Usefulness of cancer-free survival in estimating the lifetime attributable risk of cancer incidence from radiation exposure.

PubMed

Seo, Songwon; Lee, Dal Nim; Jin, Young Woo; Lee, Won Jin; Park, Sunhoo

2018-05-11

Risk projection models estimating the lifetime cancer risk from radiation exposure are generally based on exposure dose, age at exposure, attained age, gender and study-population-specific factors such as baseline cancer risks and survival rates. Because such models have mostly been based on the Life Span Study cohort of Japanese atomic bomb survivors, the baseline risks and survival rates in the target population should be considered when applying the cancer risk. The survival function used in the risk projection models that are commonly used in the radiological protection field to estimate the cancer risk from medical or occupational exposure is based on all-cause mortality. Thus, it may not be accurate for estimating the lifetime risk of high-incidence but not life-threatening cancer with a long-term survival rate. Herein, we present the lifetime attributable risk (LAR) estimates of all solid cancers except thyroid cancer, thyroid cancer, and leukemia except chronic lymphocytic leukemia in South Korea for lifetime exposure to 1 mGy per year using the cancer-free survival function, as recently applied in the Fukushima health risk assessment by the World Health Organization. Compared with the estimates of LARs using an overall survival function solely based on all-cause mortality, the LARs of all solid cancers except thyroid cancer, and thyroid cancer evaluated using the cancer-free survival function, decreased by approximately 13% and 1% for men and 9% and 5% for women, respectively. The LAR of leukemia except chronic lymphocytic leukemia barely changed for either gender owing to the small absolute difference between its incidence and mortality. Given that many cancers have a high curative rate and low mortality rate, using a survival function solely based on all-cause mortality may cause an overestimation of the lifetime risk of cancer incidence. The lifetime fractional risk was robust against the choice of survival function.

What Does the Right Hemisphere Know about Phoneme Categories?

ERIC Educational Resources Information Center

Wolmetz, Michael; Poeppel, David; Rapp, Brenda

2011-01-01

Innate auditory sensitivities and familiarity with the sounds of language give rise to clear influences of phonemic categories on adult perception of speech. With few exceptions, current models endorse highly left-hemisphere-lateralized mechanisms responsible for the influence of phonemic category on speech perception, based primarily on results…

Megaregolith insulation, internal temperatures, and bulk uranium content of the moon

NASA Technical Reports Server (NTRS)

Warren, Paul H.; Rasmussen, Kaare L.

1986-01-01

Finite-difference models are used to study the effects of insulation by the megaregolith on lunar thermal evolution. Results indicate that the megaregolith has two important influences on heat flow: (1) Because the megaregolith is exceptionally thin in mare regions, heat passes more readily through them than through highland regions, and even flows laterally from the highland toward the mare. As a result, heat flow is exceptionally high along a boundary between highland and mare regions. (2) On a global scale, megaregolith insulation combined with lithosphere insulation causes slow cooling, which as a cumulative effect results in high present-day mantle temperatures and heat flow. Assuming that the global mean megaregolith thickness is 2 km, a heat flow of 12 mW/sq m is best matched by models with bulk moon U contents of 20-21 ng/g. Independent constraints on lunar internal temperatures derived from magnetic and tectonic data are best matched by models with about 14 ng/g U. Thus the bulk moon U content is roughly 17 ng/g. These results imply that the bulk moon contents of U, and related refractory lithophile elements such as Th, Al, Ca, etc., must be considerably lower than commonly assumed.

Mortality Trajectories at Exceptionally High Ages: A Study of Supercentenarians

PubMed Central

Gavrilova, Natalia S.; Gavrilov, Leonid A.; Krut'ko, Vyacheslav N.

2017-01-01

The growing number of persons surviving to age 100 years and beyond raises questions about the shape of mortality trajectories at exceptionally high ages, and this problem may become significant for actuaries in the near future. However, such studies are scarce because of the difficulties in obtaining reliable age estimates at exceptionally high ages. The current view about mortality beyond age 110 years suggests that death rates do not grow with age and are virtually flat. The same assumption is made in the new actuarial VBT tables. In this paper, we test the hypothesis that the mortality of supercentenarians (persons living 110+ years) is constant and does not grow with age, and we analyze mortality trajectories at these exceptionally high ages. Death records of supercentenarians were taken from the International Database on Longevity (IDL). All ages of supercentenarians in the database were subjected to careful validation. We used IDL records for persons belonging to extinct birth cohorts (born before 1895) since the last deaths in IDL were observed in 2007. We also compared our results based on IDL data with a more contemporary database maintained by the Gerontology Research Group (GRG). First we attempted to replicate findings by Gampe (2010), who analyzed IDL data and came to the conclusion that “human mortality after age 110 is flat.” We split IDL data into two groups: cohorts born before 1885 and cohorts born in 1885 and later. Hazard rate estimates were conducted using the standard procedure available in Stata software. We found that mortality in both groups grows with age, although in older cohorts, growth was slower compared with more recent cohorts and not statistically significant. Mortality analysis of more numerous 1884–1894 birth cohort with the Akaike goodness-of-fit criterion showed better fit for the Gompertz model than for the exponential model (flat mortality). Mortality analyses with GRG data produced similar results. The remaining life expectancy for the 1884–1894 birth cohort demonstrates rapid decline with age. This decline is similar to the computer-simulated trajectory expected for the Gompertz model, rather than the extremely slow decline in the case of the exponential model. These results demonstrate that hazard rates after age 110 years do not stay constant and suggest that mortality deceleration at older ages is not a universal phenomenon. These findings may represent a challenge to the existing theories of aging and longevity, which predict constant mortality in the late stages of life. One possibility for reconciliation of the observed phenomenon and the existing theoretical consideration is a possibility of mortality deceleration and mortality plateau at very high yet unobservable ages. PMID:29170764

Mortality Trajectories at Exceptionally High Ages: A Study of Supercentenarians.

PubMed

Gavrilova, Natalia S; Gavrilov, Leonid A; Krut'ko, Vyacheslav N

2017-01-01

The growing number of persons surviving to age 100 years and beyond raises questions about the shape of mortality trajectories at exceptionally high ages, and this problem may become significant for actuaries in the near future. However, such studies are scarce because of the difficulties in obtaining reliable age estimates at exceptionally high ages. The current view about mortality beyond age 110 years suggests that death rates do not grow with age and are virtually flat. The same assumption is made in the new actuarial VBT tables. In this paper, we test the hypothesis that the mortality of supercentenarians (persons living 110+ years) is constant and does not grow with age, and we analyze mortality trajectories at these exceptionally high ages. Death records of supercentenarians were taken from the International Database on Longevity (IDL). All ages of supercentenarians in the database were subjected to careful validation. We used IDL records for persons belonging to extinct birth cohorts (born before 1895) since the last deaths in IDL were observed in 2007. We also compared our results based on IDL data with a more contemporary database maintained by the Gerontology Research Group (GRG). First we attempted to replicate findings by Gampe (2010), who analyzed IDL data and came to the conclusion that "human mortality after age 110 is flat." We split IDL data into two groups: cohorts born before 1885 and cohorts born in 1885 and later. Hazard rate estimates were conducted using the standard procedure available in Stata software. We found that mortality in both groups grows with age, although in older cohorts, growth was slower compared with more recent cohorts and not statistically significant. Mortality analysis of more numerous 1884-1894 birth cohort with the Akaike goodness-of-fit criterion showed better fit for the Gompertz model than for the exponential model (flat mortality). Mortality analyses with GRG data produced similar results. The remaining life expectancy for the 1884-1894 birth cohort demonstrates rapid decline with age. This decline is similar to the computer-simulated trajectory expected for the Gompertz model, rather than the extremely slow decline in the case of the exponential model. These results demonstrate that hazard rates after age 110 years do not stay constant and suggest that mortality deceleration at older ages is not a universal phenomenon. These findings may represent a challenge to the existing theories of aging and longevity, which predict constant mortality in the late stages of life. One possibility for reconciliation of the observed phenomenon and the existing theoretical consideration is a possibility of mortality deceleration and mortality plateau at very high yet unobservable ages.

The exceptional sigma model

NASA Astrophysics Data System (ADS)

Arvanitakis, Alex S.; Blair, Chris D. A.

2018-04-01

We detail the construction of the exceptional sigma model, which describes a string propagating in the "extended spacetime" of exceptional field theory. This is to U-duality as the doubled sigma model is to T-duality. Symmetry specifies the Weylinvariant Lagrangian uniquely and we show how it reduces to the correct 10-dimensional string Lagrangians. We also consider the inclusion of a Fradkin-Tseytlin (or generalised dilaton) coupling as well as a reformulation with dynamical tension.

A dislocation-based, strain–gradient–plasticity strengthening model for deformation processed metal–metal composites

DOE PAGES

Tian, Liang; Russell, Alan; Anderson, Iver

2014-01-03

Deformation processed metal–metal composites (DMMCs) are high-strength, high-electrical conductivity composites developed by severe plastic deformation of two ductile metal phases. The extraordinarily high strength of DMMCs is underestimated using the rule of mixture (or volumetric weighted average) of conventionally work-hardened metals. A dislocation-density-based, strain–gradient–plasticity model is proposed to relate the strain-gradient effect with the geometrically necessary dislocations emanating from the interface to better predict the strength of DMMCs. The model prediction was compared with our experimental findings of Cu–Nb, Cu–Ta, and Al–Ti DMMC systems to verify the applicability of the new model. The results show that this model predicts themore » strength of DMMCs better than the rule-of-mixture model. The strain-gradient effect, responsible for the exceptionally high strength of heavily cold worked DMMCs, is dominant at large deformation strain since its characteristic microstructure length is comparable with the intrinsic material length.« less

40 CFR 60.2770 - What information must I include in my annual report?

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Compliance Times for Commercial and Industrial Solid Waste Incineration Units Model Rule... inoperative, except for zero (low-level) and high-level checks. (3) The date, time, and duration that each... of control if any of the following occur. (1) The zero (low-level), mid-level (if applicable), or...

Expert Anticipatory Skill in Striking Sports: A Review and a Model

ERIC Educational Resources Information Center

Muller, Sean; Abernethy, Bruce

2012-01-01

Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this paper, we provide a review of the empirical evidence regarding expert interception in striking sports and propose a…

Characterization and diagenesis of strong-acid carboxyl groups in humic substances

USGS Publications Warehouse

Leenheer, J.A.; Wershaw, R. L.; Brown, G.K.; Reddy, M.M.

2003-01-01

A small fraction of carboxylic acid functional groups in humic substances are exceptionally acidic with pKa values as low as 0.5. A review of acid-group theory eliminated most models and explanations for these exceptionally acidic carboxyl groups. These acidic carboxyl groups in Suwannee River fulvic acid were enriched by a 2-stage fractionation process and the fractions were characterized by elemental, molecular-weight, and titrimetric analyses, and by infrared and 13C- and 1H-nuclear magnetic resonance spectrometry. An average structural model of the most acidic fraction derived from the characterization data indicated a high density of carboxyl groups clustered on oxygen-heterocycle alicyclic rings. Intramolecular H-bonding between adjacent carboxyl groups in these ring structures enhanced stabilization of the carboxylate anion which results in low pKa1 values. The standard, tetrahydrofuran tetracarboxylic acid, was shown to have similar acidity characteristics to the highly acidic fulvic acid fraction. The end products of 3 known diagenetic pathways for the formation of humic substances were shown to result in carboxyl groups clustered on oxygen-heterocycle alicyclic rings.

76 FR 19381 - Buy American Exceptions Under the American Recovery and Reinvestment Act of 2009

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-07

... Green High Rise Apartments. An exception was also granted to the Housing Authority of the City of Runge... work, using CFRFC grant funds, in connection with the Bowling Green High Rise Apartments. The exception...

What drives high flow events in the Swiss Alps? Recent developments in wavelet spectral analysis and their application to hydrology

NASA Astrophysics Data System (ADS)

Schaefli, B.; Maraun, D.; Holschneider, M.

2007-12-01

Extreme hydrological events are often triggered by exceptional co-variations of the relevant hydrometeorological processes and in particular by exceptional co-oscillations at various temporal scales. Wavelet and cross wavelet spectral analysis offers promising time-scale resolved analysis methods to detect and analyze such exceptional co-oscillations. This paper presents the state-of-the-art methods of wavelet spectral analysis, discusses related subtleties, potential pitfalls and recently developed solutions to overcome them and shows how wavelet spectral analysis, if combined to a rigorous significance test, can lead to reliable new insights into hydrometeorological processes for real-world applications. The presented methods are applied to detect potentially flood triggering situations in a high Alpine catchment for which a recent re-estimation of design floods encountered significant problems simulating the observed high flows. For this case study, wavelet spectral analysis of precipitation, temperature and discharge offers a powerful tool to help detecting potentially flood producing meteorological situations and to distinguish between different types of floods with respect to the prevailing critical hydrometeorological conditions. This opens very new perspectives for the analysis of model performances focusing on the occurrence and non-occurrence of different types of high flow events. Based on the obtained results, the paper summarizes important recommendations for future applications of wavelet spectral analysis in hydrology.

Bone Density and High Salt Diets in a Space Flight Model

NASA Technical Reports Server (NTRS)

Arnaud, S. B.; Navidi, M.; Liang, M. T. C.; Wolinsky, I.

1999-01-01

High salt diets accelerate bone loss with aging in patients with postmenopausal osteoporosis except when calcium supplementation is provided. We have observed that the decrease in mineral content of growing femurs in juvenile rats, exposed to a space flight model which unloads the hind limbs , is substantially less in animals fed excess salt. To determine whether excess dietary salt has the same effect on the skeleton of the mature animal whose response to unloading is increased resorption and bone loss rather than impaired growth, we carried out a metabolic study in mature rats with hindlimbs unloaded by tailsuspension.

An effective 2-band eg model of sulfur hydride H3S for high-Tc superconductivity

NASA Astrophysics Data System (ADS)

Nishiguchi, Kazutaka; Teranishi, Shingo; Miyao, Satoaki; Matsushita, Goh; Kusakabe, Koichi

To understand high transition temperature (Tc) superconductivity in sulfur hydride H3S, we propose an effective 2-band model having the eg symmetry as the minimal model for H3S. Two eg orbitals centered on a sulfur S atom are chosen for the smallest representation of relevant bands with the van-Hove singularity around the Fermi levels except for the Γ-centered small hole pockets by the sulfur 3 p orbitals. By using the maximally localized Wannier functions, we derive the minimal effective model preserving the body-centered cubic (bcc) crystal symmetry of the H3S phase having the highest Tc ( 203 K under pressures) among the other polymorphs of H3S.

40 CFR 86.1705-99 - General provisions; opt-in.

Code of Federal Regulations, 2011 CFR

2011-07-01

... National LEV extends only until model year 2004, except as provided in 40 CFR 86.1707. For the duration of... above. STATE's participation in National LEV extends until model year 2006, except as provided in 40 CFR... vehicles in model year 2004, 2005 or 2006, STATE's participation in National LEV extends only until model...

Asymptotic dynamics of the exceptional Bianchi cosmologies

NASA Astrophysics Data System (ADS)

Hewitt, C. G.; Horwood, J. T.; Wainwright, J.

2003-05-01

In this paper we give, for the first time, a qualitative description of the asymptotic dynamics of a class of non-tilted spatially homogeneous (SH) cosmologies, the so-called exceptional Bianchi cosmologies, which are of Bianchi type VI$_{-1/9}$. This class is of interest for two reasons. Firstly, it is generic within the class of non-tilted SH cosmologies, being of the same generality as the models of Bianchi types VIII and IX. Secondly, it is the SH limit of a generic class of spatially inhomogeneous $G_{2}$ cosmologies. Using the orthonormal frame formalism and Hubble-normalized variables, we show that the exceptional Bianchi cosmologies differ from the non-exceptional Bianchi cosmologies of type VI$_{h}$ in two significant ways. Firstly, the models exhibit an oscillatory approach to the initial singularity and hence are not asymptotically self-similar. Secondly, at late times, although the models are asymptotically self-similar, the future attractor for the vacuum-dominated models is the so-called Robinson-Trautman SH model instead of the vacuum SH plane wave models.

WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

NASA Astrophysics Data System (ADS)

Mendygral, P. J.; Radcliffe, N.; Kandalla, K.; Porter, D.; O'Neill, B. J.; Nolting, C.; Edmon, P.; Donnert, J. M. F.; Jones, T. W.

2017-02-01

We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.

High-Fidelity Modelng and Simulation for a High Flux Isotope Reactor Low-Enriched Uranium Core Design

DOE PAGES

Betzler, Benjamin R.; Chandler, David; Davidson, Eva E.; ...

2017-05-08

A high-fidelity model of the High Flux Isotope Reactor (HFIR) with a low-enriched uranium (LEU) fuel design and a representative experiment loading has been developed to serve as a new reference model for LEU conversion studies. With the exception of the fuel elements, this HFIR LEU model is completely consistent with the current highly enriched uranium HFIR model. Results obtained with the new LEU model provide a baseline for analysis of alternate LEU fuel designs and further optimization studies. The newly developed HFIR LEU model has an explicit representation of the HFIR-specific involute fuel plate geometry, including the within-plate fuelmore » meat contouring, and a detailed geometry model of the fuel element side plates. Such high-fidelity models are necessary to accurately account for the self-shielding from 238U and the depletion of absorber materials present in the side plates. In addition, a method was developed to account for fuel swelling in the high-density LEU fuel plates during the depletion simulation. In conclusion, calculated time-dependent metrics for the HFIR LEU model include fission rate and cumulative fission density distributions, flux and reaction rates for relevant experiment locations, point kinetics data, and reactivity coefficients.« less

High-Fidelity Modelng and Simulation for a High Flux Isotope Reactor Low-Enriched Uranium Core Design

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

Betzler, Benjamin R.; Chandler, David; Davidson, Eva E.

A high-fidelity model of the High Flux Isotope Reactor (HFIR) with a low-enriched uranium (LEU) fuel design and a representative experiment loading has been developed to serve as a new reference model for LEU conversion studies. With the exception of the fuel elements, this HFIR LEU model is completely consistent with the current highly enriched uranium HFIR model. Results obtained with the new LEU model provide a baseline for analysis of alternate LEU fuel designs and further optimization studies. The newly developed HFIR LEU model has an explicit representation of the HFIR-specific involute fuel plate geometry, including the within-plate fuelmore » meat contouring, and a detailed geometry model of the fuel element side plates. Such high-fidelity models are necessary to accurately account for the self-shielding from 238U and the depletion of absorber materials present in the side plates. In addition, a method was developed to account for fuel swelling in the high-density LEU fuel plates during the depletion simulation. In conclusion, calculated time-dependent metrics for the HFIR LEU model include fission rate and cumulative fission density distributions, flux and reaction rates for relevant experiment locations, point kinetics data, and reactivity coefficients.« less

[Effects of soybean isoflavone on born metabolism and morphology in animal model of osteoporosis rats].

PubMed

Yu, Qing; Su, Yi-xiang; Wang, Wen-wei; Li, An-le; Liu, Cun-li; Wang, Yi-long; Hu, Wan-li

2007-07-01

To study the effects of soybean isoflavone (SI) on born metabolism and morphology in animal model of osteoporosis rats. All 70 female Sprague-Dawley (SD) rats were randomly divided into 7 groups according to the levels of total cholesterol (TC) in serum: hyper-lipoid group, estrogen group, low-dose SI group, middle-dose SI group, high-dose SI group, sham group and normal control groups. Bilateral ovaries were extirpated except sham and normal control groups. Except the rats in normal control group, the other rats were fed with high fat diet. Body weight was weighted ad unam vice per week. The estrogen, different dose of SI or deionized water were fed with intragastric administration for 12 weeks. Vena caudalis serum were collected after being ovariectomized, administered for 4 w, 8 w and killed. Serum alkaline phosphatase (AKP) activity and bone density were measured etc. To interfere of estrogen and SI might recover AKP enzyme activity after its being ovariectomized. There almost sowed no differences between high dose SI intervention and estrogen on bone density and microstructure. Bone loss due to being ovariectomized was relieved after SI intervention. SI might protect cardiocyte myofilament and mitochondrial ultramicrostructure. There was mirror image in estrogen, high dose SI group resembling the normal control group, and there was obvious damage in hyper-lipoids group. There should be effects of high dose SI on bone metabolism and morphology in animal model of osteoporosis rats. Serum AKP enzyme activity and bone density should have significantly recovered, the serum level of calcium and phosphorus were maintained after high dose intervened but no significant effects for low dose of SI.

Mesoscale spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical model simulations

NASA Technical Reports Server (NTRS)

Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.

1988-01-01

It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation mesoscale model with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex.

Wing-Alone Aerodynamic Characteristics to High Angles of Attack at Subsonic and Transonic Speeds.

DTIC Science & Technology

1982-11-01

support subsystems, the test- ing of these models consumes a disproportionate amount of model construction effort and wind-tunnel testing time compared...constant taper ratio with the exception of the aspect ratio 4, taper ratio 0.5 wing at subsonic speeds; the anomalous behavior of this wing is likely...0000000 ...... 0 0 0i 010... 0.. .......... .. .............. tt.. 4t t * PS4 Oft* .. MM.~0o004.0 s.t~o.4

The Cerebellar Mossy Fiber Synapse as a Model for High-Frequency Transmission in the Mammalian CNS.

PubMed

Delvendahl, Igor; Hallermann, Stefan

2016-11-01

The speed of neuronal information processing depends on neuronal firing frequency. Here, we describe the evolutionary advantages and ubiquitous occurrence of high-frequency firing within the mammalian nervous system in general. The highest firing frequencies so far have been observed at the cerebellar mossy fiber to granule cell synapse. The mechanisms enabling high-frequency transmission at this synapse are reviewed and compared with other synapses. Finally, information coding of high-frequency signals at the mossy fiber synapse is discussed. The exceptionally high firing frequencies and amenability to high-resolution technical approaches both in vitro and in vivo establish the cerebellar mossy fiber synapse as an attractive model to investigate high-frequency signaling from the molecular up to the network level. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physical analysis and second-order modelling of an unsteady turbulent flow - The oscillating boundary layer on a flat plate

NASA Technical Reports Server (NTRS)

Ha Minh, H.; Viegas, J. R.; Rubesin, M. W.; Spalart, P.; Vandromme, D. D.

1989-01-01

The turbulent boundary layer under a freestream whose velocity varies sinusoidally in time around a zero mean is computed using two second order turbulence closure models. The time or phase dependent behavior of the Reynolds stresses are analyzed and results are compared to those of a previous SPALART-BALDWIN direct simulation. Comparisons show that the second order modeling is quite satisfactory for almost all phase angles, except in the relaminarization period where the computations lead to a relatively high wall shear stress.

Prediction of beef carcass and meat traits from rearing factors in young bulls and cull cows.

PubMed

Soulat, J; Picard, B; Léger, S; Monteils, V

2016-04-01

The aim of this study was to predict the beef carcass and LM (thoracis part) characteristics and the sensory properties of the LM from rearing factors applied during the fattening period. Individual data from 995 animals (688 young bulls and 307 cull cows) in 15 experiments were used to establish prediction models. The data concerned rearing factors (13 variables), carcass characteristics (5 variables), LM characteristics (2 variables), and LM sensory properties (3 variables). In this study, 8 prediction models were established: dressing percentage and the proportions of fat tissue and muscle in the carcass to characterize the beef carcass; cross-sectional area of fibers (mean fiber area) and isocitrate dehydrogenase activity to characterize the LM; and, finally, overall tenderness, juiciness, and flavor intensity scores to characterize the LM sensory properties. A random effect was considered in each model: the breed for the prediction models for the carcass and LM characteristics and the trained taste panel for the prediction of the meat sensory properties. To evaluate the quality of prediction models, 3 criteria were measured: robustness, accuracy, and precision. The model was robust when the root mean square errors of prediction of calibration and validation sub-data sets were near to one another. Except for the mean fiber area model, the obtained predicted models were robust. The prediction models were considered to have a high accuracy when the mean prediction error (MPE) was ≤0.10 and to have a high precision when the was the closest to 1. The prediction of the characteristics of the carcass from the rearing factors had a high precision ( > 0.70) and a high prediction accuracy (MPE < 0.10), except for the fat percentage model ( = 0.67, MPE = 0.16). However, the predictions of the LM characteristics and LM sensory properties from the rearing factors were not sufficiently precise ( < 0.50) and accurate (MPE > 0.10). Only the flavor intensity of the beef score could be satisfactorily predicted from the rearing factors with high precision ( = 0.72) and accuracy (MPE = 0.10). All the prediction models displayed different effects of the rearing factors according to animal categories (young bulls or cull cows). In consequence, these prediction models display the necessary adaption of rearing factors during the fattening period according to animal categories to optimize the carcass traits according to animal categories.

A Left-Hemisphere Model for Right-Hemisphere Programmers.

ERIC Educational Resources Information Center

Krantz, Gordon C.

The paper presents an action-and-decision (left-hemisphere) algorithm as a model for planning by holistic, intuitive (right-hemisphere) managers of service programs, including programs for exceptional children. Because the model is not based upon an established literature in the field of service to exceptional individuals, and because it appears…

Being Smart about Gifted Education: A Guidebook for Parents and Educators (2nd Edition)

ERIC Educational Resources Information Center

Matthews, Dona J.; Foster, Joanne F.

2009-01-01

Written for both parents and educators who work with children of advanced abilities, the authors present practical strategies to identify and nurture exceptionally high ability in children. They promote the "mastery" (rather than the "mystery") model of gifted education, and challenge several common practices and assumptions. They offer ways to…

78 FR 5148 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: General...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-24

..., except federal holidays. FOR FURTHER INFORMATION CONTACT: Joe Jacobsen, FAA, Airplane and Flight Crew... protection features include limitations on angle-of- attack, normal load factor, bank angle, pitch angle, and... characteristics, and High angle-of-attack. Section Sec. 25.143, however, does not adequately ensure that the novel...

σ 54-dependent regulome in Desulfovibrio vulgaris Hildenborough

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

Kazakov, Alexey E.; Rajeev, Lara; Chen, Amy

2015-11-10

The σ 54 subunit controls a unique class of promoters in bacteria. Such promoters, without exception, require enhancer binding proteins (EBPs) for transcription initiation. Desulfovibrio vulgaris Hildenborough, a model bacterium for sulfate reduction studies, has a high number of EBPs, more than most sequenced bacteria. Finally, the cellular processes regulated by many of these EBPs remain unknown.

Tank Tests of Models of Flying Boat Hulls Having Longitudinal Steps

NASA Technical Reports Server (NTRS)

Allison, John M; Ward, Kenneth E

1936-01-01

Four models with longitudinal steps on the forebody were developed by modification of a model of a conventional hull and were tested in the National Advisory Committee for Aeronautics (NACA) tank. Models with longitudinal steps were found to have smaller resistance at high speed and greater resistance at low speed than the parent model that had the same afterbody but a conventional V-section forebody. The models with a single longitudinal step had better performance at hump speed and as low high-speed resistance except at very light loads. Spray strips at angles from 0 degrees to 45 degrees to the horizontal were fitted at the longitudinal steps and at the chine on one of the two step models having two longitudinal steps. The resistance and the height of the spray were less with each of the spray strips than without; the most favorable angle was found to lie between 15 degrees and 30 degrees.

A comparison of the aerodynamic characteristics at transonic speeds of four wing-fuselage configurations as determined from different test techniques, 4 October 1960

NASA Technical Reports Server (NTRS)

Donlan, C. J.; Myers, B. C., II; Mattson, A. T.

1976-01-01

The high speed aerodynamic characteristics of a family of four wing-fuselage configurations of 0, 35, 45, and 60 deg sweepback were determined from transonic bump model tests that were conducted in the Langley high speed 7 by 10 foot tunnel; sting supported model tests were conducted in the Langley 8 foot high speed tunnel and in the Langley high speed 7 by 10 foot tunnel, and rocket model tests were conducted by the Langley Pilotless Aircraft Research Division. A complementary study of the effect of Mach number gradients and streamline curvature on bump results is also included. The qualitative data obtained from the various test facilities for the wing-fuselage configurations were in essential agreement as regards the relative effects of sweepback and Mach number except for drag at zero lift. Quantitatively, important differences were present.

Fatty Acid Oxidation Changes and the Correlation with Oxidative Stress in Different Preeclampsia-Like Mouse Models

PubMed Central

Ding, Xiaoyan; Yang, Zi; Han, Yiwei; Yu, Huan

2014-01-01

Background Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) expression is decreased in placenta of some cases of preeclampsia (PE) which may result in free fatty acid (FFA) increased. High FFA level will induce oxidative stress, so abnormal long-chain fatty acid-oxidation may participate in the pathogenesis of PE through oxidative stress pathway. Methods PE-like groups were ApoC3 transgenic mice with abnormal fatty acid metabolism, classical PE-like models with injection of Nw-nitro-L-arginine-methyl ester (L-NA) or lipopolysaccharide (LPS) and the antiphospholipid syndrome (APS) mouse model with β2GPI injection (ApoC3+NS, ApoC3+L-NA, L-NA, LPS and β2GPI groups). The control group was wild-type mice with normal saline injection. Except for β2GPI mice, the other mice were subdivided into pre-implantation (Pre) and mid-pregnancy (Mid) subgroups by injection time. Results All PE-like groups showed hypertension and proteinuria except ApoC3+NS mice only showed hypertension. Serum FFA levels increased significantly except in LPS group compared to controls (P<0.05). LCHAD mRNA and protein expression in the liver and placenta was significantly higher for ApoC3+NS, ApoC3+L-NA and β2GPI mice and lower for L-NA mice than controls (P<0.05) but did not differ between LPS mice and controls. P47phox mRNA and protein expression in the liver significantly increased in all PE-like groups except LPS group, while P47phox expression in the placenta only significantly increased in L-NA and β2GPI groups. Conclusions Abnormal long-chain fatty acid-oxidation may play a different role in different PE-like models and in some cases participate in the pathogenesis of PE through oxidative stress pathway. PMID:25302499

A Model of Twice-Exceptionality: Explaining and Defining the Apparent Paradoxical Combination of Disability and Giftedness in Childhood

ERIC Educational Resources Information Center

Ronksley-Pavia, Michelle

2015-01-01

The literature on twice-exceptionality suggests one of the main problems facing twice-exceptional children is that there is no consensus on the definition of the terms "disability" or "giftedness" and, consequently, the term "twice-exceptional". Endeavoring to define these specific terms loops back on itself to…

Individual reactions to high involvement work processes: investigating the role of empowerment and perceived organizational support.

PubMed

Butts, Marcus M; Vandenberg, Robert J; DeJoy, David M; Schaffer, Bryan S; Wilson, Mark G

2009-04-01

This study sought to understand how high involvement work processes (HIWP) are processed at the employee level. Using structural equation modeling techniques, the authors tested and supported a model in which psychological empowerment mediated the effects of HIWP on job satisfaction, organizational commitment, job performance, and job stress. Furthermore, perceived organizational support (POS) was hypothesized to moderate the relationships between empowerment and these outcomes. With exception for the empowerment-job satisfaction association, support was found for our predictions. Future directions for research and the practical implications of our findings for both employees and organizations are discussed.

A Regional Analysis of Non-Methane Hydrocarbons And Meteorology of The Rural Southeast United States

DTIC Science & Technology

1996-01-01

Zt is an ARIMA time series. This is a typical regression model , except that it allows for autocorrelation in the error term Z. In this work, an ARMA...data=folder; var residual; run; II Statistical output of 1992 regression model on 1993 ozone data ARIMA Procedure Maximum Likelihood Estimation Approx...at each of the sites, and to show the effect of synoptic meteorology on high ozone by examining NOAA daily weather maps and climatic data

Adapting Human Videofluoroscopic Swallow Study Methods to Detect and Characterize Dysphagia in Murine Disease Models

PubMed Central

Lever, Teresa E.; Braun, Sabrina M.; Brooks, Ryan T.; Harris, Rebecca A.; Littrell, Loren L.; Neff, Ryan M.; Hinkel, Cameron J.; Allen, Mitchell J.; Ulsas, Mollie A.

2015-01-01

This study adapted human videofluoroscopic swallowing study (VFSS) methods for use with murine disease models for the purpose of facilitating translational dysphagia research. Successful outcomes are dependent upon three critical components: test chambers that permit self-feeding while standing unrestrained in a confined space, recipes that mask the aversive taste/odor of commercially-available oral contrast agents, and a step-by-step test protocol that permits quantification of swallow physiology. Elimination of one or more of these components will have a detrimental impact on the study results. Moreover, the energy level capability of the fluoroscopy system will determine which swallow parameters can be investigated. Most research centers have high energy fluoroscopes designed for use with people and larger animals, which results in exceptionally poor image quality when testing mice and other small rodents. Despite this limitation, we have identified seven VFSS parameters that are consistently quantifiable in mice when using a high energy fluoroscope in combination with the new murine VFSS protocol. We recently obtained a low energy fluoroscopy system with exceptionally high imaging resolution and magnification capabilities that was designed for use with mice and other small rodents. Preliminary work using this new system, in combination with the new murine VFSS protocol, has identified 13 swallow parameters that are consistently quantifiable in mice, which is nearly double the number obtained using conventional (i.e., high energy) fluoroscopes. Identification of additional swallow parameters is expected as we optimize the capabilities of this new system. Results thus far demonstrate the utility of using a low energy fluoroscopy system to detect and quantify subtle changes in swallow physiology that may otherwise be overlooked when using high energy fluoroscopes to investigate murine disease models. PMID:25866882

WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

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

Mendygral, P. J.; Radcliffe, N.; Kandalla, K.

2017-02-01

We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it maymore » be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.« less

16 CFR Appendix B to Part 698 - Model Forms for Risk-Based Pricing and Credit Score Disclosure Exception Notices

Code of Federal Regulations, 2014 CFR

2014-01-01

... Credit Score Disclosure Exception Notices B Appendix B to Part 698 Commercial Practices FEDERAL TRADE COMMISSION THE FAIR CREDIT REPORTING ACT MODEL FORMS AND DISCLOSURES Pt. 698, App. B Appendix B to Part 698... set of circumstances as indicated by the title of that model form. 2. Model form B-1 is for use in...

The Voices of Youth: Perspectives and Recommendations from Young Adults Involved in Juvenile Corrections. Information Brief. Volume 5, Issue 2

ERIC Educational Resources Information Center

Stenhjem, Pam

2006-01-01

This brief describes two exceptional model programs for adjudicated youth with disabilities: Woodland Hills Residential Facility in Duluth, Minnesota and the Minnesota Correctional Facility-Walter McGinnis High School in Red Wing, Minnesota. The brief shares best practices from research about these programs as well as insight, commentary, and…

Freeboard reactions in fluidized coal combustion

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

Walsh, P.M.; Dutta, A.; Beer, J.M.

1984-05-11

The objective of this study was to determine the contribution of freeboard combustion to overall fixed carbon conversion during atmospheric pressure fluidized bed combustion of Kentucky No. 9 high volatile bituminous coal. The progress of the O/sub 2//char reaction in the freeboard was inferred from O/sub 2/ profiles determined by gas sampling. The rates of O/sub 2/ consumption were in good agreement with the O/sub 2//char rate expression of Sergeant and Smith (1973), except at the lowest temperature investigated (964 K). The discrepancy in this case might be due to catalysis of the O/sub 2//char reaction by lime, since thismore » was the first run of the series. Extrapolation of the O/sub 2/ profile to the bed surface using the rate expression of Sergeant and Smith showed that approximately all of the fixed carbon conversion could be accounted for by freeboard combustion. A simple model is proposed in which devolatilization, fragmentation, attrition, and volatile combustion are limited to the bed; with combustion of the finely ground char occurring only in the freeboard. This model predicts O/sub 2/ at the combustor outlet within 60% of the measured values, except in the low temperature/high lime case.« less

Collective Phase in Resource Competition in a Highly Diverse Ecosystem.

PubMed

Tikhonov, Mikhail; Monasson, Remi

2017-01-27

Organisms shape their own environment, which in turn affects their survival. This feedback becomes especially important for communities containing a large number of species; however, few existing approaches allow studying this regime, except in simulations. Here, we use methods of statistical physics to analytically solve a classic ecological model of resource competition introduced by MacArthur in 1969. We show that the nonintuitive phenomenology of highly diverse ecosystems includes a phase where the environment constructed by the community becomes fully decoupled from the outside world.

Giant ultrafast Kerr effect in superconductors

NASA Astrophysics Data System (ADS)

Robson, Charles W.; Fraser, Kieran A.; Biancalana, Fabio

2017-06-01

We study the ultrafast Kerr effect and high-harmonic generation in superconductors by formulating a model for a time-varying electromagnetic pulse normally incident on a thin-film superconductor. It is found that superconductors exhibit exceptionally large χ(3 ) due to the progressive destruction of Cooper pairs, and display high-harmonic generation at low incident intensities, and the highest nonlinear susceptibility of all known materials in the THz regime. Our theory opens up avenues for accessible analytical and numerical studies of the ultrafast dynamics of superconductors.

Exceptional motifs in different Markov chain models for a statistical analysis of DNA sequences.

PubMed

Schbath, S; Prum, B; de Turckheim, E

1995-01-01

Identifying exceptional motifs is often used for extracting information from long DNA sequences. The two difficulties of the method are the choice of the model that defines the expected frequencies of words and the approximation of the variance of the difference T(W) between the number of occurrences of a word W and its estimation. We consider here different Markov chain models, either with stationary or periodic transition probabilities. We estimate the variance of the difference T(W) by the conditional variance of the number of occurrences of W given the oligonucleotides counts that define the model. Two applications show how to use asymptotically standard normal statistics associated with the counts to describe a given sequence in terms of its outlying words. Sequences of Escherichia coli and of Bacillus subtilis are compared with respect to their exceptional tri- and tetranucleotides. For both bacteria, exceptional 3-words are mainly found in the coding frame. E. coli palindrome counts are analyzed in different models, showing that many overabundant words are one-letter mutations of avoided palindromes.

Oxygen-isotopic Compositions of Low-FeO relicts in High-FeO Host Chondrules in Acfer 094, a Type 3.0 Carbonaceous Chondrite Closely Related to CM

NASA Technical Reports Server (NTRS)

Rubin, Alan E.; Kunihiro, Tak; Wasson, John T.

2006-01-01

With one exception, the low-FeO relict olivine grains within high-FeO porphyritic chondrules in the type 3.0 Acfer 094 carbonaceous chondrite have DELTA O-17 ( = delta O-17 - 0.52 X delta O-18) values that are substantially more negative than those of the high-FeO olivine host materials. These results are similar to observations made earlier on chondrules in C03.0 chondrites and are consistent with two independent models: (1) Nebular solids evolved from low-FeO, low-DELTA O-17 compositions towards high-FeO, more positive DELTA O-17 compositions; and (2) the range of compositions resulted from the mixing of two independently formed components. The two models predict different trajectories on a DELTA O-17 vs. log Fe/Mg (olivine) diagram, but our sample set has too few values at intermediate Fe/Mg ratios to yield a definitive answer. Published data showing that Acfer 094 has higher volatile contents than CO chondrites suggest a closer link to CM chondrites. This is consistent with the high modal matrix abundance in Acfer 094 (49 vol.%). Acfer 094 may be an unaltered CM chondrite or an exceptionally matrix-rich CO chondrite. Chondrules in Acfer 094 and in CO and CM carbonaceous chondrites appear to sample the same population. Textural differences between Acfer 094 and CM chondrites are largely attributable to the high degree of hydrothermal alteration that the CM chondrites experienced in an asteroidal setting.

The Influence of Teacher Expectations about Twice-Exceptional Students on the Use of High Quality Gifted Curriculum: A Case Study Approach

ERIC Educational Resources Information Center

Missett, Tracy C.; Azano, Amy Price; Callahan, Carolyn M.; Landrum, Kimberly

2016-01-01

Twice-exceptional students show evidence of high academic performance or potential and also have a disability that impedes their ability to learn. Twice-exceptional students remain under-represented in gifted programs, and some researchers attribute such under-representation to the negative beliefs and low expectations about twice-exceptional…

34 CFR 300.102 - Limitation-exception to FAPE for certain ages.

Code of Federal Regulations, 2014 CFR

2014-07-01

... from high school with a regular high school diploma. (ii) The exception in paragraph (a)(3)(i) of this section does not apply to children who have graduated from high school but have not been awarded a regular high school diploma. (iii) Graduation from high school with a regular high school diploma constitutes a...

34 CFR 300.102 - Limitation-exception to FAPE for certain ages.

Code of Federal Regulations, 2012 CFR

2012-07-01

... from high school with a regular high school diploma. (ii) The exception in paragraph (a)(3)(i) of this section does not apply to children who have graduated from high school but have not been awarded a regular high school diploma. (iii) Graduation from high school with a regular high school diploma constitutes a...

34 CFR 300.102 - Limitation-exception to FAPE for certain ages.

Code of Federal Regulations, 2011 CFR

2011-07-01

... from high school with a regular high school diploma. (ii) The exception in paragraph (a)(3)(i) of this section does not apply to children who have graduated from high school but have not been awarded a regular high school diploma. (iii) Graduation from high school with a regular high school diploma constitutes a...

34 CFR 300.102 - Limitation-exception to FAPE for certain ages.

Code of Federal Regulations, 2013 CFR

2013-07-01

... from high school with a regular high school diploma. (ii) The exception in paragraph (a)(3)(i) of this section does not apply to children who have graduated from high school but have not been awarded a regular high school diploma. (iii) Graduation from high school with a regular high school diploma constitutes a...

Intake port

DOEpatents

Mendler, Edward Charles

2005-02-01

The volumetric efficiency and power of internal combustion engines is improved with an intake port having an intake nozzle, a venturi, and a surge chamber. The venturi is located almost halfway upstream the intake port between the intake valves and the intake plenum enabling the venturi throat diameter to be exceptionally small for providing an exceptionally high ram velocity and an exceptionally long and in turn high efficiency diffuser flowing into the surge chamber. The intake port includes an exceptionally large surge chamber volume for blow down of the intake air into the working cylinder of the engine.

United Network for Organ Sharing regional variations in appeal denial rates with non-standard Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease exceptions: support for a national review board.

PubMed

Gish, Robert G; Wong, Robert J; Honerkamp-Smith, Gordon; Xu, Ronghui; Osorio, Robert W

2015-06-01

Although it has been generally recognized that there are inconsistencies among Regional Review Boards in the assignment of points for model for end-stage liver disease (MELD)/pediatric end-stage liver disease (PELD) exception patients with resulting considerable variation in appeal denial rates, data to actually prove this have been limited. We reviewed 6533 MELD/PELD exception applications submitted between 2005 and 2008, calculated the variation in approval/denial rates, and followed these cases through mid-2013 to assess the effects on patient outcomes. We found highly significant regional variations in denial rates for appeals by exception patients and in transplantation rates. The odds of transplant for patients whose appeals are approved is 2.45 times that of patients not approved; that this effect does not vary by region suggests that the variation in transplant rates is driven, at least in part, by the variation in appeal denial rates. Health deterioration or death accounts for more than two-thirds of wait list removals among patients removed for reasons other than transplant. Our findings add to the weight of evidence that a national review board that uses current clinical expertise, peer review literature, and data to consistently assign priority could reduce regional inequities and move toward equitable allocation of organs and compliance with the United States Department of Health & Human Services Final Rule. © 2015 The Authors. Clinical Transplantation. Published by John Wiley & Sons Ltd.

Derivation of martian surface slope characteristics from directional thermal infrared radiometry

NASA Astrophysics Data System (ADS)

Bandfield, Joshua L.; Edwards, Christopher S.

2008-01-01

Directional thermal infrared measurements of the martian surface is one of a variety of methods that may be used to characterize surface roughness and slopes at scales smaller than can be obtained by orbital imagery. Thermal Emission Spectrometer (TES) emission phase function (EPF) observations show distinct apparent temperature variations with azimuth and emission angle that are consistent with the presence of warm, sunlit and cool, shaded slopes at typically ˜0.1 m scales. A surface model of a Gaussian distribution of azimuth independent slopes (described by θ-bar) is combined with a thermal model to predict surface temperature from each viewing angle and azimuth of the TES EPF observation. The models can be used to predict surface slopes using the difference in measured apparent temperature from 2 separate 60-70° emission angle observations taken ˜180° in azimuth relative to each other. Most martian surfaces are consistent with low to moderate slope distributions. The slope distributions display distinct correlations with latitude, longitude, and albedo. Exceptionally smooth surfaces are located at lower latitudes in both the southern highlands as well as in high albedo dusty terrains. High slopes are associated with southern high-latitude patterned ground and north polar sand dunes. There is little apparent correlation between high resolution imagery and the derived θ-bar, with exceptions such as duneforms. This method can be used to characterize potential landing sites by assuming fractal scaling behavior to meter scales. More precisely targeted thermal infrared observations from other spacecraft instruments are capable of significantly reducing uncertainty as well as reducing measurement spot size from 10s of kilometers to sub-kilometer scales.

Evaluation of hydrologic components of community land model 4 and bias identification

DOE PAGES

Du, Enhao; Vittorio, Alan Di; Collins, William D.

2015-04-01

Runoff and soil moisture are two key components of the global hydrologic cycle that should be validated at local to global scales in Earth System Models (ESMs) used for climate projection. Here, we have evaluated the runoff and surface soil moisture output by the Community Climate System Model (CCSM) along with 8 other models from the Coupled Model Intercomparison Project (CMIP5) repository using satellite soil moisture observations and stream gauge corrected runoff products. A series of Community Land Model (CLM) runs forced by reanalysis and coupled model outputs was also performed to identify atmospheric drivers of biases and uncertainties inmore » the CCSM. Results indicate that surface soil moisture simulations tend to be positively biased in high latitude areas by most selected CMIP5 models except CCSM, FGOALS, and BCC, which share similar land surface model code. With the exception of GISS, runoff simulations by all selected CMIP5 models were overestimated in mountain ranges and in most of the Arctic region. In general, positive biases in CCSM soil moisture and runoff due to precipitation input error were offset by negative biases induced by temperature input error. Excluding the impact from atmosphere modeling, the global mean of seasonal surface moisture oscillation was out of phase compared to observations in many years during 1985–2004. The CLM also underestimated runoff in the Amazon, central Africa, and south Asia, where soils all have high clay content. We hypothesize that lack of a macropore flow mechanism is partially responsible for this underestimation. However, runoff was overestimated in the areas covered by volcanic ash soils (i.e., Andisols), which might be associated with poor soil porosity representation in CLM. Finally, our results indicate that CCSM predictability of hydrology could be improved by addressing the compensating errors associated with precipitation and temperature and updating the CLM soil representation.« less

FAPE Model of Exceptional Student Education Leadership

ERIC Educational Resources Information Center

Dubberly, Russell G.

2012-01-01

The FAPE Model of Exceptional Education Leadership is defined as facilitative, affiliative, praising and rewarding, and experiential and empirical. The FAPE administrator uses a facilitative approach that guides and coaches to help employees find a pathway to success. This leader works to build emotional capacity between all members of the…

A Multidimensional Model for the Identification of Dual-Exceptional Learners

ERIC Educational Resources Information Center

Al-Hroub, Anies

2013-01-01

This research takes mathematics as a model for investigating the definitions, identification, classification and characteristics of a group of gifted student related to the notion of "dual-exceptionality". An extensive process using qualitative and quantitative methods was conducted by a multidisciplinary team to develop and implement a…

Counseling Exceptional Individuals and Their Families: A Systems Perspective

ERIC Educational Resources Information Center

Thomas, Volker; Ray, Karen E.

2006-01-01

This article presents three models of counseling exceptional students from a systems perspective. The authors present their definition of counseling, the goals of counseling, and the counseling relationship from a systems perspective. Each model is described, including assessment and intervention techniques appropriate for working with children,…

Links among high-performance work environment, service quality, and customer satisfaction: an extension to the healthcare sector.

PubMed

Scotti, Dennis J; Harmon, Joel; Behson, Scott J

2007-01-01

Healthcare managers must deliver high-quality patient services that generate highly satisfied and loyal customers. In this article, we examine how a high-involvement approach to the work environment of healthcare employees may lead to exceptional service quality, satisfied patients, and ultimately to loyal customers. Specifically, we investigate the chain of events through which high-performance work systems (HPWS) and customer orientation influence employee and customer perceptions of service quality and patient satisfaction in a national sample of 113 Veterans Health Administration ambulatory care centers. We present a conceptual model for linking work environment to customer satisfaction and test this model using structural equations modeling. The results suggest that (1) HPWS is linked to employee perceptions of their ability to deliver high-quality customer service, both directly and through their perceptions of customer orientation; (2) employee perceptions of customer service are linked to customer perceptions of high-quality service; and (3) perceived service quality is linked with customer satisfaction. Theoretical and practical implications of our findings, including suggestions of how healthcare managers can implement changes to their work environments, are discussed.

Characteristics of Tropical Cyclones in High-Resolution Models of the Present Climate

NASA Technical Reports Server (NTRS)

Shaevitz, Daniel A.; Camargo, Suzana J.; Sobel, Adam H.; Jonas, Jeffery A.; Kim, Daeyhun; Kumar, Arun; LaRow, Timothy E.; Lim, Young-Kwon; Murakami, Hiroyuki; Roberts, Malcolm J.;

Characteristics of Tropical Cyclones in High-resolution Models in the Present Climate

NASA Technical Reports Server (NTRS)

Shaevitz, Daniel A.; Camargo, Suzana J.; Sobel, Adam H.; Jonas, Jeffrey A.; Kim, Daehyun; Kumar, Arun; LaRow, Timothy E.; Lim, Young-Kwon; Murakami, Hiroyuki; Reed, Kevin;

The high-resolution spectrum of the pulsating, pre-white dwarf star PG 1159-035 (GW VIR)

NASA Technical Reports Server (NTRS)

Liebert, James; Wesemael, F.; Husfeld, D.; Wehrse, R.; Starrfield, S. G.

1989-01-01

High-resolution and low-resolution UV spectra and a high-resolution optical spectrum were obtained for PG 1159-035, revealing apparent photospheric absorption features with defined cores from N V 1240 A, N IV 1270 A, O V 1371 A, and C IV 1550 A. The photospheric velocity derived using all of these lines except for C IV is about +35 km/s. Equivalent-width measurements determined for all of the features may provide a tighter constraint on the photospheric temperature in a detailed model atmosphere analysis treating the CNO ions.

AIM for the BESt: Assessment and Intervention Model for the Bilingual Exceptional Student. A Handbook for Teachers and Planners from the Innovative Approaches Research Project.

ERIC Educational Resources Information Center

Ortiz, Alba A.; And Others

This handbook describes the Assessment and Intervention Model for the Bilingual Exceptional Student (AIM for the BESt), an instructional/intervention approach to the education of language minority students. The model aims to improve academic performance through use of shared literature and Graves writing workshops, reduce inappropriate referrals…

A passive microfluidic hydrogen-air fuel cell with exceptional stability and high performance.

PubMed

Mitrovski, Svetlana M; Nuzzo, Ralph G

2006-03-01

We describe an advanced microfluidic hydrogen-air fuel cell (FC) that exhibits exceptional durability and high performance, most notably yielding stable output power (>100 days) without the use of an anode-cathode separator membrane. This FC embraces an entirely passive device architecture and, unlike conventional microfluidic designs that exploit laminar hydrodynamics, no external pumps are used to sustain or localize the reagent flow fields. The devices incorporate high surface area/porous metal and metal alloy electrodes that are embedded and fully immersed in liquid electrolyte confined in the channels of a poly(dimethylsiloxane) (PDMS)-based microfluidic network. The polymeric network also serves as a self-supporting membrane through which oxygen and hydrogen are supplied to the cathode and alloy anode, respectively, by permeation. The operational stability of the device and its performance is strongly dependent on the nature of the electrolyte used (5 M H2SO4 or 2.5 M NaOH) and composition of the anode material. The latter choice is optimized to decrease the sensitivity of the system to oxygen cross-over while still maintaining high activity towards the hydrogen oxidation reaction (HOR). Three types of high surface area anodes were tested in this work. These include: high-surface area electrodeposited Pt (Pt); high-surface area electrodeposited Pd (Pd); and thin palladium adlayers supported on a "porous" Pt electrode (Pd/Pt). The FCs display their best performance in 5 M H2SO4 using the Pd/Pt anode. This exceptional stability and performance was ascribed to several factors, namely: the high permeabilities of O2, H2, and CO2 in PDMS; the inhibition of the formation of insoluble carbonate species due to the presence of a highly acidic electrolyte; and the selectivity of the Pd/Pt anode toward the HOR. The stability of the device for long-term operation was modeled using a stack of three FCs as a power supply for a portable display that otherwise uses a 3 V battery.

Nonlinear stability and control study of highly maneuverable high performance aircraft, phase 2

NASA Technical Reports Server (NTRS)

Mohler, R. R.

1992-01-01

This research should lead to the development of new nonlinear methodologies for the adaptive control and stability analysis of high angle-of-attack aircraft such as the F18 (HARV). The emphasis has been on nonlinear adaptive control, but associated model development, system identification, stability analysis and simulation is performed in some detail as well. Various models under investigation for different purposes are summarized in tabular form. Models and simulation for the longitudinal dynamics have been developed for all types except the nonlinear ordinary differential equation model. Briefly, studies completed indicate that nonlinear adaptive control can outperform linear adaptive control for rapid maneuvers with large changes in alpha. The transient responses are compared where the desired alpha varies from 5 degrees to 60 degrees to 30 degrees and back to 5 degrees in all about 16 sec. Here, the horizontal stabilator is the only control used with an assumed first-order linear actuator with a 1/30 sec time constant.

Creation of High Resolution Terrain Models of Barringer Meteorite Crater (Meteor Crater) Using Photogrammetry and Terrestrial Laser Scanning Methods

NASA Technical Reports Server (NTRS)

Brown, Richard B.; Navard, Andrew R.; Holland, Donald E.; McKellip, Rodney D.; Brannon, David P.

2010-01-01

Barringer Meteorite Crater or Meteor Crater, AZ, has been a site of high interest for lunar and Mars analog crater and terrain studies since the early days of the Apollo-Saturn program. It continues to be a site of exceptional interest to lunar, Mars, and other planetary crater and impact analog studies because of its relatively young age (est. 50 thousand years) and well-preserved structure. High resolution (2 meter to 1 decimeter) digital terrain models of Meteor Crater in whole or in part were created at NASA Stennis Space Center to support several lunar surface analog modeling activities using photogrammetric and ground based laser scanning techniques. The dataset created by this activity provides new and highly accurate 3D models of the inside slope of the crater as well as the downslope rock distribution of the western ejecta field. The data are presented to the science community for possible use in furthering studies of Meteor Crater and impact craters in general as well as its current near term lunar exploration use in providing a beneficial test model for lunar surface analog modeling and surface operation studies.

Bioinspired, Graphene/Al2O3 Doubly Reinforced Aluminum Composites with High Strength and Toughness.

PubMed

Zhang, Yunya; Li, Xiaodong

2017-11-08

Nacre, commonly referred to as nature's armor, has served as a blueprint for engineering stronger and tougher bioinspired materials. Nature organizes a brick-and-mortar-like architecture in nacre, with hard bricks of aragonite sandwiched with soft biopolymer layers. However, cloning nacre's entire reinforcing mechanisms in engineered materials remains a challenge. In this study, we employed hybrid graphene/Al 2 O 3 platelets with surface nanointerlocks as hard bricks for primary load bearer and mechanical interlocking, along with aluminum laminates as soft mortar for load distribution and energy dissipation, to replicate nacre's architecture and reinforcing effects in aluminum composites. Compared with aluminum, the bioinspired, graphene/Al 2 O 3 doubly reinforced aluminum composite demonstrated an exceptional, joint improvement in hardness (210%), strength (223%), stiffness (78%), and toughness (30%), which are even superior over nacre. This design strategy and model material system should guide the synthesis of bioinspired materials to achieve exceptionally high strength and toughness.

Modeling the Time-Varying Nature of Student Exceptionality Classification on Achievement Growth

ERIC Educational Resources Information Center

Nese, Joseph F. T.; Stevens, Joseph J.; Schulte, Ann C.; Tindal, Gerald; Elliott, Stephen N.

2017-01-01

Our purpose was to examine different approaches to modeling the time-varying nature of exceptionality classification. Using longitudinal data from one state's mathematics achievement test for 28,829 students in Grades 3 to 8, we describe the reclassification rate within special education and between general and special education, and compare four…

Distribution patterns of mercury in Lakes and Rivers of northeastern North America

USGS Publications Warehouse

Dennis, Ian F.; Clair, Thomas A.; Driscoll, Charles T.; Kamman, Neil; Chalmers, Ann T.; Shanley, Jamie; Norton, Stephen A.; Kahl, Steve

2005-01-01

We assembled 831 data points for total mercury (Hgt) and 277 overlapping points for methyl mercury (CH3Hg+) in surface waters from Massachussetts, USA to the Island of Newfoundland, Canada from State, Provincial, and Federal government databases. These geographically indexed values were used to determine: (a) if large-scale spatial distribution patterns existed and (b) whether there were significant relationships between the two main forms of aquatic Hg as well as with total organic carbon (TOC), a well know complexer of metals. We analyzed the catchments where samples were collected using a Geographical Information System (GIS) approach, calculating catchment sizes, mean slope, and mean wetness index. Our results show two main spatial distribution patterns. We detected loci of high Hgt values near urbanized regions of Boston MA and Portland ME. However, except for one unexplained exception, the highest Hgt and CH3Hg+ concentrations were located in regions far from obvious point sources. These correlated to topographically flat (and thus wet) areas that we relate to wetland abundances. We show that aquatic Hgt and CH3Hg+ concentrations are generally well correlated with TOC and with each other. Over the region, CH3Hg+ concentrations are typically approximately 15% of Hgt. There is an exception in the Boston region where CH3Hg+ is low compared to the high Hgt values. This is probably due to the proximity of point sources of inorganic Hg and a lack of wetlands. We also attempted to predict Hg concentrations in water with statistical models using catchment features as variables. We were only able to produce statistically significant predictive models in some parts of regions due to the lack of suitable digital information, and because data ranges in some regions were too narrow for meaningful regression analyses.

Access to Liver Transplantation in Different ABO-Blood Groups and "Exceptions Points" in a Model for End-Stage Liver Disease Allocation System: A Brazilian Single-Center Study.

PubMed

Martino, R B; Waisberg, D R; Dias, A P M; Inoue, V B S; Arantes, R M; Haddad, L B P; Rocha-Santos, V; Pinheiro, R S N; Nacif, L S; D'Albuquerque, L A C

2018-04-01

In the Model for End-Stage Liver Disease (MELD) system, patients with "MELD exceptions" points may have unfair privilege in the competition for liver grafts. Furthermore, organ distribution following identical ABO blood types may also result in unjust organ allocation. The aim of this study was to investigate access to liver transplantation in a tertiary Brazilian center, regarding "MELD exceptions" situations and among ABO-blood groups. A total of 465 adult patients on the liver waitlist from August 2015 to August 2016 were followed up until August 2017. Patients were divided into groups according to ABO-blood type and presence of "exceptions points." No differences in outcomes were observed among ABO-blood groups. However, patients from B and AB blood types spent less time on the list than patients from A and O groups (median, 46, 176, 415, and 401 days, respectively; P = .03). "Exceptions points" were granted for 141 patients (30.1%), hepatocellular carcinoma being the most common reason (52.4%). Patients with "exceptions points" showed higher transplantation rate, lower mortality on the list, and lower delta-MELD than non-exceptions patients (56.7% vs 19.1% [P < .01]; 18.4% vs 38.5% [P < .01], and 2.0 ± 2.6 vs 6.9 ± 7.0 [P < .01], respectively). Patients with refractory ascites had a higher mortality rate than those with other "exceptions" or without (48%). The MELD system provides equal access to liver transplantation among ABO-blood types, despite shorter time on the waitlist for AB and B groups. The current MELD exception system provides advantages for candidates with "exception points," resulting in superior outcomes compared with those without exceptions. Copyright © 2018 Elsevier Inc. All rights reserved.

Can superior natural amenities create high-quality employment opportunities? The case of nonconsumptive river recreation in central Idaho

USGS Publications Warehouse

McKean, J.R.; Johnson, D.M.; Johnson, Richard L.; Taylor, R.G.

2005-01-01

Central Idaho has superior environmental amenities, as evidenced by exceptionally high-value tourism, such as guided whitewater rafting. The focus of our study concerns the attainment of high-quality jobs in a high-quality natural environment. We estimate cumulative wage rate effects unique to nonconsumptive river recreation in central Idaho for comparison with other sectors. The cumulative effects are based on a detailed survey of recreation spending and a modified synthesized input–output model. Cumulative wage rate effects support using the abundance of environmental amenities to expand and attract high-wage, environmentally sensitive firms, as opposed to expanded tourism to improve employment quality.

Center variation in the use of nonstandardized model for end-stage liver disease exception points.

PubMed

Goldberg, David S; Makar, George; Bittermann, Therese; French, Benjamin

2013-12-01

The Model for End-Stage Liver Disease (MELD) score is an imperfect prognosticator of waitlist dropout, so transplant centers may apply for exception points to increase a waitlist candidate's priority on the waitlist. Exception applications are categorized as recognized exceptional diagnoses (REDs; eg, hepatocellular carcinoma) and non-REDs (eg, cholangitis). Although prior work has demonstrated regional variation in the use of exceptions, no work has examined the between-center variability. We analyzed all new waitlist candidates from February 27, 2002 to June 3, 2011 to explore variations in the use of non-REDs, for which no strict exception criteria exist. There were 58,641 new waitlist candidates, and 4356 (7.4%) applied for a non-RED exception. The number of applications increased steadily over time, as did the approval rates for such applications: from <50% in 2002 to nearly 75% in 2010. When we adjusted for patient factors, there was significant variability (P < 0.001) in the use of non-RED exceptions in 8 of 11 United Network for Organ Sharing (UNOS) regions and in the approval of these exceptions in 6 of 11 UNOS regions. The variability in the use and approval of non-REDs was clinically significant: waitlist candidates with approved exceptions were significantly more likely to undergo transplantation (68.3% versus 53.4%, P < 0.001) and were less likely to be removed for death or clinical deterioration (10.4% versus 16.2%, P < 0.001). Increased median MELD score at transplantation within a donor service area was the only center factor associated with increased odds of applying for exceptions, while no center factors were associated with having non-RED exceptions approved. Further work is needed to identify other sources of variation to ensure the appropriate and equitable use of non-RED exceptions. © 2013 American Association for the Study of Liver Diseases.

