereo imaging. The technique allows the reconstruction of three-dimensional images of objects using multiple light sources in illumination. The use of photometric techniques is demonstrated in at-line measurement of granules and on-line measurement during granulation and dry milling. Also, surface visualization and roughness measurements are briefly discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

A photometric mode identification method, including an improved non-adiabatic treatment of the atmosphere

NASA Astrophysics Data System (ADS)

Dupret, M.-A.; De Ridder, J.; De Cat, P.; Aerts, C.; Scuflaire, R.; Noels, A.; Thoul, A.

2003-02-01

We present an improved version of the method of photometric mode identification of Heynderickx et al. (\\cite{hey}). Our new version is based on the inclusion of precise non-adiabatic eigenfunctions determined in the outer stellar atmosphere according to the formalism recently proposed by Dupret et al. (\\cite{dup}). Our improved photometric mode identification technique is therefore no longer dependent on ad hoc parameters for the non-adiabatic effects. It contains the complete physical conditions of the outer atmosphere of the star, provided that rotation does not play a key role. We apply our method to the two slowly pulsating B stars HD 74560 and HD 138764 and to the beta Cephei star EN (16) Lac. Besides identifying the degree l of the pulsating stars, our method is also a tool for improving the knowledge of stellar interiors and atmospheres, by imposing constraints on parameters such as the metallicity and the mixing-length parameter alpha (a procedure we label non-adiabatic asteroseismology). The non-adiabatic eigenfunctions needed for the mode identification are available upon request from the authors.

The Young Solar Analogs Project: Initial Photometric Results

NASA Astrophysics Data System (ADS)

Saken, Jon M.; Gray, R. O.; Corbally, C. J.

2013-06-01

Since 2007 we have been conducting spectroscopic monitoring of the Ca II H & K lines and G-band for a sample of 31 YSAs in order to better understand their activity cycles and variations, as well as the effects of young stars on their solar systems. The targets cover the spectral range of stars most likely to contain Earth analogs, F8-K2, and a broad enough range of ages, 0.3 Gyr - 1.5 Gyr, to investigate how activity level changes with stellar age. These studies are already showing possible evidence for activity cycles, large variations in starspot activity, and flaring events. In order to obtain a more complete picture of the nature of the stars' activity and examine the correlations between stellar brightness and chromospheric activity, we have started a complimentary campaign of photometric monitoring of these targets in Johnson B, V, and R, Stromgren v and H-alpha, with the use of a small robotic telescope dedicated to this project. This poster will present some results from the first year of photometric monitoring, focusing on the correlations between the photometric bands, and between the photometric and spectroscopic data, as well as an investigation of short-term (1-2 minutes) spectroscopic variations using data obtained earlier this year on the 1.8 m Vatican Advanced Technology Telescope (VATT).

The most complete photometric analysis of 548 CALIFA galaxies

NASA Astrophysics Data System (ADS)

Gilhuly, Colleen

We present an extensive photometric catalog for 548 CALIFA galaxies observed as of the summer of 2015. CALIFA is currently lacking photometry matching the scale and diversity of its spectroscopy; this work is intended to meet all photometric needs for CALIFA galaxies while also identifying best photometric practices for upcoming integral field spectroscopy surveys such as SAMI and MaNGA. This catalog comprises gri surface brightness profiles derived from Sloan Digital Sky Survey (SDSS) imaging, a variety of non-parametric quantities extracted from these pro files, and parametric models fitted to the i-band pro files (1D) and original galaxy images (2D). To compliment our photometric analysis, we contrast the relative performance of our 1D and 2D modelling approaches. The ability of each measurement to characterize the global properties of galaxies is quantitatively assessed, in the context of constructing the tightest scaling relations. Where possible, we compare our photometry with existing photometrically or spectroscopically obtained measurements from the literature. Close agreement is found with Walcher et al. (2014), the current source of basic photometry and classifications of CALIFA galaxies, while comparisons with spectroscopically derived quantities reveals the effect of CALIFA's limited field of view compared to broadband imaging surveys such as the SDSS. The colour-magnitude diagram, star formation main sequence, and Tully-Fisher relation of CALIFA galaxies are studied, to give a small example of the investigations possible with this rich catalog. We conclude with a discussion of points of concern for ongoing integral field spectroscopy surveys and directions for future expansion and exploitation of this work.

The Mobile Insulin Titration Intervention (MITI) for Insulin Glargine Titration in an Urban, Low-Income Population: Randomized Controlled Trial Protocol.

PubMed

Levy, Natalie; Moynihan, Victoria; Nilo, Annielyn; Singer, Karyn; Bernik, Lidia S; Etiebet, Mary-Ann; Fang, Yixin; Cho, James; Natarajan, Sundar

2015-03-13

Patients on insulin glargine typically visit a clinician to obtain advice on how to adjust their insulin dose. These multiple clinic visits can be costly and time-consuming, particularly for low-income patients. It may be feasible to achieve insulin titration through text messages and phone calls with patients instead of face-to-face clinic visits. The objectives of this study are to (1) evaluate if the Mobile Insulin Titration Intervention (MITI) is clinically effective by helping patients reach their optimal dose of insulin glargine, (2) determine if the intervention is feasible within the setting and population, (3) assess patient satisfaction with the intervention, and (4) measure the costs associated with this intervention. This is a pilot study evaluating an approach to insulin titration using text messages and phone calls among patients with insulin-dependent type 2 diabetes in the outpatient medical clinic of Bellevue Hospital Center, a safety-net hospital in New York City. Patients will be randomized in a 1:1 ratio to either the MITI arm (texting/phone call intervention) or the usual-care arm (in-person clinic visits). Using a Web-based platform, weekday text messages will be sent to patients in the MITI arm, asking them to text back their fasting blood glucose values. In addition to daily reviews for alarm values, a clinician will rereview the texted values weekly, consult our physician-approved titration algorithm, and call the patients with advice on how to adjust their insulin dose. The primary outcome will be whether or not a patient reaches his/her optimal dose of insulin glargine within 12 weeks. Recruitment for this study occurred between June 2013 and December 2014. We are continuing to collect intervention and follow-up data from our patients who are currently enrolled. The results of our data analysis are expected to be available in 2015. This study explores the use of widely-available text messaging and voice technologies for insulin titration

Photometric Observations of 1969 Alain

NASA Astrophysics Data System (ADS)

Hayes-Gehrke, Melissa N.; Leffler, Taylor; Hampton, Karley; Chavis, Jacob; Fong, Josef; Wang, Yu; Hung, Andrew; Mahoney, James; Rizal, Muhammad Haziq Aiman Saiful Rizal

2018-01-01

CCD photometric observations of minor planet 1969 Alain by the T17 Telescope in Siding Spring, Australia in March and April 2017 were combined for lightcurve analysis. The combined data set led to a rotation period of P = 32.4 ± 0.4 h.

New approach in the treatment of data from an acid-base potentiometric titrationI. Monocomponent systems of monofunctional acids and bases.

PubMed

Maslarska, Vania; Tencheva, Jasmina; Budevsky, Omortag

2003-01-01

Based on precise analysis of the acid-base equilibrium, a new approach in the treatment of experimental data from a potentiometric titration is proposed. A new general formula giving explicitly the relation V=f([H(+)]) is derived, valid for every acid-base titration, which includes mono- and polyfunctional protolytes and their mixtures. The present study is the first practical application of this formula for the simplest case, the analysis of one monofunctional protolyte. The collected mV data during the titration are converted into pH-values by means of an auto pH-calibration procedure, thus avoiding preliminary preparation of the measuring system. The mentioned pH-calibration method is applicable also in water-organic mixtures and allows the quantitative determination of sparingly soluble substances (particularly pharmaceuticals). The treatment of the data is performed by means of ready-to-use software products, which makes the proposed approach accessible for a wide range of applications.

Entire-Dataset Analysis of NMR Fast-Exchange Titration Spectra: A Mg2+ Titration Analysis for HIV-1 Ribonuclease H Domain.

PubMed

Karki, Ichhuk; Christen, Martin T; Spiriti, Justin; Slack, Ryan L; Oda, Masayuki; Kanaori, Kenji; Zuckerman, Daniel M; Ishima, Rieko

2016-12-15

This article communicates our study to elucidate the molecular determinants of weak Mg 2+ interaction with the ribonuclease H (RNH) domain of HIV-1 reverse transcriptase in solution. As the interaction is weak (a ligand-dissociation constant >1 mM), nonspecific Mg 2+ interaction with the protein or interaction of the protein with other solutes that are present in the buffer solution can confound the observed Mg 2+ -titration data. To investigate these indirect effects, we monitored changes in the chemical shifts of backbone amides of RNH by recording NMR 1 H- 15 N heteronuclear single-quantum coherence spectra upon titration of Mg 2+ into an RNH solution. We performed the titration under three different conditions: (1) in the absence of NaCl, (2) in the presence of 50 mM NaCl, and (3) at a constant 160 mM Cl - concentration. Careful analysis of these three sets of titration data, along with molecular dynamics simulation data of RNH with Na + and Cl - ions, demonstrates two characteristic phenomena distinct from the specific Mg 2+ interaction with the active site: (1) weak interaction of Mg 2+ , as a salt, with the substrate-handle region of the protein and (2) overall apparent lower Mg 2+ affinity in the absence of NaCl compared to that in the presence of 50 mM NaCl. A possible explanation may be that the titrated MgCl 2 is consumed as a salt and interacts with RNH in the absence of NaCl. In addition, our data suggest that Na + increases the kinetic rate of the specific Mg 2+ interaction at the active site of RNH. Taken together, our study provides biophysical insight into the mechanism of weak metal interaction on a protein.

Amperometric, Bipotentiometric, and Coulometric Titration.

ERIC Educational Resources Information Center

Stock, John T.

1984-01-01

Reviews literature on amperometric, bipotentiometric, and coulometric titration methods examining: apparatus and methodology; acid-base reactions; precipitation and complexing reactions (considering methods involving silver, mercury, EDTA or analogous reagents, and other organic compounds); and oxidation-reduction reactions (considering methods…

Electroconvulsive therapy stimulus titration: Not all it seems.

PubMed

Rosenman, Stephen J

2018-05-01

To examine the provenance and implications of seizure threshold titration in electroconvulsive therapy. Titration of seizure threshold has become a virtual standard for electroconvulsive therapy. It is justified as individualisation and optimisation of the balance between efficacy and unwanted effects. Present day threshold estimation is significantly different from the 1960 studies of Cronholm and Ottosson that are its usual justification. The present form of threshold estimation is unstable and too uncertain for valid optimisation or individualisation of dose. Threshold stimulation (lowest dose that produces a seizure) has proven therapeutically ineffective, and the multiples applied to threshold to attain efficacy have never been properly investigated or standardised. The therapeutic outcomes of threshold estimation (or its multiples) have not been separated from simple dose effects. Threshold estimation does not optimise dose due to its own uncertainties and the different short-term and long-term cognitive and memory effects. Potential harms of titration have not been examined. Seizure threshold titration in electroconvulsive therapy is not a proven technique of dose optimisation. It is widely held and practiced; its benefit and harmlessness assumed but unproven. It is a prematurely settled answer to an unsettled question that discourages further enquiry. It is an example of how practices, assumed scientific, enter medicine by obscure paths.

Graphical evaluation of complexometric titration curves.

PubMed

Guinon, J L

1985-04-01

A graphical method, based on logarithmic concentration diagrams, for construction, without any calculations, of complexometric titration curves is examined. The titration curves obtained for different kinds of unidentate, bidentate and quadridentate ligands clearly show why only chelating ligands are usually used in titrimetric analysis. The method has also been applied to two practical cases where unidentate ligands are used: (a) the complexometric determination of mercury(II) with halides and (b) the determination of cyanide with silver, which involves both a complexation and a precipitation system; for this purpose construction of the diagrams for the HgCl(2)/HgCl(+)/Hg(2+) and Ag(CN)(2)(-)/AgCN/CN(-) systems is considered in detail.

Combination of Continuous Dexmedetomidine Infusion with Titrated Ultra-Low-Dose Propofol-Fentanyl for an Awake Craniotomy

PubMed Central

Das, Samaresh; Al-Mashani, Ali; Suri, Neelam; Salhotra, Neeraj; Chatterjee, Nilay

2016-01-01

An awake craniotomy is a continuously evolving technique used for the resection of brain tumours from the eloquent cortex. We report a 29-year-old male patient who presented to the Khoula Hospital, Muscat, Oman, in 2016 with a two month history of headaches and convulsions due to a space-occupying brain lesion in close proximity with the left motor cortex. An awake craniotomy was conducted using a scalp block, continuous dexmedetomidine infusion and a titrated ultra-low-dose of propofolfentanyl. The patient remained comfortable throughout the procedure and the intraoperative neuropsychological tests, brain mapping and tumour resection were successful. This case report suggests that dexmedetomidine in combination with titrated ultra-low-dose propofolfentanyl are effective options during an awake craniotomy, ensuring optimum sedation, minimal disinhibition and a rapid recovery. To the best of the authors’ knowledge, this is the first awake craniotomy conducted successfully in Oman. PMID:27606116

Documentation for the machine-readable version of photometric data for nearby stars

NASA Technical Reports Server (NTRS)

Warren, W. H., Jr.

1982-01-01

A computer list of all photometric systems (of those considered), in which each star was measured is provided. The file is a subset of a much larger and more comprehensive compilation, which lists all measured photoelectric photometric systems for any star that has been measured in at least one photoelectric system. In addition to the photometric system identifications, cross identifications to the Henry Draper and Durchmusterung catalogs and apparent visual magnitudes are included.

21 CFR 862.2160 - Discrete photometric chemistry analyzer for clinical use.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Discrete photometric chemistry analyzer for... AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2160 Discrete photometric chemistry analyzer for clinical use. (a...

21 CFR 862.2160 - Discrete photometric chemistry analyzer for clinical use.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Discrete photometric chemistry analyzer for... AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2160 Discrete photometric chemistry analyzer for clinical use. (a...

21 CFR 862.2160 - Discrete photometric chemistry analyzer for clinical use.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Discrete photometric chemistry analyzer for... AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2160 Discrete photometric chemistry analyzer for clinical use. (a...

21 CFR 862.2160 - Discrete photometric chemistry analyzer for clinical use.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Discrete photometric chemistry analyzer for... AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2160 Discrete photometric chemistry analyzer for clinical use. (a...

Characterization of a photometric anomaly in lunar Mare Nubium

NASA Astrophysics Data System (ADS)

Korokhin, Viktor; Shkuratov, Yuriy; Kaydash, Vadym; Basilevsky, Alexander; Rohachova, Larysa; Velikodsky, Yuri; Opanasenko, Nickolay; Videen, Gorden; Stankevich, Dmitry; Kaluhina, Olena

2016-03-01

A novel approach of constructing photometrically seamless mosaics of reflectance, color-ratios, and phase-curve slopes using LROC WAC images has been developed, which can be used to map the photometric parameters of the lunar surface. The approach takes into account both geometric corrections with data on local topography and photometric conjunctions using our simple photometric model. New mosaics obtained with the technique allow more reliable studies of structural and chemical characteristics of the lunar surface. This approach has been applied to analyze the photometric anomaly (21.6 S, 17.7 W, ~40 km in size) in Mare Nubium detected earlier with our Earth-based observations. For each point of the scene the parameters were calculated using the least-square method for several tens of source WAC images. Clementine mosaics also were used in the analysis, e.g., in order to estimate the parameter of maturity degree Is/FeO. The anomaly has low FeO and TiO2 abundance and reveals a higher slope of the phase function than surroundings. Thermal data from LRO Diviner measurements do not show anomalies in this region. We consider this area as a shallow flooding of an elevated formation of highland composition, the material of which could have been excavated and mixed up with upper layers of the lunar surface through meteoroid impacts. The anomalous behavior of the phase function can be explained by the difference of surface structure in the anomaly and surrounding regions on the scale of less than several centimeters. This may be due to larger quantities of small fragments of rocks and clumps on the surface and/or the presence of agglomerates having open structure.

Dent detection method by high gradation photometric stereo

NASA Astrophysics Data System (ADS)

Hasebe, Akihisa; Kato, Kunihito; Tanahashi, Hideki; Kubota, Naoki

2017-03-01

This paper describes an automatic detection method for small dents on a metal plate. We adopted the photometric stereo as a three-dimensional measurement method, which has advantages in terms of low cost and short measurement time. In addition, a high precision measurement system was realized by using an 18bit camera. Furthermore, the small dent on the surface of the metal plate is detected by the inner product of the measured normal vectors using photometric stereo. Finally, the effectiveness of our method was confirmed by detection experiments.

Rapid Inpatient Titration of Intravenous Treprostinil for Pulmonary Arterial Hypertension: Safe and Tolerable.

PubMed

El-Kersh, Karim; Ruf, Kathryn M; Smith, J Shaun

There is no standard protocol for intravenous treprostinil dose escalation. In most cases, slow up-titration is performed in the outpatient setting. However, rapid up-titration in an inpatient setting is an alternative that provides opportunity for aggressive treatment of common side effects experienced during dose escalation. In this study, we describe our experience with inpatient rapid up-titration of intravenous treprostinil. This was a single-center, retrospective study in which we reviewed the data of subjects with pulmonary arterial hypertension treated at our center who underwent inpatient rapid up-titration of intravenous treprostinil. Our treprostinil dose escalation protocol included initiation at 2 ng·kg·min with subsequent up-titration by 1 ng·kg·min every 6 to 8 hours as tolerated by side effects. A total of 16 subjects were identified. Thirteen subjects were treprostinil naive (naive group), and 3 subjects were receiving subcutaneous treprostinil but were hospitalized for further intravenous up-titration of treprostinil dose (nonnaive group). In the naive group, the median maximum dose achieved was 20 ng·kg·min with an interquartile range (IQR) of 20-23 ng·kg·min. The median up-titration interval was 6 days (IQR: 4-9). In the nonnaive group, the median maximum dose achieved was 20 ng·kg·min (range: 17-30). The median up-titration interval was 8.5 days (range: 1.5-11). Overall, the median maximum dose achieved was 20 ng·kg·min (IQR: 20-23.5), and the median up-titration interval was 6 days (IQR: 4.6-9.25), with no reported significant adverse hemodynamic events. In patients with pulmonary arterial hypertension, rapid inpatient titration of intravenous treprostinil is safe and tolerable.

Benefit of slow titration of paroxetine to treat depression in the elderly.

PubMed

Olgiati, Paolo; Bajo, Emanuele; Serretti, Alessandro

2014-11-01

Paroxetine is commonly used to treat depression in the elderly; however, titration issues have been raised. Rapid titration may lead to increased anxiety and early dropout. The aim of this cost-utility analysis was to compare the potential benefit of standard (10 mg the first day) versus slow titration (2.5 mg gradually increased). Clinical analysis was based on a naturalistic trial integrated with a decision-analytic model representing second treatments for those who initially did not respond and for dropout cases. Treatment setting was a public outpatient center for mental disorders in Italy. Service use data were estimated from best practice guidelines, whereas costs (Euros; 2012) were retrieved from Italian official sources. Slow titration approach produced 0.031 more quality-adjusted life years (remission rate: 57% vs 44% in standard titration group) at an incremental cost of €5.53 (generic paroxetine) and €54.54 (brand paroxetine syrup). Incremental cost-effectiveness ratio (ICER) values were €159 and €1768, respectively, in favor of slow titration approach. Cost-effectiveness threshold, defined as ICER < 1 GDP per capita according to World Health Organization criteria, is about €25 000 in Italy. Our results are consistent with a superiority of slow titration of paroxetine in older depressed patients. However, these findings, in part based on simulated data, need to be replicated in clinical trials. Copyright © 2014 John Wiley & Sons, Ltd.

Kepler Mission Design, Realized Photometric Performance, and Early Science

DTIC Science & Technology

2010-04-20

USA 19 Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA 20 Ball Aerospace and Technologies Corp., Boulder, CO 80306, USA 21...was to perform multi-band photometric observations using a filter set similar to the Sloan Survey (g, r, i, z ) with the addition of a filter for the...Dynamic range 7 Kp 17 Meets photometric precision Operating temperature −85 ◦C 10 mK stability Controller Ball Aerospace Design and manufacturer

[Comparison of different continuous positive airway pressure titration methods for obstructive sleep apnea hypopnea syndrome].

PubMed

Li, Jingjing; Ye, Jingying; Zhang, Peng; Kang, Dan; Cao, Xin; Zhang, Yuhuan; Ding, Xiu; Zheng, Li; Li, Hongguang; Bian, Qiuli

2014-10-01

To explore whether there were differences between the results of automatic titration and the results of manual titration for positive airway pressure treatment in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and its influencing factors, the results might provide a theoretical basis for the rational use of two pressure titration methods. Sixty one patients with OSAHS were included in this study. All patients underwent a manual titration and an automatic titration within one week. The clinical informations, polysomnography data, and the results of both two titration of all patients were obtained for analysis. The overall apnea/hypopnea index was (63.1 ± 17.7)/h, with a range of 14.9/h to 110.4/h. The treatment pressure of manual titration was (8.4 ± 2.1) cmH(2)O, which was significantly lower than the treatment pressure of automatic titration, (11.5 ± 2.7) cmH(2)O (t = -9.797, P < 0.001). After using a ΔP of 3 cmH(2)O for the cutoff value (ΔP was defined as the difference of automatic titration and manual titration), it was found that the pressure of automatic titration was significantly higher in patients with a ΔP > 3 cmH(2)O than in patients with a ΔP ≤ 3 cmH(2)O, which was (13.3 ± 2.3) cmH(2)O vs (10.0 ± 2.0) cmH(2)O (t = -6.159, P < 0.001). However, there were no differences for the pressure of manual titration between these two groups, which was (8.6 ± 2.4) cmH(2)O vs (8.3 ± 2.0)cmH(2)O (P > 0.05). There was no significant difference in age, body mass index, neck circumference, abdomen circumference, apnea hypopnea index, and arterial oxygen saturation between these two groups. The treatment pressure of automatic titration is usually higher than that of manual titration. For patients with a high treatment pressure which is derived from automatic titration, a suggestion about manual titration could be given to decrease the potential treatment pressure of continuous positive airway pressure, which may be helpful in improving the

Dust in emission nebulae of the LMC derived from photometric reddening of stars

NASA Astrophysics Data System (ADS)

Greve, A.; van Genderen, A. M.; Laval, A.

1990-10-01

VBLUW photometric observations of stars in emission nebulae of the LMC are reported. The luminosities and extinctions of the stars are derived. Agreement is found between the average photometric extinctions of the nebulae and the extinctions derived from the Balmer line decrement measured by Caplan and Deharveng (1985 and 1986). The photometric extinctions are shown in the CO map of the LMC (Cohen et al., 1988).

METAPHOR: Probability density estimation for machine learning based photometric redshifts

NASA Astrophysics Data System (ADS)

Amaro, V.; Cavuoti, S.; Brescia, M.; Vellucci, C.; Tortora, C.; Longo, G.

2017-06-01

We present METAPHOR (Machine-learning Estimation Tool for Accurate PHOtometric Redshifts), a method able to provide a reliable PDF for photometric galaxy redshifts estimated through empirical techniques. METAPHOR is a modular workflow, mainly based on the MLPQNA neural network as internal engine to derive photometric galaxy redshifts, but giving the possibility to easily replace MLPQNA with any other method to predict photo-z's and their PDF. We present here the results about a validation test of the workflow on the galaxies from SDSS-DR9, showing also the universality of the method by replacing MLPQNA with KNN and Random Forest models. The validation test include also a comparison with the PDF's derived from a traditional SED template fitting method (Le Phare).

Persistent benefits of slow titration of paroxetine in a six-month follow-up.

PubMed

Olgiati, Paolo; Serretti, Alessandro

2015-09-01

Paroxetine titration may be difficult in older individuals as they are more sensitive to side effects. The current study extends to 6 months our previously published report in which paroxetine was started at 2.5 mg/day and slowly increased by 2.5 mg on alternate days (slow titration) or rapidly titrated to target dose from 10 mg/day (standard titration) in a naturalistic setting. Here, the follow-up period was extended to 26 weeks. We performed an intent-to-treat analysis of 47 subjects from the original sample (major depressive disorder and/or generalized anxiety disorder (GAD); >60 years of age). Missing evaluations were replaced by last observations carried forward. GAD was included as a stratification factor. Patients in whom paroxetine was slowly up-titrated were more likely to remit (84.0% vs 54.5%; p = 0.028) and had lower core depression (p = 0.0015) and psychic anxiety levels (p = 0.006) after 26 weeks. Dropout rate was 20% in the slow titration group compared with 77.3% in the standard titration arm (p < 0.001). Patients with GAD accounted for all significant associations. No substantial differences were reported between slow and standard titration groups in the subsample without GAD. Despite some limitations, these findings suggest that paroxetine treatment should be started at lower doses in older depressed patients and slowly up-titrated. This strategy would allow to increase antidepressant response and the likelihood of completing treatment cycle in patients with high anxiety levels and GAD comorbidity. Copyright © 2015 John Wiley & Sons, Ltd.

Planck 2013 results. VIII. HFI photometric calibration and mapmaking

NASA Astrophysics Data System (ADS)

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Armitage-Caplan, C.; Arnaud, M.; Ashdown, M.; Atrio-Barandela, F.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bertincourt, B.; Bielewicz, P.; Bobin, J.; Bock, J. J.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Bridges, M.; Bucher, M.; Burigana, C.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chamballu, A.; Chary, R.-R.; Chen, X.; Chiang, H. C.; Chiang, L.-Y.; Christensen, P. R.; Church, S.; Clements, D. L.; Colombi, S.; Colombo, L. P. L.; Combet, C.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dupac, X.; Efstathiou, G.; Enßlin, T. A.; Eriksen, H. K.; Filliard, C.; Finelli, F.; Forni, O.; Frailis, M.; Franceschi, E.; Galeotta, S.; Ganga, K.; Giard, M.; Giardino, G.; Giraud-Héraud, Y.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Hansen, F. K.; Hanson, D.; Harrison, D.; Helou, G.; Henrot-Versillé, S.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Juvela, M.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Laureijs, R. J.; Lawrence, C. R.; Le Jeune, M.; Lellouch, E.; Leonardi, R.; Leroy, C.; Lesgourgues, J.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Mandolesi, N.; Maris, M.; Marshall, D. J.; Martin, P. G.; Martínez-González, E.; Masi, S.; Massardi, M.; Matarrese, S.; Matthai, F.; Maurin, L.; Mazzotta, P.; McGehee, P.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Moreno, R.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; Osborne, S.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Perrotta, F.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Popa, L.; Poutanen, T.; Pratt, G. W.; Prézeau, G.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Ricciardi, S.; Riller, T.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Roudier, G.; Rusholme, B.; Santos, D.; Savini, G.; Scott, D.; Shellard, E. P. S.; Spencer, L. D.; Starck, J.-L.; Stolyarov, V.; Stompor, R.; Sudiwala, R.; Sunyaev, R.; Sureau, F.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Tavagnacco, D.; Techene, S.; Terenzi, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Vittorio, N.; Wade, L. A.; Wandelt, B. D.; Yvon, D.; Zacchei, A.; Zonca, A.

2014-11-01

This paper describes the methods used to produce photometrically calibrated maps from the Planck High Frequency Instrument (HFI) cleaned, time-ordered information. HFI observes the sky over a broad range of frequencies, from 100 to 857 GHz. To obtain the best calibration accuracy over such a large range, two different photometric calibration schemes have to be used. The 545 and 857 GHz data are calibrated by comparing flux-density measurements of Uranus and Neptune with models of their atmospheric emission. The lower frequencies (below 353 GHz) are calibrated using the solar dipole. A component of this anisotropy is time-variable, owing to the orbital motion of the satellite in the solar system. Photometric calibration is thus tightly linked to mapmaking, which also addresses low-frequency noise removal. By comparing observations taken more than one year apart in the same configuration, we have identified apparent gain variations with time. These variations are induced by non-linearities in the read-out electronics chain. We have developed an effective correction to limit their effect on calibration. We present several methods to estimate the precision of the photometric calibration. We distinguish relative uncertainties (between detectors, or between frequencies) and absolute uncertainties. Absolute uncertainties lie in the range from 0.54% to 10% from 100 to 857 GHz. We describe the pipeline used to produce the maps from the HFI timelines, based on the photometric calibration parameters, and the scheme used to set the zero level of the maps a posteriori. We also discuss the cross-calibration between HFI and the SPIRE instrument on board Herschel. Finally we summarize the basic characteristics of the set of HFI maps included in the 2013 Planck data release.

Can Selforganizing Maps Accurately Predict Photometric Redshifts?

NASA Technical Reports Server (NTRS)

Way, Michael J.; Klose, Christian

2012-01-01

We present an unsupervised machine-learning approach that can be employed for estimating photometric redshifts. The proposed method is based on a vector quantization called the self-organizing-map (SOM) approach. A variety of photometrically derived input values were utilized from the Sloan Digital Sky Survey's main galaxy sample, luminous red galaxy, and quasar samples, along with the PHAT0 data set from the Photo-z Accuracy Testing project. Regression results obtained with this new approach were evaluated in terms of root-mean-square error (RMSE) to estimate the accuracy of the photometric redshift estimates. The results demonstrate competitive RMSE and outlier percentages when compared with several other popular approaches, such as artificial neural networks and Gaussian process regression. SOM RMSE results (using delta(z) = z(sub phot) - z(sub spec)) are 0.023 for the main galaxy sample, 0.027 for the luminous red galaxy sample, 0.418 for quasars, and 0.022 for PHAT0 synthetic data. The results demonstrate that there are nonunique solutions for estimating SOM RMSEs. Further research is needed in order to find more robust estimation techniques using SOMs, but the results herein are a positive indication of their capabilities when compared with other well-known methods

Studies of cellulose surfaces by titration and ESCA

NASA Astrophysics Data System (ADS)

Stenius, Per; Laine, Janne

1994-01-01

The surface properties of unbleached kraft pulp fibers of varying lignin content prepared by digestion with different amounts of excess alkali have been investigated using polyelectrolyte titration, potentiometric titration and ESCA. The surfaces contain two different acidic groups that dissociate completely above pH 7.5, one with pK ≈ 3.6 and one with pK ≈ 5.7. The amount of the latter group correlates directly with the amount of lignin in the pulp. The ESCA analysis indicates that the relative amount of carboxylic groups and alkyl carbon in the surface decreases as the lignin content decreases and also that material with high alkyl carbon content is enriched in the outermost surface of the cellulose. Thus, a combination of ESCA analysis and high-precision titrations is able to yield a very detailed picture of the effect of digestion conditions on surface properties of cellulose fibers of direct relevance to paper properties.

Photometric classification and redshift estimation of LSST Supernovae

NASA Astrophysics Data System (ADS)

Dai, Mi; Kuhlmann, Steve; Wang, Yun; Kovacs, Eve

2018-07-01

Supernova (SN) classification and redshift estimation using photometric data only have become very important for the Large Synoptic Survey Telescope (LSST), given the large number of SNe that LSST will observe and the impossibility of spectroscopically following up all the SNe. We investigate the performance of an SN classifier that uses SN colours to classify LSST SNe with the Random Forest classification algorithm. Our classifier results in an area-under-the-curve of 0.98 which represents excellent classification. We are able to obtain a photometric SN sample containing 99 per cent SNe Ia by choosing a probability threshold. We estimate the photometric redshifts (photo-z) of SNe in our sample by fitting the SN light curves using the SALT2 model with nested sampling. We obtain a mean bias (⟨zphot - zspec⟩) of 0.012 with σ (z_phot-z_spec/1+z_spec) = 0.0294 without using a host-galaxy photo-z prior, and a mean bias (⟨zphot - zspec⟩) of 0.0017 with σ (z_phot-z_spec/1+z_spec) = 0.0116 using a host-galaxy photo-z prior. Assuming a flat ΛCDM model with Ωm = 0.3, we obtain Ωm of 0.305 ± 0.008 (statistical errors only), using the simulated LSST sample of photometric SNe Ia (with intrinsic scatter σint = 0.11) derived using our methodology without using host-galaxy photo-z prior. Our method will help boost the power of SNe from the LSST as cosmological probes.

ESO & NOT photometric monitoring of the Cloverleaf quasar

NASA Astrophysics Data System (ADS)

Ostensen, R.; Remy, M.; Lindblad, P. O.; Refsdal, S.; Stabell, R.; Surdej, J.; Barthel, P. D.; Emanuelsen, P. I.; Festin, L.; Gosset, E.; Hainaut, O.; Hakala, P.; Hjelm, M.; Hjorth, J.; Hutsemekers, D.; Jablonski, M.; Kaas, A. A.; Kristen, H.; Larsson, S.; Magain, P.; Pettersson, B.; Pospieszalska-Surdej, A.; Smette, A.; Teuber, J.; Thomsen, B.; van Drom, E.

1997-12-01

The Cloverleaf quasar, H1413+117, has been photometrically monitored at ESO (La Silla, Chile) and with the NOT (La Palma, Spain) during the period 1987--1994. All good quality CCD frames have been successfully analysed using two independent methods (i.e. an automatic image decomposition technique and an interactive CLEAN algorithm). The photometric results from the two methods are found to be very similar, and they show that the four lensed QSO images vary significantly in brightness (by up to 0.45 mag), nearly in parallel. The lightcurve of the $D$ component presents some slight departures from the general trend which are very likely caused by micro-lensing effects. Upper limits, at the 99% confidence level, of 150 days on the absolute value for the time delays between the photometric lightcurves of this quadruply imaged variable QSO, are derived. This is unfortunately too large to constrain the lens model but there is little doubt that a better sampling of the lightcurves should allow to accurately derive these time delays. Pending a direct detection of the lensing galaxy (position and redshift), this system thus constitutes another good candidate for a direct and independent determination of the Hubble parameter. Based on observations collected at the European Southern Observatory (La Silla, Chile) and with the Nordic Optical Telescope (La Palma, Spain). Table 1. Logbook for the ESO and NOT observations together with photometric results for the Cloverleaf quasar. This long table can be accessed on the WWW at the URL address: http://vela.astro.ulg.ac.be/grav_lens/glp_homepage.html}

Morpho-z: improving photometric redshifts with galaxy morphology

NASA Astrophysics Data System (ADS)

Soo, John Y. H.; Moraes, Bruno; Joachimi, Benjamin; Hartley, William; Lahav, Ofer; Charbonnier, Aldée; Makler, Martín; Pereira, Maria E. S.; Comparat, Johan; Erben, Thomas; Leauthaud, Alexie; Shan, Huanyuan; Van Waerbeke, Ludovic

2018-04-01

We conduct a comprehensive study of the effects of incorporating galaxy morphology information in photometric redshift estimation. Using machine learning methods, we assess the changes in the scatter and outlier fraction of photometric redshifts when galaxy size, ellipticity, Sérsic index, and surface brightness are included in training on galaxy samples from the SDSS and the CFHT Stripe-82 Survey (CS82). We show that by adding galaxy morphological parameters to full ugriz photometry, only mild improvements are obtained, while the gains are substantial in cases where fewer passbands are available. For instance, the combination of grz photometry and morphological parameters almost fully recovers the metrics of 5-band photometric redshifts. We demonstrate that with morphology it is possible to determine useful redshift distribution N(z) of galaxy samples without any colour information. We also find that the inclusion of quasar redshifts and associated object sizes in training improves the quality of photometric redshift catalogues, compensating for the lack of a good star-galaxy separator. We further show that morphological information can mitigate biases and scatter due to bad photometry. As an application, we derive both point estimates and posterior distributions of redshifts for the official CS82 catalogue, training on morphology and SDSS Stripe-82 ugriz bands when available. Our redshifts yield a 68th percentile error of 0.058(1 + z), and a outlier fraction of 5.2 per cent. We further include a deep extension trained on morphology and single i-band CS82 photometry.

Comparison of methods for accurate end-point detection of potentiometric titrations

NASA Astrophysics Data System (ADS)

Villela, R. L. A.; Borges, P. P.; Vyskočil, L.

2015-01-01

Detection of the end point in potentiometric titrations has wide application on experiments that demand very low measurement uncertainties mainly for certifying reference materials. Simulations of experimental coulometric titration data and consequential error analysis of the end-point values were conducted using a programming code. These simulations revealed that the Levenberg-Marquardt method is in general more accurate than the traditional second derivative technique used currently as end-point detection for potentiometric titrations. Performance of the methods will be compared and presented in this paper.

Stellar variability and its implications for photometric planet detection with Kepler

NASA Astrophysics Data System (ADS)

Batalha, N. M.; Jenkins, J.; Basri, G. S.; Borucki, W. J.; Koch, D. G.

2002-01-01

Kepler is one of three candidates for the next NASA Discovery Mission and will survey the extended solar neighborhood to detect and characterize hundreds of terrestrial (and larger) planets in or near the habitable zone. Its strength lies in its ability to detect large numbers of Earth-sized planets - planets which produced a 10-4 change in relative stellar brightness during a transit across the disk of a sun-like parent star. Such a detection requires high instrumental relative precision and is facilitated by observing stars which are photometrically quiet on hourly timescales. Probing stellar variability across the HR diagram, one finds that many of the photometrically quietest stars are the F and G dwarfs. The Hipparcos photometric database shows the lowest photometric variances among stars of this spectral class. Our own Sun is a prime example with RMS variations over a few rotational cycles of typically (3 - 4)×10-4 (computed from VIRGO/DIARAD data taken Jan-Mar 2001). And variability on the hourly time scales crucial for planet detection is significantly smaller: just (2 - 5)×10-5. This bodes well for planet detection programs such as Kepler and Eddington. With significant numbers of photometrically quiet solar-type stars, Earth-sized planets should be readily identified provided they are abundant in the solar neighborhood. In support of the Kepler science objectives, we have initiated a study of stellar variability and its implications for planet detection. Herein, we summarize existing observational and theoretrical work with the objective of determining the percentage of stars in the Kepler field of view expected to be photometrically stable at a level which allows for Earth-sized planet detection.

Economic benefit of back titration in the treatment of hypertension in Jos, Nigeria.

PubMed

Okeahialam, Basil N; Adeniyi, Michael A

2017-01-01

Treatment of hypertension is expensive and cost is one of the reasons for inadequate blood pressure control. Where there are no social cost cushions, the burden is borne by patients. With pervasive poverty and inadequate control, complications are unchecked. Back titration in appropriate circumstances should, therefore, translate to economic benefit. This is an attempt to compute, in economic terms, the benefit of back titration. Thirty-nine patients who entered an antihypertensive back titration program for 12 months and who had been earlier reported on, form the subject of this study. A survey of the cost of antihypertensives in pharmacy outlets in Jos, Nigeria was undertaken. Regimens of antihypertensives that patients were on at the onset and end of the 12 months of back titration were costed in Nigerian currency and compared. Back titration translated to economic benefit in all patients with a cost reduction varying from 2.3% to 100%. This reflected in reduction in mean daily cost of treatment of N107.09-N54.61. The benefit of antihypertensive back titration apart from psychological relief of lower pill burden and side effect profile is in pharmacoeconomics. This permits greater adherence and prevents morbi-mortality consequences of hypertension. In this study, back titration over 12 months translated to average cost reduction of >50%, making treatment more affordable. In appropriate circumstances, back titration of antihypertensives results in economic relief for patients. This should improve adherence, reduce morbi-mortality and is recommended for wider application.

Initiation of Levodopa-Carbidopa Intestinal Gel Infusion Using Telemedicine (Video Communication System) Facilitates Efficient and Well-Accepted Home Titration in Patients with Advanced Parkinson's Disease.

PubMed

Willows, Thomas; Dizdar, Nil; Nyholm, Dag; Widner, Håkan; Grenholm, Peter; Schmiauke, Ursula; Urbom, Anna; Groth, Kristina; Larsson, Jörgen; Permert, Johan; Kjellander, Susanna

2017-01-01

Levodopa-carbidopa intestinal gel (LCIG; Duodopa®) is used for continuous infusion in advanced Parkinson's disease. To achieve optimal effect, the LCIG dose is individually titrated, traditionally conducted during hospitalization in Sweden. However, dose adjustment depends on surrounding conditions, physical activity, and emotional stress, which is why titration at home could be beneficial. Telemedicine (TM) using a video communication system offers alternative titration procedures, allowing LCIG initiation at home. Study objectives were to show the feasibility of TM for LCIG home titration, evaluate resource use, and assess patient, neurologist, and nurse satisfaction. Four clinics enrolled 15 patients to observe efficiency and feasibility of TM-based monitoring. Patient median (range) age was 67 (52-73) years and time since diagnosis was 10 (7-23) years. Median time between LCIG initiation and end of TM-assisted titration was 2.8 (2.0-13.8) days. Median time required for home titration by neurologists, nurses, and patients was (hours:minutes) 1 : 14 (0 : 29-1 : 52), 5 : 49 (2 : 46-10 : 3), and 8 : 53 (4 : 11-14 : 11), respectively. Neurologists and nurses considered this to be less time than required for hospital titration. TM allowed patients 92% free time from start to end of titration. Technical problems associated with TM contacts were rare, mostly related to digital link, and quickly resolved. Patients, neurologists, and nurses were satisfied using TM. No serious adverse events were reported; there was one device complaint (tube occlusion). In this study, TM-assisted LCIG titration at home was resource-efficient, technically feasible, well-accepted and was deemed satisfactory by patients, neurologists, and nurses.

A photometric study of Enceladus

NASA Technical Reports Server (NTRS)

Verbiscer, Anne J.; Veverka, Joseph

1994-01-01

We have supplemented Voyager imaging data from Enceladus (limited to phase angles of 13 deg-43 deg) with recent Earth-based CCD observations to obtain an improved determination of the Bond albedo, to construct an albedo map of the satellite, and to constrain parameters in Hapke's (1986) photometric equation. A major result is evidence of regional variations in the physical properties of Enceladus' surface. The average global photometric properties are described by single scattering albedo omega(sub 0) average = 0.998 +/- 0.001, macroscopic roughness parameter theta average = 6 +/- 1 deg, and Henyey-Greenstein asymmetry parameter g = -0.399 +/- 0.005. The value of theta average is smaller than the 14 deg found by fitting whole-disk data, which include all terrains on Enceladus. The opposition surge amplitude B(sub 0) = 0.21 +/- 0.07 and regolith compaction parameter h = 0.014 +/- 0.02 are loosely constrained by the scarcity of and uncertainty in near-opposition observations. From the solar phase curve we determine the geometric albedo of Enceladus p(sub v) = 0.99 +/- 0.06 and phase integral q = 0.92 +/- 0.05, which corresponds to a spherical albedo A = p(sub v)q = 0.91 +/- 0.1. Since the spectrum of Enceladus is fairly flat, we can approximate the Bond albedo A(sub B) with the spherical albedo. Our photometric analysis is summarized in terms of an albedo map which generally reproduces the satellite's observed lightcurve and indicates that normal reflectances range from 0.9 on the leading hemisphere to 1.4 on the trailing one. The albedo map also revels an albedo variation of 15% from longitudes 170 deg to 200 deg, corresponding to the boundary between the leading and trailing hemispheres.

Initial Evaluation of a Titration Appliance for Temporary Treatment of Obstructive Sleep Apnea.

PubMed

Levendowski, Daniel J; Morgan, Todd; Westbrook, Philip

2012-01-01

Custom oral appliances that adjustably advance the mandible provide superior outcomes when treating patients with moderate or severe sleep apnea. Custom appliances, however, are expensive, must be fitted by a dentist, and the likelihood of successful outcomes are difficult to predict. An inexpensive trial appliance, if proven efficacious, might be used to predict custom appliance outcomes or to provide temporary therapeutic benefit. The aim of this initial study was to assess the treatment efficacy of a novel titration oral appliance with that of an optimized custom appliance. Seventeen patients, treated with a custom oral appliance for at least one year, successfully completed a three-night home sleep test. The baseline obstructive sleep apnea severity was established on Night 1 with seven patients exhibiting severe, six moderate and four mild apnea/hypopnea indexes. Patients were randomly assigned to wear their custom appliance or the titration appliance on Nights 2 and 3. Significant reductions in the mean overall and supine apnea indexes (p < 0.05), and the overall (p < 0.01) and supine (p < 0.05) apnea/hypopnea indexes were observed for both the titration and custom appliances. The proportion of patients who exhibited at least a 50% reduction in the overall apnea index and supine apnea/hypopnea were similar for the titration and custom appliance (~60%). The custom appliance reduced the overall apnea/hypopnea index by 50% in a greater proportion of the patients compared to the titration appliance (77% vs. 53%). The titration appliance significantly reduced the degree of hypoxic exposure across sleep disordered breathing events overall (p < 0.05) and supine (p < 0.01). Patients found their custom appliance was more comfortable than the titration appliance, but preferred the titration appliance to no therapy. The titration appliance may be useful in assessing oral appliance treatment efficacy. When set to 70% of maximum protrusion, the titration appliance may

Initial Evaluation of a Titration Appliance for Temporary Treatment of Obstructive Sleep Apnea

PubMed Central

Levendowski, Daniel J.; Morgan, Todd; Westbrook, Philip

2015-01-01

Background Custom oral appliances that adjustably advance the mandible provide superior outcomes when treating patients with moderate or severe sleep apnea. Custom appliances, however, are expensive, must be fitted by a dentist, and the likelihood of successful outcomes are difficult to predict. An inexpensive trial appliance, if proven efficacious, might be used to predict custom appliance outcomes or to provide temporary therapeutic benefit. Objective The aim of this initial study was to assess the treatment efficacy of a novel titration oral appliance with that of an optimized custom appliance. Methods Seventeen patients, treated with a custom oral appliance for at least one year, successfully completed a three-night home sleep test. The baseline obstructive sleep apnea severity was established on Night 1 with seven patients exhibiting severe, six moderate and four mild apnea/hypopnea indexes. Patients were randomly assigned to wear their custom appliance or the titration appliance on Nights 2 and 3. Results Significant reductions in the mean overall and supine apnea indexes (p < 0.05), and the overall (p < 0.01) and supine (p < 0.05) apnea/hypopnea indexes were observed for both the titration and custom appliances. The proportion of patients who exhibited at least a 50% reduction in the overall apnea index and supine apnea/hypopnea were similar for the titration and custom appliance (~60%). The custom appliance reduced the overall apnea/hypopnea index by 50% in a greater proportion of the patients compared to the titration appliance (77% vs. 53%). The titration appliance significantly reduced the degree of hypoxic exposure across sleep disordered breathing events overall (p < 0.05) and supine (p < 0.01). Patients found their custom appliance was more comfortable than the titration appliance, but preferred the titration appliance to no therapy. Conclusion The titration appliance may be useful in assessing oral appliance treatment efficacy. When set to 70% of

Coulometrische titration von hypochloriten und chloraten.

