Stochastic transfer of polarized radiation in finite cloudy atmospheric media with reflective boundaries

NASA Astrophysics Data System (ADS)

Sallah, M.

2014-03-01

The problem of monoenergetic radiative transfer in a finite planar stochastic atmospheric medium with polarized (vector) Rayleigh scattering is proposed. The solution is presented for an arbitrary absorption and scattering cross sections. The extinction function of the medium is assumed to be a continuous random function of position, with fluctuations about the mean taken as Gaussian distributed. The joint probability distribution function of these Gaussian random variables is used to calculate the ensemble-averaged quantities, such as reflectivity and transmissivity, for an arbitrary correlation function. A modified Gaussian probability distribution function is also used to average the solution in order to exclude the probable negative values of the optical variable. Pomraning-Eddington approximation is used, at first, to obtain the deterministic analytical solution for both the total intensity and the difference function used to describe the polarized radiation. The problem is treated with specular reflecting boundaries and angular-dependent externally incident flux upon the medium from one side and with no flux from the other side. For the sake of comparison, two different forms of the weight function, which introduced to force the boundary conditions to be fulfilled, are used. Numerical results of the average reflectivity and average transmissivity are obtained for both Gaussian and modified Gaussian probability density functions at the different degrees of polarization.

Investigations of ionospheric sporadic Es layer using oblique sounding method

NASA Astrophysics Data System (ADS)

Minullin, R.

The characteristics of Es layer have been studied using oblique sounding at 28 radiolines at the frequencies of 34 -- 73 MHz at the transmission paths 400 -- 1600 km long during 30 years. Reflections from Es layer with a few hours duration were observed. The amplitude of the reflected signal reached 1000 μ V with the registration threshold 0,1 μ V. The borderlines between reflected and scattered signals were observed as sharp curves in 60 -- 100 s range on the distributions of duration of reflected signals for decameter waves. The duration of continuous Es reflections were decreased upon amplification of oblique sounding frequency. The distributions of duration of reflected signals for meter waves showed sharp curves in the range 200 -- 300 s, representing borderlines between signals reflected from meteoric traces and from Es layer. The filling coefficient for the oblique sounding as well as the Es layer emersion probability for the vertical sounding were shown to undergo daily, seasonal and periodic variations. The daily variations of the filling coefficient of Es signals showed clear-cut maximums at 10 -- 12 and 18 -- 20 hours and minimum at 4 -- 6 hours at all paths in summer time and the maximum at 12 -- 14 hours in winter time. The values of the filling coefficient for Es layer declined with the increase of oblique sounding frequency. The minimal values of the filling coefficient were observed in winter and early spring, while the maximal values were observed from May to August. Provided that the averaged filling coefficient is equal to one in summer, it reaches the level 0,25 in equinox and does not exceed the level 0,12 in winter as evident by the of oblique sounding. The filling coefficient relation to the value of the voltage detection threshold was approximated by power-mode law. The filling coefficients for summer period showed exponential relation with equivalent sounding frequencies. The experimental evidence was generalized in an analytical model. Using this model the averaged Es layer filling coefficients for particular season of the year can be forecasted in case of given sounding frequency, path length, and voltage threshold.

Color of Cultures of Staphylococcus epidermidis Determined by Spectral Reflectance Colorimetry

PubMed Central

Brown, Richard W.

1966-01-01

Brown, Richard W. (National Animal Disease Laboratory, Ames, Iowa). Color of cultures of Staphylococcus epidermidis determined by spectral reflectance colorimetry. J. Bacteriol. 91:911–918. 1966.—A colorimeter with a reflectance attachment was used to study pigment production by Staphylococcus epidermidis strains grown on a medium containing Trypticase Soy Agar (BBL) and cream. The color of each culture was first characterized by reflectance colorimetry for dominant wavelength, purity, and luminous reflectance (Y) and was then classified visually into 1 of 10 color grades. There was not complete agreement in grading colors by the two methods, inasmuch as cultures that were considered more pigmented in relation to other cultures by the reflectance method were sometimes graded visually as less pigmented, and vice versa. Nevertheless, when the cultures were visually graded as being more pigmented, there was a concomitant increase in the average values of dominant wavelength and purity with a decrease in Y for the cultures in each higher grade. Thus, the nonpigmented cultures had the lowest dominant wavelength and purity values but the highest Y (brightness) values, whereas the most pigmented cultures had the highest dominant wavelength and purity values, but the lowest Y values. These results indicated that the cultures did not produce pigments of different hues (greenish-yellow, yellow, yellowish-orange) each with high, medium, and low degrees of purity and brightness. The value (1 − z), where the chromaticity coordinate z = Z/(X + Y + Z), was found to be proportional to the purity value. An inverse relationship between the tristimulus Z and purity values was also demonstrated. All cultures tested by the reflectance method were also classified according to the type of spectral absorption curve obtained with pigments extracted from the cultures with methanol. A comparison of these methods indicated that determining the type of spectral absorption curve would be better for differentiating strains of S. epidermidis, whereas the use of the reflectance method would be better for determining differences of pigment production within strains. PMID:5932106

Optical coatings for laser fusion applications

NASA Astrophysics Data System (ADS)

Lowdermilk, W. H.; Milam, D.; Rainer, F.

1980-04-01

Lasers for fusion experiments use thin-film dielectric coatings for reflecting antireflecting and polarizing surface elements. Coatings are most important to the Nd:glass laser application. The most important requirements of these coatings are accuracy of the average value of reflectance and transmission, uniformity of amplitude and phase front of the reflected or transmitted light, and laser damage threshold. Damage resistance strongly affects the laser's design and performance. The success of advanced lasers for future experiments and for reactor applications requires significant developments in damage resistant coatings for ultraviolet laser radiation.

Damage Detection of CFRP Plates by Full-Spectral Analysis of a Fibre Bragg Grating Sensor Signal

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

Mizutani, Yoshihiro; Solid and Structures Engineering Laboratory, Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, Japan, 2-12-1-I1-70, Ookayama, Meguro-ku, Tokyo 152-8552; Groves, Roger M.

2010-05-28

This paper describes the measurement of average strain, strain distribution and vibration of cantilever beam made of Carbon Fiber Reinforced Plastics (CFRP), using a single Fibre Bragg Grating (FBG) sensor mounted on the beam surface. Average strain is determined from the displacement of the peak wavelength of reflected light from the FBG sensor. Unstrained reference FBG sensors were used to compensate for temperature drift and the photoelastic coefficient (P{sub e}), which was used to calculate the gauge factor. Measured strains agree with those measured by a resistance foil strain gauge attached to the sample. Stress distributions are measured by monitoringmore » the variation in the full width half maximum (FWHM) values of the reflected spectrum, using a proposed optical analytical model, described in the paper. FWHM values were measured for both the cantilever test beam and a for a reference beam, loaded using a four-point bending rig. The trend of the stress distribution for the test beam matches with our analytical model, however with a relatively large noise present in the experimentally determined data. The vibration of cantilever beam was measured by temporal analysis of the peak reflection wavelength. This technique is very stable as measurements are not affected by variations in the signal amplitude. Finally an application of FBG sensors for damage detection of CFRP plates is demonstrated, by measuring the average strain and natural frequency. With small defects of different sizes applied to the CFRP plate, average strains were seen to increase with damage size and the natural frequency decreased with damage size.« less

Use of thermal neutron reflection method for chemical analysis of bulk samples

NASA Astrophysics Data System (ADS)

Papp, A.; Csikai, J.

2014-09-01

Microscopic, σβ, and macroscopic, Σβ, reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σβ values are additive even for bulk samples in the z=0.5-8 cm interval and so the σβmol(z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ~1000 cm3 dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously.

The application of a geometric optical canopy reflectance model to semiarid shrub vegetation

NASA Technical Reports Server (NTRS)

Franklin, Janet; Turner, Debra L.

1992-01-01

Estimates are obtained of the average plant size and density of shrub vegetation on the basis of SPOT High Resolution Visible Multispectral imagery from Chihuahuan desert areas, using the Li and Strahler (1985) model. The aggregated predictions for a number of stands within a class were accurate to within one or two standard errors of the observed average value. Accuracy was highest for those classes of vegetation where the nonrandom scrub pattern was characterized for the class on the basis of the average coefficient of the determination of density.

Tectonic setting of Jurassic basins in Central Mongolia: Insights from the geochemistry of Tsagaan-Ovoo oil shale

NASA Astrophysics Data System (ADS)

Erdenetsogt, B. O.; Hong, S. K.; Choi, J.; Odgerel, N.; Lee, I.; Ichinnorov, N.; Tsolmon, G.; Munkhnasan, B.

2017-12-01

Tsagaan-Ovoo syncline hosting Lower-Middle Jurassic oil shale is a part of Saikhan-Ovoo the largest Jurassic sedimentary basin in Central Mongolia. It is generally accepted that early Mesozoic basins are foreland basins. In total, 18 oil shale samples were collected from an open-pit mine. The contents of organic carbon, and total nitrogen and their isotopic compositions as well as major element concentrations were analyzed. The average TOC content is 12.4±1.2 %, indicating excellent source rock potential. C/N ratios show an average of 30.0±1.2, suggesting terrestrial OM. The average value of δ15N is +3.9±0.2‰, while that of δ13Corg is -25.7±0.1‰. The isotopic compositions argue for OM derived dominantly from land plant. Moreover, changes in δ15N values of analyzed samples reflect variations in algal OM concentration of oil shale. The lowest δ15N value (+2.5‰) was obtained from base section, representing the highest amount of terrestrial OM, whereas higher δ15N values (up to +5.2‰) are recorded at top section, reflecting increased amount of algal OM. On the other hand, changes in δ15N value may also represent changes in redox state of water column in paleolake. The oil shale at bottom of section with low δ15N value was accumulated under oxic condition, when the delivery of land plant OM was high. With increase in subsidence rate through time, lake was deepened and water column was depleted in oxygen probably due to extensive phytoplankton growth, which results increase in algae derived OM contents as well as bulk δ15N of oil shale. The average value of CAI for Tsagan-Ovoo oil shale is 81.6±1.3, reflecting intensive weathering in the source area. The plotted data on A-CN-K diagram displays that oil shale was sourced mainly from Early Permian granodiorite and diorite, which are widely distributed around Tsagaan-Ovoo syncline. To infer tectonic setting, two multi-dimensional discrimination diagrams were used. The results suggest that the tectonic setting of Tsagaan-Ovoo syncline, in which the studied oil shale was deposited, was continental rift. This finding contradicts with generally accepted contractile deformation during early Mesozoic in Mongolia and China. Further detailed study is required to decipher the tectonic settings of central Mongolian Jurassic basins.

Effect of Leg-to-Body Ratio on Body Shape Attractiveness.

PubMed

Kiire, Satoru

2016-05-01

Recent studies have examined various aspects of human physical attractiveness. Attractiveness is considered an evolved psychological mechanism acquired via natural selection because an attractive body reflects an individual's health and fertility. The length of the legs is an often-emphasized aspect of attractiveness and has been investigated using the leg-to-body ratio (LBR), which reflects nutritional status of the infant, health status, fecundity, and other factors that are predictive of physical fitness. However, previous studies of leg length and physical fitness have produced mixed results. The present study investigated the relationship between LBR, defined as the height to perineum divided by total height, and perceived attractiveness. Three-dimensional stimuli (11 male and 11 female) were constructed with various LBR features. Each stimulus was rated by 40 women and 40 men in Japan on a 7-point scale. The results showed that the values closest to the average LBRs were rated as the most attractive. Furthermore, by fitting a quadratic curve on the relationship between attractiveness and LBR, an inverted U-shaped curve with the peak located at the average LBR was observed. In addition, high LBR values were rated as more attractive in females, whereas the opposite was true for males. These results suggest that average LBR is indicative of good health and good reproductive potential, whereas more extreme values are avoided because they could be indicative of diseases and other maladaptive conditions.

The effects of the physical and chemical properties of soils on the spectral reflectance of soils

NASA Technical Reports Server (NTRS)

Montgomery, O. L.; Baumgardner, M. F.

1974-01-01

The effects of organic matter, free iron oxides, texture, moisture content, and cation exchange capacity on the spectral reflectance of soils were investigated along with techniques for differentiating soil orders by computer analysis of multispectral data. By collecting soil samples of benchmark soils from the different climatic regions within the United States and using the extended wavelength field spectroradiometer to obtain reflectance values and curves for each sample, average curves were constructed for each soil order. Results indicate that multispectral analysis may be a valuable tool for delineating and quantifying differences between soils.

A relation between landsat digital numbers, surface reflectance, and the cosine of the solar zenith angle

USGS Publications Warehouse

Kowalik, William S.; Marsh, Stuart E.; Lyon, Ronald J. P.

1982-01-01

A method for estimating the reflectance of ground sites from satellite radiance data is proposed and tested. The method uses the known ground reflectance from several sites and satellite data gathered over a wide range of solar zenith angles. The method was tested on each of 10 different Landsat images using 10 small sites in the Walker Lake, Nevada area. Plots of raw Landsat digital numbers (DNs) versus the cosine of the solar zenith angle (cos Z) for the the test areas are linear, and the average correlation coefficients of the data for Landsat bands 4, 5, 6, and 7 are 0.94, 0.93, 0.94, and 0.94, respectively. Ground reflectance values for the 10 sites are proportional to the slope of the DN versus cos Z relation at each site. The slope of the DN versus cos Z relation for seven additional sites in Nevada and California were used to estimate the ground reflectances of those sites. The estimates for nearby sites are in error by an average of 1.2% and more distant sites are in error by 5.1%. The method can successfully estimate the reflectance of sites outside the original scene, but extrapolation of the reflectance estimation equations to other areas may violate assumptions of atmospheric homogeneity.

The albedo of particles in reflection nebulae

NASA Technical Reports Server (NTRS)

Rush, W. F.

1974-01-01

The relation between the apparent angular extent of a reflection nebula and the apparent magnitude of its illuminating star was reconsidered under a less restrictive set of assumptions. A computational technique was developed which permits the use of fits to the observed m-log a values to determine the albedo of particles composing reflection nebulae, providing only that a phase function and average optical thickness are assumed. Multiple scattering, anisotropic phase functions, and illumination by the general star field are considered, and the albedo of reflection nebular particles appears to be the same as that for interstellar particles in general. The possibility of continuous fluorescence contributions to the surface brightness is also considered.

Low-reflectance laser-induced surface nanostructures created with a picosecond laser

NASA Astrophysics Data System (ADS)

Sarbada, Shashank; Huang, Zhifeng; Shin, Yung C.; Ruan, Xiulin

2016-04-01

Using high-speed picosecond laser pulse irradiation, low-reflectance laser-induced periodic surface structures (LIPSS) have been created on polycrystalline silicon. The effects of laser fluence, scan speed, overlapping ratio and polarization angle on the formation of LIPSS are reported. The anti-reflective properties of periodic structures are discussed, and the ideal LIPSS for low surface reflectance is presented. A decrease of 35.7 % in average reflectance of the silicon wafer was achieved over the wavelength range of 400-860 nm when it was textured with LIPSS at high scan speeds of 4000 mm/s. Experimental results of broadband reflectance of silicon wafers textured with LIPSS have been compared with finite difference time domain simulations and are in good agreement, showing high predictability in reflectance values for different structures. The effects of changing the LIPSS profile, fill factor and valley depth on the surface reflectance were also analyzed through simulations.

Modeling englacial radar attenuation at Siple Dome, West Antarctica, using ice chemistry and temperature data

USGS Publications Warehouse

MacGregor, J.A.; Winebrenner, D.P.; Conway, H.; Matsuoka, K.; Mayewski, P.A.; Clow, G.D.

2007-01-01

The radar reflectivity of an ice-sheet bed is a primary measurement for discriminating between thawed and frozen beds. Uncertainty in englacial radar attenuation and its spatial variation introduces corresponding uncertainty in estimates of basal reflectivity. Radar attenuation is proportional to ice conductivity, which depends on the concentrations of acid and sea-salt chloride and the temperature of the ice. We synthesize published conductivity measurements to specify an ice-conductivity model and find that some of the dielectric properties of ice at radar frequencies are not yet well constrained. Using depth profiles of ice-core chemistry and borehole temperature and an average of the experimental values for the dielectric properties, we calculate an attenuation rate profile for Siple Dome, West Antarctica. The depth-averaged modeled attenuation rate at Siple Dome (20.0 ?? 5.7 dB km-1) is somewhat lower than the value derived from radar profiles (25.3 ?? 1.1 dB km-1). Pending more experimental data on the dielectric properties of ice, we can match the modeled and radar-derived attenuation rates by an adjustment to the value for the pure ice conductivity that is within the range of reported values. Alternatively, using the pure ice dielectric properties derived from the most extensive single data set, the modeled depth-averaged attenuation rate is 24.0 ?? 2.2 dB km-1. This work shows how to calculate englacial radar attenuation using ice chemistry and temperature data and establishes a basis for mapping spatial variations in radar attenuation across an ice sheet. Copyright 2007 by the American Geophysical Union.

Generation of realistic scene using illuminant estimation and mixed chromatic adaptation

NASA Astrophysics Data System (ADS)

Kim, Jae-Chul; Hong, Sang-Gi; Kim, Dong-Ho; Park, Jong-Hyun

2003-12-01

The algorithm of combining a real image with a virtual model was proposed to increase the reality of synthesized images. Currently, synthesizing a real image with a virtual model facilitated the surface reflection model and various geometric techniques. In the current methods, the characteristics of various illuminants in the real image are not sufficiently considered. In addition, despite the chromatic adaptation plays a vital role for accommodating different illuminants in the two media viewing conditions, it is not taken into account in the existing methods. Thus, it is hardly to get high-quality synthesized images. In this paper, we proposed the two-phase image synthesis algorithm. First, the surface reflectance of the maximum high-light region (MHR) was estimated using the three eigenvectors obtained from the principal component analysis (PCA) applied to the surface reflectances of 1269 Munsell samples. The combined spectral value, i.e., the product of surface reflectance and the spectral power distributions (SPDs) of an illuminant, of MHR was then estimated using the three eigenvectors obtained from PCA applied to the products of surface reflectances of Munsell 1269 samples and the SPDs of four CIE Standard Illuminants (A, C, D50, D65). By dividing the average combined spectral values of MHR by the average surface reflectances of MHR, we could estimate the illuminant of a real image. Second, the mixed chromatic adaptation (S-LMS) using an estimated and an external illuminants was applied to the virtual-model image. For evaluating the proposed algorithm, experiments with synthetic and real scenes were performed. It was shown that the proposed method was effective in synthesizing the real and the virtual scenes under various illuminants.

Effect of crack curvature on stress intensity factors for ASTM standard compact tension specimens

NASA Technical Reports Server (NTRS)

Alam, J.; Mendelson, A.

1983-01-01

The stress intensity factors (SIF) are calculated using the method of lines for the compact tension specimen in tensile and shear loading for curved crack fronts. For the purely elastic case, it was found that as the crack front curvature increases, the SIF value at the center of the specimen decreases while increasing at the surface. For the higher values of crack front curvatures, the maximum value of the SIF occurs at an interior point located adjacent to the surface. A thickness average SIF was computed for parabolically applied shear loading. These results were used to assess the requirements of ASTM standards E399-71 and E399-81 on the shape of crack fronts. The SIF is assumed to reflect the average stress environment near the crack edge.

Methods for quantitative infrared directional-hemispherical and diffuse reflectance measurements using an FTIR and a commercial integrating sphere

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

Blake, Thomas A.; Johnson, Timothy J.; Tonkyn, Russell G.

Infrared integrating sphere measurements of solid samples are important in providing reference data for contact, standoff and remote sensing applications. At the Pacific Northwest National Laboratory (PNNL) we have developed protocols to measure both the directional-hemispherical ( and diffuse (d) reflectances of powders, liquids, and disks of powders and solid materials using a commercially available, matte gold-coated integrating sphere and Fourier transform infrared spectrometer. Detailed descriptions of the sphere alignment and its use for making these reflectance measurements are given. Diffuse reflectance values were found to be dependent on the bidirectional reflection distribution function (BRDF) of the sample and themore » solid angle intercepted by the sphere’s specular exclusion port. To determine how well the sphere and protocols produce quantitative reflectance data, measurements were made of three diffuse and two specular standards prepared by the National institute of Standards and Technology (NIST, USA), LabSphere Infragold and Spectralon standards, hand-loaded sulfur and talc powder samples, and water. The five NIST standards behaved as expected: the three diffuse standards had a high degree of “diffuseness,” d/ = D > 0.9, whereas the two specular standards had D ≤ 0.03. The average absolute differences between the NIST and PNNL measurements of the NIST standards for both directional-hemispherical and diffuse reflectances are on the order of 0.01 reflectance units. Other quantitative differences between the PNNL-measured and calibration (where available) or literature reflectance values for these standards and materials are given and the possible origins of discrepancies are discussed. Random uncertainties and estimates of systematic uncertainties are presented. Corrections necessary to provide better agreement between the PNNL reflectance values as measured for the NIST standards and the NIST reflectance values for these same standards are also discussed.« less

Improved canopy reflectance modeling and scene inference through improved understanding of scene pattern

NASA Technical Reports Server (NTRS)

Franklin, Janet; Simonett, David

1988-01-01

The Li-Strahler reflectance model, driven by LANDSAT Thematic Mapper (TM) data, provided regional estimates of tree size and density within 20 percent of sampled values in two bioclimatic zones in West Africa. This model exploits tree geometry in an inversion technique to predict average tree size and density from reflectance data using a few simple parameters measured in the field (spatial pattern, shape, and size distribution of trees) and in the imagery (spectral signatures of scene components). Trees are treated as simply shaped objects, and multispectral reflectance of a pixel is assumed to be related only to the proportions of tree crown, shadow, and understory in the pixel. These, in turn, are a direct function of the number and size of trees, the solar illumination angle, and the spectral signatures of crown, shadow and understory. Given the variance in reflectance from pixel to pixel within a homogeneous area of woodland, caused by the variation in the number and size of trees, the model can be inverted to give estimates of average tree size and density. Because the inversion is sensitive to correct determination of component signatures, predictions are not accurate for small areas.

Shortwave radiation parameterization scheme for subgrid topography

NASA Astrophysics Data System (ADS)

Helbig, N.; LöWe, H.

2012-02-01

Topography is well known to alter the shortwave radiation balance at the surface. A detailed radiation balance is therefore required in mountainous terrain. In order to maintain the computational performance of large-scale models while at the same time increasing grid resolutions, subgrid parameterizations are gaining more importance. A complete radiation parameterization scheme for subgrid topography accounting for shading, limited sky view, and terrain reflections is presented. Each radiative flux is parameterized individually as a function of sky view factor, slope and sun elevation angle, and albedo. We validated the parameterization with domain-averaged values computed from a distributed radiation model which includes a detailed shortwave radiation balance. Furthermore, we quantify the individual topographic impacts on the shortwave radiation balance. Rather than using a limited set of real topographies we used a large ensemble of simulated topographies with a wide range of typical terrain characteristics to study all topographic influences on the radiation balance. To this end slopes and partial derivatives of seven real topographies from Switzerland and the United States were analyzed and Gaussian statistics were found to best approximate real topographies. Parameterized direct beam radiation presented previously compared well with modeled values over the entire range of slope angles. The approximation of multiple, anisotropic terrain reflections with single, isotropic terrain reflections was confirmed as long as domain-averaged values are considered. The validation of all parameterized radiative fluxes showed that it is indeed not necessary to compute subgrid fluxes in order to account for all topographic influences in large grid sizes.

Costs of examinations performed in a hospital laboratory in Chile.

PubMed

Andrade, Germán Lobos; Palma, Carolina Salas

2018-01-01

To determine the total average costs related to laboratory examinations performed in a hospital laboratory in Chile. Retrospective study with data from July 2014 to June 2015. 92 examinations classified in ten groups were selected according to the analysis methodology. The costs were estimated as the sum of direct and indirect laboratory costs and indirect institutional factors. The average values obtained for the costs according to examination group (in USD) were: 1.79 (clinical chemistry), 10.21 (immunoassay techniques), 13.27 (coagulation), 26.06 (high-performance liquid chromatography), 21.2 (immunological), 3.85 (gases and electrolytes), 156.48 (cytogenetic), 1.38 (urine), 4.02 (automated hematological), 4.93 (manual hematological). The value, or service fee, returned to public institutions who perform laboratory services does not adequately reflect the true total average production costs of examinations.

LANDSAT 4 band 6 data evaluation

NASA Technical Reports Server (NTRS)

1983-01-01

Satellite data collected over Lake Ontario were processed to observed surface temperature values. This involved computing apparent radiance values for each point where surface temperatures were known from averaged digital count values. These radiance values were then converted by using the LOWTRAN 5A atmospheric propagation model. This model was modified by incorporating a spectral response function for the LANDSAT band 6 sensors. A downwelled radiance term derived from LOWTRAN was included to account for reflected sky radiance. A blackbody equivalent source radiance was computed. Measured temperatures were plotted against the predicted temperature. The RMS error between the data sets is 0.51K.

Linking ecosystem services and human-values theory.

PubMed

Hicks, Christina C; Cinner, Joshua E; Stoeckl, Natalie; McClanahan, Tim R

2015-10-01

Understanding why people make the decisions they do remains a fundamental challenge facing conservation science. Ecosystem service (ES) (a benefit people derive from an ecosystem) approaches to conservation reflect efforts to anticipate people's preferences and influence their environmental behavior. Yet, the design of ES approaches seldom includes psychological theories of human behavior. We sought to alleviate this omission by applying a psychological theory of human values to a cross-cultural ES assessment. We used interviews and focus groups with fish workers from 28 coral reef fishing communities in 4 countries to qualitatively identify the motivations (i.e., human values) underlying preferences for ES; quantitatively evaluate resource user ES priorities; and identify common patterns among ES motivations and ES priorities (i.e., trade-offs and synergies). Three key findings are evident that align with human values theory. First, motivations underlying preferences for individual ESs reflected multiple human values within the same value domain (e.g., self-enhancement). Second, when averaged at community or country scales, the order of ES priorities was consistent. However, the order belied significant variation that existed among individuals. Third, in line with human values theory, ESs related to one another in a consistent pattern; certain service pairs reflected trade-off relationships (e.g., supporting and provisioning), whereas other service pairs reflected synergistic relationships (e.g., supporting and regulating). Together, these findings help improve understanding of when and why convergence and trade-offs in people's preferences for ESs occur, and this knowledge can inform the development of suitable conservation actions. © 2015 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of the Society for Conservation Biology.

7 CFR 760.641 - Adjustments made to NAMP to reflect loss of quality.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the FSA State committee. The adjustment factor will be based on the average actual market price... market price of a crop due to a reduction in the intrinsic characteristics of the production resulting... crop for which the value is reduced due to excess moisture resulting from a disaster related condition...

Outcome measures in stapes surgery: postoperative results are independent from preoperative parameters.

PubMed

Koopmann, Mario; Weiss, Daniel; Savvas, Eleftherios; Rudack, Claudia; Stenner, Markus

2015-09-01

The aim of this study was to compare audiometric results before and after stapes surgery and identify potential prognostic factors to appropriately select patients with otosclerosis who will most likely benefit from surgery. We enrolled 126 patients with otosclerosis (162 consecutive ears) in our study who underwent stapes surgery between 2007 and 2012 at our institution. Preoperative and postoperative data including pure-tone audiometry, speech audiometry, stapedial reflex audiometry and surgical data were analyzed. The average preoperative air-bone gap (ABG) was 28.9 ± 8.6 dB. Male patients and patients older than 45 years of age had greater preoperative ABGs in comparison to females and younger patients. Postoperative ABGs were 11.2 ± 7.4 dB. The average ABG gain was 17.7 ± 11.1 dB. Preoperative audiometric data, age, gender and type of surgery did not influence the postoperative results. Stapes surgery offers predictable results independent from disease progression or patient-related factors. While absolute values of hearing improvement are instrumental in reflecting audiometric results of a cohort, relative values better reflect individual's audiometric data resembling the patient's benefit.

Influence of equatorial QBO (quasi-biennial oscillation) and SST (sea-surface temperature) on polar total ozone, and the 1990 Antarctic ozone hole

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

Angell, J.K.

1990-09-01

Based on data through 1989, comparisons are made between the variation of total ozone at Resolute, Canada (75{degree}N) and South Pole, and the variation of low-stratospheric temperature at Singapore (reflecting the equatorial QBO) and SST in eastern equatorial Pacific (reflecting the ENSO phenomenon). Total-ozone variations at Resolute have been more closely related to the QBO, whereas the total-ozone variations at South Pole appear to have been almost equally related to QBO and SST. When the average of 50 mb and 30 mb June-July-August (JJA) values of Singapore temperature ({bar T}) increased from one year to the next, the decrease inmore » South Pole springtime total ozone for the same years averaged 21 {plus minus} 14% greater than when {bar T} decreased. When the JJA values of equatorial SST increased from one year to the next, the decrease in South Pole springtime total ozone for the same years averaged 18 {plus minus} 12% greater than when SST decreased. In the 6 cases when JJA values of both Singapore {bar T} and equatorial SST increased from one year to the next, the spring values of South Pole total ozone have decreased, whereas in the 6 cases when both {bar T} and SST decreased from one year to the next, South Pole total ozone has increased. Both Singapore {bar T} and equatorial SST will probably be warmer in JJA of 1990 than they were in JJA of 1989 suggesting, based on these previous relations, an even deeper Antarctic ozone hole in 1990 than in 1989 and ending the biennial variation in depth of the hole of the last 6 years.« less

S-wave attenuation of the shallow sediments in the North China basin based on borehole seismograms of local earthquakes

NASA Astrophysics Data System (ADS)

Wang, Sheng; Li, Zhiwei

2018-06-01

S-wave velocity and attenuation structures of shallow sediments play important roles in accurate prediction of strong ground motion. However, it is more difficult to investigate the attenuation than velocity structures. In this study, we developed a new approach for estimating frequency-dependent S-wave attenuation (Q_S^{ - 1}) structures of shallow sediments based on multiple time window analysis of borehole seismograms from local earthquakes. Multiple time windows for separating direct and surface-reflected S-waves in local earthquake waveforms at borehole stations are selected with a global optimization scheme. With respect to different time windows, the transfer functions between direct and surface-reflected S-waves are achieved with a weighted averaging scheme, based on which frequency dependent Q_S^{ - 1} values are obtained. Synthetic tests suggest that the proposed method can restore robust and reliableQ_S^{ - 1} values, especially when the dataset of local earthquakes is not abundant. We utilize this method for local earthquake waveforms at 14 borehole seismic stations in the North China basin, and obtain Q_S^{ - 1} values in 2 ˜ 10 Hz frequency band, as well as average {V_P}, {V_S} and {V_P}/{{}}{V_S} ratio for shallow sediments deep to a few hundred meters. Results suggest that Q_S^{ - 1} values are to 0.01˜0.06, and generally decrease with frequency. The average attenuation structure of shallow sediments within the depth of a few hundred meters beneath 14 borehole stations in the North China basin can be modeled as Q_S^{ - 1} = 0.056{f^{ - 0.61}}. It is generally consistent with the attenuation structure of sedimentary basins in other areas, such as Mississippi Embayment sediments in the United States and Sendai basin in Japan.

Comment on "Analysis of single-layer metamaterial absorber with reflection theory" [J. Appl. Phys. 117, 154906 (2015)

NASA Astrophysics Data System (ADS)

Tung, Nguyen Thanh

2016-03-01

In a recent paper, Xiong et al. [J. Appl. Phys. 117, 154906 (2015)] presented the simulated results of a Jerusalem-cross structure in an attempt to elaborate their proposed reflection theory for metamaterial absorbers. Noting that even at non-resonant frequencies the real part of the permeability shows an over-high average value and its imaginary part drops abruptly from positivity to negativity, we argue that their simulated results are unphysical, resulting from an incomplete understanding of the retrieval procedure.

Real reproduction and evaluation of color based on BRDF method

NASA Astrophysics Data System (ADS)

Qin, Feng; Yang, Weiping; Yang, Jia; Li, Hongning; Luo, Yanlin; Long, Hongli

2013-12-01

It is difficult to reproduce the original color of targets really in different illuminating environment using the traditional methods. So a function which can reconstruct the characteristics of reflection about every point on the surface of target is required urgently to improve the authenticity of color reproduction, which known as the Bidirectional Reflectance Distribution Function(BRDF). A method of color reproduction based on the BRDF measurement is introduced in this paper. Radiometry is combined with the colorimetric theories to measure the irradiance and radiance of GretagMacbeth 24 ColorChecker by using PR-715 Radiation Spectrophotometer of PHOTO RESEARCH, Inc, USA. The BRDF and BRF (Bidirectional Reflectance Factor) values of every color piece corresponding to the reference area are calculated according to irradiance and radiance, thus color tristimulus values of 24 ColorChecker are reconstructed. The results reconstructed by BRDF method are compared with values calculated by the reflectance using PR-715, at last, the chromaticity coordinates in color space and color difference between each other are analyzed. The experimental result shows average color difference and sample standard deviation between the method proposed in this paper and traditional reconstruction method depended on reflectance are 2.567 and 1.3049 respectively. The conclusion indicates that the method of color reproduction based on BRDF has the more obvious advantages to describe the color information of object than the reflectance in hemisphere space through the theoretical and experimental analysis. This method proposed in this paper is effective and feasible during the research of reproducing the chromaticity.

Retrievals of Ice Cloud Microphysical Properties of Deep Convective Systems using Radar Measurements

NASA Astrophysics Data System (ADS)

Tian, J.; Dong, X.; Xi, B.; Wang, J.; Homeyer, C. R.

2015-12-01

This study presents innovative algorithms for retrieving ice cloud microphysical properties of Deep Convective Systems (DCSs) using Next-Generation Radar (NEXRAD) reflectivity and newly derived empirical relationships from aircraft in situ measurements in Wang et al. (2015) during the Midlatitude Continental Convective Clouds Experiment (MC3E). With composite gridded NEXRAD radar reflectivity, four-dimensional (space-time) ice cloud microphysical properties of DCSs are retrieved, which is not possible from either in situ sampling at a single altitude or from vertical pointing radar measurements. For this study, aircraft in situ measurements provide the best-estimated ice cloud microphysical properties for validating the radar retrievals. Two statistical comparisons between retrieved and aircraft in situ measured ice microphysical properties are conducted from six selected cases during MC3E. For the temporal-averaged method, the averaged ice water content (IWC) and median mass diameter (Dm) from aircraft in situ measurements are 0.50 g m-3 and 1.51 mm, while the retrievals from radar reflectivity have negative biases of 0.12 g m-3 (24%) and 0.02 mm (1.3%) with correlations of 0.71 and 0.48, respectively. For the spatial-averaged method, the IWC retrievals are closer to the aircraft results (0.51 vs. 0.47 g m-3) with a positive bias of 8.5%, whereas the Dm retrievals are larger than the aircraft results (1.65 mm vs. 1.51 mm) with a positive bias of 9.3%. The retrieved IWCs decrease from ~0.6 g m-3 at 5 km to ~0.15 g m-3 at 13 km, and Dm values decrease from ~2 mm to ~0.7 mm at the same levels. In general, the aircraft in situ measured IWC and Dm values at each level are within one standard derivation of retrieved properties. Good agreements between microphysical properties measured from aircraft and retrieved from radar reflectivity measurements indicate the reasonable accuracy of our retrievals.

FULL SPECTRAL SURVEY OF ACTIVE GALACTIC NUCLEI IN THE ROSSI X-RAY TIMING EXPLORER ARCHIVE

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

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard, E-mail: erivers@ucsd.edu

2013-08-01

We have analyzed spectra for all active galactic nuclei (AGNs) in the Rossi X-ray Timing Explorer archive. We present long-term average values of absorption, Fe line equivalent width (EW), Compton reflection, and photon index, and calculate fluxes and luminosities in the 2-10 keV band for 100 AGN with sufficient brightness and overall observation time to yield high-quality spectral results. We compare these parameters across the different classifications of Seyferts and blazars. Our distributions of photon indices for Seyfert 1s and 2s are consistent with the idea that Seyferts share a common central engine; however, our distributions of Compton reflection humpmore » strengths do not support the classical picture of absorption by a torus and reflection off a Compton-thick disk with type depending only on inclination angle. We conclude that a more complex reflecting geometry such as a combined disk and torus or clumpy torus is likely a more accurate picture of the Compton-thick material. We find that Compton reflection is present in {approx}85% of Seyferts and by comparing Fe line EW's to Compton reflection hump strengths we have found that on average 40% of the Fe line arises in Compton thick material; however, this ratio was not consistent from object to object and did not seem to be dependent on optical classification.« less

Lithium isotopes and implications on chemical weathering in the catchment of Lake Donggi Cona, northeastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Weynell, Marc; Wiechert, Uwe; Schuessler, Jan A.

2017-09-01

This study presents lithium (Li) isotope ratios (δ7Li) for rocks, sediments, suspended particulate material, and dissolved Li from the Lake Donggi Cona catchment, located on the northeastern Tibetan Plateau, China. The average δ7Li = +1.9‰ of the bedrocks is estimated from local loess. δ7Li values decrease progressively within the sediment cascade from loess, to river and lake floor sediments. The lake floor sediments average at -0.7‰. The difference between bedrock and lake sediments reflects the preferential fractionation of dissolved 6Li into clay minerals (mostly illite) in the weathering zone and grain-size sorting during fluvial sediment transport. The δ7Li values of stream and lake water samples range from +13.6 to +20.8‰, whereas thermal waters fall between +5.9 and +11.6‰. The δ7Li values of lake water samples are close to +17‰ and reflect mixing of waters from two perennial inflows and thermal waters. Dissolved Li in streams represents an integrated isotopic signal derived from soil solutions in the weathering zone. An apparent isotopic fractionation of -17.8 ± 1.6‰ (αsec-sol ∼ 0.982) between secondary minerals and solution was determined. An inflow that drains a sub-catchment in the north carries a high proportion of thermal waters. Despite of the high proportion of admixed thermal waters with high Li concentrations and low δ7Li, this stream has the highest δ7Li values of about +21‰. This is consistent with admixing of thermal waters to solutions in the weathering zone and subsequent fractionation by preferential uptake of isotopically light dissolved Li into secondary phases. Based on Li isotope ratios of the dissolved and solid export flux from the weathering zone we calculated that around five times more Li is exported in particles than dissolved in streams. An average δ7Li value of about +17‰ of most streams and the lake is reflecting a low weathering intensity and chemical weathering rate of about 4 t/km2/a. Low weathering rates and an erosion dominated weathering system are consistent with moderate precipitations, the cold climate, and the high relief of the study area.

Evolution of soils on quaternary reef terraces of Barbados, West Indies

USGS Publications Warehouse

Muhs, D.R.

2001-01-01

Soils on uplifted Quaternary reef terraces of Barbados, ???125,000 to ???700,000 yr old, form a climo-chronosequence and show changes in physical, chemical, and mineralogical properties with terrace age. Parent materials are dust derived from the Sahara, volcanic ash from the Lesser Antilles island arc, and detrital carbonate from the underlying reef limestone. Although some terrace soils are probably eroded, soils or their remnants are redder and more clay-rich with increasing terrace age. Profile-average Al2O3 and Fe2O3 content increases with terrace age, which partially reflects the increasing clay content, but dithionite-extractable Fe also increases with terrace age. Profile-average K2O/TiO2, Na2O/TiO2, and P2O5/TiO2 values decrease with terrace age, reflecting the depletion of primary minerals. Average SiO2/Al2O3 values also decrease with terrace age and reflect not only loss of primary minerals but also evolution of secondary clay minerals. Although they are not present in any of the parent materials, the youngest terrace soils are dominated by smectite and interstratified kaolinite-smectite, which gradually alter to relatively pure kaolinite over ???700,000 yr. Comparisons with other tropical islands, where precipitation is higher and rates of dust fall may be lower, show that Barbados soils are less weathered than soils of comparable age. It is concluded that many soil properties in tropical regions can be potentially useful relative-age indicators in Quaternary stratigraphic studies, even when soils are eroded or changes in soil morphology are not dramatic. ?? 2001 University of Washington.

Upscaled soil-water retention using van Genuchten's function

USGS Publications Warehouse

Green, T.R.; Constantz, J.E.; Freyberg, D.L.

1996-01-01

Soils are often layered at scales smaller than the block size used in numerical and conceptual models of variably saturated flow. Consequently, the small-scale variability in water content within each block must be homogenized (upscaled). Laboratory results have shown that a linear volume average (LVA) of water content at a uniform suction is a good approximation to measured water contents in heterogeneous cores. Here, we upscale water contents using van Genuchten's function for both the local and upscaled soil-water-retention characteristics. The van Genuchten (vG) function compares favorably with LVA results, laboratory experiments under hydrostatic conditions in 3-cm cores, and numerical simulations of large-scale gravity drainage. Our method yields upscaled vG parameter values by fitting the vG curve to the LVA of water contents at various suction values. In practice, it is more efficient to compute direct averages of the local vG parameter values. Nonlinear power averages quantify a feasible range of values for each upscaled vG shape parameter; upscaled values of N are consistently less than the harmonic means, reflecting broad pore-size distributions of the upscaled soils. The vG function is useful for modeling soil-water retention at large scales, and these results provide guidance for its application.

Abrupt intensification of the SW Indian Ocean monsoon during the last deglaciation: constraints from Th, Pa, and He isotopes

NASA Astrophysics Data System (ADS)

Marcantonio, Franco; Anderson, Robert F.; Higgins, Sean; Fleisher, Martin Q.; Stute, Martin; Schlosser, Peter

2001-01-01

Sediments from western Arabian Sea core 74KL representing the last 23 ka were analyzed for helium, thorium, and protactinium isotopes. Assuming global average fluxes of extraterrestrial 3He and 230Th, the average 3He-derived sediment mass accumulation rate (MAR) is a factor of 1.8 higher than the average 230Th-derived MAR. 3He- and 230Th-derived MARs converge, however, during the Younger Dryas (YD) and during the peak of the early Holocene humid interval. These features, not seen anywhere else in the world, probably reflect a combination of climate-driven changes in the flux of 230Th and 3He. Ratios of xs 231Pa/xs 230Th, proxies of paleoproductivity, are lowest during the last glacial maximum (LGM), and increase abruptly during the Bolling-Allerod. Later, following a sudden decrease to near-LGM values during the YD, they rise abruptly to maximum values for the entire record in the early Holocene. We hypothesize that low xs 231Pa/xs 230Th ratios reflect low productivity due to the decreased intensity of the SW monsoon, whereas the opposite is true for high ratios. The correlation between Arabian Sea productivity and monsoonal upwelling, on the one hand, and North Atlantic climate variability, on the other, suggests a linkage between high- and low-latitude climates caused by changing patterns of atmospheric circulation.

Frequency selective reflection and transmission at a layer composed of a periodic dielectric

NASA Technical Reports Server (NTRS)

Bertoni, Henry L.; Cheo, Li-Hsiang S.; Tamir, Theodor

1987-01-01

The feasibility of using a periodic dielectric layer, composed of alternating bars having dielectric constants epsilon sub 1 and epsilon sub 2, as a frequency selective subreflector in order to permit feed separation in large aperture reflecting antenna systems was examined. For oblique incidence, it is found that total transmission and total reflection can be obtained at different frequencies for proper choices of epsilon sub 1, epsilon 2, and the geometric parameters. The frequencies of total reflection and transmission can be estimated from wave phenomena occurring in a layer of uniform dielectric constant equal to the average for the periodic layers. About some of the frequencies of total transmission, the bandwidth for 90% transmission is found to be 40%. However, the bandwidth for 90% reflection is always found to be much narrower; the greatest value found being 2.5%.

Internal high-reflectivity omni-directional reflectors

NASA Astrophysics Data System (ADS)

Xi, J.-Q.; Ojha, Manas; Plawsky, J. L.; Gill, W. N.; Kim, Jong Kyu; Schubert, E. F.

2005-07-01

An internal high-reflectivity omni-directional reflector (ODR) for the visible spectrum is realized by the combination of total internal reflection using a low-refractive-index (low-n) material and reflection from a one-dimensional photonic crystal (1D PC). The low-n layer limits the range of angles in the 1D PC to values below the Brewster angle, thereby enabling high reflectivity and omni-directionality. This ODR is demonstrated using GaP as ambient, nanoporous SiO2 with a very low refractive index (n=1.10), and a four-pair TiO2/SiO2 multilayer stack. The results indicate a two orders of magnitude lower angle-integrated transverse-electric-transverse-magnetic polarization averaged mirror loss of the ODR compared with conventional distributed Bragg reflectors and metal reflectors. This indicates the high potential of the internal ODRs for optoelectronic semiconductor devices, e.g., light-emitting diodes.

Implementation of ICARE learning model using visualization animation on biotechnology course

NASA Astrophysics Data System (ADS)

Hidayat, Habibi

2017-12-01

ICARE is a learning model that directly ensure the students to actively participate in the learning process using animation media visualization. ICARE have five key elements of learning experience from children and adult that is introduction, connection, application, reflection and extension. The use of Icare system to ensure that participants have opportunity to apply what have been they learned. So that, the message delivered by lecture to students can be understood and recorded by students in a long time. Learning model that was deemed capable of improving learning outcomes and interest to learn in following learning process Biotechnology with applying the ICARE learning model using visualization animation. This learning model have been giving motivation to participate in the learning process and learning outcomes obtained becomes more increased than before. From the results of student learning in subjects Biotechnology by applying the ICARE learning model using Visualization Animation can improving study results of student from the average value of middle test amounted to 70.98 with the percentage of 75% increased value of final test to be 71.57 with the percentage of 68.63%. The interest to learn from students more increasing visits of student activities at each cycle, namely the first cycle obtained average value by 33.5 with enough category. The second cycle is obtained an average value of 36.5 to good category and third cycle the average value of 36.5 with a student activity to good category.

Lunar mare TiO2 abundances estimated from UV/Vis reflectance

NASA Astrophysics Data System (ADS)

Sato, Hiroyuki; Robinson, Mark S.; Lawrence, Samuel J.; Denevi, Brett W.; Hapke, Bruce; Jolliff, Bradley L.; Hiesinger, Harald

2017-11-01

The visible (400-700 nm) and near-infrared (700-2800 nm) reflectance of the lunar regolith is dominantly controlled by variations in the abundance of plagioclase, iron-bearing silicate minerals, opaque minerals (e.g., ilmenite), and maturation products (e.g., agglutinate glass, radiation-produced rims on soil grains, and Fe-metal). The same materials control reflectance into the near-UV (250-400 nm) with varying degrees of importance. A key difference is that while ilmenite is spectrally neutral in the visible to near-infrared, it exhibits a diagnostic upturn in reflectance in the near-UV, at wavelengths shorter than about 450 nm. The Lunar Reconnaissance Orbiter Wide Angle Camera (WAC) filters were specifically designed to take advantage of this spectral feature to enable more accurate mapping of ilmenite within mare soils than previously possible. Using the reflectance measured at 321 and 415 nm during 62 months of repeated near-global WAC observations, first we found a linear correlation between the TiO2 contents of the lunar soil samples and the 321/415 nm ratio of each sample return site. We then used the coefficients from the linear regression and the near-global WAC multispectral mosaic to derive a new TiO2 map. The average TiO2 content is 3.9 wt% for the 17 major maria. The highest TiO2 values were found in Mare Tranquillitatis (∼12.6 wt%) and Oceanus Procellarum (∼11.6 wt%). Regions contaminated by highland ejecta, lunar swirls, and the low-TiO2 maria (e.g., Mare Frigoris, the northeastern units of Mare Imbrium) exhibit very low TiO2 values (<2 wt%). We find that the Clementine visible to near-infrared based TiO2 maps (Lucey et al., 2000) have systematically higher values relative to the WAC estimates. The Lunar Prospector Gamma-Ray Spectrometer (GRS) TiO2 map is consistent with the WAC TiO2 map, although there are local offsets possibly due to the different depth sensitivities and large pixel scale of the GRS relative to the WAC. We find a wide variation of TiO2 abundances (from 0 to 10 wt%) for early mare volcanism (>2.6 Ga), whereas only medium to high TiO2 values (average = 6.8 wt%, minimum = 4.5 wt%) are found for younger mare units (<2.6 Ga).

Flow over bedforms in a large sand-bed river: A field investigation

USGS Publications Warehouse

Holmes, Robert R.; Garcia, Marcelo H.

2008-01-01

An experimental field study of flows over bedforms was conducted on the Missouri River near St. Charles, Missouri. Detailed velocity data were collected under two different flow conditions along bedforms in this sand-bed river. The large river-scale data reflect flow characteristics similar to those of laboratory-scale flows, with flow separation occurring downstream of the bedform crest and flow reattachment on the stoss side of the next downstream bedform. Wave-like responses of the flow to the bedforms were detected, with the velocity decreasing throughout the flow depth over bedform troughs, and the velocity increasing over bedform crests. Local and spatially averaged velocity distributions were logarithmic for both datasets. The reach-wise spatially averaged vertical-velocity profile from the standard velocity-defect model was evaluated. The vertically averaged mean flow velocities for the velocity-defect model were within 5% of the measured values and estimated spatially averaged point velocities were within 10% for the upper 90% of the flow depth. The velocity-defect model, neglecting the wake function, was evaluated and found to estimate thevertically averaged mean velocity within 1% of the measured values.  

Effect of heliotropism on the bidirectional reflectance of irrigated cotton

NASA Technical Reports Server (NTRS)

Schutt, J. B.; Kimes, D. S.; Newcomb, W. W.

1985-01-01

The dynamic behavior of cotton leaves is described using gyroscopic coordinates. Angular movements represented as pitching, rolling, and yawing are used to follow the movement of leaf normals and their instantaneous relationships to the sun on an individual basis. A sensitivity analysis establishes that the angle between a leaf normal and the sun is most affected by changes in pitch and roll. Plots of the phase angle gamma averaged by quadrant show the pronounced heliotropic behavior of cotton leaves. Plots of pitch versus roll averaged by quadrant demonstrate the differential behavior of cotton leaves relative to the position of the sun. These results are used to interpret sections taken from bidirectional reflectance curves obtained using 0.57-0.69 micron band in terms of the evolution of gamma from sunrise until noon. The measured and experimental values of gamma are in reasonable agreement. Forescattered and backscattered exitances are observed to have distinct leaf normal directions.

Season plays a role in variability in vitamin C content of fresh fruits and vegetables in a local retail market

USDA-ARS?s Scientific Manuscript database

Seasonal variation of vitamin C in fresh fruits and vegetables is not reflected in food composition database average values, yet many factors influence content and retention. Fresh fruits and vegetables were sampled on three occasions in each season, from the same local retail outlets, for one or tw...

The influence of extractable organic matter on vitrinite reflectance suppression: A survey of kerogen and coal types

USGS Publications Warehouse

Barker, C.E.; Lewan, M.D.; Pawlewicz, M.J.

2007-01-01

The vitrinite reflectance suppression literature shows that while bitumen impregnation of the vitrinite group is often invoked as a significant contributor to suppression, its existence is not often supported by petrological evidence. This study examines bitumen impregnation as a factor in vitrinite suppression by comparing the vitrinite reflectance of source rock and coal samples before and after solvent-extraction. Bitumen, often defined as organic matter soluble or extractable in certain organic solvents, should be removed by Soxhlet method solvent extraction using chloroform. Removing the extractable bitumen should restore the suppressed reflectance to its true higher value. However, the solvent extracted samples averaged 0.014% Rv less than that of the unextracted samples. We conclude from these results and from other published data that reflectance suppression by bitumen impregnation in the vitrinite maceral group, above the huminite stage of gelification, is seemingly a rare phenomenon and whose effect on suppressing vitrinite reflectance is typically negligible. ?? 2006.

Advanced analysis of finger-tapping performance: a preliminary study.

PubMed

Barut, Cağatay; Kızıltan, Erhan; Gelir, Ethem; Köktürk, Fürüzan

2013-06-01

The finger-tapping test is a commonly employed quantitative assessment tool used to measure motor performance in the upper extremities. This task is a complex motion that is affected by external stimuli, mood and health status. The complexity of this task is difficult to explain with a single average intertap-interval value (time difference between successive tappings) which only provides general information and neglects the temporal effects of the aforementioned factors. This study evaluated the time course of average intertap-interval values and the patterns of variation in both the right and left hands of right-handed subjects using a computer-based finger-tapping system. Cross sectional study. Thirty eight male individuals aged between 20 and 28 years (Mean±SD = 22.24±1.65) participated in the study. Participants were asked to perform single-finger-tapping test for 10 seconds of test period. Only the results of right-handed (RH) 35 participants were considered in this study. The test records the time of tapping and saves data as the time difference between successive tappings for further analysis. The average number of tappings and the temporal fluctuation patterns of the intertap-intervals were calculated and compared. The variations in the intertap-interval were evaluated with the best curve fit method. An average tapping speed or tapping rate can reliably be defined for a single-finger tapping test by analysing the graphically presented data of the number of tappings within the test period. However, a different presentation of the same data, namely the intertap-interval values, shows temporal variation as the number of tapping increases. Curve fitting applications indicate that the variation has a biphasic nature. The measures obtained in this study reflect the complex nature of the finger-tapping task and are suggested to provide reliable information regarding hand performance. Moreover, the equation reflects both the variations in and the general patterns associated with the task.

Effects of Long-Term Low-Level Radiofrequency Radiation Exposure on Rats. Volume 2. Average SAR and SAR Distribution in Man Exposed to 450-MHz RFR.

DTIC Science & Technology

1983-09-01

adult man (full-scale height = 171 cm) and child (full-scale height = 86 cm), with arms down. We used the full-scale figure to reflect a worst-case... child for all orientations was much higher than that for the adult (e.g., 0.187 W/kg versus 0.063 W/kg), which is expected since the frequency is closer...to the resonance frequency for the child . Another series of scale-model measurements was conducted for determination of the average SAR values for

Limitations of signal averaging due to temporal correlation in laser remote-sensing measurements.

PubMed

Menyuk, N; Killinger, D K; Menyuk, C R

1982-09-15

Laser remote sensing involves the measurement of laser-beam transmission through the atmosphere and is subject to uncertainties caused by strong fluctuations due primarily to speckle, glint, and atmospheric-turbulence effects. These uncertainties are generally reduced by taking average values of increasing numbers of measurements. An experiment was carried out to directly measure the effect of signal averaging on back-scattered laser return signals from a diffusely reflecting target using a direct-detection differential-absorption lidar (DIAL) system. The improvement in accuracy obtained by averaging over increasing numbers of data points was found to be smaller than that predicted for independent measurements. The experimental results are shown to be in excellent agreement with a theoretical analysis which considers the effect of temporal correlation. The analysis indicates that small but long-term temporal correlation severely limits the improvement available through signal averaging.

Monitoring of degradation of porous silicon photonic crystals using digital photography

PubMed Central

2014-01-01

We report the monitoring of porous silicon (pSi) degradation in aqueous solutions using a consumer-grade digital camera. To facilitate optical monitoring, the pSi samples were prepared as one-dimensional photonic crystals (rugate filters) by electrochemical etching of highly doped p-type Si wafers using a periodic etch waveform. Two pSi formulations, representing chemistries relevant for self-reporting drug delivery applications, were tested: freshly etched pSi (fpSi) and fpSi coated with the biodegradable polymer chitosan (pSi-ch). Accelerated degradation of the samples in an ethanol-containing pH 10 aqueous basic buffer was monitored in situ by digital imaging with a consumer-grade digital camera with simultaneous optical reflectance spectrophotometric point measurements. As the nanostructured porous silicon matrix dissolved, a hypsochromic shift in the wavelength of the rugate reflectance peak resulted in visible color changes from red to green. While the H coordinate in the hue, saturation, and value (HSV) color space calculated using the as-acquired photographs was a good monitor of degradation at short times (t < 100 min), it was not a useful monitor of sample degradation at longer times since it was influenced by reflections of the broad spectral output of the lamp as well as from the narrow rugate reflectance band. A monotonic relationship was observed between the wavelength of the rugate reflectance peak and an H parameter value calculated from the average red-green-blue (RGB) values of each image by first independently normalizing each channel (R, G, and B) using their maximum and minimum value over the time course of the degradation process. Spectrophotometric measurements and digital image analysis using this H parameter gave consistent relative stabilities of the samples as fpSi > pSi-ch. PMID:25242902

Spatial averaging errors in creating hemispherical reflectance (albedo) maps from directional reflectance data

NASA Technical Reports Server (NTRS)

Kimes, D. S.; Kerber, A. G.; Sellers, P. J.

1993-01-01

Spatial averaging errors which may occur when creating hemispherical reflectance maps for different cover types from direct nadir technique to estimate the hemispherical reflectance are assessed by comparing the results with those obtained with a knowledge-based system called VEG (Kimes et al., 1991, 1992). It was found that hemispherical reflectance errors provided by using VEG are much less than those using the direct nadir techniques, depending on conditions. Suggestions are made concerning sampling and averaging strategies for creating hemispherical reflectance maps for photosynthetic, carbon cycle, and climate change studies.

Scheduling on the basis of the research of dependences among the construction process parameters

NASA Astrophysics Data System (ADS)

Romanovich, Marina; Ermakov, Alexander; Mukhamedzhanova, Olga

2017-10-01

The dependences among the construction process parameters are investigated in the article: average integrated value of qualification of the shift, number of workers per shift and average daily amount of completed work on the basis of correlation coefficient are considered. Basic data for the research of dependences among the above-stated parameters have been collected during the construction of two standard objects A and B (monolithic houses), in four months of construction (October, November, December, January). Kobb-Douglas production function has proved the values of coefficients of correlation close to 1. Function is simple to be used and is ideal for the description of the considered dependences. The development function, describing communication among the considered parameters of the construction process, is developed. The function of the development gives the chance to select optimum quantitative and qualitative (qualification) structure of the brigade link for the work during the next period of time, according to a preset value of amount of works. Function of the optimized amounts of works, which reflects interrelation of key parameters of construction process, is developed. Values of function of the optimized amounts of works should be used as the average standard for scheduling of the storming periods of construction.

Sunspot Activity Near Cycle Minimum and What it Might Suggest for Cycle 24, the Next Sunspot Cycle

NASA Technical Reports Server (NTRS)

Wilson, Robert M.; Hathaway, David H.

2009-01-01

In late 2008, 12-month moving averages of sunspot number, number of spotless days, number of groups, area of sunspots, and area per group were reflective of sunspot cycle minimum conditions for cycle 24, these values being of or near record value. The first spotless day occurred in January 2004 and the first new-cycle, high-latitude spot was reported in January 2008, although old-cycle, low-latitude spots have continued to be seen through April 2009, yielding an overlap of old and new cycle spots of at least 16 mo. New-cycle spots first became dominant over old-cycle spots in September 2008. The minimum value of the weighted mean latitude of sunspots occurred in May 2007, measuring 6.6 deg, and the minimum value of the highest-latitude spot followed in June 2007, measuring 11.7 deg. A cycle length of at least 150 mo is inferred for cycle 23, making it the longest cycle of the modern era. Based on both the maximum-minimum and amplitude-period relationships, cycle 24 is expected to be only of average to below-average size, peaking probably in late 2012 to early 2013, unless it proves to be a statistical outlier.

Characterization of Landsat-7 to Landsat-8 Reflective Wavelength and Normalized Difference Vegetation Index Continuity

NASA Technical Reports Server (NTRS)

Roy, D. P.; Kovalskyy, V.; Zhang, H. K.; Vermote, E. F.; Yan, L.; Kumar, S. S.; Egorov, A.

2016-01-01

At over 40 years, the Landsat satellites provide the longest temporal record of space-based land surface observations, and the successful 2013 launch of the Landsat-8 is continuing this legacy. Ideally, the Landsat data record should be consistent over the Landsat sensor series. The Landsat-8 Operational Land Imager (OLI) has improved calibration, signal to noise characteristics, higher 12-bit radiometric resolution, and spectrally narrower wavebands than the previous Landsat-7 Enhanced Thematic Mapper (ETM+). Reflective wavelength differences between the two Landsat sensors depend also on the surface reflectance and atmospheric state which are difficult to model comprehensively. The orbit and sensing geometries of the Landsat- 8 OLI and Landsat-7 ETM+ provide swath edge overlapping paths sensed only one day apart. The overlap regions are sensed in alternating backscatter and forward scattering orientations so Landsat bi-directional reflectance effects are evident but approximately balanced between the two sensors when large amounts of time series data are considered. Taking advantage of this configuration a total of 59 million 30m corresponding sensor observations extracted from 6,317 Landsat-7 ETM+ and Landsat-8 OLI images acquired over three winter and three summer months for all the conterminous United States (CONUS) are compared. Results considering different stages of cloud and saturation filtering, and filtering to reduce one day surface state differences, demonstrate the importance of appropriate per-pixel data screening. Top of atmosphere (TOA) and atmospherically corrected surface reflectance for the spectrally corresponding visible, near infrared and shortwave infrared bands, and derived normalized difference vegetation index (NDVI), are compared and their differences quantified. On average the OLI TOA reflectance is greater than the ETM+ TOA reflectance for all bands, with greatest differences in the near-infrared (NIR) and the shortwave infrared bands due to the quite different spectral response functions between the sensors. The atmospheric correction reduces the mean difference in the NIR and shortwave infrared but increases the mean difference in the visible bands. Regardless of whether TOA or surface reflectance are used to generate NDVI, on average, for vegetated soil and vegetation surfaces (0 = NDVI = 1), the OLI NDVI is greater than the ETM+ NDVI. Statistical functions to transform between the comparable sensor bands and sensor NDVI values are presented so that the user community may apply them in their own research to improve temporal continuity between the Landsat-7 ETM+ and Landsat-8 OLI sensor data. The transformation functions were developed using ordinary least squares (OLS) regression and were fit quite reliably (r2 values is greater than 0.7 for the reflectance data and greater than 0.9 for the NDVI data, p-values less than 0.0001).

Human Adaptation to the Tibetan Plateau

DTIC Science & Technology

1991-08-12

exercise for only 30 min on arrival. design was to make measurements during high altitude Femoral arterial and venous catheterization . After the...studied after right heart catheterization . The Tibetans had remarkably low pulmonary artery pressures. Values averaged 14 mmHg, similar to the sea...their longer duration of Lhasa residences, may reflect favorable adaptations in a population with a long history of living at high altitude

Characterization of the major histopathological components of thyroid nodules using sonographic textural features for clinical diagnosis and management.

PubMed

Chen, Shao-Jer; Yu, Sung-Nien; Tzeng, Jeh-En; Chen, Yen-Ting; Chang, Ku-Yaw; Cheng, Kuo-Sheng; Hsiao, Fu-Tsung; Wei, Chang-Kuo

2009-02-01

In this study, the characteristic sonographic textural feature that represents the major histopathologic components of the thyroid nodules was objectively quantified to facilitate clinical diagnosis and management. A total of 157 regions-of-interest thyroid ultrasound image was recruited in the study. The sonographic system used was the GE LOGIQ 700), (General Electric Healthcare, Chalfant St. Giles, UK). The parameters affecting image acquisition were kept in the same condition for all lesions. Commonly used texture analysis methods were applied to characterize thyroid ultrasound images. Image features were classified according to the corresponding pathologic findings. To estimate their relevance and performance to classification, ReliefF was used as a feature selector. Among the various textural features, the sum average value derived from co-occurrence matrix can well reflect echogenicity and can effectively differentiate between follicles and fibrosis base thyroid nodules. Fibrosis shows lowest echogenicity and lowest difference sum average value. Enlarged follicles show highest echogenicity and difference sum average values. Papillary cancer or follicular tumors show the difference sum average values and echogenicity between. The rule of thumb for the echogenicity is that the more follicles are mixed in, the higher the echo of the follicular tumor and papillary cancer will be and vice versa for fibrosis mixed. Areas with intermediate and lower echo should address the possibility of follicular or papillary neoplasm mixed with either follicles or fibrosis. These areas provide more cellular information for ultrasound guided aspiration

Deciphering seasonal variations in the diet and drinking water of modern White-Tailed deer by in situ analysis of osteons in cortical bone

NASA Astrophysics Data System (ADS)

Larson, T. E.; Longstaffe, F. J.

2007-12-01

In situ carbon and oxygen isotope values for bioapatite were obtained from longitudinal slices of cortical bone from modern domesticated sheep and free-range White-Tailed deer. The analyses were obtained using an IR-laser coupled to a GC-IRMS interface. Ablation pits averaged 200 × 50 μm, making it possible to sample individual or small bundles of osteons. Cortical bone is remodeled along osteons throughout a mammal's life. Therefore, data at this scale can record seasonal variations in diet and drinking water during the adult stages of a mammal, whereas teeth provide may provide information about the juvenile years of a mammal. Average δ18O and δ13C values for the sheep from southwestern Ontario, Canada, were 14.0 and -16.1‰, respectively. No trend was observed in the isotopic composition of the sheep's osteons, consistent with its constant diet and water supply. The δ18O (14.2 to 16.6‰) and δ13C (-19.2 to -15.6‰) values of osteons from White-Tailed deer from nearby Pinery Provincial Park, however, varied systematically and were negatively correlated. Oxygen isotope values of the osteons correlated well with changes in the δ18O values of the main water source for these deer: winter average, -10.7‰; summer average, -8.6‰. The variation in δ13C values of the osteons reflects changes in diet; summer diet consisted mainly of leafy C3 vegetation (-28.4‰), whereas winter diet comprised bark (-25.6‰), C4 grasses (δ13C, -12.7‰), and corn stalks and husks (-11.3‰).

3-D Vp/Vs Ratio Distribution in the Geothermal Reservoir at Basel, Switzerland, from Microseismic Data

NASA Astrophysics Data System (ADS)

Kummerow, J.; Reshetnikov, A.; Häring, M.; Asanuma, H.

2012-12-01

Thousands of microseismic events occurred during and after the stimulation of the 4.5km deep Basel 1 well at the Deep Heat Mining Project in Basel, Switzerland, in December 2006. The located seismicity extends about 1km in vertical direction and also 1km in NNW-SSE direction, consistent with the orientation of the maximum horizontal stress. In this study, we analyze 2100 events with magnitudes Mw>0.0, which were recorded by six borehole seismometers between December 2, 2006, and June 7, 2007. We first identify event multiplets based on waveform similarity and apply an automatic, iterative arrival time optimization to calculate high-precision P and S time picks for the multiplet events. Local estimates of the Vp/Vs ratio in the stimulated Basel geothermal reservoir are then obtained from the slope of the demeaned differential S versus P arrival times. The average value of Vp/Vs=1.70 is close to the characteristic reservoir value of 1.72, which was determined independently from sonic log measurements. Also, in the vicinity of the borehole, the depth distribution of Vp/Vs correlates well with the low-pass filtered sonic log data: Vp/Vs values are less than 1.70 at the top of the seismicity cloud at <3.9km depth, close to average at 4.0-4.4km depth, and exceed the value of 1.75 at larger depth (4.4-4.6km), consistent with the sonic log data. Furthermore, we observe a correlation of anomalous Vp/Vs values with zones of enhanced seismic reflectivity which were resolved by microseismic reflection imaging. Away from the borehole, increased Vp/Vs ratios also seem to correlate with domains of high event density, possibly indicating fluid migration paths.

Diamonds from Orapa Mine show a clear subduction signature in SIMS stable isotope data

NASA Astrophysics Data System (ADS)

Chinn, Ingrid L.; Perritt, Samantha H.; Stiefenhofer, Johann; Stern, Richard A.

2018-05-01

Spatially resolved analyses reveal considerable isotopic heterogeneity within and among diamonds ranging in size from 0.15 to 4.75 mm from the Orapa Mine, Botswana. The isotopic data are interpreted in conjunction with nitrogen aggregation state data and growth zone relationships from cathodoluminescence images. The integrated information confirms that a distinct diamond growth event (with low IaAB nitrogen aggregation states, moderately high nitrogen contents and δ13C and δ15N values compatible with average mantle values) is younger than the dominant population(s) of Type IaAB diamonds and cores of composite diamonds with more negative and positive δ13C and δ15N values, respectively. A significant proportion of the older diamond generation has high nitrogen contents, well outside the limit sector relationship, and these diamonds are likely to reflect derivation from subducted organic matter. Diamonds with low δ13C values combined with high nitrogen contents and positive δ15N values have not been previously widely recognised, even in studies of diamonds from Orapa. This may have been caused by prior analytical bias towards inclusion-bearing diamonds that are not necessarily representative of the entire range of diamond populations, and because of average measurements from heterogeneous diamonds measured by bulk combustion methods. Two distinct low nitrogen/Type II microdiamond populations were recognised that do not appear to continue into the macrodiamond sizes in the samples studied. Other populations, e.g. those containing residual singly-substituted nitrogen defects, range in size from small microdiamonds to large macrodiamonds. The total diamond content of the Orapa kimberlite thus reflects a complex assortment of multiple diamond populations.

Selected Hydrologic Applications of LANDSAT-2 Data: an Evaluation. [Snowmelt in the American River Basin and soil moisture studies at the Phoenix, Arizona Test Site and at Luverne, Minnesota

NASA Technical Reports Server (NTRS)

Wiesnet, D. R.; Mcginnis, D. F., Jr.; Matson, M. (Principal Investigator)

1978-01-01

The author has identified the following significant results. Estimates of soil moisture were obtained from visible, near-IR gamma ray and microwave data. Attempts using GOES thermal-IR were unsuccessful due to resolutions (8 km). Microwaves were the most effective at soil moisture estimates, with and without vegetative cover. Gamma rays provided only one value for the test site, produced by many data points obtained from overlapping 150 meter diameter circles. Even though the resulting averaged value was near the averaged field moisture value, this method suffers from atmospheric contaminants, the need to fly at low altitudes, and the necessity of prior calibration of a given site. Visible and near-IR relationships are present for bare fields but appear to be limited to soil moisture levels between 5 and 20%. The densely vegetated alfalfa fields correlated with near-IR reflectance only; soil moisture values from wheat fields showed no relation to either or near-IR MSS data.

Double dissociation of value computations in orbitofrontal and anterior cingulate neurons

PubMed Central

Kennerley, Steven W.; Behrens, Timothy E. J.; Wallis, Jonathan D.

2011-01-01

Damage to prefrontal cortex (PFC) impairs decision-making, but the underlying value computations that might cause such impairments remain unclear. Here we report that value computations are doubly dissociable within PFC neurons. While many PFC neurons encoded chosen value, they used opponent encoding schemes such that averaging the neuronal population eliminated value coding. However, a special population of neurons in anterior cingulate cortex (ACC) - but not orbitofrontal cortex (OFC) - multiplex chosen value across decision parameters using a unified encoding scheme, and encoded reward prediction errors. In contrast, neurons in OFC - but not ACC - encoded chosen value relative to the recent history of choice values. Together, these results suggest complementary valuation processes across PFC areas: OFC neurons dynamically evaluate current choices relative to recent choice values, while ACC neurons encode choice predictions and prediction errors using a common valuation currency reflecting the integration of multiple decision parameters. PMID:22037498

Estimation of optical properties of aerosols and bidirectional reflectance from PARASOL/POLDER data over land

NASA Astrophysics Data System (ADS)

Kusaka, Takashi; Miyazaki, Go

2014-10-01

When monitoring target areas covered with vegetation from a satellite, it is very useful to estimate the vegetation index using the surface anisotropic reflectance, which is dependent on both solar and viewing geometries, from satellite data. In this study, the algorithm for estimating optical properties of atmospheric aerosols such as the optical thickness (τ), the refractive index (Nr), the mixing ratio of small particles in the bimodal log-normal distribution function (C) and the bidirectional reflectance (R) from only the radiance and polarization at the 865nm channel received by the PARASOL/POLDER is described. Parameters of the bimodal log-normal distribution function: mean radius, r1, standard deviation, σ1, of fine aerosols, and r2, σ2 of coarse aerosols were fixed, and these values were estimated from monthly averaged size distribution at AERONET sites managed by NASA near the target area. Moreover, it is assumed that the contribution of the surface reflectance with directional anisotropy to the polarized radiance received by the satellite is small because it is shown from our ground-based polarization measurements of light ray reflected by the grassland that degrees of polarization of the reflected light by the grassland are very low values at the 865nm channel. First aerosol properties were estimated from only the polarized radiance and then the bidirectional reflectance given by the Ross-Li BRDF model was estimated from only the total radiance at target areas in PARASOL/POLDER data over the Japanese islands taken on April 28, 2012 and April 25, 2010. The estimated optical thickness of aerosols was checked with those given in AERONET sites and the estimated parameters of BRDF were compared with those of vegetation measured from the radio-controlled helicopter. Consequently, it is shown that the algorithm described in the present study provides reasonable values for aerosol properties and surface bidirectional reflectance.

Biomimetic artificial Si compound eye surface structures with broadband and wide-angle antireflection properties for Si-based optoelectronic applications

NASA Astrophysics Data System (ADS)

Leem, Jung Woo; Song, Young Min; Yu, Jae Su

2013-10-01

We report the biomimetic artificial silicon (Si) compound eye structures for broadband and wide-angle antireflection by integrating nanostructures (NSs) into periodically patterned microstructures (p-MSs) via thermal dewetting of gold and subsequent dry etching. The truncated cone microstructures with a two-dimensional hexagonal symmetry pattern were fabricated by photolithography and dry etching processes. The desirable shape and density of the nanostructures were obtained by controlled dewetting. The incorporation of p-MSs into the NS/Si surface further reduced the surface total reflectance over a wide wavelength range of 300-1030 nm at near normal incidence, indicating the average reflectance (Ravg) and solar weighted reflectance (RSWR) values of ~2.5% and 2%, respectively, compared to the only NSs on the flat Si surface (i.e., Ravg ~ 4.9% and RSWR ~ 4.5%). Additionally, the resulting structure improved the angle-dependent antireflection property due to its relatively omnidirectional shape, which exhibited the Ravg < 4.3% and RSWR < 3.7% in the wavelength region of 300-1100 nm even at a high incident light angle of 70° in the specular reflectance.We report the biomimetic artificial silicon (Si) compound eye structures for broadband and wide-angle antireflection by integrating nanostructures (NSs) into periodically patterned microstructures (p-MSs) via thermal dewetting of gold and subsequent dry etching. The truncated cone microstructures with a two-dimensional hexagonal symmetry pattern were fabricated by photolithography and dry etching processes. The desirable shape and density of the nanostructures were obtained by controlled dewetting. The incorporation of p-MSs into the NS/Si surface further reduced the surface total reflectance over a wide wavelength range of 300-1030 nm at near normal incidence, indicating the average reflectance (Ravg) and solar weighted reflectance (RSWR) values of ~2.5% and 2%, respectively, compared to the only NSs on the flat Si surface (i.e., Ravg ~ 4.9% and RSWR ~ 4.5%). Additionally, the resulting structure improved the angle-dependent antireflection property due to its relatively omnidirectional shape, which exhibited the Ravg < 4.3% and RSWR < 3.7% in the wavelength region of 300-1100 nm even at a high incident light angle of 70° in the specular reflectance. Electronic supplementary information (ESI) available: See DOI: 10.1039/c3nr02806b

PHOTONICS AND NANOTECHNOLOGY Microscopic theory of optical properties of composite media with chaotically distributed nanoparticles

NASA Astrophysics Data System (ADS)

Shalin, A. S.

2010-12-01

The boundary problem of light reflection and transmission by a film with chaotically distributed nanoinclusions is considered. Based on the proposed microscopic approach, analytic expressions are derived for distributions inside and outside the nanocomposite medium. Good agreement of the results with exact calculations and (at low concentrations of nanoparticles) with the integral Maxwell-Garnett effective-medium theory is demonstrated. It is shown that at high nanoparticle concentrations, averaging the dielectric constant in volume as is done within the framework of the effective-medium theory yields overestimated values of the optical film density compared to the values yielded by the proposed microscopic approach. We also studied the dependence of the reflectivity of a system of gold nanoparticles on their size, the size dependence of the plasmon resonance position along the wavelength scale, and demonstrated a good agreement with experimental data.

Acoustical conditions for speech communication in active elementary school classrooms

NASA Astrophysics Data System (ADS)

Sato, Hiroshi; Bradley, John

2005-04-01

Detailed acoustical measurements were made in 34 active elementary school classrooms with typical rectangular room shape in schools near Ottawa, Canada. There was an average of 21 students in classrooms. The measurements were made to obtain accurate indications of the acoustical quality of conditions for speech communication during actual teaching activities. Mean speech and noise levels were determined from the distribution of recorded sound levels and the average speech-to-noise ratio was 11 dBA. Measured mid-frequency reverberation times (RT) during the same occupied conditions varied from 0.3 to 0.6 s, and were a little less than for the unoccupied rooms. RT values were not related to noise levels. Octave band speech and noise levels, useful-to-detrimental ratios, and Speech Transmission Index values were also determined. Key results included: (1) The average vocal effort of teachers corresponded to louder than Pearsons Raised voice level; (2) teachers increase their voice level to overcome ambient noise; (3) effective speech levels can be enhanced by up to 5 dB by early reflection energy; and (4) student activity is seen to be the dominant noise source, increasing average noise levels by up to 10 dBA during teaching activities. [Work supported by CLLRnet.

Interpreting biomonitoring data for 2,4-dichlorophenoxyacetic acid: Update to Biomonitoring Equivalents and population biomonitoring data.

PubMed

Aylward, L L; Hays, S M

2015-12-01

Urinary biomonitoring data for 2,4-dichlorophenoxyacetic acid (2,4-D) reflect aggregate population exposures to trace 2,4-D residues in diet and the environment. These data can be interpreted in the context of current risk assessments by comparison to a Biomonitoring Equivalent (BE), which is an estimate of the average biomarker concentration consistent with an exposure guidance value such as the US EPA Reference Dose (RfD). BE values are updated here from previous published BE values to reflect a change in the US EPA RfD. The US EPA RfD has been updated to reflect a revised point of departure (POD) based on new information from additional toxicological studies and updated assessment of applicable uncertainty factors. In addition, new biomonitoring data from both the US National Health and Nutrition Examination Survey (NHANES) and the Canadian Health Measures Survey (CHMS) have been published. The updated US EPA chronic RfD of 0.21 mg/kg-d results in updated BE values of 10,500 and 7000 μg/L for adults and children, respectively. Comparison of the current population-representative data to these BE values shows that upper bound population biomarker concentrations are more than 5000-fold below BE values corresponding to the updated US EPA RfD. This biomonitoring-based risk assessment supports the conclusion that current use patterns in the US and Canada result in incidental exposures in the general population that can be considered negligible in the context of the current 2,4-D risk assessment. Copyright © 2015 Elsevier Inc. All rights reserved.

Source rock potential of middle cretaceous rocks in Southwestern Montana

USGS Publications Warehouse

Dyman, T.S.; Palacas, J.G.; Tysdal, R.G.; Perry, W.J.; Pawlewicz, M.J.

1996-01-01

The middle Cretaceous in southwestern Montana is composed of a marine and nonmarine succession of predominantly clastic rocks that were deposited along the western margin of the Western Interior Seaway. In places, middle Cretaceous rocks contain appreciable total organic carbon (TOC), such as 5.59% for the Mowry Shale and 8.11% for the Frontier Formation in the Madison Range. Most samples, however, exhibit less than 1.0% TOC. The genetic or hydrocarbon potential (S1+S2) of all the samples analyzed, except one, yield less than 1 mg HC/g rock, strongly indicating poor potential for generating commercial amounts of hydrocarbons. Out of 51 samples analyzed, only one (a Thermopolis Shale sample from the Snowcrest Range) showed a moderate petroleum potential of 3.1 mg HC/g rock. Most of the middle Cretaceous samples are thermally immature to marginally mature, with vitrinite reflectance ranging from about 0.4 to 0.6% Ro. Maturity is high in the Pioneer Mountains, where vitrinite reflectance averages 3.4% Ro, and at Big Sky Montana, where vitrinite reflectance averages 2.5% Ro. At both localities, high Ro values are due to local heat sources, such as the Pioneer batholith in the Pioneer Mountains.

Color change of the snapper (Pagrus auratus) and Gurnard (Chelidonichthys kumu) skin and eyes during storage: effect of light polarization and contact with ice.

PubMed

Balaban, Murat O; Stewart, Kelsie; Fletcher, Graham C; Alçiçek, Zayde

2014-12-01

Ten gurnard and 10 snapper were stored on ice. One side always contacted the ice; the other side was always exposed to air. At different intervals for up to 12 d, the fish were placed in a light box, and the images of both sides were taken using polarized and nonpolarized illumination. Image analysis resulted in average L*, a*, and b* values of skin, and average L* values of the eyes. The skin L* value of gurnard changed significantly over time while that of snapper was substantially constant. The a* and b* values of both fish decreased over time. The L* values of eyes were significantly lower for polarized images, and significantly lower for the side of fish exposed to air only. This may be a concern in quality evaluation methods such as QIM. The difference of colors between the polarized and nonpolarized images was calculated to quantify the reflection off the surface of fish. For accurate measurement of surface color and eye color, use of polarized light is recommended. © 2014 Institute of Food Technologists®

Histogram analysis parameters of apparent diffusion coefficient reflect tumor cellularity and proliferation activity in head and neck squamous cell carcinoma

PubMed Central

Winter, Karsten; Richter, Cindy; Hoehn, Anna-Kathrin

2018-01-01

Our purpose was to analyze associations between apparent diffusion coefficient (ADC) histogram analysis parameters and histopathologicalfeatures in head and neck squamous cell carcinoma (HNSCC). The study involved 32 patients with primary HNSCC. For every tumor, the following histogram analysis parameters were calculated: ADCmean, ADCmax, ADCmin, ADCmedian, ADCmode, P10, P25, P75, P90, kurtosis, skewness, and entropy. Furthermore, proliferation index KI 67, cell count, total and average nucleic areas were estimated. Spearman's correlation coefficient (p) was used to analyze associations between investigated parameters. In overall sample, all ADC values showed moderate inverse correlations with KI 67. All ADC values except ADCmax correlated inversely with tumor cellularity. Slightly correlations were identified between total/average nucleic area and ADCmean, ADCmin, ADCmedian, and P25. In G1/2 tumors, only ADCmode correlated well with Ki67. No statistically significant correlations between ADC parameters and cellularity were found. In G3 tumors, Ki 67 correlated with all ADC parameters except ADCmode. Cell count correlated well with all ADC parameters except ADCmax. Total nucleic area correlated inversely with ADCmean, ADCmin, ADCmedian, P25, and P90. ADC histogram parameters reflect proliferation potential and cellularity in HNSCC. The associations between histopathology and imaging depend on tumor grading. PMID:29805759

Automated geographic registration and radiometric correction for UAV-based mosaics

NASA Astrophysics Data System (ADS)

Thomasson, J. Alex; Shi, Yeyin; Sima, Chao; Yang, Chenghai; Cope, Dale A.