RNA Futile Cycling in Model Persisters Derived from MazF Accumulation (Open Access)

DTIC Science & Technology

2015-11-17

they remained highly metabolically active . We further uncovered a futile cycle driven by continued transcription and MazF-mediated transcript degradation...presence of antibiotics (7), although exceptions have been noted for prod- rugs that require activation (8). Rather, they are rare phenotypic variants...arise from slowly grow- ing or nongrowing bacteria with reduced metabolic activity , where antibiotic targets are inactive and resilient to antibiotic

Coupled ion redistribution and electronic breakdown in low-alkali boroaluminosilicate glass

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

Choi, Doo Hyun, E-mail: cooldoo@add.re.kr; Randall, Clive, E-mail: car4@psu.edu; Furman, Eugene, E-mail: euf1@psu.edu

2015-08-28

Dielectrics with high electrostatic energy storage must have exceptionally high dielectric breakdown strength at elevated temperatures. Another important consideration in designing a high performance dielectric is understanding the thickness and temperature dependence of breakdown strengths. Here, we develop a numerical model which assumes a coupled ionic redistribution and electronic breakdown is applied to predict the breakdown strength of low-alkali glass. The ionic charge transport of three likely charge carriers (Na{sup +}, H{sup +}/H{sub 3}O{sup +}, Ba{sup 2+}) was used to calculate the ionic depletion width in low-alkali boroaluminosilicate which can further be used for the breakdown modeling. This model predictsmore » the breakdown strengths in the 10{sup 8}–10{sup 9 }V/m range and also accounts for the experimentally observed two distinct thickness dependent regions for breakdown. Moreover, the model successfully predicts the temperature dependent breakdown strength for low-alkali glass from room temperature up to 150 °C. This model showed that breakdown strengths were governed by minority charge carriers in the form of ionic transport (mostly sodium) in these glasses.« less

A Model for Screening Twice-Exceptional Students (Gifted with Learning Disabilities) within a Response to Intervention Paradigm

ERIC Educational Resources Information Center

McCallum, R. Steve; Bell, Sherry Mee; Coles, Jeremy Thomas; Miller, Kelli Caldwell; Hopkins, Michael B.; Hilton-Prillhart, Angela

2013-01-01

The purpose of this article is to present a model for screening for twice-exceptional status (i.e., gifted students who have a learning disability). Curriculum-based measures (Monitoring Instructional Responsiveness: Reading and Monitoring Instructional Responsiveness: Math) were administered to 1,242 third-grade students within a Response to…

The Acceptance of Exceptionality: A Three Dimensional Model.

ERIC Educational Resources Information Center

Martin, Larry L.; Nivens, Maryruth K.

A model extrapolates from E. Kubler-Ross' conception of the stages of grief to apply to parent and family reactions when an exceptionality is identified. A chart lists possible parent feelings and reactions, possible school reactions to the parent in grief, and the child's reactions during each of five stages: denial, rage and anger, bargaining,…

77 FR 27661 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-11

... Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed... Deutschland GmbH (ECD) model EC135 helicopters, except the EC 135 P2+ and T2+. This proposed AD was prompted...) Applicability This AD applies to all Eurocopter Deutschland GmbH (ECD) Model EC135 helicopters, except EC 135 P2...

77 FR 72913 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-07

... Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters AGENCY: Federal Aviation Administration (FAA... Eurocopter Deutschland GmbH (ECD) Model EC135 helicopters, except the EC 135 P2+ and T2+. This AD requires... apply to all Eurocopter Deutschland GmbH (ECD) model EC135 helicopters, except the EC 135 P2+ and T2...

Characteristics of tropical cyclones in high-resolution models in the present climate

DOE PAGES

Shaevitz, Daniel A.; Camargo, Suzana J.; Sobel, Adam H.; ...

2014-12-05

The global characteristics of tropical cyclones (TCs) simulated by several climate models are analyzed and compared with observations. The global climate models were forced by the same sea surface temperature (SST) fields in two types of experiments, using climatological SST and interannually varying SST. TC tracks and intensities are derived from each model's output fields by the group who ran that model, using their own preferred tracking scheme; the study considers the combination of model and tracking scheme as a single modeling system, and compares the properties derived from the different systems. Overall, the observed geographic distribution of global TCmore » frequency was reasonably well reproduced. As expected, with the exception of one model, intensities of the simulated TC were lower than in observations, to a degree that varies considerably across models.« less

Aerodynamic Characteristics of Parachutes at Mach Numbers from 1.6 to 3

NASA Technical Reports Server (NTRS)

Maynard, Julian D.

1961-01-01

A wind-tunnel investigation has been conducted to determine the parameters affecting the aerodynamic performance of drogue parachutes in the Mach number range from 1.6 to 3. Flow studies of both rigid and flexible-parachute models were made by means of high-speed schlieren motion pictures and drag coefficients of the flexible-parachute models were measured at simulated altitudes from about 50,000 to 120,000 feet. Porosity and Mach number were found to be the most important factors influencing the drag and stability of flexible porous parachutes. Such parachutes have a limited range of stable'operation at supersonic speeds, except for those with very high porosities, but the drag coefficient decreases rapidly with increasing porosity.

Controls on Highly Siderophile Element Concentrations in Martian Basalt: Sulfide Saturation and Under-Saturation

NASA Technical Reports Server (NTRS)

Righter, Kevin

2009-01-01

Highly siderophile elements (HSE; Re, Au and the platinum group elements) in shergottites exhibit a wide range from very high, similar to the terrestrial mantle, to very low, similar to sulfide saturated mid ocean ridge basalt (e.g., [1]). This large range has been difficult to explain without good constraints on sulfide saturation or under-saturation [2]. A new model for prediction of sulfide saturation places new constraints on this problem [3]. Shergottite data: For primitive shergottites, pressure and temperature estimates are between 1.2-1.5 GPa, and 1350-1470 C [4]. The range of oxygen fugacities is from FMQ-2 to IW, where the amount of Fe2O3 is low and thus does not have a significant effect on the S saturation values. Finally, the bulk compositions of shergottites have been reported in many recent studies (e.g., [5]). All of this information will be used to test whether shergottites are sulfide saturated [3]. Modeling values and results: The database for HSE partition coefficients has been growing with many new data for silicates and oxides [6-8] to complement a large sulfide database [9- 11]. Combining these data with simple batch melting models allows HSE contents of mantle melts to be estimated for sulfide-bearing vs. sulfide-free mantle. Combining such models with fractional crystallization modeling (e.g., [12]) allows HSE contents of more evolved liquids to be modeled. Most primitive shergottites have high HSE contents (and low S contents) that can be explained by sulfide under-saturated melting of the mantle. An exception is Dhofar 019 which has high S contents and very low HSE contents suggesting sulfide saturation. Most evolved basaltic shergottites have lower S contents than saturation, and intermediate HSE contents that can be explained by olivine, pyroxene, and chromite fractionation. An exception is EET A79001 lithology B, which has very low HSE contents and S contents higher than sulfide saturation values . evidence for sulfide saturation during late fractional crystallization. These results show that shergottite HSE contents are controlled by silicates, oxides, and sulfides. In addition, the mantle producing the most primitive shergottites did not contain near chondritic relative ratios of the HSEs like the terrestrial mantle, and did not experience a late chondritic veneer.

A Year-Long Comparison of GPS TEC and Global Ionosphere-Thermosphere Models

NASA Astrophysics Data System (ADS)

Perlongo, N. J.; Ridley, A. J.; Cnossen, I.; Wu, C.

2018-02-01

The prevalence of GPS total electron content (TEC) observations has provided an opportunity for extensive global ionosphere-thermosphere model validation efforts. This study presents a year-long data-model comparison using the Global Ionosphere-Thermosphere Model (GITM) and the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM). For the entire year of 2010, each model was run and compared to GPS TEC observations. The results were binned according to season, latitude, local time, and magnetic local time. GITM was found to overestimate the TEC everywhere, except on the midlatitude nightside, due to high O/N2 ratios. TIE-GCM produced much less TEC and had lower O/N2 ratios and neutral wind speeds. Seasonal and regional biases in the models are discussed along with ideas for model improvements and further validation efforts.

Portuguese preschool children: Benefit (EPA+DHA and Se) and risk (MeHg) assessment through the consumption of selected fish species.

PubMed

Cardoso, C; Bernardo, I; Bandarra, N M; Louro Martins, L; Afonso, C

2018-05-01

This study aimed to assess the risk-benefit balance associated to fish consumption by Portuguese preschool children. For this purpose, databases (from IPMA and literature) were mined and mathematically processed by a model based on the Extreme Value Theory assuming consumption scenarios. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) and selenium (Se) and methylmercury (MeHg) were selected as critical components of fish, given their health impact and significant contents in some fish species. Assessment also took into account that Se may protect against MeHg toxicity. With exception of blue shark, Se Health Benefit Value (Se-HBV), was always positive (ranging between 3.3 and 14.9) and Se:MeHg ratio was always higher than one (3.8 to 32.3). It was also estimated that the deleterious effects of MeHg on children IQ were offset by the beneficial impact of EPA+DHA in fish except for grilled black scabbardfish consumed every day. Blue shark, regardless of the culinary treatment, yielded very high probabilities of exceeding MeHg TWI (higher than 84 % with a single weekly meal), thus raising serious concerns. EPA+DHA benefits were high in salmon regardless of culinary treatment (> 84 %). Fish consumption by children is advisable with exception of blue shark and boiled and grilled tuna. Copyright © 2018 Elsevier Ltd. All rights reserved.

Intercomparison of regional-scale hydrological models and climate change impacts projected for 12 large river basins worldwide—a synthesis

NASA Astrophysics Data System (ADS)

Krysanova, Valentina; Vetter, Tobias; Eisner, Stephanie; Huang, Shaochun; Pechlivanidis, Ilias; Strauch, Michael; Gelfan, Alexander; Kumar, Rohini; Aich, Valentin; Arheimer, Berit; Chamorro, Alejandro; van Griensven, Ann; Kundu, Dipangkar; Lobanova, Anastasia; Mishra, Vimal; Plötner, Stefan; Reinhardt, Julia; Seidou, Ousmane; Wang, Xiaoyan; Wortmann, Michel; Zeng, Xiaofan; Hattermann, Fred F.

2017-10-01

An intercomparison of climate change impacts projected by nine regional-scale hydrological models for 12 large river basins on all continents was performed, and sources of uncertainty were quantified in the framework of the ISIMIP project. The models ECOMAG, HBV, HYMOD, HYPE, mHM, SWAT, SWIM, VIC and WaterGAP3 were applied in the following basins: Rhine and Tagus in Europe, Niger and Blue Nile in Africa, Ganges, Lena, Upper Yellow and Upper Yangtze in Asia, Upper Mississippi, MacKenzie and Upper Amazon in America, and Darling in Australia. The model calibration and validation was done using WATCH climate data for the period 1971-2000. The results, evaluated with 14 criteria, are mostly satisfactory, except for the low flow. Climate change impacts were analyzed using projections from five global climate models under four representative concentration pathways. Trends in the period 2070-2099 in relation to the reference period 1975-2004 were evaluated for three variables: the long-term mean annual flow and high and low flow percentiles Q 10 and Q 90, as well as for flows in three months high- and low-flow periods denoted as HF and LF. For three river basins: the Lena, MacKenzie and Tagus strong trends in all five variables were found (except for Q 10 in the MacKenzie); trends with moderate certainty for three to five variables were confirmed for the Rhine, Ganges and Upper Mississippi; and increases in HF and LF were found for the Upper Amazon, Upper Yangtze and Upper Yellow. The analysis of projected streamflow seasonality demonstrated increasing streamflow volumes during the high-flow period in four basins influenced by monsoonal precipitation (Ganges, Upper Amazon, Upper Yangtze and Upper Yellow), an amplification of the snowmelt flood peaks in the Lena and MacKenzie, and a substantial decrease of discharge in the Tagus (all months). The overall average fractions of uncertainty for the annual mean flow projections in the multi-model ensemble applied for all basins were 57% for GCMs, 27% for RCPs, and 16% for hydrological models.

Key metrics for HFIR HEU and LEU models

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

Ilas, Germina; Betzler, Benjamin R.; Chandler, David

This report compares key metrics for two fuel design models of the High Flux Isotope Reactor (HFIR). The first model represents the highly enriched uranium (HEU) fuel currently in use at HFIR, and the second model considers a low-enriched uranium (LEU) interim design fuel. Except for the fuel region, the two models are consistent, and both include an experiment loading that is representative of HFIR's current operation. The considered key metrics are the neutron flux at the cold source moderator vessel, the mass of 252Cf produced in the flux trap target region as function of cycle time, the fast neutronmore » flux at locations of interest for material irradiation experiments, and the reactor cycle length. These key metrics are a small subset of the overall HFIR performance and safety metrics. They were defined as a means of capturing data essential for HFIR's primary missions, for use in optimization studies assessing the impact of HFIR's conversion from HEU fuel to different types of LEU fuel designs.« less

Accelerated Discovery of High-Refractive-Index Polymers Using First-Principles Modeling, Virtual High-Throughput Screening, and Data Mining

NASA Astrophysics Data System (ADS)

Afzal, Mohammad Atif Faiz; Cheng, Chong; Hachmann, Johannes

Organic materials with refractive index (RI) values higher than 1.7 have attracted considerable interest in recent years due to the tremendous potential for their application in optical, optometric, and optoelectronic devices, and thus for shaping technological innovation in numerous related areas. Our work is concerned with creating predictive models for the optical properties of organic polymers, which will guide our experimentalist partners and allow them to target the most promising candidates. The RI model is developed based on a synergistic combination of first-principles electronic structure theory and machine learning techniques. The RI values predicted for common polymers using this model are in very good agreement with the experimental values. We also benchmark different DFT approximations along with various basis sets for their predictive performance in this model. We demonstrate that this combination of first-principles and data modeling is both successful and highly economical in determining the RI values of a wide range of organic polymers. To accelerate the development process, we cast this modeling approach into the high-throughput screening, materials informatics, and rational design framework that is developed in the group. This framework is a powerful tool and has shown to be highly promising for rapidly identifying polymer candidates with exceptional RI values as well as discovering design rules for advanced materials.

WRF model sensitivity to choice of parameterization: a study of the `York Flood 1999'

NASA Astrophysics Data System (ADS)

Remesan, Renji; Bellerby, Tim; Holman, Ian; Frostick, Lynne

2015-10-01

Numerical weather modelling has gained considerable attention in the field of hydrology especially in un-gauged catchments and in conjunction with distributed models. As a consequence, the accuracy with which these models represent precipitation, sub-grid-scale processes and exceptional events has become of considerable concern to the hydrological community. This paper presents sensitivity analyses for the Weather Research Forecast (WRF) model with respect to the choice of physical parameterization schemes (both cumulus parameterisation (CPSs) and microphysics parameterization schemes (MPSs)) used to represent the `1999 York Flood' event, which occurred over North Yorkshire, UK, 1st-14th March 1999. The study assessed four CPSs (Kain-Fritsch (KF2), Betts-Miller-Janjic (BMJ), Grell-Devenyi ensemble (GD) and the old Kain-Fritsch (KF1)) and four MPSs (Kessler, Lin et al., WRF single-moment 3-class (WSM3) and WRF single-moment 5-class (WSM5)] with respect to their influence on modelled rainfall. The study suggests that the BMJ scheme may be a better cumulus parameterization choice for the study region, giving a consistently better performance than other three CPSs, though there are suggestions of underestimation. The WSM3 was identified as the best MPSs and a combined WSM3/BMJ model setup produced realistic estimates of precipitation quantities for this exceptional flood event. This study analysed spatial variability in WRF performance through categorical indices, including POD, FBI, FAR and CSI during York Flood 1999 under various model settings. Moreover, the WRF model was good at predicting high-intensity rare events over the Yorkshire region, suggesting it has potential for operational use.

High-resolution simulations of the thermophysiological effects of human exposure to 100 MHz RF energy

NASA Astrophysics Data System (ADS)

Nelson, David A.; Curran, Allen R.; Nyberg, Hans A.; Marttila, Eric A.; Mason, Patrick A.; Ziriax, John M.

2013-03-01

Human exposure to radio frequency (RF) electromagnetic energy is known to result in tissue heating and can raise temperatures substantially in some situations. Standards for safe exposure to RF do not reflect bio-heat transfer considerations however. Thermoregulatory function (vasodilation, sweating) may mitigate RF heating effects in some environments and exposure scenarios. Conversely, a combination of an extreme environment (high temperature, high humidity), high activity levels and thermally insulating garments may exacerbate RF exposure and pose a risk of unsafe temperature elevation, even for power densities which might be acceptable in a normothermic environment. A high-resolution thermophysiological model, incorporating a heterogeneous tissue model of a seated adult has been developed and used to replicate a series of whole-body exposures at a frequency (100 MHz) which approximates that of human whole-body resonance. Exposures were simulated at three power densities (4, 6 and 8 mW cm-2) plus a sham exposure and at three different ambient temperatures (24, 28 and 31 °C). The maximum hypothalamic temperature increase over the course of a 45 min exposure was 0.28 °C and occurred in the most extreme conditions (Tamb = 31 °C, PD = 8 mW cm-2). Skin temperature increases attributable to RF exposure were modest, with the exception of a ‘hot spot’ in the vicinity of the ankle where skin temperatures exceeded 39 °C. Temperature increases in internal organs and tissues were small, except for connective tissue and bone in the lower leg and foot. Temperature elevation also was noted in the spinal cord, consistent with a hot spot previously identified in the literature.

High-resolution simulations of the thermophysiological effects of human exposure to 100 MHz RF energy.

PubMed

Nelson, David A; Curran, Allen R; Nyberg, Hans A; Marttila, Eric A; Mason, Patrick A; Ziriax, John M

2013-03-21

Human exposure to radio frequency (RF) electromagnetic energy is known to result in tissue heating and can raise temperatures substantially in some situations. Standards for safe exposure to RF do not reflect bio-heat transfer considerations however. Thermoregulatory function (vasodilation, sweating) may mitigate RF heating effects in some environments and exposure scenarios. Conversely, a combination of an extreme environment (high temperature, high humidity), high activity levels and thermally insulating garments may exacerbate RF exposure and pose a risk of unsafe temperature elevation, even for power densities which might be acceptable in a normothermic environment. A high-resolution thermophysiological model, incorporating a heterogeneous tissue model of a seated adult has been developed and used to replicate a series of whole-body exposures at a frequency (100 MHz) which approximates that of human whole-body resonance. Exposures were simulated at three power densities (4, 6 and 8 mW cm(-2)) plus a sham exposure and at three different ambient temperatures (24, 28 and 31 °C). The maximum hypothalamic temperature increase over the course of a 45 min exposure was 0.28 °C and occurred in the most extreme conditions (T(AMB) = 31 °C, PD = 8 mW cm(-2)). Skin temperature increases attributable to RF exposure were modest, with the exception of a 'hot spot' in the vicinity of the ankle where skin temperatures exceeded 39 °C. Temperature increases in internal organs and tissues were small, except for connective tissue and bone in the lower leg and foot. Temperature elevation also was noted in the spinal cord, consistent with a hot spot previously identified in the literature.

Twice-Exceptional Students Enrolled in Advanced Placement Classes

ERIC Educational Resources Information Center

Schultz, Susan M.

2012-01-01

Twice-exceptional students, those who have disabilities and display areas of gifts or talents, frequently spend their high school years with a focus on their disabilities. Using semistructured interviews, this study explores the perceptions of parents, teachers, and guidance counselors regarding participation of twice-exceptional students in…

Exceptionally fast water desalination at complete salt rejection by pristine graphyne monolayers.

PubMed

Xue, Minmin; Qiu, Hu; Guo, Wanlin

2013-12-20

Desalination that produces clean freshwater from seawater holds the promise of solving the global water shortage for drinking, agriculture and industry. However, conventional desalination technologies such as reverse osmosis and thermal distillation involve large amounts of energy consumption, and the semipermeable membranes widely used in reverse osmosis face the challenge to provide a high throughput at high salt rejection. Here we find by comprehensive molecular dynamics simulations and first principles modeling that pristine graphyne, one of the graphene-like one-atom-thick carbon allotropes, can achieve 100% rejection of nearly all ions in seawater including Na(+), Cl(-), Mg(2+), K(+) and Ca(2+), at an exceptionally high water permeability about two orders of magnitude higher than those for commercial state-of-the-art reverse osmosis membranes at a salt rejection of ~98.5%. This complete ion rejection by graphyne, independent of the salt concentration and the operating pressure, is revealed to be originated from the significantly higher energy barriers for ions than for water. This intrinsic specialty of graphyne should provide a new possibility for the efforts to alleviate the global shortage of freshwater and other environmental problems.

Electroacoustic analysis, design, and implementation of a small balanced armature speaker.

PubMed

Bai, Mingsian R; You, Bo-Cheng; Lo, Yi-Yang

2014-11-01

This paper presents a new design and implementation of a balanced armature speaker (BAS), which is composed of permanent magnetic circuits, a moving armature, and a coil. The armature rocks about a pivot with the coil at one end and the permanent magnet on another. A magnetic circuit analysis is conducted for the designed BAS to formulate the force factor, which is required for modeling the coupling between the electrical and mechanical systems. In addition, an electromechanoacoustical analogous circuit is established for the BAS, which bears the same structure as the moving coil loudspeaker, except that the force factor is different. A hybrid model, which combines the lumped parameter model in the electrical and acoustical domains with a finite element model in the mechanical domain, is developed to model the high-frequency response because of the high-order modes of the membrane, the drive rod, and the armature. The electroacoustic analysis is experimentally verified. The results indicate that the sound pressure response that is simulated using the hybrid model is in superior agreement with the measured response to that simulated using the lumped parameter model.

Expert anticipatory skill in striking sports: a review and a model.

PubMed

Müller, Sean; Abernethy, Bruce

2012-06-01

Expert performers in striking sports can hit objects moving at high speed with incredible precision. Exceptionally well developed anticipation skills are necessary to cope with the severe constraints on interception. In this papr we provide a review of the empirical evidence regarding expert interception in striking sports and propose a preliminary model of expert anticipation. Central to the review and the model is the notion that the visual information used to guide the sequential phases of the striking action is systematically different between experts and nonexperts. Knowing the factors that contribute to expert anticipation, and how anticipation may guide skilled performance in striking sports, has practical implications for assessment and training across skill levels.

Chaos and the Double Function of Communication

NASA Astrophysics Data System (ADS)

Aula, P. S.

Since at least the needle model age, communication researchers have systematically sought means to explain, control and predict communication behavior between people. For many reasons, the accuracy of constructed models and the studies based upon them has not risen very high. It can be claimed that the reasons for the inaccuracy of communication models, and thus the poor predictability of everyday action, originate from the processes' innate chaos, apparent beneath their behavior. This leads to the argument that communication systems, which appear stable and have precisely identical starting points and identical operating environments, can nevertheless behave in an exceptional and completely different manner, despite the fact that their behavior is ruled or directed by the same rules or laws.

Atmospheric Fragmentation of the Canyon Diablo Meteoroid

NASA Technical Reports Server (NTRS)

Pierazzo, E.; Artemieva, N. A.

2005-01-01

About 50 kyr ago the impact of an iron meteoroid excavated Meteor Crater, Arizona, the first terrestrial structure widely recognized as a meteorite impact crater. Recent studies of ballistically dispersed impact melts from Meteor Crater indicate a compositionally unusually heterogeneous impact melt with high SiO2 and exceptionally high (10 to 25% on average) levels of projectile contamination. These are observations that must be explained by any theoretical modeling of the impact event. Simple atmospheric entry models for an iron meteorite similar to Canyon Diablo indicate that the surface impact speed should have been around 12 km/s [Melosh, personal comm.], not the 15-20 km/s generally assumed in previous impact models. This may help explaining the unusual characteristics of the impact melt at Meteor Crater. We present alternative initial estimates of the motion in the atmosphere of an iron projectile similar to Canyon Diablo, to constraint the initial conditions of the impact event that generated Meteor Crater.

High frequency sound propagation in a network of interconnecting streets

NASA Astrophysics Data System (ADS)

Hewett, D. P.

2012-12-01

We propose a new model for the propagation of acoustic energy from a time-harmonic point source through a network of interconnecting streets in the high frequency regime, in which the wavelength is small compared to typical macro-lengthscales such as street widths/lengths and building heights. Our model, which is based on geometrical acoustics (ray theory), represents the acoustic power flow from the source along any pathway through the network as the integral of a power density over the launch angle of a ray emanating from the source, and takes into account the key phenomena involved in the propagation, namely energy loss by wall absorption, energy redistribution at junctions, and, in 3D, energy loss to the atmosphere. The model predicts strongly anisotropic decay away from the source, with the power flow decaying exponentially in the number of junctions from the source, except along the axial directions of the network, where the decay is algebraic.

Aerodynamic Performance of a 0.27-Scale Model of an AH-64 Helicopter with Baseline and Alternate Rotor Blade Sets

NASA Technical Reports Server (NTRS)

Kelley, Henry L.

1990-01-01

Performance of a 27 percent scale model rotor designed for the AH-64 helicopter (alternate rotor) was measured in hover and forward flight and compared against and AH-64 baseline rotor model. Thrust, rotor tip Mach number, advance ratio, and ground proximity were varied. In hover, at a nominal thrust coefficient of 0.0064, the power savings was about 6.4 percent for the alternate rotor compared to the baseline. The corresponding thrust increase at this condition was approx. 4.5 percent which represents an equivalent full scale increase in lift capability of about 660 lbs. Comparable results were noted in forward flight except for the high thrust, high speed cases investigated where the baseline rotor was slightly superior. Reduced performance at the higher thrusts and speeds was likely due to Reynolds number effects and blade elasticity differences.

Is a "Phoenician" reading style superior to a "Chinese" reading style? Evidence from fourth graders.

PubMed

Bowey, Judith A

2008-07-01

This study compared normally achieving fourth-grade "Phoenician" readers, who identify nonwords significantly more accurately than they do exception words, with "Chinese" readers, who show the reverse pattern. Phoenician readers scored lower than Chinese readers on word identification, exception word reading, orthographic choice, spelling, reading comprehension, and verbal ability. When compared with normally achieving children who read nonwords and exception words equally well, Chinese readers scored as well as these children on word identification, regular word reading, orthographic choice, spelling, reading comprehension, phonological sensitivity, and verbal ability and scored better on exception word reading. Chinese readers also used rhyme-based analogies to read nonwords derived from high-frequency exception words just as often as did these children. As predicted, Phoenician and Chinese readers adopted somewhat different strategies in reading ambiguous nonwords constructed by analogy to high-frequency exception words. Phoenician readers were more likely than Chinese readers to read ambiguous monosyllabic nonwords via context-free grapheme-phoneme correspondences and were less likely to read disyllabic nonwords by analogy to high-frequency analogues. Although the Chinese reading style was more common than the Phoenician style in normally achieving fourth graders, there were similar numbers of poor readers with phonological dyslexia (identifying nonwords significantly more accurately than exception words) and surface dyslexia (showing the reverse pattern), although surface dyslexia was more common in the severely disabled readers. However, few of the poor readers showed pure patterns of phonological or surface dyslexia.

Finish line distinctness and accuracy in 7 intraoral scanners versus conventional impression: an in vitro descriptive comparison.

PubMed

Nedelcu, Robert; Olsson, Pontus; Nyström, Ingela; Thor, Andreas

2018-02-23

Several studies have evaluated accuracy of intraoral scanners (IOS), but data is lacking regarding variations between IOS systems in the depiction of the critical finish line and the finish line accuracy. The aim of this study was to analyze the level of finish line distinctness (FLD), and finish line accuracy (FLA), in 7 intraoral scanners (IOS) and one conventional impression (IMPR). Furthermore, to assess parameters of resolution, tessellation, topography, and color. A dental model with a crown preparation including supra and subgingival finish line was reference-scanned with an industrial scanner (ATOS), and scanned with seven IOS: 3M, CS3500 and CS3600, DWIO, Omnicam, Planscan and Trios. An IMPR was taken and poured, and the model was scanned with a laboratory scanner. The ATOS scan was cropped at finish line and best-fit aligned for 3D Compare Analysis (Geomagic). Accuracy was visualized, and descriptive analysis was performed. All IOS, except Planscan, had comparable overall accuracy, however, FLD and FLA varied substantially. Trios presented the highest FLD, and with CS3600, the highest FLA. 3M, and DWIO had low overall FLD and low FLA in subgingival areas, whilst Planscan had overall low FLD and FLA, as well as lower general accuracy. IMPR presented high FLD, except in subgingival areas, and high FLA. Trios had the highest resolution by factor 1.6 to 3.1 among IOS, followed by IMPR, DWIO, Omnicam, CS3500, 3M, CS3600 and Planscan. Tessellation was found to be non-uniform except in 3M and DWIO. Topographic variation was found for 3M and Trios, with deviations below +/- 25 μm for Trios. Inclusion of color enhanced the identification of the finish line in Trios, Omnicam and CS3600, but not in Planscan. There were sizeable variations between IOS with both higher and lower FLD and FLA than IMPR. High FLD was more related to high localized finish line resolution and non-uniform tessellation, than to high overall resolution. Topography variations were low. Color improved finish line identification in some IOS. It is imperative that clinicians critically evaluate the digital impression, being aware of varying technical limitations among IOS, in particular when challenging subgingival conditions apply.

Lubricant Rheology in Concentrated Contacts

NASA Technical Reports Server (NTRS)

Jacobson, B. O.

1984-01-01

Lubricant behavior in highly stressed situtations shows that a Newtonian model for lubricant rheology is insufficient for explanation of traction behavior. The oil film build up is predicted by using a Newtonian lubricant model except at high slide to roll ratios and at very high loads, where the nonNewtonian behavior starts to be important already outside the Hertzian contact area. Static and dynamic experiments are reported. In static experiments the pressure is applied to the lubricant more than a million times longer than in an EHD contact. Depending on the pressure-temperature history of the experiment the lubricant will become a crystallized or amorphous solid at high pressures. In dynamic experiments, the oil is in an amorphous solid state. Depending on the viscosity, time scale, elasticity of the oil and the bearing surfaces, the oil film pressure, shear strain rate and the type of lubricant, different properties of the oil are important for prediction of shear stresses in the oil. The different proposed models for the lubricant, which describe it to a Newtonian liquid, an elastic liquid, a plastic liquid and an elastic-plastic solid.

The Ventral Anterior Temporal Lobe has a Necessary Role in Exception Word Reading.

PubMed

Ueno, Taiji; Meteyard, Lotte; Hoffman, Paul; Murayama, Kou

2018-06-06

An influential account of reading holds that words with exceptional spelling-to-sound correspondences (e.g., PINT) are read via activation of their lexical-semantic representations, supported by the anterior temporal lobe (ATL). This account has been inconclusive because it is based on neuropsychological evidence, in which lesion-deficit relationships are difficult to localize precisely, and functional neuroimaging data, which is spatially precise but cannot demonstrate whether the ATL activity is necessary for exception word reading. To address these issues, we used a technique with good spatial specificity-repetitive transcranial magnetic stimulation (rTMS)-to demonstrate a necessary role of ATL in exception word reading. Following rTMS to left ventral ATL, healthy Japanese adults made more regularization errors in reading Japanese exception words. We successfully simulated these results in a computational model in which exception word reading was underpinned by semantic activations. The ATL is critically and selectively involved in reading exception words.

Hybrid diagnostic system: beacon-based exception analysis for multimissions - Livingstone integration

NASA Technical Reports Server (NTRS)

Park, Han G.; Cannon, Howard; Bajwa, Anupa; Mackey, Ryan; James, Mark; Maul, William

2004-01-01

This paper describes the initial integration of a hybrid reasoning system utilizing a continuous domain feature-based detector, Beacon-based Exceptions Analysis for Multimissions (BEAM), and a discrete domain model-based reasoner, Livingstone.

Outcomes of Liver Transplant Recipients With Model for End-Stage Liver Disease Exception: Single-Center Experience in the Northeast of Brazil.

PubMed

Coelho, G R; Praciano, A M; Viana, G N R; Lima, C A; Feitosa Neto, B A; Garcia, J H P

2018-06-01

The Model for End-Stage Liver Disease (MELD) exception policy in liver transplantation is based on symptoms and clinical conditions not included in the calculated MELD score. Therefore, patients with chronic liver disease, like refractory ascites, chronic encephalopathy, recurrent cholangitis, and refractory pruritus, may benefit with extra points. The objective of this study was to establish the profile of the patients submitted to liver transplantation with MELD exceptions based on symptoms in the University Hospital Walter Cantídio, Ceara, Brazil, between the years of 2012 and 2015, analyzing donor and recipient data, with special attention to patients with refractory ascites and recurrent encephalopathy, including survival rates. The results demonstrated acceptable survival rates for MELD exception patients (78.4% in 3 years), showing that maybe this allocation criterion should be maintained, or even expanded. Copyright © 2018 Elsevier Inc. All rights reserved.

Simulation of late inspiratory rise in airway pressure during pressure support ventilation.

PubMed

Yu, Chun-Hsiang; Su, Po-Lan; Lin, Wei-Chieh; Lin, Sheng-Hsiang; Chen, Chang-Wen

2015-02-01

Late inspiratory rise in airway pressure (LIRAP, Paw/ΔT) caused by inspiratory muscle relaxation or expiratory muscle contraction is frequently seen during pressure support ventilation (PSV), although the modulating factors are unknown. We investigated the effects of respiratory mechanics (normal, obstructive, restrictive, or mixed), inspiratory effort (-2, -8, or -15 cm H2O), flow cycle criteria (5-40% peak inspiratory flow), and duration of inspiratory muscle relaxation (0.18-0.3 s) on LIRAP during PSV using a lung simulator and 4 types of ventilators. LIRAP occurred with all lung models when inspiratory effort was medium to high and duration of inspiratory muscle relaxation was short. The normal lung model was associated with the fastest LIRAP, whereas the obstructive lung model was associated with the slowest. Unless lung mechanics were normal or mixed, LIRAP was unlikely to occur when inspiratory effort was low. Different ventilators were also associated with differences in LIRAP speed. Except for within the restrictive lung model, changes in flow cycle level did not abolish LIRAP if inspiratory effort was medium to high. Increased duration of inspiratory relaxation also led to the elimination of LIRAP. Simulation of expiratory muscle contraction revealed that LIRAP occurred only when expiratory muscle contraction occurred sometime after the beginning of inspiration. Our simulation study reveals that both respiratory resistance and compliance may affect LIRAP. Except for under restrictive lung conditions, LIRAP is unlikely to be abolished by simply lowering flow cycle criteria when inspiratory effort is strong and relaxation time is rapid. LIRAP may be caused by expiratory muscle contraction when it occurs during inspiration. Copyright © 2015 by Daedalus Enterprises.

Effects of psychosocial work factors on lifestyle changes: a cohort study.

PubMed

Allard, Karin Olofsson; Thomsen, Jane Frølund; Mikkelsen, Sigurd; Rugulies, Reiner; Mors, Ole; Kærgaard, Anette; Kolstad, Henrik A; Kaerlev, Linda; Andersen, Johan Hviid; Hansen, Ase Marie; Bonde, Jens Peter

2011-12-01

To evaluate the effect of the demand-control-support model, the effort-reward imbalance model, and emotional demands on smoking, alcohol consumption, physical activity, and body mass index. This is a 2-year prospective cohort study of 3224 public sector employees. Measures were assessed with questionnaires. Multiple regression analyses were used to predict changes in lifestyle factors. Low reward predicted smoking, low-decision latitude predicted being inactive, and high demands predicted high-alcohol consumption but only for men at follow-up even after controlling for potential confounders. There were no other significant findings in the expected direction except for some of the confounders. We found only limited and inconsistent support for the hypothesis that a poor psychosocial work environment is associated with an adverse lifestyle.

Experimental quantum computing without entanglement.

PubMed

Lanyon, B P; Barbieri, M; Almeida, M P; White, A G

2008-11-14

Deterministic quantum computation with one pure qubit (DQC1) is an efficient model of computation that uses highly mixed states. Unlike pure-state models, its power is not derived from the generation of a large amount of entanglement. Instead it has been proposed that other nonclassical correlations are responsible for the computational speedup, and that these can be captured by the quantum discord. In this Letter we implement DQC1 in an all-optical architecture, and experimentally observe the generated correlations. We find no entanglement, but large amounts of quantum discord-except in three cases where an efficient classical simulation is always possible. Our results show that even fully separable, highly mixed, states can contain intrinsically quantum mechanical correlations and that these could offer a valuable resource for quantum information technologies.

Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy

DOE PAGES

Zhang, Zijiao; Sheng, Hongwei; Wang, Zhangjie; ...

2017-02-20

Combinations of high strength and ductility are hard to attain in metals. Exceptions include materials exhibiting twinning-induced plasticity. To understand how the strength-ductility trade-off can be defeated, we apply in situ, and aberration-corrected scanning, transmission electron microscopy to examine deformation mechanisms in the medium-entropy alloy CrCoNi that exhibits one of the highest combinations of strength, ductility and toughness on record. Ab initio modelling suggests that it has negative stacking-fault energy at 0K and high propensity for twinning. With deformation we find that a three-dimensional (3D) hierarchical twin network forms from the activation of three twinning systems. This serves a dualmore » function: conventional twin-boundary (TB) strengthening from blockage of dislocations impinging on TBs, coupled with the 3D twin network which offers pathways for dislocation glide along, and cross-slip between, intersecting TB-matrix interfaces. The stable twin architecture is not disrupted by interfacial dislocation glide, serving as a continuous source of strength, ductility and toughness.« less

Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy

PubMed Central

Zhang, Zijiao; Sheng, Hongwei; Wang, Zhangjie; Gludovatz, Bernd; Zhang, Ze; George, Easo P.; Yu, Qian; Mao, Scott X.; Ritchie, Robert O.

2017-01-01

Combinations of high strength and ductility are hard to attain in metals. Exceptions include materials exhibiting twinning-induced plasticity. To understand how the strength-ductility trade-off can be defeated, we apply in situ, and aberration-corrected scanning, transmission electron microscopy to examine deformation mechanisms in the medium-entropy alloy CrCoNi that exhibits one of the highest combinations of strength, ductility and toughness on record. Ab initio modelling suggests that it has negative stacking-fault energy at 0K and high propensity for twinning. With deformation we find that a three-dimensional (3D) hierarchical twin network forms from the activation of three twinning systems. This serves a dual function: conventional twin-boundary (TB) strengthening from blockage of dislocations impinging on TBs, coupled with the 3D twin network which offers pathways for dislocation glide along, and cross-slip between, intersecting TB-matrix interfaces. The stable twin architecture is not disrupted by interfacial dislocation glide, serving as a continuous source of strength, ductility and toughness. PMID:28218267

Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy.

PubMed

Zhang, Zijiao; Sheng, Hongwei; Wang, Zhangjie; Gludovatz, Bernd; Zhang, Ze; George, Easo P; Yu, Qian; Mao, Scott X; Ritchie, Robert O

2017-02-20

Combinations of high strength and ductility are hard to attain in metals. Exceptions include materials exhibiting twinning-induced plasticity. To understand how the strength-ductility trade-off can be defeated, we apply in situ, and aberration-corrected scanning, transmission electron microscopy to examine deformation mechanisms in the medium-entropy alloy CrCoNi that exhibits one of the highest combinations of strength, ductility and toughness on record. Ab initio modelling suggests that it has negative stacking-fault energy at 0K and high propensity for twinning. With deformation we find that a three-dimensional (3D) hierarchical twin network forms from the activation of three twinning systems. This serves a dual function: conventional twin-boundary (TB) strengthening from blockage of dislocations impinging on TBs, coupled with the 3D twin network which offers pathways for dislocation glide along, and cross-slip between, intersecting TB-matrix interfaces. The stable twin architecture is not disrupted by interfacial dislocation glide, serving as a continuous source of strength, ductility and toughness.

Sensitivity analysis of source regions to PM2.5 concentration at Fukue Island, Japan.

PubMed

Ikeda, Kohei; Yamaji, Kazuyo; Kanaya, Yugo; Taketani, Fumikazu; Pan, Xiaole; Komazaki, Yuichi; Kurokawa, Jun-ichi; Ohara, Toshimasa

2014-04-01

The authors analyze the sensitivities of source regions in East Asia to PM2.5 (particulate matter with an aerodynamic diameter of < or = 2.5 microm) concentration at Fukue Island located in the western part of Japan by using a regional chemical transport model with emission sensitivity simulations for the year 2010. The temporal variations in PM2.5 concentration are generally reproduced, but the absolute concentration is underestimated by the model. Chemical composition of PM2.5 in the model is compared with filter sampling data in spring; simulated sulfate, ammonium, and elemental carbon are consistent with observations, but mass concentration of particulate organic matters is underestimated. The relative contribution from each source region shows the seasonal variation, especially in summer. The contribution from central north China (105 degrees E-124 degrees E, 34 degrees N-42 degrees N) accounts for 50-60% of PM2.5 at Fukue Island except in summer; it significantly decreases in summer (18%). Central south China (105 degrees E-123 degrees E, 26 degrees N-34 degrees N) has the relative contribution of 15-30%. The contribution from the Korean Peninsula is estimated at about 10% except in summer. The domestic contribution accounts for about 7% in spring and autumn and increases to 19% in summer. We also estimate the relative contribution to daily average concentration in high PM2.5 days (> 35 microg m(-3)). Central north China has a significant contribution of 60-70% except in summer. The relative contribution from central south China is estimated at 46% in summer and about 30% in the other seasons. The contributions from central north and south China on high PM2.5 days are generally larger than those of their seasonal mean contributions. The domestic contribution is smaller than the seasonal mean value in every season; it is less than 10% even in summer. These model results suggest that foreign anthropogenic sources have a substantial impact on attainment of the atmospheric environmental standard of Japan at Fukue Island. The contribution from several source regions in East Asia to PM2.5 concentration at Fukue Island, a remote island located in the western part of Japan and close to the Asian continent, is estimated using a three-dimensional chemical transport model. The model results suggest that PM2.5 that is attributed to foreign anthropogenic sources have a larger contribution than that of domestic pollution and have a substantial impact on attainment of the atmospheric environmental standard of Japan at Fukue Island.

Multi-Sensory Aerosol Data and the NRL NAAPS model for Regulatory Exceptional Event Analysis

NASA Astrophysics Data System (ADS)

Husar, R. B.; Hoijarvi, K.; Westphal, D. L.; Haynes, J.; Omar, A. H.; Frank, N. H.

2013-12-01

Beyond scientific exploration and analysis, multi-sensory observations along with models are finding increasing applications for operational air quality management. EPA's Exceptional Event (EE) Rule allows the exclusion of data strongly influenced by impacts from "exceptional events," such as smoke from wildfires or dust from abnormally high winds. The EE Rule encourages the use of satellite observations and other non-standard data along with models as evidence for formal documentation of EE samples for exclusion. Thus, the implementation of the EE Rule is uniquely suited for the direct application of integrated multi-sensory observations and indirectly through the assimilation into an aerosol simulation model. Here we report the results of a project: NASA and NAAPS Products for Air Quality Decision Making. The project uses of observations from multiple satellite sensors, surface-based aerosol measurements and the NRL Aerosol Analysis and Prediction System (NAAPS) model that assimilates key satellite observations. The satellite sensor data for detecting and documenting smoke and dust events include: MODIS AOD and Images; OMI Aerosol Index, Tropospheric NO2; AIRS, CO. The surface observations include the EPA regulatory PM2.5 network; the IMPROVE/STN aerosol chemical network; AIRNOW PM2.5 mass network, and surface met. data. Within this application, crucial role is assigned to the NAAPS model for estimating the surface concentration of windblown dust and biomass smoke. The operational model assimilates quality-assured daily MODIS data and 2DVAR to adjust the model concentrations and CALIOP-based climatology to adjust the vertical profiles at 6-hour intervals. The assimilation of satellite data from multiple satellites significantly contributes to the usefulness of NAAPS for EE analysis. The NAAPS smoke and dust simulations were evaluated using the IMPROVE/STN chemical data. The multi-sensory observations along with the model simulations are integrated into a web-based Exceptional Event Decision System (EE DSS) application program, designed to support air quality analysts at the Federal and Regional EPA offices and the EE-affected States. EE DSS screening tool automatically identifies the EPA PM2.5 mass samples that are candidates for EE flagging, based mainly on the NAAPS-simulated surface concentration of dust and smoke. The AQ analysts at the States and the EPA can also use the EE DSS to gather further evidence from the examination of spatio-temporal pattern, Absorbing Aerosol Index, CO and NO2 concentration, backward and forward airmass trajectories and other signatures. Since early 2013, the DSS has been used for the identification and analysis of dozens of events. Hence, integration of multi-sensory observations and modeling with data assimilation is maturing to support real-world operational AQ management applications. The remaining challenges can be resolved by seeking ';closure' of the system components; i.e. the systematic adjustments to reconcile the satellite and surface observations, the emissions and their integration through a suitable AQ model.

Regulatory Disruption and Arbitrage in Health-Care Data Protection.

PubMed

Terry, Nicolas P

This article explains how the structure of U.S. health-care data protection (specifically its sectoral and downstream properties) has led to a chronically uneven policy environment for different types of health-care data. It examines claims for health-care data protection exceptionalism and competing demands such as data liquidity. In conclusion, the article takes the position that healthcare- data exceptionalism remains a valid imperative and that even current concerns about data liquidity can be accommodated in an exceptional protective model. However, re-calibrating our protection of health-care data residing outside of the traditional health-care domain is challenging, currently even politically impossible. Notwithstanding, a hybrid model is envisioned with downstream HIPAA model remaining the dominant force within the health-care domain, but being supplemented by targeted upstream and point-of-use protections applying to health-care data in disrupted spaces.

Computational Study of the Genomic and Epigenomic Phenomena

NASA Astrophysics Data System (ADS)

Yang, Wenjing

Biological systems are perhaps the ultimate complex systems, uniquely capable of processing and communicating information, reproducing in their lifetimes, and adapting in evolutionary time scales. My dissertation research focuses on using computational approaches to understand the biocomplexity manifested in the multitude of length scales and time scales. At the molecular and cellular level, central to the complex behavior of a biological system is the regulatory network. My research study focused on epigenetics, which is essential for multicellular organisms to establish cellular identity during development or in response to intracellular and environmental stimuli. My computational study of epigenomics is greatly facilitated by recent advances in high-throughput sequencing technology, which enables high-resolution snapshots of epigenomes and transcriptomes. Using human CD4+ T cell as a model system, the dynamical changes in epigenome and transcriptome pertinent to T cell activation were investigated at the genome scale. Going beyond traditional focus on transcriptional regulation, I provided evidences that post-transcriptional regulation may serve as a major component of the regulatory network. In addition, I explored alternative polyadenylation, another novel aspect of gene regulation, and how it cross-talks with the local chromatin structure. As the renowned theoretical biologist Theodosius Dobzhansky said eloquently, "Nothing in biology makes sense except in the light of evolution''. To better understand this ubiquitous driving force in the biological world, I went beyond molecular events in a single organism, and investigated the dynamical changes of population structure along the evolutionary time scale. To this end, we used HIV virus population dynamics in the host immune system as a model system. The evolution of HIV viral population plays a key role in AIDS immunopathogenesis with its exceptionally high mutation rate. However, the theoretical studies of the effect of recombination have been rather limited. Given the phylogenetic and experimental evidences for the high recombination rate and its important role in HIV evolution and epidemics, I established a mathematical model to study the effect of recombination, and explored the complex behavior of this dynamics system.

Usefulness of a Darwinian System in a Biotechnological Application: Evolution of Optical Window Fluorescent Protein Variants under Selective Pressure

PubMed Central

Ng, David; Pauli, Jutta; Resch-Genger, Ute; Kühn, Enrico; Heuer, Steffen; Beisker, Wolfgang; Köster, Reinhard W.; Zitzelsberger, Horst; Caldwell, Randolph B

2014-01-01

With rare exceptions, natural evolution is an extremely slow process. One particularly striking exception in the case of protein evolution is in the natural production of antibodies. Developing B cells activate and diversify their immunoglobulin (Ig) genes by recombination, gene conversion (GC) and somatic hypermutation (SHM). Iterative cycles of hypermutation and selection continue until antibodies of high antigen binding specificity emerge (affinity maturation). The avian B cell line DT40, a cell line which is highly amenable to genetic manipulation and exhibits a high rate of targeted integration, utilizes both GC and SHM. Targeting the DT40's diversification machinery onto transgenes of interest inserted into the Ig loci and coupling selective pressure based on the desired outcome mimics evolution. Here we further demonstrate the usefulness of this platform technology by selectively pressuring a large shift in the spectral properties of the fluorescent protein eqFP615 into the highly stable and advanced optical imaging expediting fluorescent protein Amrose. The method is advantageous as it is time and cost effective and no prior knowledge of the outcome protein's structure is necessary. Amrose was evolved to have high excitation at 633 nm and excitation/emission into the far-red, which is optimal for whole-body and deep tissue imaging as we demonstrate in the zebrafish and mouse model. PMID:25192257

Usefulness of a Darwinian system in a biotechnological application: evolution of optical window fluorescent protein variants under selective pressure.

PubMed

Schoetz, Ulrike; Deliolanis, Nikolaos C; Ng, David; Pauli, Jutta; Resch-Genger, Ute; Kühn, Enrico; Heuer, Steffen; Beisker, Wolfgang; Köster, Reinhard W; Zitzelsberger, Horst; Caldwell, Randolph B

2014-01-01

With rare exceptions, natural evolution is an extremely slow process. One particularly striking exception in the case of protein evolution is in the natural production of antibodies. Developing B cells activate and diversify their immunoglobulin (Ig) genes by recombination, gene conversion (GC) and somatic hypermutation (SHM). Iterative cycles of hypermutation and selection continue until antibodies of high antigen binding specificity emerge (affinity maturation). The avian B cell line DT40, a cell line which is highly amenable to genetic manipulation and exhibits a high rate of targeted integration, utilizes both GC and SHM. Targeting the DT40's diversification machinery onto transgenes of interest inserted into the Ig loci and coupling selective pressure based on the desired outcome mimics evolution. Here we further demonstrate the usefulness of this platform technology by selectively pressuring a large shift in the spectral properties of the fluorescent protein eqFP615 into the highly stable and advanced optical imaging expediting fluorescent protein Amrose. The method is advantageous as it is time and cost effective and no prior knowledge of the outcome protein's structure is necessary. Amrose was evolved to have high excitation at 633 nm and excitation/emission into the far-red, which is optimal for whole-body and deep tissue imaging as we demonstrate in the zebrafish and mouse model.

Resilience Predictors of Violence and Externalizing Behavior Problems for Urban Exceptional Students.

ERIC Educational Resources Information Center

Perry, Joseph D.; Bard, E. M.

This study analyzed the association between resilience and violence as rated by teachers and parents of exceptional students (N=613) from large urban, public schools in Ohio. Multiple types of exceptionalities were represented and a high proportion of the diversity came from low socioeconomic backgrounds. Resilience predictor variables were…

Frequency domain finite-element and spectral-element acoustic wave modeling using absorbing boundaries and perfectly matched layer

NASA Astrophysics Data System (ADS)

Rahimi Dalkhani, Amin; Javaherian, Abdolrahim; Mahdavi Basir, Hadi

2018-04-01

Wave propagation modeling as a vital tool in seismology can be done via several different numerical methods among them are finite-difference, finite-element, and spectral-element methods (FDM, FEM and SEM). Some advanced applications in seismic exploration benefit the frequency domain modeling. Regarding flexibility in complex geological models and dealing with the free surface boundary condition, we studied the frequency domain acoustic wave equation using FEM and SEM. The results demonstrated that the frequency domain FEM and SEM have a good accuracy and numerical efficiency with the second order interpolation polynomials. Furthermore, we developed the second order Clayton and Engquist absorbing boundary condition (CE-ABC2) and compared it with the perfectly matched layer (PML) for the frequency domain FEM and SEM. In spite of PML method, CE-ABC2 does not add any additional computational cost to the modeling except assembling boundary matrices. As a result, considering CE-ABC2 is more efficient than PML for the frequency domain acoustic wave propagation modeling especially when computational cost is high and high-level absorbing performance is unnecessary.

Development of a model and test equipment for cold flow tests at 500 atm of small nuclear light bulb configurations

NASA Technical Reports Server (NTRS)

Jaminet, J. F.

1972-01-01

A model and test equipment were developed and cold-flow-tested at greater than 500 atm in preparation for future high-pressure rf plasma experiments and in-reactor tests with small nuclear light bulb configurations. With minor exceptions, the model chamber is similar in design and dimensions to a proposed in-reactor geometry for tests with fissioning uranium plasmas in the nuclear furnace. The model and the equipment were designed for use with the UARL 1.2-MW rf induction heater in tests with rf plasmas at pressures up to 500 atm. A series of cold-flow tests of the model was then conducted at pressures up to about 510 atm. At 504 atm, the flow rates of argon and cooling water were 3.35 liter/sec (STP) and 26 gal/min, respectively. It was demonstrated that the model is capable of being operated for extended periods at the 500-atm pressure level and is, therefore, ready for use in initial high-pressure rf plasma experiments.

Transient processes in the combustion of nitramine propellants

NASA Technical Reports Server (NTRS)

Cohen, N. S.; Strand, L. D.

1978-01-01

A transient combustion model of nitramine propellants is combined with an isentropic compression shock formation model to determine the role of nitramine propellant combustion in DDT, excluding effects associated with propellant structural properties or mechanical behavior. The model is derived to represent the closed pipe experiment that is widely used to characterize explosives, except that the combustible material is a monolithic charge rather than compressed powder. Computations reveal that the transient combustion process cannot by itself produce DDT by this model. Compressibility of the solid at high pressure is the key factor limiting pressure buildups created by the combustion. On the other hand, combustion mechanisms which promote pressure buildups are identified and related to propellant formulation variables. Additional combustion instability data for nitramine propellants are presented. Although measured combustion response continues to be low, more data are required to distinguish HMX and active binder component contributions. A design for a closed vessel apparatus for experimental studies of high pressure combustion is discussed.

Quantum models with energy-dependent potentials solvable in terms of exceptional orthogonal polynomials

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

Schulze-Halberg, Axel, E-mail: axgeschu@iun.edu; Department of Physics, Indiana University Northwest, 3400 Broadway, Gary IN 46408; Roy, Pinaki, E-mail: pinaki@isical.ac.in

We construct energy-dependent potentials for which the Schrödinger equations admit solutions in terms of exceptional orthogonal polynomials. Our method of construction is based on certain point transformations, applied to the equations of exceptional Hermite, Jacobi and Laguerre polynomials. We present several examples of boundary-value problems with energy-dependent potentials that admit a discrete spectrum and the corresponding normalizable solutions in closed form.

Automatic tissue segmentation of head and neck MR images for hyperthermia treatment planning

NASA Astrophysics Data System (ADS)

Fortunati, Valerio; Verhaart, René F.; Niessen, Wiro J.; Veenland, Jifke F.; Paulides, Margarethus M.; van Walsum, Theo

2015-08-01

A hyperthermia treatment requires accurate, patient-specific treatment planning. This planning is based on 3D anatomical models which are generally derived from computed tomography. Because of its superior soft tissue contrast, magnetic resonance imaging (MRI) information can be introduced to improve the quality of these 3D patient models and therefore the treatment planning itself. Thus, we present here an automatic atlas-based segmentation algorithm for MR images of the head and neck. Our method combines multiatlas local weighting fusion with intensity modelling. The accuracy of the method was evaluated using a leave-one-out cross validation experiment over a set of 11 patients for which manual delineation were available. The accuracy of the proposed method was high both in terms of the Dice similarity coefficient (DSC) and the 95th percentile Hausdorff surface distance (HSD) with median DSC higher than 0.8 for all tissues except sclera. For all tissues, except the spine tissues, the accuracy was approaching the interobserver agreement/variability both in terms of DSC and HSD. The positive effect of adding the intensity modelling to the multiatlas fusion decreased when a more accurate atlas fusion method was used. Using the proposed approach we improved the performance of the approach previously presented for H&N hyperthermia treatment planning, making the method suitable for clinical application.

Reconciling leaf physiological traits and canopy flux data: Use of the TRY and FLUXNET databases in the Community Land Model version 4

NASA Astrophysics Data System (ADS)

Bonan, Gordon B.; Oleson, Keith W.; Fisher, Rosie A.; Lasslop, Gitta; Reichstein, Markus

2012-06-01

The Community Land Model version 4 overestimates gross primary production (GPP) compared with estimates from FLUXNET eddy covariance towers. The revised model of Bonan et al. (2011) is consistent with FLUXNET, but values for the leaf-level photosynthetic parameterVcmaxthat yield realistic GPP at the canopy-scale are lower than observed in the global synthesis of Kattge et al. (2009), except for tropical broadleaf evergreen trees. We investigate this discrepancy betweenVcmaxand canopy fluxes. A multilayer model with explicit calculation of light absorption and photosynthesis for sunlit and shaded leaves at depths in the canopy gives insight to the scale mismatch between leaf and canopy. We evaluate the model with light-response curves at individual FLUXNET towers and with empirically upscaled annual GPP. Biases in the multilayer canopy with observedVcmaxare similar, or improved, compared with the standard two-leaf canopy and its lowVcmax, though the Amazon is an exception. The difference relates to light absorption by shaded leaves in the two-leaf canopy, and resulting higher photosynthesis when the canopy scaling parameterKn is low, but observationally constrained. Larger Kndecreases shaded leaf photosynthesis and reduces the difference between the two-leaf and multilayer canopies. The low modelVcmaxis diagnosed from nitrogen reduction of GPP in simulations with carbon-nitrogen biogeochemistry. Our results show that the imposed nitrogen reduction compensates for deficiency in the two-leaf canopy that produces high GPP. Leaf trait databases (Vcmax), within-canopy profiles of photosynthetic capacity (Kn), tower fluxes, and empirically upscaled fields provide important complementary information for model evaluation.

Integrated Formulation of Beacon-Based Exception Analysis for Multimissions

NASA Technical Reports Server (NTRS)

Mackey, Ryan; James, Mark; Park, Han; Zak, Mickail

2003-01-01

Further work on beacon-based exception analysis for multimissions (BEAM), a method of real-time, automated diagnosis of a complex electromechanical systems, has greatly expanded its capability and suitability of application. This expanded formulation, which fully integrates physical models and symbolic analysis, is described. The new formulation of BEAM expands upon previous advanced techniques for analysis of signal data, utilizing mathematical modeling of the system physics, and expert-system reasoning,

Glasses having a low non-linear refractive index for laser applications

DOEpatents

Faulstich, Marga; Jahn, Walter; Krolla, Georg; Neuroth, Norbert

1980-01-01

Glass composition ranges are described which permit the introduction of laser activators into fluorphosphate glass with exceptionally high fluorine content while forming glasses of high crystallization stability and permitting the realization of large melt volumes. The high fluorine content imparts to the glasses an exceptionally low nonlinear refractive index n.sub.2 down to O,4 .times.10.sup.-13 esu.

Unifying Type-II Strings by Exceptional Groups

NASA Astrophysics Data System (ADS)

Arvanitakis, Alex S.; Blair, Chris D. A.

2018-05-01

We construct the exceptional sigma model: a two-dimensional sigma model coupled to a supergravity background in a manifestly (formally) ED (D )-covariant manner. This formulation of the background is provided by exceptional field theory (EFT), which unites the metric and form fields of supergravity in ED (D ) multiplets before compactification. The realization of the symmetries of EFT on the world sheet uniquely fixes the Weyl-invariant Lagrangian and allows us to relate our action to the usual type-IIA fundamental string action and a form of the type-IIB (m , n ) action. This uniqueness "predicts" the correct form of the couplings to gauge fields in both Neveu-Schwarz and Ramond sectors, without invoking supersymmetry.

The structure of evaporating and combusting sprays: Measurements and predictions

NASA Technical Reports Server (NTRS)

Shuen, J. S.; Solomon, A. S. P.; Faeth, G. M.

1982-01-01

An apparatus was constructed to provide measurements in open sprays with no zones of recirculation, in order to provide well-defined conditions for use in evaluating spray models. Measurements were completed in a gas jet, in order to test experimental methods, and are currently in progress for nonevaporating sprays. A locally homogeneous flow (LHF) model where interphase transport rates are assumed to be infinitely fast; a separated flow (SF) model which allows for finite interphase transport rates but neglects effects of turbulent fluctuations on drop motion; and a stochastic SF model which considers effects of turbulent fluctuations on drop motion were evaluated using existing data on particle-laden jets. The LHF model generally overestimates rates of particle dispersion while the SF model underestimates dispersion rates. The stochastic SF flow yield satisfactory predictions except at high particle mass loadings where effects of turbulence modulation may have caused the model to overestimate turbulence levels.

A High-Resolution Integrated Model of the National Ignition Campaign Cryogenic Layered Experiments

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

Jones, O. S.; Callahan, D. A.; Cerjan, C. J.

A detailed simulation-based model of the June 2011 National Ignition Campaign (NIC) cryogenic DT experiments is presented. The model is based on integrated hohlraum-capsule simulations that utilize the best available models for the hohlraum wall, ablator, and DT equations of state and opacities. The calculated radiation drive was adjusted by changing the input laser power to match the experimentally measured shock speeds, shock merger times, peak implosion velocity, and bangtime. The crossbeam energy transfer model was tuned to match the measured time-dependent symmetry. Mid-mode mix was included by directly modeling the ablator and ice surface perturbations up to mode 60.more » Simulated experimental values were extracted from the simulation and compared against the experiment. The model adjustments brought much of the simulated data into closer agreement with the experiment, with the notable exception of the measured yields, which were 15-40% of the calculated yields.« less

A High-Resolution Integrated Model of the National Ignition Campaign Cryogenic Layered Experiments

DOE PAGES

Jones, O. S.; Callahan, D. A.; Cerjan, C. J.; ...

2012-05-29

A detailed simulation-based model of the June 2011 National Ignition Campaign (NIC) cryogenic DT experiments is presented. The model is based on integrated hohlraum-capsule simulations that utilize the best available models for the hohlraum wall, ablator, and DT equations of state and opacities. The calculated radiation drive was adjusted by changing the input laser power to match the experimentally measured shock speeds, shock merger times, peak implosion velocity, and bangtime. The crossbeam energy transfer model was tuned to match the measured time-dependent symmetry. Mid-mode mix was included by directly modeling the ablator and ice surface perturbations up to mode 60.more » Simulated experimental values were extracted from the simulation and compared against the experiment. The model adjustments brought much of the simulated data into closer agreement with the experiment, with the notable exception of the measured yields, which were 15-40% of the calculated yields.« less

Factors Distinguishing Exceptional Performance on the Uniform CPA Exam.

ERIC Educational Resources Information Center

Ashbaugh, Donald L.; Thompson, A. Frank

1993-01-01

Analysis of data from 234 Certified Public Accountant (CPA) candidates (98 of whom failed at least 1 part of the exam) showed that higher grades in the CPA review course correlated with passing the first time. Higher high school class rank and larger high school class size influenced exceptional test performance. (SK)

Comparison of Groundwater Level Models Based on Artificial Neural Networks and ANFIS

PubMed Central

Domazet, Milka; Stricevic, Ruzica; Pocuca, Vesna; Spalevic, Velibor; Pivic, Radmila; Gregoric, Enika; Domazet, Uros

2015-01-01

Water table forecasting plays an important role in the management of groundwater resources in agricultural regions where there are drainage systems in river valleys. The results presented in this paper pertain to an area along the left bank of the Danube River, in the Province of Vojvodina, which is the northern part of Serbia. Two soft computing techniques were used in this research: an adaptive neurofuzzy inference system (ANFIS) and an artificial neural network (ANN) model for one-month water table forecasts at several wells located at different distances from the river. The results suggest that both these techniques represent useful tools for modeling hydrological processes in agriculture, with similar computing and memory capabilities, such that they constitute an exceptionally good numerical framework for generating high-quality models. PMID:26759830

Comparison of Groundwater Level Models Based on Artificial Neural Networks and ANFIS.

PubMed

Djurovic, Nevenka; Domazet, Milka; Stricevic, Ruzica; Pocuca, Vesna; Spalevic, Velibor; Pivic, Radmila; Gregoric, Enika; Domazet, Uros

2015-01-01

Water table forecasting plays an important role in the management of groundwater resources in agricultural regions where there are drainage systems in river valleys. The results presented in this paper pertain to an area along the left bank of the Danube River, in the Province of Vojvodina, which is the northern part of Serbia. Two soft computing techniques were used in this research: an adaptive neurofuzzy inference system (ANFIS) and an artificial neural network (ANN) model for one-month water table forecasts at several wells located at different distances from the river. The results suggest that both these techniques represent useful tools for modeling hydrological processes in agriculture, with similar computing and memory capabilities, such that they constitute an exceptionally good numerical framework for generating high-quality models.