PubMed

Gründler, P; Holzapfel, H

1970-03-01

Hypochlorite was determined by direct coulometric titration with iron(II) in an acetate buffered solution. Chlorate was titrated with titanium(III) in 2M hydrochloric acid. Amperometric indication with one and two electrodes, respectively, was used. Mixtures of hypochlorites and chlorates, e.g., in industrial electrolytes, may be analysed. On a déterminé l'hypochlorite par titrage coulométrique direct avec le fer(II) dans une solution tamponnée à l'acétate. On a titré le chlorate avec le titane(III) en acide chlorhydrique 2M. On a utilisé l'indication ampérométrique une et deux électrodes respectivement. On peut analyser des mélanges d'hypochlorites et de chlorates, par exemple dans des électrolytes industriels.

[Determination of aluminium in flour foods with photometric method].

PubMed

Ma, Lan; Zhao, Xin; Zhou, Shuang; Yang, Dajin

2012-05-01

To establish a determination method for aluminium in flour foods with photometric method. After samples being treated with microwave digestion and wet digestion, aluminium in staple flour foods was determined by photometric method. There was a good linearity of the result in the range of 0.25 - 5.0 microg/ml aluminium, r = 0.9998; limit of detection (LOD) : 2.3 ng/ml; limit of quantitation (LOQ) : 7 ng/ml. This method of determining aluminium in flour foods is simple, rapid and reliable.

A model for oxygen conservation associated with titration during pediatric oxygen therapy

PubMed Central

Wu, Grace; Wollen, Alec; Himley, Stephen; Austin, Glenn; Delarosa, Jaclyn; Izadnegahdar, Rasa; Ginsburg, Amy Sarah; Zehrung, Darin

2017-01-01

Background Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration. Aim To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia. Methods Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration. Results Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3), respectively. For every 100 patients, 44 or 30 kiloliters would be saved—equivalent to 733 or 500 hours at 1 liter per minute. Conclusions Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems. PMID:28234903

A model for oxygen conservation associated with titration during pediatric oxygen therapy.

PubMed

Wu, Grace; Wollen, Alec; Himley, Stephen; Austin, Glenn; Delarosa, Jaclyn; Izadnegahdar, Rasa; Ginsburg, Amy Sarah; Zehrung, Darin

2017-01-01

Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration. To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia. Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration. Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3), respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute. Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

Photometric analysis in the Kepler Science Operations Center pipeline

NASA Astrophysics Data System (ADS)

Twicken, Joseph D.; Clarke, Bruce D.; Bryson, Stephen T.; Tenenbaum, Peter; Wu, Hayley; Jenkins, Jon M.; Girouard, Forrest; Klaus, Todd C.

2010-07-01

We describe the Photometric Analysis (PA) software component and its context in the Kepler Science Operations Center (SOC) Science Processing Pipeline. The primary tasks of this module are to compute the photometric flux and photocenters (centroids) for over 160,000 long cadence (~thirty minute) and 512 short cadence (~one minute) stellar targets from the calibrated pixels in their respective apertures. We discuss science algorithms for long and short cadence PA: cosmic ray cleaning; background estimation and removal; aperture photometry; and flux-weighted centroiding. We discuss the end-to-end propagation of uncertainties for the science algorithms. Finally, we present examples of photometric apertures, raw flux light curves, and centroid time series from Kepler flight data. PA light curves, centroid time series, and barycentric timestamp corrections are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and are made available to the general public in accordance with the NASA/Kepler data release policy.

Photometric Analysis in the Kepler Science Operations Center Pipeline

NASA Technical Reports Server (NTRS)

Twicken, Joseph D.; Clarke, Bruce D.; Bryson, Stephen T.; Tenenbaum, Peter; Wu, Hayley; Jenkins, Jon M.; Girouard, Forrest; Klaus, Todd C.

2010-01-01

We describe the Photometric Analysis (PA) software component and its context in the Kepler Science Operations Center (SOC) pipeline. The primary tasks of this module are to compute the photometric flux and photocenters (centroids) for over 160,000 long cadence (thirty minute) and 512 short cadence (one minute) stellar targets from the calibrated pixels in their respective apertures. We discuss the science algorithms for long and short cadence PA: cosmic ray cleaning; background estimation and removal; aperture photometry; and flux-weighted centroiding. We discuss the end-to-end propagation of uncertainties for the science algorithms. Finally, we present examples of photometric apertures, raw flux light curves, and centroid time series from Kepler flight data. PA light curves, centroid time series, and barycentric timestamp corrections are exported to the Multi-mission Archive at Space Telescope [Science Institute] (MAST) and are made available to the general public in accordance with the NASA/Kepler data release policy.

Quantitative Analysis of Sulfate in Water by Indirect EDTA Titration

ERIC Educational Resources Information Center

Belle-Oudry, Deirdre

2008-01-01

The determination of sulfate concentration in water by indirect EDTA titration is an instructive experiment that is easily implemented in an analytical chemistry laboratory course. A water sample is treated with excess barium chloride to precipitate sulfate ions as BaSO[subscript 4](s). The unprecipitated barium ions are then titrated with EDTA.…

Correct titration of non-drugs and some other methodological issues.

PubMed

Beneke, M; Rasmus, W; Rød, I S; Fritze, J

1994-01-01

Doctors' prescription and dosing behaviour was investigated using data from 9 clinical trials in 550 patients treated with psychotropics. 7 trials were conducted under double- and 2 under single-blind conditions. In 3 of these trials, oral and i.m. preparations were used demanding a double-dummy design. All patients were evaluated on a weekly or 2-week basis using psychopathological rating scales (i.e. Hamilton Anxiety Scale, Hamilton Depression Scale, Clinical Global Impressions, Simpson and Angus EPS). It was found that (a) oral-medication titration was 3- to 4-fold more broad-ranging than i.m. medication titration, (b) oral placebo was titrated to the same extent as the oral investigational drugs, and (c) the titration schedule did not follow protocol requirements. Moreover, the average doses in all drug and placebo groups were the same. Concomitant medication like sleep inducers was found to be more closely related to doctors' habits than to actual medical need. Independent of trial and investigational drug, 10-33% of all patients received additional sleep inducers.

Insights into optimal basal insulin titration in type 2 diabetes: Results of a quantitative survey

PubMed Central

Bonnemaire, Mireille; Mical, Marie; Edelman, Steve

2017-01-01

Aims Basal insulin (BI) treatment initiation and dose titration in type 2 diabetes (T2DM) are often delayed. Such “clinical inertia” results in poor glycaemic control and high risk of long‐term complications. This survey aimed to determine healthcare professional (HCP) and patient attitudes to BI initiation and titration. Methods An online survey (July–August 2015) including HCPs and patients with T2DM in the USA, France and Germany. Patients were ≥18 years old and had been on BI for 6 to 36 months, or discontinued BI within the previous 12 months. Results Participants comprised 386 HCPs and 318 people with T2DM. While >75% of HCPs reported discussing titration at the initiation visit, only 16% to 28% of patients remembered such discussions, many (32%–42%) were unaware of the need to titrate BI, and only 28% to 39% recalled mention of the time needed to reach glycaemic goals. Most HCPs and patients agreed that more effective support tools to assist BI initiation/titration are needed; patients indicated that provision of such tools would increase confidence in self‐titration. HCPs identified fear of hypoglycaemia, failure to titrate in the absence of symptoms, and low patient motivation as important titration barriers. In contrast, patients identified weight gain, the perception that titration meant worsening disease, frustration over the time to reach HbA1c goals and fear of hypoglycaemia as major factors. Conclusion A disconnect exists between HCP‐ and patient‐perceived barriers to effective BI titration. To optimize titration, strategies should be targeted to improve HCP–patient communication, and provide support and educational tools. PMID:28719066

Protometric thermometric titrations of sparingly soluble compounds in water in the presence of n-octanol.

PubMed

Burgot, G; Burgot, J-L

2002-10-15

Thermometric titrimetry permits titration of acido-basic compounds in water in the presence of n-octanol. n-Octanol permits the solubilization of protolytes and moreover may also displace the equilibria of the titration reactions. Hydrochlorides of highly insoluble derivatives such as phenothiazine derivatives can be titrated with satisfactory accuracy and precision by sodium hydroxide despite their high pK(a) values. Likewise barbiturate salts can be titrated by hydrochloric acid. In the case of some salts, the methodology may permit the sequential titration of the ion and counter ion. Copyright 2002 Elsevier Science B.V.

Initiation of Levodopa-Carbidopa Intestinal Gel Infusion Using Telemedicine (Video Communication System) Facilitates Efficient and Well-Accepted Home Titration in Patients with Advanced Parkinson’s Disease

PubMed Central

Willows, Thomas; Dizdar, Nil; Nyholm, Dag; Widner, Håkan; Grenholm, Peter; Schmiauke, Ursula; Urbom, Anna; Groth, Kristina; Larsson, Jörgen; Permert, Johan; Kjellander, Susanna

2017-01-01

Background: Levodopa-carbidopa intestinal gel (LCIG; Duodopa®) is used for continuous infusion in advanced Parkinson’s disease. To achieve optimal effect, the LCIG dose is individually titrated, traditionally conducted during hospitalization in Sweden. However, dose adjustment depends on surrounding conditions, physical activity, and emotional stress, which is why titration at home could be beneficial. Telemedicine (TM) using a video communication system offers alternative titration procedures, allowing LCIG initiation at home. Objective: Study objectives were to show the feasibility of TM for LCIG home titration, evaluate resource use, and assess patient, neurologist, and nurse satisfaction. Methods: Four clinics enrolled 15 patients to observe efficiency and feasibility of TM-based monitoring. Results: Patient median (range) age was 67 (52–73) years and time since diagnosis was 10 (7–23) years. Median time between LCIG initiation and end of TM-assisted titration was 2.8 (2.0–13.8) days. Median time required for home titration by neurologists, nurses, and patients was (hours:minutes) 1 : 14 (0 : 29–1 : 52), 5 : 49 (2 : 46–10 : 3), and 8 : 53 (4 : 11–14 : 11), respectively. Neurologists and nurses considered this to be less time than required for hospital titration. TM allowed patients 92% free time from start to end of titration. Technical problems associated with TM contacts were rare, mostly related to digital link, and quickly resolved. Patients, neurologists, and nurses were satisfied using TM. No serious adverse events were reported; there was one device complaint (tube occlusion). Conclusions: In this study, TM-assisted LCIG titration at home was resource-efficient, technically feasible, well-accepted and was deemed satisfactory by patients, neurologists, and nurses. PMID:28984615

Electrophoretic separation of alginic sodium diester and sodium hexametaphosphate in chondroitin sulfate that interfere with the cetylpyridinium chloride titration assay.

PubMed

Weiguo, Zhang; Giancaspro, Gabriel; Adams, Kristie M; Neal-Kababick, James; Hildreth, Jana; Li, Aishan; Roman, Mark C; Betz, Joseph M

2014-01-01

adulterants in CS and procedures to isolate ASD from CS matrixes containing these adulterants. The authors describe in this paper utilization of an orthogonal approach to establish the identity of Z1 as sodium hexametaphosphate and to confirm the identity of ASD, including ethanol fractionation, FTIR spectroscopy, differential scanning calorimetry, and NMR spectroscopy. The authors suggest that CAME is a cost-effective and easy to use methodfor detecting certain impurities in CS raw ingredients and recommend that CPC and CAME be used in combination by QC laboratories as a means of effectively deterring the practice of adulterating CS raw materials with the known adulterants ASD and Z1 and/or other non-chondroitin substances that can be separated from CSby CAME and that exhibit CPC titration behavior similar to CS.

Depression May Reduce Adherence during CPAP Titration Trial

PubMed Central

Law, Mandy; Naughton, Matthew; Ho, Sally; Roebuck, Teanau; Dabscheck, Eli

2014-01-01

Study Objectives: Depression is a risk factor for medication non-compliance. We aimed to identify if depression is associated with poorer adherence during home-based autotitrating continuous positive airway pressure (autoPAP) titration. Design: Mixed retrospective-observational study. Setting: Academic center. Participants: Two-hundred forty continuous positive airway pressure-naïve obstructive sleep apnea (OSA) patients. Measurements: Patients underwent approximately 1 week of home-based autoPAP titration with adherence data downloaded from the device. Electronic hospital records were reviewed in a consecutive manner for inclusion. Three areas of potential predictors were examined: (i) demographics and clinical factors, (ii) disease severity, and (iii) device-related variables. Depression and anxiety were assessed using the Hospital Anxiety and Depression Scale (HADS). Scores on the subscales were categorized as normal or clinical diagnoses of depression (≥ 8) and anxiety (≥ 11). The primary outcome variable was the mean hours of autoPAP used per night. Results: Patients were diagnosed with OSA by either attended polysomnography (n = 73, AHI 25.5[15.1-41.5]) or unattended home oximetry (n = 167, ODI3 34.0[22.4-57.4]) and had home-based autoPAP titration over 6.2 ± 1.2 nights. Mean autoPAP use was 4.5 ± 2.4 hours per night. Multiple linear regression analysis revealed that depression and lower 95th percentile pressures significantly predicted lesser hours of autoPAP use (R2 = 0.19, p < 0.001). Significantly milder OSA in those requiring lower pressures may have confounded the relationship between 95th percentile pressure and autoPAP use. Conclusion: Depression was independently associated with poorer adherence during home-based autoPAP titration. Depression may be a potential target for clinicians and future research aimed at enhancing adherence to autoPAP therapy. Citation: Law M; Naughton M; Ho S; Roebuck T; Dabscheck E. Depression may reduce adherence

Photometric measurements of solar irradiance variations due to sunspots

NASA Technical Reports Server (NTRS)

Chapman, G. A.; Herzog, A. D.; Laico, D. E.; Lawrence, J. K.; Templer, M. S.

1989-01-01

A photometric telescope constructed to obtain photometric sunspot areas and deficits on a daily basis is described. Data from this Cartesian full disk telescope (CFDT) are analyzed with attention given to the period between June 4 and June 17, 1985 because of the availability of overlapping sunspot area and irradiance deficit data from high-resolution digital spectroheliograms made with the San Fernando Observatory 28 cm vacuum solar telescope and spectroheliograph. The CFDT sunspot deficits suggest a substantial irradiance contribution from faculae and active region plage.

UBVRI PHOTOMETRIC STANDARD STARS AROUND THE CELESTIAL EQUATOR: UPDATES AND ADDITIONS

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

Landolt, Arlo U.

2009-05-15

New broadband UBVRI photoelectric observations on the Johnson-Kron-Cousins photometric system have been made of 202 stars around the sky, and centered at the celestial equator. These stars constitute both an update of and additions to a previously published list of equatorial photometric standard stars. The list is capable of providing, for both celestial hemispheres, an internally consistent homogeneous broadband standard photometric system around the sky. When these new measurements are included with those previously published by Landolt (1992), the entire list of standard stars in this paper encompasses the magnitude range 8.90 < V < 16.30, and the color indexmore » range -0.35 < (B - V) < +2.30.« less

Photometric classification and redshift estimation of LSST Supernovae

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

Dai, Mi; Kuhlmann, Steve; Wang, Yun

Supernova (SN) classification and redshift estimation using photometric data only have become very important for the Large Synoptic Survey Telescope (LSST), given the large number of SNe that LSST will observe and the impossibility of spectroscopically following up all the SNe. We investigate the performance of an SN classifier that uses SN colours to classify LSST SNe with the Random Forest classification algorithm. Our classifier results in an area-under-the-curve of 0.98 which represents excellent classification. We are able to obtain a photometric SN sample containing 99 percent SNe Ia by choosing a probability threshold. We estimate the photometric redshifts (photo-z)more » of SNe in our sample by fitting the SN light curves using the SALT2 model with nested sampling. We obtain a mean bias (⟨zphot - zspec⟩) of 0.012 with σ(z phot -z spec 1+z spec )=0.0294 σ(zphot-zspec1+zspec)=0.0294 without using a host-galaxy photo-z prior, and a mean bias (⟨zphot - zspec⟩) of 0.0017 with σ(z phot -z spec 1+z spec )=0.0116 σ(zphot-zspec1+zspec)=0.0116 using a host-galaxy photo-z prior. Assuming a flat ΛCDM model with Ωm = 0.3, we obtain Ωm of 0.305 ± 0.008 (statistical errors only), using the simulated LSST sample of photometric SNe Ia (with intrinsic scatter σint = 0.11) derived using our methodology without using host-galaxy photo-z prior. Our method will help boost the power of SNe from the LSST as cosmological probes.« less

A Photometric Observing Program at the VATT: Setting Up a Calibration Field

NASA Astrophysics Data System (ADS)

Davis Philip, A. G.; Boyle, R. P.; Janusz, R.

2009-05-01

Philip and Boyle have been making Strömgren and then Strömvil photometric observations of open and globular clusters at the Vatican Advanced Technology Telescope located on Mt. Graham in Arizona. Our aim is to obtain CCD photometric indices good to 0.01 magnitude. Indices of this quality can later be analyzed to yield estimates of temperature, luminosity and metallicity. But we have found that the CCD chip does not yield photometry of this quality without further corrections. Our most observed cluster is the open cluster, M 67. This cluster is also very well observed in the literature. We took the best published values and created a set of "standard" stars for our field. Taking our CCD results we could calculate deltas, as a function of position on the chip, which we then applied to all the CCD frames that we obtained. With this procedure we were able to obtain the precision of 0.01 magnitudes in all the fields that we observed. When we started we were able to use the "A" two-inch square Strömgren four-color set from KPNO. Later the Vatican Observatory bought a set of 3.48 inch square Strömgren filters, The Vatican Observatory had a set of circular Vilnius filters There was also an X filter. These eight filters made our Strömvil set.

Modeling of Diffuse Photometric Signatures of Satellites for Space Object Identification.

DTIC Science & Technology

1982-12-01

to provide the groundwork for devel- opment of a computer program which could serve as an aid to tactical space object identification and analysis ...I Photometric Analysis Capability at the ADIC. . . . . .. 2 Operational Limitations of the Photometric Data Analysis Module (PDA...7 PDAM Diffuse Analysis . . . . . . . . . . . . . . . . . 7 Real World SOI Requirements vs POAN Capabilities . . . . 16 Statement of the Problem

Kinetic Titration Series with Biolayer Interferometry

PubMed Central

Frenzel, Daniel; Willbold, Dieter

2014-01-01

Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1–42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations. PMID:25229647

Kinetic titration series with biolayer interferometry.

PubMed

Frenzel, Daniel; Willbold, Dieter

2014-01-01

Biolayer interferometry is a method to analyze protein interactions in real-time. In this study, we illustrate the usefulness to quantitatively analyze high affinity protein ligand interactions employing a kinetic titration series for characterizing the interactions between two pairs of interaction patterns, in particular immunoglobulin G and protein G B1 as well as scFv IC16 and amyloid beta (1-42). Kinetic titration series are commonly used in surface plasmon resonance and involve sequential injections of analyte over a desired concentration range on a single ligand coated sensor chip without waiting for complete dissociation between the injections. We show that applying this method to biolayer interferometry is straightforward and i) circumvents problems in data evaluation caused by unavoidable sensor differences, ii) saves resources and iii) increases throughput if screening a multitude of different analyte/ligand combinations.

The SimpleMix study with biphasic insulin aspart 30: a randomized controlled trial investigating patient-driven titration versus investigator-driven titration.

PubMed

Gao, Yan; Luquez, Cecilia; Lynggaard, Helle; Andersen, Henning; Saboo, Banshi

2014-12-01

The study aimed to confirm the efficacy, through non-inferiority, of patient-driven versus investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) in terms of glycemic control assessed by HbA1c change. SimpleMix was a 20 week, open-label, randomized, two-armed, parallel-group, multicenter study in five countries (Argentina, China, India, Poland, and the UK). Patients with type 2 diabetes were randomized into either patient-driven or investigator-driven BIAsp 30 titration groups. Non-inferiority of patient-driven vs. investigator-driven titration based on change in HbA1c from baseline to week 20 could not be demonstrated. Mean (SE) estimated change from baseline to week 20 was -0.72 (0.08)% in the patient-driven group and -0.97 (0.08)% in the investigator-driven group; estimated difference 0.25% (95% CI: 0.04; 0.46). Estimated mean change (SE) in fasting plasma glucose from baseline to week 20 was similar between groups: -0.94 (0.21) mmol/L for patient-driven and -1.07 (0.22) mmol/L for investigator-driven (difference non-significant). Both treatment arms were well tolerated, and hypoglycemic episode rates were similar between groups, with a rate ratio of 0.77 (95% CI: 0.54; 1.09; p = 0.143) for all hypoglycemic episodes and 0.78 (95% CI: 0.42; 1.43; p = 0.417) for nocturnal hypoglycemic episodes. Non-inferiority of patient-driven versus investigator-driven titration with regard to change from baseline to end-of-treatment HbA1c could not be confirmed. It is possible that a clinic visit 12 weeks after intensification of treatment with BIAsp 30 in patients with type 2 diabetes inadequately treated with basal insulin may benefit patient-driven titration of BIAsp 30. A limitation of the study was the relatively small number of patients recruited in each country, which does not allow country-specific analyses to be performed. Overall, treatment with BIAsp 30 was well tolerated in both treatment groups.

Insights into optimal basal insulin titration in type 2 diabetes: Results of a quantitative survey.

PubMed

Berard, Lori; Bonnemaire, Mireille; Mical, Marie; Edelman, Steve

2018-02-01

Basal insulin (BI) treatment initiation and dose titration in type 2 diabetes (T2DM) are often delayed. Such "clinical inertia" results in poor glycaemic control and high risk of long-term complications. This survey aimed to determine healthcare professional (HCP) and patient attitudes to BI initiation and titration. An online survey (July-August 2015) including HCPs and patients with T2DM in the USA, France and Germany. Patients were ≥18 years old and had been on BI for 6 to 36 months, or discontinued BI within the previous 12 months. Participants comprised 386 HCPs and 318 people with T2DM. While >75% of HCPs reported discussing titration at the initiation visit, only 16% to 28% of patients remembered such discussions, many (32%-42%) were unaware of the need to titrate BI, and only 28% to 39% recalled mention of the time needed to reach glycaemic goals. Most HCPs and patients agreed that more effective support tools to assist BI initiation/titration are needed; patients indicated that provision of such tools would increase confidence in self-titration. HCPs identified fear of hypoglycaemia, failure to titrate in the absence of symptoms, and low patient motivation as important titration barriers. In contrast, patients identified weight gain, the perception that titration meant worsening disease, frustration over the time to reach HbA1c goals and fear of hypoglycaemia as major factors. A disconnect exists between HCP- and patient-perceived barriers to effective BI titration. To optimize titration, strategies should be targeted to improve HCP-patient communication, and provide support and educational tools. © 2017 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.

A Catalog of Photometric Redshift and the Distribution of Broad Galaxy Morphologies

NASA Astrophysics Data System (ADS)

Paul, Nicholas; Virag, Nicholas; Shamir, Lior

2018-06-01

We created a catalog of photometric redshift of ~3,000,000 SDSS galaxies annotated by their broad morphology. The photometric redshift was optimized by testing and comparing several pattern recognition algorithms and variable selection strategies, trained and tested on a subset of the galaxies in the catalog that had spectra. The galaxies in the catalog have i magnitude brighter than 18 and Petrosian radius greater than 5.5''. The majority of these objects are not included in previous SDSS photometric redshift catalogs such as the photoz table of SDSS DR12. Analysis of the catalog shows that the number of galaxies in the catalog that are visually spiral increases until redshift of ~0.085, where it peaks and starts to decrease. It also shows that the number of spiral galaxies compared to elliptical galaxies drops as the redshift increases. The catalog is publicly available at https://figshare.com/articles/Morphology_and_photometric_redshift_catalog/4833593

Application of photometric models to asteroids

NASA Technical Reports Server (NTRS)

Bowell, Edward; Hapke, Bruce; Domingue, Deborah; Lumme, Kari; Peltoniemi, Jouni; Harris, Alan W.

1989-01-01

The way an asteroid or other atmosphereless solar system body varies in brightness in response to changing illumination and viewing geometry depends in a very complicated way on the physical and optical properties of its surface and on its overall shape. This paper summarizes the formulation and application of recent photometric models by Hapke (1981, 1984, 1986) and by Lumme and Bowell (1981). In both models, the brightness of a rough and porous surface is parameterized in terms of the optical properties of individual particles, by shadowing between particles, and by the way in which light is scattered among collections of particles. Both models succeed in their goal of fitting the observed photometric behavior of a wide variety of bodies, but neither has led to a very complete understanding of the properties of asteroid regoliths, primarily because, in most cases, the parameters in the present models cannot be adequately constrained by observations of integral brightness alone over a restricted range of phase angles.

Astrophysical science with a spaceborne photometric telescope

NASA Technical Reports Server (NTRS)

Granados, Arno F. (Editor); Borucki, William J. (Editor)

1994-01-01

The FRESIP Project (FRequency of Earth-Sized Inner Planets) is currently under study at NASA Ames Research Center. The goal of FRESIP is the measurement of the frequency of Earth-sized extra-solar planets in inner orbits via the photometric signature of a transit event. This will be accomplished with a spaceborne telescope/photometer capable of photometric precision of two parts in 100,000 at a magnitude of m(sub v) = 12.5. To achieve the maximum scientific value from the FRESIP mission, an astrophysical science workshop was held at the SETI Institute in Mountain View, California, November 11-12, 1993. Workshop participants were invited as experts in their field of astrophysical research and discussed the astrophysical science that can be achieved within the context of the FRESIP mission.

Clozapine Titration for People in Early Psychosis: A Chart Review and Treatment Guideline.

PubMed

Ballon, Jacob S; Ashfaq, Hera; Noordsy, Douglas L

2018-06-01

The use of clozapine, particularly in young people, is often limited by early treatment-emergent adverse effects including drowsiness and lethargy. Concerns about adverse effects, medication adherence, and the need for blood monitoring often impede the use of clozapine in this population, leading to repeated trials of less effective medications. Current clozapine dosing recommendations are based on people further in the course of their illness and thus reflect different responsiveness and sensitivities to antipsychotic medication. As such, there is a need for evidence-based guidelines for titration and dosing of clozapine among people in early psychosis. We performed a chart review of 14 people treated with clozapine within our early psychosis team. Data regarding dose titration, response, time to discontinuation, symptom severity, weight gain, and other adverse effects were gathered at clozapine initiation, 3 months, and last available visit on clozapine. People treated with slow titration within their first year of psychosis onset achieved sustained response at very low maintenance doses (mean dose = 81 mg/d, mean duration of treatment = 200 weeks) compared with slow titration with longer duration of illness (mean dose = 350 mg/d, mean duration of treatment = 68 weeks) or standard dose titration in early psychosis (mean dose = 112 mg/d, mean duration of treatment = 38 weeks). The most common adverse effects in all groups were weight gain and sedation, with the groups requiring higher mean doses reporting a broader range of adverse effects. There was no apparent difference in the clinical global impression for severity or improvement between the slow titration and standard titration groups in people with early psychosis. These observations are synthesized into a proposed treatment guideline for use of clozapine among people in early psychosis. We describe development of a slow titration approach to initiating clozapine among people in early psychosis. This

The predictive value of drug-induced sleep endoscopy for CPAP titration in OSA patients.

PubMed

Lan, Ming-Chin; Hsu, Yen-Bin; Lan, Ming-Ying; Huang, Yun-Chen; Kao, Ming-Chang; Huang, Tung-Tsun; Chiu, Tsan-Jen; Yang, Mei-Chen

2017-12-15

The aim of this study was to identify possible upper airway obstructions causing a higher continuous positive airway pressure (CPAP) titration level, utilizing drug-induced sleep endoscopy (DISE). A total of 76 patients with obstructive sleep apnea (OSA) underwent CPAP titration and DISE. DISE findings were recorded using the VOTE classification system. Polysomnographic (PSG) data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with CPAP titration levels. A significant association was found between the CPAP titration level and BMI, oxygen desaturation index (ODI), apnea-hypopnea index (AHI), and neck circumference (NC) (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively, by Spearman correlation). Patients with concentric collapse of the velum or lateral oropharyngeal collapse were associated with a significantly higher CPAP titration level (P < 0.001 and P = 0.043, respectively, by nonparametric Mann-Whitney U test; P < 0.001 and P = 0.004, respectively, by Spearman correlation). No significant association was found between the CPAP titration level and any other collapse at the tongue base or epiglottis. By analyzing PSG data, anthropometric variables, and DISE results with CPAP titration levels, we can better understand possible mechanisms resulting in a higher CPAP titration level. We believe that the role of DISE can be expanded as a tool to identify the possible anatomical structures that may be corrected by oral appliance therapy or surgical intervention to improve CPAP compliance.

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2010 CFR

2010-07-01

... Method A Appendix A to Part 425 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium ferricyanide titration method is based on method SLM 4/2 described in “Official Method of Analysis,” Society of Leather Trades...

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2012 CFR

2012-07-01

... Method A Appendix A to Part 425 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED..., App. A Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium ferricyanide titration method is based on method SLM 4/2 described in “Official Method of Analysis,” Society of...

40 CFR Appendix A to Part 425 - Potassium Ferricyanide Titration Method

Code of Federal Regulations, 2011 CFR

2011-07-01

... Method A Appendix A to Part 425 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Appendix A to Part 425—Potassium Ferricyanide Titration Method Source The potassium ferricyanide titration method is based on method SLM 4/2 described in “Official Method of Analysis,” Society of Leather Trades...

An interpretation of photometric parameters of bright desert regions of Mars and their dependence on wave length

NASA Technical Reports Server (NTRS)

Weaver, W. R.; Meador, W. E.

1977-01-01

Photometric data from the bright desert areas of Mars were used to determine the dependence of the three photometric parameters of the photometric function on wavelength and to provide qualitative predictions about the physical properties of the surface. Knowledge of the parameters allowed the brightness of these areas of Mars to be determined for any scattering geometry in the wavelength range of 0.45 to 0.70 micron. The changes that occur in the photometric parameters due to changes in wavelength were shown to be consistent with their physical interpretations, and the predictions of surface properties were shown to be consistent with conditions expected to exist in these regions of Mars. The photometric function was shown to have potential as a diagnostic tool for the qualitative determination of surface properties, and the consistency of the behavior of the photometric parameters was considered to be support for the validity of the photometric function.

Clinical Outcomes of Continuation of Metformin Titration Instructions with Electronic Prescribing.

PubMed

Delate, Thomas; Rader, Nathan; Rawlings, Julia E; Smith, Karen; Herner, Sheryl J

2015-06-01

Anecdotal evidence suggests that metformin titration instructions are not being updated and refill requests are approved without modification of the titration instructions such that the titration instructions is continued for patients newly initiated on metformin. This was a retrospective cohort analysis of adult patients who received newly initiated metformin pharmacotherapy. Patients were followed from their initial metformin purchase through two subsequent metformin refill purchases. Outcomes, including the 3-year incidence rate of patients with at least one set of continued titration instructions and proportions of patients with at least one gastrointestinal adverse effect (AE) and those with an elevated glucose measurement at follow-up, were assessed during the time period between patients' second and third metformin purchases. Analyses were performed comparing the exposure (i.e., patients with continued instructions) group to the control (i.e., patients without continued instructions) group. The exposure group had a higher mean age and chronic disease score but lower metformin starting dose than the control group (all p < 0.05). The 3-year incidence rate of patients with at least one continuation of titration instructions was 60.3 % (95 % CI 58.3-62.3). Gastrointestinal AEs were rare with equivalent proportions of patients in each group experiencing an event (p > 0.05). Control patients (48.7 % of patients with a measurement) were more likely to have had poorly controlled glucose than exposure patients (35.7 % of patients with a measurement) (p < 0.001). A high rate of continuation of titration instructions for patients newly initiated on metformin was observed; however, such continuation did not negatively affect clinical outcomes.

Determination of organic bases in non-aqueous solvents by catalytic thermometric titration.

PubMed

Vajgand, V J; Kiss, T A; Gaál, F F; Zsigrai, I J

1968-07-01

Catalytic thermometric titrations have been developed for bases (brucine, diethylaniline, potassium acetate and triethylamine) in acetic acid by continuous and discontinuous addition of the standard solution and automatic temperature recording. The determination of weak bases, e.g., antipyrine, unsuccessful in acetic acid by catalytic thermometric titration, has been achieved by using nitromethane or acetic anhydride as solvent. Catalytic thermometric titrations were also performed by coulometric generation of hydrogen ions for the determination of micro amounts of weak bases in a mixture of acetic anhyride and acetic acid.

Integration and global analysis of isothermal titration calorimetry data for studying macromolecular interactions.

PubMed

Brautigam, Chad A; Zhao, Huaying; Vargas, Carolyn; Keller, Sandro; Schuck, Peter

2016-05-01

Isothermal titration calorimetry (ITC) is a powerful and widely used method to measure the energetics of macromolecular interactions by recording a thermogram of differential heating power during a titration. However, traditional ITC analysis is limited by stochastic thermogram noise and by the limited information content of a single titration experiment. Here we present a protocol for bias-free thermogram integration based on automated shape analysis of the injection peaks, followed by combination of isotherms from different calorimetric titration experiments into a global analysis, statistical analysis of binding parameters and graphical presentation of the results. This is performed using the integrated public-domain software packages NITPIC, SEDPHAT and GUSSI. The recently developed low-noise thermogram integration approach and global analysis allow for more precise parameter estimates and more reliable quantification of multisite and multicomponent cooperative and competitive interactions. Titration experiments typically take 1-2.5 h each, and global analysis usually takes 10-20 min.

Derivation of photometric redshifts for the 3XMM catalogue

NASA Astrophysics Data System (ADS)

Georgantopoulos, I.; Corral, A.; Mountrichas, G.; Ruiz, A.; Masoura, V.; Fotopoulou, S.; Watson, M.

2017-10-01

We present the results from our ESA Prodex project that aims to derive photometric redshifts for the 3XMM catalogue. The 3XMM DR-6 offers the largest X-ray survey, containing 470,000 unique sources over 1000 sq. degrees. We cross-correlate the X-ray positions with optical and near-IR catalogues using Bayesian statistics. The optical catalogue used so far is the SDSS while currently we are employing the recently released PANSTARRS catalogue. In the near IR we use the Viking, VHS, UKIDS surveys and also the WISE W1 and W2 filters. The estimation of photometric redshifts is based on the TPZ software. The training sample is based on X-ray selected samples with available SDSS spectroscopy. We present here the results for the 40,000 3XMM sources with available SDSS counterparts. Our analysis provides very reliable photometric redshifts with sigma(mad)=0.05 and a fraction of outliers of 8% for the optically extended sources. We discuss the wide range of applications that are feasible using this unprecedented resource.

Lacosamide and sodium channel-blocking antiepileptic drug cross-titration against levetiracetam background therapy.

PubMed

Baulac, M; Byrnes, W; Williams, P; Borghs, S; Webster, E; De Backer, M; Dedeken, P

2017-04-01

To assess prospectively the effectiveness of lacosamide (LCM) added to levetiracetam (LEV) after down-titration of a concomitant sodium channel blocker (SCB) among patients with focal epilepsy not adequately controlled on LEV and SCB. In this open-label trial, LCM was initiated at 100 mg/day and up-titrated to 200-600 mg/day over 9 weeks; SCB down-titration started when LCM dose reached 200 mg/day. Patients remained on stable LCM/LEV doses for 12 weeks' maintenance (21-week treatment period). The primary outcome was retention rate on LCM. Due to recruitment challenges, fewer than the planned 300 patients participated in the trial, resulting in the trial being underpowered. Overall, 120 patients (mean age 39.7 years) started and 93 completed the trial. The most frequently used SCBs were lamotrigine (39.2%), carbamazepine (30.8%) and oxcarbazepine (27.5%). Eighty-four patients adhered to protocol and discontinued their SCB after cross-titration, but there was insufficient evidence for 36 patients. Retention rate was 73.3% (88/120) for all patients and 83.3% (70/84) for those with evidence of SCB discontinuation. Seizure freedom for patients completing maintenance was 14.0% (13/93). Discontinuation due to adverse events (6.7%) and lack of efficacy (3.3%) occurred primarily during cross-titration. Most frequently reported adverse events during treatment were dizziness (23.3%), headache (15.0%) and fatigue (8.3%). In patients with uncontrolled seizures on LEV/SCB, the LCM/LEV combination appeared to be effective and well tolerated. A cross-titration schedule-flexible LCM up-titration, concomitant SCB down-titration and stable background LEV-could present a feasible and practical approach to initiating LCM while minimizing pharmacodynamic interactions with a SCB. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Dose titration of repaglinide in patients with inadequately controlled type 2 diabetes.

PubMed

Kølendorf, Klaus; Eriksson, Johan; Birkeland, Kåre I; Kjellström, Thomas; Hreidarsson, Astradur B

2004-04-01

A total of 385 drug-therapy naïve patients, with inadequately controlled type 2 diabetes, were randomised into a multinational, parallel-group study to compare two strategies for dose titration of the oral hypoglycaemic agent repaglinide. Patients were allocated to either a fasting blood glucose (FBG) monitoring group with titration target 4.4-6.1 mmol/l or to a post-prandial blood glucose (PPBG) monitoring group with titration target 4.4-8.0 mmol/l. An initial titration period of up to 8 weeks was followed by a 12-week treatment period. Glycaemic control and hypoglycaemic outcomes were compared for the respective groups. HbA(1c) decreased significantly more in the FBG monitoring group by a mean of 1.38% compared to the PPBG group by a mean of 1.22% (P=0.03). The glycaemic control targets were met by fewer patients in the FBG group than in the PPBG group (57% versus 86% (P<0.001)) despite a higher mean dose of repaglinide in the FBG group. The within-patient blood glucose variability was significantly lower in the FBG group than in the PPBG group (P<0.001). In conclusion, repaglinide lowered the HbA(1c) effectively and safely in both groups and self-monitored FBG is a suitable parameter for titration of repaglinide. Whether a lower PPBG target might be as good a guide as FBG for titration of repaglinide should be addressed in a future study.

Photometric study of the eclipsing binary GR Bootis

NASA Astrophysics Data System (ADS)

Zhang, Z. L.; Zhang, Y. P.; Fu, J. N.; Xue, H. F.

2016-07-01

We present CCD photometry and low-resolution spectra of the eclipsing binary GR Boo. A new ephemeris is determined based on all the available times of the minimum light. The period analysis reveals that the orbital period is decreasing with a rate of dP / dt = - 2.05 ×10-10 d yr-1 . A photometric analysis for the obtained light curves is performed with the Wilson-Devinney Differential Correction program for the first time. The photometric solutions confirm the W UMa-type nature of the binary system. The mass ratio turns out to be q = 0.985 ± 0.001 . The evolutionary status and physical nature of the binary system are briefly discussed.

PHOTOMETRIC EVIDENCE FOR THE OSMOTIC BEHAVIOR OF RAT LIVER MICROSOMES

PubMed Central

Tedeschi, Henry; James, Joseph M.; Anthony, William

1963-01-01

Electron microscope observations are consistent with the interpretation that the elements of the endoplasmic reticulum are osmotically active in situ as well as after isolation. More recently, it has been reported that microsomal suspensions equilibrate almost completely with added C14-sucrose and that no osmotic behavior is evident from photometric data. These findings were considered at variance with the electron microscope data. However, equilibration with added label simply attests to a relatively high permeability, and, in addition, the photometric data need not be critical. Osmotic volume changes, measured photometrically, may be masked by concomitant events (e.g., changes in the refractive index of the test solutions at varying osmotic pressures, breakdown of the particles, and agglutination). For these reasons the photometric experiments were repeated. In this work, the reciprocal of optical density of microsomal suspensions was found to vary linearly with the reciprocal of concentration of the medium at constant refractive index. These changes probably correspond to osmotic volume changes, since the effect was found to be (a) independent of substance used and (b) osmotically reversible. The transmission of the suspension was found to vary with the refractive index of the medium, the concentration of particles, and the wavelength of incident light, according to relationships that are similar to or identical with those obtained for mitochondrial suspensions. PMID:14064105

Photometric Characteristics of Lunar Terrains

NASA Astrophysics Data System (ADS)

Sato, Hiroyuki; Hapke, Bruce W.; Denevi, Brett W.; Robinson, Mark

2016-10-01

The photometric properties of the lunar depend on albedo, surface roughness, porosity, and the internal/external structure of particles. Hapke parameter maps derived using a bidirectional reflectance model [Hapke, 2012] from Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) images demonstrated the spatial and spectral variation of the photometric properties of the Moon [Sato et al., 2014]. Using the same methodology, here we present the photometric characteristics of typical lunar terrains, which were not systematically analyzed in the previous study.We selected five representative terrain types: mare, highland, swirls, and two Copernican (fresh) crater ejecta (one mare and one highlands example). As for the datasets, we used ~39 months of WAC repeated observations, and for each image pixel, we computed latitude, longitude, incidence, emission, and phase angles using the WAC GLD100 stereo DTM [Scholten et al., 2012]. To obtain similar phase and incidence angle ranges, all sampling sites are near the equator and in the vicinity of Reiner Gamma. Three free Hapke parameters (single scattering albedo: w, HG2 phase function parameter: c, and angular width of SHOE: hs) were then calculated for the seven bands (321-689 nm). The remaining parameters were fixed by simplifying the model [Sato et al., 2014].The highlands, highland ejecta, and swirl (Reiner Gamma) showed clearly higher w than the mare and mare ejecta. The derived c values were lower (less backscattering) for the swirl and higher (more backscattering) for the highlands (and ejecta) relative to the other sites. Forward scattering materials such as unconsolidated transparent crystalline materials might be relatively enriched in the swirl. In the highlands, anorthositic agglutinates with dense internal scattering could be responsible for the strong backscattering. The mare and mare ejecta showed continuously decreasing c from UV to visible wavelengths. This might be caused by the FeO-rich pyroxene

Satellite Type Estination from Ground-based Photometric Observation

NASA Astrophysics Data System (ADS)

Endo, T.; Ono, H.; Suzuki, J.; Ando, T.; Takanezawa, T.

2016-09-01

The optical photometric observation is potentially a powerful tool for understanding of the Geostationary Earth Orbit (GEO) objects. At first, we measured in laboratory the surface reflectance of common satellite materials, for example, Multi-layer Insulation (MLI), mono-crystalline silicon cells, and Carbon Fiber Reinforced Plastic (CFRP). Next, we calculated visual magnitude of a satellite by simplified shape and albedo. In this calculation model, solar panels have dimensions of 2 by 8 meters, and the bus area is 2 meters squared with measured optical properties described above. Under these conditions, it clarified the brightness can change the range between 3 and 4 magnitudes in one night, but color index changes only from 1 to 2 magnitudes. Finally, we observed the color photometric data of several GEO satellites visible from Japan multiple times in August and September 2014. We obtained that light curves of GEO satellites recorded in the B and V bands (using Johnson filters) by a ground-base optical telescope. As a result, color index changed approximately from 0.5 to 1 magnitude in one night, and the order of magnitude was not changed in all cases. In this paper, we briefly discuss about satellite type estimation using the relation between brightness and color index obtained from the photometric observation.

Comparative study of procedures for the analysis of chloride in hardened concrete.

DOT National Transportation Integrated Search

1976-01-01

In the widely used potentiometric titration procedure for the analysis of chloride in powdered hardened concrete samples, difficulties have often been encountered when determining the endpoint. These difficulties have been eliminated through the use ...

Dose titration of BAF312 attenuates the initial heart rate reducing effect in healthy subjects.

PubMed

Legangneux, Eric; Gardin, Anne; Johns, Donald

2013-03-01

Previous studies have shown transient decreases in heart rate (HR) following administration of sphingosine 1-phosphate (S1P) receptor modulators including BAF312. This study was conducted to determine whether dose titration of BAF312 reduces or eliminates these effects. Fifty-six healthy subjects were randomized 1:1:1:1 to receive BAF312 in one of two dose titration (DT) regimens (DT1 and DT2: 0.25-10 mg over 9-10 days), no titration (10 mg starting dose) or placebo. Pharmacodynamic and pharmacokinetic parameters were assessed. Neither DT1 nor DT2 resulted in clinically significant bradycardia or atrioventricular conduction effects. Both titration regimens showed a favourable difference on each of days 1-12 vs. the non-titration regimen on day 1 for HR effects (P < 0.0001). On day 1, the geometric mean ratio of the fraction from the previous day in minimum daily HR between DT1 and non-titration was 1.18 (95% confidence interval [CI] 1.13, 1.23) and 1.14 (95% CI 1.09, 1.18) for DT2 (both P < 0.05) with significant differences noted through to day 12. Non-titration HRs showed considerable separation from placebo throughout the study. There was no statistically significant reduction in HR vs. placebo on day 1 in either titration regimen. On days 3-7 subjects in DT1 and DT2 experienced minor reductions in HR vs. placebo (approximately 5 beats min⁻¹; P ≤ 0.0001). From days 9-12, HRs in both titration regimens were comparable with placebo. Both titration regimens effectively attenuated the initial bradyarrhythmia observed on day 1 of treatment with BAF312 10 mg. © 2012 Novartis Institutes for BioMedical Research (NIBIR). British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

Dose titration of BAF312 attenuates the initial heart rate reducing effect in healthy subjects

PubMed Central

Legangneux, Eric; Gardin, Anne; Johns, Donald

2013-01-01

Aim Previous studies have shown transient decreases in heart rate (HR) following administration of sphingosine 1‐phosphate (S1P) receptor modulators including BAF312. This study was conducted to determine whether dose titration of BAF312 reduces or eliminates these effects. Methods Fifty‐six healthy subjects were randomized 1:1:1:1 to receive BAF312 in one of two dose titration (DT) regimens (DT1 and DT2: 0.25–10 mg over 9–10 days), no titration (10 mg starting dose) or placebo. Pharmacodynamic and pharmacokinetic parameters were assessed. Results Neither DT1 nor DT2 resulted in clinically significant bradycardia or atrioventricular conduction effects. Both titration regimens showed a favourable difference on each of days 1–12 vs. the non‐titration regimen on day 1 for HR effects (P < 0.0001). On day 1, the geometric mean ratio of the fraction from the previous day in minimum daily HR between DT1 and non‐titration was 1.18 (95% confidence interval [CI] 1.13, 1.23) and 1.14 (95% CI 1.09, 1.18) for DT2 (both P < 0.05) with significant differences noted through to day 12. Non‐titration HRs showed considerable separation from placebo throughout the study. There was no statistically significant reduction in HR vs. placebo on day 1 in either titration regimen. On days 3–7 subjects in DT1 and DT2 experienced minor reductions in HR vs. placebo (approximately 5 beats min−1; P ≤ 0.0001). From days 9–12, HRs in both titration regimens were comparable with placebo. Conclusion Both titration regimens effectively attenuated the initial bradyarrhythmia observed on day 1 of treatment with BAF312 10 mg. PMID:22845008

Intensity measurement of automotive headlamps using a photometric vision system

NASA Astrophysics Data System (ADS)

Patel, Balvant; Cruz, Jose; Perry, David L.; Himebaugh, Frederic G.

