Monte Carlo calculations of LR115 detector response to 222Rn in the presence of 220Rn.

PubMed

Nikezić, D; Yu, K N

2000-04-01

The sensitivities (in m) of bare LR115 detectors and detectors in diffusion chambers to 222Rn and 220Rn chains are calculated by the Monte Carlo method. The partial sensitivities of bare detectors to the 222Rn chain are larger than those to the 220Rn chain, which is due to the higher energies of alpha particles in the 220Rn chain and the upper energy limit for detection for the LR115 detector. However, the total sensitivities are approximately equal because 220Rn is always in equilibrium with its first progeny, which is not the case for the 222Rn chain. The total sensitivity of bare LR115 detectors to 222Rn chain depends linearly on the equilibrium factor. The overestimation in 222Rn measurements with bare detectors caused by 220Rn in air can reach 10% in normal environmental conditions. An analytical relationship between the equilibrium factor and the ratio between track densities on the bare detector and the detector enclosed in chamber is given in the last part of the paper. This ratio is also affected by 220Rn, which can disturb the determination of the equilibrium factor.

Spin Polarization and Quantum Spins in Au Nanoparticles

PubMed Central

Li, Chi-Yen; Karna, Sunil K.; Wang, Chin-Wei; Li, Wen-Hsien

2013-01-01

The present study focuses on investigating the magnetic properties and the critical particle size for developing sizable spontaneous magnetic moment of bare Au nanoparticles. Seven sets of bare Au nanoparticle assemblies, with diameters from 3.5 to 17.5 nm, were fabricated with the gas condensation method. Line profiles of the X-ray diffraction peaks were used to determine the mean particle diameters and size distributions of the nanoparticle assemblies. The magnetization curves M(Ha) reveal Langevin field profiles. Magnetic hysteresis was clearly revealed in the low field regime even at 300 K. Contributions to the magnetization from different size particles in the nanoparticle assemblies were considered when analyzing the M(Ha) curves. The results show that the maximum particle moment will appear in 2.4 nm Au particles. A similar result of the maximum saturation magnetization appearing in 2.3 nm Au particles is also concluded through analysis of the dependency of the saturation magnetization MP on particle size. The MP(d) curve departs significantly from the 1/d dependence, but can be described by a log-normal function. Magnetization can be barely detected for Au particles larger than 27 nm. Magnetic field induced Zeeman magnetization from the quantum confined Kubo gap opening appears in Au nanoparticles smaller than 9.5 nm in diameter. PMID:23989607

Assembling Bare Au Nanoparticles at Positively Charged Templates

DOE PAGES

Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; ...

2016-05-26

In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), displaymore » less in-plane regular packing compared to bare AuNPs.« less

[Bare Soil Moisture Inversion Model Based on Visible-Shortwave Infrared Reflectance].

PubMed

Zheng, Xiao-po; Sun, Yue-jun; Qin, Qi-ming; Ren, Hua-zhong; Gao, Zhong-ling; Wu, Ling; Meng, Qing-ye; Wang, Jin-liang; Wang, Jian-hua

2015-08-01

Soil is the loose solum of land surface that can support plants. It consists of minerals, organics, atmosphere, moisture, microbes, et al. Among its complex compositions, soil moisture varies greatly. Therefore, the fast and accurate inversion of soil moisture by using remote sensing is very crucial. In order to reduce the influence of soil type on the retrieval of soil moisture, this paper proposed a normalized spectral slope and absorption index named NSSAI to estimate soil moisture. The modeling of the new index contains several key steps: Firstly, soil samples with different moisture level were artificially prepared, and soil reflectance spectra was consequently measured using spectroradiometer produced by ASD Company. Secondly, the moisture absorption spectral feature located at shortwave wavelengths and the spectral slope of visible wavelengths were calculated after analyzing the regular spectral feature change patterns of different soil at different moisture conditions. Then advantages of the two features at reducing soil types' effects was synthesized to build the NSSAI. Thirdly, a linear relationship between NSSAI and soil moisture was established. The result showed that NSSAI worked better (correlation coefficient is 0.93) than most of other traditional methods in soil moisture extraction. It can weaken the influences caused by soil types at different moisture levels and improve the bare soil moisture inversion accuracy.

Anomalous photoconductive behavior of a single InAs nanowire photodetector

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

Li, Junshuai; Yan, Xin; Sun, Fukuan

2015-12-28

We report on a bare InAs nanowire photodetector which exhibits an anomalous photoconductive behavior. Under low-power illumination, the current is smaller than the dark current, and monotonously decreases as the excitation power increases. When the excitation power is high enough, the current starts to increase normally. The phenomenon is attributed to different electron mobilities in the “core” and “shell” of a relatively thick nanowire originating from the surface effect, which result in a quickly dropped “core current” and slowly increased “shell current” under illumination.

Nest site selection by diamond-backed terrapins (Malaclemys terrapin) on a Mid-Atlantic Barrier Island

USGS Publications Warehouse

Mitchell, Joseph C.; Walls, Susan C.

2013-01-01

We scored 48 Malaclemys terrapin nests destroyed by raccoons on Fisherman Island, Virginia, for the presence or absence of tree canopy, shrub canopy, no canopy, bare sand, grass cover, and herbaceous cover. Significantly more nests than expected were found in the open with no vegetation cover and observed distances of predator-destroyed nests from the edge of the nearest habitat island of woody vegetation were significantly different from a normal distribution; most were placed near the island margin. Our results underscore the need to understand the influence of predator search behavior on terrapin nest survival in different habitat types.

Outcomes of Prosthetic Hemodialysis Grafts after Deployment of Bare Metal versus Covered Stents at the Venous Anastomosis

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

Kim, Charles Y., E-mail: charles.kim@duke.edu; Tandberg, Daniel J.; Rosenberg, Michael D.

2012-08-15

Purpose: To compare postintervention patency rates after deployment of bare metal versus covered stents across the venous anastomosis of prosthetic arteriovenous (AV) grafts. Methods: Review of our procedural database over a 6 year period revealed 377 procedures involving stent deployment in an AV access circuit. After applying strict inclusion criteria, our study group consisted of 61 stent deployments in 58 patients (median age 58 years, 25 men, 33 women) across the venous anastomosis of an upper extremity AV graft circuit that had never been previously stented. Both patent and thrombosed AV access circuits were retrospectively analyzed. Within the bare metalmore » stent group, 20 of 32 AV grafts were thrombosed at initial presentation compared to 18 of 29 AV grafts in the covered stent group. Results: Thirty-two bare metal stents and 29 covered stents were deployed across the venous anastomosis. The 3, 6, and 12 months primary access patency rates for bare metal stents were not significantly different than for covered stents: 50, 41, and 22 % compared to 59, 52, and 29 %, respectively (p = 0.21). The secondary patency rates were also not significantly different: 78, 78, and 68 % for bare metal stents compared to 76, 69, and 61 % for covered stents, respectively (p = 0.85). However, covered stents demonstrated a higher primary stent patency rate than bare metal stents: 100, 85, and 70 % compared to 75, 67, and 49 % at 3, 6, and 12 months (p < 0.01). Conclusion: The primary and secondary access patency rates after deployment of bare metal versus covered stents at the venous anastomosis were not significantly different. However, bare metal stents developed in-stent stenoses significantly sooner.« less

LETTER TO THE EDITOR: Exact energy distribution function in a time-dependent harmonic oscillator

NASA Astrophysics Data System (ADS)

Robnik, Marko; Romanovski, Valery G.; Stöckmann, Hans-Jürgen

2006-09-01

Following a recent work by Robnik and Romanovski (2006 J. Phys. A: Math. Gen. 39 L35, 2006 Open Syst. Inf. Dyn. 13 197-222), we derive an explicit formula for the universal distribution function of the final energies in a time-dependent 1D harmonic oscillator, whose functional form does not depend on the details of the frequency ω(t) and is closely related to the conservation of the adiabatic invariant. The normalized distribution function is P(x) = \\pi^{-1} (2\\mu^2 - x^2)^{-\\frac{1}{2}} , where x=E_1- \\skew3\\bar{E}_1 ; E1 is the final energy, \\skew3\\bar{E}_1 is its average value and µ2 is the variance of E1. \\skew3\\bar{E}_1 and µ2 can be calculated exactly using the WKB approach to all orders.

Feasibility of correlating separation of ternary mixtures of neutral analytes via thin layer chromatography with supercritical fluid chromatography in support of green flash separations.

PubMed

Ashraf-Khorassani, M; Yan, Q; Akin, A; Riley, F; Aurigemma, C; Taylor, L T

2015-10-30

Method development for normal phase flash liquid chromatography traditionally employs preliminary screening using thin layer chromatography (TLC) with conventional solvents on bare silica. Extension to green flash chromatography via correlation of TLC migration results, with conventional polar/nonpolar liquid mixtures, and packed column supercritical fluid chromatography (SFC) retention times, via gradient elution on bare silica with a suite of carbon dioxide mobile phase modifiers, is reported. Feasibility of TLC/SFC correlation is individually described for eight ternary mixtures for a total of 24 neutral analytes. The experimental criteria for TLC/SFC correlation was assumed to be as follows: SFC/UV/MS retention (tR) increases among each of the three resolved mixture components; while, TLC migration (Rf) decreases among the same resolved mixture components. Successful correlation of TLC to SFC was observed for most of the polar organic solvents tested, with the best results observed via SFC on bare silica with methanol as the CO2 modifier and TLC on bare silica with a methanol/dichloromethane mixture. Copyright © 2015 Elsevier B.V. All rights reserved.

Bed load tracer mobility in a mixed bedrock/alluvial channel

NASA Astrophysics Data System (ADS)

Ferguson, R. I.; Sharma, B. P.; Hodge, R. A.; Hardy, R. J.; Warburton, J.

2017-04-01

The presence of bare or partially covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged tracer clasts to investigate bed load transport during the same sequence of floods in fully alluvial, bare rock, and partial-cover reaches of an upland stream. High-flow shear stresses in different reaches were calculated by using stage loggers. Tracers seeded in the upstream alluvial channel moved more slowly than elsewhere until the frontrunners reached bare rock and sped up. Tracers seeded on bare rock moved rapidly off it and accumulated just upstream from, and later in, a partial-cover zone with many boulders. The backwater effect of the boulder-rich zone is significant in reducing tracer mobility. Tracer movement over full or partial sediment cover was size selective but dispersion over bare rock was not. Along-channel changes in tracer mobility are interpreted in terms of measured differences in shear stress and estimated differences in threshold stress.

Where did the time go? Friction evolves with slip following large velocity steps, normal stress steps, and (?) during long holds

NASA Astrophysics Data System (ADS)

Rubin, A. M.; Bhattacharya, P.; Tullis, T. E.; Okazaki, K.; Beeler, N. M.

2016-12-01

The popular constitutive formulations of rate-and-state friction offer two end-member views on whether friction evolves only with slip (Slip law state evolution) or with time even without slip (Aging law state evolution). While rate stepping experiments show support for the Slip law, laboratory observed frictional behavior of initially bare rock surfaces near zero slip rate has traditionally been interpreted to show support for time-dependent evolution of frictional strength. Such laboratory derived support for time-dependent evolution has been one of the motivations behind the Aging law being widely used to model earthquake cycles on natural faults.Through a combination of theoretical results and new experimental data on initially bare granite, we show stronger support for the other end member view, i.e. that friction under a wide range of sliding conditions evolves only with slip. Our dataset is unique in that it combines up to 3.5 orders of magnitude rate steps, sequences of holds up to 10000s, and 5% normal stress steps at order of magnitude different sliding rates during the same experimental run. The experiments were done on the Brown rotary shear apparatus using servo feedback, making the machine stiff enough to provide very large departures from steady-state while maintaining stable, quasi-static sliding. Across these diverse sliding conditions, and in particular for both large velocity step decreases and the longest holds, the data are much more consistent with the Slip law version of slip-dependence than the time-dependence formulated in the Aging law. The shear stress response to normal stress steps is also consistently better explained by the Slip law when paired with the Linker-Dieterich type response to normal stress perturbations. However, the remarkable symmetry and slip-dependence of the normal stress step increases and decreases suggest deficiencies in the Linker-Dieterich formulation that we will probe in future experiments.High quality measurements of interface compaction from the normal-stress steps suggest that the instantaneous changes in state and contact area are opposite in sign, indicating that state evolution might be fundamentally connected to contact quality, and not quantity alone.

Effects of rainfall patterns and land cover on the subsurface flow generation of sloping Ferralsols in southern China

PubMed Central

Yang, Jie; Tang, Chongjun; Chen, Lihua; Liu, Yaojun; Wang, Lingyun

2017-01-01

Rainfall patterns and land cover are two important factors that affect the runoff generation process. To determine the surface and subsurface flows associated with different rainfall patterns on sloping Ferralsols under different land cover types, observational data related to surface and subsurface flows from 5 m × 15 m plots were collected from 2010 to 2012. The experiment was conducted to assess three land cover types (grass, litter cover and bare land) in the Jiangxi Provincial Soil and Water Conservation Ecological Park. During the study period, 114 natural rainfall events produced subsurface flow and were divided into four groups using k-means clustering according to rainfall duration, rainfall depth and maximum 30-min rainfall intensity. The results showed that the total runoff and surface flow values were highest for bare land under all four rainfall patterns and lowest for the covered plots. However, covered plots generated higher subsurface flow values than bare land. Moreover, the surface and subsurface flows associated with the three land cover types differed significantly under different rainfall patterns. Rainfall patterns with low intensities and long durations created more subsurface flow in the grass and litter cover types, whereas rainfall patterns with high intensities and short durations resulted in greater surface flow over bare land. Rainfall pattern I had the highest surface and subsurface flow values for the grass cover and litter cover types. The highest surface flow value and lowest subsurface flow value for bare land occurred under rainfall pattern IV. Rainfall pattern II generated the highest subsurface flow value for bare land. Therefore, grass or litter cover are able to convert more surface flow into subsurface flow under different rainfall patterns. The rainfall patterns studied had greater effects on subsurface flow than on total runoff and surface flow for covered surfaces, as well as a greater effect on surface flows associated with bare land. PMID:28792507

3D laser measurements of bare and shod feet during walking.

PubMed

Novak, Boštjan; Možina, Janez; Jezeršek, Matija

2014-01-01

This article presents a new system for 3D foot-shape measurements during walking. It is based on the laser-triangulation, multiple-line-illumination and color-modulation techniques. It consists of a walking stage and four measuring modules that simultaneously acquire the foot shape from the top, bottom and side views. The measuring speed is 30 fps. Custom-developed software makes it possible to analyze the foot's dimensions at an arbitrary cross-section by means of the width, height, girth and section orientation. Six subjects were measured during bare and shod walking, and the bare foot and the outside dimensions of the footwear during the entire stance phase are presented. The relative measurement repeatability of a single subject is 0.5% for bare foot and 1% for shod foot. This means that it is possible to study the differences between various influences on the foot-shape dynamics, such as a bare/shod foot, different loading conditions and the shoe's stiffness condition. Copyright © 2014 Elsevier B.V. All rights reserved.

Temperature responses of carbon monoxide and hydrogen uptake by vegetated and unvegetated volcanic cinders

PubMed Central

King, Caitlin E; King, Gary M

2012-01-01

Ecosystem succession on a large deposit of volcanic cinders emplaced on Kilauea Volcano in 1959 has resulted in a mosaic of closed-canopy forested patches and contiguous unvegetated patches. Unvegetated and unshaded surface cinders (Bare) experience substantial diurnal temperature oscillations ranging from moderate (16 °C) to extreme (55 °C) conditions. The surface material of adjacent vegetated patches (Canopy) experiences much smaller fluctuations (14–25 °C) due to shading. To determine whether surface material from these sites showed adaptations by carbon monoxide (CO) and hydrogen (H2) consumption to changes in ambient temperature regimes accompanying succession, we measured responses of CO and H2 uptake to short-term variations in temperature and long-term incubations at elevated temperature. Based on its broader temperature optimum and lower activation energy, Canopy H2 uptake was less sensitive than Bare H2 uptake to temperature changes. In contrast, Bare and Canopy CO uptake responded similarly to temperature during short-term incubations, indicating no differences in temperature sensitivity. However, during extended incubations at 55 °C, CO uptake increased for Canopy but not Bare material, which indicated that the former was capable of thermal adaptation. H2 uptake for material from both sites was completely inhibited at 55 °C throughout extended incubations. These results indicated that plant development during succession did not elicit differences in short-term temperature responses for Bare and Canopy CO uptake, in spite of previously reported differences in CO oxidizer community composition, and differences in average daily and extreme temperatures. Differences associated with vegetation due to succession did, however, lead to a notable capacity for thermophilic CO uptake by Canopy but not Bare material. PMID:22258097

Temperature responses of carbon monoxide and hydrogen uptake by vegetated and unvegetated volcanic cinders.

PubMed

King, Caitlin E; King, Gary M

2012-08-01

Ecosystem succession on a large deposit of volcanic cinders emplaced on Kilauea Volcano in 1959 has resulted in a mosaic of closed-canopy forested patches and contiguous unvegetated patches. Unvegetated and unshaded surface cinders (Bare) experience substantial diurnal temperature oscillations ranging from moderate (16 °C) to extreme (55 °C) conditions. The surface material of adjacent vegetated patches (Canopy) experiences much smaller fluctuations (14-25 °C) due to shading. To determine whether surface material from these sites showed adaptations by carbon monoxide (CO) and hydrogen (H(2)) consumption to changes in ambient temperature regimes accompanying succession, we measured responses of CO and H(2) uptake to short-term variations in temperature and long-term incubations at elevated temperature. Based on its broader temperature optimum and lower activation energy, Canopy H(2) uptake was less sensitive than Bare H(2) uptake to temperature changes. In contrast, Bare and Canopy CO uptake responded similarly to temperature during short-term incubations, indicating no differences in temperature sensitivity. However, during extended incubations at 55 °C, CO uptake increased for Canopy but not Bare material, which indicated that the former was capable of thermal adaptation. H(2) uptake for material from both sites was completely inhibited at 55 °C throughout extended incubations. These results indicated that plant development during succession did not elicit differences in short-term temperature responses for Bare and Canopy CO uptake, in spite of previously reported differences in CO oxidizer community composition, and differences in average daily and extreme temperatures. Differences associated with vegetation due to succession did, however, lead to a notable capacity for thermophilic CO uptake by Canopy but not Bare material.

Geomorphology and reflectance patterns of vegetation-covered dunes at the Tsodilo Hills, north-west Botswana

NASA Technical Reports Server (NTRS)

Jacobberger, P. A.; Hooper, D. M.

1991-01-01

Seasonal reflectance variations in semigrid environments provide a means of assessing vegetation health and density as well as monitoring landform processes. Multitemporal Landsat Thematic Mapper scenes with field measurements are used to map geomorphology and vegetation density in a stabilized dune environment and to measure seasonal reflectance changes for a series of ten geomorphological and vegetation units on the Kalahari-age linear dunes. Units were chosen based on differences in landform and proportion of trees, forbs and bare soil. Reflectance curves and normalized-difference vegetation indices (NDVI) show that dune crests have the strongest seasonal variability in color and brightness. The geomorphological link with reflectance and NDVI values are linked to biomass production and zoning of vegetation with slope, drainage and subtle soil differences.

Size-amplified acoustofluidic separation of circulating tumor cells with removable microbeads

NASA Astrophysics Data System (ADS)

Liu, Huiqin; Ao, Zheng; Cai, Bo; Shu, Xi; Chen, Keke; Rao, Lang; Luo, Changliang; Wang, Fu-Bin; Liu, Wei; Bondesson, Maria; Guo, Shishang; Guo, Feng

2018-06-01

Isolation and analysis of rare circulating tumor cells (CTCs) is of great interest in cancer diagnosis, prognosis, and treatment efficacy evaluation. Acoustofluidic cell separation becomes an attractive method due to its contactless, noninvasive, simple, and versatile features. However, the indistinctive physical difference between CTCs and normal blood cells limits the purity of CTCs using current acoustic methods. Herein, we demonstrate a size-amplified acoustic separation and release of CTCs with removable microbeads. CTCs selectively bound to size-amplifiers (40 μm-diameter anti-EpCAM/gelatin-coated SiO2 microbeads) have significant physical differences (size and mechanics) compared to normal blood cells, resulting in an amplification of acoustic radiation force approximately a hundredfold over that of bare CTCs or normal blood cells. Therefore, CTCs can be efficiently sorted out with size-amplifiers in a traveling surface acoustic wave microfluidic device and released from size-amplifiers by enzymatic degradation for further purification or downstream analysis. We demonstrate a cell separation from blood samples with a total efficiency (E total) of ∼ 77%, purity (P) of ∼ 96%, and viability (V) of ∼83% after releasing cells from size-amplifiers. Our method substantially improves the emerging application of rare cell purification for translational medicine.

Au doping effects on electrical and optical properties of vanadium dioxides

NASA Astrophysics Data System (ADS)

Zhu, YaBin; He, Fan; Na, Jie

2012-03-01

Vanadium dioxides were fabricated on normal glass substrates using reactive radio frequency (RF) magnetron sputtering. The oxygen flow volume and annealed temperatures as growth parameters are systematically investigated. The electrical and optical properties of VO2 and Au:VO2 thin films with different growth conditions are discussed. The semiconductor-metal phase transition temperature decreased by ˜10°C for the sample with Au doping compared to the sample without Au doping. However, the optical transmittance of Au:VO2 thin films is much lower than that of bare VO2. These results show that Au doping has a marked effect on the electrical and optical properties.

Effective temperatures and radiation spectra for a higher-dimensional Schwarzschild-de Sitter black hole

NASA Astrophysics Data System (ADS)

Kanti, P.; Pappas, T.

2017-07-01

The absence of a true thermodynamical equilibrium for an observer located in the causal area of a Schwarzschild-de Sitter spacetime has repeatedly raised the question of the correct definition of its temperature. In this work, we consider five different temperatures for a higher-dimensional Schwarzschild-de Sitter black hole: the bare T0, the normalized TBH, and three effective ones given in terms of both the black-hole and cosmological horizon temperatures. We find that these five temperatures exhibit similarities but also significant differences in their behavior as the number of extra dimensions and the value of the cosmological constant are varied. We then investigate their effect on the energy emission spectra of Hawking radiation. We demonstrate that the radiation spectra for the normalized temperature TBH—proposed by Bousso and Hawking over twenty years ago—leads to the dominant emission curve, while the other temperatures either support a significant emission rate only in a specific Λ regime or have their emission rates globally suppressed. Finally, we compute the bulk-over-brane emissivity ratio and show that the use of different temperatures may lead to different conclusions regarding the brane or bulk dominance.

Alternative states of a semiarid grassland ecosystem: implications for ecosystem services

USGS Publications Warehouse

Miller, Mark E.; Belote, R. Travis; Bowker, Matthew A.; Garman, Steven L.

2011-01-01

Ecosystems can shift between alternative states characterized by persistent differences in structure, function, and capacity to provide ecosystem services valued by society. We examined empirical evidence for alternative states in a semiarid grassland ecosystem where topographic complexity and contrasting management regimes have led to spatial variations in levels of livestock grazing. Using an inventory data set, we found that plots (n = 72) cluster into three groups corresponding to generalized alternative states identified in an a priori conceptual model. One cluster (biocrust) is notable for high coverage of a biological soil crust functional group in addition to vascular plants. Another (grass-bare) lacks biological crust but retains perennial grasses at levels similar to the biocrust cluster. A third (annualized-bare) is dominated by invasive annual plants. Occurrence of grass-bare and annualized-bare conditions in areas where livestock have been excluded for over 30 years demonstrates the persistence of these states. Significant differences among all three clusters were found for percent bare ground, percent total live cover, and functional group richness. Using data for vegetation structure and soil erodibility, we also found large among-cluster differences in average levels of dust emissions predicted by a wind-erosion model. Predicted emissions were highest for the annualized-bare cluster and lowest for the biocrust cluster, which was characterized by zero or minimal emissions even under conditions of extreme wind. Results illustrate potential trade-offs among ecosystem services including livestock production, soil retention, carbon storage, and biodiversity conservation. Improved understanding of these trade-offs may assist ecosystem managers when evaluating alternative management strategies.

Ada Compiler Validation Summary Report: Certificate Number: 940325S1. 11341 DDC-I, DACS Sun SPARC/SunOS to 80186 Bare Ada Cross Compiler System, Version 4.6.4 Sun SPARCstation IPX = Intel iSBC 186/100 (Bare Machine)

DTIC Science & Technology

1994-03-25

declarations requiring more digits than SYSTEM.MAXDIGITS: C24113L..Y (14 tests) C35705L..Y (14 tests) C35706L..Y (14 tests) C35707L..Y (14 tests) 2-1...before the DACS Run-Time System (RMs) libary normally searches for na-4ime routin;, in this way one can replace the standard DACS RTS routines with...SHORTINTEGER is range -128 .. 127; type INTEGER is range -32_768 .. 32_767; type LONGINTEGER is range -2147_483_648 .. 2_147_483_647; type FLOAT is digits 6

77 FR 61017 - Draft Habitat Conservation Plan and Application for an Incidental Take Permit, Yamhill County, OR

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-05

..., although they are identified as being mostly positive. Road maintenance activities will occur along 1.02... Maintenance Zones when revegetating disturbed or bare areas. 4. Restricting normal gravel road maintenance... endangered Fender's blue butterfly incidental to otherwise lawful activities associated with county road...

Size and shape-dependent cytotoxicity profile of gold nanoparticles for biomedical applications.

PubMed

Woźniak, Anna; Malankowska, Anna; Nowaczyk, Grzegorz; Grześkowiak, Bartosz F; Tuśnio, Karol; Słomski, Ryszard; Zaleska-Medynska, Adriana; Jurga, Stefan

2017-06-01

Metallic nanoparticles, in particular gold nanoparticles (AuNPs), offer a wide spectrum of applications in biomedicine. A crucial issue is their cytotoxicity, which depends greatly on various factors, including morphology of nanoparticles. Because metallic nanoparticles have an effect on cell membrane integrity, their shape and size may affect the viability of cells, due to their different geometries as well as physical and chemical interactions with cell membranes. Variations in the size and shape of gold nanoparticles may indicate particular nanoparticle morphologies that provide strong cytotoxicity effects. Synthesis of different sized and shaped bare AuNPs was performed with spherical (~ 10 nm), nanoflowers (~ 370 nm), nanorods (~ 41 nm), nanoprisms (~ 160 nm) and nanostars (~ 240 nm) morphologies. These nanostructures were characterized and interacting with cancer (HeLa) and normal (HEK293T) cell lines and cell viability tests were performed by WST-1 tests and fluorescent live/dead cell imaging experiments. It was shown that various shapes and sizes of gold nanostructures may affect the viability of the cells. Gold nanospheres and nanorods proved to be more toxic than star, flower and prism gold nanostructures. This may be attributed to their small size and aggregation process. This is the first report concerning a comparison of cytotoxic profile in vitro with a wide spectrum of bare AuNPs morphology. The findings show their possible use in biomedical applications.

Strategies for leukemic biomarker detection using long-range surface plasmon-polaritons

NASA Astrophysics Data System (ADS)

Krupin, O.; Wang, C.; Berini, P.

2014-09-01

The suitability and use of long-range surface plasmon-polaritons for leukemic biomarker detection is discussed. A novel optical biosensor comprised of gold straight waveguides embedded in CYTOP with an etched microfluidic channel was tested for detecting leukemia in patient serum. Gold surface functionalization involved the interaction of protein G (PG) with antibodies by first adsorbing PG on bare gold and then antibodies (Immunoglobulin G, IgG). Differentiation between healthy and leukemia patients was based on the difference in ratios of Ig kappa (Igκ) and Ig lambda (Igλ) light chains in both serums. The ratio for a normal patient is ~1.4 - 2, whereas for a leukemia patient this ratio is altered. As a receptor (primary antibodies), goat anti-human anti-IgGκ and anti-IgGλ were used to functionalize the surface. Diluted normal and leukemia patient serums were tested over the aforementioned surfaces. The ratios of mass surface densities of IgGκ:IgGλ for normal serum (NS) and patient serum (PS) were found to be 1.55 and 1.92 respectively.

Biocompatibility and Biocorrosion of Hydroxyapatite-Coated Magnesium Plate: Animal Experiment.

PubMed

Lim, Ho-Kyung; Byun, Soo-Hwan; Woo, Jae-Man; Kim, Sae-Mi; Lee, Sung-Mi; Kim, Bong-Ju; Kim, Hyoun-Ee; Lee, Jung-Woo; Kim, Soung-Min; Lee, Jong-Ho

2017-09-30

Magnesium (Mg) has the advantage of being resorbed in vivo, but its resorption rate is difficult to control. With uncontrolled resorption, Magnesium as a bone fixation material has minimal clinical value. During resorption not only is the strength rapidly weakened, but rapid formation of metabolite also occurs. In order to overcome these disadvantages, hydroxyapatite (HA) surface coating of pure magnesium plate was attempted in this study. Magnesium plates were inserted above the frontal bone of Sprague-Dawley rats in both the control group (Bare-Mg group) and the experimental group (HA-Mg group). The presence of inflammation, infection, hydrogen gas formation, wound dehiscence, and/or plate exposure was observed, blood tests were performed, and the resorption rate and tensile strength of the retrieved metal plates were measured. The HA-Mg group showed no gas formation or plate exposure until week 12. However, the Bare-Mg group showed consistent gas formation and plate exposure beginning in week 2. WBC (White Blood Cell), BUN (Blood Urea Nitrogen), Creatinine, and serum magnesium concentration levels were within normal range in both groups. AST (Aspartate Aminotransferase) and ALT (Alanine Aminotransferase) values, however, were above normal range in some animals of both groups. The HA-Mg group showed statistically significant advantage in resistance to degradation compared to the Bare-Mg group in weeks 2, 4, 6, 8, and 12. Degradation of HA-Mg plates proceeded after week 12. Coating magnesium plates with hydroxyapatite may be a viable method to maintain their strength long enough to allow bony healing and to control the resorption rate during the initial period.

Biocompatibility and Biocorrosion of Hydroxyapatite-Coated Magnesium Plate: Animal Experiment

PubMed Central

Woo, Jae-Man; Kim, Sae-Mi; Lee, Sung-Mi; Kim, Hyoun-Ee; Lee, Jung-Woo; Lee, Jong-Ho

2017-01-01

Magnesium (Mg) has the advantage of being resorbed in vivo, but its resorption rate is difficult to control. With uncontrolled resorption, Magnesium as a bone fixation material has minimal clinical value. During resorption not only is the strength rapidly weakened, but rapid formation of metabolite also occurs. In order to overcome these disadvantages, hydroxyapatite (HA) surface coating of pure magnesium plate was attempted in this study. Magnesium plates were inserted above the frontal bone of Sprague-Dawley rats in both the control group (Bare-Mg group) and the experimental group (HA-Mg group). The presence of inflammation, infection, hydrogen gas formation, wound dehiscence, and/or plate exposure was observed, blood tests were performed, and the resorption rate and tensile strength of the retrieved metal plates were measured. The HA-Mg group showed no gas formation or plate exposure until week 12. However, the Bare-Mg group showed consistent gas formation and plate exposure beginning in week 2. WBC (White Blood Cell), BUN (Blood Urea Nitrogen), Creatinine, and serum magnesium concentration levels were within normal range in both groups. AST (Aspartate Aminotransferase) and ALT (Alanine Aminotransferase) values, however, were above normal range in some animals of both groups. The HA-Mg group showed statistically significant advantage in resistance to degradation compared to the Bare-Mg group in weeks 2, 4, 6, 8, and 12. Degradation of HA-Mg plates proceeded after week 12. Coating magnesium plates with hydroxyapatite may be a viable method to maintain their strength long enough to allow bony healing and to control the resorption rate during the initial period. PMID:28973984

The Effects of Extravehicular Activity (EVA) Glove Pressure on Hand Strength

NASA Technical Reports Server (NTRS)

Mesloh, Miranda; England, Scott; Benson, Elizabeth; Thompson, Shelby; Rajulu, Sudhakar

2010-01-01

The purpose of this study was to characterize hand strength, while wearing a Phase VI Extravehicular Activity (EVA) glove in an Extravehicular Mobility Unit (EMU) suit. Three types of data were collected: hand grip, lateral pinch, and pulp-2 pinch, wider three different conditions: bare-handed, gloved with no Thermal Micrometeoroid Garment (TMG), and glove with TMG. In addition, during the gloved conditions, subjects were tested when unpressurized and pressurized (43 psi). As a percentage of bare-hand strength, the TMG condition showed reduction in grip strength to 55% unpressurized and 46% pressurized. Without the TMG, grip strength increased to 66% unpressurized and 58% pressurized of bare-hand strength. For lateral pinch strength, the reduction in strength was the same for both pressure conditions and with and without the TMG, about 8.5% of bare-hand Pulp-2 pinch strength with no TMG showed an increase to 122% unpressurized and 115% pressurized of bare-hand strength. While wearing the TMG, pulp-2 pinch strength was 115% of bare-hand strength for both pressure conditions.

Effectiveness of liquid soap vs. chlorhexidine gluconate for the removal of Clostridium difficile from bare hands and gloved hands.

PubMed

Bettin, K; Clabots, C; Mathie, P; Willard, K; Gerding, D N

1994-11-01

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile. C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student's t test. On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P = NS) and fingers (log10 CFU, 2.4 and 2.5, P = NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P < .01) and palms (log10 CFU 1.5 and 2.0, P < .01), but not finger/thumbtips (log10 CFU 1.6 with each, P = NS). Residual C difficile counts were lower on gloved hands than bare hands (P < 0.01 to < 0.0001). The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

Conditional ablation of glycogen synthase kinase 3β in postnatal mouse kidney.

PubMed

Ge, Yan; Si, Jin; Tian, Li; Zhuang, Shougang; Dworkin, Lance D; Gong, Rujun

2011-01-01

Glycogen synthase kinase (GSK)3 is a ubiquitously expressed serine/threonine kinase existing in two isoforms, namely GSK3α and GSK3β. Aside from the long-recognized role in insulin signal transduction and glycogen biosynthesis, GSK3β has been recently coined as a master control molecule in nuclear factor-κB activation and inflammatory kidney injury. Nevertheless, previous studies are less conclusive because they relied greatly on small molecule inhibitors, which lack selectivity and barely distinguish between the GSK3 isoforms. In addition, early embryonic lethality after global knockout of GSK3β precludes interrogation of the biological role of GSK3β in the adult kidney. To circumvent these issues, the Cre/loxP system was used to generate a conditional knockout mouse model in which the GSK3β gene was specifically deleted in kidney cortical tubules at postnatal mature stage. Kidney-specific ablation of GSK3β resulted in a phenotype no different from control littermates. Knockout mice (KO) were viable and exhibited normal development and normal kidney physiology in terms of kidney function, urine albumin excretion, and urine-concentrating ability. It is noteworthy that apart from normal glomerular and tubulointerstitial morphology, the kidneys from KO demonstrated more glycogen accumulation in the renal cortical tubules as assessed by both periodic acid-Schiff staining for light microscopy and direct biochemical assay, consistent with an elevated glycogen synthetic activity as evidenced by diminished inhibitory phosphorylation of glycogen synthase that occurred subsequent to GSK3β ablation. This finding was further validated by electron microscopic observations of increased deposition of glycogen particles in the renal tubules of KO, suggesting that GSK3α could not fully compensate for the loss of GSK3β in regulating glycogen metabolism in the kidney. Collectively, our study suggests that kidney-specific ablation of GSK3β barely affects kidney function and histology under normal circumstances. Extended examinations of these KO under diseased conditions are merited to understand the role of GSK3β in renal pathophysiology.

When the Exception Is the Rule: School Shootings, Bare Life, and the Sovereign Self

ERIC Educational Resources Information Center

Shapiro, Harvey

2015-01-01

Much discourse on school shootings tends to imply a binary separation between what is considered normal and exceptional, between an expected course of human events and sociohistorical aberrations. In this article Harvey Shapiro suggests the need for new directions in our responses: First, he shows how responses to school shootings tend to…

In situ sensors, weighing lysimeters and COSMOS under vegetated and bare conditions with subsurface drip irrigation

USDA-ARS?s Scientific Manuscript database

Long term weighing lysimeter records may have utility for assessment of climate changes occurring during the period of record. They typically enclose a depth of soil that exceeds the root zone of vegetation normally grown on them and have drainagy systems so that more or less natural hydrologic flux...

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

Kulkarni, Gourihar R.; Zhang, Kai; Zhao, Chun

Changes in the ice nucleation characteristics of atmospherically relevant mineral dust particles due to nitric acid coating are not well understood. Further, the atmospheric implications of dust coating on ice-cloud properties under different assumptions of primary ice nucleation mechanisms are unknown. We investigated ice nucleation ability of Arizona test dust, illite, K-feldspar and quartz as a function of temperature (-25 to -30°C) and relative humidity with respect to water (75 to 110%). Particles were size selected at 250 nm and transported (bare or coated) to the ice nucleation chamber to determine the fraction of particles nucleating ice at various temperaturemore » and water saturation conditions. All dust nucleated ice at water-subsaturated conditions, but the coated particles showed a reduction in their ice nucleation ability compared to bare particles. However, at water-supersaturated conditions, we observed that bare and coated particles had nearly similar ice nucleation characteristics. X-ray diffraction patterns indicated that structural properties of bare dust particles modified after acid treatment. We found that lattice parameters were slightly different, but crystallite sizes of the coated particles were reduced compared to bare particles. Next, single-column model results show that simulated ice crystal number concentrations mostly depends upon fraction of particles that are coated, primary ice nucleation mechanisms, and the competition between ice nucleation mechanisms to nucleate ice. In general, we observed that coating modify the ice-cloud properties and the picture of ice and mixed-phase cloud evolution is complex when different primary ice nucleation mechanisms are competing for fixed water vapor mass.« less

Methane emission by plant communities in an alpine meadow on the Qinghai-Tibetan Plateau: a new experimental study of alpine meadows and oat pasture.

PubMed

Wang, Shiping; Yang, Xiaoxia; Lin, Xingwu; Hu, Yigang; Luo, Caiyun; Xu, Guangping; Zhang, Zhenhua; Su, Ailing; Chang, Xiaofen; Chao, Zengguo; Duan, Jichuang

2009-08-23

Recently, plant-derived methane (CH(4)) emission has been questioned because limited evidence of the chemical mechanism has been identified to account for the process. We conducted an experiment with four treatments (i.e. winter-grazed, natural alpine meadow; naturally restored alpine meadow eight years after cultivation; oat pasture and bare soil without roots) during the growing seasons of 2007 and 2008 to examine the question of CH(4) emission by plant communities in the alpine meadow. Each treatment consumed CH(4) in closed, opaque chambers in the field, but two types of alpine meadow vegetation reduced CH(4) consumption compared with bare soil, whereas oat pasture increased consumption. This result could imply that meadow vegetation produces CH(4). However, measurements of soil temperature and water content showed significant differences between vegetated and bare soil and appeared to explain differences in CH(4) production between treatments. Our study strongly suggests that the apparent CH(4) production by vegetation, when compared with bare soil in some previous studies, might represent differences in soil temperature and water-filled pore space and not the true vegetation sources of CH(4).

Laboratory tests of oviposition by the African malaria mosquito, Anopheles gambiae, on dark soil as influenced by presence or absence of vegetation

PubMed Central

Huang, Juan; Walker, Edward D; Otienoburu, Philip E; Amimo, Fred; Vulule, John; Miller, James R

2006-01-01

Background Physical objects like vegetation can influence oviposition by mosquitoes on soil or water substrates. Anopheles gambiae s. l. is generally thought to utilize puddles over bare soil as its prime larval habitat and to avoid standing water populated with vegetation. In Kisian, Kenya near Kisumu, water often pools in grassy drainage areas both during and after periods of infrequent rains, when typical puddle habitats become scarce because of drying. This raised the question of whether An. gambiae has the behavioural flexibility to switch ovipositional sites when puddles over bare soil are unavailable. Methods To test whether presence and height of grasses influenced oviposition, wild-caught gravid An. gambiae s. l. were offered paired choices between wet, bare soil and wet soil populated with mixed grasses or grasses of differing height. No-choice tests were also conducted by giving females either grassy soil or bare soil. Results In choice tests, females laid four times more eggs on bare, wet soil than soil populated with grasses. However in no-choice tests, egg output was not significantly different whether grasses were present or not. Females laid significantly more eggs on soil populated with short grass than with medium, or tall grass. Conclusion This work shows An. gambiae s. l. has the capacity to oviposit into grassy aquatic habitats when typical puddles over bare soil are unavailable. This knowledge will need to be considered in the design and implementation of programmes aimed at reducing malaria transmission by suppression of An. gambiae s. l. immatures. PMID:17038187

Phytoremediation potential of transplanted bare-root seedlings of trees for lead/zinc and copper mine tailings.

PubMed

Shi, Xiang; Chen, Yi-Tai; Wang, Shu-Feng; Pan, Hong-Wei; Sun, Hai-Jing; Liu, Cai-Xia; Liu, Jian-Feng; Jiang, Ze-Ping

2016-11-01

Selecting plant species that can overcome unfavorable conditions and increase the recovery of degraded mined lands remains a challenge. A pot experiment was conducted to evaluate the feasibility of using transplanted tree seedlings for the phytoremediation of lead/zinc and copper mine tailings. One-year-old bare-root of woody species (Rhus chinensis Mill, Quercus acutissima Carruth, Liquidambar formosana Hance, Vitex trifolia Linn. var. simplicifolia Cham, Lespedeza cuneata and Amorpha fruticosa Linn) were transplanted into pots with mine tailings and tested as potential metal-tolerant plants. Seedling survival, plant growth, root trait, nutrient uptake, and metal accumulation and translocation were assessed. The six species grew in both tailings and showed different tolerance level. A. fruticosa was highly tolerant of Zn, Pb and Cu, and grew normally in both tailings. Metal concentrations were higher in the roots than in the shoots of the six species. All of the species had low bioconcentration and translocation factor values. However, R. chinensis and L. formosana had significantly higher translocation factor values for Pb (0.88) and Zn (1.78) than the other species. The nitrogen-fixing species, A. fruticosa, had the highest tolerance and biomass production, implying that it has great potential in the phytoremediation of tailing areas in southern China.

Three-year results of the VIBRANT trial of VIABAHN endoprosthesis versus bare nitinol stent implantation for complex superficial femoral artery occlusive disease.

PubMed

Geraghty, Patrick J; Mewissen, Mark W; Jaff, Michael R; Ansel, Gary M

2013-08-01

The predominant mode of bare nitinol stent failure is diffuse in-stent restenosis, and failure rates correlate to the length and complexity of the treated lesion. Addition of an expanded polytetrafluoroethylene lining to a nitinol stent frame, as found in the VIABAHN endoprosthesis, mitigates the ingrowth of intimal hyperplasia. We compared the long-term outcomes of complex superficial femoral artery disease intervention using the VIABAHN endoprosthesis to those obtained with bare nitinol stent implantation. One hundred forty-eight patients with symptomatic complex superficial femoral artery disease (TransAtlantic Inter-Society Consensus I class C and D lesions, accompanied by intermittent claudication or ischemic rest pain) were randomized to endovascular intervention using either bare nitinol stent implantation (76 patients) or nonheparin-bonded VIABAHN endoprosthesis deployment (72 patients). Patency, limb hemodynamics, and quality of life were evaluated at 1, 6, 12, 24, and 36 months following intervention. The average treated lesion measured 18 ± 8 cm in length, and 58.8% of lesions displayed segmental or complete occlusion. At 3 years, primary patency rates (defined by peak systolic velocity ratio ≤ 2.0 and no target lesion revascularization) did not significantly differ between patients treated with the VIABAHN stent graft and those who received a bare nitinol stent (24.2% vs 25.9%; P = .392). Stent fractures were significantly more common in bare nitinol stents (50.0%) than in the VIABAHN endoprostheses (2.6%). Primary-assisted patency rates were higher in those receiving bare nitinol stents than the VIABAHN stent graft (88.8% vs 69.8%; P = .04), although secondary patency rates did not differ between bare nitinol stent and stent graft recipients (89.3% vs 79.5%; P = .304). There were no instances of procedure-related mortality or amputation. The hemodynamic improvement and quality measures improved equally in both groups. The long-term outcomes of complex superficial femoral artery disease intervention using the VIABAHN endograft and bare nitinol stents are similar. Although primary patency rates are low in both study arms, excellent primary-assisted and secondary patency rates were achieved, with sustained augmentation of limb perfusion and quality-of-life measures. Patency rates diminish most rapidly in the first year after device implantation. Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Measurement of 241Am-Be spectra (bare and Pb-covered) using TLD pairs in multi-spheres: Spectrum unfolding by different methods

NASA Astrophysics Data System (ADS)

Tripathy, S. P.; Bakshi, A. K.; Sathian, V.; Tripathi, S. M.; Vega-carrillo, H. R.; Nandy, M.; Sarkar, P. K.; Sharma, D. N.

2009-01-01

The neutron spectra from a Pb-covered and a bare (without Pb-cover) 241Am-Be (α,n) source were measured using thermoluminescent detector (TLD) pairs of 6LiF and 7LiF with high-density polyethylene (HDPE) multi-spheres of seven different diameters. A total of 8 distinct neutron response signals (including a bare mode exposure) were obtained from which the energy distribution for the entire energy range was generated with the help of different neutron spectrum unfolding methods, viz. BUNKI, BUNKIUT and Frascati unfolding interactive tool (FRUIT). Shape of these spectra are matching very well and is also comparable with the standard IAEA 241Am-Be spectrum, thus, validating the unfolding methods used in this work. The effect of Pb-cover on the spectrum and the unfolding details are reported in the paper.

Assessing long-term variations in sagebrush habitat: characterization of spatial extents and distribution patterns using multi-temporal satellite remote-sensing data

USGS Publications Warehouse

Xian, George; Homer, Collin G.; Aldridge, Cameron L.

2012-01-01

An approach that can generate sagebrush habitat change estimates for monitoring large-area sagebrush ecosystems has been developed and tested in southwestern Wyoming, USA. This prototype method uses a satellite-based image change detection algorithm and regression models to estimate sub-pixel percentage cover for five sagebrush habitat components: bare ground, herbaceous, litter, sagebrush and shrub. Landsat images from three different months in 1988, 1996 and 2006 were selected to identify potential landscape change during these time periods using change vector (CV) analysis incorporated with an image normalization algorithm. Regression tree (RT) models were used to estimate percentage cover for five components on all change areas identified in 1988 and 1996, using unchanged 2006 baseline data as training for both estimates. Over the entire study area (24 950 km2), a net increase of 98.83 km2, or 0.7%, for bare ground was measured between 1988 and 2006. Over the same period, the other four components had net losses of 20.17 km2, or 0.6%, for herbaceous vegetation; 30.16 km2, or 0.7%, for litter; 32.81 km2, or 1.5%, for sagebrush; and 33.34 km2, or 1.2%, for shrubs. The overall accuracy for shrub vegetation change between 1988 and 2006 was 89.56%. Change patterns within sagebrush habitat components differ spatially and quantitatively from each other, potentially indicating unique responses by these components to disturbances imposed upon them.

Bare Forms and Lexical Insertions in Code-Switching: A Processing-Based Account

ERIC Educational Resources Information Center

Owens, Jonathan

2005-01-01

Bare forms (or [slashed O] forms), uninflected lexical L2 insertions in contexts where the matrix language expects morphological marking, have been recognized as an anomaly in different approaches to code-switching. Myers-Scotton (1997, 2002) has explained their existence in terms of structural incongruity between the matrix and embedded…

Stent thrombosis with drug-eluting and bare-metal stents: evidence from a comprehensive network meta-analysis.

PubMed

Palmerini, Tullio; Biondi-Zoccai, Giuseppe; Della Riva, Diego; Stettler, Christoph; Sangiorgi, Diego; D'Ascenzo, Fabrizio; Kimura, Takeshi; Briguori, Carlo; Sabatè, Manel; Kim, Hyo-Soo; De Waha, Antoinette; Kedhi, Elvin; Smits, Pieter C; Kaiser, Christoph; Sardella, Gennaro; Marullo, Antonino; Kirtane, Ajay J; Leon, Martin B; Stone, Gregg W

2012-04-14

The relative safety of drug-eluting stents and bare-metal stents, especially with respect to stent thrombosis, continues to be debated. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to accurately estimate treatment differences between stents. We compared the risk of thrombosis between bare-metal and drug-eluting stents. For this network meta-analysis, randomised controlled trials comparing different drug-eluting stents or drug-eluting with bare-metal stents currently approved in the USA were identified through Medline, Embase, Cochrane databases, and proceedings of international meetings. Information about study design, inclusion and exclusion criteria, sample characteristics, and clinical outcomes was extracted. 49 trials including 50,844 patients randomly assigned to treatment groups were analysed. 1-year definite stent thrombosis was significantly lower with cobalt-chromium everolimus eluting stents (CoCr-EES) than with bare-metal stents (odds ratio [OR] 0·23, 95% CI 0·13-0·41). The significant difference in stent thrombosis between CoCr-EES and bare-metal stents was evident as early as 30 days (OR 0·21, 95% CI 0·11-0·42) and was also significant between 31 days and 1 year (OR 0·27, 95% CI 0·08-0·74). CoCr-EES were also associated with significantly lower rates of 1-year definite stent thrombosis compared with paclitaxel-eluting stents (OR 0·28, 95% CI 0·16-0·48), permanent polymer-based sirolimus-eluting stents (OR 0·41, 95% CI 0·24-0·70), phosphorylcholine-based zotarolimus-eluting stents (OR 0·21, 95% CI 0·10-0·44), and Resolute zotarolimus-eluting stents (OR 0·14, 95% CI 0·03-0·47). At 2-year follow-up, CoCr-EES were still associated with significantly lower rates of definite stent thrombosis than were bare-metal (OR 0·35, 95% CI 0·17-0·69) and paclitaxel-eluting stents (OR 0·34, 95% CI 0·19-0·62). No other drug-eluting stent had lower definite thrombosis rates compared with bare-metal stents at 2-year follow-up. In randomised studies completed to date, CoCr-EES has the lowest rate of stent thrombosis within 2 years of implantation. The finding that CoCr-EES also reduced stent thrombosis compared with bare-metal stents, if confirmed in future randomised trials, represents a paradigm shift. The Cardiovascular Research Foundation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Alleviation in the rat of a GABA-induced reduction in food intake and growth.

PubMed

Tews, J K; Repa, J J; Harper, A E

1984-07-01

Cold exposure and diet dilution which stimulate food intake of normal rats lessened depressions of food intake and growth induced by dietary GABA. During a 3-day adaptation to the cold, rats fed a diet containing 4.5% GABA lost weight; thereafter, food intake and growth rate differed little from those of cold control rats and were usually greater than those of normal rats fed GABA. Hepatic GABA-aminotransferase activity of cold-exposed rats fed the GABA diet increased to about twice that of normal control rats. Rats fed a control diet diluted by half with cellulose ate 50% more of this diet than of the undiluted diet but gained only 20% less weight. Rats ate twice as much of a diluted, 9% GABA diet as of an undiluted, 4.5% GABA diet (thus doubling their GABA intake) and gained three times as much weight. A novel food (condensed milk) barely lessened the adverse responses to GABA. These results show that conditions requiring rats to increase their food intake in order to maintain body weight can also increase their acceptance of a diet high in GABA.

Analysis of heel pad tissues mechanics at the heel strike in bare and shod conditions.

PubMed

Fontanella, C G; Forestiero, A; Carniel, E L; Natali, A N

2013-04-01

A combined experimental and numerical approach is used to investigate the interaction phenomena occurring between foot and footwear during the heel strike phase of the gait. Two force platforms are utilised to evaluate the ground reaction forces of a subject in bare and shod walking. The reaction forces obtained from the experimental tests are assumed as loading conditions for the numerical analyses using three dimensional models of the heel region and of the running shoe. The heel pad region, as fat and skin tissues, is described by visco-hyperelastic and fibre-reinforced hyperelastic formulations respectively and bone region by a linear orthotropic formulation. Different elastomeric foams are considered with regard to the outsole, the midsole and the insole layers. The mechanical properties are described by a hyperfoam formulation. The evaluation of the mechanical behaviour of the heel pad tissues at the heel strike in bare and shod conditions is performed considering different combinations of materials for midsole and insole layers. Results allow for the definition of the influence of different material characteristics on the mechanical response of the heel pad region, in particular showing the compressive stress differentiation in the bare and shod conditions. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Acquisition of Structure and Interpretation: Cases from Mandarin Bare and Non-Bare Noun Phrases

ERIC Educational Resources Information Center

Chang, Hsiang-Hua

2011-01-01

Children's production of bare nominals is universal. When acquiring languages disallowing bare nominals, children will develop from the bare to the non-bare stage. However, Mandarin nominals may appear bare or non-bare in various positions with all kinds of interpretations. This dissertation conducts two acquisition studies to examine the…

Evaluation of Bare Ground on Rangelands using Unmanned Aerial Vehicles

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

Robert P. Breckenridge; Maxine Dakins

2011-01-01

Attention is currently being given to methods that assess the ecological condition of rangelands throughout the United States. There are a number of different indicators that assess ecological condition of rangelands. Bare Ground is being considered by a number of agencies and resource specialists as a lead indicator that can be evaluated over a broad area. Traditional methods of measuring bare ground rely on field technicians collecting data along a line transect or from a plot. Unmanned aerial vehicles (UAVs) provide an alternative to collecting field data, can monitor a large area in a relative short period of time, andmore » in many cases can enhance safety and time required to collect data. In this study, both fixed wing and helicopter UAVs were used to measure bare ground in a sagebrush steppe ecosystem. The data were collected with digital imagery and read using the image analysis software SamplePoint. The approach was tested over seven different plots and compared against traditional field methods to evaluate accuracy for assessing bare ground. The field plots were located on the Idaho National Laboratory (INL) site west of Idaho Falls, Idaho in locations where there is very little disturbance by humans and the area is grazed only by wildlife. The comparison of fixed-wing and helicopter UAV technology against field estimates shows good agreement for the measurement of bare ground. This study shows that if a high degree of detail and data accuracy is desired, then a helicopter UAV may be a good platform. If the data collection objective is to assess broad-scale landscape level changes, then the collection of imagery with a fixed-wing system is probably more appropriate.« less

Effect of the disturbance of plateau pika (Ochotona curzoniae) on soil water and soil temperature characteristics at Alpine Meadows in Qinghai-Tibet Plateau, China

NASA Astrophysics Data System (ADS)

Ma, Yujun; Wu, Yinan; Wang, Xiaoxing; Li, Xiaoyan

2015-04-01

The plateau pika (Ochotona curzoniae) is one of main small rodents at Alpine Meadows in Qinghai-Tibet Plateau, and has a positive effect on the maintenance of regional soil biodiversity. But, its excessive disturbance was also known as an important factor that leads to the vegetation degradation. Based on the field experiment, sampling analysis and continuous observation, this study compared the difference of soil water and soil temperature characteristics at different disturbance stages, which included native grassland, new mound, old mound and bare land formed by old mound. The findings of this study revealed that, after the disturbance of plateau pika, the soil bulk density at the shallow layer (0-20 cm) increased with the time-lapse. At the 20-30 cm depth, the soil bulk density of old mound, bare land and native grassland were similar, and were all higher than that of new mound. At the deep layer (under 30 cm), the soil bulk density had no significant difference between four stages, which showed that the disturbance of plateau pika mainly distributed within the shallow 30 cm depth. The unsaturated hydraulic conductivity of new mound was higher than old mound, bare soil and native grassland, with the multiple of 3.08-8.71, 4.63-16.27 and 3.70-15.25, respectively, and led to the obvious variance of soil water change for different types of land surface. After the precipitation, the soil water content change of new mound and old mound were more significant than that of bare land and native grassland. Because of the disturbance of plateau pika, the soil temperature characteristics changed, too. The heat conductivity rate of new mound and old mound decreased, significantly, and their daily temperature difference were obvious higher than bare land and native grassland. These results were essential for the study of vegetation recovery after the disturbance of plateau pika.