An exceptional fossil skull from South America and the origins of the archosauriform radiation

NASA Astrophysics Data System (ADS)

Pinheiro, Felipe L.; França, Marco A. G.; Lacerda, Marcel B.; Butler, Richard J.; Schultz, Cesar L.

2016-03-01

Birds, dinosaurs, crocodilians, pterosaurs and their close relatives form the highly diverse clade Archosauriformes. Archosauriforms have a deep evolutionary history, originating in the late Permian, prior to the end-Permian mass extinction, and radiating in the Triassic to dominate Mesozoic ecosystems. However, the origins of this clade and its extraordinarily successful body plan remain obscure. Here, we describe an exceptionally preserved fossil skull from the Lower Triassic of Brazil, representing a new species, Teyujagua paradoxa, transitional in morphology between archosauriforms and more primitive reptiles. This skull reveals for the first time the mosaic assembly of key features of the archosauriform skull, including the antorbital and mandibular fenestrae, serrated teeth, and closed lower temporal bar. Phylogenetic analysis recovers Teyujagua as the sister taxon to Archosauriformes, and is congruent with a two-phase model of early archosauriform evolution, in response to two mass extinctions occurring at the end of the Guadalupian and the Permian.

Establishment and Characterization of a Highly Tumourigenic and Cancer Stem Cell Enriched Pancreatic Cancer Cell Line as a Well Defined Model System

PubMed Central

Fredebohm, Johannes; Boettcher, Michael; Eisen, Christian; Gaida, Matthias M.; Heller, Anette; Keleg, Shereen; Tost, Jörg; Greulich-Bode, Karin M.; Hotz-Wagenblatt, Agnes; Lathrop, Mark; Giese, Nathalia A.; Hoheisel, Jörg D.

2012-01-01

Standard cancer cell lines do not model the intratumoural heterogeneity situation sufficiently. Clonal selection leads to a homogeneous population of cells by genetic drift. Heterogeneity of tumour cells, however, is particularly critical for therapeutically relevant studies, since it is a prerequisite for acquiring drug resistance and reoccurrence of tumours. Here, we report the isolation of a highly tumourigenic primary pancreatic cancer cell line, called JoPaca-1 and its detailed characterization at multiple levels. Implantation of as few as 100 JoPaca-1 cells into immunodeficient mice gave rise to tumours that were histologically very similar to the primary tumour. The high heterogeneity of JoPaca-1 was reflected by diverse cell morphology and a substantial number of chromosomal aberrations. Comparative whole-genome sequencing of JoPaca-1 and BxPC-3 revealed mutations in genes frequently altered in pancreatic cancer. Exceptionally high expression of cancer stem cell markers and a high clonogenic potential in vitro and in vivo was observed. All of these attributes make this cell line an extremely valuable model to study the biology of and pharmaceutical effects on pancreatic cancer. PMID:23152778

The relative contribution of climatic, edaphic, and biotic drivers to risk of tree mortality from drought

NASA Astrophysics Data System (ADS)

March, R. G.; Moore, G. W.; Edgar, C. B.; Lawing, A. M.; Washington-Allen, R. A.

2015-12-01

In recorded history, the 2011 Texas Drought was comparable in severity only to a drought that occurred 300 years ago. By mid-September, 88% of the state experienced 'exceptional' conditions, with the rest experiencing 'extreme' or 'severe' drought. By recent estimates, the 2011 Texas Drought killed 6.2% of all the state's trees, at a rate nearly 9 times greater than average. The vast spatial scale and relatively uniform intensity of this drought has provided an opportunity to examine the comparative interactions among forest types, terrain, and edaphic factors across major climate gradients which in 2011 were subjected to extreme drought conditions that ultimately caused massive tree mortality. We used maximum entropy modeling (Maxent) to rank environmental landscape factors with the potential to drive drought-related tree mortality and test the assumption that the relative importance of these factors are scale-dependent. Occurrence data of dead trees were collected during the summer of 2012 from 599 field plots distributed across Texas with 30% used for model evaluation. Bioclimatic variables, ecoregions, soils characteristics, and topographic variables were modeled with drought-killed tree occurrence. Their relative contribution to the model was seen as their relative importance in driving mortality. To test determinants at a more local scale, we examined Landsat 7 scenes in East and West Texas with moderate-resolution data for the same variables above with the exception of climate. All models were significantly better than random in binomial tests of omission and receiver operating characteristic analyses. The modeled spatial distribution of probability of occurrence showed high probability of mortality in the east-central oak woodlands and the mixed pine-hardwood forest region in northeast Texas. Both regional and local models were dominated by biotic factors (ecoregion and forest type, respectively). Forest density and precipitation of driest month also contributed highly to the regional model. The local models gave more importance to available water storage at root zone and hillshade. Understanding how environmental factors drive drought-related mortality can help predict vulnerable landscapes and aid in preparing for future drought events.

Scaled boundary finite element simulation and modeling of the mechanical behavior of cracked nanographene sheets

NASA Astrophysics Data System (ADS)

Honarmand, M.; Moradi, M.

2018-06-01

In this paper, by using scaled boundary finite element method (SBFM), a perfect nanographene sheet or cracked ones were simulated for the first time. In this analysis, the atomic carbon bonds were modeled by simple bar elements with circular cross-sections. Despite of molecular dynamics (MD), the results obtained from SBFM analysis are quite acceptable for zero degree cracks. For all angles except zero, Griffith criterion can be applied for the relation between critical stress and crack length. Finally, despite the simplifications used in nanographene analysis, obtained results can simulate the mechanical behavior with high accuracy compared with experimental and MD ones.

The Possible Impact of Problem-Solving Method of Instruction on Exceptional Students' Creativity

ERIC Educational Resources Information Center

Fard, Adnan Eshrati; Bahador, Ali; Moghadam, Mahsa Nazemi; Rajabi, Hooman; Moradi, Alinoor Noor

2014-01-01

The current study aimed at investigating the possible impact of the problem-solving method of instruction on the exceptional students' creativity. A sample of 50 male exceptional (Mild intellectual disability) students studying in the third grade of junior high school was chosen and divided into two equal groups. Both groups filled out the…

Connecting for High Potential..."The Exceptionality of Being Twice-Exceptional."

ERIC Educational Resources Information Center

Danielian, Jeff; Nilles, Kathleen

2015-01-01

What's not often well-known or well-understood is that students who are gifted may also have a special need or disability--just as students with disabilities may also be gifted. The term "twice-exceptional," also referred to as "2e," is used to describe gifted children who, according to the Joint Commission on Twice-Exceptional…

Investigation of Noise and Vibration in Tires Through Analytical Modeling, Tests and Simulations

NASA Astrophysics Data System (ADS)

Cao, Rui

Tire noise and vibration is an interesting topic, with more and more people paying attention to this issue. Tire noise can both propagate into the vehicle interior and radiate directly toward the immediate environment. Tire noise is not only related to vehicle passengers' comfort but also affects the residential or working area near highways, especially in high population density regions. The emerging electric vehicles also emphasize tires' role in vehicle Noise Vibration and Harshness (NVH) since power-train noises are significantly reduced. The study in this research focuses on the noise and vibration of tires from the low to high frequency range, typically from 60 kHz to 2 kHz. From the analytical point of view, forced vibration of a fully coupled 2D structural-acoustical model is presented and a 3D structural model is also investigated for various input conditions. Both circumferential and cross-sectional shearing motions in the analytical tire models can be observed. Static tire surface mobilities were also measured to verify the findings from the developed models. On the experimental side, the loading effect on tire noise radiation was studied, where applied loads ranged from 500 lbs to 1300 lbs. Results indicate that sound radiation is usually proportional to the loading, except between 1.1 kHz to 1.7 kHz where the load-noise relation is reversed. In addition, tire noise generated by road surface discontinuities was also studied experimentally. As expected, a broadband increase of the noise spectrum can be observed below 1 kHz compared to the noise on a continuous surface. However, the difference tends to diminish above 1 kHz except in a certain narrow frequency band depending on the particular tire tested. High frequency waves and motions in tire cross-sectional directions were identified as occurring in the frequency range of interest. A two-dimensional cross-sectional analytical tire model was proposed for further investigations, in order to verify the relation among high frequency tire noise properties and the fast propagating waves and cross-sectional motions in tires. Finally, a fully coupled finite element tire-wheel model was developed to simulate the tire deformation under static vertical loading and to explore the influence of various excitation forces. The forces or accelerations, depending on the boundary conditions, at the wheel center can be calculated from the tire model up to 500 Hz. The results can be potentially used as input for vehicle full body simulations, thus accelerating the optimization process of new product development.

New statistical scission-point model to predict fission fragment observables

NASA Astrophysics Data System (ADS)

Lemaître, Jean-François; Panebianco, Stefano; Sida, Jean-Luc; Hilaire, Stéphane; Heinrich, Sophie

2015-09-01

The development of high performance computing facilities makes possible a massive production of nuclear data in a full microscopic framework. Taking advantage of the individual potential calculations of more than 7000 nuclei, a new statistical scission-point model, called SPY, has been developed. It gives access to the absolute available energy at the scission point, which allows the use of a parameter-free microcanonical statistical description to calculate the distributions and the mean values of all fission observables. SPY uses the richness of microscopy in a rather simple theoretical framework, without any parameter except the scission-point definition, to draw clear answers based on perfect knowledge of the ingredients involved in the model, with very limited computing cost.

Extremely broadband, on-chip optical nonreciprocity enabled by mimicking nonlinear anti-adiabatic quantum jumps near exceptional points

NASA Astrophysics Data System (ADS)

Choi, Youngsun; Hahn, Choloong; Yoon, Jae Woong; Song, Seok Ho; Berini, Pierre

2017-01-01

Time-asymmetric state-evolution properties while encircling an exceptional point are presently of great interest in search of new principles for controlling atomic and optical systems. Here, we show that encircling-an-exceptional-point interactions that are essentially reciprocal in the linear interaction regime make a plausible nonlinear integrated optical device architecture highly nonreciprocal over an extremely broad spectrum. In the proposed strategy, we describe an experimentally realizable coupled-waveguide structure that supports an encircling-an-exceptional-point parametric evolution under the influence of a gain saturation nonlinearity. Using an intuitive time-dependent Hamiltonian and rigorous numerical computations, we demonstrate strictly nonreciprocal optical transmission with a forward-to-backward transmission ratio exceeding 10 dB and high forward transmission efficiency (~100%) persisting over an extremely broad bandwidth approaching 100 THz. This predicted performance strongly encourages experimental realization of the proposed concept to establish a practical on-chip optical nonreciprocal element for ultra-short laser pulses and broadband high-density optical signal processing.

An Analytical Performance Assessment of a Fuel Cell-powered, Small Electric Airplane

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.; Freeh, Joshua E.; Wickenheiser, Timothy J.

2003-01-01

Rapidly emerging fuel cell power technologies may be used to launch a new revolution of electric propulsion systems for light aircraft. Future small electric airplanes using fuel cell technologies hold the promise of high reliability, low maintenance, low noise, and with exception of water vapor zero emissions. This paper describes an analytical feasibility and performance assessment conducted by NASA's Glenn Research Center of a fuel cell-powered, propeller-driven, small electric airplane based on a model of the MCR 01 two-place kitplane.

The slow X-ray pulsar SXP 1062 and associated supernova remnant in the Wing of the Small Magellanic Cloud

NASA Astrophysics Data System (ADS)

Oskinova, L. M.; Guerrero, M. A.; Hénault-Brunet, V.; Sun, W.; Chu, Y.-H.; Evans, C.; Gallagher, J. S.; Gruendl, R. A.; Reyes-Iturbide, J.

2013-03-01

SXP 1062 is an exceptional case of a young neutron star in a wind-fed high-mass X-ray binary associated with a supernova remnant. A unique combination of measured spin period, its derivative, luminosity and young age makes this source a key probe for the physics of accretion and neutron star evolution. Theoretical models proposed to explain the properties of SXP 1062 shall be tested with new data.

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate_N simulation model.

PubMed

Guo, Ruiying; Nendel, Claas; Rahn, Clive; Jiang, Chunguang; Chen, Qing

2010-06-01

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate_N simulation model. EU-Rotate_N was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. Copyright 2010 Elsevier Ltd. All rights reserved.

[Geostatistics analysis on spatial patterns of Myzus persicae and Erigonidium graminicola in plum orchard].

PubMed

Ding, Chengcheng; Zou, Yunding; Bi, Shoudong; Gao, Caiqiu; Liu, Xiaolin; Cao, Cuanwang; Meng, Qinglei; Li, Changgen

2005-07-01

Investigations on the spatial construction and distribution of Myzus persicae and Erigonidium graminicola in a plum orchard were conducted from March 2003 to November 2003. The results indicated that the semivariogram of Myzus persicae could be described by spherical model, except on June 27 and November 22, which should be described by lined model, and that of Erigonidium graminicola could be described by spherical model, except on May 21, May 31, October 19 and November 22, which should be described by lined model. It could be concluded that the amount and spatial distribution of Erigonidium graminicola was closely related to those of Myzus persicae.

40 CFR Table 3 to Subpart Ggggg of... - Applicability of General Provisions to Subpart GGGGG

Code of Federal Regulations, 2010 CFR

2010-07-01

.... Content of SSMP Yes with the exception of containers using either Level 1 or Level 2 controls. § 63.6(f)(1... CMS must be operating except during breakdown, out-of-control, repair, maintenance, and high-level... Requirements Zero and High level calibration check requirements Yes.However requirements for CPMS are addressed...

Limits on an energy dependence of the speed of light from a flare of the active galaxy PKS 2155-304.

PubMed

Aharonian, F; Akhperjanian, A G; Barres de Almeida, U; Bazer-Bachi, A R; Becherini, Y; Behera, B; Beilicke, M; Benbow, W; Bernlöhr, K; Boisson, C; Bochow, A; Borrel, V; Braun, I; Brion, E; Brucker, J; Brun, P; Bühler, R; Bulik, T; Büsching, I; Boutelier, T; Carrigan, S; Chadwick, P M; Charbonnier, A; Chaves, R C G; Chounet, L-M; Clapson, A C; Coignet, G; Costamante, L; Dalton, M; Degrange, B; Deil, C; Dickinson, H J; Djannati-Ataï, A; Domainko, W; Drury, L O'C; Dubois, F; Dubus, G; Dyks, J; Egberts, K; Emmanoulopoulos, D; Espigat, P; Farnier, C; Feinstein, F; Fiasson, A; Förster, A; Fontaine, G; Füssling, M; Gabici, S; Gallant, Y A; Gérard, L; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinz, S; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; de Jager, O C; Jung, I; Katarzyński, K; Kaufmann, S; Kendziorra, E; Kerschhaggl, M; Khangulyan, D; Khélifi, B; Keogh, D; Komin, Nu; Kosack, K; Lamanna, G; Lenain, J-P; Lohse, T; Marandon, V; Martin, J M; Martineau-Huynh, O; Marcowith, A; Maurin, D; McComb, T J L; Medina, C; Moderski, R; Moulin, E; Naumann-Godo, M; de Naurois, M; Nedbal, D; Nekrassov, D; Niemiec, J; Nolan, S J; Ohm, S; Olive, J-F; de Oña Wilhelmi, E; Orford, K J; Osborne, J L; Ostrowski, M; Panter, M; Pedaletti, G; Pelletier, G; Petrucci, P-O; Pita, S; Pühlhofer, G; Punch, M; Quirrenbach, A; Raubenheimer, B C; Raue, M; Rayner, S M; Renaud, M; Rieger, F; Ripken, J; Rob, L; Rosier-Lees, S; Rowell, G; Rudak, B; Ruppel, J; Sahakian, V; Santangelo, A; Schlickeiser, R; Schöck, F M; Schröder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Skilton, J L; Sol, H; Spangler, D; Stawarz, Ł; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J-P; Terrier, R; Tibolla, O; van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Vivier, M; Völk, H J; Volpe, F; Wagner, S J; Ward, M; Zdziarski, A A; Zech, A

2008-10-24

In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived.

Fundamental studies in X-ray astrophysics

NASA Technical Reports Server (NTRS)

Lamb, D. Q.; Lightman, A. P.

1982-01-01

An analytical model calculation of the ionization structure of matter accreting onto a degenerate dwarf was carried out. Self-consistent values of the various parameters are used. The possibility of nuclear burning of the accreting matter is included. We find the blackbody radiation emitted from the stellar surface keeps hydrogen and helium ionized out to distances much larger than a typical binary separation. Except for low mass stars or high accretion rates, the assumption of complete ionization of the elements heavier than helium is a good first approximation. For low mass stars or high accretion rates the validity of assuming complete ionization depends sensitivity on the distribution of matter in the binary system.

Subband Image Coding with Jointly Optimized Quantizers

NASA Technical Reports Server (NTRS)

Kossentini, Faouzi; Chung, Wilson C.; Smith Mark J. T.

1995-01-01

An iterative design algorithm for the joint design of complexity- and entropy-constrained subband quantizers and associated entropy coders is proposed. Unlike conventional subband design algorithms, the proposed algorithm does not require the use of various bit allocation algorithms. Multistage residual quantizers are employed here because they provide greater control of the complexity-performance tradeoffs, and also because they allow efficient and effective high-order statistical modeling. The resulting subband coder exploits statistical dependencies within subbands, across subbands, and across stages, mainly through complexity-constrained high-order entropy coding. Experimental results demonstrate that the complexity-rate-distortion performance of the new subband coder is exceptional.

High-Performance Thermoelectric Semiconductors

NASA Technical Reports Server (NTRS)

Fleurial, Jean-Pierre; Caillat, Thierry; Borshchevsky, Alexander

1994-01-01

Figures of merit almost double current state-of-art thermoelectric materials. IrSb3 is semiconductor found to exhibit exceptional thermoelectric properties. CoSb3 and RhSb3 have same skutterudite crystallographic structure as IrSb3, and exhibit exceptional transport properties expected to contribute to high thermoelectric performance. These three compounds form solid solutions. Combination of properties offers potential for development of new high-performance thermoelectric materials for more efficient thermoelectric power generators, coolers, and detectors.

Genetic Signatures of Exceptional Longevity in Humans

PubMed Central

Sebastiani, Paola; Solovieff, Nadia; DeWan, Andrew T.; Walsh, Kyle M.; Puca, Annibale; Hartley, Stephen W.; Melista, Efthymia; Andersen, Stacy; Dworkis, Daniel A.; Wilk, Jemma B.; Myers, Richard H.; Steinberg, Martin H.; Montano, Monty; Baldwin, Clinton T.; Hoh, Josephine; Perls, Thomas T.

2012-01-01

Like most complex phenotypes, exceptional longevity is thought to reflect a combined influence of environmental (e.g., lifestyle choices, where we live) and genetic factors. To explore the genetic contribution, we undertook a genome-wide association study of exceptional longevity in 801 centenarians (median age at death 104 years) and 914 genetically matched healthy controls. Using these data, we built a genetic model that includes 281 single nucleotide polymorphisms (SNPs) and discriminated between cases and controls of the discovery set with 89% sensitivity and specificity, and with 58% specificity and 60% sensitivity in an independent cohort of 341 controls and 253 genetically matched nonagenarians and centenarians (median age 100 years). Consistent with the hypothesis that the genetic contribution is largest with the oldest ages, the sensitivity of the model increased in the independent cohort with older and older ages (71% to classify subjects with an age at death>102 and 85% to classify subjects with an age at death>105). For further validation, we applied the model to an additional, unmatched 60 centenarians (median age 107 years) resulting in 78% sensitivity, and 2863 unmatched controls with 61% specificity. The 281 SNPs include the SNP rs2075650 in TOMM40/APOE that reached irrefutable genome wide significance (posterior probability of association = 1) and replicated in the independent cohort. Removal of this SNP from the model reduced the accuracy by only 1%. Further in-silico analysis suggests that 90% of centenarians can be grouped into clusters characterized by different “genetic signatures” of varying predictive values for exceptional longevity. The correlation between 3 signatures and 3 different life spans was replicated in the combined replication sets. The different signatures may help dissect this complex phenotype into sub-phenotypes of exceptional longevity. PMID:22279548

Electroweak baryogenesis in the exceptional supersymmetric standard model

DOE PAGES

Chao, Wei

2015-08-28

Here, we study electroweak baryogenesis in the E 6 inspired exceptional supersymmetric standard model (E 6SSM). The relaxation coefficients driven by singlinos and the new gaugino as well as the transport equation of the Higgs supermultiplet number density in the E 6SSM are calculated. Our numerical simulation shows that both CP-violating source terms from singlinos and the new gaugino can solely give rise to a correct baryon asymmetry of the Universe via the electroweak baryogenesis mechanism.

Constrained exceptional supersymmetric standard model

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

Athron, P.; King, S. F.; Miller, D. J.

2009-08-01

We propose and study a constrained version of the exceptional supersymmetric standard model (E{sub 6}SSM), which we call the cE{sub 6}SSM, based on a universal high energy scalar mass m{sub 0}, trilinear scalar coupling A{sub 0} and gaugino mass M{sub 1/2}. We derive the renormalization group (RG) Equations for the cE{sub 6}SSM, including the extra U(1){sub N} gauge factor and the low-energy matter content involving three 27 representations of E{sub 6}. We perform a numerical RG analysis for the cE{sub 6}SSM, imposing the usual low-energy experimental constraints and successful electroweak symmetry breaking. Our analysis reveals that the sparticle spectrum ofmore » the cE{sub 6}SSM involves a light gluino, two light neutralinos, and a light chargino. Furthermore, although the squarks, sleptons, and Z{sup '} boson are typically heavy, the exotic quarks and squarks can also be relatively light. We finally specify a set of benchmark points, which correspond to particle spectra, production modes, and decay patterns peculiar to the cE{sub 6}SSM, altogether leading to spectacular new physics signals at the Large Hadron Collider.« less

Depth-varying azimuthal anisotropy in the Tohoku subduction channel

NASA Astrophysics Data System (ADS)

Liu, Xin; Zhao, Dapeng

2017-09-01

We determine a detailed 3-D model of azimuthal anisotropy tomography of the Tohoku subduction zone from the Japan Trench outer-rise to the back-arc near the Japan Sea coast, using a large number of high-quality P and S wave arrival-time data of local earthquakes recorded by the dense seismic network on the Japan Islands. Depth-varying seismic azimuthal anisotropy is revealed in the Tohoku subduction channel. The shallow portion of the Tohoku megathrust zone (<30 km depth) generally exhibits trench-normal fast-velocity directions (FVDs) except for the source area of the 2011 Tohoku-oki earthquake (Mw 9.0) where the FVD is nearly trench-parallel, whereas the deeper portion of the megathrust zone (at depths of ∼30-50 km) mainly exhibits trench-parallel FVDs. Trench-normal FVDs are revealed in the mantle wedge beneath the volcanic front and the back-arc. The Pacific plate mainly exhibits trench-parallel FVDs, except for the top portion of the subducting Pacific slab where visible trench-normal FVDs are revealed. A qualitative tectonic model is proposed to interpret such anisotropic features, suggesting transposition of earlier fabrics in the oceanic lithosphere into subduction-induced new structures in the subduction channel.

Exchange-Hole Dipole Dispersion Model for Accurate Energy Ranking in Molecular Crystal Structure Prediction.

PubMed

Whittleton, Sarah R; Otero-de-la-Roza, A; Johnson, Erin R

2017-02-14

Accurate energy ranking is a key facet to the problem of first-principles crystal-structure prediction (CSP) of molecular crystals. This work presents a systematic assessment of B86bPBE-XDM, a semilocal density functional combined with the exchange-hole dipole moment (XDM) dispersion model, for energy ranking using 14 compounds from the first five CSP blind tests. Specifically, the set of crystals studied comprises 11 rigid, planar compounds and 3 co-crystals. The experimental structure was correctly identified as the lowest in lattice energy for 12 of the 14 total crystals. One of the exceptions is 4-hydroxythiophene-2-carbonitrile, for which the experimental structure was correctly identified once a quasi-harmonic estimate of the vibrational free-energy contribution was included, evidencing the occasional importance of thermal corrections for accurate energy ranking. The other exception is an organic salt, where charge-transfer error (also called delocalization error) is expected to cause the base density functional to be unreliable. Provided the choice of base density functional is appropriate and an estimate of temperature effects is used, XDM-corrected density-functional theory is highly reliable for the energetic ranking of competing crystal structures.

Synergies Between ' and Cavity Formation in HT-9 Following High Dose Neutron Irradiation

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

Field, Kevin G.; Parish, Chad M.; Saleh, Tarik A.

Candidate cladding materials for advanced nuclear power reactors including fast reactor designs require materials capable of withstanding high dose neutron irradiation at elevated temperatures. One candidate material, HT-9, through various research programs have demonstrated the ability to withstand significant swelling and other radiation-induced degradation mechanisms in the high dose regime (>50 displacements per atom, dpa) at elevated temperatures (>300 C). Here, high efficiency multi-dimensional scanning transmission electron microscopy (STEM) acquisition with the aid of a three-dimensional (3D) reconstruction and modeling technique is used to probe the microstructural features that contribute to the exceptional swelling resistance of HT-9. In particular, themore » synergies between ' and fine-scale and moderate-scale cavity formation is investigated.« less

Fermi observations of high-energy gamma-ray emission from GRB 080916C.

PubMed

Abdo, A A; Ackermann, M; Arimoto, M; Asano, K; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Band, D L; Barbiellini, G; Baring, M G; Bastieri, D; Battelino, M; Baughman, B M; Bechtol, K; Bellardi, F; Bellazzini, R; Berenji, B; Bhat, P N; Bissaldi, E; Blandford, R D; Bloom, E D; Bogaert, G; Bogart, J R; Bonamente, E; Bonnell, J; Borgland, A W; Bouvier, A; Bregeon, J; Brez, A; Briggs, M S; Brigida, M; Bruel, P; Burnett, T H; Burrows, D; Busetto, G; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Ceccanti, M; Cecchi, C; Celotti, A; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Connaughton, V; Conrad, J; Costamante, L; Cutini, S; Deklotz, M; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Dingus, B L; do Couto E Silva, E; Drell, P S; Dubois, R; Dumora, D; Edmonds, Y; Evans, P A; Fabiani, D; Farnier, C; Favuzzi, C; Finke, J; Fishman, G; Focke, W B; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Goldstein, A; Granot, J; Greiner, J; Grenier, I A; Grondin, M-H; Grove, J E; Guillemot, L; Guiriec, S; Haller, G; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Hernando Morat, J A; Hoover, A; Hughes, R E; Jóhannesson, G; Johnson, A S; Johnson, R P; Johnson, T J; Johnson, W N; Kamae, T; Katagiri, H; Kataoka, J; Kavelaars, A; Kawai, N; Kelly, H; Kennea, J; Kerr, M; Kippen, R M; Knödlseder, J; Kocevski, D; Kocian, M L; Komin, N; Kouveliotou, C; Kuehn, F; Kuss, M; Lande, J; Landriu, D; Larsson, S; Latronico, L; Lavalley, C; Lee, B; Lee, S-H; Lemoine-Goumard, M; Lichti, G G; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Marangelli, B; Mazziotta, M N; McBreen, S; McEnery, J E; McGlynn, S; Meegan, C; Mészáros, P; Meurer, C; Michelson, P F; Minuti, M; Mirizzi, N; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Moretti, E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nelson, D; Nolan, P L; Norris, J P; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orlando, E; Ormes, J F; Ozaki, M; Paciesas, W S; Paneque, D; Panetta, J H; Parent, D; Pelassa, V; Pepe, M; Perri, M; Pesce-Rollins, M; Petrosian, V; Pinchera, M; Piron, F; Porter, T A; Preece, R; Rainò, S; Ramirez-Ruiz, E; Rando, R; Rapposelli, E; Razzano, M; Razzaque, S; Rea, N; Reimer, A; Reimer, O; Reposeur, T; Reyes, L C; Ritz, S; Rochester, L S; Rodriguez, A Y; Roth, M; Ryde, F; Sadrozinski, H F-W; Sanchez, D; Sander, A; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Segal, K N; Sgrò, C; Shimokawabe, T; Siskind, E J; Smith, D A; Smith, P D; Spandre, G; Spinelli, P; Stamatikos, M; Starck, J-L; Stecker, F W; Steinle, H; Stephens, T E; Strickman, M S; Suson, D J; Tagliaferri, G; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Tenze, A; Thayer, J B; Thayer, J G; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Turri, M; Tuvi, S; Usher, T L; van der Horst, A J; Vigiani, L; Vilchez, N; Vitale, V; von Kienlin, A; Waite, A P; Williams, D A; Wilson-Hodge, C; Winer, B L; Wood, K S; Wu, X F; Yamazaki, R; Ylinen, T; Ziegler, M

2009-03-27

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. The known distance of the burst enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.

Are V1 Simple Cells Optimized for Visual Occlusions? A Comparative Study

PubMed Central

Bornschein, Jörg; Henniges, Marc; Lücke, Jörg

2013-01-01

Simple cells in primary visual cortex were famously found to respond to low-level image components such as edges. Sparse coding and independent component analysis (ICA) emerged as the standard computational models for simple cell coding because they linked their receptive fields to the statistics of visual stimuli. However, a salient feature of image statistics, occlusions of image components, is not considered by these models. Here we ask if occlusions have an effect on the predicted shapes of simple cell receptive fields. We use a comparative approach to answer this question and investigate two models for simple cells: a standard linear model and an occlusive model. For both models we simultaneously estimate optimal receptive fields, sparsity and stimulus noise. The two models are identical except for their component superposition assumption. We find the image encoding and receptive fields predicted by the models to differ significantly. While both models predict many Gabor-like fields, the occlusive model predicts a much sparser encoding and high percentages of ‘globular’ receptive fields. This relatively new center-surround type of simple cell response is observed since reverse correlation is used in experimental studies. While high percentages of ‘globular’ fields can be obtained using specific choices of sparsity and overcompleteness in linear sparse coding, no or only low proportions are reported in the vast majority of studies on linear models (including all ICA models). Likewise, for the here investigated linear model and optimal sparsity, only low proportions of ‘globular’ fields are observed. In comparison, the occlusive model robustly infers high proportions and can match the experimentally observed high proportions of ‘globular’ fields well. Our computational study, therefore, suggests that ‘globular’ fields may be evidence for an optimal encoding of visual occlusions in primary visual cortex. PMID:23754938

Extraordinary Genetic Diversity in a Wood Decay Mushroom.

PubMed

Baranova, Maria A; Logacheva, Maria D; Penin, Aleksey A; Seplyarskiy, Vladimir B; Safonova, Yana Y; Naumenko, Sergey A; Klepikova, Anna V; Gerasimov, Evgeny S; Bazykin, Georgii A; James, Timothy Y; Kondrashov, Alexey S

2015-10-01

Populations of different species vary in the amounts of genetic diversity they possess. Nucleotide diversity π, the fraction of nucleotides that are different between two randomly chosen genotypes, has been known to range in eukaryotes between 0.0001 in Lynx lynx and 0.16 in Caenorhabditis brenneri. Here, we report the results of a comparative analysis of 24 haploid genotypes (12 from the United States and 12 from European Russia) of a split-gill fungus Schizophyllum commune. The diversity at synonymous sites is 0.20 in the American population of S. commune and 0.13 in the Russian population. This exceptionally high level of nucleotide diversity also leads to extreme amino acid diversity of protein-coding genes. Using whole-genome resequencing of 2 parental and 17 offspring haploid genotypes, we estimate that the mutation rate in S. commune is high, at 2.0 × 10(-8) (95% CI: 1.1 × 10(-8) to 4.1 × 10(-8)) per nucleotide per generation. Therefore, the high diversity of S. commune is primarily determined by its elevated mutation rate, although high effective population size likely also plays a role. Small genome size, ease of cultivation and completion of the life cycle in the laboratory, free-living haploid life stages and exceptionally high variability of S. commune make it a promising model organism for population, quantitative, and evolutionary genetics. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Chiral behaviour of the wave functions for three wave guides in the vicinity of an exceptional point of third order

NASA Astrophysics Data System (ADS)

Heiss, Walter Dieter; Wunner, Günter

2017-12-01

A matrix model that has been used to describe essential features of a parity-time symmetric set-up of three coupled wave guides is investigated. The emphasis of the study lies on the occurrence of an exceptional point of third order. It is demonstrated that the eigenfunctions in close vicinity of the exceptional point have a distinctive chiral behaviour. Using data describing realistic situations it is argued that such chiral behaviour can be tested experimentally.

Trends in the levels of halogenated flame retardants in the Great Lakes atmosphere over the period 2005-2013.

PubMed

Liu, Liang-Ying; Salamova, Amina; Venier, Marta; Hites, Ronald A

2016-01-01

Air (vapor and particle phase) samples were collected every 12days at five sites near the North American Great Lakes from 1 January 2005 to 31 December 2013 as a part of the Integrated Atmospheric Deposition Network (IADN). The concentrations of 35 polybrominated diphenyl ethers (PBDEs) and eight other halogenated flame retardants were measured in each of the ~1,300 samples. The levels of almost all of these flame retardants, except for pentabromoethylbenzene (PBEB), hexabromobenzene (HBB), and Dechlorane Plus (DP), were significantly higher in Chicago, Cleveland, and Sturgeon Point. The concentrations of PBEB and HBB were relatively high at Eagle Harbor and Sturgeon Point, respectively, and the concentrations of DP were relatively high at Cleveland and Sturgeon Point, the two sites closest to this compound's production site. The data were analyzed using a multiple linear regression model to determine significant temporal trends in these atmospheric concentrations. The concentrations of PBDEs were decreasing at the urban sites, Chicago and Cleveland, but were generally unchanging at the remote sites, Sleeping Bear Dunes and Eagle Harbor. The concentrations of PBEB were decreasing at almost all sites except for Eagle Harbor, where the highest PBEB levels were observed. HBB concentrations were decreasing at all sites except for Sturgeon Point, where HBB levels were the highest. DP concentrations were increasing with doubling times of 3-9years at all sites except those closest to its source (Cleveland and Sturgeon Point). The levels of 1,2-bis(2,4,6-tribromophenoxy)ethane (TBE) were unchanging at the urban sites, Chicago and Cleveland, but decreasing at the suburban and remote sites, Sturgeon Point and Eagle Harbor. The atmospheric concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EHTBB) and bis(2-ethylhexyl)-tetrabromophthalate (BEHTBP) were increasing at almost every site with doubling times of 3-6years. Copyright © 2016 Elsevier Ltd. All rights reserved.

Luminosity Limitations of Linear Colliders Based on Plasma Acceleration

DOE PAGES

Lebedev, Valeri; Burov, Alexey; Nagaitsev, Sergei

2016-01-01

Particle acceleration in plasma creates a possibility of exceptionally high accelerating gradients and appears as a very attractive option for future linear electron-positron and/or photon-photon colliders. These high accelerating gradients were already demonstrated in a number of experiments. Furthermore, a linear collider requires exceptionally high beam brightness which still needs to be demonstrated. In this article we discuss major phenomena which limit the beam brightness of accelerated beam and, consequently, the collider luminosity.

Performance comparison for Barnes model 12-1000, Exotech model 100, and Ideas Inc. Biometer Mark 2

NASA Technical Reports Server (NTRS)

Robinson, B. (Principal Investigator)

1981-01-01

Results of tests show that all channels of all instruments, except channel 3 of the Biometer Mark 2, were stable in response to input signals were linear, and were adequately stable in response to temperature changes. The Biometer Mark 2 is labelled with an inappropriate description of the units measured and the dynamic range is a inappropriate for field measurements causing unnecessarily high fractional errors. This instrument is, therefore, quantization limited. The dynamic range and noise performance of the Model 12-1000 are appropriate for remote sensing field research. The field of view and performance of the Model 100A and the Model 12-1000 are satisfactory. The Biometer Mark 2 has not, as yet, been satisfactorily equipped with an acceptable field of view determining device. Neither the widely used aperture plate nor the 24 deg cone are acceptable.

Semiconducting Single-Walled Carbon Nanotubes in Solar Energy Harvesting

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

Blackburn, Jeffrey L.

Semiconducting single-walled carbon nanotubes (s-SWCNTs) represent a tunable model one-dimensional system with exceptional optical and electronic properties. High-throughput separation and purification strategies have enabled the integration of s-SWCNTs into a number of optoelectronic applications, including photovoltaics (PVs). In this Perspective, we discuss the fundamental underpinnings of two model PV interfaces involving s-SWCNTs. We first discuss s-SWCNT-fullerene heterojunctions where exciton dissociation at the donor-acceptor interface drives solar energy conversion. Next, we discuss charge extraction at the interface between s-SWCNTs and a photoexcited perovskite active layer. In each case, the use of highly enriched semiconducting SWCNT samples enables fundamental insights into themore » thermodynamic and kinetic mechanisms that drive the efficient conversion of solar photons into long-lived separated charges. As a result, these model systems help to establish design rules for next-generation PV devices containing well-defined organic semiconductor layers and help to frame a number of important outstanding questions that can guide future studies.« less

Semiconducting Single-Walled Carbon Nanotubes in Solar Energy Harvesting

DOE PAGES

Blackburn, Jeffrey L.

2017-06-14

Semiconducting single-walled carbon nanotubes (s-SWCNTs) represent a tunable model one-dimensional system with exceptional optical and electronic properties. High-throughput separation and purification strategies have enabled the integration of s-SWCNTs into a number of optoelectronic applications, including photovoltaics (PVs). In this Perspective, we discuss the fundamental underpinnings of two model PV interfaces involving s-SWCNTs. We first discuss s-SWCNT-fullerene heterojunctions where exciton dissociation at the donor-acceptor interface drives solar energy conversion. Next, we discuss charge extraction at the interface between s-SWCNTs and a photoexcited perovskite active layer. In each case, the use of highly enriched semiconducting SWCNT samples enables fundamental insights into themore » thermodynamic and kinetic mechanisms that drive the efficient conversion of solar photons into long-lived separated charges. As a result, these model systems help to establish design rules for next-generation PV devices containing well-defined organic semiconductor layers and help to frame a number of important outstanding questions that can guide future studies.« less

Numerical and Physical Modeling of the Response of Resonator Liners to Intense Sound and Grazing Flow

NASA Technical Reports Server (NTRS)

Hersh, Alan S.; Tam, Christopher

2009-01-01

Two significant advances have been made in the application of computational aeroacoustics methodology to acoustic liner technology. The first is that temperature effects for discrete sound are not the same as for broadband noise. For discrete sound, the normalized resistance appears to be insensitive to temperature except at high SPL. However, reactance is lower, significantly lower in absolute value, at high temperature. The second is the numerical investigation the acoustic performance of a liner by direct numerical simulation. Liner impedance is affected by the non-uniformity of the incident sound waves. This identifies the importance of pressure gradient. Preliminary design one and two-dimensional impedance models were developed to design sound absorbing liners in the presence of intense sound and grazing flow. The two-dimensional model offers the potential to empirically determine incident sound pressure face-plate distance from resonator orifices. This represents an important initial step in improving our understanding of how to effectively use the Dean Two-Microphone impedance measurement method.

Numerical modeling of thermal conductive heating in fractured bedrock.

PubMed

Baston, Daniel P; Falta, Ronald W; Kueper, Bernard H

2010-01-01

Numerical modeling was employed to study the performance of thermal conductive heating (TCH) in fractured shale under a variety of hydrogeological conditions. Model results show that groundwater flow in fractures does not significantly affect the minimum treatment zone temperature, except near the beginning of heating or when groundwater influx is high. However, fracture and rock matrix properties can significantly influence the time necessary to remove all liquid water (i.e., reach superheated steam conditions) in the treatment area. Low matrix permeability, high matrix porosity, and wide fracture spacing can contribute to boiling point elevation in the rock matrix. Consequently, knowledge of these properties is important for the estimation of treatment times. Because of the variability in boiling point throughout a fractured rock treatment zone and the absence of a well-defined constant temperature boiling plateau in the rock matrix, it may be difficult to monitor the progress of thermal treatment using temperature measurements alone. Copyright © 2010 The Author(s). Journal compilation © 2010 National Ground Water Association.

Electroweak baryogenesis in the exceptional supersymmetric standard model

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

Chao, Wei, E-mail: chao@physics.umass.edu

2015-08-01

We study electroweak baryogenesis in the E{sub 6} inspired exceptional supersymmetric standard model (E{sub 6}SSM). The relaxation coefficients driven by singlinos and the new gaugino as well as the transport equation of the Higgs supermultiplet number density in the E{sub 6}SSM are calculated. Our numerical simulation shows that both CP-violating source terms from singlinos and the new gaugino can solely give rise to a correct baryon asymmetry of the Universe via the electroweak baryogenesis mechanism.

Electroweak baryogenesis in the exceptional supersymmetric standard model

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

Chao, Wei

2015-08-28

We study electroweak baryogenesis in the E{sub 6} inspired exceptional supersymmetric standard model (E{sub 6}SSM). The relaxation coefficients driven by singlinos and the new gaugino as well as the transport equation of the Higgs supermultiplet number density in the E{sub 6}SSM are calculated. Our numerical simulation shows that both CP-violating source terms from singlinos and the new gaugino can solely give rise to a correct baryon asymmetry of the Universe via the electroweak baryogenesis mechanism.

Non-Equilibrium Turbulence Modeling for High Lift Aerodynamics

NASA Technical Reports Server (NTRS)

Durbin, P. A.

1998-01-01

This phase is discussed in ('Non linear kappa - epsilon - upsilon(sup 2) modeling with application to high lift', Application of the kappa - epsilon -upsilon(sup 2) model to multi-component airfoils'). Further results are presented in 'Non-linear upsilon(sup 2) - f modeling with application to high-lift' The ADI solution method in the initial implementation was very slow to converge on multi-zone chimera meshes. I modified the INS implementation to use GMRES. This provided improved convergence and less need for user intervention in the solution process. There were some difficulties with implementation into the NASA compressible codes, due to their use of approximate factorization. The Helmholtz equation for f is not an evolution equation, so it is not of the form assumed by the approximate factorization method. Although The Kalitzin implementation involved a new solution algorithm ('An implementation of the upsilon(sup 2) - f model with application to transonic flows'). The algorithm involves introducing a relaxation term in the f-equation so that it can be factored. The factorization can be into a plane and a line, with GMRES used in the plane. The NASA code already evaluated coefficients in planes, so no additional memory is required except that associated the the GMRES algorithm. So the scope of this project has expanded via these interactions. . The high-lift work has dovetailed into turbine applications.

Validating high-resolution California coastal flood modeling with Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR)

NASA Astrophysics Data System (ADS)

O'Neill, A.

2015-12-01

The Coastal Storm Modeling System (CoSMoS) is a numerical modeling scheme used to predict coastal flooding due to sea level rise and storms influenced by climate change, currently in use in central California and in development for Southern California (Pt. Conception to the Mexican border). Using a framework of circulation, wave, analytical, and Bayesian models at different geographic scales, high-resolution results are translated as relevant hazards projections at the local scale that include flooding, wave heights, coastal erosion, shoreline change, and cliff failures. Ready access to accurate, high-resolution coastal flooding data is critical for further validation and refinement of CoSMoS and improved coastal hazard projections. High-resolution Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) provides an exceptional data source as appropriately-timed flights during extreme tides or storms provide a geographically-extensive method for determining areas of inundation and flooding extent along expanses of complex and varying coastline. Landward flood extents are numerically identified via edge-detection in imagery from single flights, and can also be ascertained via change detection using additional flights and imagery collected during average wave/tide conditions. The extracted flooding positions are compared against CoSMoS results for similar tide, water level, and storm-intensity conditions, allowing for robust testing and validation of CoSMoS and providing essential feedback for supporting regional and local model improvement.

Higher Education in East Asia and Singapore: Rise of the Confucian Model

ERIC Educational Resources Information Center

Marginson, Simon

2011-01-01

The paper reviews Asia-Pacific higher education and university research, focusing principally on the "Confucian" education nations Japan, Korea, China, Hong Kong China, Taiwan, Singapore and Vietnam. Except for Vietnam, these systems exhibit a special developmental dynamism--still playing out everywhere except Japan--and have created a…

Exceptional winter storms affecting Western Iberia and extremes: diagnosis, modelling and multi-model ensemble projection

NASA Astrophysics Data System (ADS)

Liberato, M. L. R.; Pinto, J. G.; Gil, V.; Ramos, A. M.; Trigo, R. M.

2017-12-01

Extratropical cyclones dominate autumn and winter weather over Western Europe and particularly over the Iberian Peninsula. Intense, high-impact storms are one of the major weather risks in the region, mostly due to the simultaneous occurrence of high winds and extreme precipitation events. These intense extratropical cyclones may result in windstorm damage, flooding and coastal storm surges, with large societal impacts. In Portugal, due to the extensive human use of coastal areas, the natural and built coastal environments have been amongst the most affected. In this work several historical winter storms that adversely affected the Western Iberian Peninsula are studied in detail in order to contribute to an improved assessment of the characteristics of these events. The diagnosis has been performed based on instrumental daily precipitation and wind records, on satellite images, on reanalysis data and through model simulations. For several examples the synoptic evolution and upper-level dynamics analysis of physical processes controlling the life cycle of extratropical storms associated with the triggering of the considered extreme events has also been accomplished. Furthermore, the space-time variability of the exceptionally severe storms affecting Western Iberia over the last century and under three climate scenarios (the historical simulation, the RCP4.5 and RCP8.5 scenarios) is presented. These studies contribute to improving the knowledge of atmospheric dynamics controlling the life cycle of midlatitude storms associated to severe weather (precipitation and wind) in the Iberian Peninsula. AcknowledgementsThis work is supported by the Portuguese Foundation for Science and Technology (FCT), Portugal, through project UID/GEO/50019/2013 - Instituto Dom Luiz. A. M. Ramos is also supported by a FCT postdoctoral grant (FCT/DFRH/SFRH/BPD/84328/2012).

Assessing health-related quality of life in Japanese children with a chronic condition: validation of the DISABKIDS chronic generic module.

PubMed

Sasaki, Hatoko; Kakee, Naoko; Morisaki, Naho; Mori, Rintaro; Ravens-Sieberer, Ulrike; Bullinger, Monika

2018-05-02

This study examined the reliability and validity of the Japanese versions of the DISABKIDS-37 generic modules, a tool for assessing the health-related quality of life (HRQOL) of children and adolescents with a chronic condition. The study was conducted using a sample of 123 children/adolescents with a chronic medical condition, aged 8-18 years, and their parents. Focus interviews were performed to ensure content validity after translation. The classical psychometric tests were used to assess reliability and scale intercorrelations. The factor structure was examined with confirmatory factor analysis (CFA). Convergent validity was assessed by the correlation between the total score and the sub-scales of DISABKIDS-37 as well as the total score of KIDSCREEN-10. Both the children/adolescent and parent versions of the score showed good to high internal consistency, and the test-retest reliability correlations were r = 0.91 or above. The CFA revealed that the modified models for all domains were better fit than the original 37 item scale model for both self-report and proxy-report. Moderate to high positive correlations were found for the associations within DISABKIDS-37 sub-scales and between the subscales and total score, except for the treatment sub-scale, which correlated weakly with the remaining sub-scales. The total score of the child-reported version of KIDSCREEN-10 correlated significantly and positively with the total score and all the sub-scales of the child-reported version of DISABKIDS-37 except the Treatment sub-scale in adolescents. The modified models of Japanese version of DISABKIDS generic module were psychometrically robust enough to assess the HRQOL of children with a chronic condition.

Tidally Heated Terrestrial Exoplanets

NASA Astrophysics Data System (ADS)

Henning, Wade Garrett

This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity excursions. Viscoelastic solutions for GJ 876d are typical of extreme short period high eccentricity objects with tidal-convectiveequilibrium heat rates between ˜10,000 to 500,000 terawatts.

Noise sensitivity and loudness derivative index for urban road traffic noise annoyance computation.

PubMed

Gille, Laure-Anne; Marquis-Favre, Catherine; Weber, Reinhard

2016-12-01

Urban road traffic composed of powered-two-wheelers (PTWs), buses, heavy, and light vehicles is a major source of noise annoyance. In order to assess annoyance models considering different acoustical and non-acoustical factors, a laboratory experiment on short-term annoyance due to urban road traffic noise was conducted. At the end of the experiment, participants were asked to rate their noise sensitivity and to describe the noise sequences they heard. This verbalization task highlights that annoyance ratings are highly influenced by the presence of PTWs and by different acoustical features: noise intensity, irregular temporal amplitude variation, regular amplitude modulation, and spectral content. These features, except irregular temporal amplitude variation, are satisfactorily characterized by the loudness, the total energy of tonal components and the sputtering and nasal indices. Introduction of the temporal derivative of loudness allows successful modeling of perceived amplitude variations. Its contribution to the tested annoyance models is high and seems to be higher than the contribution of mean loudness index. A multilevel regression is performed to assess annoyance models using selected acoustical indices and noise sensitivity. Three models are found to be promising for further studies that aim to enhance current annoyance models.

Diagnostic accuracy and measurement sensitivity of digital models for orthodontic purposes: A systematic review.

PubMed

Rossini, Gabriele; Parrini, Simone; Castroflorio, Tommaso; Deregibus, Andrea; Debernardi, Cesare L

2016-02-01

Our objective was to assess the accuracy, validity, and reliability of measurements obtained from virtual dental study models compared with those obtained from plaster models. PubMed, PubMed Central, National Library of Medicine Medline, Embase, Cochrane Central Register of Controlled Clinical trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to November 2014. A grading system described by the Swedish Council on Technology Assessment in Health Care and the Cochrane tool for risk of bias assessment were used to rate the methodologic quality of the articles. Thirty-five relevant articles were selected. The methodologic quality was high. No significant differences were observed for most of the studies in all the measured parameters, with the exception of the American Board of Orthodontics Objective Grading System. Digital models are as reliable as traditional plaster models, with high accuracy, reliability, and reproducibility. Landmark identification, rather than the measuring device or the software, appears to be the greatest limitation. Furthermore, with their advantages in terms of cost, time, and space required, digital models could be considered the new gold standard in current practice. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

Root location in random trees: a polarity property of all sampling consistent phylogenetic models except one.

PubMed

Steel, Mike

2012-10-01

Neutral macroevolutionary models, such as the Yule model, give rise to a probability distribution on the set of discrete rooted binary trees over a given leaf set. Such models can provide a signal as to the approximate location of the root when only the unrooted phylogenetic tree is known, and this signal becomes relatively more significant as the number of leaves grows. In this short note, we show that among models that treat all taxa equally, and are sampling consistent (i.e. the distribution on trees is not affected by taxa yet to be included), all such models, except one (the so-called PDA model), convey some information as to the location of the ancestral root in an unrooted tree. Copyright © 2012 Elsevier Inc. All rights reserved.

Depth dependency of neutron density produced by cosmic rays in the lunar subsurface

NASA Astrophysics Data System (ADS)

Ota, S.; Sihver, L.; Kobayashi, S.; Hasebe, N.

2014-11-01

Depth dependency of neutrons produced by cosmic rays (CRs) in the lunar subsurface was estimated using the three-dimensional Monte Carlo particle and heavy ion transport simulation code, PHITS, incorporating the latest high energy nuclear data, JENDL/HE-2007. The PHITS simulations of equilibrium neutron density profiles in the lunar subsurface were compared with the measurement by Apollo 17 Lunar Neutron Probe Experiment (LNPE). Our calculations reproduced the LNPE data except for the 350-400 mg/cm2 region under the improved condition using the CR spectra model based on the latest observations, well-tested nuclear interaction models with systematic cross section data, and JENDL/HE-2007.

Associations of psychosocial working conditions and working time characteristics with somatic complaints in German resident physicians.

PubMed

Fischer, Nina; Degen, Christiane; Li, Jian; Loerbroks, Adrian; Müller, Andreas; Angerer, Peter

2016-05-01

Somatic complaints (SC) are highly prevalent in working populations and cause suffering and extensive health-care utilization. Adverse psychosocial working conditions as conceptualized in the Job Demand-Control-Support Model (JDC-S) and adverse working time characteristics (WTC) are potential risk factors. This combination is particularly common in hospital physicians. This study examines associations of JDC-S and WTC with SC in resident physicians from Germany. A cross-sectional study was conducted among 405 physicians at the end of residency training. SC were measured using the Giessen Subjective Complaints List (GBB-24) containing the sub-categories exhaustion, gastrointestinal, musculoskeletal, and cardiovascular complaints. Data on working conditions were collected by a self-report method for work analysis in hospitals (TAA-KH-S) and by questions on WTC (i.e., working hours). Multivariable stepwise regression analyses were applied. Workload showed the most pronounced relationship with all sub-categories of SC except gastrointestinal complaints. Job autonomy was not significantly related to any SC sub-category. Social support at work was inversely associated with all SC sub-categories except for cardiovascular complaints. Free weekends were associated with reduced SC except for exhaustion. Shift work was related to an increased SC total score and musculoskeletal complaints. Working hours showed no association with SC. In resident physicians, high workload and shift work are associated with increased SC, while social support at work and free weekends are associated with decreased SC. These insights may inform the development of preventive measures to improve the health of this professional group. Prospective studies are needed though to corroborate our findings.

NuSTAR AND Swift Observations of the Very High State in GX 339-4: Weighing the Black Hole With X-Rays

NASA Technical Reports Server (NTRS)

Parker, M. L.; Tomsick, J. A.; Kennea, J. A.; Miller, J. M.; Harrison, F. A.; Barret, D.; Boggs, S. E.; Christensen, F. E.; Craig, W. W.; Fabian, A. C.;

Evaluation of WRF model-derived direct irradiance for solar thermal resource assessment over South Korea

NASA Astrophysics Data System (ADS)

Kim, Jin-Young; Yun, Chang-Yeol; Kim, Chang Ki; Kang, Yong-Heack; Kim, Hyun-Goo; Lee, Sang-Nam; Kim, Shin-Young

2017-06-01

The South Korean government has been started monitoring and reassessment for new and renewable resource under greenhouse reduction related with the climate agreement in Paris. This study investigated characteristics of the model-derived direct normal irradiance(DNI) using ten-minute data of the Weather Research and Forecasting(WRF) model with 1 km grid spacing. First, ground horizontal irradiance(GHI) and direct normal irradiance(DNI) from the model was compared with those of ground stations throughout South Korea to evaluate the uncertainty of the GHI-derived DNI. Then solar thermal resource potential was assessed using a DNI map. Uncertainty of irradiances appeared highly dependent on sky conditions. Root mean square errors in DNI(GHI) was 45.39%(18.06%) for all sky with the range of 9.92˜51.93%(14.49˜51.47%) for clear to overcast sky. These indicate DNI is further sensitive to cloud condition in Korea which is around 72% of cloud days during a whole year. Finally DNI maps showed high value over most areas except southeastern areas and Jeju island which is humid regions in South Korea.

The Extremes of the Bell Curve: Excellent and Poor School Performance and Risk for Severe Mental Disorders. Maudsley Series

ERIC Educational Resources Information Center

MacCabe, James H.

2010-01-01

It has long been claimed that there is a strong association between high intelligence, or exceptional creativity, and mental illness. In this book, James MacCabe investigates this claim, using evidence from Swedish population data. He finds evidence that children who achieve either exceptionally high, or very low grades at school, are at greater…

A high resolution computer tomography scoring system to predict culture-positive pulmonary tuberculosis in the emergency department.

PubMed

Yeh, Jun-Jun; Neoh, Choo-Aun; Chen, Cheng-Ren; Chou, Christine Yi-Ting; Wu, Ming-Ting

2014-01-01

This study evaluated the use of high-resolution computed tomography (HRCT) to predict the presence of culture-positive pulmonary tuberculosis (PTB) in adult patients with pulmonary lesions in the emergency department (ED). The study included a derivation phase and validation phase with a total of 8,245 patients with pulmonary disease. There were 132 patients with culture-positive PTB in the derivation phase and 147 patients with culture-positive PTB in the validation phase. Imaging evaluation of pulmonary lesions included morphology and segmental distribution. The post-test probability ratios between both phases in three prevalence areas were analyzed. In the derivation phase, a multivariate analysis model identified cavitation, consolidation, and clusters/nodules in right or left upper lobe (except anterior segment) and consolidation of the superior segment of the right or left lower lobe as independent positive factors for culture-positive PTB, while consolidation of the right or left lower lobe (except superior segment) were independent negative factors. An ideal cutoff point based on the receiver operating characteristic (ROC) curve analysis was obtained at a score of 1. The sensitivity, specificity, positivity predictive value, and negative predictive value from derivation phase were 98.5% (130/132), 99.7% (3997/4008), 92.2% (130/141), and 99.9% (3997/3999). Based on the predicted positive likelihood ratio value of 328.33 in derivation phase, the post-test probability was observed to be 91.5% in the derivation phase, 92.5% in the validation phase, 94.5% in a high TB prevalence area, 91.0% in a moderate prevalence area, and 76.8% in moderate-to-low prevalence area. Our model using HRCT, which is feasible to perform in the ED, can promptly diagnose culture-positive PTB in moderate and moderate-to-low prevalence areas.

Comparison of fresh-frozen cadaver and high-fidelity virtual reality simulator as methods of laparoscopic training.

PubMed

Sharma, Mitesh; Horgan, Alan

2012-08-01

The aim of this study was to compare fresh-frozen cadavers (FFC) with a high-fidelity virtual reality simulator (VRS) as training tools in minimal access surgery for complex and relatively simple procedures. A prospective comparative face validity study between FFC and VRS (LAP Mentor(™)) was performed. Surgeons were recruited to perform tasks on both FFC and VRS appropriately paired to their experience level. Group A (senior) performed a laparoscopic sigmoid colectomy, Group B (intermediate) performed a laparoscopic incisional hernia repair, and Group C (junior) performed basic laparoscopic tasks (BLT) (camera manipulation, hand-eye coordination, tissue dissection and hand-transferring skills). Each subject completed a 5-point Likert-type questionnaire rating the training modalities in nine domains. Data were analysed using nonparametric tests. Forty-five surgeons were recruited to participate (15 per skill group). Median scores for subjects in Group A were significantly higher for evaluation of FFC in all nine domains compared to VRS (p < 0.01). Group B scored FFC significantly better (p < 0.05) in all domains except task replication (p = 0.06). Group C scored FFC significantly better (p < 0.01) in eight domains but not on performance feedback (p = 0.09). When compared across groups, juniors accepted VRS as a training model more than did intermediate and senior groups on most domains (p < 0.01) except team work. Fresh-frozen cadaver is perceived as a significantly overall better model for laparoscopic training than the high-fidelity VRS by all training grades, irrespective of the complexity of the operative procedure performed. VRS is still useful when training junior trainees in BLT.

Assessment of commercially available energy-efficient room air conditioners including models with low global warming potential (GWP) refrigerants

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

Shah, N. K.; Park, W. Y.; Gerke, B.

Improving the energy efficiency of room air conditioners (RACs) while transitioning to low global-warming-potential (GWP) refrigerants will be a critical step toward reducing the energy, peak load, and emissions impacts of RACs while keeping costs low. Previous research quantified the benefits of leapfrogging to high efficiency in tandem with the transition to low-GWP refrigerants for RACs (Shah et al., 2015) and identified opportunities for initial action to coordinate energy efficiency with refrigerant transition in economies constituting about 65% of the global RAC market (Shah et al., 2017). This report describes further research performed to identify the best-performing (i.e., most efficientmore » and low-GWP-refrigerant using) RACs on the market, to support an understanding of the best available technology (BAT). Understanding BAT can help support market-transformation programs for high-efficiency and low-GWP equipment such as minimum energy performance standards (MEPS), labeling, procurement, and incentive programs. We studied RACs available in six economies—China, Europe, India, Japan, South Korea, and the United States—that together account for about 70% of global RAC demand, as well as other emerging economies. The following are our key findings: • Highly efficient RACs using low-GWP refrigerants, e.g., HFC-32 (R-32) and HC-290 (R-290), are commercially available today at prices comparable to similar RACs using high-GWP HCFC-22 (R-22) or HFC-410A (R-410A). • High efficiency is typically a feature of high-end products. However, highly efficient, cost-competitive (less than 1,000 or 1,500 U.S. dollars in retail price, depending on size) RACs are available. • Where R-22 is being phased out, high GWP R-410A still dominates RAC sales in most mature markets except Japan, where R-32 dominates. • In all of the economies studied except Japan, only a few models are energy efficient and use low-GWP refrigerants. For example, in Europe, India, and Indonesia, the highest-efficiency RAC models employ the low-GWP refrigerants R-32 or R-290. • RACs are available in most regions and worldwide that surpass the highest efficiency levels recognized by labeling programs. • Fixed-speed RACs using high-GWP and ozone-depleting R-22 refrigerant still dominate the market in many emerging economies. There is significant scope to improve RAC efficiency and transition to low-GWP refrigerants using commercially available technology and to design market-transformation programs for high-efficiency, low-GWP equipment including standards, labeling, procurement, and incentive programs.« less

Jammed Humans in High-Density Crowd Disasters

NASA Astrophysics Data System (ADS)

Bottinelli, Arianna; Sumpter, David; Silverberg, Jesse

When people gather in large groups like those found at Black Friday sales events, pilgrimages, heavy metal concerts, and parades, crowd density often becomes exceptionally high. As a consequence, these events can produce tragic outcomes such as stampedes and ''crowd crushes''. While human collective motion has been studied with active particle simulations, the underlying mechanisms for emergent behavior are less well understood. Here, we use techniques developed to study jammed granular materials to analyze an active matter model inspired by large groups of people gathering at a point of common interest. In the model, a single behavioral rule combined with body-contact interactions are sufficient for the emergence of a self-confined steady state, where particles fluctuate around a stable position. Applying mode analysis to this system, we find evidence for Goldstone modes, soft spots, and stochastic resonance, which may be the preferential mechanisms for dangerous emergent collective motions in crowds.

Influence of atropine therapy on fenthion-induced pancreatitis.

PubMed

Ela, Yuksel; Fidan, Huseyin; Sahin, Onder; Kilbas, Aynur; Bas, Orhan; Yavuz, Yucel; Kucuker, Hudaverdi; Altuntas, Irfan

2008-02-01

We searched the influence of dose and timing of atropine therapy in fenthion-induced pancreatitis model. All rats were intoxicated with fenthion except the control group. Two milligrams of atropine was administered for 24 hours in a high dose atropine group while a low dose atropine group received 100 micrograms of atropine for 24 hours. One group received 2 milligrams of atropine in the first four hours of intoxication while the other group received 2 milligrams of atropine in the last four hours before sacrifice. All rats were sacrificed 24 hours after intoxication. Pseudo-cholinesterase and lipase concentrations and histopathological markers of pancreatitis were studied. None of the models in this study completely prevented pancreatitis, however high dose atropine that is administered for 24 hours or the first four hours after intoxication prevented severe pancreatitis. Atropine administration influence on fenthion-induced pancreatitis should be studied for other organophosphates in animals and humans.

Model reconstruction using POD method for gray-box fault detection

NASA Technical Reports Server (NTRS)

Park, H. G.; Zak, M.

2003-01-01

This paper describes using Proper Orthogonal Decomposition (POD) method to create low-order dynamical models for the Model Filter component of Beacon-based Exception Analysis for Multi-missions (BEAM).

Architectural Considerations for Classrooms for Exceptional Children.

ERIC Educational Resources Information Center

Texas Education Agency, Austin.