2017-05-01

Texas A and M University has been operating a large-scale, UAV-based, agricultural remote-sensing research project since 2015. To use UAV-based images in agricultural production, many high-resolution images must be mosaicked together to create an image of an agricultural field. Two key difficulties to science-based utilization of such mosaics are geographic registration and radiometric calibration. In our current research project, image files are taken to the computer laboratory after the flight, and semi-manual pre-processing is implemented on the raw image data, including ortho-mosaicking and radiometric calibration. Ground control points (GCPs) are critical for high-quality geographic registration of images during mosaicking. Applications requiring accurate reflectance data also require radiometric-calibration references so that reflectance values of image objects can be calculated. We have developed a method for automated geographic registration and radiometric correction with targets that are installed semi-permanently at distributed locations around fields. The targets are a combination of black (≍5% reflectance), dark gray (≍20% reflectance), and light gray (≍40% reflectance) sections that provide for a transformation of pixel-value to reflectance in the dynamic range of crop fields. The exact spectral reflectance of each target is known, having been measured with a spectrophotometer. At the time of installation, each target is measured for position with a real-time kinematic GPS receiver to give its precise latitude and longitude. Automated location of the reference targets in the images is required for precise, automated, geographic registration; and automated calculation of the digital-number to reflectance transformation is required for automated radiometric calibration. To validate the system for radiometric calibration, a calibrated UAV-based image mosaic of a field was compared to a calibrated single image from a manned aircraft. Reflectance values in selected zones of each image were strongly linearly related, and the average error of UAV-mosaic reflectances was 3.4% in the red band, 1.9% in the green band, and 1.5% in the blue band. Based on these results, the proposed physical system and automated software for calibrating UAV mosaics show excellent promise.

Optical pathlengths in dental caries lesions

NASA Astrophysics Data System (ADS)

Mujat, Claudia; ten Bosch, Jaap J.; Dogariu, Aristide C.

2001-04-01

The average pathlength of light inside dental enamel and incipient lesions is measured and compared, in order to quantitatively confirm the prediction that incipient lesions have higher scattering coefficients that sound enamel. The technique used, called optical pathlength spectroscopy provides experimental access to the pathlength distribution of light inside highly scattering samples. This is desirable for complex biological materials, where current theoretical models are very difficult to apply. To minimize the effects of surface reflections the average pathlength is measured in wet sound enamel and white spots. We obtain values of 367 micrometers and 272 micrometers average pathlength for sound enamel and white spots respectively. We also investigate the differences between open and subsurface lesions, by measuring the change in the pathlength distribution of light as they go from dry to wet.

Paleoenvironmental implications of taxonomic variation among δ 15 N values of chloropigments

NASA Astrophysics Data System (ADS)

Higgins, Meytal B.; Wolfe-Simon, Felisa; Robinson, Rebecca S.; Qin, Yelun; Saito, Mak A.; Pearson, Ann

2011-11-01

Natural variations in the ratios of nitrogen isotopes in biomass reflect variations in nutrient sources utilized for growth. In order to use δ 15N values of chloropigments of photosynthetic organisms to determine the corresponding δ 15N values of biomass - and by extension, surface waters - the isotopic offset between chlorophyll and biomass must be constrained. Here we examine this offset in various geologically-relevant taxa, grown using nutrient sources that may approximate ocean conditions at different times in Earth's history. Phytoplankton in this study include cyanobacteria (diazotrophic and non-diazotrophic), eukaryotic algae (red and green), and anoxygenic photosynthetic bacteria (Proteobacteria), as well as environmental samples from sulfidic lake water. Cultures were grown using N 2, NO 3-, and NH 4+ as nitrogen sources, and were examined under different light regimes and growth conditions. We find surprisingly high variability in the isotopic difference (δ 15N biomass - δ 15N chloropigment) for prokaryotes, with average values for species ranging from -12.2‰ to +11.7‰. We define this difference as ɛpor, a term that encompasses diagenetic porphyrins and chlorins, as well as chlorophyll. Negative values of ɛpor reflect chloropigments that are 15N-enriched relative to biomass. Notably, this enrichment appears to occur only in cyanobacteria. The average value of ɛpor for freshwater cyanobacterial species is -9.8 ± 1.8‰, while for marine cyanobacteria it is -0.9 ± 1.3‰. These isotopic effects group environmentally but not phylogenetically, e.g., ɛpor values for freshwater Chroococcales resemble those of freshwater Nostocales but differ from those of marine Chroococcales. Our measured values of ɛpor for eukaryotic algae (range = 4.7-8.7‰) are similar to previous reports for pure cultures. For all taxa studied, values of ɛpor do not depend on the type of nitrogen substrate used for growth. The observed environmental control of ɛpor suggests that values of ɛpor could be useful for determining the fractional burial of eukaryotic vs. cyanobacterial organic matter in the sedimentary record.

Analysis of extreme precipitation characteristics in low mountain areas based on three-dimensional copulas—taking Kuandian County as an example

NASA Astrophysics Data System (ADS)

Wang, Cailin; Ren, Xuehui; Li, Ying

2017-04-01

We defined the threshold of extreme precipitation using detrended fluctuation analysis based on daily precipitation during 1955-2013 in Kuandian County, Liaoning Province. Three-dimensional copulas were introduced to analyze the characteristics of four extreme precipitation factors: the annual extreme precipitation day, extreme precipitation amount, annual average extreme precipitation intensity, and extreme precipitation rate of contribution. The results show that (1) the threshold is 95.0 mm, extreme precipitation events generally occur 1-2 times a year, the average extreme precipitation intensity is 100-150 mm, and the extreme precipitation amount is 100-270 mm accounting for 10 to 37 % of annual precipitation. (2) The generalized extreme value distribution, extreme value distribution, and generalized Pareto distribution are suitable for fitting the distribution function for each element of extreme precipitation. The Ali-Mikhail-Haq (AMH) copula function reflects the joint characteristics of extreme precipitation factors. (3) The return period of the three types has significant synchronicity, and the joint return period and co-occurrence return period have long delay when the return period of the single factor is long. This reflects the inalienability of extreme precipitation factors. The co-occurrence return period is longer than that of the single factor and joint return period. (4) The single factor fitting only reflects single factor information of extreme precipitation but is unrelated to the relationship between factors. Three-dimensional copulas represent the internal information of extreme precipitation factors and are closer to the actual. The copula function is potentially widely applicable for the multiple factors of extreme precipitation.

An interplanetary magnetic field ensemble at 1 AU

NASA Technical Reports Server (NTRS)

Matthaeus, W. H.; Goldstein, M. L.; King, J. H.

1985-01-01

A method for calculation ensemble averages from magnetic field data is described. A data set comprising approximately 16 months of nearly continuous ISEE-3 magnetic field data is used in this study. Individual subintervals of this data, ranging from 15 hours to 15.6 days comprise the ensemble. The sole condition for including each subinterval in the averages is the degree to which it represents a weakly time-stationary process. Averages obtained by this method are appropriate for a turbulence description of the interplanetary medium. The ensemble average correlation length obtained from all subintervals is found to be 4.9 x 10 to the 11th cm. The average value of the variances of the magnetic field components are in the approximate ratio 8:9:10, where the third component is the local mean field direction. The correlation lengths and variances are found to have a systematic variation with subinterval duration, reflecting the important role of low-frequency fluctuations in the interplanetary medium.

Interannual variability of dust-mass loading and composition of dust deposited on snow cover in the San Juan Mountains, CO, USA: Insights into effects on snow melt

NASA Astrophysics Data System (ADS)

Goldstein, H. L.; Reynolds, R. L.; Derry, J.; Kokaly, R. F.; Moskowitz, B. M.

2017-12-01

Dust deposited on snow cover (DOS) in the American West can enhance snow-melt rates and advance the timing of melting, which together can result in earlier-than-normal runoff and overall smaller late-season water supplies. Understanding DOS properties and how they affect the absorption of solar radiation can lead to improved snow-melt models by accounting for important dust components. Here, we report on the interannual variability of DOS-mass loading, particle size, organic matter, and iron mineralogy, and their correspondences to laboratory-measured reflectance of samples from the Swamp Angel Study Plot in the San Juan Mountains, Colorado, USA. Samples were collected near the end of spring in water year 2009 (WY09) and from WY11-WY16, when dust layers deposited throughout the year had merged into one layer at the snow surface. Dust-mass loading on snow ranged 2-64 g/m2, mostly as particles with median sizes of 13-33 micrometers. Average reflectance values of DOS varied little across total (0.4 to 2.50 µm) and visible (0.4 to 0.7 µm) wavelengths at 0.30-0.45 and 0.19-0.27, respectively. Reflectance values lacked correspondence to particle-size. Total reflectance values inversely corresponded to concentrations of (1) organic matter content (4-20 weight %; r2 = 0.71) that included forms of black carbon and locally derived material such as pollen, and (2) magnetite (0.05 to 0.13 weight %; r2 = 0.44). Magnetite may be a surrogate for related dark, light-absorbing minerals. Concentrations of crystalline ferric oxide minerals (hematite+goethite) based on magnetic properties at room-temperature did not show inverse association to visible reflectance values. These ferric oxide measures, however, did not account for the amounts of nano-sized ferric oxides known to exist in these samples. Quantification of such nano-sized particles is required to evaluate their possible effects on visible reflectance. Nonetheless, our results emphasize that reflectance values of year-end DOS layers at this site do not appear to be highly sensitive to variations in some measured DOS properties. These preliminary results cannot be broadly applied to other DOS sites in the American West on the basis of previous and ongoing studies.

Modified vegetation indices for Ganoderma disease detection in oil palm from field spectroradiometer data

NASA Astrophysics Data System (ADS)

Shafri, Helmi Z. M.; Anuar, M. Izzuddin; Saripan, M. Iqbal

2009-10-01

High resolution field spectroradiometers are important for spectral analysis and mobile inspection of vegetation disease. The biggest challenges in using this technology for automated vegetation disease detection are in spectral signatures pre-processing, band selection and generating reflectance indices to improve the ability of hyperspectral data for early detection of disease. In this paper, new indices for oil palm Ganoderma disease detection were generated using band ratio and different band combination techniques. Unsupervised clustering method was used to cluster the values of each class resultant from each index. The wellness of band combinations was assessed by using Optimum Index Factor (OIF) while cluster validation was executed using Average Silhouette Width (ASW). 11 modified reflectance indices were generated in this study and the indices were ranked according to the values of their ASW. These modified indices were also compared to several existing and new indices. The results showed that the combination of spectral values at 610.5nm and 738nm was the best for clustering the three classes of infection levels in the determination of the best spectral index for early detection of Ganoderma disease.

Lear jet boundary layer/shear layer laser propagation experiments

NASA Technical Reports Server (NTRS)

Gilbert, K.

1980-01-01

Optical degradations of aircraft turbulent boundary layers with shear layers generated by aerodynamic fences are analyzed. A collimated 2.5 cm diameter helium-neon laser (0.63 microns) traversed the approximate 5 cm thick natural aircraft boundary layer in double pass via a reflective airfoil. In addition, several flights examined shear layer-induced optical degradation. Flight altitudes ranged from 1.5 to 12 km, while Mach numbers were varied from 0.3 to 0.8. Average line spread function (LSF) and Modulation Transfer Function (MTF) data were obtained by averaging a large number of tilt-removed curves. Fourier transforming the resulting average MTF yields an LSF, thus affording a direct comparison of the two optical measurements. Agreement was good for the aerodynamic fence arrangement, but only fair in the case of a turbulent boundary layer. Values of phase variance inferred from the LSF instrument for a single pass through the random flow and corrected for a large aperture ranged from 0.08 to 0.11 waves (lambda = .63 microns) for the boundary layer. Corresponding values for the fence vary from 0.08 to 0.16 waves. Extrapolation of these values to 10.6 microns suggests negligible degradation for a CO2 laser transmitted through a 5 cm thick, subsonic turbulent boundary layer.

Evoked potential correlates of figure and ground.

PubMed

Landis, T; Lehmann, D; Mita, T; Skrandies, W

1984-06-01

Brain potentials averaged during the viewing of an alternating, positive and negative "hidden man" puzzle picture were averaged from 8 subjects before and after they learned to recognize the figure. After figure recognition in comparison to before recognition, there was significantly more evoked positivity at 64/96 ms latency, and more negativity at 224/256 ms and at 352-480 ms latency over parietal areas during the viewing of the positive picture (recognizable as face) referred to the values obtained during viewing of the negative picture (not recognizable as face). It is hypothesized that separate physiological changes might reflect learned meaningfulness of the figure (which entails increased attention) and figure extraction from ground.

Infrared radiation of thin plastic films.

NASA Technical Reports Server (NTRS)

Tien, C. L.; Chan, C. K.; Cunnington, G. R.

1972-01-01

A combined analytical and experimental study is presented for infrared radiation characteristics of thin plastic films with and without a metal substrate. On the basis of the thin-film analysis, a simple analytical technique is developed for determining band-averaged optical constants of thin plastic films from spectral normal transmittance data for two different film thicknesses. Specifically, the band-averaged optical constants of polyethylene terephthalate and polyimide were obtained from transmittance measurements of films with thicknesses in the range of 0.25 to 3 mil. The spectral normal reflectance and total normal emittance of the film side of singly aluminized films are calculated by use of optical constants; the results compare favorably with measured values.

Development of numerical phantoms by MRI for RF electromagnetic dosimetry: a female model.

PubMed

Mazzurana, M; Sandrini, L; Vaccari, A; Malacarne, C; Cristoforetti, L; Pontalti, R

2004-01-01

Numerical human models for electromagnetic dosimetry are commonly obtained by segmentation of CT or MRI images and complex permittivity values are ascribed to each issue according to literature values. The aim of this study is to provide an alternative semi-automatic method by which non-segmented images, obtained by a MRI tomographer, can be automatically related to the complex permittivity values through two frequency dependent transfer functions. In this way permittivity and conductivity vary with continuity--even in the same tissue--reflecting the intrinsic realistic spatial dispersion of such parameters. A female human model impinged by a plane wave is tested using finite-difference time-domain algorithm and the results of the total body and layer-averaged specific absorption rate are reported.

Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise.

PubMed

Madsen, P L; Sperling, B K; Warming, T; Schmidt, J F; Secher, N H; Wildschiødtz, G; Holm, S; Lassen, N A

1993-01-01

Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions. To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow velocity in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise, whereas a 22% (P < 0.0001) increase in MCA Vmean was observed. Hence, the exercise-induced increase in MCA Vmean is not a reflection of a proportional increase in CBF.

Eliciting the Intension of Drug Value Sets – Principles and Quality Assurance Applications

PubMed Central

Bahr, Nathan J.; Nelson, Scott D.; Winnenburg, Rainer; Bodenreider, Olivier

2018-01-01

Value sets (VSs) used in electronic clinical quality measures are lists of codes from standard terminologies (“extensional” VSs), whose purpose (“intension”) is not always explicitly stated. We elicited the intension for the 09/01/2014 release of extensional medication value sets by comparison to drug classes from the October 2014 release of RxClass. Value sets matched drug classes if they shared common ingredients, as evidenced by Jaccard similarity score. We elicited the intension of 80 extensional value sets. The average Jaccard similarity was 0.65 for single classes and 0.80 for combination classes, with 34% (27/80) of the value sets having high similarity scores. Manual review by a pharmacist indicated 51% (41/80) of the drug classes selected as the best mapping for a value set matched the intension reflected in that value set name. This approach has the potential for facilitating the development and maintenance of medication value sets. PMID:29295218

Calorimetric Measurement for Internal Conversion Efficiency of Photovoltaic Cells/Modules Based on Electrical Substitution Method

NASA Astrophysics Data System (ADS)

Saito, Terubumi; Tatsuta, Muneaki; Abe, Yamato; Takesawa, Minato

2018-02-01

We have succeeded in the direct measurement for solar cell/module internal conversion efficiency based on a calorimetric method or electrical substitution method by which the absorbed radiant power is determined by replacing the heat absorbed in the cell/module with the electrical power. The technique is advantageous in that the reflectance and transmittance measurements, which are required in the conventional methods, are not necessary. Also, the internal quantum efficiency can be derived from conversion efficiencies by using the average photon energy. Agreements of the measured data with the values estimated from the nominal values support the validity of this technique.

The influence of the reflective environment on the absorption of a human male exposed to representative base station antennas from 300 MHz to 5 GHz.

PubMed

Vermeeren, G; Gosselin, M C; Kühn, S; Kellerman, V; Hadjem, A; Gati, A; Joseph, W; Wiart, J; Meyer, F; Kuster, N; Martens, L

2010-09-21

The environment is an important parameter when evaluating the exposure to radio-frequency electromagnetic fields. This study investigates numerically the variation on the whole-body and peak spatially averaged-specific absorption rate (SAR) in the heterogeneous virtual family male placed in front of a base station antenna in a reflective environment. The SAR values in a reflective environment are also compared to the values obtained when no environment is present (free space). The virtual family male has been placed at four distances (30 cm, 1 m, 3 m and 10 m) in front of six base station antennas (operating at 300 MHz, 450 MHz, 900 MHz, 2.1 GHz, 3.5 GHz and 5.0 GHz, respectively) and in three reflective environments (a perfectly conducting wall, a perfectly conducting ground and a perfectly conducting ground + wall). A total of 72 configurations are examined. The absorption in the heterogeneous body model is determined using the 3D electromagnetic (EM) finite-difference time-domain (FDTD) solver Semcad-X. For the larger simulations, requirements in terms of computer resources are reduced by using a generalized Huygens' box approach. It has been observed that the ratio of the SAR in the virtual family male in a reflective environment and the SAR in the virtual family male in the free-space environment ranged from -8.7 dB up to 8.0 dB. A worst-case reflective environment could not be determined. ICNIRP reference levels not always showed to be compliant with the basic restrictions.

Line transport in turbulent atmosphere

NASA Astrophysics Data System (ADS)

Nikoghossian, Artur

We consider the spectral line transfer in turbulent atmospheres with a spatially correlated velocity field. Both the finite and semi-infinite media are treated. In finding the observed intensities we first deal with the problem for determining the mean intensity of radiation emerging from the medium for a fixed value of turbulent velocity at its boundary. New approach proposed in solving this problem is based on invariant imbedding technique which yields the solution of the proper problems for a family of media of different optical thicknesses and allows tackling different kinds of inhomogeneous problems. The dependence of the line profile, integral intensity and the line width on the mean correlation length and average value of the hydrodynamic velocity is studied. It is shown that the transition from a micro-turbulent regime to a macro-turbulent one occurs within a comparatively narrow range of variation in the correlation length. The diffuse reflection of the line radiation from a one-dimensional semi-infinite turbulent atmosphere is examined. In addition to the observed spectral line profile, statistical averages describing the diffusion process in the atmosphere (mean number of scattering events, average time spent by a diffusing photon in the medium) are determined. The dependence of these quantities on the average hydrodynamic velocity and correlation coefficient is studied.

Line Transport in Turbulent Atmospheres

NASA Astrophysics Data System (ADS)

Nikoghossian, A. G.

2017-07-01

The spectral line transfer in turbulent atmospheres with a spatially correlated velocity field is examined. Both the finite and semi-infinite media are treated. In finding the observed intensities we first deal with the problem for determining the mean intensity of radiation emerging from the medium for a fixed value of turbulent velocity at its boundary. A new approach proposed for solving this problem is based on the invariant imbedding technique which yields the solution of the proper problems for a family of media of different optical thicknesses and allows tackling different kinds of inhomogeneous problems. The dependence of the line profile, integral intensity, and the line width on the mean correlation length and the average value of the hydrodynamic velocity is studied. It is shown that the transition from a micro-turbulent regime to a macro-turbulence occurs within a comparatively narrow range of variation in the correlation length . Ambartsumian's principle of invariance is used to solve the problem of diffuse reflection of the line radiation from a one-dimensional semi-infinite turbulent atmosphere. In addition to the observed spectral line profile, statistical averages describing the diffusion process in the atmosphere (mean number of scattering events, average time spent by a diffusing photon in the medium) are determined. The dependence of these quantities on the average hydrodynamic velocity and correlation coefficient is studied.

Tunable microwave absorbing nano-material for X-band applications

NASA Astrophysics Data System (ADS)

Sadiq, Imran; Naseem, Shahzad; Ashiq, Muhammad Naeem; Khan, M. A.; Niaz, Shanawer; Rana, M. U.

2016-03-01

The effect of rare earth elements substitution in Sr1.96RE0.04Co2Fe27.80Mn0.2O46 (RE=Ce, Gd, Nd, La and Sm) X-type hexagonal ferrites prepared by using sol gel autocombustion method was studied. The XRD and FTIR analysis show the single phase of the prepared material. The lattice constants a (Å) and c (Å) varies with the additives. The particle size measured by Scherer formula for all the samples varies in the range of 54-100 nm and confirmed by the TEM analysis. The average grain size measured by SEM analysis lies in the range of 0.672-1.01 μm for all the samples. The Gd-substituted ferrite has higher value of coercivity (526.06 G) among all the samples which could be a good material for longitudinal recording media. The results also indicate that the Gd-substituted sample has maximum reflection loss of -25.2 dB at 11.878 GHz, can exhibit the best microwave absorption properties among all the substituted samples. Furthermore, the minimum value of reflection loss shifts towards the lower and higher frequencies with the substitution of rare earth elements which confirms that the microwave absorption properties can be tuned with the substitution of rare earth elements in pure ferrites. The peak value of attenuation constant at higher frequency agrees well the reflection loss data.

Youth Attitude Tracking Study. Fall 1975.

DTIC Science & Technology

1976-02-01

today’s youth . The positioning , as recorded in this study, reflects the .~ . cumulative effect of advertising and promotion, contacts, and influences by...The second wave of the survey is due to be conducted in A pril, 1 976. RKET FACTS Page 2 In order to compete effectively in the youth labor market, the...average scale value for the group (e.g., civi- lian advantage on freedom) or percent of the group falling into the category (e.g., Percent of positive

The sensitivity in the IR spectrum of the intact and pathological tissues by laser biophotometry.

PubMed

Ravariu, Cristian; Bondarciuc, Ala

2014-03-01

In this paper, we use the laser biophotometry for in vivo investigations, searching the most sensitive interactions of the near-infrared spectrum with different tissues. The experimental methods are based on the average reflection coefficient (ARC) measurements. For healthy persons, ARC is the average of five values provided by the biophotometer. The probe is applied on dry skin with minimum pilosity, in five regions: left-right shank, left-right forearm, and epigastrium. For the pathological tissues, the emitting terminal is moved over the suspected area, controlling the reflection coefficient level, till a minimum value occurs, as ARC-Pathological. Then, the probe is moved on the symmetrical healthy region of the body to read the complementary coefficient from intact tissue, ARC-Intact, from the same patient. The experimental results show an ARC range between 67 and 59 mW for intact tissues and a lower range, up to 58-42 mW, for pathological tissues. The method is efficient only in those pathological processes accompanied by variable skin depigmentation, water retention, inflammation, thrombosis, or swelling. Frequently, the ARC ranges are overlapping for some diseases. This induces uncertain diagnosis. Therefore, a statistical algorithm is adopted for a differential diagnosis. The laser biophotometry provides a quantitative biometric parameter, ARC, suitable for fast diagnosis in the internal and emergency medicine. These laser biophotometry measurements are representatives for the Romanian clinical trials.

Histogram analysis parameters of apparent diffusion coefficient reflect tumor cellularity and proliferation activity in head and neck squamous cell carcinoma.

PubMed

Surov, Alexey; Meyer, Hans Jonas; Winter, Karsten; Richter, Cindy; Hoehn, Anna-Kathrin

2018-05-04

Our purpose was to analyze associations between apparent diffusion coefficient (ADC) histogram analysis parameters and histopathologicalfeatures in head and neck squamous cell carcinoma (HNSCC). The study involved 32 patients with primary HNSCC. For every tumor, the following histogram analysis parameters were calculated: ADCmean, ADCmax, ADC min , ADC median , ADC mode , P10, P25, P75, P90, kurtosis, skewness, and entropy. Furthermore, proliferation index KI 67, cell count, total and average nucleic areas were estimated. Spearman's correlation coefficient (p) was used to analyze associations between investigated parameters. In overall sample, all ADC values showed moderate inverse correlations with KI 67. All ADC values except ADCmax correlated inversely with tumor cellularity. Slightly correlations were identified between total/average nucleic area and ADC mean , ADC min , ADC median , and P25. In G1/2 tumors, only ADCmode correlated well with Ki67. No statistically significant correlations between ADC parameters and cellularity were found. In G3 tumors, Ki 67 correlated with all ADC parameters except ADCmode. Cell count correlated well with all ADC parameters except ADCmax. Total nucleic area correlated inversely with ADC mean , ADC min , ADC median , P25, and P90. ADC histogram parameters reflect proliferation potential and cellularity in HNSCC. The associations between histopathology and imaging depend on tumor grading.

Discriminating quantum-optical beam-splitter channels with number-diagonal signal states: Applications to quantum reading and target detection

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

Nair, Ranjith

2011-09-15

We consider the problem of distinguishing, with minimum probability of error, two optical beam-splitter channels with unequal complex-valued reflectivities using general quantum probe states entangled over M signal and M' idler mode pairs of which the signal modes are bounced off the beam splitter while the idler modes are retained losslessly. We obtain a lower bound on the output state fidelity valid for any pure input state. We define number-diagonal signal (NDS) states to be input states whose density operator in the signal modes is diagonal in the multimode number basis. For such input states, we derive series formulas formore » the optimal error probability, the output state fidelity, and the Chernoff-type upper bounds on the error probability. For the special cases of quantum reading of a classical digital memory and target detection (for which the reflectivities are real valued), we show that for a given input signal photon probability distribution, the fidelity is minimized by the NDS states with that distribution and that for a given average total signal energy N{sub s}, the fidelity is minimized by any multimode Fock state with N{sub s} total signal photons. For reading of an ideal memory, it is shown that Fock state inputs minimize the Chernoff bound. For target detection under high-loss conditions, a no-go result showing the lack of appreciable quantum advantage over coherent state transmitters is derived. A comparison of the error probability performance for quantum reading of number state and two-mode squeezed vacuum state (or EPR state) transmitters relative to coherent state transmitters is presented for various values of the reflectances. While the nonclassical states in general perform better than the coherent state, the quantitative performance gains differ depending on the values of the reflectances. The experimental outlook for realizing nonclassical gains from number state transmitters with current technology at moderate to high values of the reflectances is argued to be good.« less

The X-ray reflectivity of the AXAF VETA-I optics

NASA Technical Reports Server (NTRS)

Kellogg, E.; Chartas, G.; Graessle, D.; Hughes, J. P.; Van Speybroeck, L.; Zhao, Ping; Weisskopf, M. C.; Elsner, R. F.; O'Dell, S. L.

1993-01-01

The study measures the X-ray reflectivity of the AXAF VETA-I optic and compares it with theoretical predictions. Measurements made at energies of 0.28, 0.9, 1.5, 2.1, and 2.3 keV are compared with predictions based on ray trace calculations. Results on the variation of the reflectivity with energy as well as the absolute value of the reflectivity are presented. A synchrotron reflectivity measurement with a high-energy resolution over the range 0.26 to 1.8 keV on a flat Zerodur sample is also reported. Evidence is found for contamination of the flat by a thin layer of carbon on the surface, and the possibility of alteration of the surface composition of the VETA-I mirror, perhaps by the polishing technique. The overall agreement between the measured and calculated effective area of VETA-I is between 2.6 and 10 percent. Measurements at individual energies deviate from the best-fitting calculation to 0.3 to 0.8 percent, averaging 0.6 percent at energies below the high energy cutoff of the mirror reflectivity, and are as high as 20.7 percent at the cutoff.

Accuracy of tissue Doppler echocardiography in the diagnosis of new-onset congestive heart failure in patients with levels of B-type natriuretic peptide in the midrange and normal left ventricular ejection fraction.

PubMed

Arques, Stephane; Roux, Emmanuel; Sbragia, Pascal; Pieri, Bertrand; Gelisse, Richard; Ambrosi, Pierre; Luccioni, Roger

2006-09-01

Based on the hypothesis that it reflects left ventricular (LV) diastolic pressures, B-type natriuretic peptide (BNP) is largely utilized as first-line diagnostic complement in the emergency diagnosis of congestive heart failure (HF). The incremental diagnostic value of tissue Doppler echocardiography, a reliable noninvasive estimate of LV filling pressures, has been reported in patients with preserved LV ejection fraction and discrepancy between BNP levels and the clinical judgment, however, its clinical validity in such patients in the presence of BNP concentrations in the midrange, which may reflect intermediate, nondiagnostic levels of LV filling pressures, is unknown. 34 patients without history of HF, presenting with acute dyspnea at rest, BNP levels of 100-400 pg/ml and normal LV ejection fraction were prospectively enrolled (17 with congestive HF and 17 with noncardiac cause). Tissue Doppler echocardiography was performed within 3 hours after admission. Unlike BNP (P = 0.78), Boston criteria (P = 0.0129), radiographic pulmonary edema (P = 0.0036) and average E/Ea ratio (P = 0.0032) were predictive of congestive HF by logistic regression analysis. In this clinical setting, radiographic pulmonary edema had a positive predictive value of 80% in the diagnosis of congestive HF. In patients without evidence of radiographic pulmonary edema, average E/Ea > 10 was a powerful predictor of congestive HF (area under the ROC curve of 0.886, P < 0.001, sensitivity 100% and specificity 78.6%). By better reflecting LV filling pressures, bedside tissue Doppler echocardiography accurately differentiates congestive HF from noncardiac cause in dyspneic patients with intermediate, nondiagnostic BNP levels and normal LV ejection fraction.

A step function model to evaluate the real monetary value of man-sievert with real GDP.

PubMed

Na, Seong H; Kim, Sun G

2009-01-01

For use in a cost-benefit analysis to establish optimum levels of radiation protection in Korea under the ALARA principle, we introduce a discrete step function model to evaluate man-sievert monetary value in the real economic value. The model formula, which is unique and country-specific, is composed of real GDP, the nominal risk coefficient for cancer and hereditary effects, the aversion factor against radiation exposure, and average life expectancy. Unlike previous researches on alpha-value assessment, we show different alpha values in the real term, differentiated with respect to the range of individual doses, which would be more realistic and informative for application to the radiation protection practices. GDP deflators of economy can reflect the society's situations. Finally, we suggest that the Korean model can be generalized simply to other countries without normalizing any country-specific factors.

Biodiversity of free-living marine nematodes in the southern Yellow Sea, China

NASA Astrophysics Data System (ADS)

Liu, Xiaoshou; Xu, Man; Hua, Er; Zhang, Zhinan

2016-02-01

Biodiversity patterns of free-living marine nematodes were studied using specific, taxonomic and phylogenetic diversity measures in the southern Yellow Sea, China. The results showed that the average of Shannon-Wiener diversity index ( H') in the study area was 3.17. The higher values were distributed in the east part of Shandong coastal waters and north part of Jiangsu coastal waters, while the lower values were distributed in the southern Yellow Sea Cold Water Mass (YSCWM). The average of taxonomic diversity ( Δ) was 62.09 in the study region. The higher values were distributed in the transitional areas between the coastal areas and the southern YSCWM, while the lower values were distributed near the north part of Jiangsu coastal waters and the YSCWM. Results of correlation analysis of species diversity and taxonomic diversity showed that some of the two kinds of diversity index were independent, which suggested that combining the two kinds of diversity indices can reflect the ecological characteristics better. A test for 95% probability funnels of average taxonomic distinctness and variation in taxonomic distinctness suggested that Station 8794 (in the YSCWM) was outside of the 95% probability funnels, which may be due to the environmental stress. Results of correlation analysis between marine nematodes biodiversity and environmental variables showed that the sediment characteristics (Mdø and Silt-clay fraction) and phaeophorbide a (Pha- a) were the most important factors to determine the biodiversity patterns of marine nematodes.

Sunshine duration and its variability in the main ridge of the Karkonosze Mountains in relation to with atmospheric circulation

NASA Astrophysics Data System (ADS)

Urban, Grzegorz; Migała, Krzysztof; Pawliczek, Piotr

2018-02-01

Sunshine duration analysis was based on a series of measurements spanning the period from 1901 to 2014 for Śnieżka (1603 m a.s.l.) and from 1961 to 2000 for Szrenica (1362 m a.s.l.). The average annual sunshine duration (SD) on Śnieżka is 1423.0 h, which is among the lowest values in Poland. On average, the main ridge of the Karkonosze range receives 31% of potential sunshine duration in annual terms: from 25% in December to 36% in August and May. The changes in sunshine duration recorded on Śnieżka point to the existence of two cycles: a short one of approx. 2-4 years and a long one of approx. 60 years. The former most probably reflects the rhythm of atmospheric circulation in the North Atlantic (North Atlantic Oscillation), while the latter reflects the impact of ocean circulation associated with the AMO (Atlantic Multidecadal Oscillation) mechanism. Annual SD totals for the years 1901-2014 exhibit a slight trend to an increase of approx. 2.5 h/10 years, and the rate of increase during the winter quarter is many times higher than during the other seasons. Average monthly sunshine duration differences between Śnieżka and Szrenica are positive for all months of the year with the average monthly difference being 10 to 11 h. This means that the average radiation conditions on Śnieżka are more favourable than the main ridge of the Karkonosze range, which lies at an altitude 200 to 250 m lower. Average daily sunshine durations recorded on Śnieżka are only shorter than those on Szrenica for macro-types of atmospheric circulation with advection from the south.

Retrievals of ice cloud microphysical properties of deep convective systems using radar measurements: Convective Cloud Microphysical Retrieval

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

Tian, Jingjing; Dong, Xiquan; Xi, Baike

This study presents new algorithms for retrieving ice cloud microphysical properties (ice water content (IWC) and median mass diameter (Dm)) for the stratiform and thick anvil regions of Deep Convective Systems (DCSs) using Next-Generation Radar (NEXRAD) reflectivity and recently developed empirical relationships from aircraft in situ measurements during the Midlatitude Continental Convective Clouds Experiment (MC3E). A classic DCS case on 20 May 2011 is used to compare the retrieved IWC profiles with other retrieval and cloud-resolving model simulations. The mean values of each retrieved and simulated IWC fall within one standard derivation of the other two. The statistical results frommore » six selected cases during MC3E show that the aircraft in situ derived IWC and Dm are 0.47 ± 0.29 g m-3 and 2.02 ± 1.3 mm, while the mean values of retrievals have a positive bias of 0.16 g m-3 (34%) and a negative bias of 0.39 mm (19%). To validate the newly developed retrieval algorithms from this study, IWC and Dm are performed with other DCS cases during Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) field campaign using composite gridded NEXRAD reflectivity and compared with in situ IWC and Dm from aircraft. A total of 64 1-min collocated aircraft and radar samples are available for comparisons, and the averages of radar retrieved and aircraft in situ measured IWCs are 1.22 g m-3 and 1.26 g m-3 with a correlation of 0.5, and their averaged Dm values are 2.15 and 1.80 mm. These comparisons have shown that the retrieval algorithms 45 developed during MC3E can retrieve similar ice cloud microphysical properties of DCS to aircraft in situ measurements during BAMEX with median errors of ~40% and ~25% for IWC and Dm retrievals, respectively. This is indicating our retrieval algorithms are suitable for other midlatitude continental DCS ice clouds, especially at stratiform rain and thick anvil regions. In addition, based on the averaged IWC and Dm values during MC3E and BAMEX, the DCS IWC values over midlatitude are significantly different, while their Dm values are close to each other. On the other hand, these DCS IWC and Dm values are 1-2 orders of magnitude larger than those of single-layered cirrus clouds over midlatitudes.« less

Orthostatic effects on echocardiographic measures of ventricular function.

PubMed

Rowland, Thomas; Unnithan, Viswanath; Barker, Piers; Guerra, Miriam; Roche, Denise; Lindley, Martin

2012-05-01

Orthostatic-induced alterations in Doppler echocardiographic measures of ventricular function have not been well-defined. Identifying such changes may provide useful insights regarding the responses of these measures to variations in ventricular loading conditions. Standard assessment of mitral inflow velocity and tissue Doppler imaging (TDI) of left ventricular longitudinal myocardial velocities was performed on 14 young males (mean age 17.9 ± 0.7 years) in the supine position and then 5 minutes after assuming a sitting position with legs dependent. Upon sitting, average values of stroke volume and cardiac output fell by 28% and 18%, respectively, while heart rate increased from 64 ± 10 to 73 ± 12 beats/min (+14%) and calculated systemic vascular resistance rose from 12.9 ± 2.2 to 16.4 ± 3.1 units (+27%). Mitral E peak velocity declined from 87 ± 16 to 64 ± 16 cm/sec, and average TDI-E' and TDI-S both decreased (by -44% and -20%, respectively). When adjusted for orthostatic decreases in left ventricular end-diastolic volume, the mean decrease in TDI-E' was reduced to -29 (P < 0.01), but no significant decline was observed in adjusted TDI-S. Average E/E' rose with sitting by 40% (P = 0.02). These findings suggest that (a) decreases in TDI measures when assuming the upright position reflect the reduction of left ventricular size; (b) orthostatic fall in TDI-E' is also related to smaller ventricular size but, in addition, to a nonspecified reduction in ventricular relaxation; and (c) values of E/E' do not reflect alterations in ventricular preload, which occur during an orthostatic challenge. © 2012, Wiley Periodicals, Inc.

Status of lipids and the frequency diseases of cardiovascular origin in smokers according to the length period of smoking and a number of cigarettes smoked daily

PubMed Central

Bišanović, Senaida; Mehić, Bakir; Sivić, Suad

2011-01-01

Cigarette smoking affects all phases of atherosclerosis from endothelial dysfunction to acute occlusive clinical events. The problem is, whether the length of the period of cigarette smoking has a more reflection to the status of lipids and illnesses of cardiovascular system or the bigger number of smoked cigarettes in a shorter time-period? The observed sample has constituted of two groups of smokers, both gender, age 25-64 years old. The first group consisted of 210 examinees divided in 7 subgroups according to a number of years they have been smoking. The second group consisted of 150 examinees, which was divided in 5 subgroups, according to average number of cigarettes smoked daily. The average values of serum cholesterol (6.98 vs. 6.13 mmol/L), triglycerides (3.15 vs. 3.13 mmol/L) and LDL-cholesterol (3.80 vs. 3.64 mmol/L) were always higher in a group of smokers according to a number of daily smoked cigarettes. Average value of smoking consumption period was higher in a group of smokers according to the length of smoking consumption period than in a group of smokers according to a number of cigarettes smoked daily (20.34 y vs. 13.55 y.). Hypertension (72% vs. 30.9%), angina pectoris (44.6% vs. 20.4%), CHD (30.6% vs. 22.8%) and myocardial infarction (16% vs. 11.4%) appeared much more in the group of smokers according to a number of cigarettes smoked daily. More reflection to the status of lipids and illnesses of cardiovascular system has the bigger number of smoked cigarettes daily than the length of the period of cigarette smoking. PMID:21342142

Limitations of quantitative analysis of deep crustal seismic reflection data: Examples from GLIMPCE

USGS Publications Warehouse

Lee, Myung W.; Hutchinson, Deborah R.

1992-01-01

Amplitude preservation in seismic reflection data can be obtained by a relative true amplitude (RTA) processing technique in which the relative strength of reflection amplitudes is preserved vertically as well as horizontally, after compensating for amplitude distortion by near-surface effects and propagation effects. Quantitative analysis of relative true amplitudes of the Great Lakes International Multidisciplinary Program on Crustal Evolution seismic data is hampered by large uncertainties in estimates of the water bottom reflection coefficient and the vertical amplitude correction and by inadequate noise suppression. Processing techniques such as deconvolution, F-K filtering, and migration significantly change the overall shape of amplitude curves and hence calculation of reflection coefficients and average reflectance. Thus lithological interpretation of deep crustal seismic data based on the absolute value of estimated reflection strength alone is meaningless. The relative strength of individual events, however, is preserved on curves generated at different stages in the processing. We suggest that qualitative comparisons of relative strength, if used carefully, provide a meaningful measure of variations in reflectivity. Simple theoretical models indicate that peg-leg multiples rather than water bottom multiples are the most severe source of noise contamination. These multiples are extremely difficult to remove when the water bottom reflection coefficient is large (>0.6), a condition that exists beneath parts of Lake Superior and most of Lake Huron.

Long-Period Fiber Grating Sensors for the Measurement of Liquid Level and Fluid-Flow Velocity

PubMed Central

Wang, Jian-Neng; Luo, Ching-Ying

2012-01-01

This paper presents the development and assessment of two types of Long Period Fiber Grating (LPFG)-based sensors including a mobile liquid level sensor and a reflective sensor for the measurement of liquid level and fluid-flow velocity. Shewhart control charts were used to assess the liquid level sensing capacity and reliability of the mobile CO2-laser engraved LPFG sensor. There were ten groups of different liquid level experiment and each group underwent ten repeated wavelength shift measurements. The results showed that all measurands were within the control limits; thus, this mobile sensor was reliable and exhibited at least 100-cm liquid level measurement capacity. In addition, a reflective sensor consisting of five LPFGs in series with a reflective end has been developed to evaluate the liquid level and fluid-flow velocity. These five LPFGs were fabricated by the electrical arc discharge method and the reflective end was coated with silver by Tollen's test. After each liquid level experiment was performed five times, the average values of the resonance wavelength shifts for LPFG Nos. 1–5 were in the range of 1.35–9.14 nm. The experimental findings showed that the reflective sensor could be used to automatically monitor five fixed liquid levels. This reflective sensor also exhibited at least 100-cm liquid level measurement capacity. The mechanism of the fluid-flow velocity sensor was based on analyzing the relationship among the optical power, time, and the LPFG's length. There were two types of fluid-flow velocity measurements: inflow and drainage processes. The differences between the LPFG-based fluid-flow velocities and the measured average fluid-flow velocities were found in the range of 8.7–12.6%. For the first time to our knowledge, we have demonstrated the feasibility of liquid level and fluid-flow velocity sensing with a reflective LPFG-based sensor without modifying LPFGs or coating chemical compounds. PMID:22666046

Long-period fiber grating sensors for the measurement of liquid level and fluid-flow velocity.

PubMed

Wang, Jian-Neng; Luo, Ching-Ying

2012-01-01

This paper presents the development and assessment of two types of Long Period Fiber Grating (LPFG)-based sensors including a mobile liquid level sensor and a reflective sensor for the measurement of liquid level and fluid-flow velocity. Shewhart control charts were used to assess the liquid level sensing capacity and reliability of the mobile CO(2)-laser engraved LPFG sensor. There were ten groups of different liquid level experiment and each group underwent ten repeated wavelength shift measurements. The results showed that all measurands were within the control limits; thus, this mobile sensor was reliable and exhibited at least 100-cm liquid level measurement capacity. In addition, a reflective sensor consisting of five LPFGs in series with a reflective end has been developed to evaluate the liquid level and fluid-flow velocity. These five LPFGs were fabricated by the electrical arc discharge method and the reflective end was coated with silver by Tollen's test. After each liquid level experiment was performed five times, the average values of the resonance wavelength shifts for LPFG Nos. 1-5 were in the range of 1.35-9.14 nm. The experimental findings showed that the reflective sensor could be used to automatically monitor five fixed liquid levels. This reflective sensor also exhibited at least 100-cm liquid level measurement capacity. The mechanism of the fluid-flow velocity sensor was based on analyzing the relationship among the optical power, time, and the LPFG's length. There were two types of fluid-flow velocity measurements: inflow and drainage processes. The differences between the LPFG-based fluid-flow velocities and the measured average fluid-flow velocities were found in the range of 8.7-12.6%. For the first time to our knowledge, we have demonstrated the feasibility of liquid level and fluid-flow velocity sensing with a reflective LPFG-based sensor without modifying LPFGs or coating chemical compounds.

Paleoenvironmental implications of taxonomic variation among δ15N values of chloropigments

USGS Publications Warehouse

Higgins, Meytal B.; Wolfe-Simon, Felisa; Robinson, Rebecca S.; Qin, Yelun; Saito, Mark A.; Pearson, Ann

2011-01-01

Natural variations in the ratios of nitrogen isotopes in biomass reflect variations in nutrient sources utilized for growth. In order to use δ15N values of chloropigments of photosynthetic organisms to determine the corresponding δ15N values of biomass – and by extension, surface waters – the isotopic offset between chlorophyll and biomass must be constrained. Here we examine this offset in various geologically-relevant taxa, grown using nutrient sources that may approximate ocean conditions at different times in Earth’s history. Phytoplankton in this study include cyanobacteria (diazotrophic and non-diazotrophic), eukaryotic algae (red and green), and anoxygenic photosynthetic bacteria (Proteobacteria), as well as environmental samples from sulfidic lake water. Cultures were grown using N2, NO3−, and NH4+ as nitrogen sources, and were examined under different light regimes and growth conditions. We find surprisingly high variability in the isotopic difference (δ15Nbiomass − δ15Nchloropigment) for prokaryotes, with average values for species ranging from −12.2‰ to +11.7‰. We define this difference as εpor, a term that encompasses diagenetic porphyrins and chlorins, as well as chlorophyll. Negative values of εpor reflect chloropigments that are 15N-enriched relative to biomass. Notably, this enrichment appears to occur only in cyanobacteria. The average value of εpor for freshwater cyanobacterial species is −9.8 ± 1.8‰, while for marine cyanobacteria it is −0.9 ± 1.3‰. These isotopic effects group environmentally but not phylogenetically, e.g., εpor values for freshwater Chroococcales resemble those of freshwater Nostocales but differ from those of marine Chroococcales. Our measured values of εpor for eukaryotic algae (range = 4.7–8.7‰) are similar to previous reports for pure cultures. For all taxa studied, values of εpor do not depend on the type of nitrogen substrate used for growth. The observed environmental control of εpor suggests that values of εpor could be useful for determining the fractional burial of eukaryotic vs. cyanobacterial organic matter in the sedimentary record.

Depth variations of the 410 and 520 km-discontinuities beneath Asia and the Pacific from PP precursors

NASA Astrophysics Data System (ADS)

Schäfer, J.; Wölbern, I.; Rümpker, G.

2009-06-01

We investigate depth variations of the 410 and 520 km-discontinuities beneath Asia and the Pacific which serve as examples for a continental and an oceanic region, respectively. The depths are derived from travel-time differences between the PP-phase and its precursors that are reflected at the discontinuities. After accounting for differences in average crustal thickness, we find that the depth of the ‘410’ is rather uniform but larger than expected beneath both regions with a value of approximately 418 km. Signals from the ‘520’ are slightly less pronounced. However, while the average depth of the ‘520’ beneath Asia is about 519 km, we obtain a value of about 531.5 km for the Pacific. Here, the depression of the discontinuities can be explained in view of thermal anomalies in relation to mantle plumes. For Asia, however, the observations seem to require a more complex pattern of thermal anomalies possibly complemented by variations in chemical composition.

Interplay of Anderson localization and quench dynamics

NASA Astrophysics Data System (ADS)

Rahmani, Armin; Vishveshwara, Smitha

2018-06-01

In the context of an isolated three-dimensional noninteracting fermionic lattice system, we study the effects of a sudden quantum quench between a disorder-free situation and one in which disorder results in a mobility edge and associated Anderson localization. Salient post-quench features hinge upon the overlap between momentum states and post-quench eigenstates and whether these latter states are extended or localized. We find that the post-quench momentum distribution directly reflects these overlaps. For the local density, we show that disorder generically prevents the equilibration of quantum expectation values to a steady state and that the persistent fluctuations have a nonmonotonic dependence on the strength of disorder. We identify two distinct types of fluctuations, namely, temporal fluctuations describing the time-dependent fluctuations of the local density around its time average and sample-to-sample fluctuations characterizing the variations of these time averages from one realization of disorder to another. We demonstrate that both of these fluctuations vanish for extremely extended as well as extremely localized states, peaking at some intermediate value.

Effect of humic acid in leachate on specific methanogenic activity of anaerobic granular sludge.

PubMed

Guo, Mengfei; Xian, Ping; Yang, Longhui; Liu, Xi; Zhan, Longhui; Bu, Guanghui

2015-01-01

In order to find out the effects of humic acid (HA) in anaerobic-treated landfill leachate on granular sludge, the anaerobic biodegradability of HA as well as the influences of HA on the total cumulative methane production, the anaerobic methanization process and the specific methanogenic activity (SMA) of granular sludge are studied in this paper. Experimental results show that as a non-biodegradable organic pollutant, HA is also difficult to be decomposed by microbes in the anaerobic reaction process. Presence of HA and changes in the concentration have no significant influences on the total cumulative methane production and the anaerobic methanization process of granular sludge. Besides, the total cumulative methane production cannot reflect the inhibition of toxics on the methanogenic activity of granular sludge on the premise of sufficient reaction time. Results also show that HA plays a promoting role on SMA of granular sludge. Without buffering agent the SMA value increased by 19.2% on average due to the buffering and regulating ability of HA, while with buffering agent the SMA value increased by 5.4% on average due to the retaining effect of HA on the morphology of the sludge particles. However, in the presence of leachate the SMA value decreased by 27.6% on average, because the toxic effect of the toxics in the leachate on granular sludge is much larger than the promoting effect of HA.

Metasurface integrated high energy efficient and high linearly polarized InGaN/GaN light emitting diode.

PubMed

Wang, Miao; Xu, Fuyang; Lin, Yu; Cao, Bing; Chen, Linghua; Wang, Chinhua; Wang, Jianfeng; Xu, Ke

2017-07-06

We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface. This significantly enhances the polarized light emission efficiency. Experimental results show that extraction efficiency of the polarized emission can be increased by 40% on average in a wide angle of ±60° compared to that with the naked bottom of sapphire substrate, or 20% compared to reflecting Al film on the bottom of a sapphire substrate. An extinction ratio (ER) of average value 20 dB within an angle of ±60° can be simultaneously obtained directly from an InGaN/GaN LED. Our results show the possibility of simultaneously achieving a high degree of polarization and high polarization extraction efficiency at the integrated device level. This advances the field of GaN LED toward energy efficiency, multi-functional applications in illumination, display, medicine, and light manipulation.

SELF BLOOD GLUCOSE MONITORING UNDERESTIMATES HYPERGLYCEMIA AND HYPOGLYCEMIA AS COMPARED TO CONTINUOUS GLUCOSE MONITORING IN TYPE 1 AND TYPE 2 DIABETES.

PubMed

Mangrola, Devna; Cox, Christine; Furman, Arianne S; Krishnan, Sridevi; Karakas, Sidika E

2018-01-01

When glucose records from self blood glucose monitoring (SBGM) do not reflect estimated average glucose from glycosylated hemoglobin (HgBA1) or when patients' clinical symptoms are not explained by their SBGM records, clinical management of diabetes becomes a challenge. Our objective was to determine the magnitude of differences in glucose values reported by SBGM versus those documented by continuous glucose monitoring (CGM). The CGM was conducted by a clinical diabetes educator (CDE)/registered nurse by the clinic protocol, using the Medtronic iPRO2 ™ system. Patients continued SBGM and managed their diabetes without any change. Data from 4 full days were obtained, and relevant clinical information was recorded. De-identified data sets were provided to the investigators. Data from 61 patients, 27 with type 1 diabetes (T1DM) and 34 with T2DM were analyzed. The lowest, highest, and average glucose recorded by SBGM were compared to the corresponding values from CGM. The lowest glucose values reported by SBGM were approximately 25 mg/dL higher in both T1DM ( P = .0232) and T2DM ( P = .0003). The highest glucose values by SBGM were approximately 30 mg/dL lower in T1DM ( P = .0005) and 55 mg/dL lower in T2DM ( P<.0001). HgBA1c correlated with the highest and average glucose by SBGM and CGM. The lowest glucose values were seen most frequently during sleep and before breakfast; the highest were seen during the evening and postprandially. SBGM accurately estimates the average glucose but underestimates glucose excursions. CGM uncovers glucose patterns that common SBGM patterns cannot. CDE = certified diabetes educator; CGM = continuous glucose monitoring; HgBA1c = glycosylated hemoglobin; MAD = mean absolute difference; SBGM = self blood glucose monitoring; T1DM = type 1 diabetes; T2DM = type 2 diabetes.

Opaque cloud detection

DOEpatents

Roskovensky, John K [Albuquerque, NM

2009-01-20

A method of detecting clouds in a digital image comprising, for an area of the digital image, determining a reflectance value in at least three discrete electromagnetic spectrum bands, computing a first ratio of one reflectance value minus another reflectance value and the same two values added together, computing a second ratio of one reflectance value and another reflectance value, choosing one of the reflectance values, and concluding that an opaque cloud exists in the area if the results of each of the two computing steps and the choosing step fall within three corresponding predetermined ranges.

Predicting top-of-atmosphere radiance for arbitrary viewing geometries from the visible to thermal infrared: generalization to arbitrary average scene temperatures

NASA Astrophysics Data System (ADS)

Florio, Christopher J.; Cota, Steve A.; Gaffney, Stephanie K.

2010-08-01

In a companion paper presented at this conference we described how The Aerospace Corporation's Parameterized Image Chain Analysis & Simulation SOftware (PICASSO) may be used in conjunction with a limited number of runs of AFRL's MODTRAN4 radiative transfer code, to quickly predict the top-of-atmosphere (TOA) radiance received in the visible through midwave IR (MWIR) by an earth viewing sensor, for any arbitrary combination of solar and sensor elevation angles. The method is particularly useful for large-scale scene simulations where each pixel could have a unique value of reflectance/emissivity and temperature, making the run-time required for direct prediction via MODTRAN4 prohibitive. In order to be self-consistent, the method described requires an atmospheric model (defined, at a minimum, as a set of vertical temperature, pressure and water vapor profiles) that is consistent with the average scene temperature. MODTRAN4 provides only six model atmospheres, ranging from sub-arctic winter to tropical conditions - too few to cover with sufficient temperature resolution the full range of average scene temperatures that might be of interest. Model atmospheres consistent with intermediate temperature values can be difficult to come by, and in any event, their use would be too cumbersome for use in trade studies involving a large number of average scene temperatures. In this paper we describe and assess a method for predicting TOA radiance for any arbitrary average scene temperature, starting from only a limited number of model atmospheres.

Soiling of building envelope surfaces and its effect on solar reflectance – Part II: Development of an accelerated aging method for roofing materials

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

Sleiman, Mohamad; Kirchstetter, Thomas W.; Berdahl, Paul

2014-01-09

Highly reflective roofs can decrease the energy required for building air conditioning, help mitigate the urban heat island effect, and slow global warming. However, these benefits are diminished by soiling and weathering processes that reduce the solar reflectance of most roofing materials. Soiling results from the deposition of atmospheric particulate matter and the growth of microorganisms, each of which absorb sunlight. Weathering of materials occurs with exposure to water, sunlight, and high temperatures. This study developed an accelerated aging method that incorporates features of soiling and weathering. The method sprays a calibrated aqueous soiling mixture of dust minerals, black carbon,more » humic acid, and salts onto preconditioned coupons of roofing materials, then subjects the soiled coupons to cycles of ultraviolet radiation, heat and water in a commercial weatherometer. Three soiling mixtures were optimized to reproduce the site-specific solar spectral reflectance features of roofing products exposed for 3 years in a hot and humid climate (Miami, Florida); a hot and dry climate (Phoenix, Arizona); and a polluted atmosphere in a temperate climate (Cleveland, Ohio). A fourth mixture was designed to reproduce the three-site average values of solar reflectance and thermal emittance attained after 3 years of natural exposure, which the Cool Roof Rating Council (CRRC) uses to rate roofing products sold in the US. This accelerated aging method was applied to 25 products₋single ply membranes, factory and field applied coatings, tiles, modified bitumen cap sheets, and asphalt shingles₋and reproduced in 3 days the CRRC's 3-year aged values of solar reflectance. In conclusion, this accelerated aging method can be used to speed the evaluation and rating of new cool roofing materials.« less

Individual selection of X-ray tube settings in computed tomography coronary angiography: Reliability of an automated software algorithm to maintain constant image quality.

PubMed

Durmus, Tahir; Luhur, Reny; Daqqaq, Tareef; Schwenke, Carsten; Knobloch, Gesine; Huppertz, Alexander; Hamm, Bernd; Lembcke, Alexander

2016-05-01

To evaluate a software tool that claims to maintain a constant contrast-to-noise ratio (CNR) in high-pitch dual-source computed tomography coronary angiography (CTCA) by automatically selecting both X-ray tube voltage and current. A total of 302 patients (171 males; age 61±12years; body weight 82±17kg, body mass index 27.3±4.6kg/cm(2)) underwent CTCA with a topogram-based, automatic selection of both tube voltage and current using dedicated software with quality reference values of 100kV and 250mAs/rotation (i.e., standard values for an average adult weighing 75kg) and an injected iodine load of 222mg/kg. The average radiation dose was estimated to be 1.02±0.64mSv. All data sets had adequate contrast enhancement. Average CNR in the aortic root, left ventricle, and left and right coronary artery was 15.7±4.5, 8.3±2.9, 16.1±4.3 and 15.3±3.9 respectively. Individual CNR values were independent of patients' body size and radiation dose. However, individual CNR values may vary considerably between subjects as reflected by interquartile ranges of 12.6-18.6, 6.2-9.9, 12.8-18.9 and 12.5-17.9 respectively. Moreover, average CNR values were significantly lower in males than females (15.1±4.1 vs. 16.6±11.7 and 7.9±2.7 vs. 8.9±3.0, 15.5±3.9 vs. 16.9±4.6 and 14.7±3.6 vs. 16.0±4.1 respectively). A topogram-based automatic selection of X-ray tube settings in CTCA provides diagnostic image quality independent of patients' body size. Nevertheless, considerable variation of individual CNR values between patients and significant differences of CNR values between males and females occur which questions the reliability of this approach. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Backscattering enhancement factor dependence of a Laguerre-Gaussian laser beam propagating on the location path in the atmosphere on optical turbulence intensity

NASA Astrophysics Data System (ADS)

Rytchkov, D. S.

2017-11-01

The paper presents the results of a study of the backscattering enhancement factor (BSE) dependence of vortex LaguerreGaussian beams propagating on monostatic location paths in the atmosphere on optical turbulence intensity. The numeric simulation split-step method of laser beam propagation was used to obtain BSE factor values of a laser beam propagated on monostatic location path in the turbulent atmosphere and reflected from a diffuse target. It is shown that BSE factor of the averaged intensity of a backscattered vortex laser beam of any topological charge is less than BSE factor values of backscattered Gaussian beam in arbitrary turbulent conditions.

Retrievals of ice cloud microphysical properties of deep convective systems using radar measurements

NASA Astrophysics Data System (ADS)

Tian, Jingjing; Dong, Xiquan; Xi, Baike; Wang, Jingyu; Homeyer, Cameron R.; McFarquhar, Greg M.; Fan, Jiwen

2016-09-01

This study presents newly developed algorithms for retrieving ice cloud microphysical properties (ice water content (IWC) and median mass diameter (Dm)) for the stratiform rain and thick anvil regions of deep convective systems (DCSs) using Next Generation Radar (NEXRAD) reflectivity and empirical relationships from aircraft in situ measurements. A typical DCS case (20 May 2011) during the Midlatitude Continental Convective Clouds Experiment (MC3E) is selected as an example to demonstrate the 4-D retrievals. The vertical distributions of retrieved IWC are compared with previous studies and cloud-resolving model simulations. The statistics from six selected cases during MC3E show that the aircraft in situ derived IWC and Dm are 0.47 ± 0.29 g m-3 and 2.02 ± 1.3 mm, while the mean values of retrievals have a positive bias of 0.19 g m-3 (40%) and negative bias of 0.41 mm (20%), respectively. To evaluate the new retrieval algorithms, IWC and Dm are retrieved for other DCSs observed during the Bow Echo and Mesoscale Convective Vortex Experiment (BAMEX) using NEXRAD reflectivity and compared with aircraft in situ measurements. During BAMEX, a total of 63, 1 min collocated aircraft and radar samples are available for comparisons, and the averages of radar retrieved and aircraft in situ measured IWC values are 1.52 g m-3 and 1.25 g m-3 with a correlation of 0.55, and their averaged Dm values are 2.08 and 1.77 mm. In general, the new retrieval algorithms are suitable for continental DCSs during BAMEX, especially within stratiform rain and thick anvil regions.

Quantifying the Significance of Heterogeneity in Supraglacial Reflectance Characteristics for Meltwater Production in Southwest Greenland

NASA Astrophysics Data System (ADS)

Irvine-Fynn, T. D.; Bunting, P.; Cook, J.; Hardy, A. J.; Hodson, A. J.; Holt, T.; Hubbard, A.; Naegeli, K.; Nilsson, J.; Ryan, J.; Roberts, O.; Tedstone, A.; Tranter, M.; Williamson, C.

2017-12-01

The seasonal melt on the southwestern margin of the Greenland Ice Sheet has been enhanced due to processes affecting the ablation area's ice surface reflectance (albedo). Recent trends in surface reflectance in the region suggest a decline potentially linked to an albedo-feedback associated with regional climate warming, emergence of organic and mineral particulates, and expansion of melt area. However, the heterogeneity of reflectance over bare ice areas in space and time has remained relatively poorly characterised. Numerous surface mass balance models utilise albedo products derived from remote sensing platforms with coarse scale resolution. Such products provide reasonable albedo estimates, but quantification of local variability in reflectance remains lacking. Consequently, there is a need to better define the distribution and representativeness of ice surface reflectance at and below the scale of satellite sensor pixel footprints to facilitate examination of albedo parameterisations. Here, we present reflectance data repeatedly collected in SW Greenland during the 2016 summer melt season over a 0.0625 km2 area proximate to the IMAU K-transect site S6 (67°04.5'N, 49°21.0'W). The Moderate Resolution Imaging Spectrometer (MODIS) albedo product MOD10A1(c6) for the study site was compared to reflectance data from Sentinel-2, centimetre resolution calibrated 12Mpix optical imagery collected using an Unmanned Aerial Vehicle (UAV) flown at a height of 70 m above the ice surface, and ground-based reflectance survey data acquired using a StellarNet Red-Dwarf/Blue-Wave visible-infrared dual system (250-1700nm) at 30 sites distributed over the area of interest. Our data highlight variability in the spatial distribution of ice surface reflectance characteristics over time. Specifically, data demonstrate marked changes in the distribution of reflectance values, despite maintaining a broadly equitable mean and median during July and August. The influence of the varied surface heterogeneity is explored further using surface energy balance modelling to quantify the impact of such changes on melt production. The findings determine the necessity to account for local variability underlying the pixel-averaged values retrieved from remote sensing platforms such as MODIS.

Mild hypothermia for treatment of diffuse axonal injury: a quantitative analysis of diffusion tensor imaging

PubMed Central

Jing, Guojie; Yao, Xiaoteng; Li, Yiyi; Xie, Yituan; Li, Wang#x2019;an; Liu, Kejun; Jing, Yingchao; Li, Baisheng; Lv, Yifan; Ma, Baoxin

2014-01-01

Fractional anisotropy values in diffusion tensor imaging can quantitatively reflect the consistency of nerve fibers after brain damage, where higher values generally indicate less damage to nerve fibers. Therefore, we hypothesized that diffusion tensor imaging could be used to evaluate the effect of mild hypothermia on diffuse axonal injury. A total of 102 patients with diffuse axonal injury were randomly divided into two groups: normothermic and mild hypothermic treatment groups. Patient's modified Rankin scale scores 2 months after mild hypothermia were significantly lower than those for the normothermia group. The difference in average fractional anisotropy value for each region of interest before and after mild hypothermia was 1.32-1.36 times higher than the value in the normothermia group. Quantitative assessment of diffusion tensor imaging indicates that mild hypothermia therapy may be beneficial for patients with diffuse axonal injury. PMID:25206800

On the past climate of the Dobrogea (Romania) during the late Quaternary as reflected by loess geochemistry

NASA Astrophysics Data System (ADS)

Duliu, Octavian G.; Tugulan, Liviu C.; Bojar, Ana-Voica; Dumitras, Delia; Zincovskaya, Inga; Culicov, Otilia A.; Frontasyeva, Marina V.

2015-04-01

Ten samples of loess and paleosoil collected from the Costinesti - Dobrogea (Romania) loess deposit that are covering a time span of about 690 ± 90 ky were analyzed by X-ray diffraction (XRD) , Instrumental Neutron Activation Analysis (INAA) and X-ray Fluorescence (XRF) in order to evidentiate the origin as well as the climatic conditions during the formation of loess material. The presence of illite and calcite, suggests reduced weathering. This was confirmed by further climate proxies as Chemical Index of Alteration (CIA) whose values are between 54.6 and 64.0, Chemical Index of Weathering (CIW) between 65.7 and 71.7 as well as Rb/Sr ratio between 0.26 and 0.47, lower than the neighboring Hungarian loess, but closer to the average Chinese and European loess. No statistical significant differences were observed between average values of loess and palaeosol samples regarding these proxies. The content of 27 trace elements, including 10 REE were, excepting Cr, Ni, Zr and Hf,very close to average rocks composition as Upper Continental Crust (UCC), North America Shale Composite (NASC) and Post-Archean Average Australian Shale (PAAS). Both mineralogical and geochemical data from Costinesti loess and palaeosol samples support a continental origin of loess material deposited in a rather arid and cold climate during the past 690 ± 90 ky.

Modelling audiovisual integration of affect from videos and music.

PubMed

Gao, Chuanji; Wedell, Douglas H; Kim, Jongwan; Weber, Christine E; Shinkareva, Svetlana V

2018-05-01

Two experiments examined how affective values from visual and auditory modalities are integrated. Experiment 1 paired music and videos drawn from three levels of valence while holding arousal constant. Experiment 2 included a parallel combination of three levels of arousal while holding valence constant. In each experiment, participants rated their affective states after unimodal and multimodal presentations. Experiment 1 revealed a congruency effect in which stimulus combinations of the same extreme valence resulted in more extreme state ratings than component stimuli presented in isolation. An interaction between music and video valence reflected the greater influence of negative affect. Video valence was found to have a significantly greater effect on combined ratings than music valence. The pattern of data was explained by a five parameter differential weight averaging model that attributed greater weight to the visual modality and increased weight with decreasing values of valence. Experiment 2 revealed a congruency effect only for high arousal combinations and no interaction effects. This pattern was explained by a three parameter constant weight averaging model with greater weight for the auditory modality and a very low arousal value for the initial state. These results demonstrate key differences in audiovisual integration between valence and arousal.

ADC histogram analysis of muscle lymphoma - Correlation with histopathology in a rare entity.

PubMed

Meyer, Hans-Jonas; Pazaitis, Nikolaos; Surov, Alexey

2018-06-21

Diffusion weighted imaging (DWI) is able to reflect histopathology architecture. A novel imaging approach, namely histogram analysis, is used to further characterize lesion on MRI. The purpose of this study is to correlate histogram parameters derived from apparent diffusion coefficient- (ADC) maps with histopathology parameters in muscle lymphoma. Eight patients (mean age 64.8 years, range 45-72 years) with histopathologically confirmed muscle lymphoma were retrospectively identified. Cell count, total nucleic and average nucleic areas were estimated using ImageJ. Additionally, Ki67-index was calculated. DWI was obtained on a 1.5T scanner by using the b values of 0 and 1000 s/mm2. Histogram analysis was performed as a whole lesion measurement by using a custom-made Matlabbased application. The correlation analysis revealed statistically significant correlation between cell count and ADCmean (p=-0.76, P=0.03) as well with ADCp75 (p=-0.79, P=0.02). Kurtosis and entropy correlated with average nucleic area (p=-0.81, P=0.02, p=0.88, P=0.007, respectively). None of the analyzed ADC parameters correlated with total nucleic area and with Ki67-index. This study identified significant correlations between cellularity and histogram parameters derived from ADC maps in muscle lymphoma. Thus, histogram analysis parameters reflect histopathology in muscle tumors. Advances in knowledge: Whole lesion ADC histogram analysis is able to reflect histopathology parameters in muscle lymphomas.

Evidence for higher-than-average air temperatures after the 8.2 ka event provided by a Central European δ18O record

NASA Astrophysics Data System (ADS)

Andersen, Nils; Lauterbach, Stefan; Erlenkeuser, Helmut; Danielopol, Dan L.; Namiotko, Tadeusz; Hüls, Matthias; Belmecheri, Soumaya; Dulski, Peter; Nantke, Carla; Meyer, Hanno; Chapligin, Bernhard; von Grafenstein, Ulrich; Brauer, Achim

2017-09-01

The so-called 8.2 ka event represents one of the most prominent cold climate anomalies during the Holocene warm period. Accordingly, several studies have addressed its trigger mechanisms, absolute dating and regional characteristics so far. However, knowledge about subsequent climate recovery is still limited although this might be essential for the understanding of rapid climatic changes. Here we present a new sub-decadally resolved and precisely dated oxygen isotope (δ18O) record for the interval between 7.7 and 8.7 ka BP (103 calendar years before AD 1950), derived from the calcareous valves of benthic ostracods preserved in the varved lake sediments of pre-Alpine Mondsee (Austria). Besides a clear reflection of the 8.2 ka event, showing a good agreement in timing, duration and magnitude with other regional stable isotope records, the high-resolution Mondsee lake sediment record provides evidence for a 75-year-long interval of higher-than-average δ18O values directly after the 8.2 ka event, possibly reflecting increased air temperatures in Central Europe. This observation is consistent with evidence from other proxy records in the North Atlantic realm, thus most probably reflecting a hemispheric-scale climate signal rather than a local phenomenon. As a possible trigger we suggest an enhanced resumption of the Atlantic meridional overturning circulation (AMOC), supporting assumptions from climate model simulations.

Direct Simulation of Extinction in a Slab of Spherical Particles

NASA Technical Reports Server (NTRS)

Mackowski, D.W.; Mishchenko, Michael I.

2013-01-01

The exact multiple sphere superposition method is used to calculate the coherent and incoherent contributions to the ensemble-averaged electric field amplitude and Poynting vector in systems of randomly positioned nonabsorbing spherical particles. The target systems consist of cylindrical volumes, with radius several times larger than length, containing spheres with positional configurations generated by a Monte Carlo sampling method. Spatially dependent values for coherent electric field amplitude, coherent energy flux, and diffuse energy flux, are calculated by averaging of exact local field and flux values over multiple configurations and over spatially independent directions for fixed target geometry, sphere properties, and sphere volume fraction. Our results reveal exponential attenuation of the coherent field and the coherent energy flux inside the particulate layer and thereby further corroborate the general methodology of the microphysical radiative transfer theory. An effective medium model based on plane wave transmission and reflection by a plane layer is used to model the dependence of the coherent electric field on particle packing density. The effective attenuation coefficient of the random medium, computed from the direct simulations, is found to agree closely with effective medium theories and with measurements. In addition, the simulation results reveal the presence of a counter-propagating component to the coherent field, which arises due to the internal reflection of the main coherent field component by the target boundary. The characteristics of the diffuse flux are compared to, and found to be consistent with, a model based on the diffusion approximation of the radiative transfer theory.

Re-Os isotopic evidence for an enriched-mantle source for the Noril'sk-type, ore-bearing intrusions, Siberia

USGS Publications Warehouse

Walker, R.J.; Morgan, J.W.; Horan, M.F.; Czamanske, G.K.; Krogstad, E.J.; Fedorenko, V.A.; Kunilov, V.E.

1994-01-01

Magmatic Cu-Ni sulfide ores and spatially associated ultramafic and mafic rocks from the Noril'sk I, Talnakh, and Kharaelakh intrusions are examined for Re-Os isotopic systematics. Neodymium and lead isotopic data also are reported for the ultramafic and mafic rocks. The Re-Os data for most samples indicate closed-system behavior since the ca. 250 Ma igneous crystallization age of the intrusions. There are small but significant differences in the initial osmium isotopic compositions of samples from the three intrusions. Ores from the Noril'sk I intrusion have ??Os values that vary from +0.4 to +8.8, but average +5.8. Ores from the Talnakh intrusion have ??Os values that range from +6.7 to +8.2, averaging +7.7. Ores from the Kharaelakh intrusion have ??Os values that range from +7.8 to +12.9, with an average value of +10.4. The osmium isotopic compositions of the ore samples from the Main Kharaelakh orebody exhibit minimal overlap with those for the Noril'sk I and Talnakh intrusions, indicating that these Kharaelakh ores were derived from a more radiogenic source of osmium than the other ores. Combined osmium and lead data for major orebodies in the three intrusions plot in three distinct fields, indicating derivation of osmium and lead from at least three isotopically distinct sources. Some of the variation in lead isotopic compositions may be the result of minor lower-crustal contamination. However, in contrast to most other isotopic and trace element data, Os-Pb variations are generally inconsistent with significant crustal contamination or interaction with the subcontinental lithosphere. Thus, the osmium and lead isotopic compositions of these intrusions probably reflect quite closely the compositions of their mantle source, and suggest that these two isotope systems were insensitive to lithospheric interaction. Ultramafic and mafic rocks have osmium and lead isotopic compositions that range only slightly beyond the compositions of the ores. These rocks also have relatively uniform ??{lunate}Nd values that range only from -0.8 to + 1.1. This limited variation in neodymium isotopic composition may reflect the characteristics of the mantle sources of the rocks, or it may indicate that somehow similar proportions of crust contaminated the parental melts. The osmium, lead, and neodymium isotopic data for these rocks most closely resemble the mantle sources of certain ocean island basalts (OIB), such as some Hawaiian basalts. Hence, these data are consistent with derivation of primary melts from a mantle source similar to that of some types of hotspot activity. The long-term Re/Os enrichment of this and similar mantle sources, relative to chondritic upper mantle, may reflect 1. (1) incorporation of recycled oceanic crust into the source more than 1 Ga ago, 2. (2) derivation from a mantle plume that originated at the outer core-lower mantle interface, or 3. (3) persistence of primordial stratification of rhenium and osmium in the mantle. ?? 1994.

Spectral decomposition of AVIRIS data

NASA Technical Reports Server (NTRS)

Gaddis, Lisa; Soderblom, Laurence; Kieffer, Hugh; Becker, Kris; Torson, Jim; Mullins, Kevin

1993-01-01

A set of techniques is presented that uses only information contained within a raw Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) scene to estimate and to remove additive components such as multiple scattering and instrument dark current. Multiplicative components (instrument gain, topographic modulation of brightness, atmospheric transmission) can then be normalized, permitting enhancement, extraction, and identification of relative reflectance information related to surface composition and mineralogy. The technique for derivation of additive-component spectra from a raw AVIRIS scene is an adaption of the 'regression intersection method' of Crippen. This method uses two surface units that are spatially extensive, and located in rugged terrain. For a given wavelength pair, subtraction of the derived additive component from individual band values will remove topography in both regions in a band/band ratio image. Normalization of all spectra in the scene to the average scene spectrum then results in cancellation of multiplicative components and production of a relative-reflectance scene. The resulting AVIRIS product contains relative-reflectance features due to mineral absorption that depart from the average spectrum. These features commonly are extremely weak and difficult to recognize, but they can be enhanced by using two simple 3-D image-processing tools. The validity of these techniques will be demonstrated by comparisons between relative-reflectance AVIRIS spectra and those derived by using JPL standard calibrations. The AVIRIS data used in this analysis were acquired over the Kelso Dunes area (34 deg 55' N, 115 deg 43' W) of the eastern Mojave Desert, CA (in 1987) and the Upheaval Dome area (38 deg 27' N, 109 deg 55' W) of the Canyonlands National Park, UT (in 1991).

A Relationship Between Visible and Near-IR Global Spectral Reflectance based on DSCOVR/EPIC

NASA Astrophysics Data System (ADS)

Wen, G.; Marshak, A.; Song, W.; Knyazikhin, Y.

2017-12-01

The launch of Deep Space Climate Observatory (DSCOVR) to the Earth's first Lagrange point (L1) allows us to see a new perspective of the Earth. The Earth Polychromatic Imaging Camera (EPIC) on the DSCOVR measures the back scattered radiation of the entire sunlit side of the Earth at 10 narrow band wavelengths ranging from ultraviolet to visible and near-infrared. We analyzed EPIC global averaged reflectance data. We found that the global averaged visible reflectance has a unique non-linear relationship with near infrared (NIR) reflectance. This non-linear relationship was not observed by any other satellite observations due to a limited spatial and temporal coverage of either low earth orbit (LEO) or geostationary satellite. The non-linear relationship is associated with the changing in the coverages of ocean, cloud, land, and vegetation as the Earth rotates. We used Terra and Aqua MODIS daily global radiance data to simulate EPIC observations. Since MODIS samples the Earth in a limited swath (2330km cross track) at a specific local time (10:30 am for Terra, 1:30 pm for Aqua) with approximately 15 orbits per day, the global average reflectance at a given time may be approximated by averaging the reflectance in the MODIS nearest-time swaths in the sunlit hemisphere. We found that MODIS simulated global visible and NIR spectral reflectance captured the major feature of the EPIC observed non-linear relationship with some errors. The difference between the two is mainly due to the sampling limitation of polar satellite. This suggests that that EPIC observations can be used to reconstruct MODIS global average reflectance time series for studying Earth system change in the past decade.

Action of polysaccharides of similar average mass but differing molecular volume and charge on fluid drainage through synovial interstitium in rabbit knees

PubMed Central

Scott, D; Coleman, P J; Mason, R M; Levick, J R

2000-01-01

Hyaluronan (HA), an anionic polysaccharide of synovial fluid, attenuates fluid loss from joints as joint pressure is raised (‘outflow buffering’). The buffering is thought to depend on the expanded molecular domain of the polymer, which causes reflection by synovial extracellular matrix, leading to flow-dependent concentration polarization. We therefore assessed the effects of polysaccharides of differing average molecular volume and charge. Trans-synovial fluid drainage(Q̇s) was measured at controlled joint fluid pressure (Pj) in knees of anaesthetized rabbits. The joints were infused with polydisperse HA of weight-average mass 2100 kDa (4 mg ml−1, n = 17), with polydisperse neutral dextran of similar average mass (2000 kDa; n = 7) or with Ringer solution vehicle (n = 2). The role of polymer charge was assessed by infusions of neutral or sulphated dextran of average molecular mass 500 kDa (n = 6). When HA was present, Q̇s increased little with pressure, forming a virtual plateau of ∼4 μl min−1 from 10 to 25 cmH2O. Neutral dextran 2000 failed to replicate this effect. Instead, Q̇s increased steeply with Pj, reaching eight times the HA value by 20 cmH2O (P = 0.0001, ANOVA). Dextran 2000 reduced flows in comparison with Ringer solution. Analysis of the aspirated joint fluid showed that 31 ± 0.07 % (s.e.m.) of dextran 2000 in the filtrand was reflected by synovium, compared with ≥ 79 % for HA. The viscometric molecular radius of the dextran, ∼31 nm, was smaller than that of HA (101–181 nm), as was its osmotic pressure. Anionic dextran 500 failed to buffer fluid drainage, but it reduced fluid escape and synovial conductance dQ̇s/dPj more than neutral dextran 500 (P < 0.0001, ANOVA). The anionic charge increased the molecular volume and viscosity of dextran 500. The results support the hypothesis that polymer molecular volume influences its reflection by interstitial matrix and outflow buffering. Polymer charge influences flow through an effect on viscosity and possibly electrostatic interactions with negatively charged interstitial matrix. PMID:11060134

Mechanisms for Magnesium Isotopic Variation in Low-grade Metamorphosed Mudrocks from the British Caledonides

NASA Astrophysics Data System (ADS)

Wang, S.; Teng, F.; Rudnick, R. L.; Li, S.

2013-12-01

We report Mg isotope ratios for low-grade metamorphosed mudrocks from three lower Paleozoic basins (northern Lake District, southern Lake District and Southern Uplands) in the British Caledonides, previously analyzed for Li, Sr and Nd isotopes (Qiu et al., 2009, GCA), with the aim of understanding the behavior of Mg isotopes during subgreenschist-facies metamorphism, and the processes responsible for Mg isotopic variations in mudrocks. The δ26Mg of mudrocks varies greatly from -0.754 to 0.251, and displays no correlation with metamorphic grade, which ranges from diagenesis to subgreenschist-facies. Thus, low-grade metamorphism has no apparent influence on Mg isotopes. The variations instead likely reflect their provenance and mineralogical components. Samples from the northern Lake District, previously interpreted to derive from ancient, heavily weathered crust have δ26Mg (-0.06 × 0.11 on average) significantly heavier than that of average upper continental crust (~ -0.22), which is consistent with this interpretation. By contrast, mudrocks from the southern Lake District are characterized by low δ26Mg values (from -0.754 to -0.093) that require the presences of an unusually light component. The previously inferred provenance for these rocks of upper continental crust and arc volcanic detritus cannot explain such light isotopic compositions. Rather, such values may reflect the presence of carbonate in these samples and uptake of sea water Mg. Samples from the Southern Uplands, which contain the heaviest Li isotopes and ɛNd, and contain volcanic arc detritus, display Mg isotopic compositions divergent from a 'normal' mantle value (-0.25) towards both high and low δ26Mg values (from -0.742 to -0.079). Therefore, these mudrocks must contain a minimum of three end-members: mature felsic upper continental crust, arc lavas and carbonate. Given that limited Mg isotope fractionation occurs during low-grade metamorphism, Mg isotopes could be a potential tracer of provenance as well as carbonate involvement for fine-grained terrigenous sediments.