1996-01-01

Requirements for automotive head lamp luminous intensity tests are introduced. The rationale for developing a non-goniometric photometric test system is discussed. The design of the Ford photometric vision system (FPVS) is presented, including hardware, software, calibration, and system use. Directional intensity plots and regulatory test results obtained from the system are compared to corresponding results obtained from a Ford goniometric test system. Sources of error for the vision system and goniometer are discussed. Directions for new work are identified.

Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

PubMed Central

Tavčar, Eva; Turk, Erika; Kreft, Samo

2012-01-01

The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes place in a sealed 4 ml cuvette. Detection is performed at 520 nm. Titration endpoint is determined from the graph of absorbance plotted against titration volume. The method has appropriate reproducibility (RSD = 4.3%), accuracy, and linearity (R 2 = 0.997). PMID:22567558

Randomized Trial of Long-Acting Insulin Glargine Titration Web Tool (LTHome) Versus Enhanced Usual Therapy of Glargine Titration (INNOVATE Trial).

PubMed

Bajaj, Harpreet S; Venn, Karri; Ye, Chenglin; Aronson, Ronnie

2016-10-01

Basal insulin titration in the real world is often unsuccessful. LTHome, a web tool, applies a rules engine-based algorithm providing insulin titration advice directly to the patient. This pilot, randomized trial evaluates basal insulin glargine titration by LTHome compared to enhanced usual therapy ([EUT]-diabetes education program) over 12 weeks. Important inclusion criteria: 18-75 years, type 2 diabetes, computer literacy, and HbA1c >7.0%. Trial protocol was approved by ethics board. We randomized 139 subjects. The achievement of primary composite outcome (four out of seven fasting plasma glucose [FPG] within 5-7.2 mmol/L + mean for three consecutive FPG within 5-7.2 mmol/L + no severe hypoglycemia) was 15% in LTHome versus 41% in EUT (noninferiority not met, P-value = 0.92). Other outcomes were similar between the LTHome and EUT arms: alternate composite outcome achievement (last five FPG mean within the range of 5-7.2 mmol/L + no hypoglycemia, 47% and 51%, P = 0.73); A1c reduction (-1.0% and -1.1%, P = 0.66); proportion achieving A1c ≤7% (14% and 20%, P = 0.36); and hypoglycemia incidence (31% and 37%, P = 0.4), respectively. Patient satisfaction score improvements were greater in LTHome versus EUT (change in fear of hypoglycemia score P = 0.04 and change in diabetes distress score P = 0.04). The mean number of additional healthcare provider visits was 0.13 for LTHome and 1.22 for EUT (P < 0.01). INNOVATE trial suggests clinical utility of LTHome compared to EUT in real-life settings. Further research is needed to evaluate the efficacy and safety of automated insulin titration algorithms.

Photometric and polarimetric mapping of water turbidity and water depth

NASA Technical Reports Server (NTRS)

Halajian, J.; Hallock, H.

1973-01-01

A Digital Photometric Mapper (DPM) was used in the Fall of 1971 in an airborne survey of New York and Boston area waters to acquire photometric, spectral and polarimetric data. The object of this study is to analyze these data with quantitative computer processing techniques to assess the potential of the DPM in the measurement and regional mapping of water turbidity and depth. These techniques have been developed and an operational potential has been demonstrated. More emphasis is placed at this time on the methodology of data acquisition, analysis and display than on the quantity of data. The results illustrate the type, quantity and format of information that could be generated operationally with the DPM-type sensor characterized by high photometric stability and fast, accurate digital output. The prototype, single-channel DPM is suggested as a unique research tool for a number of new applications. For the operational mapping of water turbidity and depth, the merits of a multichannel DPM coupled with a laser system are stressed.

On-line monitoring of fluid bed granulation by photometric imaging.

PubMed

Soppela, Ira; Antikainen, Osmo; Sandler, Niklas; Yliruusi, Jouko

2014-11-01

This paper introduces and discusses a photometric surface imaging approach for on-line monitoring of fluid bed granulation. Five granule batches consisting of paracetamol and varying amounts of lactose and microcrystalline cellulose were manufactured with an instrumented fluid bed granulator. Photometric images and NIR spectra were continuously captured on-line and particle size information was extracted from them. Also key process parameters were recorded. The images provided direct real-time information on the growth, attrition and packing behaviour of the batches. Moreover, decreasing image brightness in the drying phase was found to indicate granule drying. The changes observed in the image data were also linked to the moisture and temperature profiles of the processes. Combined with complementary process analytical tools, photometric imaging opens up possibilities for improved real-time evaluation fluid bed granulation. Furthermore, images can give valuable insight into the behaviour of excipients or formulations during product development. Copyright © 2014 Elsevier B.V. All rights reserved.

GALAXY ZOO MORPHOLOGY AND PHOTOMETRIC REDSHIFTS IN THE SLOAN DIGITAL SKY SURVEY

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

Way, M. J.

It has recently been demonstrated that one can accurately derive galaxy morphology from particular primary and secondary isophotal shape estimates in the Sloan Digital Sky Survey (SDSS) imaging catalog. This was accomplished by applying Machine Learning techniques to the Galaxy Zoo morphology catalog. Using the broad bandpass photometry of the SDSS in combination with precise knowledge of galaxy morphology should help in estimating more accurate photometric redshifts for galaxies. Using the Galaxy Zoo separation for spirals and ellipticals in combination with SDSS photometry we attempt to calculate photometric redshifts. In the best case we find that the root-mean-square error formore » luminous red galaxies classified as ellipticals is as low as 0.0118. Given these promising results we believe better photometric redshift estimates for all galaxies in the SDSS ({approx}350 million) will be feasible if researchers can also leverage their derived morphologies via Machine Learning. These initial results look to be promising for those interested in estimating weak lensing, baryonic acoustic oscillation, and other fields dependent upon accurate photometric redshifts.« less

Safety and tolerability of different titration rates of retigabine (ezogabine) in patients with partial-onset seizures.

PubMed

Biton, Victor; Gil-Nagel, Antonio; Brodie, Martin J; Derossett, Sarah E; Nohria, Virinder

2013-11-01

Retigabine (RTG; international nonproprietary name)/ezogabine (EZG; US adopted name) is an antiepileptic drug (AED) that prolongs neuronal voltage-gated potassium-channel KCNQ2-5 (Kv 7.2-7.5) opening. This double-blind study evaluated different RTG/EZG dose-titration rates. Patients (N=73) with partial-onset seizures receiving concomitant AEDs were randomized to one of three titration groups, all of which were initiated at RTG/EZG 300mg/day divided into three equal doses. Fast-, medium-, and slow-titration groups received dose increments of 150mg/day every 2, 4, and 7 days, respectively, achieving the target dose of 1200mg/day after 13, 25, and 43 days, respectively. Safety assessments were performed throughout. Discontinuation rates due to treatment-emergent adverse events (TEAEs) were numerically higher in the fast- (10/23) and medium- (7/22) titration groups than in the slow-titration group (3/23) but statistical significance was achieved only for the high-titration group compared with the low-titration group (p=0.024). Stratified analysis, with concomitant AEDs divided into enzyme inducers (carbamazepine, phenytoin, oxcarbazepine) or noninducers, showed that the risk of discontinuation due primarily to TEAEs was significantly higher in the fast- (p=0.010) but not in the medium-titration group (p=0.078) when compared with the slow-titration group. Overall, the slow-titration rate appeared to be best tolerated and was used in further efficacy and safety studies with RTG/EZG. Copyright © 2013 Elsevier B.V. All rights reserved.

Photometric Variations of Solar-type Stars: Results of the Cloudcroft Survey

NASA Technical Reports Server (NTRS)

Giampapa, M. S.

1984-01-01

The results of a synoptic program to search for the occurrence of photometric variability in solar type stars as seen in continuum band photometry are summarized. The survey disclosed the existence of photometric variability in solar type stars that is related to the presence of spots on the stellar surface. The observed variability detected in solar type stars is at enhanced levels compared to that observed for the Sun.

Evaluation of modified boehm titration methods for use with biochars.

PubMed

Fidel, Rivka B; Laird, David A; Thompson, Michael L

2013-11-01

The Boehm titration, originally developed to quantify organic functional groups of carbon blacks and activated carbons in discrete pK ranges, has received growing attention for analyzing biochar. However, properties that distinguish biochar from carbon black and activated carbon, including greater carbon solubility and higher ash content, may render the original Boehm titration method unreliable for use with biochars. Here we use seven biochars and one reference carbon black to evaluate three Boehm titration methods that use (i) acidification followed by sparging (sparge method), (ii) centrifugation after treatment with BaCl (barium method), and (iii) a solid-phase extraction cartridge followed by acidification and sparging (cartridge method) to remove carbonates and dissolved organic compounds (DOC) from the Boehm extracts before titration. Our results for the various combinations of Boehm reactants and methods indicate that no one method was free of bias for all three Boehm reactants and that the cartridge method showed evidence of bias for all pK ranges. By process of elimination, we found that a combination of the sparge method for quantifying functional groups in the lowest pK range (∼5 to 6.4), and the barium method for quantifying functional groups in the higher pK ranges (∼6.4 to 10.3 and ∼10.3 to 13) to be free of evidence for bias. We caution, however, that further testing is needed and that all Boehm titration results for biochars should be considered suspect unless efforts were undertaken to remove ash and prevent interference from DOC. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

A Laser-Pointer-Based Spectrometer for Endpoint Detection of EDTA Titrations

ERIC Educational Resources Information Center

Dahm, Christopher E.; Hall, James W.; Mattioni, Brian E.

2004-01-01

A laser spectrometer for the ethylenediaminetetra-acetic acid (EDTA) titration of magnesium or calcium ions that is designed around a handheld laser pointer as the source and a photoresistor as the detector is developed. Findings show that the use of the spectrometer reduces the degree of uncertainty and error in one part of the EDTA titrations,…

A Spectroscopic and Photometric Study of Gravitational Microlensing Events

NASA Astrophysics Data System (ADS)

Kane, Stephen R.

2000-08-01

Gravitational microlensing has generated a great deal of scientific interest over recent years. This has been largely due to the realization of its wide-reaching applications, such as the search for dark matter, the detection of planets, and the study of Galactic structure. A significant observational advance has been that most microlensing events can be identified in real-time while the source is still being lensed. More than 400 microlensing events have now been detected towards the Galactic bulge and Magellanic Clouds by the microlensing survey teams EROS, MACHO, OGLE, DUO, and MOA. The real-time detection of these events allows detailed follow-up observations with much denser sampling, both photometrically and spectroscopically. The research undertaken in this project on photometric studies of gravitational microlensing events has been performed as a member of the PLANET (Probing Lensing Anomalies NETwork) collaboration. This is a worldwide collaboration formed in the early part of 1995 to study microlensing anomalies - departures from an achromatic point source, point lens light curve - through rapidly-sampled, multi-band, photometry. PLANET has demonstrated that it can achieve 1% photometry under ideal circumstances, making PLANET observations sensitive to detection of Earth-mass planets which require characterization of 1%--2% deviations from a standard microlensing light curve. The photometric work in this project involved over 5 months using the 1.0 m telescope at Canopus Observatory in Australia, and 3 separate observing runs using the 0.9 m telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. Methods were developed to reduce the vast amount of photometric data using the image analysis software MIDAS and the photometry package DoPHOT. Modelling routines were then written to analyse a selection of the resulting light curves in order to detect any deviation from an achromatic point source - point lens light curve. The photometric

Photometric redshifts in the SWIRE Survey

NASA Astrophysics Data System (ADS)

Rowan-Robinson, Michael; Babbedge, Tom; Oliver, Seb; Trichas, Markos; Berta, Stefano; Lonsdale, Carol; Smith, Gene; Shupe, David; Surace, Jason; Arnouts, Stephane; Ilbert, Olivier; Le Févre, Olivier; Afonso-Luis, Alejandro; Perez-Fournon, Ismael; Hatziminaoglou, Evanthia; Polletta, Mari; Farrah, Duncan; Vaccari, Mattia

2008-05-01

We present the SWIRE Photometric Redshift Catalogue 1025119 redshifts of unprecedented reliability and of accuracy comparable with or better than previous work. Our methodology is based on fixed galaxy and quasi-stellar object templates applied to data at 0.36-4.5 μm, and on a set of four infrared emission templates fitted to infrared excess data at 3.6-170 μm. The galaxy templates are initially empirical, but are given greater physical validity by fitting star formation histories to them, which also allows us to estimate stellar masses. The code involves two passes through the data, to try to optimize recognition of active galactic nucleus (AGN) dust tori. A few carefully justified priors are used and are the key to supression of outliers. Extinction, AV, is allowed as a free parameter. The full reduced χ2ν (z) distribution is given for each source, so the full error distribution can be used, and aliases investigated. We use a set of 5982 spectroscopic redshifts, taken from the literature and from our own spectroscopic surveys, to analyse the performance of our method as a function of the number of photometric bands used in the solution and the reduced χ2ν. For seven photometric bands (5 optical + 3.6, 4.5 μm), the rms value of (zphot - zspec)/(1 + zspec) is 3.5 per cent, and the percentage of catastrophic outliers [defined as >15 per cent error in (1 + z)], is ~1 per cent. These rms values are comparable with the best achieved in other studies, and the outlier fraction is significantly better. The inclusion of the 3.6- and 4.5-μm IRAC bands is crucial in supression of outliers. We discuss the redshift distributions at 3.6 and 24 μm. In individual fields, structure in the redshift distribution corresponds to clusters which can be seen in the spectroscopic redshift distribution, so the photometric redshifts are a powerful tool for large-scale structure studies. 10 per cent of sources in the SWIRE photometric redshift catalogue have z > 2, and 4 per cent

Home blood pressure monitoring and self-titration of antihypertensive medications: Proposed patient selection criteria.

PubMed

Hill, James R

2016-05-01

Recent studies have demonstrated that home blood pressure monitoring (HBPM), coupled with self-titration of medications is a viable intervention to control hypertension. There are currently no established criteria to evaluate patients for inclusion in such a program. The purpose of this discussion is to propose criteria for determining if a patient is appropriate to participate in a program of HBPM and self-titration. Inclusion criteria for two self-titration trials were examined, and additional factors in clinical practice were identified and discussed. Additional selection criteria were proposed to support the decision to enroll a patient in an antihypertensive self-titration program. Inclusion criteria from self-titration trials provide a reasonable starting point for choosing appropriate patients in clinical practice, but additional research is necessary. Adaptation of these criteria and consideration of the identified factors can be used to develop decision support instruments. Such instruments should be evaluated for effectiveness and reliability prior to use in clinical practice. HBPM combined with self-titration is an effective patient-centered approach for hypertension management. Decision support instruments to determine appropriate patients are necessary for safe and effective use in clinical practice. ©2015 American Association of Nurse Practitioners.

Influence of speckle image reconstruction on photometric precision for large solar telescopes

NASA Astrophysics Data System (ADS)

Peck, C. L.; Wöger, F.; Marino, J.

2017-11-01

Context. High-resolution observations from large solar telescopes require adaptive optics (AO) systems to overcome image degradation caused by Earth's turbulent atmosphere. AO corrections are, however, only partial. Achieving near-diffraction limited resolution over a large field of view typically requires post-facto image reconstruction techniques to reconstruct the source image. Aims: This study aims to examine the expected photometric precision of amplitude reconstructed solar images calibrated using models for the on-axis speckle transfer functions and input parameters derived from AO control data. We perform a sensitivity analysis of the photometric precision under variations in the model input parameters for high-resolution solar images consistent with four-meter class solar telescopes. Methods: Using simulations of both atmospheric turbulence and partial compensation by an AO system, we computed the speckle transfer function under variations in the input parameters. We then convolved high-resolution numerical simulations of the solar photosphere with the simulated atmospheric transfer function, and subsequently deconvolved them with the model speckle transfer function to obtain a reconstructed image. To compute the resulting photometric precision, we compared the intensity of the original image with the reconstructed image. Results: The analysis demonstrates that high photometric precision can be obtained for speckle amplitude reconstruction using speckle transfer function models combined with AO-derived input parameters. Additionally, it shows that the reconstruction is most sensitive to the input parameter that characterizes the atmospheric distortion, and sub-2% photometric precision is readily obtained when it is well estimated.

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts

NASA Technical Reports Server (NTRS)

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Bock, J.;

Data fusion and photometric restoration

NASA Astrophysics Data System (ADS)

Pirzkal, Norbert; Hook, Richard N.

2001-11-01

The current generation of 8-10m optical ground-based telescopes have a symbiotic relationship with space telescopes. For direct imaging in the optical the former can collect photons relatively cheaply but the latter can still achieve, even in the era of adaptive optics, significantly higher spatial resolution, point-spread function stability and astrometric fidelity over fields of a few arcminutes. The large archives of HST imaging already in place, when combined with the ease of access to ground-based data afforded by the virtual observatory currently under development, will make space-ground data fusion a powerful tool for the future. We describe a photometric image restoration method that we have developed which allows the efficient and accurate use of high-resolution space imaging of crowded fields to extract high quality photometry from very crowded ground-based images. We illustrate the method using HST and ESO VLT/FORS imaging of a globular cluster and demonstrate quantitatively the photometric measurements quality that can achieved using the data fusion approach instead of just using data from just one telescope. This method can handle most of the common difficulties encountered when attempting this problem such as determining the geometric mapping to the requisite precision, deriving the PSF and the background.

Kinematics and age of 15 stars-photometric solar analogs

NASA Astrophysics Data System (ADS)

Galeev, A. I.; Shimansky, V. V.

2008-03-01

The radial and space velocities are inferred for 15 stars that are photometric analogs of the Sun. The space velocity components (U, V, W) of most of these stars lie within the 10-60 km/s interval. The star HD 225239, which in our previous papers we classified as a subgiant, has a space velocity exceeding 100 km/s, and belongs to the thick disk. The inferred fundamental parameters of the atmospheres of solar analogs are combined with published evolutionary tracks to estimate the masses and ages of the stars studied. The kinematics of photometric analogs is compared to the data for a large group of solar-type stars.

White Dwarfs in the SDSS Photometric Footprint

NASA Astrophysics Data System (ADS)

Gentile Fusillo, N. P.; Girven, J.; Gänsicke, B.

2013-01-01

Attempts to create a homogeneous catalogue of white dwarfs have always been faced with the challenge posed by the intrinsic faintness of these objects. In recent years, thanks to large area surveys like the Sloan Digital Sky Survey (SDSS), the size of the known white dwarf population has increased dramatically, but, in order to carry out a statical study on the population of white dwarfs, it is necessary to have a reliable and well-defined selection method. We present a method which uses cuts in colour-colour space to select from DR7 16785 bright (g ≤ 19) photometric DA white dwarf candidates (Girven et al. 2011). The selection is 62% efficient in returning DA white dwarfs and produces a DA sample which is 95% complete for Teff > 8000 K. This sample contains 4636 spectroscopically confirmed DA white dwarfs; i.e. a ˜70% increase compared to Eisenstein et al.'s sample. As a first application of the SDSS DR7 DA candidates sample we cross correlated it with Data Release 8 of UKIDSS Large Area Survey with the aim of identifying white dwarfs which exhibit an infrared excess consistent with the presence of low mass stellar companions or dusty debris discs. Our current work aims to extend the photometric selection to all types of white dwarfs, using reduced proper motion as a further constrain. We expect to find a total of ˜20 000 photometric white dwarf candidates with g ≤ 19 in the footprint of SDSS DR8.

Virtual Titrator: A Student-Oriented Instrument.

ERIC Educational Resources Information Center

Ritter, David; Johnson, Michael

1997-01-01

Describes a titrator system, constructed from a computer-interfaced pH-meter, that was designed to increase student involvement in the process. Combines automatic data collection with real-time graphical display and interactive controls to focus attention on the process rather than on bits of data. Improves understanding of concepts and…

Titration Calculations with Computer Algebra Software

ERIC Educational Resources Information Center

Lachance, Russ; Biaglow, Andrew

2012-01-01

This article examines the symbolic algebraic solution of the titration equations for a diprotic acid, as obtained using "Mathematica," "Maple," and "Mathcad." The equilibrium and conservation equations are solved symbolically by the programs to eliminate the approximations that normally would be performed by the student. Of the three programs,…

High-precision reflectivity measurements: improvements in the calibration procedure

NASA Astrophysics Data System (ADS)

Jupe, Marco; Grossmann, Florian; Starke, Kai; Ristau, Detlev

2003-05-01

The development of high quality optical components is heavily depending on precise characterization procedures. The reflectance and transmittance of laser components are the most important parameters for advanced laser applications. In the industrial fabrication of optical coatings, quality management is generally insured by spectral photometric methods according to ISO/DIS 15386 on a medium level of accuracy. Especially for high reflecting mirrors, a severe discrepancy in the determination of the absolute reflectivity can be found for spectral photometric procedures. In the first part of the CHOCLAB project, a method for measuring reflectance and transmittance with an enhanced precision was developed, which is described in ISO/WD 13697. In the second part of the CHOCLAB project, the evaluation and optimization for the presented method is scheduled. Within this framework international Round-Robin experiment is currently in progress. During this Round-Robin experiment, distinct deviations could be observed between the results of high precision measurement facilities of different partners. Based on the extended experiments, the inhomogeneity of the sample reflectivity was identified as one important origin for the deviation. Consequently, this inhomogeneity is also influencing the calibration procedure. Therefore, a method was developed that allows the calibration of the chopper blade using always the same position on the reference mirror. During the investigations, the homogeneity of several samples was characterized by a surface mapping procedure for 1064 nm. The measurement facility was extended to the additional wavelength 532 nm and a similar set-up was assembled at 10.6 μm. The high precision reflectivity procedure at the mentioned wavelengths is demonstrated for exemplary measurements.

Thermometric titration of cadmium with sodium diethyldithiocarbamate, with oxidation by hydrogen peroxide as indicator reaction.

PubMed

Hattori, T; Yoshida, H

1987-08-01

A new method of end-point indication is described for thermometric titration of cadmium with sodium diethyldithiocarbamate (DDTC). It is based on the redox reaction between hydrogen peroxide added to the system before titration, and the first excess of DDTC. Amounts of cadmium in the range 10-50 mumoles are titrated within 1% error.

Photometric redshifts for the CFHTLS T0004 deep and wide fields

NASA Astrophysics Data System (ADS)

Coupon, J.; Ilbert, O.; Kilbinger, M.; McCracken, H. J.; Mellier, Y.; Arnouts, S.; Bertin, E.; Hudelot, P.; Schultheis, M.; Le Fèvre, O.; Le Brun, V.; Guzzo, L.; Bardelli, S.; Zucca, E.; Bolzonella, M.; Garilli, B.; Zamorani, G.; Zanichelli, A.; Tresse, L.; Aussel, H.

2009-06-01

Aims: We compute photometric redshifts in the fourth public release of the Canada-France-Hawaii Telescope Legacy Survey. This unique multi-colour catalogue comprises u^*, g', r', i', z' photometry in four deep fields of 1 deg2 each and 35 deg2 distributed over three wide fields. Methods: We used a template-fitting method to compute photometric redshifts calibrated with a large catalogue of 16 983 high-quality spectroscopic redshifts from the VVDS-F02, VVDS-F22, DEEP2, and the zCOSMOS surveys. The method includes correction of systematic offsets, template adaptation, and the use of priors. We also separated stars from galaxies using both size and colour information. Results: Comparing with galaxy spectroscopic redshifts, we find a photometric redshift dispersion, σΔ z/(1+z_s), of 0.028-0.30 and an outlier rate, |Δ z| ≥ 0.15× (1+z_s), of 3-4% in the deep field at i'_AB < 24. In the wide fields, we find a dispersion of 0.037-0.039 and an outlier rate of 3-4% at i'_AB < 22.5. Beyond i'_AB = 22.5 in the wide fields the number of outliers rises from 5% to 10% at i'_AB < 23 and i'_AB < 24, respectively. For the wide sample the systematic redshift bias stays below 1% to i'_AB < 22.5, whereas we find no significant bias in the deep fields. We investigated the effect of tile-to-tile photometric variations and demonstrated that the accuracy of our photometric redshifts is reduced by at most 21%. Application of our star-galaxy classifier reduced the contamination by stars in our catalogues from 60% to 8% at i'_AB < 22.5 in our field with the highest stellar density while keeping a complete galaxy sample. Our CFHTLS T0004 photometric redshifts are distributed to the community. Our release includes 592891 (i'_AB < 22.5) and 244701 (i'_AB < 24) reliable galaxy photometric redshifts in the wide and deep fields, respectively. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is

Production of first generation adenoviral vectors for preclinical protocols: amplification, purification and functional titration.

PubMed

Armendáriz-Borunda, Juan; Bastidas-Ramírez, Blanca Estela; Sandoval-Rodríguez, Ana; González-Cuevas, Jaime; Gómez-Meda, Belinda; García-Bañuelos, Jesús

2011-11-01

Gene therapy represents a promising approach in the treatment of several diseases. Currently, the ideal vector has yet to be designed; though, adenoviral vectors (Ad-v) have provided the most utilized tool for gene transfer due principally to their simple production, among other specific characteristics. Ad-v viability represents a critical variable that may be affected by storage or shipping conditions and therefore it is advisable to be assessed previously to protocol performance. The present work is unique in this matter, as the complete detailed process to obtain Ad-v of preclinical grade is explained. Amplification in permissive HEK-293 cells, purification in CsCl gradients in a period of 10 h, spectrophotometric titration of viral particles (VP) and titration of infectious units (IU), yielding batches of AdβGal, AdGFP, AdHuPA and AdMMP8, of approximately 10¹³-10¹⁴ VP and 10¹²-10¹³ IU were carried out. In vivo functionality of therapeutic AdHuPA and AdMMP8 was evidenced in rats presenting CCl₄-induced fibrosis, as more than 60% of fibrosis was eliminated in livers after systemic delivery through iliac vein in comparison with irrelevant AdβGal. Time required to accomplish the whole Ad-v production steps, including IU titration was 20 to 30 days. We conclude that production of Ad-v following standard operating procedures assuring vector functionality and the possibility to effectively evaluate experimental gene therapy results, leaving aside the use of high-cost commercial kits or sophisticated instrumentation, can be performed in a conventional laboratory of cell culture. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Process monitored spectrophotometric titration coupled with chemometrics for simultaneous determination of mixtures of weak acids.

PubMed

Liao, Lifu; Yang, Jing; Yuan, Jintao

2007-05-15

A new spectrophotometric titration method coupled with chemometrics for the simultaneous determination of mixtures of weak acids has been developed. In this method, the titrant is a mixture of sodium hydroxide and an acid-base indicator, and the indicator is used to monitor the titration process. In a process of titration, both the added volume of titrant and the solution acidity at each titration point can be obtained simultaneously from an absorption spectrum by least square algorithm, and then the concentration of each component in the mixture can be obtained from the titration curves by principal component regression. The method only needs the information of absorbance spectra to obtain the analytical results, and is free of volumetric measurements. The analyses are independent of titration end point and do not need the accurate values of dissociation constants of the indicator and the acids. The method has been applied to the simultaneous determination of the mixtures of benzoic acid and salicylic acid, and the mixtures of phenol, o-chlorophenol and p-chlorophenol with satisfactory results.

Determination of vanadium(V) by direct automatic potentiometric titration with EDTA using a chemically modified electrode as a potentiometric sensor.

PubMed

Quintar, S E; Santagata, J P; Cortinez, V A

2005-10-15

A chemically modified electrode (CME) was prepared and studied as a potentiometric sensor for the end-point detection in the automatic titration of vanadium(V) with EDTA. The CME was constructed with a paste prepared by mixing spectral-grade graphite powder, Nujol oil and N-2-naphthoyl-N-p-tolylhydroxamic acid (NTHA). Buffer systems, pH effects and the concentration range were studied. Interference ions were separated by applying a liquid-liquid extraction procedure. The CME did not require any special conditioning before using. The electrode was constructed with very inexpensive materials and was easily made. It could be continuously used, at least two months without removing the paste. Automatic potentiometric titration curves were obtained for V(V) within 5 x 10(-5) to 2 x 10(-3)M with acceptable accuracy and precision. The developed method was applied to V(V) determination in alloys for hip prosthesis.

The Dynamic Photometric Stereo Method Using a Multi-Tap CMOS Image Sensor.

PubMed

Yoda, Takuya; Nagahara, Hajime; Taniguchi, Rin-Ichiro; Kagawa, Keiichiro; Yasutomi, Keita; Kawahito, Shoji

2018-03-05

The photometric stereo method enables estimation of surface normals from images that have been captured using different but known lighting directions. The classical photometric stereo method requires at least three images to determine the normals in a given scene. However, this method cannot be applied to dynamic scenes because it is assumed that the scene remains static while the required images are captured. In this work, we present a dynamic photometric stereo method for estimation of the surface normals in a dynamic scene. We use a multi-tap complementary metal-oxide-semiconductor (CMOS) image sensor to capture the input images required for the proposed photometric stereo method. This image sensor can divide the electrons from the photodiode from a single pixel into the different taps of the exposures and can thus capture multiple images under different lighting conditions with almost identical timing. We implemented a camera lighting system and created a software application to enable estimation of the normal map in real time. We also evaluated the accuracy of the estimated surface normals and demonstrated that our proposed method can estimate the surface normals of dynamic scenes.

Dark Energy Survey Year 1 Results: The Photometric Data Set for Cosmology

NASA Astrophysics Data System (ADS)

Drlica-Wagner, A.; Sevilla-Noarbe, I.; Rykoff, E. S.; Gruendl, R. A.; Yanny, B.; Tucker, D. L.; Hoyle, B.; Carnero Rosell, A.; Bernstein, G. M.; Bechtol, K.; Becker, M. R.; Benoit-Lévy, A.; Bertin, E.; Carrasco Kind, M.; Davis, C.; de Vicente, J.; Diehl, H. T.; Gruen, D.; Hartley, W. G.; Leistedt, B.; Li, T. S.; Marshall, J. L.; Neilsen, E.; Rau, M. M.; Sheldon, E.; Smith, J.; Troxel, M. A.; Wyatt, S.; Zhang, Y.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Banerji, M.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; DePoy, D. L.; Desai, S.; Dietrich, J. P.; Doel, P.; Evrard, A. E.; Fausti Neto, A.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gerdes, D. W.; Giannantonio, T.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; James, D. J.; Jeltema, T.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; Lahav, O.; Lima, M.; Lin, H.; Maia, M. A. G.; Martini, P.; McMahon, R. G.; Melchior, P.; Menanteau, F.; Miquel, R.; Nichol, R. C.; Ogando, R. L. C.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Zuntz, J.; DES Collaboration

2018-04-01

We describe the creation, content, and validation of the Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support of upcoming cosmological analyses. The Y1A1 GOLD data set is assembled from multiple epochs of DES imaging and consists of calibrated photometric zero-points, object catalogs, and ancillary data products—e.g., maps of survey depth and observing conditions, star–galaxy classification, and photometric redshift estimates—that are necessary for accurate cosmological analyses. The Y1A1 GOLD wide-area object catalog consists of ∼ 137 million objects detected in co-added images covering ∼ 1800 {\\deg }2 in the DES grizY filters. The 10σ limiting magnitude for galaxies is g=23.4, r=23.2, i=22.5, z=21.8, and Y=20.1. Photometric calibration of Y1A1 GOLD was performed by combining nightly zero-point solutions with stellar locus regression, and the absolute calibration accuracy is better than 2% over the survey area. DES Y1A1 GOLD is the largest photometric data set at the achieved depth to date, enabling precise measurements of cosmic acceleration at z ≲ 1.

A stable and convenient protein electrophoresis titration device with bubble removing system.

PubMed

Zhang, Qiang; Fan, Liu-Yin; Li, Wen-Lin; Cong, Feng-Song; Zhong, Ran; Chen, Jing-Jing; He, Yu-Chen; Xiao, Hua; Cao, Cheng-Xi

2017-07-01

Moving reaction boundary titration (MRBT) has a potential application to immunoassay and protein content analysis with high selectivity. However, air bubbles often impair the accuracy of MRBT, and the leakage of electrolyte greatly decreases the safety and convenience of electrophoretic titration. Addressing these two issues a reliable MRBT device with modified electrolyte chamber of protein titration was designed. Multiphysics computer simulation was conducted for optimization according to two-phase flow. The single chamber was made of two perpendicular cylinders with different diameters. After placing electrophoretic tube, the resident air in the junction next to the gel could be eliminated by a simple fast electrolyte flow. Removing the electrophoretic tube automatically prevented electrolyte leakage at the junction due to the gravity-induced negative pressure within the chamber. Moreover, the numerical simulation and experiments showed that the improved MRBT device has following advantages: (i) easy and rapid setup of electrophoretic tube within 20 s; (ii) simple and quick bubble dissipates from the chamber of titration within 2 s; (iii) no electrolyte leakage from the two chambers: and (iv) accurate protein titration and safe instrumental operation. The developed technique and apparatus greatly improves the performance of the previous MRBT device, and providing a new route toward practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Number of independent parameters in the potentiometric titration of humic substances.

PubMed

Lenoir, Thomas; Manceau, Alain

2010-03-16

With the advent of high-precision automatic titrators operating in pH stat mode, measuring the mass balance of protons in solid-solution mixtures against the pH of natural and synthetic polyelectrolytes is now routine. However, titration curves of complex molecules typically lack obvious inflection points, which complicates their analysis despite the high-precision measurements. The calculation of site densities and median proton affinity constants (pK) from such data can lead to considerable covariance between fit parameters. Knowing the number of independent parameters that can be freely varied during the least-squares minimization of a model fit to titration data is necessary to improve the model's applicability. This number was calculated for natural organic matter by applying principal component analysis (PCA) to a reference data set of 47 independent titration curves from fulvic and humic acids measured at I = 0.1 M. The complete data set was reconstructed statistically from pH 3.5 to 9.8 with only six parameters, compared to seven or eight generally adjusted with common semi-empirical speciation models for organic matter, and explains correlations that occur with the higher number of parameters. Existing proton-binding models are not necessarily overparametrized, but instead titration data lack the sensitivity needed to quantify the full set of binding properties of humic materials. Model-independent conditional pK values can be obtained directly from the derivative of titration data, and this approach is the most conservative. The apparent proton-binding constants of the 23 fulvic acids (FA) and 24 humic acids (HA) derived from a high-quality polynomial parametrization of the data set are pK(H,COOH)(FA) = 4.18 +/- 0.21, pK(H,Ph-OH)(FA) = 9.29 +/- 0.33, pK(H,COOH)(HA) = 4.49 +/- 0.18, and pK(H,Ph-OH)(HA) = 9.29 +/- 0.38. Their values at other ionic strengths are more reliably calculated with the empirical Davies equation than any existing model fit.

Characterization of Inactive Rocket Bodies Via Non-Resolved Photometric Data

NASA Astrophysics Data System (ADS)

Linares, R.; Palmer, D.; Thompson, D.; Klimenko, A.

2014-09-01

impact assessment via improved physics-based modeling. As part of this effort calibration satellite observations are used to dynamically calibrate the physics-based model and to improve its forecasting capability. The observations are collected from a variety of sources, including from LANLs own Raven-class optical telescope. This system collects both astrometric and photometric data on space objects. The photometric data will be used to estimate the space objects attitude and shape. Non-resolved photometric data have been studied by many as a mechanism for space object characterization. Photometry is the measurement of an objects flux or apparent brightness measured over a wavelength band. The temporal variation of photometric measurements is referred to as photometric signature. The photometric optical signature of an object contains information about shape, attitude, size and material composition. This work focuses on the processing of the data collected with LANLs telescope in an effort to use photometric data to expand the number of space objects that can be used as calibration satellites. A nonlinear least squares is used to estimate the attitude and angular velocity of the space object; a number of real data examples are shown. Inactive space objects are used for the real data examples and good estimation results are shown.

Kinetics of bacterial potentiometric titrations: the effect of equilibration time on buffering capacity of Pantoea agglomerans suspensions.

PubMed

Kapetas, Leon; Ngwenya, Bryne T; Macdonald, Alan M; Elphick, Stephen C

2011-07-15

Several recent studies have made use of continuous acid-base titration data to describe the surface chemistry of bacterial cells as a basis for accurately modelling metal adsorption to bacteria and other biomaterials of potential industrial importance. These studies do not share a common protocol; rather they titrate in different pH ranges and they use different stability criteria to define equilibration time during titration. In the present study we investigate the kinetics of bacterial titrations and test the effect they have on the derivation of functional group concentrations and acidity constants. We titrated suspensions of Pantoea agglomerans by varying the equilibration time between successive titrant additions until stability of 0.1 or 0.001 mV s(-1) was attained. We show that under longer equilibration times, titration results are less reproducible and suspensions exhibit marginally higher buffering. Fluorescence images suggest that cell lysis is not responsible for these effects. Rather, high DOC values and titration reversibility hysterisis after long equilibration times suggest that variability in buffering is due to the presence of bacterial exudates, as demonstrated by titrating supernatants separated from suspensions of different equilibration times. It is recommended that an optimal equilibration time is always determined with variable stability control and preliminary reversibility titration experiments. Copyright © 2011 Elsevier Inc. All rights reserved.

The Herschel Multi-Tiered Extragalactic Survey: SPIRE-mm Photometric Redshifts

NASA Technical Reports Server (NTRS)

Roseboom, I. G.; Ivison, R. J.; Greve, T. R.; Amblard, A.; Arumugam, V.; Auld, R.; Aussel, H.; Bethermin, M.; Blain, A.; Block, J.;

Study of the Effects of Photometric Geometry on Spectral Reflectance Measurements

NASA Technical Reports Server (NTRS)

Helfenstein, Paul

1998-01-01

The objective of this research is to investigate how the spectrophotometric properties of planetary surface materials depend on photometric geometry by refining and applying radiative transfer theory to data obtained from spacecraft and telescope observations of planetary surfaces, studies of laboratory analogs, and computer simulations. The goal is to perfect the physical interpretation of photometric parameters in the context of planetary surface geological properties and processes. The purpose of this report is to document the research achievements associated with this study.

Value of routine investigations to predict loop diuretic down-titration success in stable heart failure.

PubMed

Martens, Pieter; Verbrugge, Frederik H; Boonen, Levinia; Nijst, Petra; Dupont, Matthias; Mullens, Wilfried

2018-01-01

Guidelines advocate down-titration of loop diuretics in chronic heart failure (CHF) when patients have no signs of volume overload. Limited data are available on the expected success rate of this practice or how routine diagnostic tests might help steering this process. Fifty ambulatory CHF-patients on stable neurohumoral blocker/diuretic therapy for at least 3months without any clinical sign of volume overload were prospectively included to undergo loop diuretic down-titration. All patients underwent a similar pre-down-titration evaluation consisting of a dyspnea scoring, physical examination, transthoracic echocardiography (diastolic function, right ventricular function, cardiac filling pressures and valvular disease), blood sample (serum creatinine, plasma NT-pro-BNP and neurohormones). Loop diuretic maintenance dose was subsequently reduced by 50% or stopped if dose was ≤40mg furosemide equivalents. Successful down-titration was defined as a persistent dose reduction after 30days without weight increase >1.5kg or new-onset symptoms of worsening heart failure. At 30-day follow-up, down-titration was successful in 62% (n=31). In 12/19 patients exhibiting down-titration failure, this occurred within the first week. Physical examination, transthoracic echocardiography and laboratory analysis had limited predictive capability to detect patients with down-titration success/failure (positive likelihood-ratios below 1.5, or area under the curve [AUC] non-statically different from AUC=0.5). Loop diuretic down-titration is feasible in a majority of stable CHF patients in which the treating clinician felt continuation of loops was unnecessary to sustain euvolemia. Importantly, routine diagnostics which suggest euvolemia, have limited diagnostic impact on the post-test probability. Copyright © 2017 Elsevier B.V. All rights reserved.

The extinction law from photometric data: linear regression methods

NASA Astrophysics Data System (ADS)

Ascenso, J.; Lombardi, M.; Lada, C. J.; Alves, J.

2012-04-01

Context. The properties of dust grains, in particular their size distribution, are expected to differ from the interstellar medium to the high-density regions within molecular clouds. Since the extinction at near-infrared wavelengths is caused by dust, the extinction law in cores should depart from that found in low-density environments if the dust grains have different properties. Aims: We explore methods to measure the near-infrared extinction law produced by dense material in molecular cloud cores from photometric data. Methods: Using controlled sets of synthetic and semi-synthetic data, we test several methods for linear regression applied to the specific problem of deriving the extinction law from photometric data. We cover the parameter space appropriate to this type of observations. Results: We find that many of the common linear-regression methods produce biased results when applied to the extinction law from photometric colors. We propose and validate a new method, LinES, as the most reliable for this effect. We explore the use of this method to detect whether or not the extinction law of a given reddened population has a break at some value of extinction. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO programmes 069.C-0426 and 074.C-0728).

A simple micro-photometric method for urinary iodine determination.

PubMed

Grimm, Gabriele; Lindorfer, Heidelinde; Kieweg, Heidi; Marculescu, Rodrig; Hoffmann, Martha; Gessl, Alois; Sager, Manfred; Bieglmayer, Christian

2011-10-01

Urinary iodide concentration (UIC) is useful to evaluate nutritional iodine status. In clinical settings UIC helps to exclude blocking of the thyroid gland by excessive endogenous iodine, if diagnostic or therapeutic administration of radio-iodine is indicated. Therefore, this study established a simple test for the measurement of UIC. UIC was analyzed in urine samples of 200 patients. Samples were pre-treated at 95°C for 45 min with ammonium persulfate in a thermal cycler, followed by a photometric Sandell-Kolthoff reaction (SK) carried out in microtiter plates. For method comparison, UIC was analyzed in 30 samples by inductivity coupled plasma mass spectro-metry (ICP-MS) as a reference method. Incubation conditions were optimized concerning recovery. The photometric test correlated well to the reference method (SK=0.91*ICP-MS+1, r=0.962) and presented with a functional sensitivity of 20 μg/L. UIC of patient samples ranged from <20 to 750 μg/L (median 110 μg/L); 90% of the urine samples had iodide concentrations below 210 μg/L. The modified SK-test takes approximately 90 min for analyses of 20 urine samples compared with 27 h for ICP-MS. The photometric test provides satisfactory results and can be performed with the basic equipment of a clinical laboratory.

Ascorbic Acid as a Standard for Iodometric Titrations. An Analytical Experiment for General Chemistry

NASA Astrophysics Data System (ADS)

Silva, Cesar R.; Simoni, Jose A.; Collins, Carol H.; Volpe, Pedro L. O.

1999-10-01

Ascorbic acid is suggested as the weighable compound for the standardization of iodine solutions in an analytical experiment in general chemistry. The experiment involves an iodometric titration in which iodine reacts with ascorbic acid, oxidizing it to dehydroascorbic acid. The redox titration endpoint is determined by the first iodine excess that is complexed with starch, giving a deep blue-violet color. The results of the titration of iodine solution using ascorbic acid as a calibration standard were compared with the results acquired by the classic method using a standardized solution of sodium thiosulfate. The standardization of the iodine solution using ascorbic acid was accurate and precise, with the advantages of saving time and avoiding mistakes due to solution preparation. The colorless ascorbic acid solution gives a very clear and sharp titration end point with starch. It was shown by thermogravimetric analysis that ascorbic acid can be dried at 393 K for 2 h without decomposition. This experiment allows general chemistry students to perform an iodometric titration during a single laboratory period, determining with precision the content of vitamin C in pharmaceutical formulations.