Definitions are provided of the following exceptionalities: blind, partially sighted, physically handicapped, minimally brain injured, deaf, educable mentally retarded (primary, junior, and senior high levels), trainable mentally retarded, speech handicapped, and emotionally disturbed. Architectural guidelines specify classroom location, size,…

Water resources of the Myakka River basin area, southwest Florida

USGS Publications Warehouse

Joyner, Boyd F.; Sutcliffe, Horace

1976-01-01

Ground water in the Myakka River basin area of southwest Floria is obtained from a water-table aquifer and from five zones in an artesian aquifer. Wells in the water-table aquifer yield generally less than 50 gpm and dissolved solids concentration is less than 500 mg/liter except in coastal areas and the peninsula southwest of the Myakka River estuary. Wells in the Venice area that tap zone 1 usually yield less than 30 gmp. The quality of water is good except in the peninsula area. Zone 2 is the most highly developed aquifer in the heavily populated coastal areas. Wells yield as much as 200 gpm. In most areas, water is of acceptable quality. Wells that tap zone 3 yield as much as 500 gmp. Fluoride concentration ranges from 1 to 3.5 mg/liter. Zone 4 yields as much as 1,500 gpm to large diameter wells. Except in the extreme northeastern part of the area water from zone 4 usually contains high concentrations of fluoride and sulfate. Zone 5 is the most productive aquifer in the area, but dissolved solids concentrations usually are too high for public supply except in the extreme northeast. Surface water derived from natural drainage is of good quality except for occasional high color in summer. Most of the streams in the Myakka River basin area have small drainage basins, are of short channel length, and do not yield high volumes of flow. During the dry season, streamflow is maintained by groundwater discharge, and, as a result, chloride, sulfate, and dissolved solids concentrations and the hardness of the water are above drinking water standards for some streams. (Woodard-USGS)

Rayleigh-Brillouin scattering in SF6 in the kinetic regime

NASA Astrophysics Data System (ADS)

Wang, Yuanqing; Yu, Yin; Liang, Kun; Marques, Wilson; van de Water, Willem; Ubachs, Wim

2017-02-01

Rayleigh-Brillouin spectral profiles are measured with a laser-based scatterometry setup for a 90° scattering angle at a high signal-to-noise ratio (r.m.s. noise below 0.15% w.r.t. peak intensity) in sulfur-hexafluoride gas for pressures in the range 0.2-5 bar and for a wavelength of λ = 403.0 nm. The high quality data are compared to a number of light scattering models in order to address the effects of rotational and vibrational relaxation. While the vibrational relaxation rate is so slow that vibration degrees of freedom remain frozen, rotations relax on time scales comparable to those of the density fluctuations. Therefore, the heat capacity, the thermal conductivity and the bulk viscosity are all frequency-dependent transport coefficients. This is relevant for the Tenti model that depends on the values chosen for these transport coefficients. This is not the case for the other two models considered: a kinetic model based on rough-sphere interactions, and a model based on fluctuating hydrodynamics. The deviations with the experiment are similar between the three different models, except for the hydrodynamic model at pressures p≲ 2bar . As all models are in line with the ideal gas law, we hypothesize the presence of real gas effects in the measured spectra.

Information Centralization of Organization Information Structures via Reports of Exceptions.

ERIC Educational Resources Information Center

Moskowitz, Herbert; Murnighan, John Keith

A team theoretic model that establishes a criterion (decision rule) for a financial institution branch to report exceptional loan requests to headquarters for action was compared to such choices made by graduate industrial management students acting as financial vice-presidents. Results showed that the loan size criterion specified by subjects was…

Structure of scintillations in Neptune's occultation shadow

NASA Technical Reports Server (NTRS)

Hubbard, W. B.; Lellouch, Emmanuel; Sicardy, Bruno; Brahic, Andre; Vilas, Faith

1988-01-01

An exceptionally high-quality data set from a Neptune occultation is used here to derive a number of new results about the statistical properties of the fluctuations of the intensity distribution in various parts of Neptune's occultation shadow. An approximate numerical ray-tracing model which successfully accounts for many of the qualitative aspects of the observed intensity fluctuation distribution is introduced. Strong refractive scintillation is simulated by including the effects of 'turbulence' with projected atmospheric properties allowed to vary in both the direction perpendicular and parallel to the limb, and an explicit two-dimensional picture of a typical intensity distribution throughout an occulting planet's shadow is presented. The results confirm the existence of highly anisotropic turbulence.

An experimental study of helicopter rotor rotational noise in a wind tunnel

NASA Technical Reports Server (NTRS)

Lee, A.; Harris, W. L.; Widnall, S. E.

1976-01-01

The rotational noise of model helicopter rotors in forward flight was studied in an anechoic wind tunnel. The parameters under study were the rotor thrust (blade loading), blade number and advance ratio. The separate effects of each parameter were identified with the other parameters being held constant. The directivity of the noise was also measured. Twelve sets of data for rotational noise as a function of frequency were compared with the theory of Lowson and Ollerhead. In general, the agreement is reasonably good, except for the cases of (1) low and high disk loadings, (2) the four bladed rotor, and (3) low advance ratios. The theory always under-estimates the rotational noise at high harmonics.

Light generated bubble for microparticle propulsion.

PubMed

Frenkel, Ido; Niv, Avi

2017-06-06

Light activated motion of micron-sized particles with effective forces in the range of micro-Newtons is hereby proposed and demonstrated. Our investigation shows that this exceptional amount of force results from accumulation of light-generated heat by a micron-sized particle that translates into motion due to a phase transition in the nearby water. High-speed imagery indicates the role of bubble expansion and later collapse in this event. Comparing observations with known models reveals a dynamic behavior controlled by polytropic trapped vapor and the inertia of the surrounding liquid. The potential of the proposed approach is demonstrated by realization of disordered optical media with binary light-activated switching from opacity to high transparency.

Biotechnological Applications Derived from Microorganisms of the Atacama Desert

PubMed Central

González-Silva, Carlos

2014-01-01

The Atacama Desert in Chile is well known for being the driest and oldest desert on Earth. For these same reasons, it is also considered a good analog model of the planet Mars. Only a few decades ago, it was thought that this was a sterile place, but in the past years fascinating adaptations have been reported in the members of the three domains of life: low water availability, high UV radiation, high salinity, and other environmental stresses. However, the biotechnological applications derived from the basic understanding and characterization of these species, with the notable exception of copper bioleaching, are still in its infancy, thus offering an immense potential for future development. PMID:25147824

Regional temperature and precipitation changes under high-end (≥4°C) global warming.

PubMed

Sanderson, M G; Hemming, D L; Betts, R A

2011-01-13

Climate models vary widely in their projections of both global mean temperature rise and regional climate changes, but are there any systematic differences in regional changes associated with different levels of global climate sensitivity? This paper examines model projections of climate change over the twenty-first century from the Intergovernmental Panel on Climate Change Fourth Assessment Report which used the A2 scenario from the IPCC Special Report on Emissions Scenarios, assessing whether different regional responses can be seen in models categorized as 'high-end' (those projecting 4°C or more by the end of the twenty-first century relative to the preindustrial). It also identifies regions where the largest climate changes are projected under high-end warming. The mean spatial patterns of change, normalized against the global rate of warming, are generally similar in high-end and 'non-high-end' simulations. The exception is the higher latitudes, where land areas warm relatively faster in boreal summer in high-end models, but sea ice areas show varying differences in boreal winter. Many continental interiors warm approximately twice as fast as the global average, with this being particularly accentuated in boreal summer, and the winter-time Arctic Ocean temperatures rise more than three times faster than the global average. Large temperature increases and precipitation decreases are projected in some of the regions that currently experience water resource pressures, including Mediterranean fringe regions, indicating enhanced pressure on water resources in these areas.

Why are so many networks disassortative?

NASA Astrophysics Data System (ADS)

Johnson, Samuel; Torres, Joaquín J.; Marro, J.; Muñoz, Miguel A.

2011-03-01

A wide range of empirical networks—whether biological, technological, information-related or linguistic—generically exhibit important degree-degree anticorrelations (i.e., they are disassortative), the only exceptions being social ones, which tend to be positively correlated (assortative). Using an information-theory approach, we show that the equilibrium state of highly heterogeneous (scale-free) random networks is disassortative. This not only gives a parsimonious explanation to a long-standing question, but also provides a neutral model against which to compare experimental data and ascertain whether a given system is being driven from equilibrium by correlating mechanisms.

H2 spectroscopy as an agent for extinction determinations The near-infrared curve for the Orion molecular cloud

NASA Technical Reports Server (NTRS)

Davis, D. S.; Larson, H. P.; Hofmann, R.

1986-01-01

A near-infrared (1.8 to 3.5) microns extinction curve for the Orion molecular cloud is presented. The curve is derived from high-resolution spectra of the Orion H2 source recorded from the Kuiper Airborne Observatory. The data reveal that the Orion extinction law is indistinguishable from a 1/lambda form in the near-infrared, except for strongly enhanced extinction near a wavelength of about 3 microns. The implications of these results, in the context of current interstellar grain models, are discussed.

Septin Organization and Functions in Budding Yeast

PubMed Central

Glomb, Oliver; Gronemeyer, Thomas

2016-01-01

The septins are a conserved family of GTP-binding proteins present in all eukaryotic cells except plants. They were originally discovered in the baker's yeast Saccharomyces cerevisiae that serves until today as an important model organism for septin research. In yeast, the septins assemble into a highly ordered array of filaments at the mother bud neck. The septins are regulators of spatial compartmentalization in yeast and act as key players in cytokinesis. This minireview summarizes the recent findings about structural features and cell biology of the yeast septins. PMID:27857941

Microfluidic-SANS: insitu molecular insight into complex fluid processing and high throughput characterisation

NASA Astrophysics Data System (ADS)

Lopez, Carlos; Watanabe, Takaichi; Cabral, Joao; Graham, Peter; Porcar, Lionel; Martel, Anne

2014-03-01

The coupling of microfluidics and small angle neutron scattering (SANS) is successfully demonstrated for the first time. We have developed novel microdevices with suitably low SANS background and high pressure compatibility for the investigation of flow-induced phenomena and high throughput phase mapping of complex fluids. We successfully obtained scattering profiles from 50 micron channels, in 10s - 100s second acquisition times. The microfluidic geometry enables the variation of both flow type and magnitude, beyond traditional rheo-SANS setups, and is exceptionally well-suited for complex fluids due to the commensurability of relevant time and lengthscales. We demonstrate our approach by studying model flow responsive systems, including surfactant/co-surfactant/water mixtures, with well-known equilibrium phase behaviour,: sodium dodecyl sulfate (SDS)/octanol/brine, cetyltrimethyl ammonium chloride (C16TAC)/pentanol/water and a model microemulsion system (C10E4 /decane/ D20), as well as polyelectrolyte solutions. Finally, using an online micromixer we are able to implement a high throughput approach, scanning in excess of 10 scattering profiles/min for a continuous aqueous surfactant dilution over two decades in concentration.

Toward an Accurate Theoretical Framework for Describing Ensembles for Proteins under Strongly Denaturing Conditions

PubMed Central

Tran, Hoang T.; Pappu, Rohit V.

2006-01-01

Our focus is on an appropriate theoretical framework for describing highly denatured proteins. In high concentrations of denaturants, proteins behave like polymers in a good solvent and ensembles for denatured proteins can be modeled by ignoring all interactions except excluded volume (EV) effects. To assay conformational preferences of highly denatured proteins, we quantify a variety of properties for EV-limit ensembles of 23 two-state proteins. We find that modeled denatured proteins can be best described as follows. Average shapes are consistent with prolate ellipsoids. Ensembles are characterized by large correlated fluctuations. Sequence-specific conformational preferences are restricted to local length scales that span five to nine residues. Beyond local length scales, chain properties follow well-defined power laws that are expected for generic polymers in the EV limit. The average available volume is filled inefficiently, and cavities of all sizes are found within the interiors of denatured proteins. All properties characterized from simulated ensembles match predictions from rigorous field theories. We use our results to resolve between conflicting proposals for structure in ensembles for highly denatured states. PMID:16766618

Long-term spectral and temporal behavior of the high-frequency peaked BL LAC object 1ES 1959+650

NASA Astrophysics Data System (ADS)

Backes, M.; Uellenbeck, M.; Hayashida, M.; Satalecka, K.; Tescaro, D.; Terzić, T.; MAGIC Collaboration; Fuhrmann, L.; Nestoras, I.; F-GAMMA project; Lähteenmäki, A.; Tornikoski, M.; Nieppola, E.; Metsähovi; Böttcher, M.; Collmar, W.; Weidinger, M.

2012-12-01

The high-frequency peaked BL Lac object 1ES 1959+650 is well-known for an exceptional outburst, which was observed at very high energy (VHE) γ-rays by the Whipple 10m and HEGRA telescopes in 2002. Remarkably, this outburst lacked associated X-ray emission (a socalled "orphan flare") and by this cannot easily be described by standard Synchrotron Self Compton (SSC) models. Models based on hadronic emission processes have also been proposed to explain the observed behavior. Subsequent multi-wavelength observations during a low flux state at TeV energies in 2006 can, instead, be explained by a standard single-zone SSC model. In this context, 1ES 1959+650 has been regularly monitored by the MAGIC telescope since 2005. During these years, no significant variation in the VHE γ-ray flux has been observed. The low energy part of this is in very good agreement with the high-energy part of the time-integrated energy spectrum as measured by Fermi-LAT. Based on this constant flux level in VHE γ-rays, we assembled the time-integrated spectral energy distribution (SED) of 1ES 1959+650 from radio to VHE γ-rays. Despite the non-variability at very high energies, significant flux and spectral variations have been observed at optical and X-ray frequencies in the meanwhile. Furthermore, the shape of the SED at high energy γ-rays as measured by Fermi-LAT is essentially flat which cannot be explained by either conventional single-zone SSC models, or models invoking external radiation fields (EC).

Confinement in F4 Exceptional Gauge Group Using Domain Structures

NASA Astrophysics Data System (ADS)

Rafibakhsh, Shahnoosh; Shahlaei, Amir

2017-03-01

We calculate the potential between static quarks in the fundamental representation of the F4 exceptional gauge group using domain structures of the thick center vortex model. As non-trivial center elements are absent, the asymptotic string tension is lost while an intermediate linear potential is observed. SU(2) is a subgroup of F4. Investigating the decomposition of the 26 dimensional representation of F4 to the SU(2) representations, might explain what accounts for the intermediate linear potential, in the exceptional groups with no center element.

Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology.

PubMed

Akarsu, Ceyhun; Ozay, Yasin; Dizge, Nadir; Elif Gulsen, H; Ates, Hasan; Gozmen, Belgin; Turabik, Meral

Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box-Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5-15 V), initial pH (4.5-8.0) and time (30-90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P > 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R(2) and Radj(2) values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R(2) values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage-time and pH-time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic effect.

Meeting the Needs of the Highly Gifted.

ERIC Educational Resources Information Center

Morelock, Martha; And Others

1997-01-01

This supplementary insert discusses the differences between exceptionally gifted children and their more moderately gifted peers. Case studies are provided to illustrate the characteristics of exceptionally gifted children, including their tendencies toward fantasy and their ability to develop alternate realities. (CR)

Unidirectional reflectionless propagation in non-Hermitian metamaterial based on phase coupling between two resonators

NASA Astrophysics Data System (ADS)

Yin, Hongda; Bai, Ruiping; Gu, Xintong; Zhang, Cong; Gu, Guang Rui; Zhang, Ying Qiao; Jin, Xing Ri; Lee, YoungPak

2018-05-01

Unidirectional reflectionless propagation in a non-Hermitian metamaterial is obtained based on phase coupling between two resonators. The unidirectional reflectionless propagation can be obtained at exceptional point by adjusting polarization angle θ and distance d between two resonators. Moreover, coherent prefect absorptions are obtained near exceptional point with the high absorbance of ∼0.99 and high quality factor of ∼83.

Development of cookies made with cocoyam, fermented sorghum and germinated pigeon pea flour blends using response surface methodology.

PubMed

Okpala, Laura C; Okoli, Eric C

2014-10-01

Cookies were produced from blends of cocoyam, fermented sorghum and germinated pigeon pea flours. The study was carried out to evaluate the effects of varying the proportions of these components on the sensory and protein quality of the cookies. The sensory attributes studied were colour, taste, texture, crispness and general acceptability while the protein quality indices were biological value (BV) and net protein utilization (NPU). Mixture response surface methodology was used to model the sensory and protein quality with single, binary and ternary combinations of germinated pigeon pea, fermented sorghum and cocoyam flours. Results showed that BV and NPU of most of the cookies were above minimum acceptable levels. With the exception of cookies containing high levels of pigeon pea flour, cookies had acceptable sensory scores. Increase in pigeon pea flour resulted in increase in the BV and NPU. Regression equations suggested that the ternary blends produced the highest increase in all the sensory attributes (with the exception of colour).

When nursing takes ownership of financial outcomes: achieving exceptional financial performance through leadership, strategy, and execution.

PubMed

Goetz, Kristopher; Janney, Michelle; Ramsey, Kristin

2011-01-01

With nurses and unlicensed supportive personnel composing the greatest percentage of the workforce at any hospital, it is not surprising nursing leadership plays an increasing role in the attainment of financial goals. The nursing leadership team at one academic medical center reduced costs by more than $10 million over 4 years while outperforming national benchmarks on nurse-sensitive quality indicators. The most critical success factor in attaining exceptional financial performance is a personal and collective accountability to achieving outcomes. Whether it is financial improvement, advancing patient safety, or ensuring a highly engaged workforce, success will not be attained without thoughtful, focused leadership. The accountability model ensures there is a culture built around financial performance where nurses and leaders think and act, on a daily basis, in a manner necessary to understand opportunities, find answers, and overcome obstacles. While structures, processes, and tools may serve as the means to achieve a target, it is leadership's responsibility to set the right goal and motivate others.

Wavelet-based spectral finite element dynamic analysis for an axially moving Timoshenko beam

NASA Astrophysics Data System (ADS)

Mokhtari, Ali; Mirdamadi, Hamid Reza; Ghayour, Mostafa

2017-08-01

In this article, wavelet-based spectral finite element (WSFE) model is formulated for time domain and wave domain dynamic analysis of an axially moving Timoshenko beam subjected to axial pretension. The formulation is similar to conventional FFT-based spectral finite element (SFE) model except that Daubechies wavelet basis functions are used for temporal discretization of the governing partial differential equations into a set of ordinary differential equations. The localized nature of Daubechies wavelet basis functions helps to rule out problems of SFE model due to periodicity assumption, especially during inverse Fourier transformation and back to time domain. The high accuracy of WSFE model is then evaluated by comparing its results with those of conventional finite element and SFE results. The effects of moving beam speed and axial tensile force on vibration and wave characteristics, and static and dynamic stabilities of moving beam are investigated.

Anthropogenic range contractions bias species climate change forecasts

NASA Astrophysics Data System (ADS)

Faurby, Søren; Araújo, Miguel B.

2018-03-01

Forecasts of species range shifts under climate change most often rely on ecological niche models, in which characterizations of climate suitability are highly contingent on the species range data used. If ranges are far from equilibrium under current environmental conditions, for instance owing to local extinctions in otherwise suitable areas, modelled environmental suitability can be truncated, leading to biased estimates of the effects of climate change. Here we examine the impact of such biases on estimated risks from climate change by comparing models of the distribution of North American mammals based on current ranges with ranges accounting for historical information on species ranges. We find that estimated future diversity, almost everywhere, except in coastal Alaska, is drastically underestimated unless the full historical distribution of the species is included in the models. Consequently forecasts of climate change impacts on biodiversity for many clades are unlikely to be reliable without acknowledging anthropogenic influences on contemporary ranges.

Improved ground hydrology calculations for global climate models (GCMs) - Soil water movement and evapotranspiration

NASA Technical Reports Server (NTRS)

Abramopoulos, F.; Rosenzweig, C.; Choudhury, B.

1988-01-01

A physically based ground hydrology model is presented that includes the processes of transpiration, evaporation from intercepted precipitation and dew, evaporation from bare soil, infiltration, soil water flow, and runoff. Data from the Goddard Institute for Space Studies GCM were used as inputs for off-line tests of the model in four 8 x 10 deg regions, including Brazil, Sahel, Sahara, and India. Soil and vegetation input parameters were caculated as area-weighted means over the 8 x 10 deg gridbox; the resulting hydrological quantities were compared to ground hydrology model calculations performed on the 1 x 1 deg cells which comprise the 8 x 10 deg gridbox. Results show that the compositing procedure worked well except in the Sahel, where low soil water levels and a heterogeneous land surface produce high variability in hydrological quantities; for that region, a resolution better than 8 x 10 deg is needed.

HIGH-RATE FORMABILITY OF HIGH-STRENGTH ALUMINUM ALLOYS: A STUDY ON OBJECTIVITY OF MEASURED STRAIN AND STRAIN RATE

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

Upadhyay, Piyush; Rohatgi, Aashish; Stephens, Elizabeth V.

2015-02-18

Al alloy AA7075 sheets were deformed at room temperature at strain-rates exceeding 1000 /s using the electrohydraulic forming (EHF) technique. A method that combines high speed imaging and digital image correlation technique, developed at Pacific Northwest National Laboratory, is used to investigate high strain rate deformation behavior of AA7075. For strain-rate sensitive materials, the ability to accurately model their high-rate deformation behavior is dependent upon the ability to accurately quantify the strain-rate that the material is subjected to. This work investigates the objectivity of software-calculated strain and strain rate by varying different parameters within commonly used commercially available digital imagemore » correlation software. Except for very close to the time of crack opening the calculated strain and strain rates are very consistent and independent of the adjustable parameters of the software.« less

Fermi Observations of High-Energy Gamma-Ray Emission from GRB 080916C

DOE PAGES

Abdo, A. A.; Ackermann, M.; Arimoto, M.; ...

2009-02-19

Gamma-ray bursts (GRBs) are highly energetic explosions signaling the death of massive stars in distant galaxies. The Gamma-ray Burst Monitor and Large Area Telescope onboard the Fermi Observatory together record GRBs over a broad energy range spanning about 7 decades of gammaray energy. In September 2008, Fermi observed the exceptionally luminous GRB 080916C, with the largest apparent energy release yet measured. The high-energy gamma rays are observed to start later and persist longer than the lower energy photons. A simple spectral form fits the entire GRB spectrum, providing strong constraints on emission models. Finally, the known distance of the burstmore » enables placing lower limits on the bulk Lorentz factor of the outflow and on the quantum gravity mass.« less

Nonlinear effect of climate on plague during the third pandemic in China

PubMed Central

Xu, Lei; Liu, Qiyong; Stige, Leif Chr.; Ben Ari, Tamara; Fang, Xiye; Chan, Kung-Sik; Wang, Shuchun; Stenseth, Nils Chr.; Zhang, Zhibin

2011-01-01

Over the years, plague has caused a large number of deaths worldwide and subsequently changed history, not the least during the period of the Black Death. Of the three plague pandemics, the third is believed to have originated in China. Using the spatial and temporal human plague records in China from 1850 to 1964, we investigated the association of human plague intensity (plague cases per year) with proxy data on climate condition (specifically an index for dryness/wetness). Our modeling analysis demonstrates that the responses of plague intensity to dry/wet conditions were different in northern and southern China. In northern China, plague intensity generally increased when wetness increased, for both the current and the previous year, except for low intensity during extremely wet conditions in the current year (reflecting a dome-shaped response to current-year dryness/wetness). In southern China, plague intensity generally decreased when wetness increased, except for high intensity during extremely wet conditions of the current year. These opposite effects are likely related to the different climates and rodent communities in the two parts of China: In northern China (arid climate), rodents are expected to respond positively to high precipitation, whereas in southern China (humid climate), high precipitation is likely to have a negative effect. Our results suggest that associations between human plague intensity and precipitation are nonlinear: positive in dry conditions, but negative in wet conditions. PMID:21646523

Nonlinear effect of climate on plague during the third pandemic in China.

PubMed

Xu, Lei; Liu, Qiyong; Stige, Leif Chr; Ben Ari, Tamara; Fang, Xiye; Chan, Kung-Sik; Wang, Shuchun; Stenseth, Nils Chr; Zhang, Zhibin

2011-06-21

Over the years, plague has caused a large number of deaths worldwide and subsequently changed history, not the least during the period of the Black Death. Of the three plague pandemics, the third is believed to have originated in China. Using the spatial and temporal human plague records in China from 1850 to 1964, we investigated the association of human plague intensity (plague cases per year) with proxy data on climate condition (specifically an index for dryness/wetness). Our modeling analysis demonstrates that the responses of plague intensity to dry/wet conditions were different in northern and southern China. In northern China, plague intensity generally increased when wetness increased, for both the current and the previous year, except for low intensity during extremely wet conditions in the current year (reflecting a dome-shaped response to current-year dryness/wetness). In southern China, plague intensity generally decreased when wetness increased, except for high intensity during extremely wet conditions of the current year. These opposite effects are likely related to the different climates and rodent communities in the two parts of China: In northern China (arid climate), rodents are expected to respond positively to high precipitation, whereas in southern China (humid climate), high precipitation is likely to have a negative effect. Our results suggest that associations between human plague intensity and precipitation are nonlinear: positive in dry conditions, but negative in wet conditions.

Distinct Element Modeling of the Large Block Test

NASA Astrophysics Data System (ADS)

Carlson, S. R.; Blair, S. C.; Wagoner, J. L.

2001-12-01

The Yucca Mountain Site Characterization Project is investigating Yucca Mountain, Nevada as a potential nuclear waste repository site. As part of this effort, the Large Block, a 3m x 3m x 4.5m rectangular prism of Topopah Spring tuff, was excavated at Fran Ridge near Yucca Mountain. The Large Block was heated to a peak temperature of 145\\deg C along a horizontal plane 2.75m below the top of the block over a period of about one-year. Displacements were measured in three orthogonal directions with an array of six Multiple Point Borehole Extensometers (MPBX) and were numerically simulated in three dimensions with 3DEC, a distinct element code. The distinct element method was chosen to incorporate discrete fractures in the simulations. The model domain was extended 23m below the ground surface and, in the subsurface, 23m outward from each vertical face so that fixed displacement boundary conditions could be applied well away from the heated portion of the block. A single continuum model and three distinct element models, incorporating six to twenty eight mapped fractures, were tested. Two thermal expansion coefficients were tested for the six-fracture model: a higher value taken from laboratory measurements and a lower value from an earlier field test. The MPBX data show that the largest displacements occurred in the upper portion of the block despite the higher temperatures near the center. The continuum model was found to under-predict the MPBX displacements except in the east west direction near the base of the block. The high thermal expansion model over-predicted the MPBX displacements except in the north south direction near the top of the block. The highly fractured model under-predicted most of the MPBX displacements and poorly simulated the cool-down portion of the test. Although no model provided the single best fit to all of the MPBX data, the six and seven fracture models consistently provided good fits and in most cases showed much improvement over the other three models. Both provided particularly good fits to the east west displacements in the upper portion of the block throughout the entire test. This exercise demonstrates that distinct element models can surpass continuum models in their ability to simulate fractured rock mass deformation, but care needs to be taken in the selection of fractures incorporated in the models. *This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

Understanding GPU Power. A Survey of Profiling, Modeling, and Simulation Methods

DOE PAGES

Bridges, Robert A.; Imam, Neena; Mintz, Tiffany M.

2016-09-01

Modern graphics processing units (GPUs) have complex architectures that admit exceptional performance and energy efficiency for high throughput applications.Though GPUs consume large amounts of power, their use for high throughput applications facilitate state-of-the-art energy efficiency and performance. Consequently, continued development relies on understanding their power consumption. Our work is a survey of GPU power modeling and profiling methods with increased detail on noteworthy efforts. Moreover, as direct measurement of GPU power is necessary for model evaluation and parameter initiation, internal and external power sensors are discussed. Hardware counters, which are low-level tallies of hardware events, share strong correlation to powermore » use and performance. Statistical correlation between power and performance counters has yielded worthwhile GPU power models, yet the complexity inherent to GPU architectures presents new hurdles for power modeling. Developments and challenges of counter-based GPU power modeling is discussed. Often building on the counter-based models, research efforts for GPU power simulation, which make power predictions from input code and hardware knowledge, provide opportunities for optimization in programming or architectural design. Noteworthy strides in power simulations for GPUs are included along with their performance or functional simulator counterparts when appropriate. Lastly, possible directions for future research are discussed.« less

Understanding GPU Power. A Survey of Profiling, Modeling, and Simulation Methods

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

Bridges, Robert A.; Imam, Neena; Mintz, Tiffany M.

Modern graphics processing units (GPUs) have complex architectures that admit exceptional performance and energy efficiency for high throughput applications.Though GPUs consume large amounts of power, their use for high throughput applications facilitate state-of-the-art energy efficiency and performance. Consequently, continued development relies on understanding their power consumption. Our work is a survey of GPU power modeling and profiling methods with increased detail on noteworthy efforts. Moreover, as direct measurement of GPU power is necessary for model evaluation and parameter initiation, internal and external power sensors are discussed. Hardware counters, which are low-level tallies of hardware events, share strong correlation to powermore » use and performance. Statistical correlation between power and performance counters has yielded worthwhile GPU power models, yet the complexity inherent to GPU architectures presents new hurdles for power modeling. Developments and challenges of counter-based GPU power modeling is discussed. Often building on the counter-based models, research efforts for GPU power simulation, which make power predictions from input code and hardware knowledge, provide opportunities for optimization in programming or architectural design. Noteworthy strides in power simulations for GPUs are included along with their performance or functional simulator counterparts when appropriate. Lastly, possible directions for future research are discussed.« less

14 CFR 93.133 - Exceptions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Exceptions. 93.133 Section 93.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.133...

14 CFR 93.133 - Exceptions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Exceptions. 93.133 Section 93.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.133...

14 CFR 93.133 - Exceptions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Exceptions. 93.133 Section 93.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.133...

14 CFR 93.133 - Exceptions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Exceptions. 93.133 Section 93.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.133...

14 CFR 93.133 - Exceptions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Exceptions. 93.133 Section 93.133 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.133...

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

Rybicki, E.F.; Luiskutty, C.T.; Sutrick, J.S.

This User's Manual contains information for four fracture/proppant models. TUPROP1 contains a Geertsma and de Klerk type fracture model. The section of the program utilizing the proppant fracture geometry data from the pseudo three-dimensional highly elongated fracture model is called TUPROPC. The analogous proppant section of the program that was modified to accept fracture shape data from SA3DFRAC is called TUPROPS. TUPROPS also includes fracture closure. Finally there is the penny fracture and its proppant model, PENNPROP. In the first three chapters, the proppant sections are based on the same theory for determining the proppant distribution but have modifications tomore » support variable height fractures and modifications to accept fracture geometry from three different fracture models. Thus, information about each proppant model in the User's Manual builds on information supplied in the previous chapter. The exception to the development of combined treatment models is the penny fracture and its proppant model. In this case, a completely new proppant model was developed. A description of how to use the combined treatment model for the penny fracture is contained in Chapter 4. 2 refs.« less

Why Isn't Talent Development on the IEP? SEM and the Twice Exceptional Learner

ERIC Educational Resources Information Center

Baum, Susan; Novak, Cynthia

2010-01-01

Why isn't talent development included on the Individual Educational Plan of 2E students? Twice exceptional students have unique issues that respond especially well to a talent development approach especially within the context of the Schoolwide Enrichment Model. Through case studies and a review of successful projects using SEM with at risk…

76 FR 66203 - Airworthiness Directives; Bombardier, Inc. Model CL-600-2B16 (CL-601-3A, CL-601-3R, and CL-604...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... Friday, except Federal holidays. For service information identified in this proposed AD, contact... Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any... any category, serial numbers 5701 through 5752 inclusive, 5754 through 5775 inclusive, 5777, 5779...

76 FR 62658 - Airworthiness Directives; Fokker Services B.V. Model F.27 Mark 050 and F.28 Mark 0070 and 0100...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-11

...., Monday through Friday, except Federal holidays. For service information identified in this proposed AD... Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket..., 20105, 20121 through 20123 inclusive, 20130 through 20135 inclusive, 20141 through 20145 inclusive...

76 FR 66198 - Airworthiness Directives; Bombardier, Inc. Model BD-700-1A10 and BD-700-1A11 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

...., Monday through Friday, except Federal holidays. For service information identified in this proposed AD...., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory... airplanes, certificated in any category, serial numbers (S/N) 9002 through 9126 inclusive, 9128 through 9312...

75 FR 262 - Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-05

.... This proposed AD results from reports of fatigue cracks of the lower surface of the center wing box. We... 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this... Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket...

76 FR 54093 - Airworthiness Directives; Bombardier, Inc. Model DHC-8-400 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-31

... is found to be incorrect (i.e., the ring can be rotated during any torque check required by this AD), before further flight, replace all hardware at that location (except the saddle washer and retainer) in... that location (except the saddle washer and retainer) in accordance with paragraph 3.B., part B, of the...

F4 , E6 and G2 exceptional gauge groups in the vacuum domain structure model

NASA Astrophysics Data System (ADS)

Shahlaei, Amir; Rafibakhsh, Shahnoosh

2018-03-01

Using a vacuum domain structure model, we calculate trivial static potentials in various representations of F4 , E6, and G2 exceptional groups by means of the unit center element. Due to the absence of the nontrivial center elements, the potential of every representation is screened at far distances. However, the linear part is observed at intermediate quark separations and is investigated by the decomposition of the exceptional group to its maximal subgroups. Comparing the group factor of the supergroup with the corresponding one obtained from the nontrivial center elements of S U (3 ) subgroup shows that S U (3 ) is not the direct cause of temporary confinement in any of the exceptional groups. However, the trivial potential obtained from the group decomposition into the S U (3 ) subgroup is the same as the potential of the supergroup itself. In addition, any regular or singular decomposition into the S U (2 ) subgroup that produces the Cartan generator with the same elements as h1, in any exceptional group, leads to the linear intermediate potential of the exceptional gauge groups. The other S U (2 ) decompositions with the Cartan generator different from h1 are still able to describe the linear potential if the number of S U (2 ) nontrivial center elements that emerge in the decompositions is the same. As a result, it is the center vortices quantized in terms of nontrivial center elements of the S U (2 ) subgroup that give rise to the intermediate confinement in the static potentials.

A collective phase in resource competition in a highly diverse ecosystem

NASA Astrophysics Data System (ADS)

Tikhonov, Mikhail; Monasson, Remi

Recent technological advances uncovered that most habitats, including the human body, harbor hundreds of coexisting microbial ``species''. The problem of understanding such complex communities is currently at the forefront of medical and environmental sciences. A particularly intriguing question is whether the high-diversity regime (large number of species N) gives rise to qualitatively novel phenomena that could not be intuited from analysis of low-dimensional models (with few species). However, few existing approaches allow studying this regime, except in simulations. Here, we use methods of statistical physics to show that the large- N limit of a classic ecological model of resource competition introduced by MacArthur in 1969 can be solved analytically. Our results provide a tractable model where the implications of large dimensionality of eco-evolutionary problems can be investigated. In particular, we show that at high diversity, the MacArthur model exhibits a phase transition into a curious regime where the environment constructed by the community becomes a collective property, insensitive to the external conditions such as the total resource influx supplied to the community. Supported by Harvard Center of Mathematical Sciences and Applications, and the Simons Foundation. This work was completed at the Aspen Center for Physics, supported by National Science Foundation Grant PHY-1066293.

Modeling of Laser Vaporization and Plume Chemistry in a Boron Nitride Nanotube Production Rig

NASA Technical Reports Server (NTRS)

Gnoffo, Peter A.; Fay, Catharine C.

2012-01-01

Flow in a pressurized, vapor condensation (PVC) boron nitride nanotube (BNNT) production rig is modeled. A laser provides a thermal energy source to the tip of a boron ber bundle in a high pressure nitrogen chamber causing a plume of boron-rich gas to rise. The buoyancy driven flow is modeled as a mixture of thermally perfect gases (B, B2, N, N2, BN) in either thermochemical equilibrium or chemical nonequilibrium assuming steady-state melt and vaporization from a 1 mm radius spot at the axis of an axisymmetric chamber. The simulation is intended to define the macroscopic thermochemical environment from which boron-rich species, including nanotubes, condense out of the plume. Simulations indicate a high temperature environment (T > 4400K) for elevated pressures within 1 mm of the surface sufficient to dissociate molecular nitrogen and form BN at the base of the plume. Modifications to Program LAURA, a finite-volume based solver for hypersonic flows including coupled radiation and ablation, are described to enable this simulation. Simulations indicate that high pressure synthesis conditions enable formation of BN vapor in the plume that may serve to enhance formation of exceptionally long nanotubes in the PVC process.

Multichannel imaging to quantify four classes of pharmacokinetic distribution in tumors

PubMed Central

Bhatnagar, Sumit; Deschenes, Emily; Liao, Jianshan; Cilliers, Cornelius; Thurber, Greg M.

2014-01-01

Low and heterogeneous delivery of drugs and imaging agents to tumors results in decreased efficacy and poor imaging results. Systemic delivery involves a complex interplay of drug properties and physiological factors, and heterogeneity in the tumor microenvironment makes predicting and overcoming these limitations exceptionally difficult. Theoretical models have indicated that there are four different classes of pharmacokinetic behavior in tissue, depending on the fundamental steps in distribution. In order to study these limiting behaviors, we used multichannel fluorescence microscopy and stitching of high-resolution images to examine the distribution of four agents in the same tumor microenvironment. A validated generic partial differential equation model with a graphical user interface was used to select fluorescent agents exhibiting these four classes of behavior, and the imaging results agreed with predictions. BODIPY-FL exhibited higher concentrations in tissue with high blood flow, cetuximab gave perivascular distribution limited by permeability, high plasma protein and target binding resulted in diffusion-limited distribution for Hoechst 33342, and Integrisense 680 was limited by the number of binding sites in the tissue. Together, the probes and simulations can be used to investigate distribution in other tumor models, predict tumor drug distribution profiles, and design and interpret in vivo experiments. PMID:25048378

Treatment of d-galactose induced mouse aging with Lycium barbarum polysaccharides and its mechanism study.

PubMed

Tang, Tao; He, Bixiu

2013-01-01

We evaluated the effects of Lycium barbarum polysaccharides LBP) on D-galactose aging model mouse, and explored its possible mechanism. Kunming mice were randomly divided into the control group, the model group, the high-dose LBP group, and the low-dose LBP group. Except the control group, D-galactose was used for modelling. The drug was administrated when modelling. Mouse behavioural, learning and memory changes were observed, and the contents of lipid peroxidation (LPO), lipofuscin (LF) and monoamine oxidase B (MAO-B) in mouse brain tissue and the weight of immune organs were measured after 6 weeks. Compared with the control group, mouse weight gain in the model group reduced significantly. Compared with model group, after mice drank LBP, the times of electric shock was less than aging mice (in which, the high-dose LBP group, P<0.05), and electric shock incubation period was longer (P<0.01). On Day 45 after modelling and drug administration, the contents of LPO, LF and MAO-B in mouse brain tissue in the model group increased significantly, while those in the drug administration groups decreased significantly. The thymus index in the aging model group decreased significantly; the thymus index and the spleen index in the high-dose LBP group and the low-dose LBP group rebounded significantly (P<0.01). We concluded that LBP has an anti-aging effect on D-galactose induced aging model mouse, and its mechanism may be related with the alleviation of glucose metabolism disorder and the resistance of the generation of lipid peroxide and other substances, which damage cell membrane lipid.

Theoretical Modeling of (99)Tc NMR Chemical Shifts.

PubMed

Hall, Gabriel B; Andersen, Amity; Washton, Nancy M; Chatterjee, Sayandev; Levitskaia, Tatiana G

2016-09-06

Technetium-99 (Tc) displays a rich chemistry due to its wide range of accessible oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and (99)Tc nuclear magnetic resonance (NMR) spectroscopy is widely used to probe chemical environments of Tc in odd oxidation states. However, interpretation of (99)Tc NMR data is hindered by the lack of reference compounds. Density functional theory (DFT) calculations can help to fill this gap, but to date few computational studies have focused on (99)Tc NMR of compounds and complexes. This work evaluates the effectiveness of both pure generalized gradient approximation and their corresponding hybrid functionals, both with and without the inclusion of scalar relativistic effects, to model the (99)Tc NMR spectra of Tc(I) carbonyl compounds. With the exception of BLYP, which performed exceptionally well overall, hybrid functionals with inclusion of scalar relativistic effects are found to be necessary to accurately calculate (99)Tc NMR spectra. The computational method developed was used to tentatively assign an experimentally observed (99)Tc NMR peak at -1204 ppm to fac-Tc(CO)3(OH)3(2-). This study examines the effectiveness of DFT computations for interpretation of the (99)Tc NMR spectra of Tc(I) coordination compounds in high salt alkaline solutions.

Snow Densification and Recent Accumulation Along the iSTAR Traverse, Pine Island Glacier, Antarctica

NASA Astrophysics Data System (ADS)

Morris, E. M.; Mulvaney, R.; Arthern, R. J.; Davies, D.; Gurney, R. J.; Lambert, P.; De Rydt, J.; Smith, A. M.; Tuckwell, R. J.; Winstrup, M.

2017-12-01

Neutron probe measurements of snow density from 22 sites in the Pine Island Glacier basin have been used to determine mean annual accumulation using an automatic annual layer identification routine. A mean density profile which can be used to convert radar two-way travel times to depth has been derived, and the effect of annual fluctuations in density on estimates of the depth of radar reflectors is shown to be insignificant, except very near the surface. Vertical densification rates have been derived from the neutron probe density profiles and from deeper firn core density profiles available at 9 of the sites. These rates are consistent with the rates predicted by the Herron and Langway model for stage 1 densification (by grain-boundary sliding, grain growth and intracrystalline deformation) and stage 2 densification (predominantly by sintering), except in a transition zone extending from ≈8 to ≈13 m from the surface in which 10-14% of the compaction occurs. Profiles of volumetric strain rate at each site show that in this transition zone the rates are consistent with the Arthern densification model. Comparison of the vertical densification rates and volumetric strain rates indicates that the expected relation to mean annual accumulation breaks down at high accumulation rates even when corrections are made for horizontal ice velocity divergence.

Comparison of Methods of Detection of Exceptional Sequences in Prokaryotic Genomes.

PubMed

Rusinov, I S; Ershova, A S; Karyagina, A S; Spirin, S A; Alexeevski, A V

2018-02-01

Many proteins need recognition of specific DNA sequences for functioning. The number of recognition sites and their distribution along the DNA might be of biological importance. For example, the number of restriction sites is often reduced in prokaryotic and phage genomes to decrease the probability of DNA cleavage by restriction endonucleases. We call a sequence an exceptional one if its frequency in a genome significantly differs from one predicted by some mathematical model. An exceptional sequence could be either under- or over-represented, depending on its frequency in comparison with the predicted one. Exceptional sequences could be considered biologically meaningful, for example, as targets of DNA-binding proteins or as parts of abundant repetitive elements. Several methods to predict frequency of a short sequence in a genome, based on actual frequencies of certain its subsequences, are used. The most popular are methods based on Markov chain models. But any rigorous comparison of the methods has not previously been performed. We compared three methods for the prediction of short sequence frequencies: the maximum-order Markov chain model-based method, the method that uses geometric mean of extended Markovian estimates, and the method that utilizes frequencies of all subsequences including discontiguous ones. We applied them to restriction sites in complete genomes of 2500 prokaryotic species and demonstrated that the results depend greatly on the method used: lists of 5% of the most under-represented sites differed by up to 50%. The method designed by Burge and coauthors in 1992, which utilizes all subsequences of the sequence, showed a higher precision than the other two methods both on prokaryotic genomes and randomly generated sequences after computational imitation of selective pressure. We propose this method as the first choice for detection of exceptional sequences in prokaryotic genomes.

Models of violently relaxed galaxies

NASA Astrophysics Data System (ADS)

Merritt, David; Tremaine, Scott; Johnstone, Doug

1989-02-01

The properties of spherical self-gravitating models derived from two distribution functions that incorporate, in a crude way, the physics of violent relaxation are investigated. The first distribution function is identical to the one discussed by Stiavelli and Bertin (1985) except for a change in the sign of the 'temperature', i.e., e exp(-aE) to e exp(+aE). It is shown that these 'negative temperature' models provide a much better description of the end-state of violent relaxation than 'positive temperature' models. The second distribution function is similar to the first except for a different dependence on angular momentum. Both distribution functions yield single-parameter families of models with surface density profiles very similar to the R exp 1/4 law. Furthermore, the central concentration of models in both families increases monotonically with the velocity anisotropy, as expected in systems that formed through cold collapse.

An infrared scattering by evaporating droplets at the initial stage of a pool fire suppression by water sprays

NASA Astrophysics Data System (ADS)

Dombrovsky, Leonid A.; Dembele, Siaka; Wen, Jennifer X.

2018-06-01

The computational analysis of downward motion and evaporation of water droplets used to suppress a typical transient pool fire shows local regions of a high volume fraction of relatively small droplets. These droplets are comparable in size with the infrared wavelength in the range of intense flame radiation. The estimated scattering of the radiation by these droplets is considerable throughout the entire spectrum except for a narrow region in the vicinity of the main absorption peak of water where the anomalous refraction takes place. The calculations of infrared radiation field in the model pool fire indicate the strong effect of scattering which can be observed experimentally to validate the fire computational model.

Thermal and Electrical Effects of Partial Shade in Monolithic Thin-Film Photovoltaic Modules: Preprint

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

Silverman, Timothy J.; Deceglie, Michael G.; Sun, Xingshu

2015-09-02

Photovoltaic cells can be damaged by reverse bias stress, which arises during service when a monolithically integrated thin-film module is partially shaded. We introduce a model for describing a module's internal thermal and electrical state, which cannot normally be measured. Using this model and experimental measurements, we present several results with relevance for reliability testing and module engineering: Modules with a small breakdown voltage experience less stress than those with a large breakdown voltage, with some exceptions for modules having light-enhanced reverse breakdown. Masks leaving a small part of the masked cells illuminated can lead to very high temperature andmore » current density compared to masks covering entire cells.« less

Thermal and Electrical Effects of Partial Shade in Monolithic Thin-Film Photovoltaic Modules

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

Silverman, Timothy J.; Deceglie, Michael G.; Sun, Xingshu

2015-06-14

Photovoltaic cells can be damaged by reverse bias stress, which arises during service when a monolithically integrated thin-film module is partially shaded. We introduce a model for describing a module's internal thermal and electrical state, which cannot normally be measured. Using this model and experimental measurements, we present several results with relevance for reliability testing and module engineering: Modules with a small breakdown voltage experience less stress than those with a large breakdown voltage, with some exceptions for modules having light-enhanced reverse breakdown. Masks leaving a small part of the masked cells illuminated can lead to very high temperature andmore » current density compared to masks covering entire cells.« less

Three sympatric clusters of the malaria vector Anopheles culicifacies E (Diptera: Culicidae) detected in Sri Lanka.

PubMed

Harischandra, Iresha Nilmini; Dassanayake, Ranil Samantha; De Silva, Bambaranda Gammacharige Don Nissanka Kolitha

2016-01-04

The disease re-emergence threat from the major malaria vector in Sri Lanka, Anopheles culicifacies, is currently increasing. To predict malaria vector dynamics, knowledge of population genetics and gene flow is required, but this information is unavailable for Sri Lanka. This study was carried out to determine the population structure of An. culicifacies E in Sri Lanka. Eight microsatellite markers were used to examine An. culicifacies E collected from six sites in Sri Lanka during 2010-2012. Standard population genetic tests and analyses, genetic differentiation, Hardy-Weinberg equilibrium, linkage disequilibrium, Bayesian cluster analysis, AMOVA, SAMOVA and isolation-by-distance were conducted using five polymorphic loci. Five microsatellite loci were highly polymorphic with high allelic richness. Hardy-Weinberg Equilibrium (HWE) was significantly rejected for four loci with positive F(IS) values in the pooled population (p < 0.0100). Three loci showed high deviations in all sites except Kataragama, which was in agreement with HWE for all loci except one locus (p < 0.0016). Observed heterozygosity was less than the expected values for all sites except Kataragama, where reported negative F(IS) values indicated a heterozygosity excess. Genetic differentiation was observed for all sampling site pairs and was not supported by the isolation by distance model. Bayesian clustering analysis identified the presence of three sympatric clusters (gene pools) in the studied population. Significant genetic differentiation was detected in cluster pairs with low gene flow and isolation by distance was not detected between clusters. Furthermore, the results suggested the presence of a barrier to gene flow that divided the populations into two parts with the central hill region of Sri Lanka as the dividing line. Three sympatric clusters were detected among An. culicifacies E specimens isolated in Sri Lanka. There was no effect of geographic distance on genetic differentiation and the central mountain ranges in Sri Lanka appeared to be a barrier to gene flow.

A Comparative Study on Johnson Cook, Modified Zerilli-Armstrong and Arrhenius-Type Constitutive Models to Predict High-Temperature Flow Behavior of Ti-6Al-4V Alloy in α + β Phase

NASA Astrophysics Data System (ADS)

Cai, Jun; Wang, Kuaishe; Han, Yingying

2016-03-01

True stress and true strain values obtained from isothermal compression tests over a wide temperature range from 1,073 to 1,323 K and a strain rate range from 0.001 to 1 s-1 were employed to establish the constitutive equations based on Johnson Cook, modified Zerilli-Armstrong (ZA) and strain-compensated Arrhenius-type models, respectively, to predict the high-temperature flow behavior of Ti-6Al-4V alloy in α + β phase. Furthermore, a comparative study has been made on the capability of the three models to represent the elevated temperature flow behavior of Ti-6Al-4V alloy. Suitability of the three models was evaluated by comparing both the correlation coefficient R and the average absolute relative error (AARE). The results showed that the Johnson Cook model is inadequate to provide good description of flow behavior of Ti-6Al-4V alloy in α + β phase domain, while the predicted values of modified ZA model and the strain-compensated Arrhenius-type model could agree well with the experimental values except under some deformation conditions. Meanwhile, the modified ZA model could track the deformation behavior more accurately than other model throughout the entire temperature and strain rate range.

[Predicting individual risk of high healthcare cost to identify complex chronic patients].

PubMed

Coderch, Jordi; Sánchez-Pérez, Inma; Ibern, Pere; Carreras, Marc; Pérez-Berruezo, Xavier; Inoriza, José M

2014-01-01

To develop a predictive model for the risk of high consumption of healthcare resources, and assess the ability of the model to identify complex chronic patients. A cross-sectional study was performed within a healthcare management organization by using individual data from 2 consecutive years (88,795 people). The dependent variable consisted of healthcare costs above the 95th percentile (P95), including all services provided by the organization and pharmaceutical consumption outside of the institution. The predictive variables were age, sex, morbidity-based on clinical risk groups (CRG)-and selected data from previous utilization (use of hospitalization, use of high-cost drugs in ambulatory care, pharmaceutical expenditure). A univariate descriptive analysis was performed. We constructed a logistic regression model with a 95% confidence level and analyzed sensitivity, specificity, positive predictive values (PPV), and the area under the ROC curve (AUC). Individuals incurring costs >P95 accumulated 44% of total healthcare costs and were concentrated in ACRG3 (aggregated CRG level 3) categories related to multiple chronic diseases. All variables were statistically significant except for sex. The model had a sensitivity of 48.4% (CI: 46.9%-49.8%), specificity of 97.2% (CI: 97.0%-97.3%), PPV of 46.5% (CI: 45.0%-47.9%), and an AUC of 0.897 (CI: 0.892 to 0.902). High consumption of healthcare resources is associated with complex chronic morbidity. A model based on age, morbidity, and prior utilization is able to predict high-cost risk and identify a target population requiring proactive care. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.

Using Logistic Regression to Predict the Probability of Debris Flows in Areas Burned by Wildfires, Southern California, 2003-2006

USGS Publications Warehouse

Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Helsel, Dennis R.

2008-01-01

Logistic regression was used to develop statistical models that can be used to predict the probability of debris flows in areas recently burned by wildfires by using data from 14 wildfires that burned in southern California during 2003-2006. Twenty-eight independent variables describing the basin morphology, burn severity, rainfall, and soil properties of 306 drainage basins located within those burned areas were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows soon after the 2003 to 2006 fires were delineated from data in the National Elevation Dataset using a geographic information system; (2) Data describing the basin morphology, burn severity, rainfall, and soil properties were compiled for each basin. These data were then input to a statistics software package for analysis using logistic regression; and (3) Relations between the occurrence or absence of debris flows and the basin morphology, burn severity, rainfall, and soil properties were evaluated, and five multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combinations produced the most effective models, and the multivariate models that best predicted the occurrence of debris flows were identified. Percentage of high burn severity and 3-hour peak rainfall intensity were significant variables in all models. Soil organic matter content and soil clay content were significant variables in all models except Model 5. Soil slope was a significant variable in all models except Model 4. The most suitable model can be selected from these five models on the basis of the availability of independent variables in the particular area of interest and field checking of probability maps. The multivariate logistic regression models can be entered into a geographic information system, and maps showing the probability of debris flows can be constructed in recently burned areas of southern California. This study demonstrates that logistic regression is a valuable tool for developing models that predict the probability of debris flows occurring in recently burned landscapes.

Multiply Degenerate Exceptional Points and Quantum Phase Transitions

NASA Astrophysics Data System (ADS)

Borisov, Denis I.; Ružička, František; Znojil, Miloslav

2015-12-01

The realization of a genuine phase transition in quantum mechanics requires that at least one of the Kato's exceptional-point parameters becomes real. A new family of finite-dimensional and time-parametrized quantum-lattice models with such a property is proposed and studied. All of them exhibit, at a real exceptional-point time t = 0, the Jordan-block spectral degeneracy structure of some of their observables sampled by Hamiltonian H( t) and site-position Q( t). The passes through the critical instant t = 0 are interpreted as schematic simulations of non-equivalent versions of the Big-Bang-like quantum catastrophes.

Twice-Exceptionality: Parents' Perspectives on 2e Identification

ERIC Educational Resources Information Center

Dare, Lynn; Nowicki, Elizabeth Agnes

2015-01-01

Twice-exceptional students have high abilities and coexisting learning difficulties. Abilities and difficulties tend to mask each other, and these underidentified students often struggle in school and express their frustrations at home. However, few studies have examined how parents experience the identification of their children's multiple…

Examining the relationship between the food environment and adult diabetes prevalence by county economic and racial composition: an ecological study.

PubMed

Haynes-Maslow, Lindsey; Leone, Lucia A

2017-08-09

Inequitable access to healthy food may contribute to health disparities. This study examines the relationship between the prevalence of adult diabetes and food access in the U.S. by county economic/racial composition. An ecological study from 2012 was used to estimate the relationship between diabetes and retail food outlet access. County diabetes prevalence was measured based on individual responses to the Behavioral Risk Factor Surveillance Survey question, "Have you ever been told by a doctor that you have diabetes?" If the answer was "yes" individuals were classified as having diabetes. Retail food outlets included grocery stores, supercenters, farmer's markets, full-service restaurants, fast food restaurants and convenience stores. Counties were categorized as "high-poverty" or "low-poverty". Counties were categorized as low (< 4.6%), medium (4.6%-31.0%), and high (> 31.0%) percent minority residents. Multiple linear regression models estimated the association between retail food outlets and diabetes, controlling for confounders, and testing for interactions between retail food outlets and county racial composition. Regression models were conditioned on county economic composition. Data were analyzed in 2016. Density of retail foods outlets varied greatly by county economic and racial composition; counties with medium-minority populations had the least access to grocery stores and the highest access to fast food restaurants and convenience stores. Low poverty/low-minority population counties had the greatest access to farmer's markets and grocery stores. For low poverty/low-minority counties, grocery stores were associated with decreased of diabetes prevalence. Supercenters were associated with an increase in diabetes prevalence for high-poverty/low-minority counties. Only low poverty/medium-minority counties had a statistically significant relationship between farmer's markets and diabetes prevalence. Fast food restaurants were found to be positively associated with diabetes prevalence in all counties except high poverty/medium-minority. However, only low poverty/low-minority counties had a statistically significant relationship. Across all models, access to full service restaurants were significantly associated with lower prevalence of diabetes. Generally, access to convenience stores were associated with increased diabetes prevalence, except for high poverty/low-minority counties. The food environment is more strongly associated with diabetes prevalence for wealthier counties with a lower proportion of minority residents. This is important given efforts to increase food access in vulnerable communities. Availability of healthier food may not be enough to change health outcomes.

High Temperature and Salinity Enhance Soil Nitrogen Mineralization in a Tidal Freshwater Marsh

PubMed Central

Gao, Haifeng; Bai, Junhong; He, Xinhua; Zhao, Qingqing; Lu, Qiongqiong; Wang, Junjing

2014-01-01

Soil nitrogen (N) mineralization in wetlands is sensitive to various environmental factors. To compare the effects of salinity and temperature on N mineralization, wetland soils from a tidal freshwater marsh locating in the Yellow River Delta was incubated over a 48-d anaerobic incubation period under four salinity concentrations (0, 10, 20 and 35‰) and four temperature levels (10, 20, 30 and 40°C). The results suggested that accumulated ammonium nitrogen (NH4 +-N) increased with increasing incubation time under all salinity concentrations. Higher temperatures and salinities significantly enhanced soil N mineralization except for a short-term (≈10 days) inhibiting effect found under 35‰ salinity. The incubation time, temperature, salinity and their interactions exhibited significant effects on N mineralization (P<0.001) except the interactive effect of salinity and temperature (P>0.05), while temperature exhibited the greatest effect (P<0.001). Meanwhile, N mineralization processes were simulated using both an effective accumulated temperature model and a one-pool model. Both models fit well with the simulation of soil N mineralization process in the coastal freshwater wetlands under a range of 30 to 40°C (R2 = 0.88–0.99, P<0.01). Our results indicated that an enhanced NH4 +-N release with increasing temperature and salinity deriving from the projected global warming could have profound effects on nutrient cycling in coastal wetland ecosystems. PMID:24733366

Characterizing the exceptional 2014 drought event in São Paulo by drought period length

NASA Astrophysics Data System (ADS)

Zou, Yong; Macau, Elbert E. N.; Sampaio, Gilvan; Ramos, Antônio M. T.; Kurths, Jürgen

2017-09-01

In the last decade, the southeast region of Brazil has been suffering severe water shortages. Here, we propose to compute the expected drought period length to characterize the drought events in the region of São Paulo. We report the unique properties of the exceptional drought event during the austral summer 2014 by showing the differences and similarities to the very dry season in 2001 and the mild dry seasons in 2006 and 2015. Furthermore, we investigate the correlations of the abnormal precipitation deficit with the ocean and atmospheric patterns. In comparison to other drought events, we validate the hypothetical mechanism that underlies the exceptional drought 2014: (1) The existence of an anomalous high pressure center in the area acts as a blocking mechanism that prevents moisture transport from the Amazon and passage of cold front systems from south Brazil. This blocking high has been observed in all dry seasons considered, with much larger magnitude in 2014. (2) The much faster increasing trend of the anomalous sea surface temperature acts as a strong feedback which intensified the extreme climate conditions. The unprecedented increasing trend of the SST in 2014 was not observed in other climate variables representing a high pressure center. Therefore, we conclude that the exceptional drought 2014 was enhanced by the feedback mechanism of anomalous warming of SST in the South Atlantic Oceans, which was resulted from the anomalous high pressure.

The Inclusion of Multiple Exceptional Gifted Students in Talent Development Programmes: Interaction Synthesis of Both Provision Form and Content

ERIC Educational Resources Information Center

Gyarmathy, Éva; Senior, John

2018-01-01

Models of giftedness in the 21st century tend to describe talent as a social construct. Research now indicates that certain talented populations that are composed of multiple exceptional individuals are excluded from talent development programmes. Recognizing how well the environment best fits individual needs at particular key developmental…

75 FR 78596 - Airworthiness Directives; Hawker Beechcraft Corporation Models B200, B200GT, B300, and B300C...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-16

... 5 p.m., Monday through Friday, except Federal holidays. For service information identified in this AD, contact Hawker Beechcraft Corporation, P.O. Box 85, Wichita, Kansas 67201-0085; telephone: (800... Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The...

75 FR 59170 - Airworthiness Directives; British Aerospace Regional Aircraft Models Jetstream Series 3101 and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-27

... describes the unsafe condition as: As a result of the fatigue-testing programme on the Jetstream fatigue..., between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Examining the AD Docket You may... Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket...

Retest imaging of [11C]NOP-1A binding to nociceptin/orphanin FQ peptide (NOP) receptors in the brain of healthy humans.

PubMed

Lohith, Talakad G; Zoghbi, Sami S; Morse, Cheryl L; Araneta, Maria D Ferraris; Barth, Vanessa N; Goebl, Nancy A; Tauscher, Johannes T; Pike, Victor W; Innis, Robert B; Fujita, Masahiro

2014-02-15

[(11)C]NOP-1A is a novel high-affinity PET ligand for imaging nociceptin/orphanin FQ peptide (NOP) receptors. Here, we report reproducibility and reliability measures of binding parameter estimates for [(11)C]NOP-1A binding in the brain of healthy humans. After intravenous injection of [(11)C]NOP-1A, PET scans were conducted twice on eleven healthy volunteers on the same (10/11 subjects) or different (1/11 subjects) days. Subjects underwent serial sampling of radial arterial blood to measure parent radioligand concentrations. Distribution volume (VT; a measure of receptor density) was determined by compartmental (one- and two-tissue) modeling in large regions and by simpler regression methods (graphical Logan and bilinear MA1) in both large regions and voxel data. Retest variability and intraclass correlation coefficient (ICC) of VT were determined as measures of reproducibility and reliability respectively. Regional [(11)C]NOP-1A uptake in the brain was high, with a peak radioactivity concentration of 4-7 SUV (standardized uptake value) and a rank order of putamen>cingulate cortex>cerebellum. Brain time-activity curves fitted well in 10 of 11 subjects by unconstrained two-tissue compartmental model. The retest variability of VT was moderately good across brain regions except cerebellum, and was similar across different modeling methods, averaging 12% for large regions and 14% for voxel-based methods. The retest reliability of VT was also moderately good in most brain regions, except thalamus and cerebellum, and was similar across different modeling methods averaging 0.46 for large regions and 0.48 for voxels having gray matter probability >20%. The lowest retest variability and highest retest reliability of VT were achieved by compartmental modeling for large regions, and by the parametric Logan method for voxel-based methods. Moderately good reproducibility and reliability measures of VT for [(11)C]NOP-1A make it a useful PET ligand for comparing NOP receptor binding between different subject groups or under different conditions in the same subject. Copyright © 2013. Published by Elsevier Inc.

Anomalous thermal hysteresis in the high-field magnetic moments of magnetic nanoparticles embedded in multi-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Zhao, Guo-Meng; Wang, Jun; Ren, Yang; Beeli, Pieder

2012-02-01

We report high-temperature (300-1120 K) magnetic properties of Fe and Fe3O4 nanoparticles embedded in multi-walled carbon nanotubes. We unambiguously show that the magnetic moments of Fe and Fe3O4 nanoparticles are seemingly enhanced by a factor of about 3 compared with what they would be expected to have for free (unembedded) magnetic nanoparticles. What is more intriguing is that the enhanced moments were completely lost when the sample was heated up to 1120 K and the lost moments at 1120 K were completely recovered through several thermal cycles below 1020 K. The anomalous thermal hysteresis of the high-field magnetic moments is unlikely to be explained by existing physical models except for the high-field paramagnetic Meissner effect due to the existence of ultrahigh temperature superconductivity in the multi-walled carbon nanotubes.