Cumulative Expenditures under the DI, SSI, Medicare, and Medicaid Programs for a Cohort of Disabled Working-Age Adults

PubMed Central

Riley, Gerald F; Rupp, Kalman

2015-01-01

Objective To estimate cumulative DI, SSI, Medicare, and Medicaid expenditures from initial disability benefit award to death or age 65. Data Sources Administrative records for a cohort of new CY2000 DI and SSI awardees aged 18–64. Study Design Actual expenditures were obtained for 2000–2006/7. Subsequent expenditures were simulated using a regression-adjusted Markov process to assign individuals to annual disability benefit coverage states. Program expenditures were simulated conditional on assigned benefit coverage status. Estimates reflect present value of expenditures at initial award in 2000 and are expressed in constant 2012 dollars. Expenditure estimates were also updated to reflect benefit levels and characteristics of new awardees in 2012. Data Collection We matched records for a 10 percent nationally representative sample. Principal Findings Overall average cumulative expenditures are $292,401 through death or age 65, with 51.4 percent for cash benefits and 48.6 percent for health care. Expenditures are about twice the average for individuals first awarded benefits at age 18–30. Overall average expenditures increased by 10 percent when updated for a simulated 2012 cohort. Conclusions Data on cumulative expenditures, especially combined across programs, are useful for evaluating the long-term payoff of investments designed to modify entry to and exit from the disability rolls. PMID:25109322

SPECTRAL SURVEY OF X-RAY BRIGHT ACTIVE GALACTIC NUCLEI FROM THE ROSSI X-RAY TIMING EXPLORER

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

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard, E-mail: erivers@ucsd.edu

2011-03-15

Using long-term monitoring data from the Rossi X-ray Timing Explorer (RXTE), we have selected 23 active galactic nuclei (AGNs) with sufficient brightness and overall observation time to derive broadband X-ray spectra from 3 to {approx}>100 keV. Our sample includes mainly radio-quiet Seyferts, as well as seven radio-loud sources. Given the longevity of the RXTE mission, the greater part of our data is spread out over more than a decade, providing truly long-term average spectra and eliminating inconsistencies arising from variability. We present long-term average values of absorption, Fe line parameters, Compton reflection strengths, and photon indices, as well as fluxesmore » and luminosities for the hard and very hard energy bands, 2-10 keV and 20-100 keV, respectively. We find tentative evidence for high-energy rollovers in three of our objects. We improve upon previous surveys of the very hard X-ray energy band in terms of accuracy and sensitivity, particularly with respect to confirming and quantifying the Compton reflection component. This survey is meant to provide a baseline for future analysis with respect to the long-term averages for these sources and to cement the legacy of RXTE, and especially its High Energy X-ray Timing Experiment, as a contributor to AGN spectral science.« less

Using Copulas in the Estimation of the Economic Project Value in the Mining Industry, Including Geological Variability

NASA Astrophysics Data System (ADS)

Krysa, Zbigniew; Pactwa, Katarzyna; Wozniak, Justyna; Dudek, Michal

2017-12-01

Geological variability is one of the main factors that has an influence on the viability of mining investment projects and on the technical risk of geology projects. In the current scenario, analyses of economic viability of new extraction fields have been performed for the KGHM Polska Miedź S.A. underground copper mine at Fore Sudetic Monocline with the assumption of constant averaged content of useful elements. Research presented in this article is aimed at verifying the value of production from copper and silver ore for the same economic background with the use of variable cash flows resulting from the local variability of useful elements. Furthermore, the ore economic model is investigated for a significant difference in model value estimated with the use of linear correlation between useful elements content and the height of mine face, and the approach in which model parameters correlation is based upon the copula best matched information capacity criterion. The use of copula allows the simulation to take into account the multi variable dependencies at the same time, thereby giving a better reflection of the dependency structure, which linear correlation does not take into account. Calculation results of the economic model used for deposit value estimation indicate that the correlation between copper and silver estimated with the use of copula generates higher variation of possible project value, as compared to modelling correlation based upon linear correlation. Average deposit value remains unchanged.

Estimating the beam attenuation coefficient in coastal waters from AVHRR imagery

NASA Astrophysics Data System (ADS)

Gould, Richard W.; Arnone, Robert A.

1997-09-01

This paper presents an algorithm to estimate particle beam attenuation at 660 nm ( cp660) in coastal areas using the red and near-infrared channels of the NOAA AVHRR satellite sensor. In situ reflectance spectra and cp660 measurements were collected at 23 stations in Case I and II waters during an April 1993 cruise in the northern Gulf of Mexico. The reflectance spectra were weighted by the spectral response of the AVHRR sensor and integrated over the channel 1 waveband to estimate the atmospherically corrected signal recorded by the satellite. An empirical relationship between integrated reflectance and cp660 values was derived with a linear correlation coefficient of 0.88. Because the AVHRR sensor requires a strong channel 1 signal, the algorithm is applicable in highly turbid areas ( cp660 > 1.5 m -1) where scattering from suspended sediment strongly controls the shape and magnitude of the red (550-650 nm) reflectance spectrum. The algorithm was tested on a data set collected 2 years later in different coastal waters in the northern Gulf of Mexico and satellite estimates of cp660 averaged within 37% of measured values. Application of the algorithm provides daily images of nearshore regions at 1 km resolution for evaluating processes affecting ocean color distribution patterns (tides, winds, currents, river discharge). Further validation and refinement of the algorithm are in progress to permit quantitative application in other coastal areas. Published by Elsevier Science Ltd

Ultrasonic testing of plates containing edge cracks

NASA Technical Reports Server (NTRS)

Williams, J. H., Jr.; Karagulle, H.; Lee, S. S.

1985-01-01

The stress wave factor (SWF) signal is utilized for the nondestructive evaluation of plates containing perpendicular edge cracks. The effects of the existence lateral location and depth of the crack on the magnitude spectra of individual reflections in the SWF signal are studied. If the reflections in the SWF signal are not overlapped the short time Fourier analysis is applied. If the reflections are overlapped the short time homomorphic analysis (cepstrum analysis) is applied. Several reflections which have average resonant frequencies approximately at 0.9, 1.3, and 1.7 MHz are analyzed. It is observed that the magnitude ratios evaluated at average resonant frequencies decrease more with increasing d/h if the crack is located between the transducers, where h is plate thickness and d is crack depth. Moreover, for the plates, crack geometries, reflections, and frequencies considered, the average decibel drop depends mainly on the dimensionless parameter d/h and it is approximately -1 dB per 0.07 d/h. Changes in the average resonant frequencies of the magnitude spectra are also observed due to changes in the location of the crack.

Carbonate concretions as a significant component of ancient marine carbon cycles: Insights from paired organic and inorganic carbon isotope analyses of a Cretaceous shale

NASA Astrophysics Data System (ADS)

Loyd, S. J.

2014-12-01

Carbonate concretions often occur within fine-grained, organic-rich sedimentary rocks. This association reflects the common production of diagenetic minerals through biologic cycling of organic matter. Chemical analysis of carbonate concretions provides the rare opportunity to explore ancient shallow diagenetic environments, which are inherently transient due to progressive burial but are an integral component of the marine carbon cycle. The late Cretaceous Holz Shale (~80 Ma) contains abundant calcite concretions that exhibit textural and geochemical characteristics indicative of relatively shallow formation (i.e., near the sediment-water interface). Sampled concretions contain between 5.4 and 9.8 wt.% total inorganic carbon (TIC), or ~45 and 82 wt.% CaCO3, compared to host shale values which average ~1.5 wt.% TIC. Organic carbon isotope compositions (δ13Corg) are relatively constant in host and concretion samples ranging from ­-26.3 to -24.0‰ (VPDB). Carbonate carbon isotope compositions (δ13Ccarb) range from -22.5 to -3.4‰, indicating a significant but not entirely organic source of carbon. Concretions of the lower Holz Shale exhibit considerably elevated δ13Ccarb values averaging -4.8‰, whereas upper Holz Shale concretions express an average δ13Ccarb value of -17.0‰. If the remaining carbonate for lower Holz Shale concretions is sourced from marine fluids and/or dissolved marine carbonate minerals (e.g., shells), a simple mass balance indicates that ~28% of concretion carbon was sourced from organic matter and ~72% from late Cretaceous marine inorganic carbon (with δ13C ~ +2.5‰). Upper Holz Shale calculations indicate a ~73% contribution from organic matter and a ~27% contribution from inorganic carbon. When normalized for carbonate, organic contents within the concretions are ~2-13 wt.% enriched compared to host contents. This potentially reflects the protective nature of cementation that acts to limit permeability and chemical destruction of organic material. These data imply that concretion growth in shallow sediments can act as a significant and long-term sink for both marine inorganic and organic carbon.

Costs and benefits of individuals conceived after IVF: a net tax evaluation in The Netherlands.

PubMed

Moolenaar, L M; Connolly, M; Huisman, B; Postma, M J; Hompes, P G A; van der Veen, F; Mol, B W J

2014-02-01

This study evaluated the lifetime future net tax revenues from individuals conceived after IVF relative to those naturally conceived. A model based on the method of generational accounting was developed to evaluate investments in IVF. Calculations were based on average investments paid and received from the government by an individual. All costs were discounted to their net present values and adjusted for survival. The lifetime net present value of IVF-conceived individuals was -€81,374 (the minus sign reflecting negative net present value). The lifetime net present value of IVF-conceived men and women were -€47,091 and -€123,177, respectively. The lifetime net present value of naturally conceived individuals was -€70,392; respective amounts for men and women were -€36,109 and -€112,195. The model was most sensitive to changes in the growth of healthcare costs, economic growth and the discount rate. Therefore, it is concluded that, similarly to naturally conceived individuals in the Netherlands, IVF-conceived individuals have negative discounted net tax revenue at the end of life. The analytic framework described here undervalues the incremental value of an additional birth because it only considers the fiscal consequences of life and does not take into consideration broader macroeconomic benefits. This study evaluated the lifetime future net tax revenues from individuals conceived after IVF relative those naturally conceived. A model based on the method of generational accounting to evaluate investments in IVF was used. Calculations were based on average investments paid and received from the government by an individual. The lifetime net present value of IVF-conceived individuals was -€81,374 (the minus sign reflecting negative net present value). The lifetime net present value of IVF-conceived men and women were -€47,091 and -€123,177, respectively. The lifetime net present value of naturally conceived individuals was -€70,392; respective amounts for men and women were -€36,109 and -€112,195. The model was most sensitive for changes in the growth in healthcare costs, economic growth and the discount rate. Just as naturally conceived individuals in the Netherlands, IVF-conceived individuals have negative discounted net tax revenue at the end of life. The analytic framework described here undervalues the incremental value of an additional birth because it only considers the fiscal consequences of life and does not take into consideration broader macroeconomic benefits. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Topical meeting on optical interference coatings (OIC'2001): manufacturing problem.

PubMed

Dobrowolski, J A; Browning, Stephen; Jacobson, Michael; Nadal, Maria

2002-06-01

Measurements are presented of the experimental filters submitted to the first optical thin-film manufacturing problem posed in conjunction with the Topical Meeting on Optical Interference Coatings, in which the object was to produce multilayers with spectral transmittance and reflectance curves that were as close as possible to the target values that were specified in the 400- to 600-nm spectral region. No limit was set on the overall thickness of the solutions or the number of layers used in their construction. The participants were free to use the coating materials of their choice. Six different groups submitted a total of 11 different filters for evaluation. Three different physical vapor deposition processes were used for the manufacture of the coatings: magnetron sputtering, ion-beam sputtering, and plasma-ion-assisted, electron-beam gun evaporation. The solutions ranged in metric thickness from 758 to 4226 nm and consisted of between 8 and 27 layers. For all but two of the samples submitted, the average rms departure of the measured transmittances and reflectances from the target values in the spectral region of interest was between 0.98% and 1.55%.

Proxy of monsoon seasonality in carbon isotopes from paleosols of the southern Chinese Loess Plateau

USGS Publications Warehouse

Wang, Hongfang; Follmer, L.R.

1998-01-01

Soil organic matter (SOM) and soil carbonate (SC) are common constituents in soils and are directly related to plant growth. SOM accumulates gradually from the decomposition of plant material over time, whereas SC formation is biased to dry-season soil-dissolved CO2 that derives from plant respiration during a drying phase of the growing season. In some mixed C3-C4 environments, the peak of C3 and C4 plant metabolism differs seasonally, and the carbon source that contributes to the SOM and SC can be different. Consequently, ??13C(SOM) values reflect an annual average of the floral biomass, but ??13C(SC) values reflect a seasonal aspect of the plant community. The relationship between ??13C(SC) and ??13C(SOM) is mainly controlled by how different the seasonal conditions are. Our results suggest that the relationship is a seasonal proxy that can be used to differentiate the seasonality effects of Indian, East Asian, and Siberian monsoons on the Chinese Loess Plateau during the last interglacial-glacial cycle.

Coherent activity between brain regions that code for value is linked to the malleability of human behavior

PubMed Central

Cooper, Nicole; Bassett, Danielle S.; Falk, Emily B.

2017-01-01

Brain activity in medial prefrontal cortex (MPFC) during exposure to persuasive messages can predict health behavior change. This brain-behavior relationship has been linked to areas of MPFC previously associated with self-related processing; however, the mechanism underlying this relationship is unclear. We explore two components of self-related processing – self-reflection and subjective valuation – and examine coherent activity between relevant networks of brain regions during exposure to health messages encouraging exercise and discouraging sedentary behaviors. We find that objectively logged reductions in sedentary behavior in the following month are linked to functional connectivity within brain regions associated with positive valuation, but not within regions associated with self-reflection on personality traits. Furthermore, functional connectivity between valuation regions contributes additional information compared to average brain activation within single brain regions. These data support an account in which MPFC integrates the value of messages to the self during persuasive health messaging and speak to broader questions of how humans make decisions about how to behave. PMID:28240271

[Spectral reflectance characteristics and modeling of typical Takyr Solonetzs water content].

PubMed

Zhang, Jun-hua; Jia, Ke-li

2015-03-01

Based on the analysis of the spectral reflectance of the typical Takyr Solonetzs soil in Ningxia, the relationship of soil water content and spectral reflectance was determined, and a quantitative model for the prediction of soil water content was constructed. The results showed that soil spectral reflectance decreased with the increasing soil water content when it was below the water holding capacity but increased with the increasing soil water content when it was higher than the water holding capacity. Soil water content presented significantly negative correlation with original reflectance (r), smooth reflectance (R), logarithm of reflectance (IgR), and positive correlation with the reciprocal of R and logarithm of reciprocal [lg (1/R)]. The correlation coefficient of soil water content and R in the whole wavelength was 0.0013, 0.0397 higher than r and lgR, respectively. Average correlation coefficient of soil water content with 1/R and [lg (1/R)] at the wavelength of 950-1000 nm was 0.2350 higher than that of 400-950 nm. The relationships of soil water content with the first derivate differential (R') , the first derivate differential of logarithm (lgR)' and the first derivate differential of logarithm of reciprocal [lg(1/R)]' were unstable. Base on the coefficients of r, lg(1/R), R' and (lgR)', different regression models were established to predict soil water content, and the coefficients of determination were 0.7610, 0.8184, 0.8524 and 0.8255, respectively. The determination coefficient for power function model of R'. reached 0.9447, while the fitting degree between the predicted value based on this model and on-site measured value was 0.8279. The model of R' had the highest fitted accuracy, while that of r had the lowest one. The results could provide a scientific basis for soil water content prediction and field irrigation in the Takyr Solonetzs region.

An environmental tolerance index for ostracodes as indicators of physical and chemical factors in aquatic habitats

USGS Publications Warehouse

Curry, B. Brandon

1999-01-01

Continental ostracode occurrences reflect salinity, solute composition, temperature, flow conditions, and other environmental properties of the water they inhabit. Their occurrences also reflect the variability of many of these environmental parameters. Environmental tolerance indices (ETIs) offer a new way to express the nature of an ostracode's environment. As defined herein, ETIs range in value from zero to one, and may be calculated for continuous and binary variables. For continuous variables such as salinity, the ETI is the ratio of the range of values of salinity tolerated by an ostracode to the total range of salinity values from a representative database. In this investigation, the database of continuous variables consists of information from 341 sites located throughout the United States. Binary ETIs indicate whether an environmental variable such as flowing water affects ostracode presence or absence. The binary database consists of information from 784 sites primarily from Illinois, USA. ETIs were developed in this investigation to interpret paleohydrological changes implied by fossil ostracode successions. ETI profiles may be cast in terms of a weighted average, or on presence/absence. The profiles express ostracode tolerance of environmental parameters such as salinity or currents. Tolerance of a wide range of values is taken to indicate shallow water because shallow environments are conducive to thermal variability, short-term water residence, and the development of currents from wind-driven waves.

Variations in the abundance of iron on Mercury's surface from MESSENGER X-Ray Spectrometer observations

NASA Astrophysics Data System (ADS)

Weider, Shoshana Z.; Nittler, Larry R.; Starr, Richard D.; McCoy, Timothy J.; Solomon, Sean C.

2014-06-01

We present measurements of Mercury's surface composition from the analysis of MESSENGER X-Ray Spectrometer data acquired during 55 large solar flares, which each provide a statistically significant detection of Fe X-ray fluorescence. The Fe/Si data display a clear dependence on phase angle, for which the results are empirically corrected. Mercury's surface has a low total abundance of Fe, with a mean Fe/Si ratio of ˜0.06 (equivalent to ˜1.5 wt% Fe). The absolute Fe/Si values are subject to a number of systematic uncertainties, including the phase-angle correction and possible mineral mixing effects. Individual Fe/Si measurements have an intrinsic error of ˜10%. Observed Fe/Si values display small variations (significant at two standard deviations) from the planetary average value across large regions in Mercury's southern hemisphere. Larger differences are observed between measured Fe/Si values from more spatially resolved footprints on volcanic smooth plains deposits in the northern hemisphere and from those in surrounding terrains. Fe is most likely contained as a minor component in sulfide phases (e.g., troilite, niningerite, daubréelite) and as Fe metal, rather than within mafic silicates. Variations in surface reflectance (i.e., differences in overall reflectance and spectral slope) across Mercury are unlikely to be caused by variations in the abundance of Fe.

Geochemical characteristics of organic matter in the Andaman Sea sediments: Implications for source, paleovegetation and paleoclimate changes

NASA Astrophysics Data System (ADS)

Hossain, H. M. Z.; Sampei, Y.; Kawahata, H.

2016-12-01

The distribution, source, and redox variation of sedimentary organic matter in the Andaman Sea is significant for understanding its biogeochemical cycle, which we determined the total organic carbon (TOC), total nitrogen (TN), and n-alkanes contents. TOC and TN concentrations varied from 0.61 to 1.18 wt.% (average 0.87 wt.%) and 0.07 to 0.17 wt.% (average 0.13 wt.%), respectively with high TOC in the clay-rich sediments indicate hydrodynamic sorting readily controlled TOC abundances. Bulk C/N ratio (5.51 to 11.92, average 7.89) is attributed to the high inputs of organic matter from planktonic sources and an appreciable amounts of terrestrial derived organic matter. n-Alkane distributions from the Andaman Sea sediment cores are characterized mainly by C17 to C35, with odd-over-even predominance suggest a diverse origin of organic matter. High relative abundances of mid-chain n-alkanes of C23 and C25 recorded in the samples that are characteristically derived from submerges/floating aquatic macrophytes. However, odd long-chain n-alkanes from C27 to C33 with high peaks at C29 and C31 were detected in the samples reflecting a terrigenous origin of organic matter. The average chain length (ACL), carbon preference index (CPI), Paq and Pwax ratio values further suggested that major influence of organic matter from non-emergent aquatic macrophytes together significant proportions of grasses and herbs. Low Pr/Ph and Tm/Ts ratios in most section implying a more reducing to suboxic conditions prevailed during organic matter preservation in the oceanic event. However, high ACL values and low Paq values in the down-core variation could suggest initially cold and dry climates and gradually shifted to warm and humid conditions.

New estimates of changes in snow cover over Russia in recent decades

NASA Astrophysics Data System (ADS)

Bulygina, O.; Korshunova, N.; Razuvaev, V.; Groisman, P. Y.

2017-12-01

Snow covers plays critical roles in the energy and water balance of the Earth through its unique physical properties (high reflectivity and low thermal conductivity) and water storage. The main objective of this research is to monitoring snow cover change in Russia. The estimates of changes of major snow characteristics (snow cover duration, maximum winter snow depth, snow water equivalent) are described. Apart from the description of long-term averages of snow characteristics, the estimates of their change that are averaged over quasi-homogeneous climatic regions are derived and regional differences in the change of snow characteristics are studied. We used in our study daily snow observations for 820 Russian meteorological station from 1966 to 2017. All of these meteorological stations are of unprotected type. The water equivalent is analyzed from snow course survey data at 958 meteorological stations from 1966 to 2017. The time series are prepared by RIHMI-WDC. Regional analysis of snow cover data was carried out using quasi-homogeneous climatic regions. The area-averaging technique using station values converted to anomalies with respect to a common reference period (in this study, 1981-2010). Anomalies were arithmetically averaged first within 1°N x 2°E grid cells and thereafter by a weighted average value derived over the quasi-homogeneous climatic regions. This approach provides a more uniform spatial field for averaging. By using a denser network of meteorological stations, bringing into consideration snow course data and, we managed to specify changes in all observed major snow characteristics and to obtain estimates generalized for quasi-homogeneous climatic regions. The detected changes in the dates of the establishment and disappearance of the snow cover.

Productivity, pesticides, and management of the Peregrine Falcon in Arizona

USGS Publications Warehouse

Ellis, D.H.

1985-01-01

In the decade since research commenced with the Peregrine in Arizona, over 60 sites have been identified which historically or presently are occupied by breeding pairs. Productivity was determined for about 120 breeding attempts from 1975-85. Almost all sites, for which productivity information is available for two or more years, have hatched young. Average values for fledging success were ca. 1.4 young/attempt for all active sites and ca. 2.3 young/attempt for successful sites. Eggshell thickness values were highly varied, but few samples reflect thinning sufficient to cause reproductive failure, and the population appears to be increasing slightly. Management practices which can further benefit the falcon include: controlling pesticide use, habitat protection, and information management.

Multi-indication and Combination Pricing and Reimbursement of Pharmaceuticals: Opportunities for Improved Health Care through Faster Uptake of New Innovations.

PubMed

Persson, Ulf; Norlin, J M

2018-04-01

Many pharmaceuticals are effective in multiple indications and the degree of effectiveness may differ. A product-based pricing and reimbursement system with a single price per product is insufficient to reflect the variable values between different indications. The objective of this article is to present examples of actual pricing and reimbursement decisions using current value-based pricing in Sweden and to discuss their implications and possible solutions. The value of several cancer drugs was estimated for various indications based on a willingness-to-pay threshold of 1 million SEK (EUR 104,000) per QALY gained. For some drugs, the estimated value was higher than the drug acquisition cost in several indications, whilst in others, the estimated value was lower than the drug acquisition cost. Drugs used in combination present a special case. If a drug prolongs survival and consequently also a continued use of the anchor drug, the combination use may not be cost effective even at a zero price. In a product-based pricing and reimbursement system, patients may not get access to drugs or access may be delayed and manufacturers may be discouraged to invest in future indications. To overcome these issues, there are several approaches to link price and value. One approach is a "weighted-average" price based on an average of the value across all indications. Another is "multi-indication pricing," which enables price differentiation between indications. However, there are several barriers for applying multi-indication pricing and reimbursement schemes. One barrier is the lack of existing administrative infrastructure to track patients' indications.

How to get statistically significant effects in any ERP experiment (and why you shouldn't).

PubMed

Luck, Steven J; Gaspelin, Nicholas

2017-01-01

ERP experiments generate massive datasets, often containing thousands of values for each participant, even after averaging. The richness of these datasets can be very useful in testing sophisticated hypotheses, but this richness also creates many opportunities to obtain effects that are statistically significant but do not reflect true differences among groups or conditions (bogus effects). The purpose of this paper is to demonstrate how common and seemingly innocuous methods for quantifying and analyzing ERP effects can lead to very high rates of significant but bogus effects, with the likelihood of obtaining at least one such bogus effect exceeding 50% in many experiments. We focus on two specific problems: using the grand-averaged data to select the time windows and electrode sites for quantifying component amplitudes and latencies, and using one or more multifactor statistical analyses. Reanalyses of prior data and simulations of typical experimental designs are used to show how these problems can greatly increase the likelihood of significant but bogus results. Several strategies are described for avoiding these problems and for increasing the likelihood that significant effects actually reflect true differences among groups or conditions. © 2016 Society for Psychophysiological Research.

How to Get Statistically Significant Effects in Any ERP Experiment (and Why You Shouldn’t)

PubMed Central

Luck, Steven J.; Gaspelin, Nicholas

2016-01-01

Event-related potential (ERP) experiments generate massive data sets, often containing thousands of values for each participant, even after averaging. The richness of these data sets can be very useful in testing sophisticated hypotheses, but this richness also creates many opportunities to obtain effects that are statistically significant but do not reflect true differences among groups or conditions (bogus effects). The purpose of this paper is to demonstrate how common and seemingly innocuous methods for quantifying and analyzing ERP effects can lead to very high rates of significant-but-bogus effects, with the likelihood of obtaining at least one such bogus effect exceeding 50% in many experiments. We focus on two specific problems: using the grand average data to select the time windows and electrode sites for quantifying component amplitudes and latencies, and using one or more multi-factor statistical analyses. Re-analyses of prior data and simulations of typical experimental designs are used to show how these problems can greatly increase the likelihood of significant-but-bogus results. Several strategies are described for avoiding these problems and for increasing the likelihood that significant effects actually reflect true differences among groups or conditions. PMID:28000253

Surface roughness effects on the solar reflectance of cool asphalt shingles

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

Akbari, Hashem; Berdahl, Paul; Akbari, Hashem

2008-02-17

We analyze the solar reflectance of asphalt roofing shingles that are covered with pigmented mineral roofing granules. The reflecting surface is rough, with a total area approximately twice the nominal area. We introduce a simple analytical model that relates the 'micro-reflectance' of a small surface region to the 'macro-reflectance' of the shingle. This model uses a mean field approximation to account for multiple scattering effects. The model is then used to compute the reflectance of shingles with a mixture of different colored granules, when the reflectances of the corresponding mono-color shingles are known. Simple linear averaging works well, with smallmore » corrections to linear averaging derived for highly reflective materials. Reflective base granules and reflective surface coatings aid achievement of high solar reflectance. Other factors that influence the solar reflectance are the size distribution of the granules, coverage of the asphalt substrate, and orientation of the granules as affected by rollers during fabrication.« less

Water Use in Wetland Kalo Cultivation in Hawai`i

USGS Publications Warehouse

Gingerich, Stephen B.; Yeung, Chiu W.; Ibarra, Tracy-Joy N.; Engott, John A.

2007-01-01

Ten cultivation areas (8 windward, 2 leeward) were selected for a kalo water-use study, primarily on the basis of the diversity of environmental and agricultural conditions under which wetland kalo is grown and landowner permission and availability. Flow and water-temperature data were collected at the lo`i complex level and at the individual lo`i level. To ensure that flow and temperature data collected at different lo`i reflect similar irrigation conditions (continuous flooding of the mature crop), only lo`i with crops near the harvesting stage were selected for water-temperature data collection. The water need for kalo cultivation varies depending on the crop stage. In this study, data were collected during the dry season (June-October), when water requirements for cooling kalo approach upper limits. Flow measurements generally were made during the warmest part of the day, and temperature measurements were made every 15 minutes at each site for about a two-month period. Flow and temperature data were collected from kalo cultivation areas on four islands - Kaua`i, O`ahu, Maui, and Hawai`i. The average inflow value for the 19 lo`i complexes measured in this study is 260,000 gallons per acre per day, and the median inflow value is 150,000 gallons per acre per day. The average inflow value for the 17 windward sites is 270,000 gallons per acre per day, and the median inflow value is 150,000 gallons per acre per day. The average inflow value for the two leeward sites is 150,000 gallons per acre per day. The average inflow value measured for six individual lo`i is 350,000 gallons per acre per day, and the median inflow value is 270,000 gallons per acre per day. The average inflow value for the five windward lo`i is 370,000 gallons per acre per day, and the median inflow value is 320,000 gallons per acre per day. The inflow value for the one leeward lo`i is 210,000 gallons per acre per day. These inflow values are consistent with previously reported values for inflow and are significantly higher than values generally estimated for water consumption during kalo cultivation. These measurements of inflow are important for future considerations of water-use requirements for successful kalo cultivation. Of the 17 lo`i complexes where water inflow temperature was measured, only 3 had inflow temperatures that rose above 27 ?C, the threshold temperature above which wetland kalo is more susceptible to fungi and associated rotting diseases. The coldest mean inflow temperature was 20.0 ?C and the warmest inflow temperature was 24.9 ?C. All 15 of the sites where outflow temperatures were measured had some temperatures greater than 27 ?C. Outflow temperatures exceeded 27 ?C between 2.5 percent and about 40 percent of the time. Mean outflow temperatures ranged from 23.0 ?C to 26.7 ?C.

Carbon, hydrogen, and oxygen isotope studies of the regional metamorphic complex at Naxos, Greece

USGS Publications Warehouse

Rye, R.O.; Schuiling, R.D.; Rye, D.M.; Jansen, J.B.H.

1976-01-01

At Naxos, Greece, a migmatite dome is surrounded by schists and marbles of decreasing metamorphic grade. Sillimanite, kyanite, biotite, chlorite, and glaucophane zones are recognized at successively greater distances from the migmatite dome. Quartz-muscovite and quartz-biotite oxygen isotope and mineralogie temperatures range from 350 to 700??C. The metamorphic complex can be divided into multiple schist-rich (including migmatites) and marblerich zones. The ??18O values of silicate minerals in migmatite and schist units and quartz segregations in the schist-rich zones decrease with increase in metamorphic grades. The calculated ??18OH2O values of the metamorphic fluids in the schist-rich zones decrease from about 15??? in the lower grades to an average of about 8.5??? in the migmatite. The ??D values of OH-minerals (muscovite, biotite, chlorite, and glaucophane) in the schist-rich zones also decrease with increase in grade. The calculated ??DH2O values for the metamorphic fluid decrease from -5??? in the glaucophane zone to an average of about -70??? in the migmatite. The ??D values of water in fluid inclusions in quartz segregations in the higher grade rocks are consistent with this trend. The??18O values of silicate minerals and quartz segregations in marble-rich zones are usually very large and were controlled by exchange with the adjacent marbles. The ??D values of the OH minerals in some marble-rich zones may reflect the value of water contained in the rocks prior to metamorphism. Detailed data on 20 marble units show systematic variations of ??18O values which depend upon metamorphic grade. Below the 540??C isograd very steep ??18O gradients at the margins and large ??18O values in the interior of the marbles indicate that oxygen isotope exchange with the adjacent schist units was usually limited to the margins of the marbles with more exchange occurring in the stratigraphic bottom than in the top margins. Above the 540??C isograd lower ??18O values occur in the interior of the marble units reflecting a greater degree of recrystallization and the occurrence of Ca-Mg-silicates. Almost all the ??13C values of the marbles are in the range of unaltered marine limestones. Nevertheless, the ??13C values of most marble units show a general correlation with ??18O values. The CO2 H2O mole ratio of fluid inclusions in quartz segregations range from 0.01 to 2. The??13C values of the CO2 range from -8.0 to 3.6??? and indicate that at some localities CO2 in the metamorphic fluid was not in carbon isotopic equilibrium with the marbles. ?? 1976.

Microscale Solubility Measurements of Matrix-Assisted Laser Desorption-Ionization (MALDI) Matrices Using Attenuated Total Reflection (ATR) Fourier Transform Infrared Spectroscopy (FT-IR) Coupled with Partial Least Squares (PLS) Analysis.

PubMed

Gorre, Elsa; Owens, Kevin G

2016-11-01

In this work an attenuated total reflection Fourier transform infrared (FT-IR) absorption based method is used to measure the solubility of two matrix-assisted laser desorption-ionization (MALDI) matrices in a few pure solvents and mixtures of acetonitrile and water using low microliter amounts of solution. Results from a method that averages the values obtained from multiple calibration curves created by manual peak picking are compared to those predicted using a partial least squares (PLS) chemometrics approach. The PLS method provided solubility values that were in good agreement with the manual method with significantly greater ease of analysis. As a test, the solubility of adipic acid in acetone was measured using the two methods of analysis, and the values are in good agreement with solubility values reported in literature. The solubilities of the MALDI matrices α-cyano-4-hydroxy cinnamic acid (CHCA) and sinapinic acid (SA) were measured in a series of mixtures made from acetonitrile (ACN) and water; surprisingly, the results show a highly nonlinear trend. While both CHCA and SA show solubility values of less than 10 mg/mL in the pure solvents, the solubility value for SA increases to 56.3 mg/mL in a 75:25 v/v ACN:water mixture. This can have a significant effect on the matrix-to-analyte ratios in the MALDI experiment when sample protocols call for preparation of a saturated solution of the matrix in the chosen solvent system. © The Author(s) 2016.

Keratoconus: The ABCD Grading System.

PubMed

Belin, M W; Duncan, J K

2016-06-01

To propose a new keratoconus classification/staging system that utilises current tomographic data and better reflects the anatomical and functional changes seen in keratoconus. A previously published normative database was reanalysed to generate both anterior and posterior average radii of curvature (ARC and PRC) taken from a 3.0 mm optical zone centred on the thinnest point of the cornea. Mean and standard deviations were recorded and anterior data were compared to the existing Amsler-Krumeich (AK) Classification. ARC, PRC, thinnest pachymetry and distance visual acuity were then used to construct a keratoconus classification. 672 eyes of 336 patients were analysed. Anterior and posterior values were 7.65 ± 0.236 mm and 6.26 ± 0.214 mm, respectively, and thinnest pachymetry values were 534.2 ± 30.36 µm. The ARC values were 2.63, 5.47 and 6.44 standard deviations from the mean values of stages 1-3 in the AK classification, respectively. PRC staging uses the same standard deviation gates. The pachymetric values differed by 4.42 and 7.72 standard deviations for stages 2 and 3, respectively. A new keratoconus staging incorporates anterior and posterior curvature, thinnest pachymetric values, and distance visual acuity and consists of stages 0-4 (5 stages). The proposed system closely matches the existing AK classification stages 1-4 on anterior curvature. As it incorporates posterior curvature and thickness measurements based on the thinnest point, rather than apical measurements, the new staging system better reflects the anatomical changes seen in keratoconus. Georg Thieme Verlag KG Stuttgart · New York.

The Impacts of Bowtie Effect and View Angle Discontinuity on MODIS Swath Data Gridding

NASA Technical Reports Server (NTRS)

Wang, Yujie; Lyapustin, Alexei

2007-01-01

We have analyzed two effects of the MODIS viewing geometry on the quality of gridded imagery. First, the fact that the MODIS scans a swath of the Earth 10 km wide at nadir, causes abrupt change of the view azimuth angle at the boundary of adjacent scans. This discontinuity appears as striping of the image clearly visible in certain cases with viewing geometry close to principle plane over the snow of the glint area of water. The striping is a true surface Bi-directional Reflectance Factor (BRF) effect and should be preserved during gridding. Second, due to bowtie effect, the observations in adjacent scans overlap each other. Commonly used method of calculating grid cell value by averaging all overlapping observations may result in smearing of the image. This paper describes a refined gridding algorithm that takes the above two effects into account. By calculating the grid cell value by averaging the overlapping observations from a single scan, the new algorithm preserves the measured BRF signal and enhances sharpness of the image.

Hurricane coastal flood analysis using multispectral spectral images

NASA Astrophysics Data System (ADS)

Ogashawara, I.; Ferreira, C.; Curtarelli, M. P.

2013-12-01

Flooding is one of the main hazards caused by extreme events such as hurricanes and tropical storms. Therefore, flood maps are a crucial tool to support policy makers, environmental managers and other government agencies for emergency management, disaster recovery and risk reduction planning. However traditional flood mapping methods rely heavily on the interpolation of hydrodynamic models results, and most recently, the extensive collection of field data. These methods are time-consuming, labor intensive, and costly. Efficient and fast response alternative methods should be developed in order to improve flood mapping, and remote sensing has been proved as a valuable tool for this application. Our goal in this paper is to introduce a novel technique based on spectral analysis in order to aggregate knowledge and information to map coastal flood areas. For this purpose we used the Normalized Diference Water Index (NDWI) which was derived from two the medium resolution LANDSAT/TM 5 surface reflectance product from the LANDSAT climate data record (CDR). This product is generated from specialized software called Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS). We used the surface reflectance products acquired before and after the passage of Hurricane Ike for East Texas in September of 2008. We used as end member a classification of estimated flooded area based on the United States Geological Survey (USGS) mobile storm surge network that was deployed for Hurricane Ike. We used a dataset which consisted of 59 water levels recording stations. The estimated flooded area was delineated interpolating the maximum surge in each location using a spline with barriers method with high tension and a 30 meter Digital Elevation Model (DEM) from the National Elevation Dataset (NED). Our results showed that, in the flooded area, the NDWI values decreased after the hurricane landfall on average from 0.38 to 0.18 and the median value decreased from 0.36 to 0.2. However for the non-flooded area the NDWI increased after the hurricane landfall. The average value varied from 0.15 to 0.43 and the median value from 0.13 to 0.43. These results demonstrate that these differences can be explored for the mapping of flood areas. As NDWI was developed to quantify the amount of water in the leaf of the plants, the increase of the value is expected within the amount of water that the leaf will absorb. However in flooded areas the amount of water is so high that it is possible that the reflectance follows the water spectral behavior absorbing more than reflecting in the Near Infrared region. Thus, remote sensing techniques showed to be powerful tools since they could characterize flooded areas. However further studies are needed, applying and validating these techniques for other regions and different storms. Optical remote sensing is promising for many applications, since it will be an open door to studies of spatial and temporal analysis of the flood impacts mainly in areas with remote access and with a lack of in situ data.

Petrography and geochemistry of Cenozoic sedimentary sequences of the southern Samar Island, Philippines: Clues to the unroofing history of an ancient subduction zone

NASA Astrophysics Data System (ADS)

Pacle, Nichole Anthony D.; Dimalanta, Carla B.; Ramos, Noelynna T.; Payot, Betchaida D.; Faustino-Eslava, Decibel V.; Queaño, Karlo L.; Yumul, Graciano P.

2017-07-01

The Cenozoic sedimentary sequences of southern Samar Island in eastern Philippines were examined to understand the unroofing history of an ancient arc terrane. Petrographic and geochemical data revealed varying degrees of inputs from the ophiolite basement and differences in modal compositions. The sedimentary units are mostly made up of lithic fragments. The Late Oligocene to Early Miocene Daram Formation contains more chert and volcanic fragments whereas the late Middle Miocene to Early Pliocene Catbalogan Formation is dominantly composed of ultramafic components. These variances are correspondingly reflected in the geochemical signatures of these two sedimentary formations. The Catbalogan Formation clastic rocks have higher volatile-free MgO and Fe2O3 values (average: 8.4% for both oxides) compared to the Daram Formation samples (average: 5.1 and 6.3%, respectively). Geochemical variations are also reflected in the Co, Cr and Ni values: the Catbalogan Formation samples reflect higher concentrations (Co: 15-57 ppm; Cr: 231-1094 ppm; Ni: 84-484 ppm) compared to the Daram Formation samples (Co: 24-32 ppm; Cr: 234-418 ppm; Ni: 212-323 ppm). These observations suggest that the Daram Formation eroded and transported more of the crustal portions of the ophiolite, while the younger Catbalogan Formation represents a later exhumation and subsequent erosion of the ultramafic section. An oceanic island arc (OIA) setting is proposed for the two formations based on several tectonic discrimination diagrams (e.g., Th-La-Sc, La vs. Th). The OIA signature is further supported by their smooth chondrite-normalized rare earth element (REE) patterns with no obvious Eu anomaly as well as LREE enrichment which are typical of sediments deposited in OIA setting. Based on the dominantly ophiolitic provenance of the Daram and Catbalogan formations, the post-emplacement history of the nearby Samar Ophiolite is constrained during the Late Oligocene to Early Pliocene period.

The NuSTAR Extragalactic Survey: Average Broadband X-Ray Spectral Properties of the NuSTAR-detected AGNs

NASA Astrophysics Data System (ADS)

Del Moro, A.; Alexander, D. M.; Aird, J. A.; Bauer, F. E.; Civano, F.; Mullaney, J. R.; Ballantyne, D. R.; Brandt, W. N.; Comastri, A.; Gandhi, P.; Harrison, F. A.; Lansbury, G. B.; Lanz, L.; Luo, B.; Marchesi, S.; Puccetti, S.; Ricci, C.; Saez, C.; Stern, D.; Treister, E.; Zappacosta, L.

2017-11-01

We present a study of the average X-ray spectral properties of the sources detected by the NuSTAR extragalactic survey, comprising observations of the Extended Chandra Deep Field South (E-CDFS), Extended Groth Strip (EGS), and the Cosmic Evolution Survey (COSMOS). The sample includes 182 NuSTAR sources (64 detected at 8-24 keV), with 3-24 keV fluxes ranging between {f}3{--24{keV}}≈ {10}-14 and 6 × 10-13 erg cm-2 s-1 ({f}8{--24{keV}}≈ 3× {10}-14{--}3× {10}-13 erg cm-2 s-1) and redshifts in the range of z=0.04{--}3.21. We produce composite spectra from the Chandra + NuSTAR data (E≈ 2{--}40 {keV}, rest frame) for all the sources with redshift identifications (95%) and investigate the intrinsic, average spectra of the sources, divided into broad-line (BL) and narrow-line (NL) active galactic nuclei (AGNs), and also in different bins of X-ray column density and luminosity. The average power-law photon index for the whole sample is {{Γ }}={1.65}-0.03+0.03, flatter than the {{Γ }}≈ 1.8 typically found for AGNs. While the spectral slope of BL and X-ray unabsorbed AGNs is consistent with the typical values ({{Γ }}={1.79}-0.01+0.01), a significant flattening is seen in NL AGNs and heavily absorbed sources ({{Γ }}={1.60}-0.05+0.08 and {{Γ }}={1.38}-0.12+0.12, respectively), likely due to the effect of absorption and to the contribution from the Compton reflection component to the high-energy flux (E> 10 keV). We find that the typical reflection fraction in our spectra is R≈ 0.5 (for {{Γ }}=1.8), with a tentative indication of an increase of the reflection strength with X-ray column density. While there is no significant evidence for a dependence of the photon index on X-ray luminosity in our sample, we find that R decreases with luminosity, with relatively high levels of reflection (R≈ 1.2) for {L}10{--40{keV}}< {10}44 erg s-1 and R≈ 0.3 for {L}10{--40{keV}}> {10}44 erg s-1 AGNs, assuming a fixed spectral slope of {{Γ }}=1.8.

Modelling reduction of urban heat load in Vienna by modifying surface properties of roofs

NASA Astrophysics Data System (ADS)

Žuvela-Aloise, Maja; Andre, Konrad; Schwaiger, Hannes; Bird, David Neil; Gallaun, Heinz

2018-02-01

The study examines the potential of urban roofs to reduce the urban heat island (UHI) effect by changing their reflectivity and implementing vegetation (green roofs) using the example of the City of Vienna. The urban modelling simulations are performed based on high-resolution orography and land use data, climatological observations, surface albedo values from satellite imagery and registry of the green roof potential in Vienna. The modelling results show that a moderate increase in reflectivity of roofs (up to 0.45) reduces the mean summer temperatures in the densely built-up environment by approximately 0.25 °C. Applying high reflectivity materials (roof albedo up to 0.7) leads to average cooling in densely built-up area of approximately 0.5 °C. The green roofs yield a heat load reduction in similar order of magnitude as the high reflectivity materials. However, only 45 % of roof area in Vienna is suitable for greening and the green roof potential mostly applies to industrial areas in city outskirts and is therefore not sufficient for substantial reduction of the UHI effect, particularly in the city centre which has the highest heat load. The strongest cooling effect can be achieved by combining the green roofs with high reflectivity materials. In this case, using 50 or 100 % of the green roof potential and applying high reflectivity materials on the remaining surfaces have a similar cooling effect.

Preparation of poly(BMA-co-MMA) particles by soap-free emulsion polymerization and its optical properties as photonic crystals.

PubMed

Lee, Ki-Chang; Choo, Hun-Seung

2014-11-01

Narrowly dispersed poly(BMA-co-MMA) and PBMA latices with particle diameters ranging within 216-435 nm were synthesized successfully by surfactant-free emulsion polymerization with KPS and AIBA. The average particle diameter and particle size distribution, average molecular weight and its distribution, glass transition temperature, reflectance spectra in visible wavelength, and refractive indices for the respective poly(BMA-co-MMA) latices and their photonic crystals were systematically investigated in terms of BMA/MMA ratio, BMA content, polymerization temperature, and DVB effect. The rate of polymerization increased with increasing MMA concentration in BMA/MMA ratio. The particle diameter increased with BMA concentration in BMA/MMA ratio. The molecular weight increased with BMA concentration in BMA/MMA ratio and monomer concentration. The drying of the latices offered self-assembled shiny colloidal crystal films showing the characteristic structural colors in visible wavelength. All the poly(BMA-co-MMA) latices prepared in the study were fallen within the range of photonic grade microspheres. The reflectance measurement on the colloidal photonic crystals having different particle diameters clearly exhibited narrow stopbands. The reflection maxima (λ(max)) measured in this study were well close to the λ(max) calculated, derived from the Bragg's equation. The refractive indices of poly(BMA-co-MMA) photonic crystals were found to be almost same as the theoretical values and increased proportionally from 1.50 to 1.57 with BMA content in BMA/MMA ratios. It was, thus, found that the optical reflectance properties of the poly(BMA-co-MMA) colloidal photonic crystals can be controlled easily by adjusting the reaction conditions and BMA/MMA ratio in soap-free emulsion copolymerization of BMA and MMA.

Oxygen isotope geochemistry of the lassen volcanic center, California: Resolving crustal and mantle contributions to continental Arc magmatism

USGS Publications Warehouse

Feeley, T.C.; Clynne, M.A.; Winer, G.S.; Grice, W.C.

2008-01-01

This study reports oxygen isotope ratios determined by laser fluorination of mineral separates (mainly plagioclase) from basaltic andesitic to rhyolitic composition volcanic rocks erupted from the Lassen Volcanic Center (LVC), northern California. Plagioclase separates from nearly all rocks have ??18O values (6.1-8.4%) higher than expected for production of the magmas by partial melting of little evolved basaltic lavas erupted in the arc front and back-arc regions of the southernmost Cascades during the late Cenozoic. Most LVC magmas must therefore contain high 18O crustal material. In this regard, the ??18O values of the volcanic rocks show strong spatial patterns, particularly for young rhyodacitic rocks that best represent unmodified partial melts of the continental crust. Rhyodacitic magmas erupted from vents located within 3.5 km of the inferred center of the LVC have consistently lower ??18 O values (average 6.3% ?? 0.1%) at given SiO2 contents relative to rocks erupted from distal vents (>7.0 km; average 7.1% ?? 0.1%). Further, magmas erupted from vents situated at transitional distances have intermediate values and span a larger range (average 6.8% ?? 0.2%). Basaltic andesitic to andesitic composition rocks show similar spatial variations, although as a group the ??18O values of these rocks are more variable and extend to higher values than the rhyodacitic rocks. These features are interpreted to reflect assimilation of heterogeneous lower continental crust by mafic magmas, followed by mixing or mingling with silicic magmas formed by partial melting of initially high 18O continental crust (??? 9.0%) increasingly hybridized by lower ??18O (???6.0%) mantle-derived basaltic magmas toward the center of the system. Mixing calculations using estimated endmember source ??18O values imply that LVC magmas contain on a molar oxygen basis approximately 42 to 4% isotopically heavy continental crust, with proportions declining in a broadly regular fashion toward the center of the LVC. Conversely, the ??18O values of the rhyodacitic rocks suggest that the continental crust in the melt generation zones beneath the LVC has been substantially modified by intrusion of mantle-derived basaltic magmas, with the degree of hybridization ranging on a molar oxygen basis from approximately 60% at distances up to 12 km from the center of the system to 97% directly beneath the focus region. These results demonstrate on a relatively small scale the strong influence that intrusion of mantle-derived mafic magmas can have on modifying the composition of pre-existing continental crust in regions of melt production. Given this result, similar, but larger-scale, regional trends in magma compositions may reflect an analogous but more extensive process wherein the continental crust becomes progressively hybridized beneath frontal arc localities as a result of protracted intrusion of subduction-related basaltic magmas. ?? The Author 2008. Published by Oxford University Press. All rights reserved.

A comparative test of phylogenetic diversity indices.

PubMed

Schweiger, Oliver; Klotz, Stefan; Durka, Walter; Kühn, Ingolf

2008-09-01

Traditional measures of biodiversity, such as species richness, usually treat species as being equal. As this is obviously not the case, measuring diversity in terms of features accumulated over evolutionary history provides additional value to theoretical and applied ecology. Several phylogenetic diversity indices exist, but their behaviour has not yet been tested in a comparative framework. We provide a test of ten commonly used phylogenetic diversity indices based on 40 simulated phylogenies of varying topology. We restrict our analysis to a topological fully resolved tree without information on branch lengths and species lists with presence-absence data. A total of 38,000 artificial communities varying in species richness covering 5-95% of the phylogenies were created by random resampling. The indices were evaluated based on their ability to meet a priori defined requirements. No index meets all requirements, but three indices turned out to be more suitable than others under particular conditions. Average taxonomic distinctness (AvTD) and intensive quadratic entropy (J) are calculated by averaging and are, therefore, unbiased by species richness while reflecting phylogeny per se well. However, averaging leads to the violation of set monotonicity, which requires that species extinction cannot increase the index. Total taxonomic distinctness (TTD) sums up distinctiveness values for particular species across the community. It is therefore strongly linked to species richness and reflects phylogeny per se weakly but satisfies set monotonicity. We suggest that AvTD and J are best applied to studies that compare spatially or temporally rather independent communities that potentially vary strongly in their phylogenetic composition-i.e. where set monotonicity is a more negligible issue, but independence of species richness is desired. In contrast, we suggest that TTD be used in studies that compare rather interdependent communities where changes occur more gradually by species extinction or introduction. Calculating AvTD or TTD, depending on the research question, in addition to species richness is strongly recommended.

How warm is too warm for the life cycle of actinopterygian fishes?

PubMed Central

Motani, Ryosuke; Wainwright, Peter C.

2015-01-01

We investigated the highest constant temperature at which actinopterygian fishes can complete their lifecycles, based on an oxygen supply model for cleavage-stage eggs. This stage is one of the most heat-sensitive periods during the lifecycle, likely reflecting the exhaustion of maternally supplied heat shock proteins without new production. The model suggests that average eggs would not develop normally under a constant temperature of about 36 °C or higher. This estimate matches published empirical values derived from laboratory and field observations. Spermatogenesis is more heat sensitive than embryogenesis in fishes, so the threshold may indeed be lower, at about 35 °C, unless actinopterygian fishes evolve heat tolerance during spermatogenesis as in birds. Our model also predicts an inverse relationship between egg size and temperature, and empirical data support this prediction. Therefore, the average egg size, and hence hatching size, is expected to shrink in a greenhouse world but a feeding function prohibits the survival of very small hatchlings, posing a limit to the shrinkage. It was once suggested that a marine animal community may be sustained under temperatures up to about 38 °C, and this value is being used, for example, in paleotemperature reconstruction. A revision of the value is overdue. (199/200) PMID:26166622

Quantification and characterization of greywater from schools.

PubMed

Alsulaili, Abdalrahman D; Hamoda, Mohamed F

2015-01-01

Survey of schools of different education levels (primary, intermediate and secondary) in Kuwait showed an average greywater generation rate of 7.3 L/p/d and varied in the range of 2.9-16 l/p/d, reflecting the school level of education (i.e. student age). The highest rates were observed for primary schools while the lowest rates were observed in secondary schools where students are more mature and use the water more wisely. The greywater characteristics indicated waste with low chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5) values but relatively high solids, conductivity, and sodium content due to excessive use of hand soap. Total coliform values ranged between 89 and 352 most probable number (MPN)/mL with an average of 196 MPN/mL while no fecal coliform values were detected. Greywater collected from schools is classified as light greywater and contains much lower levels of organic matter and nutrients compared to residential greywater and domestic wastewater. It is suitable for non-potable reuse after minimal treatment since microbial contamination may pose a serious threat to health if greywater comes into contact with humans. It also provides a good opportunity for reuse in toilet flushing since it can be easily collected from wash sinks and fountains, as major sources, and recycled.

Phytoplankton abundance and structural parameters of the critically endangered protected area Vaya Lake (Bulgaria).

PubMed

Dimitrova, Ralits; Nenova, Elena; Uzunov, Blagoy; Shishiniova, Maria; Stoyneva, Maya

2014-09-03

Vaya (Ramsar site, protected area and Natura 2000 site) is the biggest natural lake in Bulgaria and the shallowest Black Sea coastal lake, which during the last decades has undergone significant changes and was included as critically endangered in the Red List of Bulgarian Wetlands. Our studies were conducted during the summer and autumn months of three years - 2004-2006. The paper presents results on the phytoplankton abundance (numbers, biomass and carbon content) in combination with the indices of species diversity, evenness and dominance. Phytoplankton abundance was extremely high (average values of 1135 × 10 6 cells/L for the quantity and of 46 mg/L for the biomass) and increased in the end of the studied period (years 2005-2006), when decrease of species diversity and increase of the dominance index values were detected. The carbon content of the phytoplankton was at an average value of 9.7 mg/L and also increased from 2004 to 2006. Cyanoprokaryota dominated in the formation of the total carbon content of the phytoplankton, in its numbers (88%-97.8%), and in the biomass (62%-87.9%). All data on phytoplankton abundance and structural parameters in Vaya confirm the hypertrophic status of the lake and reflect the general negative trend in its development.

Appropriateness of selecting different averaging times for modelling chronic and acute exposure to environmental odours

NASA Astrophysics Data System (ADS)

Drew, G. H.; Smith, R.; Gerard, V.; Burge, C.; Lowe, M.; Kinnersley, R.; Sneath, R.; Longhurst, P. J.

Odour emissions are episodic, characterised by periods of high emission rates, interspersed with periods of low emissions. It is frequently the short term, high concentration peaks that result in annoyance in the surrounding population. Dispersion modelling is accepted as a useful tool for odour impact assessment, and two approaches can be adopted. The first approach of modelling the hourly average concentration can underestimate total odour concentration peaks, resulting in annoyance and complaints. The second modelling approach involves the use of short averaging times. This study assesses the appropriateness of using different averaging times to model the dispersion of odour from a landfill site. We also examine perception of odour in the community in conjunction with the modelled odour dispersal, by using community monitors to record incidents of odour. The results show that with the shorter averaging times, the modelled pattern of dispersal reflects the pattern of observed odour incidents recorded in the community monitoring database, with the modelled odour dispersing further in a north easterly direction. Therefore, the current regulatory method of dispersion modelling, using hourly averaging times, is less successful at capturing peak concentrations, and does not capture the pattern of odour emission as indicated by the community monitoring database. The use of short averaging times is therefore of greater value in predicting the likely nuisance impact of an odour source and in framing appropriate regulatory controls.

Peer Teaching to Foster Learning in Physiology.

PubMed

Srivastava, Tripti K; Waghmare, Lalitbhushan S; Mishra, Ved Prakash; Rawekar, Alka T; Quazi, Nazli; Jagzape, Arunita T

2015-08-01

Peer teaching is an effective tool to promote learning and retention of knowledge. By preparing to teach, students are encouraged to construct their own learning program, so that they can explain effectively to fellow learners. Peer teaching is introduced in present study to foster learning and pedagogical skills amongst first year medical under-graduates in physiology with a Hypothesis that teaching is linked to learning on part of the teacher. Non-randomized, Interventional study, with mixed methods design. Cases experienced peer teaching whereas controls underwent tutorials for four consecutive classes. Quantitative Evaluation was done through pre/post test score analysis for Class average normalized gain and tests of significance, difference in average score in surprise class test after one month and percentage of responses in closed ended items of feedback questionnaire. Qualitative Evaluation was done through categorization of open ended items and coding of reflective statements. The average pre and post test score was statistically significant within cases (p = 0.01) and controls (p = 0.023). The average post test scores was more for cases though not statistically significant. The class average normalized gain (g) for Tutorials was 49% and for peer teaching 53%. Surprise test had average scoring of 36 marks (out of 50) for controls and 41 marks for cases. Analysed section wise, the average score was better for Long answer question (LAQ) in cases. Section wise analysis suggested that through peer teaching, retention was better for descriptive answers as LAQ has better average score in cases. Feedback responses were predominantly positive for efficacy of peer teaching as a learning method. The reflective statements were sorted into reflection in action, reflection on action, claiming evidence, describing experience, and recognizing discrepancies. Teaching can stimulate further learning as it involves interplay of three processes: metacognitive awareness; deliberate practice, and self-explanation. Coupled with immediate feedback and reflective exercises, learning can be measurably enhanced along with improved teaching skills.

Peer Teaching to Foster Learning in Physiology

PubMed Central

Srivastava, Tripti K; Waghmare, Lalitbhushan S.; Mishra, Ved Prakash; Rawekar, Alka T; Quazi, Nazli; Jagzape, Arunita T

2015-01-01

Introduction Peer teaching is an effective tool to promote learning and retention of knowledge. By preparing to teach, students are encouraged to construct their own learning program, so that they can explain effectively to fellow learners. Peer teaching is introduced in present study to foster learning and pedagogical skills amongst first year medical under-graduates in physiology with a Hypothesis that teaching is linked to learning on part of the teacher. Materials and Methods Non-randomized, Interventional study, with mixed methods design. Cases experienced peer teaching whereas controls underwent tutorials for four consecutive classes. Quantitative Evaluation was done through pre/post test score analysis for Class average normalized gain and tests of significance, difference in average score in surprise class test after one month and percentage of responses in closed ended items of feedback questionnaire. Qualitative Evaluation was done through categorization of open ended items and coding of reflective statements. Results The average pre and post test score was statistically significant within cases (p = 0.01) and controls (p = 0.023). The average post test scores was more for cases though not statistically significant. The class average normalized gain (g) for Tutorials was 49% and for peer teaching 53%. Surprise test had average scoring of 36 marks (out of 50) for controls and 41 marks for cases. Analysed section wise, the average score was better for Long answer question (LAQ) in cases. Section wise analysis suggested that through peer teaching, retention was better for descriptive answers as LAQ has better average score in cases. Feedback responses were predominantly positive for efficacy of peer teaching as a learning method. The reflective statements were sorted into reflection in action, reflection on action, claiming evidence, describing experience, and recognizing discrepancies. Conclusion Teaching can stimulate further learning as it involves interplay of three processes: metacognitive awareness; deliberate practice, and self-explanation. Coupled with immediate feedback and reflective exercises, learning can be measurably enhanced along with improved teaching skills. PMID:26435969

Detection of Coccolithophore Blooms in Ocean Color Satellite Imagery: a Generalized Approach for Use with Multiple Sensors

NASA Technical Reports Server (NTRS)

Moore, Timothy; Dowell, Mark; Franz, Bryan A.

2012-01-01

A generalized coccolithophore bloom classifier has been developed for use with ocean color imagery. The bloom classifier was developed using extracted satellite reflectance data from SeaWiFS images screened by the default bloom detection mask. In the current application, we extend the optical water type (OWT) classification scheme by adding a new coccolithophore bloom class formed from these extracted reflectances. Based on an in situ coccolithophore data set from the North Atlantic, the detection levels with the new scheme were between 1,500 and 1,800 coccolithophore cellsmL and 43,000 and 78,000 lithsmL. The detected bloom area using the OWT method was an average of 1.75 times greater than the default bloom detector based on a collection of SeaWiFS 1 km imagery. The versatility of the scheme is shown with SeaWiFS, MODIS Aqua, CZCS and MERIS imagery at the 1 km scale. The OWT scheme was applied to the daily global SeaWiFS imagery mission data set (years 19972010). Based on our results, average annual coccolithophore bloom area was more than two times greater in the southern hemisphere compared to the northern hemi- sphere with values of 2.00 106 km2 and 0.75 106 km2, respectively. The new algorithm detects larger bloom areas in the Southern Ocean compared to the default algorithm, and our revised global annual average of 2.75106 km2 is dominated by contributions from the Southern Ocean.

A 2000-yr High-resolution Stalagmite Record From Zhenzhu Cave in Hebei, North China: Interpretations of AMS 14C, 230Th/U, 210Pb Dating, and δ18O, δ13C Results

NASA Astrophysics Data System (ADS)

Li, H. C.; Yin, J.; Rao, Z.; Mii, H. S.; Shen, C. C.; Pillutla, R. K.; Li, Y. X.

2016-12-01

An 11.1-cm long stalagmite (ZZ12) collected from Zhenzhu cave (38°15'N, 113°42'E, 975m a.s.l.) located at Tiangui mountain of Hebei province, North China. The 230Th/U dates on 12 horizons exhibit large uncertainties with many reversed age sequences due to low U contents and low 230Th/232Th ratios. While the 230Th/U dating is not able to provide the chronology of this stalagmite, AMS 14C dating on 27 samples from various depths of the stalagmite yields a reliable age-depth relationship. Three AMS 14C dates from the top 5 mm appear nuclear bomb carbon indicating that this part was deposited after AD 1950. Seven samples for 210Pb dating were taken from the upper 14 mm with 2 mm intervals, showing exponential decay of excess 210Pb and supporting the AMS 14C dating results. At the base of the stalagmite, charcoal grains were included in the carbonate stalagmite. This charcoal sample has a Calibrated 14C age of 1865±20 a BP. The carbonates at adjacent depths show Calibrated 14C ages of 1900±15 and 2215±75 a BP respectively. The bomb carbon and similar ages between the charcoal and carbonates indicate that dead carbon influence on the 14C dates in some horizons may not be serious. From the 27 AMS 14C dates, we select 17 AMS 14C dates which have minimal influence of dead carbon fraction to construct the chronology. The established chronology shows that slow growth rates occurred prior to 1100 a BP and after 600 a BP. This time interval involves the Medieval Warm Period, while the fast growth rate during this interval may reflect warm and wet climatic conditions. A total of 835 samples were drilled from the stalagmite for δ18O and δ13C analyses. The current 900-year δ18O and δ13C records reveal climate and vegetation changes in the study area. Strong decadal oscillations in the δ18O record reflect variations of monsoonal rain, with relatively dry between AD 1350 and AD 1550 and after AD 1960. The δ13C record appears mainly multi-centennial variations with a 4‰ fluctuation range and an average value of -8‰ (VPDB). The δ13C values were lighter than the average during AD 1150 1480 and AD 1700 1920, whereas the δ13C values were heavier than the average during AD 1480 1700 and AD 1820 the present. The δ13C record mainly reflects the vegetation change above the cave, with lighter value indicating better vegetation coverage and vice versa.

Validation and Refinement of a Lunar Irradiance Model for Suomi NPP VIIRS Day-Night Band Quantitative Nighttime Applications

NASA Astrophysics Data System (ADS)

Miller, S. D.; Combs, C.; Wagner, S.; Viticchiè, B.; Walther, A.; Solbrig, J.

2014-12-01

The VIIRS Day-Night Band provides the first calibrated observations of nocturnal low-light visible/near-infrared (~500-900 nm response, 710 nm central wavelength) radiances, including reflected moonlight down to values of 3 × 10-5 W·m-2·sr-1. These novel measurements afford the first opportunity to attempt nighttime retrievals of optical depth for optically thick clouds when moonlight is available, thereby advancing our ability to observe the diurnal cycle of such structures as marine stratocumuli which are thought to play an important role in determining climate and climate feedbacks. In order to leverage the Day-Night Band measurements in this capacity, we must first convert the upwelling top-of-atmosphere radiances to equivalent values of reflectance. Doing so requires a detailed knowledge of the down-welling top-of-atmosphere lunar spectral irradiance which, unlike sunlight, varies significantly over the course of the ~29.5 day lunar cycle. This research summarizes the ongoing development, validation, and refinement of a lunar irradiance model designed to convert Day-Night Band radiances to equivalent lunar reflectance. Comparisons between daytime and nighttime Day-Night Band reflectance for vicarious calibration targets offering radiometric stability (e.g., White Sands, Salar de Uyuni, Dome-C, and snow fields) confirms the model's performance to within an expected ~10% uncertainty. An observed lunar-phase-dependent trend associated with the model's assumption of a disk-averaged albedo was addressed via analysis of a version of the model adapted for comparison against Meteosat Second Generation SEVIRI lunar measurements. The analysis resulted in a phase-dependent 6th order polynomial correction to the model and expected model uncertainty improvements to within ~5%. Examples of lunar reflectance imagery for operational applications and the provisional quantitative application of Day-Night Band lunar reflectance to nighttime cloud optical property retrievals, bearing relevance to the diurnally resolved global climate data record, are shown.

Prediction Models for Assessing Lycopene in Open-Field Cultivated Tomatoes by Means of a Portable Reflectance Sensor: Cultivar and Growing-Season Effects.

PubMed

Ciaccheri, Leonardo; Tuccio, Lorenza; Mencaglia, Andrea A; Sikorska-Zimny, Kalina; Hallmann, Ewelina; Kowalski, Artur; G Mignani, Anna; Kaniszewski, Stanislaw; Agati, Giovanni

2018-05-09

Reflectance spectroscopy represents a useful tool for the nondestructive assessment of tomato lycopene, even in the field. For this reason, a compact, low-cost, light emitting diode-based sensor has been developed to measure reflectance in the 400-750 nm spectral range. It was calibrated against wet chemistry and evaluated by partial least squares (PLS) regression analyses. The lycopene prediction models were defined for two open-field cultivated red-tomato varieties: the processing oblong tomatoes of the cv. Calista (average weight: 76 g) and the fresh-consumption round tomatoes of the cv. Volna (average weight: 130 g), over a period of two consecutive years. The lycopene prediction models were dependent on both cultivar and season. The lycopene root mean square error of prediction produced by the 2014 single-cultivar calibrations validated on the 2015 samples was large (33 mg kg -1 ) in the Calista tomatoes and acceptable (9.5 mg kg -1 ) in the Volna tomatoes. A more general bicultivar and biyear model could still explain almost 80% of the predicted lycopene variance, with a relative error in red tomatoes of less than 20%. In 2016, the in-field applications of the multiseasonal prediction models, built with the 2014 and 2015 data, showed significant ( P < 0.001) differences in the average lycopene estimated in the crop on two sampling dates that were 20 days apart: on August 19 and September 7, 2016, the lycopene was 98.9 ± 9.3 and 92.2 ± 10.8 mg kg -1 FW for cv. Calista and 54.6 ± 13.2 and 60.8 ± 6.8 mg kg -1 FW for cv. Volna. The sensor was also able to monitor the temporal evolution of lycopene accumulation on the very same fruits attached to the plants. These results indicated that a simple, compact reflectance device and PLS analysis could provide adequately precise and robust (through-seasons) models for the nondestructive assessment of lycopene in whole tomatoes. This technique could guarantee tomatoes with the highest nutraceutical value from the production, during storage and distribution, and finally to consumers.

42 CFR 414.26 - Determining the GAF.

Code of Federal Regulations, 2010 CFR

2010-10-01

...) Geographic indices. CMS uses the following indices to establish the GAF: (1) An index that reflects one... fee schedule areas as determined under § 414.22(a) and the national average of that work effort. (2... § 414.22(b) compared to the national average of those costs. (3) An index that reflects the relative...

42 CFR 414.26 - Determining the GAF.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Geographic indices. CMS uses the following indices to establish the GAF: (1) An index that reflects one... fee schedule areas as determined under § 414.22(a) and the national average of that work effort. (2... § 414.22(b) compared to the national average of those costs. (3) An index that reflects the relative...

42 CFR 414.26 - Determining the GAF.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Geographic indices. CMS uses the following indices to establish the GAF: (1) An index that reflects one... fee schedule areas as determined under § 414.22(a) and the national average of that work effort. (2... § 414.22(b) compared to the national average of those costs. (3) An index that reflects the relative...

42 CFR 414.26 - Determining the GAF.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Geographic indices. CMS uses the following indices to establish the GAF: (1) An index that reflects one... fee schedule areas as determined under § 414.22(a) and the national average of that work effort. (2... § 414.22(b) compared to the national average of those costs. (3) An index that reflects the relative...

42 CFR 414.26 - Determining the GAF.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Geographic indices. CMS uses the following indices to establish the GAF: (1) An index that reflects one... fee schedule areas as determined under § 414.22(a) and the national average of that work effort. (2... § 414.22(b) compared to the national average of those costs. (3) An index that reflects the relative...

Calcium and magnesium isotope systematics in rivers draining the Himalaya-Tibetan-Plateau region: Lithological or fractionation control?

NASA Astrophysics Data System (ADS)

Tipper, Edward T.; Galy, Albert; Bickle, Mike J.

2008-02-01

In rivers draining the Himalaya-Tibetan-Plateau region, the 26Mg/ 24Mg ratio has a range of 2‰ and the 44Ca/ 42Ca ratio has a range of 0.6‰. The average δ26Mg values of tributaries from each of the main lithotectonic units (Tethyan Sedimentary Series (TSS), High Himalayan Crystalline Series (HHCS) and Lesser Himalayan Series (LHS)) are within 2 standard deviation analytical uncertainty (0.14‰). The consistency of average riverine δ26Mg values is in contrast to the main rock types (limestone, dolostone and silicate) which range in their average δ26Mg values by more than 2‰. Tributaries draining the dolostones of the LHS differ in their δ44Ca values compared to tributaries from the TSS and HHCS. The chemistry of these river waters is strongly influenced by dolostone (solute Mg/Ca close to unity) and both δ26Mg (-1.31‰) and δ44Ca (0.64‰) values are within analytical uncertainty of the LHS dolostone. These are the most elevated δ44Ca values in rivers and rock reported so far demonstrating that both riverine and bedrock δ44Ca values may show greater variability than previously thought. Although rivers draining TSS limestone have the lowest δ26Mgandδ44Ca values at -1.41 and 0.42‰, respectively, both are offset to higher values compared to bedrock TSS limestone. The average δ26Mg value of rivers draining mainly silicate rock of the HHCS is -1.25‰, lower by 0.63‰ than the average silicate rock. These differences are consistent with a fractionation of δ26Mg values during silicate weathering. Given that the proportion of Mg exported from the Himalaya as solute Mg is small, the difference in 26Mg/ 24Mg ratios between silicate rock and solute Mg reflects the 26Mg/ 24Mg isotopic fractionation factor ( αsilicate-dissolvedMg) between silicate and dissolved Mg during incongruent silicate weathering. The value of αsilicate-dissolvedMg of 0.99937 implies that in the TSS, solute Mg is primarily derived from silicate weathering, whereas the source of Ca is overwhelmingly derived from carbonate weathering. The average δ44Ca value in HHCS rivers is within uncertainty of silicate rock at 0.39‰. The widespread hot springs of the High Himalaya have an average δ26Mg value of -0.46‰ and an average δ44Ca value of 0.5‰, distinct from riverine values for δ26Mg but similar to riverine δ44Ca values. Although rivers draining each major rock type have δ44Ca and δ26Mg values in part inherited from bedrock, there is no correlation with proxies for carbonate or silicate lithology such as Na/Ca ratios, suggesting that Ca and Mg are in part recycled. However, in spite of the vast contrast in vegetation density between the arid Tibetan Plateau and the tropical Lesser Himalaya, the isotopic fractionation factor for Ca and Mg between solute and rocks are not systematically different suggesting that vegetation may only recycle a small amount of Ca and Mg in these catchments. The discrepancy between solute and solid Ca and Mg isotope ratios in these rivers from diverse weathering environments highlight our lack of understanding concerning the origin and subsequent path of Ca and Mg, bound as minerals in rock, and released as cations in rivers. The fractionation of Ca and Mg isotope ratios may prove useful for tracing mechanisms of chemical alteration. Ca isotope ratios of solute riverine Ca show a greater variability than previously acknowledged. The variability of Ca isotope ratios in modern rivers will need to be better quantified and accounted for in future models of global Ca cycling, if past variations in oceanic Ca isotope ratios are to be of use in constraining the past carbon cycle.

Genetic screening of prospective parents and of workers: some scientific and social issues.

PubMed

Hubbard, R; Henifin, M S

1985-01-01

Genetic screening programs are based on assumptions and values that reflect the history of racial and social eugenics in the United States and Europe. They stigmatize individuals by shifting the focus from social, economic, and political decisions that affect the health of prospective parents, newborns, and workers to "bad genes," that is, intrapersonal factors that are given the status of "causes" of disease. Prenatal screening, at best, can help the relatively few individuals who know that their future children are at risk for a particular inherited disease or disability; it has little positive value for the average person. Workplace genetic screening has not been shown to reduce occupational disease, but it has led to employment discrimination and has drawn attention away from controlling exposures to toxic chemicals in the workplace.

Assessment and self-assessment of the pharmacists' competencies using the global competency framework (GbCF) in Serbia.

PubMed

Stojkov, Svetlana; Tadić, Ivana; Crnjanski, Tatjana; Krajnović, Dušanka

2016-09-01

Pharmacists' competence represents a dynamic framework of knowledge, skills and abilities to carry out tasks, and it reflects on improving the quality of life and on patients’ health. One of the documents for the Evaluation and Competency Development of Pharmacists is the Global Competency Framework (GbCF). The aim of this study was to implement the GBCF document into Serbian pharmacies, to perform assessment and self assessment of the competencies. The assessment and self-assessment of pharmacists’ competencies were performed during the period 2012−13 year in eight community pharmacy chains, in seven cities in Serbia. For assessment and self-assessment of pharmacists competencies the GbCF model was applied, which was adjusted to pharmaceutical practice and legislation in Serbia. External assessment was conducted by teams of pharmacists using the structured observation of the work of pharmacists during regular working hours. Evaluated pharmacists filled out the questionnaire about demographic indicators about the pharmacist and the pharmacy where they work. A total of 123 pharmacists were evaluated. Pharmacists’ Professional Competency Cluster (KK1) had the lowest score (average value 2.98), while the cluster Management and Organizational Competency (KK2) had the highest score (average value 3.15). The competence Recognition of the Diagnosis and Patient Counseling (K8), which belonged to the cluster KK1, had the lowest score (average value for assessment and self-assessment were 2.09, and 2.34, respectively) among the all evaluated competencies. GbCF might be considered as an instrument for the competencies' evaluation/selfevaluation and their improvement, accordingly.

Core shifts, magnetic fields and magnetization of extragalactic jets

NASA Astrophysics Data System (ADS)

Zdziarski, Andrzej A.; Sikora, Marek; Pjanka, Patryk; Tchekhovskoy, Alexander

2015-07-01

We study the effect of radio-jet core shift, which is a dependence of the position of the jet radio core on the observational frequency. We derive a new method of measuring the jet magnetic field based on both the value of the shift and the observed radio flux, which complements the standard method that assumes equipartition. Using both methods, we re-analyse the blazar sample of Zamaninasab et al. We find that equipartition is satisfied only if the jet opening angle in the radio core region is close to the values found observationally, ≃0.1-0.2 divided by the bulk Lorentz factor, Γj. Larger values, e.g. 1/Γj, would imply magnetic fields much above equipartition. A small jet opening angle implies in turn the magnetization parameter of ≪1. We determine the jet magnetic flux taking into account this effect. We find that the transverse-averaged jet magnetic flux is fully compatible with the model of jet formation due to black hole (BH) spin-energy extraction and the accretion being a magnetically arrested disc (MAD). We calculate the jet average mass-flow rate corresponding to this model and find it consists of a substantial fraction of the mass accretion rate. This suggests the jet composition with a large fraction of baryons. We also calculate the average jet power, and find it moderately exceeds the accretion power, dot{M} c^2, reflecting BH spin energy extraction. We find our results for radio galaxies at low Eddington ratios are compatible with MADs but require a low radiative efficiency, as predicted by standard accretion models.

Cooperation prevails when individuals adjust their social ties.

PubMed

Santos, Francisco C; Pacheco, Jorge M; Lenaerts, Tom

2006-10-20

Conventional evolutionary game theory predicts that natural selection favours the selfish and strong even though cooperative interactions thrive at all levels of organization in living systems. Recent investigations demonstrated that a limiting factor for the evolution of cooperative interactions is the way in which they are organized, cooperators becoming evolutionarily competitive whenever individuals are constrained to interact with few others along the edges of networks with low average connectivity. Despite this insight, the conundrum of cooperation remains since recent empirical data shows that real networks exhibit typically high average connectivity and associated single-to-broad-scale heterogeneity. Here, a computational model is constructed in which individuals are able to self-organize both their strategy and their social ties throughout evolution, based exclusively on their self-interest. We show that the entangled evolution of individual strategy and network structure constitutes a key mechanism for the sustainability of cooperation in social networks. For a given average connectivity of the population, there is a critical value for the ratio W between the time scales associated with the evolution of strategy and of structure above which cooperators wipe out defectors. Moreover, the emerging social networks exhibit an overall heterogeneity that accounts very well for the diversity of patterns recently found in acquired data on social networks. Finally, heterogeneity is found to become maximal when W reaches its critical value. These results show that simple topological dynamics reflecting the individual capacity for self-organization of social ties can produce realistic networks of high average connectivity with associated single-to-broad-scale heterogeneity. On the other hand, they show that cooperation cannot evolve as a result of "social viscosity" alone in heterogeneous networks with high average connectivity, requiring the additional mechanism of topological co-evolution to ensure the survival of cooperative behaviour.

SOLINS- SOLAR INSOLATION MODEL FOR COMPUTING AVAILABLE SOLAR ENERGY TO A SURFACE OF ARBITRARY ORIENTATION

NASA Technical Reports Server (NTRS)

Smith, J. H.

1994-01-01

This computer program, SOLINS, was developed to aid engineers and solar system designers in the accurate modeling of the average hourly solar insolation on a surface of arbitrary orientation. The program can be used to study insolation problems specific to residential and commercial applications where the amount of space available for solar collectors is limited by shadowing problems, energy output requirements, and costs. For tandem rack arrays, SOLINS will accommodate the use of augmentation reflectors built into the support structure to increase insolation values at the collector surface. As the use of flat plate solar collectors becomes more prevalent in the building industry, the engineer and designer must have the capability to conduct extensive sensitivity analyses on the orientation and location of solar collectors. SOLINS should prove to be a valuable aid in this area of engineering. SOLINS uses a modified version of the National Bureau of Standards model to calculate the direct, diffuse, and reflected components of total insolation on a tilted surface with a given azimuthal orientation. The model is based on the work of Liu and Jordan with corrections by Kusuda and Ishii to account for early morning and late afternoon errors. The model uses a parametric description of the average day solar climate to generate monthly average day profiles by hour of the insolation level on the collector surface. The model includes accommodation of user specified ground and landscape reflectivities at the collector site. For roof or ground mounted, tilted arrays, SOLINS will calculate insolation including the effects of shadowing and augmentation reflectors. The user provides SOLINS with data describing the array design, array orientation, the month, the solar climate parameter, the ground reflectance, and printout control specifications. For the specified array and environmental conditions, SOLINS outputs the hourly insolation the array will receive during an average day during the month specified, along with the total insolation the collector surface will receive over an average 24-hour period. This program is written in FORTRAN IV for batch execution and has been implemented on an IBM 370 computer with a central memory requirement of approximately 46K of 8 bit bytes. The SOLINS routines were developed in 1979.

Tropospheric rivers? A pilot study. [of filamentary structures of atmospheric water vapor

NASA Technical Reports Server (NTRS)

Newell, Reginald E.; Newell, Nicholas E.; Zhu, Yong; Scott, Courtney

1992-01-01

Computations of daily global tropospheric water vapor flux values show the presence of a filamentary structure. The filaments, here called rivers, have lengths many times their widths and persist for many days while being translated through the atmosphere. They are present in data analyzed for both 1981 and 1991. The water vapor flux maxima coincide quite closely to reflectivity features (averaged from wavelengths of 380 and 360 nm) as revealed by the Total Ozone Mapping Spectrometer (TOMS). It is suggested that the filamentary structure may also be present in other trace constituents.

Intensity-Value Corrections for Integrating Sphere Measurements of Solid Samples Measured Behind Glass

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

Johnson, Timothy J.; Bernacki, Bruce E.; Redding, Rebecca L.

2014-11-01

Accurate and calibrated directional-hemispherical reflectance spectra of solids are important for both in situ and remote sensing. Many solids are in the form of powders or granules and to measure their diffuse reflectance spectra in the laboratory, it is often necessary to place the samples behind a transparent medium such as glass for the ultraviolet (UV), visible, or near-infrared spectral regions. Using both experimental methods and a simple optical model, we demonstrate that glass (fused quartz in our case) leads to artifacts in the reflectance values. We report our observations that the measured reflectance values, for both hemispherical and diffusemore » reflectance, are distorted by the additional reflections arising at the air–quartz and sample–quartz interfaces. The values are dependent on the sample reflectance and are offset in intensity in the hemispherical case, leading to measured values up to ~6% too high for a 2% reflectance surface, ~3.8% too high for 10% reflecting surfaces, approximately correct for 40–60% diffuse-reflecting surfaces, and ~1.5% too low for 99% reflecting Spectralon® surfaces. For the case of diffuse-only reflectance, the measured values are uniformly too low due to the polished glass, with differences of nearly 6% for a 99% reflecting matte surface. The deviations arise from the added reflections from the quartz surfaces, as verified by both theory and experiment, and depend on sphere design. Finally, empirical correction factors were implemented into post-processing software to redress the artifact for hemispherical and diffuse reflectance data across the 300–2300 nm range.« less

Palaeomagnetism of the Upper Miocene- Lower Pliocene lavas from the East Carpathians: contribution to the paleosecular variation of geomagnetic field

PubMed Central

Vişan, Mădălina; Panaiotu, Cristian G.; Necula, Cristian; Dumitru, Anca

2016-01-01

Investigations of the paleosecular variation of the geomagnetic field on geological timescales depend on globally distributed data sets from lava flows. We report new paleomagnetic results from lava flows of the East Carpathian Mountains (23.6°E, 46.4°N) erupted between 4 and 6 Ma. The average virtual geomagnetic pole position (76 sites) includes the North Geographic Pole and the dispersion of virtual geomagnetic poles is in general agreement with the data of the Time Averaged geomagnetic Field Initiative. Based on this study and previous results from the East Carpathians obtained from 0.04–4 Ma old lava flows, we show that high value of dispersion are characteristic only for 1.5–2.8 Ma old lava flows. High values of dispersion during the Matuyama chron are also reported around 50°N, in the global paleosecular variation data set. More data are needed at a global level to determine if these high dispersions reflect the behaviour of the geomagnetic field or an artefact of inadequate number of sites. This study of the East Carpathians volcanic rocks brings new data from southeastern Europe and which can contribute to the databases for time averaged field and paleosecular variation from lavas in the last 6 Ma. PMID:26997549

Effects of spatial orientation of prairie vegetation in an agricultural landscape on curve number values

NASA Astrophysics Data System (ADS)

Franz, K.; Dziubanski, D.; Helmers, M. J.