SPLASH-SXDF Multi-wavelength Photometric Catalog

NASA Astrophysics Data System (ADS)

Mehta, Vihang; Scarlata, Claudia; Capak, Peter; Davidzon, Iary; Faisst, Andreas; Hsieh, Bau Ching; Ilbert, Olivier; Jarvis, Matt; Laigle, Clotilde; Phillips, John; Silverman, John; Strauss, Michael A.; Tanaka, Masayuki; Bowler, Rebecca; Coupon, Jean; Foucaud, Sébastien; Hemmati, Shoubaneh; Masters, Daniel; McCracken, Henry Joy; Mobasher, Bahram; Ouchi, Masami; Shibuya, Takatoshi; Wang, Wei-Hao

2018-04-01

We present a multi-wavelength catalog in the Subaru/XMM-Newton Deep Field (SXDF) as part of the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH). We include the newly acquired optical data from the Hyper-Suprime-Cam Subaru Strategic Program, accompanied by IRAC coverage from the SPLASH survey. All available optical and near-infrared data is homogenized and resampled on a common astrometric reference frame. Source detection is done using a multi-wavelength detection image including the u-band to recover the bluest objects. We measure multi-wavelength photometry and compute photometric redshifts as well as physical properties for ∼1.17 million objects over ∼4.2 deg2, with ∼800,000 objects in the 2.4 deg2 HSC-Ultra-Deep coverage. Using the available spectroscopic redshifts from various surveys over the range of 0 < z < 6, we verify the performance of the photometric redshifts and we find a normalized median absolute deviation of 0.023 and outlier fraction of 3.2%. The SPLASH-SXDF catalog is a valuable, publicly available resource, perfectly suited for studying galaxies in the early universe and tracing their evolution through cosmic time.

Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level.

PubMed

Sahoo, P; Ananthanarayanan, R; Malathi, N; Rajiniganth, M P; Murali, N; Swaminathan, P

2010-06-11

A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels. Copyright 2010 Elsevier B.V. All rights reserved.

Video Observations Encompassing the 2002 Leonid Storm: First Results and a Revised Photometric Procedure for Video Meteor Analysis

NASA Technical Reports Server (NTRS)

Cooke, William J.; Suggs, Robert; Swift, Wesley; Gural, Peter S.; Brown, Peter; Ellis, Jim (Technical Monitor)

2002-01-01

During the 2001 Leonid storm, Marshall Space Flight Center, with the cooperation of the University of Western Ontario and the United States Air Force, deployed 6 teams of observers equipped with intensified video systems to sites located in North America, the Pacific, and Mongolia. The campaign was extremely successful, with the entire period of enhanced Leonid activity (over 16 hours) captured on video tape in a consistent manner. We present the first results from the analysis of this unique, 2 terabyte data set and discuss the problems involved in reducing large amounts of video meteor data. In particular, the question of how to determine meteor masses though photometric analysis will be re-examined, and new techniques will be proposed that eliminate some of the deficiencies suffered by the techniques currently employed in video meteor analysis.

Development of a Platform to Enable Fully Automated Cross-Titration Experiments.

PubMed

Cassaday, Jason; Finley, Michael; Squadroni, Brian; Jezequel-Sur, Sylvie; Rauch, Albert; Gajera, Bharti; Uebele, Victor; Hermes, Jeffrey; Zuck, Paul

2017-04-01

In the triage of hits from a high-throughput screening campaign or during the optimization of a lead compound, it is relatively routine to test compounds at multiple concentrations to determine potency and maximal effect. Additional follow-up experiments, such as agonist shift, can be quite valuable in ascertaining compound mechanism of action (MOA). However, these experiments require cross-titration of a test compound with the activating ligand of the receptor requiring 100-200 data points, severely limiting the number tested in MOA assays in a screening triage. We describe a process to enhance the throughput of such cross-titration experiments through the integration of Hewlett Packard's D300 digital dispenser onto one of our robotics platforms to enable on-the-fly cross-titration of compounds in a 1536-well plate format. The process handles all the compound management and data tracking, as well as the biological assay. The process relies heavily on in-house-built software and hardware, and uses our proprietary control software for the platform. Using this system, we were able to automate the cross-titration of compounds for both positive and negative allosteric modulators of two different G protein-coupled receptors (GPCRs) using two distinct assay detection formats, IP1 and Ca 2+ detection, on nearly 100 compounds for each target.

Degradation analysis in the estimation of photometric redshifts from non-representative training sets

NASA Astrophysics Data System (ADS)

Rivera, J. D.; Moraes, B.; Merson, A. I.; Jouvel, S.; Abdalla, F. B.; Abdalla, M. C. B.

2018-07-01

We perform an analysis of photometric redshifts estimated by using a non-representative training sets in magnitude space. We use the ANNz2 and GPz algorithms to estimate the photometric redshift both in simulations and in real data from the Sloan Digital Sky Survey (DR12). We show that for the representative case, the results obtained by using both algorithms have the same quality, using either magnitudes or colours as input. In order to reduce the errors when estimating the redshifts with a non-representative training set, we perform the training in colour space. We estimate the quality of our results by using a mock catalogue which is split samples cuts in the r band between 19.4 < r < 20.8. We obtain slightly better results with GPz on single point z-phot estimates in the complete training set case, however the photometric redshifts estimated with ANNz2 algorithm allows us to obtain mildly better results in deeper r-band cuts when estimating the full redshift distribution of the sample in the incomplete training set case. By using a cumulative distribution function and a Monte Carlo process, we manage to define a photometric estimator which fits well the spectroscopic distribution of galaxies in the mock testing set, but with a larger scatter. To complete this work, we perform an analysis of the impact on the detection of clusters via density of galaxies in a field by using the photometric redshifts obtained with a non-representative training set.

Creation of a Unified Set of Core-Collapse Supernovae for Training of Photometric Classifiers

NASA Astrophysics Data System (ADS)

D'Arcy Kenworthy, William; Scolnic, Daniel; Kessler, Richard

2017-01-01

One of the key tasks for future supernova cosmology analyses is to photometrically distinguish type Ia supernovae (SNe) from their core collapse (CC) counterparts. In order to train programs for this purpose, it is necessary to train on a large number of core-collapse SNe. However, there are only a handful used for current programs. We plan to use the large amount of CC lightcurves available on the Open Supernova Catalog (OSC). Since this data is scraped from many different surveys, it is given in a number of photometric systems with different calibration and filters. We therefore created a program to fit smooth lightcurves (as a function of time) to photometric observations of arbitrary SNe. The Supercal method is then used to translate the smoothed lightcurves to a single photometric system. We can thus compile a training set of 782 supernovae, of which 127 are not type Ia. These smoothed lightcurves are also being contributed upstream to the OSC as derived data.

Effect of Spatial Titration on Task Performance

ERIC Educational Resources Information Center

Glowacki, Lawrence

1976-01-01

A reinforcement schedule and spatial titration method were used to determine task-reinforcement area separation most preferred and effective in two third-grade boys. Errors in task performance decreased task-reinforcement area separation, while correct responses in task performance increased task-reinforcement area separation. (Author)

Dark Energy Survey Year 1 Results: The Photometric Data Set for Cosmology

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

Drlica-Wagner, A.; Sevilla-Noarbe, I.; Rykoff, E. S.

In this paper, we describe the creation, content, and validation of the Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support of upcoming cosmological analyses. The Y1A1 GOLD data set is assembled from multiple epochs of DES imaging and consists of calibrated photometric zero-points, object catalogs, and ancillary data products—e.g., maps of survey depth and observing conditions, star–galaxy classification, and photometric redshift estimates—that are necessary for accurate cosmological analyses. The Y1A1 GOLD wide-area object catalog consists ofmore » $$\\sim 137$$ million objects detected in co-added images covering $$\\sim 1800\\,{\\deg }^{2}$$ in the DES grizY filters. The 10σ limiting magnitude for galaxies is $g=23.4$, $r=23.2$, $i=22.5$, $z=21.8$, and $Y=20.1$. Photometric calibration of Y1A1 GOLD was performed by combining nightly zero-point solutions with stellar locus regression, and the absolute calibration accuracy is better than 2% over the survey area. Finally, DES Y1A1 GOLD is the largest photometric data set at the achieved depth to date, enabling precise measurements of cosmic acceleration at z ≲ 1.« less

Dark Energy Survey Year 1 Results: The Photometric Data Set for Cosmology

DOE PAGES

Drlica-Wagner, A.; Sevilla-Noarbe, I.; Rykoff, E. S.; ...

2018-04-03

In this paper, we describe the creation, content, and validation of the Dark Energy Survey (DES) internal year-one cosmology data set, Y1A1 GOLD, in support of upcoming cosmological analyses. The Y1A1 GOLD data set is assembled from multiple epochs of DES imaging and consists of calibrated photometric zero-points, object catalogs, and ancillary data products—e.g., maps of survey depth and observing conditions, star–galaxy classification, and photometric redshift estimates—that are necessary for accurate cosmological analyses. The Y1A1 GOLD wide-area object catalog consists ofmore » $$\\sim 137$$ million objects detected in co-added images covering $$\\sim 1800\\,{\\deg }^{2}$$ in the DES grizY filters. The 10σ limiting magnitude for galaxies is $g=23.4$, $r=23.2$, $i=22.5$, $z=21.8$, and $Y=20.1$. Photometric calibration of Y1A1 GOLD was performed by combining nightly zero-point solutions with stellar locus regression, and the absolute calibration accuracy is better than 2% over the survey area. Finally, DES Y1A1 GOLD is the largest photometric data set at the achieved depth to date, enabling precise measurements of cosmic acceleration at z ≲ 1.« less

Photo-z-SQL: Integrated, flexible photometric redshift computation in a database

NASA Astrophysics Data System (ADS)

Beck, R.; Dobos, L.; Budavári, T.; Szalay, A. S.; Csabai, I.

2017-04-01

We present a flexible template-based photometric redshift estimation framework, implemented in C#, that can be seamlessly integrated into a SQL database (or DB) server and executed on-demand in SQL. The DB integration eliminates the need to move large photometric datasets outside a database for redshift estimation, and utilizes the computational capabilities of DB hardware. The code is able to perform both maximum likelihood and Bayesian estimation, and can handle inputs of variable photometric filter sets and corresponding broad-band magnitudes. It is possible to take into account the full covariance matrix between filters, and filter zero points can be empirically calibrated using measurements with given redshifts. The list of spectral templates and the prior can be specified flexibly, and the expensive synthetic magnitude computations are done via lazy evaluation, coupled with a caching of results. Parallel execution is fully supported. For large upcoming photometric surveys such as the LSST, the ability to perform in-place photo-z calculation would be a significant advantage. Also, the efficient handling of variable filter sets is a necessity for heterogeneous databases, for example the Hubble Source Catalog, and for cross-match services such as SkyQuery. We illustrate the performance of our code on two reference photo-z estimation testing datasets, and provide an analysis of execution time and scalability with respect to different configurations. The code is available for download at https://github.com/beckrob/Photo-z-SQL.

An optrode for photometric detection of ammonia in air

NASA Astrophysics Data System (ADS)

Buzanovskii, V. A.

2017-10-01

A scheme of constructing an LED optrode for photometric detection of ammonia in air is considered. The components of the device are (1) a glass plate coated with a film of polydimethylsiloxane with an ion-coupled cation of brilliant-green dye, (2) an LED emitting at a wavelength of 655 nm, and (3) a metal housing. The nominal static conversion function, sensitivity, and relative measurement error of the device are analyzed on the basis of mathematical modeling. The obtained results allow one to design an LED optrode capable of carrying out control for automated technological processes, solving problems in the area of security, etc. The device provides the ability to create photometric gas analyzers of ammonia with small overall dimensions, power consumption, and cost.

Efficacy and Tolerability of Two Different Kinds of Titration of Paroxetine Hydrocloride Solution: an Observational Study.

PubMed

Ielmini, Marta; Poloni, Nicola; Caselli, Ivano; Bianchi, Lucia; Diurni, Marcello; Vender, Simone; Callegari, Camilla

2018-03-13

Depressive disorders are expected to be the second highest cause of morbidity in the world until few years. Moreover, patients with depression frequently show many side effects and low compliance to therapy. To find a more tolerated and more efficacy therapy is a growing need. This observational study investigates the efficacy, safety and tolerability of paroxetine hydrochloride comparing slow versus standard titration in a population affected by Depressive Disoders (according to DSM 5). 186 outpatients were assessed throught the following scales: Hamilton Depression Rating Scale (HDRS) for depression and World Health Organization Quality of Life Scale Bref for the perceived quality of life (WHOQOL BREF). Treatment-emerged Adverse Events (TEAEs) were recorded throught self-reports. Statystical analysys was performed by GraphPad Prism Version 5.1. The efficacy of paroxetine was confirmed in both titrations by the number of clinical remitters (HDRS ≤ 7 at 12 weeks for 53% of the standard titration group and 58% of the slow titration group), without differences. About safety and tolerability there were more frequent TEAEs among the standard titration group (p < 0.01). Comparing WHOQOL BREF between the two groups at the recruitment and at the twelth week emerged a statistically significant difference (p = 0.003), with highest scores reached in slow titration group. Although the short observation period is an evident limit, this study is consistent to the literature about the efficacy of both titrations of paroxetine to improve depression and shows promising results about the increased tolerability of paroxetine slow titration.

A PHOTOMETRIC ANALYSIS OF SEVENTEEN BINARY STARS USING SPECKLE IMAGING

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

Davidson, James W.; Baptista, Brian J.; Horch, Elliott P.

2009-11-15

Magnitude differences obtained from speckle imaging are used in combination with other data in the literature to place the components of binary star systems on the H-R diagram. Isochrones are compared with the positions obtained, and a best-fit isochrone is determined for each system, yielding both masses of the components as well as an age range consistent with the system parameters. Seventeen systems are studied, 12 of which were observed with the 0.6 m Lowell-Tololo Telescope at Cerro Tololo Inter-American Observatory and six of which were observed with the WIYN 3.5 m Telescope (The WIYN Observatory is a joint facilitymore » of the University of Wisconsin-Madison, Indiana University, Yale University, and the National Optical Astronomy Observatories) at Kitt Peak. One system was observed from both sites. In comparing photometric masses to mass information from orbit determinations, we find that the photometric masses agree very well with the dynamical masses, and are generally more precise. For three systems, no dynamical masses exist at present, and therefore the photometrically determined values are the first mass estimates derived for these components.« less

Titration ELISA as a Method to Determine the Dissociation Constant of Receptor Ligand Interaction.

PubMed

Eble, Johannes A

2018-02-15

The dissociation constant describes the interaction between two partners in the binding equilibrium and is a measure of their affinity. It is a crucial parameter to compare different ligands, e.g., competitive inhibitors, protein isoforms and mutants, for their binding strength to a binding partner. Dissociation constants are determined by plotting concentrations of bound versus free ligand as binding curves. In contrast, titration curves, in which a signal that is proportional to the concentration of bound ligand is plotted against the total concentration of added ligand, are much easier to record. The signal can be detected spectroscopically and by enzyme-linked immunosorbent assay (ELISA). This is exemplified in a protocol for a titration ELISA that measures the binding of the snake venom-derived rhodocetin to its immobilized target domain of α2β1 integrin. Titration ELISAs are versatile and widely used. Any pair of interacting proteins can be used as immobilized receptor and soluble ligand, provided that both proteins are pure, and their concentrations are known. The difficulty so far has been to determine the dissociation constant from a titration curve. In this study, a mathematical function underlying titration curves is introduced. Without any error-prone graphical estimation of a saturation yield, this algorithm allows processing of the raw data (signal intensities at different concentrations of added ligand) directly by mathematical evaluation via non-linear regression. Thus, several titration curves can be recorded simultaneously and transformed into a set of characteristic parameters, among them the dissociation constant and the concentration of binding-active receptor, and they can be evaluated statistically. When combined with this algorithm, titration ELISAs gain the advantage of directly presenting the dissociation constant. Therefore, they may be used more efficiently in the future.

A photometric method for the estimation of the oil yield of oil shale

USGS Publications Warehouse

Cuttitta, Frank

1951-01-01

A method is presented for the distillation and photometric estimation of the oil yield of oil-bearing shales. The oil shale is distilled in a closed test tube and the oil extracted with toluene. The optical density of the toluene extract is used in the estimation of oil content and is converted to percentage of oil by reference to a standard curve. This curve is obtained by relating the oil yields determined by the Fischer assay method to the optical density of the toluene extract of the oil evolved by the new procedure. The new method gives results similar to those obtained by the Fischer assay method in a much shorter time. The applicability of the new method to oil-bearing shale and phosphatic shale has been tested.

The Dynamic Photometric Stereo Method Using a Multi-Tap CMOS Image Sensor †

PubMed Central

Yoda, Takuya; Nagahara, Hajime; Taniguchi, Rin-ichiro; Kagawa, Keiichiro; Yasutomi, Keita; Kawahito, Shoji

2018-01-01

The photometric stereo method enables estimation of surface normals from images that have been captured using different but known lighting directions. The classical photometric stereo method requires at least three images to determine the normals in a given scene. However, this method cannot be applied to dynamic scenes because it is assumed that the scene remains static while the required images are captured. In this work, we present a dynamic photometric stereo method for estimation of the surface normals in a dynamic scene. We use a multi-tap complementary metal-oxide-semiconductor (CMOS) image sensor to capture the input images required for the proposed photometric stereo method. This image sensor can divide the electrons from the photodiode from a single pixel into the different taps of the exposures and can thus capture multiple images under different lighting conditions with almost identical timing. We implemented a camera lighting system and created a software application to enable estimation of the normal map in real time. We also evaluated the accuracy of the estimated surface normals and demonstrated that our proposed method can estimate the surface normals of dynamic scenes. PMID:29510599

Potentiometric Titrations for Measuring the Capacitance of Colloidal Photodoped ZnO Nanocrystals.

PubMed

Brozek, Carl K; Hartstein, Kimberly H; Gamelin, Daniel R

2016-08-24

Colloidal semiconductor nanocrystals offer a unique opportunity to bridge molecular and bulk semiconductor redox phenomena. Here, potentiometric titration is demonstrated as a method for quantifying the Fermi levels and charging potentials of free-standing colloidal n-type ZnO nanocrystals possessing between 0 and 20 conduction-band electrons per nanocrystal, corresponding to carrier densities between 0 and 1.2 × 10(20) cm(-3). Potentiometric titration of colloidal semiconductor nanocrystals has not been described previously, and little precedent exists for analogous potentiometric titration of any soluble reductants involving so many electrons. Linear changes in Fermi level vs charge-carrier density are observed for each ensemble of nanocrystals, with slopes that depend on the nanocrystal size. Analysis indicates that the ensemble nanocrystal capacitance is governed by classical surface electrical double layers, showing no evidence of quantum contributions. Systematic shifts in the Fermi level are also observed with specific changes in the identity of the charge-compensating countercation. As a simple and contactless alternative to more common thin-film-based voltammetric techniques, potentiometric titration offers a powerful new approach for quantifying the redox properties of colloidal semiconductor nanocrystals.

Protofit: A program for determining surface protonation constants from titration data

NASA Astrophysics Data System (ADS)

Turner, Benjamin F.; Fein, Jeremy B.

2006-11-01

Determining the surface protonation behavior of natural adsorbents is essential to understand how they interact with their environments. ProtoFit is a tool for analysis of acid-base titration data and optimization of surface protonation models. The program offers a number of useful features including: (1) enables visualization of adsorbent buffering behavior; (2) uses an optimization approach independent of starting titration conditions or initial surface charge; (3) does not require an initial surface charge to be defined or to be treated as an optimizable parameter; (4) includes an error analysis intrinsically as part of the computational methods; and (5) generates simulated titration curves for comparison with observation. ProtoFit will typically be run through ProtoFit-GUI, a graphical user interface providing user-friendly control of model optimization, simulation, and data visualization. ProtoFit calculates an adsorbent proton buffering value as a function of pH from raw titration data (including pH and volume of acid or base added). The data is reduced to a form where the protons required to change the pH of the solution are subtracted out, leaving protons exchanged between solution and surface per unit mass of adsorbent as a function of pH. The buffering intensity function Qads* is calculated as the instantaneous slope of this reduced titration curve. Parameters for a surface complexation model are obtained by minimizing the sum of squares between the modeled (i.e. simulated) buffering intensity curve and the experimental data. The variance in the slope estimate, intrinsically produced as part of the Qads* calculation, can be used to weight the sum of squares calculation between the measured buffering intensity and a simulated curve. Effects of analytical error on data visualization and model optimization are discussed. Examples are provided of using ProtoFit for data visualization, model optimization, and model evaluation.

Characterization and photometric performance of the Hyper Suprime-Cam Software Pipeline

NASA Astrophysics Data System (ADS)

Huang, Song; Leauthaud, Alexie; Murata, Ryoma; Bosch, James; Price, Paul; Lupton, Robert; Mandelbaum, Rachel; Lackner, Claire; Bickerton, Steven; Miyazaki, Satoshi; Coupon, Jean; Tanaka, Masayuki

2018-01-01

The Subaru Strategic Program (SSP) is an ambitious multi-band survey using the Hyper Suprime-Cam (HSC) on the Subaru telescope. The Wide layer of the SSP is both wide and deep, reaching a detection limit of i ˜ 26.0 mag. At these depths, it is challenging to achieve accurate, unbiased, and consistent photometry across all five bands. The HSC data are reduced using a pipeline that builds on the prototype pipeline for the Large Synoptic Survey Telescope. We have developed a Python-based, flexible framework to inject synthetic galaxies into real HSC images, called SynPipe. Here we explain the design and implementation of SynPipe and generate a sample of synthetic galaxies to examine the photometric performance of the HSC pipeline. For stars, we achieve 1% photometric precision at i ˜ 19.0 mag and 6% precision at i ˜ 25.0 in the i band (corresponding to statistical scatters of ˜0.01 and ˜0.06 mag respectively). For synthetic galaxies with single-Sérsic profiles, forced CModel photometry achieves 13% photometric precision at i ˜ 20.0 mag and 18% precision at i ˜ 25.0 in the i band (corresponding to statistical scatters of ˜0.15 and ˜0.22 mag respectively). We show that both forced point spread function and CModel photometry yield unbiased color estimates that are robust to seeing conditions. We identify several caveats that apply to the version of HSC pipeline used for the first public HSC data release (DR1) that need to be taking into consideration. First, the degree to which an object is blended with other objects impacts the overall photometric performance. This is especially true for point sources. Highly blended objects tend to have larger photometric uncertainties, systematically underestimated fluxes, and slightly biased colors. Secondly, >20% of stars at 22.5 < i < 25.0 mag can be misclassified as extended objects. Thirdly, the current CModel algorithm tends to strongly underestimate the half-light radius and ellipticity of galaxy with i > 21.5 mag.

Acid-base titrations using microfluidic paper-based analytical devices.

PubMed

Karita, Shingo; Kaneta, Takashi

2014-12-16

Rapid and simple acid-base titration was accomplished using a novel microfluidic paper-based analytical device (μPAD). The μPAD was fabricated by wax printing and consisted of ten reservoirs for reaction and detection. The reaction reservoirs contained various amounts of a primary standard substance, potassium hydrogen phthalate (KHPth), whereas a constant amount of phenolphthalein was added to all the detection reservoirs. A sample solution containing NaOH was dropped onto the center of the μPAD and was allowed to spread to the reaction reservoirs where the KHPth neutralized it. When the amount of NaOH exceeded that of the KHPth in the reaction reservoirs, unneutralized hydroxide ion penetrated the detection reservoirs, resulting in a color reaction from the phenolphthalein. Therefore, the number of the detection reservoirs with no color change determined the concentration of the NaOH in the sample solution. The titration was completed within 1 min by visually determining the end point, which required neither instrumentation nor software. The volumes of the KHPth and phenolphthalein solutions added to the corresponding reservoirs were optimized to obtain reproducible and accurate results for the concentration of NaOH. The μPADs determined the concentration of NaOH at orders of magnitude ranging from 0.01 to 1 M. An acid sample, HCl, was also determined using Na2CO3 as a primary standard substance instead of KHPth. Furthermore, the μPAD was applicable to the titrations of nitric acid, sulfuric acid, acetic acid, and ammonia solutions. The μPADs were stable for more than 1 month when stored in darkness at room temperature, although this was reduced to only 5 days under daylight conditions. The analysis of acidic hot spring water was also demonstrated in the field using the μPAD, and the results agreed well with those obtained by classic acid-base titration.

The benefit of HH during the CPAP titration in the cool sleeping environment.

PubMed

Li, Yayong; Wang, Yina

2016-12-01

Upper airway symptom associated with continuous positive airway pressure (CPAP) treatment is an important factor influencing CPAP adherence. There are conflicting data on the effect of a heated humidifier (HH) during CPAP titration for patients with obstructive sleep apnea hypopnea syndrome (OSAHS). This study investigated the effects of HH during CPAP titration in the cool sleeping environment. Forty newly diagnosed OSAHS patients who received CPAP titration in the cool sleeping environment were randomly assigned to HH and non-HH groups. A questionnaire was used to evaluate upper airway symptoms, satisfaction with initial CPAP treatment, and willingness to further use CPAP. Some therapy parameters including leak, apnea hypopnea index (AHI) reduction, and optimal CPAP pressure level were analyzed. We compared these subjective and objective data between the two groups. In subjective sensation, the use of HH can alleviate upper airway symptoms associated with CPAP titration (P < 0.001). The HH group has benefit in satisfaction with initial CPAP treatment (P < 0.001) and further willingness to use CPAP (P < 0.01), although there were no significant differences in leak, AHI reduction, and optimal CPAP pressure between the two groups. The use of HH is recommended during CPAP titration in the cool sleeping environment because of its benefit in the treatment of upper airway symptoms associated with CPAP therapy and improvement of the CPAP acceptance.

Degradation analysis in the estimation of photometric redshifts from non-representative training sets

NASA Astrophysics Data System (ADS)

Rivera, J. D.; Moraes, B.; Merson, A. I.; Jouvel, S.; Abdalla, F. B.; Abdalla, M. C. B.

2018-04-01

We perform an analysis of photometric redshifts estimated by using a non-representative training sets in magnitude space. We use the ANNz2 and GPz algorithms to estimate the photometric redshift both in simulations as well as in real data from the Sloan Digital Sky Survey (DR12). We show that for the representative case, the results obtained by using both algorithms have the same quality, either using magnitudes or colours as input. In order to reduce the errors when estimating the redshifts with a non-representative training set, we perform the training in colour space. We estimate the quality of our results by using a mock catalogue which is split samples cuts in the r-band between 19.4 < r < 20.8. We obtain slightly better results with GPz on single point z-phot estimates in the complete training set case, however the photometric redshifts estimated with ANNz2 algorithm allows us to obtain mildly better results in deeper r-band cuts when estimating the full redshift distribution of the sample in the incomplete training set case. By using a cumulative distribution function and a Monte-Carlo process, we manage to define a photometric estimator which fits well the spectroscopic distribution of galaxies in the mock testing set, but with a larger scatter. To complete this work, we perform an analysis of the impact on the detection of clusters via density of galaxies in a field by using the photometric redshifts obtained with a non-representative training set.

Toward Space-like Photometric Precision from the Ground with Beam-shaping Diffusers

NASA Astrophysics Data System (ADS)

Stefansson, Gudmundur; Mahadevan, Suvrath; Hebb, Leslie; Wisniewski, John; Huehnerhoff, Joseph; Morris, Brett; Halverson, Sam; Zhao, Ming; Wright, Jason; O'rourke, Joseph; Knutson, Heather; Hawley, Suzanne; Kanodia, Shubham; Li, Yiting; Hagen, Lea M. Z.; Liu, Leo J.; Beatty, Thomas; Bender, Chad; Robertson, Paul; Dembicky, Jack; Gray, Candace; Ketzeback, William; McMillan, Russet; Rudyk, Theodore

2017-10-01

We demonstrate a path to hitherto unachievable differential photometric precisions from the ground, both in the optical and near-infrared (NIR), using custom-fabricated beam-shaping diffusers produced using specialized nanofabrication techniques. Such diffusers mold the focal plane image of a star into a broad and stable top-hat shape, minimizing photometric errors due to non-uniform pixel response, atmospheric seeing effects, imperfect guiding, and telescope-induced variable aberrations seen in defocusing. This PSF reshaping significantly increases the achievable dynamic range of our observations, increasing our observing efficiency and thus better averages over scintillation. Diffusers work in both collimated and converging beams. We present diffuser-assisted optical observations demonstrating {62}-16+26 ppm precision in 30 minute bins on a nearby bright star 16 Cygni A (V = 5.95) using the ARC 3.5 m telescope—within a factor of ˜2 of Kepler's photometric precision on the same star. We also show a transit of WASP-85-Ab (V = 11.2) and TRES-3b (V = 12.4), where the residuals bin down to {180}-41+66 ppm in 30 minute bins for WASP-85-Ab—a factor of ˜4 of the precision achieved by the K2 mission on this target—and to 101 ppm for TRES-3b. In the NIR, where diffusers may provide even more significant improvements over the current state of the art, our preliminary tests demonstrated {137}-36+64 ppm precision for a K S = 10.8 star on the 200 inch Hale Telescope. These photometric precisions match or surpass the expected photometric precisions of TESS for the same magnitude range. This technology is inexpensive, scalable, easily adaptable, and can have an important and immediate impact on the observations of transits and secondary eclipses of exoplanets.

The H,G_1,G_2 photometric system with scarce observational data

NASA Astrophysics Data System (ADS)

Penttilä, A.; Granvik, M.; Muinonen, K.; Wilkman, O.

2014-07-01

The H,G_1,G_2 photometric system was officially adopted at the IAU General Assembly in Beijing, 2012. The system replaced the H,G system from 1985. The 'photometric system' is a parametrized model V(α; params) for the magnitude-phase relation of small Solar System bodies, and the main purpose is to predict the magnitude at backscattering, H := V(0°), i.e., the (absolute) magnitude of the object. The original H,G system was designed using the best available data in 1985, but since then new observations have been made showing certain features, especially near backscattering, to which the H,G function has troubles adjusting to. The H,G_1,G_2 system was developed especially to address these issues [1]. With a sufficient number of high-accuracy observations and with a wide phase-angle coverage, the H,G_1,G_2 system performs well. However, with scarce low-accuracy data the system has troubles producing a reliable fit, as would any other three-parameter nonlinear function. Therefore, simultaneously with the H,G_1,G_2 system, a two-parameter version of the model, the H,G_{12} system, was introduced [1]. The two-parameter version ties the parameters G_1,G_2 into a single parameter G_{12} by a linear relation, and still uses the H,G_1,G_2 system in the background. This version dramatically improves the possibility to receive a reliable phase-curve fit to scarce data. The amount of observed small bodies is increasing all the time, and so is the need to produce estimates for the absolute magnitude/diameter/albedo and other size/composition related parameters. The lack of small-phase-angle observations is especially topical for near-Earth objects (NEOs). With these, even the two- parameter version faces problems. The previous procedure with the H,G system in such circumstances has been that the G-parameter has been fixed to some constant value, thus only fitting a single-parameter function. In conclusion, there is a definitive need for a reliable procedure to produce

Immediate effect of CPAP titration on perceived health related quality of life: a prospective observational study.

PubMed

Iacono Isidoro, Serena; Salvaggio, Adriana; Lo Bue, Anna; Romano, Salvatore; Marrone, Oreste; Insalaco, Giuseppe

2016-12-01

Perceived Health Related Quality of Life (HRQoL) is impaired in obstructive sleep apnea (OSA). This study examines changes in HRQoL aspects occurring immediately after CPAP titration. Furthermore, we analyzed variations in each gender and in patients undergoing home or laboratory-based CPAP titration pathways. Twohundredfive outpatients (151 M) (56.7 ± 10.3 years) were evaluated, before first visit and nocturnal diagnostic examination (T0), and the morning after CPAP titration (T1). Two self-reported HRQoL questionnaires were administered: Psychological General Well-Being Index (PGWBI), composed by six subscales, and 12-Item Short-Form Health Survey (SF-12), including Physical (PCS) and Mental Component Summaries (MCS). CPAP titration was performed using auto-adjusting CPAP units at patients' home or in the sleep laboratory. PGWBI scores at T1 improved compared to T0 (p < 0.0001). A similar improvement was observed in SF-12 MCS (p = 0.0011), but not in SF-12 PCS. Changes were independent from anthropometric parameters, OSA severity and excessive daytime sleepiness. Gender comparisons showed better HRQoL in males at both times. At T0, patients who received home or laboratory CPAP titration pathways did not show any differences in PGWBI and SF-12 scores. At T1, PGWBI and SF-12 MCS improved in both home and laboratory groups. This study gives evidence that first time CPAP application for titration can lead to a general increase in perceived well-being. Gender comparisons showed better perceived HRQoL with more subscales improvements in males after CPAP titration. The improvement was similar with both home and laboratory CPAP titration pathways.

The acid-base titration of montmorillonite

NASA Astrophysics Data System (ADS)

Bourg, I. C.; Sposito, G.; Bourg, A. C.

2003-12-01

Proton binding to clay minerals plays an important role in the chemical reactivity of soils (e.g., acidification, retention of nutrients or pollutants). If should also affect the performance of clay barriers for waste disposal. The surface acidity of clay minerals is commonly modelled empirically by assuming generic amphoteric surface sites (>SOH) on a flat surface, with fitted site densities and acidity constant. Current advances in experimental methods (notably spectroscopy) are rapidly improving our understanding of the structure and reactivity of the surface of clay minerals (arrangement of the particles, nature of the reactive surface sites, adsorption mechanisms). These developments are motivated by the difficulty of modelling the surface chemistry of mineral surfaces at the macro-scale (e.g., adsorption or titration) without a detailed (molecular-scale) picture of the mechanisms, and should be progressively incorporated into surface complexation models. In this view, we have combined recent estimates of montmorillonite surface properties (surface site density and structure, edge surface area, surface electrostatic potential) with surface site acidities obtained from the titration of alpha-Al2O3 and SiO2, and a novel method of accounting for the unknown initial net proton surface charge of the solid. The model predictions were compared to experimental titrations of SWy-1 montmorillonite and purified MX-80 bentonite in 0.1-0.5 mol/L NaClO4 and 0.005-0.5 mol/L NaNO3 background electrolytes, respectively. Most of the experimental data were appropriately described by the model after we adjusted a single parameter (silanol sites on the surface of montmorillonite were made to be slightly more acidic than those of silica). At low ionic strength and acidic pH the model underestimated the buffering capacity of the montmorillonite, perhaps due to clay swelling or to the interlayer adsorption of dissolved aluminum. The agreement between our model and the experimental

Down-titration of biologics for the treatment of rheumatoid arthritis: a systematic literature review.

PubMed

Lau, Chak Sing; Gibofsky, Allan; Damjanov, Nemanja; Lula, Sadiq; Marshall, Lisa; Jones, Heather; Emery, Paul

2017-11-01

Biologic therapies have improved the management of rheumatoid arthritis (RA) and the treat-to-target approach has resulted in many patients achieving remission. In the current treatment landscape, clinicians have begun considering dose reduction/tapering for their patients. Rheumatology guidelines in Asia, Europe, and the United States include down-titration of biologics but admit that the level of evidence is moderate. We conducted a systematic literature review to assess the published studies that evaluate down-titration of biologics in RA. The published literature was searched for studies that down-titrated the following biologics: abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab, and tocilizumab. Eligible studies included randomized controlled trials (RCTs), non-RCTs, observational, and pharmacoeconomic studies. The outcomes of interest were (1) efficacy and health-related quality of life, (2) disease flares, and (3) impact on cost. Eleven full-text publications were identified; only three were RCTs. Study results suggest that dosing down may be an option in many patients who have achieved remission or low disease activity. However, some patients are likely to experience a disease flare. Across the studies, the definition of disease flare and the down-titration criteria were inconsistent, making it difficult to conclude which patients may be appropriate and when to attempt down-titration. Studies have evaluated the practice of dosing down biologic therapy in patients with RA; however, a relatively small number of RCTs have been published. Although down-titration may be an option for some patients in LDA or remission, additional RCTs are needed to provide guidance on this practice.

Clinical, polysomnographic, and CPAP titration features of obstructive sleep apnea: Mixed versus purely obstructive type.

PubMed

Lee, Sang-Ahm; Lee, Gha-Hyun; Chung, Yoo-Sam; Kim, Woo Sung

2015-08-15

To determine whether obstructive sleep apnea syndrome (OSAS) patients with mixed sleep apnea (MSA) have different clinical, polysomnographic, and continuous positive airway pressure (CPAP) titration findings compared to OSAS patients without MSA. We retrospectively reviewed the records of OSAS patients who had undergone CPAP titration and categorized them into pure-OSA and mixed-OSA groups. Demographic features, daytime sleepiness, and apnea severity were compared between the two groups using univariate and multivariate analyses. CPAP titration findings were also compared between the two groups. One hundred and ninety-five subjects (n=126 pure-OSA; n=69 mixed-OSA) were included in the analysis. Compared to the pure-OSA group, the mixed-OSA group had a higher percentage of males (p=0.003) and a higher body mass index (p=0.044), Epworth Sleepiness Scale score (p=0.028), and apnea-hypopnea index (AHI) (p<0.001). In logistic regression analysis, older age, male sex, and higher body mass index were independently associated with mixed-OSA before PSG study. When using AHI as a covariable, the higher AHI with older age, male sex, and daytime sleepiness was independently related to mixed-OSA. The mixed-OSA group had a higher percentage of patients with complex sleep apnea, a lower percentage of patients with optimal titration, and a higher titrated pressure than the pure-OSA group. Severe OSA, older age, male sex, obesity, and daytime sleepiness were related to mixed-OSA. Complex sleep apnea, less optimal titration, and a higher titrated CPAP were also associated with MSA in OSAS patients. Copyright © 2015 Elsevier B.V. All rights reserved.

A systematic review on the effectiveness of titratable over nontitratable mandibular advancement appliances for sleep apnea.

PubMed

Sivaramakrishnan, Gowri; Sridharan, Kannan

2017-01-01

Mandibular advancement appliances are being tested for use in patients with obstructive sleep apnea (OSA). However, the effectiveness of titration of these appliances does not have conclusive evidence. Systematic reviews help us to compile all available clinical evidence using statistical principles. Hence, the aim of this systematic review is to identify the effectiveness of titratable over nontitratable mandibular advancement appliances in patients with mild to moderate OSA. This review objective is to identify if titration of these appliances produce significant benefits over fixed appliances. Electronic databases were searched to identify eligible studies based on set inclusion criteria. Data extraction form was created and the data were extracted. The participants were mild to moderate OSA patients who received mandibular advancement appliances. Studies included a comparison between titratable and nontitratable mandibular advancement appliance. Of the five included studies, three were observational and two were a randomized trial. All these studies were conducted in adults. The outcome attributes were polysomnographic readings and apnea-hypopnea index (AHI). A significant heterogeneity was seen between the eligible studies and hence a meta-analysis could not be performed. The results from this systematic review did not show significant advantages of titratable appliances, although titratable appliances performed better from individual studies as regards to reduction in AHI and polysomnography. The reason is the lack of sufficient clinical trials on the same. More high quality randomized controlled trials comparing titratable and fixed appliances have to be initiated to get to conclusive evidence.

Isothermal Titration Calorimetry in the Student Laboratory

ERIC Educational Resources Information Center

Wadso, Lars; Li, Yujing; Li, Xi

2011-01-01

Isothermal titration calorimetry (ITC) is the measurement of the heat produced by the stepwise addition of one substance to another. It is a common experimental technique, for example, in pharmaceutical science, to measure equilibrium constants and reaction enthalpies. We describe a stirring device and an injection pump that can be used with a…

Photometric Properties of Network and faculae derived by HMI data compensated for scattered-light

NASA Astrophysics Data System (ADS)

Criscuoli, Serena; Norton, Aimee Ann; Whitney, Taylor

2017-08-01

We report on the photometric properties of faculae and network as observed in full-disk,scattered-light corrected images from the Helioseismic Magnetic Imager (HMI). We usea Lucy-Richardson deconvolution routine that corrects a full-disk intensity image in lessthan one second. Faculae are distinguished from network through proximity to activeregions in addition to continuum intensity and magnetogram thresholds. This is the firstreport that full-disk image data, including center-to-limb variations, reproduce the photometric properties of faculae and network observed previously only in sub-arcsecond resolution, small field-of-view studies, i.e. that network exhibit in general higher photometric contrasts. More specifically, for magnetic flux values larger than approximately 300 G, the network is always brighter than faculae and the contrast differences increases toward the limb, where the network contrast is about twice the facular one. For lower magnetic flux values, pixels in network regions appear always darker than facular ones. Contrary to reports from previous full-disk observations, we also found that network exhibits a higher center-to-limb variation. Our results are in agreement with reports from simulations that indicate magnetic flux alone is a poor proxy of the photometric properties of magnetic features. We estimate that the facular and network contribution to irradiance variability of the current Cycle 24 is overestimated by at least 11% due to the photometric properties of network and faculae not being recognized as distinctly different.

Photometric models of disk-integrated observations of the OSIRIS-REx target Asteroid (101955) Bennu

NASA Astrophysics Data System (ADS)

Takir, Driss; Clark, Beth Ellen; Drouet d'Aubigny, Christian; Hergenrother, Carl W.; Li, Jian-Yang; Lauretta, Dante S.; Binzel, Richard P.

2015-05-01

We used ground-based photometric phase curve data of the OSIRIS-REx target Asteroid (101955) Bennu and low phase angle data from Asteroid (253) Mathilde as a proxy to fit Bennu data with Minnaert, Lommel-Seeliger, (RObotic Lunar Orbiter) ROLO, Hapke, and McEwen photometric models, which capture the global light scattering properties of the surface and subsequently allow us to calculate the geometric albedo, phase integral, spherical Bond albedo, and the average surface normal albedo for Bennu. We find that Bennu has low reflectance and geometric albedo values, such that multiple scattering is expected to be insignificant. Our photometric models relate the reflectance from Bennu's surface to viewing geometry as functions of the incidence, emission, and phase angles. Radiance Factor functions (RADFs) are used to model the disk-resolved brightness of Bennu. The Minnaert, Lommel-Seeliger, ROLO, and Hapke photometric models work equally well in fitting the best ground-based photometric phase curve data of Bennu. The McEwen model works reasonably well at phase angles from 20° to 70°. Our calculated geometric albedo values of 0.047-0.014+0.012,0.047-0.014+0.005 , and 0.048-0.022+0.012 for the Minnaert, the Lommel-Seeliger, and the ROLO models respectively are consistent with the geometric albedo of 0.045 ± 0.015 computed by Emery et al. (Emery, J.P. et al. [2014]. Icarus 234, 17-35) and Hergenrother et al. (Hergenrother, C.W. et al. [2014].

How Accurately Can We Measure Galaxy Environment at High Redshift Using Only Photometric Redshifts?

NASA Astrophysics Data System (ADS)

Florez, Jonathan; Jogee, Shardha; Sherman, Sydney; Papovich, Casey J.; Finkelstein, Steven L.; Stevans, Matthew L.; Kawinwanichakij, Lalitwadee; Ciardullo, Robin; Gronwall, Caryl; SHELA/HETDEX

2017-06-01

We use a powerful synergy of six deep photometric surveys (Herschel SPIRE, Spitzer IRAC, NEWFIRM K-band, DECam ugriz, and XMM X-ray) and a future optical spectroscopic survey (HETDEX) in the Stripe 82 field to study galaxy evolution during the 1.9 < z < 3.5 epoch when cosmic star formation and black hole activity peaked, and protoclusters began to collapse. With an area of 24 sq. degrees, a sample size of ~ 0.8 million galaxies complete in stellar mass above M* ~ 10^10 solar masses, and a comoving volume of ~ 0.45 Gpc^3, our study will allow us to make significant advancements in understanding the connection between galaxies and their respective dark matter components. In this poster, we characterize how robustly we can measure environment using only our photometric redshifts. We compare both local and large-scale measures of environment (e.g., projected two-point correlation function, projected nearest neighbor densities, and galaxy counts within some projected aperture) at different photometric redshifts to cosmological simulations in order to quantify the uncertainty in our estimates of environment. We also explore how robustly one can recover the variation of galaxy properties with environment, when using only photometric redshifts. In the era of large photometric surveys, this work has broad implications for studies addressing the impact of environment on galaxy evolution at early cosmic epochs. We acknowledge support from NSF grants AST-1614798, AST-1413652 and NSF GRFP grant DGE-1610403.

Using Spreadsheets to Produce Acid-Base Titration Curves.

ERIC Educational Resources Information Center

Cawley, Martin James; Parkinson, John

1995-01-01

Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

BVR photometric investigation of galaxy pair KPG 562

NASA Astrophysics Data System (ADS)

Hendy, Y. H. M.

2018-06-01

This work presents BVR photometric observations and analyses for galaxy pair KPG 562 selected from the Karachentsev Catalog of Isolated Pairs of Galaxies. The observations were obtained using the 1.88-m Telescope of the Kottamia Astronomical Observatory (KAO), Egypt. There is no interaction signs assigned for this pair as reported by Karachentsev Catalog. We used the surface photometry technique to obtain photometric parameters for each galaxy of the pair. The isophotal contours, the luminosity profiles, color profiles (B-V, V-R), ellipticity profiles, position angle (PA) profiles and isophotal center-shift (xc, yc) profiles have been presented. The total and absolute magnitude, ellipticity and position angle (PA) were also obtained from the studied galaxy pair. The studied galaxy pair is clearly showing signs of interaction opposed to that found by Karachentsev. We found that the galaxy KPG 562b contains one tidal tail. The length and thickness of tidal tail were obtained and presented in this study.

Impact of hypoglycemic events and HbA1c level on sulfonylurea discontinuation and down-titration.

PubMed

Laires, Pedro A; Tang, Jackson; Fan, Chun Po Steve; Li, Zhiyi; Qiu, Ying; Iglay, Kristy

2017-04-01

A retrospective cohort study using GE Centricity electronic medical records assessed the association between post-index hypoglycemia and HbA1c with discontinuation and down-titration of sulfonylureas among patients with Type 2 diabetes mellitus. Adult patients with an index prescription for a sulfonylurea and ≥12 months' continuous records pre- and post-index were eligible. Sulfonylurea discontinuation and down-titration was assessed 1-year post-index. Discontinuation occurred if the date of a prescription was >90 days from the preceding prescription plus days of supply. Down-titration occurred when a subsequent prescription was lower than the index dose. Cox regression assessed the association between post-index hypoglycemia and HbA1c with time to sulfonylurea discontinuation and down-titration, as well as other factors. 28,371 participants were included in the study; 13,459 (47.4%) were discontinuers, 717 (2.5%) were down-titraters, and 14,195 (50.0%) were continuers. 0.6% of continuers experienced hypoglycemia 1-year post-index, compared with 3.1% of down-titraters and 0.8% of discontinuers (p < 0.0001). Patients with post-index hypoglycemia had a significantly higher rate of discontinuation (hazard ratio [HR] = 1.82, 95% CI: 1.47-2.23) and down-titration (HR = 4.25, 95% CI: 1.92-8.03). Patients with higher post-index HbA1c and use of 2 nd generation sulfonylureas had an increased rate of discontinuation (HR = 1.05, 95% CI: 1.04-1.06; HR = 1.19, 95% CI: 1.14-1.24, respectively). Approximately half of participants who initiated sulfonylureas discontinued or down-titrated therapy within one year. Both post-index hypoglycemia and higher HbA1c were significant risk factors for sulfonylurea treatment change.

