Inherent smoothness of intensity patterns for intensity modulated radiation therapy generated by simultaneous projection algorithms

NASA Astrophysics Data System (ADS)

Xiao, Ying; Michalski, Darek; Censor, Yair; Galvin, James M.

2004-07-01

The efficient delivery of intensity modulated radiation therapy (IMRT) depends on finding optimized beam intensity patterns that produce dose distributions, which meet given constraints for the tumour as well as any critical organs to be spared. Many optimization algorithms that are used for beamlet-based inverse planning are susceptible to large variations of neighbouring intensities. Accurately delivering an intensity pattern with a large number of extrema can prove impossible given the mechanical limitations of standard multileaf collimator (MLC) delivery systems. In this study, we apply Cimmino's simultaneous projection algorithm to the beamlet-based inverse planning problem, modelled mathematically as a system of linear inequalities. We show that using this method allows us to arrive at a smoother intensity pattern. Including nonlinear terms in the simultaneous projection algorithm to deal with dose-volume histogram (DVH) constraints does not compromise this property from our experimental observation. The smoothness properties are compared with those from other optimization algorithms which include simulated annealing and the gradient descent method. The simultaneous property of these algorithms is ideally suited to parallel computing technologies.

The anode mechanism of a thermal argon arc

NASA Technical Reports Server (NTRS)

Busz-Peuckert, G.; Finkelnburg, W.

1984-01-01

In order to clarify the anode mechanism in freely burning argon arcs, the anode drop was determined by probe measurements in the current intensity range of 10 to 200 A and arc lengths between 2 and 10 mm. Simultaneously, the power input at the anode was determined by measuring the temperature increase in the cooling water, using a thermoelement, and compared to the electrical output at the arc and in the anodic drop area. An anodic contraction was observed in the arc, at low current intensities. The results can be explained in terms of the effects of a cathodic plasma current, and in the contracted arc, in terms of an additional anodic plasma current.

Is there competition between breast-feeding and maternal employment?

PubMed

Roe, B; Whittington, L A; Fein, S B; Teisl, M F

1999-05-01

Theory suggests that the decision to return to employment after childbirth and the decision to breast-feed may be jointly determined. We estimate models of simultaneous equations for two different aspects of the relationship between maternal employment and breast-feeding using 1993-1994 data from the U.S. Food and Drug Administration's Infant Feeding Practices Study. We first explore the simultaneous duration of breast-feeding and work leave following childbirth. We find that the duration of leave from work significantly affects the duration of breast-feeding, but the effect of breast-feeding on work leave is insignificant. We also estimate models of the daily hours of work and breast-feedings at infant ages 3 months and 6 months postpartum. At both times, the intensity of work effort significantly affects the intensity of breast-feeding, but the reverse is generally not found. Competition clearly exists between work and breast-feeding for many women in our sample.

Simultaneous detection of iodine and iodide on boron doped diamond electrodes.

PubMed

Fierro, Stéphane; Comninellis, Christos; Einaga, Yasuaki

2013-01-15

Individual and simultaneous electrochemical detection of iodide and iodine has been performed via cyclic voltammetry on boron doped diamond (BDD) electrodes in a 1M NaClO(4) (pH 8) solution, representative of typical environmental water conditions. It is feasible to compute accurate calibration curve for both compounds using cyclic voltammetry measurements by determining the peak current intensities as a function of the concentration. A lower detection limit of about 20 μM was obtained for iodide and 10 μM for iodine. Based on the comparison between the peak current intensities reported during the oxidation of KI, it is probable that iodide (I(-)) is first oxidized in a single step to yield iodine (I(2)). The latter is further oxidized to obtain IO(3)(-). This technique, however, did not allow for a reasonably accurate detection of iodate (IO(3)(-)) on a BDD electrode. Copyright © 2012 Elsevier B.V. All rights reserved.

Chemometrics-assisted simultaneous determination of cobalt(II) and chromium(III) with flow-injection chemiluminescence method

NASA Astrophysics Data System (ADS)

Li, Baoxin; Wang, Dongmei; Lv, Jiagen; Zhang, Zhujun

2006-09-01

In this paper, a flow-injection chemiluminescence (CL) system is proposed for simultaneous determination of Co(II) and Cr(III) with partial least squares calibration. This method is based on the fact that both Co(II) and Cr(III) catalyze the luminol-H 2O 2 CL reaction, and that their catalytic activities are significantly different on the same reaction condition. The CL intensity of Co(II) and Cr(III) was measured and recorded at different pH of reaction medium, and the obtained data were processed by the chemometric approach of partial least squares. The experimental calibration set was composed with nine sample solutions using orthogonal calibration design for two component mixtures. The calibration curve was linear over the concentration range of 2 × 10 -7 to 8 × 10 -10 and 2 × 10 -6 to 4 × 10 -9 g/ml for Co(II) and Cr(III), respectively. The proposed method offers the potential advantages of high sensitivity, simplicity and rapidity for Co(II) and Cr(III) determination, and was successfully applied to the simultaneous determination of both analytes in real water sample.

Autocorrelation analysis for the unbiased determination of power-law exponents in single-quantum-dot blinking.

PubMed

Houel, Julien; Doan, Quang T; Cajgfinger, Thomas; Ledoux, Gilles; Amans, David; Aubret, Antoine; Dominjon, Agnès; Ferriol, Sylvain; Barbier, Rémi; Nasilowski, Michel; Lhuillier, Emmanuel; Dubertret, Benoît; Dujardin, Christophe; Kulzer, Florian

2015-01-27

We present an unbiased and robust analysis method for power-law blinking statistics in the photoluminescence of single nanoemitters, allowing us to extract both the bright- and dark-state power-law exponents from the emitters' intensity autocorrelation functions. As opposed to the widely used threshold method, our technique therefore does not require discriminating the emission levels of bright and dark states in the experimental intensity timetraces. We rely on the simultaneous recording of 450 emission timetraces of single CdSe/CdS core/shell quantum dots at a frame rate of 250 Hz with single photon sensitivity. Under these conditions, our approach can determine ON and OFF power-law exponents with a precision of 3% from a comparison to numerical simulations, even for shot-noise-dominated emission signals with an average intensity below 1 photon per frame and per quantum dot. These capabilities pave the way for the unbiased, threshold-free determination of blinking power-law exponents at the microsecond time scale.

The Mn-53-Cr-53 System in CAIs: An Update

NASA Technical Reports Server (NTRS)

Papanastassiou, D. A.; Wasserburg, G. J.; Bogdanovski, O.

2005-01-01

High precision techniques have been developed for the measurement of Cr isotopes on the Triton mass spectrometer, at JPL. It is clear that multiple Faraday cup, simultaneous ion collection may reduce the uncertainty of isotope ratios relative to single Faraday cup ion collection, by the elimination of uncertainties from ion beam instabilities (since ion beam intensities for single cup collection are interpolated in time to calculate isotope ratios), and due to a greatly increased data collection duty cycle, for simultaneous ion collection. Efforts to measure Cr by simultaneous ion collection have not been successful in the past. Determinations on Cr-50-54Cr, by simultaneous ion collection on the Finnigan/ MAT 262 instrument at Caltech, resulted in large variations in extrinsic precision, for normal Cr, of up to 1% in Cr-53/Cr-52 (data corrected for mass fractionation, using Cr-50/Cr-52).

Electronic transport characterization of silicon wafers by spatially resolved steady-state photocarrier radiometric imaging

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

Wang, Qian; University of the Chinese Academy of Sciences, Beijing 100039; Li, Bincheng, E-mail: bcli@ioe.ac.cn

2015-09-28

Spatially resolved steady-state photocarrier radiometric (PCR) imaging technique is developed to characterize the electronic transport properties of silicon wafers. Based on a nonlinear PCR theory, simulations are performed to investigate the effects of electronic transport parameters (the carrier lifetime, the carrier diffusion coefficient, and the front surface recombination velocity) on the steady-state PCR intensity profiles. The electronic transport parameters of an n-type silicon wafer are simultaneously determined by fitting the measured steady-state PCR intensity profiles to the three-dimensional nonlinear PCR model. The determined transport parameters are in good agreement with the results obtained by the conventional modulated PCR technique withmore » multiple pump beam radii.« less

Hybrid Fabry-Perot interferometer for simultaneous liquid refractive index and temperature measurement.

PubMed

Xu, Ben; Yang, Yi; Jia, Zhenbao; Wang, D N

2017-06-26

A compact and high sensitivity sensor with a fiber-tip structure is proposed and demonstrated for simultaneously liquid refractive index (RI) and temperature sensing. The device is fabricated by inserting a tiny segment of capillary tube between single-mode fibers (SMFs) to form two cascaded Fabry-Perot interferometers (FPIs). The theoretical and experimental results demonstrate that the ambient liquid RI and temperature can be simultaneously determined by the intensity and shift of the resonant wavelength in the reflection spectrum. Our proposed device has the highest RI sensitivity of ~216.37 dB/RIU at the RI value of 1.30; a high spatial resolution owing to its compact size (with dimension <400 μm) makes it promising for high precision bio/chemical sensing applications.

When is one layer complete? Using simultaneous in-situ RHEED and x-ray reflectivity to map layer-by-layer thin-film oxide growth

NASA Astrophysics Data System (ADS)

Sullivan, M. C.; Ward, M. J.; Joress, H.; Gutierrez-Llorente, A.; White, A. E.; Woll, A.; Brock, J. D.

2014-03-01

The most popular tool for characterizing in situ layer-by-layer growth is Reflection High-Energy Electron Diffraction (RHEED). X-ray reflectivity can also be used to study layer-by-layer growth, as long as the incident angle of the x-rays is far from a Bragg peak. During layer-by-layer homoepitaxial growth, both the RHEED intensity and the reflected x-ray intensity will oscillate, and each complete oscillation indicates the addition of one layer of material. However, it is well documented, but not well understood, that the maxima in the RHEED intensity oscillations do not necessarily occur at the completion of a layer. In contrast, the maxima in the x-ray intensity oscillations do occur at the completion of a layer, thus the RHEED and x-ray oscillations are rarely in phase. We present our results on simultaneous in situ x-ray reflectivity and RHEED during layer-by-layer growth of SrTiO3 and discuss how to determine the completion of a layer for RHEED oscillations independent of the phase of the RHEED oscillation. Supported by DOE Office of Basic Energy Sciences Award DE-SC0001086, CHESS is supported by the NSF & NIH/NIGMS via NSF award DMR-0936384.

Derivative emission spectrofluorimetry for the simultaneous determination of guaifenesin and phenylephrine hydrochloride in pharmaceutical tablets.

PubMed

Maher, Hadir M; Alshehri, Mona M; Al-taweel, Shorog M

2015-05-01

Rapid, simple and sensitive derivative emission spectrofluorimetric methods have been developed for the simultaneous analysis of binary mixtures of guaifenesin (GUA) and phenylephrine hydrochloride (PHE). The methods are based upon measurement of the native fluorescence intensity of the two drugs at λex = 275 nm in methanolic solutions, followed by differentiation using first (D1) and second (D2) derivative techniques. The derivative fluorescence intensity-concentration plots were rectilinear over a range of 0.1-2 µg/mL for both GUA and PHE. The limits of detection were 0.027 (D1, GUA), 0.025 (D2, GUA), 0.031 (D1, PHE) and 0.033 (D2, PHE) µg/mL and limits of quantitation were 0.089 (D1, GUA), 0.083 (D2, GUA), 0.095 (D1, PHE) and 0.097 (D2, PHE) µg/mL. The proposed derivative emission spectrofluorimetric methods (D1 and D2) were successfully applied for the determination of the two compounds in binary mixtures and tablets with high precision and accuracy. The proposed methods were fully validated as per ICH guidelines. Copyright © 2014 John Wiley & Sons, Ltd.

Determination of coupling coefficients at various zenith angles of the basis of the cosmic ray azimuth effect

NASA Technical Reports Server (NTRS)

Belskiy, S. A.; Dmitriev, B. A.; Romanov, A. M.

1975-01-01

The value of EW asymmetry and coupling coefficients at different zenith angles were measured by means of a double coincidence crossed telescope which gives an opportunity to measure simultaneously the intensity of the cosmic ray hard component at zenith angles from 0 to 84 deg in opposite azimuths. The advantages of determining the coupling coefficients by the cosmic ray azimuth effect as compared to their measurement by the latitudinal effect are discussed.

Far-infrared line observations of planetary nebulae. 1: The O 3 spectrum

NASA Technical Reports Server (NTRS)

Dinerstein, H. L.; Lester, D. F.; Werner, M. W.

1985-01-01

Observations of the far-infrared fine structure lines of O III have been obtained for six planetary nebulae. The infrared measurements are combined with optical O III line fluxes to probe physical conditions in the gas. From the observed line intensity ratios, a simultaneous solution was obtained for electron temperature and density, as well as means of evaluating the importance of inhomogeneities. Densities determined from the far-infrared O III lines agree well density diagnostics from other ions, indicating a fairly homogeneous density in the emitting gas. Temperatures are determined separately from the O III 4363/5007 A and 5007 A/52 micron intensity ratios and compared. Systematically higher values are derived from the former ratio, which is expected from a nebula which is not isothermal. Allowance for the presence of temperature variations within these nebulae raises their derived oxygen abundances, determinations to be reconciled with the solar value.

On the Equivalence of FCS and FRAP: Simultaneous Lipid Membrane Measurements.

PubMed

Macháň, Radek; Foo, Yong Hwee; Wohland, Thorsten

2016-07-12

Fluorescence correlation spectroscopy (FCS) and fluorescence recovery after photobleaching (FRAP) are widely used methods to determine diffusion coefficients. However, they often do not yield the same results. With the advent of camera-based imaging FCS, which measures the diffusion coefficient in each pixel of an image, and proper bleaching corrections, it is now possible to measure the diffusion coefficient by FRAP and FCS in the exact same images. We thus performed simultaneous FCS and FRAP measurements on supported lipid bilayers and live cell membranes to test how far the two methods differ in their results and whether the methodological differences, in particular the high bleach intensity in FRAP, the bleach corrections, and the fitting procedures in the two methods explain observed differences. Overall, we find that the FRAP bleach intensity does not measurably influence the diffusion in the samples, but that bleach correction and fitting introduce large uncertainties in FRAP. We confirm our results by simulations. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

MRI intensity nonuniformity correction using simultaneously spatial and gray-level histogram information.

PubMed

Milles, Julien; Zhu, Yue Min; Gimenez, Gérard; Guttmann, Charles R G; Magnin, Isabelle E

2007-03-01

A novel approach for correcting intensity nonuniformity in magnetic resonance imaging (MRI) is presented. This approach is based on the simultaneous use of spatial and gray-level histogram information. Spatial information about intensity nonuniformity is obtained using cubic B-spline smoothing. Gray-level histogram information of the image corrupted by intensity nonuniformity is exploited from a frequential point of view. The proposed correction method is illustrated using both physical phantom and human brain images. The results are consistent with theoretical prediction, and demonstrate a new way of dealing with intensity nonuniformity problems. They are all the more significant as the ground truth on intensity nonuniformity is unknown in clinical images.

Simultaneous determination of PPCPs, EDCs, and artificial sweeteners in environmental water samples using a single-step SPE coupled with HPLC-MS/MS and isotope dilution.

PubMed

Tran, Ngoc Han; Hu, Jiangyong; Ong, Say Leong

2013-09-15

A high-throughput method for the simultaneous determination of 24 pharmaceuticals and personal care products (PPCPs), endocrine disrupting chemicals (EDCs) and artificial sweeteners (ASs) was developed. The method was based on a single-step solid phase extraction (SPE) coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and isotope dilution. In this study, a single-step SPE procedure was optimized for simultaneous extraction of all target analytes. Good recoveries (≥ 70%) were observed for all target analytes when extraction was performed using Chromabond(®) HR-X (500 mg, 6 mL) cartridges under acidic condition (pH 2). HPLC-MS/MS parameters were optimized for the simultaneous analysis of 24 PPCPs, EDCs and ASs in a single injection. Quantification was performed by using 13 isotopically labeled internal standards (ILIS), which allows correcting efficiently the loss of the analytes during SPE procedure, matrix effects during HPLC-MS/MS and fluctuation in MS/MS signal intensity due to instrument. Method quantification limit (MQL) for most of the target analytes was below 10 ng/L in all water samples. The method was successfully applied for the simultaneous determination of PPCPs, EDCs and ASs in raw wastewater, surface water and groundwater samples collected in a local catchment area in Singapore. In conclusion, the developed method provided a valuable tool for investigating the occurrence, behavior, transport, and the fate of PPCPs, EDCs and ASs in the aquatic environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Hybrid Ion-Detector/Data-Acquisition System for a TOF-MS

NASA Technical Reports Server (NTRS)

Burton, William D., Jr.; Schultz, J. Albert; Vaughn, Valentine; McCully, Michael; Ulrich, Steven; Egan, Thomas F.

2006-01-01

A modified ion-detector/data-acquisition system has been devised to increase the dynamic range of a time-of-flight mass spectrometer (TOF-MS) that, previously, included a microchannel-plate detector and a data-acquisition system based on counting pulses and time-tagging them by use of a time-to-digital converter (TDC). The dynamic range of the TOF-MS was limited by saturation of the microchannel plate detector, which can handle no more than a few million counts per second. The modified system includes (1) a combined microchannel plate/discrete ion multiplier and (2) a hybrid data-acquisition system that simultaneously performs analog current or voltage measurements and multianode single-ion-pulse-counting time-of-flight measurements to extend the dynamic range of a TDC into the regime in which a mass peak comprises multiple ions arriving simultaneously at the detector. The multianode data are used to determine, in real time, whether the detector is saturated. When saturation is detected, the data-acquisition system selectively enables circuitry that simultaneously determines the ion-peak intensity by measuring the time profile of the analog current or voltage detector-output signal.

Study in Parkinson Disease of Exercise (SPARX): Translating high-intensity exercise from animals to humans

PubMed Central

Moore, Charity G.; Schenkman, Margaret; Kohrt, Wendy M.; Delitto, Anthony; Hall, Deborah A.; Corcos, Daniel

2013-01-01

A burgeoning literature suggests that exercise has a therapeutic benefit in persons with Parkinson disease (PD) and in animal models of PD, especially when animals exercise at high intensity. If exercise is to be prescribed as “first-line” or “add-on” therapy in patients with PD, we must demonstrate its efficacy and dose-response effects through testing phases similar to those used in the testing of pharmacologic agents. The SPARX Trial is a multicenter, randomized, controlled, single-blinded, Phase II study that we designed to test the feasibility of using high-intensity exercise to modify symptoms of PD and to simultaneously test the nonfutility of achieving a prespecified change in patients’ motor scores on the Unified Parkinson Disease Rating Scale (UPDRS). The trial began in May 2102 and is in the process of screening, enrolling, and randomly assigning 126 patients with early-stage PD to 1 of 3 groups: usual care (wait-listed controls), moderate-intensity exercise (4 days/week at 60%–65% maximal heart rate [HRmax]), or high-intensity exercise (4 days/week at 80%–85% HRmax). At 6-month follow-up, the trial is randomly reassigning usual care participants to a moderate-intensity or high-intensity exercise group for the remaining 6 months. The goals of the Phase II trial are to determine if participants can exercise at moderate and high intensities; to determine if either exercise yields benefits consistent with meaningful clinical change (nonfutility); and to document safety and attrition. The advantage of using a non-futility approach allows us to efficiently determine if moderate- or high-intensity exercise warrants further large-scale investigation in PD. PMID:23770108

Relationship of Various Open Quotients With Acoustic Property, Phonation Types, Fundamental Frequency, and Intensity.

PubMed

Yokonishi, Hisayuki; Imagawa, Hiroshi; Sakakibara, Ken-Ichi; Yamauchi, Akihito; Nito, Takaharu; Yamasoba, Tatsuya; Tayama, Niro

2016-03-01

In the present study, we examined the relationship between various open quotients (Oqs) and phonation types, fundamental frequency (F0), and intensity by multivariate linear regression analysis (MVA) to determine which Oq best reflects vocal fold vibratory characteristics. Using high-speed digital imaging (HSDI), a sustained vowel /e/ at different phonation types, F0s, and intensities was recorded from six vocally healthy male volunteers: the types of phonation included modal, falsetto, modal breathy, and modal pressed phonations; and each phonation was performed at different F0s and intensities. Electroglottography (EGG) and sound signals were simultaneously recorded with HSDI. From the obtained data, 10 conventional Oqs (four Oqs from the glottal area function, four kymographic Oqs, and two EGG-derived Oqs) and two newly introduced Oqs (Oq(edge)+ and Oq(edge)) were evaluated. And, relationships between various Oqs and phonation types, F0, and intensity were evaluated by MVA. Among the various Oqs, Oq(edge)+ and Oq(edge) revealed the strongest correlations with an acoustic property and could best describe changes in phonation types: Oq(edge) was found to be better than Oq(edge)¯. Oq(MLK), the average of five Oqs from five-line multiline kymography was a very good alternative to Oq(edge)¯. EGG-derived Oqs were able to differentiate between modal phonation and falsetto phonation, but it was necessary to consider the change of F0 simultaneously. MVA showed the changes in Oq values between modal and other phonation types, the degree of involvement of intensity, and no relationship between F0 and Oqs. Among Oqs evaluated in this study, Oq(edge)+ and Oq(edge) were considered to best reflect the vocal fold vibratory characteristics. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

SAVLOC, computer program for automatic control and analysis of X-ray fluorescence experiments

NASA Technical Reports Server (NTRS)

Leonard, R. F.

1977-01-01

A program for a PDP-15 computer is presented which provides for control and analysis of trace element determinations by using X-ray fluorescence. The program simultaneously handles data accumulation for one sample and analysis of data from previous samples. Data accumulation consists of sample changing, timing, and data storage. Analysis requires the locating of peaks in X-ray spectra, determination of intensities of peaks, identification of origins of peaks, and determination of a real density of the element responsible for each peak. The program may be run in either a manual (supervised) mode or an automatic (unsupervised) mode.

Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex.

PubMed

Santolaria, Pilar; Pauciullo, Alfredo; Silvestre, Miguel A; Vicente-Fiel, Sandra; Villanova, Leyre; Pinton, Alain; Viruel, Juan; Sales, Ester; Yániz, Jesús L

2016-01-01

This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively). Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001) although with important differences between bulls. A simultaneous evaluation of all the measured features by discriminant analysis revealed that nuclear area and average fluorescence intensity were the variables selected by stepwise discriminant function analysis as the best discriminators between SX and SY. In the second experiment, the sperm nuclear morphometric results from CASA-Morph in nonsexed (mixed SX and SY) and sexed (SX) semen samples from four bulls were compared. FISH allowed a successful classification of spermatozoa according to their sex chromosome content. X-sexed spermatozoa displayed a larger size and fluorescence intensity than nonsexed spermatozoa (P < 0.05). We conclude that the CASA-Morph fluorescence-based method has the potential to find differences between X- and Y-chromosome-bearing spermatozoa in bovine species although more studies are needed to increase the precision of sex determination by this technique.

RADIATION WAVE DETECTION

DOEpatents

Wouters, L.F.

1960-08-30

Radiation waves can be detected by simultaneously measuring radiation- wave intensities at a plurality of space-distributed points and producing therefrom a plot of the wave intensity as a function of time. To this end. a detector system is provided which includes a plurality of nuclear radiation intensity detectors spaced at equal radial increments of distance from a source of nuclear radiation. Means are provided to simultaneously sensitize the detectors at the instant a wave of radiation traverses their positions. the detectors producing electrical pulses indicative of wave intensity. The system further includes means for delaying the pulses from the detectors by amounts proportional to the distance of the detectors from the source to provide an indication of radiation-wave intensity as a function of time.

Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Eto, Shuzo; Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi; Tanaka, Masayoshi Y.

2014-11-01

The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously.

Massive star formation in 100,000 years from turbulent and pressurized molecular clouds.

PubMed

McKee, Christopher F; Tan, Jonathan C

2002-03-07

Massive stars (with mass m* > 8 solar masses Mmiddle dot in circle) are fundamental to the evolution of galaxies, because they produce heavy elements, inject energy into the interstellar medium, and possibly regulate the star formation rate. The individual star formation time, t*f, determines the accretion rate of the star; the value of the former quantity is currently uncertain by many orders of magnitude, leading to other astrophysical questions. For example, the variation of t*f with stellar mass dictates whether massive stars can form simultaneously with low-mass stars in clusters. Here we show that t*f is determined by the conditions in the star's natal cloud, and is typically about 105yr. The corresponding mass accretion rate depends on the pressure within the cloud--which we relate to the gas surface density--and on both the instantaneous and final stellar masses. Characteristic accretion rates are sufficient to overcome radiation pressure from about 100M middle dot in circle protostars, while simultaneously driving intense bipolar gas outflows. The weak dependence of t*f on the final mass of the star allows high- and low-mass star formation to occur nearly simultaneously in clusters.

Simultaneous measurement of refractive index and temperature based on intensity demodulation using matching grating method.

PubMed

Qi, Liang; Zhao, Chun-Liu; Kang, Juan; Jin, Yongxing; Wang, Jianfeng; Ye, Manping; Jin, Shangzhong

2013-07-01

A solution refractive index (SRI) and temperature simultaneous measurement sensor with intensity-demodulation system based on matching grating method were demonstrated. Long period grating written in a photonic crystal fiber (LPG-PCF), provides temperature stable and wavelength dependent optical intensity transmission. The reflective peaks of two fiber Bragg gratings (FBGs), one of which is etched then sensitive to both SRI and temperature, another (FBG2) is only sensitive to temperature, were located in the same linear range of the LPG-PCF's transmission spectrum. An identical FBG with FBG2 was chosen as a matching FBG. When environments (SRI and temperature) change, the wavelength shifts of the FBGs are translated effectively to the reflection intensity changes. By monitoring output lights of unmatching and matching paths, the SRI and temperature were deduced by a signal processing unit. Experimental results show that the simultaneous refractive index and temperature measurement system work well. The proposed sensor system is compact and suitable for in situ applications at lower cost.

Probabilistic segmentation and intensity estimation for microarray images.

PubMed

Gottardo, Raphael; Besag, Julian; Stephens, Matthew; Murua, Alejandro

2006-01-01

We describe a probabilistic approach to simultaneous image segmentation and intensity estimation for complementary DNA microarray experiments. The approach overcomes several limitations of existing methods. In particular, it (a) uses a flexible Markov random field approach to segmentation that allows for a wider range of spot shapes than existing methods, including relatively common 'doughnut-shaped' spots; (b) models the image directly as background plus hybridization intensity, and estimates the two quantities simultaneously, avoiding the common logical error that estimates of foreground may be less than those of the corresponding background if the two are estimated separately; and (c) uses a probabilistic modeling approach to simultaneously perform segmentation and intensity estimation, and to compute spot quality measures. We describe two approaches to parameter estimation: a fast algorithm, based on the expectation-maximization and the iterated conditional modes algorithms, and a fully Bayesian framework. These approaches produce comparable results, and both appear to offer some advantages over other methods. We use an HIV experiment to compare our approach to two commercial software products: Spot and Arrayvision.

Comparative absorption spectroscopy involving 4f-4f transitions to explore the kinetics of simultaneous coordination of uracil with Nd(III) and Zn(II) and its associated thermodynamics

NASA Astrophysics Data System (ADS)

Victory Devi, Ch.; Rajmuhon Singh, N.

2011-10-01

The interaction of uracil with Nd(III) has been explored in presence and absence of Zn(II) using the comparative absorption spectroscopy involving the 4f-4f transitions in different solvents. The complexation of uracil with Nd(III) is indicated by the change in intensity of 4f-4f bands expressing in terms of significant change in oscillator strength and Judd-Ofelt parameters. Intensification of this bands became more prominent in presence of Zn(II) suggesting the stimulative effect of Zn(II) towards the complexation of Nd(III) with uracil. Other spectral parameters namely Slator-Condon ( Fk's), nephelauxetic effect ( β), bonding ( b1/2) and percent covalency ( δ) parameters are computed to correlate their simultaneous binding of metal ions with uracil. The sensitivities of the observed 4f-4f transitions towards the minor coordination changes around Nd(III) has been used to monitor the simultaneous coordination of uracil with Nd(III) and Zn(II). The variation of intensities (oscillator strengths and Judd-Ofelt parameters) of 4f-4f bands during the complexation has helped in following the heterobimetallic complexation of uracil. Rate of complexation with respect to hypersensitive transition was evaluated. Energy of activation and thermodynamic parameters for the complexation reaction were also determined.

Development of a Multi-Point Quantitation Method to Simultaneously Measure Enzymatic and Structural Components of the Clostridium thermocellum Cellulosome Protein Complex

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

Dykstra, Andrew B; St. Brice, Lois; Rodriguez, Jr., Miguel

2014-01-01

Clostridium thermocellum has emerged as a leading bioenergy-relevant microbe due to its ability to solubilize cellulose into carbohydrates, mediated by multi-component membrane-attached complexes termed cellulosomes. To probe microbial cellulose utilization rates, it is desirable to be able to measure the concentrations of saccharolytic enzymes and estimate the total amount of cellulosome present on a mass basis. Current cellulase determination methodologies involve labor-intensive purification procedures and only allow for indirect determination of abundance. We have developed a method using multiple reaction monitoring (MRM-MS) to simultaneously quantitate both enzymatic and structural components of the cellulosome protein complex in samples ranging in complexitymore » from purified cellulosomes to whole cell lysates, as an alternative to a previously-developed enzyme-linked immunosorbent assay (ELISA) method of cellulosome quantitation. The precision of the cellulosome mass concentration in technical replicates is better than 5% relative standard deviation for all samples, indicating high precision for determination of the mass concentration of cellulosome components.« less

Method for measuring pollutant formation

NASA Technical Reports Server (NTRS)

Stickler, David B. (Inventor); Annen, Kurt (Inventor)

2001-01-01

Diagnostic methods for determining an instantaneous rate of pollutant formation in a combustion system are based on measurement of chemiluminescence intensity generated simultaneously with the formation of the pollutant. The chemiluminescent signal is generated by an analog reaction which occurs in parallel with a key step in the formation of a specific pollutant of interest. The connection between the analog reaction and the pollution reaction is such that the chemiluminescent signal indicates the local, instantaneous formation rate of the pollutant of interest.

Continuous two-wave lasing in microchip Nd : YAG lasers

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

Ievlev, Ivan V; Koryukin, Igor' V; Lebedeva, Yu S

2011-08-31

Simultaneous two-wave lasing was obtained in microchip end-pumped Nd:YAG lasers at the wavelengths of 1061.5 and 1064.17 nm at room temperature. Laser wave intensities were studied as functions of crystal temperature and pump power. The ranges of parameters were determined in which the two-wave lasing occurs and the reasons for such lasing were established. A model is suggested, which adequately describes the experimental results obtained. (control of radiation parameters)

Simultaneous Multi-Filter Optical Photometry of GEO Debris

NASA Technical Reports Server (NTRS)

Seitzer, Patrick; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira; Kelecy, Thomas

2011-01-01

Information on the physical characteristics of unresolved pieces of debris comes from an object's brightness, and how it changes with time and wavelength. True colors of tumbling, irregularly shaped objects can be accurately determined only if the intensity at all wavelengths is measured at the same time. In this paper we report on simultaneous photometric observations of objects at geosynchronous orbit (GEO) using two telescopes at Cerro Tololo Inter-American Observatory (CTIO). The CTIO/SMARTS 0.9-m observes in a Johnson B filter, while the 0.6-m MODEST (Michigan Orbital DEbris Survey Telescope) observes in a Cousins R filter. The two CCD cameras are electronically synchronized so that the exposure start time and duration are the same for both telescopes. Thus we obtain the brightness as a function of time in two passbands simultaneously, and can determine the true color of the object at any time. We will report here on such calibrated measurements made on a sample of GEO objects and what is the distribution of the observed B-R colors. In addition, using this data set, we will show what colors would be observed if the observations in different filters were obtained sequentially, as would be the case for conventional imaging observations with a single detector on a single telescope. Finally, we will compare our calibrated colors of GEO debris with colors determined in the laboratory of selected materials actually used in spacecraft construction.

Determination of Spatial Distribution of Air Pollution by Dye Laser Measurement of Differential Absorption of Elastic Backscatter

NASA Technical Reports Server (NTRS)

Ahmed, S. A.; Gergely, J. S.

1973-01-01

This paper presents the results of an analytical study of a lidar system which uses tunable organic dye lasers to accurately determine spatial distribution of molecular air pollutants. Also described will be experimental work to date on simultaneous multiwavelength output dye laser sources for this system. Basically the scheme determines the concentration of air pollutants by measuring the differential absorption of an (at least) two wavelength lidar signal elastically backscattered by the atmosphere. Only relative measurements of the backscattered intensity at each of the two wavelengths, one on and one off the resonance absorption of the pollutant in question, are required. The various parameters of the scheme are examined and the component elements required for a system of this type discussed, with emphasis on the dye laser source. Potential advantages of simultaneous multiwavelength outputs are described. The use of correlation spectroscopy in this context is examined. Comparisons are also made for the use of infrared probing wavelengths and sources instead of dye lasers. Estimates of the sensitivity and accuracy of a practical dye laser system of this type, made for specific pollutants, snow it to have inherent advantages over other schemes for determining pollutant spatial distribution.

Simultaneous determination of five systemic azoles in plasma by high-performance liquid chromatography with ultraviolet detection.

PubMed

Gordien, Jean-Baptiste; Pigneux, Arnaud; Vigouroux, Stephane; Tabrizi, Reza; Accoceberry, Isabelle; Bernadou, Jean-Marc; Rouault, Audrey; Saux, Marie-Claude; Breilh, Dominique

2009-12-05

A simple, specific and automatable HPLC assay was developed for a simultaneous determination of systemic azoles (fluconazole, posaconazole, voriconazole, itraconazole and its metabolite hydroxyl-itraconazole, and ketoconazole) in plasma. The major advantage of this assay was sample preparation by a fully automatable solid phase extraction with Varian Plexa cartridges. C6-phenyl column was used for chromatographic separation, and UV detection was set at a wavelength of 260 nm. Linezolid was used as an internal standard. The assay was specific and linear over the concentration range of 0.05 to 40 microg/ml excepted for fluconazole which was between 0.05 and 100 microg/ml, and itraconazole between 0.1 and 40 microg/ml. Validation data for accuracy and precision for intra- and inter-day were good and satisfied FDA's guidance: CV between 0.24% and 11.66% and accuracy between 93.8% and 108.7% for all molecules. This assay was applied to therapeutic drug monitoring on patients hospitalized in intensive care and onco-hematologic units.

Measurement of radial artery contrast intensity to assess cardiac microbubble behavior.

PubMed

Sosnovik, David E; Januzzi, James L; Church, Charles C; Mertsch, Judith A; Sears, Andrea L; Fetterman, Robert C; Walovitch, Richard C; Picard, Michael H

2003-12-01

We sought to determine whether analysis of the contrast signal from the radial artery is better able to reflect changes in left ventricular (LV) microbubble dynamics than the signal from the LV itself. Assessment of microbubble behavior from images of the LV may be affected by attenuation from overlying microbubbles and nonuniform background signal intensities. The signal intensity from contrast in a peripheral artery is not affected by these artifacts and may, thus, be more accurate. After injection of a contrast bolus into a peripheral vein, signal intensity was followed simultaneously in the LV and radial artery. The measurements were repeated using continuous, triggered, low and high mechanical index harmonic imaging of the LV. Peak and integrated signal intensities ranged from 25 dB and 1550 dB/s, respectively, with radial artery imaging to 5.6 dB and 471 dB/s with ventricular imaging. Although differences in microbubble behavior during the different imaging protocols could be determined from both the LV and radial artery curves, analysis of the radial artery curves yielded more consistent and robust differences. The signal from microbubbles in the radial artery is not affected by shadowing and is, thus, a more accurate reflection of microbubble behavior in the LV than the signal from the LV itself. This may have important implications for the measurement of myocardial perfusion by contrast echocardiography.

Single-base-pair discrimination of terminal mismatches by using oligonucleotide microarrays and neural network analyses

NASA Technical Reports Server (NTRS)

Urakawa, Hidetoshi; Noble, Peter A.; El Fantroussi, Said; Kelly, John J.; Stahl, David A.

2002-01-01

The effects of single-base-pair near-terminal and terminal mismatches on the dissociation temperature (T(d)) and signal intensity of short DNA duplexes were determined by using oligonucleotide microarrays and neural network (NN) analyses. Two perfect-match probes and 29 probes having a single-base-pair mismatch at positions 1 to 5 from the 5' terminus of the probe were designed to target one of two short sequences representing 16S rRNA. Nonequilibrium dissociation rates (i.e., melting profiles) of all probe-target duplexes were determined simultaneously. Analysis of variance revealed that position of the mismatch, type of mismatch, and formamide concentration significantly affected the T(d) and signal intensity. Increasing the concentration of formamide in the washing buffer decreased the T(d) and signal intensity, and it decreased the variability of the signal. Although T(d)s of probe-target duplexes with mismatches in the first or second position were not significantly different from one another, duplexes with mismatches in the third to fifth positions had significantly lower T(d)s than those with mismatches in the first or second position. The trained NNs predicted the T(d) with high accuracies (R(2) = 0.93). However, the NNs predicted the signal intensity only moderately accurately (R(2) = 0.67), presumably due to increased noise in the signal intensity at low formamide concentrations. Sensitivity analysis revealed that the concentration of formamide explained most (75%) of the variability in T(d)s, followed by position of the mismatch (19%) and type of mismatch (6%). The results suggest that position of the mismatch at or near the 5' terminus plays a greater role in determining the T(d) and signal intensity of duplexes than the type of mismatch.

LONGITUDINAL AND RADIAL DEPENDENCE OF SOLAR ENERGETIC PARTICLE PEAK INTENSITIES: STEREO, ACE, SOHO, GOES, AND MESSENGER OBSERVATIONS

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

Lario, D.; Ho, G. C.; Decker, R. B.

Simultaneous measurements of solar energetic particle (SEP) events by two or more of the spacecraft located near 1 AU during the rising phase of solar cycle 24 (i.e., STEREO-A, STEREO-B, and near-Earth spacecraft such as ACE, SOHO, and GOES) are used to determine the longitudinal dependence of 71-112 keV electron, 0.7-3 MeV electron, 15-40 MeV proton, and 25-53 MeV proton peak intensities measured in the prompt component of SEP events. Distributions of the peak intensities for the selected 35 events with identifiable solar origin are approximated by the form exp [ - ({phi} - {phi}{sub 0}){sup 2}/2{sigma}{sup 2}], where {phi}more » is the longitudinal separation between the parent active region and the footpoint of the nominal interplanetary magnetic field (IMF) line connecting each spacecraft with the Sun, {phi}{sub 0} is the distribution centroid, and {sigma} determines the longitudinal gradient. The MESSENGER spacecraft, at helioradii R < 1 AU, allows us to determine a lower limit to the radial dependence of the 71-112 keV electron peak intensities measured along IMF lines. We find five events for which the nominal magnetic footpoint of MESSENGER was less than 20 Degree-Sign apart from the nominal footpoint of a spacecraft near 1 AU. Although the expected theoretical radial dependence for the peak intensity of the events observed along the same field line can be approximated by a functional form R {sup -{alpha}} with {alpha} < 3, we find two events for which {alpha} > 3. These two cases correspond to SEP events occurring in a complex interplanetary medium that favored the enhancement of peak intensities near Mercury but hindered the SEP transport to 1 AU.« less

[Comparison of SIB-IMRT treatment plans for upper esophageal carcinoma].

PubMed

Fu, Wei-hua; Wang, Lv-hua; Zhou, Zong-mei; Dai, Jian-rong; Hu, Yi-min

2003-06-01

To implement simultaneous integrated boost intensity-modulated radiotherapy(SIB-IMRT) plans for upper esophageal carcinoma and investigate the dose profiles of tumor and electively treated region and the dose to organs at risk (OARs). SIB-IMRT plans were designed for two patients with upper esophageal carcinoma. Two target volumes were predefined: PTV1, the target volume of the primary lesion, which was given to 67.2 Gy, and PTV2, the target volume of electively treated region, which was given to 50.4 Gy. With the same dose-volume constraints, but different beams arrangements (3, 5, 7, or 9 equispaced coplanar beams), four plans were generated. Indices, including dose distribution, dose volume histogram (DVH) and conformity index, were used for comparison of these plans. The plan with three intensity-modulated beams could produce good dose distribution for the two target volumes. The dose conformity to targets and the dose to OARs were improved as the beam number increased. The dose distributions in targets changed little when the beam number increased from 7 to 9. Five to seven intensity-modulated beams can produce desirable dose distributions for simultaneous integrated boost (SIB) treatment for upper esophageal carcinoma. The primary tumor can get higher equivalent dose by SIB treatments. It is easier and more efficient to design plans with equispaced coplanar beams. The efficacy of SIB-IMRT remains to be determined by the clinical outcome.

Simultaneous Time, Wavelength and Intensity Measurement of Optical Memory Subsystems

DTIC Science & Technology

1998-07-01

SIMULTANEOUS TIME, WAVELENGTH AND INTENSITY MEASUREMENT PE - 61102F OF OPTICAL MEMORY SUBSYSTEMS PR - 2300 6. AUTHOR( S ) TA - 06 WU -03 Joseph Osman and...Rebecca Bussjager 7. PERFORMING ORGANIZATION NAME( S ) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER AFRL/SNDP25 letnic AFRL-SN-RS-TR- 1998...12025 Electronic Pky Rome, NY 13441-4515 9. SPONSORING/MONITORING AGENCY NAME( S ) AND ADDRESS(ES) 10. SPONSORING/MONITORING AGENCY REPORT NUMBER

Development of Desolvation System for Single-cell Analysis Using Droplet Injection Inductively Coupled Plasma Atomic Emission Spectroscopy.

PubMed

Ishihara, Yukiko; Aida, Mari; Nomura, Akito; Miyahara, Hidekazu; Hokura, Akiko; Okino, Akitoshi

2015-01-01

With a view to enhance the sensitivity of analytical instruments used in the measurement of trace elements contained in a single cell, we have now equipped the previously reported micro-droplet injection system (M-DIS) with a desolvation system. This modified M-DIS was coupled to inductively coupled plasma atomic emission spectroscopy (ICP-AES) and evaluated for its ability to measure trace elements. A flow rate of 100 mL/min for the additional gas and a measurement point -7.5 mm above the load coil (ALC) have been determined to be the optimal parameters for recording the emission intensity of the Ca(II) spectral lines. To evaluate the influence of the desolvation system, we recorded the emission intensities of the Ca(I), Ca(II), and H-β spectral lines with and without inclusion of the desolvation system. The emission intensity of the H-β spectral line reduces and the magnitude of the Ca(II)/Ca(I) emission intensity ratio increases four-fold with inclusion of the desolvation system. Finally, the elements Ca, Mg, and Fe present in a single cell of Pseudococcomyxa simplex are simultaneously determined by coupling the M-DIS equipped with the desolvation system to ICP-AES.

Simultaneous brightness contrast of foraging Papilio butterflies

PubMed Central

Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

2012-01-01

This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

PET Imaging Stability Measurements During Simultaneous Pulsing of Aggressive MR Sequences on the SIGNA PET/MR System.

PubMed

Deller, Timothy W; Khalighi, Mohammad Mehdi; Jansen, Floris P; Glover, Gary H

2018-01-01

The recent introduction of simultaneous whole-body PET/MR scanners has enabled new research taking advantage of the complementary information obtainable with PET and MRI. One such application is kinetic modeling, which requires high levels of PET quantitative stability. To accomplish the required PET stability levels, the PET subsystem must be sufficiently isolated from the effects of MR activity. Performance measurements have previously been published, demonstrating sufficient PET stability in the presence of MR pulsing for typical clinical use; however, PET stability during radiofrequency (RF)-intensive and gradient-intensive sequences has not previously been evaluated for a clinical whole-body scanner. In this work, PET stability of the GE SIGNA PET/MR was examined during simultaneous scanning of aggressive MR pulse sequences. Methods: PET performance tests were acquired with MR idle and during simultaneous MR pulsing. Recent system improvements mitigating RF interference and gain variation were used. A fast recovery fast spin echo MR sequence was selected for high RF power, and an echo planar imaging sequence was selected for its high heat-inducing gradients. Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. A final PET quantitative stability assessment for simultaneous PET scanning during functional MRI studies was performed with a spiral in-and-out gradient echo sequence. Results: Quantitation stability of a 68 Ge flood phantom was demonstrated within 0.34%. Normalized sensitivity was stable during simultaneous scanning within 0.3%. Scatter fraction measured with a 68 Ge line source in the scatter phantom was stable within the range of 40.4%-40.6%. Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. Peak noise equivalent count rate was 224 kcps at an effective activity concentration of 18.6 kBq/mL, and the count rate curves and scatter fraction curve were consistent for the alternating MR pulsing states. A final test demonstrated quantitative stability during a spiral functional MRI sequence. Conclusion: PET stability metrics demonstrated that PET quantitation was not affected during simultaneous aggressive MRI. This stability enables demanding applications such as kinetic modeling. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

A fluorescent immunoassay for the determination of procalcitonin and C-reactive protein

NASA Astrophysics Data System (ADS)

Baldini, F.; Bolzoni, L.; Giannetti, A.; Porro, G.; Senesi, F.; Trono, C.

2009-05-01

The discrimination of viral and bacterial sepsis is an important issue in intensive care patients. For this purpose, the simultaneous measurements of different analytes such as C-reactive protein (CRP), procalcitonin (PCT), myeloperoxidase, interleukines and neopterin, are necessary. A novel optical platform was designed and realised for the implementation of fluorescence-based immunoassays. The core of the optical platform is a plastic biochip, formed by a series of microchannels each of them devoted to the determination of a single analyte. Sandwich assays for CRP and PCT spiked in serum were performed in order to demonstrate the reliability of a multi-array device.

Direct determination of arsenic in steel by glow discharge optical emission spectrometry with argon-helium mixed gas.

PubMed

Wagatsuma, Kazuaki

2003-02-01

In glow discharge optical emission spectrometry, an argon-helium mixed gas plasma was investigated to improve the detection sensitivity of arsenic in steel samples. The emission line of arsenic was enhanced and the background intensity was simultaneously reduced when an Ar-He plasma was employed instead of an Ar plasma, which is effective for the sensitive determination of arsenic. The detection limits were calculated to be 0.009 mass% for a 700-V Ar plasma, 0.004 mass% for a 700-V Ar-He plasma, and 0.001 mass% for a 900-V Ar-He plasma.

Partial F-tests with multiply imputed data in the linear regression framework via coefficient of determination.

PubMed

Chaurasia, Ashok; Harel, Ofer

2015-02-10

Tests for regression coefficients such as global, local, and partial F-tests are common in applied research. In the framework of multiple imputation, there are several papers addressing tests for regression coefficients. However, for simultaneous hypothesis testing, the existing methods are computationally intensive because they involve calculation with vectors and (inversion of) matrices. In this paper, we propose a simple method based on the scalar entity, coefficient of determination, to perform (global, local, and partial) F-tests with multiply imputed data. The proposed method is evaluated using simulated data and applied to suicide prevention data. Copyright © 2014 John Wiley & Sons, Ltd.

Robust generative asymmetric GMM for brain MR image segmentation.

PubMed

Ji, Zexuan; Xia, Yong; Zheng, Yuhui

2017-11-01

Accurate segmentation of brain tissues from magnetic resonance (MR) images based on the unsupervised statistical models such as Gaussian mixture model (GMM) has been widely studied during last decades. However, most GMM based segmentation methods suffer from limited accuracy due to the influences of noise and intensity inhomogeneity in brain MR images. To further improve the accuracy for brain MR image segmentation, this paper presents a Robust Generative Asymmetric GMM (RGAGMM) for simultaneous brain MR image segmentation and intensity inhomogeneity correction. First, we develop an asymmetric distribution to fit the data shapes, and thus construct a spatial constrained asymmetric model. Then, we incorporate two pseudo-likelihood quantities and bias field estimation into the model's log-likelihood, aiming to exploit the neighboring priors of within-cluster and between-cluster and to alleviate the impact of intensity inhomogeneity, respectively. Finally, an expectation maximization algorithm is derived to iteratively maximize the approximation of the data log-likelihood function to overcome the intensity inhomogeneity in the image and segment the brain MR images simultaneously. To demonstrate the performances of the proposed algorithm, we first applied the proposed algorithm to a synthetic brain MR image to show the intermediate illustrations and the estimated distribution of the proposed algorithm. The next group of experiments is carried out in clinical 3T-weighted brain MR images which contain quite serious intensity inhomogeneity and noise. Then we quantitatively compare our algorithm to state-of-the-art segmentation approaches by using Dice coefficient (DC) on benchmark images obtained from IBSR and BrainWeb with different level of noise and intensity inhomogeneity. The comparison results on various brain MR images demonstrate the superior performances of the proposed algorithm in dealing with the noise and intensity inhomogeneity. In this paper, the RGAGMM algorithm is proposed which can simply and efficiently incorporate spatial constraints into an EM framework to simultaneously segment brain MR images and estimate the intensity inhomogeneity. The proposed algorithm is flexible to fit the data shapes, and can simultaneously overcome the influence of noise and intensity inhomogeneity, and hence is capable of improving over 5% segmentation accuracy comparing with several state-of-the-art algorithms. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic measurements and simulations of airborne picolitre-droplet coalescence in holographic optical tweezers

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

Bzdek, Bryan R.; Reid, Jonathan P., E-mail: j.p.reid@bristol.ac.uk; Collard, Liam

We report studies of the coalescence of pairs of picolitre aerosol droplets manipulated with holographic optical tweezers, probing the shape relaxation dynamics following coalescence by simultaneously monitoring the intensity of elastic backscattered light (EBL) from the trapping laser beam (time resolution on the order of 100 ns) while recording high frame rate camera images (time resolution <10 μs). The goals of this work are to: resolve the dynamics of droplet coalescence in holographic optical traps; assign the origin of key features in the time-dependent EBL intensity; and validate the use of the EBL alone to precisely determine droplet surface tensionmore » and viscosity. For low viscosity droplets, two sequential processes are evident: binary coalescence first results from the overlap of the optical traps on the time scale of microseconds followed by the recapture of the composite droplet in an optical trap on the time scale of milliseconds. As droplet viscosity increases, the relaxation in droplet shape eventually occurs on the same time scale as recapture, resulting in a convoluted evolution of the EBL intensity that inhibits quantitative determination of the relaxation time scale. Droplet coalescence was simulated using a computational framework to validate both experimental approaches. The results indicate that time-dependent monitoring of droplet shape from the EBL intensity allows for robust determination of properties such as surface tension and viscosity. Finally, the potential of high frame rate imaging to examine the coalescence of dissimilar viscosity droplets is discussed.« less

Validation of a screening method for the simultaneous identification of fat-soluble and water-soluble vitamins (A, E, B1, B2 and B6) in an aqueous micellar medium of hexadecyltrimethylammonium chloride.

PubMed

León-Ruiz, V; Vera, S; San Andrés, M P

2005-04-01

Simultaneous determination of the fat-soluble vitamins A and E and the water-soluble vitamins B1, B2 and B6 has been carried using a screening method from fluorescence contour graphs. These graphs show different colour zones in relation to the fluorescence intensity measured for the pair of excitation/emission wavelengths. The identification of the corresponding excitation/emission wavelength zones allows the detection of different vitamins in an aqueous medium regardless of the fat or water solubility of each vitamin, owing to the presence of a surfactant which forms micelles in water at the used concentration (over the critical micelle concentration). The micelles dissolve very water insoluble compounds, such as fat-soluble vitamins, inside the aggregates. This approach avoids the use of organic solvents in determining these vitamins and offers the possibility of analysing fat- and water-soluble vitamins simultaneously. The method has been validated in terms of detection limit, cut-off limit, sensitivity, number of false positives, number of false negatives and uncertainty range. The detection limit is about microg L(-1). The screening method was applied to different samples such as pharmaceuticals, juices and isotonic drinks.

Engineering strategies for simultaneous enhancement of C-phycocyanin production and CO2 fixation with Spirulina platensis.

PubMed

Chen, Chun-Yen; Kao, Pei-Chun; Tsai, Chia-Jung; Lee, Duu-Jong; Chang, Jo-Shu

2013-10-01

Spirulina platensis produces nutraceutical product C-phycocyanin (C-PC) and simultaneously mitigates CO2 emissions during its growth. Using a designed flat-type photobioreactor, the S. platensis biomass production was markedly enhanced, leading to a CO2 removal rate and a biomass concentration of 0.23 g/L/d and 2.25 g/L, respectively. The cell growth, CO2 fixation rate and C-PC production of S. platensis were investigated when it was cultivated under different irradiation conditions. As the light intensity increased from 100 to 700 μmol/m(2)/s, the overall biomass productivity, CO2 consumption rate and maximal C-PC productivity increased significantly to 0.74, 1.53 and 0.11 g/L/d, respectively. After determining the suitable light intensity, the nitrogen concentration was also adjusted to further enhance the performance of CO2 fixation and C-PC production. The results show that with an optimal nitrogen concentration of 0.045 M, the CO2 consumption rate and maximal C-PC productivity were further increased to 1.58 and 0.13 g/L/d, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of modulated time-of-flight range image sensors

NASA Astrophysics Data System (ADS)

Payne, Andrew D.; Dorrington, Adrian A.; Cree, Michael J.; Carnegie, Dale A.

2009-01-01

A number of full field image sensors have been developed that are capable of simultaneously measuring intensity and distance (range) for every pixel in a given scene using an indirect time-of-flight measurement technique. A light source is intensity modulated at a frequency between 10-100 MHz, and an image sensor is modulated at the same frequency, synchronously sampling light reflected from objects in the scene (homodyne detection). The time of flight is manifested as a phase shift in the illumination modulation envelope, which can be determined from the sampled data simultaneously for each pixel in the scene. This paper presents a method of characterizing the high frequency modulation response of these image sensors, using a pico-second laser pulser. The characterization results allow the optimal operating parameters, such as the modulation frequency, to be identified in order to maximize the range measurement precision for a given sensor. A number of potential sources of error exist when using these sensors, including deficiencies in the modulation waveform shape, duty cycle, or phase, resulting in contamination of the resultant range data. From the characterization data these parameters can be identified and compensated for by modifying the sensor hardware or through post processing of the acquired range measurements.

Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

PubMed Central

2011-01-01

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm. Method (IIA) describes quantitative fluorescence quenching of eosin upon addition of the studied drug where the decrease in the fluorescence intensity was directly proportional to the concentration of ebastine; the fluorescence quenching was measured at 553 nm after excitation at 457 nm. This method was extended to (Method IIB) to apply first and second derivative synchronous spectrofluorimetric method (FDSFS & SDSFS) for the simultaneous analysis of EBS in presence of its alkaline, acidic, and UV degradation products. The proposed methods were successfully applied for the determination of the studied compound in its dosage forms. The results obtained were in good agreement with those obtained by a comparison method. Both methods were utilized to investigate the kinetics of the degradation of the drug. PMID:21385439

A reciprocal effects model of the temporal ordering of motivation and burnout among youth table tennis players in intensive training settings.

PubMed

Martinent, Guillaume; Decret, Jean-Claude; Guillet-Descas, Emma; Isoard-Gautheur, Sandrine

2014-01-01

Using self-determination theory (SDT) (Deci, E.L., & Ryan, R.M. (1985). Intrinsic motivation and self-determination in human behavior. New York, NY: Plenum) as the theoretical framework, we conducted a longitudinal investigation of the temporal ordering between motivation and burnout among youth athletes in intensive training setting. Data were collected from 145 table tennis players in intensive training centres at three time points during a 2-month period characterised by a simultaneous increase in social, physical and psychological demands for these athletes. Structural equation modelling of cross-lagged panel models was used to test the hypotheses. Results showed significant paths leading from athlete burnout - especially sport devaluation and reduced sense of accomplishment - at time 1 to amotivation, intrinsic and extrinsic motivations at times 2 and 3. Only two significant paths leading from motivation (introjected regulation at time 1) to burnout (emotional/physical exhaustion at time 2 and reduced sense of accomplishment at time 3) were identified. Overall, our results suggest that athlete burnout predicts motivation over time but motivation did not predict athlete burnout over time. Results are discussed in terms of current research findings on SDT.

Atlas-based segmentation of 3D cerebral structures with competitive level sets and fuzzy control.

PubMed

Ciofolo, Cybèle; Barillot, Christian

2009-06-01

We propose a novel approach for the simultaneous segmentation of multiple structures with competitive level sets driven by fuzzy control. To this end, several contours evolve simultaneously toward previously defined anatomical targets. A fuzzy decision system combines the a priori knowledge provided by an anatomical atlas with the intensity distribution of the image and the relative position of the contours. This combination automatically determines the directional term of the evolution equation of each level set. This leads to a local expansion or contraction of the contours, in order to match the boundaries of their respective targets. Two applications are presented: the segmentation of the brain hemispheres and the cerebellum, and the segmentation of deep internal structures. Experimental results on real magnetic resonance (MR) images are presented, quantitatively assessed and discussed.

Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP

PubMed Central

Guo, Wenyan; Liu, Xiuli; Liu, Yurong; Gang, Yadong; He, Xiaobin; Jia, Yao; Yin, Fangfang; Li, Pei; Huang, Fei; Zhou, Hongfu; Wang, Xiaojun; Gong, Hui; Luo, Qingming; Xu, Fuqiang; Zeng, Shaoqun

2017-01-01

The pH-sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EGFP or EYFP is good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is an urgent need. Here a pH-sensitive red fluorescent protein, pHuji, is selected and verified to remain pH-sensitive in HM20 resin. We observe 183% fluorescence intensity of pHuji in resin-embeded mouse brain and 29.08-fold fluorescence intensity of reactivated pHuji compared to the quenched state. pHuji and EGFP can be quenched and chemically reactivated simultaneously in resin, thus enabling simultaneous two-color micro-optical sectioning tomography of resin-embedded mouse brain. This method may greatly facilitate the visualization of neuronal morphology and neural circuits to promote understanding of the structure and function of the brain. PMID:28717566

Chemical reactivation of resin-embedded pHuji adds red for simultaneous two-color imaging with EGFP.

PubMed

Guo, Wenyan; Liu, Xiuli; Liu, Yurong; Gang, Yadong; He, Xiaobin; Jia, Yao; Yin, Fangfang; Li, Pei; Huang, Fei; Zhou, Hongfu; Wang, Xiaojun; Gong, Hui; Luo, Qingming; Xu, Fuqiang; Zeng, Shaoqun

2017-07-01

The pH-sensitive fluorescent proteins enabling chemical reactivation in resin are useful tools for fluorescence microimaging. EGFP or EYFP is good for such applications. For simultaneous two-color imaging, a suitable red fluorescent protein is an urgent need. Here a pH-sensitive red fluorescent protein, pHuji, is selected and verified to remain pH-sensitive in HM20 resin. We observe 183% fluorescence intensity of pHuji in resin-embeded mouse brain and 29.08-fold fluorescence intensity of reactivated pHuji compared to the quenched state. pHuji and EGFP can be quenched and chemically reactivated simultaneously in resin, thus enabling simultaneous two-color micro-optical sectioning tomography of resin-embedded mouse brain. This method may greatly facilitate the visualization of neuronal morphology and neural circuits to promote understanding of the structure and function of the brain.

Separate and Simultaneous Adjustment of Light Qualities in a Real Scene

PubMed Central

Pont, Sylvia C.; Heynderick, Ingrid

2017-01-01

Humans are able to estimate light field properties in a scene in that they have expectations of the objects’ appearance inside it. Previously, we probed such expectations in a real scene by asking whether a “probe object” fitted a real scene with regard to its lighting. But how well are observers able to interactively adjust the light properties on a “probe object” to its surrounding real scene? Image ambiguities can result in perceptual interactions between light properties. Such interactions formed a major problem for the “readability” of the illumination direction and diffuseness on a matte smooth spherical probe. We found that light direction and diffuseness judgments using a rough sphere as probe were slightly more accurate than when using a smooth sphere, due to the three-dimensional (3D) texture. We here extended the previous work by testing independent and simultaneous (i.e., the light field properties separated one by one or blended together) adjustments of light intensity, direction, and diffuseness using a rough probe. Independently inferred light intensities were close to the veridical values, and the simultaneously inferred light intensity interacted somewhat with the light direction and diffuseness. The independently inferred light directions showed no statistical difference with the simultaneously inferred directions. The light diffuseness inferences correlated with but contracted around medium veridical values. In summary, observers were able to adjust the basic light properties through both independent and simultaneous adjustments. The light intensity, direction, and diffuseness are well “readable” from our rough probe. Our method allows “tuning the light” (adjustment of its spatial distribution) in interfaces for lighting design or perception research. PMID:28203350

Towards continuous monitoring of pulse rate in neonatal intensive care unit with a webcam.

PubMed

Mestha, Lalit K; Kyal, Survi; Xu, Beilei; Lewis, Leslie Edward; Kumar, Vijay

2014-01-01

We describe a novel method to monitor pulse rate (PR) on a continuous basis of patients in a neonatal intensive care unit (NICU) using videos taken from a high definition (HD) webcam. We describe algorithms that determine PR from videoplethysmographic (VPG) signals extracted from multiple regions of interest (ROI) simultaneously available within the field of view of the camera where cardiac signal is registered. We detect motion from video images and compensate for motion artifacts from each ROI. Preliminary clinical results are presented on 8 neonates each with 30 minutes of uninterrupted video. Comparisons to hospital equipment indicate that the proposed technology can meet medical industry standards and give improved patient comfort and ease of use for practitioners when instrumented with proper hardware.

Simultaneous determination of built-in voltage and charge carrier mobility in organic diodes from light intensity dependent current-voltage characteristics

NASA Astrophysics Data System (ADS)

Huang, Fobao; Peng, Yingquan; Xu, Kun; Lv, Wenli; Xu, Sunan; Wang, Ying; Tang, Ying; Wei, Yi; Yang, Yuhuan; Liu, Guohan

2017-05-01

Built-in voltage (V bi) and charge carrier mobility are essential parameters of organic diodes, such as organic photodiodes, organic light-emitting diodes and organic solar cells. The existing methods for charge carrier mobility measurement require either expensive equipment, or stringent sample preparation. We demonstrate a method that simultaneously determines the V bi and charge carrier mobility in organic photodiodes and solar cells from incident light intensity dependent current-voltage characteristics. The V bi is determined from the saturation open-circuit voltage, while the charge carrier mobility from the space-charge limited photocurrent. The V bi for organic diodes, ‘ITO/copper phthalocyanine (CuPc)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)/Al’, ‘ITO/ lead phthalocyanine (PbPc)/BCP/Al’, ‘ITO/CuPc/C60/BCP/Al’, and ‘ITO/PbPc/C60/BCP/Al’, were measured to be 0.583  ±  0.019, 0.458  ±  0.002, 0.605  ±  0.009 and 0.538  ±  0.004 V, respectively; the hole mobility of CuPc and PbPc thin films were measured to be (1.383  ±  0.367)  ×  10-6 cm2 V-1 s-1 and (3.675  ±  0.887)  ×  10-6 cm2 V-1 s-1, respectively. The measured values for V bi and carrier mobility coincide with related experimental results reported in other literature.

Stimulated Raman diagnostics in diesel droplets

NASA Astrophysics Data System (ADS)

Golombok, Michael

1991-09-01

Stimulated Raman spectroscopy (SRS) can simultaneously measure droplet sizes and the associated component concentrations in a fuel injection. As spray evaporation is crucial in determining the performance parameters of a diesel engine, such as cold start and particulate emission formation, the new application of the method for spatially and temporally resolved measurements is a useful new diagnostic, extending our understanding of spray processes. Droplet sizes can be obtained from single shot SRS spectra by measuring the separation between morphology-dependent resonances (MDR) that correspond to standing wave modes confined near the droplet circumference. Power spectrum analysis allows the measurement of more than one droplet from a spectrum using a pumped laser sheet in the fuel spray. The MDRs are responsible for the simultaneous stimulation of multiple Raman spectral lines over and above those seen in bulk liquids. The SRS method for concentration measurement is effectively self-calibrating in that the relative intensity of two adjacent lines is used to measure concentration. Any particular fuel has a unique ratio of SRS antisymmetric to symmetric C-H stretch intensity. If individual components in a fuel blend are characterized beforehand, one can monitor the evolution of the spray during injection by measuring signal intensity ratios which yield the volume fraction of the component of interest. The SRS technique is being used to examine a number of spray dynamics phenomena such as fuel atomization, droplet evolution and front-end volatility effects, which are of current interest in diesel development studies.

Scale-Free Brain-Wave Music from Simultaneously EEG and fMRI Recordings

PubMed Central

Lu, Jing; Wu, Dan; Yang, Hua; Luo, Cheng; Li, Chaoyi; Yao, Dezhong

2012-01-01

In the past years, a few methods have been developed to translate human EEG to music. In 2009, PloS One 4 e5915, we developed a method to generate scale-free brainwave music where the amplitude of EEG was translated to music pitch according to the power law followed by both of them, the period of an EEG waveform is translated directly to the duration of a note, and the logarithm of the average power change of EEG is translated to music intensity according to the Fechner's law. In this work, we proposed to adopt simultaneously-recorded fMRI signal to control the intensity of the EEG music, thus an EEG-fMRI music is generated by combining two different and simultaneous brain signals. And most importantly, this approach further realized power law for music intensity as fMRI signal follows it. Thus the EEG-fMRI music makes a step ahead in reflecting the physiological process of the scale-free brain. PMID:23166768

Development of a Cancer Treatment with the Concomitant Use of Low-Intensity Ultrasound: Entering the Age of Simultaneous Diagnosis and Treatment

PubMed Central

Emoto, Makoto

2014-01-01

In recent years, studies using ultrasound energy for cancer treatment have advanced, thus revealing the enhancement of drug effects by employing low-intensity ultrasound. Furthermore, anti-angiogenesis against tumors is now attracting attention as a new cancer treatment. Therefore, we focused on the biological effects and the enhancement of drug effects brought by this low-intensity ultrasound energy and reported on the efficacy against a uterine sarcoma model, by implementing the basic studies, for the first time, including the concomitant use of low-intensity ultrasound irradiation, as an expected new antiangiogenic therapy for cancer treatment. Furthermore, we have succeeded in simultaneously utilizing low-intensity ultrasound in both diagnosis and treatment, upon real time evaluation of the anti-tumor effects and anti-angiogenesis effects using color Doppler ultrasound imaging. Although the biological effects of ultrasound have not yet been completely clarified, transient stomas were formed (Sonoporation) in cancer cells irradiated by low-intensity ultrasound and it is believed that the penetration effect of drugs is enhanced due to the drug being more charged inside the cell through these stomas. Furthermore, it has become clear that the concomitant therapy of anti-angiogenesis drugs and low-intensity ultrasound blocks the angiogenic factor VEGF produced by cancer cells, inhibits the induction of circulating endothelial progenitor cells in the bone marrow, and expedites angiogenic inhibitor TSP-1. Based on research achievements in recent years, we predict that the current diagnostic device for color Doppler ultrasound imaging will be improved in the near future, bringing with it the arrival of an age of “low-intensity ultrasound treatment that simultaneously enables diagnosis and treatment of cancer in real time.” PMID:26852677

A Variational Approach to Simultaneous Image Segmentation and Bias Correction.

PubMed

Zhang, Kaihua; Liu, Qingshan; Song, Huihui; Li, Xuelong

2015-08-01

This paper presents a novel variational approach for simultaneous estimation of bias field and segmentation of images with intensity inhomogeneity. We model intensity of inhomogeneous objects to be Gaussian distributed with different means and variances, and then introduce a sliding window to map the original image intensity onto another domain, where the intensity distribution of each object is still Gaussian but can be better separated. The means of the Gaussian distributions in the transformed domain can be adaptively estimated by multiplying the bias field with a piecewise constant signal within the sliding window. A maximum likelihood energy functional is then defined on each local region, which combines the bias field, the membership function of the object region, and the constant approximating the true signal from its corresponding object. The energy functional is then extended to the whole image domain by the Bayesian learning approach. An efficient iterative algorithm is proposed for energy minimization, via which the image segmentation and bias field correction are simultaneously achieved. Furthermore, the smoothness of the obtained optimal bias field is ensured by the normalized convolutions without extra cost. Experiments on real images demonstrated the superiority of the proposed algorithm to other state-of-the-art representative methods.

Contrast-enhanced optical coherence microangiography with acoustic-actuated microbubbles

NASA Astrophysics Data System (ADS)

Liu, Yu-Hsuan; Zhang, Jia-Wei; Yeh, Chih-Kuang; Wei, Kuo-Chen; Liu, Hao-Li; Tsai, Meng-Tsan

2017-04-01

In this study, we propose to use gas-filled microbubbles (MBs) simultaneously actuated by the acoustic wave to enhance the imaging contrast of optical coherence tomography (OCT)-based angiography. In the phantom experiments, MBs can result in stronger backscattered intensity, enabling to enhance the contrast of OCT intensity image. Moreover, simultaneous application of low-intensity acoustic wave enables to temporally induce local vibration of particles and MBs in the vessels, resulting in time-variant OCT intensity which can be used for enhancing the contrast of OCT intensitybased angiography. Additionally, different acoustic modes and different acoustic powers to actuate MBs are performed and compared to investigate the feasibility of contrast enhancement. Finally, animal experiments are performed. The findings suggest that acoustic-actuated MBs can effectively enhance the imaging contrast of OCT-based angiography and the imaging depth of OCT angiography is also extended.

Intensity correlation-based calibration of FRET.