2015-12-01

The simplicity of the Curve Number (CN) method, which summarizes an area's hydrologic soil group, land cover, treatment, and hydrologic condition into a single number, make it a consistently popular choice for modelers. When multiple land cover types are present, a weighted average of the CNs is used. However, the weighted CN does not account for the spatial distribution of different land cover types within the watershed. To overcome this limitation, it becomes necessary to discretize the model into homogenous subunits, perhaps even to the hillslope scale, leading to a more complex model application. The objective of this study is to empirically derive CN values that reflect the effects of placements of native prairie vegetation (NPV) within agricultural landscapes. We derived CN values using precipitation and runoff data from (May 1 - Sept 30 over a 7 year period (2008 - 2014) for 9 ephemeral watersheds in Iowa (USA) ranging from 0.47 to 3.19 ha. The watersheds were planted with varying extents of NPV (0%, 10%, 20%) in different watershed positions (footslope vs. contour strips), with the rest of the watershed as row crop. The derived CN values from watersheds with all row crop were consistent with published values and watersheds with NPV had an average CN reduction of 6.4%, with a maximum reduction of 11.6%. Four of the six sites with treatment had a lower CN than one calculated using a weighted average of look-up values, indicating that accounting for placement of vegetation within the landscape is important for modeling runoff with the CN method. The derived CNs were verified using the leave-one-year-out method (computing CN using data from 6 of the 7 years, and then estimating runoff on the seventh year with that CN). Nash-Sutcliffe Efficiency (NSE) values for the estimated runoff typically ranged from 0.4-0.6. Our results suggest that the new CNs could confidently be used in future modeling studies to explore the hydrologic impacts of the NPV treatments at increasingly larger watershed scales.

Estimating the brain pathological age of Alzheimer’s disease patients from MR image data based on the separability distance criterion

NASA Astrophysics Data System (ADS)

Li, Yongming; Li, Fan; Wang, Pin; Zhu, Xueru; Liu, Shujun; Qiu, Mingguo; Zhang, Jingna; Zeng, Xiaoping

2016-10-01

Traditional age estimation methods are based on the same idea that uses the real age as the training label. However, these methods ignore that there is a deviation between the real age and the brain age due to accelerated brain aging. This paper considers this deviation and searches for it by maximizing the separability distance value rather than by minimizing the difference between the estimated brain age and the real age. Firstly, set the search range of the deviation as the deviation candidates according to prior knowledge. Secondly, use the support vector regression (SVR) as the age estimation model to minimize the difference between the estimated age and the real age plus deviation rather than the real age itself. Thirdly, design the fitness function based on the separability distance criterion. Fourthly, conduct age estimation on the validation dataset using the trained age estimation model, put the estimated age into the fitness function, and obtain the fitness value of the deviation candidate. Fifthly, repeat the iteration until all the deviation candidates are involved and get the optimal deviation with maximum fitness values. The real age plus the optimal deviation is taken as the brain pathological age. The experimental results showed that the separability was apparently improved. For normal control-Alzheimer’s disease (NC-AD), normal control-mild cognition impairment (NC-MCI), and MCI-AD, the average improvements were 0.178 (35.11%), 0.033 (14.47%), and 0.017 (39.53%), respectively. For NC-MCI-AD, the average improvement was 0.2287 (64.22%). The estimated brain pathological age could be not only more helpful to the classification of AD but also more precisely reflect accelerated brain aging. In conclusion, this paper offers a new method for brain age estimation that can distinguish different states of AD and can better reflect the extent of accelerated aging.

Response of carbon isotopic compositions of Early-Middle Permian coals in North China to palaeo-climate change

NASA Astrophysics Data System (ADS)

Ding, Dianshi; Liu, Guijian; Sun, Xiaohui; Sun, Ruoyu

2018-01-01

To investigate the magnitude to which the carbon isotopic ratio (δ13C) varies in coals in response to their contemporary terrestrial environment, the Early-Middle Permian Huainan coals (including coals from the Shanxi Formation, Lower Shihezi Formation and Upper Shihezi Formation) in North China were systematically sampled. A 2.5‰ variation range of δ13C values (-25.15‰ to -22.65‰) was observed in Huainan coals, with an average value of -24.06‰. As coal diagenesis exerts little influence on carbon isotope fractionation, δ13C values in coals were mainly imparted by those of coal-forming flora assemblages which were linked to the contemporary climate. The δ13C values in coals from the Shanxi and Lower Shihezi Formations are variable, reflecting unstable climatic oscillations. Heavy carbon isotope is enriched in coals of the Capitanian Upper Shihezi Formation, implying a shift to high positive δ13C values of coeval atmospheric CO2. Notably, our study provides evidence of the Kamura event in the terrestrial environment for the first time.

Local and average structure of Mn- and La-substituted BiFeO3

NASA Astrophysics Data System (ADS)

Jiang, Bo; Selbach, Sverre M.

2017-06-01

The local and average structure of solid solutions of the multiferroic perovskite BiFeO3 is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space group symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO3. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions.

Local and average structure of Mn- and La-substituted BiFeO 3

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

Jiang, Bo; Selbach, Sverre M.

2017-06-01

The local and average structure of solid solutions of the multiferroic perovskite BiFeO 3 is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space groupmore » symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO 3. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions.« less

Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks.

PubMed

Khurana, Harpreet Kaur; Cho, Il Kyu; Shim, Jae Yong; Li, Qing X; Jun, Soojin

2008-02-13

Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.

Hexagonal arrays of round-head silicon nanopillars for surface anti-reflection applications

NASA Astrophysics Data System (ADS)

Yan, Wensheng; Dottermusch, Stephan; Reitz, Christian; Richards, Bryce S.

2016-10-01

We designed and fabricated an anti-reflection surface of hexagonal arrays of round-head silicon nanopillars. The measurements show a significant reduction in reflectivity across a broad spectral range. However, we then grew a conformal titanium dioxide coating via atomic layer deposition to achieve an extremely low weighted average reflection of 2.1% over the 460-1040 nm wavelength range. To understand the underlying reasons for the reduced reflectance, the simulations were conducted and showed that it is due to strong forward scattering of incident light into the silicon substrate. The calculated normalized scattering cross section demonstrates a broadband distribution feature, and the peak has a red-shift to longer wavelengths. Finally, we report two-dimensional weighted average reflectance as a function of both wavelength and angle of incidence and present the resulting analysis contour map.

Estimating soil water content from ground penetrating radar coarse root reflections

NASA Astrophysics Data System (ADS)

Liu, X.; Cui, X.; Chen, J.; Li, W.; Cao, X.

2016-12-01

Soil water content (SWC) is an indispensable variable for understanding the organization of natural ecosystems and biodiversity. Especially in semiarid and arid regions, soil moisture is the plants primary source of water and largely determine their strategies for growth and survival, such as root depth, distribution and competition between them. Ground penetrating radar (GPR), a kind of noninvasive geophysical technique, has been regarded as an accurate tool for measuring soil water content at intermediate scale in past decades. For soil water content estimation with surface GPR, fixed antenna offset reflection method has been considered to have potential to obtain average soil water content between land surface and reflectors, and provide high resolution and few measurement time. In this study, 900MHz surface GPR antenna was used to estimate SWC with fixed offset reflection method; plant coarse roots (with diameters greater than 5 mm) were regarded as reflectors; a kind of advanced GPR data interpretation method, HADA (hyperbola automatic detection algorithm), was introduced to automatically obtain average velocity by recognizing coarse root hyperbolic reflection signals on GPR radargrams during estimating SWC. In addition, a formula was deduced to determine interval average SWC between two roots at different depths as well. We examined the performance of proposed method on a dataset simulated under different scenarios. Results showed that HADA could provide a reasonable average velocity to estimate SWC without knowledge of root depth and interval average SWC also be determined. When the proposed method was applied to estimation of SWC on a real-field measurement dataset, a very small soil water content vertical variation gradient about 0.006 with depth was captured as well. Therefore, the proposed method could be used to estimate average soil water content from ground penetrating radar coarse root reflections and obtain interval average SWC between two roots at different depths. It is very promising for measuring root-zone-soil-moisture and mapping soil moisture distribution around a shrub or even in field plot scale.

Analysis of total oil and fatty acids composition by near infrared reflectance spectroscopy in edible nuts

NASA Astrophysics Data System (ADS)

Kandala, Chari V.; Sundaram, Jaya

2014-10-01

Near Infrared (NIR) Reflectance spectroscopy has established itself as an important tool in quantifying water and oil present in various food materials. It is rapid and nondestructive, easier to use, and does not require processing the samples with corrosive chemicals that would render them non-edible. Earlier, the samples had to be ground into powder form before making any measurements. With the development of new soft ware packages, NIR techniques could now be used in the analysis of intact grain and nuts. While most of the commercial instruments presently available work well with small grain size materials such as wheat and corn, the method present here is suitable for large kernel size products such as shelled or in-shell peanuts. Absorbance spectra were collected from 400 nm to 2500 nm using a NIR instrument. Average values of total oil contents (TOC) of peanut samples were determined by standard extraction methods, and fatty acids were determined using gas chromatography. Partial least square (PLS) analysis was performed on the calibration set of absorption spectra, and models were developed for prediction of total oil and fatty acids. The best model was selected based on the coefficient of determination (R2), Standard error of prediction (SEP) and residual percent deviation (RPD) values. Peanut samples analyzed showed RPD values greater than 5.0 for both absorbance and reflectance models and thus could be used for quality control and analysis. Ability to rapidly and nondestructively measure the TOC, and analyze the fatty acid composition, will be immensely useful in peanut varietal improvement as well as in the grading process of grain and nuts.

Sensitivity of Spaceborne and Ground Radar Comparison Results to Data Analysis Methods and Constraints

NASA Technical Reports Server (NTRS)

Morris, Kenneth R.; Schwaller, Mathew

2011-01-01

With the availability of active weather radar observations from space from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TR.MM) satellite, numerous studies have been performed comparing PR reflectivity and derived rain rates to similar observations from ground-based weather radars (GR). These studies have used a variety of algorithms to compute matching PR and GR volumes for comparison. Most studies have used a fixed 3-dimensional Cartesian grid centered on the ground radar, onto which the PR and GR data are interpolated using a proprietary approach and/or commonly available GR analysis software (e.g., SPRINT, REORDER). Other studies have focused on the intersection of the PR and GR viewing geometries either explicitly or using a hybrid of the fixed grid and PR/GR common fields of view. For the Dual-Frequency Precipitation Radar (DPR) of the upcoming Global Precipitation Measurement (GPM) mission, a prototype DPR/GR comparison algorithm based on similar TRMM PR data has been developed that defines the common volumes in terms of the geometric intersection of PR and GR rays, where smoothing of the PR and GR data are minimized and no interpolation is performed. The PR and GR volume-averaged reflectivity values of each sample volume are accompanied by descriptive metadata, for attributes including the variability and maximum of the reflectivity within the sample volume, and the fraction of range gates in the sample average having reflectivity values above an adjustable detection threshold (typically taken to be 18 dBZ for the PR). Sample volumes are further characterized by rain type (Stratiform or Convective), proximity to the melting layer, underlying surface (land/water/mixed), and the time difference between the PR and GR observations. The mean reflectivity differences between the PR and GR can differ between data sets produced by the different analysis methods; and for the GPM prototype, by the type of constraints and categorization applied to the data. In this paper, we will show results comparing the 3-D gridded analysis "black box" approach to the GPM prototype volume-matching approach, using matching TRMM PR and WSR-88D ground radar data. The affects of applying data constraints and data categorizations on the volume-matched data to the results will be shown, and explanations of the differences in terms of data and analysis algorithm characteristics will be presented. Implications of the differences to the determination of PR/DPR calibration differences and use of ground radar data to evaluate the PR and DPR attenuation correction algorithms will be discussed.

A Low-Cost System Based on Image Analysis for Monitoring the Crystal Growth Process.

PubMed

Venâncio, Fabrício; Rosário, Francisca F do; Cajaiba, João

2017-05-31

Many techniques are used to monitor one or more of the phenomena involved in the crystallization process. One of the challenges in crystal growth monitoring is finding techniques that allow direct interpretation of the data. The present study used a low-cost system, composed of a commercial webcam and a simple white LED (Light Emitting Diode) illuminator, to follow the calcium carbonate crystal growth process. The experiments were followed with focused beam reflectance measurement (FBRM), a common technique for obtaining information about the formation and growth of crystals. The images obtained in real time were treated with the red, blue, and green (RGB) system. The results showed a qualitative response of the system to crystal formation and growth processes, as there was an observed decrease in the signal as the growth process occurred. Control of the crystal growth was managed by increasing the viscosity of the test solution with the addition of monoethylene glycol (MEG) at 30% and 70% in a mass to mass relationship, providing different profiles of the RGB average curves. The decrease in the average RGB value became slower as the concentration of MEG was increased; this reflected a lag in the growth process that was proven by the FBRM.

Estimating the recharge properties of the deep ocean using noble gases and helium isotopes

NASA Astrophysics Data System (ADS)

Loose, Brice; Jenkins, William J.; Moriarty, Roisin; Brown, Peter; Jullion, Loic; Naveira Garabato, Alberto C.; Torres Valdes, Sinhue; Hoppema, Mario; Ballentine, Chris; Meredith, Michael P.

2016-08-01

The distribution of noble gases and helium isotopes in the dense shelf waters of Antarctica reflects the boundary conditions near the ocean surface: air-sea exchange, sea ice formation, and subsurface ice melt. We use a nonlinear least squares solution to determine the value of the recharge temperature and salinity, as well as the excess air injection and glacial meltwater content throughout the water column and in the precursor to Antarctic Bottom Water. The noble gas-derived recharge temperature and salinity in the Weddell Gyre are -1.95°C and 34.95 psu near 5500 m; these cold, salty recharge values are a result of surface cooling as well as brine rejection during sea ice formation in Antarctic polynyas. In comparison, the global value for deep water recharge temperature is -0.44°C at 5500 m, which is 1.5°C warmer than the southern hemisphere deep water recharge temperature, reflecting a distinct contribution from the north Atlantic. The contrast between northern and southern hemisphere recharge properties highlights the impact of sea ice formation on setting the gas properties in southern sourced deep water. Below 1000 m, glacial meltwater averages 3.5‰ by volume and represents greater than 50% of the excess neon and argon found in the water column. These results indicate glacial melt has a nonnegligible impact on the atmospheric gas content of Antarctic Bottom Water.

Convective rain rates and their evolution during storms in a semiarid climate

NASA Technical Reports Server (NTRS)

Doneaud, A. A.; Miller, J. R., Jr.; Ionescu-Niscov, S.

1984-01-01

The semiarid climate of the U.S. northern High Plains region has been studied with respect to rain rates and their evolution during summertime convective storms, using radar data from a total of 750 radar echo clusters. Analysis of this data suggests that the average rain rate R among storms is in a first approximation independent of the total rain volume, if the entire storm duration is considered in the averaging process. R primarily depends on the reflectivity threshold considered in calculating the area coverage integrated over the lifetime of the storm. R evolution during storms is analyzed by dividing each storm lifetime into 10 min, 1, 2, and 4 hours, as well as growing and decaying periods. The value of R remained independent of the total rain volume when the growing or decaying periods of storms were considered separately.

Scale Dependence of Spatiotemporal Intermittence of Rain

NASA Technical Reports Server (NTRS)

Kundu, Prasun K.; Siddani, Ravi K.

2011-01-01

It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

A quarter-million years of paleoenvironmental change at Bear Lake, Utah and Idaho

USGS Publications Warehouse

Kaufman, D.S.; Bright, Jordon; Dean, W.E.; Rosenbaum, J.G.; Moser, K.; Anderson, R. Scott; Colman, Steven M.; Heil, C.W.; Jiménez-Moreno, Gonzalo; Reheis, M.C.; Simmons, K.R.

2009-01-01

A continuous, 120-m-long core (BL00-1) from Bear Lake, Utah and Idaho, contains evidence of hydrologic and environmental change over the last two glacial-interglacial cycles. The core was taken at 41.95??N, 111.31??W, near the depocenter of the 60-m-deep, spring-fed, alkaline lake, where carbonate-bearing sediment has accumulated continuously. Chronological control is poor but indicates an average sedimentation rate of 0.54 mm yr-1. Analyses have been completed at multi-centennial to millennial scales, including (in order of decreasing temporal resolution) sediment magnetic properties, oxygen and carbon isotopes on bulk-sediment carbonate, organic- and inorganiccarbon contents, palynology; mineralogy (X-ray diffraction), strontium isotopes on bulk carbonate, ostracode taxonomy, oxygen and carbon isotopes on ostracodes, and diatom assemblages. Massive silty clay and marl constitute most of the core, with variable carbonate content (average = 31 ?? 19%) and oxygen-isotopic values (??18O ranging from -18??? to -5??? in bulk carbonate). These variations, as well as fluctuations of biological indicators, reflect changes in the water and sediment discharged from the glaciated headwaters of the dominant tributary, Bear River, and the processes that influenced sediment delivery to the core site, including lake-level changes. Although its influence has varied, Bear River has remained a tributary to Bear Lake during most of the last quarter-million years. The lake disconnected from the river and, except for a few brief excursions, retracted into a topographically closed basin during global interglaciations (during parts of marine isotope stages 7, 5, and 1). These intervals contain up to 80% endogenic aragonite with high ??18O values (average = -5.8 ?? 1.7???), indicative of strongly evaporitic conditions. Interglacial intervals also are dominated by small, benthic/tychoplanktic fragilarioid species indicative of reduced habitat availability associated with low lake levels, and they contain increased high-desert shrub and Juniperus pollen and decreased forest and forest-woodland pollen. The 87Sr 86Sr values (>0.7100) also increase, and the ratio of quartz to dolomite decreases, as expected in the absence of Bear River in flow. The changing paleoenvironments inferred from BL00-1 generally are consistent with other regional and global records of glacialinterglacial fluctuations; the diversity of paleoenvironmental conditions inferred from BL00-1 also reflects the influence of catchment-scale processes. Copyright ?? 2009 The Geological Society of America.

Stable water isotope patterns in a climate change hotspot: the isotope hydrology framework of Corsica (western Mediterranean).

PubMed

van Geldern, Robert; Kuhlemann, Joachim; Schiebel, Ralf; Taubald, Heinrich; Barth, Johannes A C

2014-06-01

The Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (δP) with values of-8.6(± 0.2) ‰ for δ(18)O and-58(± 2) ‰ for δ(2)H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of-0.17(± 0.02) ‰ per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.

Millennial Scale Rapid Climate Change Events of the last 60kya as Observed in Multiple Stalagmites from The Bahamas

NASA Astrophysics Data System (ADS)

Mehterian, S.; Arienzo, M. M.; Pourmand, A.; Broad, K.; Kakuk, B.; Swart, P. K.

2016-12-01

Nine stalagmites collected from various depths of a submerged cave system on the island of Abaco, Bahamas comprise a continuous record of oxygen isotopic variation between 7.3 to 63kyr. The depths from which the speleothems were collected range from 12m to 37m. The youngest age of the speleothems reflect the inundation of the cave system by rising sea level. Millennial scale rapid climate change events can be seen in the δ18O record of the Bahamian stalagmites as Heinrich Stadials H0 to H6 and Dansgaard Oeschger Events. This collection of stalagmites represents different depths in a cave in Abaco, and their collective geochemical record reflects the global climatic effects as experienced locally in the subtropical islands of the Bahamas. Separately, various stalagmites that grew during the same time periods reflect similar patterns in the δ18O values of their calcite mineralogy despite having been located at vastly different depth elevations relative to each other. In general, the average δ18O value for the stalagmites collected from this cave is -2.5‰ VPDB with a maximum and minimum δ18O value between 0.5 ‰ and -5.5‰ VPDB respectively during Heinrich stadials and D/O events. In addition to δ18O values measured in these stalagmites, ratios of Sr/Ca, Mg/Ca, and Ba/Ca are also compared with one another. This study attempts to elucidate differences, if any, that locations in a cave relative to sea level would have on recording the true climate signals of a region. Finally, results from this study are compared with stalagmites collected from Eleuthera, another Bahamian island with speleothems younger than those from Abaco in order to create a mostly continuous record of rapid climate change events dating back from present day to 63,000 years.

A Pliocene marine diatom δ18O record of terrestrial-marine feedbacks and orbitally-paced cryogenic brine formation in the McMurdo Dry Valleys

NASA Astrophysics Data System (ADS)

Dodd, J. P.; Abbott, T.; Gibbons, J. A.

2017-12-01

Orbital frequencies are well documented in a number of terrestrial and marine climate records throughout the Cenozoic; however, assessing the feedbacks and timing of terrestrial-marine systems on glacial-interglacial timescales is often challenging. This is particularly the case in high-latitude, near-shore environments where traditional proxy records like benthic foraminifera are absent. Here we present oxygen isotope (δ18O and δ17O) values from marine diatom silica in the mid-Pliocene (3.5 - 4.7Ma) section of the AND-1B core from McMurdo Sound, Antarctica. Diatom silica δ18O values range between +28.1 and +36.4‰ VSMOW. Over a range of temperatures (0 to 10°C) that reflect both growth and shallow (<100mbsf) diagenetic conditions, the calculated formation water δ18O values range from -14.7 to -6.7 (± 1.7)‰. The diatom silica δ18O values are in close agreement with the average pore water δ18O values in the nearby AND-2A sediment core of -10 ± 1‰. Pore water chemistry reflects cryogenic brines that formed through progressive freezing of seawater and mirabilite formation. Our calculated pore water δ18O values for the AND-1B core support the cryogenic brine hypothesis, with very low δ18O values during the mid-Pliocene interval. Δ17O values of the biogenic silica reflect formation water that does not fall on a mixing line between marine and meteoric waters, which also supports our cryogenic brine hypothesis. The AND-1B δ18O values have an inverse relationship with the stacked benthic foraminifera δ18O record where lower δ18O values in the AND-1B diatom silica correspond with colder intervals, and we interpret variations in the diatom δ18O values as increased brine flux from the MDV to McMurdo Sound. Currently, subsurface brines in the MDV are hydrologically connected with McMurdo Sound. Density-driven transport of these brines from the MDV to the marine costal environments during the warm mid-Pliocene indicate a potentially overlooked terrestrial source of hypersaline waters. Although the lateral extent of these brines is not known, mixing between the terrestrial cryogenic brines and seawater may represent a significant flux of hypersaline water to the marine environment during warmer-than-present global conditions.

Determination of Residual Stress Distributions in Polycrystalline Alumina using Fluorescence Microscopy

PubMed Central

Michaels, Chris A.; Cook, Robert F.

2016-01-01

Maps of residual stress distributions arising from anisotropic thermal expansion effects in a polycrystalline alumina are generated using fluorescence microscopy. The shifts of both the R1 and R2 ruby fluorescence lines of Cr in alumina are used to create maps with sub-µm resolution of either the local mean and shear stresses or local crystallographic a- and c-stresses in the material, with approximately ± 1 MPa stress resolution. The use of single crystal control materials and explicit correction for temperature and composition effects on line shifts enabled determination of the absolute values and distributions of values of stresses. Temperature correction is shown to be critical in absolute stress determination. Experimental determinations of average stress parameters in the mapped structure are consistent with assumed equilibrium conditions and with integrated large-area measurements. Average crystallographic stresses of order hundreds of MPa are determined with characteristic distribution widths of tens of MPa. The stress distributions reflect contributions from individual clusters of stress in the structure; the cluster size is somewhat larger than the grain size. An example application of the use of stress maps is shown in the calculation of stress-intensity factors for fracture in the residual stress field. PMID:27563163

Simulated color: a diagnostic tool for skin lesions like port-wine stain

NASA Astrophysics Data System (ADS)

Randeberg, Lise L.; Svaasand, Lars O.

2001-05-01

A device independent method for skin color visualization has been developed. Colors reconstructed from a reflectance spectrum are presented on a computer screen by sRGB (standard Red Green Blue) color coordinates. The colors are presented as adjacent patches surrounded by a medium grey border. CIELAB color coordinates and CIE (International Commission on Illumination) color difference (Delta) E are computed. The change in skin color due to a change in average blood content or scattering properties in dermis is investigated. This is done by analytical simulations based on the diffusion approximation. It is found that an 11% change in average blood content and a 15% change in scattering properties will give a visible color change. A supposed visibility limit for (Delta) E is given. This value is based on experimental testing and the known properties of the human visual system. This limit value can be used as a tool to determine when to terminate laser treatment of port- wine stain due to low treatment response, i.e. low (Delta) E between treatments. The visualization method presented seems promising for medical applications as port-wine stain diagnostics. The method gives good possibilities for electronic transfer of data between clinics because it is device independent.

Analysis of In-Situ Spectral Reflectance of Sago and Other Palms: Implications for Their Detection in Optical Satellite Images

NASA Astrophysics Data System (ADS)

Rendon Santillan, Jojene; Makinano-Santillan, Meriam

2018-04-01

We present a characterization, comparison and analysis of in-situ spectral reflectance of Sago and other palms (coconut, oil palm and nipa) to ascertain on which part of the electromagnetic spectrum these palms are distinguishable from each other. The analysis also aims to reveal information that will assist in selecting which band to use when mapping Sago palms using the images acquired by these sensors. The datasets used in the analysis consisted of averaged spectral reflectance curves of each palm species measured within the 345-1045 nm wavelength range using an Ocean Optics USB4000-VIS-NIR Miniature Fiber Optic Spectrometer. This in-situ reflectance data was also resampled to match the spectral response of the 4 bands of ALOS AVNIR-2, 3 bands of ASTER VNIR, 4 bands of Landsat 7 ETM+, 5 bands of Landsat 8, and 8 bands of Worldview-2 (WV2). Examination of the spectral reflectance curves showed that the near infra-red region, specifically at 770, 800 and 875 nm, provides the best wavelengths where Sago palms can be distinguished from other palms. The resampling of the in-situ reflectance spectra to match the spectral response of optical sensors made possible the analysis of the differences in reflectance values of Sago and other palms in different bands of the sensors. Overall, the knowledge learned from the analysis can be useful in the actual analysis of optical satellite images, specifically in determining which band to include or to exclude, or whether to use all bands of a sensor in discriminating and mapping Sago palms.

Using Ancient Glacial Diamictites to Track the Compositional Evolution of the Upper Continental Crust

NASA Astrophysics Data System (ADS)

Gaschnig, R. M.; Rudnick, R. L.; McDonough, W. F.; Kaufman, A. J.; Valley, J. W.; Hu, Z.; Gao, S.

2014-12-01

V.M. Goldschmidt (1933) first suggested the use of Quaternary glacial till and loess to determine the average composition of the upper continental crust (UCC). We extend this approach back in time through the geochemical study of glacial diamictites from intervals of continental glaciation in the Paleozoic, Neoproterozoic, Paleoproterozoic, and Mesoarchean. The diamictites record fundamental changes in the bulk composition of UCC through time, with the largest change occurring at the end of the Archean. Post-Archean diamictites have progressively lower Eu/Eu* and concentrations of 1st row transition metals (Sc, Cr, V, Ni, Co) and higher Th and U concentrations. δ18O whole-rock values steadily increase through the Precambrian, with average values of 6.0 ± 1.6, 8.3 ± 0.4, 12.3 ± 0.9 per mil for the Mesoarchean, Paleoproterozoic, and Neoproterozoic, respectively. All of these trends are consistent with production of a progressively more evolved UCC, which may reflect changes in the composition of primary crustal melts, as well as a change in the nature of intracrustal differentiation. Subtle increases in Lu/Hf through time imply the continual addition of juvenile crust from an increasingly depleted mantle reservoir, consistent with continuous continental growth rather than an Armstrong-like no-growth model, and suggesting that intracrustal differentiation is unlikely to be the sole driver of the other trends. In addition to these uni-directional trends, Paleoproterozoic diamictites, which are dominated by 2.8 to 2.6 Ga provenance, show unique chemical characteristics (e.g., lowest Nb/Ta and highest La/Lu and Th/Nb). These features may reflect a distinctive geodynamic setting for the Neoarchean period, which was arguably the largest pulse of crustal growth in Earth's history and was also accompanied by widespread cratonization.

Thermal/optical methods for elemental carbon quantification in soils and urban dusts: equivalence of different analysis protocols.

PubMed

Han, Yongming; Chen, Antony; Cao, Junji; Fung, Kochy; Ho, Fai; Yan, Beizhan; Zhan, Changlin; Liu, Suixin; Wei, Chong; An, Zhisheng

2013-01-01

Quantifying elemental carbon (EC) content in geological samples is challenging due to interferences of crustal, salt, and organic material. Thermal/optical analysis, combined with acid pretreatment, represents a feasible approach. However, the consistency of various thermal/optical analysis protocols for this type of samples has never been examined. In this study, urban street dust and soil samples from Baoji, China were pretreated with acids and analyzed with four thermal/optical protocols to investigate how analytical conditions and optical correction affect EC measurement. The EC values measured with reflectance correction (ECR) were found always higher and less sensitive to temperature program than the EC values measured with transmittance correction (ECT). A high-temperature method with extended heating times (STN120) showed the highest ECT/ECR ratio (0.86) while a low-temperature protocol (IMPROVE-550), with heating time adjusted for sample loading, showed the lowest (0.53). STN ECT was higher than IMPROVE ECT, in contrast to results from aerosol samples. A higher peak inert-mode temperature and extended heating times can elevate ECT/ECR ratios for pretreated geological samples by promoting pyrolyzed organic carbon (PyOC) removal over EC under trace levels of oxygen. Considering that PyOC within filter increases ECR while decreases ECT from the actual EC levels, simultaneous ECR and ECT measurements would constrain the range of EC loading and provide information on method performance. Further testing with standard reference materials of common environmental matrices supports the findings. Char and soot fractions of EC can be further separated using the IMPROVE protocol. The char/soot ratio was lower in street dusts (2.2 on average) than in soils (5.2 on average), most likely reflecting motor vehicle emissions. The soot concentrations agreed with EC from CTO-375, a pure thermal method.

Bayesian aerosol retrieval algorithm for MODIS AOD retrieval over land

NASA Astrophysics Data System (ADS)

Lipponen, Antti; Mielonen, Tero; Pitkänen, Mikko R. A.; Levy, Robert C.; Sawyer, Virginia R.; Romakkaniemi, Sami; Kolehmainen, Ville; Arola, Antti

2018-03-01

We have developed a Bayesian aerosol retrieval (BAR) algorithm for the retrieval of aerosol optical depth (AOD) over land from the Moderate Resolution Imaging Spectroradiometer (MODIS). In the BAR algorithm, we simultaneously retrieve all dark land pixels in a granule, utilize spatial correlation models for the unknown aerosol parameters, use a statistical prior model for the surface reflectance, and take into account the uncertainties due to fixed aerosol models. The retrieved parameters are total AOD at 0.55 µm, fine-mode fraction (FMF), and surface reflectances at four different wavelengths (0.47, 0.55, 0.64, and 2.1 µm). The accuracy of the new algorithm is evaluated by comparing the AOD retrievals to Aerosol Robotic Network (AERONET) AOD. The results show that the BAR significantly improves the accuracy of AOD retrievals over the operational Dark Target (DT) algorithm. A reduction of about 29 % in the AOD root mean square error and decrease of about 80 % in the median bias of AOD were found globally when the BAR was used instead of the DT algorithm. Furthermore, the fraction of AOD retrievals inside the ±(0.05+15 %) expected error envelope increased from 55 to 76 %. In addition to retrieving the values of AOD, FMF, and surface reflectance, the BAR also gives pixel-level posterior uncertainty estimates for the retrieved parameters. The BAR algorithm always results in physical, non-negative AOD values, and the average computation time for a single granule was less than a minute on a modern personal computer.

Nordic Sea Level - Analysis of PSMSL RLR Tide Gauge data

NASA Astrophysics Data System (ADS)

Knudsen, Per; Andersen, Ole

2015-04-01

Tide gauge data from the Nordic region covering a period of time from 1920 to 2000 are evaluated. 63 stations having RLR data for at least 40 years have been used. Each tide gauge data record was averaged to annual averages after the monthly average seasonal anomalies were removed. Some stations lack data, especially before around 1950. Hence, to compute representative sea level trends for the 1920-2000 period a procedure for filling in estimated sea level values in the voids, is needed. To fill in voids in the tide gauge data records a reconstruction method was applied that utilizes EOF.s in an iterative manner. Subsequently the trends were computed. The estimated trends range from about -8 mm/year to 2 mm/year reflecting both post-glacial uplift and sea level rise. An evaluation of the first EOFs show that the first EOF clearly describes the trends in the time series. EOF #2 and #3 describe differences in the inter-annual sea level variability with-in the Baltic Sea and differences between the Baltic and the North Atlantic / Norwegian seas, respectively.

Impulse radar studfinder

DOEpatents

McEwan, Thomas E.

1995-01-01

An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes.

Impulse radar studfinder

DOEpatents

McEwan, T.E.

1995-10-10

An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes. 9 figs.

Ultra-wideband radar motion sensor

DOEpatents

McEwan, Thomas E.

1994-01-01

A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion.

Ultra-wideband radar motion sensor

DOEpatents

McEwan, T.E.

1994-11-01

A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.

Numerical reproduction and explanation of road surface mirages under grazing-angle scattering.

PubMed

Lu, Jia; Zhou, Huaichun

2017-07-01

The mirror-like reflection image of the road surface under grazing-angle scattering can be easily observed in daily life. It was suggested that road surface mirages may occur due to a light-enhancing effect of the rough surface under grazing-angle scattering. The main purpose of this work is to explain the light-enhancing mechanism of rough surfaces under grazing-angle scattering. The off-specular reflection from a random rough magnesium oxide ceramic surface is analyzed by using the geometric optics approximation method. Then, the geometric optics approximation method is employed to develop a theoretical model to predict the observation effect of the grazing-angle scattering phenomenon of the road surface. The rough surface is assumed to consist of small-scale rough surface facets. The road surface mirage is reproduced from a large number of small-scale rough surface facets within the eye's resolution limit at grazing scattering angles, as the average bidirectional reflectance distribution function value at the bright location is about twice that of the surface in front of the mirage. It is suggested that the light-enhancing effect of the rough surface under grazing-angle scattering is not proper to be termed as "off-specular reflection," since it has nothing to do with the "specular" direction with respect to the incident direction.

Modeling the photoacoustic signal during the porous silicon formation

NASA Astrophysics Data System (ADS)

Ramirez-Gutierrez, C. F.; Castaño-Yepes, J. D.; Rodriguez-García, M. E.

2017-01-01

Within this work, the kinetics of the growing stage of porous silicon (PS) during the etching process was studied using the photoacoustic technique. A p-type Si with low resistivity was used as a substrate. An extension of the Rosencwaig and Gersho model is proposed in order to analyze the temporary changes that take place in the amplitude of the photoacoustic signal during the PS growth. The solution of the heat equation takes into account the modulated laser beam, the changes in the reflectance of the PS-backing heterostructure, the electrochemical reaction, and the Joule effect as thermal sources. The model includes the time-dependence of the sample thickness during the electrochemical etching of PS. The changes in the reflectance are identified as the laser reflections in the internal layers of the system. The reflectance is modeled by an additional sinusoidal-monochromatic light source and its modulated frequency is related to the velocity of the PS growth. The chemical reaction and the DC components of the heat sources are taken as an average value from the experimental data. The theoretical results are in agreement with the experimental data and hence provided a method to determine variables of the PS growth, such as the etching velocity and the thickness of the porous layer during the growing process.

Properties of Hail Storms over China and the United States from the Tropical Rainfall Measuring Mission

NASA Technical Reports Server (NTRS)

Ni, Xiang; Liu, Chuntao; Zhang, Qinghong; Cecil, Daniel J.

2016-01-01

A 16-yr record of hail reports over the southeast US and from weather stations in China are collocated with Precipitation Features (PF) derived from the Tropical Rainfall Measurement Mission (TRMM) radar and passive microwave observations. While U.S. hail reports are dominated by cases with hail size greater than 19 mm, hail reports in China mostly include diameters of 1-10 nm and mostly occur over the Tibetan Plateau. The fraction of PFs collocated with hail reports (hail PFs) reaches 3% in the plains of the U.S. In China, the fraction is higher in high elevation regions than low elevation regions. Hail PFs in the U.S. show lower brightness temperatures, higher lightning flash rates, stronger maximum reflectivity, and higher echo tops than those in China, consistent with the larger hail diameters in the U.S. reports. The average near surface maximum reflectivity of hail PFs at higher elevations (greater than or equal to 2000 m) in China is about 5 dB smaller than those at low elevations. Larger hail is reported with PFs having stronger maximum reflectivity above 6 km, though the median of maximum reflectivity values at levels below 5 km is close among the storms with large and small hail sizes.

Diffuse reflectance of TiO 2 pigmented paints: Spectral dependence of the average pathlength parameter and the forward scattering ratio

NASA Astrophysics Data System (ADS)

Vargas, William E.; Amador, Alvaro; Niklasson, Gunnar A.

2006-05-01

Diffuse reflectance spectra of paint coatings with different pigment concentrations, normally illuminated with unpolarized radiation, have been measured. A four-flux radiative transfer approach is used to model the diffuse reflectance of TiO2 (rutile) pigmented coatings through the solar spectral range. The spectral dependence of the average pathlength parameter and of the forward scattering ratio for diffuse radiation, are explicitly incorporated into this four-flux model from two novel approximations. The size distribution of the pigments has been taken into account to obtain the averages of the four-flux parameters: scattering and absorption cross sections, forward scattering ratios for collimated and isotropic diffuse radiation, and coefficients involved in the expansion of the single particle phase function in terms of Legendre polynomials.

Application of a Threshold Method to Airborne-Spaceborne Attenuating-Wavelength Radars for the Estimation of Space-Time Rain-Rate Statistics.

NASA Astrophysics Data System (ADS)

Meneghini, Robert

1998-09-01

A method is proposed for estimating the area-average rain-rate distribution from attenuating-wavelength spaceborne or airborne radar data. Because highly attenuated radar returns yield unreliable estimates of the rain rate, these are eliminated by means of a proxy variable, Q, derived from the apparent radar reflectivity factors and a power law relating the attenuation coefficient and the reflectivity factor. In determining the probability distribution function of areawide rain rates, the elimination of attenuated measurements at high rain rates and the loss of data at light rain rates, because of low signal-to-noise ratios, leads to truncation of the distribution at the low and high ends. To estimate it over all rain rates, a lognormal distribution is assumed, the parameters of which are obtained from a nonlinear least squares fit to the truncated distribution. Implementation of this type of threshold method depends on the method used in estimating the high-resolution rain-rate estimates (e.g., either the standard Z-R or the Hitschfeld-Bordan estimate) and on the type of rain-rate estimate (either point or path averaged). To test the method, measured drop size distributions are used to characterize the rain along the radar beam. Comparisons with the standard single-threshold method or with the sample mean, taken over the high-resolution estimates, show that the present method usually provides more accurate determinations of the area-averaged rain rate if the values of the threshold parameter, QT, are chosen in the range from 0.2 to 0.4.

Cycling of Volatiles and Stable Isotopes During High-P Subduction Dehydration of Serpentinite

NASA Astrophysics Data System (ADS)

Alt, J.; Garrido, C. J.; Shanks, W. C.; Turchyn, A. V.; López-Sánchez-Vizcaíno, V.; Gómez-Pugnaire, M.

2009-12-01

We present volatile contents and stable isotope compositions of high-P antigorite serpentinites and their chlorite-harzburgite dehydration products from the Cerro del Almirez complex, Spain. The serpentinites are former Tethyan seafoor consisting of antigorite with olivine, diopside, chlorite, magnetite, tremolite, and Ti-clinohumite, dehydrated to chlorite-harzburites comprising spinifex-like olivine + orthopyroxene, with chlorite, tremolite, and magnetite, at T> 650°C and P>2 GPa. The serpentinites have elevated H2O, S, and C contents, averaging (n=10) 1000 ppm S and 10 wt% H2O, and with 180-1280 ppm total C. Bulk δ18O values of 7.9-9.1‰ and δD= -49 to -61‰ are consistent with serpentinization by seawater at 50-100°C. The high sulfide contents and preliminary δ34S analyses of ~10‰ likely reflect microbial reduction of seawater sulfate, and δ13C (total C) values of -10.9 to -20.2‰ are consistent with the presence of an organic carbon component. These data and processes are similar to those for modern seafloor serpentinites. High-P dehydration of the serpentinites resulted in loss of about half of their H2O and S: chlorite-harzburgites (n=11) average 5.7 wt% H2O and 610 ppm S. The δ34S (-5.1 to 10.2‰) and δ18O (6.4-9.5‰) of the metamorphic harzburgites are unchanged from serpentinite, but hydrogen isotopes are fractionated during dehydration, from serpentinite δD values around -55‰ to chlorite-harzburgite values of ~ -70 to -90‰. Carbon contents and δ13C values of the two rock types overlap, with a broad trend of decreasing C contents and δ13C, from ~1200 to 200 ppm and -9.6 to -20.3‰, perhaps reflecting loss of CO2. Our results indicate: 1) significant uptake of H2O, S and C during serpentinization on the seafloor; 2) that recycling of serpentinites to high P and T results in loss of isotopically fractionated sulfur, water and possibly carbon to the sub-arc mantle; and 3) that fractionated sulfur, water and carbon in serpentinite dehydration products can be recycled into the mantle where they can contribute to isotope heterogeneities.

Potential oxidative stress in the bodies of electric arc welding operators: effect of photochemical smog.

PubMed

Zhu, You-Gen; Zhou, Jun-Fu; Shan, Wei-Ying; Zhou, Pei-Su; Tong, Gui-Zhong

2004-12-01

To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators. Seventy electric arc welding operators (WOs) and 70 healthy volunteers (HVs) were enrolled in a randomized controlled study design, in which the levels of vitamin C (VC) and vitamin E (VE) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and the level of lipoperoxide (LPO) in erythrocytes were determined by spectrophotometry. Compared with the average values of the above experimental parameters in the HVs group, the average values of VC and VE in plasma as well as those of SOD, CAT and GPX in erythrocytes in the WOs group were significantly decreased (P < 0.005-0.0001), while the average value of LPO in erythrocytes in the WOs group was significantly increased (P < 0.0001). The findings from the partial correlation analysis on the controlling of age suggested that with a prolonged duration of exposure to photochemical smog the values of VC, VE, SOD, and GPX, except for CAT, in the WOs were decreased gradually (P < 0.05-0.005), the value of LPO in the WOs was increased gradually (P < 0.001), and that with the ozone dose increased in the air in each worksite VC, VE, SOD, CAT and GPX decreased (P < 0.005-0.001), but LPO increased (P < 0.001). The findings from the reliability analysis for the VC, VE, SOD, CAT, GPX, and LPO values which were used to reflect oxidative stress and potential oxidative damage in the WOs showed that the reliability coefficients' alpha (6 items) was 0.8021, P < 0.0001, and that the standardized item alpha was 0.9577, P < 0.0001. Findings in the present study suggest that there exists an oxidative stress induced by long-term exposure to photochemical smog in the bodies of WOs, thereby causing potential oxidative and lipoperoxidative damages in their bodies.

Silurian carbonate high-energy deposits of potential tsunami origin: Distinguishing lateral redeposition and time averaging using carbon isotope chemostratigraphy

NASA Astrophysics Data System (ADS)

Jarochowska, Emilia; Munnecke, Axel

2015-01-01

Stable carbon isotope curves are used as a precise stratigraphic tool in the Paleozoic, even though they are commonly based on shallow-water carbonate record, characterized by low stratigraphic completeness. Identification of episodes of large-scale redeposition and erosion may improve δ13Ccarb-based correlations. Here, a series of at least three episodes of high-energy onshore redeposition are described from the Makarivka Member (new unit) of the Ustya Formation from the Homerian (middle Silurian) of Podolia, Ukraine. The Makarivka Member is emplaced within a tidal flat succession. Its most prominent part is divided into a lower polymictic conglomerate of sand- to boulder-sized clasts representing a range of subtidal facies, and an upper heterolithic unit composed of grainstone and mudstone laminae. The aim of the study is to identify the mechanism of deposition of the allochthonous conglomeratic material in this Member. Based on analogies with recent tsunami deposits, the conglomerate is interpreted to reflect the strongest landward-directed current in the tsunami run-up phase, and the heterolith - alternating high-density landward currents, stagnant intervals allowing mud and land-derived debris to settle, and backwash flows. The tsunamite was deposited during an interval of decreasing isotopic values of the Mulde excursion, a global δ13C excursion reaching + 5.2‰ in the studied sections. Clast redeposition in an interval characterized by rapidly changing δ13Ccarb offers the opportunity to evaluate the degree of temporal and spatial averaging caused by the tsunami. The clasts in the polymictic conglomerate show scattered δ13Ccarb values (- 0.3‰ to + 2.1‰) compared to homogenous (1.3‰ to 1.6‰) values in the matrix. The presence of clasts characterized by low δ13Ccarb values is explained by their decrease with bathymetry rather than erosion of pre-excursion strata, whereas high values characterize material entrained from the sea-floor and strata directly underlying the tsunamite. Close (1.3‰ and 1.5‰) average δ13Ccarb values suggest that the matrix of the conglomerate is potentially a product of clast grinding.

It's not just average faces that are attractive: computer-manipulated averageness makes birds, fish, and automobiles attractive.

PubMed

Halberstadt, Jamin; Rhodes, Gillian

2003-03-01

Average faces are attractive. We sought to distinguish whether this preference is an adaptation for finding high-quality mates (the direct selection account) or whether it reflects more general information-processing mechanisms. In three experiments, we examined the attractiveness of birds, fish, and automobiles whose averageness had been manipulated using digital image manipulation techniques common in research on facial attractiveness. Both manipulated averageness and rated averageness were strongly associated with attractiveness in all three stimulus categories. In addition, for birds and fish, but not for automobiles, the correlation between subjective averageness and attractiveness remained significant when the effect of subjective familiarity was partialled out. The results suggest that at least two mechanisms contribute to the attractiveness of average exemplars. One is a general preference for familiar stimuli, which contributes to the appeal of averageness in all three categories. The other is a preference for averageness per se, which was found for birds and fish, but not for automobiles, and may reflect a preference for features signaling genetic quality in living organisms, including conspecifics.

Measuring Changes in Salaries and Wages in Public Schools: A Basic Handbook. ERS School Management Reference Series.

ERIC Educational Resources Information Center

Educational Research Service, Arlington, VA.

A new statistical measure termed the Composite Indicator of Changes (CIC) reflects overall changes in average salaries and wages paid by public school systems in much the same way that the Dow-Jones averages reflect price changes in the stock market. The CIC is useful for comparing salary trends among various categories of personnel, among…

The contribution of testosterone to skeletal development and maintenance: lessons from the androgen insensitivity syndrome.

PubMed

Marcus, R; Leary, D; Schneider, D L; Shane, E; Favus, M; Quigley, C A

2000-03-01

Although androgen status affects bone mass in women and men, an androgen requirement for skeletal normalcy has not been established. Women with androgen insensitivity syndrome (AIS) have 46,XY genotypes with androgen receptor abnormalities rendering them partially or completely refractory to androgen. Twenty-eight women with AIS (22 complete and 6 high grade partial), aged 11-65 yr, responded to questionnaires about health history, gonadal surgery, and exogenous estrogen use and underwent bone mineral density (BMD) assessment by dual energy x-ray absortiometry. BMD values at the lumbar spine and proximal femur were compared to age-specific female normative values and listed as z-scores. Average height for adults in this cohort, 174 cm (68.5 in.), was moderately increased compared with the average height of adult American women of 162.3 cm, with skewing toward higher values: 5 women exceeded 6 ft in height, and 30% of the 18 adult women with complete AIS exceeded 5 ft, 11 in. in height. The average lumbar spine and hip BMD z-scores of the 6 women with partial AIS did not differ from population norms. In contrast, the average lumbar spine BMD z-score of women with complete AIS was significantly reduced at -1.08 (P = 0.0003), whereas the average value for hip BMD did not differ from normal. When BMD was compared between women who reported good estrogen replacement therapy compliance and those who reported poor compliance, there was a significantly greater deficit at the spine for women with poor compliance (z = -2.15 +/- 0.15 vs. -0.75 +/- 0.28; P < .0001). Furthermore, hip BMD was also significantly reduced in the noncompliant group (z = -0.95 +/- .40). Comparison of BMD values to normative male standards gave z-score reductions (z = -1.81 +/- 0.36) greater than those observed with female standards. Because of the high prevalence of tall stature in this study sample, we calculated bone mineral apparent density, a variable that adjusts for differences in bone size. Even for the estrogen-compliant group, bone mineral apparent density z-scores were subnormal at both the spine (z = -1.3 +/- 0.43; P < 0.01) and the hip (z = -1.38 +/- 0.28; P = 0.017). Six women with complete AIS had sustained cortical bone fractures, of whom 3 reported multiple (>3) fractures. We conclude that even when compliance to exogenous estrogen use is excellent, women with complete AIS show moderate deficits in spine BMD, averaging close to 1 SD from normative means, and that with correction of BMD for bone size, skeletal deficits are magnified and include the proximal femur. The results suggest that severe osteopenia in some women with AIS probably reflects a component of inadequate estrogen replacement rather than androgen lack alone.

Comparison and optimization of radar-based hail detection algorithms in Slovenia

NASA Astrophysics Data System (ADS)

Stržinar, Gregor; Skok, Gregor

2018-05-01

Four commonly used radar-based hail detection algorithms are evaluated and optimized in Slovenia. The algorithms are verified against ground observations of hail at manned stations in the period between May and August, from 2002 to 2010. The algorithms are optimized by determining the optimal values of all possible algorithm parameters. A number of different contingency-table-based scores are evaluated with a combination of Critical Success Index and frequency bias proving to be the best choice for optimization. The best performance indexes are given by Waldvogel and the severe hail index, followed by vertically integrated liquid and maximum radar reflectivity. Using the optimal parameter values, a hail frequency climatology map for the whole of Slovenia is produced. The analysis shows that there is a considerable variability of hail occurrence within the Republic of Slovenia. The hail frequency ranges from almost 0 to 1.7 hail days per year with an average value of about 0.7 hail days per year.

Joint influences of individual and work unit abusive supervision on ethical intentions and behaviors: a moderated mediation model.

PubMed

Hannah, Sean T; Schaubroeck, John M; Peng, Ann C; Lord, Robert G; Trevino, Linda K; Kozlowski, Steve W J; Avolio, Bruce J; Dimotakis, Nikolaos; Doty, Joseph

2013-07-01

We develop and test a model based on social cognitive theory (Bandura, 1991) that links abusive supervision to followers' ethical intentions and behaviors. Results from a sample of 2,572 military members show that abusive supervision was negatively related to followers' moral courage and their identification with the organization's core values. In addition, work unit contexts with varying degrees of abusive supervision, reflected by the average level of abusive supervision reported by unit members, moderated relationships between the level of abusive supervision personally experienced by individuals and both their moral courage and their identification with organizational values. Moral courage and identification with organizational values accounted for the relationship between abusive supervision and followers' ethical intentions and unethical behaviors. These findings suggest that abusive supervision may undermine moral agency and that being personally abused is not required for abusive supervision to negatively influence ethical outcomes. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Writing, self-reflection, and medical school performance: the Human Context of Health Care.

PubMed

Stephens, Mark B; Reamy, Brian V; Anderson, Denise; Olsen, Cara; Hemmer, Paul A; Durning, Steven J; Auster, Simon

2012-09-01

Finding ways to improve communication and self-reflection skills is an important element of medical education and continuing professional development. This study examines the relationship between self-reflection and educational outcomes. We correlate performance in a preclinical course that focuses on self-reflection as it relates to contextual elements of patient care (Human Context of Health Care), with educational measures such as overall grade point average, clinical clerkship scores, and Medical College Admission Test (MCAT) scores. Student performance in Human Context of Health Care correlated with MCAT-Verbal scores, MCAT-writing sample scores, clerkship grades, and overall medical school grade point average (R = 0.3; p < 0.001). Writing and self-reflection skills are often neglected in undergraduate medical curricula. Our findings suggest that these skills are important and correlate with recognized long-term educational outcomes.

Stable hydrogen isotopic composition of n-alkanes in atmospheric aerosols as a tracer for the source region of terrestrial plant waxes

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Kawamura, K.

2009-12-01

Studies on molecular composition and compound-specific carbon isotopic ratio (δ13C) of leaf wax n-alkanes in atmospheric aerosols have revealed a long-range atmospheric transport of terrestrial higher plant materials over the south Atlantic and western Pacific oceans. However, molecular and δ13C compositions of terrestrial plant waxes in the eastern part of the Asian continent are relatively constant reflecting C3-dominated vegetation, which makes it difficult to specify the source regions of plant materials in the atmospheric aerosols over the East Asia and northwest Pacific regions. Recent observation displays a large (>100‰) spatial variation in hydrogen isotopic composition (δD) of rainwater in East Asia. Because δD values of terrestrial higher plants sensitively reflect those of precipitation waters, δD of leaf waxes are expected to provide information on their source region. In this study, we measured the δD of n-alkanes in atmospheric aerosols from Tokyo to better understand the origin of leaf wax n-alkanes in atmospheric aerosols. The δD values of fossil fuel n-alkanes (C21 to C24) in Tokyo aerosols range from -65 to -94‰, which are in a range of those reported in marine crude oils. In contrast, the δD of higher molecular weight (C29 and C31) n-alkanes (δDHMW) show much larger values by ~70‰ than those of fossil fuel n-alkanes. Their values were found to exhibit concomitant variations with carbon preference index (CPI), suggesting that the δDHMW reflect the δD of leaf wax n-alkanes with a variable contribution from fossil fuel n-alkanes. Nevertheless, good positive correlation (r = 0.89, p < 0.01) between the δDHMW and CPI values enable us to remove the contribution of fossil fuels using a mass balance approach by assuming that CPI of fossil fuel is 1 and CPI of plant waxes is 5-15. Calculated n-alkane δD values averaged from -170 to -185‰ for C29 and from -155 to -168‰ for C31. These values are consistent with those reported from growing leaves in Tokyo, which confirms the usefulness of the δD of long chain n-alkanes as a tracer for the source region of terrestrial plant waxes in atmospheric aerosols.

Preparation and characterization of Ba0.2Sr0.2La0.6MnO3 nanoparticles and investigation of size & shape effect on microwave absorption

NASA Astrophysics Data System (ADS)

Peymanfar, Reza; Javanshir, Shahrzad

2017-06-01

In this paper, the design and characterization of a radar absorbing material (RAM) was investigated at microwave frequency. Ba0.2Sr0.2La0.6MnO3 magnetic nanoparticles was synthesized thru a facile hydrothermal method in the presence of polymethyl methacrylate (PMMA) and the possibility of shape and size-controlled synthesis of nanoparticles (NPs) over the range 15-50 Nm was also explored. Afterward, the effect of shape and size of the synthesized Ba0.2Sr0.2La0.6MnO3 NPs on microwave absorption properties was investigated in KU-band. The crystal structures and morphology of as-synthesized nanoparticles were characterized and confirmed by FESEM, XRD, VSM, FTIR analysis. The RAM samples were prepared by dispersion of magnetic NPs in silicone rubber in an ultrasonic bath. The maximum reflection loss (RL) values NPs were 12.04 dB at 14.82 GHz and a broad absorption band (over 1.22 GHz) with RL values <-10 dB are obtained and the maximum reflection loss (RL) values of decrease and shaped NPs were 22.36 dB at 14.78 GHz and a broad absorption band (over 2.67 GHz) with RL values <-10 dB are obtained. The results indicated that the particle size and shape play a major role on the absorption properties of the composites in the 12.4-18 GHz frequency range. It is observed that microwave absorption properties increased with the decrease in average particle size of NPs.

NEUTRON DIFFRACTION INVESTIGATIONS OF FERROMAGNETIC PALLADIUM AND IRON GROUP ALLOYS

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

Cable, J.W.; Wollan, E.O.; Koehler, W.C.

1962-03-01

In order to account for the magnetic properties of alloys It becomes important to determine the individual magnetic moments of the constituent atoms. This determination can be accomplished by means of neutron diffraction and magnetic induction measurements. Such measurements are made on the ferromagnetic alloys Pd/sub 3/Fe, PdFe, Pd/sub 3/Co, PdCo, Ni/sub 3/Co, and NiCo. The average moment values are obtained from magnetic induction measurements while the differences in the atomic moments are determined from either the ferromagnetic diffuse scattering by the disordered alloys or the superlattice reflections by the ordered alloys. (auth)

Global shortwave energy budget at the earth's surface from ERBE observations

NASA Technical Reports Server (NTRS)

Breon, Francois-Marie; Frouin, Robert

1994-01-01

A method is proposed to compute the net solar (shortwave) irradiance at the earth's surface from Earth Radiation Budget Experiment (ERBE) data in the S4 format. The S4 data are monthly averaged broadband planetary albedo collected at selected times during the day. Net surface shortwave irradiance is obtained from the shortwave irradiance incident at the top of the atmosphere (known) by subtracting both the shortwave energy flux reflected by the earth-atmosphere system (measured) and the energy flux absorbed by the atmosphere (modeled). Precalculated atmospheric- and surface-dependent functions that characterize scattering and absorption in the atmosphere are used, which makes the method easily applicable and computationally efficient. Four surface types are distinguished, namely, ocean, vegetation, desert, and snow/ice. Over the tropical Pacific Ocean, the estimates based on ERBE data compare well with those obtained from International Satellite Cloud Climatology Project (ISCCP) B3 data. For the 9 months analyzed the linear correlation coefficient and the standard difference between the two datasets are 0.95 and 14 W/sq m (about 6% of the average shortwave irradiance), respectively, and the bias is 15 W/sq m (higher ERBE values). The bias, a strong function of ISCCP satellite viewing zenith angle, is mostly in the ISCCP-based estimates. Over snow/ice, vegetation, and desert no comparison is made with other satellite-based estimates, but theoretical calculations using the discrete ordinate method suggest that over highly reflective surfaces (snow/ice, desert) the model, which accounts crudely for multiple reflection between the surface and clouds, may substantially overestimate the absorbed solar energy flux at the surface, especially when clouds are optically thick. The monthly surface shortwave irradiance fields produced for 1986 exhibit the main features characteristic of the earth's climate. As found in other studies, our values are generally higher than Esbensen and Kushnir's by as much as 80 W/sq m in the tropical oceans. A cloud parameter, defined as the difference between clear-sky and actual irradiances normalized to top-of-atmosphere clear-sky irradiance, is also examined. This parameter, minimally affected by sun zenith angle, is higher in the midlatitude regions of storm tracks than in the intertropical convergence zone (ITCZ), suggesting that, on average, the higher cloud coverage in midlatitudes is more effective at reducing surface shortwave irradiance than opaque, convective, yet sparser clouds in the ITCZ. Surface albedo estimates are realistic, generally not exceeding 0.06 in the ocean, as high as 0.9 in polar regions, and reaching 0.5 in the Sahara and Arabian deserts.

Identity, Values, and Reflection: Shaping (and Being Shaped) through Assessment

ERIC Educational Resources Information Center

Isabella, Marcy; McGovern, Heather

2018-01-01

Outlining one program's history of outcomes-based assessment, the authors examine the relationships among assessment practices, program identity, and program values. Understanding the ways in which past processes of identifying learning outcomes reflected, and failed to reflect, shared values points us toward a new set of strategies for developing…

The neuron net method for processing the clear pixels and method of the analytical formulas for processing the cloudy pixels of POLDER instrument images

NASA Astrophysics Data System (ADS)

Melnikova, I.; Mukai, S.; Vasilyev, A.

Data of remote measurements of reflected radiance with the POLDER instrument on board of ADEOS satellite are used for retrieval of the optical thickness, single scattering albedo and phase function parameter of cloudy and clear atmosphere. The method of perceptron neural network that from input values of multiangle radiance and Solar incident angle allows to obtain surface albedo, the optical thickness, single scattering albedo and phase function parameter in case of clear sky. Two last parameters are determined as optical average for atmospheric column. The calculation of solar radiance with using the MODTRAN-3 code with taking into account multiple scattering is accomplished for neural network learning. All mentioned parameters were randomly varied on the base of statistical models of possible measured parameters variation. Results of processing one frame of remote observation that consists from 150,000 pixels are presented. The methodology elaborated allows operative determining optical characteristics as cloudy as clear atmosphere. Further interpretation of these results gives the possibility to extract the information about total contents of atmospheric aerosols and absorbing gases in the atmosphere and create models of the real cloudiness An analytical method of interpretation that based on asymptotic formulas of multiple scattering theory is applied to remote observations of reflected radiance in case of cloudy pixel. Details of the methodology and error analysis were published and discussed earlier. Here we present results of data processing of pixel size 6x6 km In many studies the optical thickness is evaluated earlier in the assumption of the conservative scattering. But in case of true absorption in clouds the large errors in parameter obtained are possible. The simultaneous retrieval of two parameters at every wavelength independently is the advantage comparing with earlier studies. The analytical methodology is based on the transfer theory asymptotic formula inversion for optically thick stratus clouds. The model of horizontally infinite layer is considered. The slight horizontal heterogeneity is approximately taken into account. Formulas containing only the measured values of two-direction radiance and functions of solar and view angles were derived earlier. The 6 azimuth harmonics of reflection function are taken into account. The simple approximation of the cloud top boarder heterogeneity is used. The clouds, projecting upper the cloud top plane causes the increase of diffuse radiation in the incident flux. It is essential for calculation of radiative characteristics, which depends on lighting conditions. Escape and reflection functions describe this dependence for reflected radiance and local albedo of semi-infinite medium - for irradiance. Thus the functions depending on solar incident angle is to replace by their modifications. Firstly optical thickness of every pixel is obtained with simple formula assuming conservative scattering for all available view directions. Deviations between obtained values may be taken as a measure of the cloud top deviation from the plane. The special parameter is obtained, which takes into account the shadowing effect. Then single scattering albedo and optical thickness (with the true absorption assuming) are obtained for pairs of view directions with equal optical thickness. After that the averaging of values obtained and relative error evaluation is accomplished for all viewing directions of every pixel. The procedure is repeated for all wavelengths and pixels independently.

Facial averageness and genetic quality: Testing heritability, genetic correlation with attractiveness, and the paternal age effect.

PubMed

Lee, Anthony J; Mitchem, Dorian G; Wright, Margaret J; Martin, Nicholas G; Keller, Matthew C; Zietsch, Brendan P

2016-01-01

Popular theory suggests that facial averageness is preferred in a partner for genetic benefits to offspring. However, whether facial averageness is associated with genetic quality is yet to be established. Here, we computed an objective measure of facial averageness for a large sample ( N = 1,823) of identical and nonidentical twins and their siblings to test two predictions from the theory that facial averageness reflects genetic quality. First, we use biometrical modelling to estimate the heritability of facial averageness, which is necessary if it reflects genetic quality. We also test for a genetic association between facial averageness and facial attractiveness. Second, we assess whether paternal age at conception (a proxy of mutation load) is associated with facial averageness and facial attractiveness. Our findings are mixed with respect to our hypotheses. While we found that facial averageness does have a genetic component, and a significant phenotypic correlation exists between facial averageness and attractiveness, we did not find a genetic correlation between facial averageness and attractiveness (therefore, we cannot say that the genes that affect facial averageness also affect facial attractiveness) and paternal age at conception was not negatively associated with facial averageness. These findings support some of the previously untested assumptions of the 'genetic benefits' account of facial averageness, but cast doubt on others.

SeaWiFS Postlaunch Technical Report Series. Volume 5; The SeaWiFS Solar Radiation-Based Calibration and the Transfer-to-Orbit Experiment

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Barnes, Robert A.; Eplee, Robert E., Jr.; Biggar, Stuart F.; Thome, Kurtis J.; Zalewski, Edward F.; Slater, Philip N.; Holmes, Alan W.

1999-01-01

The solar radiation-based calibration (SRBC) of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) was performed on 1 November 1993. Measurements were made outdoors in the courtyard of the instrument manufacturer. SeaWiFS viewed the solar irradiance reflected from the sensor's diffuser in the same manner as viewed on orbit. The calibration included measurements using a solar radiometer designed to determine the transmittances of principal atmospheric constituents. The primary uncertainties in the outdoor measurements are the transmission of the atmosphere and the reflectance of the diffuser. Their combined uncertainty is about 5 or 6%. The SRBC also requires knowledge of the extraterrestrial solar spectrum. Four solar models are used. When averaged over the responses of the SeaWiFS bands, the irradiance models agree at the 3.6% level, with the greatest difference for SeaWiFS band 8. The calibration coefficients from the SRBC are lower than those from the laboratory calibration of the instrument in 1997. For a representative solar model, the ratios of the SRBC coefficients to laboratory values average 0.962 with a standard deviation of 0.012. The greatest relative difference is 0.946 for band 8. These values are within the estimated uncertainties of the calibration measurements. For the transfer-to-orbit experiment, the measurements in the manufacturer's courtyard are used to predict the digital counts from the instrument on its first day on orbit (August 1, 1997). This experiment requires an estimate of the relative change in the diffuser response for the period between the launch of the instrument and its first solar measurements on orbit (September 9, 1997). In relative terms, the counts from the instrument on its first day on orbit averaged 1.3% higher than predicted, with a standard deviation of 1.2% and a greatest difference of 2.4% or band 7. The estimated uncertainty for the transfer-to-orbit experiment is about 3 or 4%.

Data Acquisition and Analysis for Camouflage Design

DTIC Science & Technology

1981-04-01

were clustered to produce a facsimile of the original scene in 39 49 or 5 average representative colors in CIELAB notation with spectral reflectance...result of the Euclidean clustering or averaging carried out in 1976 CIELAB color space. The size and shape of these domains, along with color, provide...Reflectance Calibration .... ...... 49 Figure O-i CIE 1976 (L*a*b*) Uniform Color Coordinate System (ClELAO) 53 Figure B-2 CIELAB Clustering

The Distribution of Titanium in Lunar Soils on the Basis of Sensor and In Situ Data Fusion

NASA Technical Reports Server (NTRS)

Clark, P. E.; Evans, L.

1999-01-01

A variety of remote-sensing measurements have been used to map the distribution of elements on the Moon as a means of providing constraints on the processes from which its crust and major terranes originated. Discussed here is Ti, which is incorporated into refractory minerals such as ilmenite during the latter stages of differentiation, and is thus a most useful element for understanding mare basalt petrogenesis. One of the earliest Ti maps showed Ti variations in nearside maria on the basis of groundbased spectral reflectance measurements. A map of Ti derived from gamma-ray measurements on Apollo 15 and 16 was produced at about the same time, and was improved upon considerably by Davis and coworkers, who effectively removed sources of spurious variation from Fe and Al or REE (e.g., Th) interference, and calibrated Ti on the bases of landing-site soil averages. In recent years, spectral reflectance measurements from Clementine have been used by Lucey and coworkers to produce global Ti distribution maps as well. As we indicated previously, the Lucey and Davis maps agree to first order. Meanwhile, we are using the concept of sensor data fusion to combine measurements from the AGR (Apollo gamma-ray) and CSR (Clementine Spectral Reflectance) techniques with ground truth from lunar soils to utilize the differences between the two maps to understand the distribution of Ti within lunar soil components, as we have done with Fe. This technique should be verified and applied on Lunar Prospector gamma-ray measurements of Ti, as the calibrated data become available within the next couple of years. Lunar Ti is found principally in the mineral ilmenite, and is associated with certain components of lunar soil: crystalline Ilmenite mineral fragments and high Ti-bearing glass. All data indicate that Ti is associated with maria and mafic minerals. In AGR and CSR datasets, Ti is highest on the nearside and in the maria, particularly in southern Serenitatis/northern Tranquillitatis and northwestern Procellarum. Unlike CSR-derived values, AGR Ti values show modest increase (up to 0.7%) on the northern farside. Both techniques show a primarily unimodal distribution with a shoulder in the high Ti direction and a primary mode at approximately 0.2% (0.15% for CSR and 0.25% for AGR data), but the AGR Ti data have more structure in the shoulder, including an apparent minor mode at 1.2% Ti, representing non-highland areas. Recalibrating the two datasets on the basis of matching the peaks and range on the histograms would not account for this additional structure in the AGR data. Low Ti areas, which occur predominantly on the farside, are not represented well in the lunar sample collection, although several meteorites thought to be of lunar highland origin show Ti abundances averaging about 0.2%. (Error bars on AGR Ti values are about 0.5%.) Gamma-ray measurements reflect intrinsic Ti surface composition, regardless of the physical or chemical state of Ti. Lucey and coworkers have attempted to produce an equivalent bulk Ti map by normalizing the spectral feature at 415 nm to remove the effects of physical variations from soil to soil. The normalization is based on laboratory measurements of available samples, primarily nearside maria, and is undoubtedly optimized for the proportions in which Ti- components are found in these soils. In particular, mare soils tend to have a much higher proportion of opaque mineral grains, which appears to be well correlated with Ti abundance. The relationship between Ti abundance and proportion of Ti-bearing glass (weighted for Ti abundance) is not as direct. Also shows the relationship between landing site soil average, AGR, and CSR Ti abundances (with CSR filtered to match resolution and field of view of AGR data). AGR Ti values show the best agreement with Ti soil averages, CSR Ti values being somewhat higher in high-Ti soils, and lower in low-Ti soils. These results would tend to support the argument that the technique for deriving Ti from the CSR measurements is optimized for one of the primary Ti-bearing components, most likely opaque mineral grains, and is thus over-compensating and reporting higher Ti values in mare areas, and underreporting Ti in highland areas with much lower proportions of opaque mineral grains. More information is contained in original.

Environmental control on eastern broadleaf forest species' leaf wax distributions and D/H ratios

NASA Astrophysics Data System (ADS)

Tipple, Brett J.; Pagani, Mark

2013-06-01

Local climate and environment broadly affect the deuterium/hydrogen (D/H) ratios of plant materials, however the degree to which an individual plant's leaf waxes D/H ratios are affected by these parameters remains in question. Understanding these issues is particularly important in order to reconstruct past floral transitions and changes in the paleohydrologic cycle. For this study, we sampled five co-occurring tree species, Acer rubrum, Platanus occidentalis, Juniperus virginiana, Pinus taeda, and Pinus strobus and soils at forty sites along the East Coast of the US, from Florida to Maine. Hydrogen isotopic compositions of leaf wax n-alkanes, stem and surface waters were analyzed and compared against high-resolution temperature, precipitation, relative humidity, and vapor pressure deficit data to determine environmental controls on isotopic composition. Our results demonstrate that each tree species produce a unique distribution of n-alkanes with distinct chain length pattern. Average n-alkane chain lengths recovered from soils, A. rubrum, and J. virginiana leaves show significant correlations with mean annual temperature. δD values of A. rubrum leaf n-alkanes were strongly correlated to modeled mean annual precipitation δD values and other climate parameters related to latitude (i.e. temperature, relative humidity, vapor pressure deficit), while the δD values of J. virginiana n-alkanes were not. Differences in correspondence may reflect the timing of leaf wax synthesis between the two species. Further, soil n-alkane D/H compositions were strongly correlated to modeled mean annual precipitation δD values, while the apparent hydrogen isotopic fractionation was not. These findings indicate that the isotope ratio of n-alkanes from soils in Eastern North American forests and similar ecosystems likely represents a time-averaged value that smooth out the environmental influence any one plant experiences.

Evaluation of treatment-induced cerebral white matter injury by using diffusion-tensor MR imaging: initial experience.

PubMed

Kitahara, Sawako; Nakasu, Satoshi; Murata, Kiyoshi; Sho, Keizen; Ito, Ryuta

2005-10-01

Treatment with chemotherapy and radiation therapy for brain tumors can cause white matter (WM) injury. Conventional MR imaging, however, cannot always depict treatment-induced transient WM abnormalities. We investigated the ability of diffusion-tensor (DT) MR imaging and proton MR spectroscopy to detect the treatment-induced transient changes within normal-appearing WM. DT MR imaging and proton MR spectroscopy were performed in 8 patients treated with a combination of surgery, chemotherapy, and radiation therapy for brain tumors (17 examinations) and 11 age-matched controls. Apparent diffusion coefficient (ADC) value, fractional anisotropy (FA) value, and N-acetylaspartate (NAA)/creatine (Cr) ratio were obtained from 27 hemispheres with normal-appearing WM in the patients. We divided the datasets of isotropic ADC, FA, and NAA/Cr, on the basis of the time period after completion of radiation therapy, into 4 groups: group 1 (0-2 months; n = 10), group 2 (3-5 months; n = 5), group 3 (6-9 months; n = 7), and group 4 (10-12 months; n = 5). We compared averages of mean isotropic ADC, mean FA, and NAA/Cr of each patient group with those of the control group by using a t test. In the group 2, averages of mean FA and NAA/Cr decreased and average of mean isotopic ADC increased in comparison with those of the control group (P = .004, .04, and .0085, respectively). There were no significant differences in the averages between the control group and patient groups 1, 3, and 4. DT MR imaging and proton MR spectroscopy can provide quantitative indices that may reflect treatment-induced transient derangement of normal-appearing WM.

Wavelength dependent light absorption as a cost effective, real-time surrogate for ambient concentrations of polycyclic aromatic hydrocarbons

NASA Astrophysics Data System (ADS)

Brown, Richard J. C.; Butterfield, David M.; Goddard, Sharon L.; Hussain, Delwar; Quincey, Paul G.; Fuller, Gary W.

2016-02-01

Many monitoring stations used to assess ambient air concentrations of pollutants regulated by European air quality directives suffer from being expensive to establish and operate, and from their location being based on the results of macro-scale modelling exercises rather than measurement assessments in candidate locations. To address these issues for the monitoring of polycyclic aromatic hydrocarbons (PAHs), this study has used data from a combination of the ultraviolet and infrared channels of aethalometers (referred to as UV BC), operated as part of the UK Black Carbon Network, as a surrogate measurement. This has established a relationship between concentrations of the PAH regulated in Europe, benzo[a]pyrene (B[a]P), and the UV BC signal at locations where these measurements have been made together from 2008 to 2014. This relationship was observed to be non-linear. Relationships for individual site types were used to predict measured concentrations with, on average, 1.5% accuracy across all annual averages, and with only 1 in 36 of the predicted annual averages deviating from the measured annual average by more than the B[a]P data quality objective for uncertainty of 50% (at -65%, with the range excluding this value between + 38% and -37%). These relationships were then used to predict B[a]P concentrations at stations where UV BC measurement are made, but PAH measurements are not. This process produced results which reflected expectations based on knowledge of the pollution climate at these stations gained from the measurements of other air quality networks, or from nearby stations. The influence of domestic solid fuel heating was clear using this approach which highlighted Strabane in Northern Ireland as a station likely to be in excess of the air quality directive target value for B[a]P.

The silicon isotope composition of the upper continental crust

NASA Astrophysics Data System (ADS)

Savage, Paul S.; Georg, R. Bastian; Williams, Helen M.; Halliday, Alex N.

2013-05-01

The upper continental crust (UCC) is the major source of silicon (Si) to the oceans and yet its isotopic composition is not well constrained. In an effort to investigate the degree of heterogeneity and provide a robust estimate for the average Si isotopic composition of the UCC, a representative selection of well-characterised, continentally-derived clastic sediments have been analysed using high-precision MC-ICPMS. Analyses of loess samples define a narrow range of Si isotopic compositions (δ30Si = -0.28‰ to -0.15‰). This is thought to reflect the primary igneous mineralogy and predominance of mechanical weathering in the formation of such samples. The average loess δ30Si is -0.22 ± 0.07‰ (2 s.d.), identical to average granite and felsic igneous compositions. Therefore, minor chemical weathering does not resolvably affect bulk rock δ30Si, and loess is a good proxy for the Si isotopic composition of unweathered, crystalline, continental crust. The Si isotopic compositions of shales display much more variability (δ30Si = -0.82‰ to 0.00‰). Shale Si isotope compositions do not correlate well with canonical proxies for chemical weathering, such as CIA values, but do correlate negatively with insoluble element concentrations and Al/Si ratios. This implies that more intensive or prolonged chemical weathering of a sedimentary source, with attendant desilicification, is required before resolvable negative Si isotopic fractionation occurs. Shale δ30Si values that are more positive than those of felsic igneous rocks most likely indicate the presence of marine-derived silica in such samples. Using the data gathered in this study, combined with already published granite Si isotope analyses, a weighted average composition of δ30Si = -0.25 ± 0.16‰ (2 s.d.) for the UCC has been calculated.

[The secular trend in body height and weight in the adult population in the Czech republic].

PubMed

Kopecký, Miroslav; Kikalová, Kateřina; Charamza, Jiří

Secular changes in anthropometric parameters reflect the effect of socio-economic conditions in interaction with other factors on individuals in the course of 100-200 years. The main aim of the research was to determine the average body height and weight for the current adult population of men 19 to 94 years old and women 19 to 86 years old in the Czech Republic, and to compare the average values ​​of body height and weight of the monitored group with the reference values ​​for the adult population observed in our country from 1895 to 2001.Body height and weight were measured with standard anthropometry in 973 men aged 19-94 years and 2,606 women aged 19-86 years. The research was carried out from 2013 to 2015. Statistical tests: t-test, one-way analysis of variance (ANOVA). The average body weight and height of the current adult male is 178.58 cm and 80.86 kg, and of adult female 165.99 cm and 65.67 kg. When compared to men, women show significantly lower average height by 12.59 cm and lower weight by 15.19 kg. The results show that men today are about 10.61 cm higher and weigh 9.01 kilograms more than men in 1895. Todays women are about 9.43 centimeters taller, but weigh 0,58 kg less than women of the same age in 1895.Comparison of results from 1895 to 2015 shows that at present there is likely stagnation or decline in the positive secular trend in body height among men and women. The weight of men is increasing while there is stagnation in the body weight of women.

Bio-Optical Properties and Ocean Color Algorithms for Coastal Waters Influenced by the Mississippi River During a Cold Front Passage

NASA Technical Reports Server (NTRS)

D'Sa Eurico J.; Miller, Richard L.; DelCastillo, Carlos

2006-01-01

During the passage of a cold front in March 2002, bio-optical properties examined in coastal waters impacted by the Mississippi River indicated westward advective flows and increasing river discharge containing a larger nonalgal particle content contributed significantly to surface optical variability. A comparison of seasonal data from three cruises indicated spectral models of absorption and scattering to be generally consistent with other coastal environments, while their parameterization in terms of chlorophyll a concentration (Chl) showed seasonal variability. The exponential slope of the colored dissolved organic matter (CDOM) averaged 0.0161 plus or minus 0.00054 per nanometer, and for nonalgal absorption it averaged 0.011 per nanometer with deviations from general trends observed due to anomalous water properties. Although the phytoplankton specific absorption coefficients varied over a wide range (0.02 to 0.1 square meters (mg Chl) sup -1)) being higher in offshore surface waters, values of phytoplankton absorption spectra at the SeaWiFS wavebands were highly correlated to modeled values. The normalized scattering spectral shapes and the mean spectrum were in agreement to observations in other coastal waters, while the backscattering ratios were on average lower in phytoplankton dominated surface waters (0.0101 plus or minus 0.002) and higher in near-bottom waters (0.0191 plus or minus 0.0045) with low Chl. Average percent differences in remote sensing reflectance R (sub rs) derived form modeled and in-eater radiometric measurements were highest in the blue wavebands (52%) and at sampling stations with a ore stratified water column. Estimates of Chl and CDOM absorption derived from SeaWiFS images generated using regional empirical algorithms were highly correlated to in situ data.

A surface vitrinite reflectance anomaly related to Bell Creek oil field, Montana, U.S.A.

USGS Publications Warehouse

Barker, C.E.; Dalziel, M.C.; Pawlewicz, M.J.

1983-01-01

Vitrinite reflectance measurements from surface samples of mudrock and coal show anomalously high values over the Bell Creek oil field. The average vitrinite reflectance (Rm) increases to a maximum of 0.9 percent over the field against background values of about 0.3 percent. The Rm anomaly coincides with a geochemical anomaly indicated by diagenetic magnetite in surface rocks and a geobiologic anomaly indicated by ethane-consuming bacteria. These samples were taken from the Upper Cretaceous Hell Creek and Paleocene Fort Union Formations which form an essentially conformable sequence. The depositional environment is similar in both formations, and we expect little variation in the source and composition of the organic matter. The surface R m should be approximately constant because of a uniform thermal history across the field. Temperature studies over local oil fields with similar geology suggest the expected thermal anomaly would be less than 10?C (50?F), which is too small to account for the significantly higher rank over the field. Coal clinkers are rare in the vicinity of Bell Creek and an Rm anomaly caused by burning of the thin, discontinuous coal seams is unlikely. The limited topographic relief, less than 305 m (1,000 ft), over the shallow-dipping homoclinal structure and the poor correlation between Rm and sample locality elevation (r = -0.2) indicate that the Rm anomaly is not due to burial, deformation and subsequent erosion. We conjecture that activity by petroleum-metabolizing bacteria is a possible explanation of the Rm anomaly. Microseepage from oil reservoirs supports large colonies of these organisms, some of which can produce enzymes that can cleave hydrocarbon side-chains on the kerogen molecule. The loss of these side chains causes condensation of the ring structures (Stach and others, 1982) and consequently increases its reflectance. These data indicate that vitrinite reflectance may be a useful tool to explore for stratigraphic traps in the Powder River Basin. Further, the large variation of R across the Bell Creek area suggests that vitrinite reflectance data from surface samples should be interpreted with caution.

Intercomparison of 30+ years of AVHRR and Landsat-5 TM Surface Reflectance using Multiple Pseudo-Invariant Calibration Sites

NASA Astrophysics Data System (ADS)

Santamaría-Artigas, A. E.; Franch, B.; Vermote, E.; Roger, J. C.; Justice, C. O.