Evaluation and interpretation of Thematic Mapper ratios in equations for estimating corn growth parameters

NASA Technical Reports Server (NTRS)

Dardner, B. R.; Blad, B. L.; Thompson, D. R.; Henderson, K. E.

1985-01-01

Reflectance and agronomic Thematic Mapper (TM) data were analyzed to determine possible data transformations for evaluating several plant parameters of corn. Three transformation forms were used: the ratio of two TM bands, logarithms of two-band ratios, and normalized differences of two bands. Normalized differences and logarithms of two-band ratios responsed similarly in the equations for estimating the plant growth parameters evaluated in this study. Two-term equations were required to obtain the maximum predictability of percent ground cover, canopy moisture content, and total wet phytomass. Standard error of estimate values were 15-26 percent lower for two-term estimates of these parameters than for one-term estimates. The terms log(TM4/TM2) and (TM4/TM5) produced the maximum predictability for leaf area and dry green leaf weight, respectively. The middle infrared bands TM5 and TM7 are essential for maximizing predictability for all measured plant parameters except leaf area index. The estimating models were evaluated over bare soil to discriminate between equations which are statistically similar. Qualitative interpretations of the resulting prediction equations are consistent with general agronomic and remote sensing theory.

14C-labeled organic amendments: Characterization in different particle size fractions and humic acids in a long-term field experiment

PubMed Central

Tatzber, Michael; Stemmer, Michael; Spiegel, Heide; Katzlberger, Christian; Landstetter, Claudia; Haberhauer, Georg; Gerzabek, Martin H.

2012-01-01

Knowledge about the stabilization of organic matter input to soil is essential for understanding the influence of different agricultural practices on turnover characteristics in agricultural soil systems. In this study, soil samples from a long-term field experiment were separated into silt- and clay-sized particles. In 1967, 14C labeled farmyard manure was applied to three different cropping systems: crop rotation, monoculture and permanent bare fallow. Humic acids (HAs) were extracted from silt- and clay-sized fractions and characterized using photometry, mid-infrared and fluorescence spectroscopy. Remaining 14C was determined in size fractions as well as in their extracted HAs. Yields of carbon and remaining 14C in HAs from silt-sized particles and Corg in clay-sized particles decreased significantly in the order: crop rotation > monoculture ≫ bare fallow. Thus, crop rotation not only had the largest overall C-pool in the experiment, but it also best stabilized the added manure. Mid-infrared spectroscopy could distinguish between HAs from different particle size soil fractions. With spectroscopic methods significant differences between the cropping systems were detectable in fewer cases compared to quantitative results of HAs (yields, 14C, Corg and Nt). The trends, however, pointed towards increased humification of HAs from bare fallow systems compared to crop rotation and monoculture as well as of HAs from clay-sized particles compared to silt-sized particles. Our study clearly shows that the largest differences were observed between bare fallow on one hand and monoculture and crop rotation on the other. PMID:23482702

14C-labeled organic amendments: Characterization in different particle size fractions and humic acids in a long-term field experiment.

PubMed

Tatzber, Michael; Stemmer, Michael; Spiegel, Heide; Katzlberger, Christian; Landstetter, Claudia; Haberhauer, Georg; Gerzabek, Martin H

2012-05-01

Knowledge about the stabilization of organic matter input to soil is essential for understanding the influence of different agricultural practices on turnover characteristics in agricultural soil systems. In this study, soil samples from a long-term field experiment were separated into silt- and clay-sized particles. In 1967, 14 C labeled farmyard manure was applied to three different cropping systems: crop rotation, monoculture and permanent bare fallow. Humic acids (HAs) were extracted from silt- and clay-sized fractions and characterized using photometry, mid-infrared and fluorescence spectroscopy. Remaining 14 C was determined in size fractions as well as in their extracted HAs. Yields of carbon and remaining 14 C in HAs from silt-sized particles and C org in clay-sized particles decreased significantly in the order: crop rotation > monoculture ≫ bare fallow. Thus, crop rotation not only had the largest overall C-pool in the experiment, but it also best stabilized the added manure. Mid-infrared spectroscopy could distinguish between HAs from different particle size soil fractions. With spectroscopic methods significant differences between the cropping systems were detectable in fewer cases compared to quantitative results of HAs (yields, 14 C, C org and N t ). The trends, however, pointed towards increased humification of HAs from bare fallow systems compared to crop rotation and monoculture as well as of HAs from clay-sized particles compared to silt-sized particles. Our study clearly shows that the largest differences were observed between bare fallow on one hand and monoculture and crop rotation on the other.

TOPEX/El Niño Watch - La Niña Barely Has a Pulse, June 18, 1999

NASA Image and Video Library

1999-08-23

Lingering just a month ago in the eastern Pacific Ocean, the La Niña phenomenon, with its large volume of chilly water, barely has a pulse this month, according to new satellite data from NASA U.S.-French TOPEX/Poseidon mission. The data, taken during a 10-day cycle of data collection ending June 18, show that the equatorial Pacific Ocean is warming up and returning to normal (green) as La Niña all but vanishes. The warming trend is most apparent in the equatorial Pacific Ocean, where only a few patches of cooler, low sea levels (seen in blue and purple) remain. The blue areas are between 5 and 13 centimeters (2 and 5 inches) below normal, whereas the purple areas range from 14 to 18 centimeters (6 to 7 inches) below normal. Like its counterpart, El Niño, a La Niña condition will influence global climate and weather until it has completely subsided. As summer begins in the northern hemisphere, lower-than-normal sea surface levels and cool ocean temperatures persist in the northeastern Gulf of Alaska and along the western coast of North America. In contrast, the trend is the opposite over most of the Pacific, where above-normal sea surface heights and warmer ocean temperatures (indicated by the red and white areas) appear to be increasing and dominating the overall Pacific Ocean. Red areas are about 10 centimeters (4 inches) above normal; white areas show the sea surface height is between 14 and 32 centimeters (6 and 13 inches) above normal. Scientists are not ready to administer last rites to La Niña, though. In the last 12 months, the pool of unusually cold water in the Pacific has shrunk (warmed) several times before cooling (expanding) again. This summer's altimeter data will help them determine whether La Niña has truly dissipated or whether they will see another resurgence of cool water in the Pacific. http://photojournal.jpl.nasa.gov/catalog/PIA01586

Analyses of protein corona on bare and silica-coated gold nanorods against four mammalian cells.

PubMed

Das, Minakshi; Yi, Dong Kee; An, Seong Soo A

2015-01-01

The purpose of this study was to investigate the mechanisms responsible for the toxic effects of gold nanorods (AuNRs). Here, a comprehensive study was performed by examining the effects of bare (uncoated) AuNRs and AuNRs functionalized with silica (SiO2-AuNRs) against various mammalian cell lines, including cervical cancer cells, fibroblast cells, human umbilical vein endothelial cells, and neuroblastoma cells. The interactions between AuNRs and mammalian cells were investigated with cell viability and mortality assays. Dihydrorhodamine-123 assay was carried out for evaluating reactive oxygen species (ROS) generation, along with mass spectroscopy analysis for determining the composition of the protein corona. Our results suggest that even the lowest concentrations of AuNRs (0.7 μg/mL) induced ROS production leading to cell mortality. On the other hand, cellular viability and ROS production were maintained even at a higher concentration of SiO2-coated AuNRs (12 μg/mL). The increased production of ROS by AuNRs seemed to cause the toxicity observed in all four mammalian cell types. The protein corona on the bare AuNRs did not appear to reduce ROS generation; however, different compositions of the protein corona on bare and SiO2-coated AuNRs may affect cellular behavior differently. Therefore, it was determined that SiO2-coated AuNRs would be more advantageous than bare AuNRs for cellular applications.

FlowShape: a runoff connectivity index for patched environments, based on shape and orientation of runoff sources

NASA Astrophysics Data System (ADS)

Callegaro, Chiara; Malkinson, Dan; Ursino, Nadia; Wittenberg, Lea

2016-04-01

The properties of vegetation cover are recognized to be a key factor in determining runoff processes and yield over natural areas. Still, how the actual vegetation spatial distribution affects these processes is not completely understood. In Mediterranean semi-arid regions, patched landscapes are often found, with clumped vegetation, grass or shrubs, surrounded by bare soil patches. These two phases produce a sink-source system for runoff, as precipitation falling over bare areas barely infiltrates and rather flows downslope. In contrast, vegetated patches have high infiltrability and can partially retain the runon water. We hypothesize that, at a relatively small scale, the shape and orientation of bare soil patches with respect to the runoff flow direction is a significant for the connectivity of the runoff flow paths, and consequently for runoff values. We derive an index, FlowShape, which is candidate to be a good proxy for runoff connectivity and thus runoff production in patched environments. FlowShape is an area-weighted average of the geometrical properties of each bare soil patch. Eight experimental plots in northern Israel were monitored during 2 years after a wildfire which occurred in 2006. Runoff was collected and measured - along with rainfall depth - after each rainfall event, at different levels of vegetation cover corresponding to post-fire recovery of vegetation and seasonality. We obtained a good correlation between FlowShape and the runoff coefficient, at two conditions: a minimal percentage of vegetation cover over the plot, and minimal rainfall depth. Our results support the hypothesis that the spatial distribution of the two phases (vegetation and bare soil) in patched landscapes dictates, at least partially, runoff yield. The correlation between the runoff coefficient and FlowShape, which accounts for shape and orientation of soil patches, is higher than the correlation between the runoff coefficient and the bare soil percentage alone. Besides that, the existence of a vegetation cover threshold under which FlowShape loses correlation with runoff yield, suggests that different processes occur at different levels of vegetation cover. On bare or almost bare plots, runoff flows as a sheet, and small isolated plants do not impose a directionality to the flow or interrupt runoff connectivity. On the other hand, rainfall depth - and possibly rainfall intensity - also affect the hydrological processes of infiltration and runoff production, and thus the applicability of any purely geometrical index. We compared the correlation to runoff coefficient with the FlowShape and FlowLength, a well-known index for runoff connectivity (Mayor et al., 2008) which is defined as the average of runoff flow paths over the plot. As microtopography was not available, our plots were idealized as planar hillslopes. We found that FlowShape is a better predictor than FlowLength for runoff yield over our experimental plots.

Unilateral retinitis pigmentosa sine pigmento.

PubMed Central

Pearlman, J T; Saxton, J; Hoffman, G

1976-01-01

A patient presented with unilateral findings of night blindness shown by impaired rod function and dark adaptation, constricted visual fields with good central acuity, a barely recordable electro-retinographic b-wave, and a unilaterally impaired electro-oculogram. There were none of the pigmentary changes usually associated with retinitis pigmentosa. The unaffected right eye was normal in all respects. Therefore the case is most probably one of unilateral retinitis pigmentosa sine pigmento. Images PMID:952804

Unilateral retinitis pigmentosa sine pigmento.

PubMed

Pearlman, J T; Saxton, J; Hoffman, G

1976-05-01

A patient presented with unilateral findings of night blindness shown by impaired rod function and dark adaptation, constricted visual fields with good central acuity, a barely recordable electro-retinographic b-wave, and a unilaterally impaired electro-oculogram. There were none of the pigmentary changes usually associated with retinitis pigmentosa. The unaffected right eye was normal in all respects. Therefore the case is most probably one of unilateral retinitis pigmentosa sine pigmento.

Carpeting in hospitals: an epidemiological evaluation.

PubMed Central

Anderson, R L; Mackel, D C; Stoler, B S; Mallison, G F

1982-01-01

Epidemiological and microbiological studies were conducted in a hospital room with carpet (CR) and in one with carpet (NCR). Microbiological profiles were determined with specimens obtained from patients admitted to these rooms. Patient records were reviewed to note infection status and other case identities. Eleven-millimeter cylindrical core samples of carpet were obtained, and swab template techniques were used on the bare floor for subsequent enumeration and identification of contaminating microorganisms. In each sampling period, higher microbial counts per square inch (1 in(2) = ca 6.452 cm(2)) were measured for the carpet than for the bare floor. Recovery rates of Enterobacter spp., Klebsiella pneumoniae, and Escherichia coli were higher from carpet samples than from bare floor samples. Typable organisms (such as E. coli, Pseudomonas aeruginosa, K. pneumoniae, and Staphylococcus aureus) obtained from patients were also more frequently recovered from the carpet than from the bare flooring. Patients who stayed in the CR were shown to be colonized with the same types of organisms as those initially recovered from the carpet. However, no statistically significant differences were found in patients in the CR versus NCR in colonization with all typable and nontypable organisms first found on the floor. Disease in patients was found not to be associated with organisms found as contaminants of the carpet or the bare floor. Air above carpeting contained more consistent concentrations of organisms than air above the bare flooring. PMID:7076814

Novel High Cooperativity Photon-Magnon Cavity QED

NASA Astrophysics Data System (ADS)

Tobar, Michael; Bourhill, Jeremy; Kostylev, Nikita; G, Maxim; Creedon, Daniel

Novel microwave cavities are presented, which couple photons and magnons in YIG spheres in a super- and ultra-strong way at around 20 mK in temperature. Few/Single photon couplings (or normal mode splitting, 2g) of more than 6 GHz at microwave frequencies are obtained. Types of cavities include multiple post reentrant cavities, which co-couple photons at different frequencies with a coupling greater that the free spectral range, as well as spherical loaded dielectric cavity resonators. In such cavities we show that the bare dielectric properties can be obtained by polarizing all magnon modes to high energy using a 7 Tesla magnet. We also show that at zero-field, collective effects of the spins significantly perturb the photon modes. Other effects like time-reversal symmetry breaking are observed.

PO calculation for reduction in radar cross section of hypersonic targets using RAM

NASA Astrophysics Data System (ADS)

Liu, Song-hua; Guo, Li-xin; Pan, Wei-tao; Chen, Wei; Xiao, Yi-fan

2018-06-01

The radar cross section (RCS) reduction of hypersonic targets by radar absorbing materials (RAM) coating under different reentry cases is analyzed in the C and X bands frequency range normally used for radar detection. The physical optics method is extended to both the inhomogeneous plasma sheath and RAM layer present simultaneously. The simulation results show that the absorbing coating can reduce the RCS of the plasma cloaking system and its effectiveness is related to the maximum plasma frequency. Moreover, the amount of the RCS decrease, its maxima, and the corresponding optimal RAM thickness depend on the non-uniformity and parameters of the plasma sheath. In addition, the backward RCS of the flight vehicle shrouded by plasma shielding and man-made absorber is calculated and compared to the bare cone.

Molecular characterization of variant alpha-subunit of electron transfer flavoprotein in three patients with glutaric acidemia type II--and identification of glycine substitution for valine-157 in the sequence of the precursor, producing an unstable mature protein in a patient.

PubMed Central

Indo, Y; Glassberg, R; Yokota, I; Tanaka, K

1991-01-01

In our previous study of eight glutaric acidemia type II (GAII) fibroblast lines by using [35S]methionine labeling and immunoprecipitation, three of them had a defect in the synthesis of the alpha-subunit of electron transfer flavoprotein (alpha-ETF) (Ikeda et al. 1986). In one of them (YH1313) the labeling of the mature alpha-ETF was barely detectable, while that of the precursor (p) was stronger. In another (YH605) no synthesis of immunoreactive p alpha-ETF was detectable. In the third cell line (YH1391) the rate of variant p alpha-ETF synthesis was comparable to normal, but its electrophoretic mobility was slightly faster than normal. In the present study, the northern blot analysis revealed that all three mutant cell lines contained p alpha-ETF mRNA and that their size and amount were comparable to normal. In immunoblot analysis, both alpha- and beta-ETF bands were barely detectable in YH1313 and YH605 but were detectable in YH1391 in amounts comparable to normal. Sequencing of YH1313 p alpha-ETF cDNA via PCR identified a transversion of T-470 to G. We then devised a simple PCR method for the 119-bp section (T-443/G-561) for detecting this mutation. In the upstream primer, A-466 was artificially replaced with C, to introduce a BstNI site into the amplified copies in the presence of G-470 from the variant sequence. The genomic DNA analysis using this method demonstrated that YH1313 was homozygous for T----G-470 transversion. It was not detected either in two other alpha-ETF-deficient GAII or in seven control cell lines. The alpha-ETF cDNA sequence in YH605 was identical to normal. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:1882842

Runoff and erosion in a pinon-juniper woodland: Influence of vegetation patches

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

Reid, K.D.; Wilcox, B.P.; Breshears, D.D.

1999-12-01

In many semiarid regions, runoff and erosion differ according to vegetation patch type. These differences, although hypothesized to fundamentally affect ecological processes, have been poorly quantified. In a semiarid pinion-juniper woodland [Pinus edulis Engelm. and Juniperus monosperma (Engelm) Sarg.] in northern New Mexico, the authors measured runoff and erosion from the three patch types that compose these woodlands: Canopy patches (those beneath woody plants), vegetated patched in intercanopy areas, and bare patches in intercanopy areas. The bare intercanopy patches exhibited the highest rates, followed by vegetated intercanopy patches and then by canopy patches. Large convective summer storms, though relatively infrequent,more » generated much of the runoff and most of the sediment; prolonged frontal storms were capable of generating considerable runoff but little sediment. A portion of the runoff and most of the sediment generated from bare intercanopy patches was redistributed down-slope, probably to adjacent vegetated intercanopy patches, demonstrating connectivity between these two patch types. Their results indicate that there are significant and important differences in runoff and sediment production from the three patch types; that bare intercanopy patches act as sources of both water and sediment for the vegetated intercanopy patches; and that the transfer of water and sediment at small scales is both frequent enough and substantial enough to be considered ecologically significant.« less

Correlation between landscape fragmentation and sandy desertification: a case study in Horqin Sandy Land, China.

PubMed

Ge, Xiaodong; Dong, Kaikai; Luloff, A E; Wang, Luyao; Xiao, Jun; Wang, Shiying; Wang, Qian

2016-01-01

The exact roles of landscape fragmentation on sandy desertification are still not fully understood, especially with the impact of different land use types in spatial dimension. Taking patch size and shape into consideration, this paper selected the Ratio of Patch Size and the Fractal Dimension Index to establish a model that reveals the association between the area of bare sand land and the fragmentation of different land use types adjacent to bare sand land. Results indicated that (1) grass land and arable land contributed the most to landscape fragmentation processes in the regions adjacent to bare sand land during the period 1980 to 2010. Grass land occupied 54 % of the region adjacent to bare sand land in 1980. The Ratio of Patch Size of grass land decreased from 1980 to 2000 and increased after 2000. The Fractal Dimension Index of grass increased during the period 1980 to 1990 and decreased after 1990. Arable land expanded significantly during this period. The Ratio of Patch Size of arable land increased from 1980 to 1990 and decreased since 1990. The Fractal Dimension Index of arable land increased from 1990 to 2000 and decreased after 2000. (2) The Ratio of Patch Size and the Fractal Dimension Index were significantly related to the area of bare sand land. The role of landscape fragmentation was not linear to sandy desertification. There were both positive and negative effects of landscape fragmentation on sandy desertification. In 1980, the Ratio of Patch Size and the Fractal Dimension Index were negatively related to the area of bare sand land, showing that the landscape fragmentation and regularity of patches contributed to the expansion of sandy desertification. In 1990, 2000, and 2010, the Ratio of Patch Size and the Fractal Dimension Index were mostly positively related to the area of bare sand land, showing the landscape fragmentation and regularity of patches contributed to the reversion of sandy desertification in this phase. The absolute values of the coefficients were the highest for grass land in the regression models, so that grass land had the most important influence on sandy desertification.

Remote Sensing and GIS for Landuse/Landcover Classification and Water Quality in the Northern Ireland

NASA Astrophysics Data System (ADS)

Amer, R.; Ofterdinger, U.; Ruffell, A.; Donald, A.

2012-04-01

This study presents landuse/landcover (LULC) classifications of Northern Ireland in order to quantify land-use types driving chemical loading in the surface water bodies. The major LULC classes are agricultural land, bare land (mountainous areas), forest, urban areas, and water bodies. Three ENVISAT ASAR multi-look precision images acquired in 2011 and two Enhanced Thematic Mapper Plus (ETM+) acquired in 2003 were used for classification. The ASAR digital numbers were converted to backscattering coefficient (sigma nought) and enhanced using adaptive Gamma filter and Gaussian stretch. Supervised classifications of Maximum Likelihood, Mahalanobils Distance, Minimum Distance, Spectral Angel Mapper, Parallelepiped, and Winner Tercat were applied on ETM+ and ASAR images. A confusion matrix was used to evaluate the classification accuracy; the best results of ETM+ and ASAR were given by the winner classification (82.9 and 73.6 %), and maximum likelihood (81.7 and 72.5 %), respectively. Change detection was applied to identify the areas of significant changes in landuse/landcover over the last eight years. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model was processed to extract the drainage systems and watersheds. Water quality data of the first and second order streams were extracted from 2005 survey by Geological Survey of Northern Ireland. GIS spatially distributed modelling generated maps showing the distribution of phosphorus (P), nitrate (NO3), dissolved organic carbon (DOC), and some of the trace elements including fluoride (F), calcium (Ca), aluminium (Al), iron (Fe), copper (Cu), lead (Pb), zinc (Zn), and arsenic (As) across the watersheds of the Northern Ireland were generated. The distribution of these elements was evaluated against the LULC classes and bed rock geology. Concentration of these elements was classified into normal (safe level), moderate, high, and very high based on the World Health Organization (WHO, 2011) water quality standards. The results show that P concentration is generally high across all the watersheds. NO3 is within normal range in all watersheds. DOC is within normal range in urban areas, moderate to high in agricultural lands, and high in the forest areas and bare lands. F and Fe are within safe level in all watersheds. Al, Cu, and As are high in all watersheds around the bare land LULC class which are underlain by psammite and semipelite metamorphic rocks. Ca is within normal range in most of watersheds but it is high in the south western part of the study area because of the presence of limestone bedrock. Pb and Zn are within normal range in the urban and most of the agricultural land, and high in the mountainous areas underlain by psammite and semipelite metamorphic bed rock.

Response of Surface Soil Hydrology to the Micro-Pattern of Bio-Crust in a Dry-Land Loess Environment, China

PubMed Central

Wei, Wei; Yu, Yun; Chen, Liding

2015-01-01

The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes. PMID:26207757

Response of Surface Soil Hydrology to the Micro-Pattern of Bio-Crust in a Dry-Land Loess Environment, China.

PubMed

Wei, Wei; Yu, Yun; Chen, Liding

2015-01-01

The specific bio-species and their spatial patterns play crucial roles in regulating eco-hydrologic process, which is significant for large-scale habitat promotion and vegetation restoration in many dry-land ecosystems. Such effects, however, are not yet fully studied. In this study, 12 micro-plots, each with size of 0.5 m in depth and 1 m in length, were constructed on a gentle grassy hill-slope with a mean gradient of 8° in a semiarid loess hilly area of China. Two major bio-crusts, including mosses and lichens, had been cultivated for two years prior to the field simulation experiments, while physical crusts and non-crusted bare soils were used for comparison. By using rainfall simulation method, four designed micro-patterns (i.e., upper bio-crust and lower bare soil, scattered bio-crust, upper bare soil and lower bio-crust, fully-covered bio-crust) to the soil hydrological response were analyzed. We found that soil surface bio-crusts were more efficient in improving soil structure, water holding capacity and runoff retention particularly at surface 10 cm layers, compared with physical soil crusts and non-crusted bare soils. We re-confirmed that mosses functioned better than lichens, partly due to their higher successional stage and deeper biomass accumulation. Physical crusts were least efficient in water conservation and erosion control, followed by non-crusted bare soils. More importantly, there were marked differences in the efficiency of the different spatial arrangements of bio-crusts in controlling runoff and sediment generation. Fully-covered bio-crust pattern provides the best option for soil loss reduction and runoff retention, while a combination of upper bio-crust and lower bare soil pattern is the least one. These findings are suggested to be significant for surface-cover protection, rainwater infiltration, runoff retention, and erosion control in water-restricted and degraded natural slopes.

Modelling radiative transfer through ponded first-year Arctic sea ice with a plane-parallel model

NASA Astrophysics Data System (ADS)

Taskjelle, Torbjørn; Hudson, Stephen R.; Granskog, Mats A.; Hamre, Børge

2017-09-01

Under-ice irradiance measurements were done on ponded first-year pack ice along three transects during the ICE12 expedition north of Svalbard. Bulk transmittances (400-900 nm) were found to be on average 0.15-0.20 under bare ice, and 0.39-0.46 under ponded ice. Radiative transfer modelling was done with a plane-parallel model. While simulated transmittances deviate significantly from measured transmittances close to the edge of ponds, spatially averaged bulk transmittances agree well. That is, transect-average bulk transmittances, calculated using typical simulated transmittances for ponded and bare ice weighted by the fractional coverage of the two surface types, are in good agreement with the measured values. Radiative heating rates calculated from model output indicates that about 20 % of the incident solar energy is absorbed in bare ice, and 50 % in ponded ice (35 % in pond itself, 15 % in the underlying ice). This large difference is due to the highly scattering surface scattering layer (SSL) increasing the albedo of the bare ice.

Role of clothing in both accelerating and impeding dermal absorption of airborne SVOCs.

PubMed

Morrison, Glenn C; Weschler, Charles J; Bekö, Gabriel; Koch, Holger M; Salthammer, Tunga; Schripp, Tobias; Toftum, Jørn; Clausen, Geo

2016-01-01

To assess the influence of clothing on dermal uptake of semi-volatile organic compounds (SVOCs), we measured uptake of selected airborne phthalates for an individual wearing clean clothes or air-exposed clothes and compared these results with dermal uptake for bare-skinned individuals under otherwise identical experimental conditions. Using a breathing hood to isolate dermal from inhalation uptake, we measured urinary metabolites of diethylphthalate (DEP) and di-n-butylphthalate (DnBP) from an individual exposed to known concentrations of these compounds for 6 h in an experimental chamber. The individual wore either clean (fresh) cotton clothes or cotton clothes that had been exposed to the same chamber air concentrations for 9 days. For a 6-h exposure, the net amounts of DEP and DnBP absorbed when wearing fresh clothes were, respectively, 0.017 and 0.007 μg/kg/(μg/m(3)); for exposed clothes the results were 0.178 and 0.261 μg/kg/(μg/m(3)), respectively (values normalized by air concentration and body mass). When compared against the average results for bare-skinned participants, clean clothes were protective, whereas exposed clothes increased dermal uptake for DEP and DnBP by factors of 3.3 and 6.5, respectively. Even for non-occupational environments, wearing clothing that has adsorbed/absorbed indoor air pollutants can increase dermal uptake of SVOCs by substantial amounts relative to bare skin.

Plant-mediated effects on extracellular enzyme activities in distinct soil aggregate size classes in field

NASA Astrophysics Data System (ADS)

Kumar, Amit; Dorodnikov, Maxim; Splettstößer, Thomas; Kuzyakov, Yakov; Pausch, Johanna

2017-04-01

Soil aggregation and microbial activities within the aggregates are important factors regulating soil carbon (C) turnover. A reliable and sensitive proxy for microbial activity is activity of extracellular enzymes (EEA). In the present study, effects of soil aggregates on EEA were investigated under three maize plant densities (Low, Normal, and High). Bulk soil was fractionated into three aggregate size classes (>2000 µm large macroaggregates; 2000-250 µm small macroaggregates; <250 µm microaggregates) by optimal-moisture sieving. Microbial biomass and EEA (β-1,4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG), L-leucine aminopeptidase (LAP) and acid phosphatase (acP)) catalyzing soil organic matter (SOM) decomposition were measured in rooted soil of maize and soil from bare fallow. Microbial biomass C (Cmic) decreased with decreasing aggregate size classes. Potential and specific EEA (per unit of Cmic) increased from macro- to microaggregates. In comparison with bare fallow soil, specific EEA of microaggregates in rooted soil was higher by up to 73%, 31%, 26%, and 92% for BG, NAG, acP and LAP, respectively. Moreover, high plant density decreased macroaggregates by 9% compared to bare fallow. Enhanced EEA in three aggregate size classes demonstrated activation of microorganisms by roots. Strong EEA in microaggregates can be explained by microaggregates' localization within the soil. Originally adhering to surfaces of macroaggregates, microaggregates were preferentially exposed to C substrates and nutrients, thereby promoting microbial activity.

Comparison of the SYNERGY with the PROMUS (XIENCE V) and bare metal and polymer-only Element control stents in porcine coronary arteries.

PubMed

Wilson, Gregory J; Huibregtse, Barbara A; Pennington, Douglas E; Dawkins, Keith D

2012-06-20

This study evaluated vascular compatibility of the novel platinum chromium alloy Element stent platform delivering abluminal everolimus from a poly-lactide-co-glycolide bioabsorbable polymer (SYNERGY stent), currently undergoing clinical trial, compared with the PROMUS (XIENCE V) and bare metal and polymer-only Element stents. Stents (n=161) were implanted one per coronary artery in 72 swine at a stent-to-artery ratio of 1.1:1. Similar numbers of each device group were explanted at each of 30, 90, 180, and 360 days (except no PROMUS (XIENCE V) stent at 360 days) for pathological analysis. There was no stent thrombosis, myocardial infarction, or strut fractures in any group. Vascular response was similar between the SYNERGY and PROMUS (XIENCE V) stents, with no thrombi and complete endothelialisation on both scanning electron microscopy and histology at 30, 90 and 180 days. There were no significant differences for the morphologic parameters of luminal thrombus, endothelial cell coverage, strut tissue coverage, inflammation, internal elastic lamina (IEL) disruption, external elastic lamina (EEL) disruption and medial smooth muscle cell loss across device groups or between time points, but there was mild but greater (p<0.0001) para-strut fibrin at 30 days for both drug-eluting stents (DES) compared with the bare and polymer-only controls; this difference completely dissipated by 90 days. Inflammation was predominantly minimal to mild for all device types. No morphometric parameters, including intimal thickness, stent profile-based area stenosis, and EEL area were significantly different when comparing the SYNERGY stent with the bare metal Element and polymer-only Element control stents at 90, 180 and 360 days. In this non-injured porcine coronary artery model, the bioabsorbable polymer SYNERGY stent demonstrated vascular compatibility equivalent to the PROMUS (XIENCE V) stent and to the bare metal and polymer-only Element stents.

Perturbations of the optical properties of mineral dust particles by mixing with black carbon: a numerical simulation study

DOE PAGES

Scarnato, B. V.; China, S.; Nielsen, K.; ...

2015-06-25

Field observations show that individual aerosol particles are a complex mixture of a wide variety of species, reflecting different sources and physico-chemical transformations. The impacts of individual aerosol morphology and mixing characteristics on the Earth system are not yet fully understood. Here we present a sensitivity study on climate-relevant aerosols optical properties to various approximations. Based on aerosol samples collected in various geographical locations, we have observationally constrained size, morphology and mixing, and accordingly simulated, using the discrete dipole approximation model (DDSCAT), optical properties of three aerosols types: (1) bare black carbon (BC) aggregates, (2) bare mineral dust, and (3)more » an internal mixture of a BC aggregate laying on top of a mineral dust particle, also referred to as polluted dust. DDSCAT predicts optical properties and their spectral dependence consistently with observations for all the studied cases. Predicted values of mass absorption, scattering and extinction coefficients (MAC, MSC, MEC) for bare BC show a weak dependence on the BC aggregate size, while the asymmetry parameter ( g) shows the opposite behavior. The simulated optical properties of bare mineral dust present a large variability depending on the modeled dust shape, confirming the limited range of applicability of spheroids over different types and size of mineral dust aerosols, in agreement with previous modeling studies. The polluted dust cases show a strong decrease in MAC values with the increase in dust particle size (for the same BC size) and an increase of the single scattering albedo (SSA). Furthermore, particles with a radius between 180 and 300 nm are characterized by a decrease in SSA values compared to bare dust, in agreement with field observations.This paper demonstrates that observationally constrained DDSCAT simulations allow one to better understand the variability of the measured aerosol optical properties in ambient air and to define benchmark biases due to different approximations in aerosol parametrization.« less

Coral larvae change their settlement preference for crustose coralline algae dependent on availability of bare space

NASA Astrophysics Data System (ADS)

Elmer, Franziska; Bell, James J.; Gardner, Jonathan P. A.

2018-06-01

Competition for space is a major factor affecting coral survival. Since adult coral colonies are sessile, the settlement preferences of larvae have a strong impact on the competition for space that corals will face post-metamorphosis and will therefore influence long-term survival. Laboratory-based studies show that in simplified systems coral larvae use cues to guide them to suitable settlement locations, an adaptation that enhances post-settlement survival. Settlement preferences have also been reported from the field, where coral larvae encounter a wide variety of different potential settlement surfaces as the availability of free substratum (bare space) changes over time. In this field-based study, the abundance of different encrusting organisms and bare space present on settlement tiles was compared to their abundance under newly settled pocilloporid and poritid recruits, to determine if recruits choose their settlement substratum randomly. Tiles deployed for 3, 9, 12 and 15 months were used to determine if settlement choice varied as a function of benthic community successional stage. We found that pocilloporid and poritid larvae changed their settlement preference depending on the age of the benthic community they encountered. They reacted neutrally to crustose coralline algae (CCA) on tiles deployed for 3 months when bare space was abundant, but showed a clear preference for settlement on CCA on tiles deployed for 9-15 months once bare space was limited. Simultaneously, poritid recruits showed a decreasing preference over time to settle on biofilm. This change in preference is not linked to the availability of CCA because its abundance did not change significantly between tiles deployed for 3 versus 9-15 months. These results indicate that coral recruits react to several settlement cues simultaneously, guiding them to different settlement locations as the benthos changes over time. Furthermore, recruits from both families reacted similarly, suggesting that this is an evolutionarily old adaption.

Surface runoff and soil erosion by difference of surface cover characteristics using by an oscillating rainfall simulator

NASA Astrophysics Data System (ADS)

Kim, J. K.; Kim, M. S.; Yang, D. Y.

2017-12-01

Sediment transfer within hill slope can be changed by the hydrologic characteristics of surface material on hill slope. To better understand sediment transfer of the past and future related to climate changes, studies for the changes of soil erosion due to hydrological characteristics changes by surface materials on hill slope are needed. To do so, on-situ rainfall simulating test was conducted on three different surface conditions, i.e. well covered with litter layer condition (a), undisturbed bare condition (b), and disturbed bare condition (c) and these results from rainfall simulating test were compared with that estimated using the Limburg Soil Erosion Model (LISEM). The result from the rainfall simulating tests showed differences in the infiltration rate (a > b > c) and the highest soil erosion rate was occurred on c condition. The result from model also was similar to those from rainfall simulating tests, however, the difference from the value of soil erosion rate between two results was quite large on b and c conditions. These results implied that the difference of surface conditions could change the surface runoff and soil erosion and the result from the erosion model might significantly underestimate on bare surface conditions rather than that from rainfall simulating test.

Previous coronary stent implantation and cardiac events in patients undergoing noncardiac surgery.

PubMed

Cruden, Nicholas L M; Harding, Scott A; Flapan, Andrew D; Graham, Cat; Wild, Sarah H; Slack, Rachel; Pell, Jill P; Newby, David E

2010-06-01

Noncardiac surgery performed after coronary stent implantation is associated with an increased risk of stent thrombosis, myocardial infarction, and death. The influence of stent type and period of risk still have to be defined. We linked the Scottish Coronary Revascularisation Register with hospital admission data to undertake a Scotland-wide retrospective cohort study examining cardiac outcomes in all patients who received drug-eluting or bare-metal stents between April 2003 and March 2007 and subsequently underwent noncardiac surgery. Of 1953 patients, 570 (29%) were treated with at least 1 drug-eluting stent and 1383 (71%) with bare-metal stents only. There were no differences between drug-eluting and bare-metal stents in the primary end point of in-hospital mortality or ischemic cardiac events (14.6% versus 13.3%; P=0.3) or the secondary end points of in-hospital mortality (0.7% versus 0.6%; P=0.8) and acute myocardial infarction (1.2% versus 0.7%; P=0.3). Perioperative death and ischemic cardiac events occurred more frequently when surgery was performed within 42 days of stent implantation (42.4% versus 12.8% beyond 42 days; P<0.001), especially in patients revascularized after an acute coronary syndrome (65% versus 32%; P=0.037). There were no temporal differences in outcomes between the drug-eluting and bare-metal stent groups. Patients undergoing noncardiac surgery after recent coronary stent implantation are at increased risk of perioperative myocardial ischemia, myocardial infarction, and death, particularly after an acute coronary syndrome. For at least 2 years after percutaneous coronary intervention, cardiac outcomes after noncardiac surgery are similar for both drug-eluting and bare-metal stents.

The potential of cover crops for improving soil function

NASA Astrophysics Data System (ADS)

Stoate, Chris; Crotty, Felicity

2017-04-01

Cover crops can be grown over the autumn and winter ensuring green cover throughout the year. They have been described as improving soil structure, reducing soil erosion and potentially even a form of grass weed control. These crops retain nutrients within the plant, potentially making them available for future crops, as well as increasing soil organic matter. Over the last three years, we have investigated how different cover crop regimes affect soil quality. Three separate experiments over each autumn/winter period have investigated how different cover crops affect soil biology, physics and chemistry, with each experiment building on the previous one. There have been significant effects of cover crops on soil structure, as well as significantly lower weed biomass and increased yields in the following crop - in comparison to bare stubble. For example, the effect of drilling the cover crops on soil structure in comparison to a bare stubble control that had not been driven on by machinery was quantified, and over the winter period the soil structure of the cover crop treatments changed, with compaction reduced in the cover crop treatments, whilst the bare stubble control remained unchanged. Weeds were found in significantly lower biomass in the cover crop mixes in comparison to the bare stubble control, and significantly lower weed biomass continued to be found in the following spring oat crop where the cover crops had been, indicating a weed suppressive effect that has a continued legacy in the following crop. The following spring oats have shown similar results in the last two years, with higher yields in the previous cover crop areas compared to the bare stubble controls. Overall, these results are indicating that cover crops have the potential to provide improvements to soil quality, reduce weeds and improve yields. We discuss the economic implications.

[Iron absorption of the habitual diet in a population of low socioeconomic level].

PubMed

Morón, C; Kremenchuzky, S; Passamai, M I; D'Andrea de Rivero, S; Pérez de Galíndez, G; Gerschcovich, C

1985-06-01

Iron absorption using the extrinsic double-tag method was determined in the habitual diet consumed by a group of 32 volunteers of both sexes, pertaining to the low socioeconomic strata. The diet was made up of bread, spaghetti, vegetables and meat, totalling 2,022 kcal, 65.0 g protein, 17.57 mg iron, and 28.75 mg ascorbic acid. According to our findings, men were found to be neither anemic nor iron-deficient. Among the women, however, 4.8% had anemia and 57.1% suffered from iron deficiency. The non-heme iron absorption was very low: 1.35% at breakfast, 3.29% at lunch, and 3.82% at dinner. Among those subjects found to be normal, the absorption was half the above figures, whereas among those with iron deficiency it was threefold, the differences being highly significant. The absorption of heme-iron for lunch and dinner was 17.53%. The iron deficient group had an absorption value four times greater than the normal group, the differences also being highly significant. The daily availability of non-heme, heme and total iron was 0.44, 1.13 and 1.57 mg, respectively. In the subjects who formed the normal group, total iron available was 1.14 mg, barely covering a man's daily requirements, but not those of a woman. In the iron-deficient group, it was 4.31 mg, that is, four times greater than in the normal group; while this value improves the balance, it does not prevent deficiency in women, with great blood losses. Bearing these results in mind, it is suggested that measures tending to improve dietary iron content and bio-availability, be enforced.

Critical Configuration and Physics Measurements for Beryllium Reflected Assemblies of U(93.15)O₂ Fuel Rods (1.506-cm Pitch and 7-Tube Clusters)

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

Marshall, Margaret A.; Bess, John D.; Briggs, J. Blair

2015-03-01

Cadmium ratios were measured with enriched uranium metal foils at various locations in the assembly with the fuel tube at the 1.506-cm spacing. They are described in the following subsections. The experiment configuration was the same as the first critical configuration described in HEU-COMP-FAST-004 (Case 1). The experimenter placed 0.75-cm-diameter × 0.010-cm-thick 93.15%-235U-enriched uranium metal foils with and without 0.051-cm-thick cadmium covers at various locations in the core and top reflector. One part of the cadmium cover was cupshape and contained the uranium foil. The other part was a lid that fit over the exposed side of the foil whenmore » it was in the cup shaped section of the cover. As can be seen in the logbook, two runs were required to obtain all the measurements necessary for the cadmium ratio. The bare foil measurements within the top reflector were run first as part of the axial foil activation measurements. The results of this run are used for both the axial activation results and the cadmium ratios. Cadmium covered foils were then placed at the same location through the top reflector in a different run. Three pairs of bare and cadmium covered foils were also placed through the core tank. One pair was placed at the axial center of a fuel tube 11.35 cm from the center of the core. Two pairs of foils were placed on top of fuel tubes 3.02 and 12.06 cm from the center of the core. The activation of the uranium metal foils was measured after removal from the assembly using two lead shielded NaI scintillation detectors as follows. The NaI scintillators were carefully matched and had detection efficiencies for counting delayed-fission-product gamma rays with energies above 250 KeV within 5%. In all foil activation measurements, one foil at a specific location was used as a normalizing foil to remove the effects of the decay of fission products during the counting measurements with the NaI detectors. The normalization foil was placed on one NaI scintillator and the other foil on the other NaI detector and the activities measured simultaneously. The activation of a particular foil was compared to that of the normalization foil by dividing the count rate for each foil by that of the normalization foil. To correct for the differing efficiencies of the two NaI detectors, the normalization foil was counted in Detector 1 simultaneously with the foil at position x in Detector 2, and then the normalization foil was counted simultaneously in Detector 2 with the foil from position x in Counter 1. The activity of the foil from position x was divided by the activity of the normalization foil counted simultaneously. This resulted in obtaining two values of the ratio that were then averaged. This procedure essentially removed the effect of the differing efficiencies of the two NaI detectors. Differing efficiencies of 10% resulted in errors in the ratios measured to less than 1%. The background counting rates obatined with the foils used for the measurements on the NaI detectors before their irradiation measurement were subtracted from all count rates. The results of the cadmium ratio measurements are given in Table 1.3-1 and Figure 1.3-1. “No correction has been made for self shielding in the foils” (Reference 3).« less

Change in equilibrium position of misfit dislocations at the GaN/sapphire interface by Si-ion implantation into sapphire—I. Microstructural characterization

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

Lee, Sung Bo, E-mail: bolee@snu.ac.kr; Han, Heung Nam, E-mail: hnhan@snu.ac.kr; Lee, Dong Nyung

Much research has been done to reduce dislocation densities for the growth of GaN on sapphire, but has paid little attention to the elastic behavior at the GaN/sapphire interface. In this study, we have examined effects of the addition of Si to a sapphire substrate on its elastic property and on the growth of GaN deposit. Si atoms are added to a c-plane sapphire substrate by ion implantation. The ion implantation results in scratches on the surface, and concomitantly, inhomogeneous distribution of Si. The scratch regions contain a higher concentration of Si than other regions of the sapphire substrate surface,more » high-temperature GaN being poorly grown there. However, high-temperature GaN is normally grown in the other regions. The GaN overlayer in the normally-grown regions is observed to have a lower TD density than the deposit on the bare sapphire substrate (with no Si accommodated). As compared with the film on an untreated, bare sapphire, the cathodoluminescence defect density decreases by 60 % for the GaN layer normally deposited on the Si-ion implanted sapphire. As confirmed by a strain mapping technique by transmission electron microscopy (geometric phase analysis), the addition of Si in the normally deposited regions forms a surface layer in the sapphire elastically more compliant than the GaN overlayer. The results suggest that the layer can largely absorb the misfit strain at the interface, which produces the overlayer with a lower defect density. Our results highlight a direct correlation between threading-dislocation density in GaN deposits and the elastic behavior at the GaN/sapphire interface, opening up a new pathway to reduce threading-dislocation density in GaN deposits.« less

Numerical and experimental analysis of a darrieus-type cross flow water turbine in bare and shrouded configurations

NASA Astrophysics Data System (ADS)

Roa, A. M.; Aumelas, V.; Maître, T.; Pellone, C.

2010-08-01

The aim of this paper is to present the results of the analysis of a Darrieus-type cross flow water turbine in bare and shrouded configurations. Numerical results are compared to experimental data and differences found in values are also highlighted. The benefit of the introduction of a channelling device, which generates an efficiency increment factor varying from 2 to 5, depending on the configuration, is discussed.

Ice Nucleation of Bare and Sulfuric Acid-coated Mineral Dust Particles and Implication for Cloud Properties

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

Kulkarni, Gourihar R.; Sanders, Cassandra N.; Zhang, Kai

2014-08-27

Ice nucleation properties of different dust species coated with soluble material are not well understood. We determined the ice nucleation ability of bare and sulfuric acid coated mineral dust particles as a function of temperature (-25 to -35 deg C) and relative humidity with respect to water (RHw). Five different mineral dust species: Arizona test dust (ATD), illite, montmorillonite, quartz and kaolinite were dry dispersed and size-selected at 150 nm and exposed to sulfuric acid vapors in the coating apparatus. The condensed sulfuric acid soluble mass fraction per particle was estimated from the cloud condensation nuclei activated fraction measurements. Themore » fraction of dust particles nucleating ice at various temperatures and RHw was determined using a compact ice chamber. In water-subsaturated conditions, compared to bare dust particles, we found that only coated ATD particles showed suppression of ice nucleation ability while other four dust species did not showed the effect of coating on the fraction of particles nucleating ice. The results suggest that interactions between the dust surface and sulfuric acid vapor are important, such that interactions may or may not modify the surface via chemical reactions with sulfuric acid. At water-supersaturated conditions we did not observed the effect of coating, i.e. the bare and coated dust particles had similar ice nucleation behavior.« less

Initial Adsorption of Fe on an Ethanol-Saturated Si(111)7 × 7 Surface: Statistical Analysis in Scanning Tunneling Microscopy

NASA Astrophysics Data System (ADS)

Yang, Haoyu; Hattori, Ken

2018-03-01

We studied the initial stage of iron deposition on an ethanol-saturated Si(111)7 × 7 surface at room temperature using scanning tunneling microscopy (STM). The statistical analysis of the Si adatom height at empty states for Si(111)-C2H5OH before and after the Fe deposition showed different types of adatoms: type B (before the deposition) and type B' (after the deposition) assigned to bare adatoms, type D and type D' to C2H5O-terminated adatoms, and type E' to adatoms with Fe. The analysis of the height distribution revealed the protection of the molecule termination for the Fe capture at the initial stage. The analysis also indicated the preferential capture of a single Fe atom to a bare center-adatom rather than a bare corner-adatom which remain after the C2H5OH saturation, but no selectivity was observed in faulted and unfaulted half unit-cells. This is the first STM-based report proving that a remaining bare adatom, but not a molecule-terminated adatom, captures a metal.

The underlying biological mechanisms of biocompatibility differences between bare and TiN-coated NiTi alloys.

PubMed

Lifeng, Zhao; Yan, Hong; Dayun, Yang; Xiaoying, Lü; Tingfei, Xi; Deyuan, Zhang; Ying, Hong; Jinfeng, Yuan

2011-04-01

TiN coating has been demonstrated to improve the biocompatibility of bare NiTi alloys; however, essential biocompatibility differences between NiTi alloys before and after TiN coating are not known so far. In this study, to explore the underlying biological mechanisms of biocompatibility differences between them, the changes of bare and TiN-coated NiTi alloys in surface chemical composition, morphology, hydrophilicity, Ni ions release, cytotoxicity, apoptosis, and gene expression profiles were compared using energy-dispersive spectroscopy, scanning electron microscopy, contact angle, surface energy, Ni ions release analysis, the methylthiazoltetrazolium (MTT) method, flow cytometry and microarray methods, respectively. Pathways binding to networks and real-time polymerase chain reaction (PCR) were employed to analyze and validate the microarray data, respectively. It was found that, compared with the bare NiTi alloys, TiN coating significantly decreased Ni ions content on the surfaces of the NiTi alloys and reduced the release of Ni ions from the alloys, attenuated the inhibition of Ni ions to the expression of genes associated with anti-inflammatory, and also suppressed the promotion of Ni ions to the expression of apoptosis-related genes. Moreover, TiN coating distinctly improved the hydrophilicity and uniformity of the surfaces of the NiTi alloys, and contributed to the expression of genes participating in cell adhesion and other physiological activities. These results indicate that the TiN-coated NiTi alloys will help overcome the shortcomings of NiTi alloys used in clinical application currently, and can be expected to be a replacement of biomaterials for a medical device field.

Outcomes with various drug eluting or bare metal stents in patients with diabetes mellitus: mixed treatment comparison analysis of 22 844 patient years of follow-up from randomised trials

PubMed Central

Kumar, Sunil; Fusaro, Mario; Amoroso, Nicholas; Kirtane, Ajay J; Byrne, Robert A; Williams, David O; Slater, James; Cutlip, Donald E; Feit, Frederick

2012-01-01

Objectives To evaluate the efficacy and safety of currently used drug eluting stents compared with each other and compared with bare metal stents in patients with diabetes. Design Mixed treatment comparison meta-analysis. Data sources and study selection PubMed, Embase, and CENTRAL were searched for randomised clinical trials, until April 2012, of four durable polymer drug eluting stents (sirolimus eluting stents, paclitaxel eluting stents, everolimus eluting stents, and zotarolimus eluting stents) compared with each other or with bare metal stents for the treatment of de novo coronary lesions and enrolling at least 50 patients with diabetes. Primary outcomes Efficacy (target vessel revascularisation) and safety (death, myocardial infarction, stent thrombosis). Results From 42 trials with 22 844 patient years of follow-up, when compared with bare metal stents (reference rate ratio 1) all of the currently used drug eluting stents were associated with a significant reduction in target vessel revascularisation (37% to 69%), though the efficacy varied with the type of stent (everolimus eluting stents∼sirolimus eluting stents>paclitaxel eluting stents∼zotarolimus eluting stent>bare metal stents). There was about an 87% probability that everolimus eluting stents were the most efficacious compared with all others, though there were limited usable data for the zotarolimus eluting Resolute stent in patients with diabetes. Moreover, there was no increased risk of any safety outcome (including very late stent thrombosis) with any drug eluting stents compared with bare metal stents. There was about a 62% probability that the everolimus eluting stent was the safest stent for the outcome of “any” stent thrombosis. Conclusions Among patients with diabetes treated with coronary stents all currently available drug eluting stents were efficacious without compromising safety compared with bare metal stents. There were relative differences among the drug eluting stents, such that the everolimus eluting stent was the most efficacious and safe. PMID:22885395

GREAT-a randomized controlled trial comparing HydroSoft/HydroFrame and bare platinum coils for endovascular aneurysm treatment: procedural safety and core-lab-assessedangiographic results.

PubMed

Taschner, Christian A; Chapot, René; Costalat, Vincent; Machi, Paolo; Courthéoux, Patrick; Barreau, Xavier; Berge, Jérôme; Pierot, Laurent; Kadziolka, Kryzsztof; Jean, Betty; Blanc, Raphaël; Biondi, Alessandra; Brunel, Hervé; Gallas, Sophie; Berlis, Ansgar; Herbreteau, Denis; Berkefeld, Joachim; Urbach, Horst; El Shikh, Samer; Fiehler, Jens; Desal, Hubert; Graf, Erika; Bonafé, Alain

2016-08-01

Hybrid hydrogel-platinum coils (HydroCoil) have proven effective for endovascular aneurysm treatment. To overcome technical limitations (coil stiffness, time restriction for placement), a second generation of softer hydrogel coils has been brought to clinical practice (HydroSoft, HydroFrame). We report on procedural safety and core-lab-assessed angiographic results from an open-label multicenter randomized controlled trial. Web-based randomization occurred in 15 medical centers in France and seven in Germany between coil embolization with second-generation hydrogel coils and treatment with any bare platinum coil. Assist devices could be used as clinically required. Primary endpoint is a composite outcome including major aneurysm recurrence and poor clinical outcome at 18 months follow-up. Five hundred thirteen patients were randomized (hydrogel n = 256, bare platinum n = 257). Twenty patients were excluded for missing informed consent and nine patients for treatment related criteria. Four hundred eighty-four patients were analyzed as randomized (hydrogel n = 243, bare platinum n = 241). Two hundred eight had ruptured aneurysms (43 %). Prespecified procedural complications occurred in 58 subjects (hydrogel n = 28, bare platinum n = 30, p = 0.77). The 14-day mortality rate was 2.1 % in both arms of the study. The median calculated packing densities for aneurysms assigned to hydrogel and bare platinum were 39 and 31 % respectively (p < 0.001). No statistically significant differences were found between arms in the post procedural angiographic occlusion rate (p = 0.8). Second-generation hydrogel coils can be used in a wide spectrum of aneurysms with a risk profile equivalent to bare platinum. Packing density was significantly higher in aneurysms treated with hydrogel coils. http://www.germanctr.de , DRKS00003132.

[Micro-community characteristics of vegetations in blowouts and depositional areas of Hulunbuir grassland, Inner Mongolia].

PubMed

Man, Liang; Hasi, Eerdun; Zhang, Ping; Yan, Xu; Xia, Xian-Dong

2008-10-01

By using traditional sampling methods, the micro-communities of vegetations in fixed, semi-bare, and bare blowouts of Hulunbuir grassland were investigated, and the investigation data were statistical analyzed. The results showed that the vegetation coverage decreased in the order of fixed blowout, semi-bare blowout, and bare blowout, and was lower than that of the primary vegetation Form. Stipa grandis. Potentilla acaulis and Kengia squarrosa were the dominant species in fixed blowout, with the coverage being 5%; while P. acaulis and Carex sp. were the dominant species in semi-bare blowout, with the coverage being 2%. The dominant species in depositional areas of semi-bare blowout were P. acaulis, K. squarrosa, Agropyron cristatum, and Thymus mongolicus, and the coverage was 4%. The dominant species on the southwest slope of bare blowout was Agriophyllum pungens. The middle depositional area of bare blowout was also occupied by A. pungens (coverage 4.7%), and the edge of it was dominated by A. cristatum (coverage 2.7%), Carex sp. (coverage 2.6%), and T. mongolicus (coverage 1.7%) from the edge of the depositional area to primary grassland. The mean species importance value in fixed, semi-bare, and bare blowouts was 12.64%, 13.38%, and 20.08%, while that in the depositional area of semi-bare blowout and in the middle and edge of bare blowout was 12.55%, 40.18%, and 11.15%, respectively.