Lattice dynamics and elasticity for ε-plutonium [First-principles lattice dynamics for ε-plutonium

DOE PAGES

Söderlind, Per

2017-04-25

Here, lattice dynamics and elasticity for the high-temperature ε phase (body-centered cubic; bcc) of plutonium is predicted utilizing first-principles electronic structure coupled with a self-consistent phonon method that takes phonon-phonon interaction and strong anharmonicity into account. These predictions establish the first sensible lattice-dynamics and elasticity data on ε-Pu. The atomic forces required for the phonon scheme are highly accurate and derived from the total energies obtained from relativistic and parameter-free density-functional theory. The results appear reasonable but no data exist to compare with except those from dynamical mean-field theory that suggest ε-plutonium is mechanically unstable. Fundamental knowledge and understanding ofmore » the high-temperature bcc phase, that is generally present in all actinide metals before melting, is critically important for a proper interpretation of the phase diagram as well as practical modeling of high-temperature properties.« less

Nacre-inspired composites with different macroscopic dimensions: strategies for improved mechanical performance and applications

NASA Astrophysics Data System (ADS)

Zhao, Hewei; Yang, Zhao; Guo, Lin

2018-04-01

To develop next-generation lightweight, high-strength, and tough materials, new materials design strategies must be established. Nacre, consisting of 95 vol.% inorganic plates (CaCO3) and 5 vol.% organic matrix (protein) in layered arrangements, is famous for its significant increase (three orders of magnitude higher) in toughness compared to monolithic aragonite and has always been the model for the synthesis of high mechanical performance artificial materials. In this review, we primarily introduce the recent studies on the synthesis of nacre-inspired composites with exceptional mechanical properties, including 1D fibers, 2D films, and 3D bulk materials. In addition, design strategies for performance enhancement are summarized based on these studies, and applications of high-performance nacre-inspired composites are also discussed. Finally, a critical outlook of the future direction of developing next-generation high mechanical performance nacre-inspired composites is provided.

Water constraints on European power supply under climate change: impacts on electricity prices

NASA Astrophysics Data System (ADS)

van Vliet, Michelle T. H.; Vögele, Stefan; Rübbelke, Dirk

2013-09-01

Recent warm, dry summers showed the vulnerability of the European power sector to low water availability and high river temperatures. Climate change is likely to impact electricity supply, in terms of both water availability for hydropower generation and cooling water usage for thermoelectric power production. Here, we show the impacts of climate change and changes in water availability and water temperature on European electricity production and prices. Using simulations of daily river flows and water temperatures under future climate (2031-2060) in power production models, we show declines in both thermoelectric and hydropower generating potential for most parts of Europe, except for the most northern countries. Based on changes in power production potentials, we assess the cost-optimal use of power plants for each European country by taking electricity import and export constraints into account. Higher wholesale prices are projected on a mean annual basis for most European countries (except for Sweden and Norway), with strongest increases for Slovenia (12-15%), Bulgaria (21-23%) and Romania (31-32% for 2031-2060), where limitations in water availability mainly affect power plants with low production costs. Considering the long design life of power plant infrastructures, short-term adaptation strategies are highly recommended to prevent undesired distributional and allocative effects.

In Situ Exfoliation of Graphene in Epoxy Resins: A Facile Strategy to Efficient and Large Scale Graphene Nanocomposites.

PubMed

Li, Yan; Zhang, Han; Crespo, Maria; Porwal, Harshit; Picot, Olivier; Santagiuliana, Giovanni; Huang, Zhaohui; Barbieri, Ettore; Pugno, Nicola M; Peijs, Ton; Bilotti, Emiliano

2016-09-14

Any industrial application aiming at exploiting the exceptional properties of graphene in composites or coatings is currently limited by finding viable production methods for large volumes of good quality and high aspect ratio graphene, few layer graphene (FLG) or graphite nanoplatelets (GNP). Final properties of the resulting composites are inherently related to those of the initial graphitic nanoparticles, which typically depend on time-consuming, resource-demanding and/or low yield liquid exfoliation processes. In addition, efficient dispersion of these nanofillers in polymer matrices, and their interaction, is of paramount importance. Here we show that it is possible to produce graphene/epoxy nanocomposites in situ and with high conversion of graphite to FLG/GNP through the process of three-roll milling (TRM), without the need of any additives, solvents, compatibilisers or chemical treatments. This readily scalable production method allows for more than 5 wt % of natural graphite (NG) to be directly exfoliated into FLG/GNP and dispersed in an epoxy resin. The in situ exfoliated graphitic nanoplatelets, with average aspect ratios of 300-1000 and thicknesses of 5-17 nm, were demonstrated to conferee exceptional enhancements in mechanical and electrical properties to the epoxy resin. The above conclusions are discussed and interpreted in terms of simple analytical models.

A spatial DB model to simulate the road network efficiency in hydrogeological emergency

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

Michele, Mangiameli, E-mail: michele.mangiameli@dica.unict.it; Giuseppe, Mussumeci

We deal with the theme of the simulation of risk analysis using a technological approach based on the integration of exclusively free and open source tools: PostgreSQL as Database Management System (DBMS) and Quantum GIS-GRASS as Geographic Information System (GIS) platform. The case study is represented by a seismic land in Sicily characterized by steep slopes and frequent instability phenomena. This area includes a city of about 30.000 inhabitants (Enna) that lies on the top of a mountain at about 990 m a.s.l.. The access to the city is assured by few and very winding roads that are also highly vulnerablemore » to seismic and hydrogeological hazards. When exceptional rainfall events occur, the loss of efficiency of these roads should compromise timeliness and effectiveness of rescue operations. The data of the sample area have been structured into the adopted DBMS, and the connection to the GIS functionalities allows simulating the exceptional events. We analyzed the hazard, vulnerability and exposure related to these events and calculated the final risk defining three classes for each scenario: low (L), medium (M) and high (H). This study can be a valuable tool to prioritize risk levels and set priorities for intervention to the main road networks.« less

A spatial DB model to simulate the road network efficiency in hydrogeological emergency

NASA Astrophysics Data System (ADS)

Michele, Mangiameli; Giuseppe, Mussumeci

2015-12-01

We deal with the theme of the simulation of risk analysis using a technological approach based on the integration of exclusively free and open source tools: PostgreSQL as Database Management System (DBMS) and Quantum GIS-GRASS as Geographic Information System (GIS) platform. The case study is represented by a seismic land in Sicily characterized by steep slopes and frequent instability phenomena. This area includes a city of about 30.000 inhabitants (Enna) that lies on the top of a mountain at about 990 m a.s.l.. The access to the city is assured by few and very winding roads that are also highly vulnerable to seismic and hydrogeological hazards. When exceptional rainfall events occur, the loss of efficiency of these roads should compromise timeliness and effectiveness of rescue operations. The data of the sample area have been structured into the adopted DBMS, and the connection to the GIS functionalities allows simulating the exceptional events. We analyzed the hazard, vulnerability and exposure related to these events and calculated the final risk defining three classes for each scenario: low (L), medium (M) and high (H). This study can be a valuable tool to prioritize risk levels and set priorities for intervention to the main road networks..

Comparative studies on the performance and emissions of a direct injection diesel engine fueled with neem oil and pumpkin seed oil biodiesel with and without fuel preheater.

PubMed

Ramakrishnan, Muneeswaran; Rathinam, Thansekhar Maruthu; Viswanathan, Karthickeyan

2018-02-01

In the present experimental analysis, two non-edible oils namely neem oil and pumpkin seed oil were considered. They are converted into respective biodiesels namely neem oil methyl ester (B1) and pumpkin seed oil methyl ester (B2) through transesterification process and their physical and chemical properties were examined using ASTM standards. Diesel was used as a baseline fuel in Kirloskar TV1 model direct injection four stroke diesel engine. A fuel preheater was designed and fabricated to operate at various temperatures (60, 70, and 80 °C). Diesel showed higher brake thermal efficiency (BTE) than biodiesel samples. Lower brake specific fuel consumption (BSFC) was obtained with diesel than B1 sample. B1 exhibited lower BSFC than B2 sample without preheating process. High preheating temperature (80 °C) results in lower fuel consumption for B1 sample. The engine emission characteristics like carbon monoxide (CO), hydrocarbon (HC), and smoke were found lower with B1 sample than diesel and B2 except oxides of nitrogen (NOx) emission. In preheating of fuel, B1 sample with high preheating temperature showed lower CO, HC, and smoke emission (except NOx) than B2 sample.

Energy, momentum and propagation of non-paraxial high-order Gaussian beams in the presence of an aperture

NASA Astrophysics Data System (ADS)

Stilgoe, Alexander B.; Nieminen, Timo A.; Rubinsztein-Dunlop, Halina

2015-12-01

Non-paraxial theories of wave propagation are essential to model the interaction of highly focused light with matter. Here we investigate the energy, momentum and propagation of the Laguerre-, Hermite- and Ince-Gaussian solutions (LG, HG, and IG) of the paraxial wave equation in an apertured non-paraxial regime. We investigate the far-field relationships between the LG, HG, and IG solutions and the vector spherical wave function (VSWF) solutions of the vector Helmholtz wave equation. We investigate the convergence of the VSWF and the various Gaussian solutions in the presence of an aperture. Finally, we investigate the differences in linear and angular momentum evaluated in the paraxial and non-paraxial regimes. The non-paraxial model we develop can be applied to calculations of the focusing of high-order Gaussian modes in high-resolution microscopes. We find that the addition of an aperture in high numerical aperture optical systems does not greatly affect far-field properties except when the beam is significantly clipped by an aperture. Diffraction from apertures causes large distortions in the near-field and will influence light-matter interactions. The method is not limited to a particular solution of the paraxial wave equation. Our model is constructed in a formalism that is commonly used in scattering calculations. It is thus applicable to optical trapping and other optical investigations of matter.

A structural test of the Integrated Motivational-Volitional model of suicidal behaviour.

PubMed

Dhingra, Katie; Boduszek, Daniel; O'Connor, Rory C

2016-05-30

Suicidal behaviours are highly complex, multi-determined phenomena. Despite this, historically research has tended to focus on bivariate associations between atheoretical demographic and/or psychiatric factors and suicidal behaviour. The aim of this study was to empirically test the Integrated Motivational-Volitional model of suicidal behaviour using structural equation modelling. Healthy adults (N=1809) completed anonymous self-report surveys. The fit of the proposed model was good, and explained 79% of variance in defeat, 83% of variance in entrapment, 61% of variance in suicidal ideation, and 27% of variance in suicide attempts. All proposed paths were significant except for those between goal re-engagement and two factors of suicide resilience (Internal Protective and External Protective) and suicidal ideation; and impulsivity and discomfort intolerance and suicide attempts. These findings represent a preliminary step towards greater clarification of the mechanisms driving suicidal behaviour, and support the utility of basing future research on the Integrated Motivational-Volitional model of suicidal behaviour. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Modeling water quality, temperature, and flow in Link River, south-central Oregon

USGS Publications Warehouse

Sullivan, Annett B.; Rounds, Stewart A.

2016-09-09

The 2.1-km (1.3-mi) Link River connects Upper Klamath Lake to the Klamath River in south-central Oregon. A CE-QUAL-W2 flow and water-quality model of Link River was developed to provide a connection between an existing model of the upper Klamath River and any existing or future models of Upper Klamath Lake. Water-quality sampling at six locations in Link River was done during 2013–15 to support model development and to provide a better understanding of instream biogeochemical processes. The short reach and high velocities in Link River resulted in fast travel times and limited water-quality transformations, except for dissolved oxygen. Reaeration through the reach, especially at the falls in Link River, was particularly important in moderating dissolved oxygen concentrations that at times entered the reach at Link River Dam with marked supersaturation or subsaturation. This reaeration resulted in concentrations closer to saturation downstream at the mouth of Link River.

Maximum spreading of liquid drop on various substrates with different wettabilities

NASA Astrophysics Data System (ADS)

Choudhury, Raihan; Choi, Junho; Yang, Sangsun; Kim, Yong-Jin; Lee, Donggeun

2017-09-01

This paper describes a novel model developed for a priori prediction of the maximal spread of a liquid drop on a surface. As a first step, a series of experiments were conducted under precise control of the initial drop diameter, its falling height, roughness, and wettability of dry surfaces. The transient liquid spreading was recorded by a high-speed camera to obtain its maximum spreading under various conditions. Eight preexisting models were tested for accurate prediction of the maximum spread; however, most of the model predictions were not satisfactory except one, in comparison with our experimental data. A comparative scaling analysis of the literature models was conducted to elucidate the condition-dependent prediction characteristics of the models. The conditioned bias in the predictions was mainly attributed to the inappropriate formulations of viscous dissipation or interfacial energy of liquid on the surface. Hence, a novel model based on energy balance during liquid impact was developed to overcome the limitations of the previous models. As a result, the present model was quite successful in predicting the liquid spread in all the conditions.

From high-scale leptogenesis to low-scale one-loop neutrino mass generation

NASA Astrophysics Data System (ADS)

Zhou, Hang; Gu, Pei-Hong

2018-02-01

We show that a high-scale leptogenesis can be consistent with a low-scale one-loop neutrino mass generation. Our models are based on the SU(3)c × SU(2)L × U(1)Y × U(1) B - L gauge groups. Except a complex singlet scalar for the U(1) B - L symmetry breaking, the other new scalars and fermions (one scalar doublet, two or more real scalar singlets/triplets and three right-handed neutrinos) are odd under an unbroken Z2 discrete symmetry. The real scalar decays can produce an asymmetry stored in the new scalar doublet which subsequently decays into the standard model lepton doublets and the right-handed neutrinos. The lepton asymmetry in the standard model leptons then can be partially converted to a baryon asymmetry by the sphaleron processes. By integrating out the heavy scalar singlets/triplets, we can realize an effective theory to radiatively generate the small neutrino masses at the TeV scale. Furthermore, the lightest right-handed neutrino can serve as a dark matter candidate.

Rapid model building of beta-sheets in electron-density maps.

PubMed

Terwilliger, Thomas C

2010-03-01

A method for rapidly building beta-sheets into electron-density maps is presented. beta-Strands are identified as tubes of high density adjacent to and nearly parallel to other tubes of density. The alignment and direction of each strand are identified from the pattern of high density corresponding to carbonyl and C(beta) atoms along the strand averaged over all repeats present in the strand. The beta-strands obtained are then assembled into a single atomic model of the beta-sheet regions. The method was tested on a set of 42 experimental electron-density maps at resolutions ranging from 1.5 to 3.8 A. The beta-sheet regions were nearly completely built in all but two cases, the exceptions being one structure at 2.5 A resolution in which a third of the residues in beta-sheets were built and a structure at 3.8 A in which under 10% were built. The overall average r.m.s.d. of main-chain atoms in the residues built using this method compared with refined models of the structures was 1.5 A.

Patterns and predictors of father-infant engagement across race/ethnic groups

PubMed Central

Cabrera, Natasha J.; Hofferth, Sandra L.; Chae, Soo

2011-01-01

This study examines whether levels of father engagement (e.g., verbal stimulation, caregiving, and physical play) vary by race/ethnicity using a model that controls for fathers’ human capital, mental health, and family relationships. It also tests whether the models work similarly across race/ethnic groups. Its sample of N=5,089 infants and their families is drawn from the Early Childhood Longitudinal Study – Birth Cohort (ECLS-B). We found that, after including controls, African American and Latino fathers had higher levels of engagement in caregiving and physical play activities than White fathers. There were no differences in verbal stimulation activities across race/ethnicity. Fathers’ education (college level) predicted more verbally stimulating activities whereas fathers’ report of couple conflict predicted less caregiving and physical play. Although levels of engagement differed across the groups, the overall models did not differ by race/ethnicity, except for physical play. African American mothers who reported high levels of depressive symptoms had partners who engaged in more physical play than White mothers with high levels of depressive symptoms. PMID:22110258

Research study on high energy radiation effect and environment solar cell degradation methods

NASA Technical Reports Server (NTRS)

Horne, W. E.; Wilkinson, M. C.

1974-01-01

The most detailed and comprehensively verified analytical model was used to evaluate the effects of simplifying assumptions on the accuracy of predictions made by the external damage coefficient method. It was found that the most serious discrepancies were present in heavily damaged cells, particularly proton damaged cells, in which a gradient in damage across the cell existed. In general, it was found that the current damage coefficient method tends to underestimate damage at high fluences. An exception to this rule was thick cover-slipped cells experiencing heavy degradation due to omnidirectional electrons. In such cases, the damage coefficient method overestimates the damage. Comparisons of degradation predictions made by the two methods and measured flight data confirmed the above findings.

Shifting Paradigms to Better Serve Twice-Exceptional African-American Learners

ERIC Educational Resources Information Center

Owens, Charissa M.; Ford, Donna Y.; Lisbon, April J.; Owens, Michael T.

2016-01-01

Existing research on students with twice-exceptional abilities concentrates on strategies to improve the educational experiences of individuals who demonstrate the comorbid presence of a talent for high academic achievement (often considered a strength) and a disability (often considered a weakness). However, this body of work typically excludes…

Basic and Exceptional Calculation Abilities in a Calculating Prodigy: A Case Study.

ERIC Educational Resources Information Center

Pesenti, Mauro; Seron, Xavier; Samson, Dana; Duroux, Bruno

1999-01-01

Describes the basic and exceptional calculation abilities of a calculating prodigy whose performances were investigated in single- and multi-digit number multiplication, numerical comparison, raising of powers, and short-term memory tasks. Shows how his highly efficient long-term memory storage and retrieval processes, knowledge of calculation…

45 CFR 670.5 - Exception in extraordinary circumstances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Exception in extraordinary circumstances. 670.5 Section 670.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE... involving the safety of human life or of ships, aircraft, or equipment or facilities of high value, or the...

40 CFR 75.4 - Compliance dates.

Code of Federal Regulations, 2011 CFR

2011-07-01

....e., SO2 or NOX, as applicable): (A) Only if the relative accuracy test audit (RATA) of the high... that all certification tests are completed no later than the following dates (except as provided in... an oil-fired Phase II unit, January 1, 1995, except that installation and certification tests for...

45 CFR 670.5 - Exception in extraordinary circumstances.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Exception in extraordinary circumstances. 670.5 Section 670.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE... involving the safety of human life or of ships, aircraft, or equipment or facilities of high value, or the...

45 CFR 670.5 - Exception in extraordinary circumstances.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Exception in extraordinary circumstances. 670.5 Section 670.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE... involving the safety of human life or of ships, aircraft, or equipment or facilities of high value, or the...

45 CFR 670.5 - Exception in extraordinary circumstances.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Exception in extraordinary circumstances. 670.5 Section 670.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE... involving the safety of human life or of ships, aircraft, or equipment or facilities of high value, or the...

45 CFR 670.5 - Exception in extraordinary circumstances.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Exception in extraordinary circumstances. 670.5 Section 670.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE... involving the safety of human life or of ships, aircraft, or equipment or facilities of high value, or the...

Dissecting variation in biomass conversion factors across China's forests: implications for biomass and carbon accounting.

PubMed

Luo, Yunjian; Zhang, Xiaoquan; Wang, Xiaoke; Ren, Yin

2014-01-01

Biomass conversion factors (BCFs, defined as the ratios of tree components (i.e. stem, branch, foliage and root), as well as aboveground and whole biomass of trees to growing stock volume, Mg m-3) are considered as important parameters in large-scale forest biomass carbon estimation. To date, knowledge of possible sources of the variation in BCFs is still limited at large scales. Using our compiled forest biomass dataset of China, we presented forest type-specific values of BCFs, and examined the variation in BCFs in relation to forest type, stand development and environmental factors (climate and soil fertility). BCFs exhibited remarkable variation across forest types, and also were significantly related to stand development (especially growing stock volume). BCFs (except Stem BCF) had significant relationships with mean annual temperature (MAT) and mean annual precipitation (MAP) (P<0.001). Climatic data (MAT and MAP) collectively explained 10.0-25.0% of the variation in BCFs (except Stem BCFs). Moreover, stronger climatic effects were found on BCFs for functional components (i.e. branch, foliage and root) than BCFs for combined components (i.e. aboveground section and whole trees). A general trend for BCFs was observed to decrease and then increase from low to high soil fertility. When qualitative soil fertility and climatic data (MAT and MAP) were combined, they explained 14.1-29.7% of the variation in in BCFs (except Stem BCFs), adding only 4.1-4.9% than climatic data used. Therefore, to reduce the uncertainty induced by BCFs in forest carbon estimates, we should apply values of BCFs for a specified forest type, and also consider climatic and edaphic effects, especially climatic effect, in developing predictive models of BCFs (except Stem BCF).

Dissecting Variation in Biomass Conversion Factors across China’s Forests: Implications for Biomass and Carbon Accounting

PubMed Central

Wang, Xiaoke; Ren, Yin

2014-01-01

Biomass conversion factors (BCFs, defined as the ratios of tree components (i.e. stem, branch, foliage and root), as well as aboveground and whole biomass of trees to growing stock volume, Mg m−3) are considered as important parameters in large-scale forest biomass carbon estimation. To date, knowledge of possible sources of the variation in BCFs is still limited at large scales. Using our compiled forest biomass dataset of China, we presented forest type-specific values of BCFs, and examined the variation in BCFs in relation to forest type, stand development and environmental factors (climate and soil fertility). BCFs exhibited remarkable variation across forest types, and also were significantly related to stand development (especially growing stock volume). BCFs (except Stem BCF) had significant relationships with mean annual temperature (MAT) and mean annual precipitation (MAP) (P<0.001). Climatic data (MAT and MAP) collectively explained 10.0–25.0% of the variation in BCFs (except Stem BCFs). Moreover, stronger climatic effects were found on BCFs for functional components (i.e. branch, foliage and root) than BCFs for combined components (i.e. aboveground section and whole trees). A general trend for BCFs was observed to decrease and then increase from low to high soil fertility. When qualitative soil fertility and climatic data (MAT and MAP) were combined, they explained 14.1–29.7% of the variation in in BCFs (except Stem BCFs), adding only 4.1–4.9% than climatic data used. Therefore, to reduce the uncertainty induced by BCFs in forest carbon estimates, we should apply values of BCFs for a specified forest type, and also consider climatic and edaphic effects, especially climatic effect, in developing predictive models of BCFs (except Stem BCF). PMID:24728222

42 CFR § 414.1305 - Definitions.

Code of Federal Regulations, 2010 CFR

2017-10-01

... Payment System and Alternative Payment Model Incentive § 414.1305 Definitions. As used in this section... additional MIPS payment adjustment factors for exceptional performance. Advanced Alternative Payment Model.... Alternative Payment Model (APM) means any of the following: (1) A model under section 1115A of the Act (other...

Higher climatological temperature sensitivity of soil carbon in cold than warm climates

NASA Astrophysics Data System (ADS)

Koven, Charles D.; Hugelius, Gustaf; Lawrence, David M.; Wieder, William R.

2017-11-01

The projected loss of soil carbon to the atmosphere resulting from climate change is a potentially large but highly uncertain feedback to warming. The magnitude of this feedback is poorly constrained by observations and theory, and is disparately represented in Earth system models (ESMs). To assess the climatological temperature sensitivity of soil carbon, we calculate apparent soil carbon turnover times that reflect long-term and broad-scale rates of decomposition. Here, we show that the climatological temperature control on carbon turnover in the top metre of global soils is more sensitive in cold climates than in warm climates and argue that it is critical to capture this emergent ecosystem property in global-scale models. We present a simplified model that explains the observed high cold-climate sensitivity using only the physical scaling of soil freeze-thaw state across climate gradients. Current ESMs fail to capture this pattern, except in an ESM that explicitly resolves vertical gradients in soil climate and carbon turnover. An observed weak tropical temperature sensitivity emerges in a different model that explicitly resolves mineralogical control on decomposition. These results support projections of strong carbon-climate feedbacks from northern soils and demonstrate a method for ESMs to capture this emergent behaviour.

The Companion Dog as a Model for the Longevity Dividend

PubMed Central

Creevy, Kate E.; Austad, Steven N.; Hoffman, Jessica M.; O’Neill, Dan G.; Promislow, Daniel E.L.

2016-01-01

The companion dog is the most phenotypically diverse species on the planet. This enormous variability between breeds extends not only to morphology and behavior but also to longevity and the disorders that affect dogs. There are remarkable overlaps and similarities between the human and canine species. Dogs closely share our human environment, including its many risk factors, and the veterinary infrastructure to manage health in dogs is second only to the medical infrastructure for humans. Distinct breed-based health profiles, along with their well-developed health record system and high overlap with the human environment, make the companion dog an exceptional model to improve understanding of the physiological, social, and economic impacts of the longevity dividend (LD). In this review, we describe what is already known about age-specific patterns of morbidity and mortality in companion dogs, and then explore whether this existing evidence supports the LD. We also discuss some potential limitations to using dogs as models of aging, including the fact that many dogs are euthanized before they have lived out their natural life span. Overall, we conclude that the companion dog offers high potential as a model system that will enable deeper research into the LD than is otherwise possible. PMID:26729759

Deviation from high-entropy configurations in the atomic distributions of a multi-principal-element alloy

DOE PAGES

Santodonato, Louis J.; Zhang, Yang; Feygenson, Mikhail; ...

2015-01-20

The alloy-design strategy of combining multiple elements in near-equimolar ratios has shown great potential for producing exceptional engineering materials, often known as “high-entropy alloys”. Understanding the elemental distribution, and, thus, the evolution of the configurational entropy during solidification, is undertaken in the present study using the Al 1.3CoCrCuFeNi model alloy. Here we show that even when the material undergoes elemental segregation, precipitation, chemical ordering, and spinodal decomposition, a significant amount of disorder remains, due to the distributions of multiple elements in the major phases. In addition, the results suggest that the high-entropy-alloy-design strategy may be applied to a wide rangemore » of complex materials, and should not be limited to the goal of creating single-phase solid solutions.« less

Thermal phase transition with full 2-loop effective potential

NASA Astrophysics Data System (ADS)

Laine, M.; Meyer, M.; Nardini, G.

2017-07-01

Theories with extended Higgs sectors constructed in view of cosmological ramifications (gravitational wave signal, baryogenesis, dark matter) are often faced with conflicting requirements for their couplings; in particular those influencing the strength of a phase transition may be large. Large couplings compromise perturbative studies, as well as the high-temperature expansion that is invoked in dimensionally reduced lattice investigations. With the example of the inert doublet extension of the Standard Model (IDM), we show how a resummed 2-loop effective potential can be computed without a high-T expansion, and use the result to scrutinize its accuracy. With the exception of Tc, which is sensitive to contributions from heavy modes, the high-T expansion is found to perform well. 2-loop corrections weaken the transition in IDM, but they are moderate, whereby a strong transition remains an option.

Evaluation of preindustrial to present-day black carbon and its albedo forcing from Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP)

NASA Technical Reports Server (NTRS)

Lee, Y. H.; Lamarque, J.-F.; Flanner, M. G.; Jiao, C.; Shindell, D. T.; Bernsten, T.; Bisiaux, M. M.; Cao, J.; Collins, W. J.; Curran, M.;

Modeling the Distribution of Migratory Bird Stopovers to Inform Landscape-Scale Siting of Wind Development

PubMed Central

Pocewicz, Amy; Estes-Zumpf, Wendy A.; Andersen, Mark D.; Copeland, Holly E.; Keinath, Douglas A.; Griscom, Hannah R.

2013-01-01

Conservation of migratory birds requires understanding the distribution of and potential threats to their migratory habitats. However, although migratory birds are protected under international treaties, few maps have been available to represent migration at a landscape scale useful to target conservation efforts or inform the siting of wind energy developments that may affect migratory birds. To fill this gap, we developed models that predict where four groups of birds concentrate or stopover during their migration through the state of Wyoming, USA: raptors, wetland, riparian and sparse grassland birds. The models were based on existing literature and expert knowledge concerning bird migration behavior and ecology and validated using expert ratings and known occurrences. There was significant agreement between migratory occurrence data and migration models for all groups except raptors, and all models ranked well with experts. We measured the overlap between the migration concentration models and a predictive model of wind energy development to assess the potential exposure of migratory birds to wind development and illustrate the utility of migratory concentration models for landscape-scale planning. Wind development potential is high across 15% of Wyoming, and 73% of this high potential area intersects important migration concentration areas. From 5.2% to 18.8% of each group’s important migration areas was represented within this high wind potential area, with the highest exposures for sparse grassland birds and the lowest for riparian birds. Our approach could be replicated elsewhere to fill critical data gaps and better inform conservation priorities and landscape-scale planning for migratory birds. PMID:24098379

Highly Efficient Lead Distribution by Magnetic Sewage Sludge Biochar: Sorption Mechanisms and Bench Applications.

PubMed

Ifthikar, Jerosha; Wang, Jia; Wang, Qiliang; Wang, Ting; Wang, Huabin; Khan, Aimal; Jawad, Ali; Sun, Tingting; Jiao, Xiang; Chen, Zhuqi

2017-08-01

Highly efficient magnetic sewage sludge biochar (MSSBC) discloses feasible fabrication process with lower production cost, superior adsorption capacity, usage of waste sewage sludge as resource, selected by external magnetic field and exceptional regeneration property. 2gL -1 MSSBC exhibited a high adsorption capacity of 249.00mgg -1 in 200ppmPb(II) and the lead-MSSBC equilibrium was achieved within one hour, owing to the existence of the copious active sites. The adsorption kinetics was well described by the pseudo-second-order model while the adsorption isotherm could be fitted by Langmuir model. Mechanism study demonstrated the adsorption involved electrostatic attraction, ion exchange, inner-sphere complexation and formation of co-precipitates at the surface of MSSBC. Additionally, adsorption performance maintained remarkable in a broad pH window. These outcomes demonstrated the promising waste resource utilization by a feasible approach that turns the solid waste of sewage sludge into biochar adsorbent with auspicious applications in elimination of Pb(II) from wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rotor dynamic behaviour of a high-speed oil-free motor compressor with a rigid coupling supported on four radial magnetic bearings

NASA Technical Reports Server (NTRS)

Schmied, J.; Pradetto, J. C.

1994-01-01

The combination of a high-speed motor, dry gas seals, and magnetic bearings realized in this unit facilitates the elimination of oil. The motor is coupled with a quill shaft to the compressor. This yields higher natural frequencies of the rotor than with the use of a diaphragm coupling and helps to maintain a sufficient margin of the maximum speed to the frequency of the second compressor bending mode. However, the controller of each bearing then has to take the combined modes of both machines into account. The requirements for the controller to ensure stability and sufficient damping of all critical speeds are designed and compared with the implemented controller. The calculated closed loop behavior was confirmed experimentally, except the stability of some higher modes due to slight frequency deviations of the rotor model to the actual rotor. The influence of a mechanical damper as a device to provide additional damping to high models is demonstrated theoretically. After all, it was not necessary to install the damper, since all modes cold be stabilized by the controller.

Selective O 2 sorption at ambient temperatures via node distortions in Sc-MIL-100

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

Sava Gallis, Dorina F.; Chapman, Karena W.; Rodriguez, Mark A.

2016-04-14

In this study, oxygen selectivity in metal-organic frameworks (MOFs) at exceptionally high temperatures originally predicted by Density Functional Theory (DFT) and Grand Canonical Monte Carlo (GCMC) modeling is now confirmed by synthesis, sorption metal center access, in particular Sc and Fe. Based on DFT M-O 2 binding energies, we chose the large pored MIL-100 framework for metal center access, in particular Sc and Fe. Both resulted in preferential O 2 and N 2 gas uptake at temperatures ranging from 77 K to ambient temperatures (258 K, 298 K and 313 K).

Modeling the spectral energy distribution of the radio galaxy IC310

NASA Astrophysics Data System (ADS)

Fraija, N.; Marinelli, A.; Galván-Gámez, A.; Aguilar-Ruiz, E.

2017-03-01

The radio galaxy IC310 located in the Perseus Cluster is one of the brightest objects in the radio and X-ray bands, and one of the closest active galactic nuclei observed in very-high energies. In GeV - TeV γ-rays, IC310 was detected in low and high flux states by the MAGIC telescopes from October 2009 to February 2010. Taking into account that the spectral energy distribution (SED) up to a few GeV seems to exhibit a double-peak feature and that a single-zone synchrotron self-Compton (SSC) model can explain all of the multiwavelength emission except for the non-simultaneous MAGIC emission, we interpret, in this work, the multifrequency data set of the radio galaxy IC310 in the context of homogeneous hadronic and leptonic models. In the leptonic framework, we present a multi-zone SSC model with two electron populations to explain the whole SED whereas for the hadronic model, we propose that a single-zone SSC model describes the SED up to a few GeVs and neutral pion decay products resulting from pγ interactions could describe the TeV - GeV γ-ray spectra. These interactions occur when Fermi-accelerated protons interact with the seed photons around the SSC peaks. We show that, in the leptonic model the minimum Lorentz factor of second electron population is exceedingly high γe ∼ 105 disfavoring this model, and in the hadronic model the required proton luminosity is not extremely high ∼1044 erg/s, provided that charge neutrality between the number of electrons and protons is given. Correlating the TeV γ-ray and neutrino spectra through photo-hadronic interactions, we find that the contribution of the emitting region of IC310 to the observed neutrino and ultra-high-energy cosmic ray fluxes are negligible.

Classification of commercial wines from the Canary Islands (Spain) by chemometric techniques using metallic contents.

PubMed

Frías, Sergio; Conde, José E; Rodríguez-Bencomo, Juan J; García-Montelongo, Francisco; Pérez-Trujillo, Juan P

2003-02-06

Eleven elements, K, Na, Ca, Mg, Fe, Cu, Zn, Mn, Sr, Li and Rb, were determined in dry and sweet wines bearing the denominations of origin of El Hierro, La Palma and Lanzarote islands (Canary Islands, Spain). Analyses were performed by flame atomic absorption spectrophotometry, with the exceptions of lithium and rubidium for which flame atomic emission spectrophotometry was used. Sweet wines from La Palma were elaborated as naturally sweet with over-ripe grapes and significant differences were found in all the analysed elements with the exceptions of sodium, iron and rubidium with regard to dry wines from the same island. Contrarily, sweet wines from Lanzarote elaborated with grapes in a similar ripening state to dry wines did not present significant differences between them with the exception of strontium, the content of which was greater in dry wines. Among the three islands, significant differences in mean content were found with the exceptions of iron and copper. Cluster analysis and principal component analysis show differences in wines according to the island of origin and the ripening state of the grapes. Linear discriminant analysis using rubidium, sodium, manganese and strontium, the four most discriminant elements, gave 100% recognition ability and 95.6% prediction ability. The sensitivity and specificity obtained using soft independent modelling of class analogy (SIMCA) as a modelling multivariate technique were both 100% for El Hierro and Lanzarote, and 100 and 95%, respectively, for La Palma. The modelling and discriminant capacities of the different metals were also studied.

[Protection and bidirectional effect of rhubarb anthraquinone and tannins for rats' liver].

PubMed

Qin, Lu-shan; Zhao, Hai-ping; Zhao, Yan-ling; Ma, Zhi-jiel; Zeng, Ling-na; Zhang, Ya-ming; Zhang, Ping; Yan, Dan; Bai, Zhao-fang; Li, Yue; Hao, Qing-xiu; Zhao, Kui-jun; Wang, Jia-bo; Xiao, Xiao-he

2014-06-01

To compare the bidirectional effect of rhubarb total anthraquinone (TA) and total tannins (TT) on rats' liver. One hundred rats were randomly divided into 10 groups, i.e., the blank group, the model group, the blank + high dose TA group, the blank +low dose TA group, the blank + high dose TT group, the blank + low dose TT group, the model + high dose TA group, the model + low dose TA group, the model +high dose TT group, and the model + low dose TT group, 10 in each group. The carbon tetrachloride (CCI4) was used to prepare the acute liver injury rat model. TA and TT of rhubarb (at 5.40 g crude drugs/kg and 14.69 g crude drugs/kg) were intragastrically administrated to rats in all groups except the blank group and the model group, once daily for 6 successive days.The general state of rats, biochemical indices such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), laminin (LN), hyaluronic acid (HA), transforming growth factor beta1 (TGF-beta1), as well pathological results of rat liver tissues. Finally the protection laws of TA and TT for rats' liver were analyzed using factor analysis. Compared with the blank control group, all biochemical indices increased in the blank group (P < 0.05, P < 0.01). HA also increased in the blank + high dose TA group; AST, ALT, and HA also increased in the blank +high dose TT group (P < 0.05). Compared with the model group, AST, ALT, ALP, HA, and TGF-beta1 significantly decreased in the model + low dose TA group, the model + high dose TA group, the model + low dose TT group (P < 0.05, P < 0.01). Serum AST, ALT, and ALP also decreased in the model + high dose TT group (P < 0.05, P < 0.01). Pathological results showed that mild swollen liver cells in the model + high dose TA group. Fatty degeneration and fragmental necrosis around the central veins occurred in the blank + high dose TA group. The pathological injury was inproved in the model +low dose TA group. Two common factors, liver fibrosis and liver cell injury, were extracted by using factor analysis. TA showed stronger improvement of the two common factors than TT. Rhubarb TA and TT showed protective and harmful effects on rats' liver. At an equivalent dosage, TA had better liver protection than TT. High dose TT played a role in liver injury to some extent.

Exceptional Lithium Storage in a Co(OH) 2 Anode: Hydride Formation

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

Kim, Hyunchul; Choi, Woon Ih; Jang, Yoonjung

Current lithium ion battery technology is tied in with conventional reaction mechanisms such as insertion, conversion, and alloying reactions even though most future applications like EVs demand much higher energy densities than current ones. Exploring the exceptional reaction mechanism and related electrode materials can be critical for pushing current battery technology to a next level. Here, we introduce an exceptional reaction with a Co(OH)(2) material which exhibits an initial charge capacity of 1112 mAh g(-1), about twice its theoretical value based on known conventional conversion reaction, and retains its first cycle capacity after 30 cycles. The combined results of synchrotronmore » X-ray diffraction and X-ray absorption spectroscopy indicate that nanosized Co metal particles and LiOH are generated by conversion reaction at high voltages, and CoxHy, Li2O, and LiH are subsequently formed by hydride reaction between Co metal, LiOH, and other lithium species at low voltages, resulting in a anomalously high capacity beyond the theoretical capacity of Co(OH)(2). This is further corroborated by AIMD simulations, localized STEM, and XPS. These findings will provide not only further understanding of exceptional lithium storage of recent nanostructured materials but also valuable guidance to develop advanced electrode materials with high energy density for next-generation batteries.« less

Thermodynamic models for vapor-liquid equilibria of nitrogen + oxygen + carbon dioxide at low temperatures

NASA Astrophysics Data System (ADS)

Vrabec, Jadran; Kedia, Gaurav Kumar; Buchhauser, Ulrich; Meyer-Pittroff, Roland; Hasse, Hans

2009-02-01

For the design and optimization of CO 2 recovery from alcoholic fermentation processes by distillation, models for vapor-liquid equilibria (VLE) are needed. Two such thermodynamic models, the Peng-Robinson equation of state (EOS) and a model based on Henry's law constants, are proposed for the ternary mixture N 2 + O 2 + CO 2. Pure substance parameters of the Peng-Robinson EOS are taken from the literature, whereas the binary parameters of the Van der Waals one-fluid mixing rule are adjusted to experimental binary VLE data. The Peng-Robinson EOS describes both binary and ternary experimental data well, except at high pressures approaching the critical region. A molecular model is validated by simulation using binary and ternary experimental VLE data. On the basis of this model, the Henry's law constants of N 2 and O 2 in CO 2 are predicted by molecular simulation. An easy-to-use thermodynamic model, based on those Henry's law constants, is developed to reliably describe the VLE in the CO 2-rich region.

Monticello - A glass-rich howardite

NASA Technical Reports Server (NTRS)

Olsen, Edward J.; Dod, Bruce D.; Schmitt, Roman A.; Sipiera, Paul P.

1987-01-01

Monticello is a new howardite similar to Malvern in that it contains abundant (15 percent) glass fragments, which show a range of compositions from olivine-normative to quartz-normative. Like Kapoeta, it contains pyroxene grains that range up to highly magnesian compositions, Fs16. Because their pyroxenes are more magnesian than those occurring in diogenites, Monticello and Kapoeta are exceptions to the simple two-component mixing model in which howardites are considered to be mechanical mixtures of fragmented eucrites and diogenites. Monticello also contains clasts of what appear to be a cumulate eucrite and a noncumulate eucrite, as well as a radiating pyroxene chondrule from a chondrite. Monticello is a regolith breccia containing more evolved components than are usually considered in eucrite-diogenite genesis models. As such, it supports those models that involve reworking of a complex parent body crust rather than straightforward partial melting of primitive chondritic parent material.

Continuous description of fluctuating eccentricities

NASA Astrophysics Data System (ADS)

Blaizot, Jean-Paul; Broniowski, Wojciech; Ollitrault, Jean-Yves

2014-11-01

We consider the initial energy density in the transverse plane of a high energy nucleus-nucleus collision as a random field ρ (x), whose probability distribution P [ ρ ], the only ingredient of the present description, encodes all possible sources of fluctuations. We argue that it is a local Gaussian, with a short-range 2-point function, and that the fluctuations relevant for the calculation of the eccentricities that drive the anisotropic flow have small relative amplitudes. In fact, this 2-point function, together with the average density, contains all the information needed to calculate the eccentricities and their variances, and we derive general model independent expressions for these quantities. The short wavelength fluctuations are shown to play no role in these calculations, except for a renormalization of the short range part of the 2-point function. As an illustration, we compare to a commonly used model of independent sources, and recover the known results of this model.

New Existence Conditions for Order Complementarity Problems

NASA Astrophysics Data System (ADS)

Németh, S. Z.

2009-09-01

Complementarity problems are mathematical models of problems in economics, engineering and physics. A special class of complementarity problems are the order complementarity problems [2]. Order complementarity problems can be applied in lubrication theory [6] and economics [1]. The notion of exceptional family of elements for general order complementarity problems in Banach spaces will be introduced. It will be shown that for general order complementarity problems defined by completely continuous fields the problem has either a solution or an exceptional family of elements (for other notions of exceptional family of elements see [1, 2, 3, 4] and the related references therein). This solves a conjecture of [2] about the existence of exceptional family of elements for order complementarity problems. The proof can be done by using the Leray-Schauder alternative [5]. An application to integral operators will be given.

Exceptional longevity and exceptionally high metabolic rates in anthropoid primates are linked to a major modification of the ubiquinone reduction site of cytochrome b.

PubMed

Rottenberg, Hagai

2014-10-01

The maximal lifespan of Anthropoid primates (monkeys, apes and humans) exceed the lifespan of most other mammals of equal body mass. Unexpectedly, their exceptional longevity is associated with exceptionally high metabolic rates, in apparent contradiction to the Free Radical Theory of Aging. It was therefore suggested that in anthropoid primates (and several other taxa of mammals and birds) the mitochondrial electron transport complexes evolved to modify the relationship between basal electron transport and superoxide generation to allow for the evolution of exceptional longevity. Cytochrome b, the core protein of the bc1 complex is a major source of superoxide. The amino-acid sequence of cytochrome b evolved much faster in anthropoid than in prosimian primates, and most other mammals, resulting in a large change in the amino-acids composition of the protein. As a result of these changes cytochrome b in anthropoid primates is significantly less hydrophobic and contains more polar residues than other primates and most other mammals. Most of these changes are clustered around the reduction site of uboiquinone. In particular a key positively charged residue, arginine 313, that interacts with propionate D of heme bH, and thus raises its redox potential, is substituted in anthropoid primates with the neutral residue glutamine, most likely resulting in a lower redox potential of heme bH and faster reduction of ubiquinone at high proton motive force. It is suggested that these changes contribute to the observed increased rates of basal metabolism and reduce the rates of superoxide production, thus allowing for increased lifespan.

Wing pressure distributions from subsonic tests of a high-wing transport model. [in the Langley 14- by 22-Foot Subsonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Applin, Zachary T.; Gentry, Garl L., Jr.; Takallu, M. A.

1995-01-01

A wind tunnel investigation was conducted on a generic, high-wing transport model in the Langley 14- by 22-Foot Subsonic Tunnel. This report contains pressure data that document effects of various model configurations and free-stream conditions on wing pressure distributions. The untwisted wing incorporated a full-span, leading-edge Krueger flap and a part-span, double-slotted trailing-edge flap system. The trailing-edge flap was tested at four different deflection angles (20 deg, 30 deg, 40 deg, and 60 deg). Four wing configurations were tested: cruise, flaps only, Krueger flap only, and high lift (Krueger flap and flaps deployed). Tests were conducted at free-stream dynamic pressures of 20 psf to 60 psf with corresponding chord Reynolds numbers of 1.22 x 10(exp 6) to 2.11 x 10(exp 6) and Mach numbers of 0.12 to 0.20. The angles of attack presented range from 0 deg to 20 deg and were determined by wing configuration. The angle of sideslip ranged from minus 20 deg to 20 deg. In general, pressure distributions were relatively insensitive to free-stream speed with exceptions primarily at high angles of attack or high flap deflections. Increasing trailing-edge Krueger flap significantly reduced peak suction pressures and steep gradients on the wing at high angles of attack. Installation of the empennage had no effect on wing pressure distributions. Unpowered engine nacelles reduced suction pressures on the wing and the flaps.

Rapid and high throughput fabrication of high temperature stable structures through PDMS transfer printing

NASA Astrophysics Data System (ADS)

Hohenberger, Erik; Freitag, Nathan; Korampally, Venumadhav

2017-07-01

We report on a facile and low cost fabrication approach for structures—gratings and enclosed nanochannels, through simple solution processed chemistries in conjunction with nanotransfer printing techniques. The ink formulation primarily consisting of an organosilicate polymeric network with a small percentage of added 3-aminopropyl triethoxysilane crosslinker allows one to obtain robust structures that are not only stable towards high temperature processing steps as high as 550 °C but also exhibit exceptional stability against a host of organic solvent washes. No discernable structure distortion was observed compared to the as-printed structures (room temperature processed) when printed structures were subjected to temperatures as high as 550 °C. We further demonstrate the applicability of this technique towards the fabrication of more complex nanostructures such as enclosed channels through a double transfer method, leveraging the exceptional room temperature cross-linking ability of the printed structures and their subsequent resistance to dissolution in organic solvent washes. The exceptional temperature and physico-chemical stability of the nanotransfer printed structures makes this a useful fabrication tool that may be applied as is, or integrated with conventional lithographic techniques for the large area fabrication of functional nanostructures and devices.

Flexible Ferroelectric Sensors with Ultrahigh Pressure Sensitivity and Linear Response over Exceptionally Broad Pressure Range.

PubMed

Lee, Youngoh; Park, Jonghwa; Cho, Soowon; Shin, Young-Eun; Lee, Hochan; Kim, Jinyoung; Myoung, Jinyoung; Cho, Seungse; Kang, Saewon; Baig, Chunggi; Ko, Hyunhyub

2018-04-24

Flexible pressure sensors with a high sensitivity over a broad linear range can simplify wearable sensing systems without additional signal processing for the linear output, enabling device miniaturization and low power consumption. Here, we demonstrate a flexible ferroelectric sensor with ultrahigh pressure sensitivity and linear response over an exceptionally broad pressure range based on the material and structural design of ferroelectric composites with a multilayer interlocked microdome geometry. Due to the stress concentration between interlocked microdome arrays and increased contact area in the multilayer design, the flexible ferroelectric sensors could perceive static/dynamic pressure with high sensitivity (47.7 kPa -1 , 1.3 Pa minimum detection). In addition, efficient stress distribution between stacked multilayers enables linear sensing over exceptionally broad pressure range (0.0013-353 kPa) with fast response time (20 ms) and high reliability over 5000 repetitive cycles even at an extremely high pressure of 272 kPa. Our sensor can be used to monitor diverse stimuli from a low to a high pressure range including weak gas flow, acoustic sound, wrist pulse pressure, respiration, and foot pressure with a single device.

Comparison of Basic and Ensemble Data Mining Methods in Predicting 5-Year Survival of Colorectal Cancer Patients.

PubMed

Pourhoseingholi, Mohamad Amin; Kheirian, Sedigheh; Zali, Mohammad Reza

2017-12-01

Colorectal cancer (CRC) is one of the most common malignancies and cause of cancer mortality worldwide. Given the importance of predicting the survival of CRC patients and the growing use of data mining methods, this study aims to compare the performance of models for predicting 5-year survival of CRC patients using variety of basic and ensemble data mining methods. The CRC dataset from The Shahid Beheshti University of Medical Sciences Research Center for Gastroenterology and Liver Diseases were used for prediction and comparative study of the base and ensemble data mining techniques. Feature selection methods were used to select predictor attributes for classification. The WEKA toolkit and MedCalc software were respectively utilized for creating and comparing the models. The obtained results showed that the predictive performance of developed models was altogether high (all greater than 90%). Overall, the performance of ensemble models was higher than that of basic classifiers and the best result achieved by ensemble voting model in terms of area under the ROC curve (AUC= 0.96). AUC Comparison of models showed that the ensemble voting method significantly outperformed all models except for two methods of Random Forest (RF) and Bayesian Network (BN) considered the overlapping 95% confidence intervals. This result may indicate high predictive power of these two methods along with ensemble voting for predicting 5-year survival of CRC patients.

Modelling rainfall interception by a lowland tropical rain forest in northeastern Puerto Rico

NASA Astrophysics Data System (ADS)

Schellekens, J.; Scatena, F. N.; Bruijnzeel, L. A.; Wickel, A. J.

1999-12-01

Recent surveys of tropical forest water use suggest that rainfall interception by the canopy is largest in wet maritime locations. To investigate the underlying processes at one such location—the Luquillo Experimental Forest in eastern Puerto Rico—66 days of detailed throughfall and above-canopy climatic data were collected in 1996 and analysed using the Rutter and Gash models of rainfall interception. Throughfall occurred on 80% of the days distributed over 80 rainfall events. Measured interception loss was 50% of gross precipitation. When Penman-Monteith based estimates for the wet canopy evaporation rate (0.11 mm h -1 on average) and a canopy storage of 1.15 mm were used, both models severely underestimated measured interception loss. A detailed analysis of four storms using the Rutter model showed that optimizing the model for the wet canopy evaporation component yielded much better results than increasing the canopy storage capacity. However, the Rutter model failed to properly estimate throughfall amounts during an exceptionally large event. The analytical model, on the other hand, was capable of representing interception during the extreme event, but once again optimizing wet canopy evaporation rates produced a much better fit than optimizing the canopy storage capacity. As such, the present results support the idea that it is primarily a high rate of evaporation from a wet canopy that is responsible for the observed high interception losses.

BRAIN MYELINATION IN PREVALENT NEUROPSYCHIATRIC DEVELOPMENTAL DISORDERS

PubMed Central

BARTZOKIS, GEORGE

2008-01-01

Current concepts of addiction focus on neuronal neurocircuitry and neurotransmitters and are largely based on animal model data, but the human brain is unique in its high myelin content and extended developmental (myelination) phase that continues until middle age. The biology of our exceptional myelination process and factors that influence it have been synthesized into a recently published myelin model of human brain evolution and normal development that cuts across the current symptom-based classification of neuropsychiatric disorders. The developmental perspective of the model suggests that dysregulations in the myelination process contribute to prevalent early-life neuropsychiatric disorders, as well as to addictions. These disorders share deficits in inhibitory control functions that likely contribute to their high rates of comorbidity with addiction and other impulsive behaviors. The model posits that substances such as alcohol and psychostimulants are toxic to the extremely vulnerable myelination process and contribute to the poor outcomes of primary and comorbid addictive disorders in susceptible individuals. By increasing the scientific focus on myelination, the model provides a rational biological framework for the development of novel, myelin-centered treatments that may have widespread efficacy across multiple disease states and could potentially be used in treating, delaying, or even preventing some of the most prevalent and devastating neuropsychiatric disorders. PMID:18668184

Tests of a 1/7-Scale Semispan Model of the XB-35 Airplane in the Langley 19-Foot Pressure Tunnel

NASA Technical Reports Server (NTRS)

Teplitz, Jerome; Kayten, Gerald G.; Cancro, Patrick A.

1946-01-01

A 1/7 scale semispan model of the XB-35 airplane was tested in the Langley 10 foot pressure tunnel, primarily for the purpose of investigating the effectiveness of a leading-edge slot for alleviation of stick-fixed longitudinal instability at high angles of attack caused by early tip stalling and a device for relief of stick-free instability caused by elevon up-floating tendencies at high angles of attack. Results indicated that the slot was not adequate to provide the desired improvement in stick-fixed stability. The tab-flipper device provided improvement in stick-free stability abd two of the linkage combinations tested gave satisfactory variations of control force with airspeed for all conditions except that in which the wing-tip "pitch-control" flap was fully deflected. However, the improvement in control force characteristics was accompanied by a detrimental effect on stick-fixed stability because of the pitching moments produced by the elevon tab deflection.

Structure of health-enhancing behavior in adolescence: a latent-variable approach.

PubMed

Donovan, J E; Jessor, R; Costa, F M

1993-12-01

The structure of the interrelations among a variety of health-enhancing behaviors was examined using structural equation modeling analyses of questionnaire data from 1,280 middle school students and 2,219 high school students. The health-enhancing behaviors included seat belt use, adequate hours of sleep, attention to healthy diet, adequate exercise, low sedentary behavior, and regular toothbrushing. In the middle school sample, all of the health-enhancing behaviors correlated significantly but modestly with each other, except for sleep with toothbrushing. In the high school sample, all but three of the 15 correlations among the behaviors were significant. The results further show that a single underlying factor can account for the modest correlations among these health-enhancing behaviors in both samples. The generality of the single-factor model was also established for male, female, White, Hispanic, and Black students at each school level. These findings provide some support for the existence of health-related lifestyles in adolescence.

Exceptional mobility of an advancing rhyolitic obsidian flow at Cordón Caulle volcano in Chile.

PubMed

Tuffen, Hugh; James, Mike R; Castro, Jonathan M; Schipper, C Ian

2013-01-01

The emplacement mechanisms of rhyolitic lava flows are enigmatic and, despite high lava viscosities and low inferred effusion rates, can result in remarkably, laterally extensive (>30 km) flow fields. Here we present the first observations of an active, extensive rhyolitic lava flow field from the 2011-2012 eruption at Cordón Caulle, Chile. We combine high-resolution four-dimensional flow front models, created using automated photo reconstruction techniques, with sequential satellite imagery. Late-stage evolution greatly extended the compound lava flow field, with localized extrusion from stalled, ~35 m-thick flow margins creating >80 breakout lobes. In January 2013, flow front advance continued ~3.6 km from the vent, despite detectable lava supply ceasing 6-8 months earlier. This illustrates how efficient thermal insulation by the lava carapace promotes prolonged within-flow horizontal lava transport, boosting the extent of the flow. The unexpected similarities with compound basaltic lava flow fields point towards a unifying model of lava emplacement.

Contrasting benefits of different artemisinin combination therapies as first-line malaria treatments using model-based cost-effectiveness analysis

PubMed Central

Okell, Lucy C.; Cairns, Matthew; Griffin, Jamie T.; Ferguson, Neil M.; Tarning, Joel; Jagoe, George; Hugo, Pierre; Baker, Mark; D’Alessandro, Umberto; Bousema, Teun; Ubben, David; Ghani, Azra C.

2014-01-01

There are currently several recommended drug regimens for uncomplicated falciparum malaria in Africa. Each has different properties that determine its impact on disease burden. Two major antimalarial policy options are artemether–lumefantrine (AL) and dihydroartemisinin–piperaquine (DHA–PQP). Clinical trial data show that DHA–PQP provides longer protection against reinfection, while AL is better at reducing patient infectiousness. Here we incorporate pharmacokinetic-pharmacodynamic factors, transmission-reducing effects and cost into a mathematical model and simulate malaria transmission and treatment in Africa, using geographically explicit data on transmission intensity and seasonality, population density, treatment access and outpatient costs. DHA–PQP has a modestly higher estimated impact than AL in 64% of the population at risk. Given current higher cost estimates for DHA–PQP, there is a slightly greater cost per case averted, except in areas with high, seasonally varying transmission where the impact is particularly large. We find that a locally optimized treatment policy can be highly cost effective for reducing clinical malaria burden. PMID:25425081

PEEEC [Project for Early Education of Exceptional Children] Outreach: Annual Report 1980-1981.

ERIC Educational Resources Information Center

Millican, Jerri; Kibler, Robert G.

The document consists of the final report of the PEEEC (Project for Early Education of Exceptional Children) Outreach program, a program to stimulate high quality programs for preschool handicapped children and families in Kentucky. Following a definition of terms are sections outlining goals, objectives, and activities of three program…

The Development of Spoken Language in Deaf Children: Explaining the Unexplained Variance.

ERIC Educational Resources Information Center

Musselman, Carol; Kircaali-Iftar, Gonul

1996-01-01

This study compared 20 young deaf children with either exceptionally good or exceptionally poor spoken language for their hearing loss, age, and intelligence. Factors associated with high performance included earlier use of binaural ear-level aids, better educated mothers, auditory/verbal or auditory/oral instruction, reliance on spoken language…

Modeling & processing of ceramic and polymer precursor ceramic matrix composite materials

NASA Astrophysics Data System (ADS)

Wang, Xiaolin

Synthesis and processing of novel materials with various advanced approaches have attracted much attention of engineers and scientists for the past thirty years. Many advanced materials display a number of exceptional properties and can be produced with different novel processing techniques. For example, AlN is a promising candidate for electronic, optical and opto-electronic applications due to its high thermal conductivity, high electrical resistivity, high acoustic wave velocity and large band gap. Large bulk AlN crystal can be produced by sublimation of AlN powder. Novel nonostructured multicomponent refractory metal-based ceramics (carbides, borides and nitrides) show a lot of exceptional mechanical, thermal and chemical properties, and can be easily produced by pyrolysis of suitable preceramic precursors mixed with metal particles. The objective of this work is to study sublimation and synthesis of AlN powder, and synthesis of SiC-based metal ceramics. For AlN sublimation crystal growth, we will focus on modeling the processes in the powder source that affect significantly the sublimation growth as a whole. To understand the powder porosity evolution and vapor transport during powder sublimation, the interplay between vapor transport and powder sublimation will be studied. A physics-based computational model will be developed considering powder sublimation and porosity evolution. Based on the proposed model, the effect of a central hole in the powder on the sublimation rate is studied and the result is compared to the case of powder without a hole. The effect of hole size on the sublimation rate will be studied. The effects of initial porosity, particle size and driving force on the sublimation rate are also studied. Moreover, the optimal growth condition for large diameter crystal quality and high growth rate will be determined. For synthesis of SiC-based metal ceramics, we will focus on developing a multi-scale process model to describe the dynamic behavior of filler particle reaction, microstructure evolution, at the microscale as well as transient fluid flow, heat transfer, and species transport at the macroscale. The model comprises of (i) a microscale model and (ii) a macroscale transport model, and aims to provide optimal conditions for the fabrication process of the ceramics. The porous media macroscale model for SiC-based metal-ceramic materials processing will be developed to understand the thermal polymer pyrolysis, chemical reaction of active fillers and transport phenomena in the porous media. The macroscale model will include heat and mass transfer, curing, pyrolysis, chemical reaction and crystallization in a mixture of preceramic polymers and submicron/nano-sized metal particles of uranium, zirconium, niobium, or hafnium. The effects of heating rate, sample size, size and volume ratio of the metal particles on the reaction rate and product uniformity will be studied. The microscale model will be developed for modeling the synthesis of SiC matrix and metal particles. The macroscale model provides thermal boundary conditions to the microscale model. The microscale model applies to repetitive units in the porous structure and describes mass transport, composition changes and motion of metal particles. The unit-cell is the representation unit of the source material, and it consists of several metal particles, SiC matrix and other components produced from the synthesis process. The reactions between different components, the microstructure evolution of the product will be considered. The effects of heating rate and metal particle size on species uniformity and microstructure are investigated.

Semi-empirical correlation for binary interaction parameters of the Peng-Robinson equation of state with the van der Waals mixing rules for the prediction of high-pressure vapor-liquid equilibrium.

PubMed

Fateen, Seif-Eddeen K; Khalil, Menna M; Elnabawy, Ahmed O

2013-03-01

Peng-Robinson equation of state is widely used with the classical van der Waals mixing rules to predict vapor liquid equilibria for systems containing hydrocarbons and related compounds. This model requires good values of the binary interaction parameter kij . In this work, we developed a semi-empirical correlation for kij partly based on the Huron-Vidal mixing rules. We obtained values for the adjustable parameters of the developed formula for over 60 binary systems and over 10 categories of components. The predictions of the new equation system were slightly better than the constant-kij model in most cases, except for 10 systems whose predictions were considerably improved with the new correlation.

A rational approach to the use of Prandtl's mixing length model in free turbulent shear flow calculations

NASA Technical Reports Server (NTRS)

Rudy, D. H.; Bushnell, D. M.

1973-01-01

Prandtl's basic mixing length model was used to compute 22 test cases on free turbulent shear flows. The calculations employed appropriate algebraic length scale equations and single values of mixing length constant for planar and axisymmetric flows, respectively. Good agreement with data was obtained except for flows, such as supersonic free shear layers, where large sustained sensitivity changes occur. The inability to predict the more gradual mixing in these flows is tentatively ascribed to the presence of a significant turbulence-induced transverse static pressure gradient which is neglected in conventional solution procedures. Some type of an equation for length scale development was found to be necessary for successful computation of highly nonsimilar flow regions such as jet or wake development from thick wall flows.

A Comparative Evaluation of the Linear Dimensional Accuracy of Four Impression Techniques using Polyether Impression Material.

PubMed

Manoj, Smita Sara; Cherian, K P; Chitre, Vidya; Aras, Meena

2013-12-01

There is much discussion in the dental literature regarding the superiority of one impression technique over the other using addition silicone impression material. However, there is inadequate information available on the accuracy of different impression techniques using polyether. The purpose of this study was to assess the linear dimensional accuracy of four impression techniques using polyether on a laboratory model that simulates clinical practice. The impression material used was Impregum Soft™, 3 M ESPE and the four impression techniques used were (1) Monophase impression technique using medium body impression material. (2) One step double mix impression technique using heavy body and light body impression materials simultaneously. (3) Two step double mix impression technique using a cellophane spacer (heavy body material used as a preliminary impression to create a wash space with a cellophane spacer, followed by the use of light body material). (4) Matrix impression using a matrix of polyether occlusal registration material. The matrix is loaded with heavy body material followed by a pick-up impression in medium body material. For each technique, thirty impressions were made of a stainless steel master model that contained three complete crown abutment preparations, which were used as the positive control. Accuracy was assessed by measuring eight dimensions (mesiodistal, faciolingual and inter-abutment) on stone dies poured from impressions of the master model. A two-tailed t test was carried out to test the significance in difference of the distances between the master model and the stone models. One way analysis of variance (ANOVA) was used for multiple group comparison followed by the Bonferroni's test for pair wise comparison. The accuracy was tested at α = 0.05. In general, polyether impression material produced stone dies that were smaller except for the dies produced from the one step double mix impression technique. The ANOVA revealed a highly significant difference for each dimension measured (except for the inter-abutment distance between the first and the second die) between any two groups of stone models obtained from the four impression techniques. Pair wise comparison for each measurement did not reveal any significant difference (except for the faciolingual distance of the third die) between the casts produced using the two step double mix impression technique and the matrix impression system. The two step double mix impression technique produced stone dies that showed the least dimensional variation. During fabrication of a cast restoration, laboratory procedures should not only compensate for the cement thickness, but also for the increase or decrease in die dimensions.

Collapsible Cubes and Other Curiosities.

ERIC Educational Resources Information Center

Johnson, Scott; Walser, Hans

1997-01-01

Describes some general techniques for making collapsible models, including spiral models, for all the Platonic solids except the cube. Discusses the nature of the dissections of the faces necessary for the construction of the spiral cube. (ASK)

Validation of the educational needs assessment tool as a generic instrument for rheumatic diseases in seven European countries.