2017-12-01

The 30+ years daily surface reflectance long term data record (LTDR) from the Advanced Very High Resolution Radiometer (AVHRR) is a valuable source of information for long-term studies of the Earth surface. This LTDR was generated by combining observations from multiple AVHRR sensors aboard different NOAA satellites starting from the early 1980s, and due to the lack of on-board calibration its quality should be evaluated. Previous studies have used observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) over pseudo-invariant calibration sites (PICS) as a calibrated reference to assess the performance of AVHRR products. However, this limits the evaluation to the period after MODIS launch. In this work, the AVHRR surface reflectance LTDR was evaluated against Landsat-5 Thematic Mapper (TM) data using observations from 4 well known pseudo-invariant calibration sites (i.e. Sonoran, Saharan, Sudan1, and Libya4) over an extended time period (1984-2011). For the intercomparison, AVHRR and TM observations of each site were extracted and averaged over a 20 km x 20 km area and aggregated to monthly mean values. In order to account for the spectral differences between sensors, Hyperion hyperspectral data from the Sonoran and Libya4 sites were convolved with sensor-specific relative spectral responses, and used to compute spectral band adjustment factors (SBAFs). Results of the intercomparison are reported in terms of the root mean square difference (RMSD) and determination coefficient (r2). In general, there is good agreement between the surface reflectance products from both sensors. The overall RMSD and r2 for all the sites and AVHRR/TM combinations were 0.03 and 0.85 for the red band, and 0.04 and 0.81 for the near-infrared band. These results show the strong performance of the AVHRR surface reflectance LTDR through all of the considered period. Thus, remarking its usefulness and value for long term Earth studies. Figure 1 shows the red (filled markers) and near-infrared (empty markers) surface reflectance from AVHRR and TM for the complete evaluation period over the Saharan (diamond), Libya4 (square), Sudan1 (triangle), and Sonoran (circle) PICS.

Accuracies of genomic breeding values in American Angus beef cattle using K-means clustering for cross-validation.

PubMed

Saatchi, Mahdi; McClure, Mathew C; McKay, Stephanie D; Rolf, Megan M; Kim, JaeWoo; Decker, Jared E; Taxis, Tasia M; Chapple, Richard H; Ramey, Holly R; Northcutt, Sally L; Bauck, Stewart; Woodward, Brent; Dekkers, Jack C M; Fernando, Rohan L; Schnabel, Robert D; Garrick, Dorian J; Taylor, Jeremy F

2011-11-28

Genomic selection is a recently developed technology that is beginning to revolutionize animal breeding. The objective of this study was to estimate marker effects to derive prediction equations for direct genomic values for 16 routinely recorded traits of American Angus beef cattle and quantify corresponding accuracies of prediction. Deregressed estimated breeding values were used as observations in a weighted analysis to derive direct genomic values for 3570 sires genotyped using the Illumina BovineSNP50 BeadChip. These bulls were clustered into five groups using K-means clustering on pedigree estimates of additive genetic relationships between animals, with the aim of increasing within-group and decreasing between-group relationships. All five combinations of four groups were used for model training, with cross-validation performed in the group not used in training. Bivariate animal models were used for each trait to estimate the genetic correlation between deregressed estimated breeding values and direct genomic values. Accuracies of direct genomic values ranged from 0.22 to 0.69 for the studied traits, with an average of 0.44. Predictions were more accurate when animals within the validation group were more closely related to animals in the training set. When training and validation sets were formed by random allocation, the accuracies of direct genomic values ranged from 0.38 to 0.85, with an average of 0.65, reflecting the greater relationship between animals in training and validation. The accuracies of direct genomic values obtained from training on older animals and validating in younger animals were intermediate to the accuracies obtained from K-means clustering and random clustering for most traits. The genetic correlation between deregressed estimated breeding values and direct genomic values ranged from 0.15 to 0.80 for the traits studied. These results suggest that genomic estimates of genetic merit can be produced in beef cattle at a young age but the recurrent inclusion of genotyped sires in retraining analyses will be necessary to routinely produce for the industry the direct genomic values with the highest accuracy.

Accuracies of genomic breeding values in American Angus beef cattle using K-means clustering for cross-validation

PubMed Central

2011-01-01

Background Genomic selection is a recently developed technology that is beginning to revolutionize animal breeding. The objective of this study was to estimate marker effects to derive prediction equations for direct genomic values for 16 routinely recorded traits of American Angus beef cattle and quantify corresponding accuracies of prediction. Methods Deregressed estimated breeding values were used as observations in a weighted analysis to derive direct genomic values for 3570 sires genotyped using the Illumina BovineSNP50 BeadChip. These bulls were clustered into five groups using K-means clustering on pedigree estimates of additive genetic relationships between animals, with the aim of increasing within-group and decreasing between-group relationships. All five combinations of four groups were used for model training, with cross-validation performed in the group not used in training. Bivariate animal models were used for each trait to estimate the genetic correlation between deregressed estimated breeding values and direct genomic values. Results Accuracies of direct genomic values ranged from 0.22 to 0.69 for the studied traits, with an average of 0.44. Predictions were more accurate when animals within the validation group were more closely related to animals in the training set. When training and validation sets were formed by random allocation, the accuracies of direct genomic values ranged from 0.38 to 0.85, with an average of 0.65, reflecting the greater relationship between animals in training and validation. The accuracies of direct genomic values obtained from training on older animals and validating in younger animals were intermediate to the accuracies obtained from K-means clustering and random clustering for most traits. The genetic correlation between deregressed estimated breeding values and direct genomic values ranged from 0.15 to 0.80 for the traits studied. Conclusions These results suggest that genomic estimates of genetic merit can be produced in beef cattle at a young age but the recurrent inclusion of genotyped sires in retraining analyses will be necessary to routinely produce for the industry the direct genomic values with the highest accuracy. PMID:22122853

Evaluation of interlayer interfacial stiffness and layer wave velocity of multilayered structures by ultrasonic spectroscopy.

PubMed

Ishii, Yosuke; Biwa, Shiro

2014-07-01

An ultrasonic evaluation procedure for the interlayer interfacial normal stiffness and the intralayer longitudinal wave velocity of multilayered plate-like structures is proposed. Based on the characteristics of the amplitude reflection spectrum of ultrasonic wave at normal incidence to a layered structure with spring-type interlayer interfaces, it is shown that the interfacial normal stiffness and the longitudinal wave velocity in the layers can be simultaneously evaluated from the frequencies of local maxima and minima of the spectrum provided that all interfaces and layers have the same properties. The effectiveness of the proposed procedure is investigated from the perspective of the sensitivity of local extremal frequencies of the reflection spectrum. The feasibility of the proposed procedure is also investigated when the stiffness of each interface is subjected to small random fluctuations about a certain average value. The proposed procedure is applied to a 16-layered cross-ply carbon-fiber-reinforced composite laminate. The normal stiffness of resin-rich interfaces and the longitudinal wave velocity of plies in the thickness direction evaluated from the experimental reflection spectrum are shown to be consistent with simple theoretical estimations.

Unconditional regard buffers children's negative self-feelings.

PubMed

Brummelman, Eddie; Thomaes, Sander; Walton, Gregory M; Poorthuis, Astrid M G; Overbeek, Geertjan; Orobio de Castro, Bram; Bushman, Brad J

2014-12-01

Unconditional regard refers to the feeling that one is accepted and valued by others without conditions. Psychological theory suggests that experiences of unconditional regard lead children to feel that they are valuable despite setbacks. We hypothesized that reflecting on experiences of unconditional regard would buffer children's negative self-feelings (eg, shame, insecurity, powerlessness) in the face of setbacks. To test this hypothesis, we randomized children to reflect on experiences of unconditional regard or other experiences, and examined their response to an academic setback 3 weeks later. Participants (11-15 years old) were randomly assigned to reflect for 15 minutes on experiences of unconditional regard (n = 91), conditional regard (n = 80), or other social experiences (n = 76). Research personnel, teachers, and classmates remained blind to condition assignment. Three weeks later, after receiving their course grades, children reported their self-feelings. Course grades were obtained from school records. Receiving low course grades represents a salient and painful real-world setback for children. Replicating previous research, children who received lower grades experienced more negative self-feelings (P < .001). As predicted, this well-established relationship was significantly attenuated among children who had reflected, 3 weeks previously, on experiences of unconditional regard (Ps < .03). Reflecting on unconditional regard specifically reduced negative self-feelings after low grades (P = .01), not after average or high grades (Ps > .17). Reflecting on unconditional regard buffered children's selves against the adverse impact of an academic setback over an extended period of time. Unconditional regard may thus be an important psychological lever to reduce negative self-feelings in youth. Copyright © 2014 by the American Academy of Pediatrics.

Replacing backscattering with reduced scattering. A better formulation of reflectance function?

NASA Astrophysics Data System (ADS)

Piskozub, Jacek; McKee, David; Freda, Wlodzimierz

2014-05-01

Modern reflectance formulas all involve backscattering coefficient divided by absorption coefficient (bb/a). The backscattering (or backward scattering) coefficient describes how much of the incident radiation is scattered at angles between 90 and 180 deg. However, water leaving photons are not necessarily backscattered because it is possible for a variable fraction to exit after multiple forward scattering events. Therefore the whole angular function of scattering probability (phase function) influences the reflectance signal. This is the reason why phase functions of identical backscattering ratio may result in different reflectance values, contrary to the universally used formula. This creates the question whether there may exist a better formula using a parameter better describing phase function shape than backscattering ratio. The asymmetry parameter g (the average scattering cosine) is commonly used to parametrize phase functions. A replacement for backscattering should decrease with increasing g. Therefore, the simplest candidate to replace backscattering has the form of b(1-g), where b is the scattering coefficient. Such a parameter is well known in biomedical optics under the name of reduced scattering (sometimes transport scattering). It has even been used in parametrizing reflectance in (highly turbid) human tissues. However no attempt has been made to check its usefulness in marine optics. We perform Monte Carlo radiative transfer calculations of reflectance for multiple combinations of inherent optical properties, including different phase functions. The results are used to create a new reflectance formula as a function of reduced scattering and absorption and test its robustness to changes in phase function shape compared to the traditional bb/a formula. We discuss its usefulness as well as advantages and disadvantages compared to the traditional formulation.

Effect of free distribution of safety equipment on usage among motorcycle-taxi drivers in Tanzania--A cluster randomised controlled trial.

PubMed

Sumner, Steven A; Pallangyo, Anthony J; Reddy, Elizabeth A; Maro, Venance; Pence, Brian W; Lynch, Catherine; Turner, Elizabeth L; Egger, Joseph R; Thielman, Nathan M

2014-11-01

Deaths due to road traffic injuries, particularly motorcycle crashes, have increased rapidly in many African nations and context-specific strategies to improve preventative behaviours are needed. Although adhering to conspicuity measures by wearing reflective safety vests is a highly effective crash prevention strategy and mandated by law among motorcycle-taxi drivers in some African countries, actual use is currently low. We aimed to test whether eliminating cost-barriers through the provision of free reflective, fluorescent motorcycle safety vests would lead to increased utilisation among a high-risk population of motorcycle-taxi drivers in Tanzania. A cluster randomised controlled trial was conducted among 180 motorcycle-taxi drivers. Participants randomised to the intervention arm (90) received free, reflective, fluorescent vests; participants randomised to the control arm (90) did not receive free vests. Participants' use of reflective vests was then observed on city streets over a three month period and differential uptake was estimated using mixed-effects logistic regression. Baseline use of reflective vests was 3.3% in both arms. Seventy-nine drivers in the intervention arm and 82 drivers in the control arm were observed during follow-up. The average proportion of observations during which motorcycle drivers were using a reflective vest was 9.5% in the intervention arm, compared to 2.0% in the control arm (odds ratio: 5.5, 95% confidence interval: 1.1-26.9, p-value: 0.04). Although distribution of free reflective vests led to a statistically significant increase in vest usage, the absolute increase was modest. Additional strategies beyond removing economic barriers are important to augment adherence to road safety behaviours for injury prevention. Copyright © 2014 Elsevier Ltd. All rights reserved.

Classification of corn kernels contaminated with aflatoxins using fluorescence and reflectance hyperspectral images analysis

NASA Astrophysics Data System (ADS)

Zhu, Fengle; Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Brown, Robert; Bhatnagar, Deepak; Cleveland, Thomas

2015-05-01

Aflatoxins are secondary metabolites produced by certain fungal species of the Aspergillus genus. Aflatoxin contamination remains a problem in agricultural products due to its toxic and carcinogenic properties. Conventional chemical methods for aflatoxin detection are time-consuming and destructive. This study employed fluorescence and reflectance visible near-infrared (VNIR) hyperspectral images to classify aflatoxin contaminated corn kernels rapidly and non-destructively. Corn ears were artificially inoculated in the field with toxigenic A. flavus spores at the early dough stage of kernel development. After harvest, a total of 300 kernels were collected from the inoculated ears. Fluorescence hyperspectral imagery with UV excitation and reflectance hyperspectral imagery with halogen illumination were acquired on both endosperm and germ sides of kernels. All kernels were then subjected to chemical analysis individually to determine aflatoxin concentrations. A region of interest (ROI) was created for each kernel to extract averaged spectra. Compared with healthy kernels, fluorescence spectral peaks for contaminated kernels shifted to longer wavelengths with lower intensity, and reflectance values for contaminated kernels were lower with a different spectral shape in 700-800 nm region. Principal component analysis was applied for data compression before classifying kernels into contaminated and healthy based on a 20 ppb threshold utilizing the K-nearest neighbors algorithm. The best overall accuracy achieved was 92.67% for germ side in the fluorescence data analysis. The germ side generally performed better than endosperm side. Fluorescence and reflectance image data achieved similar accuracy.

Chemical and biochemical composition of caviar from different sturgeon species and origins.

PubMed

Wirth, M; Kirschbaum, F; Gessner, J; Krüger, A; Patriche, N; Billard, R

2000-08-01

The chemical and biochemical composition of caviar in 22 specimens of wild caught and of 2 farmed animals were measured. The results include grain size, protein and fat content, fatty acid composition of triglycerides and phospholipids, as well as the concentrations of relevant heavy metals and chlorinated hydrocarbons. The average protein content varied between 26.2 and 31.1% (wet weight) and fat from 10.9 to 19.4% (wet weight) with lowest values for caviar from farmed sturgeon. The triglycerides and phospholipids contained more n-3 fatty acids, especially eicosapentaenoic and docosahexaenoic acid than n-6 fatty acids. The copper and zinc concentrations varied between 1.20 and 1.69 and 10.3 and 12.4 mg/kg (wet weight), respectively. These values reflect the elevated requirement of sturgeons for these components. Lead content varied between 0.06 and 0.15 mg/kg (wet weight). The cadmium concentrations were less than 5 micrograms/kg (wet weight) leading to the conclusion that no accumulation took place in the eggs. The concentrations of sigma DDT and sigma PCB were extremely high in caviar from Huso huso compared to the samples of the other species thus reflecting the different food habits leading to increased bio-accumulation.

Synthesis and characterization of PVK/AgNPs nanocomposites prepared by laser ablation.

PubMed

Abd El-Kader, F H; Hakeem, N A; Elashmawi, I S; Menazea, A A

2015-03-05

Nanocomposites of Poly (n-vinylcarbazole) PVK/Ag nanoparticles were prepared by laser ablation of a silver plate in aqueous solution of chlorobenzene. The influences of laser parameters such as; time of irradiation, source power and wavelength (photon energy) on structural, morphological and optical properties have been investigated using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Ultraviolet-visible (UV-Vis) and Photoluminescence (PL). A correlation between the investigated properties has been discussed. XRD, TEM and PL indicated that the complexation between AgNPs and PVK in the composite system is possible. Only the reflection peak at 2θ=38° of AgNPs appeared in the composite nanoparticles while the other reflection peaks were destroyed. The nanoparticles shape and size distribution were evaluated from TEM images. TEM analysis revealed a lower average particle size at long laser irradiation time 40min and short laser wavelength 532nm together with high laser power 570mW. From UV-Visible spectra the values of absorption coefficient, absorption edge and energy tail were calculated. The reduction of band tail value with increasing the laser ablation parameters confirms the decrease of the disorder in such composite system. The PL and UV-Vis. spectra confirm that nanocomposite samples showed quantum confinement effect. Copyright © 2014 Elsevier B.V. All rights reserved.

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%.

Start-Up and Ongoing Practice Expenses of Behavioral Health and Primary Care Integration Interventions in the Advancing Care Together (ACT) Program.

PubMed

Wallace, Neal T; Cohen, Deborah J; Gunn, Rose; Beck, Arne; Melek, Steve; Bechtold, Donald; Green, Larry A

2015-01-01

Provide credible estimates of the start-up and ongoing effort and incremental practice expenses for the Advancing Care Together (ACT) behavioral health and primary care integration interventions. Expenditure data were collected from 10 practice intervention sites using an instrument with a standardized general format that could accommodate the unique elements of each intervention. Average start-up effort expenses were $44,076 and monthly ongoing effort expenses per patient were $40.39. Incremental expenses averaged $20,788 for start-up and $4.58 per patient for monthly ongoing activities. Variations in expenditures across practices reflect the differences in intervention specifics and organizational settings. Differences in effort to incremental expenditures reflect the extensive use of existing resources in implementing the interventions. ACT program incremental expenses suggest that widespread adoption would likely have a relatively modest effect on overall health systems expenditures. Practice effort expenses are not trivial and may pose barriers to adoption. Payers and purchasers interested in attaining widespread adoption of integrated care must consider external support to practices that accounts for both incremental and effort expense levels. Existing knowledge transfer mechanisms should be employed to minimize developmental start-up expenses and payment reform focused toward value-based, Triple Aim-oriented reimbursement and purchasing mechanisms are likely needed. © Copyright 2015 by the American Board of Family Medicine.

Comparison of AVIRIS and Landsat ETM+ detection capabilities for burn severity

USGS Publications Warehouse

Van Wagtendonk, Jan W.; Root, Ralph R.; Key, Carl H.

2004-01-01

Our study compares data on burn severity collected from multi-temporal Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) with similar data from the Enhanced Thematic Mapper Plus (ETM+) using the differenced Normalized Burn Ratio (dNBR). Two AVIRIS and ETM+ data acquisitions recorded surface conditions immediately before the Hoover Fire began to spread rapidly and again the following year. Data were validated with 63 field plots using the Composite Burn Index (CBI). The relationship between spectral channels and burn severity was examined by comparing pre- and post-fire datasets. Based on the high burn severity comparison, AVIRIS channels 47 and 60 at wavelengths of 788 and 913 nm showed the greatest negative response to fire. Post-fire reflectance values decreased the most on average at those wavelengths, while channel 210 at 2370 nm showed the greatest positive response on average. Fire increased reflectance the most at that wavelength over the entire measured spectral range. Furthermore, channel 210 at 2370 nm exhibited the greatest variation in spectral response, suggesting potentially high information content for fire severity. Based on general remote sensing principles and the logic of variable spectral responses to fire, dNBR from both sensors should produce useful results in quantifying burn severity. The results verify the band–response relationships to burn severity as seen with ETM+ data and confirm the relationships by way of a distinctly different sensor system.

Suppressing lossy-film-induced angular mismatches between reflectance and transmittance extrema: optimum optical designs of interlayers and AR coating for maximum transmittance into active layers of CIGS solar cells.

PubMed

Chang, Yin-Jung

2014-01-13

The investigation of optimum optical designs of interlayers and antireflection (AR) coating for achieving maximum average transmittance (T(ave)) into the CuIn(1-x)Ga(x)Se2 (CIGS) absorber of a typical CIGS solar cell through the suppression of lossy-film-induced angular mismatches is described. Simulated-annealing algorithm incorporated with rigorous electromagnetic transmission-line network approach is applied with criteria of minimum average reflectance (R(ave)) from the cell surface or maximum T(ave) into the CIGS absorber. In the presence of one MgF2 coating, difference in R(ave) associated with optimum designs based upon the two distinct criteria is only 0.3% under broadband and nearly omnidirectional incidence; however, their corresponding T(ave) values could be up to 14.34% apart. Significant T(ave) improvements associated with the maximum-T(ave)-based design are found mainly in the mid to longer wavelengths and are attributed to the largest suppression of lossy-film-induced angular mismatches over the entire CIGS absorption spectrum. Maximum-T(ave)-based designs with a MgF2 coating optimized under extreme deficiency of angular information is shown, as opposed to their minimum-R(ave)-based counterparts, to be highly robust to omnidirectional incidence.

A technique for global monitoring of net solar irradiance at the ocean surface. I - Model

NASA Technical Reports Server (NTRS)

Frouin, Robert; Chertock, Beth

1992-01-01

An accurate long-term (84-month) climatology of net surface solar irradiance over the global oceans from Nimbus-7 earth radiation budget (ERB) wide-field-of-view planetary-albedo data is generated via an algorithm based on radiative transfer theory. Net surface solar irradiance is computed as the difference between the top-of-atmosphere incident solar irradiance (known) and the sum of the solar irradiance reflected back to space by the earth-atmosphere system (observed) and the solar irradiance absorbed by atmospheric constituents (modeled). It is shown that the effects of clouds and clear-atmosphere constituents can be decoupled on a monthly time scale, which makes it possible to directly apply the algorithm with monthly averages of ERB planetary-albedo data. Compared theoretically with the algorithm of Gautier et al. (1980), the present algorithm yields higher solar irradiance values in clear and thin cloud conditions and lower values in thick cloud conditions.

Accounting for dropout bias using mixed-effects models.

PubMed

Mallinckrodt, C H; Clark, W S; David, S R

2001-01-01

Treatment effects are often evaluated by comparing change over time in outcome measures. However, valid analyses of longitudinal data can be problematic when subjects discontinue (dropout) prior to completing the study. This study assessed the merits of likelihood-based repeated measures analyses (MMRM) compared with fixed-effects analysis of variance where missing values were imputed using the last observation carried forward approach (LOCF) in accounting for dropout bias. Comparisons were made in simulated data and in data from a randomized clinical trial. Subject dropout was introduced in the simulated data to generate ignorable and nonignorable missingness. Estimates of treatment group differences in mean change from baseline to endpoint from MMRM were, on average, markedly closer to the true value than estimates from LOCF in every scenario simulated. Standard errors and confidence intervals from MMRM accurately reflected the uncertainty of the estimates, whereas standard errors and confidence intervals from LOCF underestimated uncertainty.

The investigation of the Cr doped ZnO thin films deposited by thermionic vacuum arc technique

NASA Astrophysics Data System (ADS)

Mohammadigharehbagh, Reza; Pat, Suat; Musaoglu, Caner; Korkmaz, Şadan; Özen, Soner

2018-02-01

Cr doped ZnO thin films were prepared onto glass and polyethylene terephthalate (PET) substrates using thermionic vacuum arc. XRD patterns show the polycrystalline nature of the films. Cr, Zn, ZnO and Cr2O3 were detected in the layers. The mean crystallite sizes of the films were calculated about 20 nm for the films onto glass and PET substrates. The maximum dislocation density and internal strain values of the films are calculated. According to the optical analysis, the average transmittance and reflectance of the films were found to be approximately 53% and 16% for glass and PET substrates, respectively. The mean refractive index of the layer decreased to 2.15 from 2.38 for the PET substrate. The band gap values of the Cr-doped ZnO thin films were determined as 3.10 and 3.13 eV for glass and PET substrates.

Spectral Absorption Properties of Aerosol Particles from 350-2500nm

NASA Technical Reports Server (NTRS)

Martins, J. Vanderlei; Artaxo, Paulo; Kaufman, Yoram J.; Castanho, Andrea D.; Remer, Lorraine A.

2009-01-01

The aerosol spectral absorption efficiency (alpha (sub a) in square meters per gram) is measured over an extended wavelength range (350 2500 nm) using an improved calibrated and validated reflectance technique and applied to urban aerosol samples from Sao Paulo, Brazil and from a site in Virginia, Eastern US, that experiences transported urban/industrial aerosol. The average alpha (sub a) values (approximately 3 square meters per gram at 550 nm) for Sao Paulo samples are 10 times larger than alpha (sub a) values obtained for aerosols in Virginia. Sao Paulo aerosols also show evidence of enhanced UV absorption in selected samples, probably associated with organic aerosol components. This extra UV absorption can double the absorption efficiency observed from black carbon alone, therefore reducing by up to 50% the surface UV fluxes, with important implications for climate, UV photolysis rates, and remote sensing from space.

Remote sensing of aerosol plumes: a semianalytical model

NASA Astrophysics Data System (ADS)

Alakian, Alexandre; Marion, Rodolphe; Briottet, Xavier

2008-04-01

A semianalytical model, named APOM (aerosol plume optical model) and predicting the radiative effects of aerosol plumes in the spectral range [0.4,2.5 μm], is presented in the case of nadir viewing. It is devoted to the analysis of plumes arising from single strong emission events (high optical depths) such as fires or industrial discharges. The scene is represented by a standard atmosphere (molecules and natural aerosols) on which a plume layer is added at the bottom. The estimated at-sensor reflectance depends on the atmosphere without plume, the solar zenith angle, the plume optical properties (optical depth, single-scattering albedo, and asymmetry parameter), the ground reflectance, and the wavelength. Its mathematical expression as well as its numerical coefficients are derived from MODTRAN4 radiative transfer simulations. The DISORT option is used with 16 fluxes to provide a sufficiently accurate calculation of multiple scattering effects that are important for dense smokes. Model accuracy is assessed by using a set of simulations performed in the case of biomass burning and industrial plumes. APOM proves to be accurate and robust for solar zenith angles between 0° and 60° whatever the sensor altitude, the standard atmosphere, for plume phase functions defined from urban and rural models, and for plume locations that extend from the ground to a height below 3 km. The modeling errors in the at-sensor reflectance are on average below 0.002. They can reach values of 0.01 but correspond to low relative errors then (below 3% on average). This model can be used for forward modeling (quick simulations of multi/hyperspectral images and help in sensor design) as well as for the retrieval of the plume optical properties from remotely sensed images.

Remote sensing of aerosol plumes: a semianalytical model.

PubMed

Alakian, Alexandre; Marion, Rodolphe; Briottet, Xavier

2008-04-10

A semianalytical model, named APOM (aerosol plume optical model) and predicting the radiative effects of aerosol plumes in the spectral range [0.4,2.5 microm], is presented in the case of nadir viewing. It is devoted to the analysis of plumes arising from single strong emission events (high optical depths) such as fires or industrial discharges. The scene is represented by a standard atmosphere (molecules and natural aerosols) on which a plume layer is added at the bottom. The estimated at-sensor reflectance depends on the atmosphere without plume, the solar zenith angle, the plume optical properties (optical depth, single-scattering albedo, and asymmetry parameter), the ground reflectance, and the wavelength. Its mathematical expression as well as its numerical coefficients are derived from MODTRAN4 radiative transfer simulations. The DISORT option is used with 16 fluxes to provide a sufficiently accurate calculation of multiple scattering effects that are important for dense smokes. Model accuracy is assessed by using a set of simulations performed in the case of biomass burning and industrial plumes. APOM proves to be accurate and robust for solar zenith angles between 0 degrees and 60 degrees whatever the sensor altitude, the standard atmosphere, for plume phase functions defined from urban and rural models, and for plume locations that extend from the ground to a height below 3 km. The modeling errors in the at-sensor reflectance are on average below 0.002. They can reach values of 0.01 but correspond to low relative errors then (below 3% on average). This model can be used for forward modeling (quick simulations of multi/hyperspectral images and help in sensor design) as well as for the retrieval of the plume optical properties from remotely sensed images.

Inclusion of cool roofs in nonresidential Title 24 prescriptive requirements

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

Levinson, Ronnen; Akbari, Hashem; Konopacki, Steve

2002-12-15

Roofs that have high solar reflectance (high ability to reflect sunlight) and high thermal emittance (high ability to radiate heat) tend to stay cool in the sun. The same is true of low-emittance roofs with exceptionally high solar reflectance. Substituting a cool roof for a noncool roof tends to decrease cooling electricity use, cooling power demand, and cooling-equipment capacity requirements, while slightly increasing heating energy consumption. Cool roofs can also lower the ambient air temperature in summer, slowing ozone formation and increasing human comfort. DOE-2.1E building energy simulations indicate that use of a cool roofing material on a prototypical Californiamore » nonresidential building with a low-sloped roof yields average annual cooling energy savings of approximately 300 kWh/1000 ft2 [3.2 kWh/m2], average annual natural gas deficits of 4.9 therm/1000 ft2 [5.6 MJ/m2], average source energy savings of 2.6 MBTU/1000 ft2 [30 MJ/m2], and average peak power demand savings of 0. 19 kW/1000 ft2 [2.1 W/m2]. The 15-year net present value (NPV) of energy savings averages $450/1000 ft2 [$4.90/m2] with time dependent valuation (TDV), and $370/1000 ft2 [$4.00/m2] without TDV. When cost savings from downsizing cooling equipment are included, the average total savings (15-year NPV + equipment savings) rises to $550/1000 ft2 [$5.90/m2] with TDV, and to $470/1000 ft2 [$5.00/m2] without TDV. Total savings range from 0.18 to 0.77 $/ft2 [1.90 to 8.30 $/m2] with TDV, and from 0.16 to 0.66 $/ft2 [1.70 to 7.10 $/m2] without TDV, across California's 16 climate zones. The typical cost premium for a cool roof is 0.00 to 0.20 $/ft2 [0.00 to 2.20 $/m2]. Cool roofs with premiums up to $0.20/ft2 [$2.20/m2] are expected to be cost effective in climate zones 2 through 16; those with premiums not exceeding $0.18/ft2 [$1.90/m2] are expected to be also cost effective in climate zone 1. Hence, this study recommends that the year-2005 California building energy efficiency code (Title 24, Pa rt 6 of the California Code of Regulations) for nonresidential buildings with low-sloped roofs include a cool-roof prescriptive requirement in all California climate zones. Buildings with roofs that do not meet prescriptive requirements may comply with the code via an ''overall-envelope'' approach (non-metal roofs only), or via a performance approach (all roof types).« less

Vertical structure of precipitating shallow echoes observed from TRMM during Indian summer monsoon

NASA Astrophysics Data System (ADS)

Kumar, Shailendra

2017-08-01

The present study explores the properties of precipitating shallow echoes (PSEs) over the tropical areas (30°S-30°N) during Indian summer monsoon season using attenuated corrected radar reflectivity factor (Ze) measured by the Tropical Rainfall Measuring Mission satellite. Radar echoes observed in study are less than the freezing height, so they belong to warm precipitation. Radar echoes with at least 0.75 km wide are considered for finding the shallow echoes climatology. Western Ghats and adjoining ocean (Arabian sea) have the highest PSEs followed by Myanmar and Burma coast, whereas the overall west coast of Latin America consists of the lowest PSEs. Tropical oceanic areas contain fewer PSEs compared to coastal areas. Average vertical profiles show nearly similar Ze characteristics which peaks between 1.5 and 2 km altitude with model value 32-34 dBZ. Slope of Ze is higher for intense PSEs as radar reflectivity decreases more rapidly in intense PSEs.

Measurement of Single Macromolecule Orientation by Total Internal Reflection Fluorescence Polarization Microscopy

PubMed Central

Forkey, Joseph N.; Quinlan, Margot E.; Goldman, Yale E.

2005-01-01

A new approach is presented for measuring the three-dimensional orientation of individual macromolecules using single molecule fluorescence polarization (SMFP) microscopy. The technique uses the unique polarizations of evanescent waves generated by total internal reflection to excite the dipole moment of individual fluorophores. To evaluate the new SMFP technique, single molecule orientation measurements from sparsely labeled F-actin are compared to ensemble-averaged orientation data from similarly prepared densely labeled F-actin. Standard deviations of the SMFP measurements taken at 40 ms time intervals indicate that the uncertainty for individual measurements of axial and azimuthal angles is ∼10° at 40 ms time resolution. Comparison with ensemble data shows there are no substantial systematic errors associated with the single molecule measurements. In addition to evaluating the technique, the data also provide a new measurement of the torsional rigidity of F-actin. These measurements support the smaller of two values of the torsional rigidity of F-actin previously reported. PMID:15894632

Scale dependence in species turnover reflects variance in species occupancy.

PubMed

McGlinn, Daniel J; Hurlbert, Allen H

2012-02-01

Patterns of species turnover may reflect the processes driving community dynamics across scales. While the majority of studies on species turnover have examined pairwise comparison metrics (e.g., the average Jaccard dissimilarity), it has been proposed that the species-area relationship (SAR) also offers insight into patterns of species turnover because these two patterns may be analytically linked. However, these previous links only apply in a special case where turnover is scale invariant, and we demonstrate across three different plant communities that over 90% of the pairwise turnover values are larger than expected based on scale-invariant predictions from the SAR. Furthermore, the degree of scale dependence in turnover was negatively related to the degree of variance in the occupancy frequency distribution (OFD). These findings suggest that species turnover diverges from scale invariance, and as such pairwise turnover and the slope of the SAR are not redundant. Furthermore, models developed to explain the OFD should be linked with those developed to explain species turnover to achieve a more unified understanding of community structure.

Complex refractive index of normal and malignant human colorectal tissue in the visible and near-infrared.

PubMed

Giannios, Panagiotis; Koutsoumpos, Spyridon; Toutouzas, Konstantinos G; Matiatou, Maria; Zografos, George C; Moutzouris, Konstantinos

2017-02-01

A multi-wavelength prism coupling refractometer is utilized to measure the angular reflectance of freshly excised human intestinal tissue specimens. Based on reflectance data, the real and imaginary part of the refractive index is calculated via Fresnel analysis for three visible (blue, green, red) and two near-infrared (963 nm and 1551 nm) wavelengths. Averaged values of the complex refractive index and corresponding Cauchy dispersion fits are given for the mucosa, submucosa and serosa layers of the colorectal wall at the normal state. The refractive constants of tumorous and normal mucosa are then cross-compared for the indicative cases of one patient diagnosed with a benign polyp and three patients diagnosed with adenocarcinomas of different phenotype. Significant index contrast exists between the normal and diseased states, indicating the potential use of refractive index as a marker of colorectal dysplasia. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Visible-infrared remote-sensing model and applications for ocean waters. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Lee, Zhongping

1994-01-01

Remote sensing has become important in the ocean sciences, especially for research involving large spatial scales. To estimate the in-water constituents through remote sensing, whether carried out by satellite or airplane, the signal emitted from beneath the sea surface, the so called water-leaving radiance (L(w)), is of prime importance. The magnitude of L(w) depends on two terms: one is the intensity of the solar input, and the other is the reflectance of the in-water constituents. The ratio of the water-leaving radiance to the downwelling irradiance (E(d)) above the sear surface (remote-sensing reflectance, R(sub rs)) is independent of the intensity of the irradiance input, and is largely a function of the optical properties of the in-water constituents. In this work, a model is developed to interpret r(sub rs) for ocean water in the visible-infrared range. In addition to terms for the radiance scattered from molecules and particles, the model includes terms that describe contributions from bottom reflectance, fluorescence of gelbstoff or colored dissolved organic matter (CDOM), and water Raman scattering. By using this model, the measured R(sub rs) of waters from the West Florida Shelf to the Mississippi River plume, which covered a (concentration of chlorophyll a) range of 0.07 - 50 mg/cu m, were well interpreted. The average percentage difference (a.p.d.) between the measured and modeled R(sub rs) is 3.4%, and, for the shallow waters, the model-required water depth is within 10% of the chart depth. Simple mathematical simulations for the phytoplankton pigment absorption coefficient (a(sub theta)) are suggested for using the R(sub rs) model. The inverse problem of R(sub rs), which is to analytically derive the in-water constituents from R(sub rs) data alone, can be solved using the a(sub theta) functions without prior knowledge of the in-water optical properties. More importantly, this method avoids problems associated with a need for knowledge of the shape and value of the chlorophyll-specific absorption coefficient. The simulation was tested for a wide range of water types, including waters from Monterey Bay, the West Florida Shelf, and the Mississippi River plume. Using the simulation, the R(sub rs)-derived in-water absorption coefficients were consistent with the values from in-water measurements (r(exp 2) greater than 0.94, slope approximately 1.0). In the remote-sensing applications, a new approach is suggested for the estimation of primary production based on remote sensing. Using this approach, the calculated primary production (PP) values based upon remotely sensed data were very close to the measured values for the euphotic zone (r(exp 2) = 0.95, slope 1.26, and 32% average difference), while traditional, pigment-based PP model provided values only one-third the size of the measured data. This indicates a potential to significantly improve the accuracy of the estimation of primary production based upon remote sensing.

Electric Field Magnitude and Radar Reflectivity as a Function of Distance from Cloud Edge

NASA Technical Reports Server (NTRS)

Ward, Jennifer G.; Merceret, Francis J.

2004-01-01

The results of analyses of data collected during a field investigation of thunderstorm anvil and debris clouds are reported. Statistics of the magnitude of the electric field are determined as a function of distance from cloud edge. Statistics of radar reflectivity near cloud edge are also determined. Both analyses use in-situ airborne field mill and cloud physics data coupled with ground-based radar measurements obtained in east-central Florida during the summer convective season. Electric fields outside of anvil and debris clouds averaged less than 3 kV/m. The average radar reflectivity at the cloud edge ranged between 0 and 5 dBZ.

Investigating the Influence of Vegetation Type on Modern Leaf Wax Hydrogen Isotopes from a High Latitude Ombrotrophic Bog to Inform Paleoclimate Interpretation

NASA Astrophysics Data System (ADS)

Balascio, N.; D'Andrea, W. J.; Anderson, R. S.

2016-12-01

Leaf wax hydrogen isotopes have been used to track changes in the isotopic composition of meteoric waters in a variety of locations. However, leaf wax compounds preserved in sedimentary environments reflect a mix of plant sources that can have a large range of molecular distributions and biosynthetic fractionation factors potentially complicating paleoclimate interpretations. Here we attempt to constrain the influence of vegetation type on leaf wax hydrogen isotope values at an ombrotrophic bog in northern Norway. We present: (i) δD values of n-alkanes from modern bog vegetation to establish the influence of vegetation type on n-alkane distributions and to provide a site-specific assessment of the biosynthetic isotopic fractionation, and (ii) δD values of n-alkanes from a sediment core spanning the last 10 ka where vegetation changes have been reconstructed based on pollen analysis. We found 14 different vegetation types growing on the bog surface that have average chain lengths from 25 to 30.5 and δD values of n-C25 to n-C33 ranging from -197‰ to -116‰. These samples also have a range of δD values among n-alkane homologues, from 1‰ to 33‰. Based on isotopic measurements of modern bog water, we calculate the average apparent fractionation of n-alkanes to be -108 ± 22‰. Sedimentary δD values of n-C25 to n-C33 over the last 10 ka range from -229 to -158‰ with distinct trends among mid- and long-chain length homologues. Changes in chain lengths and δD values, at times, correspond to vegetation shifts documented by pollen data, but also show unique trends that we interpret to represent variations in local precipitation isotopes related to past hydroclimate change.

Radar characteristics of Viking 1 landing sites

USGS Publications Warehouse

Tyler, G.L.; Campbell, D.B.; Downs, G.S.; Green, R.R.; Moore, H.J.

1976-01-01

Radar observations of Mars at centimeter wavelengths in May, June, and July 1976 provided estimates of surface roughness and reflectivity in three potential landing areas for Viking 1. Surface roughness is characterized by the distribution of surface landing slopes or tilts on lateral scales of the order of 1 to 10 meters; measurements of surface reflectivity are indicators of bulk surface density in the uppermost few centimeters. By these measures, the Viking 1 landing site at 47.5??W, 22.4??N is rougher than the martian average, although it may be near the martian average for elevations accessible to Viking, and is estimated to be near the Mars average in reflectivity. The AINW site at the center of Chryse Planitia, 43.5??W, 23.4??N, may be an area of anomalous radar characteristics, indicative of extreme, small-scale roughness, very low surface density, or a combination of these two characteristics. Low signal-to-noise ratio observations of the original Chryse site at 34??W, 19.5??N indicate that that area is at least twice as rough as the Mars average.

Arctic Tundra Vegetation Functional Types Based on Photosynthetic Physiology and Optical Properties

NASA Technical Reports Server (NTRS)

Huemmrich, Karl F.; Gamon, John; Tweedie, Craig; Campbell, Petya P. K.; Landis, David; Middleton, Elizabeth

2012-01-01

Climate change in tundra regions may alter vegetation species composition and ecosystem carbon balance. Remote sensing provides critical tools for monitoring these changes as optical signals provide a way to scale from plot measurements to regional patterns. Gas exchange measurements of pure patches of key vegetation functional types (lichens, mosses, and vascular plants) in sedge tundra at Barrow AK, show three significantly different values of light use efficiency (LUE) with values of 0.013+/-0.001, 0.0018+/-0.0002, and 0.0012 0.0001 mol C/mol absorbed quanta for vascular plants, mosses and lichens, respectively. Further, discriminant analysis of patch reflectance identifies five spectral bands that can separate each vegetation functional type as well as nongreen material (bare soil, standing water, and dead leaves). These results were tested along a 100 m transect where midsummer spectral reflectance and vegetation coverage were measured at one meter intervals. Area-averaged canopy LUE estimated from coverage fractions of the three functional types varied widely, even over short distances. Patch-level statistical discriminant functions applied to in situ hyperspectral reflectance successfully unmixed cover fractions of the vegetation functional types. These functions, developed from the tram data, were applied to 30 m spatial resolution Earth Observing-1 Hyperion imaging spectrometer data to examine regional variability in distribution of the vegetation functional types and from those distributions, the variability of LUE. Across the landscape, there was a fivefold variation in tundra LUE that was correlated to a spectral vegetation index developed to detect vegetation chlorophyll content.

Reconnaissance studies of potential petroleum source rocks in the Middle Jurassic Tuxedni Group near Red Glacier, eastern slope of Iliamna Volcano

USGS Publications Warehouse

Stanley, Richard G.; Herriott, Trystan M.; LePain, David L.; Helmold, Kenneth P.; Peterson, C. Shaun

2013-01-01

Previous geological and organic geochemical studies have concluded that organic-rich marine shale in the Middle Jurassic Tuxedni Group is the principal source rock of oil and associated gas in Cook Inlet (Magoon and Anders, 1992; Magoon, 1994; Lillis and Stanley, 2011; LePain and others, 2012; LePain and others, submitted). During May 2009 helicopter-assisted field studies, 19 samples of dark-colored, fine-grained rocks were collected from exposures of the Red Glacier Formation of the Tuxedni Group near Red Glacier, about 70 km west of Ninilchik on the eastern flank of Iliamna Volcano (figs. 1 and 3). The rock samples were submitted to a commercial laboratory for analysis by Rock-Eval pyrolysis and to the U.S. Geological Survey organic geochemical laboratory in Denver, Colorado, for analysis of vitrinite reflectance. The results show that values of vitrinite reflectance (percent Ro) in our samples average about 2 percent, much higher than the oil window range of 0.6–1.3 percent (Johnsson and others, 1993). The high vitrinite reflectance values indicate that the rock samples experienced significant heating and furthermore suggest that these rocks may have generated oil and gas in the past but no longer have any hydrocarbon source potential. The high thermal maturity of the rock samples may have resulted from (1) the thermaleffects of igneous activity (including intrusion by igneous rocks), (2) deep burial beneath Jurassic, Cretaceous, and Tertiary strata that were subsequently removed by uplift and erosion, or (3) the combined effects of igneous activity and burial.

An advanced retrieval algorithm for greenhouse gases using polarization information measured by GOSAT TANSO-FTS SWIR I: Simulation study

NASA Astrophysics Data System (ADS)

Kikuchi, N.; Yoshida, Y.; Uchino, O.; Morino, I.; Yokota, T.

2016-11-01

We present an algorithm for retrieving column-averaged dry air mole fraction of carbon dioxide (XCO2) and methane (XCH4) from reflected spectra in the shortwave infrared (SWIR) measured by the TANSO-FTS (Thermal And Near infrared Sensor for carbon Observation Fourier Transform Spectrometer) sensor on board the Greenhouse gases Observing SATellite (GOSAT). The algorithm uses the two linear polarizations observed by TANSO-FTS to improve corrections to the interference effects of atmospheric aerosols, which degrade the accuracy in the retrieved greenhouse gas concentrations. To account for polarization by the land surface reflection in the forward model, we introduced a bidirectional reflection matrix model that has two parameters to be retrieved simultaneously with other state parameters. The accuracy in XCO2 and XCH4 values retrieved with the algorithm was evaluated by using simulated retrievals over both land and ocean, focusing on the capability of the algorithm to correct imperfect prior knowledge of aerosols. To do this, we first generated simulated TANSO-FTS spectra using a global distribution of aerosols computed by the aerosol transport model SPRINTARS. Then the simulated spectra were submitted to the algorithms as measurements both with and without polarization information, adopting a priori profiles of aerosols that differ from the true profiles. We found that the accuracy of XCO2 and XCH4, as well as profiles of aerosols, retrieved with polarization information was considerably improved over values retrieved without polarization information, for simulated observations over land with aerosol optical thickness greater than 0.1 at 1.6 μm.

A real world analysis of payment per unit time in a Maryland Vascular Practice.

PubMed

Martin, John D; Warble, Patricia B; Hupp, Jon A; Mapes, Jerry E; Stanziale, Stephen F; Weiss, Linda L; Schiller, Toni B; Hanson, Louise A

2010-10-01

In 1992, Centers for Medicare and Medicaid Services instituted the Resource Based Relative Value Scale (RBRVS) system to determine physician reimbursement. Relative value units (RVU) were assigned to each Current Procedure Terminology (CPT) code and intended to reflect the time and intensity of work. Little data exist correlating actual procedural and clinical time with respect to reimbursement within the RVU value system. The purpose of this study was to determine how well this system distributes payments per hour for hospital-based procedures in a single vascular practice in the state of Maryland between July 1, 2008 and June 30, 2009. As part of an ongoing prospective outcomes program, procedural times for all vascular procedures (time into until time out of room) were recorded. Fifteen minutes were added for administrative functions on procedural day, each hospital day, and office visits during the global period. The combination of all times was reflected in the total care time (TCT) for each procedure. We recorded all physician fees collected for each procedure. This total fee collected for each procedure was then divided by the TCT to determine the procedure-specific payment per unit time. All similar procedures were grouped together and the average reimbursement per procedure was reported. Data was collected on all 1103 procedures performed during this period. Insurance carrier distribution was 75% Medicare and 25% private insurance. The average reimbursement was $316/hour for open procedures and $556/hour for endovascular. Higher reimbursing procedures included visceral endovascular procedures ($701/hour) and caval filters ($751/hour). Lower reimbursing procedures included lower extremity bypass ($292/hour), dialysis access ($268/hour) and lower extremity amputations ($223/hour). Striking was the difference between payment based on approach for similar conditions. Reimbursement for carotid stent vs carotid endarterectomy was $643/hour vs $383/hour, endovascular abdominal aortic aneurysm (AAA) repair vs open $593/hour vs $359/hour. This unique study demonstrates a "real world" experience of reimbursement per unit time and raises questions as to the validity of the RBRVS process. The disparity between payments for open and endovascular repair of similar conditions are typical of this inequality. These data do not reflect the intangible time of operative planning, administrative matters, or overhead, and these factors must be considered when interpreting this data. Regardless, this study suggests that capturing detailed financial data is possible and is a more accurate source for future discussions on reimbursement. Copyright © 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Study of optical reflectance properties in 1D annular photonic crystal containing double negative (DNG) metamaterials

NASA Astrophysics Data System (ADS)

Srivastava, Sanjeev K.; Aghajamali, Alireza

2016-05-01

Theoretical investigation of photonic band gaps or reflection bands in one-dimensional annular photonic crystal (APC) containing double negative (DNG) metamaterials and air has been presented. The proposed structure consists of the alternate layers of dispersive DNG material and air immersed in free space. In order to study photonic band gaps we obtain the reflectance spectrum of the annular PC by employing the transfer matrix method (TMM) in the cylindrical waves for both TE and TM polarizations. In this work we study the effect of azimuthal mode number (m) and starting radius (ρ0) on the three band gaps viz. zero averaged refractive index (zero-nbar) gap, zero permittivity (zero- ε) and zero permeability (zero- μ) gaps. It is found that for m ≥ 1 , zero- μ gap appears in TE mode and zero- ε gap appears in TM mode. The width of both zero- μ and zero- ε gap increases by increasing m values, but the enhancement of zero- μ gap is more appreciable. Also, the effect of ρ0 on the three band gaps (reflection bands) of annular PC structure at the given m-number has been studied, for both TE and TM polarizations. The result shows that in both polarizations zero- ε and zero- μ gaps decreases when ρ0 increases, whereas zero-nbar gap remains invariant.

Canopy reflectance modeling in a tropical wooded grassland

NASA Technical Reports Server (NTRS)

Simonett, David

1988-01-01

The Li-Strahler canopy reflectance model, driven by LANDSAT Thematic Mapper (TM) data, provided regional estimates of tree size and density in two bioclimatic zones in Africa. This model exploits tree geometry in an inversion technique to predict average tree size and density from reflectance data using a few simple patameters measured in the field and in the imagery. Reflectance properties of the trees were measured in the study sites using a pole-mounted radiometer. The measurements showed that the assumptions of the simple Li-Strahler model are reasonable for these woodlands. The field radiometer measurements were used to calculate the normalized difference vegetation index (NDVI), and the integrated NDVI over the canopy was related to crown volume. Predictions of tree size and density from the canopy model were used with allometric equations from the literature to estimate woody biomass and potential foliar biomass for the sites and for the regions. Estimates were compared with independent measurements made in the Sahelian sites, and to typical values from the literature for these regions and for similar woodlands. In order to apply the inversion procedure regionally, an area must first be stratified into woodland cover classes, and dry-season TM data were used to generate a stratum map of the study areas with reasonable accuracy. The method used was unsupervised classification of multi-data principal components images.

Acoustic emission monitoring of concrete columns and beams strengthened with fiber reinforced polymer sheets

NASA Astrophysics Data System (ADS)

Ma, Gao; Li, Hui; Zhou, Wensong; Xian, Guijun

2012-04-01

Acoustic emission (AE) technique is an effective method in the nondestructive testing (NDT) field of civil engineering. During the last two decades, Fiber reinforced polymer (FRP) has been widely used in repairing and strengthening concrete structures. The damage state of FRP strengthened concrete structures has become an important issue during the service period of the structure and it is a meaningful work to use AE technique as a nondestructive method to assess its damage state. The present study reports AE monitoring results of axial compression tests carried on basalt fiber reinforced polymer (BFRP) confined concrete columns and three-point-bending tests carried on BFRP reinforced concrete beams. AE parameters analysis was firstly utilized to give preliminary results of the concrete fracture process of these specimens. It was found that cumulative AE events can reflect the fracture development trend of both BFRP confined concrete columns and BFRP strengthened concrete beams and AE events had an abrupt increase at the point of BFRP breakage. Then the fracture process of BFRP confined concrete columns and BFRP strengthened concrete beams was studied through RA value-average frequency analysis. The RA value-average frequency tendencies of BFRP confined concrete were found different from that of BFRP strengthened concrete beams. The variation tendency of concrete crack patterns during the loading process was revealed.

Characterizing the magnetic memory signals on the surface of plasma transferred arc cladding coating under fatigue loads

NASA Astrophysics Data System (ADS)

Huang, Haihong; Han, Gang; Qian, Zhengchun; Liu, Zhifeng

2017-12-01

The metal magnetic memory signals were measured during dynamic tension tests on the surfaces of the cladding coatings by plasma transferred arc (PTA) welding and the 0.45% C steel. Results showed that the slope of the normal component Hp(y) of magnetic signal and the average value of the tangential component Hp(x) reflect the magnetization of the specimens. The signals increased sharply in the few initial cycles; and then fluctuated around a constant value during fatigue process until fracture. For the PTA cladding coating, the slope of Hp(y) was steeper and the average of Hp(x) was smaller, compared with the 0.45% C steel. The hysteresis curves of cladding layer, bonding layer and substrate were measured by vibrating sample magnetometer testing, and then saturation magnetization, initial susceptibility and coercivity were further calculated. The stress-magnetization curves were also plotted based on the J-A model, which showed that the PTA cladding coating has smaller remanence and coercivity compared with the 0.45% C steel. The microstructures of cladding coating confirmed that the dendritic structure and second-phase of alloy hinder the magnetic domain motion, which was the main factor influencing the variation of magnetic signal during the fatigue tests.

Coexistence of a well-determined kinetic law and a scale-invariant power law during the same physical process

NASA Astrophysics Data System (ADS)

Zreihan, Noam; Faran, Eilon; Vives, Eduard; Planes, Antoni; Shilo, Doron

2018-01-01

It is generally claimed that physical processes which display scale-invariant power-law distributions are subjected to a dynamic criticality that prohibits a well-defined kinetic law. In this paper, we demonstrate the coexistence of these two apparently contradicting behaviors during the same physical process—the motion of type-II twin boundaries in martensite Ni-Mn-Ga. The process is investigated by combined measurements of the temporal twin-boundary velocity and the acoustic emitted energy. Velocity values are extracted from high-resolution force measurements taken during displacement-driven mechanical tests, as well as from force-driven magnetic tests, and cover an overall range of six orders of magnitude. Acoustic emission (AE) is measured during mechanical tests. Velocity values follow a normal distribution whose characteristic value is determined by the material's kinetic relation, and its width scales with the average velocity. In addition, it is observed that velocity distributions are characterized by a heavy tail at the right (i.e., faster) end that exhibits a power law over more than one and a half orders of magnitude. At the same time, the AE signals follow a scale-invariant power-law distribution, which is not sensitive to the average twin-boundary velocity. The coexistence of these two different statistical behaviors reflects the complex nature of twin-boundary motion and suggests the possibility that the transformation proceeds through physical subprocesses that are close to criticality alongside other processes that are not.

Cluster-based analysis improves predictive validity of spike-triggered receptive field estimates

PubMed Central

Malone, Brian J.

2017-01-01

Spectrotemporal receptive field (STRF) characterization is a central goal of auditory physiology. STRFs are often approximated by the spike-triggered average (STA), which reflects the average stimulus preceding a spike. In many cases, the raw STA is subjected to a threshold defined by gain values expected by chance. However, such correction methods have not been universally adopted, and the consequences of specific gain-thresholding approaches have not been investigated systematically. Here, we evaluate two classes of statistical correction techniques, using the resulting STRF estimates to predict responses to a novel validation stimulus. The first, more traditional technique eliminated STRF pixels (time-frequency bins) with gain values expected by chance. This correction method yielded significant increases in prediction accuracy, including when the threshold setting was optimized for each unit. The second technique was a two-step thresholding procedure wherein clusters of contiguous pixels surviving an initial gain threshold were then subjected to a cluster mass threshold based on summed pixel values. This approach significantly improved upon even the best gain-thresholding techniques. Additional analyses suggested that allowing threshold settings to vary independently for excitatory and inhibitory subfields of the STRF resulted in only marginal additional gains, at best. In summary, augmenting reverse correlation techniques with principled statistical correction choices increased prediction accuracy by over 80% for multi-unit STRFs and by over 40% for single-unit STRFs, furthering the interpretational relevance of the recovered spectrotemporal filters for auditory systems analysis. PMID:28877194

Terrestrial and marine trophic pathways support young-of-year growth in a nearshore Arctic fish

USGS Publications Warehouse

von Biela, Vanessa R.; Zimmerman, Christian E.; Cohn, Brian R.; Welker, Jeffrey M.

2013-01-01

River discharge supplies nearshore communities with a terrestrial carbon source that is often reflected in invertebrate and fish consumers. Recent studies in the Beaufort Sea have documented widespread terrestrial carbon use among invertebrates, but only limited use among nearshore fish consumers. Here, we examine the carbon source and diet of rapidly growing young-of-year Arctic cisco (Coregonus autumnalis) using stable isotope values (δ13C and δ15N) from muscle and diet analysis (stomach contents) during a critical and previously unsampled life stage. Stable isotope values (δ15N and δ13C) may differentiate between terrestrial and marine sources and integrate over longer time frames (weeks). Diet analysis provides species-specific information, but only from recent foraging (days). Average δ13C for all individuals was −25.7 ‰, with the smallest individuals possessing significantly depleted δ13C values indicative of a stronger reliance of terrestrial carbon sources as compared to larger individuals. Average δ15N for all individuals was 10.4 ‰, with little variation among individuals. As fish length increased, the proportion of offshore Calanus prey and neritic Mysis prey increased. Rapid young-of-year growth in Arctic cisco appears to use terrestrial carbon sources obtained by consuming a mixture of neritic and offshore zooplankton. Shifts in the magnitude or phenology of river discharge and the delivery of terrestrial carbon may alter the ecology of nearshore fish consumers.

Are head-to-head trials of biologics needed? The role of value of information methods in arthritis research.

PubMed

Welton, Nicky J; Madan, Jason; Ades, Anthony E

2011-09-01

Reimbursement decisions are typically based on cost-effectiveness analyses. While a cost-effectiveness analysis can identify the optimum strategy, there is usually some degree of uncertainty around this decision. Sources of uncertainty include statistical sampling error in treatment efficacy measures, underlying baseline risk, utility measures and costs, as well as uncertainty in the structure of the model. The optimal strategy is therefore only optimal on average, and a decision to adopt this strategy might still be the wrong decision if all uncertainty could be eliminated. This means that there is a quantifiable expected (average) loss attaching to decisions made under uncertainty, and hence a value in collecting information to reduce that uncertainty. Value of information (VOI) analyses can be used to provide guidance on whether more research would be cost-effective, which particular model inputs (parameters) have the most bearing on decision uncertainty, and can also help with the design and sample size of further research. Here, we introduce the key concepts in VOI analyses, and highlight the inputs required to calculate it. The adoption of the new biologic treatments for RA and PsA tends to be based on placebo-controlled trials. We discuss the possible role of VOI analyses in deciding whether head-to-head comparisons of the biologic therapies should be carried out, illustrating with examples from other fields. We emphasize the need for a model of the natural history of RA and PsA, which reflects a consensus view.

26 CFR 1.312-9 - Adjustments to earnings and profits reflecting increase in value accrued before March 1, 1913.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 4 2011-04-01 2011-04-01 false Adjustments to earnings and profits reflecting... § 1.312-9 Adjustments to earnings and profits reflecting increase in value accrued before March 1..., that part of the earnings and profits which is represented by increase in value of property accrued...

BOREAS RSS-19 1994 Seasonal Understory Reflectance Data

NASA Technical Reports Server (NTRS)

Miller, John R.; Hall, Forrest G. (Editor); Nickerson, Jaime (Editor); White, H. Peter; Peddle, Derek; Freemantle, Jim; Smith, David E. (Technical Monitor)

2000-01-01

The BOREAS RSS-19 team collected airborne remotely sensed images and ground reflectance data for characterizing the radiometric properties of the boreal forest landscape. One objective of BOREAS is to further the understanding of the spectral bidirectional reflectance of typical boreal ecosystem stands in the visible/near-infrared regime. An essential input for any canopy BRDF model is an accurate estimate of the average understory reflectance, both for sunlit and shaded conditions. These variables can be expected to vary seasonally because of species-dependent differences in the phenological cycle of foliar display. In response to these requirements, the average understory reflectance for the flux tower sites of both the NSA (Thompson, Manitoba) and the SSA (Candle Lake, Saskatchewan) was observed throughout the year during five field campaigns. This was done by measuring the nadir reflectance (400 to 850 nm) of sunlit and shaded understory (vegetation and snow cover) along a surveyed LAI transect line (Chen, RSS-07) at each site near solar noon and documenting an average site reflectance. Comparisons between sites reveal differences in the green and infrared regions of the spectra, because of the differing species in the understory for each site. Temporal (seasonal) variation for each site was also observed (06-Feb-1994 to 16-Sep-1994), indicating the changing flora mixtures and changing spectral signatures as the understory matures during the growing season. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Bannatyne-Recategorized WISC-R Patterns of Mentally Retarded, Learning Disabled, Normal, and Intellectually Superior Children: A Meta-Analysis.

ERIC Educational Resources Information Center

Mueller, Horst H.; And Others

1983-01-01

Metaanalytical procedures examined the Wechsler Intelligence Scale-Revised subtest performance patterns of 36 samples of below average, normal average, learning disabled average, and above average IQ children from research. Relative patterning of WISC-R subtests as reflected in children's Bannatyne-recategorized performance profiles appeared to be…

Oxygen isotope values of tree ring α-cellulose as a proxy of hydroclimate variability in arid regions

NASA Astrophysics Data System (ADS)

Dodd, J. P.; Freimuth, E. J.; Olson, E. J.; Diefendorf, A. F.

2015-12-01

One of the main goals of tree ring isotope studies is to reconstruct climate-driven variations in the source water and antecedent precipitation; however, evaporation in the soil and leaves can significantly modify the isotope values of the source water. This is particularly the case in arid environments where evaporative effects are perhaps the most significant unknown variable when attempting to reconstruct regional-scale hydroclimate variations from tree ring isotope proxies. To quantify the effects of extreme aridity on α-cellulose δ18O values, we measured the oxygen isotope values of groundwater, xylem water, leaf water, and tree ring α-cellulose in an endemic species of drought-resistant trees (Prosopis tamarugo) from different microenvironments throughout the Atacama Desert of Northern Chile. Average annual precipitation is <5 mm/yr, and groundwater is the primary water source for P. tamarugo trees in the region. Groundwater δ18O values at the sample locations range from -6.7 to -9.7‰, and xylem water δ18O values record a systematic increase (ave. Δ18Ox-gw =+1.3‰; 2σ =1.0‰). Leaf waters are significantly affected by evaporative enrichment with a range of δ18O values from 7 to 23‰. This range most likely reflects a number of physiological and environmental conditions including tree size, canopy development, and sample time (i.e. morning vs. evening). However, despite the large variation in leaf water δ18O values, the average difference between the α-cellulose and groundwater is very consistent (Δ18Oc-gw = +39.7‰; 2σ =1.3‰). P. tamarugo samples were collected in austral spring, when tree growth was at its maximum; therefore, any seasonal variations in plant physiology not captured with this dataset will have a limited impact on cellulose production. These data demonstrate that despite the variable evaporative enrichment of 18O in the leaf water, the α-cellulose δ18O values provide a remarkably consistent record of variations in groundwater δ18O values in this extremely arid environment.

[Alternative nutrition and glutathione levels].

PubMed

Krajcovicová-Kudlácková, M; Simoncic, R; Béderová, A; Brtková, A; Magálová, T; Barteková, S

1999-08-30

Low protein quality and quantity is reported to be a possible risk of alternative nutrition. Pulses contain 18-41% of methionine in relation to reference protein, moreover, its content in cereals is by one half lower. Therefore vegetarians and vegans may have an insufficient intake of sulphur-containing amino acids that may subsequently affect glutathione values (precursors of its synthesis). In groups of adults on an alternative diet--lactoovovegetarians (n = 47) and vegans (n = 44) aged 19-62 years with average duration on a vegetarian or vegan diet of 7.6 and 4.9 years, respectively, glutathione levels (GSH) were measured in erythrocytes (spectrophotometrically), as well as the activity of GSH-dependent enzymes. As nutritional control (n = 42) served an average sample of omnivores selected from a group of 489 examined, apparently healthy subjects of the same age range living in the same region. One to low protein intake (56% of RDA) exclusively of plant origin significantly lower levels of total proteins were observed in vegans with a 16% frequency of hypoproteinaemia (vs 0% in omnivores). In comparison to omnivores a significantly lower glutathione level was found (4.28 +/- 0.12 vs 4.84 +/- 0.14 mumol/g Hb, P < 0.01). Lactoovovegetarians because of their protein intake in adequate amounts with a 27% proportion of animal proteins (dairy products, eggs) consume a balanced mixture of amino acids, which is reflected in total protein levels similar to omnivores and significantly higher values of glutathione -5.26 +/- 0.12 mumol/g Hb, P < 0.05 (intake of glutathione in diet, higher consumption of fruit and vegetable in comparison to omnivores). A sufficient supply of glutathione as the substrate for enzymatic reactions of hydrogen peroxide or lipid hydroperoxide catabolism, as well as for detoxication of xenobiotics, was reflected in lactoovovegetarians in a significantly higher activity of glutathione-peroxidase and glutathione-S-transferase in erythrocytes. Low protein intake exclusively of plant origin, significantly lower protein levels with 16% frequency of hypoproteinaemia, significantly lower glutathione values in blood in comparison to omnivores and lactoovovegetarians confirm the risk of a vegan diet also in adult age.

Infant mortality evolution in Romania: perspectives from a country in transition

NASA Astrophysics Data System (ADS)

Burlea, A.-M.; Muntele, I.

2012-04-01

In the last two decades transition was a word used to describe the important mutations that have characterized social and economic structures in Romania. All the changes left their mark on every aspects of life including on population health status, and all modifications were reflected in the evolution of health indicators. Considered one of the most sensitive indicators of living conditions, population health literacy level and healthcare system efficiency infant mortality rate is a negative indicator which reflects the intensity of children deaths before their first anniversary. Based on the current statistical data collected at county level, this research aims to underline the existing spatial differences in Romania at county level, to identify spatial patterns, time trend and to point out the territories that need special attention and a more profound analysis for understanding the causes that are generating them. Using mathematical and statistical methods we have calculated infant mortality for a previous and available period of time (1990 - 2010) and identified a trend influenced by exogenous and endogenous factors. With the help of GIS techniques we have created cartographic material for allowing us an easier identification of spatial disparities. Following the global trend, Romania achieved significant progress in reduction infant mortality. From values that exceeded 26 ‰ at the beginning of the nineties this indicator has continued to diminish until 9.79 ‰ in 2010. But, with all the improvements, value is still double in compare with European Union average. Although characteristic for Romania is the general downward trend, at the county level there can be identified different types of evolution and different spatial pattern. Having the lowest economic development level in the country, Northeast and Southeast counties maintain high values for infant mortality rate. Positive examples are given by Bucharest and some central and western districts, all with socio-economic indicators above the national average. In this context, identification, monitoring and description of infant mortality rate spatial disparities are becoming key points for policy makers and stakeholders as first steps needed for finding the most suitable measures to reduce them, measures tailored for any administrative level in which they occur.

Testing the Li-Strahler four-component canopy reflectance model in the HAPEX-Sahel shrub savanna sites using ground reflectance data

NASA Technical Reports Server (NTRS)

Franklin, J.; Duncan, J.

1992-01-01

The rate at which a light field decays in water is characterized by the diffuse attenuation coefficient k. The Li-Strahler discrete-object canopy reflectance model was tested in two sites, a shrub grass savanna and a degraded shrub savanna on bare soil, in the proposed HAPEX (Hydrologic Atmospheric Pilot Experiment) II/Sahel study area in Niger, West Africa. Average site reflectance was predicted for each site from the reflectances and cover proportions of four components: shrub canopy, background (soil or grass and soil), shaded canopy, and shaded background. Component reflectances were sampled in the SPOT wavebands using a hand-held radiometer. Predicted reflectance was compared to average site reflectance measured using the same radiometer mounted on a backpack with measurements recorded every 5 m along two 1-km transects, also in the SPOT (Systeme Probatoire d'Observation de la Terre) bands. Measurements and predictions were made for each of the three days during the summer growing season, approximately two weeks apart. Red, near infrared reflectance, and the NDVI (normalized difference vegetation index) were all predicted with a high degree of accuracy for the shrub/grass site and with reasonable accuracy for the degraded shrub site.

Design Rules for Tailoring Antireflection Properties of Hierarchical Optical Structures

DOE PAGES

Leon, Juan J. Diaz; Hiszpanski, Anna M.; Bond, Tiziana C.; ...

2017-05-18

Hierarchical structures consisting of small sub-wavelength features stacked atop larger structures have been demonstrated as an effective means of reducing the reflectance of surfaces. However, optical devices require different antireflective properties depending on the application, and general unifying guidelines on hierarchical structures' design to attain a desired antireflection spectral response are still lacking. The type of reflectivity (diffuse, specular, or total/hemispherical) and its angular- and spectral-dependence are all dictated by the structural parameters. Through computational and experimental studies, guidelines have been devised to modify these various aspects of reflectivity across the solar spectrum by proper selection of the features ofmore » hierarchical structures. In this wavelength regime, micrometer-scale substructures dictate the long-wavelength spectral response and effectively reduce specular reflectance, whereas nanometer-scale substructures dictate primarily the visible wavelength spectral response and reduce diffuse reflectance. Coupling structures having these two length scales into hierarchical arrays impressively reduces surfaces' hemispherical reflectance across a broad spectrum of wavelengths and angles. Furthermore, such hierarchical structures in silicon are demonstrated having an average total reflectance across the solar spectrum of 1.1% (average weighted reflectance of 1% in the 280–2500 nm range of the AM 1.5 G spectrum) and specular reflectance <1% even at angles of incidence as high as 67°.« less

Genetics of wellbeing and its components satisfaction with life, happiness, and quality of life: a review and meta-analysis of heritability studies.

PubMed

Bartels, Meike

2015-03-01

Wellbeing is a major topic of research across several disciplines, reflecting the increasing recognition of its strong value across major domains in life. Previous twin-family studies have revealed that individual differences in wellbeing are accounted for by both genetic as well as environmental factors. A systematic literature search identified 30 twin-family studies on wellbeing or a related measure such as satisfaction with life or happiness. Review of these studies showed considerable variation in heritability estimates (ranging from 0 to 64 %), which makes it difficult to draw firm conclusions regarding the genetic influences on wellbeing. For overall wellbeing twelve heritability estimates, from 10 independent studies, were meta-analyzed by computing a sample size weighted average heritability. Ten heritability estimates, derived from 9 independent samples, were used for the meta-analysis of satisfaction with life. The weighted average heritability of wellbeing, based on a sample size of 55,974 individuals, was 36 % (34-38), while the weighted average heritability for satisfaction with life was 32 % (29-35) (n = 47,750). With this result a more robust estimate of the relative influence of genetic effects on wellbeing is provided.

Optical losses of solar mirrors due to atmospheric contamination at Liberal, Kansas and Oologah, Oklahoma

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

Dake, L.S.; Lind, M.A.

An assessment is presented of the effect of outdoor exposure on mirrors located at two sites selected for potential solar cogeneration/repowering facilities: Liberal, Kansas and Oologah, Oklahoma. Mirror coupons were placed on tracking heliostat simulators located in the proposed heliostat fields and were removed periodically. The spectral hemispherical and diffuse reflectances of these coupons were measured. Representative samples were analyzed for the chemical composition of the dust particulates using SEM/EDX. Other samples were washed with a high pressure spray and recharacterized to determine the effects of the residual dust. Average specular reflectance losses over the entire test period (up tomore » 504 days) were 6 to 12%, with a range of 1 to 30%. Specular reflectance losses varied widely from day to day depending on local weather conditions. The losses due to scattering were 2 to 5 times greater than the losses due to absorptance. The average degradation rate over the first thirty days was an order of magnitude larger than the average degradation rate over the entire sampling period. Specular reflectance loss rates averaged 0.5% per day and greater between periods of natural cleaning. The chemical composition of the dust on the mirrors was characteristic of the indigenous soil, with some samples also showing the presence of sulfur and chlorine, possibly from cooling tower drift.« less

Premature chromosome condensation studies in human leukemia. I. Pretreatment characteristics.

PubMed

Hittelman, W N; Broussard, L C; McCredie, K

1979-11-01

The phenomenon of premature chromosome condensation (PCC) was used to compare the bone marrow proliferation characteristics of 163 patients with various forms of leukemia prior to the initiation of new therapy. The proliferative potential index (PPI, or fraction of G1 cells in late G1 phase) and the fraction of cells in S phase was determined and compared to the type of disease and the bone marrow blast infiltrate for each patient. Previously untreated patients with acute leukemia exhibited an average PPI value three times that of normal bone marrow (37.5% for acute myeloblastic leukemia [AML], acute monomyeloblastic leukemia [AMML], or acute promyelocytic leukemia [APML] and 42% for acute lymphocytic leukemia [ALL] or acute undifferentiated leukemia [AUL]). Untreated chronic myelogenous leukemia (CML) patients showed intermediate PPI values (25.2%), whereas CML patients with controlled disease exhibited nearly normal PPI values (14.6%). On the other hand, blastic-phase CML patients exhibited PPI values closer to that observed in patients with acute leukemia (35.4%). Seven patients with chronic lymphocytic leukemia (CLL) exhibited even higher PPI values. No correlations were observed between PPI values, fraction of cells in S phase, and marrow blast infiltrate. For untreated acute disease patients, PPI values were prognostic for response only at low and high PPI values. These results suggest that the PCC-determined proliferative potential is a biologic reflection of the degree of malignancy within the bone marrow.

Value of ecosystem hydropower service and its impact on the payment for ecosystem services.

PubMed

Fu, B; Wang, Y K; Xu, P; Yan, K; Li, M

2014-02-15

Hydropower is an important service provided by ecosystems. We surveyed all the hydropower plants in the Zagunao River Basin, Southwest China. Then, we assessed the hydropower service by using the InVEST (The Integrated Value and Tradeoff of Ecosystem Service Tools) model. Finally, we discussed the impact on ecological compensation. The results showed that: 1) hydropower service value of ecosystems in the Zagunao River Basin is 216.29 Euro/hm(2) on the average, of which the high-value area with more than 475.65 Euro/hm(2) is about 750.37 km(2), accounting for 16.12% of the whole watershed, but it provides 53.47% of the whole watershed service value; 2) ecosystem is an ecological reservoir with a great regulation capacity. Dams cannot completely replace the reservoir water conservation function of ecosystems, and has high economic and environmental costs that must be paid as well. Compensation for water conservation services should become an important basis for ecological compensation of hydropower development. 3) In the current PES cases, the standard of compensation is generally low. Cascade development makes the value of upstream ecosystem services become more prominent, reflecting the differential rent value, and the value of ecosystem services should be based on the distribution of differentiated ecological compensation. Copyright © 2013 Elsevier B.V. All rights reserved.

Efficiency calibration of the first multilayer-coated holographic ion-etched flight grating for a sounding rocket high-resolution spectrometer.

PubMed

Kowalski, M P; Barbee, T W; Heidemann, K F; Gursky, H; Rife, J C; Hunter, W R; Fritz, G G; Cruddace, R G

1999-11-01

We have fabricated the four flight gratings for a sounding rocket high-resolution spectrometer using a holographic ion-etching technique. The gratings are spherical (4000-mm radius of curvature), large (160 mm x 90 mm), and have a laminar groove profile of high density (3600 grooves/mm). They have been coated with a high-reflectance multilayer of Mo/Si. Using an atomic force microscope, we examined the surface characteristics of the first grating before and after multilayer coating. The average roughness is approximately 3 A rms after coating. Using synchrotron radiation, we completed an efficiency calibration map over the wavelength range 225-245 A. At an angle of incidence of 5 degrees and a wavelength of 234 A, the average efficiency in the first inside order is 10.4 +/- 0.5%, and the derived groove efficiency is 34.8 +/- 1.6%. These values exceed all previously published results for a high-density grating.

Random variable transformation for generalized stochastic radiative transfer in finite participating slab media

NASA Astrophysics Data System (ADS)

El-Wakil, S. A.; Sallah, M.; El-Hanbaly, A. M.

2015-10-01

The stochastic radiative transfer problem is studied in a participating planar finite continuously fluctuating medium. The problem is considered for specular- and diffusly-reflecting boundaries with linear anisotropic scattering. Random variable transformation (RVT) technique is used to get the complete average for the solution functions, that are represented by the probability-density function (PDF) of the solution process. In the RVT algorithm, a simple integral transformation to the input stochastic process (the extinction function of the medium) is applied. This linear transformation enables us to rewrite the stochastic transport equations in terms of the optical random variable (x) and the optical random thickness (L). Then the transport equation is solved deterministically to get a closed form for the solution as a function of x and L. So, the solution is used to obtain the PDF of the solution functions applying the RVT technique among the input random variable (L) and the output process (the solution functions). The obtained averages of the solution functions are used to get the complete analytical averages for some interesting physical quantities, namely, reflectivity and transmissivity at the medium boundaries. In terms of the average reflectivity and transmissivity, the average of the partial heat fluxes for the generalized problem with internal source of radiation are obtained and represented graphically.

Radiocarbon variability in the western equatorial Pacific inferred from a high-resolution coral record from Nauru Island

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

Guilderson, T.P.; Schrag, D.P.; Kashgarian, M.

1998-10-01

We have generated a high resolution coral {Delta}{sup 14}C record spanning the last 50 years to document the seasonal and interannual redistribution of surface waters in the western tropical Pacific. Prebomb (1947{endash}1956) {Delta}{sup 14}C values average {minus}63{per_thousand} and have a total range of 30{per_thousand}. Values begin to increase in 1957, reaching a maximum of 137{per_thousand} in mid-1983. Large interannual variability of up to 80{per_thousand} closely follows the El Ni{tilde n}o-Southern Oscillation (ENSO). During each ENSO warm phase, {Delta}{sup 14}C values begin to increase, reflecting the reduction of low-{sup 14}C water upwelling in the east and the invasion of subtropical watermore » into the western equatorial tropical Pacific. Maximum {Delta}{sup 14}C values are in phase or lag the corresponding sea surface temperature maxima in the eastern tropical Pacific, whereas the rapid return to more negative {Delta}{sup 14}C is in phase with eastern Pacific ENSO indices. The highest-amplitude excursions occur during the 1965/1966 and 1972/1973 events, when the {sup 14}C contrast is highest between the eastern Pacific and subtropics. The 1982/1983 El Ni{tilde n}o, although a larger ENSO event, has a lower {Delta}{sup 14}C amplitude, reflecting the penetration of bomb radiocarbon into the equatorial undercurrent and the reduced contrast in {Delta}{sup 14}C between thermocline and subtropical surface waters at that time. This coral record demonstrates the potential for using similar radiocarbon time series for documenting variability in Pacific shallow circulation over interannual and decadal timescales. {copyright} 1998 American Geophysical Union« less

Ultraviolet (UV)-reflective paint with ultraviolet germicidal irradiation (UVGI) improves decontamination of nosocomial bacteria on hospital room surfaces.

PubMed

Jelden, Katelyn C; Gibbs, Shawn G; Smith, Philip W; Hewlett, Angela L; Iwen, Peter C; Schmid, Kendra K; Lowe, John J

2017-06-01

An ultraviolet germicidal irradiation (UVGI) generator (the TORCH, ClorDiSys Solutions, Inc.) was used to compare the disinfection of surface coupons (plastic from a bedrail, stainless steel, and chrome-plated light switch cover) in a hospital room with walls coated with ultraviolet (UV)-reflective paint (Lumacept) or standard paint. Each surface coupon was inoculated with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus faecalis (VRE), placed at 6 different sites within a hospital room coated with UV-reflective paint or standard paint, and treated by 10 min UVC exposure (UVC dose of 0-688 mJ/cm 2 between sites with standard paint and 0-553 mJ/cm 2 with UV-reflective paint) in 8 total trials. Aggregated MRSA concentrations on plastic bedrail surface coupons were reduced on average by 3.0 log 10 (1.8 log 10 Geometric Standard Deviation [GSD]) with standard paint and 4.3 log 10 (1.3 log 10 GSD) with UV-reflective paint (p = 0.0005) with no significant reduction differences between paints on stainless steel and chrome. Average VRE concentrations were reduced by ≥4.9 log 10 (<1.2 log 10 GSD) on all surface types with UV-reflective paint and ≤4.1 log 10 (<1.7 log 10 GSD) with standard paint (p < 0.05). At 5 aggregated sites directly exposed to UVC light, MRSA concentrations on average were reduced by 5.2 log 10 (1.4 log 10 GSD) with standard paint and 5.1 log 10 (1.2 log 10 GSD) with UV-reflective paint (p = 0.017) and VRE by 4.4 log 10 (1.4 log 10 GSD) with standard paint and 5.3 log 10 (1.1 log 10 GSD) with UV-reflective paint (p < 0.0001). At one indirectly exposed site on the opposite side of the hospital bed from the UVGI generator, MRSA concentrations on average were reduced by 1.3 log 10 (1.7 log 10 GSD) with standard paint and 4.7 log 10 (1.3 log 10 GSD) with UV-reflective paint (p < 0.0001) and VRE by 1.2 log 10 (1.5 log 10 GSD) with standard paint and 4.6 log 10 (1.1 log 10 GSD) with UV-reflective paint (p < 0.0001). Coating hospital room walls with UV-reflective paint enhanced UVGI disinfection of nosocomial bacteria on various surfaces compared to standard paint, particularly at a surface placement site indirectly exposed to UVC light.

Cloudsat tropical cyclone database

NASA Astrophysics Data System (ADS)

Tourville, Natalie D.

CloudSat (CS), the first 94 GHz spaceborne cloud profiling radar (CPR), launched in 2006 to study the vertical distribution of clouds. Not only are CS observations revealing inner vertical cloud details of water and ice globally but CS overpasses of tropical cyclones (TC's) are providing a new and exciting opportunity to study the vertical structure of these storm systems. CS TC observations are providing first time vertical views of TC's and demonstrate a unique way to observe TC structure remotely from space. Since December 2009, CS has intersected every globally named TC (within 1000 km of storm center) for a total of 5,278 unique overpasses of tropical systems (disturbance, tropical depression, tropical storm and hurricane/typhoon/cyclone (HTC)). In conjunction with the Naval Research Laboratory (NRL), each CS TC overpass is processed into a data file containing observational data from the afternoon constellation of satellites (A-TRAIN), Navy's Operational Global Atmospheric Prediction System Model (NOGAPS), European Center for Medium range Weather Forecasting (ECMWF) model and best track storm data. This study will describe the components and statistics of the CS TC database, present case studies of CS TC overpasses with complementary A-TRAIN observations and compare average reflectivity stratifications of TC's across different atmospheric regimes (wind shear, SST, latitude, maximum wind speed and basin). Average reflectivity stratifications reveal that characteristics in each basin vary from year to year and are dependent upon eye overpasses of HTC strength storms and ENSO phase. West Pacific (WPAC) basin storms are generally larger in size (horizontally and vertically) and have greater values of reflectivity at a predefined height than all other basins. Storm structure at higher latitudes expands horizontally. Higher vertical wind shear (≥ 9.5 m/s) reduces cloud top height (CTH) and the intensity of precipitation cores, especially in HTC strength storms. Average zero and ten dBZ height thresholds confirm WPAC storms loft precipitation sized particles higher into the atmosphere than in other basins. Two CS eye overpasses (32 hours apart) of a weakening Typhoon Nida in 2009 reveal the collapse of precipitation cores, warm core anomaly and upper tropospheric ice water content (IWC) under steady moderate shear conditions.