Distribution of Rb atoms on the antirelaxation RbH coating

NASA Astrophysics Data System (ADS)

Zhang, Yi; Wang, Zhiguo; Xia, Tao

2017-04-01

We observe the extension of relaxation time of 131Xe with RbH coating, and compare the different depositions of Rb atoms on the inner surface of the vapor cell with and without RbH coating respectively to research the mechanism of coating prolongation. From the 5*5 um2 images of microscopy, we find that on the bare glass surface the Rb atoms form large random separated islands, and to the contrary they deposite as many regular longitudinal stripe of small islands on the RbH coating. We attribute these different distributions to the different molecular interactions between RbH coating and bare glass to Rb atom and build a simple rational physical model to explain this phenomenon. On the one hand, the small islands, or in other words, the relative uniform distribution on RbH coating may result from the relative stronger interaction of Rb to RbH than to the bare glass. On the other hand, the regular longitudinal stripe may stem from the grain boundaries which is related to the macroscopic shape of the vapor cell. And this longitudinal distribution can generate cylindrically electric gradient as used in some theoretically references before.

Impact localization on composite laminates using fiber Bragg grating sensors and a novel technique based on strain amplitude

NASA Astrophysics Data System (ADS)

Zhao, Gang; Li, Shuxin; Hu, Haixiao; Zhong, Yucheng; Li, Kun

2018-01-01

Carbon fiber reinforced composite materials have been widely used in aerospace and other high-tech fields because of their excellent performance. However barely visible impact damage can be introduced by low velocity impact, which might bring out tremendous risk. In this paper, a new method is proposed to predict the position of low velocity impact. The dynamic strain signal that is caused by low velocity impact is obtained by the fiber Bragg grating (FBG) sensor. The amplitude of the first K order natural frequency is extracted by Fast Fourier Transform (FFT). The amplitude data is normalized, and then establish k order vector matrix model is established. It is proposed that K order sum of squares of deviations can be used as the basis to predict positioning. Two different validation tests were performed. The experimental model was made of different layers. FBG were used to embed and paste type method, experiments were conducted with impact of different energy levels. The results show that proposed method is feasible.

Influence of Soil Properties on Soldierless Termite Distribution.

PubMed

Bourguignon, Thomas; Drouet, Thomas; Šobotník, Jan; Hanus, Robert; Roisin, Yves

2015-01-01

In tropical rainforests, termites constitute an important part of the soil fauna biomass, and as for other soil arthropods, variations in soil composition create opportunities for niche partitioning. The aim of this study was twofold: first, we tested whether soil-feeding termite species differ in the foraging substrate; second, we investigated whether soil-feeding termites select their foraging sites to enhance nutrients intake. To do so, we collected termites and analysed the composition and structure of their feeding substrates. Although Anoplotermes-group members are all considered soil-feeders, our results show that some species specifically feed on abandoned termite nests and very rotten wood, and that this substrate selection is correlated with previous stable isotope analyses, suggesting that one component of niche differentiation among species is substrate selection. Our results show that the composition and structure of bare soils on which different termite species foraged do not differ, suggesting that there is no species specialization for a particular type of bare soil. Finally, the bare soil on which termites forage does not differ from random soil samples. Overall, our results suggest that few species of the Anoplotermes-group are specialized toward substrates rich in organic matter, but that the vast majority forage on soil independently of its structural and chemical composition, being ecologically equivalent for this factor.

Infrared temperature measurements over bare soil and vegetation - A HAPEX perspective

NASA Technical Reports Server (NTRS)

Carlson, Toby N.; Perry, Eileen M.; Taconet, Odile

1987-01-01

Preliminary analyses of aircraft and ground measurements made in France during the HAPEX experiment show that horizontal radiometric surface temperature variations, as viewed by aircraft, can reflect the vertical profile of soil moisture (soil versus root zone) because of horizontal variations in vegetation density. Analyses based on one day's data show that, although horizontal variations in soil moisture were small, the vertical differences between a dry surface and a wet root zone were large. Horizontal temperature differences between bare soil, corn and oats reflect differences in the fractional vegetation cover, as seen by the radiometer. On the other hand, these horizontal variations in radiometric surface temperature seem to reflect real horizontal variations in surface turbulent energy fluxes.

A prospective randomized study for efficacy of an uncovered double bare metal stent compared to a single bare metal stent in malignant biliary obstruction.

PubMed

Lee, Hyun Jik; Chung, Moon Jae; Park, Jeong Yup; Park, Seung Woo; Nam, Chung Mo; Song, Si Young; Bang, Seungmin

2017-08-01

A biliary self-expandable metal stent (SEMS) is commonly used to relieve malignant biliary obstruction. The aim of this study was to compare the efficacy of a conventional uncovered SEMS with that of a newly developed uncovered double bare metal stent in reducing the risk of stent occlusion caused by tumor ingrowth. We performed a prospective, open-labeled, randomized trial in 71 patients at Severance Hospital, Yonsei University College of Medicine from June 2013 to June 2014. Patients with inoperable malignant biliary obstruction were included and randomized to receive an uncovered single bare metal stent (SBSs; S&G Biotech Inc.), an uncovered single bare metal stent (SBSt; Taewoong Medical), or an uncovered double bare metal stent (DBS; S&G Biotech Inc.). The mean age was 66.6 years (range, 35-83), and 42 (59.2%) were male. The mean duration of stent patency was 212 days (±152) in the DBS group (n = 24) compared with 124 days (±98) in the SBSs group (n = 23; P = 0.022 for noninferiority) and 116 days (±79) in the SBSt group (n = 24; P = 0.010 for noninferiority). There were no differences in the incidences of early and delayed complications or migration. The newly developed DBS is noninferior to the conventional uncovered SEMSs on duration of stent patency and tumor ingrowth occurred less frequently in the DBS group. This might decrease the need for reintervention and offer a better quality of life. The trial is registered with Clinicaltrials.gov no: NCT01869894.

The visible signal responsible for proton therapy dosimetry using bare optical fibers is not Čerenkov radiation.

PubMed

Darafsheh, Arash; Taleei, Reza; Kassaee, Alireza; Finlay, Jarod C

2016-11-01

Proton beam dosimetry using bare plastic optical fibers has emerged as a simple approach to proton beam dosimetry. The source of the signal in this method has been attributed to Čerenkov radiation. The aim of this work was a phenomenological study of the nature of the visible light responsible for the signal in bare fiber optic dosimetry of proton therapy beams. Plastic fiber optic probes embedded in solid water phantoms were irradiated with proton beams of energies 100, 180, and 225 MeV produced by a proton therapy cyclotron. Luminescence spectroscopy was performed by a CCD-coupled spectrometer. The spectra were acquired at various depths in phantom to measure the percentage depth dose (PDD) for each beam energy. For comparison, the PDD curves were acquired using a standard multilayer ion chamber device. In order to further analyze the contribution of the Čerenkov radiation in the spectra, Monte Carlo simulation was performed using fluka Monte Carlo code to stochastically simulate radiation transport, ionizing radiation dose deposition, and optical emission of Čerenkov radiation. The measured depth doses using the bare fiber are in agreement with measurements performed by the multilayer ion chamber device, indicating the feasibility of using bare fiber probes for proton beam dosimetry. The spectroscopic study of proton-irradiated fibers showed a continuous spectrum with a shape different from that of Čerenkov radiation. The Monte Carlo simulations confirmed that the amount of the generated Čerenkov light does not follow the radiation absorbed dose in a medium. The source of the optical signal responsible for the proton dose measurement using bare optical fibers is not Čerenkov radiation. It is fluorescence of the plastic material of the fiber.

Psychophysical evaluation of a variable friction tactile interface

NASA Astrophysics Data System (ADS)

Samur, Evren; Colgate, J. Edward; Peshkin, Michael A.

2009-02-01

This study explores the haptic rendering capabilities of a variable friction tactile interface through psychophysical experiments. In order to obtain a deeper understanding of the sensory resolution associated with the Tactile Pattern Display (TPaD), friction discrimination experiments are conducted. During the experiments, subjects are asked to explore the glass surface of the TPaD using their bare index fingers, to feel the friction on the surface, and to compare the slipperiness of two stimuli, displayed in sequential order. The fingertip position data is collected by an infrared frame and normal and translational forces applied by the finger are measured by force sensors attached to the TPaD. The recorded data is used to calculate the coefficient of friction between the fingertip and the TPaD. The experiments determine the just noticeable difference (JND) of friction coefficient for humans interacting with the TPaD.

Reflectance of vegetation, soil, and water. [in Hidalgo County, Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1973-01-01

The author has identified the following significant results. A study was conducted in a 340-acre (139 hectares) field of grain sorghum (Sorghum bicolor (L.) Moench) to determine if multispectral data from ERTS-1 could be used to detect differences in chlorophyll concentration between iron-deficient (chlorotic) and apparently normal (green) grain sorghum. Chlorotic sorghum areas 2.8 acres (1.1 hectares) or larger in size were identified on a computer printout of band 5 data which contains the chlorophyll absorption band at the 0.65 micron wavelength. ERTS resolution is sufficient for practical applications in detecting iron-deficient sorghum in otherwise uniform fields. The first classification map of the study county has been produced. Vegetation (crops), rangeland, bare soil, water, and an undefined (all other) category occupied 15.2, 45.0, 19.1, 0.02, and 20.6% of the land area, respectively.

Removal efficiency of particulate matters at different underlying surfaces in Beijing.

PubMed

Liu, Jiakai; Mo, Lichun; Zhu, Lijuan; Yang, Yilian; Liu, Jiatong; Qiu, Dongdong; Zhang, Zhenming; Liu, Jinglan

2016-01-01

Particulate matter (PM) pollution has been increasingly becoming serious in Beijing and has drawn the attention of the local government and general public. This study was conducted during early spring of 2013 and 2014 to monitor the concentration of PM at three different land surfaces (bare land, urban forest, and lake) in the Olympic Park in Beijing and to analyze its effect on the concentration of meteorological factors and the dry deposition onto different land cover types. The results showed that diurnal variation of PM concentrations at the three different land surfaces had no significant regulations, and sharp short-term increases in PM10 (particulate matter having an aerodynamic diameter <10 μm) occurred occasionally. The concentrations also differed from one land cover type to another at the same time, but the regulation was insignificant. The most important meteorological factor influencing the PM concentration is relative humidity; it is positively correlated with the PM concentration. While in the forests, the wind speed and irradiance also influenced the PM concentration by affecting the capture capacity of trees and dry deposition velocity. Other factors were not correlated with or influenced by the PM concentration. In addition, the hourly dry deposition in unit area (μg/m(2)) onto the three types of land surfaces and the removal efficiency based on the ratio of dry deposition and PM concentration were calculated. The results showed that the forest has the best removal capacity for both PM2.5 (particulate matter having an aerodynamic diameter <2.5 μm) and PM10 because of the faster deposition velocity and relatively low resuspension rate. The lake's PM10 removal efficiency is higher than that of the bare land because of the relatively higher PM resuspension rates on the bare land. However, the PM2.5 removal efficiency is lower than that of the bare land because of the significantly lower dry deposition velocity.

Physiological variation among native and exotic winter annual plants associated with microbiotic crusts in the Mojave Desert

USGS Publications Warehouse

DeFalco, L.A.; Detling, J.K.; Tracy, C.R.; Warren, S.D.

2001-01-01

Microbiotic crusts are important components of many aridland soils. Research on crusts typically focuses on the increase in soil fertility due to N-fixing micro-organisms, the stabilization of soils against water and wind erosion and the impact of disturbance on N-cycling. The effect of microbiotic crusts on the associated plant community has received little attention. We quantified the influence of crusts on the production, species diversity, nutrient content and water relations of winter annual plant species associated with microbiotic soil crusts in the northeast Mojave Desert. Shoot biomass of winter annuals was 37% greater and plant density was 77% greater on crusts than were biomass and density on soils lacking crust cover (=bare soils). This greater production of annuals on crusts was likely due to enhanced soil conditions including an almost two-fold increase in soil organic matter and inorganic N compared to bare soils. Crusted soils also had 53% greater volumetric water content than bare soils during November and December, the time when winter annuals become established. As plant development progressed into spring, however, soil water availability decreased: More negative plant xylem water potentials were associated with greater plant biomass on crusted soils. Plants associated with microbiotic soil crusts had lower concentrations of N in shoots (mg N g-1 dry mass). However, total shoot N (mg N m-2) was the same in plants growing on the different soil types when biomass production peaked in April. Shoots had similar patterns in their concentration and content of P. Species diversity of annuals was not statistically different between the two soil types. Yet, while native annuals comprised the greatest proportion of shoot biomass on bare soils, exotic forbs and grasses produced more biomass on crusts. Total shoot nutrient content (biomass x concentration) of the two exotic annual species examined was dramatically greater on crusts than bare soils; only one native species had greater shoot content of N and P when growing on crusts than bare soils. Microbiotic crusts appear to increase site fertility in the northeast Mojave Desert, but nutrients and water distributed within a greater biomass of annual plants growing on microbiotic crusts likely resulted in lower concentrations of nutrients in plant tissue and lower xylem pressure potentials than plants growing on bare soils. Exotic annuals growing on crusts appear to respond to the higher N availability by growing faster, potentially outcompeting native annual species.

Physiological variation among native and exotic winter annuals associated with microphytic soil crusts in the Mojave Desert

USGS Publications Warehouse

DeFalco, Lesley; Detling, James K.; Tracy, C. Richard; Warren, Steven D.

2001-01-01

Microbiotic crusts are important components of many aridland soils. Research on crusts typically focuses on the increase in soil fertility due to N-fixing micro-organisms, the stabilization of soils against water and wind erosion and the impact of disturbance on N-cycling. The effect of microbiotic crusts on the associated plant community has received little attention. We quantified the influence of crusts on the production, species diversity, nutrient content and water relations of winter annual plant species associated with microbiotic soil crusts in the northeast Mojave Desert. Shoot biomass of winter annuals was 37% greater and plant density was 77% greater on crusts than were biomass and density on soils lacking crust cover (=bare soils). This greater production of annuals on crusts was likely due to enhanced soil conditions including an almost two-fold increase in soil organic matter and inorganic N compared to bare soils. Crusted soils also had 53% greater volumetric water content than bare soils during November and December, the time when winter annuals become established. As plant development progressed into spring, however, soil water availability decreased: More negative plant xylem water potentials were associated with greater plant biomass on crusted soils. Plants associated with microbiotic soil crusts had lower concentrations of N in shoots (mg N g−1 dry mass). However, total shoot N (mg N m−2) was the same in plants growing on the different soil types when biomass production peaked in April. Shoots had similar patterns in their concentration and content of P. Species diversity of annuals was not statistically different between the two soil types. Yet, while native annuals comprised the greatest proportion of shoot biomass on bare soils, exotic forbs and grasses produced more biomass on crusts. Total shoot nutrient content (biomass×concentration) of the two exotic annual species examined was dramatically greater on crusts than bare soils; only one native species had greater shoot content of N and P when growing on crusts than bare soils. Microbiotic crusts appear to increase site fertility in the northeast Mojave Desert, but nutrients and water distributed within a greater biomass of annual plants growing on microbiotic crusts likely resulted in lower concentrations of nutrients in plant tissue and lower xylem pressure potentials than plants growing on bare soils. Exotic annuals growing on crusts appear to respond to the higher N availability by growing faster, potentially outcompeting native annual species.

Plant diversity affects GHG fluxes in an ecological engineering experiment in a disturbed Sphagnum peatland (La Guette, France)

NASA Astrophysics Data System (ADS)

Gogo, Sébastien; Laggoun-Défarge, Fatima; Leroy, Fabien; Guimbaud, Christophe; Bernard-Jannin, Léonard

2017-04-01

Many Sphagnum peatlands are experiencing vegetation change caused mainly by hydrological disturbances. In the context of these direct and indirect modifications, greenhouse gases (GHG) fluxes are affected by peat oxygenation, changes in litter composition (and thus decomposition) and rhizospheric processes (such as root exudates). This could lead a C sink system to switch to a source. To restore peatland functioning, ecological engineering works can be undertaken. Our study site, La Guette peatland (central France) is invaded by Molinia caerulea because a drain at the output decreased the water table depth. It was shown that it functioned as a source of C. In 2014, hydrological works were undertaken: 8 dams were installed, ditches were dug perpendicular to the water flow and back-filled with a mixture of shales and bentonite. In addition, a biodiversity experiment with 2 identical experimental stations was implemented: "downstream", close to the hydraulic works (relatively wet), "upstream", (relatively dry), with types of 3 vegetation plot (2m x 2m, n=4): 1) "control": intact vegetation (Molinia caerulea, Erica tetralix), 2) "bare" peat: vegetation and 5cm of peat were removed, 3) "Sphagnum": bare peat+Sphagnum. Our study aims to assess the effect of the vegetation treatment on the GHG fluxes. CO2 (ecosystem respiration or ER, Gross Primary Production or GPP, and Net Ecosystem Exchange) and CH4 fluxes (manual accumulation chamber), air and soil temperature, water table level, soil moisture were measured. After 18 months, half of the surface of "bare" and "Sphagnum" plots were covered by vegetation (Eriophorum angustifolium, Rynchospora alba, Trichophorum cespitosum). With time, as succession unfolds in these 2 types of station, ER and GPP increased. The sensitivity of ER to temperature increased sharply in "bare" and "Sphagnum" plots with years and became higher than the sensitivity in "control" plots. GPP increased with the total vegetation percentage cover, especially in "bare" peat plots. NEE were still lower in the "bare" and "sphagnum" peat plots than in "control". However, the difference tends to decrease. In November 2015, the "sphagnum" peat plots were still functioning as a sink of C, whereas the other plots functioned as a source. As a conclusion, the "bare" and "sphagnum" treatments, after 3 years, were not able to store C as much as the control during the daytime measurements undertaken. C budget for each treatment still have to be calculated to determine the sink or source functioning of the different treatment.

Increased expression of the sodium/iodide symporter in papillary thyroid carcinomas.

PubMed Central

Saito, T; Endo, T; Kawaguchi, A; Ikeda, M; Katoh, R; Kawaoi, A; Muramatsu, A; Onaya, T

1998-01-01

Iodide is concentrated to a much lesser extent by papillary thyroid carcinoma as compared with the normal gland. The Na+/I- symporter (NIS) is primarily responsible for the uptake of iodide into thyroid cells. Our objective was to compare NIS mRNA and protein expression in papillary carcinomas with those in specimens with normal thyroid. Northern blot analysis revealed a 2.8-fold increase in the level of NIS mRNA in specimens with papillary carcinoma versus specimens with normal thyroid. Immunoblot analysis using anti-human NIS antibody that was produced with a glutathione S-transferase fusion protein containing NIS protein (amino acids 466-522) showed the NIS protein at 77 kD. The NIS protein level was elevated in 7 of 17 cases of papillary carcinoma but was not elevated in the normal thyroid. Immunohistochemical staining revealed abundant NIS in 8 of 12 carcinomas, whereas NIS protein was barely detected in specimens with normal thyroid. Although considerable patient-to-patient variation was observed, our results indicate that NIS mRNA is elevated, and its protein tends to be more abundant, in a subset of papillary thyroid carcinomas than in normal thyroid tissue. PMID:9525971

Influence of different floor management strategies of the vineyard on the natural yeast population associated with grape berries.

PubMed

Cordero-Bueso, Gustavo; Arroyo, Teresa; Serrano, Ana; Valero, Eva

2011-07-15

Some oenological practices, such as the massive utilisation of commercial yeast and the consequent colonisation of wineries, can contribute to reducing the native yeast biodiversity. In this context, the vineyard could be a reservoir of autochthonous yeasts of oenological interest. Thus, the evaluation of the influence of different agricultural parameters on the biodiversity of yeast population in the vineyard is necessary. This work shows the results of the influence of some floor management strategies of the vineyard in the natural yeast population associated with the grape-berries. With this objective, a three year sampling plan was designed in the Shiraz vineyards of the Madrid region using three floor management strategies: bare soil by tillage, bare soil maintained with herbicides and soil maintained with cover crop. The results of this study have shown that bare soil by tillage could be a sustainable alternative for managing the soil, due to the reduced use of agrochemicals and the resulting high yeasts biodiversity. Nevertheless, the presence of herbicides in the vineyard has a minor impact on the diversity of grape associated yeast communities, and this could have increased the yeast populations. Hence, from the fermentative yeasts' (like Saccharomyces) point of view, in hot and arid environments where soils may be affected by the tillage management, the best option could be the maintenance of the bare soil with the use of herbicides. Copyright © 2011 Elsevier B.V. All rights reserved.

Experimental Investigation of Forces Produced by Misaligned Steel Rollers

NASA Technical Reports Server (NTRS)

Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

2010-01-01

The International Space Station Solar Alpha Rotary Joint (SARJ) uses a roller-based mechanism for positioning of the solar arrays. The forces and moments that develop at the roller interfaces are influenced by the design including the kinematic constraints and the lubrication condition. To help understand the SARJ operation, a set of dedicated experiments were completed using roller pairs. Of primary interest was to measure the axial force directed along the axis of rotation of the roller as a function of shaft misalignment. The conditions studied included dry and clean surfaces; one surface plated by a gold film, and greased surfaces. For the case of a bare 440C roller against a nitrided 15-5 roller without lubrication, the axial force can be as great as 0.4 times the normal load for a shaft angle of 0.5 degree. Such a magnitude of force on a roller in the SARJ mechanism would cause roller tipping and contact pressures much greater than anticipated by the designers. For the case of a bare 440C roller against a nitrided 15-5 roller with grease lubrication, the axial force does not exceed about 0.15 times the normal load even for the largest misalignment angles tested. Gold films provided good lubrication for the short duration testing reported herein. Grease lubrication limited the magnitude of the axial force to even smaller magnitudes than was achieved with the gold films. The experiments demonstrate the critical role of good lubrication for the SARJ mechanism.

Experimental Investigation of Forces Produced by Misaligned Steel Rollers

NASA Technical Reports Server (NTRS)

Krantz, Timothy; DellaCorte, Christopher; Dube, Michael

2010-01-01

The International Space Station (ISS) Solar Alpha Rotary Joint (SARJ) uses a roller-based mechanism for positioning of the solar arrays. The forces and moments that develop at the roller interfaces are influenced by the design including the kinematic constraints and the lubrication condition. To help understand the SARJ operation, a set of dedicated experiments were completed using roller pairs. Of primary interest was to measure the axial force directed along the axis of rotation of the roller as a function of shaft misalignment. The conditions studied included dry and clean surfaces; one surface plated by a gold film, and greased surfaces. For the case of a bare 440C roller against a nitrided 15-5 roller without lubrication, the axial force can be as great as 0.4 times the normal load for a shaft angle of 0.5 deg. Such a magnitude of force on a roller in the SARJ mechanism would cause roller tipping and contact pressures much greater than anticipated by the designers. For the case of a bare 440C roller against a nitrided 15-5 roller with grease lubrication, the axial force does not exceed about 0.15 times the normal load even for the largest misalignment angles tested. Gold films provided good lubrication for the short duration testing reported herein. Grease lubrication limited the magnitude of the axial force to even smaller magnitudes than was achieved with the gold films. The experiments demonstrate the critical role of good lubrication for the SARJ mechanism.

[Soil water reservoir properties and influencing factors of typical newly-established green belts of Shanghai Chenshan Botanical Garden, China.

PubMed

Wu, Hai Bing; Fang, Hai Lan; Peng, Hong Ling

2016-05-01

The effects of different vegetation types, compaction ways and soil basic physico-chemical properties on soil water reservoir in the typical newly-established green belts of Shanghai Chenshan Botanical Garden were studied. The results showed that the total reservoir capacity, detention capacity and effective storage for the Botanical Garden were lower than those of natural forests. However, the dead storage was very high accounting for 60.6% of the total reservoir capacity, resulting in reduced flood storage and drainage capacity for the greens. The total reservoir capacity and detention capacity of different vegetation types were in order of brush land> tree land> grassland> bamboo land> bare land. The effective storages of the brush land and the tree land were relatively high, whereas those of the bare land and the bamboo land were lower. The ratios of the dead storage over the total re-servoir capacity in the bare land and the bamboo land were relatively high with the values 65.5% and 67.6%, respectively. The total reservoir capacity, detention capacity and effective storage of the brush land were significantly different from those of the bare land. The vegetation significantly improved the water storage and retention capacity for the soil, while the compaction by large machinery and man-caused trampling reduced the total reservoir capacity, detention capacity and effective storage of soils. The water reservoir properties were influenced by soil bulk density, saturated hydraulic conductivity, capillary porosity, non-capillary porosity, total porosity, clay and organic matter contents. Therefore, improving the soil physico-chemical properties might increase the soil reservoir capacity of the urban green belt effectively.

Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents.

PubMed

Sigler, Matthias; Klötzer, Julia; Quentin, Thomas; Paul, Thomas; Möller, Oliver

2015-12-01

Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model. Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation. On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents. After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting.

Combining 3d Volume and Mesh Models for Representing Complicated Heritage Buildings

NASA Astrophysics Data System (ADS)

Tsai, F.; Chang, H.; Lin, Y.-W.

2017-08-01

This study developed a simple but effective strategy to combine 3D volume and mesh models for representing complicated heritage buildings and structures. The idea is to seamlessly integrate 3D parametric or polyhedral models and mesh-based digital surfaces to generate a hybrid 3D model that can take advantages of both modeling methods. The proposed hybrid model generation framework is separated into three phases. Firstly, after acquiring or generating 3D point clouds of the target, these 3D points are partitioned into different groups. Secondly, a parametric or polyhedral model of each group is generated based on plane and surface fitting algorithms to represent the basic structure of that region. A "bare-bones" model of the target can subsequently be constructed by connecting all 3D volume element models. In the third phase, the constructed bare-bones model is used as a mask to remove points enclosed by the bare-bones model from the original point clouds. The remaining points are then connected to form 3D surface mesh patches. The boundary points of each surface patch are identified and these boundary points are projected onto the surfaces of the bare-bones model. Finally, new meshes are created to connect the projected points and original mesh boundaries to integrate the mesh surfaces with the 3D volume model. The proposed method was applied to an open-source point cloud data set and point clouds of a local historical structure. Preliminary results indicated that the reconstructed hybrid models using the proposed method can retain both fundamental 3D volume characteristics and accurate geometric appearance with fine details. The reconstructed hybrid models can also be used to represent targets in different levels of detail according to user and system requirements in different applications.

A study on zinc distribution in calcareous soils for cowpea (Vigna Unguiculata L.) and barely ( Hordeum Vulgare L.)

NASA Astrophysics Data System (ADS)

Boroomand, Naser; Maleki, Mohammad Reza

2010-05-01

Compared to other cereals, such as wheat and barley cultivars which have low sensitivity to Zn deficiency, cowpea is sensitive to zinc (Zn) deficiency, however it extensively grows even in soils with deficient in Zn. A 8-week greenhouse experiment was conducted to study the response of cowpea and barely to Zn in calcareous soils with different DTPA- Zn. The soil samples were taken from soil surface up to 0.3 m in which their DTPA- Zn ranged from 0.5 to 3.5 mg kg-1. Shoot dry matter, concentration and uptake of Zn were found to be significantly correlated with soil DTPA- Zn in cowpea and barely. Critical deficiency level of Zn in cowpea was 1.3 mg kg-1 in soil and 28.5 mg kg-1 in shoot dry matter, however, to barely symptoms of Zn deficiency was not observed and concentration of Zn was higher than the critical level reported in literatures. Organic carbon (OC), calcium carbonate equivalent (CCE), pH and field capacity soil moisture content(FC) were significantly correlated with plant responses to Zn which were the most influenced characteristics to Zn uptake by plants.

Effects of shear load on frictional healing

NASA Astrophysics Data System (ADS)

Ryan, K. L.; Marone, C.

2014-12-01

During the seismic cycle of repeated earthquake failure, faults regain strength in a process known as frictional healing. Laboratory studies have played a central role in illuminating the processes of frictional healing and fault re-strengthening. These studies have also provided the foundation for laboratory-derived friction constitutive laws, which have been used extensively to model earthquake dynamics. We conducted laboratory experiments to assess the affect of shear load on frictional healing. Frictional healing is quantified during slide-hold-slide (SHS) tests, which serve as a simple laboratory analog for the seismic cycle in which earthquakes (slide) are followed by interseismic quiescence (hold). We studied bare surfaces of Westerly granite and layers of Westerly granite gouge (thickness of 3 mm) at normal stresses from 4-25 MPa, relative humidity of 40-60%, and loading and unloading velocities of 10-300 μm/s. During the hold period of SHS tests, shear stress on the sample was partially removed to investigate the effects of shear load on frictional healing and to isolate time- and slip-dependent effects on fault healing. Preliminary results are consistent with existing works and indicate that frictional healing increases with the logarithm of hold time and decreases with normalized shear stress τ/τf during the hold. During SHS tests with hold periods of 100 seconds, healing values ranged from (0.013-0.014) for τ/τf = 1 to (0.059-0.063) for τ/τf = 0, where τ is the shear stress during the hold period and τf is the shear stress during steady frictional sliding. Experiments on bare rock surfaces and with natural and synthetic fault gouge materials are in progress. Conventional SHS tests (i.e. τ/τf = 1) are adequately described by the rate and state friction laws. However, previous experiments in granular quartz suggest that zero-stress SHS tests are not well characterized by either the Dieterich or Ruina state evolution laws. We are investigating the processes that produce shear stress dependent frictional healing, alternate forms of the state evolution law, and comparing results for friction of bare rock surfaces and granular fault gouge.

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE... and Underground § 57.12012 Bare signal wires. The potential on bare signal wires accessible to contact...

Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984 - April 1, 1985

DOE R&D Accomplishments Database

Smalley, R. E.

1985-01-01

There have been four major areas of concentration for the study of bare metal cluster beams: neutral cluster, chemical reactivity, cold cluster ion source development (both positive and negative), bare cluster ion ICR (ion cyclotron resonance) development, and photofragmentation studies of bare metal cluster ions.

Contrasting effects of ecosystem engineering by the cordgrass Spartina maritima and the sandprawn Callianassa kraussi in a marine-dominated lagoon

NASA Astrophysics Data System (ADS)

Pillay, D.; Branch, G. M.; Dawson, J.; Henry, D.

2011-01-01

Ecosystem engineering by plants and animals significantly influences community structure and the physico-chemical characteristics of marine habitats. In this paper we document the contrasting effects of ecosystem engineering by the cordgrass Spartina maritima and the burrowing sandprawn Callianassa kraussi on physico-chemical characteristics, microflora, macrofaunal community structure and morphological attributes in the high shore intertidal sandflats of Langebaan Lagoon, a marine-dominated system on the west coast of South Africa. Comparisons were made at six sites in the lagoon within Spartina and Callianassa beds, and in a "bare zone" of sandflat between these two habitats that lacks both sandprawns and cordgrass. Sediments in Spartina habitats were consolidated by the root-shoot systems of the cordgrass, leading to low sediment penetrability, while sediments in beds of C. kraussi were more penetrable, primarily due to the destabilising effects of sandprawn bioturbation. Sediments in the "bare zone" had intermediate to low values of penetrability. Sediment organic content was lowest in bare zones and greatest in Spartina beds, while sediment chl- a levels were greatest on bare sand, but were progressively reduced in the Spartina and Callianassa beds. These differences among habitats induced by ecosystem engineering in turn affected the macrofauna. Community structure was different between all three habitats sampled, with species richness being surprisingly greater in Callianassa beds than either the bare zone or Spartina beds. In general, the binding of surface sediments by the root systems of Spartina favoured rigid-bodied, surface-dwelling and tube-building species, while the destabilising effect of bioturbation by C. kraussi favoured burrowing species. The contrasting effects of these ecosystem engineers suggest that they play important roles in increasing habitat heterogeneity. Importantly, the role of bioturbation by C. kraussi in enhancing macrofaunal richness was unexpected. By loosening sediments, reducing anoxia and enhancing organic content, C. kraussi may engineer these high shore habitats to ameliorate environmental stresses or increase food availability.

Space environmental effects on LDEF composites: A leading edge coated graphite epoxy panel

NASA Technical Reports Server (NTRS)

George, Pete E.; Dursch, Harry W.; Hill, Sylvester G.

1993-01-01

The electronics module cover for the leading edge (Row D 9) experiment M0003-8 was fabricated from T300 graphite/934 epoxy unidirectional prepreg tape in a (O(sub 2), +/- 45, O(sub 2), +/- 45, 90, 0)(sub s) layup. This 11.75 in x 16.75 in panel was covered with thermal control coatings in three of the four quadrants with the fourth quadrant uncoated. The composite panel experienced different thermal cycling extremes in each quadrant due to the different optical properties of the coatings and bare composite. The panel also experienced ultraviolet (UV) and atomic oxygen (AO) attack as well as micrometeoroid and space debris impacts. An AO reactivity of 0.99 x 10(exp -24) cm(sup 3)/atom was calculated for the bare composite based on thickness loss. The white urethane thermal control coatings (A276 and BMS 1060) prevented AO attack of the composite substrate. However, the black urethane thermal control coating (Z306) was severely eroded by AO, allowing some AO attack of the composite substrate. An interesting banding pattern on the AO eroded bare composite surface was investigated and found to match the dimensions of the graphite fiber tow widths as prepregged. Also, erosion depths were greater in the darker bands. Five micrometeoroid/space debris impacts were cross sectioned to investigate possible structural damage as well as impact/AO interactions. Local crushing and delaminations were found to some extent in all of the impacts. No signs of coating undercutting were observed despite the extensive AO erosion patterns seen in the exposed composite material at the impact sites. An extensive microcrack study was performed on the panel along with modeling of the thermal environment to estimate temperature extremes and thermal shock. The white coated composite substrate displayed almost no microcracking while the black coated and bare composite showed extensive microcracking. Significant AO erosion was seen in many of the cracks in the bare composite.

Drug-eluting stents versus bare-metal stents for off-label indications: a propensity score-matched outcome study.

PubMed

Austin, David; Oldroyd, Keith G; McConnachie, Alex; Slack, Rachel; Eteiba, Hany; Flapan, Andrew D; Jennings, Kevin P; Northcote, Robin J; Pell, Alastair C H; Starkey, Ian R; Pell, Jill P

2008-08-01

The US Food and Drug Administration recently concluded that data on off-label drug-eluting stent (DES) safety are limited. However, in actual clinical practice, DES are often used for off-label indications, and observational studies demonstrate that complications are higher when compared with on-label use. We aimed to determine whether clinical outcomes differ after DES and bare-metal stent implantation in a patient cohort defined by DES off-label indications. We used the national revascularization registry in Scotland to identify patients who underwent coronary stenting for an off-label indication between January 2003 and September 2005. Individual-level linkage to comprehensive national admission and death databases was used to ascertain the end points of death, myocardial infarction, and target-vessel revascularization. We calculated propensity scores on the basis of clinical, demographic, and angiographic variables and matched DES to bare-metal stents on a 1:1 basis. The final study population consisted of 1642 patients, well matched for important covariables at baseline. Event-free survival was calculated over 24 months with the Kaplan-Meier method. All-cause death was more common after bare-metal stent implantation during follow-up (7.7% versus 6.6%; hazard ratio 0.63; 95% confidence interval, 0.40 to 0.99; P=0.04). No difference in the rates of myocardial infarction were noted (7.3% versus 7.5%; hazard ratio 1.02; 95% confidence interval, 0.69 to 1.54; P=0.92). Target-vessel revascularization was reduced in patients treated with DES (13.9% versus 10.7%; hazard ratio 0.67; 95% confidence interval, 0.49 to 0.93; P=0.02). At 24 months, patients treated with DES for off-label indications had lower rates of death and target-vessel revascularization and similar rates of myocardial infarction, as compared with patients treated with bare-metal stents.

Comparison of the long-term safety and efficacy of drug-eluting and bare-metal stent implantation in saphenous vein grafts.

PubMed

Latib, Azeem; Ferri, Luca; Ielasi, Alfonso; Cosgrave, John; Godino, Cosmo; Bonizzoni, Erminio; Romagnoli, Enrico; Chieffo, Alaide; Valgimigli, Marco; Penzo, Carlo; Carlino, Mauro; Michev, Iassen; Sangiorgi, Giuseppe M; Montorfano, Matteo; Airoldi, Flavio; Colombo, Antonio

2010-06-01

Concerns about the long-term safety of drug-eluting stents (DES) in saphenous vein grafts has become an area of controversy and uncertainty. In this retrospective registry, we compared the outcomes in 127 patients (143 lesions) treated with DES from April 2002 to June 2006 (DES group) with 131 patients (160 lesions) treated with bare-metal stents in the preceding 36 months (bare-metal stent group). End points analyzed were cumulative death, myocardial infarction, and target vessel revascularization at 2 years after stent implantation. The DES group was significantly (P<0.05) more complex with a greater frequency of diabetes (33.1%versus 15.3%), older grafts (11.6+/-5.3 years versus 9.6+/-5.2 years), restenotic lesions (23.8% versus 4.4%), total occlusions (7.7% versus 1.2%), and smaller grafts (3.16+/-0.66 mm versus 3.44+/-0.76 mm) treated with longer stents (34.1+/-25.1 mm versus 22.7+/-11.6 mm). At 2 years, there was no statistical difference in death (8.7% versus 7.8%), myocardial infarction (6.3% versus 9.4%), or target vessel revascularization (19.7% versus 24.2%) between DES and bare-metal stents, respectively. A propensity analysis to adjust for baseline differences suggested that there was no observed association between DES and increased mortality (hazard ratio, 0.72; 95% CI, 0.21 to 2.44; P=0.60) but possibly an association with a reduction in target vessel revascularization (hazard ratio, 0.31; 95% CI, 0.14 to 0.66; P=0.002). Despite being implanted in patients and lesions more complex than the bare-metal stent group, there was no observed association between DES implantation in saphenous vein grafts and an increase in late mortality. DES may maintain their efficacy in reducing revascularization rates in diseased saphenous vein grafts over a 2-year follow-up period.

Electron beam control for barely separated beams

DOEpatents

Douglas, David R.; Ament, Lucas J. P.

2017-04-18

A method for achieving independent control of multiple beams in close proximity to one another, such as in a multi-pass accelerator where coaxial beams are at different energies, but moving on a common axis, and need to be split into spatially separated beams for efficient recirculation transport. The method for independent control includes placing a magnet arrangement in the path of the barely separated beams with the magnet arrangement including at least two multipole magnets spaced closely together and having a multipole distribution including at least one odd multipole and one even multipole. The magnetic fields are then tuned to cancel out for a first of the barely separated beams to allow independent control of the second beam with common magnets. The magnetic fields may be tuned to cancel out either the dipole component or tuned to cancel out the quadrupole component in order to independently control the separate beams.

Detecting ecosystem performance anomalies for land management in the upper colorado river basin using satellite observations, climate data, and ecosystem models

USGS Publications Warehouse

Gu, Yingxin; Wylie, B.K.

2010-01-01

This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005-2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using "percentage of bare soil" ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005-2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions. ?? 2010 by the authors.

Detecting Ecosystem Performance Anomalies for Land Management in the Upper Colorado River Basin Using Satellite Observations, Climate Data, and Ecosystem Models

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.

2010-01-01

This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005–2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using “percentage of bare soil” ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005–2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions.

Adequate Hand Washing and Glove Use Are Necessary To Reduce Cross-Contamination from Hands with High Bacterial Loads.

PubMed

Robinson, Andrew L; Lee, Hyun Jung; Kwon, Junehee; Todd, Ewen; Rodriguez, Fernando Perez; Ryu, Dojin

2016-02-01

Hand washing and glove use are the main methods for reducing bacterial cross-contamination from hands to ready-to-eat food in a food service setting. However, bacterial transfer from hands to gloves is poorly understood, as is the effect of different durations of soap rubbing on bacterial reduction. To assess bacterial transfer from hands to gloves and to compare bacterial transfer rates to food after different soap washing times and glove use, participants' hands were artificially contaminated with Enterobacter aerogenes B199A at ∼9 log CFU. Different soap rubbing times (0, 3, and 20 s), glove use, and tomato dicing activities followed. The bacterial counts in diced tomatoes and on participants' hands and gloves were then analyzed. Different soap rubbing times did not significantly change the amount of bacteria recovered from participants' hands. Dicing tomatoes with bare hands after 20 s of soap rubbing transferred significantly less bacteria (P < 0.01) to tomatoes than did dicing with bare hands after 0 s of soap rubbing. Wearing gloves while dicing greatly reduced the incidence of contaminated tomato samples compared with dicing with bare hands. Increasing soap washing time decreased the incidence of bacteria recovered from outside glove surfaces (P < 0.05). These results highlight that both glove use and adequate hand washing are necessary to reduce bacterial cross-contamination in food service environments.

Consistency of temporal and habitat-related differences among assemblages of fish in coastal lagoons

NASA Astrophysics Data System (ADS)

Gray, Charles A.; Rotherham, Douglas; Johnson, Daniel D.

2011-12-01

The consistency of habitat-related differences in coastal lagoon fish assemblages was assessed across different spatial and temporal scales. Multimesh gillnets were used to sample assemblages of fish on a monthly basis for 1-year in three habitats (shallow seagrass, shallow bare and deep substrata) at two locations (>1 km apart), in each of two coastal lagoons (approximately 500 km apart), in southeastern Australia. A total of 48 species was sampled with 34 species occurring in both lagoons and in all three habitats; species caught in only one lagoon or habitat occurred in low numbers. Ten species dominated assemblages and accounted for more than 83% of all individuals sampled. In both lagoons, assemblages in the deep habitat consistently differed to those in the shallow strata (regardless of habitat). Several species were caught more frequently or in larger numbers in the deep habitat. Assemblages in the two shallow habitats did not differ consistently and were dominated by the same species and sizes of fish, possibly due to habitat heterogeneity and the scale and method of sampling. Within each lagoon, very few between location differences in assemblages within each habitat were observed. Consistent differences in assemblages were detected between lagoons for the shallow bare and deep habitats, indicating there were some intrinsic differences in ichthyofauna between lagoons. Assemblages in spring differed to those in summer, which differed to those in winter for the shallow bare habitat in both lagoons, and the deep habitat in only one lagoon. Fish-habitat relationships are complex and differences in the fish fauna between habitats were often temporally inconsistent. This study highlights the need for greater testing of habitat relationships in space and time to assess the generality of observations and to identify the processes responsible for structuring assemblages.

Gastritis in patients undergoing sleeve gastrectomy: Prevalence, ethnic distribution, and impact on glycemic.

PubMed

Rath-Wolfson, Lea; Varona, Roy; Bubis, Golan; Tatarov, Alexander; Koren, Rumelia; Ram, Edward

2017-04-01

Laparoscopic sleeve gastrectomy (LSG) is a therapeutic option in severely obese patients. The aim of this study was to evaluate the presence of Helicobacter pylori (HP) gastritis and non-Helicobacter gastritis in the gastrectomy specimens, and its association to other variables.One hundred six sleeve gastrectomy specimens were examined histopathologically for the presence of gastritis and its relation to other factors like ethnicity, glycemic control, and postoperative complications.Twelve patients had HP gastritis, 39 had non-HP gastritis, and 55 had normal mucosa. There was a statistical difference between the Arab and Jewish Israeli patients in our study. Twenty-eight of the Arab patients had HP gastritis and 48% had non-HP gastritis. In the Jewish population 6% had HP gastritis and 34% had non-HP gastritis. The preoperative glycemic control was worse in the gastritis group with a mean HbA1c of 8.344% while in the normal mucosa group the mean HbA1c was 6.55. After operation the glycemic control reverted to normal in most the diabetic patients. There were few postoperative complications however, they were not related to HP.There is a high incidence of gastritis in obese patients. The incidence of gastritis in the Arab population in our study was higher than that in the Jewish population. The glycemic control before surgery was worse in patients with gastritis than in the normal mucosa group. HP bares no risk for postoperative complications after LSG and does not affect weight loss. However a larger cohort of patients must be studied to arrive at conclusive results.

Gastritis in patients undergoing sleeve gastrectomy

PubMed Central

Rath-Wolfson, Lea; Varona, Roy; Bubis, Golan; Tatarov, Alexander; Koren, Rumelia; Ram, Edward

2017-01-01

Abstract Laparoscopic sleeve gastrectomy (LSG) is a therapeutic option in severely obese patients. The aim of this study was to evaluate the presence of Helicobacter pylori (HP) gastritis and non-Helicobacter gastritis in the gastrectomy specimens, and its association to other variables. One hundred six sleeve gastrectomy specimens were examined histopathologically for the presence of gastritis and its relation to other factors like ethnicity, glycemic control, and postoperative complications. Twelve patients had HP gastritis, 39 had non-HP gastritis, and 55 had normal mucosa. There was a statistical difference between the Arab and Jewish Israeli patients in our study. Twenty-eight of the Arab patients had HP gastritis and 48% had non-HP gastritis. In the Jewish population 6% had HP gastritis and 34% had non-HP gastritis. The preoperative glycemic control was worse in the gastritis group with a mean HbA1c of 8.344% while in the normal mucosa group the mean HbA1c was 6.55. After operation the glycemic control reverted to normal in most the diabetic patients. There were few postoperative complications however, they were not related to HP. There is a high incidence of gastritis in obese patients. The incidence of gastritis in the Arab population in our study was higher than that in the Jewish population. The glycemic control before surgery was worse in patients with gastritis than in the normal mucosa group. HP bares no risk for postoperative complications after LSG and does not affect weight loss. However a larger cohort of patients must be studied to arrive at conclusive results. PMID:28422853

30 CFR 57.12080 - Bare conductor guards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work or...

30 CFR 57.12080 - Bare conductor guards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare conductor guards. 57.12080 Section 57... Underground Only § 57.12080 Bare conductor guards. Trolley wires and bare power conductors shall be guarded at... conductors are less than 7 feet above the rail, they shall be guarded at all points where persons work or...

30 CFR 77.515 - Bare signal or control wires; voltage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

30 CFR 56.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Guarding trolley wires and bare powerlines. 56... Electricity § 56.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded or deenergized. ...

30 CFR 77.515 - Bare signal or control wires; voltage.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal or control wires; voltage. 77.515... COAL MINES Electrical Equipment-General § 77.515 Bare signal or control wires; voltage. The voltage on bare signal or control wires accessible to personal contact shall not exceed 40 volts. ...

30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

30 CFR 57.12066 - Guarding trolley wires and bare powerlines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Guarding trolley wires and bare powerlines. 57... MINES Electricity Surface Only § 57.12066 Guarding trolley wires and bare powerlines. Where metallic tools or equipment can come in contact with trolley wires or bare powerlines, the lines shall be guarded...

Rock friction under variable normal stress

USGS Publications Warehouse

Kilgore, Brian D.; Beeler, Nicholas M.; Lozos, Julian C.; Oglesby, David

2017-01-01

This study is to determine the detailed response of shear strength and other fault properties to changes in normal stress at room temperature using dry initially bare rock surfaces of granite at normal stresses between 5 and 7 MPa. Rapid normal stress changes result in gradual, approximately exponential changes in shear resistance with fault slip. The characteristic length of the exponential change is similar for both increases and decreases in normal stress. In contrast, changes in fault normal displacement and the amplitude of small high-frequency elastic waves transmitted across the surface follow a two stage response consisting of a large immediate and a smaller gradual response with slip. The characteristic slip distance of the small gradual response is significantly smaller than that of shear resistance. The stability of sliding in response to large step decreases in normal stress is well predicted using the shear resistance slip length observed in step increases. Analysis of the shear resistance and slip-time histories suggest nearly immediate changes in strength occur in response to rapid changes in normal stress; these are manifested as an immediate change in slip speed. These changes in slip speed can be qualitatively accounted for using a rate-independent strength model. Collectively, the observations and model show that acceleration or deceleration in response to normal stress change depends on the size of the change, the frictional characteristics of the fault surface, and the elastic properties of the loading system.

Can the normalized soil moisture index improve the prediction of soil organic carbon based on hyperspectral remote sensing data?

NASA Astrophysics Data System (ADS)

van Wesemael, Bas; Nocita, Marco

2016-04-01

One of the problems for mapping of soil organic carbon (SOC) at large-scale based on visible - near and short wave infrared (VIS-NIR-SWIR) remote sensing techniques is the spatial variation of topsoil moisture when the images are collected. Soil moisture is certainly an aspect causing biased SOC estimations, due to the problems in discriminating reflectance differences due to either variations in organic matter or soil moisture, or their combination. In addition, the difficult validation procedures make the accurate estimation of soil moisture from optical airborne a major challenge. After all, the first millimeters of the soil surface reflect the signal to the airborne sensor and show a large spatial, vertical and temporal variation in soil moisture. Hence, the difficulty of assessing the soil moisture of this thin layer at the same moment of the flight. The creation of a soil moisture proxy, directly retrievable from the hyperspectral data is a priority to improve the large-scale prediction of SOC. This paper aims to verify if the application of the normalized soil moisture index (NSMI) to Airborne Prima Experiment (APEX) hyperspectral images could improve the prediction of SOC. The study area was located in the loam region of Wallonia, Belgium. About 40 samples were collected from bare fields covered by the flight lines, and analyzed in the laboratory. Soil spectra, corresponding to the sample locations, were extracted from the images. Once the NSMI was calculated for the bare fields' pixels, spatial patterns, presumably related to within field soil moisture variations, were revealed. SOC prediction models, built using raw and pre-treated spectra, were generated from either the full dataset (general model), or pixels belonging to one of the two classes of NSMI values (NSMI models). The best result, with a RMSE after validation of 1.24 g C kg-1, was achieved with a NSMI model, compared to the best general model, characterized by a RMSE of 2.11 g C kg-1. These results confirmed the advantage to controlling the effect of soil moisture on the detection of SOC. The NSMI proved to be a flexible concept, due to the possible use of different SWIR wavelengths, and ease of use, because measurements of soil moisture by other techniques are not needed. However, in the future, it will be important to assess the effectiveness of the NSMI for different soil types, and other hyperspectral sensors.

Monitoring the effects of land use/landcover changes on urban heat island

NASA Astrophysics Data System (ADS)

Gee, Ong K.; Sarker, Md Latifur Rahman

2013-10-01

Urban heat island effects are well known nowadays and observed in cities throughout the World. The main reason behind the effects of urban heat island (UHI) is the transformation of land use/ land cover, and this transformation is associated with UHI through different actions: i) removal of vegetated areas, ii) land reclamation from sea/river, iii) construction of new building as well as other concrete structures, and iv) industrial and domestic activity. In rapidly developing cities, urban heat island effects increases very hastily with the transformation of vegetated/ other types of areas into urban surface because of the increasing population as well as for economical activities. In this research the effect of land use/ land cover on urban heat island was investigated in two growing cities in Asia i.e. Singapore and Johor Bahru, (Malaysia) using 10 years data (from 1997 to 2010) from Landsat TM/ETM+. Multispectral visible band along with indices such as Normalized Difference Vegetation Index (NDVI), Normalized Difference Build Index (NDBI), and Normalized Difference Bareness Index (NDBaI) were used for the classification of major land use/land cover types using Maximum Likelihood Classifiers. On the other hand, land surface temperature (LST) was estimated from thermal image using Land Surface Temperature algorithm. Emissivity correction was applied to the LST map using the emissivity values from the major land use/ land cover types, and validation of the UHI map was carried out using in situ data. Results of this research indicate that there is a strong relationship between the land use/land cover changes and UHI. Over this 10 years period, significant percentage of non-urban surface was decreased but urban heat surface was increased because of the rapid urbanization. With the increase of UHI effect it is expected that local urban climate has been modified and some heat related health problem has been exposed, so appropriate measure should be taken in order to reduce UHI effects as soon as possible.

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 3 2012-01-01 2012-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 3 2014-01-01 2014-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

10 CFR 429.35 - Bare or covered (no reflector) medium base compact fluorescent lamps.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 3 2013-01-01 2013-01-01 false Bare or covered (no reflector) medium base compact....35 Bare or covered (no reflector) medium base compact fluorescent lamps. (a) Sampling plan for... reflector) medium base compact fluorescent lamps; and (2) For each basic model of bare or covered (no...

Bare below elbows: does this policy affect handwashing efficacy and reduce bacterial colonisation?

PubMed Central

Burger, A; Wijewardena, C; Clayson, S; Greatorex, RA

2010-01-01

INTRODUCTION UK Department of Health guidelines recommend that clinical staff are ‘bare below the elbows’. There is a paucity of evidence to support this policy. One may hypothesise that absence of clothing around wrists facilitates more effective handwashing: this study aims to establish whether dress code affects bacterial colonisation before and after handwashing. SUBJECTS AND METHODS Sixty-six clinical staff volunteered to take part in the study, noting whether they were bare below the elbows (BBE) or not bare (NB). Using a standardised technique, imprints of left and right fingers, palms, wrists and forearms were taken onto mini agar plates. Imprints were repeated after handwashing. After incubation, colonies per plate were counted, and subcultures taken. RESULTS Thirty-eight staff were BBE and 28 were not. A total of 1112 plates were cultured. Before handwashing there was no significant difference in number of colonies between BBE and NB groups (Mann–Whitney, P < 0.05). Handwashing reduced the colony count, with greatest effect on fingers, palms and dominant wrists (t-test, P < 0.05). Comparing the two groups again after handwashing revealed no significant difference (Mann–Whitney, P < 0.05). Subcultures revealed predominantly skin flora. CONCLUSIONS There was a large variation in number of colonies cultured. Handwashing resulted in a statistically significant reduction in colony count on fingers, palms and dominant wrist regardless of clothing. We conclude that handwashing produces a significant reduction in number of bacterial colonies on staff hands, and that clothing that is not BBE does not impede this reduction. PMID:20727253

Differential effects of lichens, mosses and grasses on respiration and nitrogen mineralization in soils of the New Jersey Pinelands.

PubMed

Sedia, Ekaterina G; Ehrenfeld, Joan G

2005-06-01

In the New Jersey Pinelands, severely disturbed areas often do not undergo a rapid succession to forest; rather, a patchy cover of lichens, mosses and grasses persists for decades. We hypothesized that these plant covers affect soil microbial processes in different ways, and that these effects may alter the successional dynamics of the patches. We predicted that the moss and grass covers stimulate soil microbial activity, whereas lichens inhibit it, which may in turn inhibit succession. We collected soil cores from beneath each type of cover plus bare soil within two types of highly disturbed areas--sites subjected to hot wildfires, and areas mined for sand. Organic matter (OM) content, soil respiration and potential N mineralization were measured in the cores. Soils under mosses were similar to those under grasses; they accumulated more OM and produced more mineral N, predominantly in the form of ammonium, than either the bare soils or the soils beneath lichens. Mineralization under lichens, like that of the bare soils but unlike the soils beneath mosses or grasses, was dominated by net nitrification. These patterns were reproduced in experimentally transplanted moss and lichen mats. Mosses appear to create high-nutrient microsites via high rates of OM accumulation and production of ammonium, whereas lichens maintain low-nutrient patches similar to bare soil via low OM accumulation rates and production of mineral N predominantly in the mobile nitrate form. These differences in soil properties may explain the lack of vascular plant invasion in lichen mats, in contrast to the moss-dominated areas.