PubMed

Ndosi, Mwidimi; Bremander, Ann; Hamnes, Bente; Horton, Mike; Kukkurainen, Marja Leena; Machado, Pedro; Marques, Andrea; Meesters, Jorit; Stamm, Tanja A; Tennant, Alan; de la Torre-Aboki, Jenny; Vliet Vlieland, Theodora P M; Zangi, Heidi A; Hill, Jackie

2014-12-01

To validate the educational needs assessment tool (ENAT) as a generic tool for assessing the educational needs of patients with rheumatic diseases in European Countries. A convenience sample of patients from seven European countries was included comprising the following diagnostic groups: ankylosing spondylitis, psoriatic arthritis, systemic sclerosis, systemic lupus erythematosus, osteoarthritis (OA) and fibromyalgia syndrome. Translated versions of the ENAT were completed through surveys in each country. Rasch analysis was used to assess the construct validity of the adapted ENATs including differential item functioning by culture (cross-cultural DIF). Initially, the data from each country and diagnostic group were fitted to the Rasch model separately, and then the pooled data from each diagnostic group. The sample comprised 3015 patients; the majority, 1996 (66.2%), were women. Patient characteristics (stratified by diagnostic group) were comparable across countries except the educational background, which was variable. In most occasions, the 39-item ENAT deviated significantly from the Rasch model expectations (item-trait interaction χ(2) p<0.05). After correction for local dependency (grouping the items into seven domains and analysing them as 'testlets'), fit to the model was satisfied (item-trait interaction χ(2) p>0.18) in all pooled disease group datasets except OA (χ(2)=99.91; p=0.002). The internal consistency in each group was high (Person Separation Index above 0.90). There was no significant DIF by person characteristics. Cross-cultural DIF was found in some items, which required adjustments. Subsequently, interval-level scales were calibrated to enable transformation of ENAT scores when required. The adapted ENAT is a valid tool with high internal consistency providing accurate estimation of the educational needs of people with rheumatic diseases. Cross-cultural comparison of educational needs is now possible. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Recent progress on exploring exceptionally high and anisotropic H+/OH– ion conduction in two-dimensional materials

PubMed Central

Sun, Pengzhan; Sasaki, Takayoshi

2017-01-01

Ion conducting membranes/electrolytes have been employed extensively in some important industrial and biological systems, especially in fuel cells, water electrolyzers, gas separation, sensors and biological selective ion transport, acting as one of the core components and sometimes directly determining the device performance. However, the traditional polymeric proton exchange membranes (PEMs)/anion exchange membranes (AEMs) suffer from highly toxic preparation procedures, poor thermal and chemical stabilities, and unsatisfactory ion conductivities. This has triggered researchers worldwide to explore alternative inorganic building blocks with high ion conductivities and stabilities from the new materials library, hoping to solve the above long-lasting problems. The recent burgeoning research on two-dimensional (2D) materials has unveiled exceptionally high ionic conductivities, which raises the feasibility of fabricating high-performance nanosheet-based ion conductors/membranes. In this perspective, the recent advances in measuring and understanding the exceptionally high and anisotropic H+/OH– ion conductivities of representative 2D materials, e.g. graphene oxide (GO), vermiculite and layered double hydroxide (LDH) nanosheets, are reviewed. In particular, regarding the anisotropic ionic conduction in 2D nanosheets, possible design strategies and technological innovations for fabricating macroscopic nanosheet-based ionic conductors/membranes are proposed for maximizing the high in-plane conduction, which may serve to guide future development of high-performance industrial and biological systems relying on H+/OH– conducting membranes. PMID:29629071

Recent progress on exploring exceptionally high and anisotropic H+/OH- ion conduction in two-dimensional materials.

PubMed

Sun, Pengzhan; Ma, Renzhi; Sasaki, Takayoshi

2018-01-07

Ion conducting membranes/electrolytes have been employed extensively in some important industrial and biological systems, especially in fuel cells, water electrolyzers, gas separation, sensors and biological selective ion transport, acting as one of the core components and sometimes directly determining the device performance. However, the traditional polymeric proton exchange membranes (PEMs)/anion exchange membranes (AEMs) suffer from highly toxic preparation procedures, poor thermal and chemical stabilities, and unsatisfactory ion conductivities. This has triggered researchers worldwide to explore alternative inorganic building blocks with high ion conductivities and stabilities from the new materials library, hoping to solve the above long-lasting problems. The recent burgeoning research on two-dimensional (2D) materials has unveiled exceptionally high ionic conductivities, which raises the feasibility of fabricating high-performance nanosheet-based ion conductors/membranes. In this perspective, the recent advances in measuring and understanding the exceptionally high and anisotropic H + /OH - ion conductivities of representative 2D materials, e.g. graphene oxide (GO), vermiculite and layered double hydroxide (LDH) nanosheets, are reviewed. In particular, regarding the anisotropic ionic conduction in 2D nanosheets, possible design strategies and technological innovations for fabricating macroscopic nanosheet-based ionic conductors/membranes are proposed for maximizing the high in-plane conduction, which may serve to guide future development of high-performance industrial and biological systems relying on H + /OH - conducting membranes.

Elevations of water-worn features on Mars: Implications for circulation of groundwater

USGS Publications Warehouse

Carr, M.H.

2002-01-01

Central to the model of the evolution of the martian hydrosphere by Clifford and Parker [2001] is a permanent freezing of the planet at the end of the Noachian and recharge of the global groundwater system by basal melting of ice-rich polar deposits. Acquisition of MOLA data by Mars Global Surveyor provides a means of testing the model, since discharge of water onto the surface, after development of the cryosphere, is driven by the hydrostatic head created by the difference in elevation between the base of the polar-layered terrain and the discharge site. The new data show that, while most post- Noachian water-worn features are at a lower elevation than the base of the polar-layered terrains, as required by the model, there are exceptions. Prominent among these are possible lacustrine deposits within the canyons, tributaries to the canyons, and valleys on several volcanoes. These high-standing features can be reconciled with the model if volcanic melting of ice within the cryosphere is invoked as a source for water at high elevations. An alternative is that high pressures may have developed below the cryosphere as a result of water being trapped beneath the growing cryosphere and the impermeable basement. Yet another alternative is that, since the end of the Noachian, the groundwater system has been recharged by precipitation during occasional warm periods.

High Yield Production and Radiochemical Isolation of Isotopically Pure Arsenic-72 and Novel Radioarsenic Labeling Strategies for the Development of Theranostic Radiopharmaceuticals.

PubMed

Ellison, Paul A; Barnhart, Todd E; Chen, Feng; Hong, Hao; Zhang, Yin; Theuer, Charles P; Cai, Weibo; Nickles, Robert J; DeJesus, Onofre T

2016-01-20

Radioisotopes of arsenic are of considerable interest to the field of nuclear medicine with unique nuclear and chemical properties making them well-suited for use in novel theranostic radiopharmaceuticals. However, progress must still be made in the production of isotopically pure radioarsenic and in its stable conjugation to biological targeting vectors. This work presents the production and irradiation of isotopically enriched (72)Ge(m) discs in an irrigation-cooled target system allowing for the production of isotopically pure (72)As with capability on the order of 10 GBq. A radiochemical separation procedure isolated the reactive trivalent radioarsenic in a small volume buffered aqueous solution, while reclaiming (72)Ge target material. The direct thiol-labeling of a monoclonal antibody resulted in a conjugate exhibiting exceptionally poor in vivo stability in a mouse model. This prompted further investigations to alternative radioarsenic labeling strategies, including the labeling of the dithiol-containing chelator dihydrolipoic acid, and thiol-modified mesoporous silica nanoparticles (MSN-SH). Radioarsenic-labeled MSN-SH showed exceptional in vivo stability toward dearsenylation.

High Yield Production and Radiochemical Isolation of Isotopically Pure Arsenic-72 and Novel Radioarsenic Labeling Strategies for the Development of Theranostic Radiopharmaceuticals

PubMed Central

Ellison, Paul A.; Barnhart, Todd E.; Chen, Feng; Hong, Hao; Zhang, Yin; Theuer, Charles P.; Cai, Weibo; Nickles, Robert J.; DeJesus, Onofre T.

2016-01-01

Radioisotopes of arsenic are of considerable interest to the field of nuclear medicine with unique nuclear and chemical properties making them well-suited for use in novel theranostic radiopharmaceuticals. However, progress must still be made in the production of isotopically pure radioarsenic and in its stable conjugation to biological targeting vectors. This work presents the production and irradiation of isotopically enriched 72Ge(m) discs in an irrigation-cooled target system allowing for the production of isotopically pure 72As with capability on the order of 10 GBq. A radiochemical separation procedure isolated the reactive trivalent radioarsenic in a small volume buffered aqueous solution, while reclaiming 72Ge target material. The direct thiol-labeling of a monoclonal antibody resulted in a conjugate exhibiting exceptionally poor in vivo stability in a mouse model. This prompted further investigations to alternative radioarsenic labeling strategies, including the labeling of the dithiol-containing chelator dihydrolipoic acid, and thiol-modified mesoporous silica nanoparticles (MSN-SH). Radioarsenic-labeled MSN-SH showed exceptional in vivo stability toward dearsenylation. PMID:26646989

Topography and tectonics of mid-oceanic ridge axes

NASA Technical Reports Server (NTRS)

Sleep, N. H.; Rosendahl, B. R.

1979-01-01

Numerical fluid dynamic models of mid-oceanic ridge axes were constructed using distributions of material properties constrained by seismic studies and thermal calculations. The calculations indicate that spreading is passive except for forces caused by density differences due to thermal expansion and partial melt. Except for geometric differences due to temperature distribution, one set of mechanical properties can adequately explain central rifts of slow ridges and central peaks of fast ridges. Viscous head loss in the upwelling material dominates at low spreading rates where material ascends through a narrow conduit. Thermal expansion and partial melting dominate at high spreading rates where a wide low viscosity crustal magma chamber is present. The preferred rheology is 10 to the 20th poise for the upwelling lithosphere; less than 5 x 10 to the 17th for the crustal magma chamber and axial intrusion zone at fast ridges, and a yield stress of 200 bars for the lithosphere. The calculation correctly predicts the existence of central peaks at 'hot-spot' ridges, where seismic evidence indicates a large magma chamber.

Age-Related Changes in Reasons for Using Alcohol and Marijuana From Ages 18 to 30 in a National Sample

PubMed Central

Patrick, Megan E.; Schulenberg, John E.; O’Malley, Patrick M.; Maggs, Jennifer L.; Kloska, Deborah D.; Johnston, Lloyd D.; Bachman, Jerald G.

2011-01-01

This study used up to seven waves of data from 32 consecutive cohorts of participants in the national longitudinal Monitoring the Future study to model changes in self-reported reasons for using alcohol and marijuana by age (18 to 30), gender, and recent substance use. The majority of stated reasons for use decreased in prevalence across young adulthood (e.g., social/recreational and coping with negative affect reasons); exceptions included age-related increases in using to relax (alcohol and marijuana), to sleep (alcohol), because it tastes good (alcohol), and to get high (marijuana). Women were more likely than men to report drinking for reasons involving distress (i.e., to get away from problems), while men were more likely than women to endorse all other reasons. Greater substance use at age 18 was associated with greater likelihood of all reasons except to experiment and to fit in. A better understanding of developmental changes in reasons for use is important for understanding normative changes in substance use behaviors and for informing intervention efforts involving underlying reasons for use. PMID:21417516

Cardiometabolic risk factors are associated with high urinary enterolactone concentration, independent of urinary enterodiol concentration and dietary fiber intake in adults.

PubMed

Frankenfeld, Cara L

2014-09-01

The study objective was to evaluate independent and interactive associations of dietary fiber intake and high urinary enterolignans with cardiometabolic risk factors. The analysis included 2260 adults (≥20 y of age) from the 2003-2010 NHANES. Logistic regression models were used to evaluate obesity and clinically defined cardiometabolic risk factors in relation to dietary fiber intake and urinary enterolignan concentrations. Three sets of models were created: 1) independent associations, 2) mutually adjusted associations, and 3) interactions. Models were adjusted for age, gender, race/ethnicity, education, smoking status, and energy intake. High concentrations were considered to be above the 90th percentile of urinary enterolignan concentrations. Increasing dietary fiber intake was associated with high blood pressure (P = 0.02) and low serum HDL cholesterol (P-trend = 0.03). High urinary enterodiol concentration was not associated with obesity or cardiometabolic risk factors. High urinary enterolactone concentration was inversely associated with obesity (OR: 0.44; 95% CI: 0.29, 0.66), abdominal obesity (OR: 0.58; 95% CI: 0.39, 0.87), high serum C-reactive protein (CRP; OR: 0.52; 95% CI: 0.37, 0.74), high serum triglycerides (OR: 0.39; 95% CI: 0.23, 0.61), low serum HDL cholesterol (OR: 0.37; 95% CI: 0.23, 0.61), and metabolic syndrome (OR: 0.47; 95% CI: 0.30, 0.74). In mutually adjusted models, enterolactone associations observed in independent models remained similar, but associations for dietary fiber intake were attenuated, with the exception of blood pressure. In interaction models, there were 2 significant interactions: between high urinary enterodiol concentration and dietary fiber intake for high serum CRP (P = 0.04) and high plasma glucose (P = 0.04). Overall, being in the highest 10% of urinary enterolactone concentration was associated with cardiometabolic risk factors, independent of dietary fiber intake and enterodiol concentration. Future studies are warranted to evaluate physiologic actions of enterolactone or aspects of the gut microbial profile responsible for lignan metabolism to enterolactone. © 2014 American Society for Nutrition.

A coupled THMC model of a heating and hydration laboratory experiment in unsaturated compacted FEBEX bentonite

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

Zheng, L.; Samper, J.; Montenegro, L.

2010-05-01

Unsaturated compacted bentonite is foreseen by several countries as a backfill and sealing material in high-level radioactive waste repositories. The strong interplays between thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration stage of a repository call for fully coupled THMC models. Validation of such THMC models is prevented by the lack of comprehensive THMC experiments and the difficulties of experimental methods to measure accurately the chemical composition of bentonite porewater. We present here a non-isothermal multiphase flow and multicomponent reactive solute transport model for a deformable medium of a heating and hydration experiment performed onmore » a sample of compacted FEBEX bentonite. Besides standard solute transport and geochemical processes, the model accounts for solute cross diffusion and thermal and chemical osmosis. Bentonite swelling is solved with a state-surface approach. The THM model is calibrated with transient temperature, water content and porosity data measured at the end of the experiment. The reactive transport model is calibrated with porewater chemical data derived from aqueous extract data. Model results confirm that thermal osmosis is relevant for the hydration of FEBEX bentonite while chemical osmosis can be safely neglected. Dilution and evaporation are the main processes controlling the concentration of conservative species. Dissolved cations are mostly affected by calcite dissolution-precipitation and cation exchange reactions. Dissolved sulphate is controlled by gypsum/anhydrite dissolution-precipitation. pH is mostly buffered by protonation/deprotonation via surface complexation. Computed concentrations agree well with inferred aqueous extract data at all sections except near the hydration boundary where cation data are affected by a sampling artifact. The fit of Cl{sup -} data is excellent except for the data near the heater. The largest deviations of the model from inferred aqueous extract data occur for dissolved SO{sub 4}{sup 2-} which is underpredicted by the model. There are uncertainties on the amount of gypsum available for dissolution and its dissolution mechanism (kinetics or local equilibrium).« less

Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

DOE PAGES

Mehran, Ali; AghaKouchak, Amir; Phillips, Thomas J.

2014-02-25

Numerous studies have emphasized that climate simulations are subject to various biases and uncertainties. The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies and biases for both entire data distributions and their upper tails. The results of the Volumetric Hit Index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas, but that their replication of observed precipitation over arid regions and certain sub-continentalmore » regions (e.g., northern Eurasia, eastern Russia, central Australia) is problematical. Overall, the VHI of the multi-model ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (e.g., the 75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g. western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, inter-model variations in bias over Australia and Amazonia are considerable. The Quantile Bias (QB) analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. Lastly, we found that a simple mean-field bias removal improves the overall B and VHI values, but does not make a significant improvement in these model performance metrics at high quantiles of precipitation.« less

Seawater Circulation and Thermal Sink at OCEAN Ridges - FIELD Evidence in Oman Ophiolite

NASA Astrophysics Data System (ADS)

Nicolas, A. A.; Boudier, F. I.; Cathles, L. M.; Buck, W. R.; Celerier, B. P.

2014-12-01

Exceptionally, the lowermost gabbros in the Oman ophiolite are black and totally fresh, except for minute traces of impregnation by seawater fluids at very high temperature (~1000°C). These black gabbros sharply contrast with normal, whitish gabbros altered down to Low-T~500-350°C. These hydrous alterations are ascribed to an unconventional model of seawater circulation and cooling of the permanent magma chambers of fast spreading ocean ridges. In this model, gabbros issued from the magma chamber cross a ~100 m thick thermal boundary layer (TBL) before reaching a narrow, Low-T high permeability channel where the heated return seawater is flowing towards black smokers and the local gabbros are altered. Uprising mantle diapirs in Oman diverge at ~5 km on each side of the palaeo-ridge axis and feed an overlying magma chamber that closes at this distance from axis. Preservation of black gabbros along the Moho implies that the loop of seawater alteration locally does not reach Moho beyond this ~5km distance (otherwise black gabbros would be altered in whitish gabbros). This defines an internal "thermal sink" within ~5 km to the ridge axis. There, the sink is efficiently cooled by the active hydrothermal convection that is ridge transverse. This has been documented near the Galapagos ridge by marine geophysical data, within the same distance. Beyond this critical distance, the cooling system becomes dominantly conductive and ridge-parallel. The TBL and attached return flow channels must be rising into the overcooled, accreted crust. Beyond the thermal sink, the 500°C isotherm rebounds into the crust. It is only after ~ 1My of crustal drift that this isotherm penetrates into the uppermost mantle in a sustained fashion, developing serpentinites at the expense of peridotites.

Simultaneous determination of intestinal permeability and potential drug interactions of complex mixtures using Caco-2 cells and high-resolution mass spectrometry: Studies with Rauwolfia serpentina extract.

PubMed

Flynn, Thomas J; Vohra, Sanah N

2018-06-25

Caco-2 cells are a commonly used model for estimating the intestinal bioavailability of single chemical entity pharmaceuticals. Caco-2 cells, when induced with calcitriol, also express other biological functions such as phase I (CYP) and phase II (glucuronosyltransferases) drug metabolizing enzymes which are relevant to drug-supplement interactions. Intestinal bioavailability is an important factor in the overall safety assessment of products consumed orally. Foods, including herbal dietary supplements, are complex substances with multiple chemical components. Because of potential interactions between components of complex mixtures, more reliable safety assessments can be obtained by studying the commercial products "as consumed" rather than by testing individual chemical components one at a time. The present study evaluated the apparent intestinal permeability (P app ) of a model herbal extract, Rauwolfia serpentina, using both whole plant extracts and the individual purified Rauwolfia alkaloids. All test compounds, endpoint substrates, and their metabolites were quantified using liquid chromatography and high-resolution mass spectrometry. The P app values for individual Rauwolfia alkaloids were comparable whether measured individually or as components of the complete extract. Both Rauwolfia extract and all individual Rauwolfia alkaloids except yohimbine inhibited CYP3A4 activity (midazolam 1'-hydroxylation). Both Rauwolfia extract and all individual Rauwolfia alkaloids except corynanthine and reserpic acid significantly increased glucuronosyltransferase activity (glucuronidation of 4-methylumbelliferone). The positive control, ketoconazole, significantly inhibited both CYP3A4 and glucuronosyltransferase activities. These findings suggest that the Caco-2 assay is capable of simultaneously identifying both bioavailability and potentially hazardous intestinal drug-supplement interactions in complex mixtures. Published by Elsevier B.V.

Centers of excellence in healthcare institutions: what they are and how to assemble them.

PubMed

Elrod, James K; Fortenberry, John L

2017-07-11

Centers of excellence-specialized programs within healthcare institutions which supply exceptionally high concentrations of expertise and related resources centered on particular medical areas and delivered in a comprehensive, interdisciplinary fashion-afford many advantages for healthcare providers and the populations they serve. To achieve full value from centers of excellence, proper assembly is an absolute necessity, but guidance is somewhat limited. This effectively forces healthcare providers to pursue establishment largely via trial-and-error, diminishing opportunities for success. Successful development of a center of excellence first requires the acquisition of a detailed understanding of the delivery model and its benefits. Then, concerted actions must be taken on a particular series of administrative and clinical fronts, treating them in prescribed manners to afford synergies which yield an exceptionally high level of care. To reduce hardships associated with acquiring this rather elusive knowledge, remedy shortcomings in the literature, and potentially bolster community health broadly, this article presents information and insights gleaned from Willis-Knighton Health System's extensive experience assembling and operating centers of excellence. This work is intended to educate and enlighten, but most importantly, supply guidance which will permit healthcare establishments to replicate noted processes to realize their own centers of excellence. Centers of excellence have the ability to dramatically enhance the depth and breadth of healthcare services available in communities. Given the numerous mutual benefits afforded by this delivery model, it is hoped that the light shed by this article will help healthcare providers better understand centers of excellence and be more capable and confident in associated development initiatives, affording greater opportunities for themselves and their patient populations.

A Diverging View of Role Modeling in Medical Education

ERIC Educational Resources Information Center

Sandhu, Gurjit; Rich, Jessica V.; Magas, Christopher; Walker, G. Ross

2015-01-01

Research in the area of role modeling has primarily focused on the qualities and attributes of exceptional role models, and less attention has been given to the act of role modeling itself (Elzubeir & Rizk, 2001; Jochemsen-van der Leeuw, van Dijk, van Etten-Jamaludin, & Wieringa-de Waard, 2013; Wright, 1996; Wright, Wong, & Newill,…

Towards Improved Forecasts of Atmospheric and Oceanic Circulations over the Complex Terrain of the Eastern Mediterranean

NASA Technical Reports Server (NTRS)

Chronis, Themis; Case, Jonathan L.; Papadopoulos, Anastasios; Anagnostou, Emmanouil N.; Mecikalski, John R.; Haines, Stephanie L.

2008-01-01

Forecasting atmospheric and oceanic circulations accurately over the Eastern Mediterranean has proved to be an exceptional challenge. The existence of fine-scale topographic variability (land/sea coverage) and seasonal dynamics variations can create strong spatial gradients in temperature, wind and other state variables, which numerical models may have difficulty capturing. The Hellenic Center for Marine Research (HCMR) is one of the main operational centers for wave forecasting in the eastern Mediterranean. Currently, HCMR's operational numerical weather/ocean prediction model is based on the coupled Eta/Princeton Ocean Model (POM). Since 1999, HCMR has also operated the POSEIDON floating buoys as a means of state-of-the-art, real-time observations of several oceanic and surface atmospheric variables. This study attempts a first assessment at improving both atmospheric and oceanic prediction by initializing a regional Numerical Weather Prediction (NWP) model with high-resolution sea surface temperatures (SST) from remotely sensed platforms in order to capture the small-scale characteristics.

Response surface modeling for hot, humid air decontamination of materials contaminated with Bacillus anthracis ∆Sterne and Bacillus thuringiensis Al Hakam spores

PubMed Central

2014-01-01

Response surface methodology using a face-centered cube design was used to describe and predict spore inactivation of Bacillus anthracis ∆Sterne and Bacillus thuringiensis Al Hakam spores after exposure of six spore-contaminated materials to hot, humid air. For each strain/material pair, an attempt was made to fit a first or second order model. All three independent predictor variables (temperature, relative humidity, and time) were significant in the models except that time was not significant for B. thuringiensis Al Hakam on nylon. Modeling was unsuccessful for wiring insulation and wet spores because there was complete spore inactivation in the majority of the experimental space. In cases where a predictive equation could be fit, response surface plots with time set to four days were generated. The survival of highly purified Bacillus spores can be predicted for most materials tested when given the settings for temperature, relative humidity, and time. These predictions were cross-checked with spore inactivation measurements. PMID:24949256

Preserving Charge and Oxidation State of Au(III) Ions in an Agent-Functionalized Nanocrystal Model System

PubMed Central

2011-01-01

Supporting functional molecules on crystal facets is an established technique in nanotechnology. To preserve the original activity of ionic metallorganic agents on a supporting template, conservation of the charge and oxidation state of the active center is indispensable. We present a model system of a metallorganic agent that, indeed, fulfills this design criterion on a technologically relevant metal support with potential impact on Au(III)-porphyrin-functionalized nanoparticles for an improved anticancer-drug delivery. Employing scanning tunneling microscopy and -spectroscopy in combination with photoemission spectroscopy, we clarify at the single-molecule level the underlying mechanisms of this exceptional adsorption mode. It is based on the balance between a high-energy oxidation state and an electrostatic screening-response of the surface (image charge). Modeling with first principles methods reveals submolecular details of the metal–ligand bonding interaction and completes the study by providing an illustrative electrostatic model relevant for ionic metalorganic agent molecules, in general. PMID:21736315

3D surface pressure measurement with single light-field camera and pressure-sensitive paint

NASA Astrophysics Data System (ADS)

Shi, Shengxian; Xu, Shengming; Zhao, Zhou; Niu, Xiaofu; Quinn, Mark Kenneth

2018-05-01

A novel technique that simultaneously measures three-dimensional model geometry, as well as surface pressure distribution, with single camera is demonstrated in this study. The technique takes the advantage of light-field photography which can capture three-dimensional information with single light-field camera, and combines it with the intensity-based pressure-sensitive paint method. The proposed single camera light-field three-dimensional pressure measurement technique (LF-3DPSP) utilises a similar hardware setup to the traditional two-dimensional pressure measurement technique, with exception that the wind-on, wind-off and model geometry images are captured via an in-house-constructed light-field camera. The proposed LF-3DPSP technique was validated with a Mach 5 flared cone model test. Results show that the technique is capable of measuring three-dimensional geometry with high accuracy for relatively large curvature models, and the pressure results compare well with the Schlieren tests, analytical calculations, and numerical simulations.

Effects of stiffness and volume on the transit time of an erythrocyte through a slit.

PubMed

Salehyar, Sara; Zhu, Qiang

2017-06-01

By using a fully coupled fluid-cell interaction model, we numerically simulate the dynamic process of a red blood cell passing through a slit driven by an incoming flow. The model is achieved by combining a multiscale model of the composite cell membrane with a boundary element fluid dynamics model based on the Stokes flow assumption. Our concentration is on the correlation between the transit time (the time it takes to finish the whole translocation process) and different conditions (flow speed, cell orientation, cell stiffness, cell volume, etc.) that are involved. According to the numerical prediction (with some exceptions), the transit time rises as the cell is stiffened. It is also highly sensitive to volume increase inside the cell. In general, even slightly swollen cells (i.e., the internal volume is increased while the surface area of the cell kept unchanged) travel dramatically slower through the slit. For these cells, there is also an increased chance of blockage.

Non-invasive model of neuropathogenic Escherichia coli infection in the neonatal rat.

PubMed

Dalgakiran, Fatma; Witcomb, Luci A; McCarthy, Alex J; Birchenough, George M H; Taylor, Peter W

2014-10-29

Investigation of the interactions between animal host and bacterial pathogen is only meaningful if the infection model employed replicates the principal features of the natural infection. This protocol describes procedures for the establishment and evaluation of systemic infection due to neuropathogenic Escherichia coli K1 in the neonatal rat. Colonization of the gastrointestinal tract leads to dissemination of the pathogen along the gut-lymph-blood-brain course of infection and the model displays strong age dependency. A strain of E. coli O18:K1 with enhanced virulence for the neonatal rat produces exceptionally high rates of colonization, translocation to the blood compartment and invasion of the meninges following transit through the choroid plexus. As in the human host, penetration of the central nervous system is accompanied by local inflammation and an invariably lethal outcome. The model is of proven utility for studies of the mechanism of pathogenesis, for evaluation of therapeutic interventions and for assessment of bacterial virulence.

Geophysical interpretation of the gneiss terrane of northern Washington and southern British Columbia, and its implications for uranium exploration

USGS Publications Warehouse

Cady, John W.; Fox, Kenneth F.

1984-01-01

The Omineca crystalline belt of northeastern Washington and southern British Columbia has a regional Bouguer gravity high, and individual gneiss domes within the terrane are marked by local gravity highs. Models of crustal structure that satisfy the limited available seismic-refraction data and explain the gravity high over the gneiss terrane permit the hypothesis that the core metamorphic complexes are the surface expression of a zone of dense infrastructure that makes up the upper 20 km (kilometers) of the crust within the crystalline belt. The Omineca crystalline belt is characterized regionally by low aeromagnetic relief. The gneiss domes and biotite- and biotite-muscovite granites are generally marked by low magnetic relief, whereas hornblende-biotite granites often cause magnetic highs. Exceptional magnetic highs mark zones of magnetic rock within the biotite- and biotite-muscovite granites and the gneiss domes; these areas are worthy of study, both to determine the origin and disposition of the magnetite and to explore the possible existence of uraniferous magnetite deposits.

Psychosocial work environment factors and weight change: a prospective study among Danish health care workers.

PubMed

Gram Quist, Helle; Christensen, Ulla; Christensen, Karl Bang; Aust, Birgit; Borg, Vilhelm; Bjorner, Jakob B

2013-01-17

Lifestyle variables may serve as important intermediate factors between psychosocial work environment and health outcomes. Previous studies, focussing on work stress models have shown mixed and weak results in relation to weight change. This study aims to investigate psychosocial factors outside the classical work stress models as potential predictors of change in body mass index (BMI) in a population of health care workers. A cohort study, with three years follow-up, was conducted among Danish health care workers (3982 women and 152 men). Logistic regression analyses examined change in BMI (more than +/- 2 kg/m(2)) as predicted by baseline psychosocial work factors (work pace, workload, quality of leadership, influence at work, meaning of work, predictability, commitment, role clarity, and role conflicts) and five covariates (age, cohabitation, physical work demands, type of work position and seniority). Among women, high role conflicts predicted weight gain, while high role clarity predicted both weight gain and weight loss. Living alone also predicted weight gain among women, while older age decreased the odds of weight gain. High leadership quality predicted weight loss among men. Associations were generally weak, with the exception of quality of leadership, age, and cohabitation. This study of a single occupational group suggested a few new risk factors for weight change outside the traditional work stress models.

Observation of temperatures and emission rates from the OH and O 2 nightglow over a southern high latitude station

NASA Astrophysics Data System (ADS)

Chung, J.-K.; Kim, Y. H.; Won, Y.-I.; Moon, B. K.; Oh, T. H.

2006-01-01

A Spectral Airglow Temperature Imager (SATI) was operated at King Sejong Station (62°13'S, 58°47'W), Korea Antarctic Research Station during the period of March, 2002-September, 2003. We analyze rotational temperatures and emission rates of the O 2 (0-1) and OH (6-2) nightglows obtained at 67 nights with clear sky lasting more than 4 h. A spectral analysis of the dataset shows two dominant oscillations with periods of 4 and 6 h. The 6-h oscillations have a nearly constant phase, whereas the 4-h oscillations have nearly random phases. Although the harmonic periods of both oscillations are suggestive of tidal origin, the 4-h oscillation may have interference by other sources such as gravity waves. The 6-h oscillations could be interpreted as zonally symmetric non-migrating tides because migrating tides except high order modes have very weak amplitudes at high latitudes according to the classical tidal theory. For most cases of the observed oscillations the temperature peak leads the intensity peak, which is consistent with theoretical models for zonally symmetric tides, but contrary to other theoretical models for waves. It is needed to resolve among theoretical models whether or not zonally symmetric tide cause temperature variation prior to intensity variation in mesospheric airglows.

An access control model with high security for distributed workflow and real-time application

NASA Astrophysics Data System (ADS)

Han, Ruo-Fei; Wang, Hou-Xiang

2007-11-01

The traditional mandatory access control policy (MAC) is regarded as a policy with strict regulation and poor flexibility. The security policy of MAC is so compelling that few information systems would adopt it at the cost of facility, except some particular cases with high security requirement as military or government application. However, with the increasing requirement for flexibility, even some access control systems in military application have switched to role-based access control (RBAC) which is well known as flexible. Though RBAC can meet the demands for flexibility but it is weak in dynamic authorization and consequently can not fit well in the workflow management systems. The task-role-based access control (T-RBAC) is then introduced to solve the problem. It combines both the advantages of RBAC and task-based access control (TBAC) which uses task to manage permissions dynamically. To satisfy the requirement of system which is distributed, well defined with workflow process and critically for time accuracy, this paper will analyze the spirit of MAC, introduce it into the improved T&RBAC model which is based on T-RBAC. At last, a conceptual task-role-based access control model with high security for distributed workflow and real-time application (A_T&RBAC) is built, and its performance is simply analyzed.

Multichannel imaging to quantify four classes of pharmacokinetic distribution in tumors.

PubMed

Bhatnagar, Sumit; Deschenes, Emily; Liao, Jianshan; Cilliers, Cornelius; Thurber, Greg M

2014-10-01

Low and heterogeneous delivery of drugs and imaging agents to tumors results in decreased efficacy and poor imaging results. Systemic delivery involves a complex interplay of drug properties and physiological factors, and heterogeneity in the tumor microenvironment makes predicting and overcoming these limitations exceptionally difficult. Theoretical models have indicated that there are four different classes of pharmacokinetic behavior in tissue, depending on the fundamental steps in distribution. In order to study these limiting behaviors, we used multichannel fluorescence microscopy and stitching of high-resolution images to examine the distribution of four agents in the same tumor microenvironment. A validated generic partial differential equation model with a graphical user interface was used to select fluorescent agents exhibiting these four classes of behavior, and the imaging results agreed with predictions. BODIPY-FL exhibited higher concentrations in tissue with high blood flow, cetuximab gave perivascular distribution limited by permeability, high plasma protein and target binding resulted in diffusion-limited distribution for Hoechst 33342, and Integrisense 680 was limited by the number of binding sites in the tissue. Together, the probes and simulations can be used to investigate distribution in other tumor models, predict tumor drug distribution profiles, and design and interpret in vivo experiments. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Investigation of different simulation approaches on a high-head Francis turbine and comparison with model test data: Francis-99

NASA Astrophysics Data System (ADS)

Mössinger, Peter; Jester-Zürker, Roland; Jung, Alexander

2015-01-01

Numerical investigations of hydraulic turbo machines under steady-state conditions are state of the art in current product development processes. Nevertheless allow increasing computational resources refined discretization methods, more sophisticated turbulence models and therefore better predictions of results as well as the quantification of existing uncertainties. Single stage investigations are done using in-house tools for meshing and set-up procedure. Beside different model domains and a mesh study to reduce mesh dependencies, the variation of several eddy viscosity and Reynolds stress turbulence models are investigated. All obtained results are compared with available model test data. In addition to global values, measured magnitudes in the vaneless space, at runner blade and draft tube positions in term of pressure and velocity are considered. From there it is possible to estimate the influence and relevance of various model domains depending on different operating points and numerical variations. Good agreement can be found for pressure and velocity measurements with all model configurations and, except the BSL-RSM model, all turbulence models. At part load, deviations in hydraulic efficiency are at a large magnitude, whereas at best efficiency and high load operating point efficiencies are close to the measurement. A consideration of the runner side gap geometry as well as a refined mesh is able to improve the results either in relation to hydraulic efficiency or velocity distribution with the drawbacks of less stable numerics and increasing computational time.

Thermal design and analysis of a hydrogen-burning wind tunnel model of an airframe-integrated scramjet

NASA Technical Reports Server (NTRS)

Guy, R. W.; Mueller, J. N.; Pinckney, S. Z.; Lee, L. P.

1976-01-01

An aerodynamic model of a hydrogen burning, airframe integrated scramjet engine has been designed, fabricated, and instrumented. This model is to be tested in an electric arc heated wind tunnel at an altitude of 35.39 km (116,094 ft.) but with an inlet Mach number of 6 simulating precompression on an aircraft undersurface. The scramjet model is constructed from oxygen free, high conductivity copper and is a heat sink design except for water cooling in some critical locations. The model is instrumented for pressure, surface temperature, heat transfer rate, and thrust measurements. Calculated flow properties, heat transfer rates, and surface temperature distributions along the various engine components are included for the conditions stated above. For some components, estimates of thermal strain are presented which indicate significant reductions in plastic strain by selective cooling of the model. These results show that the 100 thermal cycle life of the engine was met with minimum distortion while staying within the 2669 N (600 lbf) engine weight limitation and while cooling the engine only in critical locations.

MultiGeMS: detection of SNVs from multiple samples using model selection on high-throughput sequencing data.

PubMed

Murillo, Gabriel H; You, Na; Su, Xiaoquan; Cui, Wei; Reilly, Muredach P; Li, Mingyao; Ning, Kang; Cui, Xinping

2016-05-15

Single nucleotide variant (SNV) detection procedures are being utilized as never before to analyze the recent abundance of high-throughput DNA sequencing data, both on single and multiple sample datasets. Building on previously published work with the single sample SNV caller genotype model selection (GeMS), a multiple sample version of GeMS (MultiGeMS) is introduced. Unlike other popular multiple sample SNV callers, the MultiGeMS statistical model accounts for enzymatic substitution sequencing errors. It also addresses the multiple testing problem endemic to multiple sample SNV calling and utilizes high performance computing (HPC) techniques. A simulation study demonstrates that MultiGeMS ranks highest in precision among a selection of popular multiple sample SNV callers, while showing exceptional recall in calling common SNVs. Further, both simulation studies and real data analyses indicate that MultiGeMS is robust to low-quality data. We also demonstrate that accounting for enzymatic substitution sequencing errors not only improves SNV call precision at low mapping quality regions, but also improves recall at reference allele-dominated sites with high mapping quality. The MultiGeMS package can be downloaded from https://github.com/cui-lab/multigems xinping.cui@ucr.edu Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

VARIABILITY AND CHARACTER ASSOCIATION IN ROSE COLOURED LEADWORT (PLUMBAGO ROSEA Linn.)

PubMed Central

Kurian, Alice; Anitha, C.A.; Nybe, E.V.

2001-01-01

Forty five plumbago rosea accessions collected from different parts of Kerala state were evaluated for variability in morphological and yield related characters and plumbagin content. Highly significant variation was evident for all the characters studied except leaf size indicating wide variability in the accessions. Accessions PR 25 and PR 31 appear to be promising with respect to root yield and high plumbagin content. Character association revelated significant and positive correlation of all the characters except leaf size with yield. Hence, selection of high yielding types could easily be done based on visual characters expressing more vegetative growth but with reduced leaf size. PMID:22557037

Text messaging: are dependency and Excessive Use discretely different for Japanese university students?

PubMed

Lu, Xi; Katoh, Takahiko; Chen, Zi; Nagata, Toshiaki; Kitamura, Toshinori

2014-05-15

Text messaging may be excessive and young people may be dependent on it. We distributed the Self-perception of Text-message Dependency Scale (STDS), Hospital Anxiety and Depression Scale (HADS), Temperament and Character Inventory (TCI), and Relationship Questionnaire (RQ) to 223 Japanese university students in a two-wave study, separated by a 5-month interval. The STDS yielded a three-factor structure. The STDS scores across the two measurement occasions were stable across time (except for the Relationship Maintenance subscale). A hierarchical cluster analysis suggested a three-class structure interpreted as Normal Users, Excessive Users, and Dependent Users. Excessive Users and Dependent Users were characterized by a young age at initial mobile phone use, more frequent use of text messaging, higher Novelty Seeking, and better Other-Model patterns of adult attachment. Unlike Excessive Users, Dependent Users were characterized by lower Self-directedness, poorer Self-Model of adult attachment, and higher anxiety and depression. The Excessive Users, but not the Dependent Users, were characterized by high Reward Dependence and Co-operativeness. The present study demonstrated that the STDS has a robust factor structure, good construct validity, and temporal stability (except for Relationship Maintenance subscale); students could be classified into normal, excessive, and Dependent Users of the text messaging; and Dependent Users were characterized by Excessive Use and personality immaturity. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Competitive ability, stress tolerance and plant interactions along stress gradients.

PubMed

Qi, Man; Sun, Tao; Xue, SuFeng; Yang, Wei; Shao, DongDong; Martínez-López, Javier

2018-04-01

Exceptions to the generality of the stress-gradient hypothesis (SGH) may be reconciled by considering species-specific traits and stress tolerance strategies. Studies have tested stress tolerance and competitive ability in mediating interaction outcomes, but few have incorporated this to predict how species interactions shift between competition and facilitation along stress gradients. We used field surveys, salt tolerance and competition experiments to develop a predictive model interspecific interaction shifts across salinity stress gradients. Field survey and greenhouse tolerance tests revealed tradeoffs between stress tolerance and competitive ability. Modeling showed that along salinity gradients, (1) plant interactions shifted from competition to facilitation at high salinities within the physiological limits of salt-intolerant plants, (2) facilitation collapsed when salinity stress exceeded the physiological tolerance of salt-intolerant plants, and (3) neighbor removal experiments overestimate interspecific facilitation by including intraspecific effects. A community-level field experiment, suggested that (1) species interactions are competitive in benign and, facilitative in harsh condition, but fuzzy under medium environmental stress due to niche differences of species and weak stress amelioration, and (2) the SGH works on strong but not weak stress gradients, so SGH confusion arises when it is applied across questionable stress gradients. Our study clarifies how species interactions vary along stress gradients. Moving forward, focusing on SGH applications rather than exceptions on weak or nonexistent gradients would be most productive. © 2018 by the Ecological Society of America.

NRLMSISE-00 Empirical Model of the Atmosphere: Statistical Comparisons and Scientific Issues

NASA Technical Reports Server (NTRS)

Aikin, A. C.; Picone, J. M.; Hedin, A. E.; Drob, D. P.

2001-01-01

The new NRLMSISE-00 model and the associated NRLMSIS database now include the following data: (1) total mass density from satellite accelerometers and from orbit determination, including the Jacchia and Barlier data; (2) temperature from incoherent scatter radar, and; (3) molecular oxygen number density, [O2], from solar ultraviolet occultation aboard the Solar Maximum Mission (SMM). A new component, 'anomalous oxygen,' allows for appreciable O(+) and hot atomic oxygen contributions to the total mass density at high altitudes and applies primarily to drag estimation above 500 km. Extensive tables compare our entire database to the NRLMSISE-00, MSISE-90, and Jacchia-70 models for different altitude bands and levels of geomagnetic activity. We also investigate scientific issues related to the new data sets in the NRLMSIS database. Especially noteworthy is the solar activity dependence of the Jacchia data, with which we investigate a large O(+) contribution to the total mass density under the combination of summer, low solar activity, high latitudes, and high altitudes. Under these conditions, except at very low solar activity, the Jacchia data and the Jacchia-70 model indeed show a significantly higher total mass density than does MSISE-90. However, under the corresponding winter conditions, the MSIS-class models represent a noticeable improvement relative to Jacchia-70 over a wide range of F(sub 10.7). Considering the two regimes together, NRLMSISE-00 achieves an improvement over both MSISE-90 and Jacchia-70 by incorporating advantages of each.

Modeling the effect of snow and ice on the global environmental fate and long-range transport potential of semivolatile organic compounds.

PubMed

Stocker, Judith; Scheringer, Martin; Wegmann, Fabio; Hungerbuhler, Konrad

2007-09-01

Snow and ice have been implemented in a global multimedia box model to investigate the influence of these media on the environmental fate and long-range transport (LRT) of semivolatile organic compounds (SOCs). Investigated compounds include HCB, PCB28, PCB180, PBDE47, PBDE209, alpha-HCH, and dacthal. In low latitudes, snow acts as a transfer medium taking up chemicals from air and releasing them to water or soil during snowmelt. In high latitudes, snow and ice shield water, soil, and vegetation from chemical deposition. In the model version including snow and ice (scenario 2), the mass of chemicals in soil in high latitudes is between 27% (HCB) and 97% (alpha-HCH) of the mass calculated with the model version without snow and ice (scenario 1). Amounts in Arctic seawater in scenario 2 are 8% (alpha-HCH) to 21% (dacthal) of the amounts obtained in scenario 1. For all investigated chemicals except alpha-HCH, presence of snow and ice in the model increases the concentration in air by a factor of 2 (HCB)to 10 (PBDE209). Because of reduced net deposition to snow-covered surfaces in high latitudes, LRT to the Arctic is reduced for most chemicals whereas transport to the south is more pronounced than in scenario 1 ("southward shift"). The presence of snow and ice thus considerably changes the environmental fate of SOCs.

In the absence of a "landscape of fear": How lions, hyenas, and cheetahs coexist.

PubMed

Swanson, Alexandra; Arnold, Todd; Kosmala, Margaret; Forester, James; Packer, Craig

2016-12-01

Aggression by top predators can create a "landscape of fear" in which subordinate predators restrict their activity to low-risk areas or times of day. At large spatial or temporal scales, this can result in the costly loss of access to resources. However, fine-scale reactive avoidance may minimize the risk of aggressive encounters for subordinate predators while maintaining access to resources, thereby providing a mechanism for coexistence. We investigated fine-scale spatiotemporal avoidance in a guild of African predators characterized by intense interference competition. Vulnerable to food stealing and direct killing, cheetahs are expected to avoid both larger predators; hyenas are expected to avoid lions. We deployed a grid of 225 camera traps across 1,125 km 2 in Serengeti National Park, Tanzania, to evaluate concurrent patterns of habitat use by lions, hyenas, cheetahs, and their primary prey. We used hurdle models to evaluate whether smaller species avoided areas preferred by larger species, and we used time-to-event models to evaluate fine-scale temporal avoidance in the hours immediately surrounding top predator activity. We found no evidence of long-term displacement of subordinate species, even at fine spatial scales. Instead, hyenas and cheetahs were positively associated with lions except in areas with exceptionally high lion use. Hyenas and lions appeared to actively track each, while cheetahs appear to maintain long-term access to sites with high lion use by actively avoiding those areas just in the hours immediately following lion activity. Our results suggest that cheetahs are able to use patches of preferred habitat by avoiding lions on a moment-to-moment basis. Such fine-scale temporal avoidance is likely to be less costly than long-term avoidance of preferred areas: This may help explain why cheetahs are able to coexist with lions despite high rates of lion-inflicted mortality, and highlights reactive avoidance as a general mechanism for predator coexistence.

Cytokine response to pregnancy-associated recrudescence of Plasmodium berghei infection in mice with pre-existing immunity to malaria.

PubMed

Megnekou, Rosette; Staalsoe, Trine; Hviid, Lars

2013-11-01

During childhood, residents of areas with stable transmission of Plasmodium falciparum parasites acquire substantial protective immunity to malaria, and adults therefore rarely experience clinical disease episodes. However, susceptibility to infection reappears in pregnant women, particularly primigravidae. This is due to appearance of antigenic parasite variants that are restricted to pregnancy. Variant-specific immunity also governs pregnancy-associated recrudescence of Plasmodium berghei infection in pregnant mice. Pregnancy-related changes in the plasma cytokine levels of mice with immunity acquired prior to first pregnancy have not been studied in detail previously, and were the topic of the present study. A multiplexed bead assay was used to measure plasma levels of IL-5, IL-10, IL-12, IL-13, IFN-γ and TNF in BALB/c mice immunized against P. berghei K173 by repeated infection and drug cure before the first pregnancy. The association between cytokine levels on the one hand and parasitaemia and haemoglobin levels on the other, in mice that had never been pregnant or were pregnant for the first, second or third time were evaluated by Mann-Whitney test and Spearman rank-order correlation analysis. Pregnancy per se did not further increase the already high cytokine levels in mice previously immunized by repeated infection and drug cure. Levels of all the cytokines except IL-10 were correlated with each other, and with parasitaemia and haemoglobin levels. Furthermore, levels of all cytokines were positively correlated with parity, except IL-10, which was negatively correlated with parity. High levels of IL-10 and low levels of the other cytokines were associated with poor pregnancy outcome. High levels of IL-10 and low levels of the other cytokines were associated with poor pregnancy outcome in this mouse model of placental malaria. Since the model replicates key parasitological and immunological features of placental P. falciparum malaria, it underpins its usefulness in immunology and pathogenesis studies of this important cause of mother/child morbidity in endemic areas.

Computational modeling and molecular imprinting for the development of acrylic polymers with high affinity for bile salts.

PubMed

Yañez, Fernando; Chianella, Iva; Piletsky, Sergey A; Concheiro, Angel; Alvarez-Lorenzo, Carmen

2010-02-05

This work has focused on the rational development of polymers capable of acting as traps of bile salts. Computational modeling was combined with molecular imprinting technology to obtain networks with high affinity for cholate salts in aqueous medium. The screening of a virtual library of 18 monomers, which are commonly used for imprinted networks, identified N-(3-aminopropyl)-methacrylate hydrochloride (APMA.HCl), N,N-diethylamino ethyl methacrylate (DEAEM) and ethyleneglycol methacrylate phosphate (EGMP) as suitable functional monomers with medium-to-high affinity for cholic acid. The polymers were prepared with a fix cholic acid:functional monomer mole ratio of 1:4, but with various cross-linking densities. Compared to polymers prepared without functional monomer, both imprinted and non-imprinted microparticles showed a high capability to remove sodium cholate from aqueous medium. High affinity APMA-based particles even resembled the performance of commercially available cholesterol-lowering granules. The imprinting effect was evident in most of the networks prepared, showing that computational modeling and molecular imprinting can act synergistically to improve the performance of certain polymers. Nevertheless, both the imprinted and non-imprinted networks prepared with the best monomer (APMA.HCl) identified by the modeling demonstrated such high affinity for the template that the imprinting effect was less important. The fitting of adsorption isotherms to the Freundlich model indicated that, in general, imprinting increases the population of high affinity binding sites, except when the affinity of the functional monomer for the target molecule is already very high. The cross-linking density was confirmed as a key parameter that determines the accessibility of the binding points to sodium cholate. Materials prepared with 9% mol APMA and 91% mol cross-linker showed enough affinity to achieve binding levels of up to 0.4 mmol g(-1) (i.e., 170 mg g(-1)) under flow (1 mL min(-1)) of 0.2 mM sodium cholate solution. Copyright 2009 Elsevier B.V. All rights reserved.

Assessing the accuracy and stability of variable selection methods for random forest modeling in ecology

EPA Science Inventory

Random forest (RF) modeling has emerged as an important statistical learning method in ecology due to its exceptional predictive performance. However, for large and complex ecological datasets there is limited guidance on variable selection methods for RF modeling. Typically, e...

Carbon allocation, source-sink relations and plant growth: do we need to revise our carbon centric concepts?

NASA Astrophysics Data System (ADS)

Körner, Christian

2014-05-01

Since the discovery that plants 'eat air' 215 years ago, carbon supply was considered the largely unquestioned top driver of plant growth. The ease at which CO2 uptake (C source activity) can be measured, and the elegant algorithms that describe the responses of photosynthesis to light, temperature and CO2 concentration, explain why carbon driven growth and productivity became the starting point of all process based vegetation models. Most of these models, nowadays adopt other environmental drivers, such as nutrient availability, as modulating co-controls, but the carbon priority is retained. Yet, if we believe in the basic rules of stoichometry of all life, there is an inevitable need of 25-30 elements other then carbon, oxygen and hydrogen to build a healthy plant body. Plants compete for most of these elements, and their availability (except for N) is finite per unit land area. Hence, by pure plausibility, it is a highly unlikely situation that carbon plays the rate limiting role of growth under natural conditions, except in deep shade or on exceptionally fertile soils. Furthermore, water shortage and low temperature, both act directly upon tissue formation (meristems) long before photosynthetic limitations come into play. Hence, plants will incorporate C only to the extent other environmental drivers permit. In the case of nutrients and mature ecosystems, this sink control of plant growth may be masked in the short term by a tight, almost closed nutrient cycle or by widening the C to other element ratio. Because source and sink activity must match in the long term, it is not possible to identify the hierarchy of growth controls without manipulating the environment. Dry matter allocation to C rich structures and reserves may provide some stoichimetric leeway or periodic escapes from the more fundamental, long-term environmental controls of growth and productivity. I will explain why carbon centric explanations of growth are limited or arrive at plausible answers for the wrong reason. Suggested reading: Fatichi, Leuzinger, Körner (2013) Moving beyond photosynthesis: from carbon source to sink-driven vegetation modeling. New Phytologist. Körner C (2013) Growth controls photosynthesis - mostly. Nova Acta Leopoldina 391:273-283.

Toward a Unified View of Black-Hole High-Energy States

NASA Technical Reports Server (NTRS)

Nowak, Michael A.

1995-01-01

We present here a review of high-energy (greater than 1 keV) observations of seven black-hole candidates, six of which have estimated masses. In this review we focus on two parameters of interest: the ratio of 'nonthermal' to total luminosity as a function of the total luminosity divided by the Eddington luminosity, and the root-mean-square (rms) variability as a function of the nonthermal-to-total luminosity ratio. Below approx. 10% Eddington luminosity, the sources tend to be strictly nonthermal (the so called 'off' and 'low' states). Above this luminosity the sources become mostly thermal (the 'high' state). with the nonthermal component increasing with luminosity (the 'very high' and 'flare' states). There are important exceptions to this behavior, however, and no steady - as opposed to transient - source has been observed over a wide range of parameter space. In addition, the rms variability is positively correlated with the ratio of nonthermal to total luminosity, although there may be a minimum level of variability associated with 'thermal' states. We discuss these results in light of theoretical models and find that currently no single model describes the full range of black-hole high-energy behavior. In fact, the observations are exactly opposite from what one expects based upon simple notions of accretion disk instabilities.

Warm weather transport of broiler chickens in Manitoba. II. Truck management factors associated with death loss in transit to slaughter.

PubMed

Whiting, Terry L; Drain, Mairead E; Rasali, Drona P

2007-02-01

This observational study was conducted to identify the cause of death and load level factors associated with mortality in 1 090 733 Manitoba broiler chickens transported to slaughter in spring and early summer. Death loss in transit was 0.346% and accounted for 19% of the total carcass condemnation. The death loss pattern was clearly bimodal, with a low death loss in 180 of 198 shipments. Cumulative death loss during the growing phase of production was consistently associated with increased transport mortalities in load level models and when comparing high death loss with low death loss truckloads. High ambient temperature at the time of slaughter and loading density of the truck were the major factors associated with exceptional death loss.

The mitochondrial genome of Globodera ellingtonae is composed of two circles with segregated gene content and differential copy numbers

USDA-ARS?s Scientific Manuscript database

The evolution of animal mitochondrial (mt) genomes has yielded a highly conserved structure: a single circular chromosome approximately 14 to 20 kb long. Within the last two decades, exceptions to this conserved structure have been reported in a diverse set of organisms. One such exception is the di...

Physical Education Opportunity Program for Exceptional Learners (PEOPEL): A Teacher's Guide for Secondary Schools. Second Edition.

ERIC Educational Resources Information Center

Irmer, Larry D.; And Others

The instructional guide for PEOPEL (Physical Education Opportunity Program for Exceptional Learners) contains 36 units of instruction for use with handicapped junior and senior high school students. The units contain basic performance objectives which have been task analyzed in an effort to individualize instruction. Each unit is divided into four…

The Relationship between Self-Concept, Ability, and Academic Programming among Twice-Exceptional Youth

ERIC Educational Resources Information Center

Foley-Nicpon, Megan; Assouline, Susan G.; Fosenburg, Staci

2015-01-01

Researchers investigated the self-concept profiles of twice-exceptional students in relationship to their cognitive ability and participation in educational services. All subjects (N = 64) had high ability (IQ score at or above the 90th percentile) and were diagnosed with either an autism spectrum disorder (ASD; n = 53) or specific learning…

Characteristics of Difficult-to-Place Youth in State Custody: A Profile of the Exceptional Care Pilot Project Population

ERIC Educational Resources Information Center

Armour, Marilyn P.; Schwab, James

2007-01-01

This study examines the characteristics of Texas youth designated as "most difficult to place" recipients of service under the "Exceptional Care Pilot Project" (N = 46). Findings include, among others, high levels of comorbid psychiatric disturbance (greater than 3 diagnostic groupings), physical (78.3%) and sexual (88%)…

Source parameters and effects of bandwidth and local geology on high- frequency ground motions observed for aftershocks of the northeastern Ohio earthquake of 31 January 1986

USGS Publications Warehouse

Glassmoyer, G.; Borcherdt, R.D.

1990-01-01

A 10-station array (GEOS) yielded recordings of exceptional bandwidth (400 sps) and resolution (up to 96 dB) for the aftershocks of the moderate (mb???4.9) earthquake that occurred on 31 January 1986 near Painesville, Ohio. Nine aftershocks were recorded with seismic moments ranging between 9 ?? 1016 and 3 ?? 1019 dyne-cm (MW: 0.6 to 2.3). The aftershock recordings at a site underlain by ???8m of lakeshore sediments show significant levels of high-frequency soil amplification of vertical motion at frequencies near 8, 20 and 70 Hz. Viscoelastic models for P and SV waves incident at the base of the sediments yield estimates of vertical P-wave response consistent with the observed high-frequency site resonances, but suggest additional detailed shear-wave logs are needed to account for observed S-wave response. -from Authors

High yield recombinant production of a self-assembling polycationic peptide for silica biomineralization.

PubMed

Zerfaß, Christian; Braukmann, Sandra; Nietzsche, Sandor; Hobe, Stephan; Paulsen, Harald

2015-04-01

We report the recombinant bacterial expression and purification at high yields of a polycationic oligopeptide, P5S3. The sequence of P5S3 was inspired by a diatom silaffin, a silica precipitating peptide. Like its native model, P5S3 exhibits silica biomineralizing activity, but furthermore has unusual self-assembling properties. P5S3 is efficiently expressed in Escherichia coli as fusion with ketosteroid isomerase (KSI), which causes deposition in inclusion bodies. After breaking the fusion by cyanogen bromide reaction, P5S3 was purified by cation exchange chromatography, taking advantage of the exceptionally high content of basic amino acids. The numerous cationic charges do not prevent, but may even promote counterion-independent self-assembly which in turn leads to silica precipitation. Enzymatic phosphorylation, a common modification in native silica biomineralizing peptides, can be used to modify the precipitation activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Hydrologic Derivatives for Modeling and Analysis—A new global high-resolution database

USGS Publications Warehouse

Verdin, Kristine L.

2017-07-17

The U.S. Geological Survey has developed a new global high-resolution hydrologic derivative database. Loosely modeled on the HYDRO1k database, this new database, entitled Hydrologic Derivatives for Modeling and Analysis, provides comprehensive and consistent global coverage of topographically derived raster layers (digital elevation model data, flow direction, flow accumulation, slope, and compound topographic index) and vector layers (streams and catchment boundaries). The coverage of the data is global, and the underlying digital elevation model is a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), GMTED2010 (Global Multi-resolution Terrain Elevation Data 2010), and the SRTM (Shuttle Radar Topography Mission). For most of the globe south of 60°N., the raster resolution of the data is 3 arc-seconds, corresponding to the resolution of the SRTM. For the areas north of 60°N., the resolution is 7.5 arc-seconds (the highest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30 arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information. This database is appropriate for use in continental-scale modeling efforts. The work described in this report was conducted by the U.S. Geological Survey in cooperation with the National Aeronautics and Space Administration Goddard Space Flight Center.

High temperature annealing of fission tracks in fluorapatite, Santa Fe Springs oil field, Los Angeles Basin, California

USGS Publications Warehouse

Naeser, Nancy D.; Crowley, Kevin D.; McCulloh, Thane H.; Reaves, Chris M.; ,

1990-01-01

Annealing of fission tracks is a kinetic process dependent primarily on temperature and to a laser extent on time. Several kinetic models of apatite annealing have been proposed. The predictive capabilities of these models for long-term geologic annealing have been limited to qualitative or semiquantitative at best, because of uncertainties associated with (1) the extrapolation of laboratory observations to geologic conditions, (2) the thermal histories of field samples, and (3) to some extent, the effect of apatite composition on reported annealing temperatures. Thermal history in the Santa Fe Springs oil field, Los Angeles Basin, California, is constrained by an exceptionally well known burial history and present-day temperature gradient. Sediment burial histories are continuous and tightly constrained from about 9 Ma to present, with an important tie at 3.4 Ma. No surface erosion and virtually no uplift were recorded during or since deposition of these sediments, so the burial history is simple and uniquely defined. Temperature gradient (???40??C km-1) is well established from oil-field operations. Fission-track data from the Santa Fe Springs area should thus provide one critical field test of kinetic annealing models for apatite. Fission-track analysis has been performed on apatites from sandstones of Pliocene to Miocene age from a deep drill hole at Santa Fe Springs. Apatite composition, determined by electron microprobe, is fluorapatite [average composition (F1.78Cl0.01OH0.21)] with very low chlorine content [less than Durango apatite; sample means range from 0.0 to 0.04 Cl atoms, calculated on the basis of 26(O, F, Cl, OH)], suggesting that the apatite is not unusually resistant to annealing. Fission tracks are preserved in these apatites at exceptionally high present-day temperatures. Track loss is not complete until temperatures reach the extreme of 167-178??C (at 3795-4090 m depth). The temperature-time annealing relationships indicated by the new data from Santa Fe Springs conflict with predictions based on previously published, commonly used, kinetic annealing models for apatite. Work is proceeding on samples from another area of the basin that may resolve this discrepancy.

Highly porous organic polymers bearing tertiary amine group and their exceptionally high CO{sub 2} uptake capacities

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

Gomes, Ruth; Bhaumik, Asim, E-mail: msab@iacs.res.in

2015-02-15

We report a very simple and unique strategy for synthesis of a tertiary amine functionalized high surface area porous organic polymer (POP) PDVTA-1 through the co-polymerization of monomers divinylbenzene (DVB) and triallylamine (TAA) under solvothermal reaction conditions. Two different PDVTA-1 samples have been synthesized by varying the molar ratio of the monomers. The porous polymeric materials have been thoroughly characterized by solid state {sup 13}C CP MAS-NMR, FT-IR and UV–vis spectroscopy, N{sub 2} sorption, HR TEM and FE SEM to understand its chemical environment, nanostructure, bonding, morphology and related surface properties. PDVTA-1 with higher amine content (DVB/TAA=4.0) showed exceptionally highmore » CO{sub 2} uptake capacity of 85.8 wt% (19.5 mmol g{sup −1}) at 273 K and 43.69 wt% (9.93 mmol g{sup −1}) at 298 K under 3 bar pressure, whereas relatively low amine loaded material (DVB/TAA=7.0) shows uptake capacity of 59.2 wt% (13.45 mmol g{sup −1}) at 273 K and 34.36 wt% (7.81 mmol g{sup −1}) at 298 K. Highly porous nanostructure together with very high surface area and basicity at the surface due to the presence of abundant basic tertiary amine N-sites in the framework of PDVTA-1 could be responsible for very high CO{sub 2} adsorption. - Graphical abstract: Exceptionally high CO2 uptake (85.8 wt % at 273 K) has been observed over a high surface area porous organic polymer PDVTA-1 synthesized through copolymerization of divinylbenzene and triallyl amine. - Highlights: • Designing the synthesis of a new N-rich cross-linked porous organic polymer PDVTA-1. • PDVTA-1 showed mesoporosity with very high surface area of 903 m{sup 2} g{sup −1}. • High surface area and presence of basic sites facilitates the CO{sub 2} uptake. • PDVTA-1 showed exceptionally high CO{sub 2} adsorption capacity of 85.8 wt% at 273 K, 3 bar pressure.« less

Formation of magmatic brine lenses via focussed fluid-flow beneath volcanoes

NASA Astrophysics Data System (ADS)

Afanasyev, Andrey; Blundy, Jon; Melnik, Oleg; Sparks, Steve

2018-03-01

Many active or dormant volcanoes show regions of high electrical conductivity at depths of a few kilometres beneath the edifice. We explore the possibility that these regions represent lenses of high-salinity brine separated from a single-phase magmatic fluid containing H2O and NaCl. Since chloride-bearing fluids are highly conductive and have an exceptional capacity to transport metals, these regions can be an indication of an active hydrothermal ore-formation beneath volcanoes. To investigate this possibility we have performed hydrodynamic simulations of magma degassing into permeable rock. In our models the magma source is located at 7 km depth and the fluid salinity approximates that expected for fluids released from typical arc magmas. Our model differs from previous models of a similar process because it is (a) axisymmetric and (b) includes a static high-permeability pathway that links the magma source to the surface. This pathway simulates the presence of a volcanic conduit and/or plexus of feeder dykes that are typical of most volcanic systems. The presence of the conduit leads to a number of important hydrodynamic consequences, not observed in previous models. Importantly, we show that an annular brine lens capped by crystallised halite is likely to form above an actively degassing sub-volcanic magma body and can persist for more than 250 kyr after degassing ceases. Parametric analysis shows that brine lenses are more prevalent when the fluid is released at temperatures above the wet granite solidus, when magmatic fluid salinity is high, and when the high-permeability pathway is narrow. The calculated depth, form and electrical conductivity of our modelled system shares many features with published magnetotelluric images of volcano subsurfaces. The formation and persistence of sub-volcanic brine lenses has implications for geothermal systems and hydrothermal ore formation, although these features are not explored in the presented model.