Determination of Carbonyl Groups in Pyrolysis Bio-oils Using Potentiometric Titration: Review and Comparison of Methods

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

Black, Stuart; Ferrell, Jack R.

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here in this study, we present a modification of the traditional carbonyl oximation procedures that results inmore » less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. Some compounds such as carbohydrates are not measured by the traditional method (modified Nicolaides method), resulting in low estimations of the carbonyl content. Furthermore, we have shown that reaction completion for the traditional method can take up to 300 hours. The new method presented here (the modified Faix method) reduces the reaction time to 2 hours, uses triethanolamine (TEA) in the place of pyridine, and requires a smaller sample size for the analysis. Carbonyl contents determined using this new method are consistently higher than when using the traditional titration methods.« less

Determination of Carbonyl Groups in Pyrolysis Bio-oils Using Potentiometric Titration: Review and Comparison of Methods

DOE PAGES

Black, Stuart; Ferrell, Jack R.

2016-01-06

Carbonyl compounds present in bio-oils are known to be responsible for bio-oil property changes upon storage and during upgrading. As such, carbonyl content has previously been used as a method of tracking bio-oil aging and condensation reactions with less variability than viscosity measurements. Given the importance of carbonyls in bio-oils, accurate analytical methods for their quantification are very important for the bio-oil community. Potentiometric titration methods based on carbonyl oximation have long been used for the determination of carbonyl content in pyrolysis bio-oils. Here in this study, we present a modification of the traditional carbonyl oximation procedures that results inmore » less reaction time, smaller sample size, higher precision, and more accurate carbonyl determinations. Some compounds such as carbohydrates are not measured by the traditional method (modified Nicolaides method), resulting in low estimations of the carbonyl content. Furthermore, we have shown that reaction completion for the traditional method can take up to 300 hours. The new method presented here (the modified Faix method) reduces the reaction time to 2 hours, uses triethanolamine (TEA) in the place of pyridine, and requires a smaller sample size for the analysis. Carbonyl contents determined using this new method are consistently higher than when using the traditional titration methods.« less

Predicting the Quasar Photometric Reshift with the Sloan Digital Sky Survey Filter System

NASA Astrophysics Data System (ADS)

Laubacher, Emily M.; York, Donald G.

1999-10-01

Photometric data were obtained for a set of known quasars (QSOs) in five bands with the Sloan Digital Sky Survey (SDSS) filter system for the purpose of testing the ability of the SDSS system to accurately predict the photometric redshift of QSOs. The initial plot of the SDSS photometric redshift versus the measured redshift shows a good relationship, but a lot of scatter. A literature search was conducted on a selected sampling of 49 QSOs, 26 with redshift z <= 0.5 and 23 with 0.5 < z < 2.6, to confirm their accurate identifications as QSOs with their advertised redshifts. This search revealed 10 rejected QSOs which were not QSOs but rather Seyfert galaxies or Narrow Line Objects. Additionally, 11 QSOs were either Broad Absorption Line Systems or had spectra that were in some way incomplete, and therefore, their QSO identification could not be confirmed. The revised plot, with the rejected and unconfirmed QSOs removed, gives an excellent straight line with very little scatter. Although these results are preliminary and for only a small sampling of QSOs, they show that further study of the relationship is warranted and that eventually the SDSS method may be used to accurately predict the photometric redshift of QSOs.

Thermometric titration of acids in pyridine.

PubMed

Vidal, R; Mukherjee, L M

1974-04-01

Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

Comparison of the clinical outcomes between unattended home APAP and polysomnography manual titration in obstructive sleep apnea patients.

PubMed

Wongsritrang, Krongthong; Fueangkamloon, Sumet

2013-09-01

To compare the clinical outcomes and determine the difference in therapeutic pressure between Automatic positive airway pressure (APAP) and polysomnography manual titration. Fifty patients of obstructive sleep apnea (OSA), moderate to severe cases, were randomized into two groups of intervention: 95-percentile pressure derived from APAP titration and an optimal pressure derived from manual titration. Clinical outcomes were assessed before and after four weeks. The average 95-percentile pressure derived from APAP titration was 11.7 +/- 0.3 cmH2O with median mask leak 1.3 L/min. The average optimal pressure derived from manual titration was 8.2 +/- 0.3 cmH2O. Pearson correlation analysis showed weak positive correlation (r = 0.336, p = 0.017). The Epworth Sleepiness Score (ESS), Quality of life tests: PSQI (Pittsburg Sleep Quality Index), and SF-36 (Medical Outcomes Study 36-Item Short-Form Health Survey) were improved significantly in both groups, but there were no statistical significant differences between groups. An APAP titration is an effective method of pressure determination for conventional CPAP therapy and shows no difference in clinical outcomes comparing the standard titration.

A Titration Technique for Demonstrating a Magma Replenishment Model.

ERIC Educational Resources Information Center

Hodder, A. P. W.

1983-01-01

Conductiometric titrations can be used to simulate subduction-setting volcanism. Suggestions are made as to the use of this technique in teaching volcanic mechanisms and geochemical indications of tectonic settings. (JN)

Thermodynamic analysis of Bacillus subtilis endospore protonation using isothermal titration calorimetry

NASA Astrophysics Data System (ADS)

Harrold, Zoë R.; Gorman-Lewis, Drew

2013-05-01

Bacterial proton and metal adsorption reactions have the capacity to affect metal speciation and transport in aqueous environments. We coupled potentiometric titration and isothermal titration calorimetry (ITC) analyses to study Bacillus subtilis spore-proton adsorption. We modeled the potentiometric data using a four and five-site non-electrostatic surface complexation model (NE-SCM). Heats of spore surface protonation from coupled ITC analyses were used to determine site specific enthalpies of protonation based on NE-SCMs. The five-site model resulted in a substantially better model fit for the heats of protonation but did not significantly improve the potentiometric titration model fit. The improvement observed in the five-site protonation heat model suggests the presence of a highly exothermic protonation reaction circa pH 7 that cannot be resolved in the less sensitive potentiometric data. From the log Ks and enthalpies we calculated corresponding site specific entropies. Log Ks and site concentrations describing spore surface protonation are statistically equivalent to B. subtilis cell surface protonation constants. Spore surface protonation enthalpies, however, are more exothermic relative to cell based adsorption suggesting a different bonding environment. The thermodynamic parameters defined in this study provide insight on molecular scale spore-surface protonation reactions. Coupled ITC and potentiometric titrations can reveal highly exothermic, and possibly endothermic, adsorption reactions that are overshadowed in potentiometric models alone. Spore-proton adsorption NE-SCMs derived in this study provide a framework for future metal adsorption studies.

Standardized Photometric Calibrations for Panchromatic SSA Sensors

NASA Astrophysics Data System (ADS)

Castro, P.; Payne, T.; Battle, A.; Cole, Z.; Moody, J.; Gregory, S.; Dao, P.

2016-09-01

Panchromatic sensors used for Space Situational Awareness (SSA) have no standardized method for transforming the net flux detected by a CCD without a spectral filter into an exo-atmospheric magnitude in a standard magnitude system. Each SSA data provider appears to have their own method for computing the visual magnitude based on panchromatic brightness making cross-comparisons impossible. We provide a procedure in order to standardize the calibration of panchromatic sensors for the purposes of SSA. A technique based on theoretical modeling is presented that derives standard panchromatic magnitudes from the Johnson-Cousins photometric system defined by Arlo Landolt. We verify this technique using observations of Landolt standard stars and a Vega-like star to determine empirical panchromatic magnitudes and compare these to synthetically derived panchromatic magnitudes. We also investigate color terms caused by differences in the quantum efficiency (QE) between the Landolt standard system and panchromatic systems. We evaluate calibrated panchromatic satellite photometry by observing several GEO satellites and standard stars using three different sensors. We explore the effect of satellite color terms by comparing the satellite signatures. In order to remove other variables affecting the satellite photometry, two of the sensors are at the same site using different CCDs. The third sensor is geographically separate from the first two allowing for a definitive test of calibrated panchromatic satellite photometry.

Molecular Weight Measurement of Biobased Furan Polyamides via Non-Aqueous Potentiometric Titration

DTIC Science & Technology

2013-06-01

electromagnetic fields, all titrations were completed in a chemical hood, which acted as a Faraday cage (a shield used to blocks external static and...while using DMF as a solvent. Additionally, no Faraday cage was used in the experimental setup, so the titrations were conducted inside the chemical...monomer was becoming more soluble in glacial acetic acid and the amount of chlorobenzene had less of an effect on the solution properties (i.e

Thermodynamics study of the dimerization equilibria of rhodamine B and 6G in different ionic strengths by photometric titration and chemometrics method

NASA Astrophysics Data System (ADS)

Ghasemi, Jahanbakhsh; Niazi, Ali; Kubista, Mikael

2005-11-01

The dimerization constants of rhodamine B and 6G have been determined by studying the dependence of their absorption spectra on the temperature in the range 20-80 °C at different total concentrations of rhodamine B (5.89 × 10 -6 to 2.36 × 10 -4 M) and rhodamine 6G (2.34 × 10 -5 to 5.89 × 10 -4 M) and in different concentrations of LiCl, NaCl and KCl salts as supporting electrolytes. The monomer-dimer equilibrium of rhodamine B and 6G have been determined by chemometrics refinement of the absorption spectra obtained by thermometric titrations performed at different ionic strengths. The quantitative analysis of the data of undefined mixtures, was carried out by simultaneous resolution of the overlapping spectral bands in the whole set of absorption spectra. The dimerization constants are varied by changing the ionic strength and the degree of dimerization are decreased by increasing of the ionic strength of the medium. The enthalpy and entropy of the dimerization reactions were determined from the dependence of the equilibrium constants on the temperature (van't Hoff equation). From the thermodynamic results the TΔ S°-Δ H° plot was sketched. It shows a fairly good positive correlation which indicates the enthalpy-entropy compensation in the dimerization reactions (compensation effect).

Thermodynamics study of the dimerization equilibria of rhodamine B and 6G in different ionic strengths by photometric titration and chemometrics method.

PubMed

Ghasemi, Jahanbakhsh; Niazi, Ali; Kubista, Mikael

2005-11-01

The dimerization constants of rhodamine B and 6G have been determined by studying the dependence of their absorption spectra on the temperature in the range 20-80 degrees C at different total concentrations of rhodamine B (5.89 x 10(-6) to 2.36 x 10(-4)M) and rhodamine 6G (2.34 x 10(-5) to 5.89 x 10(-4)M) and in different concentrations of LiCl, NaCl and KCl salts as supporting electrolytes. The monomer-dimer equilibrium of rhodamine B and 6G have been determined by chemometrics refinement of the absorption spectra obtained by thermometric titrations performed at different ionic strengths. The quantitative analysis of the data of undefined mixtures, was carried out by simultaneous resolution of the overlapping spectral bands in the whole set of absorption spectra. The dimerization constants are varied by changing the ionic strength and the degree of dimerization are decreased by increasing of the ionic strength of the medium. The enthalpy and entropy of the dimerization reactions were determined from the dependence of the equilibrium constants on the temperature (van't Hoff equation). From the thermodynamic results the TDeltaS degrees -DeltaH degrees plot was sketched. It shows a fairly good positive correlation which indicates the enthalpy-entropy compensation in the dimerization reactions (compensation effect).

Concurrent determination of total serum calcium and magnesium by thermometric titration with ethylenediaminetetraacetate.

PubMed

Callicott, R H; Carr, P W

1976-07-01

Total serum calcium and magnesium may be determined in one thermometric titration, with disodium ethylenediaminetetraacetate as the titrant. A 1-ml serum sample is diluted with 1 ml of tris(hydroxymethyl)aminomethane buffer (pH 8) and titrated at a constant rate with a motorized syringe buret. Results by the thermometric method compared well with those by atomic absorption spectroscopy.

Prescribing and up-titration in recently hospitalized heart failure patients attending a disease management program.

PubMed

Carroll, Robert; Mudge, Alison; Suna, Jessica; Denaro, Charles; Atherton, John

2016-08-01

Heart failure (HF) medications improve clinical outcomes, with optimal doses defined in clinical trials. Patient, provider and system barriers may limit achievement of optimal doses in real life settings, although disease management programs (HF-DMPs) can facilitate up-titration. Secondary analysis of a prospective cohort of 216 participants recently hospitalized with systolic HF, attending 5 HF-DMPs in Queensland, Australia. Medication history at baseline (6weeks after discharge) and 6months provided data to describe prescription rates, dosage and optimal titration of HF medications, and associations with patient and system factors were explored. At baseline, 94% were on an angiotensin converting enzyme inhibitor/angiotensin II receptor blocker (ACEI/ARB), 94% on a beta-blocker (BB) and 42% on a mineralocorticoid receptor antagonist (MRA). The proportion of participants on optimal doses of ACEI/ARB increased from 38% (baseline) to 52% (6months, p=0.001) and on optimal BB dose from 23% to 49% (p<0.001). Significant barriers to ACEI/ARB up-titration were body mass index (BMI)<25, female gender, polypharmacy, previously diagnosed HF, and tertiary hospital. Significant barriers for BB up-titration were BMI<25, previously diagnosed HF and non-cardiologist care. Effective up-titration in HF DMPs is influenced by patient, disease and service factors. Better understanding of barriers to effective up-titration in women, normal weight, and established HF patients may help provide targeted strategies for improving outcomes in these groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measuring titratable alkalinity by single versus double endpoint titration: An evaluation in two cyprinodont species and implications for characterizing net H+ flux in aquatic organisms.

PubMed

Brix, Kevin V; Wood, Chris M; Grosell, Martin

2013-01-01

In this study, Na(+) uptake and acid-base balance in the euryhaline pupfish Cyprinodon variegatus variegatus were characterized when fish were exposed to pH 4.5 freshwater (7mM Na(+)). Similar to the related cyprinodont, Fundulus heteroclitus, Na(+) uptake was significantly inhibited when exposed to low pH water. However, it initially appeared that C. v. variegatus increased apparent net acid excretion at low pH relative to circumneutral pH. This result is opposite to previous observations for F. heteroclitus under similar conditions where fish were observed to switch from apparent net H(+) excretion at circumneutral pH to apparent net H(+) uptake at low pH. Further investigation revealed disparate observations between these studies were the result of using double endpoint titrations to measure titratable alkalinity fluxes in the current study, while the earlier study utilized single endpoint titrations to measure these fluxes (i.e.,. Cyprinodon acid-base transport is qualitatively similar to Fundulus when characterized using single endpoint titrations). This led to a comparative investigation of these two methods. We hypothesized that either the single endpoint methodology was being influenced by a change in the buffer capacity of the water (e.g., mucus being released by the fish) at low pH, or the double endpoint methodology was not properly accounting for ammonia flux by the fish. A series of follow-up experiments indicated that buffer capacity of the water did not change significantly, that excretion of protein (a surrogate for mucus) was actually reduced at low pH, and that the double endpoint methodology does not properly account for NH(3) excretion by fish under low pH conditions. As a result, it overestimates net H(+) excretion during low pH exposure. After applying the maximum possible correction for this error (i.e., assuming that all ammonia is excreted as NH(3)), the double endpoint methodology indicates that net H(+) transport was reduced to

A HUBBLE DIAGRAM FROM TYPE II SUPERNOVAE BASED SOLELY ON PHOTOMETRY: THE PHOTOMETRIC COLOR METHOD

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

De Jaeger, T.; González-Gaitán, S.; Galbany, L.

2015-12-20

We present a Hubble diagram of SNe II using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I for which optical and near-infrared light curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a color term. We obtain a dispersion of 0.44 mag using a combination of the (V − i) color and the r band and we are able to reduce the dispersion to 0.39 mag using our goldenmore » sample. A comparison of our photometric color method (PCM) with the standardized candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag, which compares with 0.43 mag from the PCM for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data.« less

Photometric Properties of Network and Faculae Derived from HMI Data Compensated for Scattered Light

NASA Astrophysics Data System (ADS)

Criscuoli, Serena; Norton, Aimee; Whitney, Taylor

2017-10-01

We report on the photometric properties of faculae and network, as observed in full-disk, scattered-light-corrected images from the Helioseismic Magnetic Imager. We use a Lucy-Richardson deconvolution routine that corrects an image in less than one second. Faculae are distinguished from network through proximity to active regions. This is the first report that full-disk observations, including center-to-limb variations, reproduce the photometric properties of faculae and network observed previously only in sub-arcsecond-resolution; small field-of-view studies, I.e. that network, as defined by distance from active regions, exhibit higher photometric contrasts. Specifically, for magnetic flux values larger than approximately 300 G, the network is brighter than faculae and the contrast differences increase toward the limb, where the network contrast is about twice the facular one. For lower magnetic flux values, network appear darker than faculae. Contrary to reports from previous full-disk observations, we also found that network exhibits a higher center-to-limb variation. Our results are in agreement with reports from simulations that indicate magnetic flux alone is a poor proxy of the photometric properties of magnetic features. We estimate that the contribution of faculae and network to Total Solar Irradiance variability of the current Cycle 24 is overestimated by at least 11%, due to the photometric properties of network and faculae not being recognized as different. This estimate is specific to the method employed in this study to reconstruct irradiance variations, so caution should be paid when extending it to other techniques.

Photometric Properties of Network and Faculae Derived from HMI Data Compensated for Scattered Light

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

Criscuoli, Serena; Whitney, Taylor; Norton, Aimee

We report on the photometric properties of faculae and network, as observed in full-disk, scattered-light-corrected images from the Helioseismic Magnetic Imager. We use a Lucy–Richardson deconvolution routine that corrects an image in less than one second. Faculae are distinguished from network through proximity to active regions. This is the first report that full-disk observations, including center-to-limb variations, reproduce the photometric properties of faculae and network observed previously only in sub-arcsecond-resolution; small field-of-view studies, i.e. that network, as defined by distance from active regions, exhibit higher photometric contrasts. Specifically, for magnetic flux values larger than approximately 300 G, the network ismore » brighter than faculae and the contrast differences increase toward the limb, where the network contrast is about twice the facular one. For lower magnetic flux values, network appear darker than faculae. Contrary to reports from previous full-disk observations, we also found that network exhibits a higher center-to-limb variation. Our results are in agreement with reports from simulations that indicate magnetic flux alone is a poor proxy of the photometric properties of magnetic features. We estimate that the contribution of faculae and network to Total Solar Irradiance variability of the current Cycle 24 is overestimated by at least 11%, due to the photometric properties of network and faculae not being recognized as different. This estimate is specific to the method employed in this study to reconstruct irradiance variations, so caution should be paid when extending it to other techniques.« less

Multi-complexity measures of heart rate variability and the effect of vasopressor titration: a prospective cohort study of patients with septic shock.

PubMed

Brown, Samuel M; Sorensen, Jeffrey; Lanspa, Michael J; Rondina, Matthew T; Grissom, Colin K; Shahul, Sajid; Mathews, V J

2016-10-10

Septic shock is a common and often devastating syndrome marked by severe cardiovascular dysfunction commonly managed with vasopressors. Whether markers of heart rate complexity before vasopressor up-titration could be used to predict success of the up-titration is not known. We studied patients with septic shock requiring vasopressor, newly admitted to the intensive care unit. We measured the complexity of heart rate variability (using the ratio of fractal exponents from detrended fluctuation analysis) in the 5 min before all vasopressor up-titrations in the first 24 h of an intensive care unit (ICU) admission. A successful up-titration was defined as one that did not require further up-titration (or decrease in mean arterial pressure) for 60 min. We studied 95 patients with septic shock, with a median APACHE II of 27 (IQR: 20-37). The median number of up-titrations, normalized to 24 h, was 12.2 (IQR: 8-17) with a maximum of 49. Of the up-titrations, the median proportion of successful interventions was 0.28 (IQR: 0.12-0.42). The median of mean arterial pressure (MAP) at the time of a vasopressor up-titration was 66 mmHg; the average infusion rate of norepinephrine at the time of an up-titration was 0.11 mcg/kg/min. The ratio of fractal exponents was not associated with successful up-titration on univariate or multivariate regression. On exploratory secondary analyses, however, the long-term fractal exponent was associated (p = 0.003) with success of up-titration. Independent of heart rate variability, MAP was associated (p < 0.001) with success of vasopressor up-titration, while neither Sequential Organ Failure Assessment (SOFA) nor Acute Physiology and Chronic Health Evaluation II (APACHE II) score was associated with vasopressor titration. Only a third of vasopressor up-titrations were successful among patients with septic shock. MAP and the long-term fractal exponent were associated with success of up-titration. These two, complementary variables

Report of a patient chewing fentanyl patches who was titrated onto methadone

PubMed Central

Dale, Eric; Ashby, Fleur; Seelam, Kalyan

2009-01-01

This case report discusses the clinical presentation and management of a patient presenting to substance misuse services reporting chewing fentanyl patches in addition to wearing them transdermally. The patient was successfully titrated onto methadone 30 mg. Only one previously reported case of an individual chewing fentanyl patches was found in the literature; no case reports were found where treatment involved titrating the patient onto methadone. The pharmacology and illicit use of fentanyl are also considered. PMID:22114625

Indirect photometric detection of boron cluster anions electrophoretically separated in methanol.

PubMed

Vítová, Lada; Fojt, Lukáš; Vespalec, Radim

2014-04-18

3,5-Dinitrobenzoate and picrate are light absorbing anions pertinent to indirect photometric detection of boron cluster anions in buffered methanolic background electrolytes (BGEs). Tris(hydroxymethyl)aminomethane and morpholine have been used as buffering bases, which eliminated baseline steps, and minimized the baseline noise. In methanolic BGEs, mobilities of boron cluster anions depend on both ionic constituents of the BGE buffer. This dependence can be explained by ion pair interaction of detected anions with BGE cations, which are not bonded into ion pairs with the BGE anions. The former ion pair interaction decreases sensitivity of the indirect photometric detection. Copyright © 2014 Elsevier B.V. All rights reserved.

Feasibility and Association of Neurohumoral Blocker Up-titration After Cardiac Resynchronization Therapy.

PubMed

Martens, Pieter; Verbrugge, Frederik H; Nijst, Petra; Bertrand, Philippe B; Dupont, Matthias; Tang, Wilson H; Mullens, Wilfried

2017-08-01

Cardiac resynchronization therapy (CRT) improves mortality and morbidity on top of optimal medical therapy in heart failure with reduced ejection fraction (HFrEF). This study aimed to elucidate the association between neurohumoral blocker up-titration after CRT implantation and clinical outcomes. Doses of angiotensin-converting enzyme inhibitors (ACE-Is), angiotensin receptor blockers (ARBs), and beta-blockers were retrospectively evaluated in 650 consecutive CRT patients implanted from October 2008 to August 2015 and followed in a tertiary multidisciplinary CRT clinic. All 650 CRT patients were on a maximal tolerable dose of ACE-I/ARB and beta-blocker at the time of CRT implantation. However, further up-titration was successful in 45.4% for ACE-I/ARB and in 56.8% for beta-blocker after CRT-implantation. During a mean follow-up of 37 ± 22 months, a total of 139 events occurred for the combined end point of heart failure admission and all-cause mortality. Successful, versus unsuccessful, up-titration was associated with adjusted hazard ratios of 0.537 (95% confidence interval 0.316-0.913; P = .022) for ACE-I/ARB and 0.633 (0.406-0.988; P = .044) for beta-blocker on the combined end point heart failure admission and all-cause mortality. Patients in the up-titration group exhibited a similar risk for death or heart failure admission as patients treated with the maximal dose (ACE-I/ARB: P = .133; beta-blockers: P = .709). After CRT, a majority of patients are capable of tolerating higher dosages of neurohumoral blockers. Up-titration of neurohumoral blockers after CRT implantation is associated with improved clinical outcomes, similarly to patients treated with the guideline-recommended target dose at the time of CRT implantation. Copyright © 2017 Elsevier Inc. All rights reserved.

Photometric commissioning results from MINERVA

NASA Astrophysics Data System (ADS)

Eastman, Jason D.; Swift, Jonathan; Beatty, Thomas G.; Bottom, Michael; Johnson, John; Wright, Jason; McCrady, Nate; Wittenmyer, Robert A.; Riddle, Reed L.; Plavchan, Peter; Muirhead, Philip Steven; Blake, Cullen; Zhao, Ming

2015-01-01

MINERVA is a robotic observatory with four 0.7 meter telescopes at Mt. Hopkins, Arizona, dedicated to precise photometry and radial velocity observations of bright, nearby stars for the discovery and characterization of small exoplanets. Here we present the first photometric results from MINERVA during commissioning at our test facility in Pasadena, California, demonstrating sub-millimag precision on 3-5 minute timescales over several hours. These results show that MINERVA is well-equipped to address its secondary science goal of searching for transits of known and newly discovered super-Earth exoplanets detected by radial velocity, including potential detections from the MINERVA spectrograph.

Cosmological baryonic and matter densities from 600000 SDSS luminous red galaxies with photometric redshifts

NASA Astrophysics Data System (ADS)

Blake, Chris; Collister, Adrian; Bridle, Sarah; Lahav, Ofer

2007-02-01

We analyse MegaZ-LRG, a photometric-redshift catalogue of luminous red galaxies (LRGs) based on the imaging data of the Sloan Digital Sky Survey (SDSS) 4th Data Release. MegaZ-LRG, presented in a companion paper, contains >106 photometric redshifts derived with ANNZ, an artificial neural network method, constrained by a spectroscopic subsample of ~13000 galaxies obtained by the 2dF-SDSS LRG and Quasar (2SLAQ) survey. The catalogue spans the redshift range 0.4 < z < 0.7 with an rms redshift error σz ~ 0.03(1 + z), covering 5914 deg2 to map out a total cosmic volume 2.5h-3Gpc3. In this study we use the most reliable 600000 photometric redshifts to measure the large-scale structure using two methods: (1) a spherical harmonic analysis in redshift slices, and (2) a direct re-construction of the spatial clustering pattern using Fourier techniques. We present the first cosmological parameter fits to galaxy angular power spectra from a photometric-redshift survey. Combining the redshift slices with appropriate covariances, we determine best-fitting values for the matter density Ωm and baryon density Ωb of Ωmh = 0.195 +/- 0.023 and Ωb/Ωm = 0.16 +/- 0.036 (with the Hubble parameter h = 0.75 and scalar index of primordial fluctuations nscalar = 1 held fixed). These results are in agreement with and independent of the latest studies of the cosmic microwave background radiation, and their precision is comparable to analyses of contemporary spectroscopic-redshift surveys. We perform an extensive series of tests which conclude that our power spectrum measurements are robust against potential systematic photometric errors in the catalogue. We conclude that photometric-redshift surveys are competitive with spectroscopic surveys for measuring cosmological parameters in the simplest `vanilla' models. Future deep imaging surveys have great potential for further improvement, provided that systematic errors can be controlled.

The ALHAMBRA survey: accurate merger fractions derived by PDF analysis of photometrically close pairs

NASA Astrophysics Data System (ADS)

López-Sanjuan, C.; Cenarro, A. J.; Varela, J.; Viironen, K.; Molino, A.; Benítez, N.; Arnalte-Mur, P.; Ascaso, B.; Díaz-García, L. A.; Fernández-Soto, A.; Jiménez-Teja, Y.; Márquez, I.; Masegosa, J.; Moles, M.; Pović, M.; Aguerri, J. A. L.; Alfaro, E.; Aparicio-Villegas, T.; Broadhurst, T.; Cabrera-Caño, J.; Castander, F. J.; Cepa, J.; Cerviño, M.; Cristóbal-Hornillos, D.; Del Olmo, A.; González Delgado, R. M.; Husillos, C.; Infante, L.; Martínez, V. J.; Perea, J.; Prada, F.; Quintana, J. M.

2015-04-01

Aims: Our goal is to develop and test a novel methodology to compute accurate close-pair fractions with photometric redshifts. Methods: We improved the currently used methodologies to estimate the merger fraction fm from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space; (ii) including the variation in the luminosity of the sources with z in both the sample selection and the luminosity ratio constrain; and (iii) splitting individual PDFs into red and blue spectral templates to reliably work with colour selections. We tested the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. Results: The merger fractions and rates from the ALHAMBRA survey agree excellently well with those from spectroscopic work for both the general population and red and blue galaxies. With the merger rate of bright (MB ≤ -20-1.1z) galaxies evolving as (1 + z)n, the power-law index n is higher for blue galaxies (n = 2.7 ± 0.5) than for red galaxies (n = 1.3 ± 0.4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is Nmred = 0.57 ± 0.05 for red galaxies and Nmblue = 0.26 ± 0.02 for blue galaxies. Conclusions: Our new methodology statistically exploits all the available information provided by photometric redshift codes and yields accurate measurements of the merger fraction by close pairs from using photometric redshifts alone. Current and future photometric surveys will benefit from this new methodology. Based on observations collected at the German-Spanish Astronomical Center, Calar Alto, jointly operated by the Max-Planck-Institut für Astronomie (MPIA) at Heidelberg and the Instituto de Astrofísica de Andalucía (CSIC).The catalogues, probabilities, and figures of the ALHAMBRA close pairs detected in Sect. 5.1 are available at http://https://cloud.iaa.csic.es/alhambra/catalogues/ClosePairs

DISSECTING PHOTOMETRIC REDSHIFT FOR ACTIVE GALACTIC NUCLEUS USING XMM- AND CHANDRA-COSMOS SAMPLES

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

Salvato, M.; Hasinger, G.; Ilbert, O.

2011-12-01

In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library onmore » the bases of the source properties allowed us to reach an accuracy {sigma}{sub {Delta}z/(1+z{sub s{sub p{sub e{sub c)}}}}}{approx}0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2 deg{sup 2} of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by {Delta}z > 0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H{sub AB} = 24 mag). We illustrate once again the importance of a spectroscopic training sample and how an assumption about the nature of a source together, with the number and the depth of the available bands, influences the accuracy of the photometric redshifts determined for AGN. These considerations should be kept in mind when defining the observational strategies of upcoming large surveys targeting AGNs, such as eROSITA at X-ray energies and the Australian Square Kilometre Array Pathfinder Evolutionary Map of the Universe in the radio band.« less

Uncertain Photometric Redshifts with Deep Learning Methods

NASA Astrophysics Data System (ADS)

D'Isanto, A.

2017-06-01

The need for accurate photometric redshifts estimation is a topic that has fundamental importance in Astronomy, due to the necessity of efficiently obtaining redshift information without the need of spectroscopic analysis. We propose a method for determining accurate multi-modal photo-z probability density functions (PDFs) using Mixture Density Networks (MDN) and Deep Convolutional Networks (DCN). A comparison with a Random Forest (RF) is performed.

Application of cause-and-effect analysis to potentiometric titration.

PubMed

Kufelnicki, A; Lis, S; Meinrath, G

2005-08-01

A first attempt has been made to interpret physicochemical data from potentiometric titration analysis in accordance with the complete measurement-uncertainty budget approach (bottom-up) of ISO and Eurachem. A cause-and-effect diagram is established and discussed. Titration data for arsenazo III are used as a basis for this discussion. The commercial software Superquad is used and applied within a computer-intensive resampling framework. The cause-and-effect diagram is applied to evaluation of seven protonation constants of arsenazo III in the pH range 2-10.7. The data interpretation is based on empirical probability distributions and their analysis by second-order correct confidence estimates. The evaluated data are applied in the calculation of a speciation diagram including uncertainty estimates using the probabilistic speciation software Ljungskile.

Isothermal Titration Calorimetry Can Provide Critical Thinking Opportunities

ERIC Educational Resources Information Center

Moore, Dale E.; Goode, David R.; Seney, Caryn S.; Boatwright, Jennifer M.

2016-01-01

College chemistry faculties might not have considered including isothermal titration calorimetry (ITC) in their majors' curriculum because experimental data from this instrumental method are often analyzed via automation (software). However, the software-based data analysis can be replaced with a spreadsheet-based analysis that is readily…

Photometric study of the Moon with SMART-1/AMIE

NASA Astrophysics Data System (ADS)

Naranen, Jyri; Parviainen, Hannu; Muinonen, Karri; Josset, Jean-Luc; Beauvivre, Stephane; Koschny, Detlef; Foing, Bernard H.; Krieger, Bjoern; Amie Team

The Advanced Moon micro-Imager Experiment (AMIE) onboard the ESA SMART-1 lunar mission performed imaging of the Moon between November 2004 and September 2006, when the mission was ended by crashing the spacecraft into the lunar surface. AMIE was a 1024X1024 pixel miniaturized CCD camera with three colour filters and a panchromatic channel (clear filter). The images are of medium-to-high resolution, e.g. at 300 km pericenter altitude the resolution was 27 m/pix. We selected four different regions on the lunar surface imaged by AMIE for the photometric investigation reported here. These regions were selected so that as large phase angle coverage as possible was available, including the opposition geometry. Each of the regions cover a few hundred square kilometers of the lunar surface and were imaged by AMIE several tens of times. The regions examined include, e.g., Reiner gamma and Oceanus Procellarum near the crater Mairan. We utilized the latest in-flight calibration data available and we also georetrified the images to account for the aspect distortions. For the study reported here, the panchromatic filter was chosen since it is the best calibrated channel at the moment. The data was analyzed by implementing a numerical light scattering model with which we have inverted the regolith porosity and macroscopic surface roughness properties for the target areas. The model computes the bidirectional reflectance function using the geometric-optics approximation from a particulate medium constrained by a self-affine fractal random fields mimicking the regolith-covered lunar surface. Fractal description of the surface roughness is used, since it gives a more realistic way to model the true macroscopic surface roughness than the often used Gaussian correlation-model. Unlike in the previous studies, the azimuthal shadowing effects are taken into account, allowing for a more reliable inversion of surface statistics from images with large phase angles. In addition, we have

Determination of arsenate and organic arsenic via potentiometric titration of its heteropoly anions.

PubMed

Metelka, R; Slavíková, S; Vytras, K

2002-08-16

Determination of arsenate based on its conversion to molybdoarsenate heteropoly anions followed by potentiometric titration is described. The titration is realized on the ion-pairing principle using cetylpyridinium chloride (or an analogous titrant containing a lipophilic cation), and is monitored by a carbon paste electrode, although other liquid-polymeric membrane-based electrodes can also be used. Calibration plots of the titrant end-point consumption versus concentration of arsenic were constructed and used to evaluate the content of arsenic in aqueous samples. The method could be applied in the analyses of samples with quite low arsenic content (amounts approximately 10 mug As in 50 cm(3) could be titrated). Organic arsenic was determined analogously after the Schöniger combustion of the sample and conversion of its arsenic to arsenate.

High-throughput Titration of Luciferase-expressing Recombinant Viruses

PubMed Central

Garcia, Vanessa; Krishnan, Ramya; Davis, Colin; Batenchuk, Cory; Le Boeuf, Fabrice; Abdelbary, Hesham; Diallo, Jean-Simon

2014-01-01

Standard plaque assays to determine infectious viral titers can be time consuming, are not amenable to a high volume of samples, and cannot be done with viruses that do not form plaques. As an alternative to plaque assays, we have developed a high-throughput titration method that allows for the simultaneous titration of a high volume of samples in a single day. This approach involves infection of the samples with a Firefly luciferase tagged virus, transfer of the infected samples onto an appropriate permissive cell line, subsequent addition of luciferin, reading of plates in order to obtain luminescence readings, and finally the conversion from luminescence to viral titers. The assessment of cytotoxicity using a metabolic viability dye can be easily incorporated in the workflow in parallel and provide valuable information in the context of a drug screen. This technique provides a reliable, high-throughput method to determine viral titers as an alternative to a standard plaque assay. PMID:25285536

1993 Intercomparison of Photometric Units Maintained at NIST (USA) and PTB (Germany)

PubMed Central

Ohno, Yoshihiro; Sauter, Georg

1995-01-01

A bilateral intercomparison of photometric units between NIST, USA and PTB, Germany has been conducted to update the knowledge of the relationship between the photometric units disseminated in each country. The luminous intensity unit (cd) and the luminous flux unit (lm) maintained at both laboratories are compared by circulating transfer standard lamps. Also, the photometric responsivity sv is compared by circulating a V(λ)-corrected detector with a built-in current-to-voltage converter. The results show that the difference of luminous intensity unit between NIST and PTB, (PTB-NIST)/NIST, is 0.2 % with a relative expanded uncertainty (coverage factor k = 2) of 0.24 %. The difference is reduced significantly from that at the 1985 CCPR intercomparison (0.9 %). The difference in luminous flux unit, (PTB – NIST)/NIST, is found to be 1.5 % with a relative expanded uncertainty (coverage factor k =2) of 0.15 %. The difference remained nearly the same as that at the 1985 intercomparison (1.6 %). These results agree with what is predicted from the history of maintaining the units at each laboratory. PMID:29151737

A Model-independent Photometric Redshift Estimator for Type Ia Supernovae

NASA Astrophysics Data System (ADS)

Wang, Yun

2007-01-01

The use of Type Ia supernovae (SNe Ia) as cosmological standard candles is fundamental in modern observational cosmology. In this Letter, we derive a simple empirical photometric redshift estimator for SNe Ia using a training set of SNe Ia with multiband (griz) light curves and spectroscopic redshifts obtained by the Supernova Legacy Survey (SNLS). This estimator is analytical and model-independent it does not use spectral templates. We use all the available SNe Ia from SNLS with near-maximum photometry in griz (a total of 40 SNe Ia) to train and test our photometric redshift estimator. The difference between the estimated redshifts zphot and the spectroscopic redshifts zspec, (zphot-zspec)/(1+zspec), has rms dispersions of 0.031 for 20 SNe Ia used in the training set, and 0.050 for 20 SNe Ia not used in the training set. The dispersion is of the same order of magnitude as the flux uncertainties at peak brightness for the SNe Ia. There are no outliers. This photometric redshift estimator should significantly enhance the ability of observers to accurately target high-redshift SNe Ia for spectroscopy in ongoing surveys. It will also dramatically boost the cosmological impact of very large future supernova surveys, such as those planned for the Advanced Liquid-mirror Probe for Astrophysics, Cosmology, and Asteroids (ALPACA) and the Large Synoptic Survey Telescope (LSST).

Trace analysis of acids and bases by conductometric titration with multiparametric non-linear regression.

PubMed

Coelho, Lúcia H G; Gutz, Ivano G R

2006-03-15

A chemometric method for analysis of conductometric titration data was introduced to extend its applicability to lower concentrations and more complex acid-base systems. Auxiliary pH measurements were made during the titration to assist the calculation of the distribution of protonable species on base of known or guessed equilibrium constants. Conductivity values of each ionized or ionizable species possibly present in the sample were introduced in a general equation where the only unknown parameters were the total concentrations of (conjugated) bases and of strong electrolytes not involved in acid-base equilibria. All these concentrations were adjusted by a multiparametric nonlinear regression (NLR) method, based on the Levenberg-Marquardt algorithm. This first conductometric titration method with NLR analysis (CT-NLR) was successfully applied to simulated conductometric titration data and to synthetic samples with multiple components at concentrations as low as those found in rainwater (approximately 10 micromol L(-1)). It was possible to resolve and quantify mixtures containing a strong acid, formic acid, acetic acid, ammonium ion, bicarbonate and inert electrolyte with accuracy of 5% or better.

Galaxy clustering with photometric surveys using PDF redshift information

DOE PAGES

Asorey, J.; Carrasco Kind, M.; Sevilla-Noarbe, I.; ...

2016-03-28

Here, photometric surveys produce large-area maps of the galaxy distribution, but with less accurate redshift information than is obtained from spectroscopic methods. Modern photometric redshift (photo-z) algorithms use galaxy magnitudes, or colors, that are obtained through multi-band imaging to produce a probability density function (PDF) for each galaxy in the map. We used simulated data to study the effect of using different photo-z estimators to assign galaxies to redshift bins in order to compare their effects on angular clustering and galaxy bias measurements. We found that if we use the entire PDF, rather than a single-point (mean or mode) estimate, the deviations are less biased, especially when using narrow redshift bins. When the redshift bin widths aremore » $$\\Delta z=0.1$$, the use of the entire PDF reduces the typical measurement bias from 5%, when using single point estimates, to 3%.« less

Photometric Study of the Pulsating, Eclipsing Binary OO Dra

NASA Astrophysics Data System (ADS)

Zhang, X. B.; Deng, L. C.; Tian, J. F.; Wang, K.; Sun, J. J.; Liu, Q. L.; Xin, H. Q.; Zhou, Q.; Yan, Z. Z.; Luo, Z. Q.; Luo, C. Q.

2014-12-01

We present a comprehensive photometric study of the pulsating, eclipsing binary OO Dra. Simultaneous B- and V-band photometry of the star was carried out on 14 nights. A revised orbital period and a new ephemeris were derived from the data. The first photometric solution of the binary system and the physical parameters of the component stars are determined. They reveal that OO Dra could be a detached system with a less-massive secondary component nearly filling its Roche lobe. By subtracting the eclipsing light changes from the data, we obtained the intrinsic pulsating light curves of the hotter, massive primary component. A frequency analysis of the residual light yields two confident pulsation modes in both B- and V-band data with the dominant frequency detected at 41.865 c/d. A brief discussion concerning the evolutionary status and the pulsation nature of the binary system is finally given.

Advanced titration to treat a floppy epiglottis in selective upper airway stimulation.

PubMed

Heiser, Clemens

2016-09-01

The following report presents a case of a patient with high residual apnea-hypopnea index at 6 months following implantation of an upper airway stimulation device who improved significantly after advanced titration via drug-induced sedated endoscopy by changing the electrode configuration for stimulation from bipolar to monopolar. This case demonstrates the utility of postsurgical advanced titration to optimize programming settings for improved clinical outcomes. Laryngoscope, 126:S22-S24, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Coulometric thermometric titration of halides in molten calcium nitrate tetrahydrate.

PubMed

Zsigrai, I J; Bartusz, D B

1983-01-01

A method for coulometric thermometric precipitation titrations of chloride, bromide and iodide in molten calcium nitrate tetrahydrate at 55 degrees with coulometrically generated silver ions has been developed. The change in temperature during the titration is followed with the aid of a thermistor bridge coupled to a recorder. To minimize the temperature effect of the passage of current through the melt, two thermistors are connected in opposition in the bridge, with one in the anodic and the other in the cathodic cell compartment. Amounts of 62-80 mumole of halide have been determined with relative error below 0.4% and relative standard deviation less than 2.7%. The relative error in determination of 40 mumole of iodide was + 2%.

Risk factors associated with treatment discontinuation and down-titration in type 2 diabetes patients treated with sulfonylureas.

PubMed

Iglay, Kristy; Qiu, Ying; Steve Fan, Chun-Po; Li, Zhiyi; Tang, Jackson; Laires, Pedro

2016-09-01

Sulfonylurea therapy among patients with type 2 diabetes mellitus (T2DM) can be disrupted due to adverse events, including hypoglycemia. A retrospective study using the MarketScan claims database quantified the frequency of sulfonylurea discontinuation or down-titration and identified associated risk factors. Adult patients with an index sulfonylurea prescription between 2008 and 2012 and 1 year continuous enrollment pre- and post-index were included. Therapy changes assessed over 1 year post-index included discontinuation and down-titration. Discontinuation occurred if the date of a fill was >90 days from the end date of the preceding fill. Down-titration occurred when a fill had a lower equivalent dose than the fill on the index date. Kaplan-Meier methods estimated the probability of either discontinuation or down-titration over 12 months, and Cox regression models identified associated risk factors. A total of 104,082 sulfonylurea users were included in the study and the probability of either discontinuation or down-titration at 3, 6 and 12 months was 23.2%, 38.9%, and 52.3%, respectively. Major risk factors associated with therapy changes included post-index hypoglycemia (discontinuation hazard ratio [HR] = 1.78 [1.68, 1.89]; down-titration HR =2.79 [2.40, 3.23]) and concomitant use of insulin (discontinuation HR =1.48 [1.40, 1.57]; down-titration HR =1.82 [1.56, 2.11]). Other risk factors included younger age, female gender, use of second generation sulfonylureas, prior cardiovascular comorbidity and liver disease. The study was not able to assess unreported, potentially mild cases of hypoglycemia, nor was it able to evaluate the association between changes in therapy and HbA1c levels or body weight. More than half of T2DM patients who initiated sulfonylurea therapy discontinued or down-titrated within 1 year. Insulin use and hypoglycemia were associated with sulfonylurea therapy change.