Corrosion protection of copper by polypyrrole film studied by electrochemical impedance spectroscopy and the electrochemical quartz microbalance

NASA Astrophysics Data System (ADS)

Lei, Yanhua; Ohtsuka, Toshiaki; Sheng, Nan

2015-12-01

Polypyrrole (PPy) films were synthesized on copper in solution of sodium di-hydrogen phosphate and phytate for corrosion protection. The protection properties of PPy films were comparatively investigated in NaCl solution. During two months immersion, the PPy film doped with phytate anions, working as a cationic perm-selective membrane, inhibited the dissolution of copper to 1% of bare copper. Differently, the PPy film doped with di-hydrogen phosphate anions, possessing anionic perm-selectivity, was gradually reduced, and inhibited the dissolution to 7.8% of bare copper. Degradation of the PPy films was studied by comparing the electrochemical impedance spectroscopy change at different immersion time and Raman spectra change after immersion.

An evaluation of models of bare soil evaporation formulated with different land surface boundary conditions and assumptions

NASA Astrophysics Data System (ADS)

Smits, Kathleen M.; Ngo, Viet V.; Cihan, Abdullah; Sakaki, Toshihiro; Illangasekare, Tissa H.

2012-12-01

Bare soil evaporation is a key process for water exchange between the land and the atmosphere and an important component of the water balance. However, there is no agreement on the best modeling methodology to determine evaporation under different atmospheric boundary conditions. Also, there is a lack of directly measured soil evaporation data for model validation to compare these methods to establish the validity of their mathematical formulations. Thus, a need exists to systematically compare evaporation estimates using existing methods to experimental observations. The goal of this work is to test different conceptual and mathematical formulations that are used to estimate evaporation from bare soils to critically investigate various formulations and surface boundary conditions. Such a comparison required the development of a numerical model that has the ability to incorporate these boundary conditions. For this model, we modified a previously developed theory that allows nonequilibrium liquid/gas phase change with gas phase vapor diffusion to better account for dry soil conditions. Precision data under well-controlled transient heat and wind boundary conditions were generated, and results from numerical simulations were compared with experimental data. Results demonstrate that the approaches based on different boundary conditions varied in their ability to capture different stages of evaporation. All approaches have benefits and limitations, and no one approach can be deemed most appropriate for every scenario. Comparisons of different formulations of the surface boundary condition validate the need for further research on heat and vapor transport processes in soil for better modeling accuracy.

Seal glass compatibility with bare and (Mn,Co) 3O 4 coated Crofer 22 APU alloy in different atmospheres

NASA Astrophysics Data System (ADS)

Mahapatra, M. K.; Lu, K.

To prevent gas mixing and leakage during solid oxide fuel/electrolyzer cell operation, the interconnect/seal glass interface should bond well and remain stable. A SrO-La 2O 3-Al 2O 3-SiO 2 (SABS-0) seal glass has been bonded to bare Crofer 22 APU alloy and (Mn,Co) 3O 4 coated Crofer 22 APU alloy. The stability of the interconnect/SABS-0 interface has been studied in air and H 2/H 2O atmospheres at 800 °C for 1000 h. The interconnect/seal glass interaction involves the oxidation of the bare and (Mn,Co) 3O 4 coated Crofer 22 APU alloy surfaces, inter-diffusion of elements, chemical reaction, and the devitrification of the SABS-0 glass. The study shows that the thermal treatment atmosphere greatly affects the interfacial stability of both bare Crofer 22 APU/SABS-0 and (Mn,Co) 3O 4 coated Crofer 22 APU/SABS-0 samples. The interfacial stability is better in the H 2/H 2O atmosphere for both samples. The instability of the (Mn,Co) 3O 4 coating under the thermal treatment conditions degrades the interfacial compatibility of the (Mn,Co) 3O 4 coated Crofer 22 APU/SABS-0 sample.

Imaging spectroscopy studies of Hawaiian ecosystems, carbon properties, and disturbance

NASA Astrophysics Data System (ADS)

Asner, Gregory P.; Vitousek, Peter M.

2005-01-01

The Hawaiian Islands contain more than two-thirds of the global life zones delineated by Holdridge1. We used high-fidelity imaging spectroscopy and shortwave-infrared (SWIR) spectral mixture analysis to analyze the lateral distribution of plant tissues and bare substrate across bioclimatic gradients and ecological life zones in Hawai'i. Unique quantities of photosynthetic and non-photosynthetic vegetation (PV, NPV) and bare substrate identified fundamental differences in ecosystem structure across life zones. There was a nearly 20-fold increase in PV fractional cover with a 10-fold increase in mean annual precipitation (< 250 to 2000 mm yr-1). NPV fractional cover remained nearly constant at ~50% in ecosystems with a mean annual precipitation < 1500 mm yr-1. Thereafter, NPV steadily declined to a minimum of ~ 20% at 3000 mm yr-1 of rainfall. Bare substrate fractions were highest (~50%) at precipitation levels < 750 mm yr-1, then declined to < 20% in the 750-1000 mm yr-1 zones. The combination of low bare substrate and high NPV cover in the 750-1000 mm yr-1 rainfall zones identified these areas as high fire risk. The results verify the applicability of SWIR imaging spectroscopy for ecosystem research on a global scale. They also set the framework for continued studies of ecosystem structure, function and invasive species throughout the Hawaiian Archipelago.

A pilot study on the improvement of the lying area of finishing pigs by a soft lying mat.

PubMed

Savary, Pascal; Gygax, Lorenz; Jungbluth, Thomas; Wechsler, Beat; Hauser, Rudolf

2011-01-01

In this pilot study, we tested whether a soft mat (foam covered with a heat-sealed thermoplastic) reduces alterations and injuries at the skin and the leg joints.The soft mat in the lying area of partly slatted pens was compared to a lying area consisting of either bare or slightly littered (100 g straw per pig and day) concrete flooring. In this study we focused on skin lesions on the legs of finishing pigs as indicators of impaired welfare. Pigs were kept in 19 groups of 8-10 individuals and were examined for skin lesions around the carpal and tarsal joints either at a weight of <35 kg, or at close to 100 kg. The likelihood of hairless patches and wounds at the tarsal joints was significantly lower in pens with the soft lying mat than in pens with a bare concrete floor. Pens with a littered concrete floor did not differ compared to pens with a bare concrete floor. The soft lying mat thus improved floor quality in the lying area in terms of preventing skin lesions compared to bare and slightly littered concrete flooring. Such soft lying mats have thus the potential to improve lying comfort and welfare of finishing pigs.

Salt dependence of compression normal forces of quenched polyelectrolyte brushes

NASA Astrophysics Data System (ADS)

Hernandez-Zapata, Ernesto; Tamashiro, Mario N.; Pincus, Philip A.

2001-03-01

We obtained mean-field expressions for the compression normal forces between two identical opposing quenched polyelectrolyte brushes in the presence of monovalent salt. The brush elasticity is modeled using the entropy of ideal Gaussian chains, while the entropy of the microions and the electrostatic contribution to the grand potential is obtained by solving the non-linear Poisson-Boltzmann equation for the system in contact with a salt reservoir. For the polyelectrolyte brush we considered both a uniformly charged slab as well as an inhomogeneous charge profile obtained using a self-consistent field theory. Using the Derjaguin approximation, we related the planar-geometry results to the realistic two-crossed cylinders experimental set up. Theoretical predictions are compared to experimental measurements(Marc Balastre's abstract, APS March 2001 Meeting.) of the salt dependence of the compression normal forces between two quenched polyelectrolyte brushes formed by the adsorption of diblock copolymers poly(tert-butyl styrene)-sodium poly(styrene sulfonate) [PtBs/NaPSS] onto an octadecyltriethoxysilane (OTE) hydrophobically modified mica, as well as onto bare mica.

Radiative transfer model of snow for bare ice regions

NASA Astrophysics Data System (ADS)

Tanikawa, T.; Aoki, T.; Niwano, M.; Hosaka, M.; Shimada, R.; Hori, M.; Yamaguchi, S.

2016-12-01

Modeling a radiative transfer (RT) for coupled atmosphere-snow-bare ice systems is of fundamental importance for remote sensing applications to monitor snow and bare ice regions in the Greenland ice sheet and for accurate climate change predictions by regional and global climate models. Recently, the RT model for atmosphere-snow system was implemented for our regional and global climate models. However, the bare ice region where recently it has been expanded on the Greenland ice sheet due to the global warming, has not been implemented for these models, implying that this region leads miscalculations in these climate models. Thus, the RT model of snow for bare ice regions is needed for accurate climate change predictions. We developed the RT model for coupled atmosphere-snow-bare ice systems, and conducted a sensitivity analysis of the RT model to know the effect of snow, bare ice and geometry parameters on the spectral radiant quantities. The RT model considers snow and bare-ice inherent optical properties (IOPs), including snow grain size, air bubble size and its concentration and bare ice thickness. The conventional light scattering theory, Mie theory, was used for IOP calculations. Monte Carlo method was used for the multiple scattering. The sensitivity analyses showed that spectral albedo for the bare ice increased with increasing the concentration of the air bubble in the bare ice for visible wavelengths because the air bubble is scatterer with no absorption. For near infrared wavelengths, spectral albedo has no dependence on the air bubble due to the strong light absorption by ice. When increasing solar zenith angle, the spectral albedo were increased for all wavelengths. This is the similar trend with spectral snow albedo. Cloud cover influenced the bare ice spectral albedo by covering direct radiation into diffuse radiation. The purely diffuse radiation has an effective solar zenith angle near 50°. Converting direct into diffuse radiation reduces the effective solar zenith angle, resulting in reducing the spectral albedo. This is also the similar trend with spectral snow albedo. Further work should focus on the validation of the RT model using in situ measurement data through field and laboratory experiments.

Adsorption heights and bonding strength of organic molecules on a Pb-Ag surface alloy

NASA Astrophysics Data System (ADS)

Stadtmüller, Benjamin; Haag, Norman; Seidel, Johannes; van Straaten, Gerben; Franke, Markus; Kumpf, Christian; Cinchetti, Mirko; Aeschlimann, Martin

2016-12-01

The understanding of the fundamental geometric and electronic properties of metal-organic hybrid interfaces is a key issue on the way to improving the performance of organic electronic and spintronic devices. Here, we studied the adsorption heights of copper-II-phthalocyanine (CuPc) and 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) on a Pb1Ag2 surface alloy on Ag(111) using the normal-incidence x-ray standing waves technique. We find a significantly larger adsorption height of both molecules on the Pb-Ag surface alloy compared to the bare Ag(111) surface which is caused by the larger size of Pb. This increased adsorption height suppresses the partial chemical interaction of both molecules with Ag surface atoms. Instead, CuPc and PTCDA molecules bond only to the Pb atoms with different interaction strength ranging from a van der Waals-like interaction for CuPc to a weak chemical interaction with additional local bonds for PTCDA. The different adsorption heights for CuPc and PTCDA on Pb1Ag2 are the result of local site-specific molecule-surface bonds mediated by functional molecular groups and the different charge donating and accepting character of CuPc and PTCDA.

Irrigation scheduling, freeze warning and soil salinity detecting. [in Cameron County Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Correlations of multispectral scanner (MSS) digital data differences between vegetated and bare soil areas with salinity levels from the eight saline areas using MSS bands seven and ten in the infrared region were significant. Correlations were derived for Cameron County, Texas. Detection of saline soils may be possible, using either film density readings or multispectral scanner data, when the lower reflectance of vegetation on highly saline soil and the higher reflectance of vegetation on lower saline soil are considered by using film on MSS contrasts between vegetation and bare soil.

Rangeland degradation in savannas of South Africa: spatial patterns of soil and vegetation

NASA Astrophysics Data System (ADS)

Sandhage-Hofmann, Alexandra; Löffler, Jörg; du Preez, Chris; Kotzé, Elmarie; Weijers, Stef; Wundram, Dirk; Zacharias, Maximilan; Amelung, Wulf

2017-04-01

Extensive bush encroachment by Acacia mellifera and associated woody species at semi-arid and arid sites are the most notable forms of rangeland degradation in savannas of South Africa. Concerns are growing over the threat of suppression and loss of nutritious perennial grass species. Grazing and different rangeland management systems (communal and freehold) are considered to be of major importance for degradation, but the process of encroachment is not restricted to communal land. A vegetation change is mostly accompanied by changes in soil properties, where soils in savanna systems can profit from woody species due to litter fall, root distribution, shadow and animal resting time. Savannas are very heterogeneous systems with high spatial variation of patches with wood, herbaceous species and bare ground. We hypothesized that the spatial patterns of soil properties in South Africás rangelands are controlled by present or past vegetation, modulated by the tenure systems with higher rangeland degradation in communal areas. To test this, we sampled soils at communal and commercial land in the Kuruman area of South Africa with the following design: three farms per tenure system, 6 randomly chosen plots (100x100m) per farm, and 25 soil samples (0-10 cm) per plot, each in a 5x5m sampling area. At every sampling point, information of overlying vegetation was recorded (species or bare soil, canopy size, height). For each sampling area, if present, trees/ shrubs were sampled and their ages estimated through the counting of annual growth rings. For each plot, high resolution UAV aerial photos were taken to evaluate the extent of bush encroachment. Analyses involved main physical and chemical soil parameters and isotopic analyses. The results of a rough aerial image classification (grass, woody species, bare ground) revealed significant differences between the tenure systems with higher coverage of bare ground and shrubs at communal farms, and higher grass cover at commercial farms. The tenure systems had no differences in main texture classes of the soils, but significant differences in the composition of the sand fraction, with higher levels of fine sand and lower levels of coarse sand in communal farms. The chemical soil properties showed a high variability both within and between the farms, with much higher variability within communal than commercial farms. Additionally, concentrations of nitrogen, carbon, calcium and pH were significant higher in communal farms. Isotopic analyses in soils showed significant differences for 15N with higher levels in commercial farms. Different photosynthetic pathways are responsible for differences found in 13C values, with higher levels (-16-18‰) in C4-grassland and lower values (-22-26‰) in soils under Acacia (C3). We found relationships between soil properties and species or bare ground, where differences in texture likely interact with both, vegetation cover and soil properties.

Role of water in the tribochemical removal of bare silicon

NASA Astrophysics Data System (ADS)

Chen, Cheng; Xiao, Chen; Wang, Xiaodong; Zhang, Peng; Chen, Lei; Qi, Yaqiong; Qian, Linmao

2016-12-01

Nanowear tests of bare silicon against a SiO2 microsphere were conducted in air (relative humidity [RH] = 0%-89%) and water using an atomic force microscope. Experimental results revealed that the water played an important role in the tribochemical wear of the bare silicon. A hillock-like wear trace with a height of 0.7 nm was generated on the bare silicon surface in dry air. As the RH increased, the wear depth increased and reached the maximum level in water. Analysis of frictional dissipated energy suggested that the wear of the bare silicon was not dominated by mechanical interactions. High-resolution transmission electron microscopy detection demonstrated that the silicon atoms and crystal lattice underneath the worn area maintained integral perfectly and thus further confirmed the tribochemical wear mechanism of the bare silicon. Finally, the role of water in the tribochemical wear of the bare silicon may be explained by the following three aspects: the hydroxylation by hydroxyl ions auto-ionized in water, the hydrolytic reaction of water molecules, and the dissolution of the tribochemical product SiOmHn in liquid water. With increasing RH, a greater water amount would adsorb to the Si/SiO2 interface and induce a more serious tribochemical wear on the bare silicon surface. The results of this paper may provide further insight into the tribochemical removal mechanism of bare monocrystalline silicon and furnish the wider reaction cognition for chemical mechanical polishing.

Resolving the optical anisotropy of low-symmetry 2D materials.

PubMed

Shen, Wanfu; Hu, Chunguang; Tao, Jin; Liu, Jun; Fan, Shuangqing; Wei, Yaxu; An, Chunhua; Chen, Jiancui; Wu, Sen; Li, Yanning; Liu, Jing; Zhang, Daihua; Sun, Lidong; Hu, Xiaotang

2018-05-03

Optical anisotropy is one of the most fundamental physical characteristics of emerging low-symmetry two-dimensional (2D) materials. It provides abundant structural information and is crucial for creating diverse nanoscale devices. Here, we have proposed an azimuth-resolved microscopic approach to directly resolve the normalized optical difference along two orthogonal directions at normal incidence. The differential principle ensures that the approach is only sensitive to anisotropic samples and immune to isotropic materials. We studied the optical anisotropy of bare and encapsulated black phosphorus (BP) and unveiled the interference effect on optical anisotropy, which is critical for practical applications in optical and optoelectronic devices. A multi-phase model based on the scattering matrix method was developed to account for the interference effect and then the crystallographic directions were unambiguously determined. Our result also suggests that the optical anisotropy is a probe to measure the thickness with monolayer resolution. Furthermore, the optical anisotropy of rhenium disulfide (ReS2), another class of anisotropic 2D materials, with a 1T distorted crystal structure, was investigated, which demonstrates that our approach is suitable for other anisotropic 2D materials. This technique is ideal for optical anisotropy characterization and will inspire future efforts in BP and related anisotropic 2D nanomaterials for engineering new conceptual nanodevices.

Thermal activation energy for bidirectional movement of actin along bipolar tracks of myosin filaments.

PubMed

Okubo, Hiroyuki; Iwai, Masanori; Iwai, Sosuke; Chaen, Shigeru

2010-05-28

Previous in vitro motility assays using bipolar myosin thick filaments demonstrated that actin filaments were capable of moving in both directions along the myosin filament tracks. The movements; however, were slower in the direction leading away from the central bare zone than towards it. To understand the mechanism underlying these different direction-dependent motilities, we have examined the effects of temperature on the velocities of the bidirectional movements along reconstituted myosin filaments. Activation energies of the movements were determined by Arrhenius plots at high and low concentrations of ATP. As a result, the thermal activation energy of the movement away from the central bare zone was significantly higher than that of the movement toward the zone. Given that the backward movement away from the central bare zone would cause the myosin heads to be constrained and the stiffness of the cross-bridges to increase, these results suggest that elastic energy required for the cross-bridge transition is supplied by thermal fluctuations. Copyright (c) 2010 Elsevier Inc. All rights reserved.

A better way of fitting clips? A comparative study with respect to physical workload.

PubMed

Gaudez, Clarisse; Wild, Pascal; Aublet-Cuvelier, Agnès

2015-11-01

The clip fitting task is a frequently encountered assembly operation in the car industry. It can cause upper limb pain. During task laboratory simulations, upper limb muscular activity and external force were compared for 4 clip fitting methods: with the bare hand, with an unpowered tool commonly used at a company and with unpowered and powered prototype tools. None of the 4 fitting methods studied induced a lower overall workload than the other three. Muscle activity was lower at the dominant limb when using the unpowered tools and at the non-dominant limb with the bare hand or with the powered tool. Fitting clips with the bare hand required a higher external force than fitting with the three tools. Evaluation of physical workload was different depending on whether external force or muscle activity results were considered. Measuring external force only, as recommended in several standards, is insufficient for evaluating physical workload. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Maps of averaged spectral deviations from soil lines and their comparison with traditional soil maps

NASA Astrophysics Data System (ADS)

Rukhovich, D. I.; Rukhovich, A. D.; Rukhovich, D. D.; Simakova, M. S.; Kulyanitsa, A. L.; Bryzzhev, A. V.; Koroleva, P. V.

2016-07-01

The analysis of 34 cloudless fragments of Landsat 5, 7, and 8 images (1985-2014) on the territory of Plavsk, Arsen'evsk, and Chern districts of Tula oblast has been performed. It is shown that bare soil surface on the RED-NIR plots derived from the images cannot be described in the form of a sector of spectral plane as it can be done for the NDVI values. The notion of spectral neighborhood of soil line (SNSL) is suggested. It is defined as the sum of points of the RED-NIR spectral space, which are characterized by spectral characteristics of the bare soil applied for constructing soil lines. The way of the SNSL separation along the line of the lowest concentration density of points on the RED-NIR spectral space is suggested. This line separates bare soil surface from vegetating plants. The SNSL has been applied to construct soil line (SL) for each of the 34 images and to delineate bare soil surface on them. Distances from the points with averaged RED-NIR coordinates to the SL have been calculated using the method of moving window. These distances can be referred to as averaged spectral deviations (ASDs). The calculations have been performed strictly for the SNSL areas. As a result, 34 maps of ASDs have been created. These maps contain ASD values for 6036 points of a grid used in the study. Then, the integral map of normalized ASD values has been built with due account for the number of points participating in the calculation (i.e., lying in the SNSL) within the moving window. The integral map of ASD values has been compared with four traditional soil maps on the studied territory. It is shown that this integral map can be interpreted in terms of soil taxa: the areas of seven soil subtypes (soddy moderately podzolic, soddy slightly podzolic, light gray forest. gray forest, dark gray forest, podzolized chernozems, and leached chernozems) belonging to three soil types (soddy-podzolic, gray forest, and chernozemic soils) can be delineated on it.

The `Chocolate Experiment' - A Demonstration of Radiation Absorption by Different Colored Surfaces

NASA Astrophysics Data System (ADS)

Fung, Dennis

2015-12-01

In the typical "cookbook" experiment comparing the radiation absorption rates of different colored surfaces, students' hands are commonly used as a measurement instrument to demonstrate that dull black and silvery surfaces are good and poor absorbers of radiation, respectively. However, college students are often skeptical about using their bare hands in this experiment because they learned in early science lessons that skin is not a reliable detector of heat transfer. Moreover, when the experiment is conducted in a school laboratory, it is often difficult for students to perceive the slight differences in heat transfer on the dull black and silvery aluminum leaves attached to their hands. Rather than replacing students' bare hands with such sophisticated apparatus as a data logger and temperature probe, I suggest using a simple (and delicious!) low-cost instrument, i.e., chocolate, which simply melts when it receives radiation.

A comparison of the abilities of the USLE-M, RUSLE2 and WEPP to model event erosion from bare fallow areas.

PubMed

Kinnell, P I A

2017-10-15

Traditionally, the Universal Soil Loss Equation (USLE) and the revised version of it (RUSLE) have been applied to predicting the long term average soil loss produced by rainfall erosion in many parts of the world. Overtime, it has been recognized that there is a need to predict soil losses over shorter time scales and this has led to the development of WEPP and RUSLE2 which can be used to predict soil losses generated by individual rainfall events. Data currently exists that enables the RUSLE2, WEPP and the USLE-M to estimate historic soil losses from bare fallow runoff and soil loss plots recorded in the USLE database. Comparisons of the abilities of the USLE-M and RUSLE2 to estimate event soil losses from bare fallow were undertaken under circumstances where both models produced the same total soil loss as observed for sets of erosion events on 4 different plots at 4 different locations. Likewise, comparisons of the abilities of the USLE-M and WEPP to model event soil loss from bare fallow were undertaken for sets of erosion events on 4 plots at 4 different locations. Despite being calibrated specifically for each plot, WEPP produced the worst estimates of event soil loss for all the 4 plots. Generally, the USLE-M using measured runoff to calculate the product of the runoff ratio, storm kinetic energy and the maximum 30-minute rainfall intensity produced the best estimates. As to be expected, ability of the USLE-M to estimate event soil loss was reduced when runoff predicted by either RUSLE2 or WEPP was used. Despite this, the USLE-M using runoff predicted by WEPP estimated event soil loss better than WEPP. RUSLE2 also outperformed WEPP. Copyright © 2017 Elsevier B.V. All rights reserved.

Edge modulation of electronics and transport properties of cliff-edge phosphorene nanoribbons

NASA Astrophysics Data System (ADS)

Guo, Caixia; Wang, Tianxing; Xia, Congxin; Liu, Yufang

2017-12-01

Based on the first-principles calculations, we study the electronic structures and transport properties of cliff-like edge phosphorene nanoribbons (CPNRs), considering different types of edge passivation. The band structures of bare CPNRs possess the metallic features; while hydrogen (H), fluorine (F), chlorine (Cl) and oxygen (O) atoms-passivated CPNRs are semiconductor materials, and the band gap values monotonically decrease when the ribbon width increases. Moreover, the H and F-passivated CPNRs exhibit the direct band gap characteristics, while the Cl and O-passivated cases show the features of indirect band gap. In addition, the edge passivated CPNRs are more energetically stable than bare edge case. Meanwhile, our results also show that the transport properties of the CPNRs can be obviously influenced by the different edge passivation.

Temperature and refractive index measurements using long-period fiber gratings fabricated by femtosecond laser

NASA Astrophysics Data System (ADS)

Yu, Yongqin; Zheng, Jiarong; Yi, Kai; Ruan, Shuangchen; Du, Chenlin; Huang, Jianhui; Zhong, Wansheng

2011-12-01

Long period fiber gratings (LPFGs) with different periods in the standard single mode fiber were fabricated, using laser direct writing method, by femtosecond laser pulses with pulse width of 200 fs and the repetition rate of 250 kHz at a center wavelength of 800 nm in air. Comparative with bare LPFG in temperature sensor, LPFG had been encapsulated using large coefficient of thermal expansion of epoxy polymer and Aluminum to enhance the temperature sensitivity. The results showed that the temperature sensitivity of encapsulated LPFG was 2 times than that of bare LPFG. In addition, we also researched the relationship between resonant wavelength and surrounding refractive index (SRI) when LPFG immersed in refractive index of solution of different index at 20 degree Celsius.

Modelling high arctic percent vegetation cover using field digital images and high resolution satellite data

NASA Astrophysics Data System (ADS)

Liu, Nanfeng; Treitz, Paul

2016-10-01

In this study, digital images collected at a study site in the Canadian High Arctic were processed and classified to examine the spatial-temporal patterns of percent vegetation cover (PVC). To obtain the PVC of different plant functional groups (i.e., forbs, graminoids/sedges and mosses), field near infrared-green-blue (NGB) digital images were classified using an object-based image analysis (OBIA) approach. The PVC analyses comparing different vegetation types confirmed: (i) the polar semi-desert exhibited the lowest PVC with a large proportion of bare soil/rock cover; (ii) the mesic tundra cover consisted of approximately 60% mosses; and (iii) the wet sedge consisted almost exclusively of graminoids and sedges. As expected, the PVC and green normalized difference vegetation index (GNDVI; (RNIR - RGreen)/(RNIR + RGreen)), derived from field NGB digital images, increased during the summer growing season for each vegetation type: i.e., ∼5% (0.01) for polar semi-desert; ∼10% (0.04) for mesic tundra; and ∼12% (0.03) for wet sedge respectively. PVC derived from field images was found to be strongly correlated with WorldView-2 derived normalized difference spectral indices (NDSI; (Rx - Ry)/(Rx + Ry)), where Rx is the reflectance of the red edge (724.1 nm) or near infrared (832.9 nm and 949.3 nm) bands; Ry is the reflectance of the yellow (607.7 nm) or red (658.8 nm) bands with R2's ranging from 0.74 to 0.81. NDSIs that incorporated the yellow band (607.7 nm) performed slightly better than the NDSIs without, indicating that this band may be more useful for investigating Arctic vegetation that often includes large proportions of senescent vegetation throughout the growing season.

Investigation of nanosecond pulsed dielectric barrier discharge using plate-to-plate electrode with asymmetric dielectric arrangement in airflow

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

Qi, Haicheng; School of Physics Science and Technology, Anshan Normal University, Anshan 114005; Fan, Zhihui

Atmospheric pressure dielectric barrier discharge plasma is produced in airflow by applying nanosecond high voltage pulses with peak voltage about 35 kV and rising time about 40 ns on a plate-to-plate electrode arrangement. The effects of airflow rate (0–50 m/s) on the discharge characteristics are investigated under different barrier conditions (the bare anode case and the bare cathode case). For both cases, the breakdown voltage and the time lag increase distinctly and the discharge intensity decreases sharply when the airflow rate increases from 0 to 30 m/s, and then keep almost constant until the airflow rate is further increased to 50 m/s. For the baremore » anode case (the cathode is covered by dielectric plate), the discharge mode transforms gradually from filamentary to diffuse discharge with the increasing airflow rate. While for the bare cathode case, some micro-discharge channels are still excited, though the discharge becomes more diffuse when the airflow rate is higher than 30 m/s. By acquiring the time-resolved images of the discharge, it is proved that it is the primary discharge which becomes diffuse when airflow is introduced and the following two discharges of the same voltage pulse occur principally at the positions where the primary discharge is more intense. And in both cases, the plasma temperatures are reduced, but the degree is different. All the phenomena can be explained mainly by the variation of the space charge distribution when the airflow is introduced into the discharge gap. And it is indicated that the bare anode case has an advantage in obtaining diffuse discharge.« less

The Color and Surface Composition of Mountains on Pluto

NASA Astrophysics Data System (ADS)

Olkin, Catherine B.; Reuter, D. C.; Stern, S. Alan; Young, Leslie; Weaver, Harold A.; Ennico, Kimberly; Binzel, Richard; Cook, Jason C.; Cruikshank, Dale P.; Dalle Ore, Cristina M.; Earle, Alissa M.; Grundy, W. M.; Howett, Carly; Parker, Alex; Protopapa, Silvia; Schmitt, Bernard; Singer, Kelsi N.; Spencer, John R.; Stansberry, John A.; Philippe, Sylvain; New Horizons Science Team

2016-10-01

The New Horizons mission revealed that there are mountains along the western edge of the large glacier that dominates Pluto's anti-Charon hemisphere. This talk will focus on the color and surface composition of the four large mountainous regions named Al Idrisi Montes, Bare Montes, Hillary Montes and Norgay Montes (all feature names are informal).The Al Idrisi Montes are large blocks up to 40 km across and 5 km high that appear to be broken off of the ice crust and transported into Sputnik Planum (Moore et al. 2016). The color of this region as a function of latitude will be presented as well as the color differences between the blocks and the interstitial material between the blocks. Moving south along the edge of Sputnik Planum, the next mountainous region is Bare Montes. Part of the Bare Montes resembles Al Idrisi Montes with its chaotic blocky structure, but there is a significant difference in color between these regions. The Bare Montes are more red than Al Idrisi Montes and this region's color more closely matches the nearby terrain of Cthulhu Regio. Continuing south, to the Hillary and Norgay Montes regions these topographic features become less red with both red and neutral colors on their slopes. The Hillary Montes show both red and neutral colors in the ices surrounding the peaks.This work will provide a quantitative comparison of the color and composition across these 4 mountainous regions using data from the Ralph instrument. Ralph has 4 color filters: blue (400-550 nm), red (540-700 nm), near IR (780-975) and methane filter (860-910 nm) and collects infrared imaging spectrometric data (from 1.25-2.5 microns).This work was supported by NASA's New Horizons project.

[The experiment research on solution refractive index sensor based on tilted fiber Bragg grating].

PubMed

Jiang, Qi; Lü, Dan-Dan; Yu, Ming-Hao; Kang, Li-Min; Ouyang, Jun

2013-12-01

The present paper analyzes the sensor's basic principle of the bare tilted fiber Bragg grating (TFBG) and surface plasmon resonance sensor (SPR) that deposited nanoscale gold-coating on the surface of the cladding. We simulated the transmission spectrums and some order cladding mode of TFBG in different concentration solutions by Integration and optical fiber grating software OptiGrating. So by the graphic observation and data analysis, a preliminary conclusion was got that in a certain sensing scope, the cladding modes of TFBG shift slightly to right with the increasing the solution refractive index(SRI),and the relation between resonance peak caused by the coupling of core mode and a certain cladding mode and the SRI was linear. Then the 45 nm thick gold coating was deposited on the surface of the TFBG cladding in a small-scale sputtering chamber KYKY SBC-12, and thermal field scanning electron microscopy presents that the effect of gold-coating was satisfactory to a certain extent in terms of microscopic level. The refractive index(RI) sensing experiments of different concentration solutions of NaCI, MgCI2, CaCI2 were carried out using bare and gold deposited TFBG. The RI sensing characteristics of both bare and gold deposited TFBGs respectively were studied by experiments. Meanwhile, it proved the conclusion that the cladding modes of TFBG drifted to right gradually when the SRI was increasing and the relations between resonance peak caused by the coupling of core mode and a certain cladding mode and the SRI were linear. And by quantitative analysis, we know that SPR sensor with the deposited namoscale gold layer on the surface of cladding enhanced the RI sensitivity dramatically by 2 to 500 nm RIU-1 which is 200 to 300 times larger than that of the bare tilted fiber Bragg grating approximately. The degrees of linear fittings of resonance peak caused by the coupling of core mode and a certain cladding mode and SRI of bare and gold-coating deposited SPR sensor are very good and both of them reach up to more than 0. 99.

Thulium fiber laser-induced vapor bubble dynamics using bare, tapered, ball, hollow steel, and muzzle brake fiber optic tips

NASA Astrophysics Data System (ADS)

Gonzalez, David A.; Hardy, Luke A.; Hutchens, Thomas C.; Irby, Pierce B.; Fried, Nathaniel M.

2018-03-01

This study characterizes laser-induced vapor bubble dynamics for five different distal fiber optic tip configurations, to provide insight into stone retropulsion commonly experienced during laser ablation of kidney stones. A thulium fiber laser with 1908-nm wavelength delivered 34-mJ energy per pulse at 500-μs pulse duration through five different fibers such as 100-μm-core / 170-μm-OD bare fiber tip, 150- to 300-μm-core tapered fiber tip, 100-μm-core / 300-μm-OD ball tip fiber, 100-μm-core / 340-μm-OD hollow steel tip fiber, and 100-μm-core / 560-μm-OD muzzle brake fiber tip. A high-speed camera with 10-μm-spatial and 9.5-μs-temporal resolution was used to image the vapor bubble dynamics. A needle hydrophone measured pressure transients in the forward (0 deg) and side (90 deg) directions while placed at a 6.8 ± 0.4 mm distance from the distal fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7 / 1.5 mm, for bare, tapered, ball, hollow steel, and muzzle brake fiber tips, respectively (n = 5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n = 5). For the hollow steel tip, forward pressure was 4 × higher than for the bare fiber. For the muzzle brake fiber tip, forward pressure was 5 × lower than the bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle brake fiber tip reduced forward pressure by partially venting vapors through the portholes, which is consistent with the observation of lower stone retropulsion in previous reports.

Soil pyrogenic carbon lacks long-term persistence

NASA Astrophysics Data System (ADS)

Lutfalla, Suzanne; Abiven, Samuel; Barré, Pierre; Wiedemeier, Daniel; Christensen, Bent; Houot, Sabine; Kätterer, Thomas; Macdonald, Andy; van Oort, Fok; Chenu, Claire

2015-04-01

In the context of climate change, one mitigation technique currently investigated is the use of pyrogenic organic carbon (PyOC) -which is biomass turned into charcoal- to sequester carbon in soils with the hypothesis that PyOC is persistent and will not be biodegraded (or mineralized). In this study, we use the unique opportunity offered by five long term bare fallow (LTBF) experiments across Europe (Askov in Denmark, Grignon and Versailles in France, Ultuna in Sweden and Rothamsted in the United Kingdom) to compare the dynamics of PyOC and soil organic carbon (SOC) in the same plots at the decadal time scale (from 25 to 80 years of bare fallow depending on the site). Bare fallow plots were regularly sampled throughout the bare fallow duration and these samples were carefully archived. In bare fallow plots, with negligible external carbon input and with continuing biodegradation, SOC is depleting. Using the Benzene Polycarboxylic Acid (BPCA) technique to estimate the PyOC quantity and quality in the soils at different sampling dates, we investigated if PyOC content was also decreasing and compared the rates of depletion of PyOC and SOC. We found that PyOC contents decreased rapidly in soils at all sites. The loss of PyOC between the first and the last soil sampling ranged from 19.8 to 57.3% of the initial PyOC content. Furthermore, PyOC quality exhibited a similar evolution at all sites, becoming more enriched in condensed material with time. We applied a one pool model with mono-exponential decay to our data and found an average mean residence time of native PyOC of 116 years across the different sites, with a standard deviation of 15 years, just 1.6 times longer than that of SOC. Our results show that, though having a longer residence time than total SOC, PyOC content can decrease rapidly in soils suggesting that the potential for long-term C storage in soil by PyOC amendments is less than currently anticipated. Our results therefore question the concept of biochar production as a climate change mitigation strategy.

Very late outcomes of drug-eluting stents coated with biodegradable polymers: insights from the 5-year follow-up of the randomized PAINT trial

PubMed Central

Marchini, Julio F.; Gomes, Wilton F.; Moulin, Bruno; Perin, Marco A.; Oliveira, Ludmilla A.R.R.; Arruda, J. Airton; Lima, Valter C.; Lima, Antonio A.G.; Caramori, Paulo R.A.; Medeiros, Cesar R.; Barbosa, Mauricio R.; Brito, Fabio S.; Ribeiro, Expedito E.

2014-01-01

Background Few studies have examined the very long-term outcomes after implantation of drug-eluting stents (DES) coated with biodegradable polymers (BP). This report presents the 5-year clinical follow-up of patients treated with BP-DES in the randomized PAINT trial. Methods The PAINT study is a prospective, multicenter randomized controlled trial that allocated 274 patients for treatment with two BP-DES formulations [paclitaxel-eluting stents (PES) or sirolimus-eluting stents (SES)] or bare metal stents (BMS) in a 1:2:2 ratio, respectively. The primary end-point of this sub-study was defined as the composite of the major cardiac adverse events (MACE) cardiac death, myocardial infarction (MI) or ischemia-driven target vessel revascularization (TVR) at 5 years. Results The 5-year MACE rates were different among the groups: 35.3%, 22.5% and 16.9% for BMS, PES and SES, respectively (P<0.05 for both DES vs. bare stent comparisons). The primary end-point was mainly driven by TVR: 31.8%, 14.1% and 12.2% for bare stents, PES and SES, respectively (P<0.05 for both DES vs. bare stent comparisons). The incidence of stent thrombosis (ST) was null for BMS during the entire follow-up. There was no definite or probable ST in the SES group after the second year, while one patient (1.0%) presented with a definite ST episode in the PES group between 4 and 5 years. Conclusions The tested biodegradable-polymer coated stents releasing either paclitaxel or sirolimus, compared with same bare metal platform, sustained their effectiveness in reducing combined major adverse cardiac events and re-intervention without an increase in ST during 5 years of follow-up. PMID:25610805

Effect of inflammatory conditions and H2O2 on bare and coated Ti-6Al-4V surfaces: Corrosion behavior, metal ion release and Ca-P formation under long-term immersion in DMEM

NASA Astrophysics Data System (ADS)

Höhn, Sarah; Virtanen, Sannakaisa

2015-12-01

The surface oxide film and calcium-phosphate (Ca-P) formation on Ti-6Al-4V during long-term immersion in biological environments play a decisive role for the biocompatibility of the implant. Hence, the aim of the study was to evaluate the corrosion resistance, metal ion release and Ca-P formation in DMEM under physiological conditions at pH values of 7.4 and in comparison under simulated inflammatory conditions with pH 5 and in presence of H2O2. Furthermore, the influence of the immersion conditions was investigated on different surface treatments: on bare Ti-6Al-4V, after anodization, and for TiO2 nanoparticle (NP) and hydroxyapatite (HA)-incorporated TiO2-NP coatings. In the absence of H2O2, the impedance response indicated a stable thin oxide film and Ca-P formation after 28 days or 56 days depending on the coating, while under inflammatory conditions the Ca-P formation on the surface is time-delayed and dissolution of the anodized oxide layer as well as selective etching of the β-phase and phase boundaries in case of the bare alloy occur. Electrochemical impedance spectroscopy (EIS), however, indicates a good general corrosion behavior in all cases. The quantities of Ti, Al and V released from the bare and coated Ti-6Al-4V alloy markedly increased with decreasing pH (pH ≤ 5). Although the rapid increase of metal release was observed for all samples at pH 5, the quantities were significantly higher for the bare and anodized alloy than after coating with TiO2-NP or HA.

Development of High-Resolution Dynamic Dust Source Function - A Case Study with a Strong Dust Storm in a Regional Model

NASA Technical Reports Server (NTRS)

Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

2017-01-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 0203 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

Response of Main Maize Varieties to Water Stress and Comprehensive Evaluation in Hebei Province

NASA Astrophysics Data System (ADS)

Yue, Haiwang; Chen, Shuping; Bu, Junzhou; Wei, Jianwei; Peng, Haicheng; Li, Yuan; Li, Chunjie; Xie, Junliang

2018-01-01

Drought is a serious threat to maize production in Hebei province. Planting drought resistant maize varieties is an effective measure to solve drought in arid and less rain areas. Drought resistance in maize is controlled by many genes, and multiple indexes should be used for comprehensive evaluation (Campos H et al.2004). In the arid rain shed, using 34 maize varieties to promote crop production compared to the drought resistance test. The experiment was conducted with two treatments of drought stress (irrigation only at seedling stage) and normal irrigation, and 12 agronomic traits related to drought resistance of maize were determined. The results showed that drought had significant effects on maize yield and main agronomic characters. Under drought stress, plant height, ear length, bare tip, ear row number, row grains, 1000-kernel weight, ASI index can be used as identification index of drought resistance of maize in different period. The results indicated that the variety with strong drought resistance is Zhongdi175, the worst drought resistance is Woyu964.

Development of High-Resolution Dynamic Dust Source Function -A Case Study with a Strong Dust Storm in a Regional Model

PubMed Central

Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

2018-01-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events. PMID:29632432

Development of High-Resolution Dynamic Dust Source Function -A Case Study with a Strong Dust Storm in a Regional Model.

PubMed

Kim, Dongchul; Chin, Mian; Kemp, Eric M; Tao, Zhining; Peters-Lidard, Christa D; Ginoux, Paul

2017-06-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

Effect of epitaxial strain on ferroelectric polarization in multiferroic BiFeO3 films

NASA Astrophysics Data System (ADS)

Kim, Dae Ho; Lee, Ho Nyung; Biegalski, Michael D.; Christen, Hans M.

2008-01-01

Multiferroic BiFeO3 epitaxial films with thicknesses ranging from 40to960nm were grown by pulsed laser deposition on SrTiO3 (001) substrates with SrRuO3 bottom electrodes. X-ray characterization shows that the structure evolves from angularly distorted tetragonal with c /a≈1.04 to more bulklike distorted rhombohedral (c/a≈1.01) as the strain relaxes with increasing thickness. Despite this significant structural evolution, the ferroelectric polarization along the body diagonal of the distorted pseudocubic unit cells, as calculated from measurements along the normal direction, barely changes.

Enhanced anatomical calibration in human movement analysis.

PubMed

Donati, Marco; Camomilla, Valentina; Vannozzi, Giuseppe; Cappozzo, Aurelio

2007-07-01

The representation of human movement requires knowledge of both movement and morphology of bony segments. The determination of subject-specific morphology data and their registration with movement data is accomplished through an anatomical calibration procedure (calibrated anatomical systems technique: CAST). This paper describes a novel approach to this calibration (UP-CAST) which, as compared with normally used techniques, achieves better repeatability, a shorter application time, and can be effectively performed by non-skilled examiners. Instead of the manual location of prominent bony anatomical landmarks, the description of which is affected by subjective interpretation, a large number of unlabelled points is acquired over prominent parts of the subject's bone, using a wand fitted with markers. A digital model of a template-bone is then submitted to isomorphic deformation and re-orientation to optimally match the above-mentioned points. The locations of anatomical landmarks are automatically made available. The UP-CAST was validated considering the femur as a paradigmatic case. Intra- and inter-examiner repeatability of the identification of anatomical landmarks was assessed both in vivo, using average weight subjects, and on bare bones. Accuracy of the identification was assessed using the anatomical landmark locations manually located on bare bones as reference. The repeatability of this method was markedly higher than that reported in the literature and obtained using the conventional palpation (ranges: 0.9-7.6 mm and 13.4-17.9, respectively). Accuracy resulted, on average, in a maximal error of 11 mm. Results suggest that the principal source of variability resides in the discrepancy between subject's and template bone morphology and not in the inter-examiner differences. The UP-CAST anatomical calibration could be considered a promising alternative to conventional calibration contributing to a more repeatable 3D human movement analysis.

Estimating fractional vegetation cover and the vegetation index of bare soil and highly dense vegetation with a physically based method

NASA Astrophysics Data System (ADS)

Song, Wanjuan; Mu, Xihan; Ruan, Gaiyan; Gao, Zhan; Li, Linyuan; Yan, Guangjian

2017-06-01

Normalized difference vegetation index (NDVI) of highly dense vegetation (NDVIv) and bare soil (NDVIs), identified as the key parameters for Fractional Vegetation Cover (FVC) estimation, are usually obtained with empirical statistical methods However, it is often difficult to obtain reasonable values of NDVIv and NDVIs at a coarse resolution (e.g., 1 km), or in arid, semiarid, and evergreen areas. The uncertainty of estimated NDVIs and NDVIv can cause substantial errors in FVC estimations when a simple linear mixture model is used. To address this problem, this paper proposes a physically based method. The leaf area index (LAI) and directional NDVI are introduced in a gap fraction model and a linear mixture model for FVC estimation to calculate NDVIv and NDVIs. The model incorporates the Moderate Resolution Imaging Spectroradiometer (MODIS) Bidirectional Reflectance Distribution Function (BRDF) model parameters product (MCD43B1) and LAI product, which are convenient to acquire. Two types of evaluation experiments are designed 1) with data simulated by a canopy radiative transfer model and 2) with satellite observations. The root-mean-square deviation (RMSD) for simulated data is less than 0.117, depending on the type of noise added on the data. In the real data experiment, the RMSD for cropland is 0.127, for grassland is 0.075, and for forest is 0.107. The experimental areas respectively lack fully vegetated and non-vegetated pixels at 1 km resolution. Consequently, a relatively large uncertainty is found while using the statistical methods and the RMSD ranges from 0.110 to 0.363 based on the real data. The proposed method is convenient to produce NDVIv and NDVIs maps for FVC estimation on regional and global scales.

Frictional behavior of large displacement experimental faults

USGS Publications Warehouse

Beeler, N.M.; Tullis, T.E.; Blanpied, M.L.; Weeks, J.D.

1996-01-01

The coefficient of friction and velocity dependence of friction of initially bare surfaces and 1-mm-thick simulated fault gouges (400 mm at 25??C and 25 MPa normal stress. Steady state negative friction velocity dependence and a steady state fault zone microstructure are achieved after ???18 mm displacement, and an approximately constant strength is reached after a few tens of millimeters of sliding on initially bare surfaces. Simulated fault gouges show a large but systematic variation of friction, velocity dependence of friction, dilatancy, and degree of localization with displacement. At short displacement (<10 mm), simulated gouge is strong, velocity strengthening and changes in sliding velocity are accompanied by relatively large changes in dilatancy rate. With continued displacement, simulated gouges become progressively weaker and less velocity strengthening, the velocity dependence of dilatancy rate decreases, and deformation becomes localized into a narrow basal shear which at its most localized is observed to be velocity weakening. With subsequent displacement, the fault restrengthens, returns to velocity strengthening, or to velocity neutral, the velocity dependence of dilatancy rate becomes larger, and deformation becomes distributed. Correlation of friction, velocity dependence of friction and of dilatancy rate, and degree of localization at all displacements in simulated gouge suggest that all quantities are interrelated. The observations do not distinguish the independent variables but suggest that the degree of localization is controlled by the fault strength, not by the friction velocity dependence. The friction velocity dependence and velocity dependence of dilatancy rate can be used as qualitative measures of the degree of localization in simulated gouge, in agreement with previous studies. Theory equating the friction velocity dependence of simulated gouge to the sum of the friction velocity dependence of bare surfaces and the velocity dependence of dilatancy rate of simulated gouge fails to quantitatively account for the experimental observations.

Weed control and persistence of two oxyfluorfen formulations in olive groves under non tillage conditions.

PubMed

Martínez, M J; Farsaoui, K; de Prado, R

2004-01-01

To obtain profitable yields in olive groves, residual preemergence herbicides are applied in October or November before the winter rains, and before the winter annual weeds germinate. Simazine, one of the herbicides most used for weed control in olive groves, has recently been banned. Oxyfluorfen is presented as a good alternative to simazine in olive fields. Experiments were carried out in 2002 and 2003 to evaluate the behaviour of two oxyfluorfen formulations, 2XL and G4F, at 480 g a.i. ha(-1) for three different soil management systems with three replications (1. bare soil; 2. bare soil and grassed buffer strips, chemically controlled and 3. bare soil and grassed buffer strips with controlled mowing; under non tillage conditions in all three cases). The most important species that survived 2XL and G4F treatments was Sagina apetala ARD. Oxyfluorfen residues were evaluated throughout 158 days after the applications. Three soil samples from each plot were collected, mixed and air dried. The herbicide extractions were made with methanol and the residues were analyzed by HPLC. We found no differences between the two formulations, but results showed that recoveries of oxyfluorfen were higher in plots with chemically controlled buffer grassed strips than in the other soil management types.

Dextran and Polymer Polyethylene Glycol (PEG) Coating Reduce Both 5 and 30 nm Iron Oxide Nanoparticle Cytotoxicity in 2D and 3D Cell Culture

PubMed Central

Yu, Miao; Huang, Shaohui; Yu, Kevin Jun; Clyne, Alisa Morss

2012-01-01

Superparamagnetic iron oxide nanoparticles are widely used in biomedical applications, yet questions remain regarding the effect of nanoparticle size and coating on nanoparticle cytotoxicity. In this study, porcine aortic endothelial cells were exposed to 5 and 30 nm diameter iron oxide nanoparticles coated with either the polysaccharide, dextran, or the polymer polyethylene glycol (PEG). Nanoparticle uptake, cytotoxicity, reactive oxygen species (ROS) formation, and cell morphology changes were measured. Endothelial cells took up nanoparticles of all sizes and coatings in a dose dependent manner, and intracellular nanoparticles remained clustered in cytoplasmic vacuoles. Bare nanoparticles in both sizes induced a more than 6 fold increase in cell death at the highest concentration (0.5 mg/mL) and led to significant cell elongation, whereas cell viability and morphology remained constant with coated nanoparticles. While bare 30 nm nanoparticles induced significant ROS formation, neither 5 nm nanoparticles (bare or coated) nor 30 nm coated nanoparticles changed ROS levels. Furthermore, nanoparticles were more toxic at lower concentrations when cells were cultured within 3D gels. These results indicate that both dextran and PEG coatings reduce nanoparticle cytotoxicity, however different mechanisms may be important for different size nanoparticles. PMID:22754315

Carotenoid-based bill coloration functions as a social, not sexual, signal in songbirds (Aves: Passeriformes).

PubMed

Dey, C J; Valcu, M; Kempenaers, B; Dale, J

2015-01-01

Many animals use coloration to communicate with other individuals. Although the signalling role of avian plumage colour is relatively well studied, there has been much less research on coloration in avian bare parts. However, bare parts could be highly informative signals as they can show rapid changes in coloration. We measured bill colour (a ubiquitous bare part) in over 1600 passerine species and tested whether interspecific variation in carotenoid-based coloration is consistent with signalling to potential mates or signalling to potential rivals in a competitive context. Our results suggest that carotenoid bill coloration primarily evolved as a signal of dominance, as this type of coloration is more common in species that live in social groups in the nonbreeding season, and species that nest in colonies; two socio-ecological conditions that promote frequent agonistic interactions with numerous and/or unfamiliar individuals. Additionally, our study suggests that carotenoid bill coloration is independent of the intensity of past sexual selection, as it is not related to either sexual dichromatism or sexual size dimorphism. These results pose a significant challenge to the conventional view that carotenoid-based avian coloration has evolved as a developmentally costly, condition-dependent sexual signal. We also suggest that bare part ornamentation may often signal different information than plumage ornaments. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Students as Customers?

ERIC Educational Resources Information Center

Cuthbert, Rob

2010-01-01

The idea that students might be treated as customers triggers academics' antipathy, which in turn can lead to managerial irritation and political frustration. There are different discourses which barely overlap as their protagonists speak past one another. This article argues that these differences can be reconciled by re-conceiving the…

Chernozems microbial community under anthropogenic impact (Russia)

NASA Astrophysics Data System (ADS)

Ivashchenko, Kristina; Ananyeva, Nadezhda; Sushko, Sofia; Vasenev, Viacheslav

2017-04-01

Chernozems is important natural resource, which in the last decade under intense influence as a result of plowing and urbanization. The parameters of soil microbial community functioning might be identify some soil deterioration under the impacts. Our research was focused on assessment of microbial community status in different soil layers of virgin steppe, bare fallow and urban ecosystems (Kursk region). In each ecosystem, we chose randomly 3-5 spatially distributed sites, where soil samples were collected by auguring up to 0.5 m depth (each layer 10 cm thickness) and up to 1.5 m depth (0-10, 10-50, 50-100, 100-150 cm layers), totally 127 samples. The bulk density was measured for these soil layers. In all soil samples the microbial biomass carbon content (Cmic) was analyzed by substrate-induced respiration (SIR) method and basal respiration (BR) was assessed by CO2 rate production. The fungi-to-bacteria ratio (selective inhibition technique with antibiotics) was determined and portion of Cmic in soil organic carbon (Corg) content was calculated in topsoil (0-10 cm). The Corg (dichromate oxidation) and pHw (potentiometry) values were measured. The Cmic and BR profile pools were calculated using bulk density and thickness of studied layers. The Cmic (0-10 cm) was varied from 84 to 1954 µg C g-1 soil, in steppe it was on average 3-4 times higher than those in bare fallow and urban. The BR rate was amounted from 0.20 to 1.57 µg CO2-C g-1 soil h-1, however no significant difference between studied ecosystems was found. It was shown the relationship between Cmic, BR and Corg (the linear regression, R2=0.92 and 0.75, respectively, p<0.05). The Cmic / Corg ratio in steppe was on average 3.3%, it was significantly higher those bare fallow and urban (1.6 and 0.7%, respectively). The fungi-to-bacteria ratio was decreased along ecosystems row: virgin steppe>bare fallow>urban, and it was on average 6.0, 5.2 and 1.8, respectively. The Cmic profile pool (0.5 m) of steppe was reached up on average 206 g C m-2, and it was 2.0 and 2.5 times higher those bare fallow and urban, respectively. The BR profile pool (0.5 m) in steppe and bare fallow was reached up 5.9 and 5.8 g CO2-C m-2 d-1, respectively, it was on average 2 times higher urban. The Cmic profile pool (1.5 m) in steppe was amounted to 372 g C m-2, and it was essentially higher those in bare fallow and urban (138 and 140 g C m-2, respectively). The BR profile pool (1.5 m) was also decreased along ecosystems row: steppe> fallow>urban, and it was on average 13.0, 8.0 and 5.6 g CO2-C m-2 d-1, respectively. Thus, we found a significant decreasing soil microbial biomass content, its portion in soil Corg, fungi content, and the Cmic and BR profile pools along Chernozems' ecosystems gradient from natural (virgin steppe) to anthropogenically transformed (bare fallow, urban). It might be illustrated some deterioration of soil microbial community functioning under plowing and urbanization. This research was supported by RFBR grants Nos. 15-04-00915 and 16-34-00398

Mapping bare soil in South West Wales, UK, using high resolution colour infra-red aerial photography for water quality and flood risk management applications

NASA Astrophysics Data System (ADS)

Sykes, Helena; Neale, Simon; Coe, Sarah

2016-04-01

Natural Resources Wales is a UK government body responsible for environmental regulation, among other areas. River walks in Water Framework Directive (WFD) priority catchments in South West Wales, UK, identified soil entering water courses due to poaching and bank erosion, leading to deterioration in the water quality and jeopardising the water quality meeting legal minimum standards. Bare soil has also been shown to cause quicker and higher hydrograph peaks in rural catchments than if those areas were vegetated, which can lead to flooding of domestic properties during peak storm flows. The aim was to target farm visits by operational staff to advise on practices likely to improve water quality and to identify areas where soft engineering solutions such as revegetation could alleviate flood risk in rural areas. High resolution colour-infrared aerial photography, 25cm in the three colour bands and 50cm in the near infrared band, was used to map bare soil in seven catchments using supervised classification of a five band stack including the Normalised Difference Vegetation Index (NDVI). Mapping was combined with agricultural land use and field boundary data to filter out arable fields, which are supposed to bare soil for part of their cycle, and was very successful when compared to ground truthing, with the exception of silage fields which contained sparse, no or unproductive vegetation at the time the imagery was acquired leading to spectral similarity to bare soil. A raindrop trace model was used to show the path sediment from bare soil areas would take when moving through the catchment to a watercourse, with hedgerows inserted as barriers following our observations from ground truthing. The findings have been used to help farmers gain funding for improvements such as fencing to keep animals away from vulnerable river banks. These efficient and automated methods can be rolled out to more catchments in Wales and updated using aerial imagery acquired more recently to examine the effects of change.