Evaluation of the impact of computed high b-value diffusion-weighted imaging on prostate cancer detection.

PubMed

Verma, Sadhna; Sarkar, Saradwata; Young, Jason; Venkataraman, Rajesh; Yang, Xu; Bhavsar, Anil; Patil, Nilesh; Donovan, James; Gaitonde, Krishnanath

2016-05-01

The purpose of this study was to compare high b-value (b = 2000 s/mm(2)) acquired diffusion-weighted imaging (aDWI) with computed DWI (cDWI) obtained using four diffusion models-mono-exponential (ME), intra-voxel incoherent motion (IVIM), stretched exponential (SE), and diffusional kurtosis (DK)-with respect to lesion visibility, conspicuity, contrast, and ability to predict significant prostate cancer (PCa). Ninety four patients underwent 3 T MRI including acquisition of b = 2000 s/mm(2) aDWI and low b-value DWI. High b = 2000 s/mm(2) cDWI was obtained using ME, IVIM, SE, and DK models. All images were scored on quality independently by three radiologists. Lesions were identified on all images and graded for lesion conspicuity. For a subset of lesions for which pathological truth was established, lesion-to-background contrast ratios (LBCRs) were computed and binomial generalized linear mixed model analysis was conducted to compare clinically significant PCa predictive capabilities of all DWI. For all readers and all models, cDWI demonstrated higher ratings for image quality and lesion conspicuity than aDWI except DK (p < 0.001). The LBCRs of ME, IVIM, and SE were significantly higher than LBCR of aDWI (p < 0.001). Receiver Operating Characteristic curves obtained from binomial generalized linear mixed model analysis demonstrated higher Area Under the Curves for ME, SE, IVIM, and aDWI compared to DK or PSAD alone in predicting significant PCa. High b-value cDWI using ME, IVIM, and SE diffusion models provide better image quality, lesion conspicuity, and increased LBCR than high b-value aDWI. Using cDWI can potentially provide comparable sensitivity and specificity for detecting significant PCa as high b-value aDWI without increased scan times and image degradation artifacts.

Dirac(-Pauli), Fokker-Planck equations and exceptional Laguerre polynomials

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

Ho, Choon-Lin, E-mail: hcl@mail.tku.edu.tw

2011-04-15

Research Highlights: > Physical examples involving exceptional orthogonal polynomials. > Exceptional polynomials as deformations of classical orthogonal polynomials. > Exceptional polynomials from Darboux-Crum transformation. - Abstract: An interesting discovery in the last two years in the field of mathematical physics has been the exceptional X{sub l} Laguerre and Jacobi polynomials. Unlike the well-known classical orthogonal polynomials which start with constant terms, these new polynomials have lowest degree l = 1, 2, and ..., and yet they form complete set with respect to some positive-definite measure. While the mathematical properties of these new X{sub l} polynomials deserve further analysis, it ismore » also of interest to see if they play any role in physical systems. In this paper we indicate some physical models in which these new polynomials appear as the main part of the eigenfunctions. The systems we consider include the Dirac equations coupled minimally and non-minimally with some external fields, and the Fokker-Planck equations. The systems presented here have enlarged the number of exactly solvable physical systems known so far.« less

Exception handling for sensor fusion

NASA Astrophysics Data System (ADS)

Chavez, G. T.; Murphy, Robin R.

1993-08-01

This paper presents a control scheme for handling sensing failures (sensor malfunctions, significant degradations in performance due to changes in the environment, and errant expectations) in sensor fusion for autonomous mobile robots. The advantages of the exception handling mechanism are that it emphasizes a fast response to sensing failures, is able to use only a partial causal model of sensing failure, and leads to a graceful degradation of sensing if the sensing failure cannot be compensated for. The exception handling mechanism consists of two modules: error classification and error recovery. The error classification module in the exception handler attempts to classify the type and source(s) of the error using a modified generate-and-test procedure. If the source of the error is isolated, the error recovery module examines its cache of recovery schemes, which either repair or replace the current sensing configuration. If the failure is due to an error in expectation or cannot be identified, the planner is alerted. Experiments using actual sensor data collected by the CSM Mobile Robotics/Machine Perception Laboratory's Denning mobile robot demonstrate the operation of the exception handling mechanism.

Docking and scoring protein complexes: CAPRI 3rd Edition.

PubMed

Lensink, Marc F; Méndez, Raúl; Wodak, Shoshana J

2007-12-01

The performance of methods for predicting protein-protein interactions at the atomic scale is assessed by evaluating blind predictions performed during 2005-2007 as part of Rounds 6-12 of the community-wide experiment on Critical Assessment of PRedicted Interactions (CAPRI). These Rounds also included a new scoring experiment, where a larger set of models contributed by the predictors was made available to groups developing scoring functions. These groups scored the uploaded set and submitted their own best models for assessment. The structures of nine protein complexes including one homodimer were used as targets. These targets represent biologically relevant interactions involved in gene expression, signal transduction, RNA, or protein processing and membrane maintenance. For all the targets except one, predictions started from the experimentally determined structures of the free (unbound) components or from models derived by homology, making it mandatory for docking methods to model the conformational changes that often accompany association. In total, 63 groups and eight automatic servers, a substantial increase from previous years, submitted docking predictions, of which 1994 were evaluated here. Fifteen groups submitted 305 models for five targets in the scoring experiment. Assessment of the predictions reveals that 31 different groups produced models of acceptable and medium accuracy-but only one high accuracy submission-for all the targets, except the homodimer. In the latter, none of the docking procedures reproduced the large conformational adjustment required for correct assembly, underscoring yet again that handling protein flexibility remains a major challenge. In the scoring experiment, a large fraction of the groups attained the set goal of singling out the correct association modes from incorrect solutions in the limited ensembles of contributed models. But in general they seemed unable to identify the best models, indicating that current scoring methods are probably not sensitive enough. With the increased focus on protein assemblies, in particular by structural genomics efforts, the growing community of CAPRI predictors is engaged more actively than ever in the development of better scoring functions and means of modeling conformational flexibility, which hold promise for much progress in the future. (c) 2007 Wiley-Liss, Inc.

A Model Technology Educator: Thomas A. Edison

ERIC Educational Resources Information Center

Pretzer, William S.; Rogers, George E.; Bush, Jeffery

2007-01-01

Reflecting back over a century ago to the small village of Menlo Park, New Jersey provides insight into a remarkable visionary and an exceptional role model for today's problem-solving and design-focused technology educator: Thomas A. Edison, inventor, innovator, and model technology educator. Since Edison could not simply apply existing knowledge…

A Model Assessment and Classification System for Men and Women in Correctional Institutions.

ERIC Educational Resources Information Center

Hellervik, Lowell W.; And Others

The report describes a manpower assessment and classification system for criminal offenders directed towards making practical training and job classification decisions. The model is not concerned with custody classifications except as they affect occupational/training possibilities. The model combines traditional procedures of vocational…

75 FR 12468 - Airworthiness Directives; Quartz Mountain Aerospace, Inc. Model 11E Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-16

... Aerospace, Inc. Model 11E Airplanes AGENCY: Federal Aviation Administration (FAA), Department of... airworthiness directive (AD) for all Quartz Mountain Aerospace, Inc. Model 11E airplanes. This proposed AD would... 5 p.m., Monday through Friday, except Federal holidays. Quartz Mountain Aerospace, Inc. is in...

The Robustness of LISREL Estimates in Structural Equation Models with Categorical Variables.

ERIC Educational Resources Information Center

Ethington, Corinna A.

1987-01-01

This study examined the effect of type of correlation matrix on the robustness of LISREL maximum likelihood and unweighted least squares structural parameter estimates for models with categorical variables. The analysis of mixed matrices produced estimates that closely approximated the model parameters except where dichotomous variables were…

Relativistic Corrections to the Bohr Model of the Atom

ERIC Educational Resources Information Center

Kraft, David W.

1974-01-01

Presents a simple means for extending the Bohr model to include relativistic corrections using a derivation similar to that for the non-relativistic case, except that the relativistic expressions for mass and kinetic energy are employed. (Author/GS)

In-vitro evaluation of the accuracy of conventional and digital methods of obtaining full-arch dental impressions.

PubMed

Ender, Andreas; Mehl, Albert

2015-01-01

To investigate the accuracy of conventional and digital impression methods used to obtain full-arch impressions by using an in-vitro reference model. Eight different conventional (polyether, POE; vinylsiloxanether, VSE; direct scannable vinylsiloxanether, VSES; and irreversible hydrocolloid, ALG) and digital (CEREC Bluecam, CER; CEREC Omnicam, OC; Cadent iTero, ITE; and Lava COS, LAV) full-arch impressions were obtained from a reference model with a known morphology, using a highly accurate reference scanner. The impressions obtained were then compared with the original geometry of the reference model and within each test group. A point-to-point measurement of the surface of the model using the signed nearest neighbour method resulted in a mean (10%-90%)/2 percentile value for the difference between the impression and original model (trueness) as well as the difference between impressions within a test group (precision). Trueness values ranged from 11.5 μm (VSE) to 60.2 μm (POE), and precision ranged from 12.3 μm (VSE) to 66.7 μm (POE). Among the test groups, VSE, VSES, and CER showed the highest trueness and precision. The deviation pattern varied with the impression method. Conventional impressions showed high accuracy across the full dental arch in all groups, except POE and ALG. Conventional and digital impression methods show differences regarding full-arch accuracy. Digital impression systems reveal higher local deviations of the full-arch model. Digital intraoral impression systems do not show superior accuracy compared to highly accurate conventional impression techniques. However, they provide excellent clinical results within their indications applying the correct scanning technique.

Evaluation of CMIP5 continental precipitation simulations relative to satellite-based gauge-adjusted observations

NASA Astrophysics Data System (ADS)

Mehran, A.; AghaKouchak, A.; Phillips, T. J.

2014-02-01

The objective of this study is to cross-validate 34 Coupled Model Intercomparison Project Phase 5 (CMIP5) historical simulations of precipitation against the Global Precipitation Climatology Project (GPCP) data, quantifying model pattern discrepancies, and biases for both entire distributions and their upper tails. The results of the volumetric hit index (VHI) analysis of the total monthly precipitation amounts show that most CMIP5 simulations are in good agreement with GPCP patterns in many areas but that their replication of observed precipitation over arid regions and certain subcontinental regions (e.g., northern Eurasia, eastern Russia, and central Australia) is problematical. Overall, the VHI of the multimodel ensemble mean and median also are superior to that of the individual CMIP5 models. However, at high quantiles of reference data (75th and 90th percentiles), all climate models display low skill in simulating precipitation, except over North America, the Amazon, and Central Africa. Analyses of total bias (B) in CMIP5 simulations reveal that most models overestimate precipitation over regions of complex topography (e.g., western North and South America and southern Africa and Asia), while underestimating it over arid regions. Also, while most climate model simulations show low biases over Europe, intermodel variations in bias over Australia and Amazonia are considerable. The quantile bias analyses indicate that CMIP5 simulations are even more biased at high quantiles of precipitation. It is found that a simple mean field bias removal improves the overall B and VHI values but does not make a significant improvement at high quantiles of precipitation.

Workshop on the Integration of Finite Element Modeling with Geometric Modeling

NASA Technical Reports Server (NTRS)

Wozny, Michael J.

1987-01-01

The workshop on the Integration of Finite Element Modeling with Geometric Modeling was held on 12 May 1987. It was held to discuss the geometric modeling requirements of the finite element modeling process and to better understand the technical aspects of the integration of these two areas. The 11 papers are presented except for one for which only the abstract is given.

Darboux partners of pseudoscalar Dirac potentials associated with exceptional orthogonal polynomials

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

Schulze-Halberg, Axel, E-mail: xbataxel@gmail.com; Department of Physics, Indiana University Northwest, 3400 Broadway, Gary, IN 46408; Roy, Barnana, E-mail: barnana@isical.ac.in

2014-10-15

We introduce a method for constructing Darboux (or supersymmetric) pairs of pseudoscalar and scalar Dirac potentials that are associated with exceptional orthogonal polynomials. Properties of the transformed potentials and regularity conditions are discussed. As an application, we consider a pseudoscalar Dirac potential related to the Schrödinger model for the rationally extended radial oscillator. The pseudoscalar partner potentials are constructed under the first- and second-order Darboux transformations.

Hydrologic Evaluation of TRMM Multisatellite Precipitation Analysis for Nanliu River Basin in Humid Southwestern China.

PubMed

Zhao, Yinjun; Xie, Qiongying; Lu, Yuan; Hu, Baoqing

2017-06-01

The accuracy of Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis (TMPA) daily accumulated precipitation products (3B42RTV7 and 3B42V7) was evaluated for a small basin (the Nanliu river basin). A direct comparison was performed against gauge observations from a period of 9 years (2000-2009) at temporal and spatial scales. The results show that the temporal-spatial precipitation characteristics of the Nanliu river basin are highly consistent with 3B42V7 relative to 3B42RTV7, with higher correlation coefficient (CC) approximately 0.9 at all temporal scales except for the daily scale and a lower relative bias percentage. 3B42V7 slightly overestimates precipitation at all temporal scales except the yearly scale; it slightly underestimates the precipitation at the daily spatial scale. The results also reveal that the precision of TMPA products increases with longer time-aggregated data, and the detection capability of daily TMPA precipitation products are enhanced by augmentation with daily precipitation rates. In addition, daily TMPA products were input into the Xin'anjiang hydrologic model; the results show that 3B42V7-based simulated outputs were well in line with actual stream flow observations, with a high CC (0.90) and Nash-Sutcliffe efficiency coefficient (NSE, 0.79), and the results adequately captured the pattern of the observed flow curve.

Influence of level of education on disability free life expectancy by sex: the ILSA study.

PubMed

Minicuci, N; Noale, M

2005-12-01

To assess the effect of education on Disability Free Life Expectancy among older Italians, using a hierarchical model as indicator of disability, with estimates based on the multistate life table method and IMaCh software. Data were obtained from the Italian Longitudinal Study on Aging which considered a random sample of 5632 individuals. Total life expectancy ranged from 16.5 years for men aged 65 years to 6 years for men aged 80. The age range for women was 19.6 and 8.4 years, respectively. For both sexes, increasing age was associated with a lower probability of recovery from a mild state of disability, with a greater probability of worsening for all individuals presenting an independent state at baseline, and with a greater probability of dying except for women from a mild state of disability. A medium/high educational level was associated with a greater probability of recovery only in men with a mild state of disability at baseline, and with a lower probability of worsening in both sexes, except for men with a mild state of disability at baseline. The positive effects of high education are well established in most research work and, being a modifiable factor, strategies focused on increasing level of education and, hence strengthening access to information and use of health services would produce significant benefits.

Demand Activated Manufacturing Architecture (DAMA) model for supply chain collaboration

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

CHAPMAN,LEON D.; PETERSEN,MARJORIE B.

The Demand Activated Manufacturing Architecture (DAMA) project during the last five years of work with the U.S. Integrated Textile Complex (retail, apparel, textile, and fiber sectors) has developed an inter-enterprise architecture and collaborative model for supply chains. This model will enable improved collaborative business across any supply chain. The DAMA Model for Supply Chain Collaboration is a high-level model for collaboration to achieve Demand Activated Manufacturing. The five major elements of the architecture to support collaboration are (1) activity or process, (2) information, (3) application, (4) data, and (5) infrastructure. These five elements are tied to the application of themore » DAMA architecture to three phases of collaboration - prepare, pilot, and scale. There are six collaborative activities that may be employed in this model: (1) Develop Business Planning Agreements, (2) Define Products, (3) Forecast and Plan Capacity Commitments, (4) Schedule Product and Product Delivery, (5) Expedite Production and Delivery Exceptions, and (6) Populate Supply Chain Utility. The Supply Chain Utility is a set of applications implemented to support collaborative product definition, forecast visibility, planning, scheduling, and execution. The DAMA architecture and model will be presented along with the process for implementing this DAMA model.« less

Statistical tests to compare motif count exceptionalities

PubMed Central

Robin, Stéphane; Schbath, Sophie; Vandewalle, Vincent

2007-01-01

Background Finding over- or under-represented motifs in biological sequences is now a common task in genomics. Thanks to p-value calculation for motif counts, exceptional motifs are identified and represent candidate functional motifs. The present work addresses the related question of comparing the exceptionality of one motif in two different sequences. Just comparing the motif count p-values in each sequence is indeed not sufficient to decide if this motif is significantly more exceptional in one sequence compared to the other one. A statistical test is required. Results We develop and analyze two statistical tests, an exact binomial one and an asymptotic likelihood ratio test, to decide whether the exceptionality of a given motif is equivalent or significantly different in two sequences of interest. For that purpose, motif occurrences are modeled by Poisson processes, with a special care for overlapping motifs. Both tests can take the sequence compositions into account. As an illustration, we compare the octamer exceptionalities in the Escherichia coli K-12 backbone versus variable strain-specific loops. Conclusion The exact binomial test is particularly adapted for small counts. For large counts, we advise to use the likelihood ratio test which is asymptotic but strongly correlated with the exact binomial test and very simple to use. PMID:17346349

High-frequency techniques for RCS prediction of plate geometries and a physical optics/equivalent currents model for the RCS of trihedral corner reflectors, parts 1 and 2

NASA Technical Reports Server (NTRS)

Balanis, Constantine A.; Polka, Lesley A.; Polycarpou, Anastasis C.

1994-01-01

Formulations for scattering from the coated plate and the coated dihedral corner reflector are included. A coated plate model based upon the Uniform Theory of Diffraction (UTD) for impedance wedges was presented in the last report. In order to resolve inaccuracies and discontinuities in the predicted patterns using the UTD-based model, an improved model that uses more accurate diffraction coefficients is presented. A Physical Optics (PO) model for the coated dihedral corner reflector is presented as an intermediary step in developing a high-frequency model for this structure. The PO model is based upon the reflection coefficients for a metal-backed lossy material. Preliminary PO results for the dihedral corner reflector suggest that, in addition to being much faster computationally, this model may be more accurate than existing moment method (MM) models. An improved Physical Optics (PO)/Equivalent Currents model for modeling the Radar Cross Section (RCS) of both square and triangular, perfectly conducting, trihedral corner reflectors is presented. The new model uses the PO approximation at each reflection for the first- and second-order reflection terms. For the third-order reflection terms, a Geometrical Optics (GO) approximation is used for the first reflection; and PO approximations are used for the remaining reflections. The previously reported model used GO for all reflections except the terminating reflection. Using PO for most of the reflections results in a computationally slower model because many integrations must be performed numerically, but the advantage is that the predicted RCS using the new model is much more accurate. Comparisons between the two PO models, Finite-Difference Time-Domain (FDTD) and experimental data are presented for validation of the new model.

Fermi-LAT observations of the gamma-ray burst GRB 130427A.

PubMed

Ackermann, M; Ajello, M; Asano, K; Atwood, W B; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Bonamente, E; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Burgess, J Michael; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cecchi, C; Chaplin, V; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cleveland, W; Cohen-Tanugi, J; Collazzi, A; Cominsky, L R; Connaughton, V; Conrad, J; Cutini, S; D'Ammando, F; de Angelis, A; DeKlotz, M; de Palma, F; Dermer, C D; Desiante, R; Diekmann, A; Di Venere, L; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Finke, J; Fitzpatrick, G; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gehrels, N; Germani, S; Gibby, M; Giglietto, N; Giles, M; Giordano, F; Giroletti, M; Godfrey, G; Granot, J; Grenier, I A; Grove, J E; Gruber, D; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Horan, D; Hughes, R E; Inoue, Y; Jogler, T; Jóhannesson, G; Johnson, W N; Kawano, T; Knödlseder, J; Kocevski, D; Kuss, M; Lande, J; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mayer, M; Mazziotta, M N; McEnery, J E; Michelson, P F; Mizuno, T; Moiseev, A A; Monzani, M E; Moretti, E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohno, M; Ohsugi, T; Okumura, A; Omodei, N; Orienti, M; Paneque, D; Pelassa, V; Perkins, J S; Pesce-Rollins, M; Petrosian, V; Piron, F; Pivato, G; Porter, T A; Racusin, J L; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Roth, M; Ryde, F; Sartori, A; Parkinson, P M Saz; Scargle, J D; Schulz, A; Sgrò, C; Siskind, E J; Sonbas, E; Spandre, G; Spinelli, P; Tajima, H; Takahashi, H; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Winer, B L; Wood, K S; Yamazaki, R; Younes, G; Yu, H-F; Zhu, S J; Bhat, P N; Briggs, M S; Byrne, D; Foley, S; Goldstein, A; Jenke, P; Kippen, R M; Kouveliotou, C; McBreen, S; Meegan, C; Paciesas, W S; Preece, R; Rau, A; Tierney, D; van der Horst, A J; von Kienlin, A; Wilson-Hodge, C; Xiong, S; Cusumano, G; La Parola, V; Cummings, J R

2014-01-03

The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

[Is there life beyond SPSS? Discover R].

PubMed

Elosua Oliden, Paula

2009-11-01

R is a GNU statistical and programming environment with very high graphical capabilities. It is very powerful for research purposes, but it is also an exceptional tool for teaching. R is composed of more than 1400 packages that allow using it for simple statistics and applying the most complex and most recent formal models. Using graphical interfaces like the Rcommander package, permits working in user-friendly environments which are similar to the graphical environment used by SPSS. This last characteristic allows non-statisticians to overcome the obstacle of accessibility, and it makes R the best tool for teaching. Is there anything better? Open, free, affordable, accessible and always on the cutting edge.

Fermi-LAT Observations of the Gamma-Ray Burst GRB 130427A

DOE PAGES

Ackermann, M.; Ajello, M.; Asano, K.; ...

2013-11-21

The Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources using the observations of the exceptionally bright gamma-ray burst (GRB) 130427A. We found that GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest γ-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock.

Fermi-LAT Observations of the Gamma-Ray Burst GRB 130427A

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Asano, K.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.;

Time trends, environmental factors and genetic basis of semen traits collected in Holstein bulls under commercial conditions.

PubMed

Karoui, Sofiene; Díaz, Clara; Serrano, Magdalena; Cue, Roger; Celorrio, Idoia; Carabaño, María J

2011-03-01

The fact that results of artificial insemination (AI) are declining in highly selected dairy cattle populations has added a renewed interest to the evaluation of male fertility. Data from 42,348 ejaculates collected from 1990 to 2007 on 502 Holstein bulls were analysed in a Bayesian framework to provide estimates of the evolution of semen traits routinely collected in AI centres throughout the last decades of intense selection for production traits and estimate genetic parameters. The traits under consideration were volume (VOL), concentration (CONC), number of spermatozoa per ejaculate (NESPZ), mass motility score (MM), individual motility (IM), and post-thawing motility (PTM). The environmental factors studied were year-season and week of collection, which account for changes in environmental and technical conditions along time, age at collection, ejaculate order, time from previous collection (TPC) and time between collection and freezing (TCF) (only for PTM). Bull's inbreeding coefficient (Fi), bull's permanent environmental and additive genetic effects were also considered. The use of reduced models was evaluated using the Bayes factor. For all the systematic effects tested, strong or very strong evidence in favour of including the effect in the model was obtained, except for Fi for motility traits and TCF for PTM. No systematic time trends for environment or bull effects were observed, except for PTM, which showed an increasing environmental trend, associated with improvements in freezing-thawing protocols. Heritability estimates were moderate (0.16-0.22), except for IM, which presented a low value (0.07). Genetic correlations among motilities and between motilities and CONC were large and positive [0.38-0.87], VOL showed a negative correlation with CONC (-0.13) but with ample HPD 95%. The magnitude of heritabilities would allow an efficient selection if required and grants the use of these traits as indicators of the sperm viability component of bulls breeding soundness. Copyright © 2011 Elsevier B.V. All rights reserved.

Vidicon intensifier

NASA Technical Reports Server (NTRS)

Carpentier, R. P.; Pietrzyk, J. P.; Beyer, R. R.; Kalafut, J. S.

1976-01-01

Computer-designed sensor, consisting of single-stage electrostatically-focused, triode image intensifier, provides high quality imaging characterized by exceptionally low geometric distortion, low shading, and high center-and-corner modulation transfer function.

High-Resolution Coarse-Grained Modeling Using Oriented Coarse-Grained Sites.

PubMed

Haxton, Thomas K

2015-03-10

We introduce a method to bring nearly atomistic resolution to coarse-grained models, and we apply the method to proteins. Using a small number of coarse-grained sites (about one per eight atoms) but assigning an independent three-dimensional orientation to each site, we preferentially integrate out stiff degrees of freedom (bond lengths and angles, as well as dihedral angles in rings) that are accurately approximated by their average values, while retaining soft degrees of freedom (unconstrained dihedral angles) mostly responsible for conformational variability. We demonstrate that our scheme retains nearly atomistic resolution by mapping all experimental protein configurations in the Protein Data Bank onto coarse-grained configurations and then analytically backmapping those configurations back to all-atom configurations. This roundtrip mapping throws away all information associated with the eliminated (stiff) degrees of freedom except for their average values, which we use to construct optimal backmapping functions. Despite the 4:1 reduction in the number of degrees of freedom, we find that heavy atoms move only 0.051 Å on average during the roundtrip mapping, while hydrogens move 0.179 Å on average, an unprecedented combination of efficiency and accuracy among coarse-grained protein models. We discuss the advantages of such a high-resolution model for parametrizing effective interactions and accurately calculating observables through direct or multiscale simulations.

Moisture fluxes towards Switzerland: investigating future changes in CMIP5 climate models

NASA Astrophysics Data System (ADS)

Fazan, Valerie; Martius, Olivia; Martynov, Andrey; Panziera, Luca

2017-04-01

High integrated vapor transport (IVT) in the atmosphere directed perpendicular to the orography is an important proxy for flood related precipitation in many mountainous areas around the world. Here we focus on flood related IVT and its changes in a warmer climate in Switzerland, where most high-impact floods events in the past 30 years were connected to exceptional IVT upstream of the mountains. Our study aims at investigating how these critical IVT values are projected to evolve in the future in a changing climate. The IVT is computed from 15 CMIP5 climate models for the past (1950-2005) and the future (2006-2100) under the RCP 8.5 scenario ("business as usual"). In order to check the accuracy of the models and the effect of the varying resolution, present day IVT from the CMIP5 models is compared with the ERA-Interim reanalysis data (period 1979-2015). A quantile mapping technique is then used to correct biases. The same bias corrections are applied to the future (2006-2100) IVT data. Finally, future changes in extreme IVT are investigated. This includes an analysis of changes in the magnitude and direction of the moisture flux in the different seasons for different regions in Switzerland.

34 CFR 75.219 - Exceptions to the procedures under § 75.217.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false Exceptions to the procedures under § 75.217. 75.219... under the procedures in § 75.217; (b)(1) The application was evaluated under the preceding competition of the program; (2) The application rated high enough to deserve selection under § 75.217; and (3...

Culture optimization for the emergent zooplanktonic model organism Oikopleura dioica

PubMed Central

Bouquet, Jean-Marie; Spriet, Endy; Troedsson, Christofer; Otterå, Helen; Chourrout, Daniel; Thompson, Eric M.

2009-01-01

The pan-global marine appendicularian, Oikopleura dioica, shows considerable promise as a candidate model organism for cross-disciplinary research ranging from chordate genetics and evolution to molecular ecology research. This urochordate, has a simplified anatomical organization, remains transparent throughout an exceptionally short life cycle of less than 1 week and exhibits high fecundity. At 70 Mb, the compact, sequenced genome ranks among the smallest known metazoan genomes, with both gene regulatory and intronic regions highly reduced in size. The organism occupies an important trophic role in marine ecosystems and is a significant contributor to global vertical carbon flux. Among the short list of bona fide biological model organisms, all share the property that they are amenable to long-term maintenance in laboratory cultures. Here, we tested diet regimes, spawn densities and dilutions and seawater treatment, leading to optimization of a detailed culture protocol that permits sustainable long-term maintenance of O. dioica, allowing continuous, uninterrupted production of source material for experimentation. The culture protocol can be quickly adapted in both coastal and inland laboratories and should promote rapid development of the many original research perspectives the animal offers. PMID:19461862

Numerical Modeling of Mixing and Venting from Explosions in Bunkers

NASA Astrophysics Data System (ADS)

Liu, Benjamin

2005-07-01

2D and 3D numerical simulations were performed to study the dynamic interaction of explosion products in a concrete bunker with ambient air, stored chemical or biological warfare (CBW) agent simulant, and the surrounding walls and structure. The simulations were carried out with GEODYN, a multi-material, Godunov-based Eulerian code, that employs adaptive mesh refinement and runs efficiently on massively parallel computer platforms. Tabular equations of state were used for all materials with the exception of any high explosives employed, which were characterized with conventional JWL models. An appropriate constitutive model was used to describe the concrete. Interfaces between materials were either tracked with a volume-of-fluid method that used high-order reconstruction to specify the interface location and orientation, or a capturing approach was employed with the assumption of local thermal and mechanical equilibrium. A major focus of the study was to estimate the extent of agent heating that could be obtained prior to venting of the bunker and resultant agent dispersal. Parameters investigated included the bunker construction, agent layout, energy density in the bunker and the yield-to-agent mass ratio. Turbulent mixing was found to be the dominant heat transfer mechanism for heating the agent.

Atomistic modeling of interphases in spider silk fibers

NASA Astrophysics Data System (ADS)

Fossey, Stephen Andrew

The objective of this work is to create an atomistic model to account for the unusual physical properties of silk fibers. Silk fibers have exceptional mechanical toughness, which makes them of interest as high performance fibers. In order to explain the toughness, a model for the molecular structure based on simple geometric reasoning was formulated. The model consists of very small crystallites, on the order of 5 nm, connected by a noncrystalline interphase. The interphase is a region between the crystalline phase and the amorphous phase, which is defined by the geometry of the system. The interphase is modeled as a very thin (<5 nm) film of noncrystalline polymer constructed using a Monte Carlo, rotational isomeric states approach followed by simulated annealing in order to achieve equilibrium chain configurations and density. No additional assumptions are made about density, orientation, or packing. The mechanical properties of the interphase are calculated using the method of Theodoreau and Suter. Finally, observable properties such as wide angle X-ray scattering and methyl rotation rates are calculated and compared with experimental data available in the literature.

Forecasting runout of rock and debris avalanches

USGS Publications Warehouse

Iverson, Richard M.; Evans, S.G.; Mugnozza, G.S.; Strom, A.; Hermanns, R.L.

2006-01-01

Physically based mathematical models and statistically based empirical equations each may provide useful means of forecasting runout of rock and debris avalanches. This paper compares the foundations, strengths, and limitations of a physically based model and a statistically based forecasting method, both of which were developed to predict runout across three-dimensional topography. The chief advantage of the physically based model results from its ties to physical conservation laws and well-tested axioms of soil and rock mechanics, such as the Coulomb friction rule and effective-stress principle. The output of this model provides detailed information about the dynamics of avalanche runout, at the expense of high demands for accurate input data, numerical computation, and experimental testing. In comparison, the statistical method requires relatively modest computation and no input data except identification of prospective avalanche source areas and a range of postulated avalanche volumes. Like the physically based model, the statistical method yields maps of predicted runout, but it provides no information on runout dynamics. Although the two methods differ significantly in their structure and objectives, insights gained from one method can aid refinement of the other.

Synchronicity in predictive modelling: a new view of data assimilation

NASA Astrophysics Data System (ADS)

Duane, G. S.; Tribbia, J. J.; Weiss, J. B.

2006-11-01

The problem of data assimilation can be viewed as one of synchronizing two dynamical systems, one representing "truth" and the other representing "model", with a unidirectional flow of information between the two. Synchronization of truth and model defines a general view of data assimilation, as machine perception, that is reminiscent of the Jung-Pauli notion of synchronicity between matter and mind. The dynamical systems paradigm of the synchronization of a pair of loosely coupled chaotic systems is expected to be useful because quasi-2D geophysical fluid models have been shown to synchronize when only medium-scale modes are coupled. The synchronization approach is equivalent to standard approaches based on least-squares optimization, including Kalman filtering, except in highly non-linear regions of state space where observational noise links regimes with qualitatively different dynamics. The synchronization approach is used to calculate covariance inflation factors from parameters describing the bimodality of a one-dimensional system. The factors agree in overall magnitude with those used in operational practice on an ad hoc basis. The calculation is robust against the introduction of stochastic model error arising from unresolved scales.

Fuel-air mixing and combustion in a two-dimensional Wankel engine

NASA Technical Reports Server (NTRS)

Shih, T. I.-P.; Schock, H. J.; Ramos, J. I.

1987-01-01

A two-equation turbulence model, an algebraic grid generalization method, and an approximate factorization time-linearized numerical technique are used to study the effects of mixture stratification at the intake port and gaseous fuel injection on the flow field and fuel-air mixing in a two-dimensional rotary engine model. The fuel distribution in the combustion chamber is found to be a function of the air-fuel mixture fluctuations at the intake port. It is shown that the fuel is advected by the flow field induced by the rotor and is concentrated near the leading apex during the intake stroke, while during compression, the fuel concentration is highest near the trailing apex and is lowest near the rotor. It is also found that the fuel concentration near the trailing apex and rotor is small except at high injection velocities.

Empathy and nonattachment independently predict peer nominations of prosocial behavior of adolescents

PubMed Central

Sahdra, Baljinder K.; Ciarrochi, Joseph; Parker, Philip D.; Marshall, Sarah; Heaven, Patrick

2015-01-01

There is a plethora of research showing that empathy promotes prosocial behavior among young people. We examined a relatively new construct in the mindfulness literature, nonattachment, defined as a flexible way of relating to one's experiences without clinging to or suppressing them. We tested whether nonattachment could predict prosociality above and beyond empathy. Nonattachment implies high cognitive flexibility and sufficient mental resources to step out of excessive self-cherishing to be there for others in need. Multilevel Poisson models using a sample of 15-year olds (N = 1831) showed that empathy and nonattachment independently predicted prosocial behaviors of helpfulness and kindness, as judged by same-sex and opposite-sex peers, except for when boys nominated girls. The effects of nonattachment remained substantial in more conservative models including self-esteem and peer nominations of liking. PMID:25852590

Efficient Flowline Simulations of Ice Shelf-Ocean Interactions: Sensitivity Studies with a Fully Coupled Model

NASA Technical Reports Server (NTRS)

Walker, Ryan Thomas; Holland, David; Parizek, Byron R.; Alley, Richard B.; Nowicki, Sophie M. J.; Jenkins, Adrian

2013-01-01

Thermodynamic flowline and plume models for the ice shelf-ocean system simplify the ice and ocean dynamics sufficiently to allow extensive exploration of parameters affecting ice-sheet stability while including key physical processes. Comparison between geophysically and laboratory-based treatments of ice-ocean interface thermodynamics shows reasonable agreement between calculated melt rates, except where steep basal slopes and relatively high ocean temperatures are present. Results are especially sensitive to the poorly known drag coefficient, highlighting the need for additional field experiments to constrain its value. These experiments also suggest that if the ice-ocean interface near the grounding line is steeper than some threshold, further steepening of the slope may drive higher entrainment that limits buoyancy, slowing the plume and reducing melting; if confirmed, this will provide a stabilizing feedback on ice sheets under some circumstances.

Transport of Ice on the Surface of Iapetus

NASA Astrophysics Data System (ADS)

Galuba, Götz G.

2014-11-01

The global black-and-white dichotomy as well as the dark floors and rims of equatorial craters on the Saturnian moon Iapetus can be explained by ice migration driven by a thermal feedback [1]. All icy moons in the Jovian and Saturnian systems are - with the exception of Titan - airless bodies. Yet it is unique, how these two types of surface features on Iapetus look. A physical model of the processes of absorption, sublimation and deposition was developed and a computational model that simulates ice migration of volatiles under these circumstances derived. The model tessellates the surfaces of an airless body into triangles of equal size that can each have different surface properties. These properties evolve while the model simulates a long-term development. A rate network of net migration is calculated from sublimation and redeposition under the assumptions ofa. a slowly rotating bodyb. undisturbed ballistic molecular trajectoriesc. isotropic emissiond. Maxwellian speed distributione. high sticking coefficients of the surfaces.The assumptions (b.) to (e.) are equally valid for all bigger outer solar system icy moons (except Titan). The very first assumption however is not equally valid throughout the moons of the outer solar system. Callisto being in many regards similar to Iapetus still has a five times higher rotation rate. So global effects depending on slow rotation are more profound on Iapetus. The computer model is complemented by a model for local ice migration from craters.First results show, that the global timescale of albedo change in our model is of the same order of magnitude as in the supporting material to [1] with a tendency towards slightly faster 2 Gyr instead of ~2.4 Gyr) darkening compared to the "Model B". The time rate of local crater darkening rates lies between the global darkening rate and rate of the opposing brightening effect as estimated in [2] to (τ between 10 and 100 MYr).[1] Formation of Iapetus’ Extreme Albedo Dichotomy by Exogenically Triggered Thermal Ice Migration, John R. Spencer , Tilmann Denk, Science 22, Vol. 327, January 2010.[2] Iapetus: Unique Surface Properties and a Global Color Dichotomy from Cassini Imaging T. Denk et al., Science 22, Vol. 327, January 2010.

Incorporating Cancer Stem Cells in Radiation Therapy Treatment Response Modeling and the Implication in Glioblastoma Multiforme Treatment Resistance

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

Yu, Victoria Y.; Nguyen, Dan; Pajonk, Frank

Purpose: To perform a preliminary exploration with a simplistic mathematical cancer stem cell (CSC) interaction model to determine whether the tumor-intrinsic heterogeneity and dynamic equilibrium between CSCs and differentiated cancer cells (DCCs) can better explain radiation therapy treatment response with a dual-compartment linear-quadratic (DLQ) model. Methods and Materials: The radiosensitivity parameters of CSCs and DCCs for cancer cell lines including glioblastoma multiforme (GBM), non–small cell lung cancer, melanoma, osteosarcoma, and prostate, cervical, and breast cancer were determined by performing robust least-square fitting using the DLQ model on published clonogenic survival data. Fitting performance was compared with the single-compartment LQ (SLQ) and universalmore » survival curve models. The fitting results were then used in an ordinary differential equation describing the kinetics of DCCs and CSCs in response to 2- to 14.3-Gy fractionated treatments. The total dose to achieve tumor control and the fraction size that achieved the least normal biological equivalent dose were calculated. Results: Smaller cell survival fitting errors were observed using DLQ, with the exception of melanoma, which had a low α/β = 0.16 in SLQ. Ordinary differential equation simulation indicated lower normal tissue biological equivalent dose to achieve the same tumor control with a hypofractionated approach for 4 cell lines for the DLQ model, in contrast to SLQ, which favored 2 Gy per fraction for all cells except melanoma. The DLQ model indicated greater tumor radioresistance than SLQ, but the radioresistance was overcome by hypofractionation, other than the GBM cells, which responded poorly to all fractionations. Conclusion: The distinct radiosensitivity and dynamics between CSCs and DCCs in radiation therapy response could perhaps be one possible explanation for the heterogeneous intertumor response to hypofractionation and in some cases superior outcome from stereotactic ablative radiation therapy. The DLQ model also predicted the remarkable GBM radioresistance, a result that is highly consistent with clinical observations. The radioresistance putatively stemmed from accelerated DCC regrowth that rapidly restored compartmental equilibrium between CSCs and DCCs.« less

Design concepts for a high-impedance narrow-band 42 GHz power TWT using a fundamental/forward ladder-based circuit

NASA Technical Reports Server (NTRS)

Karp, A.

1980-01-01

A low-cost, narrowband, millimeter wave space communications TWT design was studied. Cold test interaction structure scale models were investigated and analyses were undertaken to predict the electrical and thermal response of the hypothetical 200 W TWT at 42 GHz and 21 kV beam voltage. An intentionally narrow instantaneous bandwidth (1%, with the possibility of electronic tuning of the center frequency over several percent) was sought with a highly dispersive, high impedance "forward wave' interaction structure based on a ladder (for economy in fabrication) and nonspace harmonic interaction, for a high gain rate and a short, economically focused tube. The "TunneLadder' interaction structure devised combines ladder properties with accommodation for a pencil beam. Except for the impedance and bandwidth, there is much in common with the millimeter wave helix TWTs which provided the ideal of diamond support rods. The benefits of these are enhanced in the TunneLadder case because of spatial separation of beam interception and RF current heating.

Work ability in nursing: relationship with psychological demands and control over the work.

PubMed

Prochnow, Andrea; Magnago, Tânia Solange Bosi de Souza; Urbanetto, Janete de Souza; Beck, Carmem Lúcia Colomé; Lima, Suzinara Beatriz Soares de; Greco, Patrícia Bitencourt Toscani

2013-01-01

to evaluate the association between psychological demands, control over the work and the reduction of work ability of nursing professionals. this cross-sectional study involved 498 nursing professionals of a university hospital in the State of Rio Grande do Sul, Brazil. Data collection was carried out in 2009 using the Brazilian versions of the Work Ability Index and Job Stress Scale, with logistic regression models used for the data analysis. the prevalence of 43.3% for reduced work ability and 29.7% for high-strain in the job (high psychological demand and low control) were observed. The chances for professionals presenting reduced work ability under high-strain were higher and significant when compared to those classified as being under low-strain, even after adjusting for potential confounders, except for age and gender. a high prevalence of reduced work ability was observed. This evidence indicates the need for investigation and detailed analysis of the psychosocial aspects of the professionals with regard to the health/disease process of nursing professionals.

The Birth and Death of Redundancy in Decoherence and Quantum Darwinism

NASA Astrophysics Data System (ADS)

Riedel, Charles; Zurek, Wojciech; Zwolak, Michael

2012-02-01

Understanding the quantum-classical transition and the identification of a preferred classical domain through quantum Darwinism is based on recognizing high-redundancy states as both ubiquitous and exceptional. They are produced ubiquitously during decoherence, as has been demonstrated by the recent identification of very general conditions under which high-redundancy states develop. They are exceptional in that high-redundancy states occupy a very narrow corner of the global Hilbert space; states selected at random are overwelming likely to exhibit zero redundancy. In this letter, we examine the conditions and time scales for the transition from high-redundancy states to zero-redundancy states in many-body dynamics. We identify sufficient condition for the development of redundancy from product states and show that the destruction of redundancy can be accomplished even with highly constrained interactions.

Rapid high-amplitude circumferential slow wave propagation during normal gastric pacemaking and dysrhythmias

PubMed Central

O'Grady, Gregory; Du, Peng; Paskaranandavadivel, Nira; Angeli, Timothy R.; Lammers, Wim JEP; Asirvatham, Samuel J.; Windsor, John A.; Farrugia, Gianrico; Pullan, Andrew J.; Cheng, Leo K.

2012-01-01

Background Gastric slow waves propagate aborally as rings of excitation. Circumferential propagation does not normally occur, except at the pacemaker region. We hypothesized that: i) the unexplained high-velocity, high-amplitude activity associated with the pacemaker region is a consequence of circumferential propagation; ii) rapid, high-amplitude circumferential propagation emerges during gastric dysrhythmias; iii) the driving network conductance might switch between ICC-MP and circular ICC-IM during circumferential propagation; iv) extracellular amplitudes and velocities are correlated. Methods An experimental-theoretical study was performed. HR gastric mapping was performed in pigs during normal activation, pacing and dysrhythmia. Activation profiles, velocities and amplitudes were quantified. ICC pathways were theoretically evaluated in a bidomain model. Extracellular potentials were modelled as a function of membrane potentials. Key Results High-velocity, high-amplitude activation was only recorded in the pacemaker region when circumferential conduction occurred. Circumferential propagation accompanied dysrhythmia in 8/8 experiments, was faster than longitudinal propagation (8.9 vs 6.9 mm/s; p=0.004), and of higher amplitude (739 vs 528 μV; p=0.007). Simulations predicted that ICC-MP could be the driving network during longitudinal propagation, whereas during ectopic pacemaking, ICC-IM could outpace and activate ICC-MP in the circumferential axis. Experimental and modeling data demonstrated a linear relationship between velocities and amplitudes (p<0.001). Conclusions & Inferences The high-velocity and high-amplitude profile of the normal pacemaker region is due to localized circumferential propagation. Rapid circumferential propagation also emerges during a range of gastric dysrhythmias, elevating extracellular amplitudes and organizing transverse wavefronts. One possible explanation for these findings is bidirectional coupling between ICC-MP and circular ICC-IM networks. PMID:22709238

A CCIR aeronautical mobile satellite report

NASA Technical Reports Server (NTRS)

Davarian, Faramaz; Bishop, Dennis; Rogers, David; Smith, Ernest K.

1989-01-01

Propagation effects in the aeronautical mobile-satellite service differ from those in the fixed-satellite service and other mobile-satellite services because: small antennas are used on aircraft, and the aircraft body may affect the performance of the antenna; high aircraft speeds cause large Doppler spreads; aircraft terminals must accommodate a large dynamic range in transmission and reception; and due to their high speeds, banking maneuvers, and three-dimensional operation, aircraft routinely require exceptionally high integrity of communications, making even short-term propagation effects very important. Data and models specifically required to characterize the path impairments are discussed, which include: tropospheric effects, including gaseous attenuation, cloud and rain attenuation, fog attenuation, refraction and scintillation; surface reflection (multipath) effects; ionospheric effects such as scintillation; and environmental effects (aircraft motion, sea state, land surface type). Aeronautical mobile-satellite systems may operate on a worldwide basis, including propagation paths at low elevation angles. Several measurements of multipath parameters over land and sea were conducted. In some cases, laboratory simulations are used to compare measured data and verify model parameters. The received signals is considered in terms of its possible components: a direct wave subject to atmospheric effects, and a reflected wave, which generally contains mostly a diffuse component.

New Coumarin Derivatives as Potent Selective COX-2 Inhibitors: Synthesis, Anti-Inflammatory, QSAR, and Molecular Modeling Studies.

PubMed

Dawood, Dina H; Batran, Rasha Z; Farghaly, Thoraya A; Khedr, Mohammed A; Abdulla, Mohamed M

2015-12-01

Two new series of coumarin derivatives incorporating thiazoline and thiazolidinone moieties were designed, synthesized, and investigated in vivo for their anti-inflammatory activities using the carrageenan-induced rat paw edema model and in vitro for their inhibitory activities against the human cyclooxygenase (COX)-1 and COX-2 isoforms. Most of the synthesized compounds demonstrated exceptionally high in vivo anti-inflammatory activity and displayed superior GI safety profiles (0-7% ulceration) as compared to indomethacin. All the bioactive compounds showed in vitro high affinity and selectivity toward the COX-2 isoenzyme, compared to the reference celecoxib with IC50 values ranging from 0.31 to 0.78 μM. The ethyl thiosemicarbazone 2b, thiazoline derivatives 3a, 3b, 5b, 6a, and 7f, and the thiazolidinone compounds 8b and 9a showed the highest in vivo and in vitro anti-inflammatory activities with remarkable COX-2 selectivity. Quantitative structure-activity relationship study (QSAR) was done and resulted in a highly predictive power R(2) (0.908). A molecular docking study revealed a relationship between the docking affinity and the biological results. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

42 CFR § 414.1420 - Other payer advanced APMs.

Code of Federal Regulations, 2010 CFR

2017-10-01

... Merit-Based Incentive Payment System and Alternative Payment Model Incentive § 414.1420 Other payer... payment by the APM Entity to the payer. (2) Medicaid Medical Home Model financial risk standard. For an... APM benchmark, except for episode payment models, for which it is defined as the episode target price...

The role of production and teamwork practices in construction safety: a cognitive model and an empirical case study.

PubMed

Mitropoulos, Panagiotis Takis; Cupido, Gerardo

2009-01-01

In construction, the challenge for researchers and practitioners is to develop work systems (production processes and teams) that can achieve high productivity and high safety at the same time. However, construction accident causation models ignore the role of work practices and teamwork. This study investigates the mechanisms by which production and teamwork practices affect the likelihood of accidents. The paper synthesizes a new model for construction safety based on the cognitive perspective (Fuller's Task-Demand-Capability Interface model, 2005) and then presents an exploratory case study. The case study investigates and compares the work practices of two residential framing crews: a 'High Reliability Crew' (HRC)--that is, a crew with exceptional productivity and safety over several years, and an average performing crew from the same company. The model explains how the production and teamwork practices generate the work situations that workers face (the task demands) and affect the workers ability to cope (capabilities). The case study indicates that the work practices of the HRC directly influence the task demands and match them with the applied capabilities. These practices were guided by the 'principle' of avoiding errors and rework and included work planning and preparation, work distribution, managing the production pressures, and quality and behavior monitoring. The Task Demand-Capability model links construction research to a cognitive model of accident causation and provides a new way to conceptualize safety as an emergent property of the production practices and teamwork processes. The empirical evidence indicates that the crews' work practices and team processes strongly affect the task demands, the applied capabilities, and the match between demands and capabilities. The proposed model and the exploratory case study will guide further discovery of work practices and teamwork processes that can increase both productivity and safety in construction operations. Such understanding will enable training of construction foremen and crews in these practices to systematically develop high reliability crews.

CryoSat-2 altimetry derived Arctic bathymetry map: first results and validation

NASA Astrophysics Data System (ADS)

Andersen, O. B.; Abulaitijiang, A.; Cancet, M.; Knudsen, P.

2017-12-01

The Technical University of Denmark (DTU), DTU Space has been developing high quality high resolution gravity fields including the new highly accurate CryoSat-2 radar altimetry satellite data which extends the global coverage of altimetry data up to latitude 88°. With its exceptional Synthetic Aperture Radar (SAR) mode being operating throughout the Arctic Ocean, leads, i.e., the ocean surface heights, is used to retrieve the sea surface height with centimeter-level range precision. Combined with the long repeat cycle ( 369 days), i.e., dense cross-track coverage, the high-resolution Arctic marine gravity can be modelled using the CryoSat-2 altimetry. Further, the polar gap can be filled by the available ArcGP product, thus yielding the complete map of the Arctic bathymetry map. In this presentation, we will make use of the most recent DTU17 marine gravity, to derive the arctic bathymetry map using inversion based on best available hydrographic maps. Through the support of ESA a recent evaluation of existing hydrographic models of the Arctic Ocean Bathymetry models (RTOPO, GEBCO, IBCAO etc) and various inconsistencies have been identified and means to rectify these inconsistencies have been taken prior to perform the inversion using altimetry. Simultaneously DTU Space has been placing great effort on the Arctic data screening, filtering, and de-noising using various altimetry retracking solutions and classifications. All the pre-processing contributed to the fine modelling of Actic gravity map. Thereafter, the arctic marine gravity grids will eventually be translated (downward continuation operation) to a new altimetry enhanced Arctic bathymetry map using appropriate band-pass filtering.

A hybrid finite element - statistical energy analysis approach to robust sound transmission modeling

NASA Astrophysics Data System (ADS)

Reynders, Edwin; Langley, Robin S.; Dijckmans, Arne; Vermeir, Gerrit

2014-09-01

When considering the sound transmission through a wall in between two rooms, in an important part of the audio frequency range, the local response of the rooms is highly sensitive to uncertainty in spatial variations in geometry, material properties and boundary conditions, which have a wave scattering effect, while the local response of the wall is rather insensitive to such uncertainty. For this mid-frequency range, a computationally efficient modeling strategy is adopted that accounts for this uncertainty. The partitioning wall is modeled deterministically, e.g. with finite elements. The rooms are modeled in a very efficient, nonparametric stochastic way, as in statistical energy analysis. All components are coupled by means of a rigorous power balance. This hybrid strategy is extended so that the mean and variance of the sound transmission loss can be computed as well as the transition frequency that loosely marks the boundary between low- and high-frequency behavior of a vibro-acoustic component. The method is first validated in a simulation study, and then applied for predicting the airborne sound insulation of a series of partition walls of increasing complexity: a thin plastic plate, a wall consisting of gypsum blocks, a thicker masonry wall and a double glazing. It is found that the uncertainty caused by random scattering is important except at very high frequencies, where the modal overlap of the rooms is very high. The results are compared with laboratory measurements, and both are found to agree within the prediction uncertainty in the considered frequency range.

An R2 statistic for fixed effects in the linear mixed model.

PubMed

Edwards, Lloyd J; Muller, Keith E; Wolfinger, Russell D; Qaqish, Bahjat F; Schabenberger, Oliver

2008-12-20

Statisticians most often use the linear mixed model to analyze Gaussian longitudinal data. The value and familiarity of the R(2) statistic in the linear univariate model naturally creates great interest in extending it to the linear mixed model. We define and describe how to compute a model R(2) statistic for the linear mixed model by using only a single model. The proposed R(2) statistic measures multivariate association between the repeated outcomes and the fixed effects in the linear mixed model. The R(2) statistic arises as a 1-1 function of an appropriate F statistic for testing all fixed effects (except typically the intercept) in a full model. The statistic compares the full model with a null model with all fixed effects deleted (except typically the intercept) while retaining exactly the same covariance structure. Furthermore, the R(2) statistic leads immediately to a natural definition of a partial R(2) statistic. A mixed model in which ethnicity gives a very small p-value as a longitudinal predictor of blood pressure (BP) compellingly illustrates the value of the statistic. In sharp contrast to the extreme p-value, a very small R(2) , a measure of statistical and scientific importance, indicates that ethnicity has an almost negligible association with the repeated BP outcomes for the study.

Human factors evaluation of the HL-20 full-scale model

NASA Astrophysics Data System (ADS)

Willshire, Kelli F.; Simonsen, Lisa C.; Willshire, William L., Jr.

1993-09-01

The human factors testing of the HL-20 personnel launch system full-scale model was conducted in both the vertical and horizontal positions at NASA Langley Research Center. Three main areas of testing were considered: an anthropometric fit evaluation, the ingress and egress of a 10-person crew, and pilot viewing. The subjects, ranging from the 5th to 95th percentile size, had sufficient clearance in the model, with the exception of the last two rows of seats and the cockpit area. Adjustable seat heights and/or placement of the seats farther forward would provide more headroom. In the horizontal position, the model's seat placement and aisle width allowed a quick and orderly 10-person egress for the no-keel (a structural support running the length on the aisle), 6-in.-high keel, and 12-in.-high keel conditions. Egress times were less than 20 s. For the vertical position, the model's long cylindrical shape with the ladder in the ceiling allowed a quick and orderly egress with average times less than 30 s. Ingress and egress procedures were demonstrated using shuttle partial-pressure suits. The reduced mobility experienced while wearing the suits did increase egress times, although they still remained acceptable. The window arrangement for pilot viewing was found to be reasonably acceptable, although slight modifications, such as an increased downward view, is desirable.

Nonlinear autoregressive neural networks with external inputs for forecasting of typhoon inundation level.

PubMed

Ouyang, Huei-Tau

2017-08-01

Accurate inundation level forecasting during typhoon invasion is crucial for organizing response actions such as the evacuation of people from areas that could potentially flood. This paper explores the ability of nonlinear autoregressive neural networks with exogenous inputs (NARX) to predict inundation levels induced by typhoons. Two types of NARX architecture were employed: series-parallel (NARX-S) and parallel (NARX-P). Based on cross-correlation analysis of rainfall and water-level data from historical typhoon records, 10 NARX models (five of each architecture type) were constructed. The forecasting ability of each model was assessed by considering coefficient of efficiency (CE), relative time shift error (RTS), and peak water-level error (PE). The results revealed that high CE performance could be achieved by employing more model input variables. Comparisons of the two types of model demonstrated that the NARX-S models outperformed the NARX-P models in terms of CE and RTS, whereas both performed exceptionally in terms of PE and without significant difference. The NARX-S and NARX-P models with the highest overall performance were identified and their predictions were compared with those of traditional ARX-based models. The NARX-S model outperformed the ARX-based models in all three indexes, whereas the NARX-P model exhibited comparable CE performance and superior RTS and PE performance.

Developing a diagnostic model for estimating terrestrial vegetation gross primary productivity using the photosynthetic quantum yield and Earth Observation data.

PubMed

Ogutu, Booker O; Dash, Jadunandan; Dawson, Terence P

2013-09-01

This article develops a new carbon exchange diagnostic model [i.e. Southampton CARbon Flux (SCARF) model] for estimating daily gross primary productivity (GPP). The model exploits the maximum quantum yields of two key photosynthetic pathways (i.e. C3 and C4 ) to estimate the conversion of absorbed photosynthetically active radiation into GPP. Furthermore, this is the first model to use only the fraction of photosynthetically active radiation absorbed by photosynthetic elements of the canopy (i.e. FAPARps ) rather than total canopy, to predict GPP. The GPP predicted by the SCARF model was comparable to in situ GPP measurements (R(2)  > 0.7) in most of the evaluated biomes. Overall, the SCARF model predicted high GPP in regions dominated by forests and croplands, and low GPP in shrublands and dry-grasslands across USA and Europe. The spatial distribution of GPP from the SCARF model over Europe and conterminous USA was comparable to those from the MOD17 GPP product except in regions dominated by croplands. The SCARF model GPP predictions were positively correlated (R(2)  > 0.5) to climatic and biophysical input variables indicating its sensitivity to factors controlling vegetation productivity. The new model has three advantages, first, it prescribes only two quantum yield terms rather than species specific light use efficiency terms; second, it uses only the fraction of PAR absorbed by photosynthetic elements of the canopy (FAPARps ) hence capturing the actual PAR used in photosynthesis; and third, it does not need a detailed land cover map that is a major source of uncertainty in most remote sensing based GPP models. The Sentinel satellites planned for launch in 2014 by the European Space Agency have adequate spectral channels to derive FAPARps at relatively high spatial resolution (20 m). This provides a unique opportunity to produce global GPP operationally using the Southampton CARbon Flux (SCARF) model at high spatial resolution. © 2013 John Wiley & Sons Ltd.

Middle atmospheric ozone, nitrogen dioxide and nitrogen trioxide in 2002-2011: SD-WACCM simulations compared to GOMOS observations

NASA Astrophysics Data System (ADS)

Kyrölä, Erkki; Andersson, Monika E.; Verronen, Pekka T.; Laine, Marko; Tukiainen, Simo; Marsh, Daniel R.

2018-04-01

Most of our understanding of the atmosphere is based on observations and their comparison with model simulations. In middle atmosphere studies it is common practice to use an approach, where the model dynamics are at least partly based on temperature and wind fields from an external meteorological model. In this work we test how closely satellite measurements of a few central trace gases agree with this kind of model simulation. We use collocated vertical profiles where each satellite measurement is compared to the closest model data. We compare profiles and distributions of O3, NO2 and NO3 from the Global Ozone Monitoring by Occultation of Stars instrument (GOMOS) on the Envisat satellite with simulations by the Whole Atmosphere Community Climate Model (WACCM). GOMOS measurements are from nighttime. Our comparisons show that in the stratosphere outside the polar regions differences in ozone between WACCM and GOMOS are small, between 0 and 6%. The correlation of 5-day time series show a very high 0.9-0.95. In the tropical region 10° S-10° N below 10 hPa WACCM values are up to 20 % larger than GOMOS. In the Arctic below 6 hPa WACCM ozone values are up to 20 % larger than GOMOS. In the mesosphere between 0.04 and 1 hPa the WACCM is at most 20 % smaller than GOMOS. Above the ozone minimum at 0.01 hPa (or 80 km) large differences are found between WACCM and GOMOS. The correlation can still be high, but at the second ozone peak the correlation falls strongly and the ozone abundance from WACCM is about 60 % smaller than that from GOMOS. The total ozone columns (above 50 hPa) of GOMOS and WACCM agree within ±2 % except in the Arctic where WACCM is 10 % larger than GOMOS. Outside the polar areas and in the validity region of GOMOS NO2 measurements (0.3-37 hPa) WACCM and GOMOS NO2 agree within -5 to +25 % and the correlation is high (0.7-0.95) except in the upper stratosphere at the southern latitudes. In the polar areas, where solar particle precipitation and downward transport from the thermosphere enhance NO2 abundance, large differences up to -90 % are found between WACCM and GOMOS NO2 and the correlation varies between 0.3 and 0.9. For NO3, we find that the WACCM and GOMOS difference is between -20 and 5 % with a very high correlation of 0.7-0.95. We show that NO3 values strongly depend on temperature and the dependency can be fitted by the exponential function of temperature. The ratio of NO3 to O3 from WACCM and GOMOS closely follow the prediction from the equilibrium chemical theory. Abrupt temperature increases from sudden stratospheric warmings (SSWs) are reflected as sudden enhancements of WACCM and GOMOS NO3 values.

An Assessment of the Models to Predict Pavement Performance

DOT National Transportation Integrated Search

2018-03-23

Data collected by the Iowa Department of Transportation (DOT) regarding road conditions across the state of Iowa were used to model pavement condition index (PCI). The data were for calendar year 2013, with the exception of updated PCI values from 20...

40 CFR 600.511-80 - Determination of domestic production.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Regulations for Model Year 1978 Passenger Automobiles and for 1979 and Later Model Year Automobiles (Light Trucks and Passenger Automobiles)-Procedures for Determining Manufacturer's Average Fuel Economy and...) Except with advance approval of the Administrator, an automobile shall be considered domestically...

Differential immune gene expression profiles in susceptible and resistant full-sibling families of Atlantic salmon (Salmo salar) challenged with infectious pancreatic necrosis virus (IPNV).

PubMed

Reyes-López, Felipe E; Romeo, Jose S; Vallejos-Vidal, Eva; Reyes-Cerpa, Sebastián; Sandino, Ana M; Tort, Lluis; Mackenzie, Simon; Imarai, Mónica

2015-11-01

This study aims to identify at the expression level the immune-related genes associated with IPN-susceptible and resistant phenotypes in Atlantic salmon full-sibling families. We have analyzed thirty full-sibling families infected by immersion with IPNV and then classified as resistant or susceptible using a multivariate survival analysis based on a gamma-Cox frailty model and the Kaplan-Meier mortality curves. In four families within each group head kidneys were pooled for real-time PCR and one-color salmon-specific oligonucleotide microarray (21K) analysis at day 1 and 5 post-infection. Transcripts involved in innate response (IL-6, IFN-α), antigen presentation (HSP-70, HSP-90, MHC-I), TH1 response (IL-12, IFN-γ, CRFB6), immunosuppression (IL-10, TGF-β1) and leukocyte activation and migration (CCL-19, CD18) showed a differential expression pattern between both phenotypes, except in IL-6. In susceptible families, except for IFN-γ, the expressions dropped to basal values at day 5 post-infection. In resistant families, unlike susceptible families, levels remained high or increased (except for IL-6) at day 5. Transcriptomic analysis showed that both families have a clear differential expression pattern, resulting in a marked down-regulation in immune related genes involved in innate response, complement system, antigen recognition and activation of immune response in IPN-resistant. Down-regulation of genes, mainly related to tissue differentiation and protein degradation metabolism, was also observed in resistant families. We have identified an immune-related gene patterns associated with susceptibility and resistance to IPNV infection of Atlantic salmon. This suggests that a limited immune response is associated with resistant fish phenotype to IPNV challenge while a highly inflammatory but short response is associated with susceptibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-Resolution Microbial Community Succession of Microbially Induced Concrete Corrosion in Working Sanitary Manholes

PubMed Central

Ling, Alison L.; Robertson, Charles E.; Harris, J. Kirk; Frank, Daniel N.; Kotter, Cassandra V.; Stevens, Mark J.; Pace, Norman R.; Hernandez, Mark T.