Photometric correction of VIR high space resolution data of Ceres

NASA Astrophysics Data System (ADS)

Longobardo, Andrea; Palomba, Ernesto; De Sanctis, Maria Cristina; Ciarniello, Mauro; Tosi, Federico; Giacomo Carrozzo, Filippo; Capria, Maria Teresa; Zambon, Francesca; Raponi, Andrea; Ammannito, Eleonora; Zinzi, Angelo; Raymond, Carol; Russell, Christopher T.; VIR-Dawn Team

2016-10-01

NASA's Dawn spacecraft [1] has been orbiting Ceres since early 2015. The mission is divided into five stages, characterized by different spacecraft altitudes corresponding to different space resolutions, i.e. Approach (CSA), Rotational Characterization (CSR), Survey (CSS), High Altitude Mapping Orbit (HAMO), and Low Altitude Mapping Orbit (LAMO).Ceres is a dark body (i.e. average albedo at 1.2 um is 0.08 [2]), hence photometric correction is much more important than for brighter asteroids (e.g. S-type and achondritric). Indeed, the negligible role of multiple scattering increases the reflectance dependence on phase angle.A photometric correction of VIR data at low spatial resolution (i.e. CSA, CSR, CSS) has already been applied with different methodologies (e.g. [2], [3]), These techniques highlight a reflectance and band depths dependency on the phase angle which is homogeneous on the entire surface in agreement with C-type taxonomy.However, with increasing spatial resolution (i.e. HAMO and LAMO data), the retrieval of a unique set of parameters for the photometric correction is no longer sufficient to obtain reliable albedo/band depth maps. In this work, a new photometric correction is obtained and applied to all the high resolution VIR data of Ceres, taking into account the reflectance variations observed at small scales. The developed algorithm will be implemented on the MATISSE tool [4] in order to be visualized on the Ceres shape model.Finally, an interpretation of the obtained phase functions is given in terms of optical and physical properties of the Ceres regolith.AcknowledgementsVIR was funded and coordinated by the Italian Space Agency, and built by SELEX ES, with the scientific leadership of IAPS-INAF, Rome, Italy, and is operated by IAPS-INAF, Rome, Italy. Support of the Dawn Science, Instrument, and Operation Teams is gratefully acknowledged.References[1] Russell, C. T. et al., 2012, Science 336, 686[2] Longobardo A., et al., 2016, LPSC, 2239

A catalog of galaxy morphology and photometric redshift

NASA Astrophysics Data System (ADS)

Paul, Nicholas; Shamir, Lior

2018-01-01

Morphology carries important information about the physical characteristics of a galaxy. Here we used machine learning to produce a catalog of ~3,000,000 SDSS galaxies classified by their broad morphology into spiral and elliptical galaxies. Comparison of the catalog to Galaxy Zooshows that the catalog contains a subset of 1.7*10^6 galaxies classified with the same level of consistency as the debiased “superclean” sub-sample. In addition to the morphology, we also computed the photometric redshifts of the galaxies. Several pattern recognition algorithms and variable selection strategies were tested, and the best accuracy of mean absolute error of ~0.0062 was achieved by using random forest with a combination of manually and automatically selected variables. The catalog shows that for redshift lower than 0.085 galaxies that visually look spiral become more prevalent as the redshift gets higher. For redshift greater than 0.085 galaxies thatvisually look elliptical become more prevalent. The catalog as well as the source code used to produce it is publicly available athttps://figshare.com/articles/Morphology_and_photometric_redshift_catalog/4833593 .

Photometric metallicity map of the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Choudhury, S.; Subramaniam, A.; Cole, A. A.; Sohn, Y.-J.

2018-04-01

We have created an estimated metallicity map of the Small Magellanic Cloud (SMC) using the Magellanic Cloud Photometric Survey (MCPS) and Optical Gravitational Lensing Experiment (OGLE III) photometric data. This is a first of its kind map of metallicity up to a radius of ˜2.5°. We identify the Red Giant Branch (RGB) in the V, (V - I) colour-magnitude diagrams of small sub-regions of varying sizes in both data sets. We use the slope of the RGB as an indicator of the average metallicity of a sub-region and calibrate the RGB slope to metallicity using available spectroscopic data for selected sub-regions. The average metallicity of the SMC is found to be [Fe/H] = -0.94 dex (σ[Fe/H] = 0.09) from OGLE III and [Fe/H] = -0.95 dex (σ[Fe/H] = 0.08) from MCPS. We confirm a shallow but significant metallicity gradient within the inner SMC up to a radius of 2.5° (-0.045 ± 0.004 to -0.067 ± 0.006 dex deg-1).

Spectroscopic study on variations in illite surface properties after acid-base titration.

PubMed

Liu, Wen-xin; Coveney, R M; Tang, Hong-xiao

2003-07-01

FT-IR, Raman microscopy, XRD, 29Si and 27Al MAS NMR, were used to investigate changes in surface properties of a natural illite sample after acid-base potentiometric titration. The characteristic XRD lines indicated the presence of surface Al-Si complexes, preferable to Al(OH)3 precipitates. In the microscopic Raman spectra, the vibration peaks of Si-O and Al-O bonds diminished as a result of treatment with acid, then increased after hydroxide back titration. The varied ratio of signal intensity between (IV)Al and (VI)Al species in 27Al MAS NMR spectra, together with the stable BET surface area after acidimetric titration, suggested that edge faces and basal planes in the layer structure of illite participated in dissolution of structural components. The combined spectroscopic evidence demonstrated that the reactions between illite surfaces and acid-leaching silicic acid and aluminum ions should be considered in the model description of surface acid-base properties of the aqueous illite.

A Computer-Based Simulation of an Acid-Base Titration

ERIC Educational Resources Information Center

Boblick, John M.

1971-01-01

Reviews the advantages of computer simulated environments for experiments, referring in particular to acid-base titrations. Includes pre-lab instructions and a sample computer printout of a student's use of an acid-base simulation. Ten references. (PR)

Photometric and Polarimetric Activity of the Herbig Ae Star VX Cas

NASA Astrophysics Data System (ADS)

Shakhovskoi, D. N.; Rostopchina, A. N.; Grinin, V. P.; Minikulov, N. Kh.

2003-04-01

We present the results of our simultaneous photometric and polarimetric observations of the Herbig Ae/Be star VX Cas acquired in 1987 2001. The star belongs to the UX Ori subtype of young variable stars and exhibits a rather low level of photometric activity: only six Algol-like minima with amplitudes ΔV>1m were recorded in 15 years of observations. Two of these minima, in 1998 and 2001, were the deepest in the history of the star’s photometric studies, with V amplitudes of about 2m. In each case, the dimming was accompanied by an increase in the linear polarization in agreement with the law expected for variable circumstellar extinction. The highest V polarization was about 5%. Observations of VX Cas in the deep minima revealed a turnover of the color tracks, typical of stars of this type and due to an increased contribution from radiation scattered in the circumstellar disk. We separated the observed polarization of VX Cas into interstellar (P is) and intrinsic (P in) components. Their position angles differ by approximately 60°, with P is dominating in the bright state and P in dominating during the deep minima. The competition of these two polarization components leads to changes in both the degree and position angle of the polarization during the star’s brightness variations. Generally speaking, in terms of the behavior of the brightness, color indices, and linear polarization, VX Cas is similar to other UX Ori stars studied by us earlier. A number of episodes of photometric and polarimetric activity suggest that, in their motion along highly eccentric orbits, circumstellar gas and dust clouds can enter the close vicinity of the star (and be disrupted there).

Modeling and validation of photometric characteristics of space targets oriented to space-based observation.

PubMed

Wang, Hongyuan; Zhang, Wei; Dong, Aotuo

2012-11-10

A modeling and validation method of photometric characteristics of the space target was presented in order to track and identify different satellites effectively. The background radiation characteristics models of the target were built based on blackbody radiation theory. The geometry characteristics of the target were illustrated by the surface equations based on its body coordinate system. The material characteristics of the target surface were described by a bidirectional reflectance distribution function model, which considers the character of surface Gauss statistics and microscale self-shadow and is obtained by measurement and modeling in advance. The contributing surfaces of the target to observation system were determined by coordinate transformation according to the relative position of the space-based target, the background radiation sources, and the observation platform. Then a mathematical model on photometric characteristics of the space target was built by summing reflection components of all the surfaces. Photometric characteristics simulation of the space-based target was achieved according to its given geometrical dimensions, physical parameters, and orbital parameters. Experimental validation was made based on the scale model of the satellite. The calculated results fit well with the measured results, which indicates the modeling method of photometric characteristics of the space target is correct.

3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts, and Stellar Masses

NASA Astrophysics Data System (ADS)

Skelton, Rosalind E.; Whitaker, Katherine E.; Momcheva, Ivelina G.; Brammer, Gabriel B.; van Dokkum, Pieter G.; Labbé, Ivo; Franx, Marijn; van der Wel, Arjen; Bezanson, Rachel; Da Cunha, Elisabete; Fumagalli, Mattia; Förster Schreiber, Natascha; Kriek, Mariska; Leja, Joel; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; Maseda, Michael V.; Nelson, Erica J.; Oesch, Pascal; Pacifici, Camilla; Patel, Shannon G.; Price, Sedona; Rix, Hans-Walter; Tal, Tomer; Wake, David A.; Wuyts, Stijn

2014-10-01

The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and photometry over ≈900 arcmin2 in five fields: AEGIS, COSMOS, GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a wealth of publicly available imaging data sets in addition to the Hubble Space Telescope (HST) data, which makes it possible to construct the spectral energy distributions (SEDs) of objects over a wide wavelength range. In this paper we describe a photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary imaging data at wavelengths 0.3-8 μm. Objects were selected in the WFC3 near-IR bands, and their SEDs were determined by carefully taking the effects of the point-spread function in each observation into account. A total of 147 distinct imaging data sets were used in the analysis. The photometry is made available in the form of six catalogs: one for each field, as well as a master catalog containing all objects in the entire survey. We also provide derived data products: photometric redshifts, determined with the EAZY code, and stellar population parameters determined with the FAST code. We make all the imaging data that were used in the analysis available, including our reductions of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with the WFC3 and ACS grisms, and the photometric catalogs presented here constitute a necessary first step in the analysis of these grism data. All the data presented in this paper are available through the 3D-HST Web site (http://3dhst.research.yale.edu).

Yonsei Evolutionary Population Synthesis (YEPS). II. Spectro-photometric Evolution of Helium-enhanced Stellar Populations

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

Chung, Chul; Yoon, Suk-Jin; Lee, Young-Wook, E-mail: chulchung@yonsei.ac.kr, E-mail: sjyoon0691@yonsei.ac.kr

The discovery of multiple stellar populations in Milky Way globular clusters (GCs) has stimulated various follow-up studies on helium-enhanced stellar populations. Here we present the evolutionary population synthesis models for the spectro-photometric evolution of simple stellar populations (SSPs) with varying initial helium abundance ( Y {sub ini}). We show that Y {sub ini} brings about dramatic changes in spectro-photometric properties of SSPs. Like the normal-helium SSPs, the integrated spectro-photometric evolution of helium-enhanced SSPs is also dependent on metallicity and age for a given Y {sub ini}. We discuss the implications and prospects for the helium-enhanced populations in relation to themore » second-generation populations found in the Milky Way GCs. All of the models are available at http://web.yonsei.ac.kr/cosmic/data/YEPS.htm.« less

A preliminary comparison of photometric (MWSC) and trigonometric (TGAS) distances of open cluster stars

NASA Astrophysics Data System (ADS)

Kovaleva, Dana; Piskunov, Anatoly; Kharchenko, Nina; Scholz, Ralf-Dieter

2017-12-01

The goal of this researchwas to compare the open cluster photometric distance scale of the global survey of star clusters in the MilkyWay (MWSC) with the distances derived fromtrigonometric parallaxes fromthe Gaia DR1/TGAS catalogue and to investigate towhich degree and extent both scales agree.We compared the parallax-based and photometrybased distances of 5743 cluster stars selected as members of 1118 clusters based on their kinematic and photometric MWSC membership probabilities. We found good overall agreement between trigonometric and photometric distances of open cluster stars. The residuals between them were small and unbiased up to log(d, [pc]) ≈ 2.8. If we considered only the most populated clusters and used cluster distances obtained from the mean trigonometric parallax of their MWSC members, the good agreement of the distance scales continued up to log(d, [pc]) ≈ 3.3.

Photometric anomalies in the Apollo landing sites as seen from the Lunar Reconnaissance Orbiter

NASA Astrophysics Data System (ADS)

Kaydash, Vadym; Shkuratov, Yuriy; Korokhin, Viktor; Videen, Gorden

2011-01-01

Phase-ratio imagery is a new tool of qualitative photometric analyses of the upper layer of the lunar regolith, which allows the identification of natural surface structure anomalies and artificially altered regolith. We apply phase-ratio imagery to analyze the Apollo-14, -15, and -17 landing sites. This reveals photometric anomalies of ˜170 × 120 m size that are characterized by lower values of the phase-function steepness, indicating a smoothing of the surface microstructure caused by the engine jets of the landing modules. Other photometric anomalies characterized by higher phase-function slopes are the result of regolith loosening by astronaut boots and the wheels of the Modular Equipment Transporter and the Lunar Roving Vehicle. We also provide a possible explanation for the high brightness of the wheel tracks seen in on-surface images acquired at very large phase angles.

A catalogue of photometric sequences (suppl. 3). [for astronomical photograph calibration

NASA Technical Reports Server (NTRS)

Argue, A. N.; Miller, E. W.; Warren, W. H., Jr.

1983-01-01

In stellar photometry studies, certain difficulties have arisen because of the lack of suitable photometric sequences for calibrating astronomical photographs. In order to eliminate these difficulties, active observers were contacted with a view to drawing up lists of suitable sequences. Replies from 63 authors offering data on 412 sequences were received. Most data were in the UBV system and had been obtained between 1968 and 1973. These were included in the original catalogue. The Catalogue represents a continuation of the earlier Photometric Catalogue compiled by Sharov and Jakimova (1970). A small supplement containing 69 sequences was issued in 1973. Supplement 2 was produced in 1976 and contained 320 sequences. Supplement 3 has now been compiled. It contains 1271 sequences.

Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.

PubMed

Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui

2005-06-01

A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.

Photometric stereo endoscopy.

PubMed

Parot, Vicente; Lim, Daryl; González, Germán; Traverso, Giovanni; Nishioka, Norman S; Vakoc, Benjamin J; Durr, Nicholas J

2013-07-01

While color video endoscopy has enabled wide-field examination of the gastrointestinal tract, it often misses or incorrectly classifies lesions. Many of these missed lesions exhibit characteristic three-dimensional surface topographies. An endoscopic system that adds topographical measurements to conventional color imagery could therefore increase lesion detection and improve classification accuracy. We introduce photometric stereo endoscopy (PSE), a technique which allows high spatial frequency components of surface topography to be acquired simultaneously with conventional two-dimensional color imagery. We implement this technique in an endoscopic form factor and demonstrate that it can acquire the topography of small features with complex geometries and heterogeneous optical properties. PSE imaging of ex vivo human gastrointestinal tissue shows that surface topography measurements enable differentiation of abnormal shapes from surrounding normal tissue. Together, these results confirm that the topographical measurements can be obtained with relatively simple hardware in an endoscopic form factor, and suggest the potential of PSE to improve lesion detection and classification in gastrointestinal imaging.

Photometric stereo endoscopy

PubMed Central

Parot, Vicente; Lim, Daryl; González, Germán; Traverso, Giovanni; Nishioka, Norman S.; Vakoc, Benjamin J.

2013-01-01

Abstract. While color video endoscopy has enabled wide-field examination of the gastrointestinal tract, it often misses or incorrectly classifies lesions. Many of these missed lesions exhibit characteristic three-dimensional surface topographies. An endoscopic system that adds topographical measurements to conventional color imagery could therefore increase lesion detection and improve classification accuracy. We introduce photometric stereo endoscopy (PSE), a technique which allows high spatial frequency components of surface topography to be acquired simultaneously with conventional two-dimensional color imagery. We implement this technique in an endoscopic form factor and demonstrate that it can acquire the topography of small features with complex geometries and heterogeneous optical properties. PSE imaging of ex vivo human gastrointestinal tissue shows that surface topography measurements enable differentiation of abnormal shapes from surrounding normal tissue. Together, these results confirm that the topographical measurements can be obtained with relatively simple hardware in an endoscopic form factor, and suggest the potential of PSE to improve lesion detection and classification in gastrointestinal imaging. PMID:23864015

Photometric redshift analysis in the Dark Energy Survey Science Verification data

NASA Astrophysics Data System (ADS)

Sánchez, C.; Carrasco Kind, M.; Lin, H.; Miquel, R.; Abdalla, F. B.; Amara, A.; Banerji, M.; Bonnett, C.; Brunner, R.; Capozzi, D.; Carnero, A.; Castander, F. J.; da Costa, L. A. N.; Cunha, C.; Fausti, A.; Gerdes, D.; Greisel, N.; Gschwend, J.; Hartley, W.; Jouvel, S.; Lahav, O.; Lima, M.; Maia, M. A. G.; Martí, P.; Ogando, R. L. C.; Ostrovski, F.; Pellegrini, P.; Rau, M. M.; Sadeh, I.; Seitz, S.; Sevilla-Noarbe, I.; Sypniewski, A.; de Vicente, J.; Abbot, T.; Allam, S. S.; Atlee, D.; Bernstein, G.; Bernstein, J. P.; Buckley-Geer, E.; Burke, D.; Childress, M. J.; Davis, T.; DePoy, D. L.; Dey, A.; Desai, S.; Diehl, H. T.; Doel, P.; Estrada, J.; Evrard, A.; Fernández, E.; Finley, D.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Glazebrook, K.; Honscheid, K.; Kim, A.; Kuehn, K.; Kuropatkin, N.; Lidman, C.; Makler, M.; Marshall, J. L.; Nichol, R. C.; Roodman, A.; Sánchez, E.; Santiago, B. X.; Sako, M.; Scalzo, R.; Smith, R. C.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D. L.; Uddin, S. A.; Valdés, F.; Walker, A.; Yuan, F.; Zuntz, J.

2014-12-01

We present results from a study of the photometric redshift performance of the Dark Energy Survey (DES), using the early data from a Science Verification period of observations in late 2012 and early 2013 that provided science-quality images for almost 200 sq. deg. at the nominal depth of the survey. We assess the photometric redshift (photo-z) performance using about 15 000 galaxies with spectroscopic redshifts available from other surveys. These galaxies are used, in different configurations, as a calibration sample, and photo-z's are obtained and studied using most of the existing photo-z codes. A weighting method in a multidimensional colour-magnitude space is applied to the spectroscopic sample in order to evaluate the photo-z performance with sets that mimic the full DES photometric sample, which is on average significantly deeper than the calibration sample due to the limited depth of spectroscopic surveys. Empirical photo-z methods using, for instance, artificial neural networks or random forests, yield the best performance in the tests, achieving core photo-z resolutions σ68 ˜ 0.08. Moreover, the results from most of the codes, including template-fitting methods, comfortably meet the DES requirements on photo-z performance, therefore, providing an excellent precedent for future DES data sets.

A COMBINED SPECTROSCOPIC AND PHOTOMETRIC STELLAR ACTIVITY STUDY OF EPSILON ERIDANI

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

Giguere, Matthew J.; Fischer, Debra A.; Zhang, Cyril X. Y.

2016-06-20

We present simultaneous ground-based radial velocity (RV) measurements and space-based photometric measurements of the young and active K dwarf Epsilon Eridani. These measurements provide a data set for exploring methods of identifying and ultimately distinguishing stellar photospheric velocities from Keplerian motion. We compare three methods we have used in exploring this data set: Dalmatian, an MCMC spot modeling code that fits photometric and RV measurements simultaneously; the FF′ method, which uses photometric measurements to predict the stellar activity signal in simultaneous RV measurements; and H α analysis. We show that our H α measurements are strongly correlated with the Microvariabilitymore » and Oscillations of STars telescope ( MOST ) photometry, which led to a promising new method based solely on the spectroscopic observations. This new method, which we refer to as the HH′ method, uses H α measurements as input into the FF′ model. While the Dalmatian spot modeling analysis and the FF′ method with MOST space-based photometry are currently more robust, the HH′ method only makes use of one of the thousands of stellar lines in the visible spectrum. By leveraging additional spectral activity indicators, we believe the HH′ method may prove quite useful in disentangling stellar signals.« less

Limitations of pH-potentiometric titration for the determination of the degree of deacetylation of chitosan.

PubMed

Balázs, Nándor; Sipos, Pál

2007-01-15

The degree of deacetylation (DDA) of chitosan determines the biopolymer's physico-chemical properties and technological applications. pH-Potentiometric titration seems to offer a simple and convenient means of determining DDA. However, to obtain accurate pH-potentiometric DDA values, several factors have to be taken into consideration. We found that the moisture content of the air-dry chitosan samples can be as high as 15%, and a reasonable fraction of this humidity cannot be removed by ordinary drying. Corrections have to be made for the ash content, as in some samples it can be as high as 1% by weight. The method of equivalence point determination was also found to cause systematic variations in the results and in some samples extra acid as high as 1 mol% of the free amino content was also identified. To compensate for the latter effect, the second equivalence point of the titration has to be determined separately and the analytical concentration of the acid be corrected for it. All the corrections listed here are necessary to obtain DDA values that are in reasonable agreement with those obtained from (1)H NMR and IR spectroscopic measurements. The need for these corrections severely limits the usefulness of pH-metry for determining accurate DDA values and thus potentiometry is hardly able to compete with other standard spectroscopic procedures, that is, (1)H NMR spectroscopy.

Infrared Imaging, Spectroscopic, and Photometric Studies of Comets

NASA Technical Reports Server (NTRS)

Gehrz, Robert D.

1997-01-01

We have continued our program of infrared (IR) photometric, imaging, spectroscopic, and polarimetric temporal observations of comets to study the properties of comet dust and comet nuclei. During the first two years we digitized our IR data base on P/Halley and other recent comets to facilitate further analysis and comparison with other data bases, and found compelling evidence for the emission of a burst of small grains from P/Halley's nucleus at perihelion. We reported imaging and photometric observations of Comets Austin 1990 V and Swift-Tuttle 1992. The Swift-Tuttle 1992t observations included IR photometry, several 7-14 micron long-slit spectra of the coma and a time-sequence of more than 150 10 micron broadband images of the coma. An analysis of near-IR images of the inner coma of P/Halley obtained on three consecutive nights in 1986 March showed sunwardjets. We completed our analysis of IR imaging spectrosco-photometric data on comets. We also obtained observations of Comets Hyakutake 1996 B2 and Hale/Bopp 1995 01. We obtained infrared imaging, photometric, spectroscopic and polarimetric temporal observations of bright comets using a network of five telescopes, with emphasis on simultaneous observations of comets at many wavelengths with different instruments. Our program offers several unique advantages: 1) rapid observational response to new comets with dedicated infrared telescopes; 2) observations within a few degrees of the sun when comets are near perihelion and 3) access to advanced infrared array imagers and spectrometers. In particular, reduction, analysis, publication and archiving of our Jupiter/sl-9 and Comet Hyakutake infrared data received special emphasis. Instrumentation development included installation of the latest version of the innovative FORTH telescope control and a data acquisition system that enables us to control three telescopes remotely by telephone from anywhere in the world for comet observations in broad daylight. We have

A Photometric Machine-Learning Method to Infer Stellar Metallicity

NASA Technical Reports Server (NTRS)

Miller, Adam A.

2015-01-01

Following its formation, a star's metal content is one of the few factors that can significantly alter its evolution. Measurements of stellar metallicity ([Fe/H]) typically require a spectrum, but spectroscopic surveys are limited to a few x 10(exp 6) targets; photometric surveys, on the other hand, have detected > 10(exp 9) stars. I present a new machine-learning method to predict [Fe/H] from photometric colors measured by the Sloan Digital Sky Survey (SDSS). The training set consists of approx. 120,000 stars with SDSS photometry and reliable [Fe/H] measurements from the SEGUE Stellar Parameters Pipeline (SSPP). For bright stars (g' < or = 18 mag), with 4500 K < or = Teff < or = 7000 K, corresponding to those with the most reliable SSPP estimates, I find that the model predicts [Fe/H] values with a root-mean-squared-error (RMSE) of approx.0.27 dex. The RMSE from this machine-learning method is similar to the scatter in [Fe/H] measurements from low-resolution spectra..

Photometric study of the pulsating, eclipsing binary OO DRA

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

Zhang, X. B.; Deng, L. C.; Tian, J. F.

We present a comprehensive photometric study of the pulsating, eclipsing binary OO Dra. Simultaneous B- and V-band photometry of the star was carried out on 14 nights. A revised orbital period and a new ephemeris were derived from the data. The first photometric solution of the binary system and the physical parameters of the component stars are determined. They reveal that OO Dra could be a detached system with a less-massive secondary component nearly filling its Roche lobe. By subtracting the eclipsing light changes from the data, we obtained the intrinsic pulsating light curves of the hotter, massive primary component.more » A frequency analysis of the residual light yields two confident pulsation modes in both B- and V-band data with the dominant frequency detected at 41.865 c/d. A brief discussion concerning the evolutionary status and the pulsation nature of the binary system is finally given.« less

Magnetic cycles and rotation periods of late-type stars from photometric time series

NASA Astrophysics Data System (ADS)

Suárez Mascareño, A.; Rebolo, R.; González Hernández, J. I.

2016-10-01

Aims: We investigate the photometric modulation induced by magnetic activity cycles and study the relationship between rotation period and activity cycle(s) in late-type (FGKM) stars. Methods: We analysed light curves, spanning up to nine years, of 125 nearby stars provided by the All Sky Automated Survey (ASAS). The sample is mainly composed of low-activity, main-sequence late-A to mid-M-type stars. We performed a search for short (days) and long-term (years) periodic variations in the photometry. We modelled the light curves with combinations of sinusoids to measure the properties of these periodic signals. To provide a better statistical interpretation of our results, we complement our new results with results from previous similar works. Results: We have been able to measure long-term photometric cycles of 47 stars, out of which 39 have been derived with false alarm probabilities (FAP) of less than 0.1 per cent. Rotational modulation was also detected and rotational periods were measured in 36 stars. For 28 stars we have simultaneous measurements of activity cycles and rotational periods, 17 of which are M-type stars. We measured both photometric amplitudes and periods from sinusoidal fits. The measured cycle periods range from 2 to 14 yr with photometric amplitudes in the range of 5-20 mmag. We found that the distribution of cycle lengths for the different spectral types is similar, as the mean cycle is 9.5 yr for F-type stars, 6.7 yr for G-type stars, 8.5 yr for K-type stars, 6.0 yr for early M-type stars, and 7.1 yr for mid-M-type stars. On the other hand, the distribution of rotation periods is completely different, trending to longer periods for later type stars, from a mean rotation of 8.6 days for F-type stars to 85.4 days in mid-M-type stars. The amplitudes induced by magnetic cycles and rotation show a clear correlation. A trend of photometric amplitudes with rotation period is also outlined in the data. The amplitudes of the photometric variability

Axitinib with or without dose titration for first-line metastatic renal-cell carcinoma: a randomised double-blind phase 2 trial

PubMed Central

Rini, Brian I; Melichar, Bohuslav; Ueda, Takeshi; GrÜnwald, Viktor; Fishman, Mayer N; Arranz, José A; Bair, Angel H; Pithavala, Yazdi K; Andrews, Glen I; Pavlov, Dmitri; Kim, Sinil; Jonasch, Eric

2014-01-01

Summary Background Population pharmacokinetic data suggest axitinib plasma exposure correlates with efficacy in metastatic renal-cell carcinoma. Axitinib dose titration might optimise exposure and improve outcomes. We prospectively assessed the efficacy and safety of axitinib dose titration in previously untreated patients with metastatic renal-cell carcinoma. Methods In this randomised, double-blind, multicentre, phase 2 study, patients were enrolled from 49 hospitals and outpatient clinics in the Czech Republic, Germany, Japan, Russia, Spain, and USA. Patients with treatment-naive metastatic renal-cell carcinoma received axitinib 5 mg twice daily during a 4 week lead-in period. Those patients with blood pressure 150/90 mm Hg or lower, no grade 3 or 4 treatment-related toxic effects, no dose reductions, and no more than two antihypertensive drugs for 2 consecutive weeks were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1), and then randomly assigned (1:1) to either masked titration with axitinib to total twice daily doses of 7 mg, and then 10 mg, if tolerated, or placebo titration. Patients who did not meet these criteria continued without titration. The primary objective was comparison of the proportion of patients achieving an objective response between randomised groups. Safety analyses were based on all patients who received at least one dose of axitinib. This ongoing trial is registered with ClinicalTrials.gov, number NCT00835978. Findings Between Sept 2, 2009, and Feb 28, 2011, we enrolled 213 patients, of whom 112 were randomly assigned to either the axitinib titration group (56 patients) or the placebo titration group (56 patients). 91 were not eligible for titration, and ten withdrew during the lead-in period. 30 patients (54%, 95% CI 40–67) in the axitinib titration group had an objective response, as did 19 patients (34%, 22–48]) in the placebo titration group (one-sided p=0·019). 54 (59%, 95% CI 49–70) of non

Axitinib with or without dose titration for first-line metastatic renal-cell carcinoma: a randomised double-blind phase 2 trial.

PubMed

Rini, Brian I; Melichar, Bohuslav; Ueda, Takeshi; Grünwald, Viktor; Fishman, Mayer N; Arranz, José A; Bair, Angel H; Pithavala, Yazdi K; Andrews, Glen I; Pavlov, Dmitri; Kim, Sinil; Jonasch, Eric

2013-11-01

Population pharmacokinetic data suggest axitinib plasma exposure correlates with efficacy in metastatic renal-cell carcinoma. Axitinib dose titration might optimise exposure and improve outcomes. We prospectively assessed the efficacy and safety of axitinib dose titration in previously untreated patients with metastatic renal-cell carcinoma. In this randomised, double-blind, multicentre, phase 2 study, patients were enrolled from 49 hospitals and outpatient clinics in the Czech Republic, Germany, Japan, Russia, Spain, and USA. Patients with treatment-naive metastatic renal-cell carcinoma received axitinib 5 mg twice daily during a 4 week lead-in period. Those patients with blood pressure 150/90 mm Hg or lower, no grade 3 or 4 treatment-related toxic effects, no dose reductions, and no more than two antihypertensive drugs for 2 consecutive weeks were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1), and then randomly assigned (1:1) to either masked titration with axitinib to total twice daily doses of 7 mg, and then 10 mg, if tolerated, or placebo titration. Patients who did not meet these criteria continued without titration. The primary objective was comparison of the proportion of patients achieving an objective response between randomised groups. Safety analyses were based on all patients who received at least one dose of axitinib. Between Sept 2, 2009, and Feb 28, 2011, we enrolled 213 patients, of whom 112 were randomly assigned to either the axitinib titration group (56 patients) or the placebo titration group (56 patients). 91 were not eligible for titration, and ten withdrew during the lead-in period. 30 patients (54%, 95% CI 40-67) in the axitinib titration group had an objective response, as did 19 patients (34%, 22-48]) in the placebo titration group (one-sided p=0·019). 54 (59%, 95% CI 49-70) of non-randomised patients achieved an objective response. Common grade 3 or worse, all-causality adverse events in treated patients

Equivalence-point electromigration acid-base titration via moving neutralization boundary electrophoresis.

PubMed

Yang, Qing; Fan, Liu-Yin; Huang, Shan-Sheng; Zhang, Wei; Cao, Cheng-Xi

2011-04-01

In this paper, we developed a novel method of acid-base titration, viz. the electromigration acid-base titration (EABT), via a moving neutralization boundary (MNR). With HCl and NaOH as the model strong acid and base, respectively, we conducted the experiments on the EABT via the method of moving neutralization boundary for the first time. The experiments revealed that (i) the concentration of agarose gel, the voltage used and the content of background electrolyte (KCl) had evident influence on the boundary movement; (ii) the movement length was a function of the running time under the constant acid and base concentrations; and (iii) there was a good linearity between the length and natural logarithmic concentration of HCl under the optimized conditions, and the linearity could be used to detect the concentration of acid. The experiments further manifested that (i) the RSD values of intra-day and inter-day runs were less than 1.59 and 3.76%, respectively, indicating similar precision and stability in capillary electrophoresis or HPLC; (ii) the indicators with different pK(a) values had no obvious effect on EABT, distinguishing strong influence on the judgment of equivalence-point titration in the classic one; and (iii) the constant equivalence-point titration always existed in the EABT, rather than the classic volumetric analysis. Additionally, the EABT could be put to good use for the determination of actual acid concentrations. The experimental results achieved herein showed a new general guidance for the development of classic volumetric analysis and element (e.g. nitrogen) content analysis in protein chemistry. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Surveillance Dynamic State GSS "Intelsat 10-02" on Base Multicolored Photometrical Data

NASA Astrophysics Data System (ADS)

Sukhov, P. P.; Karpenko, G. F.; Epishev, V. P.; Motrunich, I. I.

2011-09-01

Complex coordinate and multicolored photometric observations of active geostationary satellite (GSS) "Intelsat 10-02" (28358/2004022A, sub point GSS 359.0 E, with inclination to the equator i=0.05, the eccentricity e=0.00) took place at the "Mayaki" station, located nearby Odessa, on October 6,7,12,13,14, 2010 and on March 4, 2011. On those dates the satellite was nearby the border of the Earth's shadow. On basis of multicolored photometric observations some of its optical and geometrical characteristics were calculated. The analysis of light variation of GSS in B,V,R spectral regions of Johnson's system and the color indexes variation show that during the dates of observation the systems of stabilization of the platform of the transceiver antenna and the solar panels worked in the normal operating mode. During the observations the tracking panels of GSS "Intelsat 10-02" are well preserved relatively to the direction of Sun. The rotation of SB panels happens about axis, which is perpendicular to the equatorial plane. The orientation of the main axis of the platform, within calculation errors, remained unchanged in to the direction of the Earth's mass center. The analyses of the coordinate and photometric information for this GSS show how we can effectively control the dynamic state of the satellite and evaluate the optical characteristics of visible surface of spacecraft components and their behavior on its orbit using the photometric observations

Improving photometric redshift estimation using GPZ: size information, post processing, and improved photometry

NASA Astrophysics Data System (ADS)

Gomes, Zahra; Jarvis, Matt J.; Almosallam, Ibrahim A.; Roberts, Stephen J.

2018-03-01

The next generation of large-scale imaging surveys (such as those conducted with the Large Synoptic Survey Telescope and Euclid) will require accurate photometric redshifts in order to optimally extract cosmological information. Gaussian Process for photometric redshift estimation (GPZ) is a promising new method that has been proven to provide efficient, accurate photometric redshift estimations with reliable variance predictions. In this paper, we investigate a number of methods for improving the photometric redshift estimations obtained using GPZ (but which are also applicable to others). We use spectroscopy from the Galaxy and Mass Assembly Data Release 2 with a limiting magnitude of r < 19.4 along with corresponding Sloan Digital Sky Survey visible (ugriz) photometry and the UKIRT Infrared Deep Sky Survey Large Area Survey near-IR (YJHK) photometry. We evaluate the effects of adding near-IR magnitudes and angular size as features for the training, validation, and testing of GPZ and find that these improve the accuracy of the results by ˜15-20 per cent. In addition, we explore a post-processing method of shifting the probability distributions of the estimated redshifts based on their Quantile-Quantile plots and find that it improves the bias by ˜40 per cent. Finally, we investigate the effects of using more precise photometry obtained from the Hyper Suprime-Cam Subaru Strategic Program Data Release 1 and find that it produces significant improvements in accuracy, similar to the effect of including additional features.

Photometric and polarimetric observations and model simulations of (216) Kleopatra

NASA Astrophysics Data System (ADS)

Takahashi, S.; Shinokawa, K.; Yoshida, F.; Mukai, T.; Ip, W. H.; Kawabata, K.

2004-10-01

We performed photometric and polarimetric observations, on November 8 and 9, 1999, of an M-type main belt asteroid, (216) Kleopatra by using the HBS spectropolarimeter installed at Dodaira observatory, National Astronomical Observatory of Japan (NAOJ). Photometric amplitude of lightcurve in the V band was 0.12 mag, and the averaged degree of polarization was -1.01±0.1%. It seems that the polarimetric data might also show a slight change in the degree of polarization ( ~0.2%) at the second minimum of the photometric lightcurve, but we could not confirm that the feature was real because of the large errors of data. With the assumption that the surface is uniform, we have carried out lightcurve simulations based on shape models by Ostro et al. (2000), Tanga et al. (2001) and Roche binary (Cellino et al., 1985). The results of simulations were compared to the configurations of lightcurves which had been obtained at different 4 geometric positions (1980, 1982, 1987 and 1999). The model by Cellino et al. (1985) reproduced almost all the data points without the 1987 observations within ~0.05 mag., which is the best result among the 3 models. The model by Tanga et al. (2001) well reproduced the lightcurves, but failed in reproducing the 1982 amplitude (difference Δdiff ~ 0 2 mag.). We also confirmed that the model by Ostro et al. (2000) could not explain the observed lightcurves.

Population mixtures and searches of lensed and extended quasars across photometric surveys

NASA Astrophysics Data System (ADS)

Williams, Peter; Agnello, Adriano; Treu, Tommaso

2017-04-01

Wide-field photometric surveys enable searches of rare yet interesting objects, such as strongly lensed quasars or quasars with a bright host galaxy. Past searches for lensed quasars based on their optical and near-infrared properties have relied on photometric cuts and spectroscopic preselection (as in the Sloan Quasar Lens Search), or neural networks applied to photometric samples. These methods rely on cuts in morphology and colours, with the risk of losing many interesting objects due to scatter in their population properties, restrictive training sets, systematic uncertainties in catalogue-based magnitudes and survey-to-survey photometric variations. Here, we explore the performance of a Gaussian mixture model to separate point-like quasars, quasars with an extended host and strongly lensed quasars using griz psf and model magnitudes and WISE W1, W2. The choice of optical magnitudes is due to their presence in all current and upcoming releases of wide-field surveys, whereas UV information is not always available. We then assess the contamination from blue galaxies and the role of additional features such as W3 magnitudes or psf-model terms as morphological information. As a demonstration, we conduct a search in a random 10 per cent of the SDSS footprint, and provide the catalogue of the 43 SDSS object with the highest 'lens' score in our selection that survive visual inspection, and are spectroscopically confirmed to host active nuclei. We inspect archival data and find images of 5/43 objects in the Hubble Legacy Archive, including two known lenses. The code and materials are available to facilitate follow-up.

The Nature, Significance, and Evaluation of the Schwarzschild-Villiger (SV) Effect in Photometric Procedures

PubMed Central

Howling, D. H.; Fitzgerald, P. J.

1959-01-01

The Schwarzschild-Villiger effect has been experimentally demonstrated with the optical system used in this laboratory. Using a photographic mosaic specimen as a model, it has been shown that the conclusions of Naora are substantiated and that the SV effect, in large or small magnitude, is always present in optical systems. The theoretical transmission error arising from the presence of the SV effect has been derived for various optical conditions of measurement. The results have been experimentally confirmed. The SV contribution of the substage optics of microspectrophotometers has also been considered. A simple method of evaluating a flare function f(A) is advanced which provides a measure of the SV error present in a system. It is demonstrated that measurements of specimens of optical density less than unity can be made with less than 1 per cent error, when using illuminating beam diameter/specimen diameter ratios of unity and uncoated optical surfaces. For denser specimens it is shown that care must be taken to reduce the illuminating beam/specimen diameter ratio to a value dictated by the magnitude of a flare function f(A), evaluated for a particular optical system, in order to avoid excessive transmission error. It is emphasized that observed densities (transmissions) are not necessarily true densities (transmissions) because of the possibility of SV error. The ambiguity associated with an estimation of stray-light error by means of an opaque object has also been demonstrated. The errors illustrated are not necessarily restricted to microspectrophotometry but may possibly be found in such fields as spectral analysis, the interpretation of x-ray diffraction patterns, the determination of ionizing particle tracks and particle densities in photographic emulsions, and in many other types of photometric analysis. PMID:14403512

Impact of systolic blood pressure on the safety and tolerability of initiating and up-titrating sacubitril/valsartan in patients with heart failure and reduced ejection fraction: insights from the TITRATION study.

PubMed

Senni, Michele; McMurray, John J V; Wachter, Rolf; McIntyre, Hugh F; Anand, Inder S; Duino, Vincenzo; Sarkar, Arnab; Shi, Victor; Charney, Alan

2018-03-01

The TITRATION trial investigated two strategies to initiate and up-titrate sacubitril/valsartan (LCZ696) to the same target dose, over a condensed (3-week) or conservative (6-week) period, in patients with heart failure with reduced ejection fraction (HFrEF) and systolic blood pressure (SBP) of ≥100 mmHg. This post hoc analysis examined the relationship between baseline SBP at screening and achievement of the target dose of sacubitril/valsartan of 97 mg/103 mg (also termed 'LCZ696 200 mg') twice per day during the study. Patients (n = 498) were categorized in four groups based on SBP at screening: 100-110 mmHg (n = 70); 111-120 mmHg (n = 93); 121-139 mmHg (n = 168) and ≥140 mmHg (n = 167). Overall, 72.7%, 76.1%, 85.6% and 82.9%, respectively, of patients in these SBP categories achieved and maintained the target dose of sacubitril/valsartan without down-titration/dose interruption over 12 weeks ('treatment success'). Compared with patients with SBP of 100-110 mmHg, rates of treatment success among patients in the higher SBP groups [111-120 mmHg (P = 0.96); 121-139 mmHg (P = 0.06) and ≥140 mmHg (P = 0.25)] did not differ significantly. A higher percentage of patients with lower SBP (100-110 mmHg) achieved treatment success with gradual up-titration (6 weeks) (∼80%) than with rapid up-titration (∼69%). Similar findings were observed with regard to 'tolerability success' (maintenance of the target dose for at least the final 2 weeks prior to study completion). Hypotension occurred more frequently in patients with lower SBP. The majority of patients (>80%) with SBP of ≥100 mmHg achieved and maintained the target dose of sacubitril/valsartan if the treatment was titrated gradually. These findings suggest that low SBP should not prevent clinicians from considering the initiation of sacubitril/valsartan. © 2017 The Authors. European Journal of Heart Failure © 2017 European Society of

Photometric redshift estimation based on data mining with PhotoRApToR

NASA Astrophysics Data System (ADS)

Cavuoti, S.; Brescia, M.; De Stefano, V.; Longo, G.

2015-03-01

Photometric redshifts (photo-z) are crucial to the scientific exploitation of modern panchromatic digital surveys. In this paper we present PhotoRApToR (Photometric Research Application To Redshift): a Java/C ++ based desktop application capable to solve non-linear regression and multi-variate classification problems, in particular specialized for photo-z estimation. It embeds a machine learning algorithm, namely a multi-layer neural network trained by the Quasi Newton learning rule, and special tools dedicated to pre- and post-processing data. PhotoRApToR has been successfully tested on several scientific cases. The application is available for free download from the DAME Program web site.

Impact of Uniform Methods on Interlaboratory Antibody Titration Variability: Antibody Titration and Uniform Methods.

PubMed

Bachegowda, Lohith S; Cheng, Yan H; Long, Thomas; Shaz, Beth H

2017-01-01

-Substantial variability between different antibody titration methods prompted development and introduction of uniform methods in 2008. -To determine whether uniform methods consistently decrease interlaboratory variation in proficiency testing. -Proficiency testing data for antibody titration between 2009 and 2013 were obtained from the College of American Pathologists. Each laboratory was supplied plasma and red cells to determine anti-A and anti-D antibody titers by their standard method: gel or tube by uniform or other methods at different testing phases (immediate spin and/or room temperature [anti-A], and/or anti-human globulin [AHG: anti-A and anti-D]) with different additives. Interlaboratory variations were compared by analyzing the distribution of titer results by method and phase. -A median of 574 and 1100 responses were reported for anti-A and anti-D antibody titers, respectively, during a 5-year period. The 3 most frequent (median) methods performed for anti-A antibody were uniform tube room temperature (147.5; range, 119-159), uniform tube AHG (143.5; range, 134-150), and other tube AHG (97; range, 82-116); for anti-D antibody, the methods were other tube (451; range, 431-465), uniform tube (404; range, 382-462), and uniform gel (137; range, 121-153). Of the larger reported methods, uniform gel AHG phase for anti-A and anti-D antibodies had the most participants with the same result (mode). For anti-A antibody, 0 of 8 (uniform versus other tube room temperature) and 1 of 8 (uniform versus other tube AHG), and for anti-D antibody, 0 of 8 (uniform versus other tube) and 0 of 8 (uniform versus other gel) proficiency tests showed significant titer variability reduction. -Uniform methods harmonize laboratory techniques but rarely reduce interlaboratory titer variance in comparison with other methods.

Humic substance charge determination by titration with a flexible cationic polyelectrolyte

NASA Astrophysics Data System (ADS)

Tan, Wen-Feng; Norde, Willem; Koopal, Luuk K.

2011-10-01

The anionic charge of humic substances (HS) plays a major role in the interaction of HS with other components. Therefore, the potential of the polyelectrolyte titration technique to obtain the charge density of HS in simple 1-1 electrolyte solutions has been investigated. Titrations are carried out with an automatic titrator combined with the "Mütek particle charge detector" which allows determination of the Mütek potential and the pH as a function of the added amount of titrant which is a solution of poly-diallyldimethylammonium chloride (polyDADMAC), a cationic strong polyelectrolyte. When the Mütek potential reverses its sign the iso-electric point (IEP) of the polyDADMAC-HS complex is reached. The polyDADMAC/HS mass ratio at the IEP gives information on the HS charge density and from the pH changes in solution an estimate of the charge regulation in the HS-polyDADMAC complex can be obtained. In general, for polyDADMAC-HS complexes an increase in the dissociation of the acid groups of HS is found (charge regulation). The charge regulation decreases with increasing concentration of 1-1 background electrolyte. Cation incorporation can be neglected at 1-1 electrolyte concentrations ⩽ 1 mmol L -1 and a 1-1 stoichiometry exists between the polyDADMAC and HS charge. However, at these low salt concentrations the charge regulation is substantial. A detailed analysis of purified Aldrich humic acid (PAHA) at pH 5 and a range of KCl concentrations reveals that the anionic charge of PAHA in the complex increases at 5 mmol L -1 KCl by 30% and at 150 mmol L -1 KCl by 12%. On the other hand, increasing amounts of K + become incorporated in the complex: at 5 mmol L -1 KCl 5% and at 150 mmol L -1 KCl 24% of the PAHA charge is balanced by K +. By comparing at pH 5 the mass ratios polyDADMAC/PAHA in the complex at the IEP with the theoretical mass ratios of polyDADMAC/PAHA required to neutralize PAHA in the absence of charge regulation and K + incorporation, it is found that

Titratable acidity of beverages influences salivary pH recovery.