Evidence for Active Westward Tilting of Fortymile Wash, Nye County, Nevada

NASA Astrophysics Data System (ADS)

McKague, H. L.; Sims, D. W.; Waiting, D. J.

2006-12-01

Fortymile Wash is located east and south of a potential high-level nuclear waste repository at Yucca Mountain, Nevada. Several lines of evidence suggest that this may be an area of active westward tilting associated with the continued development of Crater Flat basin and slip on the Bare Mountain normal fault. Near the southern end of Busted Butte, the incised channel of Fortymile Wash changes trend downgradient from south to south-southwest. Further southward, the incised main channel grades to a divergent distributary channel system that shows evidence of increasingly westward tilt. Viewed in profiles oriented normal to the incised channel and across the Fortymile Wash distributary system, topographic elevation of the western margin of the fan decreases southward, resulting in the elevation of the western margin of Fortymile Basin being as much as 18 m [59 ft] lower than the channel system on the eastern fan margin. Mapping of the surficial deposits within the distributary channel system (Pelletier, et al., 2005; Geophy. Res. Ltr., Vol. 32) may be interpreted to show a westward shift (downslope) of the locus of erosional activity toward the topographically lower western fan margin. Most of the older alluvium (Qa3 {86±40-16 ka}) has been eroded from the eastern portion, while incipient incision into the older alluvium is occurring on the western side of the distributary channel system. The results from level-line benchmark surveys (Gilmore, 1992; USGS OFR 92- 450) from 1915 and 1984 show gradual and systematic elevation changes east of the Bare Mountain fault to just east of Amargosa City, Nevada, where a step-like increase occurs. The level-line surveys are near and along the path of U.S. Highway 95, which traverses the distributary channel system of the Fortymile Wash alluvial fan in the southern portion of the Fortymile Wash basin. These lines of evidence indicate disequilibrium in the channel system that would result from active westward tilting of the Fortymile Wash basin. The active tilting in Fortymile Wash may be associated with continued development of Crater Flat basin and slip on the Bare Mountain fault, with the steeply dipping southern segment of the Bare Mountain fault not only controlling the southward-increasing subsidence in Southern Crater Flat, but also the changes observed in the southern Fortymile Wash basin 20 km [12.5 mi] to the southeast. An alternative interpretation is westward tilting, which is the result of active, but not evident, faulting beneath or near Fortymile Wash. Additional evidence indicating the presence of a fault beneath Fortymile Wash is the easterly dip of Miocene tuffs in Fran Ridge north of Busted Butte. This abstract is an independent product of the Center for Nuclear Waste Regulatory Analyses and does not necessarily reflect the view or regulatory position of the U.S. Nuclear Regulatory Commission.

Inclusion of Solar Elevation Angle in Land Surface Albedo Parameterization Over Bare Soil Surface.

PubMed

Zheng, Zhiyuan; Wei, Zhigang; Wen, Zhiping; Dong, Wenjie; Li, Zhenchao; Wen, Xiaohang; Zhu, Xian; Ji, Dong; Chen, Chen; Yan, Dongdong

2017-12-01

Land surface albedo is a significant parameter for maintaining a balance in surface energy. It is also an important parameter of bare soil surface albedo for developing land surface process models that accurately reflect diurnal variation characteristics and the mechanism behind the solar spectral radiation albedo on bare soil surfaces and for understanding the relationships between climate factors and spectral radiation albedo. Using a data set of field observations, we conducted experiments to analyze the variation characteristics of land surface solar spectral radiation and the corresponding albedo over a typical Gobi bare soil underlying surface and to investigate the relationships between the land surface solar spectral radiation albedo, solar elevation angle, and soil moisture. Based on both solar elevation angle and soil moisture measurements simultaneously, we propose a new two-factor parameterization scheme for spectral radiation albedo over bare soil underlying surfaces. The results of numerical simulation experiments show that the new parameterization scheme can more accurately depict the diurnal variation characteristics of bare soil surface albedo than the previous schemes. Solar elevation angle is one of the most important factors for parameterizing bare soil surface albedo and must be considered in the parameterization scheme, especially in arid and semiarid areas with low soil moisture content. This study reveals the characteristics and mechanism of the diurnal variation of bare soil surface solar spectral radiation albedo and is helpful in developing land surface process models, weather models, and climate models.

Bare Walls? Get Better Coverage from these Bulletin Boards.

ERIC Educational Resources Information Center

Bates, Sara; Wisler, Diane

1983-01-01

Five versatile basic backgrounds for bulletin boards are described. Many different options are suggested when using a sun, calculator, monkey, roller skate, or elephant as the basis for the bulletin board. (JMK)

Electronic and magnetic properties of MoSe2 armchair nanoribbons controlled by the different edge structures

NASA Astrophysics Data System (ADS)

Zhang, Hui; Zhao, Xu; Gao, Yonghui; Wang, Haiyang; Wang, Tianxing; Wei, Shuyi

2018-03-01

Tow-dimensional materials obviously have potential applications in next-generation nanodevices because of their extraordinary physical and chemical properties and the demands of the market. Using first-principle calculation based on density functional theory, we explore electronic and magnetic properties of the different nanoribbons with various edge structures, namely, with hydrogenation or not. In addition, we also calculate the binding energy to analyze the stability of the nanoribbon. Our calculations tell us that the passivated nanoribbons have the positive binding energies, which indicates the passivated nanoribbons are relative stable and hydrogenation can improve the stability of the bare nanoribbons due to the reduction of the dangling bonds. Among of them, full hydrogenation has the highest stability. We find all the nanoribbons with full and without hydrogenation are nonmagnetic semiconductors. It is worth mentioning that hydrogenation can induce the bare nanoribbons to transform gradually from indirect band gap semiconductor to direct band gap semiconductor, even to half-metal. In addition, the magnetic moment of the bare nanoribbon change bit by bit as the rate of hydrogenation increases. When the edge atoms are fully hydrogenated, the magnetic moment return to zero. What's more, our research results still confirm that electronic and magnetic properties of the nanorribons without and with different edge passivation are mainly contributed by the atoms at the edges. These studies about MoSe2 nanoribbons will shed light on the further development of the relevant nanodevices in versatile applications, such as spintronics and energy harvesting.

Study of sensor spectral responses and data processing algorithms and architectures for onboard feature identification

NASA Technical Reports Server (NTRS)

Huck, F. O.; Davis, R. E.; Fales, C. L.; Aherron, R. M.

1982-01-01

A computational model of the deterministic and stochastic processes involved in remote sensing is used to study spectral feature identification techniques for real-time onboard processing of data acquired with advanced earth-resources sensors. Preliminary results indicate that: Narrow spectral responses are advantageous; signal normalization improves mean-square distance (MSD) classification accuracy but tends to degrade maximum-likelihood (MLH) classification accuracy; and MSD classification of normalized signals performs better than the computationally more complex MLH classification when imaging conditions change appreciably from those conditions during which reference data were acquired. The results also indicate that autonomous categorization of TM signals into vegetation, bare land, water, snow and clouds can be accomplished with adequate reliability for many applications over a reasonably wide range of imaging conditions. However, further analysis is required to develop computationally efficient boundary approximation algorithms for such categorization.

The Bare Area of the Proximal Ulna: An Anatomic Study With Relevance to Chevron Osteotomy.

PubMed

Ao, Rongguang; Zhang, Xu; Li, Dejian; Chen, Fancheng; Zhou, Jianhua; Yu, Baoqing

2017-06-01

A chevron osteotomy of the ulna is widely used to obtain intra-articular access to the elbow in the treatment of type C distal humerus fractures. The trochlear notch of the proximal ulna is divided into 2 articular parts by the "bare area." Ideally, the olecranon osteotomy should be centered on the bare area to minimize damage to the joint cartilage. The goals of this study were to describe the anatomy of the bare area and design an ideal chevron-shaped osteotomy. We dissected 38 cadaver elbows and measured the width of the bare area, the distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area. We then designed a chevron osteotomy to stay within the bare area and measured the distance from the tip of the triceps insertion to the osteotomy apex as well as the angle of the osteotomy plane and the angle of the chevron cuts. The bare area existed in all 38 cadavers. The mean longitudinal and transverse widths were 4.0 mm (range, 1.0-8.6 mm) and 19.0 mm (range, 16.9-23.8 mm), respectively. The mean distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area was 19.0 mm (range, 16.0-23.0 mm). The mean transverse and longitudinal widths of the cortical notch were 3.0 mm (range, 1.6-4.5 mm) and 8.0 mm (range, 6.5-14.8 mm), respectively. The mean distance between the tip of the triceps insertion and the osteotomy apex was 22.0 mm (range, 18.0-24.0 mm) and the mean angle between the osteotomy surface and the vertical plane corresponding to the tangent plane was 20° (range, 10° to 25°). The mean angle of the V shape was 140° (range, 130° to 150°). Using the narrowest edge lacking cartilage (lateral or medial side) as a point of reference to locate the bare area, the designed chevron osteotomy entered the joint in the bare area in most specimens and decreased associated damage to the joint cartilage. This study describes the anatomy of the bare area and the design of the ideal chevron-shaped osteotomy to treat type C distal humerus fractures. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Ten Years of Post-Fire Vegetation Recovery following the 2007 Zaca Fire using Landsat Satellite Imagery

NASA Astrophysics Data System (ADS)

Hallett, J. K. E.; Miller, D.; Roberts, D. A.

2017-12-01

Forest fires play a key role in shaping eco-systems. The risk to vegetation depends on the fire regime, fuel conditions (age and amount), fire temperature, and physiological characteristics such as bark thickness and stem diameter. The 2007 Zaca Fire (24 kilometers NE of Buellton, Santa Barbara County, California) burned 826.4 km2 over the course of 2 months. In this study, we used a time series of Landsat 5 Thematic Mapper and Landsat 8 Operational Land Imager imagery, to evaluate plant burn severity and post fire recovery as defined into classes of above average recovery, normal recovery, and below average recovery. We spectrally unmixed the images into green vegetation (GV), non-photosynthetic vegetation (NPV), soil surface (SOIL), and ash with a spectral library developed using Constrained Reference Endmember Selection (CRES). We delineated the fire perimeter using the differenced Normalized Burn Ratio (dNBR) and evaluated changes in this index and the Normalized Difference Vegetation Index through time. The results showed an immediate decline in GV and NPV fractions, with a rise in soil and ash fractions directly following the fire, with a slow recovery in GV fraction and a loss of bare soil cover. The was a sharp increase in the ash fraction following the fire and gradual decrease in the year after. Most areas have recovered as of 2017, with prominent recovery in the center of the burn scar and reduced recovery in areas to the south. These results indicate how post-fire vegetation varies based on initial burn severity and pre-fire GV and NPV fractions.

Reflectance of vegetation, soil, and water

NASA Technical Reports Server (NTRS)

Wiegand, C. L.; Gausman, H. W.; Leamer, R. W.; Richardson, A. J.; Gerbermann, A. H. (Principal Investigator)

1974-01-01

The author has identified the following significant results. Iron deficient and normal grain sorghum plants were sufficiently different spectrally in ERTS-1 band 5 CCT data to detect chlorotic sorghum areas 2.8 acres (1.1 hectares) or larger in size in computer printouts of the MSS data. The ratio of band 5 to band 7 or band 7 minus band 5 relates to vegetation ground cover conditions and helps to select training samples representative of differing vegetation maturity or vigor classes and to estimate ground cover or green vegetation density in the absence of ground information. The four plant parameters; leaf area index, plant population, plant cover, and plant height explained 87 to 93% of the variability in band 6 digital counts and from 59 to 90% of the variation in bands 4 and 5. A ground area 2244 acres in size was classified on a pixel by pixel basis using simultaneously acquired aircraft support and ERTS-1 data. Overall recognition for vegetables, immature crops and mixed shrubs, and bare soil categories was 64.5% for aircraft and 59.6% for spacecraft data, respectively. Overall recognition results on a per field basis were 61.8% for aircraft and 62.8% for ERTS-1 data.

Laser damage of HR, AR-coatings, monolayers and bare surfaces at 1064 nm

NASA Technical Reports Server (NTRS)

Garnov, S. V.; Klimentov, S. M.; Said, A. A.; Soileau, M. J.

1993-01-01

Laser induced damage thresholds and morphologies were investigated in a variety of uncoated and coated surfaces, including monolayers and multi-layers of different chemical compositions. Both antireflective (AR) and highly reflective (HR) were tested. Testing was done at 1064 nm with 25 picosecond and 8 nanosecond YAG/Nd laser single pulses. Spot diameter in the experiments varied from 0.09 to 0.22 mm. The laser damage measurement procedure consisted of 1-on-1 (single laser pulse in the selected site) and N-on-1 experiments including repeated irradiation by pulses of the same fluence and subsequently raised from pulse to pulse fluence until damage occurred. The highest picosecond damage thresholds of commercially available coatings averaged 12 - 14 J/sq cm, 50 percent less than thresholds obtained in bare fused silica. Some coatings and bare surfaces revealed a palpable preconditioning effect (an increase in threshold of 1.2 to 1.8 times). Picosecond and nanosecond data were compared to draw conclusions about pulse width dependence. An attempt was made to classify damage morphologies according to the type of coating, class of irradiating, and damage level.

The application of the piecewise linear approximation to the spectral neighborhood of soil line for the analysis of the quality of normalization of remote sensing materials

NASA Astrophysics Data System (ADS)

Kulyanitsa, A. L.; Rukhovich, A. D.; Rukhovich, D. D.; Koroleva, P. V.; Rukhovich, D. I.; Simakova, M. S.

2017-04-01

The concept of soil line can be to describe the temporal distribution of spectral characteristics of the bare soil surface. In this case, the soil line can be referred to as the multi-temporal soil line, or simply temporal soil line (TSL). In order to create TSL for 8000 regular lattice points for the territory of three regions of Tula oblast, we used 34 Landsat images obtained in the period from 1985 to 2014 after their certain transformation. As Landsat images are the matrices of the values of spectral brightness, this transformation is the normalization of matrices. There are several methods of normalization that move, rotate, and scale the spectral plane. In our study, we applied the method of piecewise linear approximation to the spectral neighborhood of soil line in order to assess the quality of normalization mathematically. This approach allowed us to range normalization methods according to their quality as follows: classic normalization > successive application of the turn and shift > successive application of the atmospheric correction and shift > atmospheric correction > shift > turn > raw data. The normalized data allowed us to create the maps of the distribution of a and b coefficients of the TSL. The map of b coefficient is characterized by the high correlation with the ground-truth data obtained from 1899 soil pits described during the soil surveys performed by the local institute for land management (GIPROZEM).

Study of different HILIC, mixed-mode, and other aqueous normal-phase approaches for the liquid chromatography/mass spectrometry-based determination of challenging polar pesticides.

PubMed

Vass, Andrea; Robles-Molina, José; Pérez-Ortega, Patricia; Gilbert-López, Bienvenida; Dernovics, Mihaly; Molina-Díaz, Antonio; García-Reyes, Juan F

2016-07-01

The aim of the study was to evaluate the performance of different chromatographic approaches for the liquid chromatography/mass spectrometry (LC-MS(/MS)) determination of 24 highly polar pesticides. The studied compounds, which are in most cases unsuitable for conventional LC-MS(/MS) multiresidue methods were tested with nine different chromatographic conditions, including two different hydrophilic interaction liquid chromatography (HILIC) columns, two zwitterionic-type mixed-mode columns, three normal-phase columns operated in HILIC-mode (bare silica and two silica-based chemically bonded columns (cyano and amino)), and two standard reversed-phase C18 columns. Different sets of chromatographic parameters in positive (for 17 analytes) and negative ionization modes (for nine analytes) were examined. In order to compare the different approaches, a semi-quantitative classification was proposed, calculated as the percentage of an empirical performance value, which consisted of three main features: (i) capacity factor (k) to characterize analyte separation from the void, (ii) relative response factor, and (iii) peak shape based on analytes' peak width. While no single method was able to provide appropriate detection of all the 24 studied species in a single run, the best suited approach for the compounds ionized in positive mode was based on a UHPLC HILIC column with 1.8 μm particle size, providing appropriate results for 22 out of the 24 species tested. In contrast, the detection of glyphosate and aminomethylphosphonic acid could only be achieved with a zwitterionic-type mixed-mode column, which proved to be suitable only for the pesticides detected in negative ion mode. Finally, the selected approach (UHPLC HILIC) was found to be useful for the determination of multiple pesticides in oranges using HILIC-ESI-MS/MS, with limits of quantitation in the low microgram per kilogram in most cases. Graphical Abstract HILIC improves separation of multiclass polar pesticides.

Retrieval of aerosol optical depth over bare soil surfaces using time series of MODIS imagery

NASA Astrophysics Data System (ADS)

Yuan, Zhengwu; Yuan, Ranyin; Zhong, Bo

2014-11-01

Aerosol Optical Depth (AOD) is one of the key parameters which can not only reflect the characterization of atmospheric turbidity, but also identify the climate effects of aerosol. The current MODIS aerosol estimation algorithm over land is based on the "dark-target" approach which works only over densely vegetated surfaces. For non-densely vegetated surfaces (such as snow/ice, desert, and bare soil surfaces), this method will be failed. In this study, we develop an algorithm to derive AOD over the bare soil surfaces. Firstly, this method uses the time series of MODIS imagery to detect the " clearest" observations during the non-growing season in multiple years for each pixel. Secondly, the "clearest" observations after suitable atmospheric correction are used to fit the bare soil's bidirectional reflectance distribution function (BRDF) using Kernel model. As long as the bare soil's BRDF is established, the surface reflectance of "hazy" observations can be simulated. Eventually, the AOD over the bare soil surfaces are derived. Preliminary validation results by comparing with the ground measurements from AERONET at Xianghe sites show a good agreement.

Location of Bare Soil Surface and Soil Line on the RED-NIR Spectral Plane

NASA Astrophysics Data System (ADS)

Koroleva, P. V.; Rukhovich, D. I.; Rukhovich, A. D.; Rukhovich, D. D.; Kulyanitsa, A. L.; Trubnikov, A. V.; Kalinina, N. V.; Simakova, M. S.

2017-12-01

Soil as a separate natural body occupies certain area with its own set of spectral characteristics within the RED-NIR spectral space. This is an ellipse-shaped area, and its semi-major axis is the soil line for a satellite image. The spectral area for a bare soil surface is neighboring to the areas of black carbon, straw, vegetating plants, and missing RED-NIR values. A reliable separation of the bare soil surface within the spectral space is possible with the technology of spectral neighborhood of soil line. The accuracy of this method is 90%. The determination of the bare soil surface using vegetation indices, both relative (NDVI), and perpendicular (PVI), is incorrect; the accuracy of these methods does not exceed 65%, and for most of the survey seasons it may be lower than 50%. The flat part of the "tasseled cap" described as the soil line, is not a synonym for the area of the bare soil surface. The bare soil surface on the RED-NIR plots occupies significantly smaller areas than the area of soil line according to Kauth and Thomas.

Polygalacturonase Gene Expression in Rutgers, rin, nor, and Nr Tomato Fruits 1

PubMed Central

DellaPenna, Dean; Kates, David S.; Bennett, Alan B.

1987-01-01

Polygalacturonase (PG) gene expression was studied in normally ripening tomato fruit (Lycopersicon esculentum Mill, cv Rutgers) and in three ripening-impaired mutants, rin, nor, and Nr. Normal and mutant fruit of identical chronological age were analyzed at 41, 49, and 62 days after pollination. These stages corresponded to mature-green, ripe, and overripe, respectively, for Rutgers. The amount of PG mRNA in Rutgers was highest at 49 days and accounted for 2.3% of the total mRNA mass but at 62 days had decreased to 0.004% of the total mRNA mass. In Nr, the amount of PG mRNA steadily increased between 41 and 62 days after pollination, reaching a maximum level of 0.5% of the total mRNA mass. The mutant nor exhibited barely detectable levels of PG mRNA at all stages tested. Surprisingly, PG mRNA, comprising approximately 0.06% of the mRNA mass, was detected in 49 day rin fruit. This mRNA accumulation occurred in the absence of elevated ethylene production by the fruit and resulted in the synthesis of enzymically active PG I. The different patterns of PG mRNA accumulation in the three mutants suggests that distinct molecular mechanisms contribute to reduced PG expression in each ripening-impaired mutant. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:16665727

Vegetation associated with different walking track types in the Kosciuszko alpine area, Australia.

PubMed

Hill, Wendy; Pickering, Catherine Marina

2006-01-01

Tourism infrastructure such as walking tracks can have negative effects on vegetation including in mountain regions. In the alpine area around continental Australia's highest mountain, Mt Kosciuszko (2228 m), there is a range of walking tracks (paved, gravel and raised steel mesh surfaces) in addition to an extensive network of informal/non-hardened tracks. Vegetation characteristics were compared between track types on/under tracks, on the track verge, and in the adjacent native vegetation. For a raised steel mesh walkway there was no difference in vegetation under the walkway, on the verge, and 3m away. In contrast, for a non-hardened track there was 35% bare ground on the track surface but no other detectable impacts. Gravel and paved tracks had distinct verges largely comprising bare ground and exotic species. For non-hardened tracks there was an estimated 270 m2 of disturbance per km of track. For wide gravel tracks the combined area of bare ground, exotic plants and gravel was estimated as 4290 m2 per km, while for narrow gravel tracks it was estimated as 2940 m2 per km. For paved tracks there was around 2680 m2 per km of damage. In contrast, there was no detectable effect of raised steel mesh walkway on vegetation highlighting some of the benefits of this surface over other track types.

Method for reducing measurement errors of a Langmuir probe with a protective RF shield

NASA Astrophysics Data System (ADS)

Riaby, V.; Masherov, P.; Savinov, V.; Yakunin, V.

2018-04-01

Probe measurements were conducted in the middle cross-section of an inductive, low-pressure xenon plasma using a straight cylindrical Langmuir probe with a bare metal shield that protected the probe from radio frequency interference. As a result, reliable radial distributions of the plasma parameters were obtained. Subsequent analyses of these measurements revealed that the electron energy distribution function (EEDF) deviated substantially from the Maxwellian functions and that this deviation depended on the length of the probe shield. To evaluate the shield's influence on the measurement results, in addition to the probe (which was moved radially as its shield length varied in the range of lsh1 = lmax-0), an additional L-shaped probe was inserted at a different location. This probe was moved differently from the first probe and provided confirmational measurements in the common special position where lsh1 = 0 and lsh2 ≠ 0. In this position, the second shield decreased all the plasma parameters. A comparison of the probe datasets identified the principles of the relationships between measurement errors and EEDF distortions caused by the bare probe shields. This dependence was used to correct the measurements performed using the first probe by eliminating the influence of its shield. Physical analyses based on earlier studies showed that these peculiarities are caused by a short-circuited double-probe effect that occurs in bare metal probe protective shields.

[Study of mechanical effects of the EVA glove on finger base with finite element modeling].

PubMed

Li, Zhuoyou; Ding, Li; Yue, Guodong

2013-08-01

The hand strength of astronauts, when they are outside the space capsule, is highly influenced by the residual pressure (the pressure difference between inside pressure and outside one of the suit) of extravehicular activity spacesuit glove and the pressure exerted by braided fabric. The hand strength decreases significantly on extravehicular activity, severely reducing the operation efficiency. To measure mechanical influence caused by spacesuit glove on muscle-tendon and joints, the present paper analyzes the movement anatomy and biomechanical characteristics of gripping, and then proposes a grip model. With phalangeal joint simplified as hinges, seven muscles as a finger grip energy unit, the Hill muscle model was used to compute the effects. We also used ANSYS in this study to establish a 3-D finite element model of an index finger which included both bones and muscles with glove, and then we verified the model. This model was applied to calculate the muscle stress in various situations of bare hands or hands wearing gloves in three different sizes. The results showed that in order to achieve normal grip strength with the influence caused by superfluous press, the finger's muscle stress should be increased to 5.4 times of that in normal situation, with most of the finger grip strength used to overcome the influence of superfluous pressure. When the gap between the finger surface and the glove is smaller, the mechanical influence which superfluous press made will decrease. The results would provide a theoretical basis for the design of the EVA Glove.

Variable effects of plant colonization on black slate uptake into microbial PLFAs

NASA Astrophysics Data System (ADS)

Seifert, Anne-Gret; Trumbore, Susan; Xu, Xiaomei; Zhang, Dachung; Gleixner, Gerd

2013-04-01

Microbial degradation of carbon derived from black shale and slate has been shown in vitro. However, in natural settings where other labile carbon sources are likely to exist, this has not been previously demonstrated. We investigated the uptake of ancient carbon derived from slate weathering and from recently photosynthesised organic matter by different groups of microorganisms. Therefore we isolated microbial biomarkers (phospholipid fatty acids, PLFAs) from black slates collected at a chronosequence of waste piles which differed in age and vegetation cover. We quantified the amount of PLFAs and performed stable isotope and radiocarbon measurements on individual or grouped PLFAs to quantify the fraction of slate derived carbon. We used black slate from a pile heaped in the 1950s with either uncovered black slate material (bare site) or material slightly colonized by small plants (greened site) and from a forested leaching pile (forested site) used for alum-mining in the 19th century. Colonization by plants influenced the amount and composition of the microbial community. Greater amounts of PLFAs (5410 ng PLFA/g dw) were extracted from slate sampled at the forested site as opposed to the bare site (960 ng PLFAs/g dw) or the greened (annual grasses and mosses) rock waste pile (1050 ng PLFAs/g dw). We found the highest proportion of PLFAs representing Gram-negative bacteria on the forested site and the highest proportion of PLFAs representing Gram-positive bacteria on the bare site. The fungal PLFA was most abundant at the greened site. Sites with less plant colonization (bare and greened site) tended to have more depleted δ13C values compared to the forested site. Radiocarbon measurements on PLFAs indicated that fungi and Gram-positive bacteria were best adapted to black slate carbon uptake. In the fungal PLFA (combined bare and greened waste pile sample) and in PLFAs of Gram-positive bacteria (greened site) we measured 39.7% and 28.9% ancient carbon uptake, respectively. Our results prove that black slate degradation followed by carbon uptake takes place in situ. Results imply that plant colonization might additionally affect this process. Slight colonization with few plants increased slate derived carbon uptake in PLFAs of Gram-positive bacteria. Evidently, Gram-positive bacteria represented by specific PLFAs from the greened site held more ancient carbon than from the bare site. In contrast, no black slate derived carbon was used by microorganisms at the forested site with 2-3 times greater carbon content. Results suggest that the use of ancient slate derived carbon dominates mainly in early stages of microbial colonization of surfaces and that with increasing ecosystem development recycling of plant derived carbon dominates.

Turbulent Intensities and Velocity Spectra for Bare and Forested Gentle Hills: Flume Experiments

NASA Astrophysics Data System (ADS)

Poggi, Davide; Katul, Gabriel G.

2008-10-01

To investigate how velocity variances and spectra are modified by the simultaneous action of topography and canopy, two flume experiments were carried out on a train of gentle cosine hills differing in surface cover. The first experiment was conducted above a bare surface while the second experiment was conducted within and above a densely arrayed rod canopy. The velocity variances and spectra from these two experiments were compared in the middle, inner, and near-surface layers. In the middle layer, and for the canopy surface, longitudinal and vertical velocity variances ({σ_u^2,σ_w^2}) were in phase with the hill-induced spatial mean velocity perturbation (Δ u) around the so-called background state (taken here as the longitudinal mean at a given height) as predicted by rapid distortion theory (RDT). However, for the bare surface case, {σ_u^2 } and {σ_w^2 } remained out of phase with Δ u by about L/2, where L is the hill half-length. In the canopy layer, wake production was a significant source of turbulent energy for {σ_w^2 } , and its action was to re-align velocity variances with Δ u in those layers, a mechanism completely absent for the bare surface case. Such a lower ‘boundary condition’ resulted in longitudinal variations of {σ_w^2} to be nearly in phase with Δ u above the canopy surface. In the inner and middle layers, the spectral distortions by the hill remained significant for the background state of the bare surface case but not for the canopy surface case. In particular, in the inner and middle layers of the bare surface case, the effective exponents derived from the locally measured power spectra diverged from their expected - 5/3 value for inertial subrange scales. These departures spatially correlated with the hill surface. However, for the canopy surface case, the spectral exponents were near - 5/3 above the canopy though the minor differences from - 5/3 were also correlated with the hill surface. Inside the canopy, wake production and energy short-circuiting resulted in significant departures from - 5/3. These departures from - 5/3 also appeared correlated with the hill surface through the wake production contribution and its alignment with Δ u. Moreover, scales commensurate with Von Karman street vorticies well described wake production scales inside the canopy, confirming the important role of the mean flow in producing wakes. The spectra inside the canopy on the lee side of the hill, where a negative mean flow delineated a recirculation zone, suggested that the wake production scales there were ‘broader’ when compared to their counterpart outside the recirculation zone. Inside the recirculation zone, there was significantly more energy at higher frequencies when compared to regions outside the recirculation zone.

[Effects of different planting modes on the soil permeability of sloping farmlands in purple soil area].

PubMed

Li, Jian-Xing; He, Bing-Hui; Mei, Xue-Mei; Liang, Yan-Ling; Xiong, Jian

2013-03-01

Taking bare land as the control, this paper studied the effects of different planting modes on the soil permeability of sloping farmlands in purple soil area. For the test six planting modes, the soil permeability was in the order of Eriobotrya japonica > Citrus limon > Vetiveria zizanioides hedgerows +corn >Leucaena leucocephala hedgerows + corn> Hemerocallis fulva > corn> bare land, and decreased with increasing depth. The eigenvalues of soil infiltration were in the order of initial infiltration rate> average infiltration rate> stable infiltration rate. The soil permeability had significant positive linear correlations with soil total porosity, non-capillary porosity, initial moisture content, water holding capacity, and organic matter content, and significant negative linear correlation with soil bulk density. The common empirical infiltration model could well fit the soil moisture infiltration processes under the six planting modes, while the Kostiakov equation could not.

Field and energy relations in continuum electrodynamics.

PubMed

Crenshaw, Michael E

2005-09-01

The bare, or fundamental, electric and magnetic fields in a linear medium are identified. Through the energy relations for the bare fields, the electric permittivity is shown to combine the effects of the enhanced energy density and the polarization reaction field. The macroscopic Maxwell equations are modified to be consistent with the constitutive relations for the bare fields.

78 FR 61000 - Additional Designations, Foreign Narcotics Kingpin Designation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... To: OPERADORA Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU, S.A. DE C.V.; Linked To: ROOL EUROPE AG... REMF671011QH1 (Mexico) (individual) [SDNTK] (Linked To: OPERADORA Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU... Y ADMINISTRADORA DE RESTAURANTES Y BARES RUDU, S.A. DE C.V., Vallarta No. 2380, Col. Colinas De San...

Thulium fiber laser induced vapor bubbles using bare, tapered, ball, hollow steel, and muzzle brake fiber optic tips

NASA Astrophysics Data System (ADS)

Gonzalez, David A.; Hardy, Luke A.; Hutchens, Thomas C.; Irby, Pierce B.; Fried, Nathaniel M.

2018-02-01

This study characterizes laser-induced vapor bubbles for five distal fiber optic tip configurations, to provide insight into stone retropulsion experienced during laser ablation of kidney stones. A TFL with 1908-nm wavelength delivered 34 mJ energy per pulse at 500-μs pulse duration through five different fibers: 100-μm-core/170-μm-OD bare fiber tip, 150-μm- to 300-μm-core tapered fiber tip, 100-μm-core/300-μm-OD ball tip fiber, 100-μm-core/340- μm-OD hollow steel tip fiber, and 100-μm-core/560-μm-OD muzzle brake fiber tip. A high speed camera with 10- μm spatial and 9.5-μs temporal resolution imaged vapor bubble dynamics. A needle hydrophone measured pressure transients in forward (0°) and side (90°) directions while placed at a 6.8 +/- 0.4 mm distance from fiber tip. Maximum bubble dimensions (width/length) averaged 0.7/1.5, 1.0/1.6, 0.5/1.1, 0.8/1.9, and 0.7/1.5 mm, for bare, tapered, ball, hollow steel, and muzzle tips, respectively (n=5). The hollow steel tip exhibited the most elongated vapor bubble shape, translating into increased forward pressure in this study and consistent with higher stone retropulsion in previous reports. Relative pressures (a.u.) in (forward/side) directions averaged 1.7/1.6, 2.0/2.0, 1.4/1.2, 6.8/1.1, and 0.3/1.2, for each fiber tip (n=5). For hollow steel tip, forward pressure was 4× higher than for bare fiber. For the muzzle brake fiber tip, forward pressure was 5× lower than for bare fiber. Bubble dimensions and pressure measurements demonstrated that the muzzle tip reduced forward pressure by partially venting vapors through side holes, consistent with lower stone retropulsion observed in previous reports.

Electrochemical Properties of Organosilane Self Assembled Monolayers on Aluminum 2024

NASA Technical Reports Server (NTRS)

Hintze, Paul E.; Calle, Luz Marina

2004-01-01

Self assembled monolayers are commonly used to modify surfaces. Within the last 15 years, self assembled monolayers have been investigated as a way to protect from corrosion[1,2] or biofouling.[3] In this study, self assembled monolayers of decitriethoxysilane (C10H21Si(OC2H5)3) and octadecyltriethoxysilane (C18H37Si(OC2H5)3) were formed on aluminum 2024-T3. The modified surfaces and bare Al 2024 were characterized by dynamic water contact angle measurements, x-ray photoelectron spectroscopy (XIPS) and infrared spectroscopy. Electrochemical impedance spectroscopy (EIS) in 0.5 M NaCl was used to characterize the monolayers and evaluate their corrosion protection properties. The advancing water contact angle and infrared measurements show that the mono layers form a surface where the hydrocarbon chains are packed and oriented away from the surface, consistent with what is found in similar systems. The contact angle hysteresis measured in these systems is relatively large, perhaps indicating that the hydrocarbon chains are not as well packed as monolayers formed on other substrates. The results of the EIS measurements were modeled using a Randle's circuit modified by changing the capacitor to a constant phase element. The constant phase element values were found to characterize the monolayer. The capacitance of the monolayer modified surface starts lower than the bare Al 2024, but approaches values similar to the bare Al 2024 within 24 hours as the monolayer is degraded. The n values found for bare Al 2024 quickly approach the value of a true capacitor and are greater than 0.9 within hours after the start of exposure. For the monolayer modified structure, n can stay lower than 0.9 for a longer period of time. In fact, n for the monolayer modified surfaces is different from the bare surface even after the capacitance values have converged. This indicates that the deviation from ideal capacitance is the most sensitive indicator of the presence of the monolayer.

Tomato response to legume cover crop and nitrogen: differing enhancement patterns of fruit yield, photosynthesis and gene expression

USDA-ARS?s Scientific Manuscript database

Tomatoes responded to soil and residue from a hairy vetch cover crop differently on many levels than tomato response to inorganic nitrogen. Tomato fruit production, plant biomass parameters, and photosynthesis were higher in plants grown in vetch than bare soil. Tomato growth and photosynthesis metr...

Spatial variation and linkages of soil and vegetation in the Siberian Arctic tundra - coupling field observations with remote sensing data

NASA Astrophysics Data System (ADS)

Mikola, Juha; Virtanen, Tarmo; Linkosalmi, Maiju; Vähä, Emmi; Nyman, Johanna; Postanogova, Olga; Räsänen, Aleksi; Kotze, D. Johan; Laurila, Tuomas; Juutinen, Sari; Kondratyev, Vladimir; Aurela, Mika

2018-05-01

Arctic tundra ecosystems will play a key role in future climate change due to intensifying permafrost thawing, plant growth and ecosystem carbon exchange, but monitoring these changes may be challenging due to the heterogeneity of Arctic landscapes. We examined spatial variation and linkages of soil and plant attributes in a site of Siberian Arctic tundra in Tiksi, northeast Russia, and evaluated possibilities to capture this variation by remote sensing for the benefit of carbon exchange measurements and landscape extrapolation. We distinguished nine land cover types (LCTs) and to characterize them, sampled 92 study plots for plant and soil attributes in 2014. Moreover, to test if variation in plant and soil attributes can be detected using remote sensing, we produced a normalized difference vegetation index (NDVI) and topographical parameters for each study plot using three very high spatial resolution multispectral satellite images. We found that soils ranged from mineral soils in bare soil and lichen tundra LCTs to soils of high percentage of organic matter (OM) in graminoid tundra, bog, dry fen and wet fen. OM content of the top soil was on average 14 g dm-3 in bare soil and lichen tundra and 89 g dm-3 in other LCTs. Total moss biomass varied from 0 to 820 g m-2, total vascular shoot mass from 7 to 112 g m-2 and vascular leaf area index (LAI) from 0.04 to 0.95 among LCTs. In late summer, soil temperatures at 15 cm depth were on average 14 °C in bare soil and lichen tundra, and varied from 5 to 9 °C in other LCTs. On average, depth of the biologically active, unfrozen soil layer doubled from early July to mid-August. When contrasted across study plots, moss biomass was positively associated with soil OM % and OM content and negatively associated with soil temperature, explaining 14-34 % of variation. Vascular shoot mass and LAI were also positively associated with soil OM content, and LAI with active layer depth, but only explained 6-15 % of variation. NDVI captured variation in vascular LAI better than in moss biomass, but while this difference was significant with late season NDVI, it was minimal with early season NDVI. For this reason, soil attributes associated with moss mass were better captured by early season NDVI. Topographic attributes were related to LAI and many soil attributes, but not to moss biomass and could not increase the amount of spatial variation explained in plant and soil attributes above that achieved by NDVI. The LCT map we produced had low to moderate uncertainty in predictions for plant and soil properties except for moss biomass and bare soil and lichen tundra LCTs. Our results illustrate a typical tundra ecosystem with great fine-scale spatial variation in both plant and soil attributes. Mosses dominate plant biomass and control many soil attributes, including OM % and temperature, but variation in moss biomass is difficult to capture by remote sensing reflectance, topography or a LCT map. Despite the general accuracy of landscape level predictions in our LCT approach, this indicates challenges in the spatial extrapolation of some of those vegetation and soil attributes that are relevant for the regional ecosystem and global climate models.

Comparison of different focusing fiber tips for improved oral diode laser surgery.

PubMed

Stock, Karl; Stegmayer, Thomas; Graser, Rainer; Förster, Wolfram; Hibst, Raimund

2012-12-01

State of the art for use of the fiber guided diode laser in dental therapy is the application of bare fibers. A novel concept with delivery fiber and exchangeable fiber tips enables the use of tips with special and optimized geometries for various applications. The aim of this study is the comparison of different focusing fiber tips for enhanced cutting efficacy in oral surgery. For this purpose various designs of tip geometry were investigated and optimized by ray tracing simulations. Two applicators, one with a sphere, and another one with a taper, were realized and tested on porcine gingiva (diode laser, 940 nm, 5 W/cw; 7 W/modulated). The cutting depth and quality were determined by light microscope. Histological sections of the cuts were prepared by a cryo-microtome and microscopically analyzed to determine the cut depths and thermal damage zones. The simulations show that, using a sphere as fiber tip, an intensity increase of up to a factor of 16.2 in air, and 13.2 in water compared to a bare 200 µm fiber can be achieved. Although offering high focusing factor in water, the cutting quality of the sphere was rather poor. This is probably caused by a derogation of the focusing quality due to contamination during cutting and light scattering. Much better results were achieved with conically shaped fiber tips. Compared to bare fibers they exhibit improved handling properties with no hooking, more regular and deeper cuts (5 W/cw: 2,393 ± 468 µm, compared to the cleaved bare fiber 5 W/cw: 711 ± 268 µm). The thermal damage zones of the cuts are comparable for the various tips and fibers. In conclusion the results of our study show that cutting quality and efficiency of diode laser on soft tissue can be significantly improved using conically shaped fiber tips. Copyright © 2012 Wiley Periodicals, Inc.

Tumor targeting efficiency of bare nanoparticles does not mean the efficacy of loaded anticancer drugs: importance of radionuclide imaging for optimization of highly selective tumor targeting polymeric nanoparticles with or without drug.

PubMed

Lee, Beom Suk; Park, Kyeongsoon; Park, Sangjin; Kim, Gui Chul; Kim, Hyo Jung; Lee, Sangjoo; Kil, Heeseup; Oh, Seung Jun; Chi, Daeyoon; Kim, Kwangmeyung; Choi, Kuiwon; Kwon, Ick Chan; Kim, Sang Yoon

2010-10-15

The better understanding of polymeric nanoparticles as a drug delivery carrier is a decisive factor to get more efficient therapeutic response in vivo. Here, we report the non-invasive imaging of bare polymeric nanoparticles and drug-loaded polymeric nanoparticles to evaluate biodistribution in tumor bearing mice. To make nano-sized drug delivery carrier, glycol chitosan was modified with different degrees of hydrophobic N-acetyl histidine (NAcHis-GC-1, -2, and -3). The biodistribution of polymeric nanoparticles and drug was confirmed by using gamma camera with (131)I-labeled NAcHis-GC and (131)I-labeled doxorubicin (DOX) and by using in vivo live animal imaging with near-infrared fluorescence Cy5.5-labeled NAcHis-GC. Among bare nanoparticles, NAcHis-GC3 (7.8% NAcHis content) showed much higher tumor targeting efficiency than NAcHis-GC1 (3.3% NAcHis content) and NAcHis-GC2 (6.8% NAcHis content). In contrast, for drug-loaded nanoparticles, DOX-NAcHis-GC1 displayed two-fold higher tumor targeting property than DOX-NAcHis-GC3. These data imply that the biodistribution and tumor targeting efficiency between bare and drug-loaded nanoparticles may be greatly different. Therapeutic responses for NAcHis-GC nanoparticles after drug loading were also evaluated. In xenograft animal model, we could find out that DOX-NAcHis-GC1 with higher tumor targeting of DOX has more excellent therapeutic effect than DOX-NAcHis-GC3 and free DOX. These results mean that the hydrophobic core stability might be a critical factor for tumor targeting efficiency of nanoparticles. The present study indicates that by using molecular imaging, we can select more appropriate nanoparticles with the highest tumor targeting properties, leading to exerting more excellent therapeutic results in cancer therapy. Copyright © 2010 Elsevier B.V. All rights reserved.

Interaction of fullerene (C60) nanoparticles with humic acid and alginate coated silica surfaces: measurements, mechanisms, and environmental implications.

PubMed

Chen, Kai Loon; Elimelech, Menachem

2008-10-15

The deposition kinetics of fullerene (C60) nanoparticles onto bare silica surfaces and surfaces precoated with humic acid and alginate are investigated over a range of monovalent (NaCI) and divalent (CaCl2) salt concentrations using a quartz crystal microbalance. Because simultaneous aggregation of the fullerene nanoparticles occurs, especially at higher electrolyte concentrations, we normalize the observed deposition rates by the corresponding favorable (transport-limited) deposition rates to obtain the attachment efficiencies, alpha. The deposition kinetics of fullerene nanoparticles onto bare silica surfaces are shown to be controlled by electrostatic interactions and van der Waals attraction, consistent with the classical particle deposition behavior where both favorable and unfavorable deposition regimes are observed. The presence of dissolved humic acid and alginate in solution leads to significantly slower deposition kinetics due to steric repulsion. Precoating the silica surfaces with humic acid and alginate exerts similar steric stabilization in the presence of NaCl. In the presence of CaCl2, the deposition kinetics of fullerene nanoparticles onto both humic acid- and alginate-coated surfaces are relatively high, even at relatively low (0.3 mM) calcium concentration. This behavior is attributed to the macromolecules undergoing complex formation with calcium ions, which reduces the charge and steric influences of the adsorbed macromolecular layers.

Design and Use of a Guided Weight Impactor to Impart Barely Visible Impact Damage

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Przekop, Adam

2016-01-01

Aircraft structure is required to demonstrate satisfaction of the FAR requirements for Category 1, such as barely visible impact damage (BVID). Typical aircraft structure is impacted using a dropped weight impactor, which can impart BVID to the top surface of the structure. A recent test of a multi-bay box (MBB) composite test article, that represents an 80% scale center section of a hybrid wing body aircraft, required impact to be in a direction other than vertical from above, but still in an direction that is normal to the surface. This requirement eliminated the use of the conventional dropped weight impactor. Therefore, a design study was undertaken to determine the most effective way to efficiently and reliably impact the MBB. The chosen design was a guided weight impactor that is gravity driven. This paper describes the design of the guided weight impactor, and presents the results of its use for imparting BVID to the MBB. The guided weight impactor was seen to be a very reliable method to impart BVID, while at the same time having the capability to be highly configurable for use on other aircraft structure that is impacted at a variety of impact energies and from a variety of directions.

Normal and frictional interactions of purified human statherin adsorbed on molecularly-smooth solid substrata.

PubMed

Harvey, Neale M; Carpenter, Guy H; Proctor, Gordon B; Klein, Jacob

2011-09-01

Human salivary statherin was purified from parotid saliva and adsorbed to bare hydrophilic (HP) mica and STAI-coated hydrophobic (HB) mica in a series of Surface Force Balance experiments that measured the normal (F(n)) and friction forces (F(s)*) between statherin-coated mica substrata. Readings were taken both in the presence of statherin solution (HP and HB mica) and after rinsing (HP mica). F(n) measurements showed, for both substrata, monotonic steric repulsion that set on at a surface separation D ~20 nm, indicating an adsorbed layer whose unperturbed thickness was ca 10 nm. An additional longer-ranged repulsion, probably of electrostatic double-layer origin, was observed for rinsed surfaces under pure water. Under applied pressures of ~1 MPa, each surface layer was compressed to a thickness of ca 2 nm on both types of substratum, comparable with earlier estimates of the size of the statherin molecule. Friction measurements, in contrast with F(n) observations, were markedly different on the two different substrata: friction coefficients, μ ≡ ∂F(s)*/∂F(n), on the HB substratum (μ ≈ 0.88) were almost an order of magnitude higher than on the HP substratum (μ ≈ 0.09 and 0.12 for unrinsed and rinsed, respectively), and on the HB mica there was a lower dependence of friction on sliding speed than on the HP mica. The observations were attributed to statherin adsorbing to the mica in multimer aggregates, with internal re-arrangement of the protein molecules within the aggregate dependent on the substratum to which the aggregate adsorbed. This internal re-arrangement permitted aggregates to be of similar size on HP and HB mica but to have different internal molecular orientations, thus exposing different moieties to the solution in each case and accounting for the very different friction behaviour.

Russia: Saratov

Atmospheric Science Data Center

2013-04-17

... to differences in brightness and texture between bare soil and vegetated land. The chestnut-colored soils in this region are brighter ... of vegetation relative to the nadir camera, which sees more soil. In spring, therefore, the scene is brightest in the vertical view and ...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to... officials; (2) Map or diagram indicating location of power wires and cables required to be insulated; (3...

30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare...

30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802... Wires and Trolley Feeder Wires § 77.1802 Insulation of trolley wires, trolley feeder wires and bare...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2010 CFR

2010-07-01

... wires and cables. 75.517-2 Section 75.517-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to...

30 CFR 75.517-2 - Plans for insulation of existing bare power wires and cables.

Code of Federal Regulations, 2011 CFR

2011-07-01

... wires and cables. 75.517-2 Section 75.517-2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... Equipment-General § 75.517-2 Plans for insulation of existing bare power wires and cables. (a) On or before December 31, 1970, plans for the insulation of existing bare power wires and cables installed prior to...

Simulation of boreal Summer Monsoon Rainfall using CFSV2_SSiB model: sensitivity to Land Use Land Cover (LULC)

NASA Astrophysics Data System (ADS)

Chilukoti, N.; Xue, Y.

2016-12-01

The land surface play a vital role in determining the surface energy budget, accurate representation of land use and land cover (LULC) is necessary to improve forecast. In this study, we have investigated the influence of surface vegetation maps with different LULC on simulating the boreal summer monsoon rainfall. Using a National Centres for Environmental Prediction (NCEP) Coupled Forecast System version 2(CFSv2) model coupled with Simplified Simple Biosphere (SSiB) model, two experiments were conducted: one with old vegetation map and one with new vegetation map. The significant differences between new and old vegetation map were in semi-arid and arid areas. For example, in old map Tibetan plateau classified as desert, which is not appropriate, while in new map it was classified as grasslands or shrubs with bare soil. Old map classified the Sahara desert as a bare soil and shrubs with bare soil, whereas in new map it was classified as bare ground. In addition to central Asia and the Sahara desert, in new vegetation map, Europe had more cropped area and India's vegetation cover was changed from crops and forests to wooded grassland and small areas of grassland and shrubs. The simulated surface air temperature with new map shows a significant improvement over Asia, South Africa, and northern America by some 1 to 2ºC and 2 to 3ºC over north east China and these are consistent with the reduced rainfall biases over Africa, near Somali coast, north east India, Bangladesh, east China sea, eastern Pacific and northern USA. Over Indian continent and bay of Bengal dry rainfall anomalies that is the only area showing large dry rainfall bias, however, they were unchanged with new map simulation. Overall the CFSv2(coupled with SSiB) model with new vegetation map show a promising result in improving the monsoon forecast by improving the Land -Atmosphere interactions. To compare with the LULC forcing, experiment was conducted using the Global Forecast System (GFS) simulations forced with different observed Sea Surface Temperatures (SST) for the same period: one is from NCEP reanalysis and one from Hadley Center. They have substantial difference in Indian Ocean. Preliminary analysis shows that, the impact of these two SST data sets on Indian summer monsoon rainfall has no significant impact.

Normal Skeletal Maturation and Imaging Pitfalls in the Pediatric Shoulder.

PubMed

Zember, Jonathan S; Rosenberg, Zehava S; Kwong, Steven; Kothary, Shefali P; Bedoya, Maria A

2015-01-01

A growing number of magnetic resonance (MR) imaging studies of the shoulder are being performed as a result of greater and earlier participation of children and adolescents in competitive sports such as softball and baseball. However, scant information is available regarding the MR imaging features of the normal sequential development of the shoulder. The authors discuss the radiographic and MR imaging appearances of the normal musculoskeletal maturation patterns of the shoulder, with emphasis on (a) development of secondary ossification centers of the glenoid (including the subcoracoid and peripheral glenoid ossification centers); (b) development of preossification and secondary ossification centers of the humeral head and the variable appearance and number of the secondary ossification centers of the distal acromion, with emphasis on the formation of the os acromiale; (c) development of the growth plates, glenoid bone plates, glenoid bare area, and proximal humeral metaphyseal stripe; and (d) marrow signal alterations in the distal humerus, acromion, and clavicle. In addition, the authors discuss various imaging interpretation pitfalls inherent to the normal skeletal maturation of the shoulder, examining clues that may help distinguish normal development from true disease (eg, osteochondral lesions, labral tears, abscesses, fractures, infection, tendon disease, acromioclavicular widening, and os acromiale). Familiarity with the timing, location, and appearance of maturation patterns in the pediatric shoulder is crucial for correct image interpretation. ©RSNA, 2015.

The α-effect in gas-phase SN2 reactions of microsolvated anions: methanol as a solvent.

PubMed

Thomsen, Ditte L; Reece, Jennifer N; Nichols, Charles M; Hammerum, Steen; Bierbaum, Veronica M

2014-09-18

The α-effect, an enhanced reactivity of nucleophiles with a lone-pair adjacent to the reaction center, has been studied in solution for several decades. The gas-phase α-effect has recently been documented in studies of SN2 reactions as well as in competing reactions for both bare and microhydrated anions. In the present work we extend our studies of the significance of microsolvation on the α-effect, employing methanol as the solvent, in the expectation that the greater stability of the methanol cluster relative to the water cluster will lower the reactivity and thereby allow studies over a wider efficiency range. We compare the gas-phase reactivity of the microsolvated α-nucleophile HOO(-)(CH3OH) to that of microsolvated normal alkoxy nucleophiles, RO(-)(CH3OH) in reactions with CH3Cl and CH3Br. The results reveal enhanced reactivity of HOO(-)(CH3OH) toward both methyl halides relative to the normal nucleophiles, and clearly demonstrate the presence of an α-effect for the microsolvated α-nucleophile. The highly exothermic reactions with methyl bromide result in a smaller Brønsted βnuc value than observed for methyl chloride, and the α-effect in turn influences the reactions with methyl chloride more than with methyl bromide. Computational investigations reveal that reactions with methyl bromide proceed through earlier transition states with less advanced bond formation compared to the related reactions of methyl chloride. In addition, solvent interactions for HOO(-) are quite different from those with the normal nucleophiles at the transition state, indicating that differential solvation may well contribute to the α-effect. The greater thermodynamic and kinetic stability of the anion-methanol clusters relative to the anion-water clusters accounts well for the differences in the influence of solvation with the two protic polar solvents.