42 CFR 423.286 - Rules regarding premiums.

Code of Federal Regulations, 2011 CFR

2011-10-01

... section for the difference between the bid and the national average monthly bid amount, any supplemental... percentage as specified in paragraph (b) of this section; and (2) National average monthly bid amount... reflect difference between bid and national average bid. If the amount of the standardized bid amount...

Relationship between colorimetric (instrumental) evaluation and consumer-defined beef colour acceptability.

PubMed

Holman, Benjamin W B; Mao, Yanwei; Coombs, Cassius E O; van de Ven, Remy J; Hopkins, David L

2016-11-01

The relationship between instrumental colorimetric values (L*, a*, b*, the ratio of reflectance at 630nm and 580nm) and consumer perception of acceptable beef colour was evaluated using a web-based survey and standardised photographs of beef m. longissimus lumborum with known colorimetrics. Only L* and b* were found to relate to average consumer opinions of beef colour acceptability. Respondent nationality was also identified as a source of variation in beef colour acceptability score. Although this is a preliminary study with the findings necessitating additional investigation, these results suggest L* and b* as candidates for developing instrumental thresholds for consumer beef colour expectations. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Inferring total canopy APAR from PAR bidirectional reflectances and vegetation indices in tallgrass prairie. [Absorbed Photosynthetically Active Radiation

NASA Technical Reports Server (NTRS)

Middleton, Elizabeth M.

1992-01-01

The fraction of photosynthetically active radiation (PAR) absorbed by a vegetated canopy (APARc) or landscape (APARs) is a critical parameter in climate processes. A grassland study examined: 1) whether APARs can be estimated from PAR bidirectional exitance fractions; and 2) whether APARs is correlated with spectral vegetation indices (SVIs). Data were acquired with a high resolution continuous spectroradiometer at 4 sun angles on grassland sites. APARs was computed from the scattered surface PAR exitance fractions. The nadir APARs value was the most variable diurnally; it provided a good estimate of the average surface APARs at 95 percent. APARc was best represented by exitance factors between 30-60* forward.

Fractal rigidity in migraine

NASA Astrophysics Data System (ADS)

Latka, Miroslaw; Glaubic-Latka, Marta; Latka, Dariusz; West, Bruce J.

2004-04-01

We study the middle cerebral artery blood flow velocity (MCAfv) in humans using transcranial Doppler ultrasonography (TCD). Scaling properties of time series of the axial flow velocity averaged over a cardiac beat interval may be characterized by two exponents. The short time scaling exponent (STSE) determines the statistical properties of fluctuations of blood flow velocities in short-time intervals while the Hurst exponent describes the long-term fractal properties. In many migraineurs the value of the STSE is significantly reduced and may approach that of the Hurst exponent. This change in dynamical properties reflects the significant loss of short-term adaptability and the overall hyperexcitability of the underlying cerebral blood flow control system. We call this effect fractal rigidity.

Geoengineering by cloud seeding: influence on sea ice and climate system

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

Rasch, Philip J.; Latham, John; Chen, Chih-Chieh

2009-12-18

GCM computations using a fully coupled ocean atmosphere model indicate that increasing cloud reflectivity by seeding maritime boundary layer clouds with particles made from seawater may compensate for some of the effects on climate of increasing greenhouse gas concentrations. The chosen seeding strategy (one of many possible scenarios) can restore global averages of temperature, precipitation and sea ice to present day values, but not simultaneously. The response varies nonlinearly with extent of the seeding, and geoengineering generates local changes to important climatic features. The global tradeoffs of restoring ice cover and cooling the planet must be assessed alongside the localmore » changes to climate features.« less

Optical properties of C28 fullerene cage: A DFT study

NASA Astrophysics Data System (ADS)

Paul, Debolina; Bhattacharya, Barnali; Deb, Jyotirmoy; Sarkar, Utpal

2018-05-01

Density functional theory methodology have been used to study the optical properties of fullerene C28 with the application of average electric field. The static dielectric constant of C28 is recorded a low value of 1.4. It is observed that the fullerene shows a wide range of absorption in the UV region of the electromagnetic spectrum. The presence of the optical gap in the system as can be observed from the imaginary part of the dielectric function. The observation of small reflectivity suggests its possible uses in hybrid solar cell applications. In addition, due to strong absorption taking place in the UV region, the system could be used in the UV light protection devices.

Biodiversity Measurement Using Indices Based on Hyperspectral Reflectance on the Coast of Lagos

NASA Astrophysics Data System (ADS)

Omodanisi, E. O.; Salami, A. T.

2013-12-01

Hyperspectral measurements provide explicit measurements which can be used in the analysis of biodiversity change. This study was carried out in the coastal area of Lagos State, Nigeria. The objective of this study was to determine if gasoline seepage affects vegetation species distribution and reflectance; with the view to analyzing the vegetation condition. To evaluate the potential of different reflectance spectroscopy of species, the ASD Handheld2 Spectrometer was used. Three identified impacted plots of 30m by 30m were selected randomly and a control plot established in relatively undisturbed vegetated areas away from but perpendicular to the source of seepage. Each identified plot and the control consisted of five transects and measurement were taken at every 2m with about four reflectance measurement per sample point, to average out differences in reflectance as a result of different leaf angles. The radiance output of the spectrometer was converted into reflectance using the reflectance of a white reference over a standardized white spectralon panel. Indices such as Normalized Differential Vegetation Index, RedEdge Normalized Difference Vegetation Index, Soil Adjusted Vegetation Index, Ratio Vegetation Index and Volgelmann RedEdge Index 1 were calculated to accurately estimate the chlorophyll content in the vegetation within optimal band wavelength. Shannon-Weiner's index, Spearman's rank correlation and Analysis of Variance were used to analyze the data. Cocos nucifera was observed to be the most dominant species with a relative abundance of 47.27% while Ananas comosus recorded the lowest relative abundance of 21.8%. In the control plot, Cocos nucifera had the highest relative abundance of 42.3% and Mangifera indica with the least relative abundance of 16.7%. The relationship between the indices and chlorophyll content of the vegetation were significantly higher at (p>0.01) for all the indices in all the plots; however, RedEdgeNDVI and VOG1 indices had the highest occurring frequency among the entire plots. Thus they were used to distinguish relatively healthy from relatively unhealthy vegetation and it was statistically higher at F-ratio 4.825 (p<0.01) and 3.194 (p<0.01) respectively. It was concluded that gasoline affected the condition of vegetation.Table 2: Spearman's rank correlation analysis for relating indices with chlorophyll content for the field data at p>0.01, rho - correlation coefficient. (Source: Author: 2012) Field Spectral Indices Measurement The measurement above is the averaged value for the entire transect in each plot.(Source: Author, 2012)

Effect of AZO deposition on antireflective property of Si subwavelength grating structures

NASA Astrophysics Data System (ADS)

Leem, J. W.; Song, Y. M.; Lee, Y. T.; Yu, J. S.

2011-12-01

We investigate the effect of the aluminum-doped zinc oxide (AZO) deposition on the fabricated Si SWG structure on its antireflection characteristics for solar cell applications. The Si SWGs with the two-dimensional periodic nanostructure are fabricated by using holographic lithography and subsequent ICP etching process in SiCl4 plasma. For the antireflection analysis of AZO thin-film on the Si SWG structure, the optical reflectivity is measured experimentally. The maxima reflectance and its oscillation of the structure are significantly decreased on average than those of AZO thin-film on Si substrate over a wide wavelength range of 300-1100 nm, indicating average reflectance less than 4.5% with the maxima of <10%.

Three Sets of Case Studies Suggest Logic and Consistency Challenges with Value Frameworks.

PubMed

Cohen, Joshua T; Anderson, Jordan E; Neumann, Peter J

2017-02-01

To assess the logic and consistency of three prominent value frameworks. We reviewed the value frameworks from three organizations: the Memorial Sloan Kettering Cancer Center (DrugAbacus), the American Society of Clinical Oncologists, and the Institute for Clinical and Economic Review. For each framework, we developed case studies to explore the degree to which the frameworks have face validity in the sense that they are consistent with four important principles: value should be proportional to a therapy's benefit; components of value should matter to framework users (patients and payers); attribute weights should reflect user preferences; and value estimates used to inform therapy prices should reflect per-person benefit. All three frameworks can aid decision making by elucidating factors not explicitly addressed by conventional evaluation techniques (in particular, cost-effectiveness analyses). Our case studies identified four challenges: 1) value is not always proportional to benefit; 2) value reflects factors that may not be relevant to framework users (patients or payers); 3) attribute weights do not necessarily reflect user preferences or relate to value in ways that are transparent; and 4) value does not reflect per-person benefit. Although the value frameworks we reviewed capture value in a way that is important to various audiences, they are not always logical or consistent. Because these frameworks may have a growing influence on therapy access, it is imperative that analytic challenges be further explored. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

High order cell-centered scheme totally based on cell average

NASA Astrophysics Data System (ADS)

Liu, Ze-Yu; Cai, Qing-Dong

2018-05-01

This work clarifies the concept of cell average by pointing out the differences between cell average and cell centroid value, which are averaged cell-centered value and pointwise cell-centered value, respectively. Interpolation based on cell averages is constructed and high order QUICK-like numerical scheme is designed for such interpolation. A new approach of error analysis is introduced in this work, which is similar to Taylor’s expansion.

Occurrence and Magnitude of High Reflectance Materials on the Moon

NASA Astrophysics Data System (ADS)

Nuno, R. G.; Boyd, A. K.; Robinson, M. S.

2013-12-01

We utilize a Lunar Reconnaissance Orbiter (LRO) Wide Angle Camera (WAC) 643 nm photometrically normalized (30°, 0°, 30°; i, e, g) reflectance map to investigate the occurrence and origin of high reflectance materials on the Moon. Compositional differences (mainly iron and titanium content) and maturity state (e.g. Copernican crater rays and swirls) are the predominant factors affecting reflectance variations observed on the Moon. Therefore, comparing reflectance values of different regions yields insight into the composition and relative exposure age of lunar materials. But an accurate comparison requires precise reflectance values normalized across every region being investigated. The WAC [1] obtains monthly near-global ground coverage, each month's observations acquired with different lighting conditions. Boyd et al. [2] utilized a geologically homogeneous subset [0°N to 90°N, 146°E to 148°E] of the WAC observations to determine an equation that describes how viewing and lighting angles affect reflectance values. A normalized global reflectance map was generated by applying the local empirical solution globally, with photometric angles derived from the WAC Global Lunar Digital Terrain Model (DTM)(GLD100) [3]. The GLD100 enables accurate correction of reflectance differences caused by local topographic undulations at the scale of 300 meters. We compare reflectance values across the Moon within 80°S to 80°N latitude. The features with the highest reflectance are steep crater walls within Copernican aged craters, such as the walls of Giordano Bruno, which have normalized reflectance values up to 0.35. Near-impact ejecta of some craters have high reflectance values, such as Virtanen (0.22). There are also broad relatively flat features with high reflectance, such as the 900-km Thales-Compton region (0.24) and the 600-km extent of Anaxagoras (Copernican age) ejecta (0.20). Since the interior of Anaxagoras contains occurrences of pure anorthosite [4], the high reflectance of its ray system may be due to both composition and maturity. Some relatively small isolated features exhibit high reflectance, such as the Compton-Belkovich Volcanic Complex (0.24) and rilles in the floor of Compton crater (0.27). Features associated with pure anorthosite [4] are also found to have high reflectance values, such as occurrences in Mare Orientale (0.22). Since the photometric normalization accounted for topography up to the 300-m horizontal spatial scale, uncertainties remain for steep crater walls. We are currently reducing these uncertainties for selected craters with high resolution (15 meter baseline) stereo-based NAC DTMs. References: [1] Robinson et al. (2010), Space Sci. Rev. [2] Boyd et al. (2013) AGU, this conference. [3] Scholten et al. (2012) JGR. [4] Ohtake et al. (2009) Nature.

The effects of aortic coarctation on cerebral hemodynamics and its importance in the etiopathogenesis of intracranial aneurysms.

PubMed

Singh, Pankaj K; Marzo, Alberto; Staicu, Cristina; William, Matt G; Wilkinson, Iain; Lawford, Patricia V; Rufenacht, Daniel A; Bijlenga, Philippe; Frangi, Alejandro F; Hose, Rodney; Patel, Umang J; Coley, Stuart C

2010-01-01

Hemodynamic changes in the cerebral circulation in presence of coarctation of aorta (CoA) and their significance in the increased intracranial aneurysms (IAs) formation in these patients remain unclear. In the present study, we measured the flow-rate waveforms in the cerebral arteries of a patient with CoA, followed by an analysis of different hemodynamic indices in a coexisting IA. Phase-contrast Magnetic Resonance (pc-MR) volumetric flow-rate (VFR) measurements were performed in cerebral arteries of a 51 years old woman with coexisting CoA, and five healthy volunteers. Numerical predictions of a number of relevant hemodynamic indices were performed in an IA located in sub-clinoid part of left internal carotid artery (ICA) of the patient. Computations were performed using Ansys(®)-CFX(™) solver using the VFR values measured in the patient as boundary conditions (BCs). A second analysis was performed using the average VFR values measured in healthy volunteers. The VFR waveforms measured in the patient and healthy volunteers were compared followed by a comparison of the hemodynamic indices obtained using both approaches. The results are discussed in the background of relevant literature. Mean flow-rates were increased by 27.1% to 54.9% (2.66-5.44 ml/sec) in the cerebral circulation of patients with CoA as compared to healthy volunteers (1.2-3.95 ml/sec). Velocities were increased inside the IA by 35-45%. An exponential rise of 650% was observed in the area affected by high wall shear stress (WSS>15Pa) when flow-rates specific to CoA were used as compared to population average flow-rates. Absolute values of space and time averaged WSS were increased by 65%. Whereas values of maximum pressure on the IA wall were increased by 15% the area of elevated pressure was actually decreased by 50%, reflecting a more focalized jet impingement within the IA of the CoA patient. IAs can develop in patients with CoA several years after the surgical repair. Cerebral flow-rates in CoA patients are significantly higher as compared to average flow-rates in healthy population. The increased supra-physiological WSS (>15Pa), OSI (>0.2) and focalized pressure may play an important role in the etiopathogenesis of IAs in patients with CoA.

The Effects of Aortic Coarctation on Cerebral Hemodynamics and its Importance in the Etiopathogenesis of Intracranial Aneurysms

PubMed Central

Singh, Pankaj K; Marzo, Alberto; Staicu, Cristina; William, Matt G; Wilkinson, Iain; Lawford, Patricia V; Rufenacht, Daniel A; Bijlenga, Philippe; Frangi, Alejandro F; Hose, Rodney; Patel, Umang J; Coley, Stuart C

2010-01-01

Objectives: Hemodynamic changes in the cerebral circulation in presence of coarctation of aorta (CoA) and their significance in the increased intracranial aneurysms (IAs) formation in these patients remain unclear. In the present study, we measured the flow-rate waveforms in the cerebral arteries of a patient with CoA, followed by an analysis of different hemodynamic indices in a coexisting IA. Materials and Methods: Phase-contrast Magnetic Resonance (pc-MR) volumetric flow-rate (VFR) measurements were performed in cerebral arteries of a 51 years old woman with coexisting CoA, and five healthy volunteers. Numerical predictions of a number of relevant hemodynamic indices were performed in an IA located in sub-clinoid part of left internal carotid artery (ICA) of the patient. Computations were performed using Ansys®-CFX™ solver using the VFR values measured in the patient as boundary conditions (BCs). A second analysis was performed using the average VFR values measured in healthy volunteers. The VFR waveforms measured in the patient and healthy volunteers were compared followed by a comparison of the hemodynamic indices obtained using both approaches. The results are discussed in the background of relevant literature. Results: Mean flow-rates were increased by 27.1% to 54.9% (2.66–5.44 ml/sec) in the cerebral circulation of patients with CoA as compared to healthy volunteers (1.2–3.95 ml/sec). Velocities were increased inside the IA by 35–45%. An exponential rise of 650% was observed in the area affected by high wall shear stress (WSS>15Pa) when flow-rates specific to CoA were used as compared to population average flow-rates. Absolute values of space and time averaged WSS were increased by 65%. Whereas values of maximum pressure on the IA wall were increased by 15% the area of elevated pressure was actually decreased by 50%, reflecting a more focalized jet impingement within the IA of the CoA patient. Conclusions: IAs can develop in patients with CoA several years after the surgical repair. Cerebral flow-rates in CoA patients are significantly higher as compared to average flow-rates in healthy population. The increased supra-physiological WSS (>15Pa), OSI (>0.2) and focalized pressure may play an important role in the etiopathogenesis of IAs in patients with CoA. PMID:22518256

A kinetic model for thermally induced hydrogen and carbon isotope fractionation of individual n-alkanes in crude oil

NASA Astrophysics Data System (ADS)

Tang, Yongchun; Huang, Yongsong; Ellis, Geoffrey S.; Wang, Yi; Kralert, Paul G.; Gillaizeau, Bruno; Ma, Qisheng; Hwang, Rong

2005-09-01

A quantitative kinetic model has been proposed to simulate the large D and 13C isotope enrichments observed in individual n-alkanes (C 13-C 21) during artificial thermal maturation of a North Sea crude oil under anhydrous, closed-system conditions. Under our experimental conditions, average n-alkane δ 13C values increase by ˜4‰ and δD values increase by ˜50‰ at an equivalent vitrinite reflectance value of 1.5%. While the observed 13C-enrichment shows no significant dependence on hydrocarbon chain length, thermally induced D-enrichment increases with increasing n-alkane carbon number. This differential fractionation effect is speculated to be due to the combined effect of the greater extent of thermal cracking of higher molecular weight, n-alkanes compared to lower molecular weight homologues, and the generation of isotopically lighter, lower molecular weight compounds. This carbon-number-linked hydrogen isotopic fractionation behavior could form the basis of a new maturity indicator to quantitatively assess the extent of oil cracking in petroleum reservoirs. Quantum mechanical calculations of the average change in enthalpy (ΔΔH ‡) and entropy (ΔΔS ‡) as a result of isotopic substitution in n-alkanes undergoing homolytic cleavage of C-C bonds lead to predictions of isotopic fractionation that agree quite well with our experimental results. For n-C 20 ( n-icosane), the changes in enthalpy are calculated to be ˜1340 J mol -1 (320 cal mol -1) and 230 J mol -1 (55 cal mol -1) for D-H and 13C- 12C, respectively. Because the enthalpy term associated with hydrogen isotope fractionation is approximately six times greater than that for carbon, variations in δD values for individual long-chain hydrocarbons provide a highly sensitive measure of the extent of thermal alteration experienced by the oil. Extrapolation of the kinetic model to typical geological heating conditions predicts significant enrichment in 13C and D for n-icosane at equivalent vitrinite reflectance values corresponding to the onset of thermal cracking of normal alkanes. The experimental and theoretical results of this study have significant implications for the use of compound-specific hydrogen isotope data in petroleum geochemical and paleoclimatological studies. However, there are many other geochemical processes that will significantly affect observed hydrogen isotopic compositions (e.g., biodegradation, water washing, isotopic exchange with water and minerals) that must also be taken into consideration.

Ruminative subtypes and impulsivity in risk for suicidal behavior

PubMed Central

Valderrama, Jorge; Miranda, Regina; Jeglic, Elizabeth

2016-01-01

Rumination has been previously linked to negative psychological outcomes, including depression and suicidal behavior. However, there has been conflicting research on whether or not two different subtypes of rumination – brooding and reflection – are more or less maladaptive. The present research sought to (1) examine whether individuals high in brooding but lower in reflection would show higher trait and behavioral impulsivity, relative to individuals low in brooding and low in reflection; and (2) examine impulsivity as a mediator of the relation between ruminative subtypes and suicidal ideation. In Study 1, participants (N = 78) were recruited based on high, average, and low scores on a measure of brooding and reflective rumination. Individuals who scored high in brooding and average in reflection scored significantly higher in negative urgency, that is, in the tendency to act rashly in an attempt to reduce negative affect, than did those who scored low in brooding and low in reflection. Study 2 (N = 1638) examined the relationship between ruminative subtypes, impulsivity, and suicide risk. We found an indirect relationship between brooding and suicide risk through lack of premeditation and lack of perseverance, independently of reflection. These findings are discussed in relation to cognitive risk for suicide. PMID:26791398

Reproducing the Ensemble Average Polar Solvation Energy of a Protein from a Single Structure: Gaussian-Based Smooth Dielectric Function for Macromolecular Modeling.

PubMed

Chakravorty, Arghya; Jia, Zhe; Li, Lin; Zhao, Shan; Alexov, Emil

2018-02-13

Typically, the ensemble average polar component of solvation energy (ΔG polar solv ) of a macromolecule is computed using molecular dynamics (MD) or Monte Carlo (MC) simulations to generate conformational ensemble and then single/rigid conformation solvation energy calculation is performed on each snapshot. The primary objective of this work is to demonstrate that Poisson-Boltzmann (PB)-based approach using a Gaussian-based smooth dielectric function for macromolecular modeling previously developed by us (Li et al. J. Chem. Theory Comput. 2013, 9 (4), 2126-2136) can reproduce that ensemble average (ΔG polar solv ) of a protein from a single structure. We show that the Gaussian-based dielectric model reproduces the ensemble average ΔG polar solv (⟨ΔG polar solv ⟩) from an energy-minimized structure of a protein regardless of the minimization environment (structure minimized in vacuo, implicit or explicit waters, or crystal structure); the best case, however, is when it is paired with an in vacuo-minimized structure. In other minimization environments (implicit or explicit waters or crystal structure), the traditional two-dielectric model can still be selected with which the model produces correct solvation energies. Our observations from this work reflect how the ability to appropriately mimic the motion of residues, especially the salt bridge residues, influences a dielectric model's ability to reproduce the ensemble average value of polar solvation free energy from a single in vacuo-minimized structure.

Exploring Mercury's Surface in UltraViolet from Orbit

NASA Astrophysics Data System (ADS)

Izenberg, N.

2017-12-01

The MESSENGER Mission's Ultraviolet and Visible Spectrometer (UVVS) component of its Mercury Atmosphere and Surface Composition Spectrometer (MASCS) instrument obtained approximately 4600 point observations of Mercury's surface in middle ultraviolet (MUV; 210 nm - 300 nm) and far ultraviolet (FUV; 119.1 - 122.5 nm and 129.2 - 131.5 nm) wavelengths over the course of its orbital mission, mostly in Mercury's southern hemisphere. Given the very low (<1 to 2 wt %) average abundance of iron in the silicates of Mercury observed by multiple MESSENGER instruments, the near- to middle-ultraviolet wavelengths encompassing the oxygen metal charge transfer band (<400 nm), which is more sensitive to the presence of iron than the classic 1 micron absorption band, provides potentially useful additional compositional insight into the top layer of Mercury's regolith. The presence of nano- and microphase carbon also has potentially significant expression in the ultraviolet, and the interplay and variation between carbon and iron in mercury surface materials is an active area of investigation. Analysis of middle-UV surface reflectance and parameters appear to support the presence of varying amounts of carbon in different spectral or geologic units on Mercury. Far-UV reflectance data is currently under-utilized, but analysis of lunar surface by the Lunar Reconnaissance Orbiter (LRO) Lyman Alpha Mapping Project (LAMP) indicate that the data are sensitive to both composition and space weathering. The far-UV reflectance from MASCS may provide similar information for the Mercury surface, complementing results from longer wavelengths. MESSENGER data products for surface reflectance include middle-UV reflectance spectra, ultraviolet far-UV reflectance values, combined middle-UV through near-infrared spectra (210 nm - 1450 nm), a global `spectral cube' of near-UV to near-IR, and an upcoming UV spectral cube.

A comparison of hair colour measurement by digital image analysis with reflective spectrophotometry.

PubMed

Vaughn, Michelle R; van Oorschot, Roland A H; Baindur-Hudson, Swati

2009-01-10

While reflective spectrophotometry is an established method for measuring macroscopic hair colour, it can be cumbersome to use on a large number of individuals and not all reflective spectrophotometry instruments are easily portable. This study investigates the use of digital photographs to measure hair colour and compares its use to reflective spectrophotometry. An understanding of the accuracy of colour determination by these methods is of relevance when undertaking specific investigations, such as those on the genetics of hair colour. Measurements of hair colour may also be of assistance in cases where a photograph is the only evidence of hair colour available (e.g. surveillance). Using the CIE L(*)a(*)b(*) colour space, the hair colour of 134 individuals of European ancestry was measured by both reflective spectrophotometry and by digital image analysis (in V++). A moderate correlation was found along all three colour axes, with Pearson correlation coefficients of 0.625, 0.593 and 0.513 for L(*), a(*) and b(*) respectively (p-values=0.000), with means being significantly overestimated by digital image analysis for all three colour components (by an average of 33.42, 3.38 and 8.00 for L(*), a(*) and b(*) respectively). When using digital image data to group individuals into clusters previously determined by reflective spectrophotometric analysis using a discriminant analysis, individuals were classified into the correct clusters 85.8% of the time when there were two clusters. The percentage of cases correctly classified decreases as the number of clusters increases. It is concluded that, although more convenient, hair colour measurement from digital images has limited use in situations requiring accurate and consistent measurements.

Photographic Identification of Humpback and Blue Whales off the US West Coast: Results and Updated Abundance Estimates from 2008 Field Season

DTIC Science & Technology

2009-12-01

1990s and only being present part of the time off the US West Coast lowering the average density present (but not reflecting an actual population ...the average density present (but not reflecting an actual population decline). 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...due to our sample representing a decreasing proportion of this growing population leading to greater variation and possibly greater susceptibility to

Experiments on Bedrock Cover in a Highly Sinuous Channel

NASA Astrophysics Data System (ADS)

Parker, G.; Fernandez, R.; Stark, C. P.

2015-12-01

One of several mechanisms by which bedrock rivers can incise is abrasion of the bedrock surface by colliding sediment particles. This effect has been captured in terms of a "cover factor" corresponding to the areal fraction p of the bed that is covered with sediment. According to this formulation, a value of p equal to 1 corresponds to complete alluvial cover: sediment particles strike each other and no bedrock abrasion is accomplished. Correspondingly, a value of p equal to 0 corresponds to the absence of sediment: no particles are available to strike the bed, and again no bedrock abrasion is accomplished. Thus the condition 0 < p < 1 is hypothesized to be the condition for incision driven by abrasion. At the microscopic level, however, p can take only the binary values 0 and 1: either a point on the bedrock surface is covered or is not covered. Therefore, the value of p that enters into any morphodynamic formulation of cover must represent an average over some spatiotemporal window. Here we consider the case of a highly sinuous meandering flume. The bed is set in concrete to take the topography corresponding to purely alluvial mobile-bed equilibrium. The recirculation of sediment over this bed at below-capacity conditions leads to a complex pattern of free and forced bars that only partially cover the bed. At certain locations, such as near the inside of bends, the bed is always covered, where at other locations, such as right near the apexes of the very tight bends in the flume, the bed is almost never covered. At other locations, the instantaneous cover fluctuates between the binary values 0 and 1, reflecting the migration of bars of various sizes over the bedrock surface. The averaging of these binary values over appropriate time windows allows determination of the local spatial variation of p that can serve as input to a numerical model of the evolution of bedrock meandering channels.

How Educators Conceptualize and Teach Reflective Practice: A Survey of North American Pediatric Medical Educators.

PubMed

Butani, Lavjay; Bannister, Susan L; Rubin, Allison; Forbes, Karen L

2017-04-01

The objectives of this study were to explore pediatric undergraduate medical educators' understanding of reflective practice, the barriers they face in teaching this, the curricular activities they use, and the value they assign to reflective practice. Nine survey questions were sent to members of the Council on Medical Student Education in Pediatrics, an international pediatric undergraduate medical educator group. Quantitative data were analyzed using descriptive statistics. Open-ended responses were analyzed qualitatively through an iterative process to establish themes representing understanding of reflective practice and barriers in teaching this. Respondents representing 56% of all North American schools answered at least 1 survey question. Qualitative analysis of understanding of reflection revealed 11 themes spanning all components of reflective practice, albeit with a narrow view on triggers for reflection and a lower emphasis on understanding the why of things and on perspective-taking. The most frequent barriers in teaching this were the lack of skilled educators and limited time. Most respondents valued reflective skills but few reported confidence in their ability to teach reflection. Several curricular activities were used to teach reflection, the most common being narrative writing. Pediatric undergraduate medical educators value reflection and endorse its teaching. However, many do not have a complete understanding of the construct and few report confidence in teaching this. Implementing longitudinal curricula in reflective practice may require a culture change; opportunities exist for faculty development about the meaning and value of reflective practice and how best to teach this. Copyright © 2016 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Occupational exposure to electric fields and induced currents associated with 400 kV substation tasks from different service platforms.

PubMed

Korpinen, Leena H; Elovaara, Jarmo A; Kuisti, Harri A

2011-01-01

The aim of the study was to investigate the occupational exposure to electric fields, average current densities, and average total contact currents at 400 kV substation tasks from different service platforms (main transformer inspection, maintenance of operating device of disconnector, maintenance of operating device of circuit breaker). The average values are calculated over measured periods (about 2.5 min). In many work tasks, the maximum electric field strengths exceeded the action values proposed in the EU Directive 2004/40/EC, but the average electric fields (0.2-24.5 kV/m) were at least 40% lower than the maximum values. The average current densities were 0.1-2.3 mA/m² and the average total contact currents 2.0-143.2 µA, that is, clearly less than the limit values of the EU Directive. The average values of the currents in head and contact currents were 16-68% lower than the maximum values when we compared the average value from all cases in the same substation. In the future it is important to pay attention to the fact that the action and limit values of the EU Directive differ significantly. It is also important to take into account that generally, the workers' exposure to the electric fields, current densities, and total contact currents are obviously lower if we use the average values from a certain measured time period (e.g., 2.5 min) than in the case where exposure is defined with only the help of the maximum values. © 2010 Wiley-Liss, Inc.

Spectral Characteristics of Salinized Soils during Microbial Remediation Processes.

PubMed

Ma, Chuang; Shen, Guang-rong; Zhi, Yue-e; Wang, Zi-jun; Zhu, Yun; Li, Xian-hua

2015-09-01

In this study, the spectral reflectance of saline soils, the associated soil salt content (SSC) and the concentrations of salt ions were measured and analysed by tracing the container microbial remediation experiments for saline soil (main salt is sodium chloride) of Dongying City, Shandong Province. The sensitive spectral reflectance bands of saline soils to SSC, Cl- and Na+ in the process of microbial remediation were analysed. The average-dimension reduction of these bands was conducted by using a combination of correlation coefficient and decision coefficient, and by gradually narrowing the sampling interval method. Results showed that the tendency and magnitude of the average spectral reflectance in all bands of saline soils during the total remediation processes were nearly consistent with SSC and with Cl- coocentration, respectively. The degree of salinity of the soil, including SSC and salt ion concentrations, had a significant positive correlation with the spectral reflectance of all bands, particularly in the near-infrared band. The optimal spectral bands of SSC were 1370 to 1445 nm and 1447 to 1608 nm, whereas the optimal spectral bands of Cl- and Na+ were 1336 to 1461 nm and 1471 to 1561 nm, respectively. The relationship model among SSC, soil salt ion concentrations (Cl- and Na+) and soil spectral reflectance of the corresponding optimal spectral band was established. The largest R2 of relationship model between SSC and the average reflectance of associated optimal band reached to 0.95, and RMSEC and RMSEP were 1.076 and 0.591, respectively. Significant statistical analysis of salt factors and soil reflectance for different microbial remediation processes indicated that the spectral response characteristics and sensitivity of SSC to soil reflectance, which implied the feasibility of high spectrum test on soil microbial remediation monitoring, also provided the basis for quick nondestructive monitoring soil bioremediation process by soil spectral reflectance.

Occupational exposure assessment of magnetic fields generated by induction heating equipment-the role of spatial averaging.

PubMed

Kos, Bor; Valič, Blaž; Kotnik, Tadej; Gajšek, Peter

2012-10-07

Induction heating equipment is a source of strong and nonhomogeneous magnetic fields, which can exceed occupational reference levels. We investigated a case of an induction tempering tunnel furnace. Measurements of the emitted magnetic flux density (B) were performed during its operation and used to validate a numerical model of the furnace. This model was used to compute the values of B and the induced in situ electric field (E) for 15 different body positions relative to the source. For each body position, the computed B values were used to determine their maximum and average values, using six spatial averaging schemes (9-285 averaging points) and two averaging algorithms (arithmetic mean and quadratic mean). Maximum and average B values were compared to the ICNIRP reference level, and E values to the ICNIRP basic restriction. Our results show that in nonhomogeneous fields, the maximum B is an overly conservative predictor of overexposure, as it yields many false positives. The average B yielded fewer false positives, but as the number of averaging points increased, false negatives emerged. The most reliable averaging schemes were obtained for averaging over the torso with quadratic averaging, with no false negatives even for the maximum number of averaging points investigated.

Supplying the energy and fiber needs of dairy cows from alternate feed sources.

PubMed

Coppock, C E

1987-05-01

Alternate feeds are a major resource of the dairy industry. The major issue involving them is a method to predict accurately nutritive value from laboratory analyses. Variation in nutrient content of most alternate feeds is greater than in feed grains. Another issue is which depression factors to use in adjusting values for TDN from maintenance to production intakes. The NRC uses an average depression of 8% for all feeds; others think each feedstuff should be depressed individually, and discount factors have been proposed. For some alternate feeds, large differences in net energy estimates occur. Neutral detergent fiber has been proposed as an indicator of productive energy, but it has several deficiencies with alternate feeds high in fat, molasses, or ash. A summative equation based on fat, ash, protein, NDF, and lignin has wider application for predicting NE1 for all feeds. A roughage value index reflects a feed's property to stimulate chewing and rumination. Its use has special relevance for alternate feeds with small particle sizes, which may induce little chewing. Supplemental fat may increase the metabolizable energy converted to milk, but respiration experiments are needed.

Natural gamma-radiation in the Aeolian volcanic arc.

PubMed

Chiozzi, P; Pasquale, V; Verdoya, M; Minato, S

2001-11-01

Pulse-height distributions of gamma-rays, obtained with a field NaI(Tl) scintillation spectrometer in numerous sites of the Lipari and Vulcano islands (Aeolian volcanic arc, Italy), were measured to determine the U, Th and K concentrations of the bedrock and the relative values of the air absorbed dose rate. U is spatially related to both Th and K and the Th/U ratio is on average 3.1-3.5. The magmatic evolution is reflected by the concentration of the three radioelements, as they are more abundant within the more felsic units of the volcanic series. The higher values of U (15.7-20.0 ppm) coincide with higher Th (48.3-65.9 ppm) and K (4.9-6.1%) concentrations associated with rhyolitic rocks of the third cycle (< 50 ky). The air absorbed dose rate varies from 20 to 470 nGy h(-1). The highest values (> 350 nGy h(-1)) are observed on outcrops of rhyolitic obsidian lava flows. The cosmic-ray contribution is also evaluated to estimate the total background radiation dose rate.

Tectono-geomorphic indices of the Erin basin, NE Kashmir valley, India

NASA Astrophysics Data System (ADS)

Ahmad, Shabir; Alam, Akhtar; Ahmad, Bashir; Afzal, Ahsan; Bhat, M. I.; Sultan Bhat, M.; Farooq Ahmad, Hakim; Tectonics; Natural Hazards Research Group

2018-01-01

The present study aims to assess the tectonic activity in the Erin basin (NE Kashmir) on the basis of several relevant geomorphic indices and field observations. We use Digital Elevation Model (SRTM) and Survey of India (SoI) topographic maps in GIS environment to compute the geomorphic indices. The indices i.e., convex hypsometric curve, high hypsometric integral value (Hi > 0.5), low basin elongation ratio (Eb = 0.17), low mountain front sinuosity values (Smf = 1.08 average), low valley floor width ratios (Vf < 1), topographic assymetric character (T < 1), uneven basin asymmetry factor (AF < 50), elongated shape (Bs > 4) suggest that the area is tectonically active. Moreover, prominent irregularities (knickpoints/knickzones) along longitudinal profile of the Erin River even in homogenous resistant lithology (Panjal trap) and anomalous stream gradient index (SL) values reflect that the Erin basin is dissected by two faults (EF-1 and EF-2) with NNW-SSE and SSW-NNE trends respectively. The results of this preliminary study further substantiate the recent GPS studies, which argue that the maximum strain is accumulating in the NE part of the Kashmir Himalaya.

Electronic polarizability, optical basicity and interaction parameter for Nd2O3 doped lithium-zinc-phosphate glasses

NASA Astrophysics Data System (ADS)

Algradee, M. A.; Sultan, M.; Samir, O. M.; Alwany, A. Elwhab B.

2017-08-01

The Nd3+-doped lithium-zinc-phosphate glasses were prepared by means of conventional melt quenching method. X-ray diffraction results confirmed the glassy nature of the studied glasses. The physical parameters such as the density, molar volume, ion concentration, polaron radius, inter-ionic distance, field strength and oxygen packing density were calculated using different formulae. The transmittance and reflectance spectra of glasses were recorded in the wavelength range 190-1200 nm. The values of optical band gap and Urbach energy were determined based on Mott-Davis model. The refractive indices for the studied glasses were evaluated from optical band gap values using different methods. The average electronic polarizability of the oxide ions, optical basicity and an interaction parameter were investigated from the calculated values of the refractive index and the optical band gap for the studied glasses. The variations in the different physical and optical properties of glasses with Nd2O3 content were discussed in terms of different parameters such as non-bridging oxygen and different concentrations of Nd cation in glass system.

Comparison of tropospheric NO2 vertical columns in an urban environment using satellite, multi-axis differential optical absorption spectroscopy, and in situ measurements

NASA Astrophysics Data System (ADS)

Mendolia, D.; D'Souza, R. J. C.; Evans, G. J.; Brook, J.

2013-10-01

Tropospheric NO2 vertical column densities have been retrieved and compared for the first time in Toronto, Canada, using three methods of differing spatial scales. Remotely sensed NO2 vertical column densities, retrieved from multi-axis differential optical absorption spectroscopy and satellite remote sensing, were evaluated by comparison with in situ vertical column densities estimated using a pair of chemiluminescence monitors situated 0.01 and 0.5 km a.g.l. (above ground level). The chemiluminescence measurements were corrected for the influence of NOz, which reduced the NO2 concentrations at 0.01 and 0.5 km by an average of 8 ± 1% and 12 ± 1%, respectively. The average absolute decrease in the chemiluminescence NO2 measurement as a result of this correction was less than 1 ppb. The monthly averaged ratio of the NO2 concentration at 0.5 to 0.01 km varied seasonally, and exhibited a negative linear dependence on the monthly average temperature, with Pearson's R = 0.83. During the coldest month, February, this ratio was 0.52 ± 0.04, while during the warmest month, July, this ratio was 0.34 ± 0.04, illustrating that NO2 is not well mixed within 0.5 km above ground level. Good correlation was observed between the remotely sensed and in situ NO2 vertical column densities (Pearson's R value ranging from 0.72 to 0.81), but the in situ vertical column densities were 52 to 58% greater than the remotely sensed columns. These results indicate that NO2 horizontal heterogeneity strongly impacted the magnitude of the remotely sensed columns. The in situ columns reflected an urban environment with major traffic sources, while the remotely sensed NO2 vertical column densities were representative of the region, which included spatial heterogeneity introduced by residential neighbourhoods and Lake Ontario. Despite the difference in absolute values, the reasonable correlation between the vertical column densities determined by three distinct methods increased confidence in the validity of the values provided by each measurement technique.

Bioavailability of heavy metals in fresh water Tilapia nilotica (Oreachromis niloticus Linnaeus, 1758): potential risk to fishermen and consumers.

PubMed

El-Sadaawy, Manal M; El-Said, Ghada F; Sallam, Neama A

2013-01-01

The study was undertaken to assess the accumulation of some heavy metals (Cr, Co, Cu, Ni, Zn, Pb and Cd) in different tissues (muscle, gills, heart, liver, brain, bone and skin) of Tilapia nilotica. It is one of the most edible fish species in Egypt and was collected from a commercial fish farm in order to evaluate their potential risk to fishermen and consumers. This fish farm is fed with discharged water containing agricultural, industrial, sewage and domestic wastes. The length-weight relation and condition factor calculation of Tilapia nilotica samples showed a significant linear regression (r(2) = 0.920) and an average condition factor of 4.1 g/cm(3). This indicated that the health status for the studied fish samples was good. Metal pollution index (MPI) values for the determined heavy metals in the different tissues reflected that the muscle was the only tissue that had the lowest content. Provisional Tolerable Weekly Intake (PTWI) values for the investigated heavy metals were lower than those reported for the permissible limits. The data were evaluated by using ANOVA statistical analysis. For appraising the human health risk effects of heavy metals in fish muscle, estimated dietary intake (EDI) and hazard quotient (HQ) were determined. HQ levels indicated that Cr and Co were the only heavy metals among the determined ones that had values more than unity. Also, their relative contributions in fish consumptions were Cr> Co> Pb> Ni> Cu> Cd> Zn. The highest average HQ value of chromium determined in this study referred to the possible adverse effects of Cr on human health. Accordingly, the potential public health risks from dietary exposure to hazardous contaminants in fish species from fish farms must be continually subjected to research, regulation and debate.

Workplace exposure to nanoparticles and the application of provisional nanoreference values in times of uncertain risks

NASA Astrophysics Data System (ADS)

van Broekhuizen, Pieter; van Broekhuizen, Fleur; Cornelissen, Ralf; Reijnders, Lucas

2012-03-01

Nano reference values (NRVs) for occupational use of nanomaterials were tested as provisional substitute for Occupational Exposure Limits (OELs). NRVs can be used as provisional limit values until Health-Based OELs or derived no-effect levels (DNEL) become available. NRVs were defined for 8 h periods (time weighted average) and for short-term exposure periods (15 min-time weighted average). To assess the usefulness of these NRVs, airborne number concentrations of nanoparticles (NPs) in the workplace environment were measured during paint manufacturing, electroplating, light equipment manufacturing, non-reflective glass production, production of pigment concentrates and car refinishing. Activities monitored were handling of solid engineered NPs (ENP), abrasion, spraying and heating during occupational use of nanomaterials (containing ENPs) and machining nanosurfaces. The measured concentrations are often presumed to contain ENPs as well as process-generated NPs (PGNP). The PGNP are found to be a significant source for potential exposure and cannot be ignored in risk assessment. Levels of NPs identified in workplace air were up to several millions of nanoparticles/cm3. Conventional components in paint manufacturing like CaCO3 and talc may contain a substantial amount of nanosized particulates giving rise to airborne nanoparticle concentrations. It is argued that risk assessments carried out for e.g. paint manufacturing processes using conventional non-nano components should take into account potential nanoparticle emissions as well. The concentrations measured were compared with particle-based NRVs and with mass-based values that have also been proposed for workers protection. It is concluded that NRVs can be used for risk management for handling or processing of nanomaterials at workplaces provided that the scope of NRVs is not limited to ENPs only, but extended to the exposure to process-generated NPs as well.

Appraisal of application possibilities of smoothed splines to designation of the average values of terrain curvatures measured after the termination of hard coal exploitation conducted at medium depth

NASA Astrophysics Data System (ADS)

Orwat, J.

2018-01-01

In paper were presented results of average values calculations of terrain curvatures measured after the termination of subsequent exploitation stages in the 338/2 coal bed located at medium depth. The curvatures were measured on the neighbouring segments of measuring line No. 1 established perpendicularly to the runways of four longwalls No. 001, 002, 005 and 007. The average courses of measured curvatures were designated based on average courses of measured inclinations. In turn, the average values of observed inclinations were calculated on the basis of measured subsidence average values. In turn, they were designated on the way of average-square approximation, which was done by the use of smoothed splines, in reference to the theoretical courses determined by the S. Knothe’s and J. Bialek’s formulas. Here were used standard parameters values of a roof rocks subsidence a, an exploitation rim Aobr and an angle of the main influences range β. The values of standard deviations between the average and measured curvatures σC and the variability coefficients of random scattering of curvatures MC were calculated. They were compared with values appearing in the literature and based on this, a possibility appraisal of the use of smooth splines to designation of average course of observed curvatures of mining area was conducted.

Penguins as bioindicators of mercury contamination in the Southern Ocean: birds from the Kerguelen Islands as a case study.

PubMed

Carravieri, Alice; Bustamante, Paco; Churlaud, Carine; Cherel, Yves

2013-06-01

Seabirds have been used extensively as bioindicators of mercury (Hg) contamination in the marine environment, although information on flightless species like penguins remains limited. In order to assess the use of penguins as bioindicators of Hg contamination in subantarctic and Antarctic marine ecosystems, Hg concentrations were evaluated in the feathers of the four species that breed on the Kerguelen Islands in the southern Indian Ocean. Compared to other seabirds, adult Kerguelen penguins had low to moderate feather Hg concentrations, with an average ranging from 1.96 ± 0.41 μgg(-1) dry weight in the southern rockhopper penguin to 5.85 ± 3.00 μg g(-1) dry weight in the gentoo penguin. The species was a major determinant of Hg contamination, with feather Hg concentrations being lower in the oceanic species (king and crested penguins) than in the coastal one (gentoo penguin). In all species however, feather Hg concentrations were higher in adults than in chicks, reflecting the different periods of Hg bioaccumulation in the internal tissues of the two age classes. The relationship between adult penguin trophic ecology and Hg burdens was investigated using stable isotopes. Feeding habits (reflected by δ(15)N values) had a greater effect on adult feather Hg concentrations when compared to foraging habitats (reflected by δ(13)C values), indicating Hg biomagnification in Kerguelen neritic and oceanic waters. Dietary preferences were crucial in explaining individual feather Hg concentrations, as highlighted by intra-specific variation in Hg levels of gentoo penguins sampled at two different breeding sites of the archipelago. Penguins appear to reflect Hg bioavailability reliably in their foraging environment and could serve as efficient bioindicators of Hg contamination in the Southern Ocean on different spatial and temporal scales. Copyright © 2013 Elsevier B.V. All rights reserved.

Airborne hyperspectral sensor radiometric self-calibration using near-infrared properties of deep water and vegetation

NASA Astrophysics Data System (ADS)

Barbieux, Kévin; Nouchi, Vincent; Merminod, Bertrand

2016-10-01

Retrieving the water-leaving reflectance from airborne hyperspectral data implies to deal with three steps. Firstly, the radiance recorded by an airborne sensor comes from several sources: the real radiance of the object, the atmospheric scattering, sky and sun glint and the dark current of the sensor. Secondly, the dispersive element inside the sensor (usually a diffraction grating or a prism) could move during the flight, thus shifting the observed spectra on the wavelengths axis. Thirdly, to compute the reflectance, it is necessary to estimate, for each band, what value of irradiance corresponds to a 100% reflectance. We present here our calibration method, relying on the absorption features of the atmosphere and the near-infrared properties of common materials. By choosing proper flight height and flight lines angle, we can ignore atmospheric and sun glint contributions. Autocorrelation plots allow to identify and reduce the noise in our signals. Then, we compute a signal that represents the high frequencies of the spectrum, to localize the atmospheric absorption peaks (mainly the dioxygen peak around 760 nm). Matching these peaks removes the shift induced by the moving dispersive element. Finally, we use the signal collected over a Lambertian, unit-reflectance surface to estimate the ratio of the system's transmittances to its near-infrared transmittance. This transmittance is computed assuming an average 50% reflectance of the vegetation and nearly 0% for water in the near-infrared. Results show great correlation between the output spectra and ground measurements from a TriOS Ramses and the water-insight WISP-3.

Radar probing of surfactant films on the water surface using dual co-polarized SAR

NASA Astrophysics Data System (ADS)

Ermakov, S.; da Silva, J. C. B.; Kapustin, I.; Molkov, A.; Sergievskaya, I.; Shomina, O.

2016-10-01

Retrieving the water-leaving reflectance from airborne hyperspectral data implies to deal with three steps. Firstly, the radiance recorded by an airborne sensor comes from several sources: the real radiance of the object, the atmospheric scattering, sky and sun glint and the dark current of the sensor. Secondly, the dispersive element inside the sensor (usually a diffraction grating or a prism) could move during the flight, thus shifting the observed spectra on the wavelengths axis. Thirdly, to compute the reflectance, it is necessary to estimate, for each band, what value of irradiance corresponds to a 100% reflectance. We present here our calibration method, relying on the absorption features of the atmosphere and the near-infrared properties of common materials. By choosing proper flight height and flight lines angle, we can ignore atmospheric and sun glint contributions. Autocorrelation plots allow to identify and reduce the noise in our signals. Then, we compute a signal that represents the high frequencies of the spectrum, to localize the atmospheric absorption peaks (mainly the dioxygen peak around 760 nm). Matching these peaks removes the shift induced by the moving dispersive element. Finally, we use the signal collected over a Lambertian, unit-reflectance surface to estimate the ratio of the system's transmittances to its near-infrared transmittance. This transmittance is computed assuming an average 50% reflectance of the vegetation and nearly 0% for water in the near-infrared. Results show great correlation between the output spectra and ground measurements from a TriOS Ramses and the water-insight WISP-3.

Determination of the organic aerosol mass to organic carbon ratio in IMPROVE samples.

PubMed

El-Zanan, Hazem S; Lowenthal, Douglas H; Zielinska, Barbara; Chow, Judith C; Kumar, Naresh

2005-07-01

The ratio of organic mass (OM) to organic carbon (OC) in PM(2.5) aerosols at US national parks in the IMPROVE network was estimated experimentally from solvent extraction of sample filters and from the difference between PM(2.5) mass and chemical constituents other than OC (mass balance) in IMPROVE samples from 1988 to 2003. Archived IMPROVE filters from five IMPROVE sites were extracted with dichloromethane (DCM), acetone and water. The extract residues were weighed to determine OM and analyzed for OC by thermal optical reflectance (TOR). On average, successive extracts of DCM, acetone, and water contained 64%, 21%, and 15%, respectively, of the extractable OC, respectively. On average, the non-blank-corrected recovery of the OC initially measured in these samples by TOR was 115+/-42%. OM/OC ratios from the combined DCM and acetone extracts averaged 1.92 and ranged from 1.58 at Indian Gardens, AZ in the Grand Canyon to 2.58 at Mount Rainier, WA. The average OM/OC ratio determined by mass balance was 2.07 across the IMPROVE network. The sensitivity of this ratio to assumptions concerning sulfate neutralization, water uptake by hygroscopic species, soil mass, and nitrate volatilization were evaluated. These results suggest that the value of 1.4 for the OM/OC ratio commonly used for mass and light extinction reconstruction in IMPROVE is too low.

A comparative study on generating simulated Landsat NDVI images using data fusion and regression method-the case of the Korean Peninsula.

PubMed

Lee, Mi Hee; Lee, Soo Bong; Eo, Yang Dam; Kim, Sun Woong; Woo, Jung-Hun; Han, Soo Hee

2017-07-01

Landsat optical images have enough spatial and spectral resolution to analyze vegetation growth characteristics. But, the clouds and water vapor degrade the image quality quite often, which limits the availability of usable images for the time series vegetation vitality measurement. To overcome this shortcoming, simulated images are used as an alternative. In this study, weighted average method, spatial and temporal adaptive reflectance fusion model (STARFM) method, and multilinear regression analysis method have been tested to produce simulated Landsat normalized difference vegetation index (NDVI) images of the Korean Peninsula. The test results showed that the weighted average method produced the images most similar to the actual images, provided that the images were available within 1 month before and after the target date. The STARFM method gives good results when the input image date is close to the target date. Careful regional and seasonal consideration is required in selecting input images. During summer season, due to clouds, it is very difficult to get the images close enough to the target date. Multilinear regression analysis gives meaningful results even when the input image date is not so close to the target date. Average R 2 values for weighted average method, STARFM, and multilinear regression analysis were 0.741, 0.70, and 0.61, respectively.

Calculations of the variability of ice cloud radiative properties at selected solar wavelengths

NASA Technical Reports Server (NTRS)

Welch, R. M.; Zdunkowski, W. G.; Cox, S. K.

1980-01-01

This study shows that there is surprising little difference in values of reflectance, absorptance, and transmittance for many of the intermediate-size particle spectra. Particle size distributions with mode radii ranging from approximately 50 to 300 microns, irrespective of particle shape and nearly independent of the choice of size distribution representation, give relatively similar flux values. The very small particle sizes, however, have significantly larger values of reflectance and transmittance with corresponding smaller values of absorptance than do the larger particle sizes. The very large particle modes produce very small values of reflectance and transmittance along with very large values of absorptance. Such variations are particularly noticeable when plotted as a function of wavelength.

Properties of the Hermean Regolith. 5; New Optical Reflectance Spectra, Comparison with Lunar Anorthosites and Mineralogical Modelling

NASA Technical Reports Server (NTRS)

Warell, J.; Blewett, D. T.

2003-01-01

We present new optical (0.4-0.65 micron) spectra of Mercury and lunar pure anorthosite locations, obtained quasi-simultaneously with the Nordic Optical Telescope (NOT) in 2002. A comparative study is performed with the model of Lucey et al. between iron-poor, mature, pure anorthosite (less than 90% plagioclase feldspar) Clementine spectra from the lunar farside and a combined 0.4-1.0 micron mercurian spectrum, obtained with the NOT, calculated for standard photometric geometry. Mercury is located at more extreme locations in the Lucey ratio-reflectance diagrams than any known lunar soil, specifically with respect to the extremely iron-poor mature anorthosites. Though quantitative prediction of FeO and TiO2 abundances cannot be made without a more generally applicable model, we find qualitatively that the abundances of both these oxides must be near zero for Mercury. We utilize the theory of Hapke, with realistic photometric parameters, to model laboratory spectra of matured mineral powders and lunar soils, and remotely sensed spectra of lunar anorthosites and Mercury. An important difference between fabricated and natural powders is the high value for the internal scattering parameter necessary to interpret the spectra for the former, and the requirement of rough and non-isotropically scattering surfaces in the modelling of the latter. The mature lunar anorthosite spectra were well modelled with binary mixtures of calcic feldspars and olivines, grain sizes of 25-30 micron and a concentration of submicroscopic metallic iron (SMFe) of 0.12-0.15% in grain coatings. The mercurian spectrum is not possible to interpret from terrestrial mineral powder spectra without introducing an average particle scattering function for the bulk soil that increases in backscattering efficiency with wavelength. The observed spectrum is somewhat better predicted with binary mixture models of feldspars and pyroxenes, that single-component regoliths consisting of either albite or diopside. Correct spectral reflectance values were predicted with a concentration of 0.1 wt% SMFe in coatings of 15-30 micron sized grains. Since reasonable cosmogonical formation scenarios for Mercury, or meteoritic infall, predict iron concentrations at least this high, we draw the conclusion that the average grain size of Mercury is about a factor of two smaller than for average returned lunar soil samples. The 0.6-2.5 micron spectrum of McCord and Clark is used to further limit the possible range of mineralogical composition of Mercury. It is found that an intimately mixed and matured 3 : 1 labradorite-to-enstatite regolith composition best matches both the optical and near-infrared spectra, yielding an abundance of approx. 1.2 wt% FeO and -approx. 0 wt% TiO2.

Diagnosing ozone stress and differential tolerance in rice (Oryza sativa L.) with ethylenediurea (EDU).

PubMed

Ashrafuzzaman, Md; Lubna, Farzana Afrose; Holtkamp, Felix; Manning, William J; Kraska, Thorsten; Frei, Michael

2017-11-01

Rising tropospheric ozone concentrations in Asia necessitate the breeding of adapted rice varieties to ensure food security. However, breeding requires field-based evaluation of ample plant material, which can be technically challenging or very costly when using ozone fumigation facilities. The chemical ethylenediurea (EDU) has been proposed for estimating the effects of ozone in large-scale field applications, but controlled experiments investigating constitutive effects on rice or its suitability to detect genotypic differences in ozone tolerance are missing. This study comprised a controlled open top chamber experiment with four treatments (i) control (average ozone concentration 16 ppb), (ii) control with EDU application, (iii) ozone stress (average 77 ppb for 7 h daily throughout the season), and (iv) ozone stress with EDU application. Three contrasting rice genotypes were tested, i.e. the tolerant line L81 and the sensitive Nipponbare and BR28. The ozone treatment had significant negative effects on plant growth (height and tillering), stomatal conductance, SPAD value, spectral reflectance indices such as the normalized difference vegetation index (NDVI), lipid peroxidation, as well as biomass and grain yields. These negative effects were more pronounced in the a priori sensitive varieties, especially the widely grown Bangladeshi variety BR28, which showed grain yield reductions by 37 percent. EDU application had almost no effects on plants in the absence of ozone, but partly mitigated ozone effects on foliar symptoms, lipid peroxidation, SPAD value, stomatal conductance, several spectral reflectance parameters, panicle number, grain yield, and spikelet sterility. EDU responses were more pronounced in sensitive genotypes than in the tolerant L81. In conclusion, EDU had no constitutive effects on rice and partly offset negative ozone effects, especially in sensitive varieties. It can thus be used to diagnose ozone damage in field grown rice and for distinguishing tolerant (less EDU-responsive) and sensitive (more EDU-responsive) genotypes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermal/Optical Methods for Elemental Carbon Quantification in Soils and Urban Dusts: Equivalence of Different Analysis Protocols

PubMed Central

Han, Yongming; Chen, Antony; Cao, Junji; Fung, Kochy; Ho, Fai; Yan, Beizhan; Zhan, Changlin; Liu, Suixin; Wei, Chong; An, Zhisheng

2013-01-01

Quantifying elemental carbon (EC) content in geological samples is challenging due to interferences of crustal, salt, and organic material. Thermal/optical analysis, combined with acid pretreatment, represents a feasible approach. However, the consistency of various thermal/optical analysis protocols for this type of samples has never been examined. In this study, urban street dust and soil samples from Baoji, China were pretreated with acids and analyzed with four thermal/optical protocols to investigate how analytical conditions and optical correction affect EC measurement. The EC values measured with reflectance correction (ECR) were found always higher and less sensitive to temperature program than the EC values measured with transmittance correction (ECT). A high-temperature method with extended heating times (STN120) showed the highest ECT/ECR ratio (0.86) while a low-temperature protocol (IMPROVE-550), with heating time adjusted for sample loading, showed the lowest (0.53). STN ECT was higher than IMPROVE ECT, in contrast to results from aerosol samples. A higher peak inert-mode temperature and extended heating times can elevate ECT/ECR ratios for pretreated geological samples by promoting pyrolyzed organic carbon (PyOC) removal over EC under trace levels of oxygen. Considering that PyOC within filter increases ECR while decreases ECT from the actual EC levels, simultaneous ECR and ECT measurements would constrain the range of EC loading and provide information on method performance. Further testing with standard reference materials of common environmental matrices supports the findings. Char and soot fractions of EC can be further separated using the IMPROVE protocol. The char/soot ratio was lower in street dusts (2.2 on average) than in soils (5.2 on average), most likely reflecting motor vehicle emissions. The soot concentrations agreed with EC from CTO-375, a pure thermal method. PMID:24358286

Semen Levels of Spermatid-Specific Thioredoxin-3 Correlate with Pregnancy Rates in ART Couples

PubMed Central

Qiu, Jing; Sutovsky, Miriam; Rawe, Vanesa Y.; Manandhar, Gaurishankar; Miranda-Vizuete, Antonio; Sutovsky, Peter

2013-01-01

Spermatid specific thioredoxin-3 (SPTRX3 or TXNDC8) is a testis/male germ line specific member of thioredoxin family that accumulates in the superfluous cytoplasm of defective human spermatozoa. We hypothesized that semen levels of SPTRX3 are reflective of treatment outcome in assisted reproductive therapy (ART) couples treated by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Relationship between SPTRX3 and treatment outcome was investigated in 239 couples undergoing ART at an infertility clinic. Sperm content of SPTRX3 was evaluated by flow cytometry and epifluorescence microscopy, and correlated with clinical semen analysis parameters, and data on embryo development and pregnancy establishment. High SPTRX3 levels (>15% SPTRX3-positive spermatozoa) were found in 51% of male infertility patients (n = 72), in 20% of men from couples with unexplained, idiopathic infertility (n = 61) and in 14% of men from couples previously diagnosed with female-only infertility (n = 85). Couples with high SPTRX3 produced fewer two-pronuclear zygotes and had a reduced pregnancy rate (19.2% pregnant with >15% SPTRX3-positive spermatozoa vs. 41.2% pregnant with <5% SPTRX3-positive sperm; one-sided p<0.05). The average pregnancy rate of all 239 couples was 25.1%. Live birth rate was 19.2% and lowest average SPTRX3 levels were found in couples that delivered twins. Men with >15% of SPTRX3-positive spermatozoa, a cutoff value established by ROC analysis, had their chance of fathering children by IVF or ICSI reduced by nearly two-thirds. The percentage of SPTRX3-positive spermatozoa had predictive value for pregnancy after ART. Gradient purification and sperm swim-up failed to remove all SPTRX3-positive spermatozoa from semen prepared for ART. In summary, the elevated semen content of SPTRX3 in men from ART couples coincided with reduced incidence of pregnancy by IVF or ICSI, identifying SPTRX3 as a candidate biomarker reflective of ART outcome. PMID:23734172

Development of a Calibration Strip for Immunochromatographic Assay Detection Systems.

PubMed

Gao, Yue-Ming; Wei, Jian-Chong; Mak, Peng-Un; Vai, Mang-I; Du, Min; Pun, Sio-Hang

2016-06-29

With many benefits and applications, immunochromatographic (ICG) assay detection systems have been reported on a great deal. However, the existing research mainly focuses on increasing the dynamic detection range or application fields. Calibration of the detection system, which has a great influence on the detection accuracy, has not been addressed properly. In this context, this work develops a calibration strip for ICG assay photoelectric detection systems. An image of the test strip is captured by an image acquisition device, followed by performing a fuzzy c-means (FCM) clustering algorithm and maximin-distance algorithm for image segmentation. Additionally, experiments are conducted to find the best characteristic quantity. By analyzing the linear coefficient, an average value of hue (H) at 14 min is chosen as the characteristic quantity and the empirical formula between H and optical density (OD) value is established. Therefore, H, saturation (S), and value (V) are calculated by a number of selected OD values. Then, H, S, and V values are transferred to the RGB color space and a high-resolution printer is used to print the strip images on cellulose nitrate membranes. Finally, verification of the printed calibration strips is conducted by analyzing the linear correlation between OD and the spectral reflectance, which shows a good linear correlation (R² = 98.78%).

LWR pressure vessel surveillance dosimetry improvement program: LWR power reactor surveillance physics-dosimetry data base compendium

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

McElroy, W.N.

1985-08-01

This NRC physics-dosimetry compendium is a collation of information and data developed from available research and commercial light water reactor vessel surveillance program (RVSP) documents and related surveillance capsule reports. The data represents the results of the HEDL least-squares FERRET-SAND II Code re-evaluation of exposure units and values for 47 PWR and BWR surveillance capsules for W, B and W, CE, and GE power plants. Using a consistent set of auxiliary data and dosimetry-adjusted reactor physics results, the revised fluence values for E > 1 MeV averaged 25% higher than the originally reported values. The range of fluence values (new/old)more » was from a low of 0.80 to a high of 2.38. These HEDL-derived FERRET-SAND II exposure parameter values are being used for NRC-supported HEDL and other PWR and BWR trend curve data development and testing studies. These studies are providing results to support Revision 2 of Regulatory Guide 1.99. As stated by Randall (Ra84), the Guide is being updated to reflect recent studies of the physical basis for neutron radiation damage and efforts to correlate damage to chemical composition and fluence.« less

Measurement-based climatology of aerosol direct radiative effect, its sensitivities, and uncertainties from a background southeast US site

NASA Astrophysics Data System (ADS)

Sherman, James P.; McComiskey, Allison

2018-03-01

Aerosol optical properties measured at Appalachian State University's co-located NASA AERONET and NOAA ESRL aerosol network monitoring sites over a nearly four-year period (June 2012-Feb 2016) are used, along with satellite-based surface reflectance measurements, to study the seasonal variability of diurnally averaged clear sky aerosol direct radiative effect (DRE) and radiative efficiency (RE) at the top-of-atmosphere (TOA) and at the surface. Aerosol chemistry and loading at the Appalachian State site are likely representative of the background southeast US (SE US), home to high summertime aerosol loading and one of only a few regions not to have warmed during the 20th century. This study is the first multi-year ground truth DRE study in the SE US, using aerosol network data products that are often used to validate satellite-based aerosol retrievals. The study is also the first in the SE US to quantify DRE uncertainties and sensitivities to aerosol optical properties and surface reflectance, including their seasonal dependence.Median DRE for the study period is -2.9 W m-2 at the TOA and -6.1 W m-2 at the surface. Monthly median and monthly mean DRE at the TOA (surface) are -1 to -2 W m-2 (-2 to -3 W m-2) during winter months and -5 to -6 W m-2 (-10 W m-2) during summer months. The DRE cycles follow the annual cycle of aerosol optical depth (AOD), which is 9 to 10 times larger in summer than in winter. Aerosol RE is anti-correlated with DRE, with winter values 1.5 to 2 times more negative than summer values. Due to the large seasonal dependence of aerosol DRE and RE, we quantify the sensitivity of DRE to aerosol optical properties and surface reflectance, using a calendar day representative of each season (21 December for winter; 21 March for spring, 21 June for summer, and 21 September for fall). We use these sensitivities along with measurement uncertainties of aerosol optical properties and surface reflectance to calculate DRE uncertainties. We also estimate uncertainty in calculated diurnally-averaged DRE due to diurnal aerosol variability. Aerosol DRE at both the TOA and surface is most sensitive to changes in AOD, followed by single-scattering albedo (ω0). One exception is under the high summertime aerosol loading conditions (AOD ≥ 0.15 at 550 nm), when sensitivity of TOA DRE to ω0 is comparable to that of AOD. Aerosol DRE is less sensitive to changes in scattering asymmetry parameter (g) and surface reflectance (R). While DRE sensitivity to AOD varies by only ˜ 25 to 30 % with season, DRE sensitivity to ω0, g, and R largely follow the annual AOD cycle at APP, varying by factors of 8 to 15 with season. Since the measurement uncertainties of AOD, ω0, g, and R are comparable at Appalachian State, their relative contributions to DRE uncertainty are largely influenced by their (seasonally dependent) DRE sensitivity values, which suggests that the seasonal dependence of DRE uncertainty must be accounted for. Clear sky aerosol DRE uncertainty at the TOA (surface) due to measurement uncertainties ranges from 0.45 (0.75 W m-2) for December to 1.1 (1.6 W m-2) for June. Expressed as a fraction of DRE computed using monthly median aerosol optical properties and surface reflectance, the DRE uncertainties at TOA (surface) are 20 to 24 % (15 to 22 %) for March, June, and September and 49 (50 %) for DEC. The relatively low DRE uncertainties are largely due to the low uncertainty in AOD measured by AERONET. Use of satellite-based AOD measurements by MODIS in the DRE calculations increases DRE uncertainties by a factor of 2 to 5 and DRE uncertainties are dominated by AOD uncertainty for all seasons. Diurnal variability in AOD (and to a lesser extent g) contributes to uncertainties in DRE calculated using daily-averaged aerosol optical properties that are slightly larger (by ˜ 20 to 30 %) than DRE uncertainties due to measurement uncertainties during summer and fall, with comparable uncertainties during winter and spring.

Measurement of splanchnic photoplethysmographic signals using a new reflectance fiber optic sensor

NASA Astrophysics Data System (ADS)

Hickey, Michelle; Samuels, Neal; Randive, Nilesh; Langford, Richard M.; Kyriacou, Panayiotis A.

2010-03-01

Splanchnic organs are particularly vulnerable to hypoperfusion. Currently, there is no technique that allows for the continuous estimation of splanchnic blood oxygen saturation (SpO2). As a preliminary to developing a suitable splanchnic SpO2 sensor, a new reflectance fiber optic photoplethysmographic (PPG) sensor and processing system are developed. An experimental procedure to examine the effect of fiber source detector separation distance on acquired PPG signals is carried out before finalizing the sensor design. PPG signals are acquired from four volunteers for separation distances of 1 to 8 mm. The separation range of 3 to 6 mm provides the best quality PPG signals with large amplitudes and the highest signal-to-noise ratios (SNRs). Preliminary calculation of SpO2 shows that distances of 3 and 4 mm provide the most realistic values. Therefore, it is suggested that the separation distance in the design of a fiber optic reflectance pulse oximeter be in the range of 3 to 4 mm. Preliminary PPG signals from various splanchnic organs and the periphery are obtained from six anaesthetized patients. The normalized amplitudes of the splanchnic PPGs are, on average, approximately the same as those obtained simultaneously from the periphery. These observations suggest that fiber optic pulse oximetry may be a valid monitoring technique for splanchnic organs.

BOREAS TE-8 Aspen Bark Spectral Reflectance Data

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Spencer, Shannon L.; Rock, Barrett N.

2000-01-01

The BOREAS TE-08 team collected in-lab spectral reflectance data for aspen bark and leaves from three sites within the BOREAS SSA from 24-May-1994 to 16-Jun-1994 (IFC 1), 19-Jul-1994 to 08-Aug-1994 (IFC 2), and 30-Aug-1994 to 19-Sep-1994 (IFC 3). One to nine trees from each site were sampled during the three IFCs. Each tree was sampled in five different locations for bark spectral properties: BS, US, BR, BT, and BO. Additionally, a limited number of LV were collected. Bark samples were removed from the stem of the tree and placed in ziplock bags for transport to UNH, where they were scanned with a spectroradiometer in a controlled environment. Each sample was scanned twice: the first set of measurements was made with the bark surface moistened, and the second set was made with the bark surface air-dried for a period of 30 minutes. These data represent continuous spectra of bark reflectance. Each sample was scanned three times, rotating the sample when possible. The reported values for each sample are an average over the three scans. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Cross-Continental Reflections on Evaluation Practice: Methods, Use, and Valuing

ERIC Educational Resources Information Center

Kallemeyn, Leanne M.; Hall, Jori; Friche, Nanna; McReynolds, Clifton

2015-01-01

The evaluation theory tree typology reflects the following three components of evaluation practice: (a) methods, (b) use, and (c) valuing. The purpose of this study was to explore how evaluation practice is conceived as reflected in articles published in the "American Journal of Evaluation" ("AJE") and "Evaluation," a…

Realizing a facile and environmental-friendly fabrication of high-performance multi-crystalline silicon solar cells by employing ZnO nanostructures and an Al2O3 passivation layer

PubMed Central

Chen, Hong-Yan; Lu, Hong-Liang; Sun, Long; Ren, Qing-Hua; Zhang, Hao; Ji, Xin-Ming; Liu, Wen-Jun; Ding, Shi-Jin; Yang, Xiao-Feng; Zhang, David Wei

2016-01-01

Nowadays, the multi-crystalline silicon (mc-Si) solar cells dominate the photovoltaic industry. However, the current acid etching method on mc-Si surface used by firms can hardly suppress the average reflectance value below 25% in the visible light spectrum. Meanwhile, the nitric acid and the hydrofluoric contained in the etching solution is both environmental unfriendly and highly toxic to human. Here, a mc-Si solar cell based on ZnO nanostructures and an Al2O3 spacer layer is demonstrated. The eco-friendly fabrication is realized by low temperature atomic layer deposition of Al2O3 layer as well as ZnO seed layer. Moreover, the ZnO nanostructures are prepared by nontoxic and low cost hydro-thermal growth process. Results show that the best passivation quality of the n+ -type mc-Si surface can be achieved by balancing the Si dangling bond saturation level and the negative charge concentration in the Al2O3 film. Moreover, the average reflectance on cell surface can be suppressed to 8.2% in 400–900 nm range by controlling the thickness of ZnO seed layer. With these two combined refinements, a maximum solar cell efficiency of 15.8% is obtained eventually. This work offer a facile way to realize the environmental friendly fabrication of high performance mc-Si solar cells. PMID:27924911

Realizing a facile and environmental-friendly fabrication of high-performance multi-crystalline silicon solar cells by employing ZnO nanostructures and an Al2O3 passivation layer

NASA Astrophysics Data System (ADS)

Chen, Hong-Yan; Lu, Hong-Liang; Sun, Long; Ren, Qing-Hua; Zhang, Hao; Ji, Xin-Ming; Liu, Wen-Jun; Ding, Shi-Jin; Yang, Xiao-Feng; Zhang, David Wei

2016-12-01

Nowadays, the multi-crystalline silicon (mc-Si) solar cells dominate the photovoltaic industry. However, the current acid etching method on mc-Si surface used by firms can hardly suppress the average reflectance value below 25% in the visible light spectrum. Meanwhile, the nitric acid and the hydrofluoric contained in the etching solution is both environmental unfriendly and highly toxic to human. Here, a mc-Si solar cell based on ZnO nanostructures and an Al2O3 spacer layer is demonstrated. The eco-friendly fabrication is realized by low temperature atomic layer deposition of Al2O3 layer as well as ZnO seed layer. Moreover, the ZnO nanostructures are prepared by nontoxic and low cost hydro-thermal growth process. Results show that the best passivation quality of the n+ -type mc-Si surface can be achieved by balancing the Si dangling bond saturation level and the negative charge concentration in the Al2O3 film. Moreover, the average reflectance on cell surface can be suppressed to 8.2% in 400-900 nm range by controlling the thickness of ZnO seed layer. With these two combined refinements, a maximum solar cell efficiency of 15.8% is obtained eventually. This work offer a facile way to realize the environmental friendly fabrication of high performance mc-Si solar cells.

Do intensive care data on respiratory infections reflect influenza epidemics?

PubMed

Koetsier, Antonie; van Asten, Liselotte; Dijkstra, Frederika; van der Hoek, Wim; Snijders, Bianca E; van den Wijngaard, Cees C; Boshuizen, Hendriek C; Donker, Gé A; de Lange, Dylan W; de Keizer, Nicolette F; Peek, Niels

2013-01-01

Severe influenza can lead to Intensive Care Unit (ICU) admission. We explored whether ICU data reflect influenza like illness (ILI) activity in the general population, and whether ICU respiratory infections can predict influenza epidemics. We calculated the time lag and correlation between ILI incidence (from ILI sentinel surveillance, based on general practitioners (GP) consultations) and percentages of ICU admissions with a respiratory infection (from the Dutch National Intensive Care Registry) over the years 2003-2011. In addition, ICU data of the first three years was used to build three regression models to predict the start and end of influenza epidemics in the years thereafter, one to three weeks ahead. The predicted start and end of influenza epidemics were compared with observed start and end of such epidemics according to the incidence of ILI. Peaks in respiratory ICU admissions lasted longer than peaks in ILI incidence rates. Increases in ICU admissions occurred on average two days earlier compared to ILI. Predicting influenza epidemics one, two, or three weeks ahead yielded positive predictive values ranging from 0.52 to 0.78, and sensitivities from 0.34 to 0.51. ICU data was associated with ILI activity, with increases in ICU data often occurring earlier and for a longer time period. However, in the Netherlands, predicting influenza epidemics in the general population using ICU data was imprecise, with low positive predictive values and sensitivities.

Interatrial septal motion as a novel index to predict left atrial pressure.

PubMed

Masai, Kumiko; Kishima, Hideyuki; Takahashi, Satoshi; Ashida, Kenki; Goda, Akiko; Mine, Takanao; Asakura, Masanori; Ishihara, Masaharu; Masuyama, Tohru

2018-01-22

We investigated whether the interatrial septal (IAS) motion of each heartbeat which is observed by transesophageal echocardiography reflects left atrial pressure (LAP) in patients with atrial fibrillation (AF). We studied 100 patients (70 males, age 67 ± 9 years) who underwent catheter ablation for AF. The amplitude of IAS motion was measured using M-mode and averaged for five cardiac cycles. Left and right atrial pressures, the left to right atrial pressure gradient were directly measured during the catheter ablation. In patients with sinus rhythm during measurement, elevated mean LAP, larger maximum left to right atrial pressure gradient, and greater left atrial emptying fraction were associated with IAS motion. The optimal cut-off value of the IAS motion for predicting high LAP (mean LAP > 15 mmHg) was 8.5 mm (sensitivity 100%, specificity 70.1%) in patients with sinus rhythm during pressure measurement. In addition, all patients were divided into 6 groups based on rhythm during measurement and cutoff value of IAS motion. In patients with sinus rhythm during measurement, low IAS motion group had a highest prevalence of elevated LAP compared with high IAS motion group (64 vs. 0%, P < 0.0001). The amplitude of interatrial septal motion during sinus rhythm reflects left atrial pressure in patients with atrial fibrillation. Interatrial septal motion could be a new index to predict elevated left atrial pressure.

Multi-Decadal Pathfinder Data Sets of Global Land Biophysical Variables from AVHRR and MODIS and their Use in GCM Studies of Biogeophysics and Biogeochemistry

NASA Technical Reports Server (NTRS)

Myneni, Ranga

2003-01-01

The problem of how the scale, or spatial resolution, of reflectance data impacts retrievals of vegetation leaf area index (LAI) and fraction absorbed photosynthetically active radiation (PAR) has been investigated. We define the goal of scaling as the process by which it is established that LAI and FPAR values derived from coarse resolution sensor data equal the arithmetic average of values derived independently from fine resolution sensor data. The increasing probability of land cover mixtures with decreasing resolution is defined as heterogeneity, which is a key concept in scaling studies. The effect of pixel heterogeneity on spectral reflectances and LAI/FPAR retrievals is investigated with 1 km Advanced Very High Resolution Radiometer (AVHRR) data aggregated to different coarse spatial resolutions. It is shown that LAI retrieval errors at coarse resolution are inversely related to the proportion of the dominant land cover in such pixel. Further, large errors in LAI retrievals are incurred when forests are minority biomes in non-forest pixels compared to when forest biomes are mixed with one another, and vice-versa. A physically based technique for scaling with explicit spatial resolution dependent radiative transfer formulation is developed. The successful application of this theory to scaling LAI retrievals from AVHRR data of different resolutions is demonstrated

A Space-Time Conservation Element and Solution Element Method for Solving the Two- and Three-Dimensional Unsteady Euler Equations Using Quadrilateral and Hexahedral Meshes

NASA Technical Reports Server (NTRS)

Zhang, Zeng-Chan; Yu, S. T. John; Chang, Sin-Chung; Jorgenson, Philip (Technical Monitor)

2001-01-01

In this paper, we report a version of the Space-Time Conservation Element and Solution Element (CE/SE) Method in which the 2D and 3D unsteady Euler equations are simulated using structured or unstructured quadrilateral and hexahedral meshes, respectively. In the present method, mesh values of flow variables and their spatial derivatives are treated as independent unknowns to be solved for. At each mesh point, the value of a flow variable is obtained by imposing a flux conservation condition. On the other hand, the spatial derivatives are evaluated using a finite-difference/weighted-average procedure. Note that the present extension retains many key advantages of the original CE/SE method which uses triangular and tetrahedral meshes, respectively, for its 2D and 3D applications. These advantages include efficient parallel computing ease of implementing non-reflecting boundary conditions, high-fidelity resolution of shocks and waves, and a genuinely multidimensional formulation without using a dimensional-splitting approach. In particular, because Riemann solvers, the cornerstones of the Godunov-type upwind schemes, are not needed to capture shocks, the computational logic of the present method is considerably simpler. To demonstrate the capability of the present method, numerical results are presented for several benchmark problems including oblique shock reflection, supersonic flow over a wedge, and a 3D detonation flow.

The impact of horizontal heterogeneities, cloud fraction, and cloud dynamics on warm cloud effective radii and liquid water path from CERES-like Aqua MODIS retrievals

NASA Astrophysics Data System (ADS)

Painemal, D.; Minnis, P.; Sun-Mack, S.

2013-05-01

The impact of horizontal heterogeneities, liquid water path (LWP from AMSR-E), and cloud fraction (CF) on MODIS cloud effective radius (re), retrieved from the 2.1 μm (re2.1) and 3.8 μm (re3.8) channels, is investigated for warm clouds over the southeast Pacific. Values of re retrieved using the CERES Edition 4 algorithms are averaged at the CERES footprint resolution (~ 20 km), while heterogeneities (Hσ) are calculated as the ratio between the standard deviation and mean 0.64 μm reflectance. The value of re2.1 strongly depends on CF, with magnitudes up to 5 μm larger than those for overcast scenes, whereas re3.8 remains insensitive to CF. For cloudy scenes, both re2.1 and re3.8 increase with Hσ for any given AMSR-E LWP, but re2.1 changes more than for re3.8. Additionally, re3.8 - re2.1 differences are positive (< 1 μm) for homogeneous scenes (Hσ < 0.2) and LWP > 50 g m-2, and negative (up to -4 μm) for larger Hσ. Thus, re3.8 - re2.1 differences are more likely to reflect biases associated with cloud heterogeneities rather than information about the cloud vertical structure. The consequences for MODIS LWP are also discussed.

Carnivore stable carbon isotope niches reflect predator-prey size relationships in African savannas.

PubMed

Codron, Jacqueline; Avenant, Nico L; Wigley-Coetsee, Corli; Codron, Daryl

2018-03-01

Predator-prey size relationships are among the most important patterns underlying the structure and function of ecological communities. Indeed, these relationships have already been shown to be important for understanding patterns of macroevolution and differential extinction in the terrestrial vertebrate fossil record. Stable isotope analysis (SIA) is a powerful remote approach to examining animal diets and paleodiets. The approach is based on the principle that isotope compositions of consumer tissues reflect those of their prey. In systems where resource isotope compositions are distributed along a body size gradient, SIA could be used to reconstruct predator-prey size relationships. We analyzed stable carbon isotope distributions amongst mammalian herbivores in extant and Plio-Pleistocene African savanna assemblages, and show that the range of δ 13 C values among mammalian prey species (herbivores and rodents) increases with body mass (BM), because C 4 plant feeding (essentially grazing) is more common among larger taxa. Consequently, δ 13 C values of mammalian carnivores in these systems are related to species' BM, reflecting a higher average C 4 prey component in the diets of larger-bodied carnivores. This pattern likely emerges because only the largest carnivores in these systems have regular access to the C 4 prey base, whereas smaller carnivores do not. The δ 13 C-BM relationship observed in mammalian carnivores is a potentially powerful approach for reconstructing and parameterizing predator-prey size relationships in contemporary and fossil savanna assemblages, and for interpreting how various behavioral, ecological and environmental factors influence prey size selection. © 2017 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Aflatoxin and outcome from acute lower respiratory infection in children in The Philippines.