PubMed

Bene, László; Ungvári, Tamás; Fedor, Roland; Sasi Szabó, László; Damjanovich, László

2013-11-05

Dual-laser flow cytometric resonance energy transfer (FCET) is a statistically efficient and accurate way of determining proximity relationships for molecules of cells even under living conditions. In the framework of this algorithm, absolute fluorescence resonance energy transfer (FRET) efficiency is determined by the simultaneous measurement of donor-quenching and sensitized emission. A crucial point is the determination of the scaling factor α responsible for balancing the different sensitivities of the donor and acceptor signal channels. The determination of α is not simple, requiring preparation of special samples that are generally different from a double-labeled FRET sample, or by the use of sophisticated statistical estimation (least-squares) procedures. We present an alternative, free-from-spectral-constants approach for the determination of α and the absolute FRET efficiency, by an extension of the presented framework of the FCET algorithm with an analysis of the second moments (variances and covariances) of the detected intensity distributions. A quadratic equation for α is formulated with the intensity fluctuations, which is proved sufficiently robust to give accurate α-values on a cell-by-cell basis in a wide system of conditions using the same double-labeled sample from which the FRET efficiency itself is determined. This seemingly new approach is illustrated by FRET measurements between epitopes of the MHCI receptor on the cell surface of two cell lines, FT and LS174T. The figures show that whereas the common way of α determination fails at large dye-per-protein labeling ratios of mAbs, this presented-as-new approach has sufficient ability to give accurate results. Although introduced in a flow cytometer, the new approach can also be straightforwardly used with fluorescence microscopes. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Simultaneous quantification of tumor uptake for targeted and non-targeted liposomes and their encapsulated contents by ICP-MS

PubMed Central

Cheng, Zhiliang; Zaki, Ajlan Al; Hui, James Z; Tsourkas, Andrew

2012-01-01

Liposomes are intensively being developed for biomedical applications including drug and gene delivery. However, targeted liposomal delivery in cancer treatment is a very complicated multi-step process. Unfavorable liposome biodistribution upon intravenous administration and membrane destabilization in blood circulation could result in only a very small fraction of cargo reaching the tumors. It would therefore be desirable to develop new quantitative strategies to track liposomal delivery systems to improve the therapeutic index and decrease systemic toxicity. Here, we developed a simple and non-radiative method to quantify the tumor uptake of targeted and non-targeted control liposomes as well as their encapsulated contents simultaneously. Specifically, four different chelated lanthanide metals were encapsulated or surface-conjugated onto tumor-targeted and non-targeted liposomes, respectively. The two liposome formulations were then injected into tumor-bearing mice simultaneously and their tumor delivery was determined quantitatively via inductively coupled plasma-mass spectroscopy (ICP-MS), allowing for direct comparisons. Tumor uptake of the liposomes themselves and their encapsulated contents were consistent with targeted and non-targeted liposome formulations that were injected individually. PMID:22882145

A stimuli-responsive fluorescence platform for simultaneous determination of D-isoascorbic acid and Tartaric acid based on Maillard reaction product

NASA Astrophysics Data System (ADS)

Zhao, Yanmei; Yuan, Haiyan; Zhang, Xinling; Yang, Jidong

2018-05-01

An activatable fluorescence monitoring platform based on a novel Maillard reaction product from D-glucose and L-arginine was prepared through a facile one-pot approach and applied for simultaneous detection of D-isoascorbic acid and tartaric acid. In this work, the new Maillard reaction product GLA was first obtained, and its fluorescence intensity can be effectively quenched by KMnO4, resulting from a new complex (GLA-KMnO4) formation between GLA and KMnO4. Upon addition of D-isoascorbic acid or tartaric acid, an enhanced fluorescence was observed under the optimumed experimental conditions, indicating a stimuli-responsive fluorescence turn on platform for D-isoascorbic acid or tartaric acid can be developed. The corresponding experimental results showed that this turn on fluorescence sensing platform has a high sensitivity for D-isoascorbic acid or tartaric acid, because the detection limits were 5.9 μM and 21.5 μM, respectively. Additionally, this proposed sensing platform was applied to simultaneously detection of D-isoascorbic acid and tartaric acid in real tap water samples with satisfactory results.

Effects of front-surface target structures on properties of relativistic laser-plasma electrons.

PubMed

Jiang, S; Krygier, A G; Schumacher, D W; Akli, K U; Freeman, R R

2014-01-01

We report the results of a study of the role of prescribed geometrical structures on the front of a target in determining the energy and spatial distribution of relativistic laser-plasma electrons. Our three-dimensional particle-in-cell simulation studies apply to short-pulse, high-intensity laser pulses, and indicate that a judicious choice of target front-surface geometry provides the realistic possibility of greatly enhancing the yield of high-energy electrons while simultaneously confining the emission to narrow (<5°) angular cones.

Laser-induced breakdown spectroscopy for quantitative spectrochemical analysis of geological materials: effects of the matrix and simultaneous determination.

PubMed

Anzano, Jesús M; Villoria, Mark A; Ruíz-Medina, Antonio; Lasheras, Roberto J

2006-08-11

A microscopic laser-induced breakdown spectrometer was used to evaluate the analytical matrix effect commonly observed in the analysis of geological materials. Samples were analyzed in either the powder or pressed pellet forms. Calibration curves of a number of iron and aluminum compounds showed a linear relationship between the elemental concentration and peak intensity. A direct determination of elemental content can thus be made from extrapolation on these calibration curves. To investigate matrix effects, synthetic model samples were prepared from various iron and aluminum compounds spiked with SiO2 and CaCO3. The addition of these matrices had a pronounced analytical effect on those compounds prepared as pressed pellets. However, results indicated the absence of matrix effects when the samples were presented to the laser as loose powders on tape and results were compared to certified values, indicating the reliability of this approach for accurate analysis, provided the sample particle diameters are greater than approximately 100 microm. Finally, the simultaneous analysis of two different elements was demonstrated using powders on tape.

Regulation of glottal closure and airflow in a three-dimensional phonation model: Implications for vocal intensity control

PubMed Central

Zhang, Zhaoyan

2015-01-01

Maintaining a small glottal opening across a large range of voice conditions is critical to normal voice production. This study investigated the effectiveness of vocal fold approximation and stiffening in regulating glottal opening and airflow during phonation, using a three-dimensional numerical model of phonation. The results showed that with increasing subglottal pressure the vocal folds were gradually pushed open, leading to increased mean glottal opening and flow rate. A small glottal opening and a mean glottal flow rate typical of human phonation can be maintained against increasing subglottal pressure by proportionally increasing the degree of vocal fold approximation for low to medium subglottal pressures and vocal fold stiffening at high subglottal pressures. Although sound intensity was primarily determined by the subglottal pressure, the results suggest that, to maintain small glottal opening as the sound intensity increases, one has to simultaneously tighten vocal fold approximation and/or stiffen the vocal folds, resulting in increased glottal resistance, vocal efficiency, and fundamental frequency. PMID:25698022

Numerical evaluation of the intensity transport equation for well-known wavefronts and intensity distributions

NASA Astrophysics Data System (ADS)

Campos-García, Manuel; Granados-Agustín, Fermín.; Cornejo-Rodríguez, Alejandro; Estrada-Molina, Amilcar; Avendaño-Alejo, Maximino; Moreno-Oliva, Víctor Iván.

2013-11-01

In order to obtain a clearer interpretation of the Intensity Transport Equation (ITE), in this work, we propose an algorithm to solve it for some particular wavefronts and its corresponding intensity distributions. By simulating intensity distributions in some planes, the ITE is turns into a Poisson equation with Neumann boundary conditions. The Poisson equation is solved by means of the iterative algorithm SOR (Simultaneous Over-Relaxation).

CT to Cone-beam CT Deformable Registration With Simultaneous Intensity Correction

PubMed Central

Zhen, Xin; Gu, Xuejun; Yan, Hao; Zhou, Linghong; Jia, Xun; Jiang, Steve B.

2012-01-01

Computed tomography (CT) to cone-beam computed tomography (CBCT) deformable image registration (DIR) is a crucial step in adaptive radiation therapy. Current intensity-based registration algorithms, such as demons, may fail in the context of CT-CBCT DIR because of inconsistent intensities between the two modalities. In this paper, we propose a variant of demons, called Deformation with Intensity Simultaneously Corrected (DISC), to deal with CT-CBCT DIR. DISC distinguishes itself from the original demons algorithm by performing an adaptive intensity correction step on the CBCT image at every iteration step of the demons registration. Specifically, the intensity correction of a voxel in CBCT is achieved by matching the first and the second moments of the voxel intensities inside a patch around the voxel with those on the CT image. It is expected that such a strategy can remove artifacts in the CBCT image, as well as ensuring the intensity consistency between the two modalities. DISC is implemented on computer graphics processing units (GPUs) in compute unified device architecture (CUDA) programming environment. The performance of DISC is evaluated on a simulated patient case and six clinical head-and-neck cancer patient data. It is found that DISC is robust against the CBCT artifacts and intensity inconsistency and significantly improves the registration accuracy when compared with the original demons. PMID:23032638

Investigation of burn effect on skin using simultaneous Raman-Brillouin spectroscopy, and fluorescence microspectroscopy

NASA Astrophysics Data System (ADS)

Coker, Zachary; Meng, Zhaokai; Troyanova-Wood, Maria; Traverso, Andrew; Ballmann, Charles; Petrov, Georgi; Ibey, Bennett L.; Yakovlev, Vladislav

2017-02-01

Burns are thermal injuries that can completely damage or at least compromise the protective function of skin, and affect the ability of tissues to manage moisture. Burn-damaged tissues exhibit lower elasticity than healthy tissues, due to significantly reduced water concentrations and plasma retention. Current methods for determining burn intensity are limited to visual inspection, and potential hospital x-ray examination. We present a unique confocal microscope capable of measuring Raman and Brillouin spectra simultaneously, with concurrent fluorescence investigation from a single spatial location, and demonstrate application by investigating and characterizing the properties of burn-afflicted tissue on chicken skin model. Raman and Brillouin scattering offer complementary information about a material's chemical and mechanical structure, while fluorescence can serve as a useful diagnostic indicator and imaging tool. The developed instrument has the potential for very diverse analytical applications in basic biomedical science and biomedical diagnostics and imaging.

Laser Doppler velocimeter measurements of boundary layer velocity and turbulent intensities in Mach 2.5 flow

NASA Technical Reports Server (NTRS)

Sewell, Jesse; Chew, Larry

1994-01-01

In recent years, the interest in developing a high-speed civil transport has increased. This has led to an increase in research activity on compressible supersonic flows, in particular the boundary layer. The structure of subsonic boundary layers has been extensively documented using conditional sampling techniques which exploit the knowledge of both u and v velocities. Researchers using these techniques have been able to explore some of the complex three-dimensional motions which are responsible for Reynolds stress production and transport in the boundary layer. As interest in turbulent structure has grown to include supersonic flows, a need for simultaneous multicomponent velocity measurements in these flows has developed. The success of conditional analysis in determining the characteristics of coherent motions and structures in the boundary layer relies on accurate, simultaneous measurement of two instantaneous velocity components.

VLF wave injections from the ground

NASA Technical Reports Server (NTRS)

Helliwell, R. A.

1983-01-01

Experiments on wave-particle interactions using VLF whistler-mode waves injected into the magnetosphere from Antartica are described. The injected signals are single-frequency coherent waves whose amplitudes and frequencies may be changed slowly with time, or else two or more coherent wave trains transmitted simultaneously to determine the nature of the response to multifrequency excitation. The waves may be amplified 30 dB or more and may trigger intense emissions having bandwidths that vary from a few to several hundred Hertz. In most cases significant growth and triggering occur only when the driving signal is essentially monochromatic (bandwidth 10 Hz). If two frequencies are transmitted simultaneously the signal at the lower frequency tends to be suppressed by 20 dB or more. These results are interpreted in terms of a feedback interaction between the waves and counter-streaming cyclotron resonant electrons in a region several hundred wavelengths long, centered on the magnetic equator.

[Sound improves distinction of low intensities of light in the visual cortex of a rabbit].

PubMed

Polianskiĭ, V B; Alymkulov, D E; Evtikhin, D V; Chernyshev, B V

2011-01-01

Electrodes were implanted into cranium above the primary visual cortex of four rabbits (Orictolagus cuniculus). At the first stage, visual evoked potentials (VEPs) were recorded in response to substitution of threshold visual stimuli (0.28 and 0.31 cd/m2). Then the sound (2000 Hz, 84 dB, duration 40 ms) was added simultaneously to every visual stimulus. Single sounds (without visual stimuli) did not produce a VEP-response. It was found that the amplitude ofVEP component N1 (85-110 ms) in response to complex stimuli (visual and sound) increased 1.6 times as compared to "simple" visual stimulation. At the second stage, paired substitutions of 8 different visual stimuli (range 0.38-20.2 cd/m2) by each other were performed. Sensory spaces of intensity were reconstructed on the basis of factor analysis. Sensory spaces of complexes were reconstructed in a similar way for simultaneous visual and sound stimulation. Comparison of vectors representing the stimuli in the spaces showed that the addition of a sound led to a 1.4-fold expansion of the space occupied by smaller intensities (0.28; 1.02; 3.05; 6.35 cd/m2). Also, the addition of the sound led to an arrangement of intensities in an ascending order. At the same time, the sound 1.33-times narrowed the space of larger intensities (8.48; 13.7; 16.8; 20.2 cd/m2). It is suggested that the addition of a sound improves a distinction of smaller intensities and impairs a dis- tinction of larger intensities. Sensory spaces revealed by complex stimuli were two-dimensional. This fact can be a consequence of integration of sound and light in a unified complex at simultaneous stimulation.

The L0 Regularized Mumford-Shah Model for Bias Correction and Segmentation of Medical Images.

PubMed

Duan, Yuping; Chang, Huibin; Huang, Weimin; Zhou, Jiayin; Lu, Zhongkang; Wu, Chunlin

2015-11-01

We propose a new variant of the Mumford-Shah model for simultaneous bias correction and segmentation of images with intensity inhomogeneity. First, based on the model of images with intensity inhomogeneity, we introduce an L0 gradient regularizer to model the true intensity and a smooth regularizer to model the bias field. In addition, we derive a new data fidelity using the local intensity properties to allow the bias field to be influenced by its neighborhood. Second, we use a two-stage segmentation method, where the fast alternating direction method is implemented in the first stage for the recovery of true intensity and bias field and a simple thresholding is used in the second stage for segmentation. Different from most of the existing methods for simultaneous bias correction and segmentation, we estimate the bias field and true intensity without fixing either the number of the regions or their values in advance. Our method has been validated on medical images of various modalities with intensity inhomogeneity. Compared with the state-of-art approaches and the well-known brain software tools, our model is fast, accurate, and robust with initializations.

In-Situ Real-Time Focus Detection during Laser Processing Using Double-Hole Masks and Advanced Image Sensor Software

PubMed Central

Hoang, Phuong Le; Ahn, Sanghoon; Kim, Jeng-o; Kang, Heeshin; Noh, Jiwhan

2017-01-01

In modern high-intensity ultrafast laser processing, detecting the focal position of the working laser beam, at which the intensity is the highest and the beam diameter is the lowest, and immediately locating the target sample at that point are challenging tasks. A system that allows in-situ real-time focus determination and fabrication using a high-power laser has been in high demand among both engineers and scientists. Conventional techniques require the complicated mathematical theory of wave optics, employing interference as well as diffraction phenomena to detect the focal position; however, these methods are ineffective and expensive for industrial application. Moreover, these techniques could not perform detection and fabrication simultaneously. In this paper, we propose an optical design capable of detecting the focal point and fabricating complex patterns on a planar sample surface simultaneously. In-situ real-time focus detection is performed using a bandpass filter, which only allows for the detection of laser transmission. The technique enables rapid, non-destructive, and precise detection of the focal point. Furthermore, it is sufficiently simple for application in both science and industry for mass production, and it is expected to contribute to the next generation of laser equipment, which can be used to fabricate micro-patterns with high complexity. PMID:28671566

Shapes displayed with durations in the microsecond range do not obey Bloch's law of temporal summation

PubMed Central

Greene, Ernest; Ogden, R. Todd

2013-01-01

Shape patterns were displayed with simultaneous brief flashes from a light-emitting diode array. Flash durations in the microsecond range and luminous intensities were adjusted to vary the degree of successful shape recognition. Four experiments were conducted to test whether Bloch's law would apply in this task. Bloch's law holds that for very brief flashes the perceptual threshold is determined by the total number of photons being delivered, i.e., there is reciprocity of intensity and duration. The present results did not find that effectiveness of flashes was based on the total quantity of photons, as predicted by Bloch's law. Additionally, the evidence points to a visual mechanism that has ultra-high temporal precision that either registers the rate of photon flux or the duration of flashes. PMID:24349700

The 6300 A O/1-D/ airglow and dissociative recombination

NASA Technical Reports Server (NTRS)

Wickwar, V. B.; Cogger, L. L.; Carlson, H. C.

1974-01-01

Measurements of night-time 6300 A airglow intensities at the Arecibo Observatory have been compared with dissociative recombination calculations based on electron densities derived from simultaneous incoherent backscatter measurements. The agreement indicates that the nightglow can be fully accounted for by dissociative recombination. The comparisons are examined to determine the importance of quenching, heavy ions, ionization above the F-layer peak, and the temperature parameter of the model atmosphere. Comparable fits between the observed and calculated intensities are found for several available model atmospheres. The least-squares fitting process, used to make the comparisons, produces comparable fits over a wide range of combinations of neutral densities and of reaction constants. Yet, the fitting places constraints upon the possible combinations; these constraints indicate that the latest laboratory chemical constants and densities extrapolated to a base altitude are mutually consistent.

Simultaneous mesosphere-thermosphere-ionosphere parameter measurements over Gadanki (13.5°N, 79.2°E): First results

NASA Astrophysics Data System (ADS)

Taori, A.; Dashora, N.; Raghunath, K.; Russell, J. M., III; Mlynczak, Martin G.

2011-07-01

We report first simultaneous airglow, lidar, and total electron content measurements in the mesosphere-thermosphere-ionosphere system behavior from Gadanki (13.5°N, 79.2°E). The observed variability in mesospheric temperatures and 630 nm thermospheric emission intensity shows large variations from one night to another with clear upward propagating waves at mesospheric altitudes. The deduced mesospheric temperatures compare well with Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER)-derived temperatures, while the variability agrees well with lidar temperatures (on the night of simultaneous observations). The 630.0 nm thermospheric emission intensity and GPS-total electron content data exhibit occurrence of plasma depletions on the nights of 22-23 October and 22-23 May 2009, while no depletions are noted on the nearby nights of 23-24 October and 21-22 May 2009. These first simultaneous data reveal strong gravity-wave growth at upper mesospheric altitudes on the nights when plasma depletions were noted.

Determining the Concentrations and Temperatures of Products in a CF_4/CHF_3/N_2 Plasma via Submillimeter Absorption Spectroscopy

NASA Astrophysics Data System (ADS)

Helal, Yaser H.; Neese, Christopher F.; De Lucia, Frank C.; Ewing, Paul R.; Agarwal, Ankur; Craver, Barry; Stout, Phillip J.; Armacost, Michael D.

2017-06-01

Plasmas used for the manufacturing of semiconductor devices are similar in pressure and temperature to those used in the laboratory for the study of astrophysical species in the submillimeter (SMM) spectral region. The methods and technology developed in the SMM for these laboratory studies are directly applicable for diagnostic measurements in the semiconductor manufacturing industry. Many of the molecular neutrals, radicals, and ions present in processing plasmas have been studied and their spectra have been cataloged or are in the literature. In this work, a continuous wave, intensity calibrated SMM absorption spectrometer was developed as a remote sensor of gas and plasma species. A major advantage of intensity calibrated rotational absorption spectroscopy is its ability to determine absolute concentrations and temperatures of plasma species from first principles without altering the plasma environment. An important part of this work was the design of the optical components which couple 500-750 GHz radiation through a commercial inductively coupled plasma chamber. The measurement of transmission spectra was simultaneously fit for background and absorption signal. The measured absorption was used to calculate absolute densities and temperatures of polar species. Measurements for CHF_3, CF_2, FCN, HCN, and CN made in a CF_4/CHF_3/N_2 plasma will be presented. Temperature equilibrium among species will be shown and the common temperature is leveraged to obtain accurate density measurements for simultaneously observed species. The densities and temperatures of plasma species are studied as a function of plasma parameters, including flow rate, pressure, and discharge power.

The question of simultaneity in multisensory integration

NASA Astrophysics Data System (ADS)

Leone, Lynnette; McCourt, Mark E.

2012-03-01

Early reports of audiovisual (AV) multisensory integration (MI) indicated that unisensory stimuli must evoke simultaneous physiological responses to produce decreases in reaction time (RT) such that for unisensory stimuli with unequal RTs the stimulus eliciting the faster RT had to be delayed relative to the stimulus eliciting the slower RT. The "temporal rule" states that MI depends on the temporal proximity of unisensory stimuli, the neural responses to which must fall within a window of integration. Ecological validity demands that MI should occur only for simultaneous events (which may give rise to non-simultaneous neural activations). However, spurious neural response simultaneities which are unrelated to singular environmental multisensory occurrences must somehow be rejected. Using an RT/race model paradigm we measured AV MI as a function of stimulus onset asynchrony (SOA: +/-200 ms, 50 ms intervals) under fully dark adapted conditions for visual (V) stimuli that were either weak (scotopic 525 nm flashes; 511 ms mean RT) or strong (photopic 630 nm flashes; 356 ms mean RT). Auditory (A) stimulus (1000 Hz pure tone) intensity was constant. Despite the 155 ms slower mean RT to the scotopic versus photopic stimulus, facilitative AV MI in both conditions nevertheless occurred exclusively at an SOA of 0 ms. Thus, facilitative MI demands both physical and physiological simultaneity. We consider the mechanisms by which the nervous system may take account of variations in response latency arising from changes in stimulus intensity in order to selectively integrate only those physiological simultaneities that arise from physical simultaneities.

Meteor44 Video Meteor Photometry

NASA Technical Reports Server (NTRS)

Swift, Wesley R.; Suggs, Robert M.; Cooke, William J.

2004-01-01

Meteor44 is a software system developed at MSFC for the calibration and analysis of video meteor data. The dynamic range of the (8bit) video data is extended by approximately 4 magnitudes for both meteors and stellar images using saturation compensation. Camera and lens specific saturation compensation coefficients are derived from artificial variable star laboratory measurements. Saturation compensation significantly increases the number of meteors with measured intensity and improves the estimation of meteoroid mass distribution. Astrometry is automated to determine each image s plate coefficient using appropriate star catalogs. The images are simultaneously intensity calibrated from the contained stars to determine the photon sensitivity and the saturation level referenced above the atmosphere. The camera s spectral response is used to compensate for stellar color index and typical meteor spectra in order to report meteor light curves in traditional visual magnitude units. Recent efforts include improved camera calibration procedures, long focal length "streak" meteor photome&y and two-station track determination. Meteor44 has been used to analyze data from the 2001.2002 and 2003 MSFC Leonid observational campaigns as well as several lesser showers. The software is interactive and can be demonstrated using data from recent Leonid campaigns.

MACS, An Instrument, and a Methodology for Simulations and Global Measurements of the Coronal Electron Temperature and the Solar Wind Velocity on the Solar Corona

NASA Technical Reports Server (NTRS)

Reginald, Nelson L.; Fisher, Richard R. (Technical Monitor)

2000-01-01

The determination of the radial and latitudinal temperature and wind profiles of the solar corona is of great importance in understanding the coronal heating mechanism and the dynamics of coronal expansion. Cram presented the theory for the formation of the K-coronal spectrum and identified two important observations. He observed the existence of temperature sensitive anti-nodes at certain wavelengths in the theoretical K-coronal spectra. The anti-nodes are separated by temperature-insensitive nodes. Remarkably, Cram showed that the wavelengths of the nodes and anti-nodes are almost independent of altitude above the solar limb. Because of these features, Cram suggested that the intensity ratios at two anti-nodes could be used as a diagnostic of the electron temperature in the K-corona. Based on this temperature diagnostic technique prescribed by Cram a slit-based spectroscopic study was performed by Ichimoto et al. on the solar corona in conjunction with the total solar eclipse of 3 Nov 1994 in Putre, Chile to determine the temperature profile of the solar corona. In this thesis Cram's theory has been extended to incorporate the role of the solar wind in the formation of the K-corona, and we have identified both temperature and wind sensitive intensity ratios. The instrument, MACS, for Multi Aperture Coronal Spectrometer, a fiber optic based spectrograph, was designed for global and simultaneous measurement of the thermal electron temperature and the solar wind velocity in the solar corona. The first ever experiment of this nature was conducted in conjunction with the total solar eclipse of 11 Aug 1999 in Elazig, Turkey. In this instrument one end of each of twenty fiber optic tips were positioned in the focal plane of the telescope in such a way that we could observe conditions simultaneously at many different latitudes and two different radial distances in the solar corona. The other ends of the fibers were vertically aligned and placed at the primary focus of the collimating lens of the spectrograph to obtain simultaneous and global spectra on the solar corona. By isolating the K-coronal spectrum from the spectrum recorded by each fiber the temperature and the wind sensitive intensity ratios were calculated to obtain simultaneous and global measurements of the thermal electron temperature and the solar wind velocity. We were successful in obtaining reliable estimates of the coronal temperature at many positions in the corona. This is the first time that simultaneous measurements of coronal temperatures have been obtained at so many points. However due to instrumental scattering encountered during observations, reliable estimates of the wind velocity turned out to be impossible to obtain. Although remedial measures were taken prior to observation, this task proved to be difficult owing to the inability to replicate the conditions expected during an eclipse in the laboratory. The full extent of the instrumental scattering was apparent only when we analyzed the observational sequence. Nevertheless the experience obtained from this very first attempt to simultaneously and globally measure both the wind velocity and the temperature on the solar corona have provided valuable information to conduct any future observations successfully.

Determination of the vinyl fluoride line intensities by TDL spectroscopy: the object oriented approach of Visual Line Shape Fitting Program to line profile analysis

NASA Astrophysics Data System (ADS)

Tasinato, Nicola; Pietropolli Charmet, Andrea; Stoppa, Paolo; Giorgianni, Santi

2010-03-01

In this work the self-broadening coefficients and the integrated line intensities for a number of ro-vibrational transitions of vinyl fluoride have been determined for the first time by means of TDL spectroscopy. The spectra recorded in the atmospheric window around 8.7 µm appear very crowded with a density of about 90 lines per cm-1. In order to fit these spectral features a new fitting software has been implemented. The program, which is designed for laser spectroscopy, can fit many lines simultaneously on the basis of different theoretical profiles (Doppler, Lorentz, Voigt, Galatry and Nelkin-Ghatak). Details of the object oriented implementation of the application are given. The reliability of the program is demonstrated by determining the line parameters of some ro-vibrational lines of sulphur dioxide in the ν1 band region around 9 µm. Then the software is used for the line profile analysis of vinyl fluoride. The experimental line shapes show deviations from the Voigt profile, which can be well modelled by using a Dicke narrowed line shape function. This leads to the determination of the self-narrowing coefficient within the framework of the strong collision model.

Rapid, sensitive, and simultaneous detection of three foodborne pathogens using magnetic nanobead-based immunoseparation and quantum dot-based multiplex immunoassay.

PubMed

Wang, Hong; Li, Yanbin; Wang, Andrew; Slavik, Michael

2011-12-01

Losses caused by foodborne diseases are enormous in terms of human life, illness, medical costs, and food product recalls. Rapid detection of multiple bacterial pathogens in foods is extremely important to ensure food safety. The objective of this research was to develop a multiplex immunoassay by integrating magnetic nanobeads (MNBs) for immunoseparation with quantum dots (QDs) as fluorescent labels for rapid, sensitive, and simultaneous detection of three major pathogenic bacteria, Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes, in food products. In this research, both streptavidin-conjugated MNBs (30- and 150-nm diameter) and QDs (530-, 580-, and 620-nm emission wavelength) were separately coated with biotinylated anti-Salmonella, anti-E. coli, and anti-Listeria antibodies. The immuno-MNBs were mixed with a food sample to capture the three target bacteria. After being magnetically separated from the sample, the MNB-cell conjugates were mixed with the immuno-QDs to form the MNB-cell-QD complexes, and unattached QDs were removed. The fluorescence intensity of the MNB-cell-QD complexes was measured at wavelengths of 530, 580, and 620 nm to determine the populations of Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes, respectively. This multiplex immunoassay simultaneously detected Salmonella Typhimurium, E. coli O157:H7, and L. monocytogenes at levels as low as 20 to 50 CFU/ml in food samples in less than 2 h without enrichment. The change in fluorescence intensity was linearly correlated (R(2) > 0.96) with the logarithmic value of bacterial level in the range of 10 to 10(3) CFU/ml. More than 85% of the three target pathogens could be simultaneously separated from food samples. The multiplex immunoassay could be expanded to detect more target pathogens, depending on the availability of specific antibodies and QDs with different emission wavelengths.

The physiological effects of simultaneous exposures to heat and vibration. Ph.D. Thesis - California Univ., Berkeley

NASA Technical Reports Server (NTRS)

Spaul, W. A.

1983-01-01

Determination of the effects of exposure to vibration on the body's ability to handle heat stress, and, if so, identification of the specific vibration parameters (frequency and intensity) for both whole-body (wbv) and segmental-body vibration (sbv) that would have the most detrimental effect on the body's ability to maintain thermal homeostasis were studied. Rectal and skin temperatures, heart rates, localized sweat rates, arm-segment blood perfusion rates, respiration rates, oxygen uptakes, and respiratory exchange ratios were measured in six men (22 to 33 yr) during simultaneous exposures to heat and vibration - either wbv or sbv, and during a heated 50 min recovery period. The heat conditions were T (sub db) = 43.5 + or - 0.5 C (mean + or S.E.M.), and RH = 20 + or - 4%. All vibration exposures were divided into two exposure conditions - identical frequencies but at a high intensity (HI) and a low intensity (LI) level. The HI wbv exposure was for 25 min/day at 5 Hz, 0.37 g-rms; 10 Hz, 0.46 g-rms; 16 Hz, 0.72 g-rms; 30 Hz, 1.40 g-rms; 80 Hz, 3.70 g-rms. The LI wbv exposure was for 2.5 hr/day at the same frequencies but at the following accelerations: 0.14 g-rms; 0.18 g-rms; 0.28 g-rms; 0.55 g-rms; 1.44 g-rms. During the sbv the subject stood and grasped a vibrating, in the Z-axis, hand grip with both hands.

A Localized Surface Plasmon Resonance Sensing Method for Simultaneous Determination of Atenolol and Amiloride in Pharmaceutical Dosage Forms and Urine Samples

PubMed Central

2018-01-01

This contribution describes a simple, fast, and sensitive application of localized surface plasmon resonance effect of silver nanoparticles for simultaneous determination of antihypertensive drugs' mixture atenolol and amiloride in both pharmaceutical dosage forms and in biological samples (urine). Silver nanoparticles were prepared by chemical reduction of silver nitrate using hydroxylamine HCL in an alkaline medium. Application of silver-hydroxylamine nanoparticles (SH NPs) provides many advantages including reproducibility, sensitivity, and cost effective way of analyte determination. Amiloride has four amino groups which act as attachment points on the surface of silver nanoparticles resulting in a synergistic effect on the absorption intensity of atenolol, leading to increase the sensitivity of the determination of both compounds. This method shows excellent advantages comparing with the previously reported methods, including accuracy, precision, and selectivity. The linear range of atenolol is 1 × 10−5–1 × 10−4 mol·L−1 and of amiloride is 1 × 10−6–1 × 10−5 mol·L−1. The limit of detection (LOD) values of atenolol and amiloride are 0.89 × 10−5 and 0.42 × 10−6 mol·L−1, respectively. PMID:29576886

OPTICAL INFORMATION PROCESSING: Modulation—spectral analysis of an image transmitted across a distorting medium

NASA Astrophysics Data System (ADS)

Zubov, Vladimir A.; Mironova, T. V.

1998-05-01

The task of simultaneous determination of the structure and characteristics of a two-dimensional amplitude—phase signal and a two-dimensional complex transfer or instrumental function is considered. The solution is based on determination of four independent intensity distributions of spectral representations of the signal Isr(ωx, ωy) subjected to the action of the transfer function, of the signal Ismr(ωx, ωy which) has experienced additional modulation applied in a certain manner and the action of the transfer function, of the signal Isrn(ωx, ωy) representing the signal Isr(ωx, ωy) with certain additional modulation at the output, and of the signal Ismrn(ωx, ωy) which is the signal Ismr(ωx, ωy) with certain additional modulation at the output. These intensity distributions make it possible to calculate the amplitude and phase components of the image being analysed and of the transfer function. Additional modulations should in some way ensure visualisation of the phase information. A specific type of additional spatial modulation, in the form of linear amplitude, is discussed.

State Estimation for Linear Systems Driven Simultaneously by Wiener and Poisson Processes.

DTIC Science & Technology

1978-12-01

The state estimation problem of linear stochastic systems driven simultaneously by Wiener and Poisson processes is considered, especially the case...where the incident intensities of the Poisson processes are low and the system is observed in an additive white Gaussian noise. The minimum mean squared

Simultaneous drying and decontamination of rough rice using combined pulsed light and holding treatment

USDA-ARS?s Scientific Manuscript database

Pulsed light (PL) technology has been proven effective in food disinfection. However, increasing the light intensity or treatment time could swiftly increase the temperature of the food product. Using the thermal effect in an appropriate way may achieve a simultaneous disinfection and drying effect....

The Effect of Multitasking to Faculty Members' Academic Works

ERIC Educational Resources Information Center

Baran, Bahar

2013-01-01

Faculty members in higher education institutions which technology produced in and used actively try to overcome simultaneous one more works because of their intensive works and responsibilities. This study associated simultaneously doing one more academic works to multitasking. Multitasking may have a detrimental effect on academic works since it…

Quantitative analysis of crystalline pharmaceuticals in tablets by pattern-fitting procedure using X-ray diffraction pattern.

PubMed

Takehira, Rieko; Momose, Yasunori; Yamamura, Shigeo

2010-10-15

A pattern-fitting procedure using an X-ray diffraction pattern was applied to the quantitative analysis of binary system of crystalline pharmaceuticals in tablets. Orthorhombic crystals of isoniazid (INH) and mannitol (MAN) were used for the analysis. Tablets were prepared under various compression pressures using a direct compression method with various compositions of INH and MAN. Assuming that X-ray diffraction pattern of INH-MAN system consists of diffraction intensities from respective crystals, observed diffraction intensities were fitted to analytic expression based on X-ray diffraction theory and separated into two intensities from INH and MAN crystals by a nonlinear least-squares procedure. After separation, the contents of INH were determined by using the optimized normalization constants for INH and MAN. The correction parameter including all the factors that are beyond experimental control was required for quantitative analysis without calibration curve. The pattern-fitting procedure made it possible to determine crystalline phases in the range of 10-90% (w/w) of the INH contents. Further, certain characteristics of the crystals in the tablets, such as the preferred orientation, size of crystallite, and lattice disorder were determined simultaneously. This method can be adopted to analyze compounds whose crystal structures are known. It is a potentially powerful tool for the quantitative phase analysis and characterization of crystals in tablets and powders using X-ray diffraction patterns. Copyright 2010 Elsevier B.V. All rights reserved.

Biocapture of CO2 by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods

PubMed Central

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-01-01

Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO2 in biogas. The microalgae–fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulgaris–Ganoderma lucidum > Chlorella vulgaris–activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m−2 s−1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology. PMID:29543784

Biocapture of CO₂ by Different Microalgal-Based Technologies for Biogas Upgrading and Simultaneous Biogas Slurry Purification under Various Light Intensities and Photoperiods.

PubMed

Guo, Pengfei; Zhang, Yuejin; Zhao, Yongjun

2018-03-15

Abstract : Co-cultivation of microalgae and microbes for pollutant removal from sewage is considered as an effective wastewater treatment method. The aim of this study is to screen the optimal photoperiod, light intensity and microalgae co-cultivation method for simultaneously removing nutrients in biogas slurry and capturing CO₂ in biogas. The microalgae-fungi pellets are deemed to be a viable option because of their high specific growth rate and nutrient and CO 2 removal efficiency under the photoperiod of 14 h light:10 h dark. The order of both the biogas slurry purification and biogas upgrading is ranked the same, that is Chlorella vulga ris - Ganoderma lucidum > Chlorella vulga ris -activated sludge > Chlorella vulgaris under different light intensities. For all cultivation methods, the moderate light intensity of 450 μmol m -2 s -1 is regarded as the best choice. This research revealed that the control of photoperiod and light intensity can promote the biological treatment process of biogas slurry purification and biogas upgrading using microalgal-based technology.

SU-F-T-349: Dosimetric Comparison of Three Different Simultaneous Integrated Boost Irradiation Techniques for Multiple Brain Metastases: Intensity-Modulatedradiotherapy, Hybrid Intensity-Modulated Radiotherapy and Volumetric Modulated Arc Therapy

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

Lin, X; Sun, T; Yin, Y

Purpose: To study the dosimetric impact of intensity-modulated radiotherapy (IMRT), hybrid intensity-modulated radiotherapy (h-IMRT) and volumetric modulated arc therapy(VMAT) for whole-brain radiotherapy (WBRT) with simultaneous integrated boost in patients with multiple brain metastases. Methods: Ten patients with multiple brain metastases were included in this analysis. The prescribed dose was 45 Gy to the whole brain (PTVWBRT) and 55 Gy to individual brain metastases (PTVboost) delivered simultaneously in 25 fractions. Three treatment techniques were designed: the 7 equal spaced fields IMRT plan, hybrid IMRT plan and VMAT with two 358°arcs. In hybrid IMRT plan, two fields(90°and 270°) were planned to themore » whole brain. This was used as a base dose plan. Then 5 fields IMRT plan was optimized based on the two fields plan. The dose distribution in the target, the dose to the organs at risk and total MU in three techniques were compared. Results: For the target dose, conformity and homogeneity in PTV, no statistically differences were observed in the three techniques. For the maximum dose in bilateral lens and the mean dose in bilateral eyes, IMRT and h-IMRT plans showed the highest and lowest value respectively. No statistically significant differences were observed in the dose of optic nerve and brainstem. For the monitor units, IMRT and VMAT plans showed the highest and lowest value respectively. Conclusion: For WBRT with simultaneous integrated boost in patients with multiple brain metastases, hybrid IMRT could reduce the doses to lens and eyes. It is feasible for patients with brain metastases.« less

Robust patella motion tracking using intensity-based 2D-3D registration on dynamic bi-plane fluoroscopy: towards quantitative assessment in MPFL reconstruction surgery

NASA Astrophysics Data System (ADS)

Otake, Yoshito; Esnault, Matthieu; Grupp, Robert; Kosugi, Shinichi; Sato, Yoshinobu

2016-03-01

The determination of in vivo motion of multiple-bones using dynamic fluoroscopic images and computed tomography (CT) is useful for post-operative assessment of orthopaedic surgeries such as medial patellofemoral ligament reconstruction. We propose a robust method to measure the 3D motion of multiple rigid objects with high accuracy using a series of bi-plane fluoroscopic images and a multi-resolution, intensity-based, 2D-3D registration. A Covariance Matrix Adaptation Evolution Strategy (CMA-ES) optimizer was used with a gradient correlation similarity metric. Four approaches to register three rigid objects (femur, tibia-fibula and patella) were implemented: 1) an individual bone approach registering one bone at a time, each with optimization of a six degrees of freedom (6DOF) parameter, 2) a sequential approach registering one bone at a time but using the previous bone results as the background in DRR generation, 3) a simultaneous approach registering all the bones together (18DOF) and 4) a combination of the sequential and the simultaneous approaches. These approaches were compared in experiments using simulated images generated from the CT of a healthy volunteer and measured fluoroscopic images. Over the 120 simulated frames of motion, the simultaneous approach showed improved registration accuracy compared to the individual approach: with less than 0.68mm root-mean-square error (RMSE) for translation and less than 1.12° RMSE for rotation. A robustness evaluation was conducted with 45 trials of a randomly perturbed initialization showed that the sequential approach improved robustness significantly (74% success rate) compared to the individual bone approach (34% success) for patella registration (femur and tibia-fibula registration had a 100% success rate with each approach).

A stimuli-responsive fluorescence platform for simultaneous determination of d-isoascorbic acid and Tartaric acid based on Maillard reaction product.

PubMed

Zhao, Yanmei; Yuan, Haiyan; Zhang, Xinling; Yang, Jidong

2018-05-05

An activatable fluorescence monitoring platform based on a novel Maillard reaction product from d-glucose and L-arginine was prepared through a facile one-pot approach and applied for simultaneous detection of d-isoascorbic acid and tartaric acid. In this work, the new Maillard reaction product GLA was first obtained, and its fluorescence intensity can be effectively quenched by KMnO 4 , resulting from a new complex (GLA-KMnO 4 ) formation between GLA and KMnO 4 . Upon addition of d-isoascorbic acid or tartaric acid, an enhanced fluorescence was observed under the optimumed experimental conditions, indicating a stimuli-responsive fluorescence turn on platform for d-isoascorbic acid or tartaric acid can be developed. The corresponding experimental results showed that this turn on fluorescence sensing platform has a high sensitivity for d-isoascorbic acid or tartaric acid, because the detection limits were 5.9μM and 21.5μM, respectively. Additionally, this proposed sensing platform was applied to simultaneously detection of d-isoascorbic acid and tartaric acid in real tap water samples with satisfactory results. Copyright © 2018 Elsevier B.V. All rights reserved.

Study of the fracture kinetics in structural aluminum alloys subjected to a long-term action of a static load and a corrosive medium using specimens of a new type

NASA Astrophysics Data System (ADS)

Kablov, E. N.; Grinevich, A. V.; Lutsenko, A. N.; Erasov, V. S.; Nuzhnyi, G. A.; Gulina, I. V.

2017-04-01

A new type of specimens is proposed to study the fracture kinetics of the metallic materials subjected to a long-term simultaneous action of a tensile load and a corrosive medium. The new design of specimens makes it possible to determine the stress intensity factor at the crack opening fixed by a wedging bolt, to perform investigations in any aggressive medium, and to measure the tensile load on a specimen at any stage of tests. Standard apparatus is used for this purpose. Plate specimens made of structural aluminum alloys 1163T and V95pchT2 are tested. A paradoxical fact of increasing the conventional stress intensity factor of the V95pchT2 alloy during the development of a corrosion crack is revealed.

Requirements Analysis for Information-Intensive Systems

NASA Technical Reports Server (NTRS)

Callender, E. D.; Hartsough, C.; Morris, R. V.; Yamamoto, Y.

1986-01-01

Report discusses role of requirements analysis in development of information-intensive systems. System examined from variety of human viewpoints during design, development, and implementation. Such examination, called requirements analysis, ensures system simultaneously meets number of distinct but interacting needs. Viewpoints defined and integrated to help attain objectives.

Level set segmentation of medical images based on local region statistics and maximum a posteriori probability.

PubMed

Cui, Wenchao; Wang, Yi; Lei, Tao; Fan, Yangyu; Feng, Yan

2013-01-01

This paper presents a variational level set method for simultaneous segmentation and bias field estimation of medical images with intensity inhomogeneity. In our model, the statistics of image intensities belonging to each different tissue in local regions are characterized by Gaussian distributions with different means and variances. According to maximum a posteriori probability (MAP) and Bayes' rule, we first derive a local objective function for image intensities in a neighborhood around each pixel. Then this local objective function is integrated with respect to the neighborhood center over the entire image domain to give a global criterion. In level set framework, this global criterion defines an energy in terms of the level set functions that represent a partition of the image domain and a bias field that accounts for the intensity inhomogeneity of the image. Therefore, image segmentation and bias field estimation are simultaneously achieved via a level set evolution process. Experimental results for synthetic and real images show desirable performances of our method.

Simultaneous Laser-induced Fluorescence of Nitric Oxide and Atomic Oxygen in the Hypersonic Materials Environment Test System Arcjet Facility

NASA Technical Reports Server (NTRS)

Johansen, Craig; Lincoln, Daniel; Bathel, Brett; Inman, Jennifer; Danehy, Paul

2014-01-01

Simultaneous nitric oxide (NO) and atomic oxygen (O) laser induced fluorescence (LIF) experiments were performed in the Hypersonic Materials Environmental Test System (HYMETS) facility at the NASA Langley Research Center. The data serves as an experimental database for validation for chemical and thermal nonequilibrium models used in hypersonic flows. Measurements were taken over a wide range of stagnation enthalpies (6.7 - 18.5 MJ/kg) using an Earth atmosphere simulant with a composition of 75% N2, 20% O2, and 5% Ar (by volume). These are the first simultaneous measurements of NO and O LIF to be reported in literature for the HYMETS facility. The maximum O LIF mean signal intensity was observed at a stagnation enthalpy of approximately 12 MJ/kg while the maximum NO LIF mean signal intensity was observed at a stagnation enthalpy of 6.7 MJ/kg. Experimental results were compared to simple fluorescence model that assumes equilibrium conditions in the plenum and frozen chemistry in the isentropic nozzle expansion (Mach 5). The equilibrium calculations were performed using CANTERA v2.1.1 with 16 species. The fluorescence model captured the correlation in mean O and NO LIF signal intensities over the entire range of stagnation enthalpies tested. Very weak correlations between single-shot O and NO LIF intensities were observed in the experiments at all of the stagnation enthalpy conditions.

Photometric intensity and polarization measurements of the solar corona.

NASA Technical Reports Server (NTRS)

Mcdougal, D. S.

1971-01-01

Use of a satellite photometric observatory (SPO) to measure the solar corona from Miahuatlan, Mexico during the Mar. 7, 1970, total eclipse of the sun. The SPO is equipped with a 24-in. Cassegrainian telescope, a four-channel photoelectric photometer, a Wollaston prism, and a rotating half-wave plate. Simultaneous measurements were made of the two orthogonal components of coronal light in the B and R bands of the UBVRI system. A 1-minute arc aperture was scanned from the lunar disk center out to five solar radii in a series of spirals of gradually increasing radius. For the first time, simultaneous multicolor intensity, degree, and angle of polarization profiles are computed from photoelectric measurements. Comparison of the variations of the measurements for each spiral scan yield a detailed picture of the intensity and polarization features in the K corona.

Laughter exaggerates happy and sad faces depending on visual context

PubMed Central

Sherman, Aleksandra; Sweeny, Timothy D.; Grabowecky, Marcia; Suzuki, Satoru

2012-01-01

Laughter is an auditory stimulus that powerfully conveys positive emotion. We investigated how laughter influenced visual perception of facial expressions. We simultaneously presented laughter with a happy, neutral, or sad schematic face. The emotional face was briefly presented either alone or among a crowd of neutral faces. We used a matching method to determine how laughter influenced the perceived intensity of happy, neutral, and sad expressions. For a single face, laughter increased the perceived intensity of a happy expression. Surprisingly, for a crowd of faces laughter produced an opposite effect, increasing the perceived intensity of a sad expression in a crowd. A follow-up experiment revealed that this contrast effect may have occurred because laughter made the neutral distracter faces appear slightly happy, thereby making the deviant sad expression stand out in contrast. A control experiment ruled out semantic mediation of the laughter effects. Our demonstration of the strong context dependence of laughter effects on facial expression perception encourages a re-examination of the previously demonstrated effects of prosody, speech content, and mood on face perception, as they may similarly be context dependent. PMID:22215467

The Challenge of Changing Deeply Held Student Beliefs about the Relativity of Simultaneity.

ERIC Educational Resources Information Center

Scherr, Rachel E.; Shaffer, Peter S.; Vokos, Stamatis

2002-01-01

Describes the development and assessment of instructional materials intended to improve student understanding of the concept of time in special relativity, the relativity of simultaneity, and the role of observers in inertial reference frames. Demonstrates the effect of the curriculum and illustrates the intense cognitive conflict as students are…

Can novel management practice improve soil and environmental quality and sustain crop yield simultaneously?

USDA-ARS?s Scientific Manuscript database

Little is known about management practices that can simultaneously improve soil and environmental quality and sustain crop yields. The effect of a combination of tillage, crop rotation, and N fertilization on soil C and N, global warming potential (GWP), greenhouse gas intensity (GHGI), and malt bar...

Simultaneous topographic and amperometric membrane mapping using an AFM probe integrated biosensor.

PubMed

Stanca, Sarmiza Elena; Csaki, Andrea; Urban, Matthias; Nietzsche, Sandor; Biskup, Christoph; Fritzsche, Wolfgang

2011-02-15

The investigation of the plasma membrane with intercorrelated multiparameter techniques is a prerequisite for understanding its function. Presented here, is a simultaneous electrochemical and topographic study of the cell membrane using a miniaturized amperometric enzymatic biosensor. The fabrication of this biosensor is also reported. The biosensor combines a scanning force microscopy (AFM) gold-coated cantilever and an enzymatic transducer layer of peroxidases (PODs). When these enzymes are brought in contact with the substrate, the specific redox reaction produces an electric current. The intensity of this current is detected simultaneously with the surface imaging. For sensor characterization, hydroquinone-2-carboxylic acid (HQ) is selected as an intrinsic source of H(2)O(2). HQ has been electrochemically regenerated by the reduction of antraquinone-2-carboxylic acid (AQ). The biosensor reaches the steady state value of the current intensity in 1 ± 0.2s. Copyright © 2010 Elsevier B.V. All rights reserved.

Performance of an automated external defibrillator in a moving ambulance vehicle.

PubMed

Yun, Jong Geun; Jeung, Kyung Woon; Lee, Byung Kook; Ryu, Hyun Ho; Lee, Hyoung Youn; Kim, Mu Jin; Heo, Tag; Min, Yong Il; You, Yeonho

2010-04-01

The available data suggest that automated external defibrillators (AED) can be safely used in vibration-like moving conditions such as rigid inflatable boats and aircraft environments. However, little literature exists examining their performance in a moving ambulance. The present study was undertaken to determine whether an AED is able to analyse the heart rhythm correctly during ambulance transport. An ambulance was driven on paved (20-100 km/h) and unpaved (10 km/h) roads. The performance of two AED devices (CU ER 2, CU Medical Systems Inc., Korea, and Heartstart MRx, Phillips, USA) was determined in a moving ambulance using manikins. Vibration intensity was measured simultaneously with a digital vibrometer. AED performance was then evaluated again on manikins and on a swine model under simulated vibration intensities (0.5-5m/s(2)) measured by the vibrometer in the previous phase of the investigation. The vibration intensity increased with increasing speeds on paved roads (1.98+/-0.44 m/s(2) at 100 km/h). While driving on unpaved roads, it increased to 6.40+/-1.06 m/s(2). Both AED algorithms analysed the heart rhythm correctly under resting state. When tested on pigs, both algorithms showed substantially degraded performances, even at low vibration intensities of 0.5-1m/s(2), which corresponded to vibration intensities while driving on paved roads at 20-60 km/h. This study also showed that electrocardiograms generated on manikins were more resistant to motion artifacts than were the pig electrocardiograms. Ambulance personnel should consider the possibility of misinterpretation by an AED when this device is used while transporting a patient. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Simultaneous detection of refractive index and surface charges in nanolaser biosensors

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

Watanabe, Keisuke; Kishi, Yoji; Hachuda, Shoji

2015-01-12

The emission intensity of a GaInAsP photonic crystal nanolaser is affected by the pH of the solution, in which the nanolaser is immersed. This phenomenon can be explained by the change in the redox potential, which modifies the filling of electrons at surface states of the semiconductor and hence the nonradiative surface recombination. This phenomenon allows the nanolaser to simultaneously and independently detect the refractive index and electric charges near the surface on the basis of the variation in emission wavelength and intensity, respectively. This paper demonstrates this function through alternate deposition of charged polyelectrolytes and hybridization of deoxyribonucleic acids.

Electric-acoustic interactions in the hearing cochlea: single fiber recordings.

PubMed

Tillein, J; Hartmann, R; Kral, A

2015-04-01

The present study investigates interactions of simultaneous electric and acoustic stimulation in single auditory nerve fibers in normal hearing cats. First, the auditory nerve was accessed with a microelectrode and response areas of single nerve fibers were determined for acoustic stimulation. Second, response thresholds to extracochlear sinusoidal electric stimulation using ball electrodes positioned at the round window were measured. Third, interactions that occurred with combined electric-acoustic stimulation were investigated in two areas: (1) the spectral domain (frequency response areas) and (2) the temporal domain (phase-locking to each stimulus) at moderate stimulus intensities (electric: 6 dB re threshold, acoustic: 20-40 dB re threshold at the characteristic frequency, CF). For fibers responding to both modalities responses to both electric and acoustic stimulation could be clearly identified. CFs, thresholds, and bandwidth (Q10dB) of acoustic responses were not significantly affected by simultaneous electric stimulation. Phase-locking of electric responses decreased in the presence of acoustic stimulation. Indication for electric stimulation of inner hair cells with 125 and 250 Hz were observed. However, these did not disturb the acoustic receptive fields of auditory nerve fibers. There was a trade-off between these responses when the intensities of the stimulation were varied: Relatively more intense stimulation dominated less intense stimulation. The scarcity of interaction between the different stimulus modalities demonstrates the ability of electric-acoustic stimulation to transfer useful information through both stimulation channels at the same time despite cochlear electrophonic effects. Application of 30 Hz electric stimulation resulted in a strong suppression of acoustic activity in the anodic phase of the stimulus. An electric stimulation like this might thus be used to control acoustic responses. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling organizational determinants of hospital mortality.

PubMed Central

al-Haider, A S; Wan, T T

1991-01-01

This study examines hospital characteristics that affect the differential in hospital mortality. Death rates for 1984 Medicare inpatients in acute care hospitals, released by the Health Care Financing Administration in 1986, were analyzed. A confirmatory statistical approach to organizational determinants of hospital mortality was formulated and validated through an empirical examination of 239 hospitals. The findings suggest that the effect of hospital size and specialization on mortality was a spurious one when the effects of other variables were simultaneously controlled. A positive association existed between service intensity and hospital mortality: the more hospital services consumed, the higher the mortality rate. Community attributes accounted for more variance in hospital mortality rates than did organizational attributes. The organizational and community factors studied explained 27 percent of the total variance in hospital mortality. PMID:1869442

Crosstalk Cancellation for a Simultaneous Phase Shifting Interferometer

NASA Technical Reports Server (NTRS)

Olczak, Eugene (Inventor)

2014-01-01

A method of minimizing fringe print-through in a phase-shifting interferometer, includes the steps of: (a) determining multiple transfer functions of pixels in the phase-shifting interferometer; (b) computing a crosstalk term for each transfer function; and (c) displaying, to a user, a phase-difference map using the crosstalk terms computed in step (b). Determining a transfer function in step (a) includes measuring intensities of a reference beam and a test beam at the pixels, and measuring an optical path difference between the reference beam and the test beam at the pixels. Computing crosstalk terms in step (b) includes computing an N-dimensional vector, where N corresponds to the number of transfer functions, and the N-dimensional vector is obtained by minimizing a variance of a modulation function in phase shifted images.

Earth orientation determinations by short duration VLBI observations

NASA Astrophysics Data System (ADS)

Nothnagel, Axel; Zhihan, Qian; Nicolson, George D.; Tomasi, Paolo

1994-03-01

In May 1989 and April 1990 the radio telescopes of the Wettzell Geodetic Fundamental Station in Germany and of the Shanghai Observatory near Seshan in China observed two series of daily VLBI experiments of short duration for precise determination of UT1. In 1990 a few experiments were complemented by the Hartebeesthoek Radio Astronomy Observatory in South Africa and the Medicina telescope of the Bologna Istituto di Radioastronomia in Italy. Employing the South African station together with the east-west baseline formed by the observatories of Seshan and Medicina permitted simultaneous determinations of UT1 and polar motion. Here we report on the results of these observations. Comparing the UT1 results with those of the IRIS Intensive series gives a clear indication of the absolute accuracy of such short duration VLBI measurements which is estimated to be of the order of ±60 µs.

Unsteady flow sensing and optimal sensor placement using machine learning

NASA Astrophysics Data System (ADS)

Semaan, Richard

2016-11-01

Machine learning is used to estimate the flow state and to determine the optimal sensor placement over a two-dimensional (2D) airfoil equipped with a Coanda actuator. The analysis is based on flow field data obtained from 2D unsteady Reynolds averaged Navier-Stokes (uRANS) simulations with different jet blowing intensities and actuation frequencies, characterizing different flow separation states. This study shows how the "random forests" algorithm is utilized beyond its typical usage in fluid mechanics estimating the flow state to determine the optimal sensor placement. The results are compared against the current de-facto standard of maximum modal amplitude location and against a brute force approach that scans all possible sensor combinations. The results show that it is possible to simultaneously infer the state of flow and to determine the optimal sensor location without the need to perform proper orthogonal decomposition. Collaborative Research Center (CRC) 880, DFG.

Determination of 17-oxosteroid glucuronides and sulfates in urine and serum by fluorescence high-performance liquid chromatography using dansyl hydrazine as a prelabeling reagent.

PubMed

Kawasaki, T; Maeda, M; Tsuji, A

1982-12-10

A fluorescence high-performance liquid chromatographic method is described for the direct determination of conjugated 17-oxosteroids in biological fluids without hydrolysis. Conjugated 17-oxosteroids are extracted with Sep-Pak C18 cartridge, labeled with dansyl hydrazine in trichloroacetic acid--benzene solution and then separated by high-performance liquid chromatography on reversed-phase muBondapak C18 column using 0.01 M sodium acetate in methanol-water-acetic acid (65:35:1, v/v) as the mobile phase. The eluate is monitored by a fluorophotometer at 365 nm (excitation) and 520 nm (emission). Linearities of fluorescence intensities (peak heights) with the amounts of various conjugated 17-oxosteroids were obtained between 10 pmol and 100 pmol. This method is sensitive, reliable and useful for the simultaneous determination of conjugated 17-oxosteroids in urine and serum.

Single-image diffusion coefficient measurements of proteins in free solution.

PubMed

Zareh, Shannon Kian; DeSantis, Michael C; Kessler, Jonathan M; Li, Je-Luen; Wang, Y M

2012-04-04

Diffusion coefficient measurements are important for many biological and material investigations, such as studies of particle dynamics and kinetics, and size determinations. Among current measurement methods, single particle tracking (SPT) offers the unique ability to simultaneously obtain location and diffusion information about a molecule while using only femtomoles of sample. However, the temporal resolution of SPT is limited to seconds for single-color-labeled samples. By directly imaging three-dimensional diffusing fluorescent proteins and studying the widths of their intensity profiles, we were able to determine the proteins' diffusion coefficients using single protein images of submillisecond exposure times. This simple method improves the temporal resolution of diffusion coefficient measurements to submilliseconds, and can be readily applied to a range of particle sizes in SPT investigations and applications in which diffusion coefficient measurements are needed, such as reaction kinetics and particle size determinations. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Perceiving the Intensity of Light

ERIC Educational Resources Information Center

Purves, Dale; Williams, S. Mark; Nundy, Surajit; Lotto, R. Beau

2004-01-01

The relationship between luminance (i.e., the photometric intensity of light) and its perception (i.e., sensations of lightness or brightness) has long been a puzzle. In addition to the mystery of why these perceptual qualities do not scale with luminance in any simple way, "illusions" such as simultaneous brightness contrast, Mach bands,…

Slantingly cross loading sample system enables simultaneous performance of separation and mixture to detect molecular interactions on thin-layer chromatography.

PubMed

Shimizu-Yumoto, Hiroko; Hayashi, Nobuyuki; Ichimura, Kazuo; Nakayama, Masayoshi

2012-07-06

Anthocyanins are major flower pigments that can be affected by copigments, colorless compounds that can modify anthocyanin coloration to more intense and bluer. Thin-layer chromatography (TLC) is an available technique to separate and analyze anthocyanins and copigments. To easily and comprehensively detect copigments, we added function of mixture of compounds to TLC; by slantingly cross loading samples on TLC, compounds are symmetrically developed at various angle lines from the upper origin to individual R(f) values and cross each other in an orderly fashion, where mixture is simultaneously performed with separation. Occurrence of copigments can be detected as a coloration change on the developed line of anthocyanin. Pink sweet pea (Lathyrus odoratus L.) petals were analyzed by the cross-TLC and a more intense spot and a paler spot on the anthocyanin line were detected. As each spot overlapped with an ultraviolet absorbance line, each of these ultraviolet absorption compounds was purified and identified as kaempferol 3-rhamnoside and 2-cyanoethyl-isoxazolin-5-one, respectively. Whereas kaempferol 3-rhamnoside is a flavonoid and had a general copigment effect of more intense and bluer coloration change, 2-cyanoethyl-isoxazolin-5-one is a compound whose structure is outside of conventional categories of copigments and had a novel effect to change anthocyanin coloration paler while maintaining color tone. We determined that the search for copigments should be carried out without pre-existing prediction of structures and effects. We have shown that slantingly cross loading samples system on plate-type chromatography is an effective technique for such comprehensive analysis of molecular interaction. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Multiway analysis applied to time-resolved chemiluminescence for simultaneous determination of paracetamol and codeine in pharmaceuticals.

PubMed

Mokhtari, Ali; Jafari Delouei, Nastaran; Keyvanfard, Mohsen; Abdolhosseini, Mohammad

2016-09-01

This method is based on the enhancing effect of codeine (COD) and paracetamol (PAR) on the chemiluminescence (CL) reaction of Ru(phen)3 (2+) with Ce(IV). In the batch mode, COD gives a relatively sharp peak with the highest CL intensity at 4.0 s, whereas the maximum CL intensity of the PAR appears at ~60 s after injection of Ce(IV) solution. Whole CL time profiles allowed use of the time-resolved CL data in combination with multiway calibration techniques, as multiway partial least squares (N-PLS), for the quantitative determination of both COD and PAR in binary mixtures. In this work, we found that the impact of Ce(IV) concentration on the CL intensity was different for COD and PAR. Therefore, a Ce(IV) concentration mode was added to the time and sample modes to obtain 3D data. The percent relative standard deviation (%RSD) values for 10 determinations of 1.0 × 10(-5)  mol/L of COD and 1.0 × 10(-4)  mol/L of PAR were 6.1% and 8.7%, respectively. The limit of detection (LOD) values (S/N = 3) were 0.9 × 10(-8)  mol/L and 1.0 × 10(-6)  mol/L for COD and PAR, respectively. The proposed method was successfully applied to the determination of PAR and COD in commercial pharmaceutical formulations. Acceptable recoveries (90-110%) were obtained for the quantification of these drugs in the real samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Digital sun sensor multi-spot operation.

PubMed

Rufino, Giancarlo; Grassi, Michele

2012-11-28

The operation and test of a multi-spot digital sun sensor for precise sun-line determination is described. The image forming system consists of an opaque mask with multiple pinhole apertures producing multiple, simultaneous, spot-like images of the sun on the focal plane. The sun-line precision can be improved by averaging multiple simultaneous measures. Nevertheless, the sensor operation on a wide field of view requires acquiring and processing images in which the number of sun spots and the related intensity level are largely variable. To this end, a reliable and robust image acquisition procedure based on a variable shutter time has been considered as well as a calibration function exploiting also the knowledge of the sun-spot array size. Main focus of the present paper is the experimental validation of the wide field of view operation of the sensor by using a sensor prototype and a laboratory test facility. Results demonstrate that it is possible to keep high measurement precision also for large off-boresight angles.

Modeling the Dependency Structure of Integrated Intensity Processes

PubMed Central

Ma, Yong-Ki

2015-01-01

This paper studies an important issue of dependence structure. To model this structure, the intensities within the Cox processes are driven by dependent shot noise processes, where jumps occur simultaneously and their sizes are correlated. The joint survival probability of the integrated intensities is explicitly obtained from the copula with exponential marginal distributions. Subsequently, this result can provide a very useful guide for credit risk management. PMID:26270638

CLINICAL AVIATION MEDICINE RESEARCH: COMPARISON OF SIMULTANEOUS MEASUREMENTS OF INTRA-AORTIC AND AUSCULTATORY BLOOD PRESSURES WITH PRESSURE-FLOW DYNAMICS DURING REST AND EXERCISE,

DTIC Science & Technology

recorded simultaneously by auscultation of the brachial artery; and (2) to study the pattern of pressure and flow dynamics during bicycle work at moderate...strenuous and maximal intensities. In most instances systolic pressures measured by auscultation were in close agreement with the directly recorded

Simultaneous detection of rotational and translational motion in optical tweezers by measurement of backscattered intensity.

PubMed

Roy, Basudev; Bera, Sudipta K; Banerjee, Ayan

2014-06-01

We describe a simple yet powerful technique of simultaneously measuring both translational and rotational motion of mesoscopic particles in optical tweezers by measuring the backscattered intensity on a quadrant photodiode (QPD). While the measurement of translational motion by taking the difference of the backscattered intensity incident on adjacent quadrants of a QPD is well known, we demonstrate that rotational motion can be measured very precisely by taking the difference between the diagonal quadrants. The latter measurement eliminates the translational component entirely and leads to a detection sensitivity of around 50 mdeg at S/N of 2 for angular motion of a driven microrod. The technique is also able to resolve the translational and rotational Brownian motion components of the microrod in an unperturbed trap and can be very useful in measuring translation-rotation coupling of micro-objects induced by hydrodynamic interactions.

[Analysis of the web pages of the intensive care units of Spain].

PubMed

Navarro-Arnedo, J M

2009-01-01

In order to determine the Intensive Care Units (ICU) of Spanish hospitals that had a web site, to analyze the information they offered and to know what information they needed to offer according to a sample of ICU nurses, a cross-sectional observational, descriptive study was carried out between January and September 2008. For each ICU website, an analysis was made on the information available on the unit, its care, teaching and research activity on nursing. Simultaneously, based on a sample of intensive care nurses, the information that should be contained on an ICU website was determined. The results, expressed in absolute numbers and percentage, showed that 66 of the 292 hospitals with ICU (22.6%) had a web site; 50.7% of the sites showed the number of beds, 19.7% the activity report, 11.3% the published articles/studies and followed research lines and 9.9% the organized formation courses. 14 webs (19.7%) displayed images of nurses. However, only 1 (1.4%) offered guides on the actions followed. No web site offered a navigation section for nursing, the E-mail of the chief nursing, the nursing documentation used or if any nursing model of their own was used. It is concluded that only one-fourth of the Spanish hospitals with ICU have a web site; number of beds was the data offered by the most sites, whereas information on care, educational and investigating activities was very reduced and that on nursing was practically omitted on the web pages of intensive care units.

Simultaneous determination of 20 components in red wine by LC-MS: application to variations of red wine components in decanting.

PubMed

Cui, Yan; Li, Qing; Liu, Zhenzhen; Geng, Lulu; Zhao, Xu; Chen, Xiaohui; Bi, Kaishun

2012-11-01

The decanting of red wines has a long tradition in red wine service from the perspective of modifying the aroma or taste of a wine. A simple and sensitive liquid chromatography-mass spectrometry method was developed for the simultaneous determination of 20 organic acids and polyphenols in decanting red wine. The separation was performed on a Diamonsil C(18) column (250 mm × 4.6 mm, 5 μm) using a mobile phase composed of methanol-0.1% acetic acid under gradient elution. Analysis was performed in selected ion monitoring mode with negative electrospray ionization interface. All the linear regressions showed good linear relationships (r(2) > 0.9973) between the peak area and concentration of each marker. The assay was reproducible with overall intra and interday variation of less than 5.0%. The recoveries for the quantified compounds were observed over the range of 92.1-108.3% with RSD values less than 5.7%. The method developed was successfully applied to determine the variations of the 20 components in red wine after decanting in different conditions. Concentrations of most organic acids and polyphenols investigated in the red wine were decreased in decanting. In addition, increment of duration, temperature, and light intensity would intensify the changes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mutual transformation of light waves by reflection holograms in photorefractive crystals of the 4-bar 3m symmetry

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

Naunyka, V. N.; Shepelevich, V. V., E-mail: vasshep@inbox.ru

2011-05-15

The mutual transformation of light waves in the case of their simultaneous diffraction from a bulk reflection phase hologram, which was formed in a cubic photorefractive crystal of the 4-bar 3m symmetry class, has been studied. The indicator surfaces of the polarization-optimized values of the relative intensity of the object wave, which make it possible to determine the amplification of this wave for any crystal cut, are constructed. The linear polarization azimuths at which the energy exchange between the light waves reaches a maximum are found numerically for crystals of different cuts.

Measurement analysis of two radials with a common-origin point and its application.

PubMed

Liu, Zhenyao; Yang, Jidong; Zhu, Weiwei; Zhou, Shang; Tan, Xuanping

2017-08-01

In spectral analysis, a chemical component is usually identified by its characteristic spectra, especially the peaks. If two components have overlapping spectral peaks, they are generally considered to be indiscriminate in current analytical chemistry textbooks and related literature. However, if the intensities of the overlapping major spectral peaks are additive, and have different rates of change with respect to variations in the concentration of the individual components, a simple method, named the 'common-origin ray', for the simultaneous determination of two components can be established. Several case studies highlighting its applications are presented. Copyright © 2017 John Wiley & Sons, Ltd.

Land-use intensity and host plant simultaneously shape the composition of arbuscular mycorrhizal fungal communities in a Mediterranean drained peatland.