Dispersion and stability of bare hematite nanoparticles: effect of dispersion tools, nanoparticle concentration, humic acid and ionic strength

PubMed Central

Dickson, Dionne; Liu, Guangliang; Li, Chenzhong; Tachiev, Georgio; Cai, Yong

2012-01-01

The aggregation and sedimentation of iron oxide nanoparticles (IONPs) can significantly affect the mobility and reactivity of IONPs and subsequently influence the interaction between IONPs and environmental contaminants. Dispersing bare IONPs into a stable suspension within nanoscale range is an important step for studying the interaction of IONPs with contaminants (e.g., toxic metals). In this study, different techniques to disperse bare IONPs (vortex, bath sonication and probe ultrasonication) and the effects of important environmental factors such as dissolved organic matter and ionic strength on the stability of IONPs dispersions were investigated. Vortex minimally dispersed IONPs with hydrodynamic diameter outside the “nanosize range” (698–2400nm). Similar to vortex, bath sonication could not disperse IONPs efficiently. Probe ultrasonication was more effective at dispersing IONPs (50% or more) with hydrodynamic diameters ranging from 120–140 nm with minimal changes in size and sedimentation of IONPs for a prolonged period of time. Over the course of 168 hours, considerable amounts of IONPs remained dispersed in the presence and absence of low ionic strength (0.1 mM of NaCl) and 100 mg/L of humic acid (HA). These results indicate that IONPs can be broken down efficiently into “nanosize range” by probe ultrasonication and a degree of stability can be achieved without the use of synthetic modifiers to enhance colloidal stability. This dispersion tool could be used to develop a laboratory method to study the adsorption mechanism between dispersed bare IONPs and toxic contaminants. PMID:22289174

Heterogeneity of soil surface temperature induced by xerophytic shrub in a revegetated desert ecosystem, northwestern China

NASA Astrophysics Data System (ADS)

Zhang, Ya-Feng; Wang, Xin-Ping; Pan, Yan-Xia; Hu, Rui; Zhang, Hao

2013-06-01

Variation characteristics of the soil surface temperature induced by shrub canopy greatly affects the near-surface biological and biochemical processes in desert ecosystems. However, information regarding the effects of shrub upon the heterogeneity of soil surface temperature is scarce. Here we aimed to characterize the effects of shrub ( Caragana korshinskii) canopy on the soil surface temperature heterogeneity at areas under shrub canopy and the neighbouring bare ground. Diurnal variations of soil surface temperature were measured at areas adjacent to the shrub base (ASB), beneath the midcanopy (BMC), and in the bare intershrub spaces (BIS) at the eastern, southern, western and northern aspects of shrub, respectively. Results indicated that diurnal mean soil surface temperature under the C. korshinskii canopy (ASB and BMC) was significantly lower than in the BIS, with the highest in the BIS, followed by the BMC and ASB. The diurnal maximum and diurnal variations of soil surface temperatures under canopy vary strongly with different aspects of shrub with the diurnal variation in solar altitude, which could be used as cues to detect safe sites for under-canopy biota. A significant empirical linear relationship was found between soil surface temperature and solar altitude, suggesting an empirical predicator that solar altitude can serve for soil surface temperature. Lower soil surface temperatures under the canopy than in the bare intershrub spaces imply that shrubs canopy play a role of `cool islands' in the daytime in terms of soil surface temperature during hot summer months in the desert ecosystems characterized by a mosaic of sparse vegetation and bare ground.

In situ absorptivity measurements of metallic powders during laser powder-bed fusion additive manufacturing

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

Trapp, Johannes; Rubenchik, Alexander M.; Guss, Gabe

Here, the effective absorptivity of continuous wave 1070 nm laser light has been studied for bare and metal powder-coated discs of 316L stainless steel as well as for aluminum alloy 1100 and tungsten by use of direct calorimetric measurements. After carefully validating the applicability of the method, the effective absorptivity is plotted as a function of incident laser power from 30 up to ≈540 W for scanning speeds of 100, 500 and 1500 mm s –1. The effective absorptivity versus power curves of the bulk materials typically show a slight change in effective absorptivity from 30 W until the onsetmore » of the formation of a recoil pressure-induced surface depression. As observed using high-speed video, this change in surface morphology leads to an increase in absorption of the laser light. At the higher powers beyond the keyhole transition, a saturation value is reached for both bare discs and powder-coated disks. For ≈100 μm thick powder layers, the measured absorptivity was found to be two times that of the bare polished discs for low-laser power. There is a sharp decrease when full melting of the powder tracks is achieved, followed by a keyhole-driven increase at higher powers, similar to the bare disc case. It is shown that, under conditions associated with laser powder-bed fusion additive manufacturing, absorptivity values can vary greatly, and differ from both powder-layer measurements and liquid metal estimates from the literature.« less

In situ absorptivity measurements of metallic powders during laser powder-bed fusion additive manufacturing

DOE PAGES

Trapp, Johannes; Rubenchik, Alexander M.; Guss, Gabe; ...

2017-09-17

Here, the effective absorptivity of continuous wave 1070 nm laser light has been studied for bare and metal powder-coated discs of 316L stainless steel as well as for aluminum alloy 1100 and tungsten by use of direct calorimetric measurements. After carefully validating the applicability of the method, the effective absorptivity is plotted as a function of incident laser power from 30 up to ≈540 W for scanning speeds of 100, 500 and 1500 mm s –1. The effective absorptivity versus power curves of the bulk materials typically show a slight change in effective absorptivity from 30 W until the onsetmore » of the formation of a recoil pressure-induced surface depression. As observed using high-speed video, this change in surface morphology leads to an increase in absorption of the laser light. At the higher powers beyond the keyhole transition, a saturation value is reached for both bare discs and powder-coated disks. For ≈100 μm thick powder layers, the measured absorptivity was found to be two times that of the bare polished discs for low-laser power. There is a sharp decrease when full melting of the powder tracks is achieved, followed by a keyhole-driven increase at higher powers, similar to the bare disc case. It is shown that, under conditions associated with laser powder-bed fusion additive manufacturing, absorptivity values can vary greatly, and differ from both powder-layer measurements and liquid metal estimates from the literature.« less

Microscopic characterization of tension wood cell walls of Japanese beech (Fagus crenata) treated with ionic liquids.

PubMed

Kanbayashi, Toru; Miyafuji, Hisashi

2016-09-01

Tension wood that is an abnormal part formed in angiosperms has been barely used for wood industry. In this study, to utilize the tension wood effectively by means of liquefaction using ionic liquid, we performed morphological and topochemical determination of the changes in tension wood of Japanese beech (Fagus crenata) during ionic liquid treatment at the cellular level using light microscopy, scanning electron microscopy and confocal Raman microscopy. Ionic liquid treatment induced cell wall swelling in tension wood. Changes in the tissue morphology treated with ionic liquids were different between normal wood and tension wood, moreover the types of ionic liquids. The ionic liquid 1-ethyl-3-methylimidazolium chloride liquefied gelatinous layers rapidly, whereas 1-ethylpyridinium bromide liquefied slowly but delignified selectively. These novel insights into the deconstruction behavior of tension wood cell walls during ionic liquid treatment provide better understanding of the liquefaction mechanism. The obtained knowledge will contribute to development of an effective chemical processing of tension wood using ionic liquids and lead to efficient use of wood resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

Manipulation of polarization anisotropy in bare InAs and InAs/GaSb core-shell nanowires

NASA Astrophysics Data System (ADS)

Patra, Atanu; Roy, Anushree; Gomes, Umesh Prasad; Zannier, Valentina; Ercolani, Daniele; Sorba, Lucia

2018-04-01

In this article, we compare the excitation wavelength dependence of the polarization anisotropy (ρ) of an internal field induced Raman scattering signal in individual bare InAs and InAs/GaSb core-shell nanowires. The measured value of ρ of the Raman scattering intensity for InAs/GaSb core-shell nanowires has a minimum at ˜500 nm, while for the bare InAs nanowire, the value of ρ monotonically increases over the same range of wavelengths. We have modeled the scattering intensities of both systems by considering the joint role of Raman tensor components and confinement of electromagnetic radiation inside the nanowire at two orthogonal polarization configurations of the electromagnetic radiation. The theoretical results allow us to understand that the observed behavior of ρ is related to the nanowire geometry and to the difference in the wavelength dependence of the dielectric constants of InAs and GaSb. This work shows the possibility of manipulating the polarization anisotropy by selecting suitable diameters and materials for the core and the shell of the nanowire. We also report a six-fold increase in Raman scattering intensity due to the GaSb shell on InAs nanowires.

Computerized analysis of plantar pressure variation in flip-flops, athletic shoes, and bare feet.

PubMed

Carl, Tanya J; Barrett, Stephen L

2008-01-01

High peak plantar pressures predispose to foot problems and may exacerbate existing conditions. For podiatric physicians to make educated recommendations to their patients, it is important and necessary to begin to look at different shoes and how they affect peak plantar pressure. To determine how flip-flops change peak plantar pressure while walking, we compared peak plantar pressures in the same test subjects wearing flip-flops, wearing athletic shoes, and in bare feet. Ten women with size 7 feet and a body mass index less than 25 kg/m2 were tested with an in-shoe pressure-measurement system. These data were collected and analyzed by one-way analysis of variance and computer software. Statistically significant results were obtained for nine of the 18 comparisons. In each of these comparisons, flip-flops always demonstrated higher peak plantar pressures than athletic shoes but lower pressures than bare feet. Although these data demonstrate that flip-flops have a minor protective role as a shock absorber during the gait cycle compared with pressures measured while barefoot, compared with athletic shoes, they increase peak plantar pressures, placing the foot at greater risk for pathologic abnormalities.

Nucleon resonance structure in the finite volume of lattice QCD

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

Wu, Jia -Jun; Kamano, H.; Lee, T. -S. H.

An approach for relating the nucleon resonances extracted from πN reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of πN reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance can be related to the probability P N*(E) of finding the bare state, N*, in the πN scattering states in infinite volume. We further demonstrate that the probability P V N*(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches P N*(E) as the volumemore » increases. Our findings suggest that the comparison of P N*(E) and P V N*(E) can be used to examine whether the nucleon resonances extracted from the πN reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of P V N*(E) directly from lattice QCD. Furthermore, the practical differences between our approach and the approach using the Lüscher formalism to relate LQCD calculations to the nucleon resonance poles embedded in the data are also discussed.« less

Nucleon resonance structure in the finite volume of lattice QCD

DOE PAGES

Wu, Jia -Jun; Kamano, H.; Lee, T. -S. H.; ...

2017-06-19

An approach for relating the nucleon resonances extracted from πN reaction data to lattice QCD calculations has been developed by using the finite-volume Hamiltonian method. Within models of πN reactions, bare states are introduced to parametrize the intrinsic excitations of the nucleon. We show that the resonance can be related to the probability P N*(E) of finding the bare state, N*, in the πN scattering states in infinite volume. We further demonstrate that the probability P V N*(E) of finding the same bare states in the eigenfunctions of the underlying Hamiltonian in finite volume approaches P N*(E) as the volumemore » increases. Our findings suggest that the comparison of P N*(E) and P V N*(E) can be used to examine whether the nucleon resonances extracted from the πN reaction data within the dynamical models are consistent with lattice QCD calculation. We also discuss the measurement of P V N*(E) directly from lattice QCD. Furthermore, the practical differences between our approach and the approach using the Lüscher formalism to relate LQCD calculations to the nucleon resonance poles embedded in the data are also discussed.« less

Electronic Structure and I- V Characteristics of InSe Nanoribbons

NASA Astrophysics Data System (ADS)

Yao, A.-Long; Wang, Xue-Feng; Liu, Yu-Shen; Sun, Ya-Na

2018-04-01

We have studied the electronic structure and the current-voltage ( I-V) characteristics of one-dimensional InSe nanoribbons using the density functional theory combined with the nonequilibrium Green's function method. Nanoribbons having bare or H-passivated edges of types zigzag (Z), Klein (K), and armchair (A) are taken into account. Edge states are found to play an important role in determining their electronic properties. Edges Z and K are usually metallic in wide nanoribbons as well as their hydrogenated counterparts. Transition from semiconductor to metal is observed in hydrogenated nanoribbons HZZH as their width increases, due to the strong width dependence of energy difference between left and right edge states. Nevertheless, electronic structures of other nanoribbons vary with the width in a very limited scale. The I-V characteristics of bare nanoribbons ZZ and KK show strong negative differential resistance, due to spatial mismatch of wave functions in energy bands around the Fermi energy. Spin polarization in these nanoribbons is also predicted. In contrast, bare nanoribbons AA and their hydrogenated counterparts HAAH are semiconductors. The band gaps of nanoribbons AA (HAAH) are narrower (wider) than that of two-dimensional InSe monolayer and increase (decrease) with the nanoribbon width.

The energetic and chemical fingerprints of persistent soil organic carbon

NASA Astrophysics Data System (ADS)

Barré, Pierre; Plante, Alain F.; Cécillon, Lauric; Lutfalla, Suzanne; Baudin, François; Bernard, Sylvain; Christensen, Bent T.; Fernandez, Jose M.; Houot, Sabine; Kätterer, Thomas; Macdonald, Andy; van Oort, Folkert; Le Guillou, Corentin; Chenu, Claire

2016-04-01

A better understanding of soil organic carbon (SOC) persistence is needed to better predict SOC vulnerability to global change. The absence of convincing physical or chemical procedures to define, characterize or isolate relatively labile versus persistent SOC pools makes the study of persistent SOC difficult. Long-term bare fallow (LTBF) experiments, in which C inputs have been stopped for several decades, provide a unique opportunity to study persistent SOC without the inherent artefacts induced by extraction procedures, the hypothesis being that SOC is gradually enriched in persistent C with time as labile components decompose. We determined the evolution of thermal and chemical characteristics of bulk SOC in five LTBF experiments across Europe: Askov (DK), Grignon (FR), Rothamsted (UK), Ultuna (SW) and Versailles (FR), using a multi-technique approach involving Rock-Eval pyrolysis, thermogravimetry and differential scanning calorimetry (TG-DSC), mid-infrared diffuse reflectance spectroscopy (DRIFT-MIRS), and Near Edge X-Ray Absorption Fine Structure (NEXAFS). Results of Rock-Eval and TG analyses showed that the temperature needed to combust the SOC increased with bare fallow duration at all sites. Conversely, SOC energy density (in mJ mg-1 C) measured by DSC decreased with bare fallow duration. Rock-Eval pyrolysis results showed that hydrogen index (HI) tended to decrease with bare fallow duration whereas the oxygen index (OI) did not show consistent trends across sites. NEXAFS signals presented little differences and were dominated by carboxyl peak. Nonetheless, NEXAFS results showed a trend of increasing carboxyl groups and decreasing ketone and amide groups with bare fallow duration. Due to the mineral matrix, only a reduced part of the DRIFT-MIRS signals has been used. We observed that the bulk chemistry of aliphatic SOC (CH3 vs. CH2 functional groups) showed different trends for the different sites. Our results showed that in spite of the heterogeneity of the soils at the 5 LTBF sites, organic carbon that has persisted in soils for several decades have similar and defined thermal and energetic properties: persistent SOC burns at higher temperature and its combustion generates less energy. Persistent SOC in the studied temperate soils also shares some chemical properties: it has a lower HI values and is consistently enriched in carboxyl groups. Nonetheless, the chemical trends were less obvious than the results given by thermal techniques confirming that organo-mineral interactions are the key driver of long-term SOC stabilization. The increased burning temperature and lower energy density of persistent SOC suggest that SOC stability may be a function of the high energy cost and low energy gain from decomposition of this material. It also suggests that decomposition of the stable C pool should be more temperature sensitive and thus vulnerable to increased temperature as previously observed in several incubation studies.

Hyperspectral analysis of seagrass in Redfish Bay, Texas

NASA Astrophysics Data System (ADS)

Wood, John S.

Remote sensing using multi- and hyperspectral imaging and analysis has been used in resource management for quite some time, and for a variety of purposes. In the studies to follow, hyperspectral imagery of Redfish Bay is used to discriminate between species of seagrasses found below the water surface. Water attenuates and reflects light and energy from the electromagnetic spectrum, and as a result, subsurface analysis can be more complex than that performed in the terrestrial world. In the following studies, an iterative process is developed, using ENVI image processing software and ArcGIS software. Band selection was based on recommendations developed empirically in conjunction with ongoing research into depth corrections, which were applied to the imagery bands (a default depth of 65 cm was used). Polygons generated, classified and aggregated within ENVI are reclassified in ArcGIS using field site data that was randomly selected for that purpose. After the first iteration, polygons that remain classified as 'Mixed' are subjected to another iteration of classification in ENVI, then brought into ArcGIS and reclassified. Finally, when that classification scheme is exhausted, a supervised classification is performed, using a 'Maximum Likelihood' classification technique, which assigned the remaining polygons to the classification that was most like the training polygons, by digital number value. Producer's Accuracy by classification ranged from 23.33 % for the 'MixedMono' class to 66.67% for the 'Bare' class; User's Accuracy by classification ranged from 22.58% for the 'MixedMono' class to 69.57% for the 'Bare' classification. An overall accuracy of 37.93% was achieved. Producers and Users Accuracies for Halodule were 29% and 39%, respectively; for Thalassia, they were 46% and 40%. Cohen's Kappa Coefficient was calculated at .2988. We then returned to the field and collected spectral signatures of monotypic stands of seagrass at varying depths and at three sensor levels: above the water surface, just below the air/water interface, and at the canopy position, when it differed from the subsurface position. Analysis of plots of these spectral curves, after applying depth corrections and Multiplicative Scatter Correction, indicates that there are detectable spectral differences between Halodule and Thalassia species at all three positions. Further analysis indicated that only above-surface spectral signals could reliably be used to discriminate between species, because there was an overlap of the standard deviations in the other two positions. A recommendation for wavelengths that would produce increased accuracy in hyperspectral image analysis was made, based on areas where there is a significant amount of difference between the mean spectral signatures, and no overlap of the standard deviations in our samples. The original hyperspectral imagery was reprocessed, using the bands recommended from the research above (approximately 535, 600, 620, 638, and 656 nm). A depth raster was developed from various available sources, which was resampled and reclassified to reflect values for water absorption and water scattering, which were then applied to each band using the depth correction algorithm. Processing followed the iterative classification methods described above. Accuracy for this round of processing improved; overall accuracy increased from 38% to 57%. Improvements were noted in Producer's Accuracy, with the 'Bare' vi classification increasing from 67% to 73%, Halodule increasing from 29% to 63%, Thalassia increasing slightly, from 46% to 50%, and 'MixedMono' improving from 23% to 42%. User's Accuracy also improved, with the 'Bare' class increasing from 69% to 70%, Halodule increasing from 39% to 67%, Thalassia increasing from 40% to 7%, and 'MixedMono' increasing from 22.5% to 35%. A very recent report shows the mean percent cover of seagrasses in Redfish Bay and Corpus Christi Bay combined for all species at 68.6%, and individually by species: Halodule 39.8%, Thalassia 23.7%, Syringodium 4%, Ruppia 1% and Halophila 0.1%. Our study classifies 15% as 'Bare', 23% Halodule, 18% Thalassia, and 2% Ruppia. In addition, we classify 5% as 'Mixed', 22% as 'MixedMono', 12% as 'Bare/Halodule Mix', and 3% 'Bare/Thalassia Mix'. Aggregating the 'Bare' and 'Bare/species' classes would equate to approximately 30%, very close to what this new study produces. Other classes are quite similar, when considering that their study includes no 'Mixed' classifications. This series of research studies illustrates the application and utility of hyperspectral imagery and associated processing to mapping shallow benthic habitats. It also demonstrates that the technology is rapidly changing and adapting, which will lead to even further increases in accuracy. Future studies with hyperspectral imaging should include extensive spectral field collection, and the application of a depth correction.

Environmental and alloying effects on corrosion of metals and alloys

NASA Astrophysics Data System (ADS)

Liang, Dong

2009-12-01

In the first part of this project, corrosion studies were carried out on 304L stainless steel samples welded with Cr-free consumables, which were developed to minimize the concentration of chromate species in the weld fume. The corrosion properties of Ni-Cu and Ni-Cu-Pd Gas Tungsten Arc (GTA) welds and Shielded Metal Arc (SMA) welds are comparable to those of welds fabricated with SS308L consumable, which is the standard consumable for welding 304L. Although the breakdown potentials of the new welds from both welding processes are lower than that of the SS308L weld, the repassivation potential of these new welds is much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Our studies showed that the Ni-Cu and Ni-Cu-Pd welds are more resistant to crevice corrosion than SS308L welds, which is related to the high repassivation potential. Also, addition of Pd improved the corrosion resistance of the new welds, which is consistent with previous studies from button samples and bead-on-plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni-Cu-Pd welds can be a qualified substitute for SS308 weld. In the second part of this project, efforts are put on the connection between lab and field exposure tests because sometimes the correspondence between lab atmospheric corrosion tests (ASTM B117) and field exposures is poor as a result of differences in the critical conditions controlling chemical and electrochemical reactions on surfaces. Recent studies in atmospheric chemistry revealed the formation of extremely reactive species from interactions between UV light, chloride aerosols above oceans and oxidizing agents such as ozone or peroxide. Atmospheric corrosion of metals can be affected by these species which might be transported long distances in the atmosphere to locations far from oceans. However, these species could be missed in standard laboratory exposures such as ASTM B117. Initial efforts focused on the effects UV radiation, O3, relative humidity on the atmospheric corrosion of bare silver. Later work addressed the corrosion of silver samples deposited with NaCl particles. An exposure chamber that can simulate various environmental effects was built. The effects of UV radiation, O3, and relative humidity were varied separately while keeping the other factors the same level. The corrosion products were analyzed by the galvanostatic reduction method and characterization techniques such as SEM and EDS. It was found that both UV and O3 are necessary for fast corrosion on bare silver and this fast corrosion reaction results from atomic oxygen generated photodegradation of O3. In the presence of UV and O3, relative humidity has little effect on the atmospheric corrosion of bare silver in contrast to conventional atmospheric corrosion. The degree of corrosion is found to increase with O3 concentration. Moreover, a kinetic study of atmospheric corrosion of bare silver found that an incubation time for the atmospheric corrosion attack is needed. This incubation time is related to the chemisorption process of atomic oxygen. Though UV radiation can form reactive atomic oxygen which is more reactive than O3 alone as shown in the last chapter, the enhancement of corrosion by UV is limited for Ag with NaCl particles at low ozone concentration and high RH. The corrosion rate of silver with NaCl particles is found to increase with relative humidity, which is different than the case of bare silver. This indicates that different mechanisms control the atmospheric corrosion of silver. The incubation time for corrosion of silver with NaCl particles is shorter than for bare silver. This result from chemisorption of Cl 2 is favored over that of atomic oxygen. Interestingly, the total corrosion product of silver with NaCl particles is less than that of bare silver. This could be due to limited amount of NaCl and also higher oxidizing power of atomic oxygen. Finally, bare silver samples were exposed in salt spray chamber according to ASTM B117 up to 4 months. Very little corrosion products were detected after exposure, which is attributed to the lack of reactive species such as O and O3 in the environment. (Abstract shortened by UMI.)

Very late stent thrombosis in a bare-metal stent, 9 years after implantation.

PubMed

Almasswary, Adel A

2009-06-01

Very late bare-metal stent thrombosis occurring beyond one year after stenting is uncommon. We report a case of bare-metal stent thrombosis presenting as acute myocardial infarction. The patient's stent was implanted 9 years ago, however, he was not adherent to his antiplatelet therapy (aspirin). This case highlights the importance of antiplatelet therapy in patients with stents even many years after implantation.

Instructive Video Retrieval for Surgical Skill Coaching Using Attribute Learning

DTIC Science & Technology

2015-06-28

dance, sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited automated...including dance, sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited...sports, and surgery training. Most existing systems are either passive (for data capture only) or barely active (with limited automated feed- back to a

Endovenous laser ablation of the great saphenous vein using a bare fibre versus a tulip fibre: a randomised clinical trial.

PubMed

Vuylsteke, M E; Thomis, S; Mahieu, P; Mordon, S; Fourneau, I

2012-12-01

This clinical trial aimed to evaluate the clinical results of the use of a tulip fibre versus the use of a bare fibre for endovenous laser ablation. In a multicentre prospective randomised trial 174 patients were randomised for the treatment of great saphenous vein reflux. A duplex scan was scheduled 1 month, 6 months and 1 year postoperatively. Ecchymosis was measured on the 5th postoperative day. In addition, pain, analgesics requirement, postoperative quality of life (CIVIQ 2) and patient satisfaction rate were noted. Patients treated with a tulip fibre had significantly less postoperative ecchymosis (0.04 vs. 0.21; p < 0.001) and pain (5th day) (1.00 vs. 2.00; p < 0.001) and had a better postoperative quality of life (27 vs. 32; p = 0.023). There was no difference in analgesic intake (p = 0.11) and patient satisfaction rate (p = 0.564). The total occlusion rate at 1 year was 97.02% and there was no significant difference between the two groups (p = 0.309). Using a tulip fibre for EVLA of the great saphenous vein results, when compared with the use of a bare fibre, in equal occlusion rates at 1 year but causes less postoperative ecchymosis and pain and in a better postoperative quality of life. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Photoautotrophic organisms control microbial abundance and diversity in biological soil crusts

NASA Astrophysics Data System (ADS)

Tamm, Alexandra; Maier, Stefanie; Wu, Dianming; Caesar, Jennifer; Hoffman, Timm; Grube, Martin; Weber, Bettina

2017-04-01

Vascular vegetation is typically quite sparse or even absent in dryland ecosystems all over the world, but the ground surface is not bare and largely covered by biological soil crusts (referred to as biocrusts hereafter). These biocrust communities generally comprise poikilohydric organisms. They are usually dominated by photoautotrophic cyanobacteria, lichens and mosses, growing together with heterotrophic fungi, bacteria and archaea in varying composition. Cyanobacteria-, lichen- and moss-dominated biocrusts are known to stabilize the soil and to influence the water budgets and plant establishment. The autotrophic organisms take up atmospheric CO2, and (cyano-)bacteria fix atmospheric nitrogen. The intention of the present project was to study the relevance of the dominating photoautotrophic organisms for biocrust microbial composition and physiology. High-throughput sequencing revealed that soil microbiota of biocrusts largely differ from the bacterial community in bare soil. We observed that bacterial and fungal abundance (16S and 18S rRNA gene copy numbers) as well as alpha diversity was lowest in bare soil, and increasing from cyanobacteria-, and chlorolichen- to moss-dominated biocrusts. CO2 gas exchange measurements revealed large respiration rates of the soil in moss-dominated biocrusts, which was not observed for cyanobacteria- and chlorolichen-dominated biocrusts. Thus, soil respiration of moss-dominated biocrusts is mainly due to the activity of the microbial communities, whereas the microorganisms in the other biocrust types are either dormant or feature functionally different microbial communities. Our results indicate that biocrust type determines the pattern of microbial communities in the underlying soil layer.

Predictors of three-dimensional breast kinematics during bare-breasted running.

PubMed

Wood, Louise Ellen; White, Jennifer; Milligan, Alexandra; Ayres, Bessie; Hedger, Wendy; Scurr, Joanna

2012-07-01

This study aimed to analyze differences in breast kinematics between breast cup sizes during running and the ability of breast and body size measurements to explain these differences. Forty-eight women (A to G cup; mean ± SD: age = 26.0 ± 6.0 yr, stature = 1.667 ± 0.064 m, mass = 62.78 ± 8.24 kg) with chest sizes of 32 to 38 inches participated. Chest and breast girths, a restricted anthropometric profile, suprasternal notch to nipple distances, and body mass index were measured, and breast mass was estimated. Multiplanar relative breast displacement, velocity, and acceleration during treadmill running were then recorded. Differences in breast kinematics were compared between cup sizes before and after allometric/polynomial scaling using significant breast and body size measures. All kinematic variables significantly increased with breast cup size (P < 0.05). Mean anterior-posterior (a/p), medial-lateral (m/l), and vertical bare-breasted displacements ranged from 0.030 to 0.059 m, from 0.018 to 0.062 m, and from 0.042 to 0.099 m, respectively, across A to G cups. Breast velocities ranged from 0.428 to 1.244 m·s(-1) (a/p), 0.411 to 1.708 m·s(-1)(m/l), and 0.819 to 2.174 m·s(-1) (vertical), respectively. Increases in breast acceleration varied from 11.664 to 48.438 m·s(-1) (a/p), 15.572 to 51.987 m·s(-1) (m/l), and 23.301 to 66.447 m·s(-1) (vertical), respectively. Scaling models found that breast mass was the only anthropometric measure to consistently explain differences in breast kinematics between cup sizes. Bare-breasted kinematics significantly increased with cup size during running. Differences in breast displacement, velocity, and acceleration between cup sizes could be predicted using estimates of breast mass based on conventional brassiere sizing. These data inform the design and evaluation of effective bra support.

The potential of transferrin-pendant-type polyethyleneglycol liposomes encapsulating decahydrodecaborate-{sup 1}B (GB-10) as {sup 1}B-carriers for boron neutron capture therapy

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

Masunaga, Shin-ichiro; Kasaoka, Satoshi; Maruyama, Kazuo

2006-12-01

Purpose: To evaluate GB-10-encapsulating transferrin (TF)-pendant-type polyethyleneglycol (PEG) liposomes as tumor-targeting {sup 1}B-carriers for boron neutron capture therapy. Methods and Materials: A free mercaptoundecahydrododecaborate-{sup 1}B (BSH) or decahydrodecaborate-{sup 1}B (GB-10) solution, bare liposomes, PEG liposomes, or TF-PEG liposomes were injected into SCC VII tumor-bearing mice, and {sup 1}B concentrations in the tumors and normal tissues were measured by {gamma}-ray spectrometry. Meanwhile, tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all intratumor proliferating cells, then injected with these {sup 1}B-carriers containing BSH or GB-10 in the same manner. Right after thermal neutron irradiation, the response of quiescent (Q) cells wasmore » assessed in terms of the micronucleus frequency using immunofluorescence staining for BrdU. The frequency in the total tumor cells was determined from the BrdU nontreated tumors. Results: Transferrin-PEG liposomes showed a prolonged retention in blood circulation, low uptake by reticuloendothelial system, and the most enhanced accumulation of {sup 1}B in solid tumors. In general, the enhancing effects were significantly greater in total cells than Q cells. In both cells, the enhancing effects of GB-10-containing {sup 1}B-carriers were significantly greater than BSH-containing {sup 1}B-carriers, whether loaded in free solution or liposomes. In both cells, whether BSH or GB-10 was employed, the greatest enhancing effect was observed with TF-PEG liposomes followed in decreasing order by PEG liposomes, bare liposomes, and free BSH or GB-10 solution. In Q cells, the decrease was remarkable between PEG and bare liposomes. Conclusions: In terms of biodistribution characteristics and tumor cell-killing effect as a whole, including Q cells, GB-10 TF-PEG liposomes were regarded as promising {sup 1}B-carriers.« less

Generation and detection of pulsed T-rays for use in the study of biological and bioterrorism issues

NASA Astrophysics Data System (ADS)

Jedju, Thomas M.; Bosacchi, Bruno; Warren, Warren S.; Nahata, Ajay; Kuenstner, Todd

2004-09-01

Terahertz (T-rays) spectroscopy has recently emerged as a powerful method to access a heretofore barely explored region of the electromagnetic spectrum where fundamental molecular resonances occur. Besides their importance for fundamental research, these resonances could be used as signatures in the identification of molecular species and as sensitive probes in a wide variety of molecular processes. In this paper we consider the potential of THz spectroscopy in the application to relevant biomedical and homeland security problems such as the analysis of normal and diseased tissues and the detection of toxic biomolecules. As examples, we present preliminary experimental data which suggest that THz spectroscopy: 1) can discriminate between cancerous and normal tissue, and 2) can reveal the presence of foreign substances hidden in an envelope and even allow their specific identification. This capability is of particular relevance as a straightforward homeland security tool for the detection of anthrax and other biotoxic molecules.

Pre- and postoperative optical resolution of the cornea: a preliminary report

NASA Astrophysics Data System (ADS)

Parel, Jean-Marie A.; Simon, Gabriel; Rol, Pascal O.; Ren, Qiushi; Lee, William E.

1993-06-01

The effect of novel refractive surgical techniques on visual acuity and contrast sensitivity is normally determined by the outcome of human clinical trials. For example, ArF laser photorefractive keratoplasty follows an algorithm based on the patient's preoperative data for keratometry, refraction, pachometry, and ocular length all measured with ultrasound. A normalized ablation rate (which is function of the laser fluence), and the desired refractive correction are then used to calculate the ablation depth. On the day of surgery, the epithelium is mechanically removed and the bare cornea photoablated. Finally, the cornea may be medicated with a topical application of antibiotics and the eye is patched. On postoperative day 7, the epithelium is healed and visual acuity and keratometry are measured. With PRK, the theoretical outcome refraction should be within +/- 0.25 D. Thus far however, reproducibility is only of +/- 2 D. We believe the large discrepancy between theory and practice is due to several parameters that vary patient-to-patient.

Mystery of the Hidden Cosmos [Complex Dark Matter

DOE PAGES

Dobrescu, Bogdan A.; Lincoln, Don

2015-06-16

Scientists know there must be more matter in the universe than what is visible. Searches for this dark matter have focused on a single unseen particle, but decades of experiments have been unsuccessful at finding it. Exotic possibilities for dark matter are looking increasingly plausible. Rather than just one particle, dark matter could contain an entire world of particles and forces that barely interact with normal matter. Complex dark matter could form dark atoms and molecules and even clump together to make hidden galactic disks that overlap with the spiral arms of the Milky Way and other galaxies. Experiments aremore » under way to search for evidence of such a dark sector.« less

Compensating for environmental variability in the thermal inertia approach to remote sensing of soil moisture

NASA Technical Reports Server (NTRS)

Idso, S. B.; Jackson, R. D.; Reginato, R. J.

1976-01-01

A procedure is developed for removing data scatter in the thermal-inertia approach to remote sensing of soil moisture which arises from environmental variability in time and space. It entails the utilization of nearby National Weather Service air temperature measurements to normalize measured diurnal surface temperature variations to what they would have been for a day of standard diurnal air temperature variation, arbitrarily assigned to be 18 C. Tests of the procedure's basic premise on a bare loam soil and a crop of alfalfa indicate it to be conceptually sound. It is possible that the technique could also be useful in other thermal-inertia applications, such as lithographic mapping.

Behavior of plywood and fiberglass steel composite tube structures subjected to impact loading

NASA Astrophysics Data System (ADS)

Armaghani, Seyamend Bilind

Paratransit buses are custom built as the major vehicle manufacturer produces the custom built passenger cage installed on the chassis for the Paratransit bus. In order for these Paratransit bus members to be sufficient, they have to be evaluated for crashworthiness and energy absorption. This has prompted Florida Department of Transportation (FDOT) to fund research for the safety evaluation of Paratransit busses consisting of crash and safety analysis. There has been a large body of research done on steel subjected to static loads, but more research is needed for steel applied under dynamic loading and high speeds in order to improve crashworthiness in events such as rollovers and side impacts. Bare steel Hollow Structural Section (HSS) tubing are used a lot as structural members of Paratransit buses because of their lightness and progressive buckling under loading. The research will be conducted on quantifying the tubing's behavior under bending by conducting static three point bending and impact loading tests. In addition to the bare tubing, plywood and fiberglass composites are investigated because they are both strong and lightweight and their behavior under dynamic loading hasn't been quantified. As a result, the main purpose of this research is to quantify the differences between the dynamic and static behavior of plywood steel composite and fiberglass steel composite tubing and compare these findings with those of bare steel tubing. The differences will be quantified using detailed and thorough experiments that will examine the composites behavior under both static and dynamic loading. These tests will determine if there are any advantages of using the composite materials and thus allow for recommendations to be made to the FDOT with the goal of improving the safety of Paratransit busses. Tensile tests were conducted to determine the material properties of the tested specimens. Before the static and dynamic experiments are run to investigate the differences between static and dynamic behavior, Preliminary three point bending testing was conducted to determine the parameters for the final experiments. Static bending testing was conducted on the bare, plywood composite, and fiberglass composite steel tubing. The point of these experiments was to produce a Moment vs. Rotation plot to determine the specimens' maximum moments and their associated rotation, as that is when the steel buckles and fails. The dynamic three point bending experiments were conducted using the impact loading apparatus and had the same purpose as the static experiments. For both static and dynamic experiments, the performances of the different types of specimens were compared based upon their Moment vs. Rotation plots. This will determine the effect that the composite has on the rotation and maximum moment at which the tubing fails. After conducting these experiments, amplification factors were established for each specimen by comparing the maximum moment and their associated rotation between static and dynamic testing. lambda was calculated to quantify the ratio between the static and dynamic maximum moments. beta was used to quantify the ratio between the rotation needed to produce the maximum moment between static and dynamic events. A small amplification factor denotes that material performs well under impact loading and the material doesn't experience dramatic change in behavior during dynamic events. Amplification factors were compared between the bare, plywood, and fiberglass composite steel tubing in order to evaluate the performance of the composites. After comparing the amplification factors of the different types of tubing, recommendations can be made. Fiberglass and plywood composite were shown to be valuable because it decreased the effect of dynamic forces as beta was reduced by a factor of 2 in comparison to bare tubing. Based upon the amplification factors, it was recommended to use 14 gauge fiberglass composite tubing as Paratransit bus structural members because it was affected the least by dynamic loading.

Hybrid Materials for Thermal Management in Thin Films and Bulk Composites

DTIC Science & Technology

2012-02-01

enamel  that  cures  via  oxidative...polymerization   in   air  ( Enamel ),  a  waterborne  flat   latex  that  cures  by  coalescing  while  air  drying  (Flat...Wood   Bare   Primer   Primer   +  KPF6     Bare   Primer   Primer   +  KPF6     Bare   Primer   Enamel  

Sensitivity of spectral reflectance values to different burn and vegetation ratios: A multi-scale approach applied in a fire affected area

NASA Astrophysics Data System (ADS)

Pleniou, Magdalini; Koutsias, Nikos

2013-05-01

The aim of our study was to explore the spectral properties of fire-scorched (burned) and non fire-scorched (vegetation) areas, as well as areas with different burn/vegetation ratios, using a multisource multiresolution satellite data set. A case study was undertaken following a very destructive wildfire that occurred in Parnitha, Greece, July 2007, for which we acquired satellite images from LANDSAT, ASTER, and IKONOS. Additionally, we created spatially degraded satellite data over a range of coarser resolutions using resampling techniques. The panchromatic (1 m) and multispectral component (4 m) of IKONOS were merged using the Gram-Schmidt spectral sharpening method. This very high-resolution imagery served as the basis to estimate the cover percentage of burned areas, bare land and vegetation at pixel level, by applying the maximum likelihood classification algorithm. Finally, multiple linear regression models were fit to estimate each land-cover fraction as a function of surface reflectance values of the original and the spatially degraded satellite images. The main findings of our research were: (a) the Near Infrared (NIR) and Short-wave Infrared (SWIR) are the most important channels to estimate the percentage of burned area, whereas the NIR and red channels are the most important to estimate the percentage of vegetation in fire-affected areas; (b) when the bi-spectral space consists only of NIR and SWIR, then the NIR ground reflectance value plays a more significant role in estimating the percent of burned areas, and the SWIR appears to be more important in estimating the percent of vegetation; and (c) semi-burned areas comprising 45-55% burned area and 45-55% vegetation are spectrally closer to burned areas in the NIR channel, whereas those areas are spectrally closer to vegetation in the SWIR channel. These findings, at least partially, are attributed to the fact that: (i) completely burned pixels present low variance in the NIR and high variance in the SWIR, whereas the opposite is observed in completely vegetated areas where higher variance is observed in the NIR and lower variance in the SWIR, and (ii) bare land modifies the spectral signal of burned areas more than the spectral signal of vegetated areas in the NIR, while the opposite is observed in SWIR region of the spectrum where the bare land modifies the spectral signal of vegetation more than the burned areas because the bare land and the vegetation are spectrally more similar in the NIR, and the bare land and burned areas are spectrally more similar in the SWIR.

High Resolution Land Use Land Cover Classification using Landsat Earth Observation Data for the Continental Africa

NASA Astrophysics Data System (ADS)

Midekisa, A.; Bennet, A.; Gething, P. W.; Holl, F.; Andrade-Pacheco, R.; Savory, D. J.; Hugh, S. J.

2016-12-01

Spatially detailed and temporally dynamic land use land cover data is necessary to monitor the state of the land surface for various applications. Yet, such data at a continental to global scale is lacking. Here, we developed high resolution (30 meter) annual land use land cover layers for the continental Africa using Google Earth Engine. To capture ground truth training data, high resolution satellite imageries were visually inspected and used to identify 7, 212 sample Landsat pixels that were comprised entirely of one of seven land use land cover classes (water, man-made impervious surface, high biomass, low biomass, rock, sand and bare soil). For model validation purposes, 80% of points from each class were used as training data, with 20% withheld as a validation dataset. Cloud free Landsat 7 annual composites for 2000 to 2015 were generated and spectral bands from the Landsat images were then extracted for each of the training and validation sample points. In addition to the Landsat spectral bands, spectral indices such as normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were used as covariates in the model. Additionally, calibrated night time light imageries from the National Oceanic and Atmospheric Administration (NOAA) were included as a covariate. A decision tree classification algorithm was applied to predict the 7 land cover classes for the periods 2000 to 2015 using the training dataset. Using the validation dataset, classification accuracy including omission error and commission error were computed for each land cover class. Model results showed that overall accuracy of classification was high (88%). This high resolution land cover product developed for the continental Africa will be available for public use and can potentially enhance the ability of monitoring and studying the state of the Earth's surface.

Douglas-fir seedlings planted by four methods...results after 10 years

Treesearch

R. O. Strothman

1976-01-01

Bare-root Douglas-fir seedlings were planted by four methods in late February and late March on a hot, south-facing slope in northwestern California. The four techniques were: standard planting, deep planting at two different depths, and shading of the lower stem. After 10 growing seasons, there were no significant differences in survival attributable to planting...

Overcoming Smallness through Education Development: A Comparative Analysis of Jamaica and Singapore

ERIC Educational Resources Information Center

Welsh, Richard O.

2012-01-01

Between 1960 and 2010, Singapore's real gross domestic product (GDP) per capita skyrocketed from $4,383 to $55,862, while Jamaica's barely increased from $6,417 to $8,539. It is plausible that differing rates of GDP growth are associated with differences in the development of education systems but causally the linkage is not well understood. Using…

Effectiveness of a Coral-Derived Surfacing Material for Reducing Sediment Production on Unpaved Roads, Schoffield Barracks, Oahu, Hawaii

NASA Astrophysics Data System (ADS)

Ziegler, Alan D.; Sutherland, Ross A.

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h-1 for 30-90 min) on 0.75-m (wide) × 5.0-m (long) plots of similar slope (roughly 0.1 m m-1). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m-2 (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site—at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Effectiveness of a coral-derived surfacing material for reducing sediment production on unpaved roads, Schoffield barracks, Oahu, Hawaii.

PubMed

Ziegler, Alan D; Sutherland, Ross A

2006-01-01

This study evaluated the effectiveness of two application rates of a coral-derived surfacing material for both traffic and nontraffic road conditions using simulated rainfall (110-120 mm h(-1) for 30-90 min) on 0.75-m (wide) x 5.0-m (long) plots of similar slope (roughly 0.1 m m(-1)). The coral is a locally available material that has been applied to unpaved roads surfaces on Schoffield Barracks, Oahu, Hawaii (USA), where this experiment was conducted. The simulations show that compared with a bare control plot, the coral-based surface application rates of 80 and 160 kg m(-2) (equivalent to only 10- and 20-mm thicknesses) reduced road sediment production by 75% and 95%, respectively, for nontraffic conditions. However, after two passes of the research vehicle during wet conditions, sediment production rates for the two coral treatments were not significantly different from those on the bare road plots. The overall effectiveness of the coral-derived surfacing material is unsatisfactory, primarily because the on-road surface thickness associated with the application rates tested was too small. These rates were selected to bracket those applied to training roads in the study area. Furthermore, the composition of the coral-based material does not facilitate the development of a sealed, erosion-resistant surface. When applied at the low rates tested, the coral material breaks down under normal traffic conditions, thereby losing its ability to counter shearing forces exerted by overland flow on long hillslopes where erosion measures are most needed. These simulations, combined with observations on roads in the study area, indicate that this material is not an appropriate road surfacing material for the site-at least for the low application rates examined. These results are preliminary; extended testing of higher applications rates at the hillslope scale under natural climate and traffic conditions is needed to better judge the effectiveness of this material over time.

Glaciers bring more precipitation over south slope of the Himalayas and less moisture to the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Yang, K.; Lin, C.; Chen, D.

2017-12-01

Due to the warming climate, significant retreat of glaciers in the Himalayan region is observed. Thus, it is crucial to understand whether and how the glaciers impact (feedback to) regional climate. Due to lack of observational data, most processes with glaciers are however not well documented. For instance, convergence takes place when summertime upslope flows of warm and moist air masses meet cool and dry katabatic winds over a glacier slope, which may induce local convections and precipitations. This work intends to test this hypothesis according to an experiment conducted with the Weather Research and Forecasting (WRF) Model focusing on the Himalayan region. Three cases are designed for the experiment: a) a normal run as the control case; b) a sensitive run with land use ice/snow replaced by bare ground tundra and the maximum snow albedo set to 0.25; and c) a sensitive run with land use ice/snow replaced by bare ground tundra and no new snowing. According to differences between the control case and both the two sensitive cases, here we found that glaciers overall leads to less precipitation over glacier-covered areas and north of the Himalayas, which can be attributed to the suppressing of cooling glacier surfaces to upslope moist flows. By contrast, a zone of extra more precipitation (that can be up to 200 mm for JJA) is clearly found over the south slope of the Himalayas at elevation of 4-5 km where it meets the glacier terminus, accompanied with the convergence of upslope air masses and katabatic winds. Case b) reflects a smaller such effect when compared to case c), possibly because it takes a portion of energy for ice/snow melting. When it comes to impacts on water vapor transport, glaciers will result approximately 2% less moisture flowing into the Tibetan Plateau.

Glaciers bring more precipitation over south slope of the Himalayas and less moisture to the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Yee, L.; Isaacman-VanWertz, G. A.; Wernis, R. A.; Kreisberg, N. M.; Upshur, M. A.; Thomson, R. J.; Geiger, F.; Bering, M. S.; Glasius, M.; Offenberg, J. H.; Lewandowski, M.; Liu, Y.; McKinney, K. A.; de Sá, S. S.; Martin, S. T.; Alexander, M. L. L.; Palm, B. B.; Jimenez, J. L.; Brito, J.; Artaxo, P.; Hu, W.; Campuzano-Jost, P.; Day, D.; Viegas, J.; Manzi, A. O.; Oliveira, M. B.; de Souza, R.; Machado, L.; Longo, K.; Hering, S. V.; Goldstein, A. H.

2016-12-01

Due to the warming climate, significant retreat of glaciers in the Himalayan region is observed. Thus, it is crucial to understand whether and how the glaciers impact (feedback to) regional climate. Due to lack of observational data, most processes with glaciers are however not well documented. For instance, convergence takes place when summertime upslope flows of warm and moist air masses meet cool and dry katabatic winds over a glacier slope, which may induce local convections and precipitations. This work intends to test this hypothesis according to an experiment conducted with the Weather Research and Forecasting (WRF) Model focusing on the Himalayan region. Three cases are designed for the experiment: a) a normal run as the control case; b) a sensitive run with land use ice/snow replaced by bare ground tundra and the maximum snow albedo set to 0.25; and c) a sensitive run with land use ice/snow replaced by bare ground tundra and no new snowing. According to differences between the control case and both the two sensitive cases, here we found that glaciers overall leads to less precipitation over glacier-covered areas and north of the Himalayas, which can be attributed to the suppressing of cooling glacier surfaces to upslope moist flows. By contrast, a zone of extra more precipitation (that can be up to 200 mm for JJA) is clearly found over the south slope of the Himalayas at elevation of 4-5 km where it meets the glacier terminus, accompanied with the convergence of upslope air masses and katabatic winds. Case b) reflects a smaller such effect when compared to case c), possibly because it takes a portion of energy for ice/snow melting. When it comes to impacts on water vapor transport, glaciers will result approximately 2% less moisture flowing into the Tibetan Plateau.

Cation mobility and the sorption of chloroform in zeolite NaY: molecular dynamics study.

PubMed

Ramsahye, Naseem A; Bell, Robert G

2005-03-17

Molecular dynamics simulations at temperatures of 270, 330, and 390 K have been carried out to address the question of cation migration upon chloroform sorption in sodium zeolite Y. The results show that sodium cations located in different sites exhibit different types of mobility. These may be summarized as follows: (1) SII cations migrate toward the center of the supercage upon sorption, due to interactions with the polar sorbate molecules. (2) SI' cations hop from the sodalite cage into the supercage to fill vacant SII sites. (3) SI' cations migrate to other SI' sites within the same sodalite cage. (4) SI cations hop out of the double six-rings into SI' sites. In some instances, concerted motion of cations is observed. Furthermore, former SI' and SI cations, having crossed to SII sites, may then further migrate within the supercage, as in (1). The cation motion is dependent on the level of sorbate loading, with 10 molecules per unit cell not being enough to induce significant cation displacements, whereas the sorption of 40 molecules per unit cell results in a number of cations being displaced from their original positions. Further rearrangement of the cation positions is observed upon evacuation of the simulation cell, with some cations reverting back to sites normally occupied in bare NaY.

Soil Water Balance and Water Use Efficiency of Dryland Wheat in Different Precipitation Years in Response to Green Manure Approach

PubMed Central

Zhang, Dabin; Yao, Pengwei; Na, Zhao; Cao, Weidong; Zhang, Suiqi; Li, Yangyang; Gao, Yajun

2016-01-01

Winter wheat (Triticum aestivum L.) monoculture is conventionally cultivated followed by two to three months of summer fallow in the Loess Plateau. To develop a sustainable cropping system, we conducted a six-year field experiment to investigate the effect of leguminous green manure (LGM) instead of bare fallow on the yield and water use efficiency (WUE) of winter wheat and the soil water balance (SWB) in different precipitation years in a semi-arid region of northwest China. Results confirmed that planting LGM crop consumes soil water in the fallow season can bring varied effects to the subsequent wheat. The effect is positive or neutral when the annual precipitation is adequate, so that there is no significant reduction in the soil water supplied to wheat. If this is not the case, the effect is negative. On average, the LGM crop increased wheat yield and WUE by 13% and 28%, respectively, and had considerable potential for maintaining the SWB (0–200 cm) compared with fallow management. In conclusion, cultivation of the LGM crop is a better option than fallow to improve the productivity and WUE of the next crop and maintain the soil water balance in the normal and wet years in the Loess Plateau. PMID:27225842

Vegetation classification and soil moisture calculation using land surface temperature (LST) and vegetation index (VI)

NASA Astrophysics Data System (ADS)

Liu, Liangyun; Zhang, Bing; Xu, Genxing; Zheng, Lanfen; Tong, Qingxi

2002-03-01

In this paper, the temperature-missivity separating (TES) method and normalized difference vegetation index (NDVI) are introduced, and the hyperspectral image data are analyzed using land surface temperature (LST) and NDVI channels which are acquired by Operative Module Imaging Spectral (OMIS) in Beijing Precision Agriculture Demonstration Base in Xiaotangshan town, Beijing in 26 Apr, 2001. Firstly, the 6 kinds of ground targets, which are winter wheat in booting stage and jointing stage, bare soil, water in ponds, sullage in dry ponds, aquatic grass, are well classified using LST and NDVI channels. Secondly, the triangle-like scatter-plot is built and analyzed using LST and NDVI channels, which is convenient to extract the information of vegetation growth and soil's moisture. Compared with the scatter-plot built by red and near-infrared bands, the spectral distance between different classes are larger, and the samples in the same class are more convergent. Finally, we design a logarithm VIT model to extract the surface soil water content (SWC) using LST and NDVI channel, which works well, and the coefficient of determination, R2, between the measured surface SWC and the estimated is 0.634. The mapping of surface SWC in the wheat area are calculated and illustrated, which is important for scientific irrigation and precise agriculture.

Laid bare: religious intolerance within online commentary about 'bare below the elbows' guidance in professional journals.

PubMed

Jones, June; Shanks, Andrew

2013-09-01

The decision by the Department of Health to introduce amendments to the uniform and workwear policy for the NHS in response to increasing problems with infection control seemed uncontroversial. There was, however, some difficulty with implementing the policy, which arose largely because of the conflict this caused for staff who wished to keep their arms covered for reasons which stemmed from religious beliefs. This paper uses textual analysis to examine how those reasons and challenges were discussed in online commentary within a medical and nursing journal. The papers shows that there was a marked difference in how the two groups of professionals responded to the changes to workwear, and exposes a worrying degree of religious intolerance expressed by contributors to the nursing journal.

Fast electron propagation in Ti foils irradiated with sub-picosecond laser pulses at Iλ{sup 2}>10{sup 18} Wcm{sup −2}μm{sup 2}

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

Makita, M.; Nersisyan, G.; McKeever, K.

2014-02-15

We have studied the propagation of fast electrons through laser irradiated Ti foils by monitoring the emission of hard X-rays and K-α radiation from bare foils and foils backed by a thick epoxy layer. Key observations include strong refluxing of electrons and divergence of the electron beam in the foil with evidence of magnetic field collimation. Our diagnostics have allowed us to estimate the fast electron temperature and fraction of laser energy converted to fast electrons. We have observed clear differences between the fast electron temperatures observed with bare and epoxy backed targets which may be due to the effectsmore » of refluxing.« less

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

Krokidis, Miltiadis, E-mail: mkrokidis@hotmail.com; Fanelli, Fabrizio; Orgera, Gianluigi

The purpose of this study was to compare the clinical effectiveness of expanded polytetrafluoroethylene/fluorinated-ethylene-propylene (ePTFE/FEP)-covered stents with that of uncovered nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer. Eighty patients were enrolled in a prospective randomized study. Bare nitinol stents were used in half of the patients, and ePTFE/FEP-covered stents were used in the remaining patients. Patency, survival, complications, and mean cost were calculated in both groups. Mean patency was 166.0 {+-} 13.11 days for the bare-stent group and 234.0 {+-} 20.87 days for the covered-stent group (p = 0.007). Primary patency rates atmore » 3, 6, and 12 months were 77.5, 69.8, and 69.8% for the bare-stent group and 97.5, 92.2, and 87.6% for the covered-stent group, respectively. Mean secondary patency was 123.7 {+-} 22.5 days for the bare-stent group and 130.3 {+-} 21.4 days for the covered-stent group. Tumour ingrowth occurred exclusively in the bare-stent group in 27.5% of cases (p = 0.002). Median survival was 203.2 {+-} 11.8 days for the bare-stent group and 247.0 {+-} 20 days for the covered-stent group (p = 0.06). Complications and mean cost were similar in both groups. Regarding primary patency and ingrowth rate, ePTFE/FEP-covered stents have shown to be significantly superior to bare nitinol stents for the palliation of malignant jaundice caused by inoperable pancreatic head cancer and pose comparable cost and complications. Use of a covered stent does not significantly influence overall survival rate; nevertheless, the covered endoprosthesis seems to offer result in fewer reinterventions and better quality of patient life.« less

Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model.

PubMed

Dong, Xianglin; Xu, Tao; Ma, Shaolin; Wen, Hao

2015-06-01

The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues.

Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model

PubMed Central

DONG, XIANGLIN; XU, TAO; MA, SHAOLIN; WEN, HAO

2015-01-01

The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues. PMID:26136958

Partitioning Carbon Dioxide Emission and Assessing Dissolved Organic Carbon Leaching of a Drained Peatland Cultivated with Pineapple at Saratok, Malaysia

PubMed Central

Lim Kim Choo, Liza Nuriati; Ahmed, Osumanu Haruna

2014-01-01

Pineapples (Ananas comosus (L.) Merr.) cultivation on drained peats could affect the release of carbon dioxide (CO2) into the atmosphere and also the leaching of dissolved organic carbon (DOC). Carbon dioxide emission needs to be partitioned before deciding on whether cultivated peat is net sink or net source of carbon. Partitioning of CO2 emission into root respiration, microbial respiration, and oxidative peat decomposition was achieved using a lysimeter experiment with three treatments: peat soil cultivated with pineapple, bare peat soil, and bare peat soil fumigated with chloroform. Drainage water leached from cultivated peat and bare peat soil was also analyzed for DOC. On a yearly basis, CO2 emissions were higher under bare peat (218.8 t CO2 ha/yr) than under bare peat treated with chloroform (205 t CO2 ha/yr), and they were the lowest (179.6 t CO2 ha/yr) under cultivated peat. Decreasing CO2 emissions under pineapple were attributed to the positive effects of photosynthesis and soil autotrophic activities. An average 235.7 mg/L loss of DOC under bare peat suggests rapid decline of peat organic carbon through heterotrophic respiration and peat decomposition. Soil CO2 emission depended on moderate temperature fluctuations, but it was not affected by soil moisture. PMID:25215335

Near-Field Microwave Detection of Corrosion Precursor Pitting under Thin Dielectric Coatings in Metallic Substrate

NASA Astrophysics Data System (ADS)

Hughes, D.; Zoughi, R.; Austin, R.; Wood, N.; Engelbart, R.