PubMed

Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

2015-01-01

A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH- to reach pH 5.5, respectively). Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

3D-HST WFC3-SELECTED PHOTOMETRIC CATALOGS IN THE FIVE CANDELS/3D-HST FIELDS: PHOTOMETRY, PHOTOMETRIC REDSHIFTS, AND STELLAR MASSES

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

Skelton, Rosalind E.; Whitaker, Katherine E.; Momcheva, Ivelina G.

The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and photometry over ≈900 arcmin{sup 2} in five fields: AEGIS, COSMOS, GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a wealth of publicly available imaging data sets in addition to the Hubble Space Telescope (HST) data, which makes it possible to construct the spectral energy distributions (SEDs) of objects over a wide wavelength range. In this paper we describe a photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary imaging data at wavelengths 0.3-8 μm. Objects were selected in the WFC3 near-IR bands,more » and their SEDs were determined by carefully taking the effects of the point-spread function in each observation into account. A total of 147 distinct imaging data sets were used in the analysis. The photometry is made available in the form of six catalogs: one for each field, as well as a master catalog containing all objects in the entire survey. We also provide derived data products: photometric redshifts, determined with the EAZY code, and stellar population parameters determined with the FAST code. We make all the imaging data that were used in the analysis available, including our reductions of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with the WFC3 and ACS grisms, and the photometric catalogs presented here constitute a necessary first step in the analysis of these grism data. All the data presented in this paper are available through the 3D-HST Web site (http://3dhst.research.yale.edu)« less

CFHTLenS and RCSLenS: testing photometric redshift distributions using angular cross-correlations with spectroscopic galaxy surveys

NASA Astrophysics Data System (ADS)

Choi, A.; Heymans, C.; Blake, C.; Hildebrandt, H.; Duncan, C. A. J.; Erben, T.; Nakajima, R.; Van Waerbeke, L.; Viola, M.

2016-12-01

We determine the accuracy of galaxy redshift distributions as estimated from photometric redshift probability distributions p(z). Our method utilizes measurements of the angular cross-correlation between photometric galaxies and an overlapping sample of galaxies with spectroscopic redshifts. We describe the redshift leakage from a galaxy photometric redshift bin j into a spectroscopic redshift bin I using the sum of the p(z) for the galaxies residing in bin j. We can then predict the angular cross-correlation between photometric and spectroscopic galaxies due to intrinsic galaxy clustering when I ≠ j as a function of the measured angular cross-correlation when I = j. We also account for enhanced clustering arising from lensing magnification using a halo model. The comparison of this prediction with the measured signal provides a consistency check on the validity of using the summed p(z) to determine galaxy redshift distributions in cosmological analyses, as advocated by the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). We present an analysis of the photometric redshifts measured by CFHTLenS, which overlaps the Baryon Oscillation Spectroscopic Survey (BOSS). We also analyse the Red-sequence Cluster Lensing Survey, which overlaps both BOSS and the WiggleZ Dark Energy Survey. We find that the summed p(z) from both surveys are generally biased with respect to the true underlying distributions. If unaccounted for, this bias would lead to errors in cosmological parameter estimation from CFHTLenS by less than ˜4 per cent. For photometric redshift bins which spatially overlap in 3D with our spectroscopic sample, we determine redshift bias corrections which can be used in future cosmological analyses that rely on accurate galaxy redshift distributions.

Effects of illumination differences on photometric stereo shape-and-albedo-from-shading for precision lunar surface reconstruction

NASA Astrophysics Data System (ADS)

Chung Liu, Wai; Wu, Bo; Wöhler, Christian

2018-02-01

Photoclinometric surface reconstruction techniques such as Shape-from-Shading (SfS) and Shape-and-Albedo-from-Shading (SAfS) retrieve topographic information of a surface on the basis of the reflectance information embedded in the image intensity of each pixel. SfS or SAfS techniques have been utilized to generate pixel-resolution digital elevation models (DEMs) of the Moon and other planetary bodies. Photometric stereo SAfS analyzes images under multiple illumination conditions to improve the robustness of reconstruction. In this case, the directional difference in illumination between the images is likely to affect the quality of the reconstruction result. In this study, we quantitatively investigate the effects of illumination differences on photometric stereo SAfS. Firstly, an algorithm for photometric stereo SAfS is developed, and then, an error model is derived to analyze the relationships between the azimuthal and zenith angles of illumination of the images and the reconstruction qualities. The developed algorithm and error model were verified with high-resolution images collected by the Narrow Angle Camera (NAC) of the Lunar Reconnaissance Orbiter Camera (LROC). Experimental analyses reveal that (1) the resulting error in photometric stereo SAfS depends on both the azimuthal and the zenith angles of illumination as well as the general intensity of the images and (2) the predictions from the proposed error model are consistent with the actual slope errors obtained by photometric stereo SAfS using the LROC NAC images. The proposed error model enriches the theory of photometric stereo SAfS and is of significance for optimized lunar surface reconstruction based on SAfS techniques.

Photometric Monitoring of Short-Period Contact Binaries

NASA Astrophysics Data System (ADS)

Vanko, M.

2001-12-01

The first photoelectric B,V light curves of the contact binary FU Dra, as well as new B,V light curves of the contact binaries AH Aur, UV Lyn and YY CrB, obtained at the Stará Lesná and Skalnaté Pleso Observatories, are presented. New photometric elements of AH Aur, FU Dra and UV Lyn computed from these light curves were combined with published spectroscopic elements to derive the absolute parameters of the systems.

Quantitative Determination of NTA and Other Chelating Agents in Detergents by Potentiometric Titration with Copper Ion Selective Electrode.

PubMed

Ito, Sana; Morita, Masaki

2016-01-01

Quantitative analysis of nitrilotriacetate (NTA) in detergents by titration with Cu 2+ solution using a copper ion selective electrode was achieved. This method tolerates a wide range of pH and ingredients in detergents. In addition to NTA, other chelating agents, having relatively lower stability constants toward Cu 2+ , were also qualified with sufficient accuracy by this analytical method for model detergent formulations. The titration process was automated by automatic titrating systems available commercially.

Photometric redshift analysis in the Dark Energy Survey Science Verification data

DOE PAGES

Sanchez, C.; Carrasco Kind, M.; Lin, H.; ...

2014-10-09

In this study, we present results from a study of the photometric redshift performance of the Dark Energy Survey (DES), using the early data from a Science Verification period of observations in late 2012 and early 2013 that provided science-quality images for almost 200 sq. deg. at the nominal depth of the survey. We assess the photometric redshift (photo-z) performance using about 15 000 galaxies with spectroscopic redshifts available from other surveys. These galaxies are used, in different configurations, as a calibration sample, and photo-z's are obtained and studied using most of the existing photo-z codes. A weighting method inmore » a multidimensional colour–magnitude space is applied to the spectroscopic sample in order to evaluate the photo-z performance with sets that mimic the full DES photometric sample, which is on average significantly deeper than the calibration sample due to the limited depth of spectroscopic surveys. In addition, empirical photo-z methods using, for instance, artificial neural networks or random forests, yield the best performance in the tests, achieving core photo-z resolutions σ68 ~ 0.08. Moreover, the results from most of the codes, including template-fitting methods, comfortably meet the DES requirements on photo-z performance, therefore, providing an excellent precedent for future DES data sets.« less

Confirming LBV Candidates Through Variability: A Photometric and Spectroscopic Monitoring Study

NASA Astrophysics Data System (ADS)

Stringfellow, Guy; Gvaramadze, Vasilii

2013-02-01

Luminous Blue Variable (LBV) stars represent an extremely rare class of luminous massive stars with high mass loss rates. The paucity ( 12) of confirmed Galactic LBV precludes determining a solid evolutionary connection between LBV and other intermediate (e.g. Ofpe/WN9, WNL) phases in the life of very massive stars. We've been conducting an optical/near-IR spectral survey of a large subset of central stars residing within newly discovered it Spitzer nebulae and have identified over two dozen new candidate LBVs (cLBVs) based on spectral similarity alone; confirming them as bona fide LBVs requires demonstrating 1-3 mag photometric and spectroscopic variability. This marks a significant advancement in the study of massive stars, far outweighing the return from many studies searching for LBVs and WRs the past several decades. Monitoring from semesters 2011B-2012A already has confirmed one new cLBV as a bona fide LBV. We propose to continue optical-IR photometric monitoring of these cLBVS with the 1.3m. Chiron, replacing the RC spectrograph on the 1.5m, now allows high-resolution optical spectroscopic monitoring of bright cLBVs, 11 of which are proposed herein. Spectra are important for understanding the physics driving photometric variability, properties of the wind, and allow analysis of line profiles.

Photometric redshifts for the next generation of deep radio continuum surveys - I. Template fitting

NASA Astrophysics Data System (ADS)

Duncan, Kenneth J.; Brown, Michael J. I.; Williams, Wendy L.; Best, Philip N.; Buat, Veronique; Burgarella, Denis; Jarvis, Matt J.; Małek, Katarzyna; Oliver, S. J.; Röttgering, Huub J. A.; Smith, Daniel J. B.

2018-01-01

We present a study of photometric redshift performance for galaxies and active galactic nuclei detected in deep radio continuum surveys. Using two multiwavelength data sets, over the NOAO Deep Wide Field Survey Boötes and COSMOS fields, we assess photometric redshift (photo-z) performance for a sample of ∼4500 radio continuum sources with spectroscopic redshifts relative to those of ∼63 000 non-radio-detected sources in the same fields. We investigate the performance of three photometric redshift template sets as a function of redshift, radio luminosity and infrared/X-ray properties. We find that no single template library is able to provide the best performance across all subsets of the radio-detected population, with variation in the optimum template set both between subsets and between fields. Through a hierarchical Bayesian combination of the photo-z estimates from all three template sets, we are able to produce a consensus photo-z estimate that equals or improves upon the performance of any individual template set.

The Efficacy of Galaxy Shape Parameters in Photometric Redshift Estimation: A Neural Network Approach

NASA Astrophysics Data System (ADS)

Singal, J.; Shmakova, M.; Gerke, B.; Griffith, R. L.; Lotz, J.

2011-05-01

We present a determination of the effects of including galaxy morphological parameters in photometric redshift estimation with an artificial neural network method. Neural networks, which recognize patterns in the information content of data in an unbiased way, can be a useful estimator of the additional information contained in extra parameters, such as those describing morphology, if the input data are treated on an equal footing. We use imaging and five band photometric magnitudes from the All-wavelength Extended Groth Strip International Survey (AEGIS). It is shown that certain principal components of the morphology information are correlated with galaxy type. However, we find that for the data used the inclusion of morphological information does not have a statistically significant benefit for photometric redshift estimation with the techniques employed here. The inclusion of these parameters may result in a tradeoff between extra information and additional noise, with the additional noise becoming more dominant as more parameters are added.

Preliminary results on photometric properties of materials at the Sagan Memorial Station, Mars

USGS Publications Warehouse

Johnson, J. R.; Kirk, R.; Soderblom, L.A.; Gaddis, L.; Reid, R.J.; Britt, D.T.; Smith, P.; Lemmon, M.; Thomas, N.; Bell, J.F.; Bridges, N.T.; Anderson, R.; Herkenhoff, K. E.; Maki, J.; Murchie, S.; Dummel, A.; Jaumann, R.; Trauthan, F.; Arnold, G.

1999-01-01

Reflectance measurements of selected rocks and soils over a wide range of illumination geometries obtained by the Imager for Mars Pathfinder (IMP) camera provide constraints on interpretations of the physical and mineralogical nature of geologic materials at the landing site. The data sets consist of (1) three small "photometric spot" subframed scenes, covering phase angles from 20?? to 150??; (2) two image strips composed of three subframed images each, located along the antisunrise and antisunset lines (photometric equator), covering phase angles from ???0?? to 155??; and (3) full-image scenes of the rock "Yogi," covering phase angles from 48?? to 100??. Phase functions extracted from calibrated data exhibit a dominantly backscattering photometric function, consistent with the results from the Viking lander cameras. However, forward scattering behavior does appear at phase angles >140??, particularly for the darker gray rock surfaces. Preliminary efforts using a Hapke scattering model are useful in comparing surface properties of different rock and soil types but are not well constrained, possibly due to the incomplete phase angle availability, uncertainties related to the photometric function of the calibration targets, and/or the competing effects of diffuse and direct lighting. Preliminary interpretations of the derived Hapke parameters suggest that (1) red rocks can be modeled as a mixture of gray rocks with a coating of bright and dark soil or dust, and (2) gray rocks have macroscopically smoother surfaces composed of microscopically homogeneous, clear materials with little internal scattering, which may imply a glass-like or varnished surface. Copyright 1999 by the American Geophysical Union.

CANDELS/GOODS-S, CDFS, and ECDFS: photometric redshifts for normal and X-ray-detected galaxies

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

Hsu, Li-Ting; Salvato, Mara; Nandra, Kirpal

2014-11-20

We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4 Ms CDFS and 250 ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (∼96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time inmore » this work. Photometric redshifts for X-ray source counterparts are based on a new library of active galactic nuclei/galaxy hybrid templates appropriate for the faint X-ray population in the CDFS. Photometric redshift accuracy for normal galaxies is 0.010 and for X-ray sources is 0.014 and outlier fractions are 4% and 5.2%, respectively. The results within the CANDELS coverage area are even better, as demonstrated both by spectroscopic comparison and by galaxy-pair statistics. Intermediate-band photometry, even if shallow, is valuable when combined with deep broadband photometry. For best accuracy, templates must include emission lines.« less

Determination of the total acidity in soft drinks using potentiometric sequential injection titration.

PubMed

van Staden, J Koos F; Mashamba, M Mulalo G; Stefan, R Raluca I

2002-12-06

A potentiometric SI titration system for the determination of total acidity in soft drinks is proposed. The concept is based on the aspiration of the acid soft drink sample between two base zones into a holding coil with the volume of the first base zone twice to that of the second one and channelled by flow reversal through a reaction coil to a potentiometric sensor. A solution of 0.1 mol l(-1) sodium chloride is used as ionic strength adjustment buffer in the carrier stream. The system has been applied to the analysis of some South African soft drinks having a total acidity level of about 0.2-0.3% (w/v). The method has a sample frequency of 45 samples per h with a linear range of 0.1 and 0.6% (w/v). It is easy to use, fully computerised, and gives the results that are comparable to both automated batch titration and manual titration.

Some photometric techniques for atmosphereless solar system bodies.

PubMed

Lumme, K; Peltoniemi, J; Irvine, W M

1990-01-01

We discuss various photometric techniques and their absolute scales in relation to the information that can be derived from the relevant data. We also outline a new scattering model for atmosphereless bodies in the solar system and show how it fits Mariner 10 surface photometry of the planet Mercury. It is shown how important the correct scattering law is while deriving the topography by photoclinometry.

Probing primordial features with next-generation photometric and radio surveys

NASA Astrophysics Data System (ADS)

Ballardini, M.; Finelli, F.; Maartens, R.; Moscardini, L.

2018-04-01

We investigate the possibility of using future photometric and radio surveys to constrain the power spectrum of primordial fluctuations that is predicted by inflationary models with a violation of the slow-roll phase. We forecast constraints with a Fisher analysis on the amplitude of the parametrized features on ultra-large scales, in order to assess whether these could be distinguishable over the cosmic variance. We find that the next generation of photometric and radio surveys has the potential to test these models at a sensitivity better than current CMB experiments and that the synergy between galaxy and CMB observations is able to constrain models with many extra parameters. In particular, an SKA continuum survey with a huge sky coverage and a flux threshold of a few μJy could confirm the presence of a new phase in the early Universe at more than 3σ.

J-PLUS: The Javalambre Photometric Local Universe Survey

NASA Astrophysics Data System (ADS)

Cenarro, Javier; Marin-Franch, Antonio; Moles, Mariano; Cristobal-Hornillos, David; Mendes de Oliveira, Claudia; Sodre, Laerte

2015-08-01

The Javalambre-Photometric Local Universe Survey, J-PLUS (www.j-plus.es), is defined to observe 8500 deg2 of the sky visible from the Javalambre Observatory (Teruel, Spain) with the panoramic camera T80Cam at the JAST/T80 telescope, using a set of 12 broad, intermediate and narrow band optical filters. The Project is particularly designed to carry out the photometric calibration of J-PAS (http://j-pas.org). For this reason, some J-PLUS filters are located at key stellar spectral features that allow to retrieve very accurate spectral energy distributions for more than 5 millions of stars in our Galaxy. Beyond the calibration goals, the unusually large FOV of T80Cam, 2deg2, together with the unique width and location of some filters, turn the J-PLUS Project into a powerful 3D view of the nearby Universe, mapping more than 20 millions of galaxies with reliable distance determinations and a similar number of stars of the Milky Way halo. At a rate of 100 gigabytes of data per night, J-PLUS will provide unprecedented multi-color images of the Universe to address a wide variety of astrophysical questions related with cosmology, large scale structure, galaxy clusters, 2D stellar populations and star formation studies in galaxies, the discovery of high redshift galaxies at specific redshift slices, quasars, supernovae, Milky Way science and structure, and minor bodies in the Solar System. In addition, the repetition of the whole area over time in certain filters will allow to face variability studies in the time domain.Complementing J-PLUS, a replica of the JAST/T80 telescope, T80Cam and the J-PLUS filters have been installed at the CTIO, allowing to extend the project to the Southern Hemisphere. J-PLUS together with the southern extension, S-PLUS, constitute an All-sky Photometric Local Universe Survey whose details and scientific applications are the bulk of the present talk.

PHOTOMETRIC SUPERNOVA CLASSIFICATION WITH MACHINE LEARNING

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

Lochner, Michelle; Peiris, Hiranya V.; Lahav, Ofer

Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models tomore » curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k -nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.« less

Photometric Supernova Classification with Machine Learning

NASA Astrophysics Data System (ADS)

Lochner, Michelle; McEwen, Jason D.; Peiris, Hiranya V.; Lahav, Ofer; Winter, Max K.

2016-08-01

Automated photometric supernova classification has become an active area of research in recent years in light of current and upcoming imaging surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope, given that spectroscopic confirmation of type for all supernovae discovered will be impossible. Here, we develop a multi-faceted classification pipeline, combining existing and new approaches. Our pipeline consists of two stages: extracting descriptive features from the light curves and classification using a machine learning algorithm. Our feature extraction methods vary from model-dependent techniques, namely SALT2 fits, to more independent techniques that fit parametric models to curves, to a completely model-independent wavelet approach. We cover a range of representative machine learning algorithms, including naive Bayes, k-nearest neighbors, support vector machines, artificial neural networks, and boosted decision trees (BDTs). We test the pipeline on simulated multi-band DES light curves from the Supernova Photometric Classification Challenge. Using the commonly used area under the curve (AUC) of the Receiver Operating Characteristic as a metric, we find that the SALT2 fits and the wavelet approach, with the BDTs algorithm, each achieve an AUC of 0.98, where 1 represents perfect classification. We find that a representative training set is essential for good classification, whatever the feature set or algorithm, with implications for spectroscopic follow-up. Importantly, we find that by using either the SALT2 or the wavelet feature sets with a BDT algorithm, accurate classification is possible purely from light curve data, without the need for any redshift information.

A multi-channel photometric detector for multi-component analysis in flow injection analysis

PubMed Central

Tan, Aimin; Huang, Jialin; Geng, Liudi; Xu, Jinhua; Zhao, Xinna

1994-01-01

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors. PMID:18924688

A multi-channel photometric detector for multi-component analysis in flow injection analysis.

PubMed

Tan, A; Huang, J; Geng, L; Xu, J; Zhao, X

1994-01-01

The detector, a multi-channel photometric detector, described in this paper was developed using multi-wavelength LEDs (light emitting diode) and phototransistors for absorbance measurement controlled by an Intel 8031 8-bit single chip microcomputer. Up to four flow cells can be attached to the detector. The LEDs and phototransistors are both inexpensive, and reliable. The results given by the detector for simultaneous determination of trace amounts of cobalt and cadmium in zinc sulphate electrolyte are reported. Because of the newly developed detector, this approach employs much less hardware apparatus than by employing conventional photometric detectors.

Improved methylene blue two-phase titration method for determining cationic surfactant concentration in high-salinity brine.

PubMed

Cui, Leyu; Puerto, Maura; López-Salinas, José L; Biswal, Sibani L; Hirasaki, George J

2014-11-18

The methylene blue (MB) two-phase titration method is a rapid and efficient method for determining the concentrations of anionic surfactants. The point at which the aqueous and chloroform phases appear equally blue is called Epton's end point. However, many inorganic anions, e.g., Cl(-), NO3(-), Br(-), and I(-), can form ion pairs with MB(+) and interfere with Epton's end point, resulting in the failure of the MB two-phase titration in high-salinity brine. Here we present a method to extend the MB two-phase titration method for determining the concentration of various cationic surfactants in both deionized water and high-salinity brine (22% total dissolved solid). A colorless end point, at which the blue color is completely transferred from the aqueous phase to the chloroform phase, is proposed as titration end point. Light absorbance at the characteristic wavelength of MB is measured using a spectrophotometer. When the absorbance falls below a threshold value of 0.04, the aqueous phase is considered colorless, indicating that the end point has been reached. By using this improved method, the overall error for the titration of a permanent cationic surfactant, e.g., dodecyltrimethylammonium bromide, in deionized (DI) water and high-salinity brine is 1.274% and 1.322% with limits of detection (LOD) of 0.149 and 0.215 mM, respectively. Compared to the traditional acid-base titration method, the error of this improved method for a switchable cationic surfactant, e.g., tertiary amine surfactant (Ethomeen C12), is 2.22% in DI water and 0.106% with LOD of 0.369 and 0.439 mM, respectively.

Measuring Cosmological Parameters with Photometrically Classified Pan-STARRS Supernovae

NASA Astrophysics Data System (ADS)

Jones, David; Scolnic, Daniel; Riess, Adam; Rest, Armin; Kirshner, Robert; Berger, Edo; Kessler, Rick; Pan, Yen-Chen; Foley, Ryan; Chornock, Ryan; Ortega, Carolyn; Challis, Peter; Burgett, William; Chambers, Kenneth; Draper, Peter; Flewelling, Heather; Huber, Mark; Kaiser, Nick; Kudritzki, Rolf; Metcalfe, Nigel; Tonry, John; Wainscoat, Richard J.; Waters, Chris; Gall, E. E. E.; Kotak, Rubina; McCrum, Matt; Smartt, Stephen; Smith, Ken

2018-01-01

We use nearly 1,200 supernovae (SNe) from Pan-STARRS and ~200 low-z (z < 0.1) SNe Ia to measure cosmological parameters. Though most of these SNe lack spectroscopic classifications, in a previous paper we demonstrated that photometrically classified SNe can still be used to infer unbiased cosmological parameters by using a Bayesian methodology that marginalizes over core-collapse (CC) SN contamination. Our sample contains nearly twice as many SNe as the largest previous compilation of SNe Ia. Combining SNe with Cosmic Microwave Background (CMB) constraints from the Planck satellite, we measure the dark energy equation of state parameter w to be -0.986±0.058 (stat+sys). If we allow w to evolve with redshift as w(a) = w0 + wa(1-a), we find w0 = -0.923±0.148 and wa = -0.404±0.797. These results are consistent with measurements of cosmological parameters from the JLA and from a new analysis of 1049 spectroscopically confirmed SNe Ia (Scolnic et al. 2017). We try four different photometric classification priors for Pan-STARRS SNe and two alternate ways of modeling the CC SN contamination, finding that none of these variants gives a w that differs by more than 1% from the baseline measurement. The systematic uncertainty on w due to marginalizing over the CC SN contamination, σwCC = 0.019, is approximately equal to the photometric calibration uncertainty and is lower than the systematic uncertainty in the SN\\,Ia dispersion model (σwdisp = 0.024). Our data provide one of the best current constraints on w, demonstrating that samples with ~5% CC SN contamination can give competitive cosmological constraints when the contaminating distribution is marginalized over in a Bayesian framework.

The VISTA ZYJHKs photometric system: calibration from 2MASS

NASA Astrophysics Data System (ADS)

González-Fernández, C.; Hodgkin, S. T.; Irwin, M. J.; González-Solares, E.; Koposov, S. E.; Lewis, J. R.; Emerson, J. P.; Hewett, P. C.; Yoldaş, A. K.; Riello, M.

2018-03-01

In this paper, we describe the routine photometric calibration of data taken with the VISTA infrared camera (VIRCAM) instrument on the ESO Visible and Infrared Survey Telescope for Astronomy (VISTA) telescope. The broad-band ZYJHKs data are directly calibrated from Two Micron all Sky Survey (2MASS) point sources visible in every VISTA image. We present the empirical transformations between the 2MASS and VISTA, and Wide-Field Camera and VISTA, photometric systems for regions of low reddening. We investigate the long-term performance of VISTA+VIRCAM. An investigation of the dependence of the photometric calibration on interstellar reddening leads to these conclusions: (1) For all broad-band filters, a linear colour-dependent correction compensates the gross effects of reddening where E(B - V) < 5.0. (2) For Z and Y, there is a significantly larger scatter above E(B - V) = 5.0, and insufficient measurements to adequately constrain the relation beyond this value. (3) The JHKs filters can be corrected to a few per cent up to E(B - V) = 10.0. We analyse spatial systematics over month-long time-scales, both inter- and intradetector and show that these are present only at very low levels in VISTA. We monitor and remove residual detector-to-detector offsets. We compare the calibration of the main pipeline products: pawprints and tiles. We show how variable seeing and transparency affect the final calibration accuracy of VISTA tiles, and discuss a technique, grouting, for mitigating these effects. Comparison between repeated reference fields is used to demonstrate that the VISTA photometry is precise to better than ≃ 2 per cent for the YJHKs bands and 3 per cent for the Z bands. Finally, we present empirically determined offsets to transform VISTA magnitudes into a true Vega system.

A titration model for evaluating calcium hydroxide removal techniques.

PubMed

Phillips, Mark; McClanahan, Scott; Bowles, Walter

2015-01-01

Calcium hydroxide (Ca(OH)2) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)2 left after different endodontic irrigation methods. Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)2 for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)2 recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)2 followed by gross Ca(OH)2 removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)2 was dissolved with glycerin and titrated to measure residual Ca(OH)2 left in the root. No method completely removed all residual Ca(OH)2. The addition of 30 s PUI with or without apical file use removed Ca(OH)2 significantly better than irrigation alone. This technique allowed quantification of residual Ca(OH)2. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)2 residue compared to irrigation alone.

Determination of the titratable acidity and the pH of wine based on potentiometric flow injection analysis.

PubMed

Vahl, Katja; Kahlert, Heike; von Mühlen, Lisandro; Albrecht, Anja; Meyer, Gabriele; Behnert, Jürgen

2013-07-15

A FIA system using a pH-sensitive detector based on a graphite/quinhydrone/silicone composite electrode was applied to determine sequentially the titratable acidity and the pH of wine, as well as the sum of calcium and magnesium ions. For all measurements the same FIA configuration was used employing different carrier solutions. The results for the determination of acidity and pH are in good agreement with those obtained by classical potentiometric titrations and by pH measurements using a conventional glass electrode. The standard deviation was less than 1.5% for both kinds of measurements and the sample volume was 150 μL. The method allows about 40 determinations of titratable acidity per hour and 30 pH measurements per hour. The titration method can be adjusted to the legal requirements in USA and Europe. Copyright © 2013 Elsevier B.V. All rights reserved.

Photometric and spectroscopic gamma-ray observations of solar transient phenomena using long duration balloons

NASA Technical Reports Server (NTRS)

Pelling, M. R.; Duttweiler, F.; Lin, R. F.; Levedahl, W. K.; Primbach, H.; Curtis, D. W.; Burley, K. C.

1985-01-01

A program currently in progress to conduct extended duration spectroscopic and photometric observation of solar X-ray phenomena from balloons is described. High photometric sensitivity to weak hard X-ray bursts is attained using a 600 sq cm array of phoswich scintillators. High spectral resolution for stronger bursts is available from an array of planar germanium detectors. These instruments are carried in a novel balloon gondola dssigned for the 15 to 20 day float durations available through using conventional zero pressure balloons in the radiation controlled (RACOON) mode.

Photometric and spectroscopic gamma-ray observations of solar transient phenomena using long duration balloons

NASA Astrophysics Data System (ADS)

Pelling, M. R.; Duttweiler, F.; Lin, R. F.; Levedahl, W. K.; Primbach, H.; Curtis, D. W.; Burley, K. C.

1985-08-01

A program currently in progress to conduct extended duration spectroscopic and photometric observation of solar X-ray phenomena from balloons is described. High photometric sensitivity to weak hard X-ray bursts is attained using a 600 sq cm array of phoswich scintillators. High spectral resolution for stronger bursts is available from an array of planar germanium detectors. These instruments are carried in a novel balloon gondola dssigned for the 15 to 20 day float durations available through using conventional zero pressure balloons in the radiation controlled (RACOON) mode.

A Hubble Diagram from Type II Supernovae Based Solely on Photometry: The Photometric Color Method

NASA Astrophysics Data System (ADS)

de Jaeger, T.; González-Gaitán, S.; Anderson, J. P.; Galbany, L.; Hamuy, M.; Phillips, M. M.; Stritzinger, M. D.; Gutiérrez, C. P.; Bolt, L.; Burns, C. R.; Campillay, A.; Castellón, S.; Contreras, C.; Folatelli, G.; Freedman, W. L.; Hsiao, E. Y.; Krisciunas, K.; Krzeminski, W.; Kuncarayakti, H.; Morrell, N.; Olivares E., F.; Persson, S. E.; Suntzeff, N.

2015-12-01

We present a Hubble diagram of SNe II using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I for which optical and near-infrared light curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a color term. We obtain a dispersion of 0.44 mag using a combination of the (V - i) color and the r band and we are able to reduce the dispersion to 0.39 mag using our golden sample. A comparison of our photometric color method (PCM) with the standardized candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag, which compares with 0.43 mag from the PCM for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile, and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

Photometric classification of type Ia supernovae in the SuperNova Legacy Survey with supervised learning

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

Möller, A.; Ruhlmann-Kleider, V.; Leloup, C.

In the era of large astronomical surveys, photometric classification of supernovae (SNe) has become an important research field due to limited spectroscopic resources for candidate follow-up and classification. In this work, we present a method to photometrically classify type Ia supernovae based on machine learning with redshifts that are derived from the SN light-curves. This method is implemented on real data from the SNLS deferred pipeline, a purely photometric pipeline that identifies SNe Ia at high-redshifts (0.2 < z < 1.1). Our method consists of two stages: feature extraction (obtaining the SN redshift from photometry and estimating light-curve shape parameters)more » and machine learning classification. We study the performance of different algorithms such as Random Forest and Boosted Decision Trees. We evaluate the performance using SN simulations and real data from the first 3 years of the Supernova Legacy Survey (SNLS), which contains large spectroscopically and photometrically classified type Ia samples. Using the Area Under the Curve (AUC) metric, where perfect classification is given by 1, we find that our best-performing classifier (Extreme Gradient Boosting Decision Tree) has an AUC of 0.98.We show that it is possible to obtain a large photometrically selected type Ia SN sample with an estimated contamination of less than 5%. When applied to data from the first three years of SNLS, we obtain 529 events. We investigate the differences between classifying simulated SNe, and real SN survey data. In particular, we find that applying a thorough set of selection cuts to the SN sample is essential for good classification. This work demonstrates for the first time the feasibility of machine learning classification in a high- z SN survey with application to real SN data.« less

The efficacy of three different mask styles on a PAP titration night.

PubMed

Ebben, Matthew R; Oyegbile, Temitayo; Pollak, Charles P

2012-06-01

This study compared the efficacy of three different masks, nasal pillows, nasal masks and full face (oronasal) masks, during a single night of titration with continuous positive airway pressure (CPAP). Fifty five subjects that included men (n=33) and women (n=22) were randomly assigned to one of three masks and underwent a routine titration with incremental CPAP applied through the different masks. CPAP applied through the nasal pillows and nasal mask was equally effective in treating mild, moderate, and severe sleep apnea. However, CPAP applied through the oronasal mask required a significantly higher pressure compared to nasal masks to treat moderately severe (2.8 cm of H(2)O ± 2.1 SD) and severe (6.0 cm of H(2)O ± 3.2 SD) obstructive sleep apnea. CPAP applied with either nasal mask was effective in treating mild, moderate, and severe sleep apnea. The oronasal mask required significantly higher pressures in subjects with moderate to severe disease. Therefore, when changing from a nasal to an oronasal mask, a repeat titration is required to ensure effective treatment of sleep apnea, especially in patients with moderate to severe disease. Copyright © 2012 Elsevier B.V. All rights reserved.

Nurse-coordinated care improves the achievement of LDL cholesterol targets through more intensive medication titration.

PubMed

Snaterse, Marjolein; Jorstad, Harald T; Heiligenberg, Marlies; Ter Riet, Gerben; Boekholdt, S Matthijs; Scholte Op Reimer, Wilma; Peters, Ron J

2017-01-01

Nurse-coordinated care (NCC) improves the achievement of low-density lipoprotein-cholesterol (LDL-C) targets after an acute coronary syndrome (ACS). We hypothesised that NCC improves achievement of LDL-C targets through more intensive medication titration. We used data from Randomised Evaluation of Secondary Prevention by Outpatient Nurse Specialists (RESPONSE), a multicentre randomised trial on the efficacy of NCC in 754 ACS patients. Follow-up data were collected at 6 and 12 months. To enable comparison between the various types and dosages of statins, we used the average lipid-lowering potency (ALLP, % LDL-C lowering) as an indicator of lipid-lowering medication intensity. Most patients in NCC intervention and usual care groups (96%) had started lipid-lowering therapy during the index hospitalisation. At 6 months, titration activities (up or down) were applied in 45% of NCC patients compared with 24% of patients receiving usual care (p<0.001), and a difference was also seen at 12 months follow-up (52% vs 34%, p<0.001). In patients not on LDL-C target at baseline, titration activities at 6 months were recorded in 63% and 30% of NCC and usual care patients respectively (p<0.001), with increased titration activities in both groups at 12 months (69% vs 43%, p<0.001). NCC is associated with more frequent and intense lipid-lowering medication titration to reach LDL-C targets as compared with usual care alone. Further, merely starting the guideline-recommended dose is insufficient to reach the guideline-recommended LDL-C target level. TC1290 (Netherlands).

Use of vitreous carbon as a working electrode in coulometric titration of potassium hydrogen phthalate.

PubMed

Jennings, V J; Dodson, A; Tedds, G

1973-07-01

The use of a vitreous carbon electrode as a cathode in the amperostatic coulometric titration of aqueous potassium hydrogen phthalate solution is described. It is shown that 10 mg of the phthalate can be titrated with a precision better than 0.5%. Current-voltage curves for platinum and vitreous carbon cathodes show that there is an overpotential on the latter relative to the former.

Constant-pH molecular dynamics using stochastic titration

NASA Astrophysics Data System (ADS)

Baptista, António M.; Teixeira, Vitor H.; Soares, Cláudio M.

2002-09-01

A new method is proposed for performing constant-pH molecular dynamics (MD) simulations, that is, MD simulations where pH is one of the external thermodynamic parameters, like the temperature or the pressure. The protonation state of each titrable site in the solute is allowed to change during a molecular mechanics (MM) MD simulation, the new states being obtained from a combination of continuum electrostatics (CE) calculations and Monte Carlo (MC) simulation of protonation equilibrium. The coupling between the MM/MD and CE/MC algorithms is done in a way that ensures a proper Markov chain, sampling from the intended semigrand canonical distribution. This stochastic titration method is applied to succinic acid, aimed at illustrating the method and examining the choice of its adjustable parameters. The complete titration of succinic acid, using constant-pH MD simulations at different pH values, gives a clear picture of the coupling between the trans/gauche isomerization and the protonation process, making it possible to reconcile some apparently contradictory results of previous studies. The present constant-pH MD method is shown to require a moderate increase of computational cost when compared to the usual MD method.

Comparison of USGS and DLR topographic models of Comet Borrelly and photometric applications

USGS Publications Warehouse

Kirk, R.L.; Howington-Kraus, E.; Soderblom, L.A.; Giese, B.; Oberst, J.

2004-01-01

Stereo analysis of images obtained during the 2001 flyby of Comet Borrelly by NASA's Deep Space 1 (DS1) probe allows us to quantify the shape and photometric behavior of the nucleus. The shape is complex, with planar facets corresponding to the dark, mottled regions of the surface whereas the bright, smooth regions are convexly curved. The photometric as well as textural differences between these regions can be explained in terms of topography (roughness) at and below the image resolution, without invoking significant variations in single-particle properties; the material on Borrelly's surface could be quite uniform. A statistical comparison of the digital elevation models (DEMs) produced from the three highest-resolution images independently at the USGS and DLR shows that their difference standard deviation is 120 m, consistent with a matching error of 0.20 pixel (similar to reported matching accuracies for many other stereo datasets). The DEMs also show some systematic differences attributable to manual versus automatic matching. Disk-resolved photometric modeling of the nucleus using the DEM shows that bright, smooth terrains on Borrelly are similar in roughness (Hapke roughness ?? = 20??) to C-type asteroid Mathilde but slightly brighter and more backscattering (single-scattering albedo w = 0.056, Henyey-Greenstein phase parameter g = -0.32). The dark, mottled terrain is photometrically consistent with the same particles but with roughnesses as large as 60??. Intrinsically darker material is inconsistent with the phase behavior of these regions. Many local radiance variations are clearly related to topography, and others are consistent with a topographic explanation; one need not invoke albedo variations greater than a few tens of percent to explain the appearance of Borrelly. Published by Elsevier Inc.

GPZ: non-stationary sparse Gaussian processes for heteroscedastic uncertainty estimation in photometric redshifts

NASA Astrophysics Data System (ADS)

Almosallam, Ibrahim A.; Jarvis, Matt J.; Roberts, Stephen J.

2016-10-01

The next generation of cosmology experiments will be required to use photometric redshifts rather than spectroscopic redshifts. Obtaining accurate and well-characterized photometric redshift distributions is therefore critical for Euclid, the Large Synoptic Survey Telescope and the Square Kilometre Array. However, determining accurate variance predictions alongside single point estimates is crucial, as they can be used to optimize the sample of galaxies for the specific experiment (e.g. weak lensing, baryon acoustic oscillations, supernovae), trading off between completeness and reliability in the galaxy sample. The various sources of uncertainty in measurements of the photometry and redshifts put a lower bound on the accuracy that any model can hope to achieve. The intrinsic uncertainty associated with estimates is often non-uniform and input-dependent, commonly known in statistics as heteroscedastic noise. However, existing approaches are susceptible to outliers and do not take into account variance induced by non-uniform data density and in most cases require manual tuning of many parameters. In this paper, we present a Bayesian machine learning approach that jointly optimizes the model with respect to both the predictive mean and variance we refer to as Gaussian processes for photometric redshifts (GPZ). The predictive variance of the model takes into account both the variance due to data density and photometric noise. Using the Sloan Digital Sky Survey (SDSS) DR12 data, we show that our approach substantially outperforms other machine learning methods for photo-z estimation and their associated variance, such as TPZ and ANNZ2. We provide a MATLAB and PYTHON implementations that are available to download at https://github.com/OxfordML/GPz.

Unbiased estimates of galaxy scaling relations from photometric redshift surveys

NASA Astrophysics Data System (ADS)

Rossi, Graziano; Sheth, Ravi K.

2008-06-01

Many physical properties of galaxies correlate with one another, and these correlations are often used to constrain galaxy formation models. Such correlations include the colour-magnitude relation, the luminosity-size relation, the fundamental plane, etc. However, the transformation from observable (e.g. angular size, apparent brightness) to physical quantity (physical size, luminosity) is often distance dependent. Noise in the distance estimate will lead to biased estimates of these correlations, thus compromising the ability of photometric redshift surveys to constrain galaxy formation models. We describe two methods which can remove this bias. One is a generalization of the Vmax method, and the other is a maximum-likelihood approach. We illustrate their effectiveness by studying the size-luminosity relation in a mock catalogue, although both methods can be applied to other scaling relations as well. We show that if one simply uses photometric redshifts one obtains a biased relation; our methods correct for this bias and recover the true relation.

Rapid chromatographic determination of caseins in milk with photometric and fluorimetric detection using a hydrophobic monolithic column.

PubMed

Ramírez-Palomino, P; Fernández-Romero, J M; Gómez-Hens, A

2014-01-01

Reverse-phase liquid chromatographic methods using a hydrophobic C18 monolithic column and on-line photometric and fluorimetric detection for the determination of the major casein (CN) proteins in milk are presented. The separation of αs1-CN, αs2-CN, β-CN and κ-CN was achieved in only five minutes. Fluorimetric detection enabled better analytical results than photometric detection. Thus, the dynamic ranges of the calibration graphs and detection limits obtained using fluorimetric detection were (mgmL(-)(1)): αs1-CN (0.74-10.0, 0.22), αs2-CN (0.15-10.0, 0.045), β-CN (0.68-10.0, 0.20) and κ-CN (0.21-10.0, 0.06). The analytical features of the photometric method, which does not allow the quantification of β-casein, were (mgmL(-)(1)): αs1-CN (1.5-9.0, 0.45), αs2-CN (1.4-10.0, 0.43) and κ-CN (0.4-9.0, 0.12). Precision data, expressed as relative standard deviation, ranged between 0.6% and 5.3% for the fluorimetric method and between 2.4% and 6.2% for the photometric method. Both methods were applied to the analysis of three different milk samples, obtaining recoveries in the ranges of 86.6-103.2% and 92.0-106.5% using fluorimetric and photometric detection, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Search for Photometric Variability in the Young T3.5 Planetary-mass Companion GU Psc b

NASA Astrophysics Data System (ADS)

Naud, Marie-Eve; Artigau, Étienne; Rowe, Jason F.; Doyon, René; Malo, Lison; Albert, Loïc; Gagné, Jonathan; Bouchard, Sandie

2017-10-01

We present a photometric J-band variability study of GU Psc b, a T3.5 co-moving planetary-mass companion (9-13 {M}{Jup}) to a young (˜150 Myr) M3 member of the AB Doradus Moving Group. The large separation between GU Psc b and its host star (42″) provides a rare opportunity to study the photometric variability of a planetary-mass companion. The study presented here is based on observations obtained from 2013 to 2014 over three nights with durations of 5-6 hr each with the WIRCam imager at Canada-France-Hawaii Telescope. Photometric variability with a peak-to-peak amplitude of 4 ± 1% at a timescale of ˜6 hr was marginally detected on 2014 October 11. No high-significance variability was detected on 2013 December 22 and 2014 October 10. The amplitude and timescale of the variability seen here, as well as its evolving nature, is comparable to what was observed for a variety of field T dwarfs and suggests that mechanisms invoked to explain brown dwarf variability may be applicable to low-gravity objects such as GU Psc b. Rotation-induced photometric variability due to the formation and dissipation of atmospheric features such as clouds is a plausible hypothesis for the tentative variation detected here. Additional photometric measurements, particularly on longer timescales, will be required to confirm and characterize the variability of GU Psc b, determine its periodicity and to potentially measure its rotation period.

Equivalence of Nasal and Oronasal Masks during Initial CPAP Titration for Obstructive Sleep Apnea Syndrome

PubMed Central

Teo, Ming; Amis, Terence; Lee, Sharon; Falland, Karina; Lambert, Stephen; Wheatley, John

2011-01-01

Study Objective: Continuous positive airway pressure (CPAP) titration studies are commonly performed using a nasal mask but some patients may prefer a full-face or oronasal mask. There is little evidence regarding the equivalence of different mask interfaces used to initiate treatment. We hypothesized that oronasal breathing when using an oronasal mask increases upper airway collapsibility and that a higher pressure may be required to maintain airway patency. We also assessed patient preferences for the 2 mask interfaces. Design: Prospective, randomized, cross-over design with 2 consecutive CPAP titration nights. Setting: Accredited laboratory in a university hospital. Patients or Participants: Twenty-four treatment-naive subjects with obstructive sleep apnea syndrome and respiratory disturbance index of greater than 15 events per hour. Interventions: CPAP titration was performed using an auto-titrating machine with randomization to a nasal or oronasal mask, followed by a second titration night using the alternate mask style. Measurements and Results: There was no significant difference in the mean pressures determined between nasal and oronasal masks, although 43% of subjects had nasal-to-oronasal mask-pressure differences of 2 cm H2O or more. Residual respiratory events, arousals, and measured leak were all greater with the oronasal mask. Seventy-nine percent of subjects preferred the nasal mask. Conclusions: Patients with obstructive sleep apnea syndrome can generally switch between nasal and oronasal masks without changing machine pressure, although there are individual differences that may be clinically significant. Measured leak is greater with the oronasal mask. Most patients with obstructive sleep apnea syndrome prefer a nasal mask as the interface for initiation of CPAP. Clinical Trial Registration: Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12611000243910. URL: http://www.ANZCTR.org.au/ACTRN12611000243910.aspx Citation: Teo M

Effect of neuromonitor-guided titrated care on brain tissue hypoxia after opioid overdose cardiac arrest.