PubMed

Ciccolini, Valentina; Ercoli, Laura; Davison, John; Vasar, Martti; Öpik, Maarja; Pellegrino, Elisa

2016-12-01

Land-use change is known to be a major threat to biodiversity and ecosystem services in Mediterranean areas. However, the potential for different host plants to modulate the effect of land-use intensification on community composition of arbuscular mycorrhizal fungi (AMF) is still poorly understood. To test the hypothesis that low land-use intensity promotes AMF diversity at different taxonomic scales and to determine whether any response is dependent upon host plant species identity, we characterised AMF communities in the roots of 10 plant species across four land use types of differing intensity in a Mediterranean peatland system. AMF were identified using 454 pyrosequencing. This revealed an overall low level of AMF richness in the peaty soils; lowest AMF richness in the intense cropping system at both virtual taxa and family level; strong modulation by the host plant of the impact of land-use intensification on AMF communities at the virtual taxa level; and a significant effect of land-use intensification on AMF communities at the family level. These findings have implications for understanding ecosystem stability and productivity and should be considered when developing soil-improvement strategies in fragile ecosystems, such as Mediterranean peatlands. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Simultaneous three-dimensional velocity and mixing measurements by use of laser Doppler velocimetry and fluorescence probes in a water tunnel

NASA Technical Reports Server (NTRS)

Neuhart, Dan H.; Wing, David J.; Henderson, Uleses C., Jr.

1994-01-01

A water tunnel investigation was conducted to demonstrate the capabilities of a laser-based instrument that can measure velocity and fluorescence intensity simultaneously. Fluorescence intensity of an excited fluorescent dye is directly related to concentration level and is used to indicate the extent of mixing in flow. This instrument is a three-dimensional laser Doppler velocimeter (LDV) in combination with a fluorometer for measuring fluorescence intensity variations. This capability allows simultaneous flow measurements of the three orthogonal velocity components and mixing within the same region. Two different flows which were generated by two models were studied: a generic nonaxisymmetric nozzle propulsion simulation model with an auxiliary internal water source that generated a jet flow and an axisymmetric forebody model with a circular sector strake that generated a vortex flow. The off-body flow fields around these models were investigated in the Langley 16- by 24-Inch Water Tunnel. The experimental results were used to calculate 17 quantities that included mean and fluctuating velocities, Reynolds stresses, mean and fluctuating dye fluorescence intensities (proportional to concentration), and fluctuating velocity and dye concentration correlations. An uncertainty analysis was performed to establish confidence levels in the experimental results. In general, uncertainties in mean velocities varied between 1 and 7 percent of free-stream velocity; uncertainties in fluctuating velocities varied between 1 and 5 percent of reference values. The results show characteristics that are unique to each type of flow.

Intensity inhomogeneity compensation and tissue segmentation for magnetic resonance imaging with noise-suppressed multiplicative intrinsic component optimization

NASA Astrophysics Data System (ADS)

Dong, Huaipeng; Zhang, Qi; Shi, Jun

2017-12-01

Magnetic resonance (MR) images suffer from intensity inhomogeneity. Segmentation-based approaches can simultaneously achieve both intensity inhomogeneity compensation (IIC) and tissue segmentation for MR images with little noise, but they often fail for images polluted by severe noise. Here, we propose a noise-robust algorithm named noise-suppressed multiplicative intrinsic component optimization (NSMICO) for simultaneous IIC and tissue segmentation. Considering the spatial characteristics in an image, an adaptive nonlocal means filtering term is incorporated into the objective function of NSMICO to decrease image deterioration due to noise. Then, a fuzzy local factor term utilizing the spatial and gray-level relationship among local pixels is embedded into the objective function to reach a balance between noise suppression and detail preservation. Experimental results on synthetic natural and MR images with various levels of intensity inhomogeneity and noise, as well as in vivo clinical MR images, have demonstrated the effectiveness of the NSMICO and its superiority to three competing approaches. The NSMICO could be potentially valuable for MR image IIC and tissue segmentation.

A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

PubMed

Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

2013-11-15

A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.

Image Tracking for the High Similarity Drug Tablets Based on Light Intensity Reflective Energy and Artificial Neural Network

PubMed Central

Liang, Zhongwei; Zhou, Liang; Liu, Xiaochu; Wang, Xiaogang

2014-01-01

It is obvious that tablet image tracking exerts a notable influence on the efficiency and reliability of high-speed drug mass production, and, simultaneously, it also emerges as a big difficult problem and targeted focus during production monitoring in recent years, due to the high similarity shape and random position distribution of those objectives to be searched for. For the purpose of tracking tablets accurately in random distribution, through using surface fitting approach and transitional vector determination, the calibrated surface of light intensity reflective energy can be established, describing the shape topology and topography details of objective tablet. On this basis, the mathematical properties of these established surfaces have been proposed, and thereafter artificial neural network (ANN) has been employed for classifying those moving targeted tablets by recognizing their different surface properties; therefore, the instantaneous coordinate positions of those drug tablets on one image frame can then be determined. By repeating identical pattern recognition on the next image frame, the real-time movements of objective tablet templates were successfully tracked in sequence. This paper provides reliable references and new research ideas for the real-time objective tracking in the case of drug production practices. PMID:25143781

An in-fiber integrated optofluidic device based on an optical fiber with an inner core.

PubMed

Yang, Xinghua; Yuan, Tingting; Teng, Pingping; Kong, Depeng; Liu, Chunlan; Li, Entao; Zhao, Enming; Tong, Chengguo; Yuan, Libo

2014-06-21

A new kind of optofluidic in-fiber integrated device based on a specially designed hollow optical fiber with an inner core is designed. The inlets and outlets are built by etching the surface of the optical fiber without damaging the inner core. A reaction region between the end of the fiber and a solid point obtained after melting is constructed. By injecting samples into the fiber, the liquids can form steady microflows and react in the region. Simultaneously, the emission from the chemiluminescence reaction can be detected from the remote end of the optical fiber through evanescent field coupling. The concentration of ascorbic acid (AA or vitamin C, Vc) is determined by the emission intensity of the reaction of Vc, H2O2, luminol, and K3Fe(CN)6 in the optical fiber. A linear sensing range of 0.1-3.0 mmol L(-1) for Vc is obtained. The emission intensity can be determined within 2 s at a total flow rate of 150 μL min(-1). Significantly, this work presents information for the in-fiber integrated optofluidic devices without spatial optical coupling.

Algorithmic Approaches for Place Recognition in Featureless, Walled Environments

DTIC Science & Technology

2015-01-01

inertial measurement unit LIDAR light detection and ranging RANSAC random sample consensus SLAM simultaneous localization and mapping SUSAN smallest...algorithm 38 21 Typical input image for general junction based algorithm 39 22 Short exposure image of hallway junction taken by LIDAR 40 23...discipline of simultaneous localization and mapping ( SLAM ) has been studied intensively over the past several years. Many technical approaches

Field Air Sampling and Simultaneous Chemical and Sensory Analysis of Livestock Odorants with Sorbent Tube GC-MS/Olfactometry

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

Zhang Shicheng; Department of Environmental Science and Engineering, Fudan University, Shanghai 200433; Cai Lingshuang

2009-05-23

Characterization and quantification of livestock odorants is one of the most challenging analytical tasks because odor-causing gases are very reactive, polar and often present at very low concentrations in a complex matrix of less important or irrelevant gases. The objective of this research was to develop a novel analytical method for characterization of the livestock odorants including their odor character, odor intensity, and hedonic tone and to apply this method for quantitative analysis of the key odorants responsible for livestock odor. Sorbent tubes packed with Tenax TA were used for field sampling. The automated one-step thermal desorption module coupled withmore » multidimensional gas chromatography-mass spectrometry/olfactometry system was used for simultaneous chemical and odor analysis. Fifteen odorous VOCs and semi-VOCs identified from different livestock species operations were quantified. Method detection limits ranges from 40 pg for skatole to 3590 pg for acetic acid. In addition, odor character, odor intensity and hedonic tone associated with each of the target odorants are also analyzed simultaneously. We found that the mass of each VOCs in the sample correlates well with the log stimulus intensity. All of the correlation coefficients (R{sup 2}) are greater than 0.74, and the top 10 correlation coefficients were greater than 0.90.« less

HERMES: Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy

PubMed Central

Chan, Kimberly L.; Puts, Nicolaas A. J.; Schär, Michael; Barker, Peter B.; Edden, Richard A. E.

2017-01-01

Purpose To investigate a novel Hadamard-encoded spectral editing scheme and evaluate its performance in simultaneously quantifying N-acetyl aspartate (NAA) and N-acetyl aspartyl glutamate (NAAG) at 3 Tesla. Methods Editing pulses applied according to a Hadamard encoding scheme allow the simultaneous acquisition of multiple metabolites. The method, called HERMES (Hadamard Encoding and Reconstruction of MEGA-Edited Spectroscopy), was optimized to detect NAA and NAAG simultaneously using density-matrix simulations and validated in phantoms at 3T. In vivo data were acquired in the centrum semiovale of 12 normal subjects. The NAA:NAAG concentration ratio was determined by modeling in vivo data using simulated basis functions. Simulations were also performed for potentially coedited molecules with signals within the detected NAA/NAAG region. Results Simulations and phantom experiments show excellent segregation of NAA and NAAG signals into the intended spectra, with minimal crosstalk. Multiplet patterns show good agreement between simulations and phantom and in vivo data. In vivo measurements show that the relative peak intensities of the NAA and NAAG spectra are consistent with a NAA:NAAG concentration ratio of 4.22:1 in good agreement with literature. Simulations indicate some coediting of aspartate and glutathione near the detected region (editing efficiency: 4.5% and 78.2%, respectively, for the NAAG reconstruction and 5.1% and 19.5%, respectively, for the NAA reconstruction). Conclusion The simultaneous and separable detection of two otherwise overlapping metabolites using HERMES is possible at 3T. PMID:27089868

Efficient Simultaneous Reconstruction of Time-Varying Images and Electrode Contact Impedances in Electrical Impedance Tomography.

PubMed

Boverman, Gregory; Isaacson, David; Newell, Jonathan C; Saulnier, Gary J; Kao, Tzu-Jen; Amm, Bruce C; Wang, Xin; Davenport, David M; Chong, David H; Sahni, Rakesh; Ashe, Jeffrey M

2017-04-01

In electrical impedance tomography (EIT), we apply patterns of currents on a set of electrodes at the external boundary of an object, measure the resulting potentials at the electrodes, and, given the aggregate dataset, reconstruct the complex conductivity and permittivity within the object. It is possible to maximize sensitivity to internal conductivity changes by simultaneously applying currents and measuring potentials on all electrodes but this approach also maximizes sensitivity to changes in impedance at the interface. We have, therefore, developed algorithms to assess contact impedance changes at the interface as well as to efficiently and simultaneously reconstruct internal conductivity/permittivity changes within the body. We use simple linear algebraic manipulations, the generalized singular value decomposition, and a dual-mesh finite-element-based framework to reconstruct images in real time. We are also able to efficiently compute the linearized reconstruction for a wide range of regularization parameters and to compute both the generalized cross-validation parameter as well as the L-curve, objective approaches to determining the optimal regularization parameter, in a similarly efficient manner. Results are shown using data from a normal subject and from a clinical intensive care unit patient, both acquired with the GE GENESIS prototype EIT system, demonstrating significantly reduced boundary artifacts due to electrode drift and motion artifact.

Clinical characteristics and HLA alleles of a family with simultaneously occurring alopecia areata.

PubMed

Emre, Selma; Metin, Ahmet; Caykoylu, Ali; Akoglu, Gulsen; Ceylan, Gülay G; Oztekin, Aynure; Col, Esra S

2016-06-01

Alopecia areata (AA) is a T-cell-mediated autoimmune disease resulting in partial or total noncicatricial hair loss. HLA class II antigens are the most important markers that constitute genetic predisposition to AA. Various life events and intense psychological stress may play an important role in triggering AA attacks. We report an unusual case series of 4 family members who had simultaneously occurring active AA lesions. Our aim was to evaluate the clinical and psychiatric features of 4 cases of active AA lesions occurring simultaneously in a family and determine HLA alleles. The clinical and psychological features of all patients were examined. HLA antigen DNA typing was performed by polymerase chain reaction with sequence-specific primers. All patients had typical AA lesions over the scalp and/or beard area. Psychological examinations revealed obsessive-compulsive personality disorder in the proband's parents as well as anxiety and lack of self-confidence in both the proband and his sister. HLA antigen types were not commonly shared with family members. These findings suggest that AA presenting concurrently in members of the same family was not associated with genetic predisposition. Shared psychological disorders and stressful life events might be the major key points in the concurrent presentation of these familial AA cases and development of resistance against treatments.

DETERMINATION OF ELASTIC WAVE VELOCITY AND RELATIVE HYPOCENTER LOCATIONS USING REFRACTED WAVES. II. APPLICATION TO THE HAICHENG, CHINA, AFTERSHOCK SEQUENCE.

USGS Publications Warehouse

Shedlock, Kaye M.; Jones, Lucile M.; Ma, Xiufang

1985-01-01

The authors located the aftershocks of the February 4, 1975 Haicheng, China, aftershock sequence using an arrival time difference (ATD) simultaneous inversion method for determining the near-source (in situ) velocity and the location of the aftershocks with respect to a master event. The aftershocks define a diffuse zone, 70 km multiplied by 25 km, trending west-northwest, perpendicular to the major structural trend of the region. The main shock and most of the large aftershocks have strike-slip fault plane solutions. The preferred fault plane strikes west-northwest, and the inferred sense of motion is left-lateral. The entire Haicheng earthauake sequence appears to have been the response of an intensely faulted range boundary to a primarily east-west crustal compression and/or north-south extension.

Liquid chromatography tandem mass spectrometry for the simultaneous determination of mequindox and its metabolites in porcine tissues.

PubMed

Zeng, Dongping; Shen, Xiangguang; He, Limin; Ding, Huanzhong; Tang, Youzhi; Sun, Yongxue; Fang, Binghu; Zeng, Zhenling

2012-06-01

A rapid liquid chromatography tandem mass spectrometric method was developed for the simultaneous determination of mequindox and its five metabolites (2-isoethanol mequindox, 2-isoethanol 1-desoxymequindox, 1-desoxymequindox, 1,4-bisdesoxymequindox, and 2-isoethanol bisdesoxymequindox) in porcine muscle, liver, and kidney, fulfilling confirmation criteria with two transitions for each compound with acceptable relative ion intensities. The method involved acid hydrolysis, purification by solid-phase extraction, and subsequent analysis with liquid chromatography tandem mass spectrometry using electrospray ionization operated in positive polarity with a total run time of 15 min. The decision limit values of five analytes in porcine tissues ranged from 0.6 to 2.9 μg/kg, and the detection capability values ranged from 1.2 to 5.7 μg/kg. The results of the inter-day study, which was performed by fortifying porcine muscle (2, 4, and 8 μg/kg), liver, and kidney (10, 20, and 40 μg/kg) samples on three separate days, showed that the accuracy of the method for the various analytes ranged between 75.3 and 107.2% with relative standard deviation less than 12% for each analyte. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Impact of Intensive Insulin Protocols and Restrictive Blood Transfusion Strategies on Glucose Measurement in American Burn Association (ABA) Verified Burn Centers

DTIC Science & Technology

2008-10-01

of these therapies is to concomi- tantly increase the prevalence of anemia and hypoglycemia in intensive care unit patients. Such a development is...ence of hypoglycemia . We hypothesized that most American Burn Association (ABA) veri- fied burn centers have adopted intensive insulin therapy while...simultaneously restricting blood transfusions potentially increasing risk of hypoglycemia . All ABA verified burn cen- ters (N 44) were contacted

Nosocomial Transmission and Genetic Diversity of Rhinovirus in a Neonatal Intensive Care Unit.

PubMed

Marcone, Débora Natalia; Carballal, Guadalupe; Irañeta, Mariela; Rubies, Yamile; Vidaurreta, Santiago M; Echavarría, Marcela

2018-02-01

Rhinoviruses were detected as sole pathogens in 6 preterm infants who developed severe respiratory infections while hospitalized in a neonatal intensive care unit. We confirmed 2 nosocomial rhinovirus transmission episodes and describe the genetic diversity of rhinovirus strains that circulated simultaneously during a winter season. Copyright © 2017 Elsevier Inc. All rights reserved.

A dual-wavelength light-emitting diode based detector for flow-injection analysis process analysers.

PubMed

Huang, J; Liu, H; Tan, A; Xu, J; Zhao, X

1992-06-01

In this paper, a small dual-wavelength light-emitting diode (LED) based detector for FIA process analysers is designed. The detector's optical parts include a flow cell, a dual-wavelength LED and a photodiode. Neither mirrors nor lenses are used. The optical paths for the different light beams are almost the same, distinguishing it from previously reported LED based detectors. The detector's electronic components, including a signal amplifier, an A/D and D/A converter, and an Intel 8031 single-chip microcomputer, are integrated on one small board. In order to obtain response signals of approximate intensity for the two colours, the D/A converter and a multiplexer are used to adjust the emission intensity of the two colours respectively. Under microcomputer control, light beams are rapidly electronically modulated. Therefore, dark current and intensity of the light beams are measured almost simultaneously; as a result, the effect of drift is negligible. While a solution of absorbance 0.875 was measured repeatedly, an RSD (relative standard deviation) of 0.24% could be reached. Furthermore, such a detector with a red/yellow LED has been coupled with the FIA technique for the determination of 10(-6)M levels of cobalt.

Laughter exaggerates happy and sad faces depending on visual context.

PubMed

Sherman, Aleksandra; Sweeny, Timothy D; Grabowecky, Marcia; Suzuki, Satoru

2012-04-01

Laughter is an auditory stimulus that powerfully conveys positive emotion. We investigated how laughter influenced the visual perception of facial expressions. We presented a sound clip of laughter simultaneously with a happy, a neutral, or a sad schematic face. The emotional face was briefly presented either alone or among a crowd of neutral faces. We used a matching method to determine how laughter influenced the perceived intensity of the happy, neutral, and sad expressions. For a single face, laughter increased the perceived intensity of a happy expression. Surprisingly, for a crowd of faces, laughter produced an opposite effect, increasing the perceived intensity of a sad expression in a crowd. A follow-up experiment revealed that this contrast effect may have occurred because laughter made the neutral distractor faces appear slightly happy, thereby making the deviant sad expression stand out in contrast. A control experiment ruled out semantic mediation of the laughter effects. Our demonstration of the strong context dependence of laughter effects on facial expression perception encourages a reexamination of the previously demonstrated effects of prosody, speech content, and mood on face perception, as they may be similarly context dependent.

Measurement of neutron and charged particle fluxes toward earthquake prediction

NASA Astrophysics Data System (ADS)

Maksudov, Asatulla U.; Zufarov, Mars A.

2017-12-01

In this paper, we describe a possible method for predicting the earthquakes, which is based on simultaneous recording of the intensity of fluxes of neutrons and charged particles by detectors, commonly used in nuclear physics. These low-energy particles originate from radioactive nuclear processes in the Earth's crust. The variations in the particle flux intensity can be the precursor of the earthquake. A description is given of an electronic installation that records the fluxes of charged particles in the radial direction, which are a possible response to the accumulated tectonic stresses in the Earth's crust. The obtained results showed an increase in the intensity of the fluxes for 10 or more hours before the occurrence of the earthquake. The previous version of the installation was able to indicate for the possibility of an earthquake (Maksudov et al. in Instrum Exp Tech 58:130-131, 2015), but did not give information about the direction of the epicenter location. In this regard, the installation was modified by adding eight directional detectors. With the upgraded setup, we have received both the predictive signals, and signals determining the directions of the location of the forthcoming earthquake, starting 2-3 days before its origin.

Increased vocal intensity due to the Lombard effect in speakers with Parkinson's disease: simultaneous laryngeal and respiratory strategies.

PubMed

Stathopoulos, Elaine T; Huber, Jessica E; Richardson, Kelly; Kamphaus, Jennifer; DeCicco, Devan; Darling, Meghan; Fulcher, Katrina; Sussman, Joan E

2014-01-01

The objective of the present study was to investigate whether speakers with hypophonia, secondary to Parkinson's disease (PD), would increases their vocal intensity when speaking in a noisy environment (Lombard effect). The other objective was to examine the underlying laryngeal and respiratory strategies used to increase vocal intensity. Thirty-three participants with PD were included for study. Each participant was fitted with the SpeechVive™ device that played multi-talker babble noise into one ear during speech. Using acoustic, aerodynamic and respiratory kinematic techniques, the simultaneous laryngeal and respiratory mechanisms used to regulate vocal intensity were examined. Significant group results showed that most speakers with PD (26/33) were successful at increasing their vocal intensity when speaking in the condition of multi-talker babble noise. They were able to support their increased vocal intensity and subglottal pressure with combined strategies from both the laryngeal and respiratory mechanisms. Individual speaker analysis indicated that the particular laryngeal and respiratory interactions differed among speakers. The SpeechVive™ device elicited higher vocal intensities from patients with PD. Speakers used different combinations of laryngeal and respiratory physiologic mechanisms to increase vocal intensity, thus suggesting that disease process does not uniformly affect the speech subsystems. Readers will be able to: (1) identify speech characteristics of people with Parkinson's disease (PD), (2) identify typical respiratory strategies for increasing sound pressure level (SPL), (3) identify typical laryngeal strategies for increasing SPL, (4) define the Lombard effect. Copyright © 2014 Elsevier Inc. All rights reserved.

[Concept for a department of intensive care].

PubMed

Nierhaus, A; de Heer, G; Kluge, S

2014-10-01

Demographic change and increasing complexity are among the reasons for high-tech critical care playing a major and increasing role in today's hospitals. At the same time, intensive care is one of the most cost-intensive departments in the hospital. To guarantee high-quality care, close cooperation of specialised intensive care staff with specialists of all other medical areas is essential. A network of the intensive care units within the hospital may lead to synergistic effects concerning quality of care, simultaneously optimizing the use of human and technical resources. Notwithstanding any organisational concepts, development and maintenance of the highest possible quality of care should be of overriding importance.

NMR relaxometric properties and cytotoxicity of Gd2O3 nanoparticle suspensions in an organic liquid

NASA Astrophysics Data System (ADS)

Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

2014-10-01

Gd2O3 nanoparticles and their agglomerates from approximately 10 to 80 nm in size suspended in an organic liquid were synthesized via polyol route. The reaction between diethylene glycol and added acetic acid, which occurred simultaneously with the synthesis of Gd2O3 nanoparticles, was catalyzed by sodium bisulfate to transform as much as possible diethylene glycol in corresponding ester at the end of complete reaction. The produced nanosized material of gadolinium oxide was investigated by TEM, DLS, FTIR spectroscopy, and NMR relaxometry. Biological evaluation of this material was done by MTT and crystal violet assays to determine the cell viability. Longitudinal and transverse relaxivities of water-diluted Gd2O3 nanoparticle suspensions estimated to be r 1 = 13.6 and r 2 = 14.7 s-1 mM-1 are about three times higher compared to the relaxivities obtained for standard contrast agent Gd-DTPA (Magnevist). Good MRI signal intensities of the water-diluted Gd2O3 nanoparticle suspensions were recorded in the Gd concentration range 0.2-0.3 mM for which the suspensions were not toxic exhibiting simultaneously higher signal intensities than those for Magnevist in the Gd concentration range 0.4-1 mM for which this standard contrast agent was not toxic. These properties make the produced Gd2O3 nanoparticle material promising for potential application as MRI contrast agent.

Body molt of male long-tailed ducks in the nearshore waters of the north slope, Alaska

USGS Publications Warehouse

Howell, M.D.; Grand, J.B.; Flint, Paul L.

2003-01-01

We examined the timing and intensity of body molt in relation to stage of remige growth for postbreeding adult male Long-tailed Ducks (Clangula hyemalis) off the coast of northern Alaska. During this period, remige and rectrix feathers are molted simultaneously with body feathers during the prebasic molt, which results in a period of increased energetic and nutritional demands. We collected birds from late July through mid-August and recorded intensity of molt in eight regions: head and neck, back and rump, greater coverts, lesser coverts, flank and sides, breast, belly, and tail. Using nonlinear regression, we estimated the peak intensity and variation for each region in relation to ninth primary length. We found little evidence of molt in the head and neck region. The greater and lesser coverts, and back and rump reached peak molt intensities earliest and were followed by tail, breast, and belly. Molt intensity in the flank and side region was highly variable and indicated a more prolonged molting pattern in relation to other regions. While body molt occurs simultaneously with wing molt, we found that molt among regions occurred in a staggered pattern. Long-tailed Ducks may employ this staggered molting pattern to minimize the energetic and nutritional requirements of molt.

Stacking order dynamics in the quasi-two-dimensional dichalcogenide 1 T-TaS 2 probed with MeV ultrafast electron diffraction

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

Le Guyader, L.; Chase, T.; Reid, A. H.

Transitions between different charge density wave (CDW) states in quasi-two-dimensional materials may be accompanied also by changes in the inter-layer stacking of the CDW. Using MeV ultrafast electron diffraction, the out-of-plane stacking order dynamics in the quasi-two-dimensional dichalcogenide 1 T-TaS 2 is investigated for the first time. From the intensity of the CDW satellites aligned around the commensurate l = 1/6 characteristic stacking order, it is found out that this phase disappears with a 0.3 ps time constant. Simultaneously, in the same experiment, the emergence of the incommensurate phase, with a slightly slower 2.0 ps time constant, is determined frommore » the intensity of the CDW satellites aligned around the incommensurate l = 1/3 characteristic stacking order. Finally, these results might be of relevance in understanding the metallic character of the laser-induced metastable “hidden” state recently discovered in this compound.« less

Temperature Dependence of Brillouin Light Scattering Spectra of Acoustic Phonons in Silicon

NASA Astrophysics Data System (ADS)

Somerville, Kevin; Klimovich, Nikita; An, Kyongmo; Sullivan, Sean; Weathers, Annie; Shi, Li; Li, Xiaoqin

2015-03-01

Thermal management represents an outstanding challenge in many areas of technology. Electrons, optical phonons, and acoustic phonons are often driven out of local equilibrium in electronic devices or during laser-material interaction processes. Interest in non-equilibrium transport processes has motivated the development of Raman spectroscopy as a local temperature sensor of optical phonons and intermediate frequency acoustic phonons, whereas Brillouin light scattering (BLS) has recently been explored as a temperature sensor of low-frequency acoustic phonons. Here, we report temperature dependent BLS spectra of silicon, with Raman spectra taken simultaneously for comparison. The origins of the observed temperature dependence of the BLS peak position, linewidth, and intensity are examined in order to evaluate their potential use as temperature sensors for acoustic phonons. We determine that the integrated BLS intensity can be used measure the temperature of specific acoustic phonon modes. This work is supported by National Science Foundation (NSF) Thermal Transport Processes Program under Grant CBET-1336968.

Simultaneous Measurement of Thermophysical Properties of Tissue-Mimicking Phantoms for High Intensity Focused Ultrasound (HIFU) Exposures

NASA Astrophysics Data System (ADS)

Gao, Jing; You, Jiang; Huang, Zhihong; Cochran, Sandy; Corner, George

2012-03-01

Tissue-mimicking phantoms, including bovine serum albumin phantoms and egg white phantoms, have been developed for, and in laboratory use for, real-time visualization of high intensity focused ultrasound-induced thermal coagulative necrosis since 2001. However, until now, very few data are available concerning their thermophysical properties. In this article, a step-wise transient plane source method has been used to determine the values of thermal conductivity, thermal diffusivity, and specific heat capacity of egg white phantoms with elevated egg white concentrations (0 v/v% to 40 v/v%, by 10 v/v% interval) at room temperature (~20 °C). The measured thermophysical properties were close to previously reported values; the thermal conductivity and thermal diffusivity were linearly proportional to the egg white concentration within the investigation range, while the specific heat capacity decreased as the egg white concentration increased. Taking account of large differences between real experiment and ideal model, data variations within 20 % were accepted.

Stacking order dynamics in the quasi-two-dimensional dichalcogenide 1T-TaS2 probed with MeV ultrafast electron diffraction.

PubMed

Le Guyader, L; Chase, T; Reid, A H; Li, R K; Svetin, D; Shen, X; Vecchione, T; Wang, X J; Mihailovic, D; Dürr, H A

2017-07-01

Transitions between different charge density wave (CDW) states in quasi-two-dimensional materials may be accompanied also by changes in the inter-layer stacking of the CDW. Using MeV ultrafast electron diffraction, the out-of-plane stacking order dynamics in the quasi-two-dimensional dichalcogenide 1 T -TaS 2 is investigated for the first time. From the intensity of the CDW satellites aligned around the commensurate l  = 1/6 characteristic stacking order, it is found out that this phase disappears with a 0.3 ps time constant. Simultaneously, in the same experiment, the emergence of the incommensurate phase, with a slightly slower 2.0 ps time constant, is determined from the intensity of the CDW satellites aligned around the incommensurate l  = 1/3 characteristic stacking order. These results might be of relevance in understanding the metallic character of the laser-induced metastable "hidden" state recently discovered in this compound.

Stacking order dynamics in the quasi-two-dimensional dichalcogenide 1 T-TaS 2 probed with MeV ultrafast electron diffraction

DOE PAGES

Le Guyader, L.; Chase, T.; Reid, A. H.; ...

2017-05-03

Transitions between different charge density wave (CDW) states in quasi-two-dimensional materials may be accompanied also by changes in the inter-layer stacking of the CDW. Using MeV ultrafast electron diffraction, the out-of-plane stacking order dynamics in the quasi-two-dimensional dichalcogenide 1 T-TaS 2 is investigated for the first time. From the intensity of the CDW satellites aligned around the commensurate l = 1/6 characteristic stacking order, it is found out that this phase disappears with a 0.3 ps time constant. Simultaneously, in the same experiment, the emergence of the incommensurate phase, with a slightly slower 2.0 ps time constant, is determined frommore » the intensity of the CDW satellites aligned around the incommensurate l = 1/3 characteristic stacking order. Finally, these results might be of relevance in understanding the metallic character of the laser-induced metastable “hidden” state recently discovered in this compound.« less

A pilot study of a novel smartphone application for the estimation of sleep onset.

PubMed

Scott, Hannah; Lack, Leon; Lovato, Nicole

2018-02-01

The aim of the study was to investigate the accuracy of Sleep On Cue: a novel iPhone application that uses behavioural responses to auditory stimuli to estimate sleep onset. Twelve young adults underwent polysomnography recording while simultaneously using Sleep On Cue. Participants completed as many sleep-onset trials as possible within a 2-h period following their normal bedtime. On each trial, participants were awoken by the app following behavioural sleep onset. Then, after a short break of wakefulness, commenced the next trial. There was a high degree of correspondence between polysomnography-determined sleep onset and Sleep On Cue behavioural sleep onset, r = 0.79, P < 0.001. On average, Sleep On Cue overestimated sleep-onset latency by 3.17 min (SD = 3.04). When polysomnography sleep onset was defined as the beginning of N2 sleep, the discrepancy was reduced considerably (M = 0.81, SD = 1.96). The discrepancy between polysomnography and Sleep On Cue varied between individuals, which was potentially due to variations in auditory stimulus intensity. Further research is required to determine whether modifications to the stimulus intensity and behavioural response could improve the accuracy of the app. Nonetheless, Sleep On Cue is a viable option for estimating sleep onset and may be used to administer Intensive Sleep Retraining or facilitate power naps in the home environment. © 2017 European Sleep Research Society.

Attentional bias to emotional stimuli is altered during moderate- but not high-intensity exercise.

PubMed

Tian, Qu; Smith, J Carson

2011-12-01

Little is known regarding how attention to emotional stimuli is affected during simultaneously performed exercise. Attentional biases to emotional face stimuli were assessed in 34 college students (17 women) using the dot-probe task during counterbalanced conditions of moderate- (heart rate at 45% peak oxygen consumption) and high-intensity exercise (heart rate at 80% peak oxygen consumption) compared with seated rest. The dot-probe task consisted of 1 emotional face (pleasant or unpleasant) paired with a neutral face for 1,000 ms; 256 trials (128 trials for each valence) were presented during each condition. Each condition lasted approximately 10 min. Participants were instructed to perform each trial of the dot-probe task as quickly and accurately as possible during the exercise and rest conditions. During moderate-intensity exercise, participants exhibited significantly greater attentional bias scores to pleasant compared with unpleasant faces (p < .01), whereas attentional bias scores to emotional faces did not differ at rest or during high-intensity exercise (p > .05). In addition, the attentional bias to unpleasant faces was significantly reduced during moderate-intensity exercise compared with that during rest (p < .05). These results provide behavioral evidence that during exercise at a moderate intensity, there is a shift in attention allocation toward pleasant emotional stimuli and away from unpleasant emotional stimuli. Future work is needed to determine whether acute exercise may be an effective treatment approach to reduce negative bias or enhance positive bias in individuals diagnosed with mood or anxiety disorders, or whether attentional bias during exercise predicts adherence to exercise. (c) 2011 APA, all rights reserved.

Validity of Various Methods for Determining Velocity, Force, and Power in the Back Squat.

PubMed

Banyard, Harry G; Nosaka, Ken; Sato, Kimitake; Haff, G Gregory

2017-10-01

To examine the validity of 2 kinematic systems for assessing mean velocity (MV), peak velocity (PV), mean force (MF), peak force (PF), mean power (MP), and peak power (PP) during the full-depth free-weight back squat performed with maximal concentric effort. Ten strength-trained men (26.1 ± 3.0 y, 1.81 ± 0.07 m, 82.0 ± 10.6 kg) performed three 1-repetition-maximum (1RM) trials on 3 separate days, encompassing lifts performed at 6 relative intensities including 20%, 40%, 60%, 80%, 90%, and 100% of 1RM. Each repetition was simultaneously recorded by a PUSH band and commercial linear position transducer (LPT) (GymAware [GYM]) and compared with measurements collected by a laboratory-based testing device consisting of 4 LPTs and a force plate. Trials 2 and 3 were used for validity analyses. Combining all 120 repetitions indicated that the GYM was highly valid for assessing all criterion variables while the PUSH was only highly valid for estimations of PF (r = .94, CV = 5.4%, ES = 0.28, SEE = 135.5 N). At each relative intensity, the GYM was highly valid for assessing all criterion variables except for PP at 20% (ES = 0.81) and 40% (ES = 0.67) of 1RM. Moreover, the PUSH was only able to accurately estimate PF across all relative intensities (r = .92-.98, CV = 4.0-8.3%, ES = 0.04-0.26, SEE = 79.8-213.1 N). PUSH accuracy for determining MV, PV, MF, MP, and PP across all 6 relative intensities was questionable for the back squat, yet the GYM was highly valid at assessing all criterion variables, with some caution given to estimations of MP and PP performed at lighter loads.

Optimized scheduling of VLBI UT1 intensive sessions for twin telescopes employing impact factor analysis

NASA Astrophysics Data System (ADS)

Leek, Judith; Artz, Thomas; Nothnagel, Axel

2015-09-01

Daily Very Long Baseline Interferometry (VLBI) intensive measurements make an important contribution to the regular monitoring of Earth rotation variations. Since these variations are quite rapid, their knowledge is important for navigation with global navigation satellite system and for investigations in Earth sciences. Unfortunately, the precision of VLBI intensive observations is 2-3 times worse than the precision of regular 24h-VLBI measurements with networks of 5-10 radio telescopes. The major advancement of research in this paper is the improvement of VLBI intensive results by (a) using twin telescopes instead of single telescopes and (b) applying an entirely new scheduling concept for the individual observations. Preparatory investigations of standardintensive sessions suggest that the impact factors of the observations are well suited for the identification of the most influential observations which are needed for the determination of certain parameters within the entire design of a VLBI session. Based on this experience, the scheduling method is designed for optimizing the observations' geometry for a given network of radio telescopes and a predefined set of parameters to be estimated. The configuration of at least two twin telescopes, or one twin and two single telescopes, offers the possibility of building pairwise sub-nets that observe two different sources simultaneously. In addition to an optimized observing plan, a special parametrization for twin telescopes leads to an improved determination of Earth rotation variations, as it is shown by simulated observations. In general, an improvement of about 50 % in the formal errors can be realized using twin radio telescopes. This result is only due to geometric improvements as higher slew rates of the twin telescopes are not taken into account.

Analysis of calibration-free wavelength-scanned wavelength modulation spectroscopy for practical gas sensing using tunable diode lasers

NASA Astrophysics Data System (ADS)

Sun, K.; Chao, X.; Sur, R.; Goldenstein, C. S.; Jeffries, J. B.; Hanson, R. K.

2013-12-01

A novel strategy has been developed for analysis of wavelength-scanned, wavelength modulation spectroscopy (WMS) with tunable diode lasers (TDLs). The method simulates WMS signals to compare with measurements to determine gas properties (e.g., temperature, pressure and concentration of the absorbing species). Injection-current-tuned TDLs have simultaneous wavelength and intensity variation, which severely complicates the Fourier expansion of the simulated WMS signal into harmonics of the modulation frequency (fm). The new method differs from previous WMS analysis strategies in two significant ways: (1) the measured laser intensity is used to simulate the transmitted laser intensity and (2) digital lock-in and low-pass filter software is used to expand both simulated and measured transmitted laser intensities into harmonics of the modulation frequency, WMS-nfm (n = 1, 2, 3,…), avoiding the need for an analytic model of intensity modulation or Fourier expansion of the simulated WMS harmonics. This analysis scheme is valid at any optical depth, modulation index, and at all values of scanned-laser wavelength. The method is demonstrated and validated with WMS of H2O dilute in air (1 atm, 296 K, near 1392 nm). WMS-nfm harmonics for n = 1 to 6 are extracted and the simulation and measurements are found in good agreement for the entire WMS lineshape. The use of 1f-normalization strategies to realize calibration-free wavelength-scanned WMS is also discussed.

On the relationship between image intensity and velocity in a turbulent boundary layer seeded with smoke particles

NASA Astrophysics Data System (ADS)

Melnick, M. Blake; Thurow, Brian S.

2014-02-01

Simultaneous particle image velocimetry (PIV) and flow visualization measurements were performed in a turbulent boundary layer in an effort to better quantify the relationship between the velocity field and the image intensity typically observed in a classical flow visualization experiment. The freestream flow was lightly seeded with smoke particles to facilitate PIV measurements, whereas the boundary layer was densely seeded with smoke through an upstream slit in the wall to facilitate both PIV and classical flow visualization measurements at Reynolds numbers, Re θ , ranging from 2,100 to 8,600. Measurements were taken with and without the slit covered as well as with and without smoke injection. The addition of a narrow slit in the wall produces a minor modification of the nominal turbulent boundary layer profile whose effect is reduced with downstream distance. The presence of dense smoke in the boundary layer had a minimal effect on the observed velocity field and the associated proper orthogonal decomposition (POD) modes. Analysis of instantaneous images shows that the edge of the turbulent boundary layer identified from flow visualization images generally matches the edge of the boundary layer determined from velocity and vorticity. The correlation between velocity deficit and smoke intensity was determined to be positive and relatively large (>0.7) indicating a moderate-to-strong relationship between the two. This notion was extended further through the use of a direct correlation approach and a complementary POD/linear stochastic estimation (LSE) approach to estimate the velocity field directly from flow visualization images. This exercise showed that, in many cases, velocity fields estimated from smoke intensity were similar to the actual velocity fields. The complementary POD/LSE approach proved better for these estimations, but not enough to suggest using this technique to approximate velocity measurements from a smoke intensity image. Instead, the correlations further validate the use of flow visualization techniques for determining the edge and large-scale shape of a turbulent boundary layer, specifically when quantitative velocity measurements, such as PIV, are not possible in a given experiment.

Short rise time intense electron beam generator

DOEpatents

Olson, Craig L.

1987-01-01

A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

Short rise time intense electron beam generator

DOEpatents

Olson, C.L.

1984-03-16

A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

Measured electric field intensities near electric cloud discharges detected by the Kennedy Space Center's Lightning Detection and Ranging System, LDAR

NASA Technical Reports Server (NTRS)

Poehler, H. A.

1977-01-01

For a summer thunderstorm, for which simultaneous, airborne electric field measurements and Lightning Detection and Ranging (LDAR) System data was available, measurements were coordinated to present a picture of the electric field intensity near cloud electrical discharges detected by the LDAR System. Radar precipitation echos from NOAA's 10 cm weather radar and measured airborne electric field intensities were superimposed on LDAR PPI plots to present a coordinated data picture of thunderstorm activity.

Blue intensity matters for cell cycle profiling in fluorescence DAPI-stained images.

PubMed

Ferro, Anabela; Mestre, Tânia; Carneiro, Patrícia; Sahumbaiev, Ivan; Seruca, Raquel; Sanches, João M

2017-05-01

In the past decades, there has been an amazing progress in the understanding of the molecular mechanisms of the cell cycle. This has been possible largely due to a better conceptualization of the cycle itself, but also as a consequence of technological advances. Herein, we propose a new fluorescence image-based framework targeted at the identification and segmentation of stained nuclei with the purpose to determine DNA content in distinct cell cycle stages. The method is based on discriminative features, such as total intensity and area, retrieved from in situ stained nuclei by fluorescence microscopy, allowing the determination of the cell cycle phase of both single and sub-population of cells. The analysis framework was built on a modified k-means clustering strategy and refined with a Gaussian mixture model classifier, which enabled the definition of highly accurate classification clusters corresponding to G1, S and G2 phases. Using the information retrieved from area and fluorescence total intensity, the modified k-means (k=3) cluster imaging framework classified 64.7% of the imaged nuclei, as being at G1 phase, 12.0% at G2 phase and 23.2% at S phase. Performance of the imaging framework was ascertained with normal murine mammary gland cells constitutively expressing the Fucci2 technology, exhibiting an overall sensitivity of 94.0%. Further, the results indicate that the imaging framework has a robust capacity to both identify a given DAPI-stained nucleus to its correct cell cycle phase, as well as to determine, with very high probability, true negatives. Importantly, this novel imaging approach is a non-disruptive method that allows an integrative and simultaneous quantitative analysis of molecular and morphological parameters, thus awarding the possibility of cell cycle profiling in cytological and histological samples.

Simultaneous 3D coincidence imaging of cationic, anionic, and neutral photo-fragments

NASA Astrophysics Data System (ADS)

Shahi, Abhishek; Albeck, Yishai; Strasser, Daniel

2018-01-01

We present the design and simulations of a 3D coincidence imaging spectrometer for fast beam photofragmentation experiments. Coincidence detection of cationic, neutral, and anionic fragments involves spectrometer aberrations that are successfully corrected by an analytical model combined with exact numerical simulations. The spectrometer performance is experimentally demonstrated by characterization of four different channels of intense 800 nm pulse interaction with F2-: F- + F photodissociation, F + F dissociative photodetachment, F+ + F dissociative ionization, and F+ + F+ coulomb explosion. Improved measurement of F2- photodissociation with a 400 nm photon allows a better determination of the F2- anion dissociation energy, 1.256 ± 0.005 eV.

Least-Squares Self-Calibration of Imaging Array Data

NASA Technical Reports Server (NTRS)

Arendt, R. G.; Moseley, S. H.; Fixsen, D. J.

2004-01-01

When arrays are used to collect multiple appropriately-dithered images of the same region of sky, the resulting data set can be calibrated using a least-squares minimization procedure that determines the optimal fit between the data and a model of that data. The model parameters include the desired sky intensities as well as instrument parameters such as pixel-to-pixel gains and offsets. The least-squares solution simultaneously provides the formal error estimates for the model parameters. With a suitable observing strategy, the need for separate calibration observations is reduced or eliminated. We show examples of this calibration technique applied to HST NICMOS observations of the Hubble Deep Fields and simulated SIRTF IRAC observations.

Simultaneous optical flow and source estimation: Space–time discretization and preconditioning

PubMed Central

Andreev, R.; Scherzer, O.; Zulehner, W.

2015-01-01

We consider the simultaneous estimation of an optical flow field and an illumination source term in a movie sequence. The particular optical flow equation is obtained by assuming that the image intensity is a conserved quantity up to possible sources and sinks which represent varying illumination. We formulate this problem as an energy minimization problem and propose a space–time simultaneous discretization for the optimality system in saddle-point form. We investigate a preconditioning strategy that renders the discrete system well-conditioned uniformly in the discretization resolution. Numerical experiments complement the theory. PMID:26435561

Improved Optics For Quasi-Elastic Light Scattering

NASA Technical Reports Server (NTRS)

Cheung, Harry Michael

1995-01-01

Improved optical train devised for use in light-scattering measurements of quasi-elastic light scattering (QELS) and laser spectroscopy. Measurements performed on solutions, microemulsions, micellular solutions, and colloidal dispersions. Simultaneous measurements of total intensity and fluctuations in total intensity of light scattered from sample at various angles provides data used, in conjunction with diffusion coefficients, to compute sizes of particles in sample.

Model and reconstruction of a K-edge contrast agent distribution with an X-ray photon-counting detector

PubMed Central

Meng, Bo; Cong, Wenxiang; Xi, Yan; De Man, Bruno; Yang, Jian; Wang, Ge

2017-01-01

Contrast-enhanced computed tomography (CECT) helps enhance the visibility for tumor imaging. When a high-Z contrast agent interacts with X-rays across its K-edge, X-ray photoelectric absorption would experience a sudden increment, resulting in a significant difference of the X-ray transmission intensity between the left and right energy windows of the K-edge. Using photon-counting detectors, the X-ray intensity data in the left and right windows of the K-edge can be measured simultaneously. The differential information of the two kinds of intensity data reflects the contrast-agent concentration distribution. K-edge differences between various matters allow opportunities for the identification of contrast agents in biomedical applications. In this paper, a general radon transform is established to link the contrast-agent concentration to X-ray intensity measurement data. An iterative algorithm is proposed to reconstruct a contrast-agent distribution and tissue attenuation background simultaneously. Comprehensive numerical simulations are performed to demonstrate the merits of the proposed method over the existing K-edge imaging methods. Our results show that the proposed method accurately quantifies a distribution of a contrast agent, optimizing the contrast-to-noise ratio at a high dose efficiency. PMID:28437900

Acquisition of a full-resolution image and aliasing reduction for a spatially modulated imaging polarimeter with two snapshots

PubMed Central

Zhang, Jing; Yuan, Changan; Huang, Guohua; Zhao, Yinjun; Ren, Wenyi; Cao, Qizhi; Li, Jianying; Jin, Mingwu

2018-01-01

A snapshot imaging polarimeter using spatial modulation can encode four Stokes parameters allowing instantaneous polarization measurement from a single interferogram. However, the reconstructed polarization images could suffer a severe aliasing signal if the high-frequency component of the intensity image is prominent and occurs in the polarization channels, and the reconstructed intensity image also suffers reduction of spatial resolution due to low-pass filtering. In this work, a method using two anti-phase snapshots is proposed to address the two problems simultaneously. The full-resolution target image and the pure interference fringes can be obtained from the sum and the difference of the two anti-phase interferograms, respectively. The polarization information reconstructed from the pure interference fringes does not contain the aliasing signal from the high-frequency component of the object intensity image. The principles of the method are derived and its feasibility is tested by both computer simulation and a verification experiment. This work provides a novel method for spatially modulated imaging polarization technology with two snapshots to simultaneously reconstruct a full-resolution object intensity image and high-quality polarization components. PMID:29714224

A fiber-optic interferometer based on non-adiabatic fiber taper and long-period fiber grating for simultaneous measurement of magnetic field and temperature

NASA Astrophysics Data System (ADS)

Kang, Shouxin; Zhang, Hao; Liu, Bo; Lin, Wei; Zhang, Ning; Miao, Yinping

2016-01-01

A dual-parameter sensor based on a fiber-optic interferometer consisting of a non-adiabatic fiber taper and a long-period fiber grating (LPFG) integrated with magnetic nanoparticle fluids has been proposed and experimentally demonstrated. Due to the Mach-Zehnder interference induced by the concatenation of the fiber taper and long-period grating, an interferometric spectrum could be acquired within the transmission resonance spectral envelope of the LPFG. Thanks to different magnetic field and temperature sensitivities of difference interference dips, simultaneous measurement of the magnetic field intensity and environmental temperature could be achieved. Moreover, due to the variation in coupling coefficients of the fiber taper and the LPFG in response to the change of the applied magnetic field intensity, some of the interference dips would exhibit opposite magnetic-field-intensity-dependent transmission loss variation behavior. Magnetic field intensity and temperature sensitivities of 0.017 31 dB Oe-1 and 0.0315 dB K-1, and -0.024 55 dB Oe-1 and -0.056 28 dB K-1 were experimentally acquired for the experimentally monitored interference dips.

Subadditive responses to extremely short blue and green pulsed light on visual evoked potentials, pupillary constriction and electroretinograms.

PubMed

Lee, Soomin; Uchiyama, Yuria; Shimomura, Yoshihiro; Katsuura, Tetsuo

2017-11-17

The simultaneous exposure to blue and green light was reported to result in less melatonin suppression than monochromatic exposure to blue or green light. Here, we conducted an experiment using extremely short blue- and green-pulsed light to examine their visual and nonvisual effects on visual evoked potentials (VEPs), pupillary constriction, electroretinograms (ERGs), and subjective evaluations. Twelve adult male subjects were exposed to three light conditions: blue-pulsed light (2.5-ms pulse width), green-pulsed light (2.5-ms pulse width), and simultaneous blue- and green-pulsed light with white background light. We measured the subject's pupil diameter three times in each condition. Then, after 10 min of rest, the subject was exposed to the same three light conditions. We measured the averaged ERG and VEP during 210 pulsed-light exposures in each condition. We also determined subjective evaluations using a visual analog scale (VAS) method. The pupillary constriction during the simultaneous exposure to blue- and green-pulsed light was significantly lower than that during the blue-pulsed light exposure despite the double irradiance intensity of the combination. We also found that the b/|a| wave of the ERGs during the simultaneous exposure to blue- and green-pulsed light was lower than that during the blue-pulsed light exposure. We confirmed the subadditive response to pulsed light on pupillary constriction and ERG. However, the P100 of the VEPs during the blue-pulsed light were smaller than those during the simultaneous blue- and green-pulsed light and green-pulsed light, indicating that the P100 amplitude might depend on the luminance of light. Our findings demonstrated the effect of the subadditive response to extremely short pulsed light on pupillary constriction and ERG responses. The effects on ipRGCs by the blue-pulsed light exposure are apparently reduced by the simultaneous irradiation of green light. The blue versus yellow (b/y) bipolar cells in the retina might be responsible for this phenomenon.

Experimental Determination of Infrared Extinction Coefficients of Interplanetary Dust Particles

NASA Technical Reports Server (NTRS)

Spann, J. F., Jr.; Abbas, M. M.

1998-01-01

This technique is based on irradiating a single isolated charged dust particle suspended in balance by an electric field, and measuring the scattered radiation as a function of angle. The observed scattered intensity profile at a specific wavelength obtained for a dust particle of known composition is compared with Mie theory calculations, and the variable parameters relating to the particle size and complex refractive index are adjusted for a best fit between the two profiles. This leads to a simultaneous determination of the particle radius, the complex refractive index, and the scattering and extinction coefficients. The results of these experiments can be utilized to examine the IRAS and DIRBE (Diffuse Infrared Background Experiment) infrared data sets in order to determine the dust particle physical characteristics and distributions by using infrared models and inversion techniques. This technique may also be employed for investigation of the rotational bursting phenomena whereby large size cosmic and interplanetary particles are believed to fragment into smaller dust particles.

Oximeter for reliable clinical determination of blood oxygen saturation in a fetus

DOEpatents

Robinson, Mark R.; Haaland, David M.; Ward, Kenneth J.

1996-01-01

With the crude instrumentation now in use to continuously monitor the status of the fetus at delivery, the obstetrician and labor room staff not only over-recognize the possibility of fetal distress with the resultant rise in operative deliveries, but at times do not identify fetal distress which may result in preventable fetal neurological harm. The invention, which addresses these two basic problems, comprises a method and apparatus for non-invasive determination of blood oxygen saturation in the fetus. The apparatus includes a multiple frequency light source which is coupled to an optical fiber. The output of the fiber is used to illuminate blood containing tissue of the fetus. In the preferred embodiment, the reflected light is transmitted back to the apparatus where the light intensities are simultaneously detected at multiple frequencies. The resulting spectrum is then analyzed for determination of oxygen saturation. The analysis method uses multivariate calibration techniques that compensate for nonlinear spectral response, model interfering spectral responses and detect outlier data with high sensitivity.

Simultaneous quantification and identification of individual chemicals in metabolite mixtures by two-dimensional extrapolated time-zero (1)H-(13)C HSQC (HSQC(0)).

PubMed

Hu, Kaifeng; Westler, William M; Markley, John L

2011-02-16

Quantitative one-dimensional (1D) (1)H NMR spectroscopy is a useful tool for determining metabolite concentrations because of the direct proportionality of signal intensity to the quantity of analyte. However, severe signal overlap in 1D (1)H NMR spectra of complex metabolite mixtures hinders accurate quantification. Extension of 1D (1)H to 2D (1)H-(13)C HSQC leads to the dispersion of peaks along the (13)C dimension and greatly alleviates peak overlapping. Although peaks are better resolved in 2D (1)H-(13)C HSQC than in 1D (1)H NMR spectra, the simple proportionality of cross peaks to the quantity of individual metabolites is lost by resonance-specific signal attenuation during the coherence transfer periods. As a result, peaks for individual metabolites usually are quantified by reference to calibration data collected from samples of known concentration. We show here that data from a series of HSQC spectra acquired with incremented repetition times (the time between the end of the first (1)H excitation pulse to the beginning of data acquisition) can be extrapolated back to zero time to yield a time-zero 2D (1)H-(13)C HSQC spectrum (HSQC(0)) in which signal intensities are proportional to concentrations of individual metabolites. Relative concentrations determined from cross peak intensities can be converted to absolute concentrations by reference to an internal standard of known concentration. Clustering of the HSQC(0) cross peaks by their normalized intensities identifies those corresponding to metabolites present at a given concentration, and this information can assist in assigning these peaks to specific compounds. The concentration measurement for an individual metabolite can be improved by averaging the intensities of multiple, nonoverlapping cross peaks assigned to that metabolite.

Simultaneous determination of clebopride and a major metabolite N-desbenzylclebopride in plasma by capillary gas chromatography-negative-ion chemical ionization mass spectrometry.

PubMed

Robinson, P R; Jones, M D; Maddock, J; Rees, L W

1991-03-08

A procedure for the simultaneous assay of clebopride and its major metabolite N-desbenzylclebopride in plasma has been developed. The method utilizes capillary gas chromatography-negative-ion chemical ionization mass spectrometry with selected-ion monitoring of characteristic ions. Employing 2-ethoxy analogues as internal standards, the benzamides were extracted from basified plasma using dichloromethane. Subsequent reaction with heptafluorobutyric anhydride produced volatile mono- and diheptafluorobutyryl derivatives of clebopride and N-desbenzylclebopride, respectively. The methane negative-ion mass spectra of these derivatives exhibited intense high-mass ions ideal for specific quantitation of low levels in biological fluids. Using this procedure the recovery of the drug and metabolite from human plasma was found to be 84.4 +/- 1.5% (n = 3) and 77.4 +/- 4.7% (n = 3), respectively, at 0.5 ng/ml. Measurement of both compounds down to 0.10 ng/ml with a coefficient of variation of less than 10.5% is described. Plasma levels are reported in four volunteers up to 24 h following oral administration of 1 mg of clebopride malate salt.

Quantum-electrodynamic cascades in intense laser fields

NASA Astrophysics Data System (ADS)

Narozhny, N. B.; Fedotov, A. M.

2015-01-01

It is shown that in an intense laser field, along with cascades similar to extensive air showers, self-sustaining field-energized cascades can develop. For intensities of 1024~ \\text {W cm}-2 or higher, such cascades can even be initiated by a particle at rest in the focal area of a tightly focused laser pulse. The cascade appearance effect can considerably alter the progression of any process occurring in a high-intensity laser field. At very high intensities, the evolvement of such cascades can lead to the depletion of the laser field. This paper presents a design of an experiment to observe these two cascade types simultaneously already in next-generation laser facilities.

Monitoring electrostatically-induced deflection, strain and doping in suspended graphene using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Metten, Dominik; Froehlicher, Guillaume; Berciaud, Stéphane

2017-03-01

Electrostatic gating offers elegant ways to simultaneously strain and dope atomically thin membranes. Here, we report on a detailed in situ Raman scattering study on graphene, suspended over a Si/SiO2 substrate. In such a layered structure, the intensity of the Raman G- and 2D-mode features of graphene are strongly modulated by optical interference effects and allow an accurate determination of the electrostatically-induced membrane deflection, up to irreversible collapse. The membrane deflection is successfully described by an electromechanical model, which we also use to provide useful guidelines for device engineering. In addition, electrostatically-induced tensile strain is determined by examining the softening of the Raman features. Due to a small residual charge inhomogeneity, we find that non-adiabatic anomalous phonon softening is negligible compared to strain-induced phonon softening. These results open perspectives for innovative Raman scattering-based readout schemes in two-dimensional nanoresonators.

Efficient energy absorption of intense ps-laser pulse into nanowire target

NASA Astrophysics Data System (ADS)

Habara, H.; Honda, S.; Katayama, M.; Sakagami, H.; Nagai, K.; Tanaka, K. A.

2016-06-01

The interaction between ultra-intense laser light and vertically aligned carbon nanotubes is investigated to demonstrate efficient laser-energy absorption in the ps laser-pulse regime. Results indicate a clear enhancement of the energy conversion from laser to energetic electrons and a simultaneously small plasma expansion on the surface of the target. A two-dimensional plasma particle calculation exhibits a high absorption through laser propagation deep into the nanotube array, even for a dense array whose structure is much smaller than the laser wavelength. The propagation leads to the radial expansion of plasma perpendicular to the nanotubes rather than to the front side. These features may contribute to fast ignition in inertial confinement fusion and laser particle acceleration, both of which require high current and small surface plasma simultaneously.

Multiplexed 3D FRET imaging in deep tissue of live embryos

PubMed Central

Zhao, Ming; Wan, Xiaoyang; Li, Yu; Zhou, Weibin; Peng, Leilei

2015-01-01

Current deep tissue microscopy techniques are mostly restricted to intensity mapping of fluorophores, which significantly limit their applications in investigating biochemical processes in vivo. We present a deep tissue multiplexed functional imaging method that probes multiple Förster resonant energy transfer (FRET) sensors in live embryos with high spatial resolution. The method simultaneously images fluorescence lifetimes in 3D with multiple excitation lasers. Through quantitative analysis of triple-channel intensity and lifetime images, we demonstrated that Ca2+ and cAMP levels of live embryos expressing dual FRET sensors can be monitored simultaneously at microscopic resolution. The method is compatible with a broad range of FRET sensors currently available for probing various cellular biochemical functions. It opens the door to imaging complex cellular circuitries in whole live organisms. PMID:26387920

Impurity gettering in semiconductors

DOEpatents

Sopori, B.L.

1995-06-20

A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device is disclosed. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500 C to about 700 C for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal. 1 fig.

Impurity gettering in semiconductors

DOEpatents

Sopori, Bhushan L.

1995-01-01

A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

Frequency-resolved Raman for transient thermal probing and thermal diffusivity measurement

DOE PAGES

Wang, Tianyu; Xu, Shen; Hurley, David H.; ...

2015-12-18

Steady state Raman has been widely used for temperature probing and thermal conductivity/conductance measurement in combination with temperature coefficient calibration. In this work, a new transient Raman thermal probing technique: frequency-resolved Raman (FR-Raman) is developed for probing the transient thermal response of materials and measuring their thermal diffusivity. The FR-Raman uses an amplitude modulated square-wave laser for simultaneous material heating and Raman excitation. The evolution profile of Raman properties: intensity, Raman wavenumber, and emission, against frequency are measured experimentally and reconstructed theoretically. They are used for fitting to determine the thermal diffusivity of the material under test. A Si cantilevermore » is used to investigate the capacity of this new technique. The cantilever’s thermal diffusivity is determined as 9.57 × 10 -5 m 2/s, 11.00 × 10 -5 m 2/s and 9.02 × 10 -5 m 2/s by fitting the Raman intensity, wavenumber and emission. The deviation from the reference value is largely attributed to thermal stress-induced material deflection and Raman drift, which could be significantly suppressed by using a higher sensitivity Raman spectrometer with lower laser energy. As a result, the FR-Raman provides a novel way for transient thermal characterization of materials with a ?m spatial resolution.« less

Fully Automated Complementary DNA Microarray Segmentation using a Novel Fuzzy-based Algorithm.

PubMed

Saberkari, Hamidreza; Bahrami, Sheyda; Shamsi, Mousa; Amoshahy, Mohammad Javad; Ghavifekr, Habib Badri; Sedaaghi, Mohammad Hossein

2015-01-01

DNA microarray is a powerful approach to study simultaneously, the expression of 1000 of genes in a single experiment. The average value of the fluorescent intensity could be calculated in a microarray experiment. The calculated intensity values are very close in amount to the levels of expression of a particular gene. However, determining the appropriate position of every spot in microarray images is a main challenge, which leads to the accurate classification of normal and abnormal (cancer) cells. In this paper, first a preprocessing approach is performed to eliminate the noise and artifacts available in microarray cells using the nonlinear anisotropic diffusion filtering method. Then, the coordinate center of each spot is positioned utilizing the mathematical morphology operations. Finally, the position of each spot is exactly determined through applying a novel hybrid model based on the principle component analysis and the spatial fuzzy c-means clustering (SFCM) algorithm. Using a Gaussian kernel in SFCM algorithm will lead to improving the quality in complementary DNA microarray segmentation. The performance of the proposed algorithm has been evaluated on the real microarray images, which is available in Stanford Microarray Databases. Results illustrate that the accuracy of microarray cells segmentation in the proposed algorithm reaches to 100% and 98% for noiseless/noisy cells, respectively.

Fluorescence lifetime measurements in flow cytometry

NASA Astrophysics Data System (ADS)

Beisker, Wolfgang; Klocke, Axel

1997-05-01

Fluorescence lifetime measurements provide insights int eh dynamic and structural properties of dyes and their micro- environment. The implementation of fluorescence lifetime measurements in flow cytometric systems allows to monitor large cell and particle populations with high statistical significance. In our system, a modulated laser beam is used for excitation and the phase shift of the fluorescence signal recorded with a fast computer controlled digital oscilloscope is processed digitally to determine the phase shift with respect to a reference beam by fast fourier transform. Total fluorescence intensity as well as other parameters can be determined simultaneously from the same fluorescence signal. We use the epi-illumination design to allow the use of high numerical apertures to collect as much light as possible to ensure detection of even weak fluorescence. Data storage and processing is done comparable to slit-scan flow cytometric data using data analysis system. The results are stored, displayed, combined with other parameters and analyzed as normal listmode data. In our report we discuss carefully the signal to noise ratio for analog and digital processed lifetime signals to evaluate the theoretical minimum fluorescence intensity for lifetime measurements. Applications to be presented include DNA staining, parameters of cell functions as well as different applications in non-mammalian cells such as algae.

Single-shot Z(eff) dense plasma diagnostic through simultaneous refraction and attenuation measurements with a Talbot-Lau x-ray moiré deflectometer.

PubMed

Valdivia, M P; Stutman, D; Finkenthal, M

2015-04-01

The Talbot-Lau x-ray moiré deflectometer is a powerful plasma diagnostic capable of delivering simultaneous refraction and attenuation information through the accurate detection of x-ray phase shift and intensity. The diagnostic can provide the index of refraction n=1-δ+iβ of an object (dense plasma, for example) placed in the x-ray beam by independently measuring both δ and β, which are directly related to the electron density n(e) and the attenuation coefficient μ, respectively. Since δ and β depend on the effective atomic number Z(eff), a map can be obtained from the ratio between phase and absorption images acquired in a single shot. The Talbot-Lau x-ray moiré deflectometer and its corresponding data acquisition and processing are briefly described to illustrate how the above is achieved; Z(eff) values of test objects within the 4-12 range were obtained experimentally through simultaneous refraction and attenuation measurements. We show that Z(eff) mapping of objects does not require previous knowledge of sample length or shape. The determination of Z(eff) from refraction and attenuation measurements with moiré deflectometry could be of high interest to various domains of high energy density research, such as shocked materials and inertial confinement fusion experiments, as well as material science and nondestructive testing.

Composition of Renaissance paint layers: simultaneous particle induced X-ray emission and backscattering spectrometry.

PubMed

de Viguerie, L; Beck, L; Salomon, J; Pichon, L; Walter, Ph

2009-10-01

Particle induced X-ray emission spectroscopy (PIXE) is now routinely used in the field of cultural heritage. Various setups have been developed to investigate the elemental composition of wood/canvas paintings or of cross-section samples. However, it is not possible to obtain information concerning the quantity of organic binder. Backscattering spectrometry (BS) can be a useful complementary method to overcome this limitation. In the case of paint layers, PIXE brings the elemental composition (major elements to traces) and the BS spectrum can give access to the proportion of pigment and binder. With the use of 3 MeV protons for PIXE and BS simultaneously, it was possible to perform quantitative analysis including C and O for which the non-Rutherford cross sections are intense. Furthermore, with the use of the same conditions for PIXE and BS, the experiment time and the potential damage by the ion beam were reduced. The results obtained with the external beam of the Accélérateur Grand Louvre pour l'Analyse Elementaire (AGLAE) facility on various test painting samples and on cross sections from Italian Renaissance masterpieces are shown. Simultaneous combination of PIXE and BS leads to a complete characterization of the paint layers: elemental composition and proportion of the organic binder have been determined and thus provide useful information about ancient oil painting recipes.

Use of DNA probes to study tetracycline resistance determinants in gram-negative bacteria from swine

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

Lee, C.Y.

1989-01-01

Specific {sup 32}P-labeled DNA probes were prepared and used to evaluate the distribution of tetracycline resistance determinants carried by gram-negative enteric bacteria isolated from pigs in 3 swine herds with different histories of antibiotic exposure. Plasmid DNA, ranging in size from 2.1 to 186 Kb, was observed in over 84% of 114 isolates studied. Two of 78 tetracycline resistant strains did not harbor plasmids. The DNA probes were isolated from plasmids pSL18, pRT29/Tn10, pBR322 and pSL106, respectively, and they represented class A, B, C and D tetracycline resistance determinants. Hybridization conditions using 0.5X SSPE at 65{degrees}C minimize cross-hybridization between themore » different class of tetracycline resistance genes. Cross-hybridization between class A and class C determinants could be distinguished by simultaneous comparison of the intensity of their hybridization signals. Plasmids from over 44% of the tetracycline resistant isolates did not hybridize to DNA probes for the determinants tested. Class B determinant occurred more frequently than class A or C. None of the isolates hybridized with the class D probe.« less

High-Performance X-ray Detection in a New Analytical Electron Microscope

NASA Technical Reports Server (NTRS)

Lyman, C. E.; Goldstein, J. I.; Williams, D. B.; Ackland, D. W.; vonHarrach, S.; Nicholls, A. W.; Statham, P. J.

1994-01-01

X-ray detection by energy-dispersive spectrometry in the analytical electron microscope (AEM) is often limited by low collected X-ray intensity (P), modest peak-to-background (P/B) ratios, and limitations on total counting time (tau) due to specimen drift and contamination. A new AFM has been designed with maximization of P. P/B, and tau as the primary considerations. Maximization of P has been accomplished by employing a field-emission electron gun, X-ray detectors with high collection angles, high-speed beam blanking to allow only one photon into the detector at a time, and simultaneous collection from two detectors. P/B has been maximized by reducing extraneous background signals generated at the specimen holder, the polepieces and the detector collimator. The maximum practical tau has been increased by reducing specimen contamination and employing electronic drift correction. Performance improvments have been measured using the NIST standard Cr thin film. The 0-3 steradian solid angle of X-ray collection is the highest value available. The beam blanking scheme for X-ray detection provides 3-4 times greater throughput of X-rays at high count rates into a recorded spectrum than normal systems employing pulse-pileup rejection circuits. Simultaneous X-ray collection from two detectors allows the highest X-ray intensity yet recorded to be collected from the NIST Cr thin film. The measured P/B of 6300 is the highest level recorded for an AEM. In addition to collected X-ray intensity (cps/nA) and P/B measured on the standard Cr film, the product of these can be used as a figure-of-merit to evaluate instruments. Estimated minimum mass fraction (MMF) for Cr measured on the standard NIST Cr thin film is also proposed as a figure-of-merit for comparing X-ray detection in AEMs. Determinations here of the MMF of Cr detectable show at least a threefold improvement over previous instruments.

Macroelemental composition of cadmium stressed lettuce plants grown under conditions of intensive sulphur nutrition.

PubMed

Matraszek, Renata; Hawrylak-Nowak, Barbara; Chwil, Stanisław; Chwil, Mirosława

2016-09-15

Lettuce (Lactuca sativa L.) is moderately sensitive to cadmium (Cd) and shows high accumulation of this metal. Thus, this species is considered to be a good model for both identifying determinants controlling Cd accumulation in plant tissues and for developing breeding strategies aimed at limiting the accumulation of this metal in edible tissues. Simultaneously, lettuce is characterised by medium requirements for sulphur (S) - a macronutrient whose role is associated not only with proper growth and development, but also with stress tolerance. The common use of NPK fertilizers without sulphates (S-SO4) together with the progressive process of reducing emissions of S compounds to the natural environment may lead to deficiency of this element in plants. The present study evaluated the changes in macronutrient content and accumulation in Cd-stressed lettuce 'Justyna' supplied with different S doses. Four concentrations of Cd (0, 0.0002, 0.02 or 0.04 mM) and three levels of S applied in the form of S-SO4 (2, 6 or 9 mM S) were used. Cd exposure impaired the macronutrient balance and accumulation in lettuce. Intensive S nutrition to some extent alleviated Cd-induced toxicity. High S doses, especially 6 mM S, partially improved macronutrient status and restored the macronutrient balance. In Cd-stressed plants supplemented with additional S, an increase in root and shoot biomass and in the content of N, K and Mg was found, without significant changes in the Ca content. Simultaneously, the P and S contents in the biomass of both above- and underground organs remained unchanged. In the leaves, as opposite to the roots, intensive S nutrition reduced the accumulation of Cd. However, the foliar Cd concentration still exceeded the acceptable limits established for consumption. All the obtained results concerning the content of macronutrients and their ratios were referred, inter alia, to the standards i.e. the Diagnosis and Recommendation Integrated System (DRIS) norms. Copyright © 2016. Published by Elsevier Ltd.