2003-03-01

Detection of corrosion precursor pitting on metallic surfaces under various coatings and on bare metal is of keen interest in evaluation of aircraft fuselage. Near-field microwave nondestructive testing methods, utilizing open-ended rectangular waveguides and coaxial probes, have been used extensively for detection of surface flaws in metals, both on bare metal and under a dielectric coating. This paper presents the preliminary results of using microwave techniques to detect corrosion precursor pitting under paint and primer, applique and on bare metal. Machined pits of 500 μm diameter were detected using open-ended rectangular waveguides at V-Band under paint and primer and applique, and on bare metal. Using coaxial probes, machined pits with diameters down to 150 μm on bare metal were also detected. Relative pit size and density were shown on a corrosion-pitted sample using open-ended rectangular waveguides at frequencies of 35 GHz to 70 GHz. The use of Boeing's MAUS™ scanning systems provided improved results by alleviating standoff variation and scanning artifact. Typical results of this investigation are also presented.

Synthesis, characterization and antibacterial activity of superparamagnetic nanoparticles modified with glycol chitosan

NASA Astrophysics Data System (ADS)

Inbaraj, Baskaran Stephen; Tsai, Tsung-Yu; Chen, Bing-Huei

2012-02-01

Iron oxide nanoparticles (IONPs) were synthesized by coprecipitation of iron salts in alkali media followed by coating with glycol chitosan (GC-coated IONPs). Both bare and GC-coated IONPs were subsequently characterized and evaluated for their antibacterial activity. Comparison of Fourier transform infrared spectra and thermogravimetric data of bare and GC-coated IONPs confirmed the presence of GC coating on IONPs. Magnetization curves showed that both bare and GC-coated IONPs are superparamagnetic and have saturation magnetizations of 70.3 and 59.8 emu g-1, respectively. The IONP size was measured as ~8-9 nm by transmission electron microscopy, and their crystal structure was assigned to magnetite from x-ray diffraction patterns. Both bare and GC-coated IONPs inhibited the growths of Escherichia coli ATCC 8739 and Salmonella enteritidis SE 01 bacteria better than the antibiotics linezolid and cefaclor, as evaluated by the agar dilution assay. GC-coated IONPs showed higher potency against E. coli O157:H7 and Staphylococcus aureus ATCC 10832 than bare IONPs. Given their biocompatibility and antibacterial properties, GC-coated IONPs are a potential nanomaterial for in vivo applications.

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: patient level meta-analysis

PubMed Central

Sabaté, Manel; Kaiser, Christoph; Brugaletta, Salvatore; de la Torre Hernandez, Jose Maria; Galatius, Soeren; Cequier, Angel; Eberli, Franz; de Belder, Adam; Serruys, Patrick W; Ferrante, Giuseppe

2014-01-01

Objectives To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Design Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Data sources and study selection Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. Primary outcomes The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. Results The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets. Conclusions This meta-analysis offers evidence that compared with bare metal stents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis. PMID:25378023

Effects of cobalt-chromium everolimus eluting stents or bare metal stent on fatal and non-fatal cardiovascular events: patient level meta-analysis.

PubMed

Valgimigli, Marco; Sabaté, Manel; Kaiser, Christoph; Brugaletta, Salvatore; de la Torre Hernandez, Jose Maria; Galatius, Soeren; Cequier, Angel; Eberli, Franz; de Belder, Adam; Serruys, Patrick W; Ferrante, Giuseppe

2014-11-04

To examine the safety and effectiveness of cobalt-chromium everolimus eluting stents compared with bare metal stents. Individual patient data meta-analysis of randomised controlled trials. Cox proportional regression models stratified by trial, containing random effects, were used to assess the impact of stent type on outcomes. Hazard ratios with 95% confidence interval for outcomes were reported. Medline, Embase, the Cochrane Central Register of Controlled Trials. Randomised controlled trials that compared cobalt-chromium everolimus eluting stents with bare metal stents were selected. The principal investigators whose trials met the inclusion criteria provided data for individual patients. The primary outcome was cardiac mortality. Secondary endpoints were myocardial infarction, definite stent thrombosis, definite or probable stent thrombosis, target vessel revascularisation, and all cause death. The search yielded five randomised controlled trials, comprising 4896 participants. Compared with patients receiving bare metal stents, participants receiving cobalt-chromium everolimus eluting stents had a significant reduction of cardiac mortality (hazard ratio 0.67, 95% confidence interval 0.49 to 0.91; P=0.01), myocardial infarction (0.71, 0.55 to 0.92; P=0.01), definite stent thrombosis (0.41, 0.22 to 0.76; P=0.005), definite or probable stent thrombosis (0.48, 0.31 to 0.73; P<0.001), and target vessel revascularisation (0.29, 0.20 to 0.41; P<0.001) at a median follow-up of 720 days. There was no significant difference in all cause death between groups (0.83, 0.65 to 1.06; P=0.14). Findings remained unchanged at multivariable regression after adjustment for the acuity of clinical syndrome (for instance, acute coronary syndrome v stable coronary artery disease), diabetes mellitus, female sex, use of glycoprotein IIb/IIIa inhibitors, and up to one year v longer duration treatment with dual antiplatelets. This meta-analysis offers evidence that compared with bare metal stents the use of cobalt-chromium everolimus eluting stents improves global cardiovascular outcomes including cardiac survival, myocardial infarction, and overall stent thrombosis. © Valgimigli et al 2014.

The effects of ecological restoration on CO2 fluxes from a climatically marginal upland blanket bog

NASA Astrophysics Data System (ADS)

Dixon, Simon; Qassim, Suzane; Rowson, James; Worrall, Fred; Evans, Martin

2013-04-01

A legacy of gully incision, deposition of industrially-derived aerial pollutants, inappropriate management and wildfire has left large expanses of the topographic Bleaklow Plateau (Peak District National Park, England, UK) bare of vegetation and susceptible to massive erosion of the peat soils. The consequence of such degradation has been to decrease the capacity of the peatland on the plateau to provide important ecosystem services including; loss of net C sink function, discolouration of surface waters, mobilisation to surface waters of stored heavy metals and infilling of upland reservoirs with peat-derived sediment. In response to on-going and worsening degradation a programme of ecological restoration has been undertaken. Restoration methods include: seeding with a lawn grass mix; liming; fertilisation; slope stabilisation; and gully blocking. This talk will present data from a five-year, observational-study of CO2 fluxes from eight sites, with four sites sampling different restoration treatments and four sampling bare and least disturbed areas. The results of the analysis reveal that sites with revegetation alongside slope stabilisation were most productive and were the largest net (daylight hours) sinks of CO2. Unrestored, bare sites, while having relatively low gross fluxes of CO2 were the largest net sources of CO2. Revegetation without slope stabilisation took longer (~18 months) to show an impact on CO2 flux in comparison to the sites with slope stabilisation. Binary logistic regression indicated that a ten centimetre increase in water table depth decreases the odds of observing a net CO2 sink, on a given site, by up to 30%. Sites with slope stabilisation were between 5-8x more likely to be net CO2 sinks than the bare sites. Sites without slope stabilisation were only 2-2.3x more likely to be net CO2 sinks compared to the bare sites. The most important conclusion of this research is that revegetation appears to be effective at increasing the likelihood of net CO2 behaviour on degraded, climatically marginal blanket peat, with revegetation alongside slope stabilisation having the greatest impact.

CSF Flow in the Brain in the Context of Normal Pressure Hydrocephalus.

PubMed

Bradley, W G

2015-05-01

CSF normally flows back and forth through the aqueduct during the cardiac cycle. During systole, the brain and intracranial vasculature expand and compress the lateral and third ventricles, forcing CSF craniocaudad. During diastole, they contract and flow through the aqueduct reverses. Hyperdynamic CSF flow through the aqueduct is seen when there is ventricular enlargement without cerebral atrophy. Therefore, patients presenting with clinical normal pressure hydrocephalus who have hyperdynamic CSF flow have been found to respond better to ventriculoperitoneal shunting than those with normal or decreased CSF flow. Patients with normal pressure hydrocephalus have also been found to have larger intracranial volumes than sex-matched controls, suggesting that they may have had benign external hydrocephalus as infants. While their arachnoidal granulations clearly have decreased CSF resorptive capacity, it now appears that this is fixed and that the arachnoidal granulations are not merely immature. Such patients appear to develop a parallel pathway for CSF to exit the ventricles through the extracellular space of the brain and the venous side of the glymphatic system. This pathway remains functional until late adulthood when the patient develops deep white matter ischemia, which is characterized histologically by myelin pallor (ie, loss of lipid). The attraction between the bare myelin protein and the CSF increases resistance to the extracellular outflow of CSF, causing it to back up, resulting in hydrocephalus. Thus idiopathic normal pressure hydrocephalus appears to be a "2 hit" disease: benign external hydrocephalus in infancy followed by deep white matter ischemia in late adulthood. © 2015 by American Journal of Neuroradiology.

Analysis of the habitat of Henslow's sparrows and Grasshopper sparrows compared to random grassland areas

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

Maier, Kristen; Walton, Rod; Kasper, Peter

2005-01-01

Henslow's Sparrows are endangered prairie birds, and Grasshopper Sparrows are considered rare prairie birds. Both of these birds were abundant in Illinois, but their populations have been declining due to loss of the grasslands. This begins an ongoing study of the birds habitat so Fermilab can develop a land management plan for the Henslow's and Grasshoppers. The Henslow's were found at ten sites and Grasshoppers at eight sites. Once the birds were located, the vegetation at their sites was studied. Measurements of the maximum plant height, average plant height, and duff height were taken and estimates of the percent ofmore » grass, forbs, duff, and bare ground were recorded for each square meter studied. The same measurements were taken at ten random grassland sites on Fermilab property. Several t-tests were performed on the data, and it was found that both Henslow's Sparrows and Grasshopper Sparrows preferred areas with a larger percentage of grass than random areas. Henslow's also preferred areas with less bare ground than random areas, while Grasshoppers preferred areas with more bare ground than random areas. In addition, Grasshopper Sparrows preferred a lower percentage of forbs than was found in random areas and a shorter average plant height than the random locations. Two-sample variance tests suggested significantly less variance for both Henslow's Sparrows and Grasshopper Sparrows for maximum plant height in comparison to the random sites. For both birds, the test suggested a significant difference in the variance of the percentage of bare ground compared to random sites, but only the Grasshopper Sparrow showed significance in the variation in the percentage of forbs.« less

Ionic liquid-modified silica-coated magnetic nanoparticles: promising adsorbents for ultra-fast extraction of paraquat from aqueous solution.

PubMed

Latifeh, Farzad; Yamini, Yadollah; Seidi, Shahram

2016-03-01

In the present study, ionic liquid-modified silica-coated magnetic nanoparticles (Fe3O4@SiO2@IL) were synthesized and applied as adsorbents for extraction and determination of paraquat (PQ) followed by high-performance liquid chromatography. For assurance of the extraction efficiency, the obtained results were compared with those obtained by bared magnetic nanoparticles (MNPs). Experimental design and response surface methodology were used for optimization of different parameters which affect extraction efficiency of paraquat using both adsorbents. Under the optimized conditions, extraction recoveries in the range of 20-25 and 35-40 % with satisfactory repeatability values (RSDs%, n = 4) less than 5.0 % were obtained for bared MNPs and Fe3O4@SiO2@IL, respectively. The limits of detection were 0.1 and 0.25 μg/L using Fe3O4@SiO2@IL and bared MNPs, respectively. The linearity was obtained in the range of 0.25 to 25 μg/L and 0.5 to 25 μg/L for Fe3O4@SiO2@IL and bared MNPs, respectively, with the coefficients of determination better than 0.9950. Finally, Fe3O4@SiO2@IL was chosen as superior adsorbent due to more dispersion ability, higher extraction recovery, lower detection limit, as well as better linearity and repeatability. Calculated errors (%) were in the range of 3 to 10 % depicting acceptable accuracy for the analysis of PQ by the proposed method. Finally, the method was successfully applied for extraction and determination of PQ in some water and countryside soil samples.

Polyethylene glycol hydrogel polymer sealant for vitrectomy surgery: an in vitro study of sutureless vitrectomy incision closure.

PubMed

Hariprasad, Seenu M; Singh, Ajay

2011-03-01

To test a novel hydrogel sealant to secure sutureless sclerotomies under variable intraocular pressure conditions. In cadaver eyes, 23- and 20-gauge (G) sclerotomies were constructed. Sixteen 23-G beveled sclerotomies were constructed in 4 eyes: 8 of the incisions were treated with hydrogel sealant, while 8 were left bare. All sclerotomies were monitored for leaks while the intraocular pressure was elevated. The pressure on incision leakage was recorded as the leak pressure (maximum tested = 140 mm Hg). Additionally, sixteen 20-G sclerotomies were constructed in 4 other eyes: 8 of the incisions were treated with hydrogel sealant, while 8 were sutured. These incisions were similarly pressure tested. Among the 23-G incisions, hydrogel sealant application to the incisions significantly increased the leak pressure relative to bare incisions: mean (SE), 131.8 (8.2) vs 39.5 (5.2) mm Hg, respectively (P < .001). Only 1 of the 8 sealant-treated 23-G incisions leaked below 140 mm Hg, compared with all of the 8 bare incisions. Among the 20-G incisions, there was no difference in leak pressure among sealant-treated and sutured incisions: mean (SE), 140.0 (0.0) vs 136.3 (3.8) mm Hg, respectively (P = .35). None of the 8 sealant-treated 20-G incisions leaked below 140 mm Hg, compared with 1 of the 8 sutured incisions. Hydrogel sealant significantly increased the leak pressure among 23-G incisions relative to 23-G bare incisions and was equivalent to suturing among 20-G incisions. Hydrogel sealants effectively close vitrectomy incisions and may decrease the incidence of postoperative endophthalmitis and hypotony.

Numerical Modeling of Water Fluxes in the Root Zone of Irrigated Pecan

NASA Astrophysics Data System (ADS)

Shukla, M. K.; Deb, S.

2010-12-01

Information is still limited on the coupled liquid water, water vapor, heat transport and root water uptake for irrigated pecan. Field experiments were conducted in a sandy loam mature pecan field in Las Cruces, New Mexico. Three pecan trees were chosen to monitor diurnal soil water content under the canopy (approximately half way between trunk and the drip line) and outside the drip line (bare spot) along a transect at the depths of 5, 10, 20, 40, and 60 cm using TDR sensors. Soil temperature sensors were installed at an under-canopy locations and bare spot to monitor soil temperature data at depths of 5, 10, 20, and 40 cm. Simulations of the coupled transport of liquid water, water vapor, and heat with and without root water uptake were carried out using the HYDRUS-1D code. Measured soil hydraulic and thermal properties, continuous meteorological data, and pecan characteristics, e.g. rooting depth, leaf area index, were used in the model simulations. Model calibration was performed for a 26-day period from DOY 204 through DOY 230, 2009 based on measured soil water content and soil temperature data at different soil depths, while the model was validated for a 90-day period from DOY 231 through DOY 320, 2009 at bare spot. Calibrated parameters were also used to apply the model at under-canopy locations for a 116-day period from DOY 204 to 320. HYDRUS-1D simulated water contents and soil temperatures correlated well with the measured data at each depth. Numerical assessment of various transport mechanisms and quantitative estimates of isothermal and thermal water fluxes with and without root water uptake in the unsaturated zone within canopy and bare spot is in progress and will be presented in the conference.

Bacterial recolonization of the skin and wound contamination during cardiac surgery: a randomized controlled trial of the use of plastic adhesive drape compared with bare skin.

PubMed

Falk-Brynhildsen, K; Söderquist, B; Friberg, O; Nilsson, U G

2013-06-01

Sternal wound infection after cardiac surgery is a serious complication. Various perioperative strategies, including plastic adhesive drapes, are used to reduce bacterial contamination of surgical wounds. To compare plastic adhesive drape to bare skin regarding bacterial growth in wound and time to recolonization of the adjacent skin intraoperatively, in cardiac surgery patients. This single-blinded randomized controlled trial (May 2010 to May 2011) included 140 patients scheduled for cardiac surgery via median sternotomy. The patients were randomly allocated to the adhesive drape (chest covered with plastic adhesive drape) or bare skin group. Bacterial samples were taken preoperatively and intraoperatively every hour during surgery until skin closure. Disinfection with 0.5% chlorhexidine solution in 70% alcohol decreased coagulase-negative staphylococci (CoNS), while the proportion colonized with Propionibacterium acnes was not significantly reduced and was still present in more than 50% of skin samples. P. acnes was significantly more common in men than in women. Progressive bacterial recolonization of the skin occurred within 2-3 h. At 120 min there were significantly more positive cultures in the adhesive drape group versus bare skin group for P. acnes (63% vs 44%; P = 0.034) and for CoNS (45% vs 24%; P = 0.013). The only statistically significant difference in bacterial growth in the surgical wound was higher proportion of CoNS at the end of surgery in the adhesive drape group (14.7% vs 4.4%; P = 0.044). Plastic adhesive drape does not reduce bacterial recolonization. P. acnes colonized men more frequently, and was not decreased by disinfection with chlorhexidine solution in alcohol. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Effect of blocking tactile information from the fingertips on adaptation and execution of grip forces to friction at the grasping surface.

PubMed

Bilaloglu, Seda; Lu, Ying; Geller, Daniel; Rizzo, John Ross; Aluru, Viswanath; Gardner, Esther P; Raghavan, Preeti

2016-03-01

Adaptation of fingertip forces to friction at the grasping surface is necessary to prevent use of inadequate or excessive grip forces. In the current study we investigated the effect of blocking tactile information from the fingertips noninvasively on the adaptation and efficiency of grip forces to surface friction during precision grasp. Ten neurologically intact subjects grasped and lifted an instrumented grip device with 18 different frictional surfaces under three conditions: with bare hands or with a thin layer of plastic (Tegaderm) or an additional layer of foam affixed to the fingertips. The coefficient of friction at the finger-object interface of each surface was obtained for each subject with bare hands and Tegaderm by measuring the slip ratio (grip force/load force) at the moment of slip. We found that the foam layer reduced sensibility for two-point discrimination and pressure sensitivity at the fingertips, but Tegaderm did not. However, Tegaderm reduced static, but not dynamic, tactile discrimination. Adaptation of fingertip grip forces to surface friction measured by the rate of change of peak grip force, and grip force efficiency measured by the grip-load force ratio at lift, showed a proportional relationship with bare hands but were impaired with Tegaderm and foam. Activation of muscles engaged in precision grip also varied with the frictional surface with bare hands but not with Tegaderm and foam. The results suggest that sensitivity for static tactile discrimination is necessary for feedforward and feedback control of grip forces and for adaptive modulation of muscle activity during precision grasp. Copyright © 2016 the American Physiological Society.

[Spectrum similarities-based analysis of spatial difference of snow cover for multi-scale satellite data-a case study of MODIS and HJ-1B data].

PubMed

Liu, Yan; Li, Yang; Yang, Yun; Jian, Ji

2014-05-01

Vegetation and bare soil were collected in the areas of Miyaluo district in northwest of Sichuan province, the Qilian Mountains in Qinghai province and northern areas of Xinjiang during the years of 2007 and 2013. Then these data were converted to spectral reflectance by applying sensor response function of MODIS and HJ-1B respectively within the range of visible light, near-infrared and shortwave infrared. Comprehensive analysis was made on spectral characteristics and reflectivity similarities and differences of different sensors between old and new snowmelt, under the condition of different snow depth and different snow cover. The conclusions can be drawn That is, there exists high consistency of spectral response between new snow and dirty snow for each sensor in the visible wavelength range, also it is true for bare soil and low vegetation. However, low consistency happens to other types of snow; especially snowmelt and frozen snow. The range of NDSI is relatively stable under the condition of different snow depth for full snow cover and the trend of NDSI shows great consistency for different sensors; NDSI threshold method for monitoring snow by using MODIS and HJ-1B data showed very obvious difference in spatial scales, which is a reasonable explanation of the existence of mixed pixels.

Laboratory observations of fault strength in response to changes in normal stress

USGS Publications Warehouse

Kilgore, Brian D.; Lozos, Julian; Beeler, Nicholas M.; Oglesby, David

2012-01-01

Changes in fault normal stress can either inhibit or promote rupture propagation, depending on the fault geometry and on how fault shear strength varies in response to the normal stress change. A better understanding of this dependence will lead to improved earthquake simulation techniques, and ultimately, improved earthquake hazard mitigation efforts. We present the results of new laboratory experiments investigating the effects of step changes in fault normal stress on the fault shear strength during sliding, using bare Westerly granite samples, with roughened sliding surfaces, in a double direct shear apparatus. Previous experimental studies examining the shear strength following a step change in the normal stress produce contradictory results: a set of double direct shear experiments indicates that the shear strength of a fault responds immediately, and then is followed by a prolonged slip-dependent response, while a set of shock loading experiments indicates that there is no immediate component, and the response is purely gradual and slip-dependent. In our new, high-resolution experiments, we observe that the acoustic transmissivity and dilatancy of simulated faults in our tests respond immediately to changes in the normal stress, consistent with the interpretations of previous investigations, and verify an immediate increase in the area of contact between the roughened sliding surfaces as normal stress increases. However, the shear strength of the fault does not immediately increase, indicating that the new area of contact between the rough fault surfaces does not appear preloaded with any shear resistance or strength. Additional slip is required for the fault to achieve a new shear strength appropriate for its new loading conditions, consistent with previous observations made during shock loading.

SIMS chemical analysis of extended impacts on the leading and trailing edges of LDEF experiment AO187-2

NASA Technical Reports Server (NTRS)

Amari, S.; Foote, J.; Simon, Charles G.; Swan, P.; Walker, R. M.; Zinner, E.; Jessberger, E. K.; Lange, G.; Stadermann, F.

1992-01-01

The Long Duration Exposure Facility (LDEF) Experiment AO187-2 consisted of 237 capture cells, 120 on the leading edge and 117 on the trailing edge. Each cell was made of polished Ge plates covered with 2.5 micron thick mylar foil at 200 microns from the Ge. Although all leading edge cells and 105 trailing edge cells had lost their plastic covers during flight, optical and electron microscope examination revealed extended impacts in bare cells from either edge that apparently were produced by high velocity projectiles while the plastic foils were still in place. Detailed optical scanning yielded 53 extended impacts on 100 bare cells from the trailing edge that were selected for SIMS chemical analysis. Lateral multi-element ion probe profiles were obtained on 40 of these impacts. Material that can be attributed to the incoming projectiles was found in all analyzed extended compact features and most seem to be associated with cosmic dust particles. However, LDEF deposits are systematically enriched in the refractory elements Al, Ca, and Ti relative to Mg and Fe when compared to IDP's collected in the stratosphere and to chondritic compositions. These differences are most likely due to elemental fractionation effects during the high velocity impact but real differences between interplanetary particles captured on LDEF and stratospheric IDP's cannot be excluded. Recently we extended our studies to cells from the leading edge and the covered cells from the trailing edge. The 12 covered cells contain 20 extended impact candidates. Ion probe analysis of 3 yielded results similar to those obtained for impacts on the bare cells from the trailing edge. Optical scanning of the bare leading edge cell also reveals many extended impacts (42 on 22 cells scanned to date), demonstrating that the cover foils remained intact at least for some time. However, SIMS analysis showed elements that can reasonably be attributed to micrometeoroids in only 2 out of 11 impacts. Eight impacts have residues dominated by Al and one dominated by Ti, indicating a preponderance of orbital debris in leading edge impacts.

Quantifying vegetation distribution and structure using high resolution drone-based structure-from-motion photogrammetry

NASA Astrophysics Data System (ADS)

Zhang, J.; Okin, G.

2017-12-01

Vegetation is one of the most important driving factors of different ecosystem processes in drylands. The structure of vegetation controls the spatial distribution of moisture and heat in the canopy and the surrounding area. Also, the structure of vegetation influences both airflow and boundary layer resistance above the land surface. Multispectral satellite remote sensing has been widely used to monitor vegetation coverage and its change; however, it can only capture 2D images, which do not contain the vertical information of vegetation. In situ observation uses different methods to measure the structure of vegetation, and their results are accurate; however, these methods are laborious and time-consuming, and susceptible to undersampling in spatial heterogeneity. Drylands are sparsely covered by short plants, which allows the drone fly at a relatively low height to obtain ultra-high resolution images. Structure-from-motion (SfM) is a photogrammetric method that was proved to produce 3D model based on 2D images. Drone-based remote sensing can obtain the multiangle images for one object, which can be used to constructed 3D models of vegetation in drylands. Using these images detected by the drone, the orthomosaics and digital surface model (DSM) can be built. In this study, the drone-based remote sensing was conducted in Jornada Basin, New Mexico, in the spring of 2016 and 2017, and three derived vegetation parameters (i.e., canopy size, bare soil gap size, and plant height) were compared with those obtained with field measurement. The correlation coefficient of canopy size, bare soil gap size, and plant height between drone images and field data are 0.91, 0.96, and 0.84, respectively. The two-year averaged root-mean-square error (RMSE) of canopy size, bare soil gap size, and plant height between drone images and field data are 0.61 m, 1.21 m, and 0.25 cm, respectively. The two-year averaged measure error (ME) of canopy size, bare soil gap size, and plant height between drone images and field data are 0.02 m, -0.03, and -0.1 m, respectively. These results indicate a good agreement between drone-based remote sensing and field measurement.

The polarization phase difference of orchard trees

NASA Technical Reports Server (NTRS)

Wang, James R.; Mo, Tsan

1990-01-01

An image obtained by the Jet Propulsion Laboratory's airborne L-band polarimeter (SAR) over an agricultural area near Fresno, California, was analyzed for the signatures of polarization phase difference (PPD). The PPD of orchard trees was found to be distinctly different from that of bare fields or fields covered with other crops. Thus the PPD signatures obtained from a polarimeter may be useful in the understanding of the radar remote sensing of the earth's surface.

Improving the long-term stability of Ti6Al4V abutment screw by coating micro/nano-crystalline diamond films.

PubMed

Xie, Youneng; Zhou, Jing; Wei, Qiuping; Yu, Z M; Luo, Hao; Zhou, Bo; Tang, Z G

2016-10-01

Abutment screw loosening is the most common complication of implanting teeth. Aimed at improving the long-term stability of them, well-adherent and homogeneous micro-crystalline diamond (MCD) and nano-crystalline diamond (NCD) were deposited on DIO(®) (Dong Seo, Korea) abutment screws using a hot filament chemical vapor deposition (HFCVD) system. Compared with bare DIO(®) screws, diamond coated ones showed higher post reverse toque values than the bare ones (p<0.05) after cyclic loading one million times under 100N, and no obvious flaking happened after loading test. Diamond coated disks showed lower friction coefficients of 0.15 and 0.18 in artificial saliva when countered with ZrO2 than that of bare Ti6Al4V disks of 0.40. Though higher cell apoptosis rate was observed on film coated disks, but no significant difference between MCD group and NCD group. And the cytotoxicity of diamond films was acceptable for the fact that the cell viability of them was still higher than 70% after cultured for 72h. It can be inferred that coating diamond films might be a promising modification method for Ti6Al4V abutment screws. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can Rice (Oryza sativa) Mitigate Pesticides and Nutrients in Agricultural Runoff?

PubMed

Moore, M T; Locke, M A

2018-01-01

Phytoremediation of nutrients and pesticides in runoff is a growing conservation effort, particularly in agriculturally intensive areas such as the lower Mississippi River Valley. In the current study, rice (Oryza sativa) was examined for its mitigation capacity of nitrogen, phosphorus, diazinon, and permethrin. Twenty-two high density polyethylene circular containers (56 cm x 45 cm) were used as mesocosms, with 12 mesocosms planted with rice and 10 mesocosms remaining unvegetated. Mesocosms were hydraulically connected and arranged in a series of two, with each system providing a 4 h hydraulic retention time (HRT) for a total system retention time of 8 h. Two treatments (RICE/RICE and RICE/BARE) of four replicates each were utilized, with three replicates of controls (BARE/BARE). Systems with RICE/RICE (8 h HRT) significantly reduced diazinon (p = 0.0126), cis-permethrin (p = 0.0442), filtered orthophosphate (p = 0.0058), and total orthophosphate (p = 0.0123) compared to control systems. No significant differences were noted for trans-permethrin, nitrate, or ammonium. Results indicate promise in phytoremediation of agricultural runoff by rice. If further studies reveal contaminants are not transferred into seeds, then rice could potentially serve as both a remediation tool and food source in countries facing agricultural pollution challenges.

An Improved Shock Model for Bare and Covered Explosives

NASA Astrophysics Data System (ADS)

Scholtes, Gert; Bouma, Richard

2017-06-01

TNO developed a toolbox to estimate the probability of a violent event on a ship or other platform, when the munition bunker is hit by e.g. a bullet or fragment from a missile attack. To obtain the proper statistical output, several millions of calculations are needed to obtain a reliable estimate. Because millions of different scenarios have to be calculated, hydrocode calculations cannot be used for this type of application, but a fast and good engineering solutions is needed. At this moment the Haskins and Cook-model is used for this purpose. To obtain a better estimate for covered explosives and munitions, TNO has developed a new model which is a combination of the shock wave model at high pressure, as described by Haskins and Cook, in combination with the expanding shock wave model of Green. This combined model gives a better fit with the experimental values for explosives response calculations, using the same critical energy fluence values for covered as well as for bare explosives. In this paper the theory is explained and results of the calculations for several bare and covered explosives will be presented. To show this, the results will be compared with the experimental values from literature for composition B, Composition B-3 and PBX-9404.

Fairy circle landscapes under the sea

PubMed Central

Ruiz-Reynés, Daniel; Gomila, Damià; Sintes, Tomàs; Hernández-García, Emilio; Marbà, Núria; Duarte, Carlos M.

2017-01-01

Short-scale interactions yield large-scale vegetation patterns that, in turn, shape ecosystem function across landscapes. Fairy circles, which are circular patches bare of vegetation within otherwise continuous landscapes, are characteristic features of semiarid grasslands. We report the occurrence of submarine fairy circle seascapes in seagrass meadows and propose a simple model that reproduces the diversity of seascapes observed in these ecosystems as emerging from plant interactions within the meadow. These seascapes include two extreme cases, a continuous meadow and a bare landscape, along with intermediate states that range from the occurrence of persistent but isolated fairy circles, or solitons, to seascapes with multiple fairy circles, banded vegetation, and “leopard skin” patterns consisting of bare seascapes dotted with plant patches. The model predicts that these intermediate seascapes extending across kilometers emerge as a consequence of local demographic imbalances along with facilitative and competitive interactions among the plants with a characteristic spatial scale of 20 to 30 m, consistent with known drivers of seagrass performance. The model, which can be extended to clonal growth plants in other landscapes showing fairy rings, reveals that the different seascapes observed hold diagnostic power as to the proximity of seagrass meadows to extinction points that can be used to identify ecosystems at risks. PMID:28782035

The effect of the serum corona on interactions between a single nano-object and a living cell

NASA Astrophysics Data System (ADS)

Dror, Yael; Sorkin, Raya; Brand, Guy; Boubriak, Olga; Urban, Jill; Klein, Jacob

2017-04-01

Nanoparticles (NPs) which enter physiological fluids are rapidly coated by proteins, forming a so-called corona which may strongly modify their interaction with tissues and cells relative to the bare NPs. In this work the interactions between a living cell and a nano-object, and in particular the effect on this of the adsorption of serum proteins, are directly examined by measuring the forces arising as an Atomic Force Microscope tip (diameter 20 nm) - simulating a nano-object - approaches and contacts a cell. We find that the presence of a serum protein corona on the tip strongly modifies the interaction as indicated by pronounced increase in the indentation, hysteresis and work of adhesion compared to a bare tip. Classically one expects an AFM tip interacting with a cell surface to be repelled due to cell elastic distortion, offset by tip-cell adhesion, and indeed such a model fits the bare-tip/cell interaction, in agreement with earlier work. However, the force plots obtained with serum-modified tips are very different, indicating that the cell is much more compliant to the approaching tip. The insights obtained in this work may promote better design of NPs for drug delivery and other nano-medical applications.

Implanted Deuterium Retention and Release in Carbon-Coated Beryllium

NASA Astrophysics Data System (ADS)

Anderl, R. A.; Longhurst, G. R.; Pawelko, R. J.; Oates, M. A.

1997-06-01

Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Å. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Å revealed that exposure to a temperature of 400°C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400°C and an incident deuterium flux of approximately 6 × 1019 D/m2-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples.

The effect of the serum corona on interactions between a single nano-object and a living cell

PubMed Central

Dror, Yael; Sorkin, Raya; Brand, Guy; Boubriak, Olga; Urban, Jill; Klein, Jacob

2017-01-01

Nanoparticles (NPs) which enter physiological fluids are rapidly coated by proteins, forming a so-called corona which may strongly modify their interaction with tissues and cells relative to the bare NPs. In this work the interactions between a living cell and a nano-object, and in particular the effect on this of the adsorption of serum proteins, are directly examined by measuring the forces arising as an Atomic Force Microscope tip (diameter 20 nm) - simulating a nano-object - approaches and contacts a cell. We find that the presence of a serum protein corona on the tip strongly modifies the interaction as indicated by pronounced increase in the indentation, hysteresis and work of adhesion compared to a bare tip. Classically one expects an AFM tip interacting with a cell surface to be repelled due to cell elastic distortion, offset by tip-cell adhesion, and indeed such a model fits the bare-tip/cell interaction, in agreement with earlier work. However, the force plots obtained with serum-modified tips are very different, indicating that the cell is much more compliant to the approaching tip. The insights obtained in this work may promote better design of NPs for drug delivery and other nano-medical applications. PMID:28383528

Mulching as a means of exploiting dew for arid agriculture?

NASA Astrophysics Data System (ADS)

Graf, Alexander; Kuttler, Wilhelm; Werner, Julius

2008-03-01

A traditional mulching technique used in Lanzarote, Canary Islands, allows dry farming as well as pronounced water savings in irrigation. It is known to reduce evaporational losses, but is also supposed to enhance the nocturnal condensation of water vapour from the atmosphere. The mulch layer consists of porous volcanic rock fragments abundantly available on the island. The mulched surface is believed to cool rapidly and to be more hygroscopic than a bare soil surface. This was investigated during a field experiment conducted over 68 nights during different seasons in 2001 and 2002, as well as some simple laboratory measurements. It was found that nocturnal condensation on the mulch surface (max 0.33 mm) was lower than on the bare soil surface (max 0.57 mm) or any one of three alternative mulch substrates. However, a slightly stronger nocturnal cooling of the mulched as compared to the bare surface was present. It is shown that these contrary findings can be explained by the higher hygroscopicity of the dry loam soil, resulting in condensation gains beyond the strict definition of dew. Differences in plant-availability of non-hygroscopic dew water and hygroscopic water uptakes are discussed, and conditions under which mulching would show positive condensation effects are defined. This includes a theoretical section demonstrating that non-hygroscopic mulch layers of a proper thickness can provide small amounts of dew to plant roots at the mulch-soil interface. This condensation could also happen during the day and would be favoured by a high amplitude of the diurnal atmospheric moisture cycle.

Preoperative Subconjunctival Injection of Mitomycin C Versus Intraoperative Topical Application as an Adjunctive Treatment for Surgical Removal of Primary Pterygium

PubMed Central

Ghoneim, Ehab M.; Abd-El Ghny, Ahmed A.; Gab-Allah, Amro A.; Kamal, Mohamed Z.

2011-01-01

Purpose: To compare the efficacy of preoperative local injection of mitomycin C (MMC) to intraoperative application of MMC in the prevention of pterygium recurrence after surgical removal. Materials and Methods: Seventy eyes of 70 patients with primary pterygia were randomly allocated to two groups. The first group (Group A, 35 eyes) received 0.1 ml of 0.15 mg/ml of subconjunctival MMC injected into the head of the pterygium 24 h before surgical excision with the bare sclera technique. The second group (Group B 35 eyes) underwent surgical removal with the bare sclera technique with intraoperative application of MMC (0.15 mg/ml) over bare sclera for 3 min. The study was performed between March 2007 and December 2008, and follow up was performed for 1 year postoperatively. Differences between frequencies in both groups were compared by the Chi-square test or Fisher exact test. Differences between means in both groups were compared by Student’s t-test. P < 0.05 was considered significant. Results: The rate of pterygium recurrence was 5.70% in Group A and 8.57% in Group B at 1 year postoperatively (P>0.05). Postoperatively, scleral thinning occurred in one eye in each group that resolved by 5 months postoperatively. No serious postoperative complications occurred in either group. Conclusion: Preoperative local injection of 0.15 mg/ml MMC is as effective as intraoperative topical application of 0.15 mg/ml MMC for preventing pterygium recurrence after surgical removal. PMID:21572732

Thin scale ecohydrological data and relations at semi-arid regions: a methodological approach

USDA-ARS?s Scientific Manuscript database

In semi-arid regions worldwide the vegetation is organized in patches surrounded by bare soil with marked differences in their soil properties that play important roles in runoff and infiltration. Chihuahuan-Sonoran and Patagonian Monte deserts regions show floristic similarity greater than that ex...

Chiral symmetry breaking in quenched massive strong-coupling four-dimensional QED

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

Hawes, F.T.; Williams, A.G.

1995-03-15

We present results from a study of subtractive renormalization of the fermion propagator Dyson-Schwinger equation (DSE) in massive strong-coupling quenched four-dimensional QED. The results are compared for three different fermion-photon proper vertex [ital Ansa]$[ital uml---tze]: bare [gamma][sup [mu

Story Problem Formats: Verbal Versus Telegraphic.

ERIC Educational Resources Information Center

Moyer, John C.; And Others

1984-01-01

Students in grades three to seven were given tests on which problems were presented in either verbal or telegraphic format. Only in grade six was a significant difference found, favoring the verbal format. Problems with conventional syntax appeared to be easier to interpret than those with bare bones syntax. (MNS)

Laboratory Simulation of Urban Runoff and Estimation of Runoff Hydrographs with Experimental Curve Numbers Implemented in USEPA SWMM

EPA Science Inventory

The prognostic capabilities of a lumped hydrologic modeling approach may be complicated by routing and connectivity among infiltrative and impervious surfaces. We used artificial rainfall to generate runoff from impervious and bare soil boxes arranged in series to simulate differ...

ZnO Functionalization of Surface Pre-treated Multi-walled Carbon Nanotubes for Methane Sensing

EPA Science Inventory

Bare carbon nanotubes (CNTs) cannot be used to sense most gases due to poor bonding between the chemically inert graphitic surface and the different compounds CNTs are exposed to. Consequently, for gas sensing applications, functionalization of CNTs with reactive compounds is req...

5. American elevator looking east barely visible behind American malt ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. American elevator looking east barely visible behind American malt house with Russell-Miller flour mill to right (now Eonacara and idle). - American Elevator, 87 Childs Street, Buffalo, Erie County, NY

Recent Advances in Laser-Ablative Synthesis of Bare Au and Si Nanoparticles and Assessment of Their Prospects for Tissue Engineering Applications.

PubMed

Al-Kattan, Ahmed; Nirwan, Viraj P; Popov, Anton; Ryabchikov, Yury V; Tselikov, Gleb; Sentis, Marc; Fahmi, Amir; Kabashin, Andrei V

2018-05-24

Driven by surface cleanness and unique physical, optical and chemical properties, bare (ligand-free) laser-synthesized nanoparticles (NPs) are now in the focus of interest as promising materials for the development of advanced biomedical platforms related to biosensing, bioimaging and therapeutic drug delivery. We recently achieved significant progress in the synthesis of bare gold (Au) and silicon (Si) NPs and their testing in biomedical tasks, including cancer imaging and therapy, biofuel cells, etc. We also showed that these nanomaterials can be excellent candidates for tissue engineering applications. This review is aimed at the description of our recent progress in laser synthesis of bare Si and Au NPs and their testing as functional modules (additives) in innovative scaffold platforms intended for tissue engineering tasks.

Renormalization of the inflationary perturbations revisited

NASA Astrophysics Data System (ADS)

Markkanen, Tommi

2018-05-01

In this work we clarify aspects of renormalization on curved backgrounds focussing on the potential ramifications on the amplitude of inflationary perturbations. We provide an alternate view of the often used adiabatic prescription by deriving a correspondence between the adiabatic subtraction terms and traditional renormalization. Specifically, we show how adiabatic subtraction can be expressed as a set of counter terms that are introduced by redefining the bare parameters of the action. Our representation of adiabatic subtraction then allows us to easily find other renormalization prescriptions differing only in the finite parts of the counter terms. As our main result, we present for quadratic inflation how one may consistently express the renormalization of the spectrum of perturbations from inflation as a redefinition of the bare cosmological constant and Planck mass such that the observable predictions coincide with the unrenormalized result.

Oxidation and hot corrosion of coated and bare oxide dispersion strengthened superalloy MA-755E

NASA Technical Reports Server (NTRS)

Glasgow, T. K.; Santoro, G. J.

1981-01-01

Cyclic hot corrosion and oxidation of an experimental oxide dispersion strengthened (ODS) superalloy MA-755E were conducted in a hot gas stream at Mach 0.3. The response of the ODS alloy, bare or with protective coatings, was similar to that of a conventional cast alloy, IN-792, in hot corrosion at 900 C. However, during oxidation at 1100 and 1150 C the ODS alloy differed from the cast alloy by developing a greater amount of subsurface porosity. Compared with a diffused aluminide coating, an electron beam vapor deposited NiCrAlY coating offered superior oxidation protection and decreased porosity formation. In additional testing, the tendency to form porosity was associated with the large grains of recrystallized powder metallurgy alloys but was independent of the presence of an oxide dispersion.

Richard E. Smalley, Buckminsterfullerene (the Buckyball), and Nanotubes

Science.gov Websites

: 723-730; July 1997 Supersonic Bare Metal Cluster Beams. Technical Progress Report, March 16, 1984  – April 1, 1985 Includes early cold ion beam technology research Supersonic Bare Metal Cluster Beams

Radiometric measurements over bare and vegetated fields at 1.4 GHz and 5 GHz frequencies. [Beltsville Agricultural Research Center, Maryland

NASA Technical Reports Server (NTRS)

Wang, J. R.; Mcmurtrey, J. E., III; Engman, E. T.; Jackson, T. J.; Schmugge, T. J.; Gould, W. I.; Glazar, W. S.; Fuchs, J. E. (Principal Investigator)

1981-01-01

Microwave emission from bare and vegetated fields was measured with dual polarized radiometers at 1.4 GHz and 5 GHz frequencies. The measured brightness temperatures over bare fields are shown to compare favorably with those calculated from radiative transfer theory with two constant parameters characterizing surface roughness effect. The presence of vegetation cover is found to reduce the sensitivity to soil moisture variation. This sensitivity reduction is generally pronounced the denser, the vegetation cover and the higher the frequency of observation. The effect of vegetation cover is also examined with respect to the measured polarization factor at both frequencies. With the exception of dry corn fields, the measured polarization factor over vegetated fields is found appreciably reduced compared to that over bare fields. A much larger reduction in this factor is found at 5GHz than at 1.4GHz frequency.

Gene Deletion in Barley Mediated by LTR-retrotransposon BARE

PubMed Central

Shang, Yi; Yang, Fei; Schulman, Alan H.; Zhu, Jinghuan; Jia, Yong; Wang, Junmei; Zhang, Xiao-Qi; Jia, Qiaojun; Hua, Wei; Yang, Jianming; Li, Chengdao

2017-01-01

A poly-row branched spike (prbs) barley mutant was obtained from soaking a two-rowed barley inflorescence in a solution of maize genomic DNA. Positional cloning and sequencing demonstrated that the prbs mutant resulted from a 28 kb deletion including the inflorescence architecture gene HvRA2. Sequence annotation revealed that the HvRA2 gene is flanked by two LTR (long terminal repeat) retrotransposons (BARE) sharing 89% sequence identity. A recombination between the integrase (IN) gene regions of the two BARE copies resulted in the formation of an intact BARE and loss of HvRA2. No maize DNA was detected in the recombination region although the flanking sequences of HvRA2 gene showed over 73% of sequence identity with repetitive sequences on 10 maize chromosomes. It is still unknown whether the interaction of retrotransposons between barley and maize has resulted in the recombination observed in the present study. PMID:28252053

The structures of bare and deuterated Co{sub 19}

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

Parks, E.K.; Riley, S.J.

1997-07-01

The structures of bare Co{sub 19} and deuterated Co{sub 19}D{sub m} clusters are examined by the chemical probe method, and earlier assignments of bare Co{sub 19} as an fcc octahedron are reconsidered. New experimental measurements of the reactivity of Co{sub 19} with ammonia, nitrogen, and deuterium are presented, and together with earlier measurements of the reactivity with water suggest that bare Co{sub 19} has an hcp structure (D{sub 3h} symmetry). The adsorption of deuterium on Co{sub 19} is found to proceed in steps, leading to successive saturation levels at Co{sub 19}D{sub 4}, Co{sub 19}D{sub 14}, and Co{sub 19}D{sub 18}. Usingmore » binding rules derived from earlier studies of larger cobalt and nickel clusters, possible D-atom binding sites on Co{sub 19}D{sub m} (both fcc and hcp) are proposed.« less

Fluvial process and the establishment of bottomland trees

USGS Publications Warehouse

Scott, Michael L.; Friedman, Jonathan M.; Auble, Gregor T.

1996-01-01

The relation between streamflow and establishment of bottomland trees is conditioned by the dominant fluvial process or processes acting along a stream. For successful establishment, cottonwoods, poplars, and willows require bare, moist surfaces protected from disturbance. Channel narrowing, channel meandering, and flood deposition promote different spatial and temporal patterns of establishment. During channel narrowing, the site requirements are met on portions of the bed abandoned by the stream, and establishment is associated with a period of low flow lasting one to several years. During channel meandering, the requirements are met on point bars following moderate or higher peak flows. Following flood deposition, the requirements are met on flood deposits ;high above the channel bed. Flood deposition can occur along most streams, but where a channel is constrained by a narrow valley, this process may be the only mechanism that can produce a bare, moist surface high enough to be safe from future disturbance. Because of differences in local bedrock, tributary influence, or geologic history, two nearby reaches of the same stream may be dominated by different fluvial processes and have different spatial and temporal patterns of trees. We illustrate this phenomenon with examples from forests of plains cottonwood (Populus deltoides ssp. monilifera) along meandering and constrained reaches of the Missouri River in Montana.

Bare Bones of Bioactive Glass

NASA Technical Reports Server (NTRS)

2000-01-01

Paul Ducheyne, a principal investigator in the microgravity materials science program and head of the University of Pernsylvania's Center for Bioactive Materials and Tissue Engineering, is leading the trio as they use simulated microgravity to determine the optimal characteristics of tiny glass particles for growing bone tissue. The result could make possible a much broader range of synthetic bone-grafting applications. Even in normal gravity, bioactive glass particles enhance bone growth in laboratory tests with flat tissue cultures. Ducheyne and his team believe that using the bioactive microcarriers in a rotating bioreactor in microgravity will produce improved, three-dimensional tissue cultures. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: NASA and University of Pennsylvania Center for Bioactive Materials and Tissue Engineering.

Sex differences in structural brain asymmetry predict overt aggression in early adolescents.

PubMed

Visser, Troy A W; Ohan, Jeneva L; Whittle, Sarah; Yücel, Murat; Simmons, Julian G; Allen, Nicholas B

2014-04-01

The devastating social, emotional and economic consequences of human aggression are laid bare nightly on newscasts around the world. Aggression is principally mediated by neural circuitry comprising multiple areas of the prefrontal cortex and limbic system, including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), amygdala and hippocampus. A striking characteristic of these regions is their structural asymmetry about the midline (i.e. left vs right hemisphere). Variations in these asymmetries have been linked to clinical disorders characterized by aggression and the rate of aggressive behavior in psychiatric patients. Here, we show for the first time that structural asymmetries in prefrontal cortical areas are also linked to aggression in a normal population of early adolescents. Our findings indicate a relationship between parent reports of aggressive behavior in adolescents and structural asymmetries in the limbic and paralimbic ACC and OFC, and moreover, that this relationship varies by sex. Furthermore, while there was no relationship between aggression and structural asymmetries in the amygdala or hippocampus, hippocampal volumes did predict aggression in females. Taken together, the results suggest that structural asymmetries in the prefrontal cortex may influence human aggression, and that the anatomical basis of aggression varies substantially by sex.

Satellite-derived land covers for runoff estimation using SCS-CN method in Chen-You-Lan Watershed, Taiwan

NASA Astrophysics Data System (ADS)

Zhang, Wen-Yan; Lin, Chao-Yuan

2017-04-01

The Soil Conservation Service Curve Number (SCS-CN) method, which was originally developed by the USDA Natural Resources Conservation Service, is widely used to estimate direct runoff volume from rainfall. The runoff Curve Number (CN) parameter is based on the hydrologic soil group and land use factors. In Taiwan, the national land use maps were interpreted from aerial photos in 1995 and 2008. Rapid updating of post-disaster land use map is limited due to the high cost of production, so the classification of satellite images is the alternative method to obtain the land use map. In this study, Normalized Difference Vegetation Index (NDVI) in Chen-You-Lan Watershed was derived from dry and wet season of Landsat imageries during 2003 - 2008. Land covers were interpreted from mean value and standard deviation of NDVI and were categorized into 4 groups i.e. forest, grassland, agriculture and bare land. Then, the runoff volume of typhoon events during 2005 - 2009 were estimated using SCS-CN method and verified with the measured runoff data. The result showed that the model efficiency coefficient is 90.77%. Therefore, estimating runoff by using the land cover map classified from satellite images is practicable.

Nanocomposite thin films for triggerable drug delivery.

PubMed

Vannozzi, Lorenzo; Iacovacci, Veronica; Menciassi, Arianna; Ricotti, Leonardo

2018-05-01

Traditional drug release systems normally rely on a passive delivery of therapeutic compounds, which can be partially programmed, prior to injection or implantation, through variations in the material composition. With this strategy, the drug release kinetics cannot be remotely modified and thus adapted to changing therapeutic needs. To overcome this issue, drug delivery systems able to respond to external stimuli are highly desirable, as they allow a high level of temporal and spatial control over drug release kinetics, in an operator-dependent fashion. Areas covered: On-demand drug delivery systems actually represent a frontier in this field and are attracting an increasing interest at both research and industrial level. Stimuli-responsive thin films, enabled by nanofillers, hold a tremendous potential in the field of triggerable drug delivery systems. The inclusion of responsive elements in homogeneous or heterogeneous thin film-shaped polymeric matrices strengthens and/or adds intriguing properties to conventional (bare) materials in film shape. Expert opinion: This Expert Opinion review aims to discuss the approaches currently pursued to achieve an effective on-demand drug delivery, through nanocomposite thin films. Different triggering mechanisms allowing a fine control on drug delivery are described, together with current challenges and possible future applications in therapy and surgery.

Improving GLOBALlAND30 Artificial Type Extraction Accuracy in Low-Density Residents

NASA Astrophysics Data System (ADS)

Hou, Lili; Zhu, Ling; Peng, Shu; Xie, Zhenlei; Chen, Xu

2016-06-01

GlobalLand 30 is the first 30m resolution land cover product in the world. It covers the area within 80°N and 80°S. There are ten classes including artificial cover, water bodies, woodland, lawn, bare land, cultivated land, wetland, sea area, shrub and snow,. The TM imagery from Landsat is the main data source of GlobalLand 30. In the artificial surface type, one of the omission error happened on low-density residents' part. In TM images, hash distribution is one of the typical characteristics of the low-density residents, and another one is there are a lot of cultivated lands surrounded the low-density residents. Thus made the low-density residents part being blurred with cultivated land. In order to solve this problem, nighttime light remote sensing image is used as a referenced data, and on the basis of NDBI, we add TM6 to calculate the amount of surface thermal radiation index TR-NDBI (Thermal Radiation Normalized Difference Building Index) to achieve the purpose of extracting low-density residents. The result shows that using TR-NDBI and the nighttime light remote sensing image are a feasible and effective method for extracting low-density residents' areas.

Static Structures, Changing Demographics: Educating Teachers for Shifting Populations in Stable Schools

ERIC Educational Resources Information Center

Portes, Pedro; Smagorinsky, Peter

2010-01-01

Portes and Smagorinsky examine the degree to which stable schools and authoritarian instruction accommodate the needs of learners exhibiting difference, with special attention to Spanish-speaking English Language Learners in a Southern setting. They find that the influx of immigrant students in Southern schools lays bare the normative…

Mulch your tomatoes to fight weeds, retain soil moisture and save money

USDA-ARS?s Scientific Manuscript database

An on-farm experiment was conducted to determine whether different types of mulches were a cost-effective means of weed management in organic tomato production. Three mulch treatment, bare soil, straw and grass, were applied to drip-irrigated tomatoes at a depth of 7.5 cm. Weed biomass was reduced s...

Very Large Scale Aerial (VLSA) imagery for assessing postfire bitterbrush recovery

Treesearch

Corey A. Moffet; J. Bret Taylor; D. Terrance Booth

2008-01-01

Very large scale aerial (VLSA) imagery is an efficient tool for monitoring bare ground and cover on extensive rangelands. This study was conducted to determine whether VLSA images could be used to detect differences in antelope bitterbrush (Purshia tridentata Pursh DC) cover and density among similar ecological sites with varying postfire recovery...

Modality, Infinitives, and Finite Bare Verbs in Dutch and English Child Language

ERIC Educational Resources Information Center

Blom, Elma

2007-01-01

This article focuses on the meaning of nonfinite clauses ("root infinitives") in Dutch and English child language. I present experimental and naturalistic data confirming the claim that Dutch root infinitives are more often modal than English root infinitives. This cross-linguistic difference is significantly smaller than previously assumed,…

Extra-Vehicular Activity (EVA) glove evaluation test protocol

NASA Technical Reports Server (NTRS)

Hinman-Sweeney, E. M.

1994-01-01

One of the most critical components of a space suit is the gloves, yet gloves have traditionally presented significant design challenges. With continued efforts at glove development, a method for evaluating glove performance is needed. This paper presents a pressure-glove evaluation protocol. A description of this evaluation protocol, and its development is provided. The protocol allows comparison of one glove design to another, or any one design to bare-handed performance. Gloves for higher pressure suits may be evaluated at current and future design pressures to drive out differences in performance due to pressure effects. Using this protocol, gloves may be evaluated during design to drive out design problems and determine areas for improvement, or fully mature designs may be evaluated with respect to mission requirements. Several different test configurations are presented to handle these cases. This protocol was run on a prototype glove. The prototype was evaluated at two operating pressures and in the unpressurized state, with results compared to bare-handed performance. Results and analysis from this test series are provided, as is a description of the configuration used for this test.