2015-01-01

Microbially-induced concrete corrosion in headspaces threatens wastewater infrastructure worldwide. Models for predicting corrosion rates in sewer pipe networks rely largely on information from culture-based investigations. In this study, the succession of microbes associated with corroding concrete was characterized over a one-year monitoring campaign using rRNA sequence-based phylogenetic methods. New concrete specimens were exposed in two highly corrosive manholes (high concentrations of hydrogen sulfide and carbon dioxide gas) on the Colorado Front Range for up to a year. Community succession on corroding surfaces was assessed using Illumina MiSeq sequencing of 16S bacterial rRNA amplicons and Sanger sequencing of 16S universal rRNA clones. Microbial communities associated with corrosion fronts presented distinct succession patterns which converged to markedly low α-diversity levels (< 10 taxa) in conjunction with decreasing pH. The microbial community succession pattern observed in this study agreed with culture-based models that implicate acidophilic sulfur-oxidizer Acidithiobacillus spp. in advanced communities, with two notable exceptions. Early communities exposed to alkaline surface pH presented relatively high α-diversity, including heterotrophic, nitrogen-fixing, and sulfur-oxidizing genera, and one community exposed to neutral surface pH presented a diverse transition community comprised of less than 20% sulfur-oxidizers. PMID:25748024

High-resolution microbial community succession of microbially induced concrete corrosion in working sanitary manholes.

PubMed

Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

2015-01-01

Microbially-induced concrete corrosion in headspaces threatens wastewater infrastructure worldwide. Models for predicting corrosion rates in sewer pipe networks rely largely on information from culture-based investigations. In this study, the succession of microbes associated with corroding concrete was characterized over a one-year monitoring campaign using rRNA sequence-based phylogenetic methods. New concrete specimens were exposed in two highly corrosive manholes (high concentrations of hydrogen sulfide and carbon dioxide gas) on the Colorado Front Range for up to a year. Community succession on corroding surfaces was assessed using Illumina MiSeq sequencing of 16S bacterial rRNA amplicons and Sanger sequencing of 16S universal rRNA clones. Microbial communities associated with corrosion fronts presented distinct succession patterns which converged to markedly low α-diversity levels (< 10 taxa) in conjunction with decreasing pH. The microbial community succession pattern observed in this study agreed with culture-based models that implicate acidophilic sulfur-oxidizer Acidithiobacillus spp. in advanced communities, with two notable exceptions. Early communities exposed to alkaline surface pH presented relatively high α-diversity, including heterotrophic, nitrogen-fixing, and sulfur-oxidizing genera, and one community exposed to neutral surface pH presented a diverse transition community comprised of less than 20% sulfur-oxidizers.

Archaean ultra-depleted komatiites formed by hydrous melting of cratonic mantle.

PubMed

Wilson, A H; Shirey, S B; Carlson, R W

2003-06-19

Komatiites are ultramafic volcanic rocks containing more than 18 per cent MgO (ref. 1) that erupted mainly in the Archaean era (more than 2.5 gigayears ago). Although such compositions occur in later periods of Earth history (for example, the Cretaceous komatiites of Gorgona Island), the more recent examples tend to have lower MgO content than their Archaean equivalents. Komatiites are also characterized by their low incompatible-element content, which is most consistent with their generation by high degrees of partial melting (30-50 per cent). Current models for komatiite genesis include the melting of rock at great depth in plumes of hot, diapirically rising mantle or the melting of relatively shallow mantle rocks at less extreme, but still high, temperatures caused by fluxing with water. Here we report a suite of ultramafic lava flows from the Commondale greenstone belt, in the southern part of the Kaapvaal Craton, which represents a previously unrecognized type of komatiite with exceptionally high forsterite content of its igneous olivines, low TiO(2)/Al(2)O(3) ratio, high silica content, extreme depletion in rare-earth elements and low Re/Os ratio. We suggest a model for their formation in which a garnet-enriched residue left by earlier cratonic volcanism was melted by hydration from a subducting slab.

Effects and Location of Coplanar and Noncoplanar PCB in a Lipid Bilayer: A Solid-State NMR Study.

PubMed

Totland, Christian; Nerdal, Willy; Steinkopf, Signe

2016-08-02

Coplanar and noncoplanar polychlorinated biphenyls (PCBs) are known to have different routes and degree of toxicity. Here, the effects of noncoplanar PCB 52 and coplanar PCB 77 present at 2 mol % in a model system consisting of POPC liposomes (50% hydrated) are investigated by solid-state (13)C and (31)P NMR at 298 K. Both PCBs intercalate horizontally in the outer part of the bilayer, near the segments of the acyl chain close to the glycerol group. Despite similar membrane locations, the coplanar PCB 77 shows little effect on the bilayer properties overall, except for the four nearest neighboring lipids, while the effect of PCB 52 is more dramatic. The first ∼2 layers of lipids around each PCB 52 in the bilayer form a high fluidity lamellar phase, whereas lipids beyond these layers form a lamellar phase with a slight increase in fluidity compared to a bilayer without PCB 52. Further, a third high mobility domain is observed. The explanation for this is the interference of several high fluidity lamellar phases caused by interactions of PCB 52 molecules in different leaflets of the model bilayer. This causes formation of high curvature toroidal region in the bilayer and might induce formation of channels.

Comparison of hadron production models for π±, k±, protons and antiprotons production in proton-carbon interactions at 60 GeV/c

NASA Astrophysics Data System (ADS)

Ajaz, M.; Ullah, S.; Ali, Y.; Younis, H.

2018-02-01

In this research paper, the comprehensive results on the double differential yield of π± and k± mesons, protons and antiprotons as a function of laboratory momentum are reported. These hadrons are produced in proton-carbon interaction at 60 GeV/c. EPOS 1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. Comparing the predictions of these models show that QGSJETII-04 model predicts higher yields of all the hadrons in most of the cases at the peak of the distribution. In this interval, the EPOS 1.99 and EPOS-LHC produce similar results. In most of the cases at higher momentum of the hadrons, all the three models are in good agreement. For protons, all models are in good agreement. EPOS-LHC gives high yield of antiprotons at high momentum values as compared to the other two models. EPOS-LHC gives higher prediction at the peak value for π+ mesons and protons at higher polar angle intervals of 100 < 𝜃 < 420 and 100 < 𝜃 < 360, respectively, and EPOS 1.99 gives higher prediction at the peak value for π- mesons for 140 < 𝜃 < 420. The model predictions, except for antiprotons, are compared with the data obtained by the NA61/SHINE experiment at 31 GeV/c proton-carbon collision, which clearly shows that the behavior of the distributions in models are similar to the ones from the data but the yield in data is low because of lower beam energy.

Habitat selection of Rocky Mountain elk in a nonforested environment

USGS Publications Warehouse

Sawyer, H.; Nielson, R.M.; Lindzey, F.G.; Keith, L.; Powell, J.H.; Abraham, A.A.

2007-01-01

Recent expansions by Rocky Mountain elk (Cervus elaphus) into nonforested habitats across the Intermountain West have required managers to reconsider the traditional paradigms of forage and cover as they relate to managing elk and their habitats. We examined seasonal habitat selection patterns of a hunted elk population in a nonforested high-desert region of southwestern Wyoming, USA. We used 35,246 global positioning system locations collected from 33 adult female elk to model probability of use as a function of 6 habitat variables: slope, aspect, elevation, habitat diversity, distance to shrub cover, and distance to road. We developed resource selection probability functions for individual elk, and then we averaged the coefficients to estimate population-level models for summer and winter periods. We used the population-level models to generate predictive maps by assigning pixels across the study area to 1 of 4 use categories (i.e., high, medium-high, medium-low, or low), based on quartiles of the predictions. Model coefficients and predictive maps indicated that elk selected for summer habitats characterized by higher elevations in areas of high vegetative diversity, close to shrub cover, northerly aspects, moderate slopes, and away from roads. Winter habitat selection patterns were similar, except elk shifted to areas with lower elevations and southerly aspects. We validated predictive maps by using 528 locations collected from an independent sample of radiomarked elk (n = 55) and calculating the proportion of locations that occurred in each of the 4 use categories. Together, the high- and medium-high use categories of the summer and winter predictive maps contained 92% and 74% of summer and winter elk locations, respectively. Our population-level models and associated predictive maps were successful in predicting winter and summer habitat use by elk in a nonforested environment. In the absence of forest cover, elk seemed to rely on a combination of shrubs, topography, and low human disturbance to meet their thermal and hiding cover requirements.

FEL (free-electron lasers) undulator technology and synchrotron radiation source requirements

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

Robinson, K.; Quimby, D.; Slater, J.

This paper describes design and construction considerations of the THUNDER undulator, for use in free-electron laser experiments at visible wavelengths. For the parameters of these experiments, an unusually high degree of optimization of the electron-photon interaction is required and, as a result, THUNDER is built to especially high mechanical and magnetic precision. Except for its narrow magnet gap, the 5-meter THUNDER undulator is quite similar to insertion devices under consideration for the proposed 6-GeV storage ring. The engineering and physics approach adopted for this FEL modulator design is directly applicable to insertion device development. The tolerance limits to THUNDER, establishedmore » by modeling and design and achieved through careful control of mechanical and magnetic errors, are essential to the next generation of insertion devices.« less

50 CFR 218.84 - Mitigation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... aircraft conducting high-frequency or non-hull-mounted mid-frequency active sonar activities associated... or aircraft conducting high-frequency active sonar activities associated with anti-submarine warfare...). (2) High-frequency and non-hull mounted mid-frequency active sonar (except helicopter dipping). (3...

Global scale modeling of riverine sediment loads: tropical rivers in a global context

NASA Astrophysics Data System (ADS)

Cohen, Sagy; Syvitski, James; Kettner, Albert

2015-04-01

A global scale riverine sediment flux model (termed WBMsed) is introduced. The model predicts spatially and temporally explicit water, suspended sediment and nutrients flux in relatively high resolutions (6 arc-min and daily). Modeled riverine suspended sediment flux through global catchments is used in conjunction with observational data for 35 tropical basins to highlight key basin scaling relationships. A 50 year, daily model simulation illuminates how precipitation, relief, lithology and drainage basin area affect sediment load, yield and concentration. Tropical river systems, wherein much of a drainage basin experiences tropical climate are strongly influenced by the annual and inter-annual variations of the Inter-tropical Convergence Zone (ITCZ) and its derivative monsoonal winds, have comparatively low inter-annual variation in sediment yield. Rivers draining rainforests and those subjected to tropical monsoons typically demonstrate high runoff, but with notable exceptions. High rainfall intensities from burst weather events are common in the tropics. The release of rain-forming aerosols also appears to uniquely increase regional rainfall, but its geomorphic manifestation is hard to detect. Compared to other more temperate river systems, climate-driven tropical rivers do not appear to transport a disproportionate amount of particulate load to the world's oceans, and their warmer, less viscous waters are less competent. Multiple-year hydrographs reveal that seasonality is a dominant feature of most tropical rivers, but the rivers of Papua New Guinea are somewhat unique being less seasonally modulated. Local sediment yield within the Amazon is highest near the Andes, but decreases towards the ocean as the river's discharge is diluted by water influxes from sediment-deprived rainforest tributaries

14 CFR 93.221 - Transfer of slots.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Operations at High Density Traffic Airports § 93.221 Transfer of slots. (a) Except as otherwise provided in... high density traffic airport. Transfers, including leases, shall comply with the following conditions...

14 CFR 93.221 - Transfer of slots.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Operations at High Density Traffic Airports § 93.221 Transfer of slots. (a) Except as otherwise provided in... high density traffic airport. Transfers, including leases, shall comply with the following conditions...

14 CFR 93.221 - Transfer of slots.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Operations at High Density Traffic Airports § 93.221 Transfer of slots. (a) Except as otherwise provided in... high density traffic airport. Transfers, including leases, shall comply with the following conditions...

14 CFR 93.221 - Transfer of slots.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Operations at High Density Traffic Airports § 93.221 Transfer of slots. (a) Except as otherwise provided in... high density traffic airport. Transfers, including leases, shall comply with the following conditions...

14 CFR 93.221 - Transfer of slots.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Operations at High Density Traffic Airports § 93.221 Transfer of slots. (a) Except as otherwise provided in... high density traffic airport. Transfers, including leases, shall comply with the following conditions...

Northern African and Indian Precipitation at the end of the 21st Century: An Integrated Application of Regional and Global Climate Models

NASA Astrophysics Data System (ADS)

Patricola, C. M.; Cook, K. H.

2008-12-01

As greenhouse warming continues there is growing concern about the future climate of both Africa, which is highlighted by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4) as exceptionally vulnerable to climate change, and India. Precipitation projections from the AOGCMs of the IPCC AR4 are relatively consistent over India, but not over northern Africa. Inconsistencies can be related to the model's inability to capture climate process correctly, deficiencies in physical parameterizations, different SST projections, or horizontal atmospheric resolution that is too coarse to realistically represent the tight gradients over West Africa and complex topography of East Africa and India. Treatment of the land surface in a model may also be an issue over West Africa and India where land-surface/atmosphere interactions are very important. Here a method for simulating future climate is developed and applied using a high-resolution regional model in conjunction with output from a suite of AOGCMs, drawing on the advantages of both the regional and global modeling approaches. Integration by the regional model allows for finer horizontal resolution and regionally appropriate selection of parameterizations and land-surface model. AOGCM output is used to provide SST projections and lateral boundary conditions to constrain the regional model. The control simulation corresponds to 1981-2000, and eight future simulations representing 2081-2100 are conducted, each constrained by a different AOGCM and forced by CO2 concentrations from the SRES A2 emissions scenario. After model spin-up, May through October remain for investigation. Analysis is focused on climate change parameters important for impacts on agriculture and water resource management, and is presented in a format compatible with the IPCC reports. Precipitation projections simulated by the regional model are quite consistent, with 75% or more ensemble members agreeing on the sign of the anomaly over vast regions of Africa and India. Over West Africa, where the regional model provides the greatest improvement over the AOGCMs in consistency of ensemble members, precipitation at the end of the century is generally projected to increase during May and decrease in June and July. Wetter conditions are simulated during August though October, with the exception of drying close to the Guinean Coast in August. In late summer, high rainfall rates are simulated more frequently in the future, indicating the possibility for increases in flooding events. The regional model's projections over India are in stark contrast to the AOGCM's, producing intense and generally widespread drying in August and September. The very promising method developed here is young and further potential developments are recognized, including the addition of ocean, vegetation, and dust models. Ensembles which employ other regional models, sets of parameterizations, and emissions scenarios should also be explored.

Latitudinal distributions of particulate carbon export across the North Western Atlantic Ocean

NASA Astrophysics Data System (ADS)

Puigcorbé, Viena; Roca-Martí, Montserrat; Masqué, Pere; Benitez-Nelson, Claudia; Rutgers van der Loeff, Michiel; Bracher, Astrid; Moreau, Sebastien

2017-11-01

234Th-derived carbon export fluxes were measured in the Atlantic Ocean under the GEOTRACES framework to evaluate basin-scale export variability. Here, we present the results from the northern half of the GA02 transect, spanning from the equator to 64°N. As a result of limited site-specific C/234Th ratio measurements, we further combined our data with previous work to develop a basin wide C/234Th ratio depth curve. While the magnitude of organic carbon fluxes varied depending on the C/234Th ratio used, latitudinal trends were similar, with sizeable and variable organic carbon export fluxes occurring at high latitudes and low to negligible fluxes occurring in oligotrophic waters. Our results agree with previous studies, except at the boundaries between domains, where fluxes were relatively enhanced. Three different models were used to obtain satellite-derived net primary production (NPP). In general, NPP estimates had similar trends along the transect, but there were significant differences in the absolute magnitude depending on the model used. Nevertheless, organic carbon export efficiencies were generally < 25%, with the exception of a few stations located in the transition area between the riverine and the oligotrophic domains and between the oligotrophic and the temperate domains. Satellite-derived organic carbon export models from Dunne et al. (2005) (D05), Laws et al. (2011) (L11) and Henson et al. (2011) (H11) were also compared to our 234Th-derived carbon exports fluxes. D05 and L11 provided estimates closest to values obtained with the 234Th approach (within a 3-fold difference), but with no clear trends. The H11 model, on the other hand, consistently provided lower export estimates. The large increase in export data in the Atlantic Ocean derived from the GEOTRACES Program, combined with satellite observations and modeling efforts continue to improve the estimates of carbon export in this ocean basin and therefore reduce uncertainty in the global carbon budget. However, our results also suggest that tuning export models and including biological parameters at a regional scale is necessary for improving satellite-modeling efforts and providing export estimates that are more representative of in situ observations.

76 FR 36980 - Airworthiness Directives; PIAGGIO AERO INDUSTRIES S.p.A Model PIAGGIO P-180 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-24

... Airworthiness Directives; PIAGGIO AERO INDUSTRIES S.p.A Model PIAGGIO P-180 Airplanes AGENCY: Federal Aviation... Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket...-P ...

End-of-life of starch-polyvinyl alcohol biopolymers.

PubMed

Guo, M; Stuckey, D C; Murphy, R J

2013-01-01

This study presents a life cycle assessment (LCA) model comparing the waste management options for starch-polyvinyl alcohol (PVOH) biopolymers including landfill, anaerobic digestion (AD), industrial composting and home composting. The ranking of biological treatment routes for starch-PVOH biopolymer wastes depended on their chemical compositions. AD represents the optimum choice for starch-PVOH biopolymer containing N and S elements in global warming potential (GWP(100)), acidification and eutrophication but not on the remaining impact categories, where home composting was shown to be a better option due to its low energy and resource inputs. For those starch-PVOH biopolymers with zero N and S contents home composting delivered the best environmental performance amongst biological treatment routes in most impact categories (except for GWP(100)). The landfill scenario performed generally well due largely to the 100-year time horizon and efficient energy recovery system modeled but this good performance is highly sensitive to assumptions adopted in landfill model. Copyright © 2012 Elsevier Ltd. All rights reserved.

New Careers in Nursing: An Effective Model for Increasing Nursing Workforce Diversity.

PubMed

Craft-Blacksheare, Melva

2018-03-01

The Robert Wood Johnson Foundation and the American Association of Colleges of Nursing developed the New Careers in Nursing (NCIN) program to address the nursing shortage, increase workforce diversity, and raise the profession's educational level. The program provided scholarships to second-degree underrepresented or economically disadvantaged (UED) students attending an accelerated nursing program to earn a Bachelor of Science in Nursing degree. A midwestern university received three academic-year cycles of NCIN funding. The program's model, resources, and functioning are described. The NCIN provided exceptional financial and program support that received high marks from participants. During the three award cycles, 20 UED scholars graduated with a Bachelor of Science in Nursing degree. Nineteen of the 20 scholars passed the NCLEX-RN on the first attempt. While the NCIN program has ended, nursing school administrators and faculty wishing to promote UED student success should consider using the program's model and resources as the basis for their own program. [J Nurs Educ. 2018;57(3):178-183.]. Copyright 2018, SLACK Incorporated.

Due Date Assignment in a Dynamic Job Shop with the Orthogonal Kernel Least Squares Algorithm

NASA Astrophysics Data System (ADS)

Yang, D. H.; Hu, L.; Qian, Y.

2017-06-01

Meeting due dates is a key goal in the manufacturing industries. This paper proposes a method for due date assignment (DDA) by using the Orthogonal Kernel Least Squares Algorithm (OKLSA). A simulation model is built to imitate the production process of a highly dynamic job shop. Several factors describing job characteristics and system state are extracted as attributes to predict job flow-times. A number of experiments under conditions of varying dispatching rules and 90% shop utilization level have been carried out to evaluate the effectiveness of OKLSA applied for DDA. The prediction performance of OKLSA is compared with those of five conventional DDA models and back-propagation neural network (BPNN). The experimental results indicate that OKLSA is statistically superior to other DDA models in terms of mean absolute lateness and root mean squares lateness in most cases. The only exception occurs when the shortest processing time rule is used for dispatching jobs, the difference between OKLSA and BPNN is not statistically significant.

Networks with fourfold connectivity in two dimensions.

PubMed

Tessier, Frédéric; Boal, David H; Discher, Dennis E

2003-01-01

The elastic properties of planar, C4-symmetric networks under stress and at nonzero temperature are determined by simulation and mean field approximations. Attached at fourfold coordinated junction vertices, the networks are self-avoiding in that their elements (or bonds) may not intersect each other. Two different models are considered for the potential energy of the elements: either Hooke's law springs or flexible tethers (square well potential). For certain ranges of stress and temperature, the properties of the networks are captured by one of several models: at large tensions, the networks behave like a uniform system of square plaquettes, while at large compressions or high temperatures, they display many characteristics of an ideal gas. Under less severe conditions, mean field models with more general shapes (parallelograms) reproduce many essential features of both networks. Lastly, the spring network expands without limit at a two-dimensional tension equal to the force constant of the spring; however, it does not appear to collapse under compression, except at zero temperature.

New Chandra observations of the jet in 3C273. 1. Softer X-ray than radio spectra and the X-ray emission mechanism

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

Jester, Sebastian; /Fermilab; Harris, D.E.

2006-05-01

The jet in 3C273 is a high-power quasar jet with radio, optical and X-ray emission whose size and brightness allow a detailed study of the emission processes acting in it. We present deep Chandra observations of this jet and analyze the spectral properties of the jet emission from radio through X-rays. We find that the X-ray spectra are significantly softer than the radio spectra in all regions of the bright part of the jet except for the first bright ''knot A'', ruling out a model in which the X-ray emission from the entire jet arises from beamed inverse-Compton scattering ofmore » cosmic microwave background photons in a single-zone jet flow. Within two-zone jet models, we find that a synchrotron origin for the jet's X-rays requires fewer additional assumptions than an inverse-Compton model, especially if velocity shear leads to efficient particle acceleration in jet flows.« less

Computational simulation of biomolecules transport with multi-physics near microchannel surface for development of biomolecules-detection devices.

PubMed

Suzuki, Yuma; Shimizu, Tetsuhide; Yang, Ming

2017-01-01

The quantitative evaluation of the biomolecules transport with multi-physics in nano/micro scale is demanded in order to optimize the design of microfluidics device for the biomolecules detection with high detection sensitivity and rapid diagnosis. This paper aimed to investigate the effectivity of the computational simulation using the numerical model of the biomolecules transport with multi-physics near a microchannel surface on the development of biomolecules-detection devices. The biomolecules transport with fluid drag force, electric double layer (EDL) force, and van der Waals force was modeled by Newtonian Equation of motion. The model validity was verified in the influence of ion strength and flow velocity on biomolecules distribution near the surface compared with experimental results of previous studies. The influence of acting forces on its distribution near the surface was investigated by the simulation. The trend of its distribution to ion strength and flow velocity was agreement with the experimental result by the combination of all acting forces. Furthermore, EDL force dominantly influenced its distribution near its surface compared with fluid drag force except for the case of high velocity and low ion strength. The knowledges from the simulation might be useful for the design of biomolecules-detection devices and the simulation can be expected to be applied on its development as the design tool for high detection sensitivity and rapid diagnosis in the future.

Asymmetry of bifurcated features in radio pulsar profiles

NASA Astrophysics Data System (ADS)

Dyks, J.; Rudak, B.

2012-03-01

High-quality integrated radio profiles of some pulsars contain bifurcated, highly symmetric emission components (BECs). They are observed when our line of sight traverses through a split-fan shaped emission beam. It is shown that for oblique cuts through such a beam, the features appear asymmetric at nearly all frequencies, except for a single 'frequency of symmetry'νsym, at which both peaks in the BEC have the same height. Around νsym, the ratio of flux in the two peaks of a BEC evolves in a way resembling the multifrequency behaviour of J1012+5307. Because of the inherent asymmetry resulting from the oblique traverse of the sightline, each minimum in double notches can be modelled independently. Such a composed model reproduces the double notches of B1929+10 if the fitted function is the microscopic beam of curvature radiation in the orthogonal polarization mode. These results confirm our view that some of the double components in radio pulsar profiles directly reveal the microscopic nature of the emitted radiation beam as the microbeam of the curvature radiation polarized orthogonally to the trajectory of electrons.

Sustainability of cross-functional teams for marketing strategy development and implementation.

PubMed

Kono, Ken; Antonucci, Don

2006-01-01

This article presents a case study on a cross-functional team used for marketing strategy development and execution at a health insurance company. The study found a set of success factors that contributed to the initial success of the team, but the factors were not enough to maintain the team's high level of productivity over time. The study later identified a set of 8 factors that helped sustain the team's high-productivity level. The 2 sets (ie, success and its subsequent sustainability factors) are analyzed against a normative model of team effectiveness. All the factors are explained by the normative model except for 1 sustainability factor, "challenge motivator." In fact, the study found the "challenge motivator" to be the most critical factor to keep up the team's productivity over time. Apart from a performance crisis, the authors developed 3 "challenge motivators"--first, more granular market information that could unearth hidden performance issues; second, constant value creation to shareholders as the firm being publicly traded; and third, the firm's strategic mandate to meet and exceed customer expectations that puts ultimate performance pressure on the marketing strategy team.

The NEST Dry-Run Mode: Efficient Dynamic Analysis of Neuronal Network Simulation Code.

PubMed

Kunkel, Susanne; Schenck, Wolfram

2017-01-01

NEST is a simulator for spiking neuronal networks that commits to a general purpose approach: It allows for high flexibility in the design of network models, and its applications range from small-scale simulations on laptops to brain-scale simulations on supercomputers. Hence, developers need to test their code for various use cases and ensure that changes to code do not impair scalability. However, running a full set of benchmarks on a supercomputer takes up precious compute-time resources and can entail long queuing times. Here, we present the NEST dry-run mode, which enables comprehensive dynamic code analysis without requiring access to high-performance computing facilities. A dry-run simulation is carried out by a single process, which performs all simulation steps except communication as if it was part of a parallel environment with many processes. We show that measurements of memory usage and runtime of neuronal network simulations closely match the corresponding dry-run data. Furthermore, we demonstrate the successful application of the dry-run mode in the areas of profiling and performance modeling.

The NEST Dry-Run Mode: Efficient Dynamic Analysis of Neuronal Network Simulation Code

PubMed Central

Kunkel, Susanne; Schenck, Wolfram

2017-01-01

NEST is a simulator for spiking neuronal networks that commits to a general purpose approach: It allows for high flexibility in the design of network models, and its applications range from small-scale simulations on laptops to brain-scale simulations on supercomputers. Hence, developers need to test their code for various use cases and ensure that changes to code do not impair scalability. However, running a full set of benchmarks on a supercomputer takes up precious compute-time resources and can entail long queuing times. Here, we present the NEST dry-run mode, which enables comprehensive dynamic code analysis without requiring access to high-performance computing facilities. A dry-run simulation is carried out by a single process, which performs all simulation steps except communication as if it was part of a parallel environment with many processes. We show that measurements of memory usage and runtime of neuronal network simulations closely match the corresponding dry-run data. Furthermore, we demonstrate the successful application of the dry-run mode in the areas of profiling and performance modeling. PMID:28701946

Metal Cluster Models for Heterogeneous Catalysis: A Matrix-Isolation Perspective.

PubMed

Hübner, Olaf; Himmel, Hans-Jörg

2018-02-19

Metal cluster models are of high relevance for establishing new mechanistic concepts for heterogeneous catalysis. The high reactivity and particular selectivity of metal clusters is caused by the wealth of low-lying electronically excited states that are often thermally populated. Thereby the metal clusters are flexible with regard to their electronic structure and can adjust their states to be appropriate for the reaction with a particular substrate. The matrix isolation technique is ideally suited for studying excited state reactivity. The low matrix temperatures (generally 4-40 K) of the noble gas matrix host guarantee that all clusters are in their electronic ground-state (with only a very few exceptions). Electronically excited states can then be selectively populated and their reactivity probed. Unfortunately, a systematic research in this direction has not been made up to date. The purpose of this review is to provide the grounds for a directed approach to understand cluster reactivity through matrix-isolation studies combined with quantum chemical calculations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preclinical Investigations Reveal the Broad-Spectrum Neutralizing Activity of Peptide Pep19-2.5 on Bacterial Pathogenicity Factors

PubMed Central

Sánchez-Gómez, Susana; Martinez de Tejada, Guillermo; Dömming, Sabine; Brandenburg, Julius; Kaconis, Yani; Hornef, Mathias; Dupont, Aline; Marwitz, Sebastian; Goldmann, Torsten; Ernst, Martin; Gutsmann, Thomas; Schürholz, Tobias

2013-01-01

Bacterial infections are known to cause severe health-threatening conditions, including sepsis. All attempts to get this disease under control failed in the past, and especially in times of increasing antibiotic resistance, this leads to one of the most urgent medical challenges of our times. We designed a peptide to bind with high affinity to endotoxins, one of the most potent pathogenicity factors involved in triggering sepsis. The peptide Pep19-2.5 reveals high endotoxin neutralization efficiency in vitro, and here, we demonstrate its antiseptic/anti-inflammatory effects in vivo in the mouse models of endotoxemia, bacteremia, and cecal ligation and puncture, as well as in an ex vivo model of human tissue. Furthermore, we show that Pep19-2.5 can bind and neutralize not only endotoxins but also other bacterial pathogenicity factors, such as those from the Gram-positive bacterium Staphylococcus aureus. This broad neutralization efficiency and the additive action of the peptide with common antibiotics makes it an exceptionally appropriate drug candidate against bacterial sepsis and also offers multiple other medication opportunities. PMID:23318793

The formation of acrylamide in UK cereal products.

PubMed

Sadd, Peter; Hamlet, Colin

2005-01-01

Many bakery products sold in the UK such as crumpets, batch bread and Naan might be expected to show high levels of acrylamide because they have strong Maillard colours and flavours. However, analysis of commercial products has shown that the highest levels of acrylamide are seen in dry biscuit type products. With the exception of spiced products such as ginger cake, moist high sugar products (e.g. cakes and fruit loaves) show relatively low levels of acrylamide, even in darkly browned crusts. This is in contrast to bread where acrylamide levels in excess of 100 microg/kg are common in the crust region, but are diluted by low levels in the crumb. Acrylamide levels in bread are significantly raised by domestic toasting, but other products such as crumpets and Naan bread have been found to be less sensitive. A mathematical model has been developed (and validated against tests on model dough) which shows that once obvious recipe differences are allowed for, the key factor limiting acrylamide levels is crust moisture. Chemical decay of acrylamide and depletion of amino acids are also limiting factors at higher temperatures.

Pharmacokinetics of aniracetam and its metabolites in rats.

PubMed

Ogiso, T; Iwaki, M; Tanino, T; Ikeda, K; Paku, T; Horibe, Y; Suzuki, H

1998-05-01

The pharmacokinetics of aniracetam (AP), a new cognitive performance enhancer, and its main metabolites was investigated after intravenous (iv) and oral administrations to rat. The plasma levels of AP, 4-p-anisamidobutyric acid (ABA), and p-anisic acid (AA) were determined simultaneously by the HPLC method. The plasma concentrations of the parent drug and ABA quickly declined in a biexponential manner, with rapid terminal decay and a small mean residence time. However, AA yielded nonlinearly high levels at the initial times and the plasma concentrations of 2-pyrrolidinone (PD) were sustained over a relatively long time. When AA was administered intravenously, nonlinearity of the plasma concentrations was also found at higher doses. To describe the time course of the plasma levels of AP and its metabolites after iv administration, a pharmacokinetic model with seven compartments was applied, which included 10 first-order rate constants and one Michaelis-Menten constant. An approximate fit was obtained between the observed and calculated curves based on the model, except for the plasma concentrations of ABA. The plasma concentration-time profiles of AP and its metabolites following oral administration of AP (50 and 100 mg/kg) were similar to those after iv dosing, with the exception of PD, which showed much lower plasma levels than those after iv administration. Elimination of AP and ABA was rapid after oral dosing, and the bioavailability of AP was extremely small (11.4 and 8.6%). As a result, AP was largely metabolized to ABA, AA, and PD in rat.

A COGNITIVE PERSPECTIVE ON AGGRESSIVE MIMICRY

PubMed Central

JACKSON, ROBERT R.; CROSS, FIONA R.

2013-01-01

We use the term ‘aggressive mimic’ for predators that communicate with their prey by making signals to indirectly manipulate prey behaviour. For understanding why the aggressive mimic’s signals work, it is important to appreciate that these signals interface with the prey’s perceptual system, and that the aggressive mimic can be envisaged as playing mind games with its prey. Examples of aggressive mimicry vary from instances in which specifying a model is straight forward to instances where a concise characterisation of the model is difficult. However, the less straightforward examples of aggressive mimicry may be the more interesting examples in the context of animal cognition. In particular, there are spiders that prey on other spiders by entering their prey’s web and making signals. Web invasion brings about especially intimate contact with their prey’s perceptual system because the prey spider’s web is an important component of the prey spider’s sensory apparatus. For the web-invading spider, often there is also a large element of risk when practising aggressive mimicry because the intended prey is also a potential predator. This element of risk, combined with exceptionally intimate interfacing with prey perceptual systems, may have favoured the web-invading aggressive mimic’s strategy becoming strikingly cognitive in character. Yet a high level of flexibility may be widespread among aggressive mimics in general and, on the whole, we propose that research on aggressive mimicry holds exceptional potential for advancing our understanding of animal cognition. PMID:23976823

Coaching: Learning and Using Environment and Agent Models for Advice

DTIC Science & Technology

2005-03-31

The (x, y) location of the passer at the start of the pass Player locations For all teammates (except for the goalie ) and opponents, the distance and...angle of opponent number 10 is between 151 and 180 degrees. Line 6 instructs all players on our team (except the goalie who is number 1) to pass the ball...inside the penalty box (if the ball is kicked into the penalty box with no one nearby, the goalie will just grab it). Second, the clear has additional

Scrambling of quantum information in quantum many-body systems

NASA Astrophysics Data System (ADS)

Iyoda, Eiki; Sagawa, Takahiro

2018-04-01

We systematically investigate scrambling (or delocalizing) processes of quantum information encoded in quantum many-body systems by using numerical exact diagonalization. As a measure of scrambling, we adopt the tripartite mutual information (TMI) that becomes negative when quantum information is delocalized. We clarify that scrambling is an independent property of the integrability of Hamiltonians; TMI can be negative or positive for both integrable and nonintegrable systems. This implies that scrambling is a separate concept from conventional quantum chaos characterized by nonintegrability. Specifically, we argue that there are a few exceptional initial states that do not exhibit scrambling, and show that such exceptional initial states have small effective dimensions. Furthermore, we calculate TMI in the Sachdev-Ye-Kitaev (SYK) model, a fermionic toy model of quantum gravity. We find that disorder does not make scrambling slower but makes it smoother in the SYK model, in contrast to many-body localization in spin chains.

BASC-2 PRS profiles for students with high-functioning autism spectrum disorders.

PubMed

Volker, Martin A; Lopata, Christopher; Smerbeck, Audrey M; Knoll, Valerie A; Thomeer, Marcus L; Toomey, Jennifer A; Rodgers, Jonathan D

2010-02-01

BASC-2 PRS profiles of 62 children with high-functioning autism spectrum disorders (HFASDs) were compared with those of 62 typically-developing children matched by age, gender, and ethnicity. Results indicated that, except for the Somatization, Conduct Problems, and Aggression scales, significant differences were found between the HFASD and typically-developing groups on all PRS scores. Mean HFASD scores were in the clinically significant range on the Behavioral Symptoms Index, Atypicality, Withdrawal, and Developmental Social Disorders scales. At-risk range HFASD means were obtained on the Adaptive Skills composite, all adaptive scales, remaining content scales (except Bullying), and Hyperactivity, Attention Problems, and Depression clinical scales. Screening indices suggested that the Developmental Social Disorders scale was highly effective in differentiating between the two groups.

Science of Global Climate Modeling: Confirmation from Discoveries on Mars

NASA Astrophysics Data System (ADS)

Hartmann, William K.

2012-10-01

As early as 1993, analysis of obliquity changes on Mars revealed irregular cycles of high excursion, over 45°1. Further obliquity analyses indicated that insolation and climatic conditions vary with time, with the four most recent episodes of obliquity >45° occurring about 5.5, 8, 9, and 15 My.2 Various researchers applied global climate models, using Martian parameters and obliquity changes. The models (independent of Martian geomorphological observations) indicate exceptional climate conditions during the high-obliquity episodes at >45°3,4, with localized massive ice deposition effects east of Hellas and on the west slopes of Tharsis.5 At last year’s DPS my co-authors and I detailed evidence of unusual active glaciation in Greg crater, near the center of the predicted area of ice accumulation during high obliquity.6 We found that the timescale of glacial surface layer activity matches the general 5-15 My timescale of the last episodes of high obliquity and ice deposition. Radar results confirm ice deposits in debris aprons concentrated in the same area.7 Less direct evidence has also been found for glacial ice deposits in the west Tharsis region.8 Here I emphasize that if the models can be adjusted to Mars and then successfully indicate unusual, specific features that we see there, it is an argument for the robustness of climate modeling in general. In recent years we have see various public figures casting doubt on the validity of terrestrial global modeling. The successful match of Martian climate modeling with direct Martian geological and chronometric observations provides an interesting and teachable refutation of the attacks on climate science. References: 1. Science 259:1294-1297; 2. LPSC XXXV, Abs. 1600; 3. Nature 412:411-413; 4. Science 295:110-113; 5. Science 311:368-371; 6. EPSC-DPS Abs. 1394; 7. Science 322:1235-1238; 8. Nature 434:346-351.

Size of graphene sheets determines the structural and mechanical properties of 3D graphene foams

NASA Astrophysics Data System (ADS)

Shen, Zhiqiang; Ye, Huilin; Zhou, Chi; Kröger, Martin; Li, Ying

2018-03-01

Graphene is recognized as an emerging 2D nanomaterial for many applications. Assembly of graphene sheets into 3D structures is an attractive way to enable their macroscopic applications and to preserve the exceptional mechanical and physical properties of their constituents. In this study, we develop a coarse-grained (CG) model for 3D graphene foams (GFs) based on the CG model for a 2D graphene sheet by Ruiz et al (2015 Carbon 82 103-15). We find that the size of graphene sheets plays an important role in both the structural and mechanical properties of 3D GFs. When their size is smaller than 10 nm, the graphene sheets can easily stack together under the influence of van der Waals interactions (vdW). These stacks behave like building blocks and are tightly packed together within 3D GFs, leading to high density, small pore radii, and a large Young’s modulus. However, if the sheet sizes exceed 10 nm, they are staggered together with a significant amount of deformation (bending). Therefore, the density of 3D GFs has been dramatically reduced due to the loosely packed graphene sheets, accompanied by large pore radii and a small Young’s modulus. Under uniaxial compression, rubber-like stress-strain curves are observed for all 3D GFs. This material characteristic is dominated by the vdW interactions between different graphene layers and slightly affected by the out-of-plane deformation of the graphene sheets. We find a simple scaling law E˜ {ρ }4.2 between the density ρ and Young’s modulus E for a model of 3D GFs. The simulation results reveal structure-property relations of 3D GFs, which can be applied to guide the design of 3D graphene assemblies with exceptional properties.

A community-based validation study of the short-form 36 version 2 Philippines (Tagalog) in two cities in the Philippines.

PubMed

Castillo-Carandang, Nina T; Sison, Olivia T; Grefal, Mary Lenore; Sy, Rody G; Alix, Oliver C; Llanes, Elmer Jasper B; Reganit, Paul Ferdinand M; Gumatay, Allan Wilbert G; Punzalan, Felix Eduardo R; Velandria, Felicidad V; Tai, E Shyong; Wee, Hwee-Lin

2013-01-01

To evaluate the validity and reliability of the Philippines (Tagalog) Short Form 36 Health Survey version 2 (SF-36v2(®)) standard questionnaire among Filipinos residing in two cities. The official Philippines (Tagalog) SF-36v2 standard (4-week recall) version was pretested on 30 participants followed by formal and informal cognitive debriefing. To obtain the feedback on translation by bilingual respondents, each SF-36v2 question was stated first in English followed by Tagalog. No revisions to the original questionnaire were needed except that participants thought it was appropriate to incorporate "po" in the instructions to make it more polite. Face-to-face interviews of 562 participants aged 20-50 years living in two barangays (villages) in the highly urbanized city of Makati City (Metro Manila) and in urban and rural barangays in Tanauan City (province of Batangas) were subsequently conducted. Content validity, item level validity, reliability and factor structure of the SF-36v2 (Tagalog) were examined. Content validity of the SF-36v2 was assessed to be adequate for assessing health status among Filipinos. Item means of Philippines (Tagalog) SF-36v2 were similar with comparable scales in the US English, Singapore (English and Chinese) and Thai SF-36 version 1. Item-scale correlation exceeded 0.4 for all items except the bathing item in PF (correlation: 0.31). In exploratory factor analysis, the US two-component model was supported. However, in confirmatory factor analysis, the Japanese three-component model fit the Tagalog data better than the US two-component model. The Philippines (Tagalog) SF-36v2 is a valid and reliable instrument for measuring health status among residents of Makati City (Metro Manila) and Tanauan City (Province of Batangas).

Study of Four Young TeV Pulsar Wind Nebulae with a Spectral Evolution Model

NASA Astrophysics Data System (ADS)

Tanaka, Shuta J.; Takahara, Fumio

2011-11-01

We study four young pulsar wind nebulae (PWNe) detected in TeV γ-rays, G21.5-0.9, G54.1+0.3, Kes 75, and G0.9+0.1, using the spectral evolution model developed and applied to the Crab Nebula in our previous work. We model the evolution of the magnetic field and the particle distribution function inside a uniformly expanding PWN considering a time-dependent injection from the pulsar and radiative and adiabatic losses. Considering uncertainties in the interstellar radiation field (ISRF) and their distance, we study two cases for each PWN. Because TeV PWNe have a large TeV γ-ray to X-ray flux ratio, the magnetic energy of the PWNe accounts for only a small fraction of the total energy injected (typically a few × 10-3). The γ-ray emission is dominated by inverse Compton scattering off the infrared photons of the ISRF. A broken power-law distribution function for the injected particles reproduces the observed spectrum well, except for G0.9+0.1. For G0.9+0.1, we do not need a low-energy counterpart because adiabatic losses alone are enough to reproduce the radio observations. High-energy power-law indices at injection are similar (2.5-2.6), while low-energy power-law indices range from 1.0 to 1.6. The lower limit of the particle injection rate indicates that the pair multiplicity is larger than 104. The corresponding upper limit of the bulk Lorentz factor of the pulsar winds is close to the break energy of the broken power-law injection, except for Kes 75. The initial rotational energy and the magnetic energy of the pulsars seem anticorrelated, although the statistics are poor.

The Use of an Eight-Step Instructional Model to Train School Staff in Partner-Augmented Input

ERIC Educational Resources Information Center

Senner, Jill E.; Baud, Matthew R.

2017-01-01

An eight-step instruction model was used to train a self-contained classroom teacher, speech-language pathologist, and two instructional assistants in partner-augmented input, a modeling strategy for teaching augmentative and alternative communication use. With the exception of a 2-hr training session, instruction primarily was conducted during…

Measuring the "Unmeasurable": An Inquiry Model and Test for the Social Studies.

ERIC Educational Resources Information Center

Van Scotter, Richard D.; Haas, John D.

New social studies materials are based on inquiry modes of learning and teaching; however, little is known as to what students actually learn from an inquiry model (except for cognitive knowledge). An inquiry model and test to measure the "unmeasurable" in the social studies--namely, a student's ability to use the scientific process, attitudes…

SWMF Global Magnetosphere Simulations of January 2005: Geomagnetic Indices and Cross-Polar Cap Potential

NASA Astrophysics Data System (ADS)

Haiducek, John D.; Welling, Daniel T.; Ganushkina, Natalia Y.; Morley, Steven K.; Ozturk, Dogacan Su

2017-12-01

We simulated the entire month of January 2005 using the Space Weather Modeling Framework (SWMF) with observed solar wind data as input. We conducted this simulation with and without an inner magnetosphere model and tested two different grid resolutions. We evaluated the model's accuracy in predicting Kp, SYM-H, AL, and cross-polar cap potential (CPCP). We find that the model does an excellent job of predicting the SYM-H index, with a root-mean-square error (RMSE) of 17-18 nT. Kp is predicted well during storm time conditions but overpredicted during quiet times by a margin of 1 to 1.7 Kp units. AL is predicted reasonably well on average, with an RMSE of 230-270 nT. However, the model reaches the largest negative AL values significantly less often than the observations. The model tended to overpredict CPCP, with RMSE values on the order of 46-48 kV. We found the results to be insensitive to grid resolution, with the exception of the rate of occurrence for strongly negative AL values. The use of the inner magnetosphere component, however, affected results significantly, with all quantities except CPCP improved notably when the inner magnetosphere model was on.

The Exceptionally High Life Expectancy of Costa Rican Nonagenarians

PubMed Central

ROSERO-BIXBY, LUIS

2008-01-01

Robust data from a voter registry show that Costa Rican nonagenarians have an exceptionally high live expectancy. Mortality at age 90 in Costa Rica is at least 14% lower than an average of 13 high-income countries. This advantage increases with age by 1% per year. Males have an additional 12% advantage. Age-90 life expectancy for males is 4.4 years, one-half year more than any other country in the world. These estimates do not use problematic data on reported ages, but ages are computed from birth dates in the Costa Rican birth-registration ledgers. Census data confirm the exceptionally high survival of elderly Costa Ricans, especially males. Comparisons with the United States and Sweden show that the Costa Rican advantage comes mostly from reduced incidence of cardiovascular diseases, coupled with a low prevalence of obesity, as the only available explanatory risk factor. Costa Rican nonagenarians are survivors of cohorts that underwent extremely harsh health conditions when young, and their advantage might be just a heterogeneity in frailty effect that might disappear in more recent cohorts. The availability of reliable estimates for the oldest-old in low-income populations is extremely rare. These results may enlighten the debate over how harsh early-life health conditions affect older-age mortality. PMID:18939667

Exceptionally high levels of recombination across the honey bee genome.

PubMed

Beye, Martin; Gattermeier, Irene; Hasselmann, Martin; Gempe, Tanja; Schioett, Morten; Baines, John F; Schlipalius, David; Mougel, Florence; Emore, Christine; Rueppell, Olav; Sirviö, Anu; Guzmán-Novoa, Ernesto; Hunt, Greg; Solignac, Michel; Page, Robert E

2006-11-01

The first draft of the honey bee genome sequence and improved genetic maps are utilized to analyze a genome displaying 10 times higher levels of recombination (19 cM/Mb) than previously analyzed genomes of higher eukaryotes. The exceptionally high recombination rate is distributed genome-wide, but varies by two orders of magnitude. Analysis of chromosome, sequence, and gene parameters with respect to recombination showed that local recombination rate is associated with distance to the telomere, GC content, and the number of simple repeats as described for low-recombining genomes. Recombination rate does not decrease with chromosome size. On average 5.7 recombination events per chromosome pair per meiosis are found in the honey bee genome. This contrasts with a wide range of taxa that have a uniform recombination frequency of about 1.6 per chromosome pair. The excess of recombination activity does not support a mechanistic role of recombination in stabilizing pairs of homologous chromosome during chromosome pairing. Recombination rate is associated with gene size, suggesting that introns are larger in regions of low recombination and may improve the efficacy of selection in these regions. Very few transposons and no retrotransposons are present in the high-recombining genome. We propose evolutionary explanations for the exceptionally high genome-wide recombination rate.

Discovery of small molecule inhibitors of ubiquitin-like poxvirus proteinase I7L using homology modeling and covalent docking approaches

NASA Astrophysics Data System (ADS)

Katritch, Vsevolod; Byrd, Chelsea M.; Tseitin, Vladimir; Dai, Dongcheng; Raush, Eugene; Totrov, Maxim; Abagyan, Ruben; Jordan, Robert; Hruby, Dennis E.

2007-10-01

Essential for viral replication and highly conserved among poxviridae, the vaccinia virus I7L ubiquitin-like proteinase (ULP) is an attractive target for development of smallpox antiviral drugs. At the same time, the I7L proteinase exemplifies several interesting challenges from the rational drug design perspective. In the absence of a published I7L X-ray structure, we have built a detailed 3D model of the I7L ligand binding site (S2-S2' pocket) based on exceptionally high structural conservation of this site in proteases of the ULP family. The accuracy and limitations of this model were assessed through comparative analysis of available X-ray structures of ULPs, as well as energy based conformational modeling. The 3D model of the I7L ligand binding site was used to perform covalent docking and VLS of a comprehensive library of about 230,000 available ketone and aldehyde compounds. Out of 456 predicted ligands, 97 inhibitors of I7L proteinase activity were confirmed in biochemical assays (˜20% overall hit rate). These experimental results both validate our I7L ligand binding model and provide initial leads for rational optimization of poxvirus I7L proteinase inhibitors. Thus, fragments predicted to bind in the prime portion of the active site can be combined with fragments on non-prime side to yield compounds with improved activity and specificity.

Sandia National Laboratories: Research: Research Foundations: Radiation

Science.gov Websites

Effects and High Energy Density Science Sandia National Laboratories Exceptional service in the Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects & High Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy

Sandia National Laboratories: Research: Research Foundations

Science.gov Websites

Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density Science Science Geoscience Materials Science Nanodevices and Microsystems Radiation Effects and High Energy Nanodevices and Microsystems Radiation Effects and High Energy Density Science Exceptional service in the

A latent modeling approach to genotype-phenotype relationships: maternal problem behavior clusters, prenatal smoking, and MAOA genotype.

PubMed

McGrath, L M; Mustanski, B; Metzger, A; Pine, D S; Kistner-Griffin, E; Cook, E; Wakschlag, L S

2012-08-01

This study illustrates the application of a latent modeling approach to genotype-phenotype relationships and gene × environment interactions, using a novel, multidimensional model of adult female problem behavior, including maternal prenatal smoking. The gene of interest is the monoamine oxidase A (MAOA) gene which has been well studied in relation to antisocial behavior. Participants were adult women (N = 192) who were sampled from a prospective pregnancy cohort of non-Hispanic, white individuals recruited from a neighborhood health clinic. Structural equation modeling was used to model a female problem behavior phenotype, which included conduct problems, substance use, impulsive-sensation seeking, interpersonal aggression, and prenatal smoking. All of the female problem behavior dimensions clustered together strongly, with the exception of prenatal smoking. A main effect of MAOA genotype and a MAOA × physical maltreatment interaction were detected with the Conduct Problems factor. Our phenotypic model showed that prenatal smoking is not simply a marker of other maternal problem behaviors. The risk variant in the MAOA main effect and interaction analyses was the high activity MAOA genotype, which is discrepant from consensus findings in male samples. This result contributes to an emerging literature on sex-specific interaction effects for MAOA.

Experimental and Computational Aerothermodynamics of a Mars Entry Vehicle

NASA Technical Reports Server (NTRS)

Hollis, Brian R.

1996-01-01

An aerothermodynamic database has been generated through both experimental testing and computational fluid dynamics simulations for a 70 deg sphere-cone configuration based on the NASA Mars Pathfinder entry vehicle. The aerothermodynamics of several related parametric configurations were also investigated. Experimental heat-transfer data were obtained at hypersonic test conditions in both a perfect gas air wind tunnel and in a hypervelocity, high-enthalpy expansion tube in which both air and carbon dioxide were employed as test gases. In these facilities, measurements were made with thin-film temperature-resistance gages on both the entry vehicle models and on the support stings of the models. Computational results for freestream conditions equivalent to those of the test facilities were generated using an axisymmetric/2D laminar Navier-Stokes solver with both perfect-gas and nonequilibrium thermochemical models. Forebody computational and experimental heating distributions agreed to within the experimental uncertainty for both the perfect-gas and high-enthalpy test conditions. In the wake, quantitative differences between experimental and computational heating distributions for the perfect-gas conditions indicated transition of the free shear layer near the reattachment point on the sting. For the high enthalpy cases, agreement to within, or slightly greater than, the experimental uncertainty was achieved in the wake except within the recirculation region, where further grid resolution appeared to be required. Comparisons between the perfect-gas and high-enthalpy results indicated that the wake remained laminar at the high-enthalpy test conditions, for which the Reynolds number was significantly lower than that of the perfect-gas conditions.

Modeling human risk: Cell & molecular biology in context

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

NONE

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small butmore » highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with those of radiation exposure. A select panel will evaluate the utilizing experiments and models to accurately predict the risks associated with exposure to HZE particles. Topics of research include cellular and tissue response, health effects associated with radiation damage, model animal systems, and critical markers of Radiation response.« less

The impact of on-site wastewater from high density cluster developments on groundwater quality

NASA Astrophysics Data System (ADS)

Morrissey, P. J.; Johnston, P. M.; Gill, L. W.

2015-11-01

The net impact on groundwater quality from high density clusters of unsewered housing across a range of hydro(geo)logical settings has been assessed. Four separate cluster development sites were selected, each representative of different aquifer vulnerability categories. Groundwater samples were collected on a monthly basis over a two year period for chemical and microbiological analysis from nested multi-horizon sampling boreholes upstream and downstream of the study sites. The field results showed no statistically significant difference between upstream and downstream water quality at any of the study areas, although there were higher breakthroughs in contaminants in the High and Extreme vulnerability sites linked to high intensity rainfall events; these however, could not be directly attributed to on-site effluent. Linked numerical models were then built for each site using HYDRUS 2D to simulate the attenuation of contaminants through the unsaturated zone from which the resulting hydraulic and contaminant fluxes at the water table were used as inputs into MODFLOW MT3D models to simulate the groundwater flows. The results of the simulations confirmed the field observations at each site, indicating that the existing clustered on-site wastewater discharges would only cause limited and very localised impacts on groundwater quality, with contaminant loads being quickly dispersed and diluted downstream due to the relatively high groundwater flow rates. Further simulations were then carried out using the calibrated models to assess the impact of increasing cluster densities revealing little impact at any of the study locations up to a density of 6 units/ha with the exception of the Extreme vulnerability site.

Measurement of the Solar Absorptance and Thermal Emittance of Lunar Simulants

NASA Technical Reports Server (NTRS)

Gaier, James R.; Street, Kenneth W.; Gutafson, Robert J.

2010-01-01

The first comparative study of the reflectance spectra of lunar simulants is presented. All of the simulants except one had a wavelength-dependant reflectivity ( ( )) near 0.10 over the wavelength range of 8 to 25 m, so they are highly emitting at room temperature and lower. The 300 K emittance ( ) of all the lunar simulants except one ranged from 0.884 to 0.906. The 300 K of JSC Mars-1 simulant was 0.927. There was considerably more variation in the lunar simulant reflectance in the solar spectral range (250 to 2500 nm) than in the thermal infrared. Larger particle size simulants reflected much less than those with smaller particle size. As expected, the lunar highlands simulants were more reflective in this wavelength range than the lunar mare simulants. The integrated solar absorptance ( ) of the simulants ranged from 0.413 to 0.817 for those with smaller particles, and 0.669 to 0.906 for those with larger particles. Although spectral differences were observed, the for the simulants appears to be similar to that of lunar soils (0.65 to 0.88). These data are now available to be used in modeling the effects of dust on thermal control surfaces.

Age-related changes in reasons for using alcohol and marijuana from ages 18 to 30 in a national sample.

PubMed

Patrick, Megan E; Schulenberg, John E; O'Malley, Patrick M; Maggs, Jennifer L; Kloska, Deborah D; Johnston, Lloyd D; Bachman, Jerald G

2011-06-01

This study used up to seven waves of data from 32 consecutive cohorts of participants in the national longitudinal Monitoring the Future study to model changes in self-reported reasons for using alcohol and marijuana by age (18 to 30), gender, and recent substance use. The majority of stated reasons for use decreased in prevalence across young adulthood (e.g., social/recreational and coping with negative affect reasons); exceptions included age-related increases in using to relax (alcohol and marijuana), to sleep (alcohol), because it tastes good (alcohol), and to get high (marijuana). Women were more likely than men to report drinking for reasons involving distress (i.e., to get away from problems), while men were more likely than women to endorse all other reasons. Greater substance use at age 18 was associated with greater likelihood of all reasons except to experiment and to fit in. A better understanding of developmental changes in reasons for use is important for understanding normative changes in substance use behaviors and for informing intervention efforts involving underlying reasons for use. (PsycINFO Database Record (c) 2011 APA, all rights reserved).

Measurement of the Solar Absorptance and Thermal Emittance of Lunar Simulants

NASA Technical Reports Server (NTRS)

Gaier, James R.; Street, Kenneth W.; Gustafson, Robert J.

2010-01-01

The first comparative study of the reflectance spectra of lunar simulants is presented. All of the simulants except one had a wavelength-dependent reflectivity, rho(lambda), near 0.10 over the wavelength range of 8 to 25 microns, so they are highly emitting at room temperature and lower. The 300 K emittance, epsilon, of all the lunar simulants except one ranged from 0.884 to 0.906. The 300 K epsilon of JSC Mars-1 simulant was 0.927. There was considerably more variation in the lunar simulant reflectance in the solar spectral range (250 to 2500 nm) than in the thermal infrared. Larger particle size simulants reflected much less than those with smaller particle size. As expected, the lunar highlands simulants were more reflective in this wavelength range than the lunar mare simulants. The alpha of the simulants ranged from 0.413 to 0.817 for those with smaller particles and 0.669 to 0.906 for large particles. Although spectral differences were observed, the total integrated alpha for the simulants appears to be similar to that of lunar soils (0.65 to 0.88). These data are now available to be used in modeling the effects of dust on thermal control surfaces.

The relationship between consanguineous marriage and death in fetus and infants.

PubMed

Mohammadi, Majid Mehr; Hooman, Heidar Ali; Afrooz, Gholam Ali; Daramadi, Parviz Sharifi

2012-05-01

Given the high prevalence of consanguineous marriages in rural and urban areas of Iran, the aim of this study was to identify its role in increasing fetal and infant deaths. This was a cross-sectional study in which 494 mothers with more than one exceptional child (mentally retarded and physically-dynamically disabled) or with normal children were selected based on multi-stage random sampling method. Data was gathered using the features of parents with more than one exceptional child questionnaire. The validity and reliability of this questionnaire was acceptable. Hierarchical log-linear method was used for statistical analysis. Consanguineous marriage significantly increased the number of births of exceptional children. Moreover, there was a significant relation between the history of fetal/infant death and belonging to the group. There was a significant relation between consanguineous marriage and the history of fetal/infant death which means consanguineous marriage increased the prevalence of fetal/infant death in parents with exceptional children rather than in parents with normal children. The rate of fetal/infant death in exceptional births of consanguineous marriages was higher than that of non-consanguineous marriages.

Accounting for undetected compounds in statistical analyses of mass spectrometry 'omic studies.

PubMed

Taylor, Sandra L; Leiserowitz, Gary S; Kim, Kyoungmi

2013-12-01

Mass spectrometry is an important high-throughput technique for profiling small molecular compounds in biological samples and is widely used to identify potential diagnostic and prognostic compounds associated with disease. Commonly, this data generated by mass spectrometry has many missing values resulting when a compound is absent from a sample or is present but at a concentration below the detection limit. Several strategies are available for statistically analyzing data with missing values. The accelerated failure time (AFT) model assumes all missing values result from censoring below a detection limit. Under a mixture model, missing values can result from a combination of censoring and the absence of a compound. We compare power and estimation of a mixture model to an AFT model. Based on simulated data, we found the AFT model to have greater power to detect differences in means and point mass proportions between groups. However, the AFT model yielded biased estimates with the bias increasing as the proportion of observations in the point mass increased while estimates were unbiased with the mixture model except if all missing observations came from censoring. These findings suggest using the AFT model for hypothesis testing and mixture model for estimation. We demonstrated this approach through application to glycomics data of serum samples from women with ovarian cancer and matched controls.

A comparison between two simulation models for spread of foot-and-mouth disease.

PubMed

Halasa, Tariq; Boklund, Anette; Stockmarr, Anders; Enøe, Claes; Christiansen, Lasse E

2014-01-01

Two widely used simulation models of foot-and-mouth disease (FMD) were used in order to compare the models' predictions in term of disease spread, consequence, and the ranking of the applied control strategies, and to discuss the effect of the way disease spread is modeled on the predicted outcomes of each model. The DTU-DADS (version 0.100), and ISP (version 2.001.11) were used to simulate a hypothetical spread of FMD in Denmark. Actual herd type, movements, and location data in the period 1st October 2006 and 30th September 2007 was used. The models simulated the spread of FMD using 3 different control scenarios: 1) A basic scenario representing EU and Danish control strategies, 2) pre-emptive depopulation of susceptible herds within a 500 meters radius around the detected herds, and 3) suppressive vaccination of susceptible herds within a 1,000 meters radius around the detected herds. Depopulation and vaccination started 14 days following the detection of the first infected herd. Five thousand index herds were selected randomly, of which there were 1,000 cattle herds located in high density cattle areas and 1,000 in low density cattle areas, 1,000 swine herds located in high density swine areas and 1,000 in low density swine areas, and 1,000 sheep herds. Generally, DTU-DADS predicted larger, longer duration and costlier epidemics than ISP, except when epidemics started in cattle herds located in high density cattle areas. ISP supported suppressive vaccination rather than pre-emptive depopulation, while DTU-DADS was indifferent to the alternative control strategies. Nonetheless, the absolute differences between control strategies were small making the choice of control strategy during an outbreak to be most likely based on practical reasons.

Integrated Model of Chemical Perturbations of a Biological Pathway Using 18 In Vitro High-Throughput Screening Assays for the Estrogen Receptor

PubMed Central

Judson, Richard S.; Magpantay, Felicia Maria; Chickarmane, Vijay; Haskell, Cymra; Tania, Nessy; Taylor, Jean; Xia, Menghang; Huang, Ruili; Rotroff, Daniel M.; Filer, Dayne L.; Houck, Keith A.; Martin, Matthew T.; Sipes, Nisha; Richard, Ann M.; Mansouri, Kamel; Setzer, R. Woodrow; Knudsen, Thomas B.; Crofton, Kevin M.; Thomas, Russell S.

2015-01-01

We demonstrate a computational network model that integrates 18 in vitro, high-throughput screening assays measuring estrogen receptor (ER) binding, dimerization, chromatin binding, transcriptional activation, and ER-dependent cell proliferation. The network model uses activity patterns across the in vitro assays to predict whether a chemical is an ER agonist or antagonist, or is otherwise influencing the assays through a manner dependent on the physics and chemistry of the technology platform (“assay interference”). The method is applied to a library of 1812 commercial and environmental chemicals, including 45 ER positive and negative reference chemicals. Among the reference chemicals, the network model correctly identified the agonists and antagonists with the exception of very weak compounds whose activity was outside the concentration range tested. The model agonist score also correlated with the expected potency class of the active reference chemicals. Of the 1812 chemicals evaluated, 111 (6.1%) were predicted to be strongly ER active in agonist or antagonist mode. This dataset and model were also used to begin a systematic investigation of assay interference. The most prominent cause of false-positive activity (activity in an assay that is likely not due to interaction of the chemical with ER) is cytotoxicity. The model provides the ability to prioritize a large set of important environmental chemicals with human exposure potential for additional in vivo endocrine testing. Finally, this model is generalizable to any molecular pathway for which there are multiple upstream and downstream assays available. PMID:26272952