Structure and dynamics of coronal plasmas

NASA Technical Reports Server (NTRS)

Golub, Leon

1995-01-01

The Normal Incidence X-ray Telescope (NIXT) obtained a unique set of high resolution full disk solar images which were exposed simultaneously by X-rays in a passband at 63.5 A and by visible light. The perfect alignment of a photospheric visible light image with a coronal X-ray image enables us to present observations of X-ray intensity vs an accurately determined height above the visible limb. The height at which the observed X-ray intensity peak varies from 4000 km in active regions to 9000 km in quiet regions of the sun. The interpretation of the observations stems from the previously established fact that, for the coronal loops, emission in the NIXT bandpass peaks sharply just above the footpoints. Because there is not a sharp peak in the observed X-ray intensity vs off limb height, we conclude that the loop footpoints, when viewed at the limb, are obscured by absorption in chromospheric material along the line of sight. We calculate the X-ray intensity vs height predicted by a number of different idealizations of the solar atmosphere, and we compare these calculations with the observed X-ray intensity vs height. The calculations use existing coronal and chromospheric models. In order for the calculations to reproduce the observed off limb X-ray intensities, we are forced to assume an atmosphere in which the footpoints of coronal loops are interspersed along the line of sight with cooler chromospheric material extending to heights well above the loop footpoints. We argue that the absorption coefficient for NIXT X-rays by chromospheric material is roughly proportional to the neutral hydrogen density, and we estimate an average neutral hydrogen density and scale height implied by the data.

Randomized phase II--study evaluating EGFR targeting therapy with cetuximab in combination with radiotherapy and chemotherapy for patients with locally advanced pancreatic cancer--PARC: study protocol [ISRCTN56652283].

PubMed

Krempien, R; Muenter, M W; Huber, P E; Nill, S; Friess, H; Timke, C; Didinger, B; Buechler, P; Heeger, S; Herfarth, K K; Abdollahi, A; Buchler, M W; Debus, J

2005-10-11

Pancreatic cancer is the fourth commonest cause of death from cancer in men and women. Advantages in surgical techniques, radiation therapy techniques, chemotherapeutic regimes, and different combined-modality approaches have yielded only a modest impact on the prognosis of patients with pancreatic cancer. Thus there is clearly a need for additional strategies. One approach involves using the identification of a number of molecular targets that may be responsible for the resistance of cancer cells to radiation or to other cytotoxic agents. As such, these molecular determinants may serve as targets for augmentation of the radiotherapy or chemotherapy response. Of these, the epidermal growth factor receptor (EGFR) has been a molecular target of considerable interest and investigation, and there has been a tremendous surge of interest in pursuing targeted therapy of cancers via inhibition of the EGFR. The PARC study is designed as an open, controlled, prospective, randomized phase II trial. Patients in study arm A will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine infusions weekly over 4 weeks. Patients in study arm B will be treated with chemoradiation using intensity modulated radiation therapy (IMRT) combined with gemcitabine and simultaneous cetuximab infusions. After chemoradiation the patients receive gemcitabine weekly over 4 weeks and cetuximab infusions over 12 weeks. A total of 66 patients with locally advanced adenocarcinoma of the pancreas will be enrolled. An interim analysis for patient safety reasons will be done one year after start of recruitment. Evaluation of the primary endpoint will be performed two years after the last patient's enrollment. The primary objective of this study is to evaluate the feasibility and the toxicity profile of trimodal therapy in pancreatic adenocarcinoma with chemoradiation therapy with gemcitabine and intensity modulated radiation therapy (IMRT) and EGFR-targeted therapy using cetuximab and to compare between two different methods of cetuximab treatment schedules (concomitant versus concomitant and sequential cetuximab treatment). Secondary objectives are to determine the role and the mechanism of cetuximab in patient's chemoradiation regimen, the response rate, the potential of this combined modality treatment to concert locally advanced lesions to potentially resectable lesions, the time to progression interval and the quality of life.

Development of a high-throughput Candida albicans biofilm chip.

PubMed

Srinivasan, Anand; Uppuluri, Priya; Lopez-Ribot, Jose; Ramasubramanian, Anand K

2011-04-22

We have developed a high-density microarray platform consisting of nano-biofilms of Candida albicans. A robotic microarrayer was used to print yeast cells of C. albicans encapsulated in a collagen matrix at a volume as low as 50 nL onto surface-modified microscope slides. Upon incubation, the cells grow into fully formed "nano-biofilms". The morphological and architectural complexity of these biofilms were evaluated by scanning electron and confocal scanning laser microscopy. The extent of biofilm formation was determined using a microarray scanner from changes in fluorescence intensities due to FUN 1 metabolic processing. This staining technique was also adapted for antifungal susceptibility testing, which demonstrated that, similar to regular biofilms, cells within the on-chip biofilms displayed elevated levels of resistance against antifungal agents (fluconazole and amphotericin B). Thus, results from structural analyses and antifungal susceptibility testing indicated that despite miniaturization, these biofilms display the typical phenotypic properties associated with the biofilm mode of growth. In its final format, the C. albicans biofilm chip (CaBChip) is composed of 768 equivalent and spatially distinct nano-biofilms on a single slide; multiple chips can be printed and processed simultaneously. Compared to current methods for the formation of microbial biofilms, namely the 96-well microtiter plate model, this fungal biofilm chip has advantages in terms of miniaturization and automation, which combine to cut reagent use and analysis time, minimize labor intensive steps, and dramatically reduce assay costs. Such a chip should accelerate the antifungal drug discovery process by enabling rapid, convenient and inexpensive screening of hundreds-to-thousands of compounds simultaneously.

Interactive effects of herbivory and competition intensity determine invasive plant performance.

PubMed

Huang, Wei; Carrillo, Juli; Ding, Jianqing; Siemann, Evan

2012-10-01

Herbivory can reduce plant fitness, and its effects can be increased by competition. Though numerous studies have examined the joint effects of herbivores and competitors on plant performance, these interactive effects are seldom considered in the context of plant invasions. Here, we examined variation in plant performance within a competitive environment in response to both specialist and generalist herbivores using Chinese tallow as a model species. We combined tallow plants from native and invasive populations to form all possible pairwise combinations, and designated invasive populations as stronger neighbours and native populations as weaker neighbours. We found that when no herbivory was imposed, invasive populations always had higher total biomass than natives, regardless of their neighbours, which is consistent with our assumption of increased competitive ability. Defoliation by either generalist or specialist herbivores suppressed plant growth but the effects of specialists were generally stronger for invasive populations. Invasive populations had their lowest biomass when fed upon by specialists while simultaneously competing with stronger neighbours. The root/shoot ratios of invasive populations were lower than those of native populations under almost all conditions, and invasive plants were taller than native plants overall, especially when herbivores were present, suggesting that invasive populations may adopt an "aboveground first" strategy to cope with herbivory and competition. These results suggest that release from herbivores, especially specialists, improves an invader's performance and helps to increase its competitive ability. Therefore, increasing interspecific competition intensity by planting a stronger neighbour while simultaneously releasing a specialist herbivore may be an especially effective method of managing invasive plants.

Spectral Line Parameters Including Temperature Dependences of Self- and Air-Broadening in the 2 (left arrow) 0 Band of CO at 2.3 micrometers

NASA Technical Reports Server (NTRS)

Devi, V. Malathy; Benner, D. Chris; Smith, M. A. H.; Mantz, A. W.; Sung, K.; Brown, L. R.; Predoi-Cross, A.

2012-01-01

Temperature dependences of pressure-broadened half-width and pressure-induced shift coefficients along with accurate positions and intensities have been determined for transitions in the 2<--0 band of C-12 O-16 from analyzing high-resolution and high signal-to-noise spectra recorded with two different Fourier transform spectrometers. A total of 28 spectra, 16 self-broadened and 12 air-broadened, recorded using high- purity (greater than or equal to 99.5% C-12-enriched) CO samples and CO diluted with dry air(research grade) at different temperatures and pressures, were analyzed simultaneously to maximize the accuracy of the retrieved parameters. The sample temperatures ranged from 150 to 298K and the total pressures varied between 5 and 700 Torr. A multispectrum nonlinear least squares spectrum fitting technique was used to adjust the rovibrational constants (G, B, D, etc.) and intensity parameters (including Herman-Wallis coefficients), rather than determining individual line positions and intensities. Self-and air-broadened Lorentz half-width coefficients, their temperature dependence exponents, self- and air-pressure-induced shift coefficients, their temperature dependences, self- and air-line mixing coefficients, their temperature dependences and speed dependence have been retrieved from the analysis. Speed-dependent line shapes with line mixing employing off-diagonal relaxation matrix element formalism were needed to minimize the fit residuals. This study presents a precise and complete set of spectral line parameters that consistently reproduce the spectrum of carbon monoxide over terrestrial atmospheric conditions.

Intensive comprehensive aphasia programs: an international survey of practice.

PubMed

Rose, Miranda L; Cherney, Leora R; Worrall, Linda E

2013-01-01

In response to the need to simultaneously address multiple domains of the International Classification of Functioning, Disability and Health (ICF) in aphasia therapy and to incorporate intensive treatment doses consistent with principles of neuroplasticity, a potentially potent treatment option termed intensive comprehensive aphasia programs (ICAPs) has been developed. To conduct an international survey of ICAPs to determine the extent of their use and to explore current ICAP practices. A 32-item online survey was distributed internationally through Survey Monkey between May and August 2012. The survey addressed ICAP staffing, philosophy, values, funding, admission criteria, activities, family involvement, outcome measures, and factors considered important to success. Twelve ICAPs responded: 8 from the United States, 2 from Canada, and 1 each from Australia and the United Kingdom. The majority of ICAPs are affiliated with university programs and are funded through participant self-pay. ICAPs emphasize individualized treatment goals and evidence-based practices, with a focus on applying the principles of neuroplasticity related to repetition and intensity of treatment. On average, 6 people with aphasia attend each ICAP, for 4 days per week for 4 weeks, receiving about 100 hours of individual, group, and computer-based treatment. Speech-language pathologists, students, and volunteers staff the majority of ICAPs. ICAPs are increasing in number but remain a rare service delivery option. They address the needs of individuals who want access to intensive treatment and are interested in making significant changes to their communication skills and psychosocial well-being in a short period of time. Their efficacy and cost-effectiveness require future investigation.

Pancreas Islet Transplantation for Patients With Type 1 Diabetes Mellitus: A Clinical Evidence Review.

PubMed

2015-01-01

Type 1 diabetes mellitus is caused by the autoimmune destruction of pancreatic beta (β) cells, resulting in severe insulin deficiency. Islet transplantation is a β-cell replacement therapeutic option that aims to restore glycemic control in patients with type 1 diabetes. The objective of this study was to determine the clinical effectiveness of islet transplantation in patients with type 1 diabetes, with or without kidney disease. We conducted a systematic review of the literature on islet transplantation for type 1 diabetes, including relevant health technology assessments, systematic reviews, meta-analyses, and observational studies. We used a two-step process: first, we searched for systematic reviews and health technology assessments; second, we searched primary studies to update the chosen health technology assessment. The Assessment of Multiple Systematic Reviews measurement tool was used to examine the methodological quality of the systematic reviews and health technology assessments. We assessed the quality of the body of evidence and the risk of bias according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Our searched yielded 1,354 citations. One health technology assessment, 11 additional observational studies to update the health technology assessment, one registry report, and four guidelines were included; the observational studies examined islet transplantation alone, islet-after-kidney transplantation, and simultaneous islet-kidney transplantation. In general, low to very low quality of evidence exists for islet transplantation in patients with type 1 diabetes with difficult-to-control blood glucose levels, with or without kidney disease, for these outcomes: health-related quality of life, secondary complications of diabetes, glycemic control, and adverse events. However, high quality of evidence exists for the specific glycemic control outcome of insulin independence compared with intensive insulin therapy. For patients without kidney disease, islet transplantation improves glycemic control and diabetic complications for patients with type 1 diabetes when compared with intensive insulin therapy. However, results for health-related quality of life outcomes were mixed, and adverse events were increased compared with intensive insulin therapy. For patients with type 1 diabetes with kidney disease, islet-after-kidney transplantation or simultaneous islet-kidney transplantation also improved glycemic control and secondary diabetic complications, although the evidence was more limited for this patient group. Compared with intensive insulin therapy, adverse events for islet-after-kidney transplantation or simultaneous islet-kidney transplantation were increased, but were in general less severe than with whole pancreas transplantation. For patients with type 1 diabetes with difficult-to-control blood glucose levels, islet transplantation may be a beneficial β-cell replacement therapy to improve glycemic control and secondary complications of diabetes. However, there is uncertainty in the estimates of effectiveness because of the generally low to very low quality of evidence for all outcomes of interest.

Simultaneous Chandra/Swift Observations of the RT Cru Symbiotic System

NASA Astrophysics Data System (ADS)

Kashyap, Vinay; Kennea, J. A.; Karovska, M.; Calibration, Chandra

2013-04-01

The symbiotic star RT Cru was observed simultaneously by the Chandra/HRC-I and Swift/XRT in Dec 2012. The observations were carried out as part of a program to calibrate the Chandra PSF. The Chandra light curve shows a number of brightenings by factors of 2, with strong indications of a softening of the spectrum at these times. Swift observations cover a brief part of the Chandra light curve, and the intensities over this duration are tightly correlated. The Swift spectral data confirm the anticorrelation between intensity and spectral hardness. However, there are differences in the correlations at different periods that are not understood. We report on our analysis of the data, with emphasis on the spectral modeling at different times and intensity levels, and discuss the implications of the results on the emission mechanisms on symbiotic stars. We also report our inferences on the structure and energy dependence of the Chandra PSF anomaly, and on the high-energy cross-calibration between the HRC-I and XRT. This work is supported by the NASA contract NAS8-03060 to the Chandra X-ray Center.

Kinetics and its accompanying thermodynamics studies on simultaneous complexation of heterobimetallic neodymium (III) with zinc (II) and L-tryptophan in aquated DMF using 4f-4f absorption spectra.

PubMed

Huidrom, Bimola; Singh, N Rajmuhon

2014-01-24

The 4f-4f absorption spectra of the simultaneous heterobimetallic complexation of trivalent neodymium ion with l-tryptophan and divalent zinc ion in aquated DMF (50%, v/v) at pH 6.0 was recorded at the time interval of 1h. From the observed absorption spectra, the values of intensity parameters such as oscillator strength (P) and Judd-Ofelt intensity (Tλ) parameters, kinetics and thermodynamics parameters were evaluated. The rate constant increases with an increase in the temperature along with the oscillator strengths and Judd-Ofelt intensity parameters. The positive values of the change in the standard enthalpy (ΔH°) and entropy (ΔS°) indicate that the complexation is endothermic. The negative values of the change in the standard free energy (ΔG°) in the range from 293.15 K to 308.15 K, indicate that the reaction occurs spontaneously and hence the formation of heterobimetallic complex in the solution is favored kinetically and thermodynamically. Copyright © 2013 Elsevier B.V. All rights reserved.

Kinetics and its accompanying thermodynamics studies on simultaneous complexation of heterobimetallic neodymium (III) with zinc (II) and L-tryptophan in aquated DMF using 4f-4f absorption spectra

NASA Astrophysics Data System (ADS)

Huidrom, Bimola; Rajmuhon Singh, N.

2014-01-01

The 4f-4f absorption spectra of the simultaneous heterobimetallic complexation of trivalent neodymium ion with L-tryptophan and divalent zinc ion in aquated DMF (50%, v/v) at pH 6.0 was recorded at the time interval of 1 h. From the observed absorption spectra, the values of intensity parameters such as oscillator strength (P) and Judd-Ofelt intensity (Tλ) parameters, kinetics and thermodynamics parameters were evaluated. The rate constant increases with an increase in the temperature along with the oscillator strengths and Judd-Ofelt intensity parameters. The positive values of the change in the standard enthalpy (ΔH°) and entropy (ΔS°) indicate that the complexation is endothermic. The negative values of the change in the standard free energy (ΔG°) in the range from 293.15 K to 308.15 K, indicate that the reaction occurs spontaneously and hence the formation of heterobimetallic complex in the solution is favored kinetically and thermodynamically.

Phytoplankton productivity in relation to light intensity: A simple equation

USGS Publications Warehouse

Peterson, D.H.; Perry, M.J.; Bencala, K.E.; Talbot, M.C.

1987-01-01

A simple exponential equation is used to describe photosynthetic rate as a function of light intensity for a variety of unicellular algae and higher plants where photosynthesis is proportional to (1-e-??1). The parameter ?? (=Ik-1) is derived by a simultaneous curve-fitting method, where I is incident quantum-flux density. The exponential equation is tested against a wide range of data and is found to adequately describe P vs. I curves. The errors associated with photosynthetic parameters are calculated. A simplified statistical model (Poisson) of photon capture provides a biophysical basis for the equation and for its ability to fit a range of light intensities. The exponential equation provides a non-subjective simultaneous curve fitting estimate for photosynthetic efficiency (a) which is less ambiguous than subjective methods: subjective methods assume that a linear region of the P vs. I curve is readily identifiable. Photosynthetic parameters ?? and a are used widely in aquatic studies to define photosynthesis at low quantum flux. These parameters are particularly important in estuarine environments where high suspended-material concentrations and high diffuse-light extinction coefficients are commonly encountered. ?? 1987.

Rough Sets and Stomped Normal Distribution for Simultaneous Segmentation and Bias Field Correction in Brain MR Images.

PubMed

Banerjee, Abhirup; Maji, Pradipta

2015-12-01

The segmentation of brain MR images into different tissue classes is an important task for automatic image analysis technique, particularly due to the presence of intensity inhomogeneity artifact in MR images. In this regard, this paper presents a novel approach for simultaneous segmentation and bias field correction in brain MR images. It integrates judiciously the concept of rough sets and the merit of a novel probability distribution, called stomped normal (SN) distribution. The intensity distribution of a tissue class is represented by SN distribution, where each tissue class consists of a crisp lower approximation and a probabilistic boundary region. The intensity distribution of brain MR image is modeled as a mixture of finite number of SN distributions and one uniform distribution. The proposed method incorporates both the expectation-maximization and hidden Markov random field frameworks to provide an accurate and robust segmentation. The performance of the proposed approach, along with a comparison with related methods, is demonstrated on a set of synthetic and real brain MR images for different bias fields and noise levels.

Spin texture and magnetoroton excitations at nu=1/3.

PubMed

Groshaus, Javier G; Dujovne, Irene; Gallais, Yann; Hirjibehedin, Cyrus F; Pinczuk, Aron; Tan, Yan-Wen; Stormer, Horst; Dennis, Brian S; Pfeiffer, Loren N; West, Ken W

2008-02-01

Neutral spin texture (ST) excitations at nu=1/3 are directly observed for the first time by resonant inelastic light scattering. They are determined to involve two simultaneous spin flips. At low magnetic fields, the ST energy is below that of the magnetoroton minimum. With increasing in-plane magnetic field these mode energies cross at a critical ratio of the Zeeman and Coulomb energies of eta(c)=0.020+/-0.001. Surprisingly, the intensity of the ST mode grows with temperature in the range in which the magnetoroton modes collapse. The temperature dependence is interpreted in terms of a competition between coexisting phases supporting different excitations. We consider the role of the ST excitations in activated transport at nu=1/3.

Electromyographic activity of mystacial pad musculature during whisking behavior in the rat.

PubMed

Carvell, G E; Simons, D J; Lichtenstein, S H; Bryant, P

1991-01-01

Cinematographic measurements of whisker movements generated by behaving rats were compared with electromyographic (EMG) activity recorded simultaneously from mystacial pad musculature. Muscle activity consisted of repetitive bursts, each of which initiated a "whisking" cycle consisting of a protraction followed by a retraction. Protraction amplitude and velocity were directly proportional to the amount of EMG activity during forward whisker movement. Overtime, the intensity of muscle discharge determined the set point about which the vibrissae moved; higher levels of muscle activity resulted in a greater degree of overall whisker protraction. These findings are consistent with the known anatomy of the facial musculature and underscore the importance of whisker protraction in the acquisition of tactile information by the vibrissae.

New Zealand SIR-B science investigations

NASA Technical Reports Server (NTRS)

Collins, M. A.; Oliver, P. J.; Cochrane, G. R.; Cole, J.; Coombs, D. S.; Barnes, E. J.; Ching, N. P.; Bennets, R. L.; Stephens, P. H.; Laing, A. K.

1984-01-01

It is proposed that shuttle imaging radar (SIR) data be used to study unusual geological features of New Zealand. Particular attention is planned for geological faults. SIR-B imagery is to be compared with LANDSAT multispectral imagery. Three other investigations which are to use SIR data are discussed. An ocean eddy is to be studied from a correlation of SIR-B and advanced very high resolution radiometer imagery. Timber volume is to be assessed by determining the age and size of pine forests from SIR-B data. Soil moisture is to be investigated by comparing SIR-B data with simultaneous gravimetric data. Land cover in a region already subjected to intensive investigation using LANDSAT and aircraft scanner data is to be discriminated by SIR-B data.

Coupled Low-thrust Trajectory and System Optimization via Multi-Objective Hybrid Optimal Control

NASA Technical Reports Server (NTRS)

Vavrina, Matthew A.; Englander, Jacob Aldo; Ghosh, Alexander R.

2015-01-01

The optimization of low-thrust trajectories is tightly coupled with the spacecraft hardware. Trading trajectory characteristics with system parameters ton identify viable solutions and determine mission sensitivities across discrete hardware configurations is labor intensive. Local independent optimization runs can sample the design space, but a global exploration that resolves the relationships between the system variables across multiple objectives enables a full mapping of the optimal solution space. A multi-objective, hybrid optimal control algorithm is formulated using a multi-objective genetic algorithm as an outer loop systems optimizer around a global trajectory optimizer. The coupled problem is solved simultaneously to generate Pareto-optimal solutions in a single execution. The automated approach is demonstrated on two boulder return missions.

High-intensity drinking and nonmedical use of prescription drugs: Results from a national survey of 12th grade students.

PubMed

McCabe, Sean Esteban; Veliz, Philip; Patrick, Megan E

2017-09-01

Nearly 10% of U.S. 12th graders report high-intensity drinking (10+ or 15+ drinks in a row), but the extent to which these drinkers also engage in nonmedical use of prescription drugs (NMUPD) is largely unknown. This study examined the associations between different thresholds of past two-week high-intensity drinking and past-month NMUPD among U.S. 12th graders. The sample consisted of eleven nationally representative cross-sections of 12th graders in the Monitoring the Future study (2005-2015) who answered questions on past two-week drinking behaviors and past-month nonmedical use of prescription opioids, sedative, stimulants, and tranquilizers (N=26,502 respondents). High-intensity drinking during the past two-weeks was associated with an increased risk of past-month NMUPD. The odds of NMUPD were four times larger among 12th graders who indicated drinking 15 or more drinks on at least one occasion (AOR=4.43, 95% CI=3.18, 5.01) relative to those who had 0-4 drinks during the past two-weeks, after adjusting for relevant covariates. These associations were similar across different classes of prescription drugs and tended to be stronger among non-white respondents. A sub-analysis revealed simultaneous co-ingestion of alcohol and NMUPD was more prevalent among high-intensity drinkers. More than 1 in every 4 U.S 12th graders who engage in high-intensity drinking (15+ drinks in a row) also report NMUPD. Given the greater likelihood of simultaneous co-ingestion of alcohol and prescription drugs among high-intensity drinkers, adolescent substance use interventions need to address the risks associated with mixing alcohol and prescription drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantum-dot-tagged microbeads for multiplexed optical coding of biomolecules.

PubMed

Han, M; Gao, X; Su, J Z; Nie, S

2001-07-01

Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots (zinc sulfide-capped cadmium selenide nanocrystals) into polymeric microbeads at precisely controlled ratios. Their novel optical properties (e.g., size-tunable emission and simultaneous excitation) render these highly luminescent quantum dots (QDs) ideal fluorophores for wavelength-and-intensity multiplexing. The use of 10 intensity levels and 6 colors could theoretically code one million nucleic acid or protein sequences. Imaging and spectroscopic measurements indicate that the QD-tagged beads are highly uniform and reproducible, yielding bead identification accuracies as high as 99.99% under favorable conditions. DNA hybridization studies demonstrate that the coding and target signals can be simultaneously read at the single-bead level. This spectral coding technology is expected to open new opportunities in gene expression studies, high-throughput screening, and medical diagnostics.

A technique for simultaneous detection of individual vortex states of Laguerre-Gaussian beams transmitted through an aqueous suspension of microparticles

NASA Astrophysics Data System (ADS)

Khonina, S. N.; Karpeev, S. V.; Paranin, V. D.

2018-06-01

A technique for simultaneous detection of individual vortex states of the beams propagating in a randomly inhomogeneous medium is proposed. The developed optical system relies on the correlation method that is invariant to the beam wandering. The intensity distribution formed at the optical system output does not require digital processing. The proposed technique based on a multi-order phase diffractive optical element (DOE) is studied numerically and experimentally. The developed detection technique is used for the analysis of Laguerre-Gaussian vortex beams propagating under conditions of intense absorption, reflection, and scattering in transparent and opaque microparticles in aqueous suspensions. The performed experimental studies confirm the relevance of the vortex phase dependence of a laser beam under conditions of significant absorption, reflection, and scattering of the light.

Efficient energy absorption of intense ps-laser pulse into nanowire target

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

Habara, H.; Honda, S.; Katayama, M.

The interaction between ultra-intense laser light and vertically aligned carbon nanotubes is investigated to demonstrate efficient laser-energy absorption in the ps laser-pulse regime. Results indicate a clear enhancement of the energy conversion from laser to energetic electrons and a simultaneously small plasma expansion on the surface of the target. A two-dimensional plasma particle calculation exhibits a high absorption through laser propagation deep into the nanotube array, even for a dense array whose structure is much smaller than the laser wavelength. The propagation leads to the radial expansion of plasma perpendicular to the nanotubes rather than to the front side. Thesemore » features may contribute to fast ignition in inertial confinement fusion and laser particle acceleration, both of which require high current and small surface plasma simultaneously.« less

Model independent approach to the single photoelectron calibration of photomultiplier tubes

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

Saldanha, R.; Grandi, L.; Guardincerri, Y.

2017-08-01

The accurate calibration of photomultiplier tubes is critical in a wide variety of applications in which it is necessary to know the absolute number of detected photons or precisely determine the resolution of the signal. Conventional calibration methods rely on fitting the photomultiplier response to a low intensity light source with analytical approximations to the single photoelectron distribution, often leading to biased estimates due to the inability to accurately model the full distribution, especially at low charge values. In this paper we present a simple statistical method to extract the relevant single photoelectron calibration parameters without making any assumptions aboutmore » the underlying single photoelectron distribution. We illustrate the use of this method through the calibration of a Hamamatsu R11410 photomultiplier tube and study the accuracy and precision of the method using Monte Carlo simulations. The method is found to have significantly reduced bias compared to conventional methods and works under a wide range of light intensities, making it suitable for simultaneously calibrating large arrays of photomultiplier tubes.« less

Spatiotemporal Analysis of Coronal Loops Using Seismology of Damped Kink Oscillations and Forward Modeling of EUV Intensity Profiles

NASA Astrophysics Data System (ADS)

Pascoe, D. J.; Anfinogentov, S. A.; Goddard, C. R.; Nakariakov, V. M.

2018-06-01

The shape of the damping profile of kink oscillations in coronal loops has recently allowed the transverse density profile of the loop to be estimated. This requires accurate measurement of the damping profile that can distinguish the Gaussian and exponential damping regimes, otherwise there are more unknowns than observables. Forward modeling of the transverse intensity profile may also be used to estimate the width of the inhomogeneous layer of a loop, providing an independent estimate of one of these unknowns. We analyze an oscillating loop for which the seismological determination of the transverse structure is inconclusive except when supplemented by additional spatial information from the transverse intensity profile. Our temporal analysis describes the motion of a coronal loop as a kink oscillation damped by resonant absorption, and our spatial analysis is based on forward modeling the transverse EUV intensity profile of the loop under the isothermal and optically thin approximations. We use Bayesian analysis and Markov chain Monte Carlo sampling to apply our spatial and temporal models both individually and simultaneously to our data and compare the results with numerical simulations. Combining the two methods allows both the inhomogeneous layer width and density contrast to be calculated, which is not possible for the same data when each method is applied individually. We demonstrate that the assumption of an exponential damping profile leads to a significantly larger error in the inferred density contrast ratio compared with a Gaussian damping profile.

Nonlinear polarization rotation and orthogonal polarization generation experienced in a single-beam configuration

NASA Astrophysics Data System (ADS)

Minkovski, N.; Petrov, G. I.; Saltiel, S. M.; Albert, O.; Etchepare, J.

2004-09-01

Nonlinear polarization rotation and generation of a polarization component orthogonal to the input beam were observed along fourfold axes of YVO4 and BaF2 crystals. We demonstrate experimentally that in both crystals the angle of rotation is proportional, at low intensities, to the square of the product of the input intensity and the crystal length and is the result of simultaneous action of two third-order processes. This type of nonlinear polarization rotation is driven by the real part of the cubic susceptibility. The recorded energy exchange between the two orthogonal components can exceed 10%. It is to our knowledge the highest energy-conversion efficiency achieved in a single beam nonresonant χ(3) interaction. A simple theoretical model is elaborated to describe the dependence of nonlinear polarization rotation and orthogonal polarization generation on the intensity of the input beam at both low- and high-intensity levels. It reveals the potential contributions from the real and the imaginary parts of the susceptibility tensor. Moreover, this kind of measurement is designed to permit the determination of the magnitude and the sign of the anisotropy of the real part of third-order nonlinearity in crystals with cubic or tetragonal symmetry on the basis of polarization-rotation measurements. The χxxxx(3) component of the third-order susceptibility tensor and its anisotropy sign and amplitude value for BaF2 and YVO4 crystals are estimated and discussed.

Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

ERIC Educational Resources Information Center

Correia, Paulo R. M.; Oliveira, Pedro V.

2004-01-01

The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

H-point standard additions method for simultaneous determination of sulfamethoxazole and trimethoprim in pharmaceutical formulations and biological fluids with simultaneous addition of two analytes

NASA Astrophysics Data System (ADS)

Givianrad, M. H.; Saber-Tehrani, M.; Aberoomand-Azar, P.; Mohagheghian, M.

2011-03-01

The applicability of H-point standard additions method (HPSAM) to the resolving of overlapping spectra corresponding to the sulfamethoxazole and trimethoprim is verified by UV-vis spectrophotometry. The results show that the H-point standard additions method with simultaneous addition of both analytes is suitable for the simultaneous determination of sulfamethoxazole and trimethoprim in aqueous media. The results of applying the H-point standard additions method showed that the two drugs could be determined simultaneously with the concentration ratios of sulfamethoxazole to trimethoprim varying from 1:18 to 16:1 in the mixed samples. Also, the limits of detections were 0.58 and 0.37 μmol L -1 for sulfamethoxazole and trimethoprim, respectively. In addition the means of the calculated RSD (%) were 1.63 and 2.01 for SMX and TMP, respectively in synthetic mixtures. The proposed method has been successfully applied to the simultaneous determination of sulfamethoxazole and trimethoprim in some synthetic, pharmaceutical formulation and biological fluid samples.

H-point standard additions method for simultaneous determination of sulfamethoxazole and trimethoprim in pharmaceutical formulations and biological fluids with simultaneous addition of two analytes.

PubMed

Givianrad, M H; Saber-Tehrani, M; Aberoomand-Azar, P; Mohagheghian, M

2011-03-01

The applicability of H-point standard additions method (HPSAM) to the resolving of overlapping spectra corresponding to the sulfamethoxazole and trimethoprim is verified by UV-vis spectrophotometry. The results show that the H-point standard additions method with simultaneous addition of both analytes is suitable for the simultaneous determination of sulfamethoxazole and trimethoprim in aqueous media. The results of applying the H-point standard additions method showed that the two drugs could be determined simultaneously with the concentration ratios of sulfamethoxazole to trimethoprim varying from 1:18 to 16:1 in the mixed samples. Also, the limits of detections were 0.58 and 0.37 μmol L(-1) for sulfamethoxazole and trimethoprim, respectively. In addition the means of the calculated RSD (%) were 1.63 and 2.01 for SMX and TMP, respectively in synthetic mixtures. The proposed method has been successfully applied to the simultaneous determination of sulfamethoxazole and trimethoprim in some synthetic, pharmaceutical formulation and biological fluid samples. Copyright © 2011 Elsevier B.V. All rights reserved.

Dynamic measurement of fluorescent proteins spectral distribution on virus infected cells

NASA Astrophysics Data System (ADS)

Lee, Ja-Yun; Wu, Ming-Xiu; Kao, Chia-Yun; Wu, Tzong-Yuan; Hsu, I.-Jen

2006-09-01

We constructed a dynamic spectroscopy system that can simultaneously measure the intensity and spectral distributions of samples with multi-fluorophores in a single scan. The system was used to monitor the fluorescence distribution of cells infected by the virus, which is constructed by a recombinant baculoviruses, vAcD-Rhir-E, containing the red and green fluorescent protein gene that can simultaneously produce dual fluorescence in recombinant virus-infected Spodoptera frugiperda 21 cells (Sf21) under the control of a polyhedrin promoter. The system was composed of an excitation light source, a scanning system and a spectrometer. We also developed an algorithm and fitting process to analyze the pattern of fluorescence distribution of the dual fluorescence produced in the recombinant virus-infected cells. All the algorithm and calculation are automatically processed in a visualized scanning program and can monitor the specific region of sample by calculating its intensity distribution. The spectral measurement of each pixel was performed at millisecond range and the two dimensional distribution of full spectrum was recorded within several seconds. We have constructed a dynamic spectroscopy system to monitor the process of virus-infection of cells. The distributions of the dual fluorescence were simultaneously measured at micrometer resolution.

Single scan femtosecond laser transverse writing of depressed cladding waveguides enabled by three-dimensional focal field engineering.

PubMed

Zhang, Qian; Yang, Dong; Qi, Jia; Cheng, Ya; Gong, Qihuang; Li, Yan

2017-06-12

We report single scan transverse writing of depressed cladding waveguides inside ZBLAN glass with the longitudinally oriented annular ring-shaped focal intensity distribution of the femtosecond laser. The entire region of depressed cladding at the cross section, where a negative change of refraction index is induced, can be modified simultaneously with the ring-shaped focal intensity profile. The fabricated waveguides exhibit good single guided mode.

Intense blue up-conversion luminescence in Tm 3+/Yb 3+ codoped oxyfluoride glass-ceramics containing β-PbF 2 nanocrystals

NASA Astrophysics Data System (ADS)

Zhang, Junjie; Duan, Zhongchao; He, Dongbing; Dai, Shixun; Zhang, Liyan; Hu, Lili

2005-12-01

Up-conversion luminescence properties of a Tm 3+/Yb 3+ codoped oxyfluoride glass-ceramics under 980 nm excitation are investigated. Intense blue emission centered at 476 nm, corresponding to 1G 4 → 3H 6 transitions of Tm 3+ was simultaneously observed in the transparent oxyfluoride glass ceramics at room temperature. The intensity of the blue up-conversion luminescence in a 1 mol% YbF 3-containing glass-ceramic was found to be about 40 times stronger than that in the precursor oxyfluoride glass. The reason for the intense Tm 3+ up-conversion luminescence in the oxyfluoride glass-ceramics is discussed. The dependence of up-conversion intensities on excitation power and possible up-conversion mechanism are also evaluated.

Intense blue up-conversion luminescence in Tm3+/Yb3+ codoped oxyfluoride glass-ceramics containing beta-PbF2 nanocrystals.

PubMed

Zhang, Junjie; Duan, Zhongchao; He, Dongbing; Dai, Shixun; Zhang, Liyan; Hu, Lili

2005-12-01

Up-conversion luminescence properties of a Tm3+/Yb3+ codoped oxyfluoride glass-ceramics under 980 nm excitation are investigated. Intense blue emission centered at 476 nm, corresponding to 1G4-->3H6 transitions of Tm3+ was simultaneously observed in the transparent oxyfluoride glass ceramics at room temperature. The intensity of the blue up-conversion luminescence in a 1 mol% YbF3-containing glass-ceramic was found to be about 40 times stronger than that in the precursor oxyfluoride glass. The reason for the intense Tm3+ up-conversion luminescence in the oxyfluoride glass-ceramics is discussed. The dependence of up-conversion intensities on excitation power and possible up-conversion mechanism are also evaluated.

Hot prominence detected in the core of a coronal mass ejection. II. Analysis of the C III line detected by SOHO/UVCS

NASA Astrophysics Data System (ADS)

Jejčič, S.; Susino, R.; Heinzel, P.; Dzifčáková, E.; Bemporad, A.; Anzer, U.

2017-11-01

Context. We study the physics of erupting prominences in the core of coronal mass ejections (CMEs) and present a continuation of a previous analysis. Aims: We determine the kinetic temperature and microturbulent velocity of an erupting prominence embedded in the core of a CME that occurred on August 2, 2000 using the Ultraviolet Coronagraph and Spectrometer observations (UVCS) on board the Solar and Heliospheric Observatory (SOHO) simultaneously in the hydrogen Lα and C III lines. We develop the non-LTE (departures from the local thermodynamic equilibrium - LTE) spectral diagnostics based on Lα and Lβ measured integrated intensities to derive other physical quantities of the hot erupting prominence. Based on this, we synthesize the C III line intensity to compare it with observations. Methods: Our method is based on non-LTE modeling of eruptive prominences. We used a general non-LTE radiative-transfer code only for optically thin prominence points because optically thick points do not allow the direct determination of the kinetic temperature and microturbulence from the line profiles. The input parameters of the code were the kinetic temperature and microturbulent velocity derived from the Lα and C III line widths, as well as the integrated intensity of the Lα and Lβ lines. The code runs in three loops to compute the radial flow velocity, electron density, and effective thickness as the best fit to the Lα and Lβ integrated intensities within the accuracy defined by the absolute radiometric calibration of UVCS data. Results: We analyzed 39 observational points along the whole erupting prominence because for these points we found a solution for the kinetic temperature and microturbulent velocity. For these points we ran the non-LTE code to determine best-fit models. All models with τ0(Lα) ≤ 0.3 and τ0(C III) ≤ 0.3 were analyzed further, for which we computed the integrated intensity of the C III line using a two-level atom. The best agreement between computed and observed integrated intensity led to 30 optically thin points along the prominence. The results are presented as histograms of the kinetic temperature, microturbulent velocity, effective thickness, radial flow velocity, electron density, and gas pressure. We also show the relation between the microturbulence and kinetic temperature together with a scatter plot of computed versus observed C III integrated intensities and the ratio of the computed to observed C III integrated intensities versus kinetic temperature. Conclusions: The erupting prominence embedded in the CME is relatively hot with a low electron density, a wide range of effective thicknesses, a rather narrow range of radial flow velocities, and a microturbulence of about 25 km s-1. This analysis shows a disagreement between observed and synthetic intensities of the C III line, the reason for which most probably is that photoionization is neglected in calculations of the ionization equilibrium. Alternatively, the disagreement might be due to non-equilibrium processes.

Interpreting Methanol v(sub 2)-Band Emission in Comets Using Empirical Fluorescence g-Factors

NASA Technical Reports Server (NTRS)

DiSanti, Michael; Villanueva, G. L.; Bonev, B. P.; Mumma, M. J.; Paganini, L.; Gibb, E. L.; Magee-Sauer, K.

2011-01-01

For many years we have been developing the ability, through high-resolution spectroscopy targeting ro-vibrational emission in the approximately 3 - 5 micrometer region, to quantify a suite of (approximately 10) parent volatiles in comets using quantum mechanical fluorescence models. Our efforts are ongoing and our latest includes methanol (CH3OH). This is unique among traditionally targeted species in having lacked sufficiently robust models for its symmetric (v(sub 3) band) and asymmetric (v(sub 2) and v(sub 9) bands) C-H3 stretching modes, required to provide accurate predicted intensities for individual spectral lines and hence rotational temperatures and production rates. This has provided the driver for undertaking a detailed empirical study of line intensities, and has led to substantial progress regarding our ability to interpret CH3OH in comets. The present study concentrates on the spectral region from approximately 2970 - 3010 per centimeter (3.367 - 3.322 micrometer), which is dominated by emission in the (v(sub 7) band of C2H6 and the v(sub 2) band of CH3OH, with minor contributions from CH3OH (v(sub 9) band), CH4 (v(sub 3)), and OH prompt emissions (v(sub 1) and v(sub 2)- v(sub 1)). Based on laboratory jet-cooled spectra (at a rotational temperature near 20 K)[1], we incorporated approximately 100 lines of the CH3OH v(sub 2) band, having known frequencies and lower state rotational energies, into our model. Line intensities were determined through comparison with several comets we observed with NIRSPEC at Keck 2, after removal of continuum and additional molecular emissions and correcting for atmospheric extinction. In addition to the above spectral region, NIRSPEC allows simultaneous sampling of the CH3OH v(sub 3) band (centered at 2844 per centimeter, or 3.516 micrometers and several hot bands of H2O in the approximately 2.85 - 2.9 micrometer region, at a nominal spectral resolving power of approximately 25,000 [2]. Empirical g-factors for v(sub 2) lines were based on the production rate as determined from the v(sub 3) Q-branch intensity; application to comets spanning a range of rotational temperatures (approximately 50 - 90 K) will be reported. This work represents an extension of that presented for comet 21P/Giacobini-Zinner at the 2010 Division for Planetary Sciences meeting [3]. Our empirical study also allows for quantifying CH3OH in comets using IR spectrometers for which the v(sub 3) and v(sub 2) bands are not sampled simultaneously, for example CSHELL/NASA IRTF or CRIRES/VLT.

Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing.

PubMed

Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

2016-06-02

Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species.

Particle-in-cell simulation study on halo formation in anisotropic beams

NASA Astrophysics Data System (ADS)

Ikegami, Masanori

2000-11-01

In a recent paper (M. Ikegami, Nucl. Instr. and Meth. A 435 (1999) 284), we investigated halo formation processes in transversely anisotropic beams based on the particle-core model. The effect of simultaneous excitation of two normal modes of core oscillation, i.e., high- and low-frequency modes, was examined. In the present study, self-consistent particle simulations are performed to confirm the results obtained in the particle-core analysis. In these simulations, it is confirmed that the particle-core analysis can predict the halo extent accurately even in anisotropic situations. Furthermore, we find that the halo intensity is enhanced in some cases where two normal modes of core oscillation are simultaneously excited as expected in the particle-core analysis. This result is of practical importance because pure high-frequency mode oscillation has frequently been assumed in preceding halo studies. The dependence of halo intensity on the 2:1 fixed point locations is also discussed.

Surface Measurements of Solar Spectral Radiative Flux in the Cloud-Free Atmosphere

NASA Technical Reports Server (NTRS)

Pilewskie, Peter; Goetz, A. F. H.; Bergstrom, R.; Beal, D.; Gore, Warren J. Y. (Technical Monitor)

1997-01-01

Recent studies (Charlock, et al.; Kato, et. al) have indicated a potential discrepancy between measured solar irradiance in the cloud-free atmosphere and model derived downwelling solar irradiance. These conclusions were based primarily on broadband integrated solar flux. Extinction (both absorption and scattering) phenomena, however, typically have spectral characteristics that would be present in moderate resolution (e.g., 10 nm) spectra, indicating the need for such measurements to thoroughly investigate the cause of any discrepancies. The 1996 Department of Energy Atmospheric Radiation Measurement Program (ARM) Intensive Observation Period (IOP), held simultaneously with the NASA Subsonic Aircraft: Contrail and Cloud Effects Special Study (SUCCESS) Program, provided an opportunity for two simultaneous but independent measurements of moderate resolution solar spectral downwelling irradiance at the surface. The instruments were the NASA Ames Solar Spectral Flux Radiometer and the Analytical Spectral Devices, Inc., FieldSpecT-FR. Spectral and band integrated quantities from both sets of measurements will be presented, along with estimates of the downwelling solar irradiance from band model and line by line calculations, in an effort to determine the compatibility between measured and calculated solar irradiance in the cloud-free atmosphere.

Pain Relief in CRPS-II after Spinal Cord and Motor Cortex Simultaneous Dual Stimulation.

PubMed

Lopez, William Oc; Barbosa, Danilo C; Teixera, Manoel J; Paiz, Martin; Moura, Leonardo; Monaco, Bernardo A; Fonoff, Erich T

2016-05-01

We describe a case of a 30-year-old woman who suffered a traumatic injury of the right brachial plexus, developing severe complex regional pain syndrome type II (CRPS-II). After clinical treatment failure, spinal cord stimulation (SCS) was indicated with initial positive pain control. However, after 2 years her pain progressively returned to almost baseline intensity before SCS. Additional motor cortex electrode implant was then proposed as a rescue therapy and connected to the same pulse generator. This method allowed simultaneous stimulation of the motor cortex and SCS in cycling mode with independent stimulation parameters in each site. At 2 years follow-up, the patient reported sustained improvement in pain with dual stimulation, reduction of painful crises, and improvement in quality of life. The encouraging results in this case suggests that this can be an option as add-on therapy over SCS as a possible rescue therapy in the management of CRPS-II. However, comparative studies must be performed in order to determine the effectiveness of this therapy. Chronic neuropathic pain, Complex regional pain syndrome Type II, brachial plexus injury, motor cortex stimulation, spinal cord stimulation.

Fourier Transform-Plasmon Waveguide Spectroscopy: A Nondestructive Multifrequency Method for Simultaneously Determining Polymer Thickness and Apparent Index of Refraction

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

Bobbitt, Jonathan M; Weibel, Stephen C; Elshobaki, Moneim

2014-12-16

Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [ Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an averagemore » percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).« less

Fourier transform-plasmon waveguide spectroscopy: a nondestructive multifrequency method for simultaneously determining polymer thickness and apparent index of refraction.

PubMed

Bobbitt, Jonathan M; Weibel, Stephen C; Elshobaki, Moneim; Chaudhary, Sumit; Smith, Emily A

2014-12-16

Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an average percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).

In Vivo Dual Fluorescence Imaging to Detect Joint Destruction.

PubMed

Cho, Hongsik; Bhatti, Fazal-Ur-Rehman; Lee, Sangmin; Brand, David D; Yi, Ae-Kyung; Hasty, Karen A

2016-10-01

Diagnosis of cartilage damage in early stages of arthritis is vital to impede the progression of disease. In this regard, considerable progress has been made in near-infrared fluorescence (NIRF) optical imaging technique. Arthritis can develop due to various mechanisms but one of the main contributors is the production of matrix metalloproteinases (MMPs), enzymes that can degrade components of the extracellular matrix. Especially, MMP-1 and MMP-13 have main roles in rheumatoid arthritis and osteoarthritis because they enhance collagen degradation in the process of arthritis. We present here a novel NIRF imaging strategy that can be used to determine the activity of MMPs and cartilage damage simultaneously by detection of exposed type II collagen in cartilage tissue. In this study, retro-orbital injection of mixed fluorescent dyes, MMPSense 750 FAST (MMP750) dye and Alexa Fluor 680 conjugated monoclonal mouse antibody immune-reactive to type II collagen, was administered in the arthritic mice. Both dyes were detected with different intensity according to degree of joint destruction in the animal. Thus, our dual fluorescence imaging method can be used to detect cartilage damage as well as MMP activity simultaneously in early stage arthritis. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Contactless and pose invariant biometric identification using hand surface.

PubMed

Kanhangad, Vivek; Kumar, Ajay; Zhang, David

2011-05-01

This paper presents a novel approach for hand matching that achieves significantly improved performance even in the presence of large hand pose variations. The proposed method utilizes a 3-D digitizer to simultaneously acquire intensity and range images of the user's hand presented to the system in an arbitrary pose. The approach involves determination of the orientation of the hand in 3-D space followed by pose normalization of the acquired 3-D and 2-D hand images. Multimodal (2-D as well as 3-D) palmprint and hand geometry features, which are simultaneously extracted from the user's pose normalized textured 3-D hand, are used for matching. Individual matching scores are then combined using a new dynamic fusion strategy. Our experimental results on the database of 114 subjects with significant pose variations yielded encouraging results. Consistent (across various hand features considered) performance improvement achieved with the pose correction demonstrates the usefulness of the proposed approach for hand based biometric systems with unconstrained and contact-free imaging. The experimental results also suggest that the dynamic fusion approach employed in this work helps to achieve performance improvement of 60% (in terms of EER) over the case when matching scores are combined using the weighted sum rule.

Immunoprevalence to Six Waterborne Pathogens in Beachgoers at Boquerón Beach, Puerto Rico: Application of a Microsphere-Based Salivary Antibody Multiplex Immunoassay

PubMed Central

Augustine, Swinburne A. J.; Simmons, Kaneatra J.; Eason, Tarsha N.; Curioso, Clarissa L.; Griffin, Shannon M.; Wade, Timothy J.; Dufour, Alfred; Fout, G. Shay; Grimm, Ann C.; Oshima, Kevin H.; Sams, Elizabeth A.; See, Mary Jean; Wymer, Larry J.

2017-01-01

Waterborne infectious diseases are a major public health concern worldwide. Few methods have been established that are capable of measuring human exposure to multiple waterborne pathogens simultaneously using non-invasive samples such as saliva. Most current methods measure exposure to only one pathogen at a time, require large volumes of individual samples collected using invasive procedures, and are very labor intensive. In this article, we applied a multiplex bead-based immunoassay capable of measuring IgG antibody responses to six waterborne pathogens simultaneously in human saliva to estimate immunoprevalence in beachgoers at Boquerón Beach, Puerto Rico. Further, we present approaches for determining cutoff points to assess immunoprevalence to the pathogens in the assay. For the six pathogens studied, our results show that IgG antibodies against antigens from noroviruses GI.I and GII.4 were more prevalent (60 and 51.6%, respectively) than Helicobacter pylori (21.4%), hepatitis A virus (20.2%), Campylobacter jejuni (8.7%), and Toxoplasma gondii (8%) in the saliva of the study participants. The salivary antibody multiplex immunoassay can be used to examine immunoprevalence of specific pathogens in human populations. PMID:28507984

Emperor penguin mates: keeping together in the crowd

PubMed Central

Ancel, André; Beaulieu, Michaël; Le Maho, Yvon; Gilbert, Caroline

2009-01-01

As emperor penguins have no breeding territories, a key issue for both members of a pair is not to be separated until the egg is laid and transferred to the male. Both birds remain silent after mating and thereby reduce the risk of having the pair bond broken by unpaired birds. However, silence prevents finding each other if the pair is separated. Huddles—the key to saving energy in the cold and the long breeding fast—continuously form and break up, but not all birds are involved simultaneously. We studied the behaviour of four pairs before laying. Temperature and light intensity measurements allowed us to precisely detect the occurrence of huddling episodes and to determine the surrounding temperature. The four pairs huddled simultaneously for only 6 per cent of the time when weather conditions were harshest. Despite this asynchrony, the huddling behaviour and the resulting benefits were similar between pairs. By contrast, the huddling behaviour of mates was synchronized for 84 per cent of events. By coordinating their huddling behaviour during courtship despite the apparent confusion within a huddle and its ever-changing structure, both individuals save energy while securing their partnership. PMID:19324739

Vehicle Surveillance with a Generic, Adaptive, 3D Vehicle Model.

PubMed

Leotta, Matthew J; Mundy, Joseph L

2011-07-01

In automated surveillance, one is often interested in tracking road vehicles, measuring their shape in 3D world space, and determining vehicle classification. To address these tasks simultaneously, an effective approach is the constrained alignment of a prior model of 3D vehicle shape to images. Previous 3D vehicle models are either generic but overly simple or rigid and overly complex. Rigid models represent exactly one vehicle design, so a large collection is needed. A single generic model can deform to a wide variety of shapes, but those shapes have been far too primitive. This paper uses a generic 3D vehicle model that deforms to match a wide variety of passenger vehicles. It is adjustable in complexity between the two extremes. The model is aligned to images by predicting and matching image intensity edges. Novel algorithms are presented for fitting models to multiple still images and simultaneous tracking while estimating shape in video. Experiments compare the proposed model to simple generic models in accuracy and reliability of 3D shape recovery from images and tracking in video. Standard techniques for classification are also used to compare the models. The proposed model outperforms the existing simple models at each task.

Intensive agriculture erodes β-diversity at large scales.

PubMed

Karp, Daniel S; Rominger, Andrew J; Zook, Jim; Ranganathan, Jai; Ehrlich, Paul R; Daily, Gretchen C

2012-09-01

Biodiversity is declining from unprecedented land conversions that replace diverse, low-intensity agriculture with vast expanses under homogeneous, intensive production. Despite documented losses of species richness, consequences for β-diversity, changes in community composition between sites, are largely unknown, especially in the tropics. Using a 10-year data set on Costa Rican birds, we find that low-intensity agriculture sustained β-diversity across large scales on a par with forest. In high-intensity agriculture, low local (α) diversity inflated β-diversity as a statistical artefact. Therefore, at small spatial scales, intensive agriculture appeared to retain β-diversity. Unlike in forest or low-intensity systems, however, high-intensity agriculture also homogenised vegetation structure over large distances, thereby decoupling the fundamental ecological pattern of bird communities changing with geographical distance. This ~40% decline in species turnover indicates a significant decline in β-diversity at large spatial scales. These findings point the way towards multi-functional agricultural systems that maintain agricultural productivity while simultaneously conserving biodiversity. © 2012 Blackwell Publishing Ltd/CNRS.

Method for calibration-free scanned-wavelength modulation spectroscopy for gas sensing

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

Hanson, Ronald K.; Jeffries, Jay B.; Sun, Kai

A method of calibration-free scanned-wavelength modulation spectroscopy (WMS) absorption sensing is provided by obtaining absorption lineshape measurements of a gas sample on a sensor using 1f-normalized WMS-2f where an injection current to an injection current-tunable diode laser (TDL) is modulated at a frequency f, where a wavelength modulation and an intensity modulation of the TDL are simultaneously generated, extracting using a numerical lock-in program and a low-pass filter appropriate band-width WMS-nf (n=1, 2, . . . ) signals, where the WMS-nf signals are harmonics of the f, determining a physical property of the gas sample according to ratios of themore » WMS-nf signals, determining the zero-absorption background using scanned-wavelength WMS, and determining non-absorption losses using at least two of the harmonics, where a need for a non-absorption baseline measurement is removed from measurements in environments where collision broadening has blended transition linewidths, where calibration free WMS measurements without knowledge of the transition linewidth is enabled.« less

HIGH-THROUGHPUT IDENTIFICATION OF THE PREDOMINANT MALARIA PARASITE CLONE IN COMPLEX BLOOD STAGE INFECTIONS USING A MULTI-SNP MOLECULAR HAPLOTYPING ASSAY

PubMed Central

COLE-TOBIAN, JENNIFER L.; ZIMMERMAN, PETER A.; KING, CHRISTOPHER L.

2013-01-01

Individuals living in malaria endemic areas are often infected with multiple parasite clones. Currently used single nucleotide polymorphism (SNP) genotyping methods for malaria parasites are cumbersome; furthermore, few methods currently exist that can rapidly determine the most abundant clone in these complex infections. Here we describe an oligonucleotide ligation assay (OLA) to distinguish SNPs in the Plasmodium vivax Duffy binding protein gene (Pvdbp) at 14 polymorphic residues simultaneously. Allele abundance is determined by the highest mean fluorescent intensity of each allele. Using mixtures of plasmids encoding known haplotypes of the Pvdbp, single clones of P. vivax parasites from infected Aotus monkeys, and well-defined mixed infections from field samples, we were able to identify the predominant Pvdbp genotype with > 93% accuracy when the dominant clone is twice as abundant as a lesser genotype and > 97% of the time if the ratio was 5:1 or greater. Thus, the OLA can accurately, reproducibly, and rapidly determine the predominant parasite haplotype in complex blood stage infections. PMID:17255222

Single-shot Z eff dense plasma diagnostic through simultaneous refraction and attenuation measurements with a Talbot–Lau x-ray moiré deflectometer

DOE PAGES

Valdivia, M. P.; Stutman, D.; Finkenthal, M.

2015-03-23

The Talbot–Lau x-ray moiré deflectometer is a powerful plasma diagnostic capable of delivering simultaneous refraction and attenuation information through the accurate detection of x-ray phase shift and intensity. The diagnostic can provide the index of refraction n=1₋δ + iβ of an object (dense plasma, for example) placed in the x-ray beam by independently measuring both δ and β, which are directly related to the electron density n e and the attenuation coefficient μ respectively. Since δ and β depend on the effective atomic number Z eff, a map can be obtained from the ratio between phase and absorption images acquiredmore » in a single shot. The Talbot–Lau x-ray moiré deflectometer and its corresponding data acquisition and processing are briefly described to illustrate how the above is achieved; Z eff values of test objects within the 4₋12 range were obtained experimentally through simultaneous refraction and attenuation measurements. We show that Z eff mapping of objects does not require previous knowledge of sample length or shape. In conclusion, the determination of Z eff from refraction and attenuation measurements with moiré deflectometry could be of high interest to various domains of high energy density research, such as shocked materials and inertial confinement fusion experiments, as well as material science and nondestructive testing.« less

Single-shot Z eff dense plasma diagnostic through simultaneous refraction and attenuation measurements with a Talbot–Lau x-ray moiré deflectometer

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

Valdivia, M. P.; Stutman, D.; Finkenthal, M.

The Talbot–Lau x-ray moiré deflectometer is a powerful plasma diagnostic capable of delivering simultaneous refraction and attenuation information through the accurate detection of x-ray phase shift and intensity. The diagnostic can provide the index of refraction n=1₋δ + iβ of an object (dense plasma, for example) placed in the x-ray beam by independently measuring both δ and β, which are directly related to the electron density n e and the attenuation coefficient μ respectively. Since δ and β depend on the effective atomic number Z eff, a map can be obtained from the ratio between phase and absorption images acquiredmore » in a single shot. The Talbot–Lau x-ray moiré deflectometer and its corresponding data acquisition and processing are briefly described to illustrate how the above is achieved; Z eff values of test objects within the 4₋12 range were obtained experimentally through simultaneous refraction and attenuation measurements. We show that Z eff mapping of objects does not require previous knowledge of sample length or shape. In conclusion, the determination of Z eff from refraction and attenuation measurements with moiré deflectometry could be of high interest to various domains of high energy density research, such as shocked materials and inertial confinement fusion experiments, as well as material science and nondestructive testing.« less

observation and analysis of the structure of winter precipitation-generating clouds using ground-based sensor measurements

NASA Astrophysics Data System (ADS)

Menéndez José Luis, Marcos; Gómez José Luis, Sánchez; Campano Laura, López; Ortega Eduardo, García; Suances Andrés, Merino; González Sergio, Fernández; Salvador Estíbaliz, Gascón; González Lucía, Hermida

2015-04-01

In this study, we used a 28-day database corresponding to December, January and February of 2011/2012 and 2012/2013 campaigns to analyze cloud structure that produced precipitation in the Sierra Norte near Madrid, Spain. We used remote sensing measurements, both active type like the K-band Micro Rain Radar (MRR) and passive type like the Radiometrics MP-3000A multichannel microwave radiometer. Using reflectivity data from the MRR, we determined the important microphysical parameters of Ice Water Content (IWC) and its integrated value over the atmospheric column, or Ice Water Path (IWP). Among the measurements taken by the MP-3000A were Liquid Water Path (LWP) and Integrated Water Vapor (IWV). By representing these data together, sharp declines in LWP and IWV were evident, coincident with IWP increases. This result indicates the ability of a K-band radar to measure the amount of ice in the atmospheric column, simultaneously revealing the Wegener-Bergeron-Findeisen mechanism. We also used a Present Weather Sensor (VPF-730; Biral Ltd., Bristol, UK) to determine the type and amount of precipitation at the surface. With these data, we used regression equations to establish the relationship between visibility and precipitation intensity. In addition, through theoretical precipitation visibility-intensity relationships, we estimated the type of crystal, degree of accretion (riming), and moisture content of fallen snow crystals.

Verification of Loop Diagnostics

NASA Technical Reports Server (NTRS)

Winebarger, A.; Lionello, R.; Mok, Y.; Linker, J.; Mikic, Z.

2014-01-01

Many different techniques have been used to characterize the plasma in the solar corona: density-sensitive spectral line ratios are used to infer the density, the evolution of coronal structures in different passbands is used to infer the temperature evolution, and the simultaneous intensities measured in multiple passbands are used to determine the emission measure. All these analysis techniques assume that the intensity of the structures can be isolated through background subtraction. In this paper, we use simulated observations from a 3D hydrodynamic simulation of a coronal active region to verify these diagnostics. The density and temperature from the simulation are used to generate images in several passbands and spectral lines. We identify loop structures in the simulated images and calculate the loop background. We then determine the density, temperature and emission measure distribution as a function of time from the observations and compare with the true temperature and density of the loop. We find that the overall characteristics of the temperature, density, and emission measure are recovered by the analysis methods, but the details of the true temperature and density are not. For instance, the emission measure curves calculated from the simulated observations are much broader than the true emission measure distribution, though the average temperature evolution is similar. These differences are due, in part, to inadequate background subtraction, but also indicate a limitation of the analysis methods.

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

Liang, Xiaodong, E-mail: lxdctopone@sina.com; Ni, Lingqin; Hu, Wei

The objective of this study was to evaluate the dose conformity and feasibility of whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in patients with 1 to 3 brain metastases. Forward intensity-modulated radiation therapy plans were generated for 10 patients with 1 to 3 brain metastases on Pinnacle 6.2 Treatment Planning System. The prescribed dose was 30 Gy to the whole brain (planning target volume [PTV]{sub wbrt}) and 40 Gy to individual brain metastases (PTV{sub boost}) simultaneously, and both doses were given in 10 fractions. The maximum diameters of individual brain metastases ranged from 1.6 tomore » 6 cm, and the summated PTVs per patient ranged from 1.62 to 69.81 cm{sup 3}. Conformity and feasibility were evaluated regarding conformation number and treatment delivery time. One hundred percent volume of the PTV{sub boost} received at least 95% of the prescribed dose in all cases. The maximum doses were less than 110% of the prescribed dose to the PTV{sub boost}, and all of the hot spots were within the PTV{sub boost}. The volume of the PTV{sub wbrt} that received at least 95% of the prescribed dose ranged from 99.2% to 100%. The mean values of conformation number were 0.682. The mean treatment delivery time was 2.79 minutes. Ten beams were used on an average in these plans. Whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in 1 to 3 brain metastases is feasible, and treatment delivery time is short.« less

A Triple Functional Approach To Simultaneously Determine the Type, Concentration, and Size of Titanium Dioxide Particles.

PubMed

Zhao, Bin; Yang, Tianxi; Zhang, Zhiyun; Hickey, Michael E; He, Lili

2018-03-06

The large-scale manufacturing and use of titanium dioxide (TiO 2 ) particles in food and consumer products significantly increase the likelihood of human exposure and release into the environment. We present a simple and innovative approach to rapidly identify the type (anatase or rutile), as well as to estimate, the size and concentration of TiO 2 particles using Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS). The identification and discrimination of rutile and anatase were based on their intrinsic Raman signatures. The concentration of the TiO 2 particles was determined based on Raman peak intensity. Particle sizes were estimated based on the ratio between the Raman intensity of TiO 2 and the SERS intensity of myricetin bound to the nanoparticles (NPs), which was proven to be independent of TiO 2 nanoparticle concentrations. The ratio that was calculated from the 100 nm particles was used as a cutoff value when estimating the presence of nanosized particles within a mixture. We also demonstrated the practical use of this approach when determining the type, concentration, and size of E171: a mixture that contains TiO 2 particles of various sizes which are commonly used in many food products as food additives. The presence of TiO 2 anatase NPs in E171 was confirmed using the developed approach and was validated by transmission electron micrographs. TiO 2 presence in pond water was also demonstrated to be an analytical capability of this method. Our approach shows great promise for the rapid screening of nanosized rutile and anatase TiO 2 particles in complex matrixes. This approach will strongly improve the measurement of TiO 2 quality during production, as well as the survey capacity and risk assessment of TiO 2 NPs in food, consumer goods, and environmental samples.

Simultaneous Remote Observations of Intense Reconnection Effects by DMSP and MMS Spacecraft During a Storm Time Substorm

PubMed Central

Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Owen, C. J.; Petrukovich, A. A.; Yao, Z.; Nakamura, T. K. M.; Kubyshkina, M. V.; Sotirelis, T.; Burch, J. L.; Genestreti, K. J.; Vörös, Z.; Andriopoulou, M.; Gershman, D. J.; Avanov, L. A.; Magnes, W.; Russell, C. T.; Plaschke, F.; Khotyaintsev, Y. V.; Giles, B. L.; Coffey, V. N.; Dorelli, J. C.; Strangeway, R. J.; Torbert, R. B.; Lindqvist, P.‐A.; Ergun, R.

2017-01-01

Abstract During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high‐energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X‐line was located relatively close to the Earth, approximately at 16–18 RE. PMID:29399431

Simultaneous Remote Observations of Intense Reconnection Effects by DMSP and MMS Spacecraft During a Storm Time Substorm

NASA Astrophysics Data System (ADS)

Varsani, A.; Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Owen, C. J.; Petrukovich, A. A.; Yao, Z.; Nakamura, T. K. M.; Kubyshkina, M. V.; Sotirelis, T.; Burch, J. L.; Genestreti, K. J.; Vörös, Z.; Andriopoulou, M.; Gershman, D. J.; Avanov, L. A.; Magnes, W.; Russell, C. T.; Plaschke, F.; Khotyaintsev, Y. V.; Giles, B. L.; Coffey, V. N.; Dorelli, J. C.; Strangeway, R. J.; Torbert, R. B.; Lindqvist, P.-A.; Ergun, R.

2017-11-01

During a magnetic storm on 23 June 2015, several very intense substorms took place, with signatures observed by multiple spacecraft including DMSP and Magnetospheric Multiscale (MMS). At the time of interest, DMSP F18 crossed inbound through a poleward expanding auroral bulge boundary at 23.5 h magnetic local time (MLT), while MMS was located duskward of 22 h MLT during an inward crossing of the expanding plasma sheet boundary. The two spacecraft observed a consistent set of signatures as they simultaneously crossed the reconnection separatrix layer during this very intense reconnection event. These include (1) energy dispersion of the energetic ions and electrons traveling earthward, accompanied with high electron energies in the vicinity of the separatrix; (2) energy dispersion of polar rain electrons, with a high-energy cutoff; and (3) intense inward convection of the magnetic field lines at the MMS location. The high temporal resolution measurements by MMS provide unprecedented observations of the outermost electron boundary layer. We discuss the relevance of the energy dispersion of the electrons, and their pitch angle distribution, to the spatial and temporal evolution of the boundary layer. The results indicate that the underlying magnetotail magnetic reconnection process was an intrinsically impulsive and the active X-line was located relatively close to the Earth, approximately at 16-18 RE.

Flat-plate solar array project process development area: Process research of non-CZ silicon material

NASA Technical Reports Server (NTRS)

Campbell, R. B.

1986-01-01

Several different techniques to simultaneously diffuse the front and back junctions in dendritic web silicon were investigated. A successful simultaneous diffusion reduces the cost of the solar cell by reducing the number of processing steps, the amount of capital equipment, and the labor cost. The three techniques studied were: (1) simultaneous diffusion at standard temperatures and times using a tube type diffusion furnace or a belt furnace; (2) diffusion using excimer laser drive-in; and (3) simultaneous diffusion at high temperature and short times using a pulse of high intensity light as the heat source. The use of an excimer laser and high temperature short time diffusion experiment were both more successful than the diffusion at standard temperature and times. The three techniques are described in detail and a cost analysis of the more successful techniques is provided.

Spectral study and protein labeling of inclusion complex between dye and calixarene sulfonate.

PubMed

Fei, Xuening; Zhang, Yong; Zhu, Sen; Liu, Lijuan; Yu, Lu

2013-05-01

The host-guest inclusion complex of calix[6]arene sulfonate (SCA6) with thiazole orange (TO) formed in aqueous solution was studied. Absorption and fluorescence techniques were used for the analysis of this inclusion complex. The addition of calixarene sulfonate leads to a decrease in both absorption and fluorescence intensity of the dye, indicating that the inclusion complex was formed. Simultaneously, the inclusion phenomenon of another cyanine dye, Cy3, with calixarene sulfonate was investigated. The stability constant of the two complexes was determined, and the results were compared. The water solubility of TO dye was increased in the presence of calixarene sulfonate, and further protein labeling experiments suggested that this TO-SCA6 complex can act as a fluorescent probe for labeling of biomolecules.