PubMed

Elmer, Jonathan; Flickinger, Katharyn L; Anderson, Maighdlin W; Koller, Allison C; Sundermann, Matthew L; Dezfulian, Cameron; Okonkwo, David O; Shutter, Lori A; Salcido, David D; Callaway, Clifton W; Menegazzi, James J

2018-04-18

Brain tissue hypoxia may contribute to preventable secondary brain injury after cardiac arrest. We developed a porcine model of opioid overdose cardiac arrest and post-arrest care including invasive, multimodal neurological monitoring of regional brain physiology. We hypothesized brain tissue hypoxia is common with usual post-arrest care and can be prevented by modifying mean arterial pressure (MAP) and arterial oxygen concentration (PaO 2 ). We induced opioid overdose and cardiac arrest in sixteen swine, attempted resuscitation after 9 min of apnea, and randomized resuscitated animals to three alternating 6-h blocks of standard or titrated care. We invasively monitored physiological parameters including brain tissue oxygen (PbtO 2 ). During standard care blocks, we maintained MAP > 65 mmHg and oxygen saturation 94-98%. During titrated care, we targeted PbtO2 > 20 mmHg. Overall, 10 animals (63%) achieved ROSC after a median of 12.4 min (range 10.8-21.5 min). PbtO 2 was higher during titrated care than standard care blocks (unadjusted β = 0.60, 95% confidence interval (CI) 0.42-0.78, P < 0.001). In an adjusted model controlling for MAP, vasopressors, sedation, and block sequence, PbtO 2 remained higher during titrated care (adjusted β = 0.75, 95%CI 0.43-1.06, P < 0.001). At three predetermined thresholds, brain tissue hypoxia was significantly less common during titrated care blocks (44 vs 2% of the block duration spent below 20 mmHg, P < 0.001; 21 vs 0% below 15 mmHg, P < 0.001; and, 7 vs 0% below 10 mmHg, P = .01). In this model of opioid overdose cardiac arrest, brain tissue hypoxia is common and treatable. Further work will elucidate best strategies and impact of titrated care on functional outcomes. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of kinetics on the determination of the surface reactivity of oxide suspensions by acid-base titration.

PubMed

Duc, M; Adekola, F; Lefèvre, G; Fédoroff, M

2006-11-01

The effect of acid-base titration protocol and speed on pH measurement and surface charge calculation was studied on suspensions of gamma-alumina, hematite, goethite, and silica, whose size and porosity have been well characterized. The titration protocol has an important effect on surface charge calculation as well as on acid-base constants obtained by fitting of the titration curves. Variations of pH versus time after addition of acid or base to the suspension were interpreted as diffusion processes. Resulting apparent diffusion coefficients depend on the nature of the oxide and on its porosity.

Comparison of a gel microcolumn assay with the conventional tube test for red blood cell alloantibody titration.

PubMed

Finck, Rachel; Lui-Deguzman, Carrie; Teng, Shih-Mao; Davis, Rebecca; Yuan, Shan

2013-04-01

Titration is a semiquantitative method used to estimate red blood cell (RBC) alloantibody reactivity. The conventional tube test (CTT) technique is the traditional method for performing titration studies. The gel microcolumn assay (GMA) is also a sensitive method to detect RBC alloantibodies. The aim of this study was to compare a GMA with the CTT technique in the performance of Rh and K alloantibody titration. Patient serum samples that contained an RBC alloantibody with a singular specificity were identified by routine blood bank workflow. Parallel titration studies were performed on these samples by both the CTT method and a GMA (ID-Micro Typing System anti-IgG gel card, Micro Typing Systems, Inc., an Ortho-Clinical Diagnostics Company). Forty-eight samples were included, including 11 anti-D, five anti-c, 13 anti-E, one anti-C, three anti-e, and 15 anti-K. Overall, the two methods generated identical results in 21 of 48 samples. For 42 samples (87.5%) the two methods generated results that were within one serial dilution, and for the remaining six samples, results were within two dilutions. GMA systems may perform comparably to the CTT in titrating alloantibodies to Rh and Kell antigens. © 2012 American Association of Blood Banks.

A photometric investigation of Comet P/Encke

NASA Technical Reports Server (NTRS)

Millis, R. L.

1981-01-01

A photometric investigation of Comet P/Encke was undertaken using the 2.2 m telescope and the 0.6 m telescope. The two primary scientific objectives were: (1) measurement of the production rates of OH, CN, C3, and C2 as a function of heliocentric distance; and (2) determination of the comet's rotational period by searching for periodic brightness variations in the inner coma. Synoptic observation in the Canary Islands; Cambridge, Massachusetts; Flagstaff, Arizona; and Mauna Kea were planned for the study of the comet's rotation.

SPECTROSCOPIC AND PHOTOMETRIC VARIABILITY IN THE A0 SUPERGIANT HR 1040

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

Corliss, David J.; Morrison, Nancy D.; Adelman, Saul J., E-mail: david.corliss@wayne.edu

2015-12-15

A time-series analysis of spectroscopic and photometric observables of the A0 Ia supergiant HR 1040 has been performed, including equivalent widths, radial velocities, and Strömgren photometric indices. The data, obtained from 1993 through 2007, include 152 spectroscopic observations from the Ritter Observatory 1 m telescope and 269 Strömgren photometric observations from the Four College Automated Photoelectric Telescope. Typical of late B- and early A-type supergiants, HR 1040 has a highly variable Hα profile. The star was found to have an intermittent active phase marked by correlation between the Hα absorption equivalent width and blue-edge radial velocity and by photospheric connectionsmore » observed in correlations to equivalent width, second moment and radial velocity in Si ii λλ6347, 6371. High-velocity absorption (HVA) events were observed only during this active phase. HVA events in the wind were preceded by photospheric activity, including Si ii radial velocity oscillations 19–42 days prior to onset of an HVA event and correlated increases in Si ii W{sub λ} and second moment from 13 to 23 days before the start of the HVA event. While increases in various line equivalent widths in the wind prior to HVA events have been reported in the past in other stars, our finding of precursors in enhanced radial velocity variations in the wind and at the photosphere is a new result.« less

Photometric evidence on long-term stability of albedo and colour markings on Io

NASA Technical Reports Server (NTRS)

Morrison, D.; Pieri, D.; Johnson, T. V.; Veverka, J.

1979-01-01

Photometric measurements of the color and albedo of Io during the last 50 years are examined in order to determine the stability of the Ionian surface. Brightness measurements of Io relative to Ganymede show a slight, however inconclusive, increase with time, while light curve amplitudes and shapes are found to agree well during this period. The extent of volcanic activity observed by Voyager 1, however, is shown to be undetectable with the precision attainable by earth-based albedo determinations, and just barely detectable as color changes, which explains the observed photometric stability. Possible mechanisms for the preservation of the observed longitudinal distribution of color on Io are also discussed.

Photometric and Spectroscopic Observations of GRB 140629A

NASA Astrophysics Data System (ADS)

Xin, Li-Ping; Zhong, Shu-Qing; Liang, En-Wei; Wang, Jing; Liu, Hao; Zhang, Tian-Meng; Huang, Xiao-Li; Li, Hua-Li; Qiu, Yu-Lei; Han, Xu-Hui; Wei, Jian-Yan

2018-06-01

We present our optical photometric and spectroscopical observations of GRB 140629A. A redshift of z = 2.275 ±0.043 is measured through the metal absorption lines in our spectroscopic data. Using our photometric data and multiple observational data from other telescopes, we show that its optical light curve is well interpreted with the standard forward shock models in the thin shell case. Its optical–X-ray afterglow spectrum is jointly fitted with a single power-law function, yielding a photon index of ‑1.90 ± 0.05. The optical extinction and neutral hydrogen absorption of the gamma-ray burst (GRB) host galaxy are negligible. The fit to the light curve with the standard models shows that the ambient density is 60 ± 9 cm‑3 and the GRB radiating efficiency is as low as ∼0.24%, likely indicating a baryonic-dominated ejecta of this GRB. This burst agrees well with the {L}{{p},{iso}}{--}{E}p{\\prime }{--}{{{Γ }}}0 relation, but confidently violates those empirical relations involving geometric corrections (or jet break time). This gives rise to an issue of the possible selection effect on these relations since the jet opening angle of this GRB is extremely narrow (0.04 rad).

A photometric function of planetary surfaces for gourmets

NASA Astrophysics Data System (ADS)

Shkuratov, Yuriy; Korokhin, Viktor; Shevchenko, Vasilij; Mikhalchenko, Olga; Belskaya, Irina; Kaydash, Vadym; Videen, Gorden; Zubko, Evgenij; Velikodsky, Yuriy

2018-03-01

A new photometric model with small number of parameters is presented. The model is based on an assumption that there exist such surfaces for which spatial brightness variations caused by small topography undulations can be reproduced exactly by corresponding spatial variations of albedo. This indistinguishability results in a differential equation suggesting a new photometric function that generalizes, in particular, the Akimov disk-function. Our model provides excellent fits in a wide phase-angle range for integral observations of asteroids of different albedos. We also carried out fitting to integral observations of the Moon and Mercury, confirming difficulties in describing Mercury's phase function at large phase angles, which were also found for the Hapke model. Comparisons of global latitude and longitude trends with our model calculations have shown good coincidence for the Moon. To retrieve the lunar trends, we use the phase-ratio technique, applying it to our telescope observations. Mapping the model parameters using LROC WAC data were carried out for a region comprising the Reiner Gamma formation. This mapping allows us to calculate phase-ratio images of the region, showing at large phase angles systematically steeper phase curves of young craters and smaller steepness for the very Reiner Gamma formation.

VizieR Online Data Catalog: Trumpler 5 photometric BV catalog (Donati+, 2015)

NASA Astrophysics Data System (ADS)

Donati, P.; Cocozza, G.; Bragaglia, A.; Pancino, E.; Cantat-Gaudin, T.; Carrera, R.; Tosi, M.

2014-11-01

We combined high-quality photometric observations obtained with WFI and high-resolution spectra obtained with FLAMES to determine accurate cluster parameters, namely age, distance, reddening, and metallicity. (2 data files).

VizieR Online Data Catalog: LY And photometric followup (Lu+, 2017)

NASA Astrophysics Data System (ADS)

Lu, H.-P.; Zhang, L.-Y.; Han, X. L.; Pi, Q.-F.; Wang, D.-M.

2017-04-01

We obtained our first photometric data set in R and I bands for LY And on November 24, 2014 using the 1-m RCC reflecting telescope at Yunnan Observatory, which was equipped with an Andor DW436 2048x2048 CCD camera with a field of view of 7.3'x7.3'. The exposure times were 300s for both R and I bands. We obtained our second photometric data set in B, V, R and I bands using the SARA 914-mm telescope at Kitt Peak National Observatory on October 23, 2015. This telescope was equipped with a 2048x2048 pixels CCD and each pixel after 2x2 binning is about 0.86". The exposure times were 120s in B band and 60 s in V, R and I bands, respectively. (3 data files).

Photometric geodesy of main-belt asteroids. II - Analysis of lightcurves for poles, periods, and shapes

NASA Technical Reports Server (NTRS)

Drummond, J. D.; Weidenschilling, S. J.; Chapman, C. R.; Davis, D. R.

1988-01-01

The assumption that asteroids can be modeled as smooth, featureless, triaxial ellipsoids that rotate about their shortest axes is presently used to study all but one of the 26 asteroids treated in the Weidenschilling et al. (1987) 'photometric geodesy' program. Rotational poles derived from three independent methods are used to determine each asteroid's sidereal period and triaxial ellipsoid axial ratios, together with their associated photometric parameters. The asteroids appear to have rotational poles that do not lie along their orbital planes.

Developing and Demonstrating an Augmented Reality Colorimetric Titration Tool

ERIC Educational Resources Information Center

Tee, Nicholas Yee Kwang; Gan, Hong Seng; Li, Jonathan; Cheong, Brandon Huey-Ping; Tan, Han Yen; Liew, Oi Wah; Ng, Tuck Wah

2018-01-01

The handling of chemicals in the laboratory presents a challenge in instructing large class sizes and when students are relatively new to the laboratory environment. In this work, we describe and demonstrate an augmented reality colorimetric titration tool that operates out of the smartphone or tablet of students. It allows multiple students to…

1969 - 2010: Multicolor Photometric Observations of Population II Field Horizontal-Branch Stars

NASA Astrophysics Data System (ADS)

Philip, A. G. Davis

2010-05-01

From 1969 to 2010 I have been involved in a photometric study of Population II Field Horizontal-Branch stars. I started by making Stromgren four-color observations at Kitt Peak National Observatory and then Cerro Tololo Inter-American Observatory. I had taken spectral plates of all my selected areas on which I marked all the A-type stars. These stars were then observed photometrically. New FHB stars could be identified by their large c1 indices, caused by their greater (u-b) colors. Later four new filters were added ( U V B S ). With Richard Boyle of the Vatican Observatory we observed on Mt. Graham (Arizona) on the Vatican Advanced Technology Telescope.We plan follow-up observations of the new FHB stars found.

VizieR Online Data Catalog: SNLS and SDSS SN surveys photometric calibration (Betoule+, 2013)

NASA Astrophysics Data System (ADS)

Betoule, M.; Marriner, J.; Regnault, N.; Cuillandre, J.-C.; Astier, P.; Guy, J.; Balland, C.; El, Hage P.; Hardin, D.; Kessler, R.; Le Guillou, L.; Mosher, J.; Pain, R.; Rocci, P.-F.; Sako, M.; Schahmaneche, K.

2012-11-01

We present a joined photometric calibration for the SNLS and the SDSS supernova surveys. Our main delivery are catalogs of natural AB magnitudes for a large set of selected tertiary standard stars covering the science field of both surveys. Those catalogs are calibrated to the AB flux scale through observations of 5 primary spectrophotometric standard stars, for which HST-STIS spectra are available in the CALSPEC database. The estimate of the uncertainties associated to this calibration are delivered as a single covariance matrix. We also provide a model of the transmission efficiency of the SNLS photometric instrument MegaCam. Those transmission functions are required for the interpretation of MegaCam natural magnitudes in term of physical fluxes. Similar curves for the SDSS photometric instrument have been published in Doi et al. (2010AJ....139.1628D). Last, we release the measured magnitudes of the five CALSPEC standard stars in the magnitude system of the tertiary catalogs. This makes it possible to update the calibration of the tertiary catalogs if CALSPEC spectra for the primary standards are revised. (11 data files).

Photometric correction for an optical CCD-based system based on the sparsity of an eight-neighborhood gray gradient.

PubMed

Zhang, Yuzhong; Zhang, Yan

2016-07-01

In an optical measurement and analysis system based on a CCD, due to the existence of optical vignetting and natural vignetting, photometric distortion, in which the intensity falls off away from the image center, affects the subsequent processing and measuring precision severely. To deal with this problem, an easy and straightforward method used for photometric distortion correction is presented in this paper. This method introduces a simple polynomial fitting model of the photometric distortion function and employs a particle swarm optimization algorithm to get these model parameters by means of a minimizing eight-neighborhood gray gradient. Compared with conventional calibration methods, this method can obtain the profile information of photometric distortion from only a single common image captured by the optical CCD-based system, with no need for a uniform luminance area source used as a standard reference source and relevant optical and geometric parameters in advance. To illustrate the applicability of this method, numerical simulations and photometric distortions with different lens parameters are evaluated using this method in this paper. Moreover, the application example of temperature field correction for casting billets also demonstrates the effectiveness of this method. The experimental results show that the proposed method is able to achieve the maximum absolute error for vignetting estimation of 0.0765 and the relative error for vignetting estimation from different background images of 3.86%.

Control of OSA During Automatic Positive Airway Pressure Titration in a Clinical Case Series: Predictors and Accuracy of Device Download Data

PubMed Central

Huang, Hsin-Chia Carol; Hillman, David R.; McArdle, Nigel

2012-01-01

Study Objectives: To investigate the factors associated with physiologic control of obstructive sleep apnea (OSA) during automatic positive airway pressure (APAP) titration in a clinical series. To also assess the usefulness of apnea-hypopnea index (AHI) data downloaded from the APAP device (Dev AHI). Design: Retrospective review of a consecutive series of patients with OSA who underwent APAP titration (Autoset Spirit, ResMed, Bella Vista, New South Wales, Australia ) with simultaneous polysomnographic (PSG) monitoring in the sleep laboratory. Setting: Tertiary sleep clinic. Participants: There were 190 consecutive patients with OSA referred for APAP titration. Measurements and Results: There were 58% of patients who achieved optimal or good control of OSA (titration PSG AHI < 10, or at least 50% reduction in AHI if diagnostic AHI < 15/hr) during APAP titration. The independent predictors of titration PSG AHI were a history of cardiac disease and elevated central apnea and arousal indices during the diagnostic study. Although the median and interquartile range (IQR) AHI from the device (7.0, 3.9-11.6 events/hr) was only slightly less than the PSG AHI (7.8, 3.9-14.4 events/hr, P = 0.04) during titration, case-by-case agreement between the two measures was poor (chi-square < 0.001). Conclusion: In a clinical sample control of OSA during APAP titration is often poor, and close clinical follow-up is particularly needed in patients with a history of cardiac disease or with high arousal or central apnea indices on the diagnostic study. Device AHI does not reliably assess control during APAP titration, and PSG assessment may be required if clinical response to treatment is poor. The findings relate to the ResMed AutoSet device and may not apply to other devices. Citation: Huang HCC; Hillman DR; McArdle N. Control of OSA during automatic positive airway pressure titration in a clinical case series: predictors and accuracy of device download data. SLEEP 2012;35(9):1277�

Photometric microlensing and stellar mass determination

NASA Astrophysics Data System (ADS)

Samadi, R.

Microlensing was suggested for stellar mass determination of nearby stars by several authors (e.g. Paczynski 1995 and Miralada-Escude 1996). There are two aspects in gravitational microlensing: photometry and astrometry. Here only the photometric aspect -i.e. magnification of a background source by a stellar lens- will be considered. The first study in this domain was done by Paczyński (1995). An attempt to investigate some observational constraints (Alard et al. 1996), takes its origin in this study. It will be shown here that blending of the source by the lens, not only induces a degeneracy which has been pointed out by Wozniak and Paczynski (1997) and can be removed by measuring the flux of the source outside the microlensing event, but also strongly reduces the photometric cross section as well as the duration of microlensing events. The expected number of events decreases strongly with blending. Blending effects can be reduced by selecting faint lens candidates. Unfortunately however, it is difficult to monitor a sufficient number of lens candidates per night, and restricting oneself to nearby and high proper motion objects would lead to a very small number of lens candidates. In the case of short duration events, the light curve must be sampled at short time intervals. When sampling daily, the condition is very strong and the expected rate of events very small. Observing from space would increase significantly the rate, but this gain is still insufficient. We conclude that the event rate will be very small and that the project does not seem to be feasible at least under current observing conditions and even in the near future.

Photometric Data from Non-Resolved Objects for Space Object Characterization and Improved Atmospheric Modeling

NASA Astrophysics Data System (ADS)

Linares, R.; Palmer, D.; Thompson, D.; Koller, J.

2013-09-01

impact assessment via improved physics-based modeling. As part of this effort calibration satellite observations are used to dynamically calibrate the physics-based model and to improve its forecasting capability. The observations are collected from a variety of sources, including from LANL's own Raven-class optical telescope. This system collects both astrometric and photometric data on space objects. The photometric data will be used to estimate the space objects' attitude and shape. Non-resolved photometric data have been studied by many as a mechanism for space object characterization. Photometry is the measurement of an object's flux or apparent brightness measured over a wavelength band. The temporal variation of photometric measurements is referred to as photometric signature. The photometric optical signature of an object contains information about shape, attitude, size and material composition. This work focuses on the processing of the data collected with LANL's telescope in an effort to use photometric data to expand the number of space objects that can be used as calibration satellites. An Unscented Kalman filter is used to estimate the attitude and angular velocity of the space object; both real data and simulated data scenarios are shown. A number of inactive space objects are used for the real data examples and good estimation results are shown.

Determination of the intrinsic redox potentials of FeS centers of respiratory complex I from experimental titration curves

PubMed Central

Medvedev, Emile S.; Couch, Vernon A.

2014-01-01

Recently, Euro et al. [Biochem. 47, 3185 (2008)] have reported titration data for seven of nine FeS redox centers of complex I from E. coli. There is a significant uncertainty in the assignment of the titration data. Four of the titration curves were assigned to N1a, N1b, N6b, and N2 centers; one curve either to N3 or N7; one more either to N4 or N5; and the last one denoted Nx could not be assigned at all. In addition, the assignment of the titration data to N6b/N6a pair is also uncertain. In this paper, using our calculated interaction energies [Couch et al. BBA 1787, 1266 (2009)], we perform statistical analysis of these data, considering a variety of possible assignments, find the best fit, and determine the intrinsic redox potentials of the centers. The intrinsic potentials could be determined with uncertainty of less than ±10 mV at 95% confidence level for best fit assignments. We also find that the best agreement between theoretical and experimental titration curves is obtained with the N6b-N2 interaction equal to 71±14 or 96±26 mV depending on the N6b/N6a titration data assignment, which is stronger than was expected and may indicate a close distance of N2 center to the membrane surface. PMID:20513348

Estimating photometric redshifts for X-ray sources in the X-ATLAS field using machine-learning techniques

NASA Astrophysics Data System (ADS)

Mountrichas, G.; Corral, A.; Masoura, V. A.; Georgantopoulos, I.; Ruiz, A.; Georgakakis, A.; Carrera, F. J.; Fotopoulou, S.

2017-12-01

We present photometric redshifts for 1031 X-ray sources in the X-ATLAS field using the machine-learning technique TPZ. X-ATLAS covers 7.1 deg2 observed with XMM-Newton within the Science Demonstration Phase of the H-ATLAS field, making it one of the largest contiguous areas of the sky with both XMM-Newton and Herschel coverage. All of the sources have available SDSS photometry, while 810 additionally have mid-IR and/or near-IR photometry. A spectroscopic sample of 5157 sources primarily in the XMM/XXL field, but also from several X-ray surveys and the SDSS DR13 redshift catalogue, was used to train the algorithm. Our analysis reveals that the algorithm performs best when the sources are split, based on their optical morphology, into point-like and extended sources. Optical photometry alone is not enough to estimate accurate photometric redshifts, but the results greatly improve when at least mid-IR photometry is added in the training process. In particular, our measurements show that the estimated photometric redshifts for the X-ray sources of the training sample have a normalized absolute median deviation, nmad ≈ 0.06, and a percentage of outliers, η = 10-14%, depending upon whether the sources are extended or point like. Our final catalogue contains photometric redshifts for 933 out of the 1031 X-ray sources with a median redshift of 0.9. The table of the photometric redshifts is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/608/A39

Developments in Titrimetry.

ERIC Educational Resources Information Center

Parry-Jones, R.

1980-01-01

Described are some new uses and procedures of titration procedures. Topics included are titration in non-aqueous solvents, thermometric titration and catalytic methods for end-point detection, titration finish in organic elemental analysis, and sub-micro analysis and automatic titration procedures. (CS)

Photometric Properties of Enceladus' South Polar Terrain

NASA Astrophysics Data System (ADS)

Annex, Andrew; Verbiscer, A. J.; Helfenstein, P.

2012-10-01

Cassini images reveal in exquisite detail the complex and varied terrains within the geologically active south pole of Enceladus. The region is dominated by four parallel rifts or sulci, informally known as tiger stripes, from which plumes comprised primarily of water vapor erupt [1,2]. The rich data set of Cassini images acquired at high spatial resolution (< 0.5 km/pixel) and a variety of viewing and illumination geometries enables the quantitative analysis of surface scattering properties through disk-resolved photometry. Here we investigate the photometric properties of individual terrain units [3] through fits of the Hapke photometric model [4] to data acquired in the clear (CL1 CL2), UV3, GRN, and IR3 filters, centered at 0.61, 0.34, 0.57, and 0.93 μm, respectively. Terrain units include the tiger stripe smooth and platy plank formations, tiger stripe medial dorsum structures, relict tiger stripe structures, south pole funiscular (ropy) plains, south pole lateral fold-and-wedge formations, and the south pole reticulated plains. Despite the constant, ubiquitous infall of plume particles onto the surface, differences in scattering properties, texture, and albedo among terrain units can be discerned. Work supported by NASA's Cassini Data Analysis Program. [1] Porco et al. 2006 Science 311, 1393-1401. [2] Hansen et al. 2008 Nature 456, 477-479. [3] Spencer et al. 2009 in Saturn from Cassini-Huygens (M. K. Dougherty et al. Eds.) 683-724. [4] Hapke 2002 Icarus 157, 523-534.

Titration of Serum Lipoproteins with Lipoprotein Precipitants.

DTIC Science & Technology

1981-12-01

Lipid Res 11:583 (1970). 6. Grove, T. H. Effect of reagent pH on determination of high-density lipo- protein cholesterol by precipitation with sodium ...of choles- terol in the supernate plateaued at 43 mg/dl after the beta and prebeta lipo- proteins had been precipitated . The intensities of the two...AD-A113 370 SCHOOL OF AEROSPACE MEDICINE BROOKS AFS TX F/S 6/1 TITRATION OF SERU’LIPOPROTEINS WITH LIPOPROTEIN PRECIPITANTS .(Ul DEC 81 0 A CLARK. J A

Turbidimetric and photometric determination of total tannins in tea using a micro-flow-batch analyzer.

PubMed

Lima, Marcelo B; Andrade, Stéfani I E; Harding, David P; Pistonesi, Marcelo F; Band, Beatriz S F; Araújo, Mário C U

2012-01-15

Both turbidimetric and photometric determinations of total tannins in samples of green and black tea, using a micro-flow-batch analyzer (μFBA) were studied. The miniaturized system was formed using photocurable urethane-acrylate resin and ultraviolet lithography technique. The turbidimetric method was based on the precipitation reaction of Cu (II) with tannins in acetate medium at a pH of 4.5. The photometric method was based on the complexation reaction of tannins with ferrous tartrate. The turbidimetric μFBA was able to test 200 samples per hour. The photometric μFBA allowed 300 analyses per hour, generating 136μL of residue per analysis. The paired t test, at a 95% confidence level, showed no statistically significant differences between results obtained by both methods and the reference method. The urethane-acrylate μFBA maintained satisfactory physical and chemical properties, and represents an improvement over conventional flow-batch analyzer. Copyright © 2011 Elsevier B.V. All rights reserved.

Transformations between the 2MASS, SDSS, and BV I photometric systems for late-type giants

NASA Astrophysics Data System (ADS)

Yaz, E.; Bilir, S.; Karaali, S.; Ak, S.; Coşkunoğlu, B.; Cabrera-Lavers, A.

2010-08-01

We present colour transformations from Two Micron All Sky Survey (2MASS) photometric system to Johnson-Cousins system and to Sloan Digital Sky Survey (SDSS) system for late-type giants and vice versa. The giant star sample was formed using surface gravity constraints ({2 < log g ≤ 3}) to Cayrel de Strobel et al.' s (2001) spectroscopic catalogue. 2MASS, SDSS and Johnson-Cousins photometric data was taken from \\cite{Cu03}, \\cite{Ofek08}, and \\cite{vanLeeuwen2007}, respectively. The final sample was refined applying the following steps: (1) the data were dereddened, (2) the sample stars selected are of the highest photometric quality. We give two-colour dependent transformations as a function of metallicity as well as independent of metallicity. The transformations provide absolute magnitudes and distance determinations which can be used in space density evaluations at relatively short distances where some or all of the SDSS magnitudes of late-type giants are saturated.

Expert Comment: Is Medication Titration in Heart Failure too Complex?

PubMed Central

Hickey, Annabel

2017-01-01

Abstract Large-scale randomised controlled trials (RCTs) have demonstrated that angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and beta-blockers decrease mortality and hospitalisation in patients with heart failure (HF) associated with a reduced left ventricular ejection fraction. This has led to high prescription rates; however, these drugs are generally prescribed at much lower doses than the doses achieved in the RCTs. A number of strategies have been evaluated to improve medication titration in HF, including forced medication up-titration protocols, point-of-care decision support and extended scope of clinical practice for nurses and pharmacists. Most successful strategies have been multifaceted and have adapted existing multidisciplinary models of care. Furthermore, given the central role of general practitioners in long-term monitoring and care coordination in HF patients, these strategies should engage with primary care to facilitate the transition between the acute and primary healthcare sectors. PMID:28785472

Control of OSA during automatic positive airway pressure titration in a clinical case series: predictors and accuracy of device download data.

PubMed

Huang, Hsin-Chia Carol; Hillman, David R; McArdle, Nigel

2012-09-01

To investigate the factors associated with physiologic control of obstructive sleep apnea (OSA) during automatic positive airway pressure (APAP) titration in a clinical series. To also assess the usefulness of apnea-hypopnea index (AHI) data downloaded from the APAP device (Dev AHI). Retrospective review of a consecutive series of patients with OSA who underwent APAP titration (Autoset Spirit, ResMed, Bella Vista, New South Wales, Australia ) with simultaneous polysomnographic (PSG) monitoring in the sleep laboratory. Tertiary sleep clinic. There were 190 consecutive patients with OSA referred for APAP titration. There were 58% of patients who achieved optimal or good control of OSA (titration PSG AHI < 10, or at least 50% reduction in AHI if diagnostic AHI < 15/hr) during APAP titration. The independent predictors of titration PSG AHI were a history of cardiac disease and elevated central apnea and arousal indices during the diagnostic study. Although the median and interquartile range (IQR) AHI from the device (7.0, 3.9-11.6 events/hr) was only slightly less than the PSG AHI (7.8, 3.9-14.4 events/hr, P = 0.04) during titration, case-by-case agreement between the two measures was poor (chi-square < 0.001). In a clinical sample control of OSA during APAP titration is often poor, and close clinical follow-up is particularly needed in patients with a history of cardiac disease or with high arousal or central apnea indices on the diagnostic study. Device AHI does not reliably assess control during APAP titration, and PSG assessment may be required if clinical response to treatment is poor. The findings relate to the ResMed AutoSet device and may not apply to other devices.

Detecting paraprotein interference on a direct bilirubin assay by reviewing the photometric reaction data.

PubMed

García-González, Elena; Aramendía, Maite; González-Tarancón, Ricardo; Romero-Sánchez, Naiara; Rello, Luis

2017-07-26

The direct bilirubin (D-Bil) assay on the AU Beckman Coulter instrumentation can be interfered by paraproteins, which may result in spurious D-Bil results. In a previous work, we took advantage of this fact to detect this interference, thus helping with the identification of patients with unsuspected monoclonal gammopathies. In this work, we investigate the possibility to detect interference based on the review of the photometric reactions, regardless of the D-Bil result. The D-Bil assay was carried out in a set of 2164 samples. It included a group of 164 samples with paraproteins (67 of which caused interference on the assay), as well as different groups of samples for which high absorbance background readings could also be expected (i.e. hemolyzed, lipemic, or icteric samples). Photometric reaction data were reviewed and receiver operating characteristics (ROC) curves were used to establish a cut-off for absorbance that best discriminates interference. The best cut-off was 0.0100 for the absorbance at the first photometric point of the complementary wavelength in the blank cuvette. Once the optimal cut-off for probable interference was selected, all samples analyzed in our laboratory that provided absorbance values above this cut-off were further investigated to try to discover paraproteins. During a period of 6 months, we detected 44 samples containing paraproteins, five of which belonged to patients with non-diagnosed monoclonal gammopathies. Review of the photometric reaction data permits the systematic detection of paraprotein interference on the D-Bil AU assay, even for samples for which reasonable results are obtained.

Barriers to and enablers of insulin self-titration in adults with Type 2 diabetes: a qualitative study.

PubMed

McBain, H; Begum, S; Rahman, S; Mulligan, K

2017-02-01

To identify the barriers to and enablers of effective insulin self-titration in people with Type 2 diabetes. A qualitative semi-structured interview approach was used. Questions were structured according to the Theoretical Domains Framework, which outlines 14 domains that can act as barriers to and enablers of changing behaviour. Interviews were audio-recorded and transcribed verbatim. The data were coded according to the 14 domains, belief statements were created within each domain, and a frequency count of the most reported barriers and enablers was then carried out. Analyses were conducted by two researchers, and discrepancies agreed with a third researcher. A total of 18 adults with Type 2 diabetes took part in an interview. The majority were of South-Asian ethnicity (n = 8) and were men (n = 12). Their mean age was 61 years old. The mean duration of diabetes was 16 years and time on insulin 9 years. Inter-rater reliability for each of the domains varied (29-100%). The most frequently reported domains were Social Influence and Beliefs about Consequences; the least frequently reported were Optimism and Reinforcement. Interviewees reported receiving support to self-titrate from a range of sources. Self-titrating was perceived to have a range of both positive and negative consequences, as was not titrating. The findings highlight that those interviewed experienced a range of barriers and enablers when attempting to self-titrate. Improved education and training when initiating insulin treatment among adults with Type 2 diabetes, and throughout their journey on insulin therapy could help identify and address these barriers in order to optimize self-titration. © 2016 Diabetes UK.

Barriers to Beta-Blocker Use and Up-Titration Among Patients with Heart Failure with Reduced Ejection Fraction.

PubMed

Levitan, Emily B; Van Dyke, Melissa K; Loop, Matthew Shane; O'Beirne, Ronan; Safford, Monika M

2017-12-01

For patients with heart failure with reduced ejection fraction (HFrEF), guidelines recommend use of beta-blockers with gradual up-titration. However, many patients with HFrEF do not use beta-blockers and up-titration is rare. Our purpose was to identify and rank barriers to beta-blocker use and up-titration from the perspective of primary care physicians. We conducted 4 moderated, structured group discussions among 19 primary care physicians using the nominal group technique; 16 participants also completed a survey. Participants generated lists of barriers to beta-blocker use and up-titration among patients with HFrEF. Each participant had six votes with three votes assigned to the item ranked most important, two to the second most important item, and one to the third most important item. Investigators characterized items into themes. The percentage of available votes was calculated for each theme. Fifteen of 16 participating primary care physicians who completed the survey reported that management of beta-blockers was their responsibility. Treatment/side effects, particularly hypotension, were identified as the most important barrier for beta-blocker use (72% of available votes) followed by polypharmacy (11%), healthcare system barriers (10%), and comorbidities (6%). Barriers to up-titration included treatment/side effects (49% of available votes), patient communication/buy-in (21%), polypharmacy (13%), and healthcare system barriers (8%). Many barriers to guideline concordant use of beta-blockers among patients with HFrEF identified by primary care providers are not readily modifiable. Addressing these barriers may require development, testing, and dissemination of protocols for beta-blocker initiation and up-titration that are safe and appropriate in primary care.

Equivalence of nasal and oronasal masks during initial CPAP titration for obstructive sleep apnea syndrome.

PubMed

Teo, Ming; Amis, Terence; Lee, Sharon; Falland, Karina; Lambert, Stephen; Wheatley, John

2011-07-01

Continuous positive airway pressure (CPAP) titration studies are commonly performed using a nasal mask but some patients may prefer a full-face or oronasal mask. There is little evidence regarding the equivalence of different mask interfaces used to initiate treatment. We hypothesized that oronasal breathing when using an oronasal mask increases upper airway collapsibility and that a higher pressure may be required to maintain airway patency. We also assessed patient preferences for the 2 mask interfaces. Prospective, randomized, cross-over design with 2 consecutive CPAP titration nights. Accredited laboratory in a university hospital. Twenty-four treatment-naive subjects with obstructive sleep apnea syndrome and respiratory disturbance index of greater than 15 events per hour. CPAP titration was performed using an auto-titrating machine with randomization to a nasal or oronasal mask, followed by a second titration night using the alternate mask style. There was no significant difference in the mean pressures determined between nasal and oronasal masks, although 43% of subjects had nasal-to-oronasal mask-pressure differences of 2 cm H(2)O or more. Residual respiratory events, arousals, and measured leak were all greater with the oronasal mask. Seventy-nine percent of subjects preferred the nasal mask. Patients with obstructive sleep apnea syndrome can generally switch between nasal and oronasal masks without changing machine pressure, although there are individual differences that may be clinically significant. Measured leak is greater with the oronasal mask. Most patients with obstructive sleep apnea syndrome prefer a nasal mask as the interface for initiation of CPAP. Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12611000243910. URL: http://www.ANZCTR.org.au/ACTRN12611000243910.aspx

The influence of graded degrees of chronic hypercapnia on the acute carbon dioxide titration curve

PubMed Central

Goldstein, Marc B.; Gennari, F. John; Schwartz, William B.

1971-01-01

Studies were carried out to determine the influence of the chronic level of arterial carbon dioxide tension upon the buffering response to acute changes in arterial carbon dioxide tension. After chronic adaptation to six levels of arterial CO2 tension, ranging between 35 and 110 mm Hg, unanesthetized dogs underwent acute whole body CO2 titrations. In each instance a linear relationship was observed between the plasma hydrogen ion concentration and the arterial carbon dioxide tension. Because of this linear relationship, it has been convenient to compare the acute buffering responses among dogs in terms of the slope, dH+/dPaco2. With increasing chronic hypercapnia there was a decrease in this slope, i.e. an improvement in buffer capacity, which is expressed by the equation dH+/dPaco2=-0.005 (Paco2)chronic + 0.95. In effect, the ability to defend pH during acute titration virtually doubled as chronic Paco2 increased from 35 to 110 mm Hg. The change in slope, dH+/dPaco2, was the consequence of the following two factors: the rise in plasma bicarbonate concentration which occurs with chronic hypercapnia of increasing severity, and the greater change in bicarbonate concentration which occurred during the acute CO2 titration in the animals with more severe chronic hypercapnia. These findings demonstrate the importance of the acid-base status before acute titration in determining the character of the carbon dioxide titration curve. They also suggest that a quantitative definition of the interplay between acute and chronic hypercapnia in man should assist in the rational analysis of acid-base disorders in chronic pulmonary insufficiency. PMID:5543876

Nurse-coordinated care improves the achievement of LDL cholesterol targets through more intensive medication titration

PubMed Central

Snaterse, Marjolein; Jorstad, Harald T; Heiligenberg, Marlies; ter Riet, Gerben; Boekholdt, S Matthijs; Scholte op Reimer, Wilma; Peters, Ron J

2017-01-01

Background Nurse-coordinated care (NCC) improves the achievement of low-density lipoprotein-cholesterol (LDL-C) targets after an acute coronary syndrome (ACS). We hypothesised that NCC improves achievement of LDL-C targets through more intensive medication titration. Methods We used data from Randomised Evaluation of Secondary Prevention by Outpatient Nurse Specialists (RESPONSE), a multicentre randomised trial on the efficacy of NCC in 754 ACS patients. Follow-up data were collected at 6 and 12 months. To enable comparison between the various types and dosages of statins, we used the average lipid-lowering potency (ALLP, % LDL-C lowering) as an indicator of lipid-lowering medication intensity. Results Most patients in NCC intervention and usual care groups (96%) had started lipid-lowering therapy during the index hospitalisation. At 6 months, titration activities (up or down) were applied in 45% of NCC patients compared with 24% of patients receiving usual care (p<0.001), and a difference was also seen at 12 months follow-up (52% vs 34%, p<0.001). In patients not on LDL-C target at baseline, titration activities at 6 months were recorded in 63% and 30% of NCC and usual care patients respectively (p<0.001), with increased titration activities in both groups at 12 months (69% vs 43%, p<0.001). Conclusion NCC is associated with more frequent and intense lipid-lowering medication titration to reach LDL-C targets as compared with usual care alone. Further, merely starting the guideline-recommended dose is insufficient to reach the guideline-recommended LDL-C target level. Trial Registration number TC1290 (Netherlands). PMID:28761680

Ground-Based Photometric Measurements HAES Program Support.

DTIC Science & Technology

1979-01-31

photometric system such as the MTP can be optimized to a certain extent, but the fundamental limitations on 16 A z I- z -e 0 / LUJ LU z 00 04 LUL 0’ -1...Introduction 12 2.2 Background and Relevance 12 2.3 Measurement Requirements 15 2.4 MTP Optical Design 16 2.5 Digital Photon-Counting Data System 19 2.6...optical head 17 3 Block diagram of modular photometer, digital data and control systems 20 4 Flow diagram of computer program used to analyze three beam

Volumetric determination of uranium titanous sulfate as reductant before oxidimetric titration

USGS Publications Warehouse

Wahlberg, J.S.; Skinner, D.L.; Rader, L.F.

1957-01-01

Need for a more rapid volumetric method for the routine determination of uranium in uranium-rich materials has led to the development of a method that uses titanous sulfate as a reductant before oxidimetric titration. Separation of the hydrogen sulfide group is not necessary. Interfering elements precipitated by cupferron are removed by automatic filtrations made simultaneously rather than by the longer chloroform extraction method. Uranium is reduced from VI to IV by addition of an excess of titanous sulfate solution, cupric ion serving as an indicator by forming red metallic copper when reduction is complete. The copper is reoxidized by addition of mercuric perchlorate. The reduced uranium is then determined by addition of excess ferric sulfate and titration with ceric sulfate. The method has proved to be rapid, accurate, and economical.

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid.

PubMed

van Staden, J F; Mashamba, Mulalo G; Stefan, Raluca I

2002-09-01

An on-line potentiometric sequential injection titration process analyser for the determination of acetic acid is proposed. A solution of 0.1 mol L(-1) sodium chloride is used as carrier. Titration is achieved by aspirating acetic acid samples between two strong base-zone volumes into a holding coil and by channelling the stack of well-defined zones with flow reversal through a reaction coil to a potentiometric sensor where the peak widths were measured. A linear relationship between peak width and logarithm of the acid concentration was obtained in the range 1-9 g/100 mL. Vinegar samples were analysed without any sample pre-treatment. The method has a relative standard deviation of 0.4% with a sample frequency of 28 samples per hour. The results revealed good agreement between the proposed sequential injection and an automated batch titration method.

Titration of Alanine Monitored by NMR Spectroscopy: A Biochemistry Laboratory Experiment

ERIC Educational Resources Information Center

Waller, Francis J.; And Others

1977-01-01

The experiment described here involves simultaneous monitoring of pH and NMR chemical shifts during an aqueous titration of alpha- and beta-alanine. This experiment is designed for use in an undergraduate biochemistry course. (MR)

CCD and photon-counting photometric observations of peculiar asteroids

NASA Astrophysics Data System (ADS)

Fulvio, D.; Blanco, C.; Cigna, M.; Gandolfi, D.

The photometric observational programme of main-belt asteroids undertaken, since 1980, at the Physics and Astronomy Department of Catania University, mainly by using photoelectric acquisition, has been extended to the Near-Earth Objects, because of the importance of their study to improve the knowledge of the mechanics and the physics of the inner Solar System. The wideness of the observational programme was pursued by using an expressly built CCD camera having a Kodak 4200 detector 2048x2048 pixel class 1, front-illuminated chip with 9 mu m pixel-size, equipped with BVRI Johnson filters. New observations of 4 Vesta, 27 Euterpe, 173 Ino, 182 Elsa, 849 Ara (carried out at M.G. Fracastoro Station of Catania Astrophysical Observatory), 984 Gretia, 3199 Nefertiti and 2004 UE (carried out at Asiago Station of Padova Astronomical Observatory) are presented. The improvement of the rotational period value (for 182 Elsa and 2004 UE it is the first determination), of the lightcurve amplitude and of the B-V colour index was obtained. For 4 Vesta indications on surface mineralogic morphology are deduced from the UBV photometric behaviour while for 182 Elsa, the H-G magnitude relation was carried out.

Natural monocrystalline pyrite as a sensor in non-aqueous solution Part I: Potentiometric titration of weak acids in, N,N-dimethylformamide, methylpyrrolidone and pyridine.

PubMed

Mihajlović, Lj V; Mihajlović, R P; Antonijević, M M; Vukanović, B V

2004-11-15

The possibility of applying natural monocrystaline pyrite as a sensor for the potentiometric titration of weak acids in N,N-dimethylformamide, methylpyrrolidone and pyridine was investigated. The potential of this electrode in N,N-dimethylformamide, methylpyrrolidone and pyridine exhibits a sub-Nernst dependence. In N,N-dimethylformamide the slope (mV/pH) is 39.0 and in methylpyrrolidone it is 45.0. The potential jumps at the titration end-point obtained in the titration of weak acids are higher than those obtained by the application of a glass electrode as the indicator electrode The potential in the course of the titration and at the titration end-point (TEP) are rapidly established. Sodium methylate, potassium hydroxide and tetrabutylammonium hydroxide (TBAH) proved to be very suitable titrating agents for these titrations. The results obtained in the determination of the investigated weak acids deviate by 0.1-0.35% with respect to those obtained by using a glass electrode as the indicator electrode.

Inferring Binary and Trinary Stellar Populations in Photometric and Astrometric Surveys

NASA Astrophysics Data System (ADS)

Widmark, Axel; Leistedt, Boris; Hogg, David W.

2018-04-01

Multiple stellar systems are ubiquitous in the Milky Way but are often unresolved and seen as single objects in spectroscopic, photometric, and astrometric surveys. However, modeling them is essential for developing a full understanding of large surveys such as Gaia and connecting them to stellar and Galactic models. In this paper, we address this problem by jointly fitting the Gaia and Two Micron All Sky Survey photometric and astrometric data using a data-driven Bayesian hierarchical model that includes populations of binary and trinary systems. This allows us to classify observations into singles, binaries, and trinaries, in a robust and efficient manner, without resorting to external models. We are able to identify multiple systems and, in some cases, make strong predictions for the properties of their unresolved stars. We will be able to compare such predictions with Gaia Data Release 4, which will contain astrometric identification and analysis of binary systems.

A rapid method for infectivity titration of Andes hantavirus using flow cytometry.

PubMed

Barriga, Gonzalo P; Martínez-Valdebenito, Constanza; Galeno, Héctor; Ferrés, Marcela; Lozach, Pierre-Yves; Tischler, Nicole D

2013-11-01

The focus assay is currently the most commonly used technique for hantavirus titer determination. This method requires an incubation time of between 5 and 11 days to allow the appearance of foci after several rounds of viral infection. The following work presents a rapid Andes virus (ANDV) titration assay, based on viral nucleocapsid protein (N) detection in infected cells by flow cytometry. To this end, an anti-N monoclonal antibody was used that was developed and characterized previously. ANDV N could be detected as early as 6 h post-infection, while viral release was not observed until 24-48 h post-infection. Given that ANDV detection was performed during its first round of infection, a time reduction for titer determination was possible and provided results in only two days. The viral titer was calculated from the percentage of N positive cells and agreed with focus assay titers. Furthermore, the assay was applied to quantify the inhibition of ANDV cell entry by patient sera and by preventing endosome acidification. This novel hantavirus titration assay is a highly quantitative and sensitive tool that facilitates infectivity titration of virus stocks, rapid screening for antiviral drugs, and may be further used to detect and quantify infectious virus in human samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Titration effectiveness of two autoadjustable continuous positive airway pressure devices driven by different algorithms in patients with obstructive sleep apnoea.