PubMed

Denning, D W; Quiepo, S C; Altman, D G; Makarananda, K; Neal, G E; Camallere, E L; Morgan, M R; Tupasi, T E

1995-09-01

Aflatoxin is immunosuppressive in experimental conditions. This study addressed its potentially contributory role in the poor outcome of acute lower respiratory infections (ALRI) in children in The Philippines. The catchment area included peri-urban slums and middle-class housing. One hundred and fifteen children (mean age 2.1, range 0.08-12 years) were enrolled and their serum and urine obtained at presentation with ALRI. Aflatoxins in serum and aflatoxin metabolites in urine were measured by previously validated ELISA tests. Using the 1986 WHO criteria for the severity of ALRI, 31% had mild, 12% moderate, 49% severe and 8% severe complicated pneumonia. Eighty of 97 (82%) chest radiographs were abnormal. Ninety per cent of the children were below average weight for age, using Filipino standards, with a mean of 79% (range 27-157%). Thirteen (11%) children died. Aflatoxin in their serum, reflecting recent ingestion, was detected in 33%, with a mean positive value of 462 pg/ml. Aflatoxin metabolites (reflecting chronic ingestion) were detected in 64 of 65 urines collected, with a mean value of 0.1-4.77ng/ml. None of the children with detectable serum aflatoxin died. Anorexia and impaired consciousness were strongly associated with a poor outcome (prolonged fever or death). There was a strong association between undetectable serum aflatoxin concentrations and death (p = 0.004), perhaps reflecting anorexia. There was no relationship between the concentration of urinary aflatoxin metabolites and outcome. Serum was also obtained from 29 mothers on admission and none contained detectable aflatoxin. As virtually all the children had evidence of exposure to aflatoxin, a potentially immunosuppressive role in the context of pneumonia cannot be excluded.

Spatial and temporal variation in tree-ring α-cellulose oxygen and hydrogen isotope values as a record of water availability in the Atacama Desert

NASA Astrophysics Data System (ADS)

Olson, E. J.; Dodd, J. P.

2015-12-01

Previous studies have documented that tree ring oxygen and hydrogen isotopes primarily reflect source water; however, biosynthetic fractionation processes modify this signal and can have a varied response to environmental conditions. The degree to which source water contributes to δ2H and δ18O values of plant α-cellulose is species-specific and modern calibration studies are necessary. Here we present a calibration data set of P. tamarugo α-cellulose δ2H and δ18O values from the Atacama Desert in Northern Chile. P. tamarugo trees are endemic to the region and have adapted to the extremely arid environment where average annual precipitation is < 5mm/yr. This modern isotope chronology has been constructed from living P. tamarugo trees (n=12) from the Pampa del Tamarugal Basin in the northern Atacama. Generally, the tree-ring α-cellulose δ18O values are poorly correlated with meteorological data from coastal stations (i.e. Iquique); however, there is good agreement between regional groundwater depth and α-cellulose δ18O values. Most notably, average α-cellulose δ18O values increase by >2 ‰ over the past 20 years associated with a ~1.1 m lowering of the local groundwater table throughout the area. The correlation between a-cellulose isotope values and hydrologic conditions in modern times provides a baseline for interpretation of tree-ring isotope chronologies from the past 9.5 kya. A high-resolution Holocene (1.8-9.1 kya) age record of Prosopis sp. tree ring α-cellulose δ18O values provides a proxy for climatic and hydrologic conditions. During the early Holocene δ18O values range from 31 to 35‰ (2σ=0.58‰), while during the late Holocene values are much more variable (27.4 to 41‰; 2σ=2.64‰). Anthropogenic demand on local water sources is the most significant environmental factor affecting the variation in modern α-cellulose δ18O values; however, climate induced changes in regional water availability are the dominant driver of variability in the paleo-record. Increased variability in α-cellulose δ18O values in the late Holocene most likely indicates a reduction in annual recharge and an increase in episodic flood events driven by ENSO and other modes of atmospheric variability.

Computational method for determining n and k for a thin film from the measured reflectance, transmittance, and film thickness.

PubMed

Bennett, J M; Booty, M J

1966-01-01

A computational method of determining n and k for an evaporated film from the measured reflectance, transmittance, and film thickness has been programmed for an IBM 7094 computer. The method consists of modifications to the NOTS multilayer film program. The basic program computes normal incidence reflectance, transmittance, phase change on reflection, and other parameters from the optical constants and thicknesses of all materials. In the modification, n and k for the film are varied in a prescribed manner, and the computer picks from among these values one n and one k which yield reflectance and transmittance values almost equalling the measured values. Results are given for films of silicon and aluminum.

Methanol Oxidative Dehydrogenation on Oxide Catalysts: Molecular and Dissociative Routes and Hydrogen Addition Energies as Descriptors of Reactivity

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

Deshlahra, Prashant; Iglesia, Enrique

The oxidative dehydrogenation (ODH) of alkanols on oxide catalysts is generally described as involving H-abstraction from alkoxy species formed via O–H dissociation. Kinetic and isotopic data cannot discern between such routes and those involving kinetically-relevant H-abstraction from undissociated alkanols. Here, we combine such experiments with theoretical estimates of activation energies and entropies to show that the latter molecular routes prevail over dissociative routes for methanol reactions on polyoxometalate (POM) clusters at all practical reaction temperatures. The stability of the late transition states that mediate H-abstraction depend predominantly on the stability of the O–H bond formed, making H-addition energies (HAE) accuratemore » and single-valued descriptors of reactivity. Density functional theory-derived activation energies depend linearly on HAE values at each O-atom location on clusters with a range of composition (H3PMo12, H4SiMo12, H3PW12, H4PV1Mo11, and H4PV1W11); both barriers and HAE values reflect the lowest unoccupied molecular orbital energy of metal centers that accept the electron and the protonation energy of O-atoms that accept the proton involved in the H-atom transfer. Bridging O-atoms form O–H bonds that are stronger than those of terminal atoms and therefore exhibit more negative HAE values and higher ODH reactivity on all POM clusters. For each cluster composition, ODH turnover rates reflect the reactivity-averaged HAE of all accessible O-atoms, which can be evaluated for each cluster composition to provide a rigorous and accurate predictor of ODH reactivity for catalysts with known structure. These relations together with oxidation reactivity measurements can then be used to estimate HAE values and to infer plausible structures for catalysts with uncertain active site structures.« less

Spectrophotometric Measurement of Minimal Erythema Dose Sites after Narrowband Ultraviolet B Phototesting: Clinical Implication of Spetrophotometric Values in Phototherapy

PubMed Central

Jeon, Su-Young; Lee, Chae-Young; Song, Ki-Hoon

2014-01-01

Background The spectrophotometer is well known to be a useful tool for estimating the objective minimal erythema dose (MED) during planning of phototherapy protocol. However, only a few spectrophotometric values are used to evaluate the erythema and pigmentation of the MED site during phototesting. Objective To determinea new meaning of the relationships among spectrophotometric values during phototesting. Methods Twenty-five patients with psoriasis and 23 patients with vitiligo were selected before undergoing narrowband ultraviolet B phototherapy. We interpreted the gross findings of erythema and measured the L*a*b* values using a spectrophotometer at each phototest spot. We compared MEDs, basic spectrophotometric values (L*a*b*), and b*/L* values separately according to skin type, and determined the correlation of each spectrophotometric value and the correlation between a* and b*/L* values. Results Among L*a*b* values, only b* values showed a statistically significant difference between the type III and IV groups (p=0.003). There was a positive correlation only between MEDs and b* values (p<0.05). The average b*/L*value in the type IV group was significantly higher than the type III group (p<0.05). Conclusion The higher b* values in type IV skin indicates that skin tanning develops more prominently than type III. The correlation between MEDs and b* values may signify that the skin pigmentation status is deepened with the higher MEDs. The difference in b*/L*values between type III and IV skin reflects that the b*/L*value is thought to be an index of tanning. The a* value, known as an index of erythema, does not influence the degree of tanning. PMID:24648682

Reduction of Averaging Time for Evaluation of Human Exposure to Radiofrequency Electromagnetic Fields from Cellular Base Stations

NASA Astrophysics Data System (ADS)

Kim, Byung Chan; Park, Seong-Ook

In order to determine exposure compliance with the electromagnetic fields from a base station's antenna in the far-field region, we should calculate the spatially averaged field value in a defined space. This value is calculated based on the measured value obtained at several points within the restricted space. According to the ICNIRP guidelines, at each point in the space, the reference levels are averaged over any 6min (from 100kHz to 10GHz) for the general public. Therefore, the more points we use, the longer the measurement time becomes. For practical application, it is very advantageous to spend less time for measurement. In this paper, we analyzed the difference of average values between 6min and lesser periods and compared it with the standard uncertainty for measurement drift. Based on the standard deviation from the 6min averaging value, the proposed minimum averaging time is 1min.

Modulation of thyroid hormone receptors by non-thyroidal stimuli

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

ErkenBrack, D.E.; Clemons, G.K.

1988-01-01

The ability of non-thyroidal stimuli to affect the binding affinity and capacity of solubilized nuclear receptors for thyroid hormones was studied in a normal homeostatic system (erythropoiesis) and a pathobiologic one (lung-ozone interaction). No significant effects on affinity were found, as Kd control values for receptors derived from rat bone marrow averaged 57 (+/- 28) pM while experimental (hypoxic) values averaged 89 (+/- 55) pM. Kd control values in rat lung were found to average 142 (+/- 22) pM while average values derived from experimental protocols with ozone and methimazole were 267 (+/- 44) pM and 161 (+/- 35) pMmore » respectively. Finally, Kd control values for receptors derived from cultured MEL cells averaged 19 (+/- 2.6) pM while experimental values during exposure to DMSO or IGF1 were 23 (+/- 3.6) pM and 26 (+/- 11) pM respectively. In contrast, binding capacity (expressed as fmoles of hormone bound per unit protein of solubilized receptor) was markedly perturbed in several tissues by various agents: ozone effects on lung were shown by an average control value of 3.3 (+/- 0.4) as opposed to an experimental average of 28 (+/- 1.9); and hypoxia effects on erythroid tissue were displayed by an average control value of 0.7 (+/- 0.07) as opposed to the experimental figure of 1.8 (+/- 0.03). In cultured MEL cells, binding capacity was seen to be increased from control values of 388 (+/- 15) sites/cell to 1243 (+/- 142) sites/cell after DMSO exposure and 2002 (+/- 10) sites/cell after IGF1 exposure. Parallel experiments done with receptors derived from rat liver yielded values similar to those reported by other investigators and were unaffected by the experimental agents.« less

Properties of hail storms over China and the United States from the Tropical Rainfall Measuring Mission

PubMed Central

Ni, Xiang; Liu, Chuntao; Zhang, Qinghong; Cecil, Daniel J.

2018-01-01

A 16-yr record of hail reports over the south U.S. and from weather stations in China are collocated with Precipitation Features (PF) derived from the Tropical Rainfall Measuring Mission (TRMM) radar and passive microwave observations. Differences in the way hail is reported in the two nations make it difficult to draw meaningful conclusions about storm frequency. But taking the two together yields a wide spectrum of hail sizes, suitable for comparing with remote sensing measurements. While U.S. hail reports are dominated by cases with hail size greater than 19 mm, hail reports in China mostly include diameters of 1–10 mm and mostly occur over the Tibetan Plateau. The fraction of PFs collocated with hail reports (hail PFs) reaches 3% in the plains of the U.S. In China, the fraction is higher in high elevation regions than low elevation regions. Hail PFs (as reported in the U.S.) show lower brightness temperatures, higher lightning flash rates, stronger maximum reflectivity, and higher echo tops than those with smaller hail, as reported in China. The average near surface maximum reflectivity of hail PFs at high elevations (≥ 2000 m) in China is about 5 dB smaller than those at low elevations. Larger hail is reported with PFs having stronger maximum reflectivity above 6 km, though the median of maximum reflectivity values at levels below 5 km is similar among the storms with large and small hail sizes. PMID:29377045

Satellite observations of turbidity in the Dead Sea

NASA Astrophysics Data System (ADS)

Nehorai, R.; Lensky, I. M.; Hochman, L.; Gertman, I.; Brenner, S.; Muskin, A.; Lensky, N. G.

2013-06-01

A methodology to attain daily variability of turbidity in the Dead Sea by means of remote sensing was developed. 250 m/pixel moderate resolution imaging spectroradiometer (MODIS) surface reflectance data were used to characterize the seasonal cycle of turbidity and plume spreading generated by flood events in the lake. Fifteen minutes interval images from meteosat second generation 1.6 km/pixel high-resolution visible (HRV) channel were used to monitor daily variations of turbidity. The HRV reflectance was normalized throughout the day to correct for the changing geometry and then calibrated against available MODIS surface reflectance. Finally, hourly averaged reflectance maps are presented for summer and winter. The results show that turbidity is concentrated along the silty shores of the lake and the southern embayments, with a gradual decrease of turbidity values from the shoreline toward the center of the lake. This pattern is most pronounced following the nighttime hours of intense winds. A few hours after winds calm the concentric turbidity pattern fades. In situ and remote sensing observations show a clear relation between wind intensity, wave amplitude and water turbidity. In summer and winter similar concentric turbidity patterns are observed but with a much narrower structure in winter. A simple Lagrangain trajectory model suggests that the combined effects of horizontal transport and vertical mixing of suspended particles leads to more effective mixing in winter. The dynamics of suspended matter contributions from winter desert floods are also presented in terms of hourly turbidity maps showing the spreading of the plumes and their decay.

Biophysical properties affecting vegetative canopy reflectance and absorbed photosynthetically active radiation at the FIFE site

NASA Technical Reports Server (NTRS)

Walter-Shea, E. A.; Blad, B. L.; Hays, C. J.; Mesarch, M. A.; Deering, D. W.; Middleton, E. M.

1992-01-01

Leaves of the dominant grass species of the ISCLP FIFE site reflect and transmit radiation in a like manner to other healthy green leaves. Visible reflectance factors (RFs) and transmittance factors (TFs) were less for older leaves than younger leaves except during senescence, when RF and TF values were greater. NIR-RF values increased and TF values decreased with leaf age, with the reverse occurring as the leaf went through senescence.

Exploring Students' Articulation of Value in a Social Research Methods Class: Towards a Phenomenography of Value Making

ERIC Educational Resources Information Center

Guglietti, Maria

2015-01-01

This study describes journalism students' value making of social research methods, such as sampling, data gathering strategies and quantitative and qualitative data analysis, by using a mixed-­method approach to analyze 260 written reflection assignments. In their reflections, 26 student participants assessed the value of their new knowledge of…

Darkfield reflection visible microspectroscopy equipped with a color mapping system of a brown altered granite.

PubMed

Onga, Chie; Nakashima, Satoru

2014-01-01

Visible darkfield reflectance spectroscopy equipped with a color mapping system has been developed and applied to a brown-colored Rokko granite sample. Sample reflectance spectra converted to Kubelka-Munk (KM) spectra show similar features to goethite and lepidocrocite. Raman microspectroscopy on the granite sample surface confirms the presence of these minerals. Here, L*a*b* color values (second Commission Internationale d'Eclairage [CIELab] 1976 color space) were determined from the sample reflection spectra. Grey, yellow, and brown zones of the granite show different L*, a*, and b* values. In the a*-b* diagram, a* and b* values in the grey and brown zones are on the lepidocrocite/ferrihydrite trends, but their values in the brown zone are larger than those in the grey zone. The yellow zone shows data points close to the goethite trend. Iron (hydr)oxide-rich areas can be visualized by means of large a* and b* values in the L*, a*, and b* maps. Although the present method has some problems and limitations, the visible darkfield reflectance spectroscopy can be a useful method for colored-material characterization.

Storm impacts upon the composition of organic matrices in Nagara River--a study based on molecular weight and activated carbon adsorbability.

PubMed

Li, Fusheng; Yuasa, Akira; Chiharada, Hajime; Matsui, Yoshihiko

2003-09-01

The impacts of a heavy storm of rain on the composition of natural organic matter (NOM) in Nagara River water were studied in terms of molecular weights (MWs) and activated carbon (AC) adsorbabilities using six water samples collected during a critical Typhoon weather condition. The composition in MWs was analyzed using a HPSEC system and that in adsorbabilities was characterized using parameters devised to reflect NOMs average adsorptive strength (K(M)), adsorptive strength polydispersity (sigma), affinity to AC (1/n) and non-adsorbable fraction (C(non)/C(T0)), respectively. These parameters were determined by model description of observed isotherms with a distributed fictive component method. The heavy storm of rain brought higher content of larger organic components into the river source, thus causing changes of NOMs weight-averaged MWs in the range of 2962-3495 Dalton and MW polydispersity in the narrow range of 1.153-1.226. Comparison of K(M) and sigma values for all samples assessed with both indices of TOC and UV260 showed that large proportions of the storm-induced organic components had adsorptive strengths similar to those existent before the storm, with the presence levels for components revealing much strong and weak adsorbabilities being low. Among all organic components brought into the river by the storm of rain, the percentages of non-adsorbable ones was lower (smaller C(non)/C(T0) values); and the adsorbable ones had generally more affinity to the adsorbents used (smaller 1/n values).

The Assessment and Potential Implications of the Myocardial Performance Index Post Exercise in an at Risk Population.

PubMed

Ruisi, Michael; Levine, Michael; Finkielstein, Dennis

2013-12-01

The myocardial performance index (MPI) first described by Chuwa Tei in 1995 is a relatively new echocardiographic variable used for assessment of overall cardiac function. Previous studies have demonstrated the MPI to be a sum representation of both left ventricular systolic and diastolic function with prognostic value in patients with coronary artery disease as well as symptomatic heart failure. Ninety patients with either established coronary artery disease (CAD) or CAD risk factors underwent routine treadmill exercise stress testing with two-dimensional Doppler echocardiography using the standard Bruce protocol. Both resting and stress MPI values were measured for all 90 of the patients. Using a normal MPI cut off of ≤ 0.47, the prevalence of an abnormal resting MPI in our 90 subjects was 72/90 or 80% and the prevalence of an abnormal stress MPI in our 90 subjects was 48/90 or 53.33%. The average MPI observed in the resting portion of the stress test for the cohort was: 0.636 with a standard deviation of 0.182. The average MPI in the stress portion of the stress test for the cohort was 0.530 with a standard deviation of 0.250. The P value with the use of a one-tailed dependent T test was calculated to be < 0.05. We postulate that these findings reflect that the MPI (Tei) index assessed during exercise may be a sensitive indicator of occult coronary disease in an at risk group independent of wall motion assessment.

Isotope hydrology of the Chalk River Laboratories site, Ontario, Canada

USGS Publications Warehouse

Peterman, Zell; Neymark, Leonid; King-Sharp, K.J.; Gascoyne, Mel

2016-01-01

This paper presents results of hydrochemical and isotopic analyses of groundwater (fracture water) and porewater, and physical property and water content measurements of bedrock core at the Chalk River Laboratories (CRL) site in Ontario. Density and water contents were determined and water-loss porosity values were calculated for core samples. Average and standard deviations of density and water-loss porosity of 50 core samples from four boreholes are 2.73 ± 12 g/cc and 1.32 ± 1.24 percent. Respective median values are 2.68 and 0.83 indicating a positive skewness in the distributions. Groundwater samples from four deep boreholes were analyzed for strontium (87Sr/86Sr) and uranium (234U/238U) isotope ratios. Oxygen and hydrogen isotope analyses and selected solute concentrations determined by CRL are included for comparison. Groundwater from borehole CRG-1 in a zone between approximately +60 and −240 m elevation is relatively depleted in δ18O and δ2H perhaps reflecting a slug of water recharged during colder climatic conditions. Porewater was extracted from core samples by centrifugation and analyzed for major dissolved ions and for strontium and uranium isotopes. On average, the extracted water contains 15 times larger concentration of solutes than the groundwater. 234U/238U and correlation of 87Sr/86Sr with Rb/Sr values indicate that the porewater may be substantially older than the groundwater. Results of this study show that the Precambrian gneisses at Chalk River are similar in physical properties and hydrochemical aspects to crystalline rocks being considered for the construction of nuclear waste repositories in other regions.

The Beauty of Teachers' Work in Reflections of Ukrainian and Polish Teachers

ERIC Educational Resources Information Center

Semenog, Olena

2014-01-01

The values of human labor and teacher's work have been reflected on the basis of lexicographical sources and research reflections of famous Ukrainian and Polish pedagogues, such as T. Novatskiy, N. Nychkalo, Pope Paul II, G. Skovoroda, Z. Vyatrovskiy, I. Zyazyun. Among the existing values presented in lexicographical sources the following…

Using Technology for Enhancing Reflective Writing, Metacognition and Learning

ERIC Educational Resources Information Center

Mair, Carolyn

2012-01-01

There exists broad agreement on the value of reflective practice for personal and professional development. However, many students in higher education (HE) struggle with the concept of reflection, so they do not engage well with the process, and its full value is seldom realised. An online resource was developed to facilitate and structure the…

Discrimination of various paper types using diffuse reflectance ultraviolet-visible near-infrared (UV-Vis-NIR) spectroscopy: forensic application to questioned documents.

PubMed

Kumar, Raj; Kumar, Vinay; Sharma, Vishal

2015-06-01

Diffuse reflectance ultraviolet-visible-near-infrared (UV-Vis-NIR) spectroscopy is applied as a means of differentiating various types of writing, office, and photocopy papers (collected from stationery shops in India) on the basis of reflectance and absorbance spectra that otherwise seem to be almost alike in different illumination conditions. In order to minimize bias, spectra from both sides of paper were obtained. In addition, three spectra from three different locations (from one side) were recorded covering the upper, middle, and bottom portions of the paper sample, and the mean average reflectivity of both the sides was calculated. A significant difference was observed in mean average reflectivity of Side A and Side B of the paper using Student's pair >t-test. Three different approaches were used for discrimination: (1) qualitative features of the whole set of samples, (2) principal component analysis, and (3) a combination of both approaches. On the basis of the first approach, i.e., qualitative features, 96.49% discriminating power (DP) was observed, which shows highly significant results with the UV-Vis-NIR technique. In the second approach the discriminating power is further enhanced by incorporating the principal component analysis (PCA) statistical method, where this method describes each UV-Vis spectrum in a group through numerical loading values connected to the first few principal components. All components described 100% variance of the samples, but only the first three PCs are good enough to explain the variance (PC1 = 51.64%, PC2 = 47.52%, and PC3 = 0.54%) of the samples; i.e., the first three PCs described 99.70% of the data, whereas in the third approach, the four samples, C, G, K, and N, out of a total 19 samples, which were not differentiated using qualitative features (approach no. 1), were therefore subjected to PCA. The first two PCs described 99.37% of the spectral features. The discrimination was achieved by using a loading plot between PC1 and PC2. It is therefore concluded that maximum discrimination of writing, office, and photocopy paper could be achieved on the basis of the second approach. Hence, the present inexpensive analytical method can be appropriate for application to routine questioned document examination work in forensic laboratories because it provides nondestructive, quantitative, reliable, and repeatable results.

Using reflectance spectroscopy to predict beef tenderness.

PubMed

Bowling, M B; Vote, D J; Belk, K E; Scanga, J A; Tatum, J D; Smith, G C

2009-05-01

A study was conducted to determine if reflectance measurements made in the near-infrared region of the spectrum were additive to reflectance measurements made in the visible region of the spectrum for predicting Warner-Bratzler shear force (WBSF) values. Eighty seven strip loins were collected following fabrication over 3d at a commercial beef processing facility from heifer carcasses with Slight or Traces marbling scores. Spectroscopic measurements were made at approximately 50h postmortem using a Hunter-Lab UltraScan. Subsequently, all strip loins were aged for 14d, cooked to an internal temperature of 70°C, and sheared to obtain WBSF values. Reflectance measurements obtained in the near-infrared region of the spectrum were correlated with WBSF values, however, these measurements were not additive to the predictive ability of reflectance measurements (R(2) values did not differ) made in the visible portion of the spectrum when the use of broad-band wavelength filters were simulated. It was therefore determined, that both the visible and near-infrared spectra measure reflectance and that both methods are acceptable methods of tenderness prediction.

Music Structure Analysis from Acoustic Signals

NASA Astrophysics Data System (ADS)

Dannenberg, Roger B.; Goto, Masataka

Music is full of structure, including sections, sequences of distinct musical textures, and the repetition of phrases or entire sections. The analysis of music audio relies upon feature vectors that convey information about music texture or pitch content. Texture generally refers to the average spectral shape and statistical fluctuation, often reflecting the set of sounding instruments, e.g., strings, vocal, or drums. Pitch content reflects melody and harmony, which is often independent of texture. Structure is found in several ways. Segment boundaries can be detected by observing marked changes in locally averaged texture.

Effect of word familiarity on visually evoked magnetic fields.

PubMed

Harada, N; Iwaki, S; Nakagawa, S; Yamaguchi, M; Tonoike, M

2004-11-30

This study investigated the effect of word familiarity of visual stimuli on the word recognizing function of the human brain. Word familiarity is an index of the relative ease of word perception, and is characterized by facilitation and accuracy on word recognition. We studied the effect of word familiarity, using "Hiragana" (phonetic characters in Japanese orthography) characters as visual stimuli, on the elicitation of visually evoked magnetic fields with a word-naming task. The words were selected from a database of lexical properties of Japanese. The four "Hiragana" characters used were grouped and presented in 4 classes of degree of familiarity. The three components were observed in averaged waveforms of the root mean square (RMS) value on latencies at about 100 ms, 150 ms and 220 ms. The RMS value of the 220 ms component showed a significant positive correlation (F=(3/36); 5.501; p=0.035) with the value of familiarity. ECDs of the 220 ms component were observed in the intraparietal sulcus (IPS). Increments in the RMS value of the 220 ms component, which might reflect ideographical word recognition, retrieving "as a whole" were enhanced with increments of the value of familiarity. The interaction of characters, which increased with the value of familiarity, might function "as a large symbol"; and enhance a "pop-out" function with an escaping character inhibiting other characters and enhancing the segmentation of the character (as a figure) from the ground.

Ruminative subtypes and impulsivity in risk for suicidal behavior.

PubMed

Valderrama, Jorge; Miranda, Regina; Jeglic, Elizabeth

2016-02-28

Rumination has been previously linked to negative psychological outcomes, including depression and suicidal behavior. However, there has been conflicting research on whether or not two different subtypes of rumination - brooding and reflection - are more or less maladaptive. The present research sought to (1) examine whether individuals high in brooding but lower in reflection would show higher trait and behavioral impulsivity, relative to individuals low in brooding and low in reflection; and (2) examine impulsivity as a mediator of the relation between ruminative subtypes and suicidal ideation. In Study 1, participants (N=78) were recruited based on high, average, and low scores on a measure of brooding and reflective rumination. Individuals who scored high in brooding and average in reflection scored significantly higher in negative urgency, that is, in the tendency to act rashly in an attempt to reduce negative affect, than did those who scored low in brooding and low in reflection. Study 2 (N=1638) examined the relationship between ruminative subtypes, impulsivity, and suicide risk. We found an indirect relationship between brooding and suicide risk through lack of premeditation and lack of perseverance, independently of reflection. These findings are discussed in relation to cognitive risk for suicide. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

49 CFR 537.9 - Determination of fuel economy values and average fuel economy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 6 2014-10-01 2014-10-01 false Determination of fuel economy values and average fuel economy. 537.9 Section 537.9 Transportation Other Regulations Relating to Transportation... ECONOMY REPORTS § 537.9 Determination of fuel economy values and average fuel economy. (a) Vehicle...

49 CFR 537.9 - Determination of fuel economy values and average fuel economy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 6 2012-10-01 2012-10-01 false Determination of fuel economy values and average fuel economy. 537.9 Section 537.9 Transportation Other Regulations Relating to Transportation... ECONOMY REPORTS § 537.9 Determination of fuel economy values and average fuel economy. (a) Vehicle...

49 CFR 537.9 - Determination of fuel economy values and average fuel economy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 6 2013-10-01 2013-10-01 false Determination of fuel economy values and average fuel economy. 537.9 Section 537.9 Transportation Other Regulations Relating to Transportation... ECONOMY REPORTS § 537.9 Determination of fuel economy values and average fuel economy. (a) Vehicle...

49 CFR 537.9 - Determination of fuel economy values and average fuel economy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 6 2011-10-01 2011-10-01 false Determination of fuel economy values and average fuel economy. 537.9 Section 537.9 Transportation Other Regulations Relating to Transportation... ECONOMY REPORTS § 537.9 Determination of fuel economy values and average fuel economy. (a) Vehicle...

Profile of Prospective Physics Teachers on Assessment Literacy

NASA Astrophysics Data System (ADS)

Efendi, R.; Rustaman, N. Y.; Kaniawati, I.

2017-02-01

A study about assessment literacy of prospective Physics teachers was conducted with the involvement of 45 prospective physics teachers. Data collected by using test consisted of seven competencies. The profile of prospective physics teachers on assessment literacy determined in descriptive statistics, in the form of respondent average values. Research finding shows that prospective physics teachers were weak at all competency areas. The average values of the Choosing assessment methods appropriate for instructional decisions is the highest average values and the average values of the communicating assessment results to students, parents, other lay audiences, and other educators is the lowest average values. In depth study to detect the reason underlined the results was still in progress so far, as another aspect was planned to be administered on the next semester.

In-Scene-Based Atmospheric Correction of Uncalibrated VISible-SWIR (VIS-SWIR) Hyper- and Multispectral Imagery

DTIC Science & Technology

2008-01-01

resolution , it is very likely that near-zero reflectance values exist in each spectral channel, corresponding to the minimum data values in the scene...radiometrically uncalibrated data. Quite good agreement was previously demonstrated for the retrieved pixel spectral reflectances between QUAC and the physics...precluding the use of physics-based codes to retrieve surface reflectance. The ability to retrieve absolute spectral reflectances from such sensors

On the Origin of GEMS

NASA Technical Reports Server (NTRS)

Keller, L. P.; Messenger, S.

2004-01-01

GEMS (glass with embedded metal and sulfides) are a major component of anhydrous interplanetary dust particles (IDPs) their physical and chemical characteristics show marked similarities to contemporary interstellar dust. Recent oxygen isotopic measurements confirm that at least a small fraction (less than 5%) of GEMS are demonstrably presolar, while the remainder have ratios that are indistinguishable from solar values. GEMS with solar oxygen isotopic compositions either (1) had their isotopic compositions homogenized through processing in the interstellar medium (ISM), or (2) formed in the early solar system. Isotopic homogenization necessarily implies chemical homogenization, so (interstellar) GEMS compositions should reflect the average composition of dust in the local ISM. We performed a systematic examination of the bulk chemistry of GEMS in primitive IDPs in order to test this hypothesis.

Light reflection by the cuticle of C. aurigans scarabs: a biological broadband reflector of left handed circularly polarized light

NASA Astrophysics Data System (ADS)

Libby, E.; Azofeifa, D. E.; Hernández-Jiménez, M.; Barboza-Aguilar, C.; Solís, A.; García-Aguilar, I.; Arce-Marenco, L.; Hernández, A.; Vargas, W. E.

2014-08-01

Measured reflection spectra from elytra of Chrysina aurigans scarabs are reported. They show a broad reflection band for wavelengths from 0.525 to 1.0 μm with a sequence of maxima and minima reflection values superimposed on a mean value of around 40% for the high reflection band. Different mechanisms contributing to the reflection spectra have been considered, with the dominant effect, reflection of left handed circularly polarized light, being produced by a laminated left handed twisted structure whose pitch changes with depth through the procuticle in a more complex way than that characterizing broad band circular polarizers based on cholesteric liquid crystals.

Effect of an electric field on the structural and optical properties of fluorinated freely suspended smectic films

NASA Astrophysics Data System (ADS)

Śliwa, I.; Zakharov, A. V.

2017-12-01

Within the framework of the generalized mean-field model that takes into account the anisotropic interactions between the nearest neighbors of molecules forming freely suspended smectic films (FSSFs) and the stabilizing effects of the smectic-A (SmA)-air interface, a numerical study was performed of the structural, thermodynamic, and optical properties of these systems in the process of their layer-by-layer thinning. The results of calculating the disjoining pressure P, the average thickness of the smectic layers L, and the reflectivity index R of a FSSF formed by 5- n-alkyl-2-(4- n-(perfluoroalkyl-methylene oxide)-pentyl) (H10F5MOPP) molecules showed that these values undergo precipitous changes in the process of layer-bylayer thinning of the film. Calculations of R( T) as a function of temperature T exceeding the phase transition temperature of SmA into an isotropic state in the bulk of the liquid crystal material are in good agreement with the experimentally obtained data for the reflectivity of the FSSF formed by H10F5MOPP molecules.

Quantitative analysis of comparative genomic hybridization

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

Manoir, S. du; Bentz, M.; Joos, S.

1995-01-01

Comparative genomic hybridization (CGH) is a new molecular cytogenetic method for the detection of chromosomal imbalances. Following cohybridization of DNA prepared from a sample to be studied and control DNA to normal metaphase spreads, probes are detected via different fluorochromes. The ratio of the test and control fluorescence intensities along a chromosome reflects the relative copy number of segments of a chromosome in the test genome. Quantitative evaluation of CGH experiments is required for the determination of low copy changes, e.g., monosomy or trisomy, and for the definition of the breakpoints involved in unbalanced rearrangements. In this study, a programmore » for quantitation of CGH preparations is presented. This program is based on the extraction of the fluorescence ratio profile along each chromosome, followed by averaging of individual profiles from several metaphase spreads. Objective parameters critical for quantitative evaluations were tested, and the criteria for selection of suitable CGH preparations are described. The granularity of the chromosome painting and the regional inhomogeneity of fluorescence intensities in metaphase spreads proved to be crucial parameters. The coefficient of variation of the ratio value for chromosomes in balanced state (CVBS) provides a general quality criterion for CGH experiments. Different cutoff levels (thresholds) of average fluorescence ratio values were compared for their specificity and sensitivity with regard to the detection of chromosomal imbalances. 27 refs., 15 figs., 1 tab.« less

Thermal Index Evaluation of Local SAR in MRI-Based Head Models of Adult and Children for Portable Telephones

NASA Astrophysics Data System (ADS)

Fujiwara, Osamu; Miyamoto, Kayoko; Wang, Jianqing

Biological hazards due to radio-frequency (RF) waves result mainly from the temperature rise in tissue. It should be, therefore, clarified to what extent the RF waves of portable telephones increase the temperature-rise in human brain that includes the central part governing the body-temperature regulation function. In this paper, we calculated both the specific absorption rate (SAR) and the resultant temperature-rise for 900 MHz and 2 GHz portable telephones using the finite-difference time-domain (FDTD) method for three typical use positions, i.e., the vertical position, cheek position and tilt position. As a result, we found that there was an increase for median and 1% value of the cumulative distribution of temperature-rise in children’s brains for any use positions of the portable telephones compared to that in the adult’s brain, and also that the increasing trend in children’s brains for temperature-rise is identical to the temperature-rise trend in children’s hypothalamus. In addition, we found that the ten-gram averaged peak SAR among the adult and children heads had the same trend as that of the 0.1% value of the relatively cumulative distribution of temperature-rise, which shows that the ten-gram averaged peak SAR reflects only the localized temperature-rise in the brain surface.

Effect of aperiodicity on the broadband reflection of silicon nanorod structures for photovoltaics.

PubMed

Lin, Chenxi; Huang, Ningfeng; Povinelli, Michelle L

2012-01-02

We carry out a systematic numerical study of the effects of aperiodicity on silicon nanorod anti-reflection structures. We use the scattering matrix method to calculate the average reflection loss over the solar spectrum for periodic and aperiodic arrangements of nanorods. We find that aperiodicity can either improve or deteriorate the anti-reflection performance, depending on the nanorod diameter. We use a guided random-walk algorithm to design optimal aperiodic structures that exhibit lower reflection loss than both optimal periodic and random aperiodic structures.

The x ray reflectivity of the AXAF VETA-I optics

NASA Technical Reports Server (NTRS)

Kellogg, Edwin M.; Chartas, G.; Graessle, D.; Hughes, John P.; Vanspeybroeck, Leon; Zhao, Ping; Weisskopf, M. C.; Elsner, R. F.; Odell, S. L.

1992-01-01

The x-ray reflectivity of the VETA-I optic, the outermost shell of the AXAF x-ray telescope, with a bare Zerodur surface, is measured and compared with theoretical predictions. Measurements made at energies of 0.28, 0.9, 1.5, 2.1, and 2.3 keV are compared with predictions based on ray trace calculations. The data were obtained at the x-ray calibrations facility at Marshall Space Flight Center with an electron impact x-ray source located 528 m from the grazing incidence mirror. The source used photoelectric absorption filters to eliminate bremsstrahlung continuum. The mirror has a diameter of 1.2 m and a focal length of 10 m. The incident and reflected x-ray flux are detected using two proportional counters, one located in the incident beam of x-rays at the entrance aperture of the VETA-I, and the other in the focal plane behind an aperture of variable size. Results on the variation of the reflectivity with energy as well as the absolute value of the reflectivity are presented. We also present a synchrotron reflectivity measurement with high energy resolution over the range 0.26 to 1.8 keV on a flat Zerodur sample, done at NSLS. We present evidence for contamination of the flat by a thin layer of carbon on the surface, and the possibility of alteration of the surface composition of the VETA-I mirror perhaps by the polishing technique. The overall agreement between the measured and calculated effective area of VETA-I is between 2.6 percent and 10 percent, depending on which model for the surface composition is adopted. Measurements at individual energies deviate from the best-fitting calculation to 0.3 to 0.8 percent, averaging 0.6 percent at energies below the high energy cutoff of the mirror reflectivity, and are as high as 20.7 percent at the cutoff. We also discuss the approach to the final preflight calibration of the full AXAF flight mirror.

Macular pigment optical density measurements: evaluation of a device using heterochromatic flicker photometry

PubMed Central

de Kinkelder, R; van der Veen, R L P; Verbaak, F D; Faber, D J; van Leeuwen, T G; Berendschot, T T J M

2011-01-01

Purpose Accurate assessment of the amount of macular pigment (MPOD) is necessary to investigate the role of carotenoids and their assumed protective functions. High repeatability and reliability are important to monitor patients in studies investigating the influence of diet and supplements on MPOD. We evaluated the Macuscope (Macuvision Europe Ltd., Lapworth, Solihull, UK), a recently introduced device for measuring MPOD using the technique of heterochromatic flicker photometry (HFP). We determined agreement with another HFP device (QuantifEye; MPS 9000 series: Tinsley Precision Instruments Ltd., Croydon, Essex, UK) and a fundus reflectance method. Methods The right eyes of 23 healthy subjects (mean age 33.9±15.1 years) were measured. We determined agreement with QuantifEye and correlation with a fundus reflectance method. Repeatability of QuantifEye was assessed in 20 other healthy subjects (mean age 32.1±7.3 years). Repeatability was also compared with measurements by a fundus reflectance method in 10 subjects. Results We found low agreement between test and retest measurements with Macuscope. The average difference and the limits of agreement were −0.041±0.32. We found high agreement between test and retest measurements of QuantifEye (−0.02±0.18) and the fundus reflectance method (−0.04±0.18). MPOD data obtained by Macuscope and QuantifEye showed poor agreement: −0.017±0.44. For Macuscope and the fundus reflectance method, the correlation coefficient was r=0.05 (P=0.83). A significant correlation of r=0.87 (P<0.001) was found between QuantifEye and the fundus reflectance method. Conclusions Because repeatability of Macuscope measurements was low (ie, wide limits of agreement) and MPOD values correlated poorly with the fundus reflectance method, and agreed poorly with QuantifEye, the tested Macuscope protocol seems less suitable for studying MPOD. PMID:21057522

Anti-reflective coating with a conductive indium tin oxide layer on flexible glass substrates.

PubMed

Sung, Yilin; Malay, Robert E; Wen, Xin; Bezama, Christian N; Soman, Varun V; Huang, Ming-Huang; Garner, Sean M; Poliks, Mark D; Klotzkin, David

2018-03-20

Flexible glass has many applications including photovoltaics, organic light-emitting device (OLED) lighting, and displays. Its ability to be processed in a roll-to-roll facility enables high-throughput continuous manufacturing compared to conventional glass processing. For photovoltaic, OLED lighting, and display applications, transparent conductors are required with minimal optical reflection losses. Here, we demonstrate an anti-reflective coating (ARC) that incorporates a useful transparent conductor that is realizable on flexible substrates. This reduces the average reflectivity to less than 6% over the visible band from normal incidence to incident angles up to 60°. This ARC is designed by the average uniform algorithm method. The coating materials consist of a multilayer stack of an electrically functional conductive indium tin oxide with conductivity 2.95×10 5   Siemens/m (31 Ω/□), and AlSiO 2 . The coatings showed modest changes in reflectivity and no delamination after 10,000 bending cycles. This demonstrates that effective conductive layers can be integrated into ARCs and can be realized on flexible glass substrates with proper design and process control.

EXPLORING VALUES OF HEALTH TECHNOLOGY ASSESSMENT AGENCIES USING REFLECTIVE MULTICRITERIA AND RARE DISEASE CASE.

PubMed

Goetghebeur, Mireille M; Wagner, Monika; Samaha, Dima; O'Neil, William; Badgley, Danielle; Castro-Jaramillo, Hector; Abrishami, Payam; Sarria-Santamera, Antonio; Cleemput, Irina; Tringali, Michele

2017-01-01

Tackling ethical dilemmas faced by reimbursement decision makers requires deeper understanding of values on which health technology assessment (HTA) agencies are founded and how trade-offs are made. This was explored in this study including the case of rare disease. Representatives from eight HTA explored values on which institutions are founded using a narrative approach and reflective multicriteria (developed from EVIDEM, criteria derived from ethical imperatives of health care). Trade-offs between criteria and the impact of incorporating defined priorities (including for rare diseases) were explored through a quantitative values elicitation exercise. Participants reported a diversity of substantive and procedural values with a common emphasis on scientific excellence, stakeholder involvement, independence, and transparency. Examining the ethical imperatives behind EVIDEM criteria was found to be useful to further explore substantive values. Most criteria were deemed to reflect institutions' values, while 70 percent of the criteria were reported by at least half of participants to be considered formally by their institutions. The quantitative values elicitation highlighted the difficulty to balance imperatives of "alleviating or preventing patient suffering," "serving the whole population equitably," "upholding healthcare system sustainability," and "making decisions informed by evidence and context" but may help share the ethical reasoning behind decisions. Incorporating "Priorities" (including for rare diseases) helped reveal trade-offs from other criteria and their underlying ethical imperatives. Reflective multicriteria are useful to explore substantive values of HTAs, reflect how these values and their ethical underpinnings can be operationalized into criteria, and explore the ethical reasoning at the heart of the healthcare debate.

Measurement of the infrared optical constants for spectral modeling: n and k values for (NH4)2SO4 via single-angle reflectance and ellipsometric methods

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

Blake, Thomas A.; Brauer, Carolyn S.; Kelly-Gorham, Molly Rose K.

The optical constants n and k can be used to model infrared spectra, including refraction, absorption, reflectance, and emissivity, but obtaining reliable values for solid materials (pure or otherwise) presents a challenge: In the past, the best results for n and k have been obtained from bulk, homogeneous materials, free of defects. That is, materials where the Fresnel equations are operant since there is no light scattering. Since it is often not possible to obtain a pure macroscopic (crystalline) material, it may be possible to press the material into a (uniform, void-free) disk. We have recently been able to domore » this with ammonium sulfate powder and then measured the n & k values via two independent methods: 1) Ellipsometry - which measures the changes in amplitude and phase of light reflected from the material of interest as a function of wavelength and angle of incidence, and 2) Single angle specular reflectance with an FT spectrometer using a specular reflectance device within an FT instrument which measures the change in amplitude of light reflected from the material of interest as a function of wavelength and angle of incidence over a wide wavelength range. The quality of the derived n & k values was tested by generating the reflectance spectra of the pellet and comparing to the calculated to measured reflectance spectra of the pure material which has been previously published. The comparison to literature values showed good accuracy and good agreement, indicating promise to measure other materials by such methods.« less

Paraboloid Structured Silicon Surface for Enhanced Light Absorption: Experimental and Simulative Investigations

NASA Astrophysics Data System (ADS)

Khan, Firoz; Baek, Seong-Ho; Kaur, Jasmeet; Fareed, Imran; Mobin, Abdul; Kim, Jae Hyun

2015-09-01

In this paper, we present an optical model that simulates the light trapping and scattering effects of a paraboloid texture surface first time. This model was experimentally verified by measuring the reflectance values of the periodically textured silicon (Si) surface with the shape of a paraboloid under different conditions. A paraboloid texture surface was obtained by electrochemical etching Si in the solution of hydrofluoric acid, dimethylsulfoxide (DMSO), and deionized (DI) water. The paraboloid texture surface has the advantage of giving a lower reflectance value than the hemispherical, random pyramidal, and regular pyramidal texture surfaces. In the case of parabola, the light can be concentrated in the direction of the Si surface compared to the hemispherical, random pyramidal, and regular pyramidal textured surfaces. Furthermore, in a paraboloid textured surface, there can be a maximum value of 4 or even more by anisotropic etching duration compared to the hemispherical or pyramidal textured surfaces which have a maximum h/ D (depth and diameter of the texture) value of 0.5. The reflectance values were found to be strongly dependent on the h/ D ratio of the texture surface. The measured reflectance values were well matched with the simulated ones. The minimum reflectance value of ~4 % was obtained at a wavelength of 600 nm for an h/ D ratio of 3.75. The simulation results showed that the reflectance value for the h/ D ratio can be reduced to ~0.5 % by reducing the separations among the textures. This periodic paraboloidal structure can be applied to the surface texturing technique by substituting with a conventional pyramid textured surface or moth-eye antireflection coating.

Extent of Fock-exchange mixing for a hybrid van der Waals density functional?

NASA Astrophysics Data System (ADS)

Jiao, Yang; Schröder, Elsebeth; Hyldgaard, Per

2018-05-01

The vdW-DF-cx0 exchange-correlation hybrid design [K. Berland et al., J. Chem. Phys. 146, 234106 (2017)] has a truly nonlocal correlation component and aims to facilitate concurrent descriptions of both covalent and non-covalent molecular interactions. The vdW-DF-cx0 design mixes a fixed ratio, a, of the Fock exchange into the consistent-exchange van der Waals density functional, vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B 89, 035412 (2014)]. The mixing value a is sometimes taken as a semi-empirical parameter in hybrid formulations. Here, instead, we assert a plausible optimum average a value for the vdW-DF-cx0 design from a formal analysis; A new, independent determination of the mixing a is necessary since the Becke fit [A. D. Becke, J. Chem. Phys. 98, 5648 (1993)], yielding a' = 0.2, is restricted to semilocal correlation and does not reflect non-covalent interactions. To proceed, we adapt the so-called two-legged hybrid construction [K. Burke et al., Chem. Phys. Lett. 265, 115 (1997)] to a starting point in the vdW-DF-cx functional. For our approach, termed vdW-DF-tlh, we estimate the properties of the adiabatic-connection specification of the exact exchange-correlation functional, by combining calculations of the Fock exchange and of the coupling-constant variation in vdW-DF-cx. We find that such vdW-DF-tlh hybrid constructions yield accurate characterizations of molecular interactions (even if they lack self-consistency). The accuracy motivates trust in the vdW-DF-tlh determination of system-specific values of the Fock-exchange mixing. We find that an average value a' = 0.2 best characterizes the vdW-DF-tlh description of covalent and non-covalent interactions, although there exists some scatter. This finding suggests that the original Becke value, a' = 0.2, also represents an optimal average Fock-exchange mixing for the new, truly nonlocal-correlation hybrids. To enable self-consistent calculations, we furthermore define and test a zero-parameter hybrid functional vdW-DF-cx0p (having fixed mixing a' = 0.2) and document that this truly nonlocal correlation hybrid works for general molecular interactions (at reference and at relaxed geometries). It is encouraging that the vdW-DF-cx0p functional remains useful also for descriptions of some extended systems.

DRG benchmarking: analysis of service structures and -differences in dermatology departments.

PubMed

Fürstenberg, Torsten; Gierling, Patrick; Irps, Sebastian; Gollnick, Harald; Kaufmann, Roland; Stadler, Rudolf; Rompel, Rainer; Hensen, Peter

2014-07-01

In the context of DRG-based hospital funding, the analysis of services provided in dermatologic inpatient care is highly relevant. We analyzed and compared clinical service structures and varieties in dermatologic hospitals through a benchmarking technique. For this multicenter cross-sectional study, routine data from 46 German dermatologic clinics and departments were collected, processed, and analyzed. In total, 95 257 data sets from 2011 were available. The data were grouped according to the G-DRG-system 2013 version. The average length of stay for all cases was 6.3 days (DRG "inliers": 5.7 days), and average patient age was 52 years. In total, 55 % of all cases were grouped to medical, 45 % to surgical DRGs. 71 % of all hospitals provide services within or close to this average value (± 10 %). No association was found between the number of hospital beds and the variety of clinical services provided in our sample. We found huge varieties in several parameters assessing the coding quality. The results reflect the heterogeneous reality in German inpatient dermatology. The varieties in dermatologic service range still depend on patient-related factors as well as infrastructural conditions and the resources available at each site. © 2014 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Diffusion in biofilms respiring on electrodes

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

Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.

2012-11-15

The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed for noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensionalmore » De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that (1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; (2) Drs at a given location decreases with G. sulfurreducens biofilm age; (3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and (4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.« less

Tracking of Pacific walruses in the Chukchi Sea using a single hydrophone.

PubMed

Mouy, Xavier; Hannay, David; Zykov, Mikhail; Martin, Bruce

2012-02-01

The vocal repertoire of Pacific walruses includes underwater sound pulses referred to as knocks and bell-like calls. An extended acoustic monitoring program was performed in summer 2007 over a large region of the eastern Chukchi Sea using autonomous seabed-mounted acoustic recorders. Walrus knocks were identified in many of the recordings and most of these sounds included multiple bottom and surface reflected signals. This paper investigates the use of a localization technique based on relative multipath arrival times (RMATs) for potential behavior studies. First, knocks are detected using a semi-automated kurtosis-based algorithm. Then RMATs are matched to values predicted by a ray-tracing model. Walrus tracks with vertical and horizontal movements were obtained. The tracks included repeated dives between 4.0 m and 15.5 m depth and a deep dive to the sea bottom (53 m). Depths at which bell-like sounds are produced, average knock production rate and source levels estimates of the knocks were determined. Bell sounds were produced at all depths throughout the dives. Average knock production rates varied from 59 to 75 knocks/min. Average source level of the knocks was estimated to 177.6 ± 7.5 dB re 1 μPa peak @ 1 m. © 2012 Acoustical Society of America

Character Education in Taiwan: A Reflection of Historical Shifts in Sociocultural Contexts

ERIC Educational Resources Information Center

Ho, Hsiu-Zu; Lam, Yeana W.; Yeh, Kuang-Hui

2013-01-01

Education systems across the world reflect the values of the cultures and societies they represent. Character education is often framed as a response to certain values emphasized in a given context, reflecting the commonly accepted traits of good character and responsible citizenship in which learners are engaged. This article describes the nature…

[The study of aluminium diffuser calibration in the UV].

PubMed

Li, Cong; Wang, Yong-Mei; Zhang, Zhong-Mou

2008-04-01

A bi-directional reflectance distribution function (BRDF) measurement setup in the ultraviolet spectral range was established. The BRDF of the aluminium diffusers at a given orientation was measured. The relative accuracy of the BRDF measurement is better than 2.5%. The hemispheric reflectance of the aluminium diffusers was measured in the wavelength range from 250 to 650 nm. It increases with the wavelength, and changes about 6% from 300 to 360 nm. It decreases with the time. Since the diffuser was made (about one year ago), from 250 to 300 nm, the peak decrease in the hemispheric reflectance can reach 2.6%, and the average decrease is 1.5%. From 300 to 360 nm, it has an average decrease of 0.9% decrease, and 0.8% when wavelength is longer than 360 nm.

Calculation of vitrinite reflectance from thermal histories: A comparison of some methods

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

Morrow, D.W.; Issler, D.R.

1993-04-01

Vitrinite reflectance values (%R[sub o]) calculated from commonly used methods are compared with respect to time invariant temperatures and constant heating rates. Two monofunctional methods, one involving a time-temperature index to vitrinite reflectance correlation (TTI-%R[sub o]) to depth correlation, yield vitrinite reflectance values that are similar to those calculated by recently published Arrhenius-based methods, such as EASY%R[sub o]. The approximate agreement between these methods supports the perception that the EASY%R[sub o] algorithm is the most accurate method for the prediction of vitrinite reflectances throughout the range of organic maturity normally encountered. However, calibration of these methods against vitrinite reflectance datamore » from two basin sequences with well-documented geologic histories indicates that, although the EASY%R[sub o] method has wide applicability, it slightly overestimates vitrinite reflectances in strata of low to medium maturity up to a %R[sub o] value of 0.9%. The two monofunctional methods may be more accurate for prediction of vitrinite reflectances in similar sequences of low maturity. An older, but previously widely accepted TTI-%R[sub O] correlation consistently overestimates vitrinite reflectances with respect to other methods. Underestimation of paleogeothermal gradients in the original calibration of time-temperature history to vitrinite reflectance may have introduced a systematic bias to the TTI-%R[sub o] correlation used in this method. Also, incorporation of TAI (thermal alteration index) data and its conversion to %R[sub o]-equivalent values may have introduced inaccuracies. 36 refs., 7 figs.« less

[Estimation of average traffic emission factor based on synchronized incremental traffic flow and air pollutant concentration].

PubMed

Li, Run-Kui; Zhao, Tong; Li, Zhi-Peng; Ding, Wen-Jun; Cui, Xiao-Yong; Xu, Qun; Song, Xian-Feng

2014-04-01

On-road vehicle emissions have become the main source of urban air pollution and attracted broad attentions. Vehicle emission factor is a basic parameter to reflect the status of vehicle emissions, but the measured emission factor is difficult to obtain, and the simulated emission factor is not localized in China. Based on the synchronized increments of traffic flow and concentration of air pollutants in the morning rush hour period, while meteorological condition and background air pollution concentration retain relatively stable, the relationship between the increase of traffic and the increase of air pollution concentration close to a road is established. Infinite line source Gaussian dispersion model was transformed for the inversion of average vehicle emission factors. A case study was conducted on a main road in Beijing. Traffic flow, meteorological data and carbon monoxide (CO) concentration were collected to estimate average vehicle emission factors of CO. The results were compared with simulated emission factors of COPERT4 model. Results showed that the average emission factors estimated by the proposed approach and COPERT4 in August were 2.0 g x km(-1) and 1.2 g x km(-1), respectively, and in December were 5.5 g x km(-1) and 5.2 g x km(-1), respectively. The emission factors from the proposed approach and COPERT4 showed close values and similar seasonal trends. The proposed method for average emission factor estimation eliminates the disturbance of background concentrations and potentially provides real-time access to vehicle fleet emission factors.

Value of Reflected Light Microscopy in Teaching.

ERIC Educational Resources Information Center

Pasteris, Jill Dill

1983-01-01

Briefly reviews some optical and other physical properties of minerals that can be determined in reflected/incident light. Topics include optical properties of minerals, reflectance, internal reflections, color, bireflectance and reflection pleochroism, anisotropism, zonation, and reflected light microscopy as a teaching tool in undergraduate…

Development and Testing of the VAHIRR Radar Product

NASA Technical Reports Server (NTRS)

Barrett, Joe III; Miller, Juli; Charnasky, Debbie; Gillen, Robert; Lafosse, Richard; Hoeth, Brian; Hood, Doris; McNamara, Todd

2008-01-01

Lightning Launch Commit Criteria (LLCC) and Flight Rules (FR) are used for launches and landings at government and commercial spaceports. They are designed to avoid natural and triggered lightning strikes to space vehicles, which can endanger the vehicle, payload, and general public. The previous LLCC and FR were shown to be overly restrictive, potentially leading to costly launch delays and scrubs. A radar algorithm called Volume Averaged Height Integrated Radar Reflectivity (VAHIRR), along with new LLCC and FR for anvil clouds, were developed using data collected by the Airborne Field Mill II research program. VAHIRR is calculated at every horizontal position in the coverage area of the radar and can be displayed similar to a two-dimensional derived reflectivity product, such as composite reflectivity or echo tops. It is the arithmetic product of two quantities not currently generated by the Weather Surveillance Radar 1988 Doppler (WSR-88D): a volume average of the reflectivity measured in dBZ and the average cloud thickness based on the average echo top height and base height. This presentation will describe the VAHIRR algorithm, and then explain how the VAHIRR radar product was implemented and tested on a clone of the National Weather Service's (NWS) Open Radar Product Generator (ORPG-clone). The VAHIRR radar product was then incorporated into the Advanced Weather Interactive Processing System (AWIPS), to make it more convenient for weather forecasters to utilize. Finally, the reliability of the VAHIRR radar product was tested with real-time level II radar data from the WSR-88D NWS Melbourne radar.

Methane contamination of drinking water accompanying gas-well drilling and hydraulic fracturing

PubMed Central

Osborn, Stephen G.; Vengosh, Avner; Warner, Nathaniel R.; Jackson, Robert B.

2011-01-01

Directional drilling and hydraulic-fracturing technologies are dramatically increasing natural-gas extraction. In aquifers overlying the Marcellus and Utica shale formations of northeastern Pennsylvania and upstate New York, we document systematic evidence for methane contamination of drinking water associated with shale-gas extraction. In active gas-extraction areas (one or more gas wells within 1 km), average and maximum methane concentrations in drinking-water wells increased with proximity to the nearest gas well and were 19.2 and 64 mg CH4 L-1 (n = 26), a potential explosion hazard; in contrast, dissolved methane samples in neighboring nonextraction sites (no gas wells within 1 km) within similar geologic formations and hydrogeologic regimes averaged only 1.1 mg L-1 (P < 0.05; n = 34). Average δ13C-CH4 values of dissolved methane in shallow groundwater were significantly less negative for active than for nonactive sites (-37 ± 7‰ and -54 ± 11‰, respectively; P < 0.0001). These δ13C-CH4 data, coupled with the ratios of methane-to-higher-chain hydrocarbons, and δ2H-CH4 values, are consistent with deeper thermogenic methane sources such as the Marcellus and Utica shales at the active sites and matched gas geochemistry from gas wells nearby. In contrast, lower-concentration samples from shallow groundwater at nonactive sites had isotopic signatures reflecting a more biogenic or mixed biogenic/thermogenic methane source. We found no evidence for contamination of drinking-water samples with deep saline brines or fracturing fluids. We conclude that greater stewardship, data, and—possibly—regulation are needed to ensure the sustainable future of shale-gas extraction and to improve public confidence in its use. PMID:21555547

Silicone Hydrogel and Rigid Gas-Permeable Scleral Lens Tear Exchange.

PubMed

Paugh, Jerry R; Chen, Elaine; Heinrich, Colton; Miller, Heidi; Gates, Tiffany; Nguyen, Andrew Loc; Edrington, Timothy; Weissman, Barry A

2018-03-01

To quantify tear elimination rate (ER) underneath silicone hydrogel (Si-Hy) and scleral gas permeable (GP) contact lenses (CLs). Subjects successfully using either well-fitting soft Si-Hy CLs or scleral GP CLs were recruited. Most scleral GP CL wearers had irregular corneas (e.g., keratoconus). An objective fluorometer measured decay of fluorescein isothiocyanate dextran dye signal (70 kD MW) from which the tear ER in %/min was calculated. For GP scleral lenses, the ER was determined for both the initial settling period and the 30- to 60-min period, and without lenses. All ERs were calculated from 5 to 30 min to avoid reflex tearing effects. Fourteen soft Si-Hy CL and 12 scleral GP CL wearers completed the study. The ER for the scleral GP CL wearers averaged 0.57 (±0.6) %/min for the 0- to 30-min and 0.42 (±0.5) %/min for the 30- to 60-min period (P=0.515). Non-CL wear tear ER in these same subjects averaged 34.17 (±15.9) %/min and was significantly different versus both scleral GP wear periods (both P values <0.001). The ER for the soft Si-Hy CL wearers, 5 to 30 min, averaged 6.09 (±2.8) %/min. Our data demonstrate significantly less ER in well-fit scleral GP CL wearers compared with soft Si-Hy CL wearers for both the settling and longer wear periods (both P values <0.001). Moreover, slightly greater tear exchange was observed during the scleral GP CL settling period than later, which may reflect a change over time in tear vault thickness.

Fast EEG spike detection via eigenvalue analysis and clustering of spatial amplitude distribution

NASA Astrophysics Data System (ADS)

Fukami, Tadanori; Shimada, Takamasa; Ishikawa, Bunnoshin

2018-06-01

Objective. In the current study, we tested a proposed method for fast spike detection in electroencephalography (EEG). Approach. We performed eigenvalue analysis in two-dimensional space spanned by gradients calculated from two neighboring samples to detect high-amplitude negative peaks. We extracted the spike candidates by imposing restrictions on parameters regarding spike shape and eigenvalues reflecting detection characteristics of individual medical doctors. We subsequently performed clustering, classifying detected peaks by considering the amplitude distribution at 19 scalp electrodes. Clusters with a small number of candidates were excluded. We then defined a score for eliminating spike candidates for which the pattern of detected electrodes differed from the overall pattern in a cluster. Spikes were detected by setting the score threshold. Main results. Based on visual inspection by a psychiatrist experienced in EEG, we evaluated the proposed method using two statistical measures of precision and recall with respect to detection performance. We found that precision and recall exhibited a trade-off relationship. The average recall value was 0.708 in eight subjects with the score threshold that maximized the F-measure, with 58.6  ±  36.2 spikes per subject. Under this condition, the average precision was 0.390, corresponding to a false positive rate 2.09 times higher than the true positive rate. Analysis of the required processing time revealed that, using a general-purpose computer, our method could be used to perform spike detection in 12.1% of the recording time. The process of narrowing down spike candidates based on shape occupied most of the processing time. Significance. Although the average recall value was comparable with that of other studies, the proposed method significantly shortened the processing time.

Wavelet assessment of cerebrospinal compensatory reserve and cerebrovascular reactivity.

PubMed

Latka, M; Kolodziej, W; Turalska, M; Latka, D; Zub, W; West, B J

2007-05-01

We introduce a wavelet transfer model to relate spontaneous arterial blood pressure (ABP) fluctuations to intracranial pressure (ICP) fluctuations. We employ a complex continuous wavelet transform to develop a consistent mathematical framework capable of parametrizing both cerebral compensatory reserve and cerebrovascular reactivity. The frequency-dependent gain and phase of the wavelet transfer function are introduced because of the non-stationary character of the ICP and ABP time series. The gain characterizes the dampening of spontaneous ABP fluctuations and is interpreted as a novel measure of cerebrospinal compensatory reserve. For a group of 12 patients who died as a result of cerebral lesions (Glasgow Outcome Scale (GOS) = 1) the average gain in the low-frequency (0.02- 0.07 Hz) range was 0.51 +/- 0.13 and significantly exceeded that of 17 patients with GOS = 2 having an average gain of 0.26 +/- 0.11 with p = 1x10(-4) (Kruskal-Wallis test). A time-averaged synchronization index (which may vary from 0 to 1) defined in terms of the wavelet transfer function phase yields information about the stability of the phase difference of the ABP and ICP signals and is used as a cerebrovascular reactivity index. A low value of synchronization index reflects a normally reactive vascular bed, while a high value indicates pathological entrainment of ABP and ICP fluctuations. Such entrainment is strongly pronounced in patients with fatal outcome (for this group the low-frequency synchronization index was 0.69 +/- 0.17). The gain and synchronization parameters define a cerebral hemodynamic state space (CHS) in which the patients with GOS = 1 are to large extent partitioned away from those with GOS = 2. The concept of CHS elucidates the interplay of vascular and compensatory mechanisms.

Thermal Infrared Spectrometer for Earth Science Remote Sensing Applications—Instrument Modifications and Measurement Procedures

PubMed Central

Hecker, Christoph; Hook, Simon; van der Meijde, Mark; Bakker, Wim; van der Werff, Harald; Wilbrink, Henk; van Ruitenbeek, Frank; de Smeth, Boudewijn; van der Meer, Freek

2011-01-01

In this article we describe a new instrumental setup at the University of Twente Faculty ITC with an optimized processing chain to measure absolute directional-hemispherical reflectance values of typical earth science samples in the 2.5 to 16 μm range. A Bruker Vertex 70 FTIR spectrometer was chosen as the base instrument. It was modified with an external integrating sphere with a 30 mm sampling port to allow measuring large, inhomogeneous samples and quantitatively compare the laboratory results to airborne and spaceborne remote sensing data. During the processing to directional-hemispherical reflectance values, a background radiation subtraction is performed, removing the effect of radiance not reflected from the sample itself on the detector. This provides more accurate reflectance values for low-reflecting samples. Repeat measurements taken over a 20 month period on a quartz sand standard show that the repeatability of the system is very high, with a standard deviation ranging between 0.001 and 0.006 reflectance units depending on wavelength. This high level of repeatability is achieved even after replacing optical components, re-aligning mirrors and placement of sample port reducers. Absolute reflectance values of measurements taken by the instrument here presented compare very favorably to measurements of other leading laboratories taken on identical sample standards. PMID:22346683

Thermal infrared spectrometer for Earth science remote sensing applications-instrument modifications and measurement procedures.

PubMed

Hecker, Christoph; Hook, Simon; van der Meijde, Mark; Bakker, Wim; van der Werff, Harald; Wilbrink, Henk; van Ruitenbeek, Frank; de Smeth, Boudewijn; van der Meer, Freek

2011-01-01

In this article we describe a new instrumental setup at the University of Twente Faculty ITC with an optimized processing chain to measure absolute directional-hemispherical reflectance values of typical earth science samples in the 2.5 to 16 μm range. A Bruker Vertex 70 FTIR spectrometer was chosen as the base instrument. It was modified with an external integrating sphere with a 30 mm sampling port to allow measuring large, inhomogeneous samples and quantitatively compare the laboratory results to airborne and spaceborne remote sensing data. During the processing to directional-hemispherical reflectance values, a background radiation subtraction is performed, removing the effect of radiance not reflected from the sample itself on the detector. This provides more accurate reflectance values for low-reflecting samples. Repeat measurements taken over a 20 month period on a quartz sand standard show that the repeatability of the system is very high, with a standard deviation ranging between 0.001 and 0.006 reflectance units depending on wavelength. This high level of repeatability is achieved even after replacing optical components, re-aligning mirrors and placement of sample port reducers. Absolute reflectance values of measurements taken by the instrument here presented compare very favorably to measurements of other leading laboratories taken on identical sample standards.

Monitoring and evaluation of antibiotic-resistant bacteria at a municipal wastewater treatment plant in China.

PubMed

Huang, Jing-Jing; Hu, Hong-Ying; Lu, Sun-Qin; Li, Yi; Tang, Fang; Lu, Yun; Wei, Bin

2012-07-01

The prevalence of antibiotic-resistant bacteria in municipal wastewater treatment plants (WWTPs) is becoming a concern of public health. In order to acquire information on the emission of antibiotic-resistant bacteria from WWTP effluents into natural waters, both average antibiotic tolerance and concentrations of antibiotic-resistant bacteria in the effluent of a WWTP in Beijing, China were investigated. A new index of IC(50)/MIC ratio (the antibiotic concentration required to inhibit 50% of total heterotrophic bacteria compared to the highest minimum inhibitory concentration value of a group of pathogens according to a specific antibiotic, as defined by CLSI) was used to reflect the average antibiotic tolerance of total heterotrophic bacteria in the secondary effluent. The results showed that the IC(50)/MIC ratios of heterotrophic bacteria in the secondary effluent to penicillin, ampicillin, cephalothin, chloramphenicol and rifampicin were >2, >1, >1, and 1.08, respectively, which reflected a significantly high general level of heterotrophic bacteria found in the secondary effluent resistant to these five antibiotics. The concentrations of penicillin-, ampicillin-, cephalothin-, and chloramphenicol-resistant bacteria were as high as 1.5×10(4)-1.9×10(5), 1.2×10(4)-1.5×10(5), 8.9×10(3)-1.9×10(5) and 2.6×10(4)-2.0×10(5) CFU/mL, and the average percentages in relation to total heterotrophic bacteria were 63%, 47%, 55%, and 69%, respectively. The concentrations of tetracycline- and rifampicin-resistant bacteria were 840-6.1×10(3) and 310-6.1×10(4) CFU/mL with average percentages of 2.6% and 11%, respectively. Furthermore, our study found that five- and six-antibiotic-resistant bacteria were widely distributed in four types of enterobacteria from the secondary effluent. The presence of multiple-antibiotic-resistant bacteria from effluents of WWTPs into natural waters could pose a serious problem as a secondary pollutant of drinking water. Copyright © 2011 Elsevier Ltd. All rights reserved.

Self-organized coherent bursts of stimulated Raman scattering and speckle interaction in multi-speckled laser beams

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

Yin, L.; Albright, B. J.; Rose, H. A.

2013-01-15

Nonlinear physics governing the kinetic behavior of stimulated Raman scattering (SRS) in multi-speckled laser beams has been identified in the trapping regime over a wide range of k{lambda}{sub D} values (here k is the wave number of the electron plasma waves and {lambda}{sub D} is the Debye length) in homogeneous and inhomogeneous plasmas. Hot electrons from intense speckles, both forward and side-loss hot electrons produced during SRS daughter electron plasma wave bowing and filamentation, seed and enhance the growth of SRS in neighboring speckles by reducing Landau damping. Trapping-enhanced speckle interaction through transport of hot electrons, backscatter, and sidescatter SRSmore » light waves enable the system of speckles to self-organize and exhibit coherent, sub-ps SRS bursts with more than 100% instantaneous reflectivity, resulting in an SRS transverse coherence width much larger than a speckle width and a SRS spectrum that peaks outside the incident laser cone. SRS reflectivity is found to saturate above a threshold laser intensity at a level of reflectivity that depends on k{lambda}{sub D}: higher k{lambda}{sub D} leads to lower SRS and the reflectivity scales as {approx}(k{lambda}{sub D}){sup -4}. As k{lambda}{sub D} and Landau damping increase, speckle interaction via sidescattered light and side-loss hot electrons decreases and the occurrence of self-organized events becomes infrequent, leading to the reduction of time-averaged SRS reflectivity. It is found that the inclusion of a moderately strong magnetic field in the laser direction can effectively control SRS by suppressing transverse speckle interaction via hot electron transport.« less

Monitoring the reflection from an artificial defect in rail track using guided wave ultrasound

NASA Astrophysics Data System (ADS)

Loveday, Philip W.; Taylor, Rebecca M. C.; Long, Craig S.; Ramatlo, Dineo A.

2018-04-01

Guided wave ultrasound has the potential to detect relatively large defects in continuously welded rail track at long range. As monitoring can be performed in near real time it would be acceptable to only detect fairly large cracks provided this is achieved prior to complete rail breakage. Heavy haul rail lines are inspected periodically by conventional ultrasound and sections with even relatively small cracks are removed; therefore, no sizable defects are available to demonstrate monitoring in the presence of realistic environmental operating conditions. Instead, we glued a small mass to the rail to simulate reflection from a crack and monitored the guided wave signals as the glue joint deteriorated over time. Data was collected over a two week period on an operational heavy haul line. A piezoelectric transducer mounted under the head of the rail was used in pulse-echo mode to transmit and receive a mode of propagation with energy confined mainly in the head of the rail. The small mass was attached under the head of the rail, at a distance of 375m from the transducer, using a cyanoacrylate glue, which was not expected to remain intact for long. Pre-processing of the collected signals involved rejection of signals containing train noise, averaging, filtering and dispersion compensation. Reflections from aluminothermic welds were used to stretch and scale the signals to reduce the influence of temperature variations. Singular value decomposition and independent component analysis were then applied to the signals with the aim of separating the reflection caused by the artificial defect from the background signal. The performance of these techniques was compared for different time spans. The reflection from the artificial defect showed unanticipated fluctuations.

Can reflecting on personal values online increase positive beliefs about counseling?

PubMed

Lannin, Daniel G; Vogel, David L; Heath, Patrick J

2017-04-01

This research developed and tested an online values-affirmation exercise to attenuate threat and enhance positive beliefs about counseling among individuals struggling with mental health concerns. There is evidence that reflecting on personal values (values-affirmation) is an effective approach to eliciting self-affirmation-a psychological process that temporarily bolsters self-worth in order to forestall maladaptive, self-protective responses to counseling information. The present study utilized a randomized 2-group between-subjects design to test the effectiveness of a values-affirmation exercise with an online sample (N = 186) of adults who reported struggling with a mental health concern. It was predicted that values-affirmation would reduce threat related to reading mental health information and increase positive beliefs about counseling. Results indicated that those in the values-affirmation condition reported fewer negative emotions such as feeling upset, irritable, hostile, and scared after reading mental health information, indicating that the information was perceived as less threatening. There was also evidence that engaging in values-affirmation was associated with greater anticipated growth in counseling and greater intent to seek counseling, reflecting greater positive beliefs about counseling. Overall, the results suggest that reflecting on personal values may have the potential to enhance the positive effects of online psychoeducation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Signal-averaged P wave in patients with paroxysmal atrial fibrillation.

PubMed

Rosenheck, S

1997-10-01

The theoretical and experimental rational of atrial signal-averaged ECG in patients with AF is delay in the intra-atrial and interatrial conduction. Similar to the ventricular signal-averaged ECG, the atrial signal-averaged ECG is an averaging of a high number of consecutive P waves that match the template created earlier P wave triggering is preferred over QRS triggering because of more accurate aligning. However, the small amplitude of the atrial ECG and its gradual increase from the isoelectric line may create difficulties in defining the start point if P wave triggering is used. Studies using P wave triggering and those using QRS triggering demonstrate a prolonged P wave duration in patients with paroxysmal AF. The negative predictive value of this test is relatively high at 60%-80%. The positive predictive value of atrial signal-averaged ECGs in predicting the risk of AF is considerably lower than the negative predictive value. All the data accumulated prospectively on the predictive value of P wave signal-averaging was determined only in patients undergoing coronary bypass surgery or following MI; its value in other patients with paroxysmal AF is still not determined. The clinical role of frequency-domain analysis (alone or added to time-domain analysis) remains undefined. Because of this limited knowledge on the predictive value of P wave signal-averaging, it is still not clinical medicine, and further research is needed before atrial signal-averaged ECG will be part of clinical testing.

Creating "Intelligent" Climate Model Ensemble Averages Using a Process-Based Framework

NASA Astrophysics Data System (ADS)

Baker, N. C.; Taylor, P. C.

2014-12-01

The CMIP5 archive contains future climate projections from over 50 models provided by dozens of modeling centers from around the world. Individual model projections, however, are subject to biases created by structural model uncertainties. As a result, ensemble averaging of multiple models is often used to add value to model projections: consensus projections have been shown to consistently outperform individual models. Previous reports for the IPCC establish climate change projections based on an equal-weighted average of all model projections. However, certain models reproduce climate processes better than other models. Should models be weighted based on performance? Unequal ensemble averages have previously been constructed using a variety of mean state metrics. What metrics are most relevant for constraining future climate projections? This project develops a framework for systematically testing metrics in models to identify optimal metrics for unequal weighting multi-model ensembles. A unique aspect of this project is the construction and testing of climate process-based model evaluation metrics. A climate process-based metric is defined as a metric based on the relationship between two physically related climate variables—e.g., outgoing longwave radiation and surface temperature. Metrics are constructed using high-quality Earth radiation budget data from NASA's Clouds and Earth's Radiant Energy System (CERES) instrument and surface temperature data sets. It is found that regional values of tested quantities can vary significantly when comparing weighted and unweighted model ensembles. For example, one tested metric weights the ensemble by how well models reproduce the time-series probability distribution of the cloud forcing component of reflected shortwave radiation. The weighted ensemble for this metric indicates lower simulated precipitation (up to .7 mm/day) in tropical regions than the unweighted ensemble: since CMIP5 models have been shown to overproduce precipitation, this result could indicate that the metric is effective in identifying models which simulate more realistic precipitation. Ultimately, the goal of the framework is to identify performance metrics for advising better methods for ensemble averaging models and create better climate predictions.

Implications of Liebig’s law of the minimum for tree-ring reconstructions of climate

NASA Astrophysics Data System (ADS)

Stine, A. R.; Huybers, P.

2017-11-01

A basic principle of ecology, known as Liebig’s Law of the Minimum, is that plant growth reflects the strongest limiting environmental factor. This principle implies that a limiting environmental factor can be inferred from historical growth and, in dendrochronology, such reconstruction is generally achieved by averaging collections of standardized tree-ring records. Averaging is optimal if growth reflects a single limiting factor and noise but not if growth also reflects locally variable stresses that intermittently limit growth. In this study a collection of Arctic tree ring records is shown to follow scaling relationships that are inconsistent with the signal-plus-noise model of tree growth but consistent with Liebig’s Law acting at the local level. Also consistent with law-of-the-minimum behavior is that reconstructions based on the least-stressed trees in a given year better-follow variations in temperature than typical approaches where all tree-ring records are averaged. Improvements in reconstruction skill occur across all frequencies, with the greatest increase at the lowest frequencies. More comprehensive statistical-ecological models of tree growth may offer further improvement in reconstruction skill.

Wind regime peculiarities in the lower thermosphere in the winter of 1983/84

NASA Technical Reports Server (NTRS)

Lysenko, I. A.; Makarov, N. A.; Portnyagin, Yu. I.; Petrov, B. I.; Greisiger, K. M.; Schminder, R.; Kurschner, D.

1987-01-01

Temporal variations of prevailing winds at 90 to 100 km obtained from measurements carried out in winter 1983 to 1984 at three sites in the USSR and two sites in East Germany are reported. These variations are compared with those of the thermal stratospheric regime. Measurements were carried out using the drifts D2 method (meteor wind radar) and the D1 method (ionospheric drifts). Temporal variations of zonal and meridional prevailing wind components for all the sites are given. Also presented are zonal wind data obtained using the partial reflection wind radar. Wind velocity values were obtained by averaging data recorded at between 105 and 91 km altitude. Wind velocity data averaged in such a way can be related to about the same height interval to which the data obtained by the meteor radar and ionospheric methods at other sites, i.e., the mean height of the meteor zone (about 95 km). The results presented show that there are significant fluctuations about the seasonal course of both zonal and meridional prevailing winds.

Preference limits of the visual dynamic range for ultra high quality and aesthetic conveyance

NASA Astrophysics Data System (ADS)

Daly, Scott; Kunkel, Timo; Sun, Xing; Farrell, Suzanne; Crum, Poppy

2013-03-01

A subjective study was conducted to investigate the preferred maximum and minimum display luminances in order to determine the dynamic ranges for future displays. Two studies address the diffuse reflective regions, and a third study tested preferences of highlight regions. Preferences, as opposed to detection thresholds, were studied to provide results more directly relevant to the viewing of entertainment or art. Test images were specifically designed to test these limits without the perceptual conflicts that usually occur in these types of studies. For the diffuse range, we found a display with a dynamic range having luminances between 0.1 and 650 cd/m2 matches the average preferences. However, to satisfy 90% of the population, a dynamic range from 0.005 and ~3,000 cd/m2 is needed. Since a display should be able to produce values brighter than the diffuse white maximum, as in specular highlights and emissive sources, the highlight study concludes that even the average preferred maximum luminance for highlight reproduction is ~4,000 cd/m2.

Path attenuation statistics influenced by orientation of rain cells

NASA Technical Reports Server (NTRS)

Goldhirsh, J.

1976-01-01

The influence of path azimuth on fade and space diversity statistics associated with propagation along earth-satellite paths at a frequency of 18 GHz is examined. A radar rain reflectivity data base obtained during the summer of 1973 is injected into a modeling program and the attenuation along parallel earth-satellite paths are obtained for a conglomeration of azimuths. Statistics are separated into two groupings: one pertaining to earth-satellite paths oriented in the northwest-southeast and the other in the northeast-southwest quadrants using a fixed elevation angle of 45 deg. The latter case shows fading to be greater with a degraded space diversity suggesting rain cells to be elongated along this direction. Cell dimensions are analyzed for both sets of quadrants and are found to have average values larger by 2 km in the northeast-southwest quadrants; a result consistent with the fade and space diversity results. Examination of the wind direction for the 14 rain days of data analyzed shows good correlation of the average or median wind directions with the directions of maximum fading and degraded space diversity.

The radiation balance of the earth-atmosphere system from Nimbus 3 radiation measurements

NASA Technical Reports Server (NTRS)

Raschke, E.; Vonderhaar, T. H.; Pasternak, M.; Bandeen, W. R.

1973-01-01

The radiation balance of the earth-atmosphere system and its components was computed from global measurements of radiation reflected and emitted from the earth to space. These measurements were made from the meteorological satellite Nimbus 3 during the periods from April 16 to August 15, 1969; October 3 to 17, 1969; and January 21 to February 3, 1970. Primarily the method of evaluation, its inherent assumptions, and possible error sources were discussed. Results are presented by various methods: (1) global, hemispherical, and zonal averages obtained from measurements in all semimonthly periods and (2) global maps of the absorbed solar radiation, the albedo, the outgoing longwave radiation, and the radiation balance obtained from measurements during semimonthly periods in each season (May 1 to 15, July 16 to 31, and October 3 to 17, 1969, and January 21 to February 3, 1970). Annual global averages of the albedo and of the outgoing longwave radiation were determined. These values balance to within 1 percent the annual global energy input by solar radiation that was computed for a solar constant.