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

Igarashi, Noriyuki, E-mail: noriyuki.igarashi@kek.jp; Nitani, Hiroaki; Takeichi, Yasuo

BL-15A is a new x-ray undulator beamline at the Photon Factory. It will be dedicated to two independent research activities, simultaneous XAFS/XRF/XRD experiments, and SAXS/WAXS/GI-SAXS studies. In order to supply a choice of micro-focus, low-divergence and collimated beams, a double surface bimorph mirror was recently developed. To achieve further mirror surface optimization, the pencil beam scanning method was applied for “in-situ” beam inspection and the Inverse Matrix method was used for determination of optimal voltages on the piezoelectric actuators. The corrected beam profiles at every focal spot gave good agreement with the theoretical values and the resultant beam performance ismore » promising for both techniques. Quick and stable switching between highly focused and intense collimated beams was established using this new mirror with the simple motorized stages.« less

Experimental measurement of the 12C+16O fusion cross sections at astrophysical energies

NASA Astrophysics Data System (ADS)

Fang, X.; Tan, W. P.; Beard, M.; deBoer, R. J.; Gilardy, G.; Jung, H.; Liu, Q.; Lyons, S.; Robertson, D.; Setoodehnia, K.; Seymour, C.; Stech, E.; Vande Kolk, B.; Wiescher, M.; de Souza, R.; Hudan, S.; Singh, V.; Tang, X. D.; Uberseder, E.

2018-05-01

The total cross sections of the 12C+16O fusion have been experimentally determined at low energies to investigate the role of this reaction during late stellar evolution burning phases. A high-intensity oxygen beam was produced by the 5MV pelletron accelerator at the University of Notre Dame impinging on a thick ultra-pure graphite target. Protons and γ-rays were measured simultaneously in the center-of-mass energy range from 3.64 to 5.01 MeV, using strip silicon and HPGe detectors. Statistical model calculations were employed to interpret the experimental results. A new broad resonance-like structure is observed for the 12C+16O reaction, and a decreasing trend of its S-factor towards low energies is found.

Flexible particle manipulation techniques with conical refraction-based optical tweezers

NASA Astrophysics Data System (ADS)

McDougall, C.; Henderson, Robert; Carnegie, David J.; Sokolovskii, Grigorii S.; Rafailov, Edik U.; McGloin, David

2012-10-01

We present an optimized optical tweezers system based upon the conical refraction of circularly polarized light in a biaxial crystal. The described optical arrangement avoids distortions to the Lloyd plane rings that become apparent when working with circularly polarized light in conventional optical tweezers. We demonstrate that the intensity distribution of the conically diffracted light permits optical manipulation of high and low refractive index particles simultaneously. Such trapping is in three dimensions and not limited to the Lloyd plane rings. By removal of a quarter waveplate the system also permits the study of linearly polarized conical refraction. We show that particle position in the Raman plane is determined by beam power, and indicates that true optical tweezing is not taking place in this part of the beam.

The effect of light, salinity, and nitrogen availability on lipid production by Nannochloropsis sp.

PubMed

Pal, Dipasmita; Khozin-Goldberg, Inna; Cohen, Zvi; Boussiba, Sammy

2011-05-01

We examined responses of batch cultures of the marine microalga Nannochloropsis sp. to combined alterations in salinity (13, 27, and 40 g/l NaCl) and light intensity (170 and 700 μmol photons/m(2)·s). Major growth parameters and lipid productivity (based on total fatty acid determination) were determined in nitrogen-replete and nitrogen-depleted cultures of an initial biomass of 0.8 and 1.4 g/l, respectively. On the nitrogen-replete medium, increases in light intensity and salinity increased the cellular content of dry weight and lipids due to enhanced formation of triacylglycerols (TAG). Maximum average productivity of ca. 410 mg TFA/l/d were obtained at 700 μmol photons/m(2)·s and 40 g/l NaCl within 7 days. Under stressful conditions, content of the major LC-PUFA, eicosapentaenoic acid (EPA), was significantly reduced while TAG reached 25% of biomass. In contrast, lower salinity tended to improve major growth parameters, consistent with less variation in EPA contents. Combined higher salinity and light intensity was detrimental to lipid productivity under nitrogen starvation; biomass TFA content, and lipid productivity amounted for only 33% of DW and ca. 200 mg TFA/l/day, respectively. The highest biomass TFA content (ca. 47% DW) and average lipid productivity of ca. 360 mg TFA/l/day were achieved at 13 g/l NaCl and 700 μmol photons/m(2)·s. Our data further support selecting Nannochloropsis as promising microalgae for biodiesel production. Moreover, appropriate cultivation regimes may render Nannochloropsis microalgae to produce simultaneously major valuable components, EPA, and TAG, while sustaining relatively high biomass growth rates.

Analysis of Photosystem I Donor and Acceptor Sides with a New Type of Online-Deconvoluting Kinetic LED-Array Spectrophotometer.

PubMed

Schreiber, Ulrich; Klughammer, Christof

2016-07-01

The newly developed Dual/KLAS-NIR spectrophotometer, technical details of which were reported very recently, is used in measuring redox changes of P700, plastocyanin (PC) and ferredoxin (Fd) in intact leaves of Hedera helix, Taxus baccata and Brassica napus An overview of various light-/dark-induced changes of deconvoluted P700 + , PC + and Fd - signals is presented demonstrating the wealth of novel information and the consistency of the obtained results. Fd - changes are particularly large after dark adaptation. PC oxidation precedes P700 oxidation during dark-light induction and in steady-state light response curves. Fd reoxidation during induction correlates with the secondary decline of simultaneously measured fluorescence yield, both of which are eliminated by removal of O 2 By determination of 100% redox changes, relative contents of PC/P700 and Fd/P700 can be assessed, which show considerable variations between different leaves, with a trend to higher values in sun leaves. Based on deconvoluted P700 + signals, the complementary quantum yields of PSI, Y(I) (photochemical energy use), Y(ND) (non-photochemical loss due to oxidized primary donor) and Y(NA) (non-photochemical loss due to reduced acceptor) are determined as a function of light intensity and compared with the corresponding complementary quantum yields of PSII, Y(II) (photochemical energy use), Y(NPQ) (regulated non-photochemical loss) and Y(NO) (non-regulated non-photochemical loss). The ratio Y(I)/Y(II) increases with increasing intensities. In the low intensity range, a two-step increase of PC + is indicative of heterogeneous PC pools. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Combined SERS biotags (SBTs) and microfluidic platform for the quantitative ratiometric discrimination between noncancerous and cancerous cells in flow

NASA Astrophysics Data System (ADS)

Pallaoro, Alessia; Hoonejani, Mehran R.; Braun, Gary B.; Meinhart, Carl; Moskovits, Martin

2012-10-01

SERS biotags are made from polymer-encapsulated silver nanoparticle dimers infused with unique Raman reporter molecules, and carry peptides as cell recognition moieties. We demonstrate their potential use for early and rapid identification of malignant cells, a central goal in cancer research. SERS biotags (SBTs) can be routinely synthesized and simultaneously excited with a single, low intensity laser source, making the determination of the relative contribution of the individual SBTs to the overall spectrum tractable. Importantly for biomedical applications, SERS employs tissuepenetrating lasers in the red to near-infrared range resulting in low autofluorescence. We have previously described a multiplexed, ratiometric method that can confidently distinguish between cancerous and noncancerous epithelial prostate cells in vitro based on receptor overexpression. Here we present the progress towards the application of this quantitative methodology for the identification of cancer cells in a microfluidic flow-focusing device. Beads are used as cell mimics to characterize the devices. Cells (and beads) are simultaneously incubated with two sets of SBTs while in suspension (simulating cells' capture from blood), then injected into the device for laser interrogation under flow. Each cell event is characterized by a composite Raman spectrum, deconvoluted into its single components to ultimately determine their relative contribution. We show that using SBTs ratiometrically can provide cell identification insensitive to normal causes of uncertainty in optical measurements such as variations in focal plane, cell concentration, autofluorescence, and turbidity.

Simultaneous titration and phenotypic antiviral drug susceptibility testing for herpes simplex virus 1 and 2.

PubMed

Tardif, Keith D; Jorgensen, Shane; Langer, Janine; Prichard, Mark; Schlaberg, Robert

2014-11-01

Most herpes simplex virus (HSV) isolates from treatment-naïve patients are susceptible to antivirals. However, prolonged antiviral therapy can select for drug-resistant strains, especially in immunocompromised patients. Standard phenotypic methods for antiviral resistance testing are labor and time-intense and molecular resistance determinants are insufficiently understood for routine diagnostic use of genotypic resistance testing. To enable rapid, scalable antiviral susceptibility testing and minimize viral passage, we developed a 7-day, 96-well assay for simultaneous HSV 1/2 titration and phenotypic resistance testing for acyclovir and foscarnet. The assay was optimized and validated by testing clinical isolates and laboratory strains (n=39) with known IC50 for acyclovir (23 resistant) and foscarnet (1 resistant) based on plaque reduction or dye-uptake assays. A chemiluminescent detection reagent is used for quantification of cytopathic effect instead of plaque counting or measuring dye-uptake. Drug concentrations inhibiting 50% of chemiluminescent signal reduction (IC50) were determined concurrently at each of three virus dilutions. Results agree for 92.3% (acyclovir) and 100% (foscarnet) of isolates. For all three discordant samples, results of reference testing by plaque reduction agreed with the chemiluminescent assay. Reproducibility studies showed 100% qualitative agreement and 3-37% coefficient of variation based on IC50. Chemiluminescence detection as a surrogate for cellular viability with an automated plate reader provides improved throughput and workflow, as well as high accuracy and reproducibility for antiviral drug susceptibility testing. Copyright © 2014 Elsevier B.V. All rights reserved.

A Conceptual Model for Shear-Induced Phase Behavior in Crystallizing Cocoa Butter

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

Mazzanti,G.; Guthrie, S.; Marangoni, A.

2007-01-01

We propose a conceptual model to explain the quantitative data from synchrotron X-ray diffraction experiments on the shear-induced phase behavior of cocoa butter, the main structural component of chocolate. We captured two-dimensional diffraction patterns from cocoa butter at crystallization temperatures of 17.5, 20.0, and 22.5 {sup o}C under shear rates from 45 to 1440 s{sup -1} and under static conditions. From the simultaneous analysis of the integrated intensity, correlation length, lamellar thickness, and crystalline orientation, we postulate a conceptual model to provide an explanation for the distribution of phases II, IV, V, and X and the kinetics of the process.more » As previously proposed in the literature, we assume that the crystallites grow layer upon layer of slightly different composition. The shear rate and temperature applied define these compositions. Simultaneously, the shear and temperature define the crystalline interface area available for secondary nucleation by promoting segregation and affecting the size distribution of the crystallites. The combination of these factors (composition, area, and size distribution) favors dramatically the early onset of phase V under shear and determines the proportions of phases II, IV, V, and X after the transition. The experimental observations, the methodology used, and the proposed explanation are of fundamental and industrial interest, since the structural properties of crystalline networks are determined by their microstructure and polymorphic crystalline state. Different proportions of the phases will thus result in different characteristics of the final material.« less

An amplified chemiluminescence system based on Si-doped carbon dots for detection of catecholamines.

PubMed

Amjadi, Mohammad; Hallaj, Tooba; Manzoori, Jamshid L; Shahbazsaghir, Tahmineh

2018-08-05

We report on a chemiluminescence (CL) system based on simultaneous enhancing effect of Si-doped carbon dots (Si-CDs) and cetyltrimethylammonium bromide (CTAB) on HCO 3 - -H 2 O 2 reaction . The possible CL mechanism is investigated and discussed. Excited-state Si-CDs was found to be the final emitting species, which are probably produced via electron and hole injection by oxy-radicals. The effect of several other heteroatom-doped CDs and undoped CDs was also investigated and compared with Si-CDs. Furthermore, it was found that catecholamines such as dopamine, adrenaline and noradrenaline remarkably diminish the CL intensity of Si-CD-HCO 3 - -H 2 O 2 -CTAB system. By taking advantage of this fact, a sensitive probe was designed for determination of dopamine, adrenaline and noradrenaline with a limit of detection of 0.07, 0.60 and 0.01 μM, respectively. The method was applied to the determination of catecholamines in human plasma samples. Copyright © 2018 Elsevier B.V. All rights reserved.

External cavity-quantum cascade laser (EC-QCL) spectroscopy for protein analysis in bovine milk.

PubMed

Kuligowski, Julia; Schwaighofer, Andreas; Alcaráz, Mirta Raquel; Quintás, Guillermo; Mayer, Helmut; Vento, Máximo; Lendl, Bernhard

2017-04-22

The analytical determination of bovine milk proteins is important in food and non-food industrial applications and yet, rather labour-intensive wet-chemical, low-throughput methods have been employed since decades. This work proposes the use of external cavity-quantum cascade laser (EC-QCL) spectroscopy for the simultaneous quantification of the most abundant bovine milk proteins and the total protein content based on the chemical information contained in mid-infrared (IR) spectral features of the amide I band. Mid-IR spectra of protein standard mixtures were used for building partial least squares (PLS) regression models. Protein concentrations in commercial bovine milk samples were calculated after chemometric compensation of the matrix contribution employing science-based calibration (SBC) without sample pre-processing. The use of EC-QCL spectroscopy together with advanced multivariate data analysis allowed the determination of casein, α-lactalbumin, β-lactoglobulin and total protein content within several minutes. Copyright © 2017 Elsevier B.V. All rights reserved.

Laser Doppler measurement techniques for spacecraft

NASA Technical Reports Server (NTRS)

Kinman, Peter W.; Gagliardi, Robert M.

1986-01-01

Two techniques are proposed for using laser links to measure the relative radial velocity of two spacecraft. The first technique determines the relative radial velocity from a measurement of the two-way Doppler shift on a transponded radio-frequency subcarrier. The subcarrier intensity-modulates reciprocating laser beams. The second technique determines the relative radial velocity from a measurement of the two-way Doppler shift on an optical frequency carrier which is transponded between spacecraft using optical Costas loops. The first technique might be used in conjunction with noncoherent optical communications, while the second technique is compatible with coherent optical communications. The first technique simultaneously exploits the diffraction advantage of laser beams and the maturity of radio-frequency phase-locked loop technology. The second technique exploits both the diffraction advantage of laser beams and the large Doppler effect at optical frequencies. The second technique has the potential for greater accuracy; unfortunately, it is more difficult to implement since it involves optical Costas loops.

Plasmonic metasurface for simultaneous detection of polarization and spectrum.

PubMed

Pelzman, Charles; Cho, Sang-Yeon

2016-03-15

We present a new plasmonic metasurface for simultaneous detection of polarization and spectrum of incident light. The demonstrated metasurface is a rationally designed cluster of artificial atoms that are engineered to exhibit polarization and wavelength-selective optical transmission. The fundamental building block of this structure is periodically coupled subwavelength aperture arrays with different orientations and lattice constants. When integrated with pixelated photodetectors, the metasurface can be used to measure the polarization and spectral information of an optical input. In this Letter, simultaneous detection of the polarization and spectrum of polarized light was experimentally demonstrated by analyzing the transmitted intensity distribution through the metasurface. The demonstrated metasurface offers great potential for many applications, such as polarimetric multispectral imaging and polarization-division multiplexing in optical communications.

Simultaneous Rayleigh lidar and airglow measurements of middle atmospheric waves over low latitudes in India

NASA Astrophysics Data System (ADS)

Taori, A.; Kamalakar, V.; Raghunath, K.; Rao, S. V. B.; Russell, J. M.

2012-04-01

We utilize simultaneous Rayleigh lidar and mesospheric OH and O2 airglow measurements to identify the dominant and propagating waves within 40-95 km altitude regions over a low latitude station Gadanki (13.8° N, 79.2 °E). It is found that waves with 0.4-0.6 h periodicity are common throughout the altitude range of 40-95 km with significant amplitudes. The ground based temperature measurements with lidar and airglow monitoring are found to compare well with SABER data. With simultaneous Rayleigh lidar (temperature) and mesospheric airglow (emission intensity and temperature) measurements, we estimate the amplitude growth and Krassovsky parameters to characterize the propagation and dissipation of these upward propagating waves.

Simultaneously measuring multiple protein interactions and their correlations in a cell by Protein-interactome Footprinting

PubMed Central

Luo, Si-Wei; Liang, Zhi; Wu, Jia-Rui

2017-01-01

Quantitatively detecting correlations of multiple protein-protein interactions (PPIs) in vivo is a big challenge. Here we introduce a novel method, termed Protein-interactome Footprinting (PiF), to simultaneously measure multiple PPIs in one cell. The principle of PiF is that each target physical PPI in the interactome is simultaneously transcoded into a specific DNA sequence based on dimerization of the target proteins fused with DNA-binding domains. The interaction intensity of each target protein is quantified as the copy number of the specific DNA sequences bound by each fusion protein dimers. Using PiF, we quantitatively reveal dynamic patterns of PPIs and their correlation network in E. coli two-component systems. PMID:28338015

Emission coefficients for the OH Meinel band system; calculations and nightglow comparisons

NASA Astrophysics Data System (ADS)

Slanger, T. G.

2016-12-01

The OH Meinel band system is an extensive series of bands that are transitions between the vibrational levels of the X2Π ground-state of the molecule. The exothermicity of the source reaction is sufficient to populate up to OH(v = 9), and in fact the nascent reaction puts most of the product into that level. Subsequently, relaxation of the population to lower levels takes place via collisions with the ambient atmosphere and radiation within the OH(v) manifold. Considerable effort has been spent in determining the emission coefficients of the OH Meinel band system. This emission is a prominent feature of the terrestrial nightglow, and because it is relatively intense, there have been numerous investigations, generally based on ground-based instrumentation. The very exothermic source reaction, H + O3 → OH(v) + O2, results in the production of vibrationally and rotationally hot OH(v), and leads to a great number of OH emission lines, covering a wide spectral range, 500-2000 nm. The full range of energy-accessible OH vibrational levels, up to v = 9, is produced in the reaction, and in this presentation we make the case that it is essential to simultaneously measure as many OH bands as possible, to retrieve the maximum amount of spectroscopic and dynamic information. In order to do so, we must agree on the emission coefficients (A-factors) associated with the individual OH bands, and this determination has presented problems in the past. A major advance in the study of atmospheric OH Meinel band emission took place when astronomical sky spectra were utilized to record all accessible OH bands simultaneously, from Mauna Kea [Cosby and Slanger, 2007]. Subsequently, similar studies were undertaken at the VLT [Noll et al. 2015 a,b], and at the GIANO-TNG [Oliva et al., 2015]. With these intensity-calibrated spectra, it becomes possible to compare the OH optical data with sets of A-factor calculations that have been presented over the years [Mies, 1974; Turnbull and Lowe, 1989; Langhoff et al., 1986; Goldman et al., 1998; Pendleton and Taylor, 2002; van der Loo and Groenenboom, 2007; Brooke et al., 2016] and others. We conclude that the most recent determinations provide the best representation of the Meinel band A-factors. AcknowledgementsThis work has been supported by NSF Aeronomy grants, with the participation of Dr. Philip Cosby.

Direct fluorescence characterisation of a picosecond seeded optical parametric amplifier

NASA Astrophysics Data System (ADS)

Stuart, N. H.; Bigourd, D.; Hill, R. W.; Robinson, T. S.; Mecseki, K.; Patankar, S.; New, G. H. C.; Smith, R. A.

2015-02-01

The temporal intensity contrast of high-power lasers based on optical parametric amplification (OPA) can be limited by parametric fluorescence from the non-linear gain stages. Here we present a spectroscopic method for direct measurement of unwanted parametric fluorescence widely applicable from unseeded to fully seeded and saturated OPA operation. Our technique employs simultaneous spectroscopy of fluorescence photons slightly outside the seed bandwidth and strongly attenuated light at the seed central wavelength. To demonstrate its applicability we have characterised the performance of a two-stage picosecond OPA pre-amplifier with 2.8×105 gain, delivering 335 μJ pulses at 1054 nm. We show that fluorescence from a strongly seeded OPA is reduced by ~500× from the undepleted to full pump depletion regimes. We also determine the vacuum fluctuation driven noise term seeding this OPA fluorescence to be 0.7±0.4 photons ps-1 nm-1 bandwidth. The resulting shot-to-shot statistics highlights a 1.5% probability of a five-fold and 0.3% probability of a ten-fold increase of fluorescence above the average value. Finally, we show that OPA fluorescence can be limited to a few-ps pedestal with 3×10-9 temporal intensity contrast 1.3 ps ahead of an intense laser pulse, a level highly attractive for large scale chirped-pulse OPA laser systems.

The influence of fundamental frequency on perceived duration in spectrally comparable sounds

PubMed Central

Aalto, Daniel; Simko, Juraj; Vainio, Martti

2017-01-01

The perceived duration of a sound is affected by its fundamental frequency and intensity: higher sounds are judged to be longer, as are sounds with greater intensity. Since increasing intensity lengthens the perceived duration of the auditory object, and increasing the fundamental frequency increases the sound’s perceived loudness (up to ca. 3 kHz), frequency modulation of duration could be potentially explained by a confounding effect where the primary cause of the modulation would be variations in intensity. Here, a series of experiments are described that were designed to disentangle the contributions of fundamental frequency, intensity, and duration to perceived loudness and duration. In two forced-choice tasks, participants judged duration and intensity differences between two sounds varying simultaneously in intensity, fundamental frequency, fundamental frequency gliding range, and duration. The results suggest that fundamental frequency and intensity each have an impact on duration judgments, while frequency gliding range did not influence the present results. We also demonstrate that the modulation of perceived duration by sound fundamental frequency cannot be fully explained by the confounding relationship between frequency and intensity. PMID:28879063

The influence of fundamental frequency on perceived duration in spectrally comparable sounds.

PubMed

Dawson, Caitlin; Aalto, Daniel; Simko, Juraj; Vainio, Martti

2017-01-01

The perceived duration of a sound is affected by its fundamental frequency and intensity: higher sounds are judged to be longer, as are sounds with greater intensity. Since increasing intensity lengthens the perceived duration of the auditory object, and increasing the fundamental frequency increases the sound's perceived loudness (up to ca. 3 kHz), frequency modulation of duration could be potentially explained by a confounding effect where the primary cause of the modulation would be variations in intensity. Here, a series of experiments are described that were designed to disentangle the contributions of fundamental frequency, intensity, and duration to perceived loudness and duration. In two forced-choice tasks, participants judged duration and intensity differences between two sounds varying simultaneously in intensity, fundamental frequency, fundamental frequency gliding range, and duration. The results suggest that fundamental frequency and intensity each have an impact on duration judgments, while frequency gliding range did not influence the present results. We also demonstrate that the modulation of perceived duration by sound fundamental frequency cannot be fully explained by the confounding relationship between frequency and intensity.

Simultaneous voltammetric determination of dopamine and epinephrine in human body fluid samples using a glassy carbon electrode modified with nickel oxide nanoparticles and carbon nanotubes within a dihexadecylphosphate film.

PubMed

Figueiredo-Filho, Luiz C S; Silva, Tiago A; Vicentini, Fernando C; Fatibello-Filho, Orlando

2014-06-07

A simple and highly selective electrochemical method was developed for the single or simultaneous determination of dopamine (DA) and epinephrine (EP) in human body fluids using a glassy carbon electrode modified with nickel oxide nanoparticles and carbon nanotubes within a dihexadecylphosphate film using square-wave voltammetry (SWV) or differential-pulse voltammetry (DPV). Using DPV with the proposed electrode, a separation of ca. 360 mV between the peak reduction potentials of DA and EP present in binary mixtures was obtained. The analytical curves for the simultaneous determination of dopamine and epinephrine showed an excellent linear response, ranging from 7.0 × 10(-8) to 4.8 × 10(-6) and 3.0 × 10(-7) to 9.5 × 10(-6) mol L(-1) for DA and EP, respectively. The detection limits for the simultaneous determination of DA and EP were 5.0 × 10(-8) mol L(-1) and 8.2 × 10(-8) mol L(-1), respectively. The proposed method was successfully applied in the simultaneous determination of these analytes in human body fluid samples of cerebrospinal fluid, human serum and lung fluid.

Sensitive determination of thiols in wine samples by a stable isotope-coded derivatization reagent d0/d4-acridone-10-ethyl-N-maleimide coupled with high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry analysis.

PubMed

Lv, Zhengxian; You, Jinmao; Lu, Shuaimin; Sun, Weidi; Ji, Zhongyin; Sun, Zhiwei; Song, Cuihua; Chen, Guang; Li, Guoliang; Hu, Na; Zhou, Wu; Suo, Yourui

2017-03-31

As the key aroma compounds, varietal thiols are the crucial odorants responsible for the flavor of wines. Quantitative analysis of thiols can provide crucial information for the aroma profiles of different wine styles. In this study, a rapid and sensitive method for the simultaneous determination of six thiols in wine using d 0 /d 4 -acridone-10-ethyl-N-maleimide (d 0 /d 4 -AENM) as stable isotope-coded derivatization reagent (SICD) by high performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) has been developed. Quantification of thiols was performed by using d 4 -AENM labeled thiols as the internal standards (IS), followed by stable isotope dilution HPLC-ESI-MS/MS analysis. The AENM derivatization combined with multiple reactions monitoring (MRM) not only allowed trace analysis of thiols due to the extremely high sensitivity, but also efficiently corrected the matrix effects during HPLC-MS/MS and the fluctuation in MS/MS signal intensity due to instrument. The obtained internal standard calibration curves for six thiols were linear over the range of 25-10,000pmol/L (R 2 ≥0.9961). Detection limits (LODs) for most of analytes were below 6.3pmol/L. The proposed method was successfully applied for the simultaneous determination of six kinds of thiols in wine samples with precisions ≤3.5% and recoveries ≥78.1%. In conclusion, the developed method is expected to be a promising tool for detection of trace thiols in wine and also in other complex matrix. Copyright © 2017 Elsevier B.V. All rights reserved.

Knocking Combustion Observed in a Spark-Ignition Engine with Simultaneous Direct and Schlieren High-Speed Motion Pictures and Pressure Records

NASA Technical Reports Server (NTRS)

Osterstrom, Gordon E

1948-01-01

Simultaneous direct and Schlieren photographs at 40,000 frames per second and correlated pressure records were taken of knocking combustion in a special spark-ignition engine to ascertain the intensity of certain end-zone reactions previously noted from Schlieren photography alone. A violent propagated homogeneous autoignition, or a similar phenomenon, previously observed, was again observed. The pressure records show autoignition of varying violence before the passage of a probable detonation wave. Extensive autoignition without occurrence of gas vibrations was seen in one explosion.

Pancreas Islet Transplantation for Patients With Type 1 Diabetes Mellitus: A Clinical Evidence Review

PubMed Central

2015-01-01

Background Type 1 diabetes mellitus is caused by the autoimmune destruction of pancreatic beta (β) cells, resulting in severe insulin deficiency. Islet transplantation is a β-cell replacement therapeutic option that aims to restore glycemic control in patients with type 1 diabetes. The objective of this study was to determine the clinical effectiveness of islet transplantation in patients with type 1 diabetes, with or without kidney disease. Methods We conducted a systematic review of the literature on islet transplantation for type 1 diabetes, including relevant health technology assessments, systematic reviews, meta-analyses, and observational studies. We used a two-step process: first, we searched for systematic reviews and health technology assessments; second, we searched primary studies to update the chosen health technology assessment. The Assessment of Multiple Systematic Reviews measurement tool was used to examine the methodological quality of the systematic reviews and health technology assessments. We assessed the quality of the body of evidence and the risk of bias according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Results Our searched yielded 1,354 citations. One health technology assessment, 11 additional observational studies to update the health technology assessment, one registry report, and four guidelines were included; the observational studies examined islet transplantation alone, islet-after-kidney transplantation, and simultaneous islet-kidney transplantation. In general, low to very low quality of evidence exists for islet transplantation in patients with type 1 diabetes with difficult-to-control blood glucose levels, with or without kidney disease, for these outcomes: health-related quality of life, secondary complications of diabetes, glycemic control, and adverse events. However, high quality of evidence exists for the specific glycemic control outcome of insulin independence compared with intensive insulin therapy. For patients without kidney disease, islet transplantation improves glycemic control and diabetic complications for patients with type 1 diabetes when compared with intensive insulin therapy. However, results for health-related quality of life outcomes were mixed, and adverse events were increased compared with intensive insulin therapy. For patients with type 1 diabetes with kidney disease, islet-after-kidney transplantation or simultaneous islet-kidney transplantation also improved glycemic control and secondary diabetic complications, although the evidence was more limited for this patient group. Compared with intensive insulin therapy, adverse events for islet-after-kidney transplantation or simultaneous islet-kidney transplantation were increased, but were in general less severe than with whole pancreas transplantation. Conclusions For patients with type 1 diabetes with difficult-to-control blood glucose levels, islet transplantation may be a beneficial β-cell replacement therapy to improve glycemic control and secondary complications of diabetes. However, there is uncertainty in the estimates of effectiveness because of the generally low to very low quality of evidence for all outcomes of interest. PMID:26644812

A rapid NGS strategy for comprehensive molecular diagnosis of Birt-Hogg-Dubé syndrome in patients with primary spontaneous pneumothorax.

PubMed

Zhang, Xinxin; Ma, Dehua; Zou, Wei; Ding, Yibing; Zhu, Chengchu; Min, Haiyan; Zhang, Bin; Wang, Wei; Chen, Baofu; Ye, Minhua; Cai, Minghui; Pan, Yanqing; Cao, Lei; Wan, Yueming; Jin, Yu; Gao, Qian; Yi, Long

2016-05-27

Primary spontaneous pneumothorax (PSP) or pulmonary cysts is one of the manifestations of Birt-Hogg-Dube syndrome (BHDS) that is caused by heterozygous mutations in FLCN gene. Most of the mutations are SNVs and small indels, and there are also approximately 10 % large intragenic deletions and duplications of the mutations. These molecular findings are generally obtained by disparate methods including Sanger sequencing and Multiple Ligation-dependent Probe Amplification in the clinical laboratory. In addition, as a genetically heterogeneous disorder, PSP may be caused by mutations in multiple genes include FBN1, COL3A1, CBS, SERPINA1 and TSC1/TSC2 genes. For differential diagnosis, these genes should also be screened which makes the diagnostic procedure more time-consuming and labor-intensive. Forty PSP patients were divided into 2 groups. Nineteen patients with different pathogenic mutations of FLCN previously identified by conventional Sanger sequencing and MLPA were included in test group, 21 random PSP patients without any genetic screening were included in blinded sample group. 7 PSP genes including FLCN, FBN1, COL3A1, CBS, SERPINA1 and TSC1/TSC2 were designed and enriched by Haloplex system, sequenced on a Miseq platform and analyzed in the 40 patients to evaluate the performance of the targeted-NGS method. We demonstrated that the full spectrum of genes associated with pneumothorax including FLCN gene mutations can be identified simultaneously in multiplexed sequence data. Noteworthy, by our in-house copy number analysis of the sequence data, we could not only detect intragenic deletions, but also determine approximate deletion junctions simultaneously. NGS based Haloplex target enrichment technology is proved to be a rapid and cost-effective screening strategy for the comprehensive molecular diagnosis of BHDS in PSP patients, as it can replace Sanger sequencing and MLPA by simultaneously detecting exonic and intronic SNVs, small indels, large intragenic deletions and determining deletion junctions in PSP-related genes.

Use of analyte-modulated modal power distribution in multimode optical fibers for simultaneous single-wavelength evanescent-wave refractometry and spectrometry.

PubMed

Potyrailo, R A; Ruddy, V P; Hieftje, G M

1999-11-01

A new method is described for the simultaneous determination of absorbance and refractive index of a sample medium. The method is based on measurement of the analyte-modulated modal power distribution (MPD) in a multimode waveguide. In turn, the MPD is quantified by the far-field spatial pattern and intensity of light, i.e., the Fraunhofer diffraction pattern (registered on a CCD camera), that emerges from a multimode optical fiber. Operationally, light that is sent down the fiber interacts with the surrounding analyte-containing medium by means of the evanescent wave at the fiber boundary. The light flux in the propagating beam and the internal reflection angles within the fiber are both affected by optical absorption connected with the analyte and by the refractive index of the analyte-containing medium. In turn, these angles are reflected in the angular divergence of the beam as it leaves the fiber. As a result, the Fraunhofer diffraction pattern of that beam yields two parameters that can, together, be used to deduce refractive index and absorbance. This MPD based detection offers important advantages over traditional evanescent-wave detection strategies which rely on recording only the total transmitted optical power or its lost fraction. First, simultaneous determination of sample refractive index and absorbance is possible at a single probe wavelength. Second, the sensitivity of refractometric and absorption measurements can be controlled simply, either by adjusting the distance between the end face of the fiber and the CCD detector or by monitoring selected modal groups at the fiber output. As a demonstration of these capabilities, several weakly absorbing solutions were examined, with refractive indices in the range from 1.3330 to 1.4553 and with absorption coefficients in the range 0-16 cm-1. The new detection strategy is likely to be important in applications in which sample coloration varies and when it is necessary to compensate for variations in the refractive index of a sample.

Phase I Trial of Simultaneous In-Field Boost With Helical Tomotherapy for Patients With One to Three Brain Metastases

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

Rodrigues, George, E-mail: george.rodrigues@lhsc.on.ca; Yartsev, Slav; Yaremko, Brian

2011-07-15

Purpose: Stereotactic radiosurgery is an alternative to surgical resection for selected intracranial lesions. Integrated image-guided intensity-modulated-capable radiotherapy platforms such as helical tomotherapy (HT) could potentially replace traditional radiosurgery apparatus. The present study's objective was to determine the maximally tolerated dose of a simultaneous in-field boost integrated with whole brain radiotherapy for palliative treatment of patients with one to three brain metastases using HT. Methods and Materials: The inclusion/exclusion criteria and endpoints were consistent with the Radiation Therapy Oncology Group 9508 radiosurgery trial. The cohorts were constructed with a 3 + 3 design; however, additional patients were enrolled in the lowermore » dose tolerable cohorts during the toxicity assessment periods. Whole brain radiotherapy (30 Gy in 10 fractions) was delivered with a 5-30-Gy (total lesion dose of 35-60 Gy in 10 fractions) simultaneous in-field boost delivered to the brain metastases. The maximally tolerated dose was determined by the frequency of neurologic Grade 3-5 National Cancer Institute Common Toxicity Criteria, version 3.0, dose-limiting toxicity events within each Phase I cohort. Results: A total of 48 patients received treatment in the 35-Gy (n = 3), 40-Gy (n = 16), 50-Gy (n = 15), 55-Gy (n = 8), and 60-Gy (n = 6) cohorts. No patients experienced dose-limiting toxicity events in any of the trial cohorts. The 3-month RECIST assessments available for 32 of the 48 patients demonstrated a complete response in 2, a partial response in 16, stable disease in 6, and progressive disease in 8 patients. Conclusion: The delivery of 60 Gy in 10 fractions to one to three brain metastases synchronously with 30 Gy whole brain radiotherapy was achieved without dose-limiting central nervous system toxicity as assessed 3 months after treatment. This approach is being tested in a Phase II efficacy trial.« less

Effects of stress management program on the quality of nursing care and intensive care unit nurses

PubMed Central

Pahlavanzadeh, Saied; Asgari, Zohreh; Alimohammadi, Nasrollah

2016-01-01

Background: High level of stress in intensive care unit nurses affects the quality of their nursing care. Therefore, this study aimed to determine the effects of a stress management program on the quality of nursing care of intensive care unit nurses. Materials and Methods: This study is a randomized clinical trial that was conducted on 65 nurses. The samples were selected by stratified sampling of the nurses working in intensive care units 1, 2, 3 in Al-Zahra Hospital in Isfahan, Iran and were randomly assigned to two groups. The intervention group underwent an intervention, including 10 sessions of stress management that was held twice a week. In the control group, placebo sessions were held simultaneously. Data were gathered by demographic checklist and Quality Patient Care Scale before, immediately after, and 1 month after the intervention in both groups. Then, the data were analyzed by Student's t-test, Mann–Whitney, Chi-square, Fisher's exact test, and analysis of variance (ANOVA) through SPSS software version 18. Results: Mean scores of overall and dimensions of quality of care in the intervention group were significantly higher immediately after and 1 month after the intervention, compared to pre-intervention (P < 0.001). The results showed that the quality of care in the intervention group was significantly higher immediately after and 1 month after the intervention, compared to the control group (P < 0.001). Conclusions: As stress management is an effective method to improve the quality of care, the staffs are recommended to consider it in improvement of the quality of nursing care. PMID:27186196

Critical analysis of commonly used fluorescence metrics to characterize dissolved organic matter.

PubMed

Korak, Julie A; Dotson, Aaron D; Summers, R Scott; Rosario-Ortiz, Fernando L

2014-02-01

The use of fluorescence spectroscopy for the analysis and characterization of dissolved organic matter (DOM) has gained widespread interest over the past decade, in part because of its ease of use and ability to provide bulk DOM chemical characteristics. However, the lack of standard approaches for analysis and data evaluation has complicated its use. This study utilized comparative statistics to systematically evaluate commonly used fluorescence metrics for DOM characterization to provide insight into the implications for data analysis and interpretation such as peak picking methods, carbon-normalized metrics and the fluorescence index (FI). The uncertainty associated with peak picking methods was evaluated, including the reporting of peak intensity and peak position. The linear relationship between fluorescence intensity and dissolved organic carbon (DOC) concentration was found to deviate from linearity at environmentally relevant concentrations and simultaneously across all peak regions. Comparative analysis suggests that the loss of linearity is composition specific and likely due to non-ideal intermolecular interactions of the DOM rather than the inner filter effects. For some DOM sources, Peak A deviated from linearity at optical densities a factor of 2 higher than that of Peak C. For carbon-normalized fluorescence intensities, the error associated with DOC measurements significantly decreases the ability to distinguish compositional differences. An in-depth analysis of FI determined that the metric is mostly driven by peak emission wavelength and less by emission spectra slope. This study also demonstrates that fluorescence intensity follows property balance principles, but the fluorescence index does not. Copyright © 2013 Elsevier Ltd. All rights reserved.

MACS, An Instrument and a Methodology for Simultaneous and Global Measurements of the Coronal Electron Temperature and the Solar Wind Velocity on the Solar Corona

NASA Technical Reports Server (NTRS)

Reginald, Nelson L.

2000-01-01

In Cram's theory for the formation of the K-coronal spectrum he observed the existence of temperature sensitive anti-nodes, which were separated by temperature insensitive nodes, at certain wave-lengths in the K-coronal spectrum. Cram also showed these properties were remarkably independent of altitude above the solar limb. In this thesis Cram's theory has been extended to incorporate the role of the solar wind in the formation of the K-corona, and we have identified both temperature and wind sensitive intensity ratios. The instrument, MACS, for Multi Aperture Coronal Spectrometer, a fiber optic based spectrograph, was designed for global and simultaneous measurements of the thermal electron temperature and the solar wind velocity in the solar corona. The first ever experiment of this nature was conducted in conjunction with the total solar eclipse of 11 August 1999 in Elazig, Turkey. Here twenty fiber optic tips were positioned in the focal plane of the telescope to observe simultaneously at many different latitudes and two different radial distances in the solar corona. The other ends were vertically stacked and placed at the primary focus of the spectrograph. By isolating the K-coronal spectrum from each fiber the temperature and the wind sensitive intensity ratios were calculated.

Simultaneous hydrogen utilization and in situ biogas upgrading in an anaerobic reactor.

PubMed

Luo, Gang; Johansson, Sara; Boe, Kanokwan; Xie, Li; Zhou, Qi; Angelidaki, Irini

2012-04-01

The possibility of converting hydrogen to methane and simultaneous upgrading of biogas was investigated in both batch tests and fully mixed biogas reactor, simultaneously fed with manure and hydrogen. Batch experiments showed that hydrogen could be converted to methane by hydrogenotrophic methanogenesis with conversion of more than 90% of the consumed hydrogen to methane. The hydrogen consumption rates were affected by both P(H₂) (hydrogen partial pressure) and mixing intensity. Inhibition of propionate and butyrate degradation by hydrogen (1 atm) was only observed under high mixing intensity (shaking speed 300 rpm). Continuous addition of hydrogen (flow rate of 28.6 mL/(L/h)) to an anaerobic reactor fed with manure, showed that more than 80% of the hydrogen was utilized. The propionate and butyrate level in the reactor was not significantly affected by the hydrogen addition. The methane production rate of the reactor with H₂ addition was 22% higher, compared to the control reactor only fed with manure. The CO₂ content in the produced biogas was only 15%, while it was 38% in the control reactor. However, the addition of hydrogen resulted in increase of pH (from 8.0 to 8.3) due to the consumption of bicarbonate, which subsequently caused slight inhibition of methanogenesis. Copyright © 2011 Wiley Periodicals, Inc.

Model-Based, Noninvasive Monitoring of Intracranial Pressure

DTIC Science & Technology

2012-10-01

nICP) estimate requires simultaneous measurement of the waveforms of arterial blood pressure ( ABP ), obtained via radial artery catheter or finger...initial database comprises subarachnoid hemorrhage patients in neuro-intensive care at our partner hospital, for whom ICP, ABP and CBFV are currently

Sharp-Tailed Grouse Nest Survival and Nest Predator Habitat Use in North Dakota's Bakken Oil Field.

PubMed

Burr, Paul C; Robinson, Aaron C; Larsen, Randy T; Newman, Robert A; Ellis-Felege, Susan N

2017-01-01

Recent advancements in extraction technologies have resulted in rapid increases of gas and oil development across the United States and specifically in western North Dakota. This expansion of energy development has unknown influences on local wildlife populations and the ecological interactions within and among species. Our objectives for this study were to evaluate nest success and nest predator dynamics of sharp-tailed grouse (Tympanuchus phasianellus) in two study sites that represented areas of high and low energy development intensities in North Dakota. During the summers of 2012 and 2013, we monitored 163 grouse nests using radio telemetry. Of these, 90 nests also were monitored using miniature cameras to accurately determine nest fates and identify nest predators. We simultaneously conducted predator surveys using camera scent stations and occupancy modeling to estimate nest predator occurrence at each site. American badgers (Taxidea taxus) and striped skunks (Mephitis mephitis) were the primary nest predators, accounting for 56.7% of all video recorded nest depredations. Nests in our high intensity gas and oil area were 1.95 times more likely to succeed compared to our minimal intensity area. Camera monitored nests were 2.03 times more likely to succeed than non-camera monitored nests. Occupancy of mammalian nest predators was 6.9 times more likely in our study area of minimal gas and oil intensity compared to the high intensity area. Although only a correlative study, our results suggest energy development may alter the predator community, thereby increasing nest success for sharp-tailed grouse in areas of intense development, while adjacent areas may have increased predator occurrence and reduced nest success. Our study illustrates the potential influences of energy development on the nest predator-prey dynamics of sharp-tailed grouse in western North Dakota and the complexity of evaluating such impacts on wildlife.

Infrared non-destructive evaluation method and apparatus

DOEpatents

Baleine, Erwan; Erwan, James F; Lee, Ching-Pang; Stinelli, Stephanie

2014-10-21

A method of nondestructive evaluation and related system. The method includes arranging a test piece (14) having an internal passage (18) and an external surface (15) and a thermal calibrator (12) within a field of view (42) of an infrared sensor (44); generating a flow (16) of fluid characterized by a fluid temperature; exposing the test piece internal passage (18) and the thermal calibrator (12) to fluid from the flow (16); capturing infrared emission information of the test piece external surface (15) and of the thermal calibrator (12) simultaneously using the infrared sensor (44), wherein the test piece infrared emission information includes emission intensity information, and wherein the thermal calibrator infrared emission information includes a reference emission intensity associated with the fluid temperature; and normalizing the test piece emission intensity information against the reference emission intensity.

The potential of inductively coupled plasma mass spectrometry (ICP-MS) for the simultaneous determination of trace elements in whole blood, plasma and serum.

PubMed

Krachler, M; Irgolic, K J

1999-11-01

The advantages accruing to biochemical and clinical investigations from a method that allows the simultaneous quantification (RSD < or = 10%) of many elements in blood, plasma, and serum at concentrations equal to one-hundredth of the lower limits of the normal ranges are undeniable. The suitability of inductively coupled argon plasma low-resolution quadrupole mass spectrometry (ICP-MS), a simultaneous method with low detection limits, is evaluated for the quantification of inorganic constituents in whole blood, plasma, and serum with consideration of the dilution associated with the mineralization of the samples, of isobaric and polyatomic interferences and of normal ranges. Of the 3 bulk elements, the 3 major electrolytes, the 15 essential elements, the 8 toxic elements, the 4 therapeutic elements, and the 14 elements of potential interest (total of 47 elements) only 7 elements (Ca, Cu, K, Mg, Rb, Sr, Zn) can be simultaneously quantified under these rigorous conditions in serum and only 8 elements (additional element Pb) in whole blood. Quantification of elements in the Seronorm Standards "Whole Blood" and "Serum" showed, that this list of simultaneously determinable elements in these matrices is reasonable. Although this list is disappointingly short, the number of elements determinable simultaneously by ICP-MS is still larger than that by ICP-AES or GFAAS. Improved detectors, more efficient nebulizers, avoidance of interferences, better instrument design, and high-resolution mass spectrometers promise to increase the number of elements that can be determined simultaneously.

Hybrid MEFPI/FBG sensor for simultaneous measurement of strain and magnetic field

NASA Astrophysics Data System (ADS)

Chen, Mao-qing; Zhao, Yong; Lv, Ri-qing; Xia, Feng

2017-12-01

A hybrid fiber-optic sensor consisting of a micro extrinsic Fabry-Perot Interferometer (MEFPI) and an etched fiber Bragg grating (FBG) is proposed, which can measure strain and magnetic field simultaneously. The etched FBG is sealed in a capillary with ferrofluids to detect the surrounding magnetic field. FBG with small diameter will be more sensitive to magnetic field is confirmed by simulation results. The MEFPI sensor that is prepared through welding a short section of hollow-core fiber (HCF) with single-mode fiber (SMF) is effective for strain detection. The experiment shows that strain and magnetic field can be successfully simultaneously detected based on hybrid MEFPI/FBG sensor. The sensitivities of the strain and magnetic field intensity are measured to be up to 1.41 pm/με and 5.11 pm/mT respectively. There is a negligible effect on each other, hence simultaneously measuring strain and magnetic field is feasible. It is anticipated that such easy preparation, compact and low-cost fiber-optic sensors for simultaneous measurement of strain and magnetic field could find important applications in practice.

Simultaneous measurement of liposome extravasation and content release in tumors.

PubMed

Wu, N Z; Braun, R D; Gaber, M H; Lin, G M; Ong, E T; Shan, S; Papahadjopoulos, D; Dewhirst, M W

1997-03-01

The success of liposome-based drug delivery systems for tumor targeting relies on maximum extravasation of liposomes into tumor interstitium, as well as optimal release of contents from the liposomes once within the tumor Liposome extravasation and content release are two separate processes that can be individually or jointly manipulated so a method is needed to monitor these two processes independently and simultaneously. In this report, we describe a method to measure liposome extravasation and content release in tumor tissues growing in a rat skinfold window chamber preparation. Mixtures of liposomes containing either doxorubicin or calcein, both of which are fluorescent, and liposomes surface-labeled with rhodamine were injected intravenously. Fluorescent, light intensities in a tumor region in two fluorescent channels were measured using an image-processing system. Light intensities of plasma from blood samples were also measured using this system. These measurements were used to calculate the amounts of liposomes and released contents in both plasma and tumor interstitium. The calculations were based on the fact that the liposome surface labels and contents emit fluorescent light at different wavelengths and when encapsulated, the contents fluorescence is self-quenched. The model included equations to account for fluorescent light "cross-contamination" by the two fluorochromes as well as equations relating the measured fluorescent light intensities to the amounts of liposomes and released contents. This method was applied to three situations in which liposome extravasation and content release were manipulated in different, predictable ways. Our results indicate that this method can perform simultaneous independent and quantitative measurements of liposome extravasation and content release. This method can potentially be used to study drug delivery of other carrier systems in vivo.

Feasibility study for combination of field-flow fractionation (FFF)-based separation of size-coded particle probes with amplified surface enhanced Raman scattering (SERS) tagging for simultaneous detection of multiple miRNAs.

PubMed

Shin, Kayeong; Choi, Jaeyeong; Kim, Yeoju; Lee, Yoonjeong; Kim, Joohoon; Lee, Seungho; Chung, Hoeil

2018-06-29

We propose a new analytical scheme in which field-flow fractionation (FFF)-based separation of target-specific polystyrene (PS) particle probes of different sizes are incorporated with amplified surface-enhanced Raman scattering (SERS) tagging for the simultaneous and sensitive detection of multiple microRNAs (miRNAs). For multiplexed detection, PS particles of three different diameters (15, 10, 5 μm) were used for the size-coding, and a probe single stranded DNA (ssDNA) complementary to a target miRNA was conjugated on an intended PS particle. After binding of a target miRNA on PS probe, polyadenylation reaction was executed to generate a long tail composed of adenine (A) serving as a binding site to thymine (T) conjugated Au nanoparticles (T-AuNPs) to increase SERS intensity. The three size-coded PS probes bound with T-AuNPs were then separated in a FFF channel. With the observation of extinction-based fractograms, separation of three size-coded PS probes was clearly confirmed, thereby enabling of measuring three miRNAs simultaneously. Raman intensities of FFF fractions collected at the peak maximum of 15, 10 and 5 μm PS probes varied fairy quantitatively with the change of miRNA concentrations, and the reproducibility of measurement was acceptable. The proposed method is potentially useful for simultaneous detection of multiple miRNAs with high sensitivity. Copyright © 2018 Elsevier B.V. All rights reserved.

White light upconversion emission in Yb3+/ Er3+/ Tm3+ codoped oxy-fluoride lithium tungsten tellurite glass ceramics

NASA Astrophysics Data System (ADS)

Ansari, Ghizal F.; Mahajan, S. K.

2012-02-01

The bright white upconversion emission ( tri-colour UC) is generated in Er/Tm/Yb tri -doped oxy-fluoride lithium tungsten tellurite (TWLOF)glass ceramics containing crystalline phase LiYbF4 under the excitation of 980nm laser diode. The most appropriate combination of rare-earth ions (2mol% YbF3 1mol% ErF3 and 1mol%TmF3 )of glass ceramic sample has been determined to tune the primary colour (RGB and generate white light emission. By varying the pump power, intense and weak blue (487nm, 437nm), green (525nm and 545nm) and red (662nm) emission are simultaneously observed at room temperature. The dependence of upconversion emission intensity suggest that a theephoton process is responsible for the blue emission of Tm3+ ions and red emission due to both Tm3+ and Er3+ ions , while green emission originated from two photon processes in Er3+ ions. Also tri colour upconvesion and energy transfer in this glass ceramics sample were studied under 808nm laser diode excitation. The Upconversion mechanisms and Tm3+ ions plays role of both emitter and activator (transfer energy to Er) were discussed.

[Effect of low-intensity laser radiation on the function of vascular endothelium in patients with chronic viral hepatitis].

PubMed

Burduli, N M; Krifaridi, A S

2009-01-01

The aim of the study was to measure plasma levels of stable metabolites of nitric oxide, nitrates, and nitrites (NOx) in patients with chronic viral hepatitis and evaluate the possibility of their correction by low-power laser irradiation. NO metabolites (total nitrites and nitrates) were measured colorimetrically from the development of colour in the reaction of nitrite with sulfanilamide diazotization in Griess reagent. Colour intensity was determined with Victor2 enzyme immunoanalyzer, Perkin Elmaer (Finland). The patients were divided into three groups. In group 1 (control, n = 30) they received combined medicamentous therapy, in group 2 (n = 45) medicamentous therapy and a course of intravenous laser therapy, in goup 3 (n = 45) medicamentous therapy and skin laserotherapy. The results indicate that medicamentous treatment of patients with chronic hepatitis does not bring any beneficial changes in plasma NOx whose levels are significantly improved in case of simultaneous laser therapy. It is concluded that different laserotherapeutic modalities have beneficial effect on NO-producing function of endothelium and thereby improve its functional state. Compensation of NO deficit by laser therapy ensures overall protection of the organism against free radicals and decreases severity of oxidative stress.

A compact multi-channel fluorescence sensor with ambient light suppression

NASA Astrophysics Data System (ADS)

Egly, Dominik; Geörg, Daniel; Rädle, Matthias; Beuermann, Thomas

2012-03-01

A multi-channel fluorescence sensor has been developed for process monitoring and fluorescence diagnostics. It comprises a fiber-optic set-up with an immersion probe and an intensity-modulated high power ultraviolet light-emitting diode as a light source for fluorescence excitation. By applying an electronic lock-in procedure, fluorescence signals are selectively detectable at ambient light levels of 1000 000 times higher intensity. The sensor was designed to be compact, low cost and easily adaptable to a wide field of application. The set-up was used to simultaneously monitor three important metabolic fluorophores: NAD(P)H, flavins and porphyrins during the cultivation of a baker's yeast. Moreover, the accumulation and degradation kinetics of protoporphyrin IX induced by 5-aminolevulinic acid on the skin could be recorded by the sensor. The detection limit for protoporphyrin IX was determined to be 4 × 10-11 mol L-1. The linear signal amplification of the sensor and time courses of fluorescence signals monitored during yeast fermentations were validated using a commercial CCD spectrometer. The robust and flexible set-up of the fiber-optic measurement system promises easy implementation of this non-invasive analytical tool to fluorescence monitoring and diagnostics in R&D and production.

Active workstation allows office workers to work efficiently while sitting and exercising moderately.

PubMed

Koren, Katja; Pišot, Rado; Šimunič, Boštjan

2016-05-01

To determine the effects of a moderate-intensity active workstation on time and error during simulated office work. The aim of the study was to analyse simultaneous work and exercise for non-sedentary office workers. We monitored oxygen uptake, heart rate, sweating stains area, self-perceived effort, typing test time with typing error count and cognitive performance during 30 min of exercise with no cycling or cycling at 40 and 80 W. Compared baseline, we found increased physiological responses at 40 and 80 W, which corresponds to moderate physical activity (PA). Typing time significantly increased by 7.3% (p = 0.002) in C40W and also by 8.9% (p = 0.011) in C80W. Typing error count and cognitive performance were unchanged. Although moderate intensity exercise performed on cycling workstation during simulated office tasks increases working task execution time with, it has moderate effect size; however, it does not increase the error rate. Participants confirmed that such a working design is suitable for achieving the minimum standards for daily PA during work hours. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Correlation of pretreatment clinical parameters and PSA nadir after high-intensity focused ultrasound (HIFU) for localised prostate cancer.

PubMed

Ganzer, Roman; Bründl, Johannes; Koch, Daniel; Wieland, Wolf F; Burger, Maximilian; Blana, Andreas

2015-01-01

To determine which pretreatment clinical parameters were predictive of a low prostate-specific antigen (PSA) nadir following high-intensity focused ultrasound (HIFU) treatment. Retrospective study of patients with clinically localised prostate cancer undergoing HIFU at a single centre between December 1997 and September 2009. Whole-gland treatment was applied. Patients also included if they had previously undergone transurethral resection of the prostate (TURP). TURP was also conducted simultaneously to HIFU. Biochemical failure based on Phoenix definition (PSA nadir + 2). Univariate and multivariate analysis of pretreatment clinical parameters conducted to assess those factors predictive of a PSA nadir ≤0.2 and >0.2 ng/ml. Mean (SD) follow-up was 6.2 (2.8) years; median (range) was 6.3 (1.1-12.2) years. Kaplan-Meier estimate of biochemical disease-free survival rate at 8 years was 83 and 48 % for patients achieving a PSA nadir of ≤0.2 and >0.2 ng/ml, respectively. Prostate volume and incidental finding of cancer were significant predictors of low PSA nadir (≤0.2 ng/ml). Prostate volume and incidental finding of cancer could be predictors for oncologic success of HIFU based on post-treatment PSA nadir.

Optical properties of embedded metal nanoparticles at low temperatures

NASA Astrophysics Data System (ADS)

Heilmann, A.; Kreibig, U.

2000-06-01

Metal nanoparticles (gold, silver, copper) that are embedded in an insulating organic host material exhibit optical plasma resonance absorption in the visible and near-infrared region. The spectral position, the half width and the intensity of the plasma resonance absorption all depend on the particle size, the particle shape, and the optical behavior of the cluster and the host material. The optical extinction of various gold, silver or copper particle assemblies embedded in plasma polymer or gelatin was measured at 4.2 K and 1.2 K as well as at room temperature. The packing density of several samples was high enough to resolve a reversible increase of the plasma resonance absorption intensity towards lower temperatures. Additionally, at larger silver particles D_m > 50 nm a significant blue shift of the plasma resonance absorption was measured. Particle size and shape distribution were determined by transmission electron microscopy (TEM). For the first time, simultaneous measurements of the electrical and optical properties at one and the same particle assembly were performed at low temperatures. Contrary to the increasing optical extinction, the d.c. conductivity decreased to two orders of magnitude. At silver particles embedded in a plasma polymer made from thiophene a significant photocurrent was measured.

Trend discrepancies among three best track data sets of western North Pacific tropical cyclones

NASA Astrophysics Data System (ADS)

Song, Jin-Jie; Wang, Yuan; Wu, Liguang

2010-06-01

The hot debate over the influence of global warming on tropical cyclone (TC) activity in the western North Pacific over the past several decades is partly due to the diversity of TC data sets used in recent publications. This study investigates differences of track, intensity, frequency, and the associated long-term trends for those TCs that were simultaneously recorded by the best track data sets of the Joint Typhoon Warning Center (JTWC), the Regional Specialized Meteorological Center (RSMC) Tokyo, and the Shanghai Typhoon Institute (STI). Though the differences in TC tracks among these data sets are negligibly small, the JTWC data set tends to classify TCs of category 2-3 as category 4-5, leading to an upward trend in the annual frequency of category 4-5 TCs and the annual accumulated power dissipation index, as reported by Webster et al. (2005) and Emanuel (2005). This trend and potential destructiveness over the period 1977-2007 are found only with the JTWC data set, but downward trends are apparent in the RSMC and STI data sets. It is concluded that the different algorithms used in determining TC intensity may cause the trend discrepancies of TC activity in the western North Pacific.

Inequalities in body size among mermithid nematodes parasitizing earwigs.

PubMed

Maure, Fanny; Poulin, Robert

2016-12-01

Variation among body sizes of adult parasitic worms determines the relative genetic contribution of individuals to the next generation as it affects the effective parasite population size. Here, we investigate inequalities in body size and how they are affected by intensity of infection in Mermis nigrescens (Mermithidae: Nematoda) parasitizing the European earwig Forficula auricularia in New Zealand. Among a population of pre-adult worms prior to their emergence from the host, we observed only modest inequalities in body length; however, among worms sharing the same individual host, inequalities in body sizes decreased with increasing intensity of infection. Thus, the more worms occurred in a host, the more the second-longest, third-longest and even fourth-longest worms approached the longest worm in body length. This pattern, also known from another mermithid species, suggests that worms sharing the same host may have infected it roughly simultaneously, when the host encountered a clump of eggs in the environment. Thus, the life history and mode of infection of the parasite may explain the modest inequalities in the sizes achieved by pre-adult worms, which are lower than those reported for endoparasitic helminths of vertebrates.

Development of normalized spectra manipulating spectrophotometric methods for simultaneous determination of Dimenhydrinate and Cinnarizine binary mixture.

PubMed

Lamie, Nesrine T; Yehia, Ali M

2015-01-01

Simultaneous determination of Dimenhydrinate (DIM) and Cinnarizine (CIN) binary mixture with simple procedures were applied. Three ratio manipulating spectrophotometric methods were proposed. Normalized spectrum was utilized as a divisor for simultaneous determination of both drugs with minimum manipulation steps. The proposed methods were simultaneous constant center (SCC), simultaneous derivative ratio spectrophotometry (S(1)DD) and ratio H-point standard addition method (RHPSAM). Peak amplitudes at isoabsorptive point in ratio spectra were measured for determination of total concentrations of DIM and CIN. For subsequent determination of DIM concentration, difference between peak amplitudes at 250 nm and 267 nm were used in SCC. While the peak amplitude at 275 nm of the first derivative ratio spectra were used in S(1)DD; then subtraction of DIM concentration from the total one provided the CIN concentration. The last RHPSAM was a dual wavelength method in which two calibrations were plotted at 220 nm and 230 nm. The coordinates of intersection point between the two calibration lines were corresponding to DIM and CIN concentrations. The proposed methods were successfully applied for combined dosage form analysis, Moreover statistical comparison between the proposed and reported spectrophotometric methods was applied. Copyright © 2015 Elsevier B.V. All rights reserved.

Segmentation and intensity estimation of microarray images using a gamma-t mixture model.

PubMed

Baek, Jangsun; Son, Young Sook; McLachlan, Geoffrey J

2007-02-15

We present a new approach to the analysis of images for complementary DNA microarray experiments. The image segmentation and intensity estimation are performed simultaneously by adopting a two-component mixture model. One component of this mixture corresponds to the distribution of the background intensity, while the other corresponds to the distribution of the foreground intensity. The intensity measurement is a bivariate vector consisting of red and green intensities. The background intensity component is modeled by the bivariate gamma distribution, whose marginal densities for the red and green intensities are independent three-parameter gamma distributions with different parameters. The foreground intensity component is taken to be the bivariate t distribution, with the constraint that the mean of the foreground is greater than that of the background for each of the two colors. The degrees of freedom of this t distribution are inferred from the data but they could be specified in advance to reduce the computation time. Also, the covariance matrix is not restricted to being diagonal and so it allows for nonzero correlation between R and G foreground intensities. This gamma-t mixture model is fitted by maximum likelihood via the EM algorithm. A final step is executed whereby nonparametric (kernel) smoothing is undertaken of the posterior probabilities of component membership. The main advantages of this approach are: (1) it enjoys the well-known strengths of a mixture model, namely flexibility and adaptability to the data; (2) it considers the segmentation and intensity simultaneously and not separately as in commonly used existing software, and it also works with the red and green intensities in a bivariate framework as opposed to their separate estimation via univariate methods; (3) the use of the three-parameter gamma distribution for the background red and green intensities provides a much better fit than the normal (log normal) or t distributions; (4) the use of the bivariate t distribution for the foreground intensity provides a model that is less sensitive to extreme observations; (5) as a consequence of the aforementioned properties, it allows segmentation to be undertaken for a wide range of spot shapes, including doughnut, sickle shape and artifacts. We apply our method for gridding, segmentation and estimation to cDNA microarray real images and artificial data. Our method provides better segmentation results in spot shapes as well as intensity estimation than Spot and spotSegmentation R language softwares. It detected blank spots as well as bright artifact for the real data, and estimated spot intensities with high-accuracy for the synthetic data. The algorithms were implemented in Matlab. The Matlab codes implementing both the gridding and segmentation/estimation are available upon request. Supplementary material is available at Bioinformatics online.

Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

PubMed Central

Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

2016-01-01

Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

Simultaneous Determination of Caffeine and Vitamin B6 in Energy Drinks by High-Performance Liquid Chromatography (HPLC)

ERIC Educational Resources Information Center

Leacock, Rachel E.; Stankus, John J.; Davis, Julian M.

2011-01-01

A high-performance liquid chromatography experiment to determine the concentration of caffeine and vitamin B6 in sports energy drinks has been developed. This laboratory activity, which is appropriate for an upper-level instrumental analysis course, illustrates the standard addition method and simultaneous determination of two species. (Contains 1…

Simultaneous identification of multi-combustion-intermediates of alkanol-air flames by femtosecond filament excitation for combustion sensing

PubMed Central

Li, Helong; Chu, Wei; Xu, Huailiang; Cheng, Ya; Chin, See-Leang; Yamanouchi, Kaoru; Sun, Hong-Bo

2016-01-01

Laser filamentation produced by the propagation of intense laser pulses in flames is opening up new possibility in application to combustion diagnostics that can provide useful information on understanding combustion processes, enhancing combustion efficiency and reducing pollutant products. Here we present simultaneous identification of multiple combustion intermediates by femtosecond filament excitation for five alkanol-air flames fueled by methanol, ethanol, n-propanol, n-butanol, and n-pentanol. We experimentally demonstrate that the intensities of filament-induced photoemission signals from the combustion intermediates C, C2, CH, CN increase with the increasing number of carbons in the fuel molecules, and the signal ratios between the intermediates (CH/C, CH/C2, CN/C, CH/C2, CN/CH) are different for different alkanol combustion flames. Our observation provides a way for sensing multiple combustion components by femtosecond filament excitation in various combustion conditions that strongly depend on the fuel species. PMID:27250021

Static and Impulsive Models of Solar Active Regions

NASA Technical Reports Server (NTRS)

Patsourakos, S.; Klimchuk, James A.

2008-01-01

The physical modeling of active regions (ARs) and of the global coronal is receiving increasing interest lately. Recent attempts to model ARs using static equilibrium models were quite successful in reproducing AR images of hot soft X-ray (SXR) loops. They however failed to predict the bright EUV warm loops permeating ARs: the synthetic images were dominated by intense footpoint emission. We demonstrate that this failure is due to the very weak dependence of loop temperature on loop length which cannot simultaneously account for both hot and warm loops in the same AR. We then consider time-dependent AR models based on nanoflare heating. We demonstrate that such models can simultaneously reproduce EUV and SXR loops in ARs. Moreover, they predict radial intensity variations consistent with the localized core and extended emissions in SXR and EUV AR observations respectively. We finally show how the AR morphology can be used as a gauge of the properties (duration, energy, spatial dependence, repetition time) of the impulsive heating.

Noninvasive optical monitoring multiple physiological parameters response to cytokine storm

NASA Astrophysics Data System (ADS)

Li, Zebin; Li, Ting

2018-02-01

Cancer and other disease originated by immune or genetic problems have become a main cause of death. Gene/cell therapy is a highlighted potential method for the treatment of these diseases. However, during the treatment, it always causes cytokine storm, which probably trigger acute respiratory distress syndrome and multiple organ failure. Here we developed a point-of-care device for noninvasive monitoring cytokine storm induced multiple physiological parameters simultaneously. Oxy-hemoglobin, deoxy-hemoglobin, water concentration and deep-tissue/tumor temperature variations were simultaneously measured by extended near infrared spectroscopy. Detection algorithms of symptoms such as shock, edema, deep-tissue fever and tissue fibrosis were developed and included. Based on these measurements, modeling of patient tolerance and cytokine storm intensity were carried out. This custom device was tested on patients experiencing cytokine storm in intensive care unit. The preliminary data indicated the potential of our device in popular and milestone gene/cell therapy, especially, chimeric antigen receptor T-cell immunotherapy (CAR-T).

Is 9 louder than 1? Audiovisual cross-modal interactions between number magnitude and judged sound loudness.

PubMed

Alards-Tomalin, Doug; Walker, Alexander C; Shaw, Joshua D M; Leboe-McGowan, Launa C

2015-09-01

The cross-modal impact of number magnitude (i.e. Arabic digits) on perceived sound loudness was examined. Participants compared a target sound's intensity level against a previously heard reference sound (which they judged as quieter or louder). Paired with each target sound was a task irrelevant Arabic digit that varied in magnitude, being either small (1, 2, 3) or large (7, 8, 9). The degree to which the sound and the digit were synchronized was manipulated, with the digit and sound occurring simultaneously in Experiment 1, and the digit preceding the sound in Experiment 2. Firstly, when target sounds and digits occurred simultaneously, sounds paired with large digits were categorized as loud more frequently than sounds paired with small digits. Secondly, when the events were separated, number magnitude ceased to bias sound intensity judgments. In Experiment 3, the events were still separated, however the participants held the number in short-term memory. In this instance the bias returned. Copyright © 2015 Elsevier B.V. All rights reserved.

Simultaneous reconstruction of 3D refractive index, temperature, and intensity distribution of combustion flame by double computed tomography technologies based on spatial phase-shifting method

NASA Astrophysics Data System (ADS)

Guo, Zhenyan; Song, Yang; Yuan, Qun; Wulan, Tuya; Chen, Lei

2017-06-01

In this paper, a transient multi-parameter three-dimensional (3D) reconstruction method is proposed to diagnose and visualize a combustion flow field. Emission and transmission tomography based on spatial phase-shifted technology are combined to reconstruct, simultaneously, the various physical parameter distributions of a propane flame. Two cameras triggered by the internal trigger mode capture the projection information of the emission and moiré tomography, respectively. A two-step spatial phase-shifting method is applied to extract the phase distribution in the moiré fringes. By using the filtered back-projection algorithm, we reconstruct the 3D refractive-index distribution of the combustion flow field. Finally, the 3D temperature distribution of the flame is obtained from the refractive index distribution using the Gladstone-Dale equation. Meanwhile, the 3D intensity distribution is reconstructed based on the radiation projections from the emission tomography. Therefore, the structure and edge information of the propane flame are well visualized.

Confocal fluorescence techniques in industrial application

NASA Astrophysics Data System (ADS)

Eggeling, Christian; Gall, Karsten; Palo, Kaupo; Kask, Peet; Brand, Leif

2003-06-01

The FCS+plus family of evaluation tools for confocal fluorescence spectroscopy, which was developed during recent years, offers a comprehensive view to a series of fluorescence properties. Originating in fluorescence correlation spectroscopy (FCS) and using similar experimental equipment, a system of signal processing methods such as fluorescence intensity distribution analysis (FIDA) was created to analyze in detail the fluctuation behavior of fluorescent particles within a small area of detection. Giving simultaneous access to molecular parameters like concentration, translational and rotational diffusion, molecular brightness, and multicolor coincidence, this portfolio was enhanced by more traditional techniques of fluorescence lifetime as well as time-resolved anisotropy determination. The cornerstones of the FCS+plus methodology will be shortly described. The inhibition of a phosphatase enzyme activity gives a comprehensive industrial application that demonstrates FCS+plus' versatility and its potential for pharmaceutical drug discovery.

Numerical modeling of thermal refraction inliquids in the transient regime.

PubMed

Kovsh, D; Hagan, D; Van Stryland, E

1999-04-12

We present the results of modeling of nanosecond pulse propagation in optically absorbing liquid media. Acoustic and electromagnetic wave equations must be solved simultaneously to model refractive index changes due to thermal expansion and/or electrostriction, which are highly transient phenomena on a nanosecond time scale. Although we consider situations with cylindrical symmetry and where the paraxial approximation is valid, this is still a computation-intensive problem, as beam propagation through optically thick media must be modeled. We compare the full solution of the acoustic wave equation with the approximation of instantaneous expansion (steady-state solution) and hence determine the regimes of validity of this approximation. We also find that the refractive index change obtained from the photo-acoustic equation overshoots its steady-state value once the ratio between the pulsewidth and the acoustic transit time exceeds a factor of unity.

Advances in tumor diagnosis using OCT and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Zakharov, V. P.; Bratchenko, I. A.; Kozlov, S. V.; Moryatov, A. A.; Kornilin, D. V.; Myakinin, O. O.; Artemyev, D. N.

2014-05-01

Complex investigation of malignant tumors was performed with combined optical coherence tomography (OCT) and Raman spectroscopy (RS) setup: 22 ex vivo lung tissue samples and 23 in vivo experiments with skin tumors. It was shown that combined RS-OCT unit may be used for precise tissue morphology visualization with simultaneous tumor type determination (BCC, malignant melanoma of skin tissues, adenocarcinoma and squamous cell carcinoma of lung). Fast RS phase method for skin and lung tumors identification was proposed. It is based on alteration of Raman spectral intensity in 1300-1340, 1440-1460 and 1640-1680 cm-1 bands for healthy and malignant tissue. Complex method could identify: malignant melanoma with 88.9% sensitivity and 87.8% specificity; adenocarcinoma with 100% sensitivity and 81.5% specificity; squamous cell carcinomas with 90.9% sensitivity and 77.8% specificity.

Application of time–frequency wavelet analysis in the reflectometry of thin films

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

Astaf’ev, S. B., E-mail: bard@crys.ras.ru; Shchedrin, B. M.; Yanusova, L. G.

2017-03-15

The application of time–frequency wavelet analysis for solving the reflectometry inverse problem is considered. It is shown that a simultaneous transform of specular intensity curve, depending on the grazing angle and spatial frequency, allows one to determine not only the thickness but also the alteration order of individual regions (layers) with characteristic behavior of electron density. This information makes it possible to reconstruct the electron density profile in the film cross section as a whole (i.e., to solve the inverse reflectometry problem). The application of the time–frequency transform is illustrated by examples of reconstructing (based on X-ray reflectivity data) themore » layer alternation order in models of two-layer films with inverted arrangement of layers and a four-layer film on a solid substrate.« less

Thyroid storm precipitated by duodenal ulcer perforation.

PubMed

Natsuda, Shoko; Nakashima, Yomi; Horie, Ichiro; Ando, Takao; Kawakami, Atsushi

2015-01-01

Thyroid storm is a rare and life-threatening complication of thyrotoxicosis that requires prompt treatment. Thyroid storm is also known to be associated with precipitating events. The simultaneous treatment of thyroid storm and its precipitant, when they are recognized, in a patient is recommended; otherwise such disorders, including thyroid storm, can exacerbate each other. Here we report the case of a thyroid storm patient (a 55-year-old Japanese male) complicated with a perforated duodenal ulcer. The patient was successfully treated with intensive treatment for thyroid storm and a prompt operation. Although it is believed that peptic ulcer rarely coexists with hyperthyroidism, among patients with thyroid storm, perforation of a peptic ulcer has been reported as one of the causes of fatal outcome. We determined that surgical intervention was required in this patient, reported despite ongoing severe thyrotoxicosis, and reported herein a successful outcome.

A Bright Future for Serial Femtosecond Crystallography with XFELs.

PubMed

Johansson, Linda C; Stauch, Benjamin; Ishchenko, Andrii; Cherezov, Vadim

2017-09-01

X-ray free electron lasers (XFELs) have the potential to revolutionize macromolecular structural biology due to the unique combination of spatial coherence, extreme peak brilliance, and short duration of X-ray pulses. A recently emerged serial femtosecond (fs) crystallography (SFX) approach using XFEL radiation overcomes some of the biggest hurdles of traditional crystallography related to radiation damage through the diffraction-before-destruction principle. Intense fs XFEL pulses enable high-resolution room-temperature structure determination of difficult-to-crystallize biological macromolecules, while simultaneously opening a new era of time-resolved structural studies. Here, we review the latest developments in instrumentation, sample delivery, data analysis, crystallization methods, and applications of SFX to important biological questions, and conclude with brief insights into the bright future of structural biology using XFELs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Temporal formation of optical anisotropy and surface relief during polarization holographic recording in polymethylmethacrylate with azobenzene side groups

NASA Astrophysics Data System (ADS)

Sasaki, Tomoyuki; Izawa, Masahiro; Noda, Kohei; Nishioka, Emi; Kawatsuki, Nobuhiro; Ono, Hiroshi

2014-03-01

The formation of polarization holographic gratings with both optical anisotropy and surface relief (SR) deformation was studied for polymethylmethacrylate with azobenzene side groups. Temporal contributions of isotropic and anisotropic phase gratings were simultaneously determined by observing transitional intensity and polarization states of the diffraction beams and characterizing by means of Jones calculus. To clarify the mechanism of SR deformation, cross sections of SR were characterized based on the optical gradient force model; experimental observations were in good agreement with the theoretical expectation. We clarified that the anisotropic phase change originating in the reorientation of the azobenzene side groups was induced immediately at the beginning of the holographic recording, while the response time of the isotropic phase change originating in the molecular migration due to the optical gradient force was relatively slow.

Real time quantitative phase microscopy based on single-shot transport of intensity equation (ssTIE) method

NASA Astrophysics Data System (ADS)

Yu, Wei; Tian, Xiaolin; He, Xiaoliang; Song, Xiaojun; Xue, Liang; Liu, Cheng; Wang, Shouyu

2016-08-01

Microscopy based on transport of intensity equation provides quantitative phase distributions which opens another perspective for cellular observations. However, it requires multi-focal image capturing while mechanical and electrical scanning limits its real time capacity in sample detections. Here, in order to break through this restriction, real time quantitative phase microscopy based on single-shot transport of the intensity equation method is proposed. A programmed phase mask is designed to realize simultaneous multi-focal image recording without any scanning; thus, phase distributions can be quantitatively retrieved in real time. It is believed the proposed method can be potentially applied in various biological and medical applications, especially for live cell imaging.

Anomalous Quantum Correlations of Squeezed Light

NASA Astrophysics Data System (ADS)

Kühn, B.; Vogel, W.; Mraz, M.; Köhnke, S.; Hage, B.

2017-04-01

Three different noise moments of field strength, intensity, and their correlations are simultaneously measured. For this purpose a homodyne cross-correlation measurement [1] is implemented by superimposing the signal field and a weak local oscillator on an unbalanced beam splitter. The relevant information is obtained via the intensity noise correlation of the output modes. Detection details like quantum efficiencies or uncorrelated dark noise are meaningless for our technique. Yet unknown insight in the quantumness of a squeezed signal field is retrieved from the anomalous moment, correlating field strength with intensity noise. A classical inequality including this moment is violated for almost all signal phases. Precognition on quantum theory is superfluous, as our analysis is solely based on classical physics.

Relationship of extinction to perceptual thresholds for single stimuli.

PubMed

Meador, K J; Ray, P G; Day, L J; Loring, D W

2001-04-24

To demonstrate the effects of target stimulus intensity on extinction to double simultaneous stimuli. Attentional deficits contribute to extinction in patients with brain lesions, but extinction (i.e., masking) can also be produced in healthy subjects. The relationship of extinction to perceptual thresholds for single stimuli remains uncertain. Brief electrical pulses were applied simultaneously to the left and right index fingers of 16 healthy volunteers (8 young and 8 elderly adults) and 4 patients with right brain stroke (RBS). The stimulus to be perceived (i.e., target stimulus) was given at the lowest perceptual threshold to perceive any single stimulus (i.e., Minimal) and at the threshold to perceive 100% of single stimuli. The mask stimulus (i.e., stimulus given to block the target) was applied to the contralateral hand at intensities just below discomfort. Extinction was less for target stimuli at 100% than Minimal threshold for healthy subjects. Extinction of left targets was greater in patients with RBS than elderly control subjects. Left targets were extinguished less than right in healthy subjects. In contrast, the majority of left targets were extinguished in patients with RBS even when right mask intensity was reduced below right 100% threshold for single stimuli. RBS patients had less extinction for right targets despite having greater left mask - threshold difference than control subjects. In patients with RBS, right "targets" at 100% threshold extinguished left "masks" (20%) almost as frequently as left masks extinguished right targets (32%). Subtle changes in target intensity affect extinction in healthy adults. Asymmetries in mask and target intensities (relative to single-stimulus perceptual thresholds) affect extinction in RBS patients less for left targets but more for right targets as compared with control subjects.

Selection of Wavelengths for Optimum Precision in Simultaneous Spectrophotometric Determinations.

ERIC Educational Resources Information Center

DiTusa, Michael R.; Schilt, Alfred A.

1985-01-01

Although many textbooks include a description of simultaneous determinations employing absorption spectrophotometry and treat the mathematics necessary for analytical quantitations, treatment of analytical wavelength selection has been mostly qualitative. Therefore, a general method for selecting wavelengths for optimum precision in simultaneous…

Hydrogen production in single chamber microbial electrolysis cells with different complex substrates.

PubMed

Montpart, Nuria; Rago, Laura; Baeza, Juan A; Guisasola, Albert

2015-01-01

The use of synthetic wastewater containing carbon sources of different complexity (glycerol, milk and starch) was evaluated in single chamber microbial electrolysis cell (MEC) for hydrogen production. The growth of an anodic syntrophic consortium between fermentative and anode respiring bacteria was operationally enhanced and increased the opportunities of these complex substrates to be treated with this technology. During inoculation, current intensities achieved in single chamber microbial fuel cells were 50, 62.5, and 9 A m⁻³ for glycerol, milk and starch respectively. Both current intensities and coulombic efficiencies were higher than other values reported in previous works. The simultaneous degradation of the three complex substrates favored power production and COD removal. After three months in MEC operation, hydrogen production was only sustained with milk as a single substrate and with the simultaneous degradation of the three substrates. The later had the best results in terms of current intensity (150 A m⁻³), hydrogen production (0.94 m³ m⁻³ d⁻¹) and cathodic gas recovery (91%) at an applied voltage of 0.8 V. Glycerol and starch as substrates in MEC could not avoid the complete proliferation of hydrogen scavengers, even under low hydrogen retention time conditions induced by continuous nitrogen sparging.

Development of acousto-optic spatial light modulator unit for effective control of light beam intensity and diffraction angle in 3D holographic display applications

NASA Astrophysics Data System (ADS)

Kondalkar, Vijay V.; Ryu, Geonhee; Lee, Yongbeom; Lee, Keekeun

2018-07-01

An acousto-optic (AO) based holographic display unit was developed using surface acoustic wave (SAW) with different wavelength to modulate the diffraction angles, intensities, and phases of light. The new configurations were employed to control two beams simultaneously by using a single chirp inter-digital transducer (IDT), and a micro-lens array was integrated at the end of the waveguide layer to focus the diffracted light on to the screen. Two incident light beams were simultaneously modulated by using different refractive grating periods generated from chirp IDT. A diffraction angle of about 5° was obtained by using a SAW with a frequency of 430 MHz. The increase in the SAW input power enhances the diffraction efficiency of the light beam at the exit. The obtained maximum diffraction efficiency is ~70% at a frequency of 430 MHz. The sloped shape of the waveguide entrance and a tall rounded Ni poles help in coupling the incident light to the waveguide layer. The diffracted beam was collected through the lens, which increased the intensity of light in the viewing plane. COMSOL multi-physics and coupling of mode (COM) modeling were performed to predict the device performance and compared with the experimental results.

Comparative Evaluation of Accuracy of Pulse Oximeters and Factors Affecting Their Performance in a Tertiary Intensive Care Unit

PubMed Central

Sahi, Malvinder Singh; Mahawar, Bablesh; Rajpurohit, Sajjan

2017-01-01

Introduction Pulse oximetry is a widely used tool, unfortunately there is a paucity of data investigating its accuracy in Intensive Care Units (ICU) and if they are able to meet mandated FDA criteria as claimed by them in critically ill patients. Aim To assess bias, precision and accuracy of pulse oximeters used in ICU and factors affecting them. Materials and Methods A prospective cohort study, including 129 patients admitted to the ICU of a tertiary referral centre. Pulse oximetry and blood gas were done simultaneously. Pulse oximetry was done using two pulse oximetres: Nonin and Philips. All physiological variables like haemoglobin, lactate, use of vasopressors and blood pressure were recorded. Bland Altman curves were constructed to determine bias and limits of agreement. Effect of physiological variables on bias and difference between performance characteristics of bias was determined using SPSS. Results Pulse oximetry overestimated arterial oxygen saturation (SaO2) by 1.44%. There was negative correlation between bias and SaO2 (r=-0.32) and positive correlation with lactate (r=0.16). The Philips pulse oximeter had significant higher bias and variability than Nonin pulse oximeter. (2.49±2.99 versus 0.46±1.68, mean difference = 1.98, 95% C.I. = 1.53 – 2.43, p-value <0.001). Conclusion Pulse oximetry overestimates SaO2. Bias tends to increase with rising lactate and hypoxia. There is heterogeneity in performance of various pulse oximetry devices in ICU. PMID:28764215

Comparative Evaluation of Accuracy of Pulse Oximeters and Factors Affecting Their Performance in a Tertiary Intensive Care Unit.

PubMed

Singh, Anupam Kumar; Sahi, Malvinder Singh; Mahawar, Bablesh; Rajpurohit, Sajjan

2017-06-01

Pulse oximetry is a widely used tool, unfortunately there is a paucity of data investigating its accuracy in Intensive Care Units (ICU) and if they are able to meet mandated FDA criteria as claimed by them in critically ill patients. To assess bias, precision and accuracy of pulse oximeters used in ICU and factors affecting them. A prospective cohort study, including 129 patients admitted to the ICU of a tertiary referral centre. Pulse oximetry and blood gas were done simultaneously. Pulse oximetry was done using two pulse oximetres: Nonin and Philips. All physiological variables like haemoglobin, lactate, use of vasopressors and blood pressure were recorded. Bland Altman curves were constructed to determine bias and limits of agreement. Effect of physiological variables on bias and difference between performance characteristics of bias was determined using SPSS. Pulse oximetry overestimated arterial oxygen saturation (SaO 2 ) by 1.44%. There was negative correlation between bias and SaO 2 (r=-0.32) and positive correlation with lactate (r=0.16). The Philips pulse oximeter had significant higher bias and variability than Nonin pulse oximeter. (2.49±2.99 versus 0.46±1.68, mean difference = 1.98, 95% C.I. = 1.53 - 2.43, p-value <0.001). Pulse oximetry overestimates SaO 2 . Bias tends to increase with rising lactate and hypoxia. There is heterogeneity in performance of various pulse oximetry devices in ICU.

Development of Artificial Neural Network Model for Diesel Fuel Properties Prediction using Vibrational Spectroscopy.

PubMed

Bolanča, Tomislav; Marinović, Slavica; Ukić, Sime; Jukić, Ante; Rukavina, Vinko

2012-06-01

This paper describes development of artificial neural network models which can be used to correlate and predict diesel fuel properties from several FTIR-ATR absorbances and Raman intensities as input variables. Multilayer feed forward and radial basis function neural networks have been used to rapid and simultaneous prediction of cetane number, cetane index, density, viscosity, distillation temperatures at 10% (T10), 50% (T50) and 90% (T90) recovery, contents of total aromatics and polycyclic aromatic hydrocarbons of commercial diesel fuels. In this study two-phase training procedures for multilayer feed forward networks were applied. While first phase training algorithm was constantly the back propagation one, two second phase training algorithms were varied and compared, namely: conjugate gradient and quasi Newton. In case of radial basis function network, radial layer was trained using K-means radial assignment algorithm and three different radial spread algorithms: explicit, isotropic and K-nearest neighbour. The number of hidden layer neurons and experimental data points used for the training set have been optimized for both neural networks in order to insure good predictive ability by reducing unnecessary experimental work. This work shows that developed artificial neural network models can determine main properties of diesel fuels simultaneously based on a single and fast IR or Raman measurement.

Doses of Nearby Nature Simultaneously Associated with Multiple Health Benefits

PubMed Central

Cox, Daniel T. C.; Shanahan, Danielle F.; Hudson, Hannah L.; Fuller, Richard A.; Anderson, Karen; Hancock, Steven; Gaston, Kevin J.

2017-01-01

Exposure to nature provides a wide range of health benefits. A significant proportion of these are delivered close to home, because this offers an immediate and easily accessible opportunity for people to experience nature. However, there is limited information to guide recommendations on its management and appropriate use. We apply a nature dose-response framework to quantify the simultaneous association between exposure to nearby nature and multiple health benefits. We surveyed ca. 1000 respondents in Southern England, UK, to determine relationships between (a) nature dose type, that is the frequency and duration (time spent in private green space) and intensity (quantity of neighbourhood vegetation cover) of nature exposure and (b) health outcomes, including mental, physical and social health, physical behaviour and nature orientation. We then modelled dose-response relationships between dose type and self-reported depression. We demonstrate positive relationships between nature dose and mental and social health, increased physical activity and nature orientation. Dose-response analysis showed that lower levels of depression were associated with minimum thresholds of weekly nature dose. Nearby nature is associated with quantifiable health benefits, with potential for lowering the human and financial costs of ill health. Dose-response analysis has the potential to guide minimum and optimum recommendations on the management and use of nearby nature for preventative healthcare. PMID:28208789

Doses of Nearby Nature Simultaneously Associated with Multiple Health Benefits.

PubMed

Cox, Daniel T C; Shanahan, Danielle F; Hudson, Hannah L; Fuller, Richard A; Anderson, Karen; Hancock, Steven; Gaston, Kevin J

2017-02-09

Exposure to nature provides a wide range of health benefits. A significant proportion of these are delivered close to home, because this offers an immediate and easily accessible opportunity for people to experience nature. However, there is limited information to guide recommendations on its management and appropriate use. We apply a nature dose-response framework to quantify the simultaneous association between exposure to nearby nature and multiple health benefits. We surveyed ca. 1000 respondents in Southern England, UK, to determine relationships between (a) nature dose type, that is the frequency and duration (time spent in private green space) and intensity (quantity of neighbourhood vegetation cover) of nature exposure and (b) health outcomes, including mental, physical and social health, physical behaviour and nature orientation. We then modelled dose-response relationships between dose type and self-reported depression. We demonstrate positive relationships between nature dose and mental and social health, increased physical activity and nature orientation. Dose-response analysis showed that lower levels of depression were associated with minimum thresholds of weekly nature dose. Nearby nature is associated with quantifiable health benefits, with potential for lowering the human and financial costs of ill health. Dose-response analysis has the potential to guide minimum and optimum recommendations on the management and use of nearby nature for preventative healthcare.

High-pressure cell for simultaneous dielectric and neutron spectroscopy.

PubMed

Sanz, Alejandro; Hansen, Henriette Wase; Jakobsen, Bo; Pedersen, Ib H; Capaccioli, Simone; Adrjanowicz, Karolina; Paluch, Marian; Gonthier, Julien; Frick, Bernhard; Lelièvre-Berna, Eddy; Peters, Judith; Niss, Kristine

2018-02-01

In this article, we report on the design, manufacture, and testing of a high-pressure cell for simultaneous dielectric and neutron spectroscopy. This cell is a unique tool for studying dynamics on different time scales, from kilo- to picoseconds, covering universal features such as the α relaxation and fast vibrations at the same time. The cell, constructed in cylindrical geometry, is made of a high-strength aluminum alloy and operates up to 500 MPa in a temperature range between roughly 2 and 320 K. In order to measure the scattered neutron intensity and the sample capacitance simultaneously, a cylindrical capacitor is positioned within the bore of the high-pressure container. The capacitor consists of two concentric electrodes separated by insulating spacers. The performance of this setup has been successfully verified by collecting simultaneous dielectric and neutron spectroscopy data on dipropylene glycol, using both backscattering and time-of-flight instruments. We have carried out the experiments at different combinations of temperature and pressure in both the supercooled liquid and glassy state.

High-pressure cell for simultaneous dielectric and neutron spectroscopy

NASA Astrophysics Data System (ADS)

Sanz, Alejandro; Hansen, Henriette Wase; Jakobsen, Bo; Pedersen, Ib H.; Capaccioli, Simone; Adrjanowicz, Karolina; Paluch, Marian; Gonthier, Julien; Frick, Bernhard; Lelièvre-Berna, Eddy; Peters, Judith; Niss, Kristine

2018-02-01

In this article, we report on the design, manufacture, and testing of a high-pressure cell for simultaneous dielectric and neutron spectroscopy. This cell is a unique tool for studying dynamics on different time scales, from kilo- to picoseconds, covering universal features such as the α relaxation and fast vibrations at the same time. The cell, constructed in cylindrical geometry, is made of a high-strength aluminum alloy and operates up to 500 MPa in a temperature range between roughly 2 and 320 K. In order to measure the scattered neutron intensity and the sample capacitance simultaneously, a cylindrical capacitor is positioned within the bore of the high-pressure container. The capacitor consists of two concentric electrodes separated by insulating spacers. The performance of this setup has been successfully verified by collecting simultaneous dielectric and neutron spectroscopy data on dipropylene glycol, using both backscattering and time-of-flight instruments. We have carried out the experiments at different combinations of temperature and pressure in both the supercooled liquid and glassy state.

Identification of Analytical Factors Affecting Complex Proteomics Profiles Acquired in a Factorial Design Study with Analysis of Variance: Simultaneous Component Analysis.

PubMed

Mitra, Vikram; Govorukhina, Natalia; Zwanenburg, Gooitzen; Hoefsloot, Huub; Westra, Inge; Smilde, Age; Reijmers, Theo; van der Zee, Ate G J; Suits, Frank; Bischoff, Rainer; Horvatovich, Péter

2016-04-19

Complex shotgun proteomics peptide profiles obtained in quantitative differential protein expression studies, such as in biomarker discovery, may be affected by multiple experimental factors. These preanalytical factors may affect the measured protein abundances which in turn influence the outcome of the associated statistical analysis and validation. It is therefore important to determine which factors influence the abundance of peptides in a complex proteomics experiment and to identify those peptides that are most influenced by these factors. In the current study we analyzed depleted human serum samples to evaluate experimental factors that may influence the resulting peptide profile such as the residence time in the autosampler at 4 °C, stopping or not stopping the trypsin digestion with acid, the type of blood collection tube, different hemolysis levels, differences in clotting times, the number of freeze-thaw cycles, and different trypsin/protein ratios. To this end we used a two-level fractional factorial design of resolution IV (2(IV)(7-3)). The design required analysis of 16 samples in which the main effects were not confounded by two-factor interactions. Data preprocessing using the Threshold Avoiding Proteomics Pipeline (Suits, F.; Hoekman, B.; Rosenling, T.; Bischoff, R.; Horvatovich, P. Anal. Chem. 2011, 83, 7786-7794, ref 1) produced a data-matrix containing quantitative information on 2,559 peaks. The intensity of the peaks was log-transformed, and peaks having intensities of a low t-test significance (p-value > 0.05) and a low absolute fold ratio (<2) between the two levels of each factor were removed. The remaining peaks were subjected to analysis of variance (ANOVA)-simultaneous component analysis (ASCA). Permutation tests were used to identify which of the preanalytical factors influenced the abundance of the measured peptides most significantly. The most important preanalytical factors affecting peptide intensity were (1) the hemolysis level, (2) stopping trypsin digestion with acid, and (3) the trypsin/protein ratio. This provides guidelines for the experimentalist to keep the ratio of trypsin/protein constant and to control the trypsin reaction by stopping it with acid at an accurately set pH. The hemolysis level cannot be controlled tightly as it depends on the status of a patient's blood (e.g., red blood cells are more fragile in patients undergoing chemotherapy) and the care with which blood was sampled (e.g., by avoiding shear stress). However, its level can be determined with a simple UV spectrophotometric measurement and samples with extreme levels or the peaks affected by hemolysis can be discarded from further analysis. The loadings of the ASCA model led to peptide peaks that were most affected by a given factor, for example, to hemoglobin-derived peptides in the case of the hemolysis level. Peak intensity differences for these peptides were assessed by means of extracted ion chromatograms confirming the results of the ASCA model.

Measurement of relative cross sections for simultaneous ionization and excitation of the helium 4 2s and 4 2p states

NASA Technical Reports Server (NTRS)

Sutton, J. F.

1972-01-01

The relative cross sections for simultaneous ionization and excitation of helium by 200-eV electrons into the 4 2s and 4 2p states were measured via a fast delayed coincidence technique. Results show good agreement with the relative cross sections for single electron excitation of helium and hydrogen. An application of the results of the measurement to the development of ultraviolet intensity standard is suggested. This technique involves the use of known branching ratios, a visible light flux reference, and the measured relative cross sections.

Resolution enhancement using simultaneous couple illumination

NASA Astrophysics Data System (ADS)

Hussain, Anwar; Martínez Fuentes, José Luis

2016-10-01

A super-resolution technique based on structured illumination created by a liquid crystal on silicon spatial light modulator (LCOS-SLM) is presented. Single and simultaneous pairs of tilted beams are generated to illuminate a target object. Resolution enhancement of an optical 4f system is demonstrated by using numerical simulations. The resulting intensity images are recorded at a charged couple device (CCD) and stored in the computer memory for further processing. One dimension enhancement can be performed with only 15 images. Two dimensional complete improvement requires 153 different images. The resolution of the optical system is extended three times compared to the band limited system.

High prevalence of simultaneous rib and vertebral fractures in patients with hip fracture.

PubMed

Lee, Bong-Gun; Sung, Yoon-Kyoung; Kim, Dam; Choi, Yun Young; Kim, Hunchul; Kim, Yeesuk

2017-02-01

The purpose was to evaluate the prevalence and location of simultaneous fracture using bone scans in patients with hip fracture and to determine the risk factors associated with simultaneous fracture. One hundred eighty two patients with hip fracture were reviewed for this study. Clinical parameters and bone mineral density (BMD) of the lumbar vertebra and femoral neck were investigated. To identify acute simultaneous fracture, a bone scan was performed at 15.4±4.1days after hip fracture. The prevalence and location of simultaneous fracture were evaluated, and multivariate logistic regression analysis was performed to determine the risk factors. Simultaneous fracture was observed in 102 of 182 patients, a prevalence of 56.0%. Rib fracture was the most common type of simultaneous fracture followed by rib with vertebral fracture. The BMD of the lumbar vertebra was significantly lower in patients with simultaneous fracture (p=0.044) and was identified as an independent risk factor (odds ratio: OR 0.05, 95% confidence interval: CI 0.01-0.57). The prevalence of simultaneous fracture was relatively high among patients with hip fracture, and BMD was significantly lower in patients with simultaneous fracture than in patients without it. Surgeons should be aware of the possibility of simultaneous fracture in patients with hip fracture. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Millimetre-Wave Cuboid Solid Immersion Lens with Intensity-Enhanced Amplitude Mask Apodization

NASA Astrophysics Data System (ADS)

Yue, Liyang; Yan, Bing; Monks, James N.; Dhama, Rakesh; Wang, Zengbo; Minin, Oleg V.; Minin, Igor V.

2018-06-01

Photonic jet is a narrow, highly intensive, weak-diverging beam propagating into a background medium and can be produced by a cuboid solid immersion lens (SIL) in both transmission and reflection modes. Amplitude mask apodization is an optical method to further improve the spatial resolution of a SIL imaging system via reduction of waist size of photonic jet, but always leading to intensity loss due to central masking of the incoming plane wave. In this letter, we report a particularly sized millimetre-wave cuboid SIL with the intensity-enhanced amplitude mask apodization for the first time. It is able to simultaneously deliver extra intensity enhancement and waist narrowing to the produced photonic jet. Both numerical simulation and experimental verification of the intensity-enhanced apodization effect are demonstrated using a copper-masked Teflon cuboid SIL with 22-mm side length under radiation of a plane wave with 8-mm wavelength. Peak intensity enhancement and the lateral resolution of the optical system increase by about 36.0% and 36.4% in this approach, respectively.

Simultaneous electrochemical determination of L-cysteine and L-cysteine disulfide at carbon ionic liquid electrode.

PubMed

Safavi, Afsaneh; Ahmadi, Raheleh; Mahyari, Farzaneh Aghakhani

2014-04-01

A linear sweep voltammetric method is used for direct simultaneous determination of L-cysteine and L-cysteine disulfide (cystine) based on carbon ionic liquid electrode. With carbon ionic liquid electrode as a high performance electrode, two oxidation peaks for L-cysteine (0.62 V) and L-cysteine disulfide (1.3 V) were observed with a significant separation of about 680 mV (vs. Ag/AgCl) in phosphate buffer solution (pH 6.0). The linear ranges were obtained as 1.0-450 and 5.0-700 μM and detection limits were estimated to be 0.298 and 4.258 μM for L-cysteine and L-cysteine disulfide, respectively. This composite electrode was applied for simultaneous determination of L-cysteine and L-cysteine disulfide in two real samples, artificial urine and nutrient broth. Satisfactory results were obtained which clearly indicate the applicability of the proposed electrode for simultaneous determination of these compounds in complex matrices.

Group Therapy Techniques for Sexually Abused Preteen Girls.

ERIC Educational Resources Information Center

Berman, Pearl

1990-01-01

Describes an open-ended, structured, highly intensive therapy group for sexually abused preteen girls that was the primary mode of treatment for 11 girls from low-income, rural White families with numerous problems. Unique features of the group included simultaneous group and individualized goals. (Author/BB)

Performance: The Pursuit Of Folly

ERIC Educational Resources Information Center

Campbell, Paul N.

1971-01-01

Communication aesthetics" indicates clearly that our concerns transcend the folly of a narrow, conventional concept of performance; simultaneously, the label is an intensely mixed matrix whose pull is toward new views of the symbolic process-views that stress the complexity and the urgency of aesthetic aspects of language. (Author)

Participant observation of time allocation, direct patient contact and simultaneous activities in hospital physicians.

PubMed

Weigl, Matthias; Müller, Andreas; Zupanc, Andrea; Angerer, Peter

2009-06-29

Hospital physicians' time is a critical resource in medical care. Two aspects are of interest. First, the time spent in direct patient contact - a key principle of effective medical care. Second, simultaneous task performance ('multitasking') which may contribute to medical error, impaired safety behaviour, and stress. There is a call for instruments to assess these aspects. A preliminary study to gain insight into activity patterns, time allocation and simultaneous activities of hospital physicians was carried out. Therefore an observation instrument for time-motion-studies in hospital settings was developed and tested. 35 participant observations of internists and surgeons of a German municipal 300-bed hospital were conducted. Complete day shifts of hospital physicians on wards, emergency ward, intensive care unit, and operating room were continuously observed. Assessed variables of interest were time allocation, share of direct patient contact, and simultaneous activities. Inter-rater agreement of Kappa = .71 points to good reliability of the instrument. Hospital physicians spent 25.5% of their time at work in direct contact with patients. Most time was allocated to documentation and conversation with colleagues and nursing staff. Physicians performed parallel simultaneous activities for 17-20% of their work time. Communication with patients, documentation, and conversation with colleagues and nursing staff were the most frequently observed simultaneous activities. Applying logit-linear analyses, specific primary activities increase the probability of particular simultaneous activities. Patient-related working time in hospitals is limited. The potential detrimental effects of frequently observed simultaneous activities on performance outcomes need further consideration.

Time-resolved study of SrTiO3 homoepitaxial pulsed-laser deposition using surface x-ray diffraction

NASA Astrophysics Data System (ADS)

Eres, G.; Tischler, J. Z.; Yoon, M.; Larson, B. C.; Rouleau, C. M.; Lowndes, D. H.; Zschack, P.

2002-05-01

Homoepitaxy of SrTiO3 by pulsed-laser deposition has been studied using in situ time-resolved surface x-ray diffraction in the temperature range of 310 °C to 780 °C. Using a two-detector configuration, surface x-ray diffraction intensities were monitored simultaneously at the (0 0 1/2) specular and the (0 1 1/2) off-specular truncation rod positions. Abrupt intensity changes in both the specular and off-specular rods after laser pulses indicated prompt crystallization into SrTiO3 layers followed by slower intra- and interlayer surface rearrangements on time scales of seconds. Specular rod intensity oscillations indicated layer-by-layer growth, while off-specular rod intensity measurements suggested the presence of transient in-plane lattice distortions for depositions above 600 °C.

Thermoregulatory responses to heat and vibration in men

NASA Technical Reports Server (NTRS)

Spaul, W. A.; Spear, R. C.; Greenleaf, J. E.

1986-01-01

The effect of vibration on thermoregulatory responses was studied in heat-acclimated men exposed suddenly to simultaneous heat and whole body vibrations (WBVs) at two intensity levels, each at graded frequencies between 5 and 80 Hz. The mean rectal temperature (Tre) became elevated more quickly in the WBV exposures than in the controls (heat exposure alone). Both intensity- and frequency-dependent WBV relationships were recorded in localized blood flows and in sweat rates. Thus, vibration appears to reduce the efficiency of the cooling mechanisms during a heat exposure.

Energy and charge transfer dynamics between Alq3 and CdSeS nanocrystals.

PubMed

Zhang, Shuping; Liu, Yuqiang; Yang, Yanqiang

2010-03-01

The photoluminescence properties of the blend films consisting of organic small molecules and nanocrystals (NCs)--Alq3 and CdSeS NCs--were studied by steady-state and time-resolved photoluminescence (PL) spectroscopy with different excited wavelengths. Both the fluorescence intensity and lifetime are intensively dependent on the NC concentration. The detailed analysis of experiment data proves that Forster energy transfer from the Alq3 to the NCs exists simultaneously with the charge transfer and both compete with each other in the blend films.

The extended atmosphere of Lambda Pavonis at the time of the emergence of H-emissions from minimum intensity

NASA Technical Reports Server (NTRS)

Sahade, Jorge; Rovira, Marta; Ringuelet, Adela E.; Kondo, Yoji; Cidale, Lydia

1988-01-01

A study of the Be star Lambda Pavonis, particularly of the changes in the Balmer discontinuity in the interval 1949-1982, is presented. Nearly simultaneous observations carried out with the ESO 1.5 m reflector at La Silla and with the IUE satellite correspond to an epoch when the H emission is starting to increase intensity immediately after having reached its minimum strength. These observations suggest the presence of four distinct regions of line formation, with the material moving outward in the transition region.

Determination of differential cross sections and kinetic energy release of co-products from central sliced images in photo-initiated dynamic processes.

PubMed

Chen, Kuo-mei; Chen, Yu-wei

2011-04-07

For photo-initiated inelastic and reactive collisions, dynamic information can be extracted from central sliced images of state-selected Newton spheres of product species. An analysis framework has been established to determine differential cross sections and the kinetic energy release of co-products from experimental images. When one of the reactants exhibits a high recoil speed in a photo-initiated dynamic process, the present theory can be employed to analyze central sliced images from ion imaging or three-dimensional sliced fluorescence imaging experiments. It is demonstrated that the differential cross section of a scattering process can be determined from the central sliced image by a double Legendre moment analysis, for either a fixed or continuously distributed recoil speeds in the center-of-mass reference frame. Simultaneous equations which lead to the determination of the kinetic energy release of co-products can be established from the second-order Legendre moment of the experimental image, as soon as the differential cross section is extracted. The intensity distribution of the central sliced image, along with its outer and inner ring sizes, provide all the clues to decipher the differential cross section and the kinetic energy release of co-products.

Total reflection X-ray Fluorescence determination of interfering elements rubidium and uranium by profile fitting

NASA Astrophysics Data System (ADS)

Dhara, Sangita; Khooha, Ajay; Singh, Ajit Kumar; Tiwari, M. K.; Misra, N. L.

2018-06-01

Systematic studies to assess the analytical parameters obtained in the total reflection X-ray fluorescence (TXRF) determinations of interfering elements Rb and U using profile fitting are reported in the present manuscript. The X-ray lines Rb Kα and U Lα having serious spectral interference (ΔE = 218 eV), have been used as analytical lines. The intensities of these X-ray lines have been assessed using profile fitting. In order to compare the analytical results of Rb determinations in presence of U, with and without U excitation, synchrotron radiation was tuned to energy just above and below the U Labs edge. This approach shall excite both Rb Kα and U Lα simultaneously and Rb Kα selectively. Finally, the samples were also analyzed with a laboratory based TXRF spectrometer. The analytical results obtained in all these conditions were comparable. The authenticity of the results was assessed by analyzing U with respect to Rb in Rb2U(SO4)3, a standard reference material for U. The average precision obtained for TXRF determinations was below 3% (RSD, n = 3, 1σ) and the percent deviation of TXRF values from the expected values calculated on the basis of sample preparation was within 3%.

Coherent Synchrotron Radiation for Rotational Spectroscopy: Application to the Rotational Spectrum of Propynal in the 200-750 GHz Range

NASA Astrophysics Data System (ADS)

Barros, J.; Roy, P.; Appadoo, D.; Naughton, D. Mc; Robertson, E.; Manceron, L.

2013-06-01

In storage rings, short electron bunches can produce an intense THz radiation called Coherent Synchrotron Radiation (CSR). The flux of this emission between 250 and 750 GHz (in the mW range, up the 10000 times the regular synchrotron emission) is very advantageous for broad band absorption spectroscopy, using interferometric techniques. This source is, however, inherently difficult to stabilize, and intensity fluctuations lead to artifacts on the FT-based measurements, which strongly limit the use of CSR in particular for high-resolution measurements. At SOLEIL however, by screening different currents and bunch lengths, we defined stable CSR conditions for which the signal-to-noise ratio (S/N) allows for measurements at high resolution. Moreover, we developed an artifact correction system, based on a simultaneous detection of the input and the output signals of the interferometer, which allows to further improve the S/N. For this purpose, the optics and electronics of two bolometers were matched. The stable CSR combined with this ingenious technique allowed us to record for the first time high-resolution FT spectra in the sub-THz range, with a S/N of 100 in a few hours. This enables many applications such as broadband rotational spectra in the THz range, studies of molecules with low frequency torsional modes, absolute intensities determinations, or studies of unstable species. Results obtained on Propynal illustrate these possibilities and enabled to improve significantly the ground state spectroscopic constants.

Tailoring Ion Charge State Distribution in Tetramethyltin Clusters under Influence of Moderate Intensity Picosecond Laser Pulse: Role of Laser Wavelength and Rate of Energy Deposition

NASA Astrophysics Data System (ADS)

Sharma, Pramod; Das, Soumitra; Vatsa, Rajesh K.

2017-07-01

Systematic manipulation of ionic-outcome in laser-cluster interaction process has been realized for studies carried out on tetramethyltin (TMT) clusters under picosecond laser conditions, determined by choice of laser wavelength and intensity. As a function of laser intensity, TMT clusters exhibit gradual enhancement in overall ionization of its cluster constituents, up to a saturation level of ionization, which was distinct for different wavelengths (266, 355, and 532 nm). Simultaneously, systematic appearance of higher multiply charged atomic ions and shift in relative abundance of multiply charged atomic ions towards higher charge state was observed, using time-of-flight mass spectrometer. At saturation level, multiply charged atomic ions up to (C2+, Sn2+) at 266 nm, (C4+, Sn4+) at 355 nm, and (C4+, Sn6+) at 532 nm were detected. In addition, at 355 nm intra-cluster ion chemistry within the ionized cluster leads to generation of molecular hydrogen ion (H2 +) and triatomic molecular hydrogen ion (H3 +). Generation of multiply charged atomic ions is ascribed to efficient coupling of laser pulse with the cluster media, facilitated by inner-ionized electrons produced within the cluster, at the leading edge of laser pulse. Role of inner-ionized electrons is authenticated by measuring kinetic energy distribution of electrons liberated upon disintegration of excessively ionized cluster, under the influence of picosecond laser pulse.

Qualitative assessment of gene expression in affymetrix genechip arrays

NASA Astrophysics Data System (ADS)

Nagarajan, Radhakrishnan; Upreti, Meenakshi

2007-01-01

Affymetrix Genechip microarrays are used widely to determine the simultaneous expression of genes in a given biological paradigm. Probes on the Genechip array are atomic entities which by definition are randomly distributed across the array and in turn govern the gene expression. In the present study, we make several interesting observations. We show that there is considerable correlation between the probe intensities across the array which defy the independence assumption. While the mechanism behind such correlations is unclear, we show that scaling behavior and the profiles of perfect match (PM) as well as mismatch (MM) probes are similar and immune-to-background subtraction. We believe that the observed correlations are possibly an outcome of inherent non-stationarities or patchiness in the array devoid of biological significance. This is demonstrated by inspecting their scaling behavior and profiles of the PM and MM probe intensities obtained from publicly available Genechip arrays from three eukaryotic genomes, namely: Drosophila melanogaster (fruit fly), Homo sapiens (humans) and Mus musculus (house mouse) across distinct biological paradigms and across laboratories, with and without background subtraction. The fluctuation functions were estimated using detrended fluctuation analysis (DFA) with fourth-order polynomial detrending. The results presented in this study provide new insights into correlation signatures of PM and MM probe intensities and suggests the choice of DFA as a tool for qualitative assessment of Affymetrix Genechip microarrays prior to their analysis. A more detailed investigation is necessary in order to understand the source of these correlations.

Diastolic Backward-Traveling Decompression (Suction) Wave Correlates With Simultaneously Acquired Indices of Diastolic Function and Is Reduced in Left Ventricular Stunning.

PubMed

Ladwiniec, Andrew; White, Paul A; Nijjer, Sukhjinder S; O'Sullivan, Michael; West, Nick E J; Davies, Justin E; Hoole, Stephen P

2016-09-01

Wave intensity analysis can distinguish proximal (propulsion) and distal (suction) influences on coronary blood flow and is purported to reflect myocardial performance and microvascular function. Quantifying the amplitude of the peak, backwards expansion wave (BEW) may have clinical utility. However, simultaneously acquired wave intensity analysis and left ventricular (LV) pressure-volume loop data, confirming the origin and effect of myocardial function on the BEW in humans, have not been previously reported. Patients with single-vessel left anterior descending coronary disease and normal ventricular function (n=13) were recruited prospectively. We simultaneously measured LV function with a conductance catheter and derived wave intensity analysis using a pressure-low velocity guidewire at baseline and again 30 minutes after a 1-minute coronary balloon occlusion. The peak BEW correlated with the indices of diastolic LV function: LV dP/dtmin (rs=-0.59; P=0.002) and τ (rs=-0.59; P=0.002), but not with systolic function. In 12 patients with paired measurements 30 minutes post balloon occlusion, LV dP/dtmax decreased from 1437.1±163.9 to 1299.4±152.9 mm Hg/s (median difference, -110.4 [-183.3 to -70.4]; P=0.015) and τ increased from 48.3±7.4 to 52.4±7.9 ms (difference, 4.1 [1.3-6.9]; P=0.01), but basal average peak coronary flow velocity was unchanged, indicating LV stunning post balloon occlusion. However, the peak BEW amplitude decreased from -9.95±5.45 W·m(-2)/s(2)×10(5) to -7.52±5.00 W·m(-2)/s(2)×10(5) (difference 2.43×10(5) [0.20×10(5) to 4.67×10(5); P=0.04]). Peak BEW assessed by coronary wave intensity analysis correlates with invasive indices of LV diastolic function and mirrors changes in LV diastolic function confirming the origin of the suction wave. This may have implications for physiological lesion assessment after percutaneous coronary intervention. URL: http://www.isrctn.org. Unique identifier: ISRCTN42864201. © 2016 American Heart Association, Inc.

Combining Optical Coherence Tomography with Fluorescence Molecular Imaging: Towards Simultaneous Morphology and Molecular Imaging

PubMed Central

Yuan, Shuai; Roney, Celeste A.; Wierwille, Jerry; Chen, Chao-Wei; Xu, Biying; Jiang, James; Ma, Hongzhou; Cable, Alex; Summers, Ronald M.; Chen, Yu

2010-01-01

Optical coherence tomography (OCT) provides high-resolution, cross-sectional imaging of tissue microstructure in situ and in real-time, while fluorescence molecular imaging (FMI) enables the visualization of basic molecular processes. There are great interests in combining these two modalities so that the tissue's structural and molecular information can be obtained simultaneously. This could greatly benefit biomedical applications such as detecting early diseases and monitoring therapeutic interventions. In this research, an optical system that combines OCT and FMI was developed. The system demonstrated that it could co-register en face OCT and FMI images with a 2.4 × 2.4 mm field of view. The transverse resolutions of OCT and FMI of the system are both ~10 μm. Capillary tubes filled with fluorescent dye Cy 5.5 in different concentrations under a scattering medium are used as the phantom. En face OCT images of the phantoms were obtained and successfully co-registered with FMI images that were acquired simultaneously. A linear relationship between FMI intensity and dye concentration was observed. The relationship between FMI intensity and target fluorescence tube depth measured by OCT images was also observed and compared with theoretical modeling. This relationship could help in correcting reconstructed dye concentration. Imaging of colon polyps of APCmin mouse model is presented as an example of biological applications of this co-registered OCT/FMI system. PMID:20009192

Widespread, Very Heavy Precipitation Events in Contemporary and Scenario Summer Climates from NARCCAP Simulations

NASA Astrophysics Data System (ADS)

Kawazoe, S.; Gutowski, W. J., Jr.

2015-12-01

We analyze the ability of regional climate models (RCMs) to simulate very heavy daily precipitation and supporting processes for both contemporary and future-scenario simulations during summer (JJA). RCM output comes from North American Regional Climate Change Assessment Program (NARCCAP) simulations, which are all run at a spatial resolution of 50 km. Analysis focuses on the upper Mississippi basin for summer, between 1982-1998 for the contemporary climate, and 2052-2068 during the scenario climate. We also compare simulated precipitation and supporting processes with those obtained from observed precipitation and reanalysis atmospheric states. Precipitation observations are from the University of Washington (UW) and the Climate Prediction Center (CPC) gridded dataset. Utilizing two observational datasets helps determine if any uncertainties arise from differences in precipitation gridding schemes. Reanalysis fields come from the North American Regional Reanalysis. The NARCCAP models generally reproduce well the precipitation-vs.-intensity spectrum seen in observations, while producing overly strong precipitation at high intensity thresholds. In the future-scenario climate, there is a decrease in frequency for light to moderate precipitation intensities, while an increase in frequency is seen for the higher intensity events. Further analysis focuses on precipitation events exceeding the 99.5 percentile that occur simultaneously at several points in the region, yielding so-called "widespread events". For widespread events, we analyze local and large scale environmental parameters, such as 2-m temperature and specific humidity, 500-hPa geopotential heights, Convective Available Potential Energy (CAPE), vertically integrated moisture flux convergence, among others, to compare atmospheric states and processes leading to such events in the models and observations. The results suggest that an analysis of atmospheric states supporting very heavy precipitation events is a more fruitful path for understanding and detecting changes than simply looking at precipitation itself.

Diagnostic fragment-ion-based and extension strategy coupled to DFIs intensity analysis for identification of chlorogenic acids isomers in Flos Lonicerae Japonicae by HPLC-ESI-MS(n).

PubMed

Zhang, Jia-Yu; Zhang, Qian; Li, Ning; Wang, Zi-Jian; Lu, Jian-Qiu; Qiao, Yan-Jiang

2013-01-30

A method of modified diagnostic fragment-ion-based extension strategy (DFIBES) coupled to DFIs (diagnostic fragmentation ions) intensity analysis was successfully established to simultaneously screen and identify the chlorogenic acids (CGAs) in Flos Lonicerae Japonicae (FLJ) by HPLC-ESI-MS(n). DFIs, such as m/z 191 [quinic acid-H](-), m/z 179 [caffeic acid-H](-) and m/z 173 [quinic acid-H-H2O](-) were determined or proposed from the fragmentation patterns analysis of corresponding reference substances for every chemical family of CGAs. A "structure extension" method was then proposed based on the well-demonstrated fragmentation patterns and was successively applied into the rapid screening of CGAs in FLJ. Considering that substitution isomerism is a common phenomenon, a full ESI-MS(n) fragmentation analysis according to the intensity of DFIs has been performed to identify the CGA isomers. Based on the DFIs and intensity analysis, 41 peaks attributed to CGAs including 4 caffeoylquinic acids (CQA), 7 CQA glycosides, 6 dicaffeoylquinic acids (DiCQA), 10 DiCQA glycosides, 1 tricaffeoylquinic acids (TriCQA), 4p-coumaroylquinic acids (pCoQA), 3 feruloylquinic acids (FQA) and 6 caffeoylferuloylquinic acids (CFQA) were identified preliminarily in a 65-min chromatographic run. It was the first time to systematically report the presence of CGAs in FLJ, especially for CQA glycosides, DiCQA glycosides, TriCQA, pCoQA and CFQA. All the results indicated that the method of developed DFIBES coupled to DFIs analysis was feasible, reliable and universal for screening and identifying the constituents with the same carbon skeletons especially the isomeric compounds from the complex extract of TCMs. Copyright © 2012 Elsevier B.V. All rights reserved.

Simultaneous acquisition of corrugator electromyography and functional magnetic resonance imaging: A new method for objectively measuring affect and neural activity concurrently

PubMed Central

Heller, Aaron S.; Greischar, Lawrence L; Honor, Ann; Anderle, Michael J; Davidson, Richard J.

2011-01-01

The development of functional neuroimaging of emotion holds the promise to enhance our understanding of the biological bases of affect and improve our knowledge of psychiatric diseases. However, up to this point, researchers have been unable to objectively, continuously and unobtrusively measure the intensity and dynamics of affect concurrently with functional magnetic resonance imaging (fMRI). This has hindered the development and generalizability of our field. Facial electromyography (EMG) is an objective, reliable, valid, sensitive, and unobtrusive measure of emotion. Here, we report the successful development of a method for simultaneously acquiring fMRI and facial EMG. The ability to simultaneously acquire brain activity and facial physiology will allow affective neuroscientists to address theoretical, psychiatric, and individual difference questions in a more rigorous and generalizable way. PMID:21742043

Structured-illumination reflectance imaging coupled with spiral phase transform for bruise detection and three-dimensional geometry reconstruction of apples

USDA-ARS?s Scientific Manuscript database

Structured-illumination reflectance imaging (SIRI) is a new, promising imaging technique with enhanced, versatile capabilities for quality evaluation of food products. SIRI enables simultaneous acquisition of higher-contrast/resolution and better depth-controlled intensity and phase images for detec...

An Ecological Study of Glee in Small Groups of Preschool Children

ERIC Educational Resources Information Center

Sherman, Lawrence W.

1975-01-01

Presents a description and analysis of group glee (joyful screaming, laughing and intense physical acts occurring in simultaneous bursts or in a contagious fashion), studied by means of videotapes of 596 formal lessons in a preschool. Information collected concerned occurrence, location, frequency and duration, teachers' responses, incidence of…

Reflex Augmentation of a Tap-Elicited Eyeblink: The Effects of Tone Frequency and Tap Intensity.

ERIC Educational Resources Information Center

Cohen, Michelle E.; And Others

1986-01-01

Describes two experiments that examined whether the amplitude of the human eyeblink by a mild tap between the eyebrows can be increased if a brief tone is presented simultaneously with the tap and how these effects change from newborn infants to adults. (HOD)

Influence of low light intensity and soil flooding on cacao physiology

USDA-ARS?s Scientific Manuscript database

Growth and development of plants frequently are limited by multiple abiotic stresses that occur simultaneously in the environment. Cabruca’ an agroforestry system is a main cropping system invariably adapted for cultivation of cacao in southern Bahia, Brazil. In this system of management cacao is gr...

Intense Terahertz Fields for Fast Energy Release

DTIC Science & Technology

2016-11-01

could allow us to monitor shock propagation in the sample and observe any effects of THz irradiation . In order to optimize the system, we moved a...the response and access for the THz light needed to simultaneously irradiate the sample. Preliminary measurements of sample responses to each of the

SIMULTANEOUS DETERMINATION OF ORGANOTIN, ORGANOLEAD, AND ORGANOMERCURY COMPOUNDS IN ENVIRONMENTAL SAMPLES USING CAPILLARY GAS CHROMATOGRAPHY WITH ATOMIC EMISSION DETECTION

EPA Science Inventory

As part of a continuing evaluation of new analytical and sample preparation techniques conducted by the US Environmental Protection Agency (EPA), the use of capillary gas chromatography with atomic emission detection (GC-AED) for the simultaneous determination of organotin, organ...

Simultaneous determination of estrogens and progestogens in honey using high performance liquid chromatography-tandem mass spectrometry

USDA-ARS?s Scientific Manuscript database

This work describes the development and validation of a method for the simultaneous determination of 13 estrogens and progestogens in honey by high performance liquid chromatography-tandem mass spectrometry. The target compounds were preconcentrated by solid phase extraction. Pretreatment variables ...

Decadal-scale relationship between measurements of aerosols, land-use change, and fire over Southeast Asia

NASA Astrophysics Data System (ADS)

Blake Cohen, Jason; Lecoeur, Eve; Loong Ng, Daniel Hui

2017-01-01

A simultaneous analysis of 13 years of remotely sensed data of land cover, fires, precipitation, and aerosols from the MODIS, TRMM, and MISR satellites and the AERONET network over Southeast Asia is performed, leading to a set of robust relationships between land-use change and fire being found on inter-annual and intra-annual scales over Southeast Asia, reflecting the heavy amounts of anthropogenic influence over land-use change and fires in this region of the world. First, we find that fires occur annually, but with a considerable amount of variance in their onset, duration, and intensity from year to year, and from two separate regions within Southeast Asia. Second, we show that a simple regression model of the land-cover, fire, and precipitation data can be used to recreate a robust representation of the timing and magnitude of measured aerosol optical depth (AOD) from multiple measurements sources of this region using either 8-day (better for onset and duration) or monthly (better for magnitude) measurements, but not daily measurements. We find that the reconstructed AOD matches the timing and intensity from AERONET measurements to within 70 to 90 % and the timing and intensity of MISR measurements to within 50 to 95 %. This is a unique finding in this part of the world since cloud-covered regions are large, yet the model is still robustly capable, including over regions where no fires are observed and hence no emissions would be expected to contribute to AOD. Third, we determine that while Southeast Asia is a source region of such intense smoke emissions, portions of it are also impacted by smoke transported from other regions. There are regions in northern Southeast Asia which have two annual AOD peaks, one during the local fire season and the other, smaller peak corresponding to a combination of some local smoke sources as well as transport of aerosols from fires in southern Southeast Asia and possibly even from anthropogenic sources in South Asia. Overall, this study highlights the importance of taking into account a simultaneous use of land-use, fire, and precipitation for understanding the impacts of fires on the atmospheric loading and distribution of aerosols in Southeast Asia over both space and time. Furthermore, it highlights that there are significant advantages of using 8-day and monthly average values (instead of daily data) in order to better quantify the magnitude and timing of Southeast Asia fires.

Endurance exercise intensity determination in the rehabilitation of coronary artery disease patients: a critical re-appraisal of current evidence.

PubMed

Hansen, Dominique; Stevens, An; Eijnde, Bert O; Dendale, Paul

2012-01-01

In the care of coronary artery disease (CAD) patients, the benefits of exercise therapy are generally established. Even though the selected endurance exercise intensity might affect medical safety, therapy adherence and effectiveness in the rehabilitation of CAD patients in how to determine endurance exercise intensity properly remains difficult. The aim of this review is to describe the available methods for endurance exercise intensity determination in the rehabilitation of CAD patients, accompanied with their (dis)advantages, validity and reproducibility. In general, endurance exercise intensity can objectively be determined in CAD patients by calculating a fraction of maximal exercise tolerance and/or determining ventilatory threshold after execution of a cardiopulmonary exercise test with ergospirometry. This can be translated to a corresponding training heart rate (HR) or workload. In the absence of ergospirometry equipment, target exercise HR can be calculated directly by different ways (fraction of maximal HR and/or Karvonen formula), and/or anaerobic threshold can be determined. However, the use of HR for determining exercise intensity during training sessions seems complicated, because many factors/conditions affect the HR. In this regard, proper standardization of the exercise sessions, as well as exercise testing, might be required to improve the accuracy of exercise intensity determination. Alternatively, subjective methods for the determination of endurance exercise intensity in CAD patients, such as the Borg ratings of perceived exertion and the talk test, have been developed. However, these methods lack proper validity and reliability to determine endurance exercise intensity in CAD patients. In conclusion, a practical and systematic approach for the determination of endurance exercise intensity in CAD patients is presented in this article.

Simultaneous mapping of the unsteady flow fields by Particle Displacement Velocimetry (PDV)

NASA Technical Reports Server (NTRS)

Huang, Thomas T.; Fry, David J.; Liu, Han-Lieh; Katz, Joseph; Fu, Thomas C.

1992-01-01

Current experimental and computational techniques must be improved in order to advance the prediction capability of the longitudinal vortical flows shed by underwater vehicles. The generation, development, and breakdown mechanisms of the shed vortices at high Reynolds numbers are not fully understood. The ability to measure hull separated vortices associated with vehicle maneuvering does not exist at present. The existing point-by-point measurement techniques can only capture approximately the large 'mean' eddies but fail to meet the dynamics of small vortices during the initial stage of generation. A new technique, which offers a previously unavailable capability to measure the unsteady cross-flow distribution in the plane of the laser light sheet, is called Particle Displacement Velocimetry (PDV). PDV consists of illuminating a thin section of the flowfield with a pulsed laser. The water is seeded with microscopic, neutrally buoyant particles containing imbedded fluorescing dye which responds with intense spontaneous fluorescence with the illuminated section. The seeded particles in the vortical flow structure shed by the underwater vehicle are illuminated by the pulse laser and the corresponding particle traces are recorded in a single photographic frame. Two distinct approaches were utilized for determining the velocity distribution from the particle traces. The first method is based on matching the traces of the same particle and measuring the distance between them. The direction of the flow can be identified by keeping one of the pulses longer than the other. The second method is based on selecting a small window within the image and finding the mean shift of all the particles within that region. The computation of the auto-correlation of the intensity distribution within the selected sample window is used to determine the mean displacement of particles. The direction of the flow is identified by varying the intensity of the laser light between pulses. Considerable computational resources are required to compute the auto-correction of the intensity distribution. Parallel processing will be employed to speed up the data reduction. A few examples of measured unsteady vortical flow structures shed by the underwater vehicles will be presented.

Three electron beams from a laser-plasma wakefield accelerator and the energy apportioning question

PubMed Central

Yang, X.; Brunetti, E.; Gil, D. Reboredo; Welsh, G. H.; Li, F. Y.; Cipiccia, S.; Ersfeld, B.; Grant, D. W.; Grant, P. A.; Islam, M. R.; Tooley, M. P.; Vieux, G.; Wiggins, S. M.; Sheng, Z. M.; Jaroszynski, D. A.

2017-01-01

Laser-wakefield accelerators are compact devices capable of delivering ultra-short electron bunches with pC-level charge and MeV-GeV energy by exploiting the ultra-high electric fields arising from the interaction of intense laser pulses with plasma. We show experimentally and through numerical simulations that a high-energy electron beam is produced simultaneously with two stable lower-energy beams that are ejected in oblique and counter-propagating directions, typically carrying off 5–10% of the initial laser energy. A MeV, 10s nC oblique beam is ejected in a 30°–60° hollow cone, which is filled with more energetic electrons determined by the injection dynamics. A nC-level, 100s keV backward-directed beam is mainly produced at the leading edge of the plasma column. We discuss the apportioning of absorbed laser energy amongst the three beams. Knowledge of the distribution of laser energy and electron beam charge, which determine the overall efficiency, is important for various applications of laser-wakefield accelerators, including the development of staged high-energy accelerators. PMID:28281679

Site-Selection in Single-Molecule Junction for Highly Reproducible Molecular Electronics.

PubMed

Kaneko, Satoshi; Murai, Daigo; Marqués-González, Santiago; Nakamura, Hisao; Komoto, Yuki; Fujii, Shintaro; Nishino, Tomoaki; Ikeda, Katsuyoshi; Tsukagoshi, Kazuhito; Kiguchi, Manabu

2016-02-03

Adsorption sites of molecules critically determine the electric/photonic properties and the stability of heterogeneous molecule-metal interfaces. Then, selectivity of adsorption site is essential for development of the fields including organic electronics, catalysis, and biology. However, due to current technical limitations, site-selectivity, i.e., precise determination of the molecular adsorption site, remains a major challenge because of difficulty in precise selection of meaningful one among the sites. We have succeeded the single site-selection at a single-molecule junction by performing newly developed hybrid technique: simultaneous characterization of surface enhanced Raman scattering (SERS) and current-voltage (I-V) measurements. The I-V response of 1,4-benzenedithiol junctions reveals the existence of three metastable states arising from different adsorption sites. Notably, correlated SERS measurements show selectivity toward one of the adsorption sites: "bridge sites". This site-selectivity represents an essential step toward the reliable integration of individual molecules on metallic surfaces. Furthermore, the hybrid spectro-electric technique reveals the dependence of the SERS intensity on the strength of the molecule-metal interaction, showing the interdependence between the optical and electronic properties in single-molecule junctions.

The Correlation of Tree Phenology with nest number of Orang Utan Sumatera (Pongo abelii) on Primary Forest, Resort Sei Betung, Gunung Leuser National Park

NASA Astrophysics Data System (ADS)

Hartini, K. S.; Patana, P.; Oktaviani, M.

2017-03-01

Food availability affect the orangutan activities, including activities to make nests. This study was conducted to determine the correlation between the phenology of trees with the number of nests made by orangutans in primary forest Resort Sei Betung, Gunung Leuser National Park. Multi linear regression was used in this study to determine the relation and correlation between phenology and the presence of orangutan nests on a track that has been created. It took over 6 months (March - August 2015). There were 15 orangutan nests found on the track during the study. The equation model was : = 27,649 -0,011X1-0,104X2-0,056X3, and there was no significant differences (sig >0,05). The value of R2 was 70,3%. It means that all predictors simultaneously explain 70,3% of the presence of orangutan’s nest, and there is an expected predictors that may be the most affect on nest presence. The season or the intensity of rain may consider as an expected predictor.

Limbic and prefrontal responses to facial emotion expressions in depersonalization.

PubMed

Lemche, Erwin; Surguladze, Simon A; Giampietro, Vincent P; Anilkumar, Ananthapadmanabha; Brammer, Michael J; Sierra, Mauricio; Chitnis, Xavier; Williams, Steven C R; Gasston, David; Joraschky, Peter; David, Anthony S; Phillips, Mary L

2007-03-26

Depersonalization disorder, characterized by emotional detachment, has been associated with increased prefrontal cortical and decreased autonomic activity to emotional stimuli. Event-related fMRI with simultaneous measurements of skin conductance levels occurred in nine depersonalization disorder patients and 12 normal controls to neutral, mild and intense happy and sad facial expressions. Patients, but not controls, showed decreases in subcortical limbic activity to increasingly intense happy and sad facial expressions, respectively. For both happy and sad expressions, negative correlations between skin conductance measures in bilateral dorsal prefrontal cortices occurred only in depersonalization disorder patients. Abnormal decreases in limbic activity to increasingly intense emotional expressions, and increases in dorsal prefrontal cortical activity to emotionally arousing stimuli may underlie the emotional detachment of depersonalization disorder.

Simultaneous determination of three major lignans in rat plasma by LC-MS/MS and its application to a pharmacokinetic study after oral administration of Diphylleia sinensis extract.

PubMed

Zhao, Chengliang; Zhang, Nan; He, Weiyan; Li, Rui; Shi, Dan; Pang, Li; Dong, Ning; Xu, Hong; Ji, Honglei

2014-04-01

A sensitive and selective liquid chromatography tandem mass spectrometry was developed and validated for the simultaneous determination of three major lignans (podophyllotoxin, epipodophyllotoxin, and 4'-demethylpodophyllotoxin) in rat plasma using diphenhydramine as the internal standard. The analytes were detected using a triple quadrupole mass spectrometer that was equipped with an electrospray ionization source in the positive ion and selected reaction monitoring modes. The linearity of the calibration curve was good, with coefficients of determination (r(2) ) >0.9914 for all of the analytes. The developed method was successfully applied for the simultaneous determination of the three lignans in rat plasma following oral administration of Diphylleia sinensis extract to rats. Copyright © 2013 John Wiley & Sons, Ltd.

[Simultaneous determination of five active constitutents in Xiaochaihu Tang by HPLC].

PubMed

Liu, Qingchun; Zhao, Junning; Yan, Liangchun; Yi, Jinhai; Song, Jun

2010-03-01

To establish a HPLC-PDA method for the determination of baicalin, wogonoside, baicalein, wogonin and glycyrrhizic acid in Xiaochaihu Tang. A Symmetry Shield RP18 (4.6 mm x 250 mm, 5.0 microm) was used with a mobile phase of acetonitrile-0.01% H3PO4 in gradient elution. The detection wavelength was 251 nm,the flow rate was 0.45 mL x min(-1) and the column temperature was maintained at 30 degrees C. The accuracy, precision, sensitivity, specificity and linearity of this method met the requirements. The contents of the five effective fractions were determined simultaneously. The method is rapid,simple and accurate and it can be suitable for the determination of baicalin, wogonoside, baicalein, wogonin and glycyrrhizic acid in Xiaochaihu Tang simultaneously.

Micro-hole array fluorescent sensor based on AC-Dielectrophoresis (DEP) for simultaneous analysis of nano-molecules

NASA Astrophysics Data System (ADS)

Kim, Hye Jin; Kang, Dong-Hoon; Lee, Eunji; Hwang, Kyo Seon; Shin, Hyun-Joon; Kim, Jinsik

2018-02-01

We propose a simple fluorescent bio-chip based on two types of alternative current-dielectrophoretic (AC-DEP) force, attractive (positive DEP) and repulsive (negative DEP) force, for simultaneous nano-molecules analysis. Various radius of micro-holes on the bio-chip are designed to apply the different AC-DEP forces, and the nano-molecules are concentrated inside the micro-hole arrays according to the intensity of the DEP force. The bio-chip was fabricated by Micro Electro Mechanical system (MEMS) technique, and was composed of two layers; a SiO2 layer and Ta/Pt layer were accomplished for an insulation layer and a top electrode with micro-hole arrays to apply electric fields for DEP force, respectively. Each SiO2 and Ta/Pt layers were deposited by thermal oxidation and sputtering, and micro-hole arrays were fabricated with Inductively Coupled Plasma (ICP) etching process. For generation of each positive and negative DEP at micro-holes, we applied two types of sine-wave AC voltage with different frequency range alternately. The intensity of the DEP force was controlled by the radius of the micro-hole and size of nano-molecule, and calculated with COMSOL multi-physics. Three types of nano-molecules labelled with different fluorescent dye were used and the intensity of nano-molecules was examined by the fluorescent optical analysis after applying the DEP force. By analyzing the fluorescent intensities of the nano-molecules, we verify the various nano-molecules in analyte are located successfully inside corresponding micro-holes with different radius according to their size.

Performance of JMA Earthquake Early Warning for the 2011 off the Pacific coast of Tohoku Earthquake (Mw9.0)

NASA Astrophysics Data System (ADS)

Hoshiba, M.; Wakayama, A.; Ishigaki, Y.; Doi, K.

2011-12-01

This presentation outlines the Earthquake Early Warning of the Japan Meteorological Agency (JMA) for the 2011 off the Pacific coast of Tohoku Earthquake (Mw9.0). EEW has been operational nationwide in Japan by JMA since October, 2007. For JMA EEW, the hypocenter is determined by a combination of several techniques, using approximately 1,100 stations from the JMA network and the Hi-net network of NIED; magnitude is mainly from maximum displacement amplitudes. JMA EEWs are updated as available data increases with elapsed time. Accordingly EEWs are issued repeatedly with improving accuracy for a single earthquake. JMA EEWs are divided into two grades depending on the expected intensities. The JMA intensity scale is based on instrumental measurements in which not only the amplitude but also the frequency and duration of the shaking are considered. The 10-degree JMA intensity scale rounds off the instrumental intensity value to the integer. Intensities of 5 and 6 are divided into two degrees, namely 5-lower, 5-upper, 6-lower and 6-upper, respectively. Intensity 1 corresponds to ground motion that people can barely detect, and 7 is the upper limit. JMA EEWs are announced to general public when intensity 5-lower (or greater) is expected. The JMA EEW system was triggered for the Mw 9.0 earthquake when station OURI (138km from the epicenter) detected the initial P wave at 14:46:40.2 (Japan Standard Time). The first EEW, the first of 15 announcements, was issued 5.4 s later. The waveform started with small amplitude, which was comparable to noise level for displacement. The small amplitude does not indicate that the initial rupture of the Mw 9.0 event is large, and does not suggest a large magnitude event. By the fourth EEW, 8.6 s after the first trigger, the expected intensity exceeded the criteria of the warning to the general public. JMA issued the fourth EEW announcements to the general public of the Tohoku district, and then the warning was automatically broadcast through TV, radios and cellular phone mails, which was before the strong ground motion hit cities. The EEW was earlier than the S wave arrival, and more than 15 s earlier than the strong ground motion (intensity 5-lower or greater) everywhere in the district. The EEW system expected intensity of 4 in the Tokyo region in the twelfth to fifteenth (final) issues. But actual observations reached 5-upper, which is greater than the criterion of the warning to the general public. The underestimation can be attributed to the large extent of the later fault rupture. For several weeks after the mainshock, when earthquakes sometimes occurred simultaneously over the wide source region, the system became confused, and did not always determine the location and magnitude correctly. In 49 days from the mainshock to April 28, 2011, 70 EEWs were announced to general public, but actual observed intensities did not exceed 2 at any observation stations in 17 of the 70 events.