Monthly changes of glycogen, lipid and free amino acid of oyster

NASA Astrophysics Data System (ADS)

Zhicui, Zhang; Changhu, Xue; Xin, Gao; Zhaojie, Li; Qi, Wang

2006-07-01

Monthly difference of the chemical composition of oyster cultured along the eastern coast of Shandong Province was analyzed. The components analyzed included glycogen, fatty acid and free amino acid (FAA). The content of glycogen was high in January and March (2.89 and 2.82 g(100g)-1 on average, respectively) and low in October (2.07 g(100g)-1 on avarage). The low content of neutral lipids in October reflected a relatively poor nutritional value of oyster (1.42 g(100 g)-1 on average). The main fatty acids of oyster were palmitic acid (16:0), oleic acid (18:1), eicosapentaenoic acid (EPA, 20: 5ω-3) and docosahexaenoic acid (DHA, 22:6ω-3). The major FAAs of oyster were Taurine, Glutamicacid, Glycin, Alanine, Arginine and Proline. Taurine was the most abundant FAA with its content ranging from 603 mg (100g)-1 to 1139 mg(100g)-1. The high contents of glycogen, polyunsaturated fatty acid and FAA showed that oyster cultured along the eastern coast of Shandong Province was nutritionally good in January and March.

Measuring Changes in Salaries and Wages in Public Schools: 1988 Edition. ERS School Management Reference Series.

ERIC Educational Resources Information Center

Educational Research Service, Arlington, VA.

The Educational Research Service annually reports an important statistical measure, the Composite Indicator of Changes in Average Salaries and Wages Paid by Public School Systems (CIC), which is designed to reflect overall changes in average salaries and wages paid by school systems in much the same way that the Dow Jones Average or the Standard…

Take a Selfie of Life: A Qualitative Exploration of College Students' Self-Reflections on Free Time Use and Personal Values

ERIC Educational Resources Information Center

Chen, Hsin-Yu; Yarnal, Careen; Hustad, John T. P.; Sims, Damon

2016-01-01

Adopting a qualitative approach, this study explores college students' self-reflections on free time use and personal values. Data were collected from 111 students' final reflection papers for a class entitled "Leisure and Human Behavior." The findings suggest that leisure education may empower students with fundamental knowledge about…

Skin colour of the Ainu of Hidaka, Hokkaido, Northern Japan.

PubMed

Harvey, R G; Lord, J M

1978-09-01

Quantitative data on skin colour variation are presented for Ainu of the Hidaka District, Hokkaido. Measurements of upper arm reflectance were taken using 8 filters of an EEL reflectance spectrophotometer. The results are compared with those published for the Japanese by Hulse (1976). Sexual dimorphism is well marked in both populations and among the Ainu appears to be due largely to clothing habits. There is no statistical evidence for an association between skin colour and age. Ainu reflectance values at 545 nm and antilog transforms at 685 nm lie between those reported for Eskinomos of Greenland and Brazilian whites. Although the Ainu have consistently higher reflectance values than a Japanese sample assigned to the northern part of Japan, the results give little indication of the relative contributions of genetic and environmental factors to the differences observed. However, comparison of mean reflectance for Hokkaido Ainu and 'Central' Japanese with values predicted on the basis of world trends indicates that the differences are no greater than would be expected for two populations separated by over 7 degrees latitude and differing from one another in respect of temperature and humidity. Correspondence between observed and predicted reflectance values is excellent at the longest wavelength but poor at 470 nm.

Affirming Independence: Exploring Mechanisms Underlying a Values Affirmation Intervention for First-Generation Students

PubMed Central

Tibbetts, Yoi; Harackiewicz, Judith M.; Canning, Elizabeth A.; Boston, Jilana S.; Priniski, Stacy J.; Hyde, Janet S.

2016-01-01

First-generation college students (students for whom neither parent has a 4-year college degree) earn lower grades and worry more about whether they belong in college, compared to continuing-generation students (who have at least one parent with a 4-year college degree). We conducted a longitudinal follow-up of participants from a study in which a values-affirmation intervention improved performance in a biology course for first-generation college students, and found that the treatment effect on grades persisted three years later. First-generation students in the treatment condition obtained a GPA that was, on average, .18 points higher than first-generation students in the control condition, three years after values affirmation was implemented (Study 1A). We explored mechanisms by testing if the values-affirmation effects were predicated on first-generation students reflecting on interdependent values (thus affirming their values that are consistent with working-class culture) or independent values (thus affirming their values that are consistent with the culture of higher education). We found that when first-generation students wrote about their independence, they obtained higher grades (both in the semester in which values affirmation was implemented and in subsequent semesters) and felt less concerned about their background. In a separate laboratory experiment (Study 2) we manipulated the extent to which participants wrote about independence and found that encouraging first-generation students to write more about their independence improved their performance on a math test. These studies highlight the potential of having FG students focus on their own independence. PMID:27176770

Assessment of a prototype computer colour matching system to reproduce natural tooth colour on ceramic restorations.

PubMed

Kristiansen, Joshua; Sakai, Maiko; Da Silva, John D; Gil, Mindy; Ishikawa-Nagai, Shigemi

2011-12-01

The aim of this study was to assess the accuracy of a prototype computer colour matching (CCM) system for dental ceramics targeting the colour of natural maxillary central incisors employing a dental spectrophotometer and the Kubelka-Munk theory. Seventeen human volunteers with natural intact maxillary central incisors were selected to participate in this study. One central incisor from each subject was measured in the body region by a spectrophotometer and the reflectance values were used by the CCM system in order to generate a prescription for a ceramic mixture to reproduce the target tooth's colour. Ceramic discs were fabricated based on these prescriptions and layered on a zirconia ceramic core material of a specified colour. The colour match of each two-layered specimen to the target natural tooth was assessed by CIELAB colour coordinates (ΔE(*), ΔL(*), Δa(*) and Δb(*)). The average colour difference ΔE(*) value was 2.58±84 for the ceramic specimen-natural tooth (CS-NT) pairs. ΔL(*) values ranged from 0.17 to 2.71, Δa(*) values ranged from -1.70 to 0.61, and Δb(*) values ranged from -1.48 to 3.81. There was a moderate inverse correlation (R=-0.44, p-value=0.0721) between L(*) values for natural target teeth and ΔE(*) values; no such correlation was found for a(*) and b(*) values. The newly developed prototype CCM system has the potential to be used as an efficient tool in the reproduction of natural tooth colour. Copyright © 2011. Published by Elsevier Ltd.

Extrinsic and intrinsic index finger muscle attachments in an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-04-01

Musculoskeletal models allow estimation of muscle function during complex tasks. We used objective methods to determine possible attachment locations for index finger muscles in an OpenSim upper-extremity model. Data-driven optimization algorithms, Simulated Annealing and Hook-Jeeves, estimated tendon locations crossing the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints by minimizing the difference between model-estimated and experimentally-measured moment arms. Sensitivity analysis revealed that multiple sets of muscle attachments with similar optimized moment arms are possible, requiring additional assumptions or data to select a single set of values. The most smooth muscle paths were assumed to be biologically reasonable. Estimated tendon attachments resulted in variance accounted for (VAF) between calculated moment arms and measured values of 78% for flex/extension and 81% for ab/adduction at the MCP joint. VAF averaged 67% at the PIP joint and 54% at the DIP joint. VAF values at PIP and DIP joints partially reflected the constant moment arms reported for muscles about these joints. However, all moment arm values found through optimization were non-linear and non-constant. Relationships between moment arms and joint angles were best described with quadratic equations for tendons at the PIP and DIP joints.

Degradation rates of alachlor, atrazine and bentazone in the profiles of Polish Luvisols

NASA Astrophysics Data System (ADS)

Paszko, Tadeusz; Muszyński, Paweł

2017-07-01

The degradation rates of three herbicides (alachlor, atrazine, and bentazone) were examined according to OECD Guideline 307 in three profiles of grey-brown podzolic soil (Luvisol) in a laboratory experiment. The aim of the experiment was to determine herbicide degradation parameters and their relationships with soil properties. Degradation processes were effectively described by a first-order model. However, in some cases, the best results were produced by bi-phasic kinetics (hockey-stick and bi-exponential model). The degradation rates of the tested herbicides at 25°C and 40% maximum water holding capacity, established based on half-life values in the Ap horizon, increased in the following order: atrazine (32.6-42.8 days) < bentazone (3.4-16.6 days < alachlor (4.4-5.7 days). The correlation analysis and the Principal Component Analysis revealed significant positive correlations between the herbicide degradation rates and the organic matter content of soils. The depth-dependent degradation factors obtained for topsoil and two subsoil horizons (1: 0.42: 0.11 - based on average values, and 1: 0.31: 0.12 - based on median values) reflect the degradation abilities of Polish Luvisols. The values noted are soil-specific; therefore, they can also be applied to other pesticides in Polish Luvisols.

A trust evaluation algorithm for wireless sensor networks based on node behaviors and D-S evidence theory.

PubMed

Feng, Renjian; Xu, Xiaofeng; Zhou, Xiang; Wan, Jiangwen

2011-01-01

For wireless sensor networks (WSNs), many factors, such as mutual interference of wireless links, battlefield applications and nodes exposed to the environment without good physical protection, result in the sensor nodes being more vulnerable to be attacked and compromised. In order to address this network security problem, a novel trust evaluation algorithm defined as NBBTE (Node Behavioral Strategies Banding Belief Theory of the Trust Evaluation Algorithm) is proposed, which integrates the approach of nodes behavioral strategies and modified evidence theory. According to the behaviors of sensor nodes, a variety of trust factors and coefficients related to the network application are established to obtain direct and indirect trust values through calculating weighted average of trust factors. Meanwhile, the fuzzy set method is applied to form the basic input vector of evidence. On this basis, the evidence difference is calculated between the indirect and direct trust values, which link the revised D-S evidence combination rule to finally synthesize integrated trust value of nodes. The simulation results show that NBBTE can effectively identify malicious nodes and reflects the characteristic of trust value that 'hard to acquire and easy to lose'. Furthermore, it is obvious that the proposed scheme has an outstanding advantage in terms of illustrating the real contribution of different nodes to trust evaluation.

49 CFR 536.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... manufactured by a manufacturer in that compliance category in a particular model year have greater average fuel.... 32905) than that manufacturer's fuel economy standard for that compliance category and model year... year have lower average fuel economy (calculated in a manner that reflects the incentives for...

49 CFR 536.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... manufactured by a manufacturer in that compliance category in a particular model year have greater average fuel.... 32905) than that manufacturer's fuel economy standard for that compliance category and model year... year have lower average fuel economy (calculated in a manner that reflects the incentives for...

Geothermal flux and basal melt rate in the Dome C region inferred from radar reflectivity and heat modelling

NASA Astrophysics Data System (ADS)

Passalacqua, Olivier; Ritz, Catherine; Parrenin, Frédéric; Urbini, Stefano; Frezzotti, Massimo

2017-09-01

Basal melt rate is the most important physical quantity to be evaluated when looking for an old-ice drilling site, and it depends to a great extent on the geothermal flux (GF), which is poorly known under the East Antarctic ice sheet. Given that wet bedrock has higher reflectivity than dry bedrock, the wetness of the ice-bed interface can be assessed using radar echoes from the bedrock. But, since basal conditions depend on heat transfer forced by climate but lagged by the thick ice, the basal ice may currently be frozen whereas in the past it was generally melting. For that reason, the risk of bias between present and past conditions has to be evaluated. The objective of this study is to assess which locations in the Dome C area could have been protected from basal melting at any time in the past, which requires evaluating GF. We used an inverse approach to retrieve GF from radar-inferred distribution of wet and dry beds. A 1-D heat model is run over the last 800 ka to constrain the value of GF by assessing a critical ice thickness, i.e. the minimum ice thickness that would allow the present local distribution of basal melting. A regional map of the GF was then inferred over a 80 km × 130 km area, with a N-S gradient and with values ranging from 48 to 60 mW m-2. The forward model was then emulated by a polynomial function to compute a time-averaged value of the spatially variable basal melt rate over the region. Three main subregions appear to be free of basal melting, two because of a thin overlying ice and one, north of Dome C, because of a low GF.

Orientations to Reflective Practice.

ERIC Educational Resources Information Center

Wellington, Bud; Austin, Patricia

1996-01-01

Delineates five orientations to reflective practice: immediate, technical, deliberative, dialectic, and transpersonal, each reflecting different social science bases and beliefs and values about education. Views them as interactive, interdependent, noncompeting, aspects of reflective practice. (SK)

Empirical parameterization of setup, swash, and runup

USGS Publications Warehouse

Stockdon, H.F.; Holman, R.A.; Howd, P.A.; Sallenger, A.H.

2006-01-01

Using shoreline water-level time series collected during 10 dynamically diverse field experiments, an empirical parameterization for extreme runup, defined by the 2% exceedence value, has been developed for use on natural beaches over a wide range of conditions. Runup, the height of discrete water-level maxima, depends on two dynamically different processes; time-averaged wave setup and total swash excursion, each of which is parameterized separately. Setup at the shoreline was best parameterized using a dimensional form of the more common Iribarren-based setup expression that includes foreshore beach slope, offshore wave height, and deep-water wavelength. Significant swash can be decomposed into the incident and infragravity frequency bands. Incident swash is also best parameterized using a dimensional form of the Iribarren-based expression. Infragravity swash is best modeled dimensionally using offshore wave height and wavelength and shows no statistically significant linear dependence on either foreshore or surf-zone slope. On infragravity-dominated dissipative beaches, the magnitudes of both setup and swash, modeling both incident and infragravity frequency components together, are dependent only on offshore wave height and wavelength. Statistics of predicted runup averaged over all sites indicate a - 17 cm bias and an rms error of 38 cm: the mean observed runup elevation for all experiments was 144 cm. On intermediate and reflective beaches with complex foreshore topography, the use of an alongshore-averaged beach slope in practical applications of the runup parameterization may result in a relative runup error equal to 51% of the fractional variability between the measured and the averaged slope.

Dissociation kinetics of metal clusters on multiple electronic states including electronic level statistics into the vibronic soup

NASA Astrophysics Data System (ADS)

Shvartsburg, Alexandre A.; Siu, K. W. Michael

2001-06-01

Modeling the delayed dissociation of clusters had been over the last decade a frontline development area in chemical physics. It is of fundamental interest how statistical kinetics methods previously validated for regular molecules and atomic nuclei may apply to clusters, as this would help to understand the transferability of statistical models for disintegration of complex systems across various classes of physical objects. From a practical perspective, accurate simulation of unimolecular decomposition is critical for the extraction of true thermochemical values from measurements on the decay of energized clusters. Metal clusters are particularly challenging because of the multitude of low-lying electronic states that are coupled to vibrations. This has previously been accounted for assuming the average electronic structure of a conducting cluster approximated by the levels of electron in a cavity. While this provides a reasonable time-averaged description, it ignores the distribution of instantaneous electronic structures in a "boiling" cluster around that average. Here we set up a new treatment that incorporates the statistical distribution of electronic levels around the average picture using random matrix theory. This approach faithfully reflects the completely chaotic "vibronic soup" nature of hot metal clusters. We found that the consideration of electronic level statistics significantly promotes electronic excitation and thus increases the magnitude of its effect. As this excitation always depresses the decay rates, the inclusion of level statistics results in slower dissociation of metal clusters.

Distinguishing succulent plants from crop and woody plants

NASA Technical Reports Server (NTRS)

Gausman, H. W.; Escobar, D. E.; Everitt, J. H.; Richardson, A. J.; Rodriguez, R. R.

1978-01-01

We compared laboratory spectrophotometrically measured leaf reflectances of six succulents (peperomia, possum-grape, prickly pear, spiderwort, Texas tuberose, wolfberry) with those of four nonsucculents (cenizo, honey mesquite, cotton, sugarcane) for plant species discrimination. Succulents (average leaf water content of 92.2 percent) could be distinguished from nonsucculents (average leaf water content of 71.2 percent) within the near-infrared water absorption waveband (1.35 to 2.5 microns). This was substantiated by field spectrophotometric reflectances of plant canopies. Sensor bands encompassing either the 1.6- or 2.2-wavelengths may be useful to distinguish succulent from nonsucculent plant species.

Constraining Holocene hydrological changes in the Carpathian-Balkan region using speleothem δ18O and pollen-based temperature reconstructions

NASA Astrophysics Data System (ADS)

Drăguşin, V.; Staubwasser, M.; Hoffmann, D. L.; Ersek, V.; Onac, B. P.; Veres, D.

2014-07-01

Here we present a speleothem isotope record (POM2) from Ascunsă Cave (Romania) that provides new data on past climate changes in the Carpathian-Balkan region from 8.2 ka until the present. This paper describes an approach to constrain the effect of temperature changes on calcite δ18O values in stalagmite POM2 over the course of the middle Holocene (6-4 ka), and across the 8.2 and 3.2 ka rapid climate change events. Independent pollen temperature reconstructions are used to this purpose. The approach combines the temperature-dependent isotope fractionation of rain water during condensation and fractionation resulting from calcite precipitation at the given cave temperature. The only prior assumptions are that pollen-derived average annual temperature reflects average cave temperature, and that pollen-derived coldest and warmest month temperatures reflect the range of condensation temperatures of rain above the cave site. This approach constrains a range of values between which speleothem δ18O changes should be found if controlled only by surface temperature variations at the cave site. Deviations of the change in δ18Ocspel values from the calculated temperature-constrained range of change are interpreted towards large-scale variability of climate-hydrology. Following this approach, we show that an additional ∼0.6‰ enrichment of δ18Oc in the POM2 stalagmite was caused by changing hydrological patterns in SW Romania across the middle Holocene, most likely comprising local evaporation from the soil and an increase in Mediterranean moisture δ18O. Further, by extending the calculations to other speleothem records from around the entire Mediterranean basin, it appears that all eastern Mediterranean speleothems recorded a similar isotopic enrichment due to changing hydrology, whereas all changes recorded in speleothems from the western Mediterranean are fully explained by temperature variation alone. This highlights a different hydrological evolution between the two sides of the Mediterranean. Our results also demonstrate that during the 8.2 ka event, POM2 stable isotope data essentially fit the temperature-constrained isotopic variability. In the case of the 3.2 ka event, an additional climate-related hydrological factor is more evident. This implies a different rainfall pattern in the Southern Carpathian region during this event at the end of the Bronze Age.

Individual specialization in diet by a generalist marine predator reflects specialization in foraging behaviour.

PubMed

Woo, Kerry J; Elliott, Kyle Hamish; Davidson, Melissa; Gaston, Anthony J; Davoren, Gail K

2008-11-01

1. We studied chick diet in a known-age, sexed population of a long-lived seabird, the Brünnich's guillemot (Uria lomvia), over 15 years (N = 136; 1993-2007) and attached time-depth-temperature recorders to examine foraging behaviour in multiple years (N = 36; 2004-07). 2. Adults showed specialization in prey fed to offspring, described by multiple indices calculated over 15 years: 27% of diet diversity was attributable to among-individual variation (within-individual component of total niche width = 0.73); average similarity of an individual's diet to the overall diet was 65% (mean proportional similarity between individuals and population = 0.65); diet was significantly more specialized than expected for 70% of individuals (mean likelihood = 0.53). These indices suggest higher specialization than the average for an across-taxa comparison of 49 taxa. 3. Foraging behaviour varied along three axes: flight time, dive depth and dive shape. Individuals showed specialized individual foraging behaviour along each axis. These foraging strategies were reflected in the prey type delivered to their offspring and were maintained over scales of hours to years. 4. Specialization in foraging behaviour and diet was greater over short time spans (hours, days) than over long time spans (years). Regardless of sex or age, the main component of variation in foraging behaviour and chick diet was between individuals. 5. Plasma stable isotope values were similar across years, within a given individual, and variance was low relative to that expected from prey isotope values, suggesting adult diet specialized across years. Stable isotope values were similar among individuals that fed their nestlings similar prey items and there was no difference in trophic level between adults and chicks. We suggest that guillemots specialize on a single foraging strategy regardless of whether chick-provisioning and self-feeding. With little individual difference in body mass and physiology, specialization likely represents learning and memorizing optimal feeding locations and behaviours. 6. There was no difference in survival or reproductive success between specialists and generalists, suggesting these are largely equivalent strategies in terms of evolutionary fitness, presumably because different strategies were advantageous at different levels of prey abundance or predictability. The development of individual specialization may be an important precursor to diversification among seabirds.

Modelling CO emission - II. The physical characteristics that determine the X factor in Galactic molecular clouds

NASA Astrophysics Data System (ADS)

Shetty, Rahul; Glover, Simon C.; Dullemond, Cornelis P.; Ostriker, Eve C.; Harris, Andrew I.; Klessen, Ralf S.

2011-08-01

We investigate how the X factor, the ratio of the molecular hydrogen column density (?) to velocity-integrated CO intensity (W), is determined by the physical properties of gas in model molecular clouds (MCs). The synthetic MCs are results of magnetohydrodynamic simulations, including a treatment of chemistry. We perform radiative transfer calculations to determine the emergent CO intensity, using the large velocity gradient approximation for estimating the CO population levels. In order to understand why observations generally find cloud-averaged values of X = XGal˜ 2 × 1020 cm-2 K-1 km-1 s, we focus on a model representing a typical Milky Way MC. Using globally integrated ? and W reproduces the limited range in X found in observations and a mean value X = XGal= 2.2 × 1020 cm-2 K-1 km-1 s. However, we show that when considering limited velocity intervals, X can take on a much larger range of values due to CO line saturation. Thus, the X factor strongly depends on both the range in gas velocities and the volume densities. The temperature variations within individual MCs do not strongly affect X, as dense gas contributes most to setting the X factor. For fixed velocity and density structure, gas with higher temperatures T has higher W, yielding X ∝ T-1/2 for T ˜ 20-100 K. We demonstrate that the linewidth-size scaling relationship does not influence the X factor - only the range in velocities is important. Clouds with larger linewidths σ, regardless of the linewidth-size relationship, have a higher W, corresponding to a lower value of X, scaling roughly as X ∝σ-1/2. The 'mist' model, often invoked to explain a constant XGal consisting of optically thick cloudlets with well-separated velocities, does not accurately reflect the conditions in a turbulent MC. We propose that the observed cloud-averaged values of X ˜ XGal are simply a result of the limited range in ?, temperatures and velocities found in Galactic MCs - a nearly constant value of X therefore does not require any linewidth-size relationship, or that MCs are virialized objects. Since gas properties likely differ (albeit even slightly) from cloud to cloud, masses derived through a standard value of the X factor should only be considered as a rough first estimate. For temperatures T ˜ 10-20 K, velocity dispersions σ˜ 1-6 km s-1and ? cm-2, we find cloud-averaged values X ˜ 2-4 × 1020 cm-2 K-1 km-1 s for solar-metallicity models.

[Clinical use of continuous glucose monitoring system in gestational diabetes mellitus and type 2 diabetes complicated with pregnancy].

PubMed

Song, Yilin; Yang, Huixia

2014-08-01

To compare the clinical use of continuous glucose monitoring system (CGMS) and self-monitoring blood glucose (SMBG) when monitoring blood glucose level of patients with gestational diabetes mellitus (GDM) or type 2 diabetes mellitus (DM) complicated with pregnancy. A total of 99 patients with GDM (n = 70) and type 2 DM complicated with pregnancy (n = 29) that whether hospitalized or in clinical of Peking University First Hospital were recruited from Aug 2012 to Apr 2013. The CGMS was used to monitor their blood glucose level during the 72-hour time period, while the SMBG was also taken seven times daily. The correlation between these blood glucose levels and their glycosylated hemoglobin (HbA1c) levels were analyzed by comparing the average value, the maximum and the minimum value of blood glucose, and the appeared time of these extremum values in these two monitoring methods, and the amount of insulin usage was recorded as well. (1) The maximum, minimum and the average blood glucose value in the GDM group were (8.7 ± 1.2), (4.5 ± 0.6)and (6.3 ± 0.6)mmol/L of SMBG vs. (10.1 ± 1.7), (3.1 ± 0.7), (6.0 ± 0.6) mmol/L of CGMS. These values in DM group were(10.1 ± 2.2), (4.5 ± 1.0), (6.9 ± 1.1)mmol/L of SMBG vs.(12.2 ± 2.6), (2.8 ± 0.8), (6.6 ± 1.1) mmol/L of CGMS. By using the two methods, the maximum and the average value of the two groups showed significant differences (P < 0.01) while the minimum value showed no significant differences (P > 0.05). (2) In the GDM group, the average blood glucose values of CGMS and SMBG were significantly correlated (r = 0.864, P < 0.01). The maximum values presented the same result (r = 0.734, P < 0.01). Correlation was not found in the minimum values of CGMS and SMBG (r = 0.138, P > 0.05). In the DM group, the average valves of two methods were significantly correlated (r = 0.962, P < 0.01), the maximum values showed the same result (r = 0.831, P < 0.01).It can also be observed in the minimum values (r = 0.460, P < 0.05). (3) There was significant correlation between the average value of CGMS and HbA1c level (r = 0.400, P < 0.01), and the average value of SMBG and HbA1c level were correlated (r = 0.031, P < 0.05) in the GDM group; the average values of CGMS (r = 0.695, P < 0.01) and SMBG (r = 0.673, P < 0.01) were both significantly correlated with the HbA1c level in the DM group. (4) In the GDM group, 37% (26/70) of the minimum values of SMBG appeared 30 minutes before breakfast, while 34% (24/70) of them appeared 30 minutes before lunch; 86% (60/70) of the maximum values of SMBG were evenly distributed 2 hours after each of the three meals. In the DM group, 41% (12/29) of the minimum values of SMBG presented 30 minutes before lunch, while 21% (6/29) and 14% (4/29) of them were showed 30 minutes before breakfast and dinner respectively; about 30% of the maximum values of SMBG appeared 2 hours after each of the three meals. (5) In the GDM group, 23% (16/70) of the minimum values of CGMS occurred between 0:00-2:59 am., and most of the other minimum values of CGMS were evenly distributed in the rest of the day, except for 3% (2/70) of them were found during 18:00- 20:59 pm. 43% (30/70) of the maximum values of CGMS appeared during 6:00-8:59 am., only 1% (1/70) and 3% (2/70) of them presented during 0:00-2:59 am. and 21:00-23:59 pm., and the rest were evenly distributed for the other times of the day. In the DM group, 34% (10/29) of the minimum values of CGMS were found during 0:00-2:59 am., 14% (4/29) of them appeared during 9:00-11:59 am. and 15:00-17:59 pm., 45% (13/29) of the maximum values of the CGMS presented during 6:00-8:59 am., none was found during 21:00-23:59 pm.,0:00-2:59 am. and 3:00-5:59 am., and the rest were evenly distributed for the other times of the day. (6) 64% (45/70) of the patients in the GDM group did not require for insulin treatment, while 36% (25/70) of them did. For those patients who received insulin treatment, after CGMS, 64% (16/25) of them adjusted the insulin dosage according to their blood glucose levels. In the DM group, 14% (4/29) of them did not receive insulin treatment, while for the others who did (86%, 25/29); 60% (15/25) of them adjusted the insulin dosage according to their blood glucose levels after CGMS. Both CGMS and SMBG could correctly reflect patients' blood glucose levels. It was more difficult to control the blood glucose levels in patients with type 2 DM complicated with pregnancy than the GDM patients. Compared with SMBG, CGMS could detect postprandial hyperglycemia and nocturnal hypoglycemia more effectively.

What Can We Expect from Value-Based Funding of Medicines? A Retrospective Study.

PubMed

Harris, Anthony; Li, Jing Jing; Yong, Karen

2016-04-01

Deciding on public funding for pharmaceuticals on the basis of value for money is now widespread. We suggest that evidence-based assessment of value has restricted the availability of medicines in Australia in a way that reflects the relative bargaining power of government and the pharmaceutical industry. We propose a simple informal game-theoretic model of bargaining between the funding agency and industry and test its predictions using a logistic multiple regression model of past funding decisions made by the Pharmaceutical Benefits Advisory Committee in Australia. The model estimates the probability of a drug being recommended for subsidy as a function of incremental cost per quality-adjusted life-year (QALY), as well as other drug and market characteristics. Data are major submissions or resubmissions from 1993 to 2009 where there was a claim of superiority and evidence of a difference in quality of life. Independent variables measure the incremental cost per QALY, the cost to the public budget, the strength and quality of the clinical and economic evidence, need as measured by severity of illness and the availability of alternative treatments, whether or not a resubmission, and newspaper reports as a measure of public pressure. We report the odds ratio for each variable and calculate the ratio of the marginal effect of each variable to the marginal effect of the cost per QALY as a measure of the revealed willingness to pay for each of the variables that influence the decision. The results are consistent with a bargaining model where a 10,000 Australian dollar ($A) fall in value (increase in cost per QALY) reduces the average probability of public funding from 37 to 33% (95% CI 34-32). If the condition is life threatening or the drug has no active comparator, then the odds of a positive recommendation are 3.18 (95% CI 1.00-10.11) and 2.14 (95% CI 0.95-4.83) greater, equivalent to a $A33,000 and a $A21,000 increase in value (fall in cost per QALY). If both conditions are met, the odds are increased by 4.41 (95% CI 1.28-15.24) times, equivalent to an increase in value of $A46,000. Funding is more likely as time elapses and price falls, but we did not find clear evidence that public or corporate pressure influences decisions. Evidence from Australia suggests that the determinants of public funding and pricing decisions for medicines reflect the relative bargaining power of government and drug companies. Value for money depends on the quality of evidence, timing, patient need, perceived benefit and opportunity cost; these factors reflect the potential gains from striking a bargain and the risk of loss from not doing so.

Modeling of Light Reflection from Human Skin

NASA Astrophysics Data System (ADS)

Delgado, J. A.; Cornejo, A.; Rivas-Silva, J. F.; Rodríguez, E. E.

2006-09-01

In this work a two-layer model is used to simulate the spectral reflectance of adult human skin. We report and discuss diffuse reflectance spectra of this model for three values of the volume fraction of melanosomes fme, namely a) lightly pigmented skin fme = 4%, b) moderately pigmented skin fme = 14% and c) heavily pigmented skin fme = 30% at a volume fraction of blood fbl = 0.2%. We also considered the modeling of reflectance spectra for two values of fbl (0.2% and 1%) with fme = 4%. Both simulations were done in the 400-700 nm spectral range using the Monte Carlo simulation code MCML in standard C. Results showed that the principal signatures of human skin reflectance spectrum are obtained with this model and that it could be of valuable use to made predictions of diffuse reflectance of human skin for different values of the parameters related to skin characterization. These parameters can be associated to distinct medical conditions, such as erythema, jaundice, etc.

Temporal δ13C records from bottlenose dolphins (Tursiops truncatus) reflect variation in foraging location and global carbon cycling

NASA Astrophysics Data System (ADS)

Rossman, S. L.; Barros, N. B.; Ostrom, P. H.; Gandhi, H.; Wells, R. S.

2010-12-01

With four decades of data on a population of bottlenose dolphins (Tursiops truncatus) resident to Sarasota Bay (SB), The Sarasota Dolphin Research Program offers an unparalleled platform for ground-truthing stable isotope data and exploring bottlenose dolphin ecology in a natural setting. We explored carbon isotope value fidelity to habitat utilization by comparing δ13C data from whole teeth and muscle to the individual dolphin's proclivity towards foraging in seagrass beds based on observational data. We then examined variation in habitat use based on temporal isotope records. Whole tooth protein isotope values do not show a significant correlation with the observed percentage of foraging in seagrass habitat. In contrast, δ13C values from muscle showed a significant positive relationship with the observational data. Differences in the degree of tissue turn over may account for this distinction between tooth and muscle. Dolphin teeth consist of annually deposited layers that are inert once formed. Thus, the isotopic composition of protein in annuli reflect foraging at the time of deposition. In addition to incorporating variation associated with differences in foraging over the lifetime of the individual, whole tooth isotope values are confounded because a disproportionate amount of tooth protein derives from the first few years of life. Given the turnover time of muscle tissue, isotope values reflect diet over the past several months. From 1991 to 2008, muscle δ13C values showed a significant decline, -13.5‰ to -15.1‰.This time period encompasses a state wide net fishing ban (1995) however other factors such as a series of red tide harmful algal blooms, a decline in predators, increases in shallow water boat traffic and an increase in string ray abundance may also contribute to the temporal isotope trend. To examine changes in dolphin foraging habitat further back in time we analyzed the tip of crown of the tooth which records the isotopic signal from the first year of life. Given the age of bottlenose dolphins from SB (ca. 60 years), our isotopic data provide a record beginning in 1944. While carbon isotope values show a striking decline over time, the data must be corrected for the Suess effect. The Suess effect results from burning of 13C depleted hydrocarbons which causes a decrease in the δ13C of atmospheric CO2 that subsequent depresses isotope values in food webs. To account for the Suess effect, δ13C values are adjusted by 0.15‰ per decade. Suess corrected δ13C values do not show a temporal linear trend however the average isotope value prior to 1960 is significantly higher than that after 1960 (-10.1 vs -11.66, p=0.038). While documented declines in seagrass abundance prior to 1980 may influence our data, the decline in δ13C of atmospheric CO2 is likely an important factor that controls the isotopic composition of dolphin tissues. Our results suggest that isotope-based estimates of foraging should account for the Suess effect, and that dolphins act as environmental sentinels whose δ13C values records perturbations in global carbon cycling.

Interpreting values conflicts experienced by obstetrics-gynecology clerkship students using reflective writing.

PubMed

Cohn, Felicia G; Shapiro, Johanna; Lie, Désirée A; Boker, John; Stephens, Frances; Leung, Lee Ann

2009-05-01

To examine students' responses to reflective practice assignments used in medical ethics and professionalism education. The study goals include an examination of what reflective writing reveals about students' personal and professional values, identification of the narrative typologies students use to tell stories of ethical dilemmas, and a determination of the usefulness of reflective writing in informing ethics/professionalism curricula assessment and development. This study employed a mixed-methods design generating both descriptive data and interpretive analysis. Students' reflective writing assignments, guided by a series of six questions designed to elicit students' perceptions of moral conflicts they have encountered and their personal and professional ethical values, were collected from three successive cohorts of third-year medical students (n = 299) from July 2002 to January 2006 during an obstetrics-gynecology clerkship at the University of California, Irvine, School of Medicine. Content, thematic, and global narrative analyses of students' reflective writing were conducted, drawing on content analysis, grounded theory, and narrative methodologies. Values conflicts usually were patient centered (181; 60.5%) and student centered (172; 57.5%), without much regard for important contextual issues such as patients' socioeconomic status, insurance coverage, or culture. Common personal values included religious beliefs (82; 27.4%), respect (72; 24.1%), and the Golden Rule (66; 22.1%); frequent professional values were respect (72; 25.1%), beneficence (71; 23.7%), nonmaleficence (69; 23.1%), and autonomy (65; 21.7%). Whereas 35.5% (106) claimed to have addressed conflicts, 23.4% (70) said they did nothing. Restitution narratives (113; 37.8%) dominated. This analytic approach facilitated assessment of student values, conflict sources, and narrative types. Findings reveal aspects of the influence of the hidden curriculum and can inform strategies for effective implementation of bioethics/professionalism curricula.

JND measurements of the speech formants parameters and its implication in the LPC pole quantization

NASA Astrophysics Data System (ADS)

Orgad, Yaakov

1988-08-01

The inherent sensitivity of auditory perception is explicitly used with the objective of designing an efficient speech encoder. Speech can be modelled by a filter representing the vocal tract shape that is driven by an excitation signal representing glottal air flow. This work concentrates on the filter encoding problem, assuming that excitation signal encoding is optimal. Linear predictive coding (LPC) techniques were used to model a short speech segment by an all-pole filter; each pole was directly related to the speech formants. Measurements were made of the auditory just noticeable difference (JND) corresponding to the natural speech formants, with the LPC filter poles as the best candidates to represent the speech spectral envelope. The JND is the maximum precision required in speech quantization; it was defined on the basis of the shift of one pole parameter of a single frame of a speech segment, necessary to induce subjective perception of the distortion, with .75 probability. The average JND in LPC filter poles in natural speech was found to increase with increasing pole bandwidth and, to a lesser extent, frequency. The JND measurements showed a large spread of the residuals around the average values, indicating that inter-formant coupling and, perhaps, other, not yet fully understood, factors were not taken into account at this stage of the research. A future treatment should consider these factors. The average JNDs obtained in this work were used to design pole quantization tables for speech coding and provided a better bit-rate than the standard quantizer of reflection coefficient; a 30-bits-per-frame pole quantizer yielded a speech quality similar to that obtained with a standard 41-bits-per-frame reflection coefficient quantizer. Owing to the complexity of the numerical root extraction system, the practical implementation of the pole quantization approach remains to be proved.

Quantitative assessment of local perfusion change in acute intracerebral hemorrhage areas with and without "dynamic spot sign" using CT perfusion imaging.

PubMed

Fu, Fan; Sui, Binbin; Liu, Liping; Su, Yaping; Sun, Shengjun; Li, Yingying

2018-01-01

Background Positive "dynamic spot sign" has been proven to be a potential risk factor for acute intracerebral hemorrhage (ICH) expansion, but local perfusion change has not been quantitatively investigated. Purpose To quantitatively evaluate perfusion changes at the ICH area using computed tomography perfusion (CTP) imaging. Material and Methods Fifty-three patients with spontaneous ICH were recruited. Unenhanced computed tomography (NCCT), CTP within 6 h, and follow-up NCCT were performed for 21 patients in the "spot sign"-positive group and 32 patients in the control group. Cerebral perfusion change was quantitatively measured on regional cerebral blood flow/regional cerebral blood volume (rCBF/rCBV) maps. Regions of interest (ROIs) were set at the "spot-sign" region and the whole hematoma area for "spot-sign"-positive cases, and at one of the highest values of three interested areas and the whole hematoma area for the control group. Hematoma expansion was determined by follow-up NCCT. Results For the "spot-sign"-positive group, the average rCBF (rCBV) values at the "spot-sign" region and the whole hematoma area were 21.34 ± 15.24 mL/min/100 g (21.64 ± 21.48 mL/100g) and 5.78 ± 6.32 mL/min/100 g (6.07 ± 5.45 mL/100g); for the control group, the average rCBF (rCBV) values at the interested area and whole hematoma area were 2.50 ± 1.83 mL/min/100 g (3.13 ± 1.96 mL/100g) and 3.02 ± 1.80 mL/min/100 g (3.40 ± 1.44 mL/100g), respectively. Average rCBF and rCBV values of the "spot-sign" region were significantly different from other regions ( P < 0.001; P = 0.004). The average volumes of hematoma expansion in the "spot-sign"-positive and control groups were 25.24 ± 19.38 mL and -0.41 ± 1.34 mL, respectively. Conclusion The higher perfusion change at ICH on CTP images may reflect the contrast extravasation and be associated with the hematoma expansion.

Colour differences in Caucasian and Oriental women's faces illuminated by white LED sources.

PubMed

Melgosa, M; Richard, N; Fernández-Maloigne, C; Xiao, K; de Clermont-Gallerande, H; Jost-Boissard, S; Okajima, K

2018-04-10

To provide an approach to facial contrast, analysing CIELAB colour differences (ΔE* ab,10 ) and its components in women's faces from two different ethnic groups, illuminated by modern white light-emitting diodes (LEDs) or traditional illuminants recommended by the International Commission on Illumination (CIE). We performed spectrophotometric measurements of spectral reflectance factors on forehead and cheek of 87 young healthy women (50 Caucasians and 37 Orientals), plus 5 commercial red lipsticks. We considered a set of 10 white LED illuminants, representative of technologies currently available on the market, plus 8 main illuminants currently recommended by the CIE, representative of conventional incandescent, daylight, and fluorescent light sources. Under each of these 18 illuminants we analysed the magnitude and components of ΔE* ab,10 between Caucasian and Oriental women (considering cheek and forehead), as well as for cheek-forehead and cheek-lipsticks in Caucasian and Oriental women. Colour-inconstancy indices for cheek, forehead, and lipsticks were computed, assuming D65 and A as reference illuminants. ΔE* ab,10 between forehead and cheek were quantitatively and qualitatively different in Orientals and Caucasians, but discrepancies with respect to average values for 18 illuminants were small (1.5% and 5.0% for Orientals and Caucasians, respectively). ΔE* ab,10 between Caucasians and Orientals were also quantitatively and qualitatively different both for forehead and cheek, and discrepancies with respect to average values were again small (1.0% and 3.9% for forehead and cheek, respectively). ΔE* ab,10 between lipsticks and cheek were at least 2 times higher than those between forehead and cheek. Regarding ΔE* ab,10 between lipsticks and cheeks, discrepancies with respect to average values were in the range 1.5% - 12.3%, although higher values of up to 54.2% were found for a white RGB LED. This white RGB LED provided the highest average colour-inconstancy indices: 17.1 and 11.5 CIELAB units, under reference illuminants D65 and A, respectively. Colour contrasts in women's faces under CIE standard illuminants for outdoor and indoor conditions may be strongly altered by using specific white LEDs. More research needs to be done on the impact of spectral power distribution of light sources with high colour rendering indices on visual colour appearance of cosmetic products. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparison of TOMS, SBW & SBUV/2 Version 8 Total Column Ozone Data with Data from Groundstations

NASA Technical Reports Server (NTRS)

Labow, G. J.; McPeters, R. D.; Bhartia, P. K.

2004-01-01

The Nimbus-7 and Earth Probe Total Ozone Mapping Spectrometer (TOMS) data as well as SBUV and SBUV/2 data have been reprocessed with a new retrieval algorithm (Version 8) and an updated calibration procedure. An overview will be presented systematically comparing ozone values to an ensemble of Brewer and Dobson spectrophotometers. The comparisons were made as a function of latitude, solar zenith angle, reflectivity and total ozone. Results show that the accuracy of the TOMS retrieval has been improved when aerosols are present in the atmosphere, when snow/ice and sea glint are present, and when ozone in the northern hemisphere is extremely low. TOMS overpass data are derived from the single TOMS best match measurement, almost always located within one degree of the ground station and usually made within an hour of local noon. The Version 8 Earth Probe TOMS ozone values have decreased by an average of about 1% due to a much better understanding of the calibration of the instrument. N-7 SBUV as well as the series of NOAA SBUV/2 column ozone values have also been processed with the Version 8 algorithm and have been compared to values from an ensemble of groundstations. Results show that the SBW column ozone values agree well with the groundstations and the datasets are useful for trend studies.

A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain)

PubMed Central

Villaverde Bonilla, Valentín; Ródenas Marín, Isabel; Murcia Mascarós, Sonia

2016-01-01

In this work we analyze the pigments used in the decoration of red and yellow motifs present in the portable art of the Parpalló Cave (Gandía, Spain), one of the most important Palaeolithic sites in the Spanish Mediterranean region. Energy dispersive X-ray fluorescence spectrometry (EDXRF) and spectrophotometry in the visible region (CIEL*a*b*color coordinates and spectral reflectance curves) were used to perform in situ fast analyses of the red and yellow motifs with portable equipment and to characterize their elemental composition and their colorimetric perception, respectively. According to the elemental composition, the intensity of the fluorescence iron signals in red and yellow motifs are higher than average values in the rock substrates. As expected, red motifs possess high values of the chromatic coordinate a* and yellow motifs possess high values of b*. This characterization was complemented with FT-IR analyses of microsamples detached from the red and yellow colored zones of a small set of plaquettes. Our results show that the artists used red and yellow pigments in the decoration likely derived from natural iron oxides as hematite and goethite. PMID:27732605

Modeling the kinetics of survival of Staphylococcus aureus in regional yogurt from goat's milk.

PubMed

Bednarko-Młynarczyk, E; Szteyn, J; Białobrzewski, I; Wiszniewska-Łaszczych, A; Liedtke, K

2015-01-01

The aim of this study was to determine the kinetics of the survival of the test strain of Staphylococcus aureus in the product investigated. Yogurt samples were contaminated with S. aure to an initial level of 10(3)-10(4) cfu/g. The samples were then stored at four temperatures: 4, 6, 20, 22°C. During storage, the number of S. aureus forming colonies in a gram of yogurt was determined every two hours. Based on the results of the analysis culture the curves of survival were plotted. Three primary models were selected to describe the kinetics of changes in the count of bacteria: Cole's model, a modified model of Gompertz and the model of Baranyi and Roberts. Analysis of the model fit carried out based on the average values of Pearson's correlation coefficient, between the modeled and measured values, showed that the Cole's model had the worst fit. The modified Gompertz model showed the count of S. aureus as a negative value. These drawbacks were not observed in the model of Baranyi and Roberts. For this reason, this model best reflects the kinetics of changes in the number of staphylococci in yogurt.

Reliability measurement for mixed mode failures of 33/11 kilovolt electric power distribution stations.

PubMed

Alwan, Faris M; Baharum, Adam; Hassan, Geehan S

2013-01-01

The reliability of the electrical distribution system is a contemporary research field due to diverse applications of electricity in everyday life and diverse industries. However a few research papers exist in literature. This paper proposes a methodology for assessing the reliability of 33/11 Kilovolt high-power stations based on average time between failures. The objective of this paper is to find the optimal fit for the failure data via time between failures. We determine the parameter estimation for all components of the station. We also estimate the reliability value of each component and the reliability value of the system as a whole. The best fitting distribution for the time between failures is a three parameter Dagum distribution with a scale parameter [Formula: see text] and shape parameters [Formula: see text] and [Formula: see text]. Our analysis reveals that the reliability value decreased by 38.2% in each 30 days. We believe that the current paper is the first to address this issue and its analysis. Thus, the results obtained in this research reflect its originality. We also suggest the practicality of using these results for power systems for both the maintenance of power systems models and preventive maintenance models.

Reliability Measurement for Mixed Mode Failures of 33/11 Kilovolt Electric Power Distribution Stations

PubMed Central

Alwan, Faris M.; Baharum, Adam; Hassan, Geehan S.

2013-01-01

The reliability of the electrical distribution system is a contemporary research field due to diverse applications of electricity in everyday life and diverse industries. However a few research papers exist in literature. This paper proposes a methodology for assessing the reliability of 33/11 Kilovolt high-power stations based on average time between failures. The objective of this paper is to find the optimal fit for the failure data via time between failures. We determine the parameter estimation for all components of the station. We also estimate the reliability value of each component and the reliability value of the system as a whole. The best fitting distribution for the time between failures is a three parameter Dagum distribution with a scale parameter and shape parameters and . Our analysis reveals that the reliability value decreased by 38.2% in each 30 days. We believe that the current paper is the first to address this issue and its analysis. Thus, the results obtained in this research reflect its originality. We also suggest the practicality of using these results for power systems for both the maintenance of power systems models and preventive maintenance models. PMID:23936346

A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain).

PubMed

Roldán García, Clodoaldo; Villaverde Bonilla, Valentín; Ródenas Marín, Isabel; Murcia Mascarós, Sonia

2016-01-01

In this work we analyze the pigments used in the decoration of red and yellow motifs present in the portable art of the Parpalló Cave (Gandía, Spain), one of the most important Palaeolithic sites in the Spanish Mediterranean region. Energy dispersive X-ray fluorescence spectrometry (EDXRF) and spectrophotometry in the visible region (CIEL*a*b*color coordinates and spectral reflectance curves) were used to perform in situ fast analyses of the red and yellow motifs with portable equipment and to characterize their elemental composition and their colorimetric perception, respectively. According to the elemental composition, the intensity of the fluorescence iron signals in red and yellow motifs are higher than average values in the rock substrates. As expected, red motifs possess high values of the chromatic coordinate a* and yellow motifs possess high values of b*. This characterization was complemented with FT-IR analyses of microsamples detached from the red and yellow colored zones of a small set of plaquettes. Our results show that the artists used red and yellow pigments in the decoration likely derived from natural iron oxides as hematite and goethite.

Area G Perimeter Surface-Soil and Single-Stage Water Sampling: Environmental Surveillance for Fiscal Years 1996 and 1997, Group ESH-19

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

Marquis Childs; Ron Conrad

1998-10-01

Area Gin Technical Area 54, has been the principal facility at Los Alamos National Laboratory for the storage and disposal of low-level, solid mixed, and transuranic radioactive waste since 1957. Soil samples were analyzed for tritium, isotopic plutonium, americium-241, and cesium-137. Thirteen metals-silver, arsenic, barium, beryllium, cadmium, chromium, mercury, nickel, lead, antimony, selenium, thallium and zinc-were analyzed on filtered-sediment fractions of the single-stage samples using standard analytical chemistry techniques. During the two years of sampling discussed in this report elevated levels of tritium (as high as 716,000 pCi/L) in soil were found for sampling sites adjacent to the tritium burialmore » shafts located on the south- central perimeter of Area G. Additionally, tritium concentrations in soil as high as 38,300 pCi/L were detected adjacent to the TRU pads in the northeast comer of Area G. Plutonium-238 activities in FY96 soils ranged from 0.001-2.866 pCi/g, with an average concentration of 0.336& 0.734 pCdg. Pu-238 activities in FY97 soils ranged from 0.002-4.890 pCi/g, with an average concentration of 0.437 & 0.928 pCdg. Pu-239 activities in FY96 soils ranged from 0.009 to 1.62 pCdg, with an average of 0.177- 0.297 pCdg. Pu-239 activities in FY97 soils ranged from 0.005 to 1.71 pCi/g, with an average of 0.290- 0.415 pCi/g. The locations of elevated plutonium readings were consistent with the history of plutonium disposal at Area G. The two areas of elevated Am-241 activity reflected the elevated activities found for plutonium, the average values for Am-241 on soils were 0.6-2.07 pCi/g, and 0.10-0.14 pCi/g respectively for samples collected in FY96 and FY97. CS-137 activities in soils had average values of 0.33 pCi/g, and 0.28 pCi/g respectively for samples collected in FY96 and 97. There was no perimeter area where soil concentrations of CS-137 were significantly elevated.« less

Measuring melittin uptake into hydrogel nanoparticles with near-infrared single nanoparticle surface plasmon resonance microscopy.

PubMed

Cho, Kyunghee; Fasoli, Jennifer B; Yoshimatsu, Keiichi; Shea, Kenneth J; Corn, Robert M

2015-01-01

This paper describes how changes in the refractive index of single hydrogel nanoparticles (HNPs) detected with near-infrared surface plasmon resonance microscopy (SPRM) can be used to monitor the uptake of therapeutic compounds for potential drug delivery applications. As a first example, SPRM is used to measure the specific uptake of the bioactive peptide melittin into N-isopropylacrylamide (NIPAm)-based HNPs. Point diffraction patterns in sequential real-time SPRM differential reflectivity images are counted to create digital adsorption binding curves of single 220 nm HNPs from picomolar nanoparticle solutions onto hydrophobic alkanethiol-modified gold surfaces. For each digital adsorption binding curve, the average single nanoparticle SPRM reflectivity response, ⟨Δ%RNP⟩, was measured. The value of ⟨Δ%RNP⟩ increased linearly from 1.04 ± 0.04 to 2.10 ± 0.10% when the melittin concentration in the HNP solution varied from zero to 2.5 μM. No change in the average HNP size in the presence of melittin is observed with dynamic light scattering measurements, and no increase in ⟨Δ%RNP⟩ is observed in the presence of either FLAG octapeptide or bovine serum albumin. Additional bulk fluorescence measurements of melittin uptake into HNPs are used to estimate that a 1% increase in ⟨Δ%RNP⟩ observed in SPRM corresponds to the incorporation of approximately 65000 molecules into each 220 nm HNP, corresponding to roughly 4% of its volume. The lowest detected amount of melittin loading into the 220 nm HNPs was an increase in ⟨Δ%RNP⟩ of 0.15%, corresponding to the absorption of 10000 molecules.

Near-infrared optical properties of ex-vivo human skin and subcutaneous tissues using reflectance and transmittance measurements

NASA Astrophysics Data System (ADS)

Simpson, Rebecca; Laufer, Jan G.; Kohl-Bareis, Matthias; Essenpreis, Matthias; Cope, Mark

1997-08-01

The vast majority of 'non-invasive' measurements of human tissues using near infrared spectroscopy rely on passing light through the dermis and subdermis of the skin. Accurate knowledge of the optical properties of these tissues is essential to put into models of light transport and predict the effects of skin perfusion on measurements of deep tissue. Additionally, the skin could be a useful accessible organ for non-invasively determining the constituents of blood flowing through it. Samples of abdominal human skin (including subdermal tissue) were obtained from either post mortem examinations or plastic surgery. The samples were separated into a dermal layer (epidermis and dermis, 1.5 to 2 mm tick), and a sub-cutaneous layer comprised largely of fat. They were enclosed between two glass coverslips and placed in an integrating sphere to measure their reflectance and transmittance over a range of wavelengths from 600 to 1000 nm. The reflectance and transmittance values were converted into average absorption and reduced scattering coefficients by comparison with a Monte Carlo model of light transport. Improvements to the Monte Carlo model and measurement technique removed some previous uncertainties. The results show excellent separation of reduced scattering and absorption coefficient, with clear absorption peaks of hemoglobin, water and lipid. The effect of tissue storage upon measured optical properties was investigated.

The Journal Impact Factor: Moving Toward an Alternative and Combined Scientometric Approach

PubMed Central

Nurmashev, Bekaidar

2017-01-01

The Journal Impact Factor (JIF) is a single citation metric, which is widely employed for ranking journals and choosing target journals, but is also misused as the proxy of the quality of individual articles and academic achievements of authors. This article analyzes Scopus-based publication activity on the JIF and overviews some of the numerous misuses of the JIF, global initiatives to overcome the ‘obsession’ with impact factors, and emerging strategies to revise the concept of the scholarly impact. The growing number of articles on the JIF, most of which are in English, reflects interest of experts in journal editing and scientometrics toward its uses, misuses, and options to overcome related problems. Solely displaying values of the JIFs on the journal websites is criticized by experts as these average metrics do not reflect skewness of citation distribution of individual articles. Emerging strategies suggest to complement the JIFs with citation plots and alternative metrics, reflecting uses of individual articles in terms of downloads and distribution of related information through social media and networking platforms. It is also proposed to revise the original formula of the JIF calculation and embrace the concept of the impact and importance of individual articles. The latter is largely dependent on ethical soundness of the journal instructions, proper editing and structuring of articles, efforts to promote related information through social media, and endorsements of professional societies. PMID:28049225

The Journal Impact Factor: Moving Toward an Alternative and Combined Scientometric Approach.

PubMed

Gasparyan, Armen Yuri; Nurmashev, Bekaidar; Yessirkepov, Marlen; Udovik, Elena E; Baryshnikov, Aleksandr A; Kitas, George D

2017-02-01

The Journal Impact Factor (JIF) is a single citation metric, which is widely employed for ranking journals and choosing target journals, but is also misused as the proxy of the quality of individual articles and academic achievements of authors. This article analyzes Scopus-based publication activity on the JIF and overviews some of the numerous misuses of the JIF, global initiatives to overcome the 'obsession' with impact factors, and emerging strategies to revise the concept of the scholarly impact. The growing number of articles on the JIF, most of which are in English, reflects interest of experts in journal editing and scientometrics toward its uses, misuses, and options to overcome related problems. Solely displaying values of the JIFs on the journal websites is criticized by experts as these average metrics do not reflect skewness of citation distribution of individual articles. Emerging strategies suggest to complement the JIFs with citation plots and alternative metrics, reflecting uses of individual articles in terms of downloads and distribution of related information through social media and networking platforms. It is also proposed to revise the original formula of the JIF calculation and embrace the concept of the impact and importance of individual articles. The latter is largely dependent on ethical soundness of the journal instructions, proper editing and structuring of articles, efforts to promote related information through social media, and endorsements of professional societies.

Interfaces in Si/Ge atomic layer superlattices on (001)Si: Effect of growth temperature and wafer misorientation

NASA Astrophysics Data System (ADS)

Baribeau, J.-M.; Lockwood, D. J.; Syme, R. W. G.

1996-08-01

We have used x-ray diffraction, specular reflectivity, and diffuse scattering, complemented by Raman spectroscopy, to study the interfaces in a series of (0.5 nm Ge/2 nm Si)50 atomic layer superlattices on (001)Si grown by molecular beam epitaxy in the temperature range 150-650 °C. X-ray specular reflectivity revealed that the structures have a well-defined periodicity with interface widths of about 0.2-0.3 nm in the 300-590 °C temperature range. Offset reflectivity scans showed that the diffuse scattering peaks at values of perpendicular wave vector transfer corresponding to the superlattice satellite peaks, indicating that the interfaces are vertically correlated. Transverse rocking scans of satellite peaks showed a diffuse component corresponding to an interface corrugation of typical length scale of ˜0.5 μm. The wavelength of the undulations is a minimum along the miscut direction and is typically 30-40 times larger than the surface average terrace width assuming monolayer steps, independently of the magnitude of the wafer misorientation. The amplitude of the undulation evolves with growth temperature and is minimum for growth at ˜460 °C and peaks at ˜520 °C. Raman scattering showed the chemical abruptness of the interfaces at low growth temperatures and indicated a change in the growth mode near 450 °C.

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2014 CFR

2014-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

40 CFR 439.52 - Effluent limitations attainable by the application of the best practicable control technology...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., kg) per day, must reflect not less than 74 percent reduction in the long-term average daily COD load... long-term average daily BOD5 or COD mass loading of the raw process wastewater (i.e., the base number..., calculation of the long-term average daily BOD5 or COD load in the influent to the wastewater treatment system...

Continuous Record of Permeability inside the Wenchuan Earthquake Fault Zone

NASA Astrophysics Data System (ADS)

Xue, Lian; Li, Haibing; Brodsky, Emily

2013-04-01

Faults are complex hydrogeological structures which include a highly permeable damage zone with fracture-dominated permeability. Since fractures are generated by earthquakes, we would expect that in the aftermath of a large earthquake, the permeability would be transiently high in a fault zone. Over time, the permeability may recover due to a combination of chemical and mechanical processes. However, the in situ fault zone hydrological properties are difficult to measure and have never been directly constrained on a fault zone immediately after a large earthquake. In this work, we use water level response to solid Earth tides to constrain the hydraulic properties inside the Wenchuan Earthquake Fault Zone. The transmissivity and storage determine the phase and amplitude response of the water level to the tidal loading. By measuring phase and amplitude response, we can constrain the average hydraulic properties of the damage zone at 800-1200 m below the surface (~200-600 m from the principal slip zone). We use Markov chain Monte Carlo methods to evaluate the phase and amplitude responses and the corresponding errors for the largest semidiurnal Earth tide M2 in the time domain. The average phase lag is ~ 30o, and the average amplitude response is 6×10-7 strain/m. Assuming an isotropic, homogenous and laterally extensive aquifer, the average storage coefficient S is 2×10-4 and the average transmissivity T is 6×10-7 m2 using the measured phase and the amplitude response. Calculation for the hydraulic diffusivity D with D=T/S, yields the reported value of D is 3×10-3 m2/s, which is two orders of magnitude larger than pump test values on the Chelungpu Fault which is the site of the Mw 7.6 Chi-Chi earthquake. If the value is representative of the fault zone, then this means the hydrology processes should have an effect on the earthquake rupture process. This measurement is done through continuous monitoring and we could track the evolution for hydraulic properties after Wenchuan earthquake. We observed the permeability decreases 35% per year. For the purpose of comparison, we convert the permeability measurements to into equivalent seismic velocity. The possible range of seismic wave velocity increase is 0.03%~ 0.8% per year. Our results are comparable to the results of the previous hydraulic and seismic studies after earthquakes. This temporal decrease of permeability may reflect the healing process after Wenchuan Earthquake.

Continuous Record of Permeability inside the Wenchuan Earthquake Fault Zone

NASA Astrophysics Data System (ADS)

Xue, L.; Li, H.; Brodsky, E. E.; Wang, H.; Pei, J.

2012-12-01

Faults are complex hydrogeological structures which include a highly permeable damage zone with fracture-dominated permeability. Since fractures are generated by earthquakes, we would expect that in the aftermath of a large earthquake, the permeability would be transiently high in a fault zone. Over time, the permeability may recover due to a combination of chemical and mechanical processes. However, the in situ fault zone hydrological properties are difficult to measure and have never been directly constrained on a fault zone immediately after a large earthquake. In this work, we use water level response to solid Earth tides to constrain the hydraulic properties inside the Wenchuan Earthquake Fault Zone. The transmissivity and storage determine the phase and amplitude response of the water level to the tidal loading. By measuring phase and amplitude response, we can constrain the average hydraulic properties of the damage zone at 800-1200 m below the surface (˜200-600 m from the principal slip zone). We use Markov chain Monte Carlo methods to evaluate the phase and amplitude responses and the corresponding errors for the largest semidiurnal Earth tide M2 in the time domain. The average phase lag is ˜30°, and the average amplitude response is 6×10-7 strain/m. Assuming an isotropic, homogenous and laterally extensive aquifer, the average storage coefficient S is 2×10-4 and the average transmissivity T is 6×10-7 m2 using the measured phase and the amplitude response. Calculation for the hydraulic diffusivity D with D=T/S, yields the reported value of D is 3×10-3 m2/s, which is two orders of magnitude larger than pump test values on the Chelungpu Fault which is the site of the Mw 7.6 Chi-Chi earthquake. If the value is representative of the fault zone, then this means the hydrology processes should have an effect on the earthquake rupture process. This measurement is done through continuous monitoring and we could track the evolution for hydraulic properties after Wenchuan earthquake. We observed the permeability decreases 35% per year. For the purpose of comparison, we convert the permeability measurements to into equivalent seismic velocity. The possible range of seismic wave velocity increase is 0.03%~ 0.8% per year. Our results are comparable to the results of the previous hydraulic and seismic studies after earthquakes. This temporal decrease of permeability may reflect the healing process after Wenchuan Earthquake.

The comparison of fossil carbon fraction and greenhouse gas emissions through an analysis of exhaust gases from urban solid waste incineration facilities.

PubMed

Kim, Seungjin; Kang, Seongmin; Lee, Jeongwoo; Lee, Seehyung; Kim, Ki-Hyun; Jeon, Eui-Chan

2016-10-01

In this study, in order to understand accurate calculation of greenhouse gas emissions of urban solid waste incineration facilities, which are major waste incineration facilities, and problems likely to occur at this time, emissions were calculated by classifying calculation methods into 3 types. For the comparison of calculation methods, the waste characteristics ratio, dry substance content by waste characteristics, carbon content in dry substance, and (12)C content were analyzed; and in particular, CO2 concentration in incineration gases and (12)C content were analyzed together. In this study, 3 types of calculation methods were made through the assay value, and by using each calculation method, emissions of urban solid waste incineration facilities were calculated then compared. As a result of comparison, with Calculation Method A, which used the default value as presented in the IPCC guidelines, greenhouse gas emissions were calculated for the urban solid waste incineration facilities A and B at 244.43 ton CO2/day and 322.09 ton CO2/day, respectively. Hence, it showed a lot of difference from Calculation Methods B and C, which used the assay value of this study. It is determined that this was because the default value as presented in IPCC, as the world average value, could not reflect the characteristics of urban solid waste incineration facilities. Calculation Method B indicated 163.31 ton CO2/day and 230.34 ton CO2/day respectively for the urban solid waste incineration facilities A and B; also, Calculation Method C indicated 151.79 ton CO2/day and 218.99 ton CO2/day, respectively. This study intends to compare greenhouse gas emissions calculated using (12)C content default value provided by the IPCC (Intergovernmental Panel on Climate Change) with greenhouse gas emissions calculated using (12)C content and waste assay value that can reflect the characteristics of the target urban solid waste incineration facilities. Also, the concentration and (12)C content were calculated by directly collecting incineration gases of the target urban solid waste incineration facilities, and greenhouse gas emissions of the target urban solid waste incineration facilities through this survey were compared with greenhouse gas emissions, which used the previously calculated assay value of solid waste.

No Measured Effect of a Familiar Contextual Object on Color Constancy.

PubMed

Kanematsu, Erika; Brainard, David H

2014-08-01

Some familiar objects have a typical color, such as the yellow of a banana. The presence of such objects in a scene is a potential cue to the scene illumination, since the light reflected from them should on average be consistent with their typical surface reflectance. Although there are many studies on how the identity of an object affects how its color is perceived, little is known about whether the presence of a familiar object in a scene helps the visual system stabilize the color appearance of other objects with respect to changes in illumination. We used a successive color matching procedure in three experiments designed to address this question. Across the experiments we studied a total of 6 subjects (2 in Experiment 1, 3 in Experiment 2, and 4 in Experiment 3) with partial overlap of subjects between experiments. We compared measured color constancy across conditions in which a familiar object cue to the illuminant was available with conditions in which such a cue was not present. Overall, our results do not reveal a reliable improvement in color constancy with the addition of a familiar object to a scene. An analysis of the experimental power of our data suggests that if there is such an effect, it is small: less than approximately a change of 0.09 in a constancy index where an absence of constancy corresponds to an index value of 0 and perfect constancy corresponds to an index value of 1.

Bulk hydrogen abundances in the lunar highlands: Measurements from orbital neutron data

NASA Astrophysics Data System (ADS)

Lawrence, David J.; Peplowski, Patrick N.; Plescia, Jeffrey B.; Greenhagen, Benjamin T.; Maurice, Sylvestre; Prettyman, Thomas H.

2015-07-01

The first map of bulk hydrogen concentrations in the lunar highlands region is reported. This map is derived using data from the Lunar Prospector Neutron Spectrometer (LP-NS). We resolve prior ambiguities in the interpretation of LP-NS data with respect to non-polar hydrogen concentrations by comparing the LP-NS data with maps of the 750 nm albedo reflectance, optical maturity, and the wavelength position of the thermal infrared Christiansen Feature. The best explanation for the variations of LP-NS epithermal neutron data in the lunar highlands is variable amounts of solar-wind-implanted hydrogen. The average hydrogen concentration across the lunar highlands and away from the lunar poles is 65 ppm. The highest hydrogen values range from 120 ppm to just over 150 ppm. These values are consistent with the range of hydrogen concentrations from soils and regolith breccias at the Apollo 16 highlands landing site. Based on a moderate-to-strong correlation of epithermal neutrons and orbit-based measures of surface maturity, the map of highlands hydrogen concentration represents a new global maturity index that can be used for studies of the lunar soil maturation process. We interpret these hydrogen concentrations to represent a bulk soil property related to the long-term impact of the space environment on the lunar surface. Consequently, the derived hydrogen concentrations are not likely related to the surficial enhancements (top tens to hundreds of microns) or local time variations of OH/H2O measured with spectral reflectance data.

Optical Coherence Tomography of the Labial Salivary Glands Reveals Age‐Related Differences in Women

PubMed Central

Grulkowski, Ireneusz; Karnowski, Karol; Wojtkowski, Maciej; Walkowiak, Jaroslaw

2015-01-01

Abstract The labial minor salivary glands (LSGs) play a role in medical research and practice due to their superficial location and involvement in both systemic and localized diseases. Swept‐source optical coherence tomography (OCT) is a noninvasive modality that enables in vivo, micrometer resolution, wide‐field three‐dimensional imaging in seconds. A purpose‐built swept‐source OCT instrument was employed to acquire three‐dimensional datasets covering the area of 2.43 cm2 of the mucosa of the lower lip to the depth of 3.4 mm in young (n = 14; mean age ± SD: 27 ± 3 years; body mass index [BMI] 20.4 ± 2.3 kg/m2) and middle‐aged women (n = 11; 54 ± 6 years; 25.5 ± 3.2 kg/m2). Glandular tissue reflectivity mode (range 0–255; 86 ± 17 vs. 68 ± 12, p = 0.005), average single LSG area in tissue sample (5.26 ± 2.62 mm2 vs. 2.87 ± 1.26 mm2, p = 0.011), and LSG surface filling factor (0.23 ± 0.13 vs. 0.11 ± 0.10, p = 0.027) had higher values in younger than in middle‐aged women. A correlation between BMI and glandular tissue reflectivity mode (Spearman's ρ = –0.60) was found (p = 0.002). The results highlight the potential value of LSGs’ OCT morphometry in research regarding ageing. PMID:26530049

No Measured Effect of a Familiar Contextual Object on Color Constancy

PubMed Central

Kanematsu, Erika; Brainard, David H.

2013-01-01

Some familiar objects have a typical color, such as the yellow of a banana. The presence of such objects in a scene is a potential cue to the scene illumination, since the light reflected from them should on average be consistent with their typical surface reflectance. Although there are many studies on how the identity of an object affects how its color is perceived, little is known about whether the presence of a familiar object in a scene helps the visual system stabilize the color appearance of other objects with respect to changes in illumination. We used a successive color matching procedure in three experiments designed to address this question. Across the experiments we studied a total of 6 subjects (2 in Experiment 1, 3 in Experiment 2, and 4 in Experiment 3) with partial overlap of subjects between experiments. We compared measured color constancy across conditions in which a familiar object cue to the illuminant was available with conditions in which such a cue was not present. Overall, our results do not reveal a reliable improvement in color constancy with the addition of a familiar object to a scene. An analysis of the experimental power of our data suggests that if there is such an effect, it is small: less than approximately a change of 0.09 in a constancy index where an absence of constancy corresponds to an index value of 0 and perfect constancy corresponds to an index value of 1. PMID:25313267

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

NASA Astrophysics Data System (ADS)

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

2015-05-01

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

Provenance, tectonic setting and source-area weathering of the lower Cambrian sediments of the Parahio valley in the Spiti basin, India

NASA Astrophysics Data System (ADS)

Pandey, Shivani; Parcha, Suraj K.

2017-03-01

The geochemical study of siliciclastic rocks from the Lower Cambrian of Parahio Valley has been studied to describe the provenance, chemical weathering and tectonic setting. The K2O/Al2O3 ratio and positive correlation of Co ( r=0.85), Ni ( r=0.86), Zn ( r=0.82), Rb ( r=0.98) with K2O reflects that the presence of clay minerals control the abundances of these elements and suggests a warm and humid climate for this region. The chondrite normalized REE pattern of the samples is equivalent to upper continental crust, which reflects enriched LREE and flat HREE with negative Eu anomaly. The tectonic setting discriminant diagram log[K2O/Na2O] vs. SiO2; [SiO2/Al2O3] vs. log[K2O/Na2O]; [SiO2/20] - [K2O+Na2O] - [TiO2+Fe2O3+MgO] indicates transitional tectonic setting from an active continental margin to a passive margin. The discriminant function plot indicates quartzose sedimentary provenance, and to some extent, the felsic igneous provenance, derived from weathered granite, gneissic terrain and/or from pre-existing sedimentary terrain. The CIA value indicates low to moderate degree of chemical weathering and the average ICV values suggests immature sediments deposited in tectonically active settings. The A-CN-K diagram indicates that these sediments were generated from source rocks of the upper continental crust.

Behavioral economic analysis of drug preference using multiple choice procedure data.

PubMed

Greenwald, Mark K

2008-01-11

The multiple choice procedure has been used to evaluate preference for psychoactive drugs, relative to money amounts (price), in human subjects. The present re-analysis shows that MCP data are compatible with behavioral economic analysis of drug choices. Demand curves were constructed from studies with intravenous fentanyl, intramuscular hydromorphone and oral methadone in opioid-dependent individuals; oral d-amphetamine, oral MDMA alone and during fluoxetine treatment, and smoked marijuana alone or following naltrexone pretreatment in recreational drug users. For each participant and dose, the MCP crossover point was converted into unit price (UP) by dividing the money value ($) by the drug dose (mg/70kg). At the crossover value, the dose ceases to function as a reinforcer, so "0" was entered for this and higher UPs to reflect lack of drug choice. At lower UPs, the dose functions as a reinforcer and "1" was entered to reflect drug choice. Data for UP vs. average percent choice were plotted in log-log space to generate demand functions. Rank of order of opioid inelasticity (slope of non-linear regression) was: fentanyl>hydromorphone (continuing heroin users)>methadone>hydromorphone (heroin abstainers). Rank order of psychostimulant inelasticity was d-amphetamine>MDMA>MDMA+fluoxetine. Smoked marijuana was more inelastic with high-dose naltrexone. These findings show this method translates individuals' drug preferences into estimates of population demand, which has the potential to yield insights into pharmacotherapy efficacy, abuse liability assessment, and individual differences in susceptibility to drug abuse.

Behavioral Economic Analysis of Drug Preference Using Multiple Choice Procedure Data

PubMed Central

Greenwald, Mark K.

2008-01-01

The Multiple Choice Procedure has been used to evaluate preference for psychoactive drugs, relative to money amounts (price), in human subjects. The present re-analysis shows that MCP data are compatible with behavioral economic analysis of drug choices. Demand curves were constructed from studies with intravenous fentanyl, intramuscular hydromorphone and oral methadone in opioid-dependent individuals; oral d-amphetamine, oral MDMA alone and during fluoxetine treatment, and smoked marijuana alone or following naltrexone pretreatment in recreational drug users. For each participant and dose, the MCP crossover point was converted into unit price (UP) by dividing the money value ($) by the drug dose (mg/70 kg). At the crossover value, the dose ceases to function as a reinforcer, so “0” was entered for this and higher UPs to reflect lack of drug choice. At lower UPs, the dose functions as a reinforcer and “1” was entered to reflect drug choice. Data for UP vs. average percent choice were plotted in log-log space to generate demand functions. Rank of order of opioid inelasticity (slope of non-linear regression) was: fentanyl > hydromorphone (continuing heroin users) > methadone > hydromorphone (heroin abstainers). Rank order of psychostimulant inelasticity was d-amphetamine > MDMA > MDMA + fluoxetine. Smoked marijuana was more inelastic with high-dose naltrexone. These findings show this method translates individuals’ drug preferences into estimates of population demand, which has the potential to yield insights into pharmacotherapy efficacy, abuse liability assessment, and individual differences in susceptibility to drug abuse. PMID:17949924

A satellite AOT derived from the ground sky transmittance measurements

NASA Astrophysics Data System (ADS)

Lim, H. S.; MatJafri, M. Z.; Abdullah, K.; Tan, K. C.; Wong, C. J.; Saleh, N. Mohd.

2008-10-01

The optical properties of aerosols such as smoke from burning vary due to aging processes and these particles reach larger sizes at high concentrations. The objectives of this study are to develop and evaluate an algorithm for estimating atmospheric optical thickness from Landsat TM image. This study measured the sky transmittance at the ground using a handheld spectroradiometer in a wide wavelength spectrum to retrieve atmospheric optical thickness. The in situ measurement of atmospheric transmittance data were collected simultaneously with the acquisition of remotely sensed satellite data. The digital numbers for the three visible bands corresponding to the in situ locations were extracted and then converted into reflectance values. The reflectance measured from the satellite was subtracted by the amount given by the surface reflectance to obtain the atmospheric reflectance. These atmospheric reflectance values were used for calibration of the AOT algorithm. This study developed an empirical method to estimate the AOT values from the sky transmittance values. Finally, a AOT map was generated using the proposed algorithm and colour-coded for visual interpretation.

Global Inventory and Characterization of Pyroclastic Deposits on Mercury: New Insights into Pyroclastic Activity from MESSENGER Orbital Data

NASA Technical Reports Server (NTRS)

Goudge, Timothy A.; Head, James W.; Kerber, Laura; Blewett, David T.; Denevi, Brett W.; Domingue, Deborah L.; Gillis-Davis, Jeffrey J.; Gwinner, Klaus; Helbert, Joern; Holsclaw, Gregory M.;

Comparisons of Reflectivities from the TRMM Precipitation Radar and Ground-Based Radars

NASA Technical Reports Server (NTRS)

Wang, Jianxin; Wolff, David B.

2008-01-01

Given the decade long and highly successful Tropical Rainfall Measuring Mission (TRMM), it is now possible to provide quantitative comparisons between ground-based radars (GRs) with the space-borne TRMM precipitation radar (PR) with greater certainty over longer time scales in various tropical climatological regions. This study develops an automated methodology to match and compare simultaneous TRMM PR and GR reflectivities at four primary TRMM Ground Validation (GV) sites: Houston, Texas (HSTN); Melbourne, Florida (MELB); Kwajalein, Republic of the Marshall Islands (KWAJ); and Darwin, Australia (DARW). Data from each instrument are resampled into a three-dimensional Cartesian coordinate system. The horizontal displacement during the PR data resampling is corrected. Comparisons suggest that the PR suffers significant attenuation at lower levels especially in convective rain. The attenuation correction performs quite well for convective rain but appears to slightly over-correct in stratiform rain. The PR and GR observations at HSTN, MELB and KWAJ agree to about 1 dB on average with a few exceptions, while the GR at DARW requires +1 to -5 dB calibration corrections. One of the important findings of this study is that the GR calibration offset is dependent on the reflectivity magnitude. Hence, we propose that the calibration should be carried out using a regression correction, rather than simply adding an offset value to all GR reflectivities. This methodology is developed towards TRMM GV efforts to improve the accuracy of tropical rain estimates, and can also be applied to the proposed Global Precipitation Measurement and other related activities over the globe.

Carbon and nitrogen isotopic compositions of particulate organic matter in four large river systems across the United States

USGS Publications Warehouse

Kendall, C.; Silva, S.R.; Kelly, V.J.

2001-01-01

Riverine particulate organic matter (POM) samples were collected bi-weekly to monthly from 40 sites in the Mississippi, Colorado, Rio Grande, and Columbia River Basins (USA) in 1996-97 and analysed for carbon and nitrogen stable isotopic compositions. These isotopic compositions and C : N ratios were used to identify four endmember sources of POM: Plankton, fresh terrestrial plant material, aquatic plants, and soil organic material. This large-scale study also incorporated ancillary chemical and hydrologic data to refine and extend the interpretations of POM sources beyond the source characterizations that could be done solely with isotopic and elemental ratios. The ancillary data were especially useful for differentiating between seasonal changes in POM source materials and the effects of local nutrient sources and in-stream biogeochemical processes. Average values of ??13 C and C : N for all four river systems suggested that plankton is the dominant source of POM in these rivers, with higher percentages of plankton downstream of reservoirs. Although the temporal patterns in some rivers are complex, the low ??13C and C : N values in spring and summer probably indicate plankton blooms, whereas relatively elevated values in fall and winter are consistent with greater proportions of decaying aquatic vegetation and/or terrestrial material. Seasonal shifts in the ??13C of POM when the C : N remains relatively constant probably indicate changes in the relative rates of photosynthesis and respiration. Periodic inputs of plant detritus are suggested by C : N ratios >15, principally on the Columbia and Ohio Rivers. The ??15N and ??13C also reflect the importance of internal and external sources of dissolved carbon and nitrogen, and the degree of in-stream processing. Elevated ??15N values at some sites probably reflect inputs from sewage and/or animal waste. This information on the spatial and temporal variation in sources of POM in four major river systems should prove useful in future food web and nutrient transport studies.

Temporal and spatial analysis of vegetation coverage changes in Ordos area based on time series GIMMS-NDVI data

NASA Astrophysics Data System (ADS)

Han, Ruimei; Zou, Youfeng; Ma, Chao; Liu, Pei

2014-11-01

Ordos area is the desert-wind erosion desertification steppe transition zone and the complex ecological zone. As the research area, Ordos City has the similar natural geographic environment to ShenDong coalfield. To research its ecological patterns and natural evolution law, it has instructive to reveal temporal and spatial changes of ecological environment with artificial disturbance in western mining. In this paper, a time series of AVHRR-NDVI(Normalized Difference Vegetation Index) data was used to monitor the change of vegetation temporal and spatial dynamics from 1981 to 2006 in Ordos City and ShenDong coalfield, where were as the research area. The MVC (Maximum Value Composites) method, average operation, linear regression, and gradation for NDVI change trend were used to obtained some results, as follows: ¬vegetation coverage had obvious characteristics with periodic change in research area for 26 years, and vegetation growth peak appeared on August, while the lowest appeared on January. The extreme values in Ordos City were 0.2351 and 0.1176, while they were 0.2657 and 0.1272 in ShenDong coalfield. The NDVI value fluctuation was a modest rise trend overall in research area. The extreme values were 0.3071 and 0.1861 in Ordos City, while they were 0.3454 and 0.1904 in ShenDong coalfield. In spatial distribution, slight improvement area and slight degradation area were accounting for 42.49% and 8.37% in Ordos City, while slight improvement area moderate improvement area were accounting for 70.59% and 29.41% in ShenDong coalfield. Above of results indicated there was less vegetation coverage in research area, which reflected the characteristics of fragile natural geographical environment. In addition, vegetation coverage was with a modest rise on the whole, which reflected the natural environment change.

42 CFR 423.286 - Rules regarding premiums.

Code of Federal Regulations, 2010 CFR

2010-10-01

... in paragraphs (d)(3) and (e) of this section, and with regard to employer group waivers, the monthly... difference between the bid and the national average monthly bid amount, any supplemental benefits and for any... adjusted to reflect any of the following scenarios, if applicable. (1) Adjustment to reflect difference...

47 CFR 73.310 - FM technical definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... The term “center frequency” means: (1) The average frequency of the emitted wave when modulated by a sinusoidal signal. (2) The frequency of the emitted wave without modulation. Composite antenna pattern. The... exist at a point in the absence of waves reflected from the earth or other reflecting objects. Frequency...

Effect of four different reflective barriers on black-globe temperatures in calf hutches

NASA Astrophysics Data System (ADS)

Friend, T. H.; Haberman, J. A.; Binion, W. R.

2014-12-01

Polyethylene hutches are a popular method of housing dairy calves from 0 to 60 or more days of age, although these hutches get hot when in full sun. This study characterized the relative differences in the ability of four different types of radiant barriers to reduce black-globe temperature within these hutches. Treatments included three different types of covers (two types of laminates (Cadpak P and Cadpak ESD) and an aluminized 3.0-mil white low-density polyethylene (LDPE)) and a reflective paint (LO/MIT-1). The reflective covers were 1.8 × 3 m finished size, and covered the top and sides of the hutch down to 0.15 m above the ground, leaving the front and back exposed. The LO/MIT-1 paint covered the entire sides and roof of the hutch. Two 24-h trials 1 week apart were conducted during relatively hot and clear days in early August. Black-globe temperatures were recorded in duplicate and averaged at 20-min intervals using blackened table tennis balls mounted 0.3 m above the floor in the center of each hutch. Ambient temperature (shade) during the hottest 2-h period for both trials averaged 39.9 °C while the uncovered control averaged 41.1 °C, and LO/MIT-1 averaged 39.9 °C; both of which were significantly higher ( P < 0.01) than the Cadpak P (38.9 °C), Cadpak ESD (38.6 °C), and aluminized LDPE (38.7 °C). During periods of high solar radiation, the hutches with covers had lowest black-globe temperatures followed by hutches painted with reflective paint, while control hutches had the highest temperature.