Determination of ground and excited state dipole moments via electronic Stark spectroscopy: 5-methoxyindole

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

Wilke, Josefin; Wilke, Martin; Schmitt, Michael, E-mail: mschmitt@uni-duesseldorf.de

2016-01-28

The dipole moments of the ground and lowest electronically excited singlet state of 5-methoxyindole have been determined by means of optical Stark spectroscopy in a molecular beam. The resulting spectra arise from a superposition of different field configurations, one with the static electric field almost parallel to the polarization of the exciting laser radiation, the other nearly perpendicular. Each field configuration leads to different intensities in the rovibronic spectrum. With an automated evolutionary algorithm approach, the spectra can be fit and the ratio of both field configurations can be determined. A simultaneous fit of two spectra with both field configurationsmore » improved the precision of the dipole moment determination by a factor of two. We find a reduction of the absolute dipole moment from 1.59(3) D to 1.14(6) D upon electronic excitation to the lowest electronically excited singlet state. At the same time, the dipole moment orientation rotates by 54{sup ∘} showing the importance of the determination of the dipole moment components. The dipole moment in the electronic ground state can approximately be obtained from a vector addition of the indole and the methoxy group dipole moments. However, in the electronically excited state, vector addition completely fails to describe the observed dipole moment. Several reasons for this behavior are discussed.« less

Spatiotemporal dynamics of Gaussian laser pulse in a multi ions plasma

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

Jafari Milani, M. R., E-mail: mrj.milani@gmail.com

Spatiotemporal evolutions of Gaussian laser pulse propagating through a plasma with multiple charged ions are studied, taking into account the ponderomotive nonlinearity. Coupled differential equations for beam width and pulse length parameters are established and numerically solved using paraxial ray approximation. In one-dimensional geometry, effects of laser and plasma parameters such as laser intensity, plasma density, and temperature on the longitudinal pulse compression and the laser intensity distribution are analyzed for plasmas with singly and doubly charged ions. The results demonstrate that self-compression occurs in a laser intensity range with a turning point intensity in which the self-compression process hasmore » its strongest extent. The results also show that the multiply ionized ions have different effect on the pulse compression above and below turning point intensity. Finally, three-dimensional geometry is used to analyze the simultaneous evolution of both self-focusing and self-compression of Gaussian laser pulse in such plasmas.« less

Dynamics in the solar chromosphere as a function of the magnetic field topology

NASA Astrophysics Data System (ADS)

Karlsen, N.; Carlsson, M.

2002-06-01

We have looked at the coupling between the magnetic field and chromospheric dynamics. Observations with the SUMER spectrograph of the continuum radiation at 1319 Å have been correlated with simultaneous MDI magnetograms and dopplergrams in high resolution mode. We have used 7 different observing runs for our analysis, all from 1996. The absolute value of the magnetic field crossing the SUMER slit lies in the range 0-100 gauss. We observe a correlation between continuum intensity and magnetic field strength all the way to the sensitivity limit of MDI (about 2 G as 3σ in the mean value). Relative intensity fluctuations at frequencies corresponding to propagating acoustic waves (>4.5 mHz) have smaller amplitudes with increasing radiation temperature (or magnetic field strength). The absolute intensity fluctuations show an increase with increasing radiation temperature. These findings are consistent with a picture where a basic intensity level is set by a magnetic heating process even in the darkest internetwork areas with superimposed intensity variations caused by acoustic waves.

Simultaneous determination of zinc and chromate in cooling water by differential pulse polarography

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

Jindal, V.K.; Kham, M.A.; Bhatnagar, R.M.

1985-01-01

The use of differential pulse polarography (DPP) for the simultaneous determination of zinc and chromate in cooling water is reported where zinc (5 ppm), chromate (20 ppm), and polyphosphate (50 ppm) formulation is used as a corrosion inhibitor. This will help in effective control of cooling tower performance. The DPP method has been applied for the simultaneous determination of zinc and chromate ions in process and cooling water samples from fertilizer plants in India. The method is based on the reduction of Cr and Zn on SMDE in 1 M NH3-0.1 M NH/sub 4/Cl and 0.005% gelatine supporting electrolyte. Duemore » to interference it is essential to complex calcium ions by adding polyphosphate and to destroy NO/sub 2//sup -//NO/sub 3//sup -/ by adding sulfamic acid along with hydrochloric acid before the actual recording of DP polarograms. The present DP polarographic method for the simultaneous determination of zinc and chromate is comparable in its utility and applicability with spectrophotometric methods. The method has a better accuracy and higher sensitivity and is quick, as both of the ions can be determined in a single scan. 10 references, 4 figures, 5 tables.« less

Estimated intensity of the EMP from lightning discharges necessary for elves initiation based on balloon experiment

NASA Astrophysics Data System (ADS)

Kondo, S.; Yoshida, A.; Takahashi, Y.; Chikada, S.; Adachi, T.; Sakanoi, T.

2007-12-01

Transient optical phenomena in the mesosphere and lower ionosphere called transient luminous events (TLEs) have been investigated extensively since the first discovery in 1989. In the lower ionosphere, elves are generated by the electromagnetic pulses (EMPs) radiated from the intense lightning current. On the ground-based observation, cameras can not always identify the occurrence of elves because elves emission is sometimes reduced significantly by the atmosphere and blocked by clouds. Therefore, it has been difficult to determine the threshold of intensity of EMPs necessary for initiation of elves. We simultaneously carried out optical and sferics measurements for TLEs and lightning discharges using a high altitude balloon launched at Sanriku Balloon Center on the night of August 25 / 26 in 2006. We fixed four CCD cameras on the gondola, each of which had horizontal FOV of ~100 degree. They cover 360 degree in horizontal direction and imaged the TLEs without atmospheric extinction nor blocking by clouds. The frame rate is 30 fps. We installed three dipole antennas at the gondola, which received the vertical and horizontal electric fields radiated from lightning discharges. The frequency range of the VLF receiver is 1-25 kHz. We also make use of VLF sferics data obtained by ground-based antennas located at Tohoku University in Sendai. We picked up six elves from the image data set obtained by the CCD cameras, and examined the maximum amplitudes of the vertical electric field for 22 lightning discharge events including the six elves events observed both at the balloon and at Sendai. It is found that the maximum amplitudes of the vertical electric field in the five elves events are much larger than those in the other lightning events. We estimate the intensity of the radiated electric field necessary for elves. About one elves event, we don't see intense vertical electric field in the balloon data.

Line Positions and Intensities for the ν12 Band of 13C12CH_6

NASA Astrophysics Data System (ADS)

Devi, V. Malathy; Benner, D. Chris; Sung, Keeyoon; Crawford, Timothy J.; Mantz, Arlan; Smith, Mary Ann H.

2014-06-01

High-resolution, high signal-to-noise spectra of mono-substituted 13C-ethane (13C12CH_6) in the 12.2 μm region were recorded with a Bruker IFS 125HR Fourier transform spectrometer. The spectra were obtained for four sample pressures at three different temperatures between 130 and 208 K using a 99% 13C-enriched ethane sample contained in a 20.38-cm long coolable absorption cell. A multispectrum nonlinear least squares fitting technique was used to fit the same intervals in the four spectra simultaneously to determine line positions and intensities. Similar to our previous analyses of 12C_2H_6 spectra in this same region, constraints were applied to accurately fit each pair of doublet components arising from torsional Coriolis interaction of the excited ν12 = 1 state with the nearby torsional ν_6 = 3 state. Line intensities corresponding to each spectrum temperature (130 K, 178 K and 208 K) are reported for 1660 ν12 absorption lines for which the assignments are known, and integrated intensities are estimated as the summation of the measured values. The measured line positions and intensities (re-scaled to 296 K) are compared with values in recent editions of spectroscopic databases. K. Sung, A. W. Mantz, L. R. Brown, et al., J. Mol. Spectrosc., 162 (2010) 124-134. D. C. Benner, C. P. Rinsland, V. Malathy Devi, M. A. H. Smith and D. Atkins, JQSRT, 53 (1995) 705-721. V. Malathy Devi, C. P. Rinsland, D. Chris Benner, et al., JQSRT, 111 (2010) 1234-1251 V. Malathy Devi, D. Chris Benner, C. P. Rinsland, et al., JQSRT, 111 (2010) 2481-2504. Research described in this paper was performed at Connecticut College, the College of William and Mary, NASA Langley Research Center and the Jet Propulsion Laboratory, California Institute of Technology, under contracts and cooperative agreements with the National Aeronautics and Space Administration.

A proposed cell model for multiple-occurrence regional landslide events: Implications for landslide susceptibility mapping

NASA Astrophysics Data System (ADS)

Crozier, M. J.

2017-10-01

Multiple-occurrence regional landslide events (MORLEs) consist of hundreds to thousands of shallow landslides occurring more or less simultaneously within defined areas, ranging from tens to thousands of square kilometres. While MORLEs can be triggered by rainstorms and earthquakes, this paper is confined to those landslide events triggered by rainstorms. Globally, MORLEs occur in a range of geological settings in areas of moderate to steep slopes subject to intense rainstorms. Individual landslides in rainstorm-triggered events are dominantly small, shallow debris and earth flows, and debris and earth slides involving regolith or weathered bedrock. The model used to characterise these events assumes that energy distribution within the event area is represented on the land surface by a cell structure; with maximum energy expenditure within an identifiable core and rapid dissipation concentrically away from the centre. The version of the model presented here has been developed for rainfall-triggered landslide events. It proposes that rainfall intensity can be used to determine different critical landslide response zones within the cell (referred to as core, middle, and periphery zones). These zones are most readily distinguished by two conditions: the proportion of the slope that fails and the particular type of the slope stability factor that assumes dominance in determining specific sites of landslide occurrence. The latter condition means that the power of any slope stability factor to distinguish between stable and unstable sites varies throughout the affected area in accordance with the landslide response zones within the cell; certain factors critical for determining the location of landslide sites in one part of the event area have little influence in other parts of the event area. The implication is that landslide susceptibility maps (and subsequently derived mitigation measures) based on conventional slope stability factors may have only limited validity for many events. The overall ability to predict the impact of these events and consequently the development of effective mitigation measures is limited by the ability to predict the travel path, storm centre, and intensity range within the cell structure of extreme weather systems.

Reprint of "A proposed cell model for multiple-occurrence regional landslide events: Implications for landslide susceptibility mapping"

NASA Astrophysics Data System (ADS)

Crozier, M. J.

2018-04-01

Multiple-occurrence regional landslide events (MORLEs) consist of hundreds to thousands of shallow landslides occurring more or less simultaneously within defined areas, ranging from tens to thousands of square kilometres. While MORLEs can be triggered by rainstorms and earthquakes, this paper is confined to those landslide events triggered by rainstorms. Globally, MORLEs occur in a range of geological settings in areas of moderate to steep slopes subject to intense rainstorms. Individual landslides in rainstorm-triggered events are dominantly small, shallow debris and earth flows, and debris and earth slides involving regolith or weathered bedrock. The model used to characterise these events assumes that energy distribution within the event area is represented on the land surface by a cell structure; with maximum energy expenditure within an identifiable core and rapid dissipation concentrically away from the centre. The version of the model presented here has been developed for rainfall-triggered landslide events. It proposes that rainfall intensity can be used to determine different critical landslide response zones within the cell (referred to as core, middle, and periphery zones). These zones are most readily distinguished by two conditions: the proportion of the slope that fails and the particular type of the slope stability factor that assumes dominance in determining specific sites of landslide occurrence. The latter condition means that the power of any slope stability factor to distinguish between stable and unstable sites varies throughout the affected area in accordance with the landslide response zones within the cell; certain factors critical for determining the location of landslide sites in one part of the event area have little influence in other parts of the event area. The implication is that landslide susceptibility maps (and subsequently derived mitigation measures) based on conventional slope stability factors may have only limited validity for many events. The overall ability to predict the impact of these events and consequently the development of effective mitigation measures is limited by the ability to predict the travel path, storm centre, and intensity range within the cell structure of extreme weather systems.

Velocity changes, long runs, and reversals in the Chromatium minus swimming response.

PubMed Central

Mitchell, J G; Martinez-Alonso, M; Lalucat, J; Esteve, I; Brown, S

1991-01-01

The velocity, run time, path curvature, and reorientation angle of Chromatium minus were measured as a function of light intensity, temperature, viscosity, osmotic pressure, and hydrogen sulfide concentration. C. minus changed both velocity and run time. Velocity decreased with increasing light intensity in sulfide-depleted cultures and increased in sulfide-replete cultures. The addition of sulfide to cultures grown at low light intensity (10 microeinsteins m-2 s-1) caused mean run times to increase from 10.5 to 20.6 s. The addition of sulfide to cultures grown at high light intensity (100 microeinsteins m-2 s-1) caused mean run times to decrease from 15.3 to 7.7 s. These changes were maintained for up to an hour and indicate that at least some members of the family Chromatiaceae simultaneously modulate velocity and turning frequency for extended periods as part of normal taxis. Images PMID:1991736

Direct observations of low-energy solar electrons associated with a type 3 solar radio burst

NASA Technical Reports Server (NTRS)

Frank, L. A.; Gurnett, D. A.

1972-01-01

On 6 April 1971 a solar X-ray flare and a type 3 solar radio noise burst were observed with instrumentation on the eccentric-orbiting satellite IMP 6. The type 3 solar radio noise burst was detected down to a frequency of 31 kHz. A highly anisotropic packet of low-energy solar electron intensities arrived at the satellite approximately 6000 seconds after the onset of the solar flare. This packet of solar electron intensities was observed for 4200 seconds. Maximum differential intensities of the solar electrons were in the energy range of one to several keV. The frequency drift rate of the type 3 radio noise at frequencies below 178 kHz also indicated an average particle speed corresponding to that of a 3-keV electron. The simultaneous observations of these solar electron intensities and of the type 3 solar radio burst are presented, and their interrelationships are explored.

Positive affect and cognitive control: approach-motivation intensity influences the balance between cognitive flexibility and stability.

PubMed

Liu, Ya; Wang, Zhenhong

2014-05-01

In most prior research, positive affect has been consistently found to promote cognitive flexibility. However, the motivational dimensional model of affect assumes that the influence of positive affect on cognitive processes is modulated by approach-motivation intensity. In the present study, we extended the motivational dimensional model to the domain of cognitive control by examining the effect of low- versus high-approach-motivated positive affect on the balance between cognitive flexibility and stability in an attentional-set-shifting paradigm. Results showed that low-approach-motivated positive affect promoted cognitive flexibility but also caused higher distractibility, whereas high-approach-motivated positive affect enhanced perseverance but simultaneously reduced distractibility. These results suggest that the balance between cognitive flexibility and stability is modulated by the approach-motivation intensity of positive affective states. Therefore, it is essential to incorporate motivational intensity into studies on the influence of affect on cognitive control.

Simultaneous determination of natural-abundance δ15N values and quantities of individual amino acids in proteins from milk of lactating women and from infant hair using gas chromatography/isotope ratio mass spectrometry.

PubMed

Tea, Illa; Le Guennec, Adrien; Frasquet-Darrieux, Marine; Julien, Maxime; Romek, Katarzyna; Antheaume, Ingrid; Hankard, Régis; Robins, Richard J

2013-06-30

In isotope tracer experiments used in nutritional studies, it is frequently desirable both to determine the (15)N/(14)N ratios of target compounds and to quantify these compounds. This report shows how this can be achieved in a single chromatographic run for protein amino acids using an isotope ratio mass spectrometer. Protein hydrolysis by acidic digestion was used to release amino acids, which were then derivatized as their N-pivaloyl-O-isopropyl esters. Suitable conditions for sample preparation were established for both hair and milk proteins. The N-pivaloyl-O-isopropyl esters of amino acids were separated by gas chromatography (GC) on a 60 m ZB-WAX column linked via a combustion interface to an isotope ratio mass spectrometer. The (15)N/(14)N ratios were obtained from the m/z 28, 29 and 30 peak intensities and the quantities from the Area All (Vs) integrated peak areas. It is shown from a five-point calibration curve that both parameters can be measured reliably within the range of 1.0 to 2.0 mg/mL for the major amino acids derived from the hydrolysis of human maternal milk or hair samples. The method was validated in terms of inter-day and inter-user repeatability for both parameters for 14 amino acids. The amino acid percentage composition showed a good correlation with literature values. The method was applied to determine the variability in a population of lactating mothers and their infants. It has been established that δ(15)N values can be simultaneously determined for a complex mixture of amino acids at variable concentrations. It is shown that the percentage composition obtained correlates well with that obtained by calculation from the protein composition or from literature values. This procedure should provide a significant saving in analysis time, especially in those cases where the GC run-time is necessarily long. It allows the satisfactory determination of the variation within a sample population. Copyright © 2013 John Wiley & Sons, Ltd.

Plasmonic fiber-optic vector magnetometer

NASA Astrophysics Data System (ADS)

Zhang, Zhaochuan; Guo, Tuan; Zhang, Xuejun; Xu, Jian; Xie, Wenping; Nie, Ming; Wu, Qiang; Guan, Bai-Ou; Albert, Jacques

2016-03-01

A compact fiber-optic vector magnetometer based on directional scattering between polarized plasmon waves and ferro-magnetic nanoparticles is demonstrated. The sensor configuration reported in this work uses a short section of tilted fiber Bragg grating (TFBG) coated with a nanometer scale gold film and packaged with a magnetic fluid (Fe3O4) inside a capillary. The transmission spectrum of the sensor provides a fine comb of narrowband resonances that overlap with a broader absorption of the surface plasmon resonance (SPR). The wavelength of the SPR attenuation in transmission shows high sensitivity to slight perturbations by magnetic fields, due to the strong directional scattering between the SPR attenuated cladding modes and the magnetic fluid near the fiber surface. Both the orientation (2 nm/deg) and the intensity (1.8 nm/mT) of magnetic fields can be determined unambiguously from the TFBG spectrum. Temperature cross sensitivity can be referenced out by monitoring the wavelength of the core mode resonance simultaneously.

Three-dimensional motion measurements of free-swimming microorganisms using digital holographic microscopy

NASA Astrophysics Data System (ADS)

Lee, Sang Joon; Seo, Kyung Won; Choi, Yong Seok; Sohn, Myong Hwan

2011-06-01

A digital holographic microscope is employed to measure the 3D motion of free-swimming microorganisms. The focus function used to quantify image sharpness provides a better depth-directional accuracy with a smaller depth-of-focus compared with the intensity method in determining the depth-directional position of spherical particles of various diameters. The focus function is then applied to measure the 3D positions of free-swimming microorganisms, namely dinoflagellates C. polykrikoides and P. minimum. Both automatic segmentation and proper selection of a focus function for a selected segment are important processes in measuring the positional information of two free-swimming microorganisms of different shapes with various width-to-length ratios. The digital holographic microscopy technique improved in this work is useful for measuring 3D swimming trajectories, velocities and attitudes of hundreds of microorganisms simultaneously. It also exhibits exceptional depth-directional accuracy.

PORTR: Pre-Operative and Post-Recurrence Brain Tumor Registration

PubMed Central

Niethammer, Marc; Akbari, Hamed; Bilello, Michel; Davatzikos, Christos; Pohl, Kilian M.

2014-01-01

We propose a new method for deformable registration of pre-operative and post-recurrence brain MR scans of glioma patients. Performing this type of intra-subject registration is challenging as tumor, resection, recurrence, and edema cause large deformations, missing correspondences, and inconsistent intensity profiles between the scans. To address this challenging task, our method, called PORTR, explicitly accounts for pathological information. It segments tumor, resection cavity, and recurrence based on models specific to each scan. PORTR then uses the resulting maps to exclude pathological regions from the image-based correspondence term while simultaneously measuring the overlap between the aligned tumor and resection cavity. Embedded into a symmetric registration framework, we determine the optimal solution by taking advantage of both discrete and continuous search methods. We apply our method to scans of 24 glioma patients. Both quantitative and qualitative analysis of the results clearly show that our method is superior to other state-of-the-art approaches. PMID:24595340

Interplanetary baseline observations of type 3 solar radio bursts. [by Helios satellites

NASA Technical Reports Server (NTRS)

Weber, R. R.; Fitzenreiter, R. J.; Novaco, J. C.; Fainberg, J.

1977-01-01

Simultaneous observations of type III radio bursts using spacecraft separated by several tenths of an AU were made using the solar orbiters HELIOS-A and -B. The burst beginning at 1922 UT on March 28, 1976, was located from the intersection of the source directions measured at each spacecraft, and from the burst arrival time differences. Wide baseline observations give the radial distance of the source at each observing frequency. Consequently, coronal electron densities and exciter velocity were determined directly, without the need to assume a density model as is done with single spacecraft observations. The separation of HELIOS-A and -B also provided the first measurements of burst directivity at low frequencies. For the March 28 burst, the intensity observed from near the source longitude (HELIOS-B) was significantly greater than from 60 W of the source (HELIOS-A).

Intelligent cooperation: A framework of pedagogic practice in the operating room.

PubMed

Sutkin, Gary; Littleton, Eliza B; Kanter, Steven L

2018-04-01

Surgeons who work with trainees must address their learning needs without compromising patient safety. We used a constructivist grounded theory approach to examine videos of five teaching surgeries. Attending surgeons were interviewed afterward while watching cued videos of their cases. Codes were iteratively refined into major themes, and then constructed into a larger framework. We present a novel framework, Intelligent Cooperation, which accounts for the highly adaptive, iterative features of surgical teaching in the operating room. Specifically, we define Intelligent Cooperation as a sequence of coordinated exchanges between attending and trainee that accomplishes small surgical steps while simultaneously uncovering the trainee's learning needs. Intelligent Cooperation requires the attending to accurately determine learning needs, perform real-time needs assessment, provide critical scaffolding, and work with the learner to accomplish the next step in the surgery. This is achieved through intense, coordinated verbal and physical cooperation. Copyright © 2017 Elsevier Inc. All rights reserved.

Protein mass analysis of histones.

PubMed

Galasinski, Scott C; Resing, Katheryn A; Ahn, Natalie G

2003-09-01

Posttranslational modification of chromatin-associated proteins, including histones and high-mobility-group (HMG) proteins, provides an important mechanism to control gene expression, genome integrity, and epigenetic inheritance. Protein mass analysis provides a rapid and unbiased approach to monitor multiple chemical modifications on individual molecules. This review describes methods for acid extraction of histones and HMG proteins, followed by separation by reverse-phase chromatography coupled to electrospray ionization mass spectrometry (LC/ESI-MS). Posttranslational modifications are detected by analysis of full-length protein masses. Confirmation of protein identity and modification state is obtained through enzymatic digestion and peptide sequencing by MS/MS. For differentially modified forms of each protein, the measured intensities are semiquantitative and allow determination of relative abundance and stoichiometry. The method simultaneously detects covalent modifications on multiple proteins and provides a facile assay for comparing chromatin modification states between different cell types and/or cellular responses.

Representation of radiative strength functions within a practical model of cascade gamma decay

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

Vu, D. C., E-mail: vuconghnue@gmail.com; Sukhovoj, A. M., E-mail: suchovoj@nf.jinr.ru; Mitsyna, L. V., E-mail: mitsyna@nf.jinr.ru

A practical model developed at the Joint Institute for Nuclear Research (JINR, Dubna) in order to describe the cascade gamma decay of neutron resonances makes it possible to determine simultaneously, from an approximation of the intensities of two-step cascades, parameters of nuclear level densities and partial widths with respect to the emission of nuclear-reaction products. The number of the phenomenological ideas used isminimized in themodel version considered in the present study. An analysis of new results confirms what was obtained earlier for the dependence of dynamics of the interaction of fermion and boson nuclear states on the nuclear shape. Frommore » the ratio of the level densities for excitations of the vibrational and quasiparticle types, it also follows that this interaction manifests itself in the region around the neutron binding energy and is probably different in nuclei that have different parities of nucleons.« less

Quantifying liquid boundary and vapor distributions in a fuel spray by rainbow schlieren deflectometry.

PubMed

Taber Wanstall, C; Agrawal, Ajay K; Bittle, Joshua A

2017-10-20

The rainbow schlieren deflectometry (RSD) technique is used to determine the liquid boundary and the fuel volume fraction distributions in the vapor region of a high-pressure fuel spray. Experiments were conducted in a constant pressure flow vessel, whereby a customized single-hole common-rail diesel injector is used to introduce n-heptane fuel into a coflow of low-speed ambient air at two different test conditions. Only the quasi-steady period of the fuel spray is considered, and multiple injections are performed to acquire statistically significant data at an image acquisition rate of 20 kHz. An algorithm to identify the liquid boundary using intensity recorded by the RSD images is presented. The results are compared against measurements obtained by the Mie scattering technique. Results demonstrate that the RSD can be a powerful optical diagnostics technique to simultaneously quantify both the vapor and liquid regions in the high-pressure fuel sprays.

Dust grain resonant capture: A statistical study

NASA Technical Reports Server (NTRS)

Marzari, F.; Vanzani, V.; Weidenschilling, S. J.

1993-01-01

A statistical approach, based on a large number of simultaneous numerical integrations, is adopted to study the capture in external mean motion resonances with the Earth of micron size dust grains perturbed by solar radiation and wind forces. We explore the dependence of the resonant capture phenomenon on the initial eccentricity e(sub 0) and perihelion argument w(sub 0) of the dust particle orbit. The intensity of both the resonant and dissipative (Poynting-Robertson and wind drag) perturbations strongly depends on the eccentricity of the particle while the perihelion argument determines, for low inclination, the mutual geometrical configuration of the particle's orbit with respect to the Earth's orbit. We present results for three j:j+1 commensurabilities (2:3, 4:5 and 6:7) and also for particle sizes s = 15, 30 microns. This study extends our previous work on the long term orbital evolution of single dust particles trapped into resonances with the Earth.

Influence of auditory fatigue on masked speech intelligibility

NASA Technical Reports Server (NTRS)

Parker, D. E.; Martens, W. L.; Johnston, P. A.

1980-01-01

Intelligibility of PB word lists embedded in simultaneous masking noise was evaluated before and after fatiguing-noise exposure, which was determined by observing the number of words correctly repeated during a shadowing task. Both the speech signal and the masking noise were filtered to a 2825-3185-Hz band. Masking-noise leves were varied from 0- to 90-dB SL. Fatigue was produced by a 1500-3000-Hz octave band of noise at 115 dB (re 20 micron-Pa) presented continuously for 5 min. The results of three experiments indicated that speed intelligibility was reduced when the speech was presented against a background of silence but that the fatiguing-noise exposure had no effect on intelligibility when the speech was made more intense and embedded in masking noise of 40-90-dB SL. These observations are interpreted by considering the recruitment produced by fatigue and masking noise.

Early Detection of Salt Stress Damage by Biophotons in Red Bean Seedling

NASA Astrophysics Data System (ADS)

Ohya, Tomoyuki; Kurashige, Hideaki; Okabe, Hirotaka; Kai, Shoichi

2000-06-01

The optical detection of the stress damage to plants by NaCl solutions was attempted during germination of a seed and growth of a root. We compared the photon intensity of red beans before and after NaCl treatment and found that the photon intensity after NaCl treatment decreased as the NaCl concentration increased. For the saturated NaCl concentration (4.5 M), however, the observed photon intensity drastically increased, and the simultaneous destruction of cell membranes was observed. The intensity of biophoton emission from red beans showed characteristic change with salt concentrations. When the salt stress was applied to the red beans at an early growth stage, their root elongations were suppressed and photon intensity from the root decreased. This was not the case for the root at the late stage. This shows that biophoton intensity due to salt stress depends on not only NaCl concentration but also the growth stage of the plant. We may conclude that the extent of damage to roots by salt stress can be evaluated from biophoton response.

Development of conductometric biosensor array for simultaneous determination of maltose, lactose, sucrose and glucose.

PubMed

Soldatkin, O O; Peshkova, V M; Saiapina, O Y; Kucherenko, I S; Dudchenko, O Y; Melnyk, V G; Vasylenko, O D; Semenycheva, L M; Soldatkin, A P; Dzyadevych, S V

2013-10-15

The aim of this work was to develop an array of biosensors for simultaneous determination of four carbohydrates in solution. Several enzyme systems selective to lactose, maltose, sucrose and glucose were immobilised on the surface of four conductometric transducers and served as bio-recognition elements of the biosensor array. Direct enzyme analysis carried out by the developed biosensors was highly sensitive to the corresponding substrates. The analysis lasted 2 min. The dynamic range of substrate determination extended from 0.001 mM to 1.0-3.0mM, and strongly depended on the enzyme system used. An effect of the solution pH, ionic strength and buffer capacity on the biosensors responses was investigated; the conditions of simultaneous operation of all biosensors were optimised. The data on cross-impact of the substrates of all biosensors were obtained; the biosensor selectivity towards possible interfering carbohydrates was tested. The developed biosensor array showed good signal reproducibility and storage stability. The biosensor array is suited for simultaneous, quick, simple, and selective determination of maltose, lactose, sucrose and glucose. © 2013 Elsevier B.V. All rights reserved.

Development and validation of simple spectrophotometric and chemometric methods for simultaneous determination of empagliflozin and metformin: Applied to recently approved pharmaceutical formulation

NASA Astrophysics Data System (ADS)

Ayoub, Bassam M.

2016-11-01

New univariate spectrophotometric method and multivariate chemometric approach were developed and compared for simultaneous determination of empagliflozin and metformin manipulating their zero order absorption spectra with application on their pharmaceutical preparation. Sample enrichment technique was used to increase concentration of empagliflozin after extraction from tablets to allow its simultaneous determination with metformin without prior separation. Validation parameters according to ICH guidelines were satisfactory over the concentration range of 2-12 μg mL- 1 for both drugs using simultaneous equation with LOD values equal to 0.20 μg mL- 1 and 0.19 μg mL- 1, LOQ values equal to 0.59 μg mL- 1 and 0.58 μg mL- 1 for empagliflozin and metformin, respectively. While the optimum results for the chemometric approach using partial least squares method (PLS-2) were obtained using concentration range of 2-10 μg mL- 1. The optimized validated methods are suitable for quality control laboratories enable fast and economic determination of the recently approved pharmaceutical combination Synjardy® tablets.

The H-alpha/H-beta ratio in solar flares

NASA Technical Reports Server (NTRS)

Zirin, H.; Liggett, M.; Patterson, A.

1982-01-01

The present investigation involves the study of an extensive body of data accumulated of simultaneous H-alpha and H-beta cinematography of flares. The data were obtained with two telescopes simultaneously photographing flares in H-alpha and H-beta. The results of measurements in a number of flares are presented in a table. The flares were selected purely by optical quality of the data. That the measured ratios are not too different from those in stellar flares is suggested by the last two columns of the table. These columns show that a variety of possible line width ratios could give an integrated intensity ratio of less than unity.

Simultaneous detection of folic acid and methotrexate by an optical sensor based on molecularly imprinted polymers on dual-color CdTe quantum dots.

PubMed

Ensafi, Ali A; Nasr-Esfahani, Parisa; Rezaei, B

2017-12-15

In this work, molecularly imprinted polymers (MIPs) were used on the surface of cadmium telluride quantum dots (CdTe QDs) for the simultaneous determination of folic acid (FA) and methotrexate (MTX). For this purpose, two different sizes of CdTe QDs with emission peaks in the yellow (QD Y ) and orange (QD O ) spectral regions were initially synthesized and capped with MIPs. FA and MTX were used as templates for the synthesis of the two composites and designated as QD Y -MIPs and QD O -MIPs, respectively. Fourier transform infrared spectroscopy, transmission electron microscopy, and fluorescence spectroscopy were employed to characterize the composites. QD Y -MIPs and QD O -MIPs were then mixed (to form QDs-MIPs) and excited at identical excitation wavelengths; they emitted two different emission wavelengths without any spectral overlap. The fluorescence signals of QD Y -MIPs and QD O -MIPs diminished in intensity with increasing concentration of the corresponding template molecules. Under optimal conditions, the dynamic range was 0.5-20 μmol L -1 for FA and MTX, and the detection limits for FA and MTX were 32.0 nmol L -1 and 34.0 nmol L -1 , respectively. The reproducibility of the method was checked for 12.5 μmol L -1 of FA and MTX to find RSD values of 4.2% and 6.3%, respectively. Finally, the applicability of the method was checked using human blood plasma samples. Results indicated the successful application of the method as a fluorescent probe for the rapid and simultaneous detection of FA and MTX in real samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Emission Patterns of Solar Type III Radio Bursts: Stereoscopic Observations

NASA Technical Reports Server (NTRS)

Thejappa, G.; MacDowall, R.; Bergamo, M.

2012-01-01

Simultaneous observations of solar type III radio bursts obtained by the STEREO A, B, and WIND spacecraft at low frequencies from different vantage points in the ecliptic plane are used to determine their directivity. The heliolongitudes of the sources of these bursts, estimated at different frequencies by assuming that they are located on the Parker spiral magnetic field lines emerging from the associated active regions into the spherically symmetric solar atmosphere, and the heliolongitudes of the spacecraft are used to estimate the viewing angle, which is the angle between the direction of the magnetic field at the source and the line connecting the source to the spacecraft. The normalized peak intensities at each spacecraft Rj = Ij /[Sigma]Ij (the subscript j corresponds to the spacecraft STEREO A, B, and WIND), which are defined as the directivity factors are determined using the time profiles of the type III bursts. It is shown that the distribution of the viewing angles divides the type III bursts into: (1) bursts emitting into a very narrow cone centered around the tangent to the magnetic field with angular width of approximately 2 deg and (2) bursts emitting into a wider cone with angular width spanning from [approx] -100 deg to approximately 100 deg. The plots of the directivity factors versus the viewing angles of the sources from all three spacecraft indicate that the type III emissions are very intense along the tangent to the spiral magnetic field lines at the source, and steadily fall as the viewing angles increase to higher values. The comparison of these emission patterns with the computed distributions of the ray trajectories indicate that the intense bursts visible in a narrow range of angles around the magnetic field directions probably are emitted in the fundamental mode, whereas the relatively weaker bursts visible to a wide range of angles are probably emitted in the harmonic mode.

A search for optical counterparts of gamma-ray bursts. Final report

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

Park, Hye-Sook

Gamma Ray Bursts (GRBS) are mysterious flashes of gamma rays lasting several tens to hundreds of seconds that occur approximately once per day. NASA launched the orbiting Compton Gamma Ray Observatory to study GRBs and other gamma ray phenomena. CGRO carries the Burst and Transient Experiment (BATSE) specifically to study GRBS. Although BATSE has collected data on over 600 GRBS, and confirmed that GRBs are localized, high intensity point sources of MeV gamma rays distributed isotropically in the sky, the nature and origin of GRBs remains a fundamental problem in astrophysics. BATSE`s 8 gamma ray sensors located on the comersmore » of the box shaped CGRO can detect the onset of GRBs and record their intensity and energy spectra as a function of time. The position of the burst on the sky can be determined to < {plus_minus}10{degrees} from the BATSE data stream. This position resolution is not sufficient to point a large, optical telescope at the exact position of a GRB which would determine its origin by associating it with a star. Because of their brief duration it is not known if GRBs are accompanied by visible radiation. Their seemingly large energy output suggests thatthis should be. Simply scaling the ratio of visible to gamma ray intensities of the Crab Nebula to the GRB output suggests that GRBs ought to be accompanied by visible flashes of magnitude 10 or so. A few photographs of areas containing a burst location that were coincidentally taken during the burst yield lower limits on visible output of magnitude 4. The detection of visible light during the GRB would provide information on burst physics, provide improved pointing coordinates for precise examination of the field by large telescope and provide the justification for larger dedicated optical counterpart instruments. The purpose of this experiment is to detect or set lower limits on optical counterpart radiation simultaneously accompanying the gamma rays from« less

Pilot assessment of soil-transmitted helminthiasis in the context of transmission assessment surveys for lymphatic filariasis in Benin and Tonga.

PubMed

Chu, Brian K; Gass, Katherine; Batcho, Wilfrid; 'Ake, Malakai; Dorkenoo, Améyo M; Adjinacou, Elvire; Mafi, 'Eva; Addiss, David G

2014-02-01

Mass drug administration (MDA) for lymphatic filariasis (LF) programs has delivered more than 2 billion treatments of albendazole, in combination with either ivermectin or diethylcarbamazine, to communities co-endemic for soil-transmitted helminthiasis (STH), reducing the prevalence of both diseases. A transmission assessment survey (TAS) is recommended to determine if MDA for LF can be stopped within an evaluation unit (EU) after at least five rounds of annual treatment. The TAS also provides an opportunity to simultaneously assess the impact of these MDAs on STH and to determine the frequency of school-based MDA for STH after community-wide MDA is no longer needed for LF. Pilot studies conducted in Benin and Tonga assessed the feasibility of a coordinated approach. Of the schools (clusters) selected for a TAS in each EU, a subset of 5 schools per STH ecological zone was randomly selected, according to World Health Organization (WHO) guidelines, for the coordinated survey. In Benin, 519 children were sampled in 5 schools and 22 (4.2%) had STH infection (A. lumbricoides, T. trichiura, or hookworm) detected using the Kato-Katz method. All infections were classified as light intensity under WHO criteria. In Tonga, 10 schools were chosen for the coordinated TAS and STH survey covering two ecological zones; 32 of 232 (13.8%) children were infected in Tongatapu and 82 of 320 (25.6%) in Vava'u and Ha'apai. All infections were light-intensity with the exception of one with moderate-intensity T. trichiura. Synchronous assessment of STH with TAS is feasible and provides a well-timed evaluation of infection prevalence to guide ongoing treatment decisions at a time when MDA for LF may be stopped. The coordinated field experiences in both countries also suggest potential time and cost savings. Refinement of a coordinated TAS and STH sampling methodology should be pursued, along with further validation of alternative quantitative diagnostic tests for STH that can be used with preserved stool specimens.

Effects of a prior high-intensity knee-extension exercise on muscle recruitment and energy cost: a combined local and global investigation in humans.

PubMed

Layec, Gwenael; Bringard, Aurélien; Le Fur, Yann; Vilmen, Christophe; Micallef, Jean-Paul; Perrey, Stéphane; Cozzone, Patrick J; Bendahan, David

2009-06-01

The effects of a priming exercise bout on both muscle energy production and the pattern of muscle fibre recruitment during a subsequent exercise bout are poorly understood. The purpose of the present study was to determine whether a prior exercise bout which is known to increase O(2) supply and to induce a residual acidosis could alter energy cost and muscle fibre recruitment during a subsequent heavy-intensity knee-extension exercise. Fifteen healthy subjects performed two 6 min bouts of heavy exercise separated by a 6 min resting period. Rates of oxidative and anaerobic ATP production, determined with (31)P-magnetic resonance spectroscopy, and breath-by-breath measurements of pulmonary oxygen uptake were obtained simultaneously. Changes in muscle oxygenation and muscle fibre recruitment occurring within the quadriceps were measured using near-infrared spectroscopy and surface electromyography. The priming heavy-intensity exercise increased motor unit recruitment (P < 0.05) in the early part of the subsequent exercise bout but did not alter muscle energy cost. We also observed a reduced deoxygenation time delay, whereas the deoxygenation amplitude was increased (P < 0.01). These changes were associated with an increased oxidative ATP cost after approximately 50 s (P < 0.05) and a slight reduction in the overall anaerobic rate of ATP production (0.11 +/- 0.04 mM min(-1) W(-1) for bout 1 and 0.06 +/- 0.11 mM min(-1) W(-1) for bout 2; P < 0.05). We showed that a priming bout of heavy exercise led to an increased recruitment of motor units in the early part of the second bout of heavy exercise. Considering the increased oxidative cost and the unaltered energy cost, one could suggest that our results illustrate a reduced metabolic strain per fibre.

A photoelectric skylight polarimeter.

PubMed

Hariharan, T A; Sekera, Z

1966-09-01

A photoelectric skylight polarimeter to measure directly the Stokes parameters for plane polarized light is described. The basic principle of the instrument consists in the simultaneous measurement of the intensity of light (in the chosen spectral region) transmitted by polarizers oriented in four specific directions. The main features and performance characteristics of the instrument are briefly discussed.

Addressing Three Common Issues in Research on Youth Activities: An Integrative Approach for Operationalizing and Analyzing Involvement

ERIC Educational Resources Information Center

Busseri, Michael A.; Rose-Krasnor, Linda

2010-01-01

Youth activity involvement has been operationalized and analyzed using a wide range of approaches. Researchers face the challenges of distinguishing between the effects of involvement versus noninvolvement and intensity of involvement in a particular activity, accounting simultaneously for cumulative effects of involvement, and addressing multiple…

Characteristics of Information Systems and Business Informatics Study Programs

ERIC Educational Resources Information Center

Helfert, Markus

2011-01-01

Over the last decade there is an intensive discussion within the Information Systems (IS) and Informatics community about the characteristics and identity of the discipline. Simultaneously with the discussion, there is an ongoing debate on essential skills and capabilities of IS and Business Informatics graduates as well as the profile of IS…

The source of electrostatic fluctuations in the solar-wind

NASA Technical Reports Server (NTRS)

Lemons, D. S.; Asbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gary, S. P.; Gosling, J. T.

1979-01-01

Solar wind electron and ion distribution functions measured simultaneously with or close to times of intense electrostatic fluctuations are subjected to a linear Vlasov stability analysis. Although all distributions tested were found to be stable, the analysis suggests that the ion beam instability is the most likely source of the fluctuations.

Larval Behavioral Toxicity Screening: Light Intensity and the Order of Stimulus Presentation Affect the Outcome

EPA Science Inventory

The U.S. Environmental Protection Agency is screening large numbers of chemicals using 6 day old zebrafish (Danio rerio). We use a behavioral testing paradigm that simultaneously tests individual zebrafish under both light and dark conditions in a 96-well plate using a video tr...

Using the Larval Zebrafish Locomotor Assay in Functional Neurotoxicity Screening: Light Intensity and the Order of Stimulus Presentation Affect the Outcome

EPA Science Inventory

The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize large numbers of chemicals using 6 day old zebrafish (Danio rerio) as an alternative test model for detecting neurotoxic chemicals. We use a behavioral testing paradigm that simultaneously tes...

Simultaneous Femtosecond X-ray Spectroscopy and Diffraction of Photosystem II at Room Temperature

PubMed Central

Kern, Jan; Alonso-Mori, Roberto; Tran, Rosalie; Hattne, Johan; Gildea, Richard J.; Echols, Nathaniel; Glöckner, Carina; Hellmich, Julia; Laksmono, Hartawan; Sierra, Raymond G.; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Lampe, Alyssa; Han, Guangye; Gul, Sheraz; DiFiore, Dörte; Milathianaki, Despina; Fry, Alan R.; Miahnahri, Alan; Schafer, Donald W.; Messerschmidt, Marc; Seibert, M. Marvin; Koglin, Jason E.; Sokaras, Dimosthenis; Weng, Tsu-Chien; Sellberg, Jonas; Latimer, Matthew J.; Grosse-Kunstleve, Ralf W.; Zwart, Petrus H.; White, William E.; Glatzel, Pieter; Adams, Paul D.; Bogan, Michael J.; Williams, Garth J.; Boutet, Sébastien; Messinger, Johannes; Zouni, Athina; Sauter, Nicholas K.; Yachandra, Vittal K.; Bergmann, Uwe; Yano, Junko

2013-01-01

Intense femtosecond X-ray pulses produced at the Linac Coherent Light Source (LCLS) were used for simultaneous X-ray diffraction (XRD) and X-ray emission spectroscopy (XES) of microcrystals of Photosystem II (PS II) at room temperature. This method probes the overall protein structure and the electronic structure of the Mn4CaO5 cluster in the oxygen-evolving complex of PS II. XRD data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. Our simultaneous XRD/XES study shows that the PS II crystals are intact during our measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies. PMID:23413188

Simultaneous femtosecond X-ray spectroscopy and diffraction of photosystem II at room temperature.

PubMed

Kern, Jan; Alonso-Mori, Roberto; Tran, Rosalie; Hattne, Johan; Gildea, Richard J; Echols, Nathaniel; Glöckner, Carina; Hellmich, Julia; Laksmono, Hartawan; Sierra, Raymond G; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Lampe, Alyssa; Han, Guangye; Gul, Sheraz; Difiore, Dörte; Milathianaki, Despina; Fry, Alan R; Miahnahri, Alan; Schafer, Donald W; Messerschmidt, Marc; Seibert, M Marvin; Koglin, Jason E; Sokaras, Dimosthenis; Weng, Tsu-Chien; Sellberg, Jonas; Latimer, Matthew J; Grosse-Kunstleve, Ralf W; Zwart, Petrus H; White, William E; Glatzel, Pieter; Adams, Paul D; Bogan, Michael J; Williams, Garth J; Boutet, Sébastien; Messinger, Johannes; Zouni, Athina; Sauter, Nicholas K; Yachandra, Vittal K; Bergmann, Uwe; Yano, Junko

2013-04-26

Intense femtosecond x-ray pulses produced at the Linac Coherent Light Source (LCLS) were used for simultaneous x-ray diffraction (XRD) and x-ray emission spectroscopy (XES) of microcrystals of photosystem II (PS II) at room temperature. This method probes the overall protein structure and the electronic structure of the Mn4CaO5 cluster in the oxygen-evolving complex of PS II. XRD data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. Our simultaneous XRD-XES study shows that the PS II crystals are intact during our measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation-sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies.

Simultaneous multicolor imaging of wide-field epi-fluorescence microscopy with four-bucket detection

PubMed Central

Park, Kwan Seob; Kim, Dong Uk; Lee, Jooran; Kim, Geon Hee; Chang, Ki Soo

2016-01-01

We demonstrate simultaneous imaging of multiple fluorophores using wide-field epi-fluorescence microscopy with a monochrome camera. The intensities of the three lasers are modulated by a sinusoidal waveform in order to excite each fluorophore with the same modulation frequency and a different time-delay. Then, the modulated fluorescence emissions are simultaneously detected by a camera operating at four times the excitation frequency. We show that two different fluorescence beads having crosstalk can be clearly separated using digital processing based on the phase information. In addition, multiple organelles within multi-stained single cells are shown with the phase mapping method, demonstrating an improved dynamic range and contrast compared to the conventional fluorescence image. These findings suggest that wide-field epi-fluorescence microscopy with four-bucket detection could be utilized for high-contrast multicolor imaging applications such as drug delivery and fluorescence in situ hybridization. PMID:27375944

CalQuo: automated, simultaneous single-cell and population-level quantification of global intracellular Ca2+ responses.

PubMed

Fritzsche, Marco; Fernandes, Ricardo A; Colin-York, Huw; Santos, Ana M; Lee, Steven F; Lagerholm, B Christoffer; Davis, Simon J; Eggeling, Christian

2015-11-13

Detecting intracellular calcium signaling with fluorescent calcium indicator dyes is often coupled with microscopy techniques to follow the activation state of non-excitable cells, including lymphocytes. However, the analysis of global intracellular calcium responses both at the single-cell level and in large ensembles simultaneously has yet to be automated. Here, we present a new software package, CalQuo (Calcium Quantification), which allows the automated analysis and simultaneous monitoring of global fluorescent calcium reporter-based signaling responses in up to 1000 single cells per experiment, at temporal resolutions of sub-seconds to seconds. CalQuo quantifies the number and fraction of responding cells, the temporal dependence of calcium signaling and provides global and individual calcium-reporter fluorescence intensity profiles. We demonstrate the utility of the new method by comparing the calcium-based signaling responses of genetically manipulated human lymphocytic cell lines.

High performance liquid chromatography with two simultaneous on-line antioxidant assays: Evaluation and comparison of espresso coffees

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

Barnett, Neil W; Gritti, Fabrice; Guiochon, Georges A

The antioxidant profiles of various espresso coffees were established using HPLC with UV-absorbance detection and two rapid, simultaneous, on-line chemical assays that enabled the relative reactivity of sample components to be screened. The assays were based on (i) the colour change associated with reduction of the 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH{sm_bullet}); and (ii) the emission of light (chemiluminescence) upon reaction with acidic potassium permanganate. Results from the two approaches were similar and reflected the complex array of antioxidant species present in the samples. However, some differences in selectivity were observed. Chromatograms generated with the chemiluminescence assay contained more peaks, which was ascribedmore » to the greater sensitivity of the reagent towards minor, readily oxidisable sample components. The three coffee samples produced closely related profiles, signifying their fundamentally similar chemical compositions and origin. Nevertheless, the overall intensity and complexity of the samples in both UV absorption and antioxidant assay chromatograms were aligned with the manufacturers description of flavour intensity and character.« less

Design and fabrication of a new electrolarynx and voice amplifier for laryngectomees.

PubMed

Sundeep Krishna, M; Jayanthy, A K; Divakar, C; Mekhala, R

2005-01-01

A Laryngectomee is a person whose vocal cords i.e. voice box is surgically removed owing to cancer or due to automobile accidents, burns or trauma. The patient, therefore permanently loses the ability to speak normally. An Electrolarynx is an electronic speech aid that enables the Laryngectomee to communicate with other people as quickly as possible after the successful removal of the larynx. A neck type Electrolarynx has been designed. Earlier designs could not alter frequency and intensity simultaneously during conversation. The Electrolarynx developed can control both frequency and intensity simultaneously during conversation. The device has been tested on the patient and found to be very effective. A portable, pocket size, battery powered voice amplifier (PA system) has also been developed which uses an electret condenser microphone as the input. The voice amplifier developed is a two stage amplifier which uses a preamplifier stage and a power amplifier stage. The output of the power amplifier is connected to a speaker. The device is being used by the patient and found to be very useful.

Localizing the sources of two independent noises: Role of time varying amplitude differences

PubMed Central

Yost, William A.; Brown, Christopher A.

2013-01-01

Listeners localized the free-field sources of either one or two simultaneous and independently generated noise bursts. Listeners' localization performance was better when localizing one rather than two sound sources. With two sound sources, localization performance was better when the listener was provided prior information about the location of one of them. Listeners also localized two simultaneous noise bursts that had sinusoidal amplitude modulation (AM) applied, in which the modulation envelope was in-phase across the two source locations or was 180° out-of-phase. The AM was employed to investigate a hypothesis as to what process listeners might use to localize multiple sound sources. The results supported the hypothesis that localization of two sound sources might be based on temporal-spectral regions of the combined waveform in which the sound from one source was more intense than that from the other source. The interaural information extracted from such temporal-spectral regions might provide reliable estimates of the sound source location that produced the more intense sound in that temporal-spectral region. PMID:23556597

Localizing the sources of two independent noises: role of time varying amplitude differences.

PubMed

Yost, William A; Brown, Christopher A

2013-04-01

Listeners localized the free-field sources of either one or two simultaneous and independently generated noise bursts. Listeners' localization performance was better when localizing one rather than two sound sources. With two sound sources, localization performance was better when the listener was provided prior information about the location of one of them. Listeners also localized two simultaneous noise bursts that had sinusoidal amplitude modulation (AM) applied, in which the modulation envelope was in-phase across the two source locations or was 180° out-of-phase. The AM was employed to investigate a hypothesis as to what process listeners might use to localize multiple sound sources. The results supported the hypothesis that localization of two sound sources might be based on temporal-spectral regions of the combined waveform in which the sound from one source was more intense than that from the other source. The interaural information extracted from such temporal-spectral regions might provide reliable estimates of the sound source location that produced the more intense sound in that temporal-spectral region.

Simultaneous enhancement of Chlorella vulgaris growth and lipid accumulation through the synergy effect between light and nitrate in a planar waveguide flat-plate photobioreactor.

PubMed

Liao, Qiang; Sun, Yahui; Huang, Yun; Xia, Ao; Fu, Qian; Zhu, Xun

2017-11-01

Interval between adjacent planar waveguides and light intensity emitted from waveguide surface were the primary two factors affecting light distribution characteristics in the planar waveguide flat-plate photobioreactor (PW-PBR). In this paper, the synergy effect between light and nitrate in the PW-PBR was realized to simultaneously enhance microalgae growth and lipid accumulation. Under an interval of 10mm between adjacent planar waveguides, 100% of microalgae cells in regions between adjacent waveguides could be illuminated. Chlorella vulgaris growth and lipid accumulation were synchronously elevated as light intensities emitted from planar waveguide surface increasing. With an identical initial nitrate concentration of 18mM, the maximum lipid content (41.66% in dry biomass) and lipid yield (2200.25mgL -1 ) were attained under 560μmolm -2 s -1 , which were 86.82% and 133.56% higher relative to those obtained under 160μmolm -2 s -1 , respectively. The PW-PBR provides a promising way for microalgae lipid production. Copyright © 2017 Elsevier Ltd. All rights reserved.

A microfluidics-based technique for automated and rapid labeling of cells for flow cytometry

NASA Astrophysics Data System (ADS)

Patibandla, Phani K.; Estrada, Rosendo; Kannan, Manasaa; Sethu, Palaniappan

2014-03-01

Flow cytometry is a powerful technique capable of simultaneous multi-parametric analysis of heterogeneous cell populations for research and clinical applications. In recent years, the flow cytometer has been miniaturized and made portable for application in clinical- and resource-limited settings. The sample preparation procedure, i.e. labeling of cells with antibodies conjugated to fluorescent labels, is a time consuming (˜45 min) and labor-intensive procedure. Microfluidics provides enabling technologies to accomplish rapid and automated sample preparation. Using an integrated microfluidic device consisting of a labeling and washing module, we demonstrate a new protocol that can eliminate sample handling and accomplish sample and reagent metering, high-efficiency mixing, labeling and washing in rapid automated fashion. The labeling module consists of a long microfluidic channel with an integrated chaotic mixer. Samples and reagents are precisely metered into this device to accomplish rapid and high-efficiency mixing. The mixed sample and reagents are collected in a holding syringe and held for up to 8 min following which the mixture is introduced into an inertial washing module to obtain ‘analysis-ready’ samples. The washing module consists of a high aspect ratio channel capable of focusing cells to equilibrium positions close to the channel walls. By introducing the cells and labeling reagents in a narrow stream at the center of the channel flanked on both sides by a wash buffer, the elution of cells into the wash buffer away from the free unbound antibodies is accomplished. After initial calibration experiments to determine appropriate ‘holding time’ to allow antibody binding, both modules were used in conjunction to label MOLT-3 cells (T lymphoblast cell line) with three different antibodies simultaneously. Results confirm no significant difference in mean fluorescence intensity values for all three antibodies labels (p < 0.01) between the conventional procedure (45 min) and our microfluidic approach (12 min).

Oral decontamination is cost-saving in the prevention of ventilator-associated pneumonia in intensive care units.

PubMed

van Nieuwenhoven, Christianne A; Buskens, Erik; Bergmans, Dennis C; van Tiel, Frank H; Ramsay, Graham; Bonten, Marc J M

2004-01-01

Although the development of ventilator-associated pneumonia (VAP) is assumed to increase costs of intensive care unit stay, it is unknown whether prevention of VAP by means of oropharyngeal decontamination is cost-effective. Because of wide ranges of individual patient costs, crude cost comparisons did not show significant cost reductions. Based on actual cost data of 181 individual patients included in a former randomized clinical trial, cost-effectiveness of prevention of VAP was determined using a decision model and univariate sensitivity analyses, and bootstrapping was used to assess the impact of variability in the various outcomes. Published data on prevention of VAP by oropharyngeal decontamination, which resulted in a relative risk for VAP of 0.45, with a baseline rate of VAP of 29% among control patients. The mean costs of the intervention were 351 dollars per patient (32 dollars per patient per day). All other costs were derived from the hospital administrative database for all individual patients. Prevention of VAP led to mean total costs of 16,119 dollars and 18,268 dollars for patients without preventive measures administered. Thus, costs were saved and instances of VAP were prevented. Similar results were observed in terms of overall survival. Prevention of VAP remains cost-saving if the relative risk for VAP because of intervention is <0.923, the costs of the intervention are less than 2,500 dollars, and the prevalence of VAP without intervention is >4%. Bootstrapping confirmed that, with about 80% certainty, oropharyngeal decontamination results in prevention of VAP and simultaneously saves costs. In terms of a survival benefit, the results are less evident; the results indicate that with only about 60% certainty can we confirm that oropharyngeal decontamination would result in a survival benefit and simultaneously save costs. This study provides strong evidence that prevention of VAP by means of oropharyngeal decontamination is cost-effective.

Thermospheric nitric oxide from the ATLAS 1 and Spacelab 1 missions

NASA Technical Reports Server (NTRS)

Torr, Marsha R.; Torr, D. G.; Chang, T.; Richards, P.; Swift, W.; Li, N.

1995-01-01

Spectral and spatial images obtained with the Imaging Spectrometric Observatory on the ATLAS 1 and Spacelab 1 missions are used to study the ultraviolet emissions of nitric oxide in the thermosphere. By synthetically fitting the measured NO gamma bands, intensities are derived as a function of altitude and latitude. We find that the NO concentrations inferred from the ATLAS 1 measurements are higher than predicted by our thermospheric airglow model and tend to lie to the high side of a number of earlier measurements. By comparison with synthetic spectral fits, the shape of the NO gamma bands is used to derive temperature as a function of altitude. Using the simultaneous spectral and spatial imaging capability of the instrument, we present the first simultaneously acquired altitude images of NO gamma band temperature and intensity in the thermosphere. The lower thermospheric temperature images show structure as a function of altitude. The spatial imaging technique appears to be a viable means of obtaining temperatures in the middle and lower thermosphere, provided that good information is also obtained at the higher altitudes, as the contribution of the overlying, hotter NO is nonnegligible. By fitting both self-absorbed and nonabsorbed bands of the NO gamma system, we show that the self absorption effects are observable up to 200 km, although small above 150 km. The spectral resolution of the instrument (1.6 A) allows separation of the N(+)(S-5) doublet, and we show the contribution of this feature to the combination of the NO gamma (1, 0) band and the N(+)(S-5) doublet as a function of altitude (less than 10% below 200 km). Spectral images including the NO delta bands support previous findings that the fluorescence efficiency is much higher than that determined from laboratory measurements. The Spacelab 1 data indicate the presence of a significant population of hot NO in the vehicle environment of that early shuttle mission.

Crisis route to chaos in semiconductor lasers subjected to external optical feedback

NASA Astrophysics Data System (ADS)

Wishon, Michael J.; Locquet, Alexandre; Chang, C. Y.; Choi, D.; Citrin, D. S.

2018-03-01

Semiconductor lasers subjected to optical feedback have been intensively used as archetypical testbeds for high-speed (sub-ns) and high-dimensional nonlinear dynamics. By simultaneously extracting all the dynamical variables, we demonstrate that for larger current, the commonly named "quasiperiodic" route is in fact based on mixed external-cavity solutions that lock the oscillation frequency of the intensity, voltage, and separation in optical frequency through a mechanism involving successive rejections along the unstable manifold of an antimode. We show that chaos emerges from a crisis resulting from the inability to maintain locking as the unstable manifold becomes inaccessible.

A modulation wave approach to the order hidden in disorder

PubMed Central

Withers, Ray

2015-01-01

The usefulness of a modulation wave approach to understanding and interpreting the highly structured continuous diffuse intensity distributions characteristic of the reciprocal spaces of the very large family of inherently flexible materials which exhibit ordered ‘disorder’ is pointed out. It is shown that both longer range order and truly short-range order are simultaneously encoded in highly structured diffuse intensity distributions. The long-range ordered crystal chemical rules giving rise to such diffuse distributions are highlighted, along with the existence and usefulness of systematic extinction conditions in these types of structured diffuse distributions. PMID:25610629

Prediction of light aircraft interior sound pressure level from the measured sound power flowing in to the cabin

NASA Technical Reports Server (NTRS)

Atwal, Mahabir S.; Heitman, Karen E.; Crocker, Malcolm J.

1986-01-01

The validity of the room equation of Crocker and Price (1982) for predicting the cabin interior sound pressure level was experimentally tested using a specially constructed setup for simultaneous measurements of transmitted sound intensity and interior sound pressure levels. Using measured values of the reverberation time and transmitted intensities, the equation was used to predict the space-averaged interior sound pressure level for three different fuselage conditions. The general agreement between the room equation and experimental test data is considered good enough for this equation to be used for preliminary design studies.

Simultaneous determination of some cholesterol-lowering drugs in their binary mixture by novel spectrophotometric methods

NASA Astrophysics Data System (ADS)

Lotfy, Hayam Mahmoud; Hegazy, Maha Abdel Monem

2013-09-01

Four simple, specific, accurate and precise spectrophotometric methods manipulating ratio spectra were developed and validated for simultaneous determination of simvastatin (SM) and ezetimibe (EZ) namely; extended ratio subtraction (EXRSM), simultaneous ratio subtraction (SRSM), ratio difference (RDSM) and absorption factor (AFM). The proposed spectrophotometric procedures do not require any preliminary separation step. The accuracy, precision and linearity ranges of the proposed methods were determined, and the methods were validated and the specificity was assessed by analyzing synthetic mixtures containing the cited drugs. The four methods were applied for the determination of the cited drugs in tablets and the obtained results were statistically compared with each other and with those of a reported HPLC method. The comparison showed that there is no significant difference between the proposed methods and the reported method regarding both accuracy and precision.

Respiratory muscle activity and patient–ventilator asynchrony during different settings of noninvasive ventilation in stable hypercapnic COPD: does high inspiratory pressure lead to respiratory muscle unloading?

PubMed Central

Duiverman, Marieke L; Huberts, Anouk S; van Eykern, Leo A; Bladder, Gerrie; Wijkstra, Peter J

2017-01-01

Introduction High-intensity noninvasive ventilation (NIV) has been shown to improve outcomes in stable chronic obstructive pulmonary disease patients. However, there is insufficient knowledge about whether with this more controlled ventilatory mode optimal respiratory muscle unloading is provided without an increase in patient–ventilator asynchrony (PVA). Patients and methods Ten chronic obstructive pulmonary disease patients on home mechanical ventilation were included. Four different ventilatory settings were investigated in each patient in random order, each for 15 min, varying the inspiratory positive airway pressure and backup breathing frequency. With surface electromyography (EMG), activities of the intercostal muscles, diaphragm, and scalene muscles were determined. Furthermore, pressure tracings were derived simultaneously in order to assess PVA. Results Compared to spontaneous breathing, the most pronounced decrease in EMG activity was achieved with the high-pressure settings. Adding a high breathing frequency did reduce EMG activity per breath, while the decrease in EMG activity over 1 min was comparable with the high-pressure, low-frequency setting. With high backup breathing frequencies less breaths were pressure supported (25% vs 97%). PVAs occurred more frequently with the low-frequency settings (P=0.017). Conclusion High-intensity NIV might provide optimal unloading of respiratory muscles, without undue increases in PVA. PMID:28138234

Novel Hamiltonian method for collective dynamics analysis of an intense charged particle beam propagating through a periodic focusing quadrupole lattice a)

NASA Astrophysics Data System (ADS)

Startsev, Edward A.; Davidson, Ronald C.

2011-05-01

Identifying regimes for quiescent propagation of intense beams over long distances has been a major challenge in accelerator research. In particular, the development of systematic theoretical approaches that are able to treat self-consistently the applied oscillating force and the nonlinear self-field force of the beam particles simultaneously has been a major challenge of modern beam physics. In this paper, the recently developed Hamiltonian averaging technique [E. A. Startsev, R. C. Davidson, and M. Dorf, Phys. Rev. ST Accel. Beams 13, 064402 (2010)] which incorporates both the applied periodic focusing force and the self-field force of the beam particles, is generalized to the case of time-dependent beam distributions. The new formulation allows not only a determination of quasi-equilibrium solutions of the non-linear Vlasov-Poison system of equations but also a detailed study of their stability properties. The corrections to the well-known "smooth-focusing" approximation are derived, and the results are applied to a matched beam with thermal equilibrium distribution function. It is shown that the corrections remain small even for moderate values of the vacuum phase advance συ. Nonetheless, because the corrections to the average self-field potential are non-axisymmetric, the stability properties of the different beam quasi-equilibria can change significantly.

Few-Nucleon Charge Radii and a Precision Isotope Shift Measurement in Helium

NASA Astrophysics Data System (ADS)

Hassan Rezaeian, Nima; Shiner, David

2015-05-01

Precision atomic theory and experiment provide a valuable method to determine few nucleon charge radii, complementing the more direct scattering approaches, and providing sensitive tests of few-body nuclear theory. Some puzzles with respect to this method exist, particularly in the muonic and electronic measurements of the proton radius, and as well with respect to measurements of nuclear size in helium. We perform precision measurements of the isotope shift of the 23S -23P transitions in 3He and 4He. A tunable laser frequency discriminator and electro-optic modulation technique give precise frequency and intensity control. We select (ts <50 ms) and stabilize the intensity of the required sideband and eliminate the unused sidebands (<= 10¬5) . The technique uses a MEMS fiber switch (ts = 10 ms) and several temperature stabilized narrow band (3 GHz) fiber gratings. A fiber based optical circulator and amplifier provide the desired isolation and net gain for the selected frequency. A beam with both species of helium is achieved using a custom fiber laser for simultaneous optical pumping. A servo-controlled retro-reflected laser beam eliminates Doppler effects. Careful detection design and software control allows for unbiased data collection. Current results will be discussed. This work is supported by NSF PHY-1068868 and PHY-1404498.

Respiratory muscle activity and patient-ventilator asynchrony during different settings of noninvasive ventilation in stable hypercapnic COPD: does high inspiratory pressure lead to respiratory muscle unloading?

PubMed

Duiverman, Marieke L; Huberts, Anouk S; van Eykern, Leo A; Bladder, Gerrie; Wijkstra, Peter J

2017-01-01

High-intensity noninvasive ventilation (NIV) has been shown to improve outcomes in stable chronic obstructive pulmonary disease patients. However, there is insufficient knowledge about whether with this more controlled ventilatory mode optimal respiratory muscle unloading is provided without an increase in patient-ventilator asynchrony (PVA). Ten chronic obstructive pulmonary disease patients on home mechanical ventilation were included. Four different ventilatory settings were investigated in each patient in random order, each for 15 min, varying the inspiratory positive airway pressure and backup breathing frequency. With surface electromyography (EMG), activities of the intercostal muscles, diaphragm, and scalene muscles were determined. Furthermore, pressure tracings were derived simultaneously in order to assess PVA. Compared to spontaneous breathing, the most pronounced decrease in EMG activity was achieved with the high-pressure settings. Adding a high breathing frequency did reduce EMG activity per breath, while the decrease in EMG activity over 1 min was comparable with the high-pressure, low-frequency setting. With high backup breathing frequencies less breaths were pressure supported (25% vs 97%). PVAs occurred more frequently with the low-frequency settings ( P =0.017). High-intensity NIV might provide optimal unloading of respiratory muscles, without undue increases in PVA.

Differential sympathetic neural control of oxygenation in resting and exercising human skeletal muscle.

PubMed Central

Hansen, J; Thomas, G D; Harris, S A; Parsons, W J; Victor, R G

1996-01-01

Metabolic products of skeletal muscle contraction activate metaboreceptor muscle afferents that reflexively increase sympathetic nerve activity (SNA) targeted to both resting and exercising skeletal muscle. To determine effects of the increased sympathetic vasoconstrictor drive on muscle oxygenation, we measured changes in tissue oxygen stores and mitochondrial cytochrome a,a3 redox state in rhythmically contracting human forearm muscles with near infrared spectroscopy while simultaneously measuring muscle SNA with microelectrodes. The major new finding is that the ability of reflex-sympathetic activation to decrease muscle oxygenation is abolished when the muscle is exercised at an intensity > 10% of maximal voluntary contraction (MVC). During high intensity handgrip, (45% MVC), contraction-induced decreases in muscle oxygenation remained stable despite progressive metaboreceptor-mediated reflex increases in SNA. During mild to moderate handgrips (20-33% MVC) that do not evoke reflex-sympathetic activation, experimentally induced increases in muscle SNA had no effect on oxygenation in exercising muscles but produced robust decreases in oxygenation in resting muscles. The latter decreases were evident even during maximal metabolic vasodilation accompanying reactive hyperemia. We conclude that in humans sympathetic neural control of skeletal muscle oxygenation is sensitive to modulation by metabolic events in the contracting muscles. These events are different from those involved in either metaboreceptor muscle afferent activation or reactive hyperemia. PMID:8755671

Velocity analysis of simultaneous-source data using high-resolution semblance—coping with the strong noise

NASA Astrophysics Data System (ADS)

Gan, Shuwei; Wang, Shoudong; Chen, Yangkang; Qu, Shan; Zu, Shaohuan

2016-02-01

Direct imaging of simultaneous-source (or blended) data, without the need of deblending, requires a precise subsurface velocity model. In this paper, we focus on the velocity analysis of simultaneous-source data using the normal moveout-based velocity picking approach.We demonstrate that it is possible to obtain a precise velocity model directly from the blended data in the common-midpoint domain. The similarity-weighted semblance can help us obtain much better velocity spectrum with higher resolution and higher reliability compared with the traditional semblance. The similarity-weighted semblance enforces an inherent noise attenuation solely in the semblance calculation stage, thus it is not sensitive to the intense interference. We use both simulated synthetic and field data examples to demonstrate the performance of the similarity-weighted semblance in obtaining reliable subsurface velocity model for direct migration of simultaneous-source data. The migrated image of blended field data using prestack Kirchhoff time migration approach based on the picked velocity from the similarity-weighted semblance is very close to the migrated image of unblended data.

A Graphical Procedure for the Simultaneous Determination of the Distribution Constant of Iodine and the Stability Constants of Trihalide Anions.

ERIC Educational Resources Information Center

Kahwa, I. A.

1984-01-01

Discusses a graphical procedure which allows the distribution constant of iodine to be determined simultaneously with the trihalide anion stability constant. In addition, the procedure extends the experimental chemistry from distribution equilibria to important thermodynamic and bonding features. Advantages of using the procedure are also…

Net analyte signal standard addition method (NASSAM) as a novel spectrofluorimetric and spectrophotometric technique for simultaneous determination, application to assay of melatonin and pyridoxine

NASA Astrophysics Data System (ADS)

Asadpour-Zeynali, Karim; Bastami, Mohammad

2010-02-01

In this work a new modification of the standard addition method called "net analyte signal standard addition method (NASSAM)" is presented for the simultaneous spectrofluorimetric and spectrophotometric analysis. The proposed method combines the advantages of standard addition method with those of net analyte signal concept. The method can be applied for the determination of analyte in the presence of known interferents. The accuracy of the predictions against H-point standard addition method is not dependent on the shape of the analyte and interferent spectra. The method was successfully applied to simultaneous spectrofluorimetric and spectrophotometric determination of pyridoxine (PY) and melatonin (MT) in synthetic mixtures and in a pharmaceutical formulation.

Fourth-order derivative spectrophotometric method for simultaneous determination of pseudoephedrine and naproxen in pharmaceutical dosage forms

PubMed Central

Souri, Effat; Mosafer, Amir; Tehrani, Maliheh Barazandeh

2016-01-01

Combination dosage forms of naproxen sodium and pseudoephedrine hydrochloride are used for symptomatic treatment of cold and sinus disorders. In this study, fourth-order derivative spectrophotometric method was used for simultaneous determination of naproxen sodium and pseudoephedrine hydrochloride. The method was linear over the range of 2-28 μg/ml for pseudoephedrine hydrochloride and 4-200 μg/ml for naproxen sodium. The within-day and between-day coefficient of variation values were less than 5.8% and 2.5% for pseudoephedrine hydrochloride and naproxen sodium, respectively. The application of the proposed method for simultaneous determination of naproxen and pseudoephedrine in dosage forms was demonstrated without any special pretreatment. PMID:27168748

Hexuronic Acid Stereochemistry Determination in Chondroitin Sulfate Glycosaminoglycan Oligosaccharides by Electron Detachment Dissociation

NASA Astrophysics Data System (ADS)

Leach, Franklin E.; Ly, Mellisa; Laremore, Tatiana N.; Wolff, Jeremy J.; Perlow, Jacob; Linhardt, Robert J.; Amster, I. Jonathan

2012-09-01

Electron detachment dissociation (EDD) has previously provided stereo-specific product ions that allow for the assignment of the acidic C-5stereochemistry in heparan sulfate glycosaminoglycans (GAGs), but application of the same methodology to an epimer pair in the chondroitin sulfate glycoform class does not provide the same result. A series of experiments have been conducted in which glycosaminoglycan precursor ions are independently activated by electron detachment dissociation (EDD), electron induced dissociation (EID), and negative electron transfer dissociation (NETD) to assign the stereochemistry in chondroitin sulfate (CS) epimers and investigate the mechanisms for product ion formation during EDD in CS glycoforms. This approach allows for the assignment of electronic excitation products formed by EID and detachment products to radical pathways in NETD, both of which occur simultaneously during EDD. The uronic acid stereochemistry in electron detachment spectra produces intensity differences when assigned glycosidic and cross-ring cleavages are compared. The variations in the intensities of the doubly deprotonated 0,2X3 and Y3 ions have been shown to be indicative of CS-A/DS composition during the CID of binary mixtures. These ions can provide insight into the uronic acid composition of binary mixtures in EDD, but the relative abundances, although reproducible, are low compared with those in a CID spectrum acquired on an ion trap. The application of principal component analysis (PCA) presents a multivariate approach to determining the uronic acid stereochemistry spectra of these GAGs by taking advantage of the reproducible peak distributions produced by electron detachment.

Quantitative Fluorescence Studies in Living Cells: Extending Fluorescence Fluctuation Spectroscopy to Peripheral Membrane Proteins

NASA Astrophysics Data System (ADS)

Smith, Elizabeth Myhra

The interactions of peripheral membrane proteins with both membrane lipids and proteins are vital for many cellular processes including membrane trafficking, cellular signaling, and cell growth/regulation. Building accurate biophysical models of these processes requires quantitative characterization of the behavior of peripheral membrane proteins, yet methods to quantify their interactions inside living cells are very limited. Because peripheral membrane proteins usually exist both in membrane-bound and cytoplasmic forms, the separation of these two populations is a key challenge. This thesis aims at addressing this challenge by extending fluorescence fluctuation spectroscopy (FFS) to simultaneously measure the oligomeric state of peripheral membrane proteins in the cytoplasm and at the plasma membrane. We developed a new method based on z-scan FFS that accounts for the fluorescence contributions from cytoplasmic and membrane layers by incorporating a fluorescence intensity z-scan through the cell. H-Ras-EGFP served as a model system to demonstrate the feasibility of the technique. The resolvability and stability of z-scanning was determined as well as the oligomeric state of H-Ras-EGFP at the plasma membrane and in the cytoplasm. Further, we successfully characterized the binding affinity of a variety of proteins to the plasma membrane by quantitative analysis of the z-scan fluorescence intensity profile. This analysis method, which we refer to as z-scan fluorescence profile deconvoution, was further used in combination with dual-color competition studies to determine the lipid specificity of protein binding. Finally, we applied z-scan FFS to provide insight into the early assembly steps of the HTLV-1 retrovirus.

Objective classification of historical tropical cyclone intensity

NASA Astrophysics Data System (ADS)

Chenoweth, Michael

2007-03-01

Preinstrumental records of historical tropical cyclone activity require objective methods for accurately categorizing tropical cyclone intensity. Here wind force terms and damage reports from newspaper accounts in the Lesser Antilles and Jamaica for the period 1795-1879 are compared with wind speed estimates calculated from barometric pressure data. A total of 95 separate barometric pressure readings and colocated simultaneous wind force descriptors and wind-induced damage reports are compared. The wind speed estimates from barometric pressure data are taken as the most reliable and serve as a standard to compare against other data. Wind-induced damage reports are used to produce an estimated wind speed range using a modified Fujita scale. Wind force terms are compared with the barometric pressure data to determine if a gale, as used in the contemporary newspapers, is consistent with the modern definition of a gale. Results indicate that the modern definition of a gale (the threshold point separating the classification of a tropical depression from a tropical storm) is equivalent to that in contemporary newspaper accounts. Barometric pressure values are consistent with both reported wind force terms and wind damage on land when the location, speed and direction of movement of the tropical cyclone are determined. Damage reports and derived wind force estimates are consistent with other published results. Biases in ships' logbooks are confirmed and wind force terms of gale strength or greater are identified. These results offer a bridge between the earlier noninstrumental records of tropical cyclones and modern records thereby offering a method of consistently classifying storms in the Caribbean region into tropical depressions, tropical storms, nonmajor and major hurricanes.

Bluetooth Heart Rate Monitors For Spaceflight

NASA Technical Reports Server (NTRS)

Buxton, R. E.; West, M. R.; Kalogera, K. L.; Hanson, A. M.

2016-01-01

Heart rate monitoring is required for crewmembers during exercise aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data are required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health aboard the ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) were worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_HRM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the 2 data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. RESULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6% error), followed by CS4 (3.3% error), CS3 (6.4% error), and CS2 (9.2% error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, but unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to obtain the best quality data. CS2 will be used in an ISS Bluetooth validation study, because it simultaneously transmits magnetic pulse that is integrated with existing exercise hardware on ISS. The simultaneous data streams allow for beat-to-beat comparison between the current ISS standard and CS2. Upon Bluetooth validation aboard ISS, the research team will down select a new BT_HRM for operational use.

Bluetooth(Registered Trademark) Heart Rate Monitors for Spaceflight

NASA Technical Reports Server (NTRS)

Buxton, Roxanne E.; West, Michael R.; Kalogera, Kent L.; Hanson, Andrea M.

2016-01-01

Heart rate monitoring is required during exercise for crewmembers aboard the International Space Station (ISS) and will be for future exploration missions. The cardiovascular system must be sufficiently stressed throughout a mission to maintain the ability to perform nominal and contingency/emergency tasks. High quality heart rate data is required to accurately determine the intensity of exercise performed by the crewmembers and show maintenance of VO2max. The quality of the data collected on ISS is subject to multiple limitations and is insufficient to meet current requirements. PURPOSE: To evaluate the performance of commercially available Bluetooth® heart rate monitors (BT_HRM) and their ability to provide high quality heart rate data to monitor crew health on board ISS and during future exploration missions. METHODS: Nineteen subjects completed 30 data collection sessions of various intensities on the treadmill and/or cycle. Subjects wore several BT_HRM technologies for each testing session. One electrode-based chest strap (CS) was worn, while one or more optical sensors (OS) was worn. Subjects were instrumented with a 12-lead ECG to compare the heart rate data from the Bluetooth sensors. Each BT_RHM data set was time matched to the ECG data and a +/-5bpm threshold was applied to the difference between the two data sets. Percent error was calculated based on the number of data points outside the threshold and the total number of data points. REULTS: The electrode-based chest straps performed better than the optical sensors. The best performing CS was CS1 (1.6%error), followed by CS4 (3.3%error), CS3 (6.4%error), and CS2 (9.2%error). The OS resulted in 10.4% error for OS1 and 14.9% error for OS2. CONCLUSIONS: The highest quality data came from CS1, unfortunately it has been discontinued by the manufacturer. The optical sensors have not been ruled out for use, but more investigation is needed to determine how to get the best quality data. CS2 will be used in an ISS Bluetooth validation study, because it simultaneously transmits Magnetic Pulse which is integrated with existing exercise hardware on ISS. The simultaneous data streams allow for beat to beat comparison between the current ISS standard and CS2.Upon Bluetooth(Registered Trademark) validation aboard ISS, down select of a new BT_HRM for operational use will be made.

Surface area generation and droplet size control in solvent extraction systems utilizing high intensity electric fields

DOEpatents

Scott, Timothy C.; Wham, Robert M.

1988-01-01

A method and system for solvent extraction where droplets are shattered by a high intensity electric field. These shattered droplets form a plurality of smaller droplets which have a greater combined surface area than the original droplet. Dispersion, coalescence and phase separation are accomplished in one vessel through the use of the single pulsing high intensity electric field. Electric field conditions are chosen so that simultaneous dispersion and coalescence are taking place in the emulsion formed in the electric field. The electric field creates a large amount of interfacial surface area for solvent extraction when the droplet is disintegrated and is capable of controlling droplet size and thus droplet stability. These operations take place in the presence of a counter current flow of the continuous phase.

Orientation of ripples induced by ultrafast laser pulses on copper in different liquids

NASA Astrophysics Data System (ADS)

Maragkaki, Stella; Elkalash, Abdallah; Gurevich, Evgeny L.

2017-12-01

Formation of laser-induced periodic surface structures (LIPSS or ripples) was studied on a metallic surface of polished copper using irradiation with multiple femtosecond laser pulses in different environmental conditions (air, water, ethanol and methanol). Uniform LIPSS have been achieved by controlling the peak fluence and the overlapping rate. Ripples in both orientations, perpendicular and parallel to laser polarization, were observed in all liquids simultaneously. The orientation of these ripples in the center of the ablated line was changing with the incident light intensity. For low intensities the orientation of the ripples is perpendicular to the laser polarization, whereas for high intensities it turns parallel to it without considerable changes in the period. Multi-directional LIPSS formation was also observed for moderate peak fluence in liquid environments.

Simultaneous in situ Optical Monitoring Techniques during Crystal Growth of ZnSe by Physical Vapor Transport

NASA Technical Reports Server (NTRS)

Su, C.- H.; Feth, S.; Lehoczky, S. L.

1998-01-01

ZnSe crystals grown in sealed ampoules by the physical vapor transport method were monitored in situ using three techniques, simultaneously. A Michelson interferometer was set-up to observe the growth rate and surface morphological evolution. An interference pattern (interferogram) is formed by the interaction between the reflection of a HeNe laser (632.8 nm wavelength) off the crystal-vapor interface and a reference beam from the same laser. Preliminary results indicate that the rate of growth/thermal-etching can be calculated using analog data acquisition and simple fringe counting techniques. Gross surface features may also be observed using a digital frame grabber and fringe analysis software. The second in situ technique uses optical absorption to determine the partial pressures of the vapor species. The Se2 and Zn vapor species present in the sealed ampoule absorb light at characteristic wavelengths. The optical absorption is determined by monitoring the light intensity difference between the sample and reference beams. The Se2 Partial pressure profile along the length of the ampoule was estimated from the vibronic absorption peaks at 340.5, 350.8, 361.3 and 379.2 nm using the Beer's law constants established in the calibration runs of pure Se. Finally, because the high temperature crystal growth furnace contains windows, in situ visual observation of the growing crystal is also possible. The use of these techniques not only permits in situ investigation of high temperature vapor growth of semiconductors, but also offers the potential for real time feed back on the growing crystal and allows the possibility of actively controlling the growth process.

Demonstration of uneven distribution of intracranial pulsatility in hydrocephalus patients.

PubMed

Eide, Per K

2008-11-01

Data from intracranial pressure (ICP) recordings in patients with hydrocephalus were reviewed to determine whether intracranial pulsatility within the cerebrospinal fluid (CSF) of cerebral ventricles (ICP(LV)) may differ from that within the brain parenchyma (ICP(PAR)), and whether pulsatility may differ between noncommunicating ventricles. The authors retrieved data from recordings previously obtained in 7 patients with hydrocephalus (noncommunicating in 4 and communicating in 3) and shunt failure who received both an external ventricular drainage (EVD) and an ICP sensor as part of surveillance during intensive care. Simultaneous ICP(LV) and ICP(PAR) signals were available in 6 cases, and simultaneous signals from the lateral and fourth ventricles (ICP(LV) and ICP4V, respectively) were recorded in 1 case. The recordings with both signals were parsed into 6-second time windows. Pulsatility was characterized by the wave amplitude and rise time coefficient, and differences in pulsatility between the ICP(LV) and ICP(PAR) signals (6 cases) or ICP(LV) and ICP4V signals (1 case) were determined. There was uneven distribution of intracranial pulsatility in all 7 patients, shown as significantly elevated pulsatility (that is, higher wave amplitudes and rise time coefficients) within the ventricles (ICP(LV)) than within brain parenchyma (ICP(PAR)) in 6 patients, and significantly higher pulsatility in the fourth (ICP4V) than in the lateral (ICP(LV)) ventricles in 1 patient. Differences > or = 1 mm Hg in ICP wave amplitude were found in 0.5-100% (median 9.4%) of observations in the 7 patients (total number of 6-second time windows, 68,242). The present observations demonstrate uneven distribution of intracranial pulsatility in patients with hydrocephalus, higher pulse pressure amplitudes within the ventricular CSF (ICP(LV)) than within the brain parenchyma (ICP(PAR)). This may be one mechanism behind ventricular enlargement in hydrocephalus.

The impact of training and working conditions on junior doctors’ intention to leave clinical practice

PubMed Central

2014-01-01

Background The shortage of physicians is an evolving problem throughout the world. In this study we aimed to identify to what extent junior doctors’ training and working conditions determine their intention to leave clinical practice after residency training. Methods A prospective cohort study was conducted in 557 junior doctors undergoing residency training in German hospitals. Self-reported specialty training conditions, working conditions and intention to leave clinical practice were measured over three time points. Scales covering training conditions were assessed by structured residency training, professional support, and dealing with lack of knowledge; working conditions were evaluated by work overload, job autonomy and social support, based on the Demand–Control–Support model. Multivariate ordinal logistic regression analyses with random intercept for longitudinal data were applied to determine the odds ratio of having a higher level of intention to leave clinical practice. Results In the models that considered training and working conditions separately to predict intention to leave clinical practice we found significant baseline effects and change effects. After modelling training and working conditions simultaneously, we found evidence that the change effect of job autonomy (OR 0.77, p = .005) was associated with intention to leave clinical practice, whereas for the training conditions, only the baseline effects of structured residency training (OR 0.74, p = .017) and dealing with lack of knowledge (OR 0.74, p = .026) predicted intention to leave clinical practice. Conclusions Junior doctors undergoing specialty training experience high workload in hospital practice and intense requirements in terms of specialty training. Our study indicates that simultaneously improving working conditions over time and establishing a high standard of specialty training conditions may prevent junior doctors from considering leaving clinical practice after residency training. PMID:24942360

Side-entry laser-beam zigzag irradiation of multiple channels in a microchip for simultaneous and highly sensitive detection of fluorescent analytes.

PubMed

Anazawa, Takashi; Yokoi, Takahide; Uchiho, Yuichi

2015-09-01

A simple and highly sensitive technique for laser-induced fluorescence detection on multiple channels in a plastic microchip was developed, and its effectiveness was demonstrated by laser-beam ray-trace simulations and experiments. In the microchip, with refractive index nC, A channels and B channels are arrayed alternately and respectively filled with materials with refractive indexes nA for electrophoresis analysis and nB for laser-beam control. It was shown that a laser beam entering from the side of the channel array traveled straight and irradiated all A channels simultaneously and effectively because the refractive actions by the A and B channels were counterbalanced according to the condition nA < nC < nB. This technique is thus called "side-entry laser-beam zigzag irradiation". As a demonstration of the technique, when nC = 1.53, nA = 1.41, nB = 1.66, and the cross sections of both eight A channels and seven B channels were the same isosceles trapezoids with 97° base angle, laser-beam irradiation efficiency on the eight A channels by the simulations was 89% on average and coefficient of variation was 4.4%. These results are far superior to those achieved by other conventional methods such as laser-beam expansion and scanning. Furthermore, fluorescence intensity on the eight A channels determined by the experiments agreed well with that determined by the simulations. Therefore, highly sensitive and uniform fluorescence detection on eight A channels was achieved. It is also possible to fabricate the microchips at low cost by plastic-injection molding and to make a simple and compact detection system, thereby promoting actual use of the proposed side-entry laser-beam zigzag irradiation in various fields.

Using counts to simultaneously estimate abundance and detection probabilities in a salamander community

USGS Publications Warehouse

Dodd, C.K.; Dorazio, R.M.

2004-01-01

A critical variable in both ecological and conservation field studies is determining how many individuals of a species are present within a defined sampling area. Labor intensive techniques such as capture-mark-recapture and removal sampling may provide estimates of abundance, but there are many logistical constraints to their widespread application. Many studies on terrestrial and aquatic salamanders use counts as an index of abundance, assuming that detection remains constant while sampling. If this constancy is violated, determination of detection probabilities is critical to the accurate estimation of abundance. Recently, a model was developed that provides a statistical approach that allows abundance and detection to be estimated simultaneously from spatially and temporally replicated counts. We adapted this model to estimate these parameters for salamanders sampled over a six vear period in area-constrained plots in Great Smoky Mountains National Park. Estimates of salamander abundance varied among years, but annual changes in abundance did not vary uniformly among species. Except for one species, abundance estimates were not correlated with site covariates (elevation/soil and water pH, conductivity, air and water temperature). The uncertainty in the estimates was so large as to make correlations ineffectual in predicting which covariates might influence abundance. Detection probabilities also varied among species and sometimes among years for the six species examined. We found such a high degree of variation in our counts and in estimates of detection among species, sites, and years as to cast doubt upon the appropriateness of using count data to monitor population trends using a small number of area-constrained survey plots. Still, the model provided reasonable estimates of abundance that could make it useful in estimating population size from count surveys.

Rapid and high-precision measurement of sulfur isotope and sulfur concentration in sediment pore water by multi-collector inductively coupled plasma mass spectrometry.

PubMed

Bian, Xiao-Peng; Yang, Tao; Lin, An-Jun; Jiang, Shao-Yong

2015-01-01

We have developed a technique for the rapid, precise and accurate determination of sulfur isotopes (δ(34)S) by MC-ICP-MS applicable to a range of sulfur-bearing solutions of different sulfur content. The 10 ppm Alfa-S solution (ammonium sulfate solution, working standard of the lab of the authors) was used to bracket other Alfa-S solutions of different concentrations and the measured δ(34)SV-CDT values of Alfa-S solutions deviate from the reference value to varying degrees (concentration effect). The stability of concentration effect has been verified and a correction curve has been constructed based on Alfa-S solutions to correct measured δ(34)SV-CDT values. The curve has been applied to AS solutions (dissolved ammonium sulfate from the lab of the authors) and pore water samples successfully, validating the reliability of our analytical method. This method also enables us to measure the sulfur concentration simultaneously when analyzing the sulfur isotope composition. There is a strong linear correlation (R(2)>0.999) between the sulfur concentrations and the intensity ratios of samples and the standard. We have constructed a regression curve based on Alfa-S solutions and this curve has been successfully used to determine sulfur concentrations of AS solutions and pore water samples. The analytical technique presented here enable rapid, precise and accurate S isotope measurement for a wide range of sulfur-bearing solutions - in particular for pore water samples with complex matrix and varying sulfur concentrations. Also, simultaneous measurement of sulfur concentrations is available. Copyright © 2014 Elsevier B.V. All rights reserved.

Clinical results of conformal versus intensity-modulated radiotherapy using a focal simultaneous boost for muscle-invasive bladder cancer in elderly or medically unfit patients.

PubMed

Lutkenhaus, Lotte J; van Os, Rob M; Bel, Arjan; Hulshof, Maarten C C M

2016-03-18

For elderly or medically unfit patients with muscle-invasive bladder cancer, cystectomy or chemotherapy are contraindicated. This leaves radical radiotherapy as the only treatment option. It was the aim of this study to retrospectively analyze the treatment outcome and associated toxicity of conformal versus intensity-modulated radiotherapy (IMRT) using a focal simultaneous tumor boost for muscle-invasive bladder cancer in patients not suitable for cystectomy. One hundred eighteen patients with T2-4 N0-1 M0 bladder cancer were analyzed retrospectively. Median age was 80 years. Treatment consisted of either a conformal box technique or IMRT and included a simultaneous boost to the tumor. To enable an accurate boost delivery, fiducial markers were placed around the tumor. Patients were treated with 40 Gy in 20 fractions to the elective treatment volumes, and a daily tumor boost up to 55-60 Gy. Clinical complete response was seen in 87 % of patients. Three-year overall survival was 44 %, with a locoregional control rate of 73 % at 3 years. Toxicity was low, with late urinary and intestinal toxicity rates grade ≥ 2 of 14 and 5 %, respectively. The use of IMRT reduced late intestinal toxicity, whereas fiducial markers reduced acute urinary toxicity. Radical radiotherapy using a focal boost is feasible and effective for elderly or unfit patients, with a 3-year locoregional control of 73 %. Toxicity rates were low, and were reduced by the use of IMRT and fiducial markers.

Simultaneous measurement for strain and temperature based on the twisted-tapering fiber structure

NASA Astrophysics Data System (ADS)

Ni, Wenjun; Lu, Ping; Liu, Deming; Zhang, Jiangshan

2017-10-01

A novel special fiber fabrication method based on a common single mode fiber (SMF) for dual-parameters measurement has been proposed and experimentally demonstrated. The fabrication setup is based on a three dimensional electric displacement platform which can realize the function of twisting and tapering at the same time. The proposed novel structure simultaneously undergoes the aforementioned two processes. Then a twisted-tapering fiber structure is formed. There are two dominant resonant wavelengths in the spectrum. Thus, simultaneous measurement for strain and temperature can be achieved. The following result shows that the strain measurement can be achieved by intensity demodulation, with the sensitivity of -0.01565 dB/μɛ and 0.00705 dB/μɛ corresponding to the dip1 and dip2, respectively. Therefore, the total sensitivity of the strain is 0.0227 dB/μɛ. Moreover, the cross impacts of the wavelength shift are - 0.772 pm/μɛ and 0.895 pm/μɛ. Similarly, the wavelength demodulation is selected to temperature measurement. The temperature sensitivity of 50.53pm/°C and 45.12pm/°C are obtained. The cross sensitivity of the intensity variation are 0.04058dB/°C and 0.02031 dB/°C. As a result, the dual-parameters can be described to a cross matrix of the sensitivity value. The proposed sensor has a great potential for engineering applications due to its compact structure, simple manufacture and low cost.

Novel algorithm for simultaneous component detection and pseudo-molecular ion characterization in liquid chromatography-mass spectrometry.

PubMed

Zhang, Yufeng; Wang, Xiaoan; Wo, Siukwan; Ho, Hingman; Han, Quanbin; Fan, Xiaohui; Zuo, Zhong

2015-01-01

Resolving components and determining their pseudo-molecular ions (PMIs) are crucial steps in identifying complex herbal mixtures by liquid chromatography-mass spectrometry. To tackle such labor-intensive steps, we present here a novel algorithm for simultaneous detection of components and their PMIs. Our method consists of three steps: (1) obtaining a simplified dataset containing only mono-isotopic masses by removal of background noise and isotopic cluster ions based on the isotopic distribution model derived from all the reported natural compounds in dictionary of natural products; (2) stepwise resolving and removing all features of the highest abundant component from current simplified dataset and calculating PMI of each component according to an adduct-ion model, in which all non-fragment ions in a mass spectrum are considered as PMI plus one or several neutral species; (3) visual classification of detected components by principal component analysis (PCA) to exclude possible non-natural compounds (such as pharmaceutical excipients). This algorithm has been successfully applied to a standard mixture and three herbal extract/preparations. It indicated that our algorithm could detect components' features as a whole and report their PMI with an accuracy of more than 98%. Furthermore, components originated from excipients/contaminants could be easily separated from those natural components in the bi-plots of PCA. Copyright © 2014 Elsevier B.V. All rights reserved.

Development of a multichannel optical system for differential cortical measurement

NASA Astrophysics Data System (ADS)

Maki, Atsushi; Yamashita, Yuichi; Watanabe, Eiju; Koizumi, Hideaki

1997-08-01

A prototype system based on intensity-modulation spectroscopy (IMS) was produced with the goal of developing 'optoencephalography' as a new instrument for clinical application and for investigating human brain functions. This system can use dual wavelengths (787 and 827 nm) to simultaneously measure reflectances at 8 measurement positions on the human head. Using the system, we measured the changes in blood circulation and oxygenation changes caused by epileptic seizures and specific brain functions. The former measurements were made simultaneously with tests to determine the epileptic focus by using single-photon-emission computed tomography (SPECT) and electrodes set in the brian. Four measurement positions were fixed in each temporal region. The areas where cerebral blood flow increased, as observed by SPECT, corresponded to the positions where the regional cerebral blood volume (rCBV) increased, as measured by the IMS system. Furthermore, the timing of the epileptic seizures, as measured by the depth-electrodes, corresponded to the timing of the increase in rCBV measured by the prototype system. Our measurements of changes in blood circulation as a result of brain functions were made for motor functions to compare the differences between the right and left hemisphere in how they respond to specific functions. Four measurement positions were set in bilateral motor areas. Significant differences in blood circulation in connection with brain activities were observed between the right and left hemispheres.

Simultaneous minimization of leaf travel distance and tongue-and-groove effect for segmental intensity-modulated radiation therapy.

PubMed

Dai, Jianrong; Que, William

2004-12-07

This paper introduces a method to simultaneously minimize the leaf travel distance and the tongue-and-groove effect for IMRT leaf sequences to be delivered in segmental mode. The basic idea is to add a large enough number of openings through cutting or splitting existing openings for those leaf pairs with openings fewer than the number of segments so that all leaf pairs have the same number of openings. The cutting positions are optimally determined with a simulated annealing technique called adaptive simulated annealing. The optimization goal is set to minimize the weighted summation of the leaf travel distance and tongue-and-groove effect. Its performance was evaluated with 19 beams from three clinical cases; one brain, one head-and-neck and one prostate case. The results show that it can reduce the leaf travel distance and (or) tongue-and-groove effect; the reduction of the leaf travel distance reaches its maximum of about 50% when minimized alone; the reduction of the tongue-and-groove reaches its maximum of about 70% when minimized alone. The maximum reduction in the leaf travel distance translates to a 1 to 2 min reduction in treatment delivery time per fraction, depending on leaf speed. If the method is implemented clinically, it could result in significant savings in treatment delivery time, and also result in significant reduction in the wear-and-tear of MLC mechanics.

The outcomes of simultaneous liver and kidney transplantation using donation after cardiac death organs.

PubMed

Alhamad, Tarek; Spatz, Christin; Uemura, Tadahiro; Lehman, Eric; Farooq, Umar

2014-12-15

There has been a remarkable increase in simultaneous liver and kidney transplantations (SLK). As organ demand has increased, so has the use of donation after cardiac death (DCD). However, little is known about the outcomes of DCD in SLK. We performed a retrospective analysis using the United Network for Organ Sharing database to compare the outcomes of DCD SLK to donation after brain death (DBD) and determine the impact of donor and recipient factors on allograft and patient survival. Between 2002 and 2011, a total of 3,026 subjects received SLK from DBD and 98 from DCD. Kidney, liver, and patient survival from DCD donors were inferior to DBD at 1, 3, and 5 years (P=0.0056, P=0.0035, and P=0.0205, respectively). With the use of the Cox model, DCD was a significant risk factor for kidney and liver allograft failure and patient mortality. Recipient factors that were associated with worse allograft and patient outcomes included black race, diabetes, being on a ventilator, hospitalization, delayed graft function, hepatocellular carcinoma, and intensive care unit stay. Older age of the donor was also associated with worse outcomes. Despite the decreased allograft and patient survival compared with DBD, DCD SLK provides an acceptable option for SLK, with a survival probability of more than 50% at 5 years.

The detection of the electric field vertical distribution underneath thundercloud: Principle and applications

NASA Technical Reports Server (NTRS)

Soula, Serge; Chauzy, Serge

1991-01-01

During the Florida 89 experiment at Kennedy Space Center, a new system was used in order to obtain the vertical distribution of the electric field underneath thunderstorms. It consists of a standard shutter field mill at ground level and five other field sensors suspended from a cable fastened to a tethered balloon located at an altitude of about 1000 meters. It also includes a reception station for telemetered information transmitted by sensors, a processing system in order to store data, and real time display on a screen to show the simultaneous field variations at each level along with the instantaneous electric field profile. The first results obtained show the great importance of the electric field vertical distribution. The field detected at a height of 600m reaches 65 kV/m while that at the surface does not exceed 5 kV/m. The field intensity in altitude is a better criterion for determining the right moment to launch a rocket devoted to flash triggering. Using Gauss's law, the simultaneous field variations at several levels are used in order to evaluate charge densities. Average values close to 1nC.m(-3) are calculated in layers up to 600 m. The calculation of different average charge densities leads to the characterization of the layer between cloud and ground just before the leader propagation in the case of cloud to ground flash.

Spectrophotometric simultaneous determination of Rabeprazole Sodium and Itopride Hydrochloride in capsule dosage form

NASA Astrophysics Data System (ADS)

Sabnis, Shweta S.; Dhavale, Nilesh D.; Jadhav, Vijay. Y.; Gandhi, Santosh V.

2008-03-01

A new simple, economical, rapid, precise and accurate method for simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form has been developed. The method is based on ratio spectra derivative spectrophotometry. The amplitudes in the first derivative of the corresponding ratio spectra at 231 nm (minima) and 260 nm were selected to determine rabeprazole sodium and itopride hydrochloride, respectively. The method was validated with respect to linearity, precision and accuracy.

Spectrophotometric simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form.

PubMed

Sabnis, Shweta S; Dhavale, Nilesh D; Jadhav, Vijay Y; Gandhi, Santosh V

2008-03-01

A new simple, economical, rapid, precise and accurate method for simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form has been developed. The method is based on ratio spectra derivative spectrophotometry. The amplitudes in the first derivative of the corresponding ratio spectra at 231nm (minima) and 260nm were selected to determine rabeprazole sodium and itopride hydrochloride, respectively. The method was validated with respect to linearity, precision and accuracy.

Müller glial cells contribute to dim light vision in the spectacled caiman (Caiman crocodilus fuscus): Analysis of retinal light transmission.

PubMed

Agte, Silke; Savvinov, Alexey; Karl, Anett; Zayas-Santiago, Astrid; Ulbricht, Elke; Makarov, Vladimir I; Reichenbach, Andreas; Bringmann, Andreas; Skatchkov, Serguei N

2018-05-16

In this study, we show the capability of Müller glial cells to transport light through the inverted retina of reptiles, specifically the retina of the spectacled caimans. Thus, confirming that Müller cells of lower vertebrates also improve retinal light transmission. Confocal imaging of freshly isolated retinal wholemounts, that preserved the refractive index landscape of the tissue, indicated that the retina of the spectacled caiman is adapted for vision under dim light conditions. For light transmission experiments, we used a setup with two axially aligned objectives imaging the retina from both sides to project the light onto the inner (vitreal) surface and to detect the transmitted light behind the retina at the receptor layer. Simultaneously, a confocal microscope obtained images of the Müller cells embedded within the vital tissue. Projections of light onto several representative Müller cell trunks within the inner plexiform layer, i.e. (i) trunks with a straight orientation, (ii) trunks which are formed by the inner processes and (iii) trunks which get split into inner processes, were associated with increases in the intensity of the transmitted light. Projections of light onto the periphery of the Müller cell endfeet resulted in a lower intensity of transmitted light. In this way, retinal glial (Müller) cells support dim light vision by improving the signal-to-noise ratio which increases the sensitivity to light. The field of illuminated photoreceptors mainly include rods reflecting the rod dominance of the of tissue. A subpopulation of Müller cells with downstreaming cone cells led to a high-intensity illumination of the cones, while the surrounding rods were illuminated by light of lower intensity. Therefore, Müller cells that lie in front of cones may adapt the intensity of the transmitted light to the different sensitivities of cones and rods, presumably allowing a simultaneous vision with both receptor types under dim light conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparative evaluation of non-structural protein-antibody detecting ELISAs for foot-and-mouth disease sero-surveillance under intensive vaccination.

PubMed

Sharma, Gaurav Kumar; Mohapatra, Jajati Keshari; Mahajan, Sonalika; Matura, Rakesh; Subramaniam, Saravanan; Pattnaik, Bramhadev

2014-10-01

Foot-and-mouth disease is a highly infectious and contagious disease of livestock animals with transboundary and economical importance. Animals in the endemic settings are regularly vaccinated in addition to intensive surveillance for control of the disease. Under intensive vaccination, detection of infected animals among the vaccinated population is essential to monitor the infection and to track down the virus movement. Sero-surveillance and retrospective disease diagnosis is performed primarily by detecting antibodies against non-structural proteins (NSPs) of FMD virus which are usually absent in the inactivated vaccine formulations. The study was conducted with an objective to compare simultaneously performance of six NSP ELISAs in detecting infected animals in the areas covered under intensive vaccination, and to assess their fit-for-purpose attribute for sero-surveillance of FMD in India. A panel of bovine serum samples consisting of samples collected from infected with FMDV, vaccinated and naive animals were constituted. In addition, samples collected at random from areas having varied FMD situation and vaccination coverage were tested simultaneously by the six NSP ELISAs to compare their performances. The four indigenous assays showed varying degrees of correlation with the two commercial kits. The study validated that, in all the groups of samples, the indigenous assays were equally sensitive and specific as the two commercial kits. Among all the six assays, PrioCheck and in-house 3ABC I-ELISAs showed maximum sensitivity for detection of infected animals, whereas 3AB3 I-ELISA and 3ABC C-ELISA showed maximum specificity. The study concluded that the in-house available assays are equally capable as the commercially available kits for differentiation of infected animals under intensive vaccination and identifies the 3AB3 I-ELISA with optimum sensitivity and specificity for the purpose of sero-surveillance in India. Copyright © 2014 Elsevier B.V. All rights reserved.

Simultaneous determination of macronutrients, micronutrients and trace elements in mineral fertilizers by inductively coupled plasma optical emission spectrometry

NASA Astrophysics Data System (ADS)

de Oliveira Souza, Sidnei; da Costa, Silvânio Silvério Lopes; Santos, Dayane Melo; dos Santos Pinto, Jéssica; Garcia, Carlos Alexandre Borges; Alves, José do Patrocínio Hora; Araujo, Rennan Geovanny Oliveira

2014-06-01

An analytical method for simultaneous determination of macronutrients (Ca, Mg, Na and P), micronutrients (Cu, Fe, Mn and Zn) and trace elements (Al, As, Cd, Pb and V) in mineral fertilizers was optimized. Two-level full factorial design was applied to evaluate the optimal proportions of reagents used in the sample digestion on hot plate. A Doehlert design for two variables was used to evaluate the operating conditions of the inductively coupled plasma optical emission spectrometer in order to accomplish the simultaneous determination of the analyte concentrations. The limits of quantification (LOQs) ranged from 2.0 mg kg- 1 for Mn to 77.3 mg kg- 1 for P. The accuracy and precision of the proposed method were evaluated by analysis of standard reference materials (SRMs) of Western phosphate rock (NIST 694), Florida phosphate rock (NIST 120C) and Trace elements in multi-nutrient fertilizer (NIST 695), considered to be adequate for simultaneous determination. Twenty-one samples of mineral fertilizers collected in Sergipe State, Brazil, were analyzed. For all samples, the As, Ca, Cd and Pb concentrations were below the LOQ values of the analytical method. For As, Cd and Pb the obtained LOQ values were below the maximum limit allowed by the Brazilian Ministry of Agriculture, Livestock and Food Supply (Ministério da Agricultura, Pecuária e Abastecimento - MAPA). The optimized method presented good accuracy and was effectively applied to quantitative simultaneous determination of the analytes in mineral fertilizers by inductively coupled plasma optical emission spectrometry (ICP OES).

Simultaneous spectrophotometric determination of paracetamol and salicylamide in human serum and pharmaceutical formulations by a differential kinetic method.

PubMed

Zarei, Ali Reza; Afkhami, Abbas; Sarlak, Nahid

2005-01-01

A rapid, simple, and sensitive differential kinetic method is presented for the determinations of acetaminophen (also known as paracetamol) and salicylamide. The method is based on their oxidation reaction by Fe3+ ion in the presence of 1, 10-phenanthroline as indicator. The reactions can be monitored spectrophotometrically by measuring the increase in the absorbance of the solution at 510 nm. Two times were selected one in which only paracetamol is oxidized by Fe3+ ion and the other in which both drugs are oxidized by Fe3+ ion. The data were evaluated by the proportional equations method. The method allowed the simultaneous determination of paracetamol and salicylamide at concentrations between 0.5-20 and 1-40 microg/mL with relative standard deviations of 3.47 and 2.58%, respectively. The method was applied to the simultaneous determination of paracetamol and salicylamide in human serum and pharmaceutical formulations.

[Simultaneous determination of trace amounts of zinc, cadmium, lead and copper by the method of anodic voltammetry using factor experimental design].

PubMed

Koen, E

1975-01-01

Using the method of factor planning of the experiment, the author studies and demonstrates the influence exerted by the potential and time of electrolysis, and by the concentration of the background and elements on the heights of anodal peaks upon simultaneous determination of zinc, cadmium, lead and copper microconcentrations. On the ground of statistical elaboration of the results, the optimal condition for polarographic determination through anodal voltamperometry are outlined. According to the cyclic voltametry method, the electrod processes reversibility for zinc, cadmium and lead, as well as the incomplete reversibility for copper are established; the number of electrons participating in the electrochemical reaction are found using the method of gas coulometry. The possibility of simultaneous determination of the four elements' ultramicroconcentrations after the method of voltamperometry with enrichment is proved. The standard deviation is in the range 3.02 to 4.9.

Air- and Self-Broadened Half Widths, Pressure-Induced Shifts, and Line Mixing in the Nu(sub 2) Band of (12)CH4

NASA Technical Reports Server (NTRS)

Smith, M. A. H.; Benner, D. Chris; Pedroi-Cross, A.; Devi, V. Malathy

2013-01-01

Lorentz self- and air-broadened half width and pressure-induced shift coefficients and their dependences on temperature have been measured from laboratory absorption spectra for nearly 130 transitions in the nu(sub 2) band of (12)CH4. In addition line mixing coefficients (using the relaxation matrix element formalism) for both self- and airbroadening were experimentally determined for the first time for a small number of transitions in this band. Accurate line positions and absolute line intensities were also determined. These parameters were obtained by analyzing high-resolution (approx. 0.003 to 0.01 per cm) laboratory spectra of high-purity natural CH4 and air-broadened CH4 recorded at temperatures between 226 and 297 K using the McMath-Pierce Fourier transform spectrometer (FTS) located at the National Solar Observatory on Kitt Peak, Arizona. A multispectrum nonlinear least squares technique was used to fit short (5-15 per cm) spectral intervals in 24-29 spectra simultaneously. Parameters were determined for nu(sub 2) transitions up to J" = 16. The variations of the measured broadening and shift parameters with the rotational quantum number index and tetrahedral symmetry species are examined. The present results are also compared with previous measurements available in the literature.

Spectrophotometric and Spectrofluorimetric Studies on Azilsartan Medoxomil and Chlorthalidone to Be Utilized in Their Determination in Pharmaceuticals

PubMed Central

Ebeid, Walid M; Elkady, Ehab F; El-Zaher, Asmaa A; El-Bagary, Ramzia I; Patonay, Gabor

2014-01-01

The recently approved angiotensin II receptor blocker, azilsartan medoxomil (AZL), was determined spectrophotometrically and spectrofluorimetrically in its combination with chlorthalidone (CLT) in their combined dosage form. The UV-spectrophotometric technique depends on simultaneous measurement of the first derivative spectra for AZL and CLT at 286 and 257 nm, respectively, in methanol. The spectrofluorimetric technique depends on measurement of the fourth derivative of the synchronous spectra intensities of AZL in presence of CLT at 298 nm in methanol. The effects of different solvents on spectrophotometric and spectrofluorimetric responses were studied. For, the spectrofluorimetric study, the effect of pH and micelle-assisted fluorescence enhancement were also studied. Linearity, accuracy, and precision were found to be satisfactory over the concentration ranges of 8–50 μg mL−1 and 2–20 μg mL−1 for AZL and CLT, respectively, in the spectrophotometric method as well as 0.01–0.08 μg mL−1 for AZL in the spectrofluorimetric method. The methods were successfully applied for the determination of the studied drugs in their co-formulated tablets. The developed methods are inexpensive and simple for the quality control and routine analysis of the cited drugs in bulk and in pharmaceuticals. PMID:24855334

Feasibility Study of Extended-Gate-Type Silicon Nanowire Field-Effect Transistors for Neural Recording

PubMed Central

Kang, Hongki; Kim, Jee-Yeon; Choi, Yang-Kyu; Nam, Yoonkey

2017-01-01

In this research, a high performance silicon nanowire field-effect transistor (transconductance as high as 34 µS and sensitivity as 84 nS/mV) is extensively studied and directly compared with planar passive microelectrode arrays for neural recording application. Electrical and electrochemical characteristics are carefully characterized in a very well-controlled manner. We especially focused on the signal amplification capability and intrinsic noise of the transistors. A neural recording system using both silicon nanowire field-effect transistor-based active-type microelectrode array and platinum black microelectrode-based passive-type microelectrode array are implemented and compared. An artificial neural spike signal is supplied as input to both arrays through a buffer solution and recorded simultaneously. Recorded signal intensity by the silicon nanowire transistor was precisely determined by an electrical characteristic of the transistor, transconductance. Signal-to-noise ratio was found to be strongly dependent upon the intrinsic 1/f noise of the silicon nanowire transistor. We found how signal strength is determined and how intrinsic noise of the transistor determines signal-to-noise ratio of the recorded neural signals. This study provides in-depth understanding of the overall neural recording mechanism using silicon nanowire transistors and solid design guideline for further improvement and development. PMID:28350370

Feasibility Study of Extended-Gate-Type Silicon Nanowire Field-Effect Transistors for Neural Recording.

PubMed

Kang, Hongki; Kim, Jee-Yeon; Choi, Yang-Kyu; Nam, Yoonkey

2017-03-28

In this research, a high performance silicon nanowire field-effect transistor (transconductance as high as 34 µS and sensitivity as 84 nS/mV) is extensively studied and directly compared with planar passive microelectrode arrays for neural recording application. Electrical and electrochemical characteristics are carefully characterized in a very well-controlled manner. We especially focused on the signal amplification capability and intrinsic noise of the transistors. A neural recording system using both silicon nanowire field-effect transistor-based active-type microelectrode array and platinum black microelectrode-based passive-type microelectrode array are implemented and compared. An artificial neural spike signal is supplied as input to both arrays through a buffer solution and recorded simultaneously. Recorded signal intensity by the silicon nanowire transistor was precisely determined by an electrical characteristic of the transistor, transconductance. Signal-to-noise ratio was found to be strongly dependent upon the intrinsic 1/f noise of the silicon nanowire transistor. We found how signal strength is determined and how intrinsic noise of the transistor determines signal-to-noise ratio of the recorded neural signals. This study provides in-depth understanding of the overall neural recording mechanism using silicon nanowire transistors and solid design guideline for further improvement and development.

Simultaneous detection of Escherichia coli O157:H7 and Salmonella Typhimurium using quantum dots as fluorescence labels.

PubMed

Yang, Liju; Li, Yanbin

2006-03-01

In this study, we explored the use of semiconductor quantum dots (QDs) as fluorescence labels in immunoassays for simultaneous detection of two species of foodborne pathogenic bacteria, Escherichia coli O157:H7 and Salmonella Typhimurium. QDs with different sizes can be excited with a single wavelength of light, resulting in different emission peaks that can be measured simultaneously. Highly fluorescent semiconductor quantum dots with different emission wavelengths (525 nm and 705 nm) were conjugated to anti-E. coli O157 and anti-Salmonella antibodies, respectively. Target bacteria were separated from samples by using specific antibody coated magnetic beads. The bead-cell complexes reacted with QD-antibody conjugates to form bead-cell-QD complexes. Fluorescent microscopic images of QD labeled E. coli and Salmonella cells demonstrated that QD-antibody conjugates could evenly and completely attach to the surface of bacterial cells, indicating that the conjugated QD molecules still retain their effective fluorescence, while the conjugated antibody molecules remain active and are able to recognize their specific target bacteria in a complex mixture. The intensities of fluorescence emission peaks at 525 nm and 705 nm of the final complexes were measured for quantitative detection of E. coli O157:H7 and S. Typhimurium simultaneously. The fluorescence intensity (FI) as a function of cell number (N) was found for Salmonella and E. coli, respectively. The regression models can be expressed as: FI = 60.6 log N- 250.9 with R(2) = 0.97 for S. Typhimurium, and FI = 77.8 log N- 245.2 with R(2) = 0.91 for E. coli O157:H7 in the range of cell numbers from 10(4) to 10(7) cfu ml(-1). The detection limit of this method was 10(4) cfu ml(-1). The detection could be completed within 2 hours. The principle of this method could be extended to detect multiple species of bacteria (3-4 species) simultaneously, depending on the availability of each type of QD-antibody conjugates with a unique emission peak and the antibody coated magnetic beads specific to each species of bacteria.

Simultaneous determination of mercury and organic carbon using a direct mercury analyzer: Mercury profiles in sediment cores from oxbow lakes in the Mississippi Delta

USDA-ARS?s Scientific Manuscript database

Sediment cores from seasonal wetland and open water areas from six oxbow lakes in the Mississippi River alluvial flood plain were analyzed for total-mercury (Hg) using a direct mercury analyzer (DMA). In the process we evaluated the feasibility of simultaneously determining organic matter content by...

Simultaneous spectrophotometric determination of salbutamol and bromhexine in tablets.

PubMed

Habib, I H I; Hassouna, M E M; Zaki, G A

2005-03-01

Typical anti-mucolytic drugs called salbutamol hydrochloride and bromhexine sulfate encountered in tablets were determined simultaneously either by using linear regression at zero-crossing wavelengths of the first derivation of UV-spectra or by application of multiple linear partial least squares regression method. The results obtained by the two proposed mathematical methods were compared with those obtained by the HPLC technique.

Health Sector Reform and Social Determinants of Health: building up theoretical and methodological interconnections to approach complex global challenges.

PubMed

Junior, Garibaldi Dantas Gurgel

2014-01-01

Health Sector Reform and Social Determinants of Health are central issues for the current international policy debate, considering the turbulent scenario and the threat of economic recession in a global scale. Although these themes have been discussed for a long time, three major issues still calls the attention of the scientific community and health policymakers. The first one is the matter of how to approach scientifically the intricate connections between them in order to understand the consequences of policies for healthcare services, once this debate will become much more tensioned in the coming years. The second one is the lack of explanatory frameworks to investigate the policies of reform strategies, simultaneously observed in a variety of countries within distinct health services, which aim to achieve multiple and contradictory goals vis-à-vis the so-called social determinants of health. The third one is the challenge that governments face in developing and sustaining equitable health services, bearing in mind the intense political dispute behind the health sector reform processes. This article discusses an all-embracing theoretical and methodological scheme to address these questions. The aim is to connect macro- and middle-range theories to examine Social Determinants and Health Sector Reform interdependent issues, with view to developing new knowledge and attaining scientific understanding upon the role of universal and equitable healthcare systems, in order to avoid deepening economic crises.

Effect of High-Pass Filtering on the Neonatal Auditory Brainstem Response to Air- and Bone-Conducted Clicks.

ERIC Educational Resources Information Center

Stuart, Andrew; Yang, Edward Y.

1994-01-01

Simultaneous 3- channel recorded auditory brainstem responses (ABR) were obtained from 20 neonates with various high-pass filter settings and low intensity levels. Results support the advocacy of less restrictive high-pass filtering for neonatal and infant ABR screening to air-conducted and bone-conducted clicks. (Author/JDD)

Project ERIC - The search for environmental reactions induced by comets

NASA Astrophysics Data System (ADS)

Mendillo, M.; Sigwarth, J. B.; Craven, J. D.; Frank, L. A.; Holt, J.; Tetenbaum, D.

A sounding rocket experiment was conducted to release molecules of H2O and CO2 into the daytime ionosphere within the simultaneous fields of view of the Millstone Hill radar and the Dynamics Explorer UV imager. Preliminary results confirm the creation of chemically-induced F-region plasma depletions and reduced UV intensities from the modified region.

A microhistological technique for analysis of food habits of mycophagous rodents.

Treesearch

Patrick W. McIntire; Andrew B. Carey

1989-01-01

We present a technique, based on microhistological analysis of fecal pellets, for quantifying the diets of forest rodents. This technique provides for the simultaneous recording of fungal spores and vascular plant material. Fecal samples should be freeze dried, weighed, and rehydrated with distilled water. We recommend a minimum sampling intensity of 50 fields of view...

Odor and odorous chemical emissions from animal buildings: Part 5 - Correlations between odor intensities and chemical concentrations (GC-MS/O)

USDA-ARS?s Scientific Manuscript database

Simultaneous chemical and sensory analysis based on gas chromatography-mass spectrometry-olfactometry (GC-MS-O) of air samples from livestock operations is a very useful approach for quantification of target odorous gases and also for ranking of odorous compounds. This information can help link spec...

Redundancy in Simultaneously Presented Audio-Visual Message Elements as a Determinant of Recall. Final Report.

ERIC Educational Resources Information Center

Baldwin, Thomas F.

Man seems unable to retain different information from different senses or channels simultaneously; one channel gains full attention. However, it is hypothesized that if the message elements arriving simultaneously from audio and visual channels are redundant, man will retain the information. An attempt was made to measure redundancy in the audio…

Fire suppression effectiveness for simultaneous fires: an examination of fire histories

Treesearch

Larry F. Bednar; Romain Mees; David Strauss

1990-01-01

We examined fire and weather records for areas of the western United States for the period 1970-1984 to determine the effects of simultaneous wildfire occurrence on fire suppression efforts. Burning conditions were accounted for by use of short strings of fires which involved simultaneous suppression efforts. These strings were matched with closely preceding isolated...

Striatal and Hippocampal Entropy and Recognition Signals in Category Learning: Simultaneous Processes Revealed by Model-Based fMRI

ERIC Educational Resources Information Center

Davis, Tyler; Love, Bradley C.; Preston, Alison R.

2012-01-01

Category learning is a complex phenomenon that engages multiple cognitive processes, many of which occur simultaneously and unfold dynamically over time. For example, as people encounter objects in the world, they simultaneously engage processes to determine their fit with current knowledge structures, gather new information about the objects, and…

Method for the Simultaneous Quantitation of Apolipoprotein E Isoforms using Tandem Mass Spectrometry

PubMed Central

Wildsmith, Kristin R.; Han, Bomie; Bateman, Randall J.

2009-01-01

Using Apolipoprotein E (ApoE) as a model protein, we developed a protein isoform analysis method utilizing Stable Isotope Labeling Tandem Mass Spectrometry (SILT MS). ApoE isoforms are quantitated using the intensities of the b and y ions of the 13C-labeled tryptic isoform-specific peptides versus unlabeled tryptic isoform-specific peptides. The ApoE protein isoform analysis using SILT allows for the simultaneous detection and relative quantitation of different ApoE isoforms from the same sample. This method provides a less biased assessment of ApoE isoforms compared to antibody-dependent methods, and may lead to a better understanding of the biological differences between isoforms. PMID:19653990

Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

DOEpatents

Dolbeare, F.A.; Gray, J.W.

1983-10-18

A method for the simultaneous flow cylometric measurement of total cellular DNA content and of the uptake of DNA precursors as a measure of DNA synthesis during various phases of the cell cycle in normal and malignant cells in vitro and in vivo is described. The method comprises reacting cells with labelled halodeoxyuridine (HdU), partially denaturing cellular DNA, adding to the reaction medium monoclonal antibodies (mabs) reactive with HdU, reacting the bound mabs with a second labelled antibody, incubating the mixture with a DNA stain, and measuring simultaneously the intensity of the DNA stain as a measure of the total cellular DNA and the HdU incorporated as a measure of DNA synthesis. (ACR)

A battery-less photo-detector enabled with simultaneous ferroelectric sensing and energy harnessing mechanism

NASA Astrophysics Data System (ADS)

Lai, Szu Cheng; Yao, Kui; Chen, Yi Fan

2013-08-01

A self-sustainable mechanism for simultaneously sensing and harnessing photon energy was proposed and implemented to create a battery-less and wire-less ultraviolet sensor made of ferroelectric lead lanthanum zirconate titanate thin film with in-plane polarization configuration. The mechanism involved accumulating and storing the photovoltaic charge, and transferring the stored charge via a piezoelectric switch to a radio frequency transmitter. The time-interval between the radio frequency pulses generated by the transmitter was inversely proportional to the photo-intensity. The sustainability of the operation was ascribed to the low leakage, high photovoltage, and linear current-voltage characteristics of ferroelectric sensing material instead of semiconductors.

Individual and simultaneous spectrophotometric determination of dapsone and metoclopramide HCl in pharmaceutical dosage forms and synthetic binary mixtures.

PubMed

Omran, Ahmed Ahmed

2005-11-01

A rapid, sensitive and selective spectrophotometric method has been developed for the quantitative determination of dapsone (DAP) and metoclopramide hydrochloride (MCP) in both pure and dosage forms. Individual and simultaneous methods are based on the diazo coupling reaction of these drugs with benzoylacetone (BAC) in alkaline medium. The resulting azo dyes exhibit maximum absorption at 437 and 411 nm with a molar absorptivity of 4.14x10(4) and 2.97x10(4) l mol-1 cm-1 for DAP and MCP, respectively. Simultaneous determination of DAP and MCP was developed utilizing first-order digital derivative spectrophotometry. All variables have been optimized. No interferences were observed from drug excipients and the validity of the methods was tested against reference methods.

Simultaneous quantitative determination of fluorine and sodium monofluorophosphate in oral hygiene products.

PubMed

Wang, L H

2001-01-01

An ion chromatographic method for simultaneous quantitative determination of fluorine and sodium monofluorophosphate in oral hygiene products is described. The liquid chromatographic system consisted of an IC A1 polymethacrylate-based anion exchanger and carbonate buffer (pH 9.85) as the mobile phase with a conductive detector. Various excipient ions were investigated with respect to their interference with the determination of fluoride. Comparison with results obtained from a fluoride-ion electrode technique show good agreement.

A quantitative method for determining spatial discriminative capacity.

PubMed

Zhang, Zheng; Tannan, Vinay; Holden, Jameson K; Dennis, Robert G; Tommerdahl, Mark

2008-03-10

The traditional two-point discrimination (TPD) test, a widely used tactile spatial acuity measure, has been criticized as being imprecise because it is based on subjective criteria and involves a number of non-spatial cues. The results of a recent study showed that as two stimuli were delivered simultaneously, vibrotactile amplitude discrimination became worse when the two stimuli were positioned relatively close together and was significantly degraded when the probes were within a subject's two-point limen. The impairment of amplitude discrimination with decreasing inter-probe distance suggested that the metric of amplitude discrimination could possibly provide a means of objective and quantitative measurement of spatial discrimination capacity. A two alternative forced-choice (2AFC) tracking procedure was used to assess a subject's ability to discriminate the amplitude difference between two stimuli positioned at near-adjacent skin sites. Two 25 Hz flutter stimuli, identical except for a constant difference in amplitude, were delivered simultaneously to the hand dorsum. The stimuli were initially spaced 30 mm apart, and the inter-stimulus distance was modified on a trial-by-trial basis based on the subject's performance of discriminating the stimulus with higher intensity. The experiment was repeated via sequential, rather than simultaneous, delivery of the same vibrotactile stimuli. Results obtained from this study showed that the performance of the amplitude discrimination task was significantly degraded when the stimuli were delivered simultaneously and were near a subject's two-point limen. In contrast, subjects were able to correctly discriminate between the amplitudes of the two stimuli when they were sequentially delivered at all inter-probe distances (including those within the two-point limen), and improved when an adapting stimulus was delivered prior to simultaneously delivered stimuli. Subjects' capacity to discriminate the amplitude difference between two vibrotactile stimulations was degraded as the inter-stimulus distance approached the limit of their two-point spatial discriminative capacity. This degradation of spatial discriminative capacity lessened when an adapting stimulus was used. Performance of the task, as well as improvement on the task with adaptation, would most likely be impaired if the cortical information processing capacity of a subject or subject population were systemically altered, and thus, the methods described could be effective measures for use in clinical or clinical research applications.

Temperature dependence of optically stimulated luminescence of α-Al2O3:C,Mg

NASA Astrophysics Data System (ADS)

Kalita, J. M.; Chithambo, M. L.

2017-11-01

Thermal assistance and thermal quenching are two independently acting thermodynamic phenomena that simultaneously affect the stimulation of luminescence. We have studied thermal assistance to luminescence optically stimulated from α-Al2O3:C,Mg. Since thermal assistance causes only a minor change in the luminescence intensity, measurements were made after the sample had been pre-exposed to stimulating light to reduce its intensity significantly, that is, in the slow component of its decay curve. The luminescence intensity was monitored as a function of measurement temperature between 30 and 130 °C. The intensity goes through a peak at 60 °C due to competing effects of thermal assistance and thermal quenching. The initial increase of intensity is attributed to dominant thermal assistance whereas the subsequent decrease of intensity is ascribed to dominant thermal quenching. The activation energy for thermal assistance was calculated for the main electron trap of an un-annealed sample as 0.324 ± 0.020 eV and in a sample annealed at 900 °C as 0.416 ± 0.028 eV. Implications of such differences in the value of the activation energy for thermal assistance are considered.

ESR signals in a core from the lake Baikal: implications for climate change

NASA Astrophysics Data System (ADS)

Toyoda, S.; Hidaka, K.; Takamatsu, N.

2002-12-01

Electron spin resonance dating method has been used for obtaining ages of Quaternary events using speleothem, corals, shells, hydroxyapatite in tooth enamel, gypsum, and quartz (Ikeya, 1993). Recently, it was also found that an ESR signal in quartz of loess is useful to discuss the variation of its origin (e. g. Ono et al., 1998). The method is based on the signal intensity of the heat treated (gamma ray irradiation and heating, Toyoda and Ikeya, 1991) E 1_f center (an unpaired electron at an oxygen vacancy) correlates the original (crystallization) age of quartz (e.g. Toyoda and Hattori, 2000). If there is variation in ages of basement rocks (origin of loess), ESR signal intensity may differentiate the origins. We applied the present method to sediments taken from the core of the lake Baikal with the length of 600m. The ESR intensity of the heat treated E1_f center was determined by an ESR measurement at room temperature for about 100 mg of the bulk samples, with a microwave power of 0.01 mW, field modulation amplitude of 0.1 mT, and with a scan range of 5 mT around g=2.001 after gamma ray irradiation to 1 kGy and subsequent heating at 300C. The ESR signal of the E1_f center was clearly observed although other minerals are also included in the bulk sample. The peak to peak height was taken as the signal intensity after normalizing the height with the gain (the instrumental setting at the time of measurement), mass, and the intensity of the standard simultaneously measured with the sample. The concentrations of the quartz in the bulk samples were obtained by the X ray diffraction study, normalizing the peak intensity with a standard CeO sample. The variation of the ESR signal intensity with depth of the core will be presented together with the possible climate change which may have caused the variation. References M. Ikeya (1993) New applications of electron spin resonance, dating, dosimetry and imaging, World Scientific. Y. Ono, T. Naruse, M. Ikeya, H. Kohno, and S. Toyoda (1998) Global Planet. Change, 18, 129-135. S. Toyoda and M. Ikeya (1991) Geochem. J. 25, 437-445. S. Toyoda and W. Hattori (2000) Appl. Radiat. Isot., 52, 1351-1356.

Computational method for multi-modal microscopy based on transport of intensity equation

NASA Astrophysics Data System (ADS)

Li, Jiaji; Chen, Qian; Sun, Jiasong; Zhang, Jialin; Zuo, Chao

2017-02-01

In this paper, we develop the requisite theory to describe a hybrid virtual-physical multi-modal imaging system which yields quantitative phase, Zernike phase contrast, differential interference contrast (DIC), and light field moment imaging simultaneously based on transport of intensity equation(TIE). We then give the experimental demonstration of these ideas by time-lapse imaging of live HeLa cell mitosis. Experimental results verify that a tunable lens based TIE system, combined with the appropriate post-processing algorithm, can achieve a variety of promising imaging modalities in parallel with the quantitative phase images for the dynamic study of cellular processes.

Time-resolved ESR spectra of the α-hydroxybenzyl-amine complex

NASA Astrophysics Data System (ADS)

Kawai, Akio; Kobori, Yasuhiro; Obi, Kinichi

1993-11-01

Time-resolved ESR spectra of the α-hydroxybenzyl radical were measured in benzene and 2-propanol solutions by the photo-dissociation of benzoin. The hyperfine structure (hfs) of α-hydroxybenzyl depends on the solvents. In a benzene solution containing triethylamine, two species with different hyperfine structure appeared simultaneously. As the ratio of intensity for the two species depends on the concentration of triethylamine, one of them is assigned to the bare α-hydroxybenzyl and the other to the 1:1 complex of α-hydroxybenzyl and triethylamine. The equilibrium constant of complex formation was estimated to be about 450 M -1 from the analysis of CIDEP intensities.

Retinal injury resulting from simultaneous exposure to radiation from two lasers with different wavelengths

NASA Astrophysics Data System (ADS)

Stolarski, David J.; Cain, Clarence P.; Schuster, Kurt J.; Imholte, Michelle; Carothers, Val C.; Buffington, Gavin D.; Edwards, Michael; Thomas, Robert J.; Rockwell, Benjamin A.

2005-04-01

To assess the retinal hazards related to simultaneous exposure from two lasers of separate wavelengths, the retinal effects of 5-second laser irradiation from 532 nm and 647 nm were determined in non-human primates. A total of six eyes were exposed using equal amounts of power to determine the damage levels. The results were combined with those of previous, two-wavelength studies done by our group and compared to damage models developed in our lab. The data were also compared to the calculations resulting from use of the currently accepted method of predicting hazards from simultaneous lasing.

Barium versus nonbarium stimuli: differences in taste intensity, chemesthesis, and swallowing behavior in healthy adult women.

PubMed

Nagy, Ahmed; Steele, Catriona M; Pelletier, Cathy A

2014-06-01

The authors examined the impact of barium on the perceived taste intensity of 7 different liquid tastant stimuli and the modulatory effect that these differences in perceived taste intensity have on swallowing behaviors. Participants were 80 healthy women, stratified by age group (<40; >60) and genetic taste status (supertasters; nontasters). Perceived taste intensity and chemesthetic properties (fizziness; burning-stinging) were rated for 7 tastant solutions (each prepared with and without barium) using the general Labeled Magnitude Scale. Tongue-palate pressures and submental surface electromyography (sEMG) were simultaneously measured during swallowing of these same randomized liquids. Path analysis differentiated the effects of stimulus, genetic taste status, age, barium condition, taste intensity, and an effortful saliva swallow strength covariate on swallowing. Barium stimuli were rated as having reduced taste intensity compared with nonbarium stimuli. Barium also dampened fizziness but did not influence burning-stinging sensation. The amplitudes of tongue-palate pressure or submental sEMG did not differ when swallowing barium versus nonbarium stimuli. Despite impacting taste intensity, the addition of barium to liquid stimuli does not appear to alter behavioral parameters of swallowing. Barium solutions can be considered to elicit behaviors that are similar to those used with nonbarium liquids outside the assessment situation.

Application of growth-phase based light-feeding strategies to simultaneously enhance Chlorella vulgaris growth and lipid accumulation.

PubMed

Sun, Yahui; Liao, Qiang; Huang, Yun; Xia, Ao; Fu, Qian; Zhu, Xun; Fu, Jingwei; Li, Jun

2018-05-01

Considering the variations of optimal light intensity required by microalgae cells along with growth phases, growth-phase light-feeding strategies were proposed and verified in this paper, aiming at boosting microalgae lipid productivity from the perspective of light conditions optimization. Experimental results demonstrate that under an identical time-averaged light intensity, the light-feeding strategies characterized by stepwise incremental light intensities showed a positive effect on biomass and lipid accumulation. The lipid productivity (235.49 mg L -1  d -1 ) attained under light-feeding strategy V (time-averaged light intensity: 225 μmol m -2  s -1 ) was 52.38% higher over that obtained under a constant light intensity of 225 μmol m -2  s -1 . Subsequently, based on light-feeding strategy V, microalgae lipid productivity was further elevated to 312.92 mg L -1  d -1 employing a two-stage based light-feeding strategy V 560 (time-averaged light intensity: 360 μmol m -2  s -1 ), which was 79.63% higher relative to that achieved under a constant light intensity of 360 μmol m -2  s -1 . Copyright © 2018 Elsevier Ltd. All rights reserved.

Time Series Modeling of Nano-Gold Immunochromatographic Assay via Expectation Maximization Algorithm.

PubMed

Zeng, Nianyin; Wang, Zidong; Li, Yurong; Du, Min; Cao, Jie; Liu, Xiaohui

2013-12-01

In this paper, the expectation maximization (EM) algorithm is applied to the modeling of the nano-gold immunochromatographic assay (nano-GICA) via available time series of the measured signal intensities of the test and control lines. The model for the nano-GICA is developed as the stochastic dynamic model that consists of a first-order autoregressive stochastic dynamic process and a noisy measurement. By using the EM algorithm, the model parameters, the actual signal intensities of the test and control lines, as well as the noise intensity can be identified simultaneously. Three different time series data sets concerning the target concentrations are employed to demonstrate the effectiveness of the introduced algorithm. Several indices are also proposed to evaluate the inferred models. It is shown that the model fits the data very well.

High-power THz to IR emission by femtosecond laser irradiation of random 2D metallic nanostructures.

PubMed

Zhang, Liangliang; Mu, Kaijun; Zhou, Yunsong; Wang, Hai; Zhang, Cunlin; Zhang, X-C

2015-07-24

Terahertz (THz) spectroscopic sensing and imaging has identified its potentials in a number of areas such as standoff security screening at portals, explosive detection at battle fields, bio-medical research, and so on. With these needs, the development of an intense and broadband THz source has been a focus of THz research. In this work, we report an intense (~10 mW) and ultra-broadband (~150 THz) THz to infrared (IR) source with a Gaussian wavefront, emitted from nano-pore-structured metallic thin films with femtosecond laser pulse excitation. The underlying mechanism has been proposed as thermal radiation. In addition, an intense coherent THz signal was generated through the optical rectification process simultaneously with the strong thermal signal. This unique feature opens up new avenues in biomedical research.

A chemometric-assisted method for the simultaneous determination of malachite green and crystal violet in water based on absorbance-pH data generated by a homemade pH gradient apparatus.

PubMed

Yu, Shuling; Yuan, Xuejie; Yang, Jing; Yuan, Jintao; Shi, Jiahua; Wang, Yali; Chen, Yuewen; Gao, Shufang

2015-01-01

An attractive method of generating second-order data was developed by a dropping technique to generate pH gradient simultaneously coupled with diode-array spectrophotometer scanning. A homemade apparatus designed for the pH gradient. The method and the homemade apparatus were used to simultaneously determine malachite green (MG) and crystal violet (CV) in water samples. The absorbance-pH second-order data of MG or CV were obtained from the spectra of MG or CV in a series of pH values of HCl-KCl solution. The second-order data of mixtures containing MG and CV that coexisted with interferents were analyzed using multidimensional partial least-squares with residual bilinearization. The method and homemade apparatus were used to simultaneously determine MG and CV in fish farming water samples and in river ones with satisfactory results. The presented method and the homemade apparatus could serve as an alternative tool to handle some analysis problems. Copyright © 2015 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.