[Variation characteristics and influencing factors of actual evapotranspiration under various vegetation types: A case study in the Huaihe River Basin, China.

PubMed

Wu, Rong Jun; Xing, Xiao Yong

2016-06-01

The actual evapotranspiration was modelled utilizing the boreal ecosystem productivity simulator (BEPS) in Huaihe River Basin from 2001 to 2012. In the meantime, the quantitative analyses of the spatial-temporal variations of actual evapotranspiration characteristics and its influencing factors under different vegetation types were conducted. The results showed that annual evapotranspiration gradually decreased from southeast to northwest, tended to increase annually, and the monthly change for the average annual evapotranspiration was double-peak curve. The differences of evapotranspiration among vegetation types showed that the farmland was the largest contributor for the evapotranspiration of Huaihe Basin. The annual actual evapotranspiration of the mixed forest per unit area was the largest, and that of the bare ground per unit area was the smallest. The changed average annual evapotranspiration per unit area for various vegetation types indicated an increased tendency other than the bare ground, with a most significant increase trend for the evergreen broadleaf forest. The thermodynamic factors (such as average temperature) were the dominant factors affecting the actual evapotranspiration in the Huaihe Basin, followed by radiation and moisture factors.

Pre- and postoperative magnetic resonance imaging appearance of the normal residual pituitary gland following macroadenoma resection: Clinical implications

PubMed Central

Maio, Salvatore Di; Biswas, Arundhati; Vézina, Jean Lorrain; Hardy, Jules; Mohr, Gérard

2012-01-01

Background: To assess the relationship between the preoperative magnetic resonance imaging (MRI) appearance of the normal residual pituitary gland (NRPG) and pituitary functional outcome following transsphenoidal resection of pituitary macroadenomas. Methods: We retrospectively reviewed the medical records of 100 consecutive patients with a pituitary macroadenoma, who underwent transsphenoidal resection. The preoperative configuration of the displaced NRPG was stratified as superior, superolateral or lateral. The extent of postoperative restitution of the NRPG was divided into four groups: Group 1 — normal residual gland or almost normal; Group 2 — more than 50% restitution; Group 3 — less than 50% of the normal residual gland; and Group 4 — barely visible or absent residual gland. The pre- and postoperative NRPG appearance was correlated with pituitary functional status. Results: Preoperatively, the NRPG was identifiable in 79 patients, with extrasellar displacement in 53%. The displacement pattern was superior in 8%, superolateral in 32%, and lateral in 58% of the patients. If the NRPG was displaced laterally, the ipsilateral cavernous sinus was not invaded by the pituitary macroadenoma. Partial or complete pituitary function was lost in 6 / 23 (26.1%) patients with superior or superolateral displacement of the NRPG, compared to only 1 / 36 (2.8%) patients without superior displacement of the NRPG (P = 0.025). Progressive postoperative reconstitution of the NRPG was related to the preservation of the pituitary hormonal axis (Pearson Chi-Square P < 0.001). Conclusions: Progressive displacement of the NRPG preoperatively, and lack of restitution of the NRPG on postoperative MRI appeared to correlate with the postoperative pituitary functional loss. PMID:22754732

The Pseudogap in Multiband Superconductivity

NASA Astrophysics Data System (ADS)

Kristoffel, N.; Rubin, P.

2012-11-01

The pseudogap (PG) excitation is analyzed as a natural event in multiband superconductivity. It corresponds to minimal quasiparticle excitation energy of an electron band not touched by the chemical potential. The critical points of the phase diagram are determined by vanishing conditions for normal state pseudogaps (NPG). For two bands (gapped or overlapping) these are positioned on edges of the superconducting dome. Theoretical background for a three-band system with two interband pairing channels is developed. There are three independent superconducting gaps (SCG). The PG is associated with the band component possessing a bare gap which can be quenched by doping. At low doping the PG and the SCG of another band component coexist. The critical point is not fixed in respect of the transition temperature (Tc) dome background. The depletion of the PG associated states is restored here. This effect can also be indirect by the participation of these states in determining the chemical potential position. At the critical point the PG looses its normal state contribution and continues as the SCG of the same band. Illustrative examples on the doping scale have been calculated.

How Spatial Heterogeneity of Cover Affects Patterns of Shrub Encroachment into Mesic Grasslands

PubMed Central

Montané, Francesc; Casals, Pere; Dale, Mark R. T.

2011-01-01

We used a multi-method approach to analyze the spatial patterns of shrubs and cover types (plant species, litter or bare soil) in grassland-shrubland ecotones. This approach allows us to assess how fine-scale spatial heterogeneity of cover types affects the patterns of Cytisus balansae shrub encroachment into mesic mountain grasslands (Catalan Pyrenees, Spain). Spatial patterns and the spatial associations between juvenile shrubs and different cover types were assessed in mesic grasslands dominated by species with different palatabilities (palatable grass Festuca nigrescens and unpalatable grass Festuca eskia). A new index, called RISES (“Relative Index of Shrub Encroachment Susceptibility”), was proposed to calculate the chances of shrub encroachment into a given grassland, combining the magnitude of the spatial associations and the surface area for each cover type. Overall, juveniles showed positive associations with palatable F. nigrescens and negative associations with unpalatable F. eskia, although these associations shifted with shrub development stage. In F. eskia grasslands, bare soil showed a low scale of pattern and positive associations with juveniles. Although the highest RISES values were found in F. nigrescens plots, the number of juvenile Cytisus was similar in both types of grasslands. However, F. nigrescens grasslands showed the greatest number of juveniles in early development stage (i.e. height<10 cm) whereas F. eskia grasslands showed the greatest number of juveniles in late development stages (i.e. height>30 cm). We concluded that in F. eskia grasslands, where establishment may be constrained by the dominant cover type, the low scale of pattern on bare soil may result in higher chances of shrub establishment and survival. In contrast, although grasslands dominated by the palatable F. nigrescens may be more susceptible to shrub establishment; current grazing rates may reduce juvenile survival. PMID:22174858

Increase in soil stable carbon isotope ratio relates to loss of organic carbon: results from five long-term bare fallow experiments.

PubMed

Menichetti, Lorenzo; Houot, Sabine; van Oort, Folkert; Kätterer, Thomas; Christensen, Bent T; Chenu, Claire; Barré, Pierre; Vasilyeva, Nadezda A; Ekblad, Alf

2015-03-01

Changes in the (12)C/(13)C ratio (expressed as δ(13)C) of soil organic C (SOC) has been observed over long time scales and with depth in soil profiles. The changes are ascribed to the different reaction kinetics of (12)C and (13)C isotopes and the different isotopic composition of various SOC pool components. However, experimental verification of the subtle isotopic shifts associated with SOC turnover under field conditions is scarce. We determined δ(13)C and SOC in soil sampled during 1929-2009 in the Ap-horizon of five European long-term bare fallow experiments kept without C inputs for 27-80 years and covering a latitudinal range of 11°. The bare fallow soils lost 33-65% of their initial SOC content and showed a mean annual δ(13)C increase of 0.008-0.024‰. The (13)C enrichment could be related empirically to SOC losses by a Rayleigh distillation equation. A more complex mechanistic relationship was also examined. The overall estimate of the fractionation coefficient (ε) was -1.2 ± 0.3‰. This coefficient represents an important input to studies of long-term SOC dynamics in agricultural soils that are based on variations in (13)C natural abundance. The variance of ε may be ascribed to site characteristics not disclosed in our study, but the very similar kinetics measured across our five experimental sites suggest that overall site-specific factors (including climate) had a marginal influence and that it may be possible to isolate a general mechanism causing the enrichment, although pre-fallow land use may have some impact on isotope abundance and fractionation.

Vertical distribution and retention mechanism of nitrogen and phosphorus in soils with different macrophytes of a natural river mouth wetland.

PubMed

Huang, Wei; Chen, Qiuwen; Ren, Kuixiao; Chen, Kaining

2015-03-01

Wetland vegetation can improve water quality through several processes including direct assimilation and the indirect effects of sedimentation and mineralization. This research takes the Zhucao River mouth of Daxi reservoir as a study case to investigate the vertical distribution of nitrogen and phosphorus in the soil of a natural wetland covered by different plants prior to any restoration action. There are four native emergent macrophytes (Typha latifolia L., Polygonum hydropiper L., Juncus effuses L., Phragmites communis L.) in the wetland. The total nitrogen (TN) and nitrate contents decreased with the soil depth for all vegetation types, and the mean TN and nitrate concentrations were higher in vegetative soil than in bare ground. The maximum TN concentration was found in the surface soil (0-2 cm) covered by P. communis. Ammonium decreased with the soil depth in vegetative areas, while it increased with soil depth in bare ground. The rank order of P fractions was organic P (OP) > P associated with Ca (Ca-P) > P associated with Fe/Al (Fe/Al-P). Total phosphorus (TP) and OP showed vertical profiles similar to that of TN. The mean concentrations of TP, Ca-P and Fe/Al-P were higher in vegetative soil than in bare ground. The maximum mean TP was also found in soil covered by P. communis. Loss on ignition (LOI) was significantly correlated with TN and TP (P < 0.05). Organic matter accumulation may be the main pathway to retain nitrogen and phosphorus in the wetland. Nitrogen and phosphorus sequestration in P. communis soil was the highest of the four dominant plants. The results could support the restoration of other degraded river mouth wetlands of the reservoir.

Antennas in matter: Fundamentals, theory, and applications

NASA Technical Reports Server (NTRS)

King, R. W. P.; Smith, G. S.; Owens, M.; Wu, T. T.

1981-01-01

The volume provides an introduction to antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. After a fundamental analysis of insulated and bare antennas, an advanced treatment of antennas in various media is presented, including a detailed study of the electromagnetic equations in homogeneous isotropic media, the complete theory of the bare dipole in a general medium, and a rigorous analysis of the insulated antenna as well as bare and insulated loop antennas. Finally, experimental models and measuring techniques related to antennas and probes in a general dissipative or dielectric medium are examined.

A systematic review and meta-analysis of randomized trials and prospective studies comparing covered and bare self-expandable metal stents for the treatment of malignant obstruction in the digestive tract.

PubMed

Yang, Zhiping; Wu, Qiong; Wang, Fang; Ye, Xiaofei; Qi, Xingshun; Fan, Daiming

2013-01-01

Self-expandable metal stents (SEMS) are widely used for the palliative treatment of malignant gastrointestinal obstruction. Our aim was to evaluate the evidence comparing covered and bare SEMS in the digestive tract using meta-analytical techniques. A literature search was performed using PubMed, Cochrane Library, and Embase databases for comparative studies assessing the two types of stents. The primary outcomes of interest were stent patency and patient survival; second outcomes included technical success, clinical success, tumor ingrowth, tumor overgrowth, and stent migration. A random-effects model was conducted. Pooled analysis was done separately based on the different segments of the digestive tract. Eleven studies (8 randomized controlled trials and 3 prospective cohort studies) including a total of 1376 patients were identified. Covered SEMS were equivalent to bare SEMS in terms of technical success, clinical success, stent patency (gastroduodenal obstruction: HR =0.87, 95% CI 0.53-1.42; colorectal obstruction: HR =0.89, 95% CI 0.18-4.45; biliary obstruction: HR =0.73, 95% CI 0.41-1.32) and survival rates (esophageal obstruction: HR =1.80, 95% CI 0.73-4.44; gastroduodenal obstruction: HR =0.83, 95% CI 0.55-1.26; biliary obstruction: HR =0.99, 95% CI 0.77-1.28), although bare stents were more prone to tumor ingrowth (esophageal obstruction: RR =0.10, 95% CI 0.01-0.77; gastroduodenal obstruction: RR =0.12, 95% CI 0.03-0.55; colorectal obstruction: RR =0.21, 95% CI 0.06-0.70; biliary obstruction: RR =0.21, 95% CI 0.06-0.69), whereas covered stents had the higher risk of stent migration (gastroduodenal obstruction: RR =5.01, 95% CI 1.53-16.43; colorectal obstruction: RR =11.70, 95% CI 2.84-48.27; biliary obstruction: RR =8.11, 95% CI 1.47-44.76) and tumor overgrowth (biliary obstruction: RR =2.03, 95% CI 1.08-3.78). Both covered and bare SEMS are comparable in efficacy for the palliative treatment of malignant obstruction in the digestive tract. Each type of the stents has its own merit and demerit relatively.

Modeling the Impact of Soil and Water Conservation on Surface and Ground Water Based on the SCS and Visual Modflow

PubMed Central

Wang, Hong; Gao, Jian-en; Zhang, Shao-long; Zhang, Meng-jie; Li, Xing-hua

2013-01-01

Soil and water conservation measures can impact hydrological cycle, but quantitative analysis of this impact is still difficult in a watershed scale. To assess the effect quantitatively, a three-dimensional finite-difference groundwater flow model (MODFLOW) with a surface runoff model–the Soil Conservation Service (SCS) were calibrated and applied based on the artificial rainfall experiments. Then, three soil and water conservation scenarios were simulated on the sand-box model to assess the effect of bare slope changing to grass land and straw mulching on water volume, hydraulic head, runoff process of groundwater and surface water. Under the 120 mm rainfall, 60 mm/h rainfall intensity, 5 m2 area, 3° slope conditions, the comparative results indicated that the trend was decrease in surface runoff and increase in subsurface runoff coincided with the land-use converted from bare slope to grass land and straw mulching. The simulated mean surface runoff modulus was 3.64×10−2 m3/m2/h in the bare slope scenario, while the observed values were 1.54×10−2 m3/m2/h and 0.12×10−2 m3/m2/h in the lawn and straw mulching scenarios respectively. Compared to the bare slope, the benefits of surface water reduction were 57.8% and 92.4% correspondingly. At the end of simulation period (T = 396 min), the simulated mean groundwater runoff modulus was 2.82×10−2 m3/m2/h in the bare slope scenario, while the observed volumes were 3.46×10−2 m3/m2/h and 4.91×10−2 m3/m2/h in the lawn and straw mulching scenarios respectively. So the benefits of groundwater increase were 22.7% and 60.4% correspondingly. It was concluded that the soil and water conservation played an important role in weakening the surface runoff and strengthening the underground runoff. Meanwhile the quantitative analysis using a modeling approach could provide a thought for the study in a watershed scale to help decision-makers manage water resources. PMID:24244427

Negative plant soil feedback explaining ring formation in clonal plants.

PubMed

Cartenì, Fabrizio; Marasco, Addolorata; Bonanomi, Giuliano; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

2012-11-21

Ring shaped patches of clonal plants have been reported in different environments, but the mechanisms underlying such pattern formation are still poorly explained. Water depletion in the inner tussocks zone has been proposed as a possible cause, although ring patterns have been also observed in ecosystems without limiting water conditions. In this work, a spatially explicit model is presented in order to investigate the role of negative plant-soil feedback as an additional explanation for ring formation. The model describes the dynamics of the plant biomass in the presence of toxicity produced by the decomposition of accumulated litter in the soil. Our model qualitatively reproduces the emergence of ring patterns of a single clonal plant species during colonisation of a bare substrate. The model admits two homogeneous stationary solutions representing bare soil and uniform vegetation cover which depend only on the ratio between the biomass death and growth rates. Moreover, differently from other plant spatial patterns models, but in agreement with real field observations of vegetation dynamics, we demonstrated that the pattern dynamics always lead to spatially homogeneous vegetation covers without creation of stable Turing patterns. Analytical results show that ring formation is a function of two main components, the plant specific susceptibility to toxic compounds released in the soil by the accumulated litter and the decay rate of these same compounds, depending on environmental conditions. These components act at the same time and their respective intensities can give rise to the different ring structures observed in nature, ranging from slight reductions of biomass in patch centres, to the appearance of marked rings with bare inner zones, as well as the occurrence of ephemeral waves of plant cover. Our results highlight the potential role of plant-soil negative feedback depending on decomposition processes for the development of transient vegetation patterns. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Effect of Light Intensity, Temperature, and Oxygen Pressure on the Photo-Oxidation Rate of Bare PbS Quantum Dots.

PubMed

Liu, Huiyan; Dong, Qian; Lopez, Rene

2018-05-18

The oxidation speed of PbS quantum dots has been a subject of controversy for some time. In this study, we reveal the precise functional form of the oxidation rate constant for bare quantum dots through analysis of their photoluminescence as a function of temperature, oxygen pressure, and excitation-laser intensity. The combined effect of these factors results in a reduced energy barrier that allows the oxidation to proceed at a high rate. Each absorbed photon is found to have a 10 -8 probability of oxidizing a PbS atomic pair. This highlights the importance of photo-excitation on the speed of the oxidation process, even at low illumination conditions. The procedure used here may set up a quantitative standard useful for characterizing the stability of quantum dots coated with ligands/linkers, and to compare different protection schemes in a fair quantitative way.

Biogeomorphic feedback between plant growth and flooding causes alternative stable states in an experimental floodplain

NASA Astrophysics Data System (ADS)

Wang, Chen; Wang, Qiao; Meire, Dieter; Ma, Wandong; Wu, Chuanqing; Meng, Zhen; Van de Koppel, Johan; Troch, Peter; Verhoeven, Ronny; De Mulder, Tom; Temmerman, Stijn

2016-07-01

It is important to understand the mechanisms of vegetation establishment on bare substrate in a disturbance-driven ecosystem because of many valuable ecosystem services. This study tested for empirical indications of local alternative stable states controlled by biogeomorphic feedbacks using flume experiments with alfalfa: (1) single flood experiments different in flood intensity and plant growth, (2) long-term evolution experiments with repeated flooding and seeding. We observed: (1) a combination of thresholds in plant growth and flooding magnitude for upgrowing seedlings to survive; (2) bimodality in vegetation biomass after floods indicating the existence of two alternative states, either densely vegetated or bare; (3) facilitation of vegetation establishment by the spatial pattern formation of channels and sand bars. In conclusion, empirical indicators were demonstrated for local alternative stable states in a disturbance-driven ecosystem associated with biogeomorphic feedbacks, which could contribute to the protection and restoration of vegetation in such ecosystems.

Tropical Wetland Monitoring Using RapidEye and Sentinel 1 Satellite Images in Ifakara (Tanzania)

NASA Astrophysics Data System (ADS)

Kirimi, Fridah; Menz, Gunter

2016-08-01

Food insecurity has been a topic of concern particularly for the developing countries. Wetlands have a consistent supply of water throughout the year. To determine whether the utilization of the wetland for increased food production is viable, there was need to analyse the land uses in different months of the year to better understand the dynamics of existing vegetation.Support Vector Machine was used to classify the optical to establish the dynamics of changing vegetation. Bare land coverage gives an indication of the potentially available land that can be utilized for crop growth. The optical images are affected by cloud coverage. As a remedial action the use of SAR images in monitoring the wetlands is assessed. A great percentage of land remains bare. Quantification of this from the classified images forms a basis upon which decisions on strategic plans of increasing production sustainably in the region can be implemented.

Endovascular treatment of the extracranial carotid pseudoaneurysms resulting from stab penetrating injury using overlapping bare stents.

PubMed

Pan, Yao-hua; Lin, Yong; Ding, Sheng-hao; Chen, Lei; Liang, Yu-ming; Yin, Yu-hua; Bao, Ying-hui; Gao, Guo-Yi; Qiu, Yong-ming; Jiang, Ji-yao

2014-05-01

Injury pertaining to the common carotid artery may result in complete or partial arterial transection, pseudoaneurysms, or arteriovenous connections. Endovascular treatment option of the pseudoaneurysm has already been established with favorable success rate and minimal morbidity. Our purpose is to report one 18-year-old male patient having 2 traumatic pseudoaneurysms as a result of penetrating stab injury in the extracranial common carotid. The patient was successfully treated using 2 overlapping bare-metal stents. The 2 common carotid pseudoaneurysms had different degree inflow angles defined as the space between the lines indicating the direction of blood flow from the parent artery and through the aneurysmal neck to the dome. Computed tomography angiography was utilized to follow the evolution of the pseudoaneurysms until total occlusion was demonstrated. The treatment modality used in this report represents an alternative approach of the endovascular treatment for the extracranial carotid pseudoaneurysm.

[Study of the microwave emissivity characteristics over different land cover types].

PubMed

Zhang, Yong-Pan; Jiang, Ling-Mei; Qiu, Yu-Bao; Wu, Sheng-Li; Shi, Jian-Cheng; Zhang, Li-Xin

2010-06-01

The microwave emissivity over land is very important for describing the characteristics of the lands, and it is also a key factor for retrieving the parameters of land and atmosphere. Different land covers have their emission behavior as a function of structure, water content, and surface roughness. In the present study the global land surface emissivities were calculated using six month (June, 2003-August, 2003, Dec, 2003-Feb, 2004) AMSR-E L2A brightness temperature, MODIS land surface temperature and the layered atmosphere temperature, and humidity and pressure profiles data retrieved from MODIS/Aqua under clear sky conditions. With the information of IGBP land cover types, "pure" pixels were used, which are defined when the fraction cover of each land type is larger than 85%. Then, the emissivity of sixteen land covers at different frequencies, polarization and their seasonal variation were analyzed respectively. The results show that the emissivity of vegetation including forests, grasslands and croplands is higher than that over bare soil, and the polarization difference of vegetation is smaller than that of bare soil. In summer, the emissivity of vegetation is relatively stable because it is in bloom, therefore the authors can use it as its emissivity in our microwave emissivity database over different land cover types. Furthermore, snow cover can heavily impact the change in land cover emissivity, especially in winter.

Evaporation from bare ground with different water-table depths based on an in-situ experiment in Ordos Plateau, China

NASA Astrophysics Data System (ADS)

Zhang, Zaiyong; Wang, Wenke; Wang, Zhoufeng; Chen, Li; Gong, Chengcheng

2018-03-01

The dynamic processes of ground evaporation are complex and are related to a multitude of factors such as meteorological influences, water-table depth, and materials in the unsaturated zone. To investigate ground evaporation from a homogeneous unsaturated zone, an in-situ experiment was conducted in Ordos Plateau of China. Two water-table depths were chosen to explore the water movement in the unsaturated zone and ground evaporation. Based on the experimental and calculated results, it was revealed that (1) bare ground evaporation is an atmospheric-limited stage for the case of water-table depth being close to the capillary height; (2) the bare ground evaporation is a water-storage-limited stage for the case of water-table depth being beyond the capillary height; (3) groundwater has little effect on ground-surface evaporation when the water depth is larger than the capillary height; and (4) ground evaporation is greater at nighttime than that during the daytime; and (5) a liquid-vapor interaction zone at nearly 20 cm depth is found, in which there exists a downward vapor flux on sunny days, leading to an increasing trend of soil moisture between 09:00 to 17:00; the maximum value is reached at midday. The results of this investigation are useful to further understand the dynamic processes of ground evaporation in arid areas.

Quantifying the influence of deep soil moisture on ecosystem albedo: The role of vegetation

NASA Astrophysics Data System (ADS)

Sanchez-Mejia, Zulia Mayari; Papuga, Shirley Anne; Swetish, Jessica Blaine; van Leeuwen, Willem Jan Dirk; Szutu, Daphne; Hartfield, Kyle

2014-05-01

As changes in precipitation dynamics continue to alter the water availability in dryland ecosystems, understanding the feedbacks between the vegetation and the hydrologic cycle and their influence on the climate system is critically important. We designed a field campaign to examine the influence of two-layer soil moisture control on bare and canopy albedo dynamics in a semiarid shrubland ecosystem. We conducted this campaign during 2011 and 2012 within the tower footprint of the Santa Rita Creosote Ameriflux site. Albedo field measurements fell into one of four Cases within a two-layer soil moisture framework based on permutations of whether the shallow and deep soil layers were wet or dry. Using these Cases, we identified differences in how shallow and deep soil moisture influence canopy and bare albedo. Then, by varying the number of canopy and bare patches within a gridded framework, we explore the influence of vegetation and soil moisture on ecosystem albedo. Our results highlight the importance of deep soil moisture in land surface-atmosphere interactions through its influence on aboveground vegetation characteristics. For instance, we show how green-up of the vegetation is triggered by deep soil moisture, and link deep soil moisture to a decrease in canopy albedo. Understanding relationships between vegetation and deep soil moisture will provide important insights into feedbacks between the hydrologic cycle and the climate system.

[Assessment of the course of ischemic heart disease after placement of stents with drug covering and uncovered metal stents: data of 3 years follow-up].

PubMed

Buza, V V; Karpov, Iu A; Samko, A N; Deev, A D; Lopukhova, V V; Levitskiĭ, I V; Sozykin, A V

2009-01-01

The placement of sirolimus-eluting stents decreases the frequency of repeat revascularization procedures in patients undergoing percutaneous coronary intervention (PCI) in randomized clinical trials. However, there is uncertainty about the effectiveness of sirolimus-eluting stents, and increasing concern about their safety in routine clinical practice. From the prof. Samko PCI laboratory in Moscow, Russia, we identified 426 patients, who received either bare-metal stents alone or sirolimus-eluting stents alone during an index PCI procedure between March 1, 2002, and September 31, 2004.The primary outcomes of the study were the rates of target-lesion revascularization, myocardial infarction, death, late stent thrombosis. The 3-year rate of target-lesion revascularization was significantly lower among patients who received sirolimus-eluting stents than among those who received bare-metal stents (3.1% vs. 19 %, p=0.001). The 3-year mortality rate was not different between the bare-metal stent group and the sirolimus eluting stent group (5.9% vs. 7.2%, p=0.68), the 3-year rate of all ARC late stent thrombosis was similar in the two groups (5.9% and 7.2%, respectively; p=0.95). Sirolimus-eluting stents are effective in reducing the need for target-vessel revascularization without significantly increased rates of death, late stent thrombosis, myocardial infarction.

Study on functional relationships between ergonomics indexes of manual performance

NASA Astrophysics Data System (ADS)

Hu, Hui-Min; Ding, Li; Chen, Shou-Ping; Yang, Chun-Xin; Yuan, Xiu-Gan

This paper investigates functional relationships between some of the key ergonomics indexes in manual performance, and attempts to condense the ergonomics appraisal indexes system and thus evaluate hand performance wearing EVA (extravehicular activity) glove, design and improve EVA glove's performance. Four types of ergonomics indexes were studied, i.e., dexterity, tactile sensibility (TS), strength and fatigue. Two test items of insert sticks into a holes-board (ISIHB) and nuts-bolts assembly task (NBAT) were used to measure dexterity, while shape discrimination (SD) was employed for TS, and grip force (GF) for strength and fatigue. The variables measured in this investigation included accomplishing time (AT) of ISIHB and NBAT, correct rate (CR) of SD, maximal grip force (MGF), instant grip force (IGF) and endurance time of grip force (ETGF). Experiments were conducted on 31 undergraduates (eight female and 23 male) with two experiment conditions of bare-hand group and gloved hand group. Results demonstrated that dexterity and TS performance of gloved hand group declined significantly compared with those of bare-hand group (p<0.001). There were not significant differences in strength and fatigue between two conditions (p>0.05). Four effective functional relationships were developed between four pairs of ergonomics indexes in bare-hand group. In gloved hand group, in addition to above-mentioned four pairs of relationships, another formula was found, which was y^=0.02061+0.01233x ( p<0.01, dexterity and TS).

Comparison and analysis of empirical equations for soil heat flux for different cropping systems and irrigation methods

USGS Publications Warehouse

Irmak, A.; Singh, Ramesh K.; Walter-Shea, Elizabeth; Verma, S.B.; Suyker, A.E.

2011-01-01

We evaluated the performance of four models for estimating soil heat flux density (G) in maize (Zea mays L.) and soybean (Glycine max L.) fields under different irrigation methods (center-pivot irrigated fields at Mead, Nebraska, and subsurface drip irrigated field at Clay Center, Nebraska) and rainfed conditions at Mead. The model estimates were compared against measurements made during growing seasons of 2003, 2004, and 2005 at Mead and during 2005, 2006, and 2007 at Clay Center. We observed a strong relationship between the G and net radiation (Rn) ratio (G/Rn) and the normalized difference vegetation index (NDVI). When a significant portion of the ground was bare soil, G/Rn ranged from 0.15 to 0.30 and decreased with increasing NDVI. In contrast to the NDVI progression, the G/Rn ratio decreased with crop growth and development. The G/Rn ratio for subsurface drip irrigated crops was smaller than for the center-pivot irrigated crops. The seasonal average G was 13.1%, 15.2%, 10.9%, and 12.8% of Rn for irrigated maize, rainfed maize, irrigated soybean, and rainfed soybean, respectively. Statistical analyses of the performance of the four models showed a wide range of variation in G estimation. The root mean square error (RMSE) of predictions ranged from 15 to 81.3 W m-2. Based on the wide range of RMSE, it is recommended that local calibration of the models should be carried out for remote estimation of soil heat flux.

The gut microbiome restores intrinsic and extrinsic nerve function in germ-free mice accompanied by changes in calbindin.

PubMed

McVey Neufeld, K A; Perez-Burgos, A; Mao, Y K; Bienenstock, J; Kunze, W A

2015-05-01

The microbiome is essential for normal myenteric intrinsic primary afferent neuron (IPAN) excitability. These neurons control gut motility and modulate gut-brain signaling by exciting extrinsic afferent fibers innervating the enteric nervous system via an IPAN to extrinsic fiber sensory synapse. We investigated effects of germ-free (GF) status and conventionalization on extrinsic sensory fiber discharge in the mesenteric nerve bundle and IPAN electrophysiology, and compared these findings with those from specific pathogen-free (SPF) mice. As we have previously shown that the IPAN calcium-dependent slow afterhyperpolarization (sAHP) is enhanced in GF mice, we also examined the expression of the calcium-binding protein calbindin in these neurons in these different animal groups. IPAN sAHP and mesenteric nerve multiunit discharge were recorded using ex vivo jejunal gut segments from SPF, GF, or conventionalized (CONV) mice. IPANs were excited by adding 5 μM TRAM-34 to the serosal superfusate. We probed for calbindin expression using immunohistochemical techniques. SPF mice had a 21% increase in mesenteric nerve multiunit firing rate and CONV mice a 41% increase when IPANs were excited by TRAM-34. For GF mice, this increase was barely detectable (2%). TRAM-34 changed sAHP area under the curve by -77 for SPF, +3 for GF, or -54% for CONV animals. Calbindin-immunopositive neurons per myenteric ganglion were 36% in SPF, 24% in GF, and 52% in CONV animals. The intact microbiome is essential for normal intrinsic and extrinsic nerve function and gut-brain signaling. © 2015 John Wiley & Sons Ltd.

Change in size and impact performance of football helmets from the 1970s to 2010.

PubMed

Viano, David C; Halstead, David

2012-01-01

Linear impactor tests were conducted on football helmets from the 1970s-1980s to complement recently reported tests on 1990 s and 2010 s helmets. Helmets were placed on the Hybrid III head with an array of accelerometers to determine translational and rotational acceleration. Impacts were at four sites on the helmet shell at 3.6-11.2 m/s. The four generations of helmets show a continuous improvement in response from bare head impacts in terms of Head Injury Criterion (HIC), peak head acceleration and peak rotational acceleration. Helmets of 2010 s weigh 1.95 ± 0.2 kg and are 2.7 times heavier than 1970s designs. They are also 4.3 cm longer, 7.6 cm higher, and 4.9 cm wider. The extra size and weight allow the use of energy absorbing padding that lowers forces in helmet impacts. For frontal impacts at 7.4 m/s, the four best performing 2010 s helmets have HIC of 148 ± 23 compared to 179 ± 42 for the 1990 s baseline, 231 ± 27 for the 1980s, 253 ± 22 for the 1970s helmets, and 354 ± 3 for the bare head. The additional size and padding of the best 2010 s helmets provide superior attenuation of impact forces in normal play and in conditions associated with concussion than helmets of the 1970s-1990 s.

Relationship Between Oral Perception and Habitual Chewing Side for Bare Bone Graft With Dental Implants After Mandibular Reconstruction.

PubMed

Noguchi, Tadahide; Tsuchiya, Yoshiyuki; Sarukawa, Shunji; Yamazaki, Yuko; Hayasaka, Jun-Ichi; Sasaguri, Ken-Ichi; Jinbu, Yoshinori; Mori, Yoshiyuki

2016-07-01

The purpose of this study was to investigate the relationship between habitual chewing side and perception of the oral mucosa following reconstruction with dental implants. Five patients comprised 2 males and 3 females, with ameloblastoma in 2 patients, odontogenic myxoma in 2 patients, and oral squamous cell carcinoma in 1 patient. They were treated using mandibular reconstruction with bare bone graft after segmental resection of the mandible. Perception (tactile, warm, and cold) was measured at 8 points (chin, lower lip, gingiva, and lateral edge of the tongue, bilaterally). Habitual chewing side was evaluated using a computerized index, the first chewing cycle, and a question on chewing. Perception on resected sides was improved at all measurement points for tactile and cold sensitive evaluation, although sensitivities on the resected side remained below the normal range. In the relationship between habitual chewing side and implanted prostheses in reconstructed bone, the chewing side was the resected side in 2 of the 5 patients. When those 2 patients underwent prosthesis implantation after removal of denture, the chewing side changed from the nonresected side to the resected side. Implant prostheses on resected side were suggested to contribute to masticatory function. Perception in those patients was incomplete but was improved compared with other patients. When prosthesis implantation is performed on the reconstructed side, the resected side may become the habitual chewing side. Recovery of perception can influence acquisition of the habitual chewing side.

Detection of damaged areas caused by the oil extraction in a steppe region using winter landsat imagery

NASA Astrophysics Data System (ADS)

Mjachina, Ksenya; Hu, Zhiyong; Chibilyev, Alexander

2018-01-01

Oil production in a steppe region disturbs the landscape and damages the steppe ecosystem. The objective of this research was to detect areas damaged by oil production in an oil field within the Russian Volga-Ural steppe region using winter Landsat imagery. We developed a practicable and effective approach using winter snow season multispectral Landsat satellite imagery. To this end, we applied seven algorithms of spectral or texture-based transformation: K-means, maximum likelihood estimation, topsoil grain size index, soil brightness, normalized differential snow index, tasselled cap, and co-occurrence measures. The co-occurrence texture measure variance shows the optimal result of identifying damaged areas. The unique feature of our method is that it can differentiate damaged areas from the bare soil of cropland within a cold steppe region where the area damaged by oil production is mixed with bare (fallow) croplands that have a polygonal shape similar to well pads. Such similarities can lead to confusion in object-based classification. Using the co-occurrence measures, we found that from 1988 to 2015, damaged area is nearly three times as big in the peak period of the oil field development (2001 and 2009) as in 1988. Landscape fragmentation also peaked in 2001 and 2009. Our approach for this project is useful and cost effective regular monitoring of damages from oil production for both the Volga-Ural steppe region and other cold steppe regions.

Stent-protected carotid angioplasty using a membrane stent: a comparative cadaver study.

PubMed

Müller-Hülsbeck, Stefan; Gühne, Albrecht; Tsokos, Michael; Hüsler, Erhard J; Schaffner, Silvio R; Paulsen, Friedrich; Hedderich, Jürgen; Heller, Martin; Jahnke, Thomas

2006-01-01

To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n = 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 microm effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. Absolute numbers of particles (median; >100 microm) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A = 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p = 0.011) and the largest number (p = 0.054) of particles. On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.

Compact Polarimetry in a Low Frequency Spaceborne Context

NASA Technical Reports Server (NTRS)

Truong-Loi, M-L.; Freeman, A.; Dubois-Fernandez, P.; Pottier, E.

2011-01-01

Compact polarimetry has been shown to be an interesting alternative mode to full polarimetry when global coverage and revisit time are key issues. It consists on transmitting a single polarization, while receiving on two. Several critical points have been identified, one being the Faraday rotation (FR) correction and the other the calibration. When a low frequency electromagnetic wave travels through the ionosphere, it undergoes a rotation of the polarization plane about the radar line of sight for a linearly polarized wave, and a simple phase shift for a circularly polarized wave. In a low frequency radar, the only possible choice of the transmit polarization is the circular one, in order to guaranty that the scattering element on the ground is illuminated with a constant polarization independently of the ionosphere state. This will allow meaningful time series analysis, interferometry as long as the Faraday rotation effect is corrected for the return path. In full-polarimetric (FP) mode, two techniques allow to estimate the FR: Freeman method using linearly polarized data, and Bickel and Bates theory based on the transformation of the measured scattering matrix to a circular basis. In CP mode, an alternate procedure is presented which relies on the bare surface scattering properties. These bare surfaces are selected by the conformity coefficient, invariant with FR. This coefficient is compared to other published classifications to show its potential in distinguishing three different scattering types: surface, doublebounce and volume. The performances of the bare surfaces selection and FR estimation are evaluated on PALSAR and airborne data. Once the bare surfaces are selected and Faraday angle estimated over them, the correction can be applied over the whole scene. The algorithm is compared with both FP techniques. In the last part of the paper, the calibration of a CP system from the point of view of classical matrix transformation methods in polarimetry is proposed.

Empirical Model for Evaluating PM10 Concentration Caused by River Dust Episodes

PubMed Central

Lin, Chao-Yuan; Chiang, Mon-Ling; Lin, Cheng-Yu

2016-01-01

Around the estuary of the Zhuo-Shui River in Taiwan, the waters recede during the winter, causing an increase in bare land area and exposing a large amount of fine earth and sand particles that were deposited on the riverbed. Observations at the site revealed that when northeastern monsoons blow over bare land without vegetation or water cover, the fine particles are readily lifted by the wind, forming river dust, which greatly endangers the health of nearby residents. Therefore, determining which factors affect river dust and constructing a model to predict river dust concentration are extremely important in the research and development of a prototype warning system for areas at risk of river dust emissions. In this study, the region around the estuary of the Zhuo-Shui River (from the Zi-Qiang Bridge to the Xi-Bin Bridge) was selected as the research area. Data from a nearby air quality monitoring station were used to screen for days with river dust episodes. The relationships between PM10 concentration and meteorological factors or bare land area were analyzed at different temporal scales to explore the factors that affect river dust emissions. Study results showed that no single factor alone had adequate power to explain daily average or daily maximum PM10 concentration. Stepwise regression analysis of multiple factors showed that the model could not effectively predict daily average PM10 concentration, but daily maximum PM10 concentration could be predicted by a combination of wind velocity, temperature, and bare land area; the coefficient of determination for this model was 0.67. It was inferred that river dust episodes are caused by the combined effect of multiple factors. In addition, research data also showed a time lag effect between meteorological factors and hourly PM10 concentration. This characteristic was applied to the construction of a prediction model, and can be used in an early warning system for local residents. PMID:27271642

Empirical Model for Evaluating PM10 Concentration Caused by River Dust Episodes.

PubMed

Lin, Chao-Yuan; Chiang, Mon-Ling; Lin, Cheng-Yu

2016-06-02

Around the estuary of the Zhuo-Shui River in Taiwan, the waters recede during the winter, causing an increase in bare land area and exposing a large amount of fine earth and sand particles that were deposited on the riverbed. Observations at the site revealed that when northeastern monsoons blow over bare land without vegetation or water cover, the fine particles are readily lifted by the wind, forming river dust, which greatly endangers the health of nearby residents. Therefore, determining which factors affect river dust and constructing a model to predict river dust concentration are extremely important in the research and development of a prototype warning system for areas at risk of river dust emissions. In this study, the region around the estuary of the Zhuo-Shui River (from the Zi-Qiang Bridge to the Xi-Bin Bridge) was selected as the research area. Data from a nearby air quality monitoring station were used to screen for days with river dust episodes. The relationships between PM10 concentration and meteorological factors or bare land area were analyzed at different temporal scales to explore the factors that affect river dust emissions. Study results showed that no single factor alone had adequate power to explain daily average or daily maximum PM10 concentration. Stepwise regression analysis of multiple factors showed that the model could not effectively predict daily average PM10 concentration, but daily maximum PM10 concentration could be predicted by a combination of wind velocity, temperature, and bare land area; the coefficient of determination for this model was 0.67. It was inferred that river dust episodes are caused by the combined effect of multiple factors. In addition, research data also showed a time lag effect between meteorological factors and hourly PM10 concentration. This characteristic was applied to the construction of a prediction model, and can be used in an early warning system for local residents.

Impact of Fluoropolymer-Based Paclitaxel Delivery on Neointimal Proliferation and Vascular Healing: A Comparative Peripheral Drug-Eluting Stent Study in the Familial Hypercholesterolemic Swine Model of Femoral Restenosis.

PubMed

Gasior, Pawel; Cheng, Yanping; Valencia, Andres F; McGregor, Jenn; Conditt, Gerard B; Kaluza, Grzegorz L; Granada, Juan F

2017-05-01

A polymer-free peripheral paclitaxel-eluting stent (PES, Zilver PTX, Cook, IN) has shown to improve vessel patency after superficial femoral angioplasty. A new-generation fluoropolymer-based PES (FP-PES; Eluvia, Boston Scientific, MA) displaying more controlled and sustained paclitaxel delivery promise to improve the clinical outcomes of first-generation PES. We sought to compare the biological effect of paclitaxel delivered by 2 different stent-coating technologies (fluoropolymer-based versus polymer-free) on neointimal proliferation and healing response in the familial hypercholesterolemic swine model of femoral restenosis. The biological efficacy of clinically available FP-PES (n=12) and PES (n=12) was compared against a bare metal stent control (n=12; Innova, Boston Scientific, MA) after implantation in the femoral arteries of 18 familial hypercholesterolemic swine. Longitudinal quantitative vascular angiography and optical coherence tomography were performed at baseline and at 30 and 90 days. Histological evaluation was performed at 90 days. Ninety-day quantitative vascular angiography results showed a lower percent diameter stenosis for FP-PES (38.78% [31.27-47.66]) compared with PES (54.16% [42.60-61.97]) and bare metal stent (74.52% [47.23-100.00]; P <0.001). Ninety-day optical coherence tomography results demonstrated significantly lower neointimal area in FP-PES (8.01 mm 2 [7.65-9.21]) compared with PES (10.95 mm 2 [9.64-12.46]) and bare metal stent (13.83 mm 2 [11.53-17.03]; P <0.001). Histological evaluation showed larger lumen areas and evidence of higher biological activity (smooth muscle cell loss and fibrin deposition) in the FP-PES compared with PES and bare metal stent. In the familial hypercholesterolemic swine model of femoral restenosis, the implantation of an FP-PES resulted in lower levels of neointimal proliferation and sustained biological effect ≤90 days compared with a polymer-free stent-based approach. © 2017 American Heart Association, Inc.

Preventing fall-related vertebral fractures: effect of floor stiffness on peak impact forces during backward falls.

PubMed

Sran, Meena M; Robinovitch, Stephen N

2008-08-01

In vivo biomechanical study of 11 male volunteers. To measure the peak forces applied to the buttocks in a backward fall from standing, and to determine whether this force is lowered by reductions in floor stiffness. Fall-related vertebral fractures are common and backward falls result in impact to the buttocks. Compliant flooring may reduce impact force and risk for vertebral fracture during a fall. However, we have little knowledge of the peak forces applied to the body during a backward fall, or how floor stiffness affects this force. Eleven males, mean age 25 +/- 5 (SD) years, were suddenly released from a backward lean of 15 degrees , falling backward onto the ground which was covered with 4.5, 7.5, or 10.5 cm of ethylene vinyl acetate foam rubber. We measured 3-dimensional impact forces applied to the buttocks at 960 Hz with a force plate. We used repeated measures analysis of variance and post hoc t tests to compare peak forces between conditions. We also modeled peak vertical force for falls onto a bare floor. RESULTS.: There was a significant difference in peak vertical force between falls onto the 10.5 cm foam condition compared with the 7.5 cm (P = 0.002) and 4.5 cm (P < 0.001) conditions. Peak vertical force (N) was (mean +/- SD) 5099 +/- 868, 4788 +/- 702, and 4544 +/- 672 for the 4.5, 7.5, and 10.5 cm foam conditions, respectively, and estimated at 6027 +/- 988 for the rigid (bare floor) condition. Compared with the bare floor, these foam floors provided, on average, 24, 20, and 15% force attenuation respectively. In a backward fall onto the buttocks, peak impact forces are 6.4 to 9.0 times body weight in a fall onto a bare floor. Reducing floor stiffness using even a thin (4.5 cm) layer of foam may provide 15% vertical force attenuation during a fall onto the buttocks.

Understanding Life Cycle Assessment: Applications for OSWER's Land and Materials Managment

EPA Science Inventory

The Office of Superfund Remediation and Technology Innovation (OSRTI) is hosting an informative webcast presentation by Jane Bare, expert on Life Cycle Impact Assessment (LCIA) in EPA's Office of Research and Development. Ms. Bare's presentation will provide an overview of LCIA, ...

Exploiting Defect Clustering to Screen Bare Die for Infant Mortality Failure: An Experimental Study

NASA Technical Reports Server (NTRS)

Lakin, David R., II; Singh, Adit D.

1999-01-01

We present the first experimental results to establish that a binning strategy based on defect clustering can be used to screen bare die for early life failures. The data for this study comes from the SEMATECH test methods experiment.

Trojan horse measurement of the 10B(p ,α0)7Be cross section in the energy range from 3 keV to 2.2 MeV

NASA Astrophysics Data System (ADS)

Cvetinović, A.; Spitaleri, C.; Spartá, R.; Rapisarda, G. G.; Puglia, S. M. R.; La Cognata, M.; Cherubini, S.; Guardo, G. L.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Sergi, M. L.; Tumino, A.

2018-06-01

The 10B(p ,α0)7Be excitation function has been studied in a wide energy range, from 2.2 MeV down to astrophysical energies, reproducing the cross section above and below the Coulomb barrier in a single experiment. An optimized experimental setup ensured good energy resolution and for the first time a clear separation of α0 and α1 channels of the 10B+2H interaction has been achieved by applying the Trojan Horse method. An improved normalization of the Trojan Horse bare-nucleus astrophysical S (E )-factor to direct data was performed and a value of Ue=391 ±74 eV was obtained for the electron screening potential.

Carbon buffer layers for smoothing superpolished glass surfaces as substrates for molybdenum /silicon multilayer soft-x-ray mirrors.

PubMed

Stock, H J; Hamelmann, F; Kleineberg, U; Menke, D; Schmiedeskamp, B; Osterried, K; Heidemann, K F; Heinzmann, U

1997-03-01

Zerodur and BK7 glass substrates (developed by Fa. Glaswerke Schott, D-55014 Mainz, Germany) from Carl Zeiss Oberkochen polished to a standard surface roughness of varsigma = 0.8 nm rms were coated with a C layer by electron-beam evaporation in the UHV. The roughness of the C-layer surfaces is reduced to 0.6 nm rms. A normal-incidence reflectance of 50% at a wavelength of 13 nm was measured for a Mo/Si multilayer soft-x-ray mirror with 30 double layers (N = 30) deposited onto the BK7/C substrate, whereas a similar Mo/Si multilayer (N = 30) evaporated directly onto the bare BK7 surface turned out to show a reflectance of only 42%.

Effect of varying Nd:YAG laser fiber tips on porcine dermal tissue

NASA Astrophysics Data System (ADS)

Pergadia, Vani R.; Vari, Sandor G.; Snyder, Wendy J.; Duffy, J. T.; Weiss, Andrew B.; Fishbein, Michael C.; Thomas, Reem; Shi, Wei-Qiang; Tausend, Kevin J.; Grundfest, Warren S.

1994-02-01

We evaluated the effect of the 600 micrometers bare (flat tip) and 600/100 micrometers conical tip fibers on porcine skin. We compared their effect in both the continuous-wave (cw) and pulsed (P) modes (20 ms ON/OFF) at 20 W to that of the electrocautery at 100 W in the pure and blend 3 modes. On 11 farmer pigs, 6 cuts were made for each parameter combination. The samples were processed for histological evaluation. The cutting depth, cutting width, and total thermal damage (carbonization, coagulation and denaturation) were recorded for each parameter combination. The results show that the 600/100 micrometers conical fiber provides deeper resective capabilities than the 600 micrometers bare and electrocautery. In addition, the 600/100 micrometers conical tip fiber allows for narrower cuts with significantly less thermal necrosis when compared to the 600 micrometers bare and electrocautery. The results indicate that there is an advantage to using the sculptured tip fiber for creating incisions when compared to the bare fiber and electrocautery.

Applications of the silicon wafer direct-bonding technique to electron devices

NASA Astrophysics Data System (ADS)

Furukawa, K.; Nakagawa, A.

1990-01-01

A silicon wafer direct-bonding (SDB) technique has been developed. A pair of bare silicon wafers, as well as an oxidized wafer pair, are bonded throughout the wafer surfaces without any bonding material. Conventional semiconductor device processes can be used for the bonded wafers, since the bonded interface is stable thermally, chemically, mechanically and electrically. Therefore, the SDB technique is very attractive, and has been applied to several kinds of electron devices. Bare silicon to bare silicon bonding is an alternative for epitaxial growth. A thick, high quality and high resistivity layer on a low resistivity substrate was obtained without autodoping. 1800 V insulated gate bipolar transistors were developed using these SDB wafers. No electrical resistance was observed at the bonded bare silicon interfaces. If oxidized wafers are bonded, the two wafers are electrically isolated, providing silicon on insulator (SOI) wafers. Dielectrically isolated photodiode arrays were fabricated on the SOI wafers and 500 V power IC's are now being developed.

Bacterial repopulation of drinking water pipe walls after chlorination.

PubMed

Mathieu, Laurence; Francius, Grégory; El Zein, Racha; Angel, Edith; Block, Jean-Claude

2016-09-01

The short-term kinetics of bacterial repopulation were evaluated after chlorination of high-density polyethylene (HDPE) colonized with drinking water biofilms and compared with bare HDPE surfaces. The effect of chlorination was partial as a residual biofilm persisted and was time-limited as repopulation occurred immediately after water resupply. The total number of bacteria reached the same levels on both the bare and chlorinated biofilm-fouled HDPE after a seven-day exposure to drinking water. Due to the presence of a residual biofilm, the hydrophobicity of chlorinated biofilm-fouled surface exhibited much lower adhesion forces (2.1 nN) compared to bare surfaces (8.9 nN). This could explain the rapid repopulation after chlorination, with a twofold faster bacterial accumulation rate on the bare HDPE surface. γ-Proteobacteria dominated the early stages of repopulation of both surfaces and a shift in the dominance occurred over the colonization time. Such observations define a timescale for cleaning frequency in industrial environments and guidelines for a rinsing procedure using drinking water.

Oceanic corrosion test of bare and zinc-protected aluminum alloys for seawater heat exchangers

NASA Technical Reports Server (NTRS)

Sasscer, D. S.; Morgan, T. O.; Rivera, C.; Ernst, R.; Scott, A. C.; Summerson, T. J.

1982-01-01

Bare 3004 tubes, 7072 Alclad 3004 tubes, and bare and zinc diffusion treated 3003 extrusions from a brazed aluminum, plate-fin heat exchanger were exposed to 1.8 m/sec flowing seawater aboard an open ocean test facility moored 3.4 km off the southeast coast of Puerto Rico. After six months exposure, the average corrosion rates for most varieties of aluminum materials converged to a low value of 0.015 mm/yr (0.6 mils/yr). Pitting did not occur in bare 3003 and 3004 samples during the six month test. Pitting did occur to varying degrees in the Alclad and zinc diffusion treated material, but did not penetrate to the base metal. Biofouling countermeasures (intermittent chlorination and brushing) did not affect the corrosion rates to any significant extent. Intermittent chlorination at a level of 0.5 ppm for 28 minutes daily controlled microbiofouling of the samples but did not prevent the development of a macrobiofouling community in areas of the plumbing with low flow.

Test of Lorentz and CPT violation with short baseline neutrino oscillation excesses

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Dharmapalan, R.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Grange, J.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Huelsnitz, W.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Mauger, C.; McGary, V. T.; McGregor, G.; Metcalf, W.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Mousseau, J.; Nelson, R. H.; Nienaber, P.; Nowak, J. A.; Osmanov, B.; Ouedraogo, S.; Patterson, R. B.; Pavlovic, Z.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Schirato, R.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Spitz, J.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R. G.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2013-01-01

The sidereal time dependence of MiniBooNE νe and νbare appearance data is analyzed to search for evidence of Lorentz and CPT violation. An unbinned Kolmogorov-Smirnov (K-S) test shows both the νe and νbare appearance data are compatible with the null sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit with a Lorentz-violating oscillation model derived from the Standard Model Extension (SME) to describe any excess events over background, we find that the νe appearance data prefer a sidereal time-independent solution, and the νbare appearance data slightly prefer a sidereal time-dependent solution. Limits of order 10-20 GeV are placed on combinations of SME coefficients. These limits give the best limits on certain SME coefficients for νμ →νe and νbarμ →νbare oscillations. The fit values and limits of combinations of SME coefficients are provided.

Near-edge wrack effects on bare sediments: Small scale variation matters in the monitoring of sandy beaches.

PubMed

MacMillan, Mitchell R; Tummon Flynn, Paula; Duarte, Cristian; Quijón, Pedro A

2016-12-01

The influence of wrack on sandy beach communities is well-documented but its effect on bare sediments located immediately beyond its edge has not yet been tested. This study aimed to explore these effects by surveying bare sediments located at increasing distances (0.5-2 m) from the wrack in five sandy beaches on Prince Edward Island, Atlantic Canada. In addition, we tested the influence of wrack with a field manipulation using wrack patches made up of rockweed bundles. The survey indicated that a modest but significant number of amphipods and beetles occupied bare sediments located 0.5 m from the edge of the wrack, but that those numbers dropped in sediments 1 m away and farther. The outcome of the field manipulation showed a similar pattern. Although small in spatial scale, our results have implications for the monitoring sandy beaches affected by scattered as well as heavy wrack input. Copyright © 2016 Elsevier Ltd. All rights reserved.

Retrieval of Soil Moisture and Roughness from the Polarimetric Radar Response

NASA Technical Reports Server (NTRS)

Sarabandi, Kamal; Ulaby, Fawwaz T.

1997-01-01

The main objective of this investigation was the characterization of soil moisture using imaging radars. In order to accomplish this task, a number of intermediate steps had to be undertaken. In this proposal, the theoretical, numerical, and experimental aspects of electromagnetic scattering from natural surfaces was considered with emphasis on remote sensing of soil moisture. In the general case, the microwave backscatter from natural surfaces is mainly influenced by three major factors: (1) the roughness statistics of the soil surface, (2) soil moisture content, and (3) soil surface cover. First the scattering problem from bare-soil surfaces was considered and a hybrid model that relates the radar backscattering coefficient to soil moisture and surface roughness was developed. This model is based on extensive experimental measurements of the radar polarimetric backscatter response of bare soil surfaces at microwave frequencies over a wide range of moisture conditions and roughness scales in conjunction with existing theoretical surface scattering models in limiting cases (small perturbation, physical optics, and geometrical optics models). Also a simple inversion algorithm capable of providing accurate estimates of soil moisture content and surface rms height from single-frequency multi-polarization radar observations was developed. The accuracy of the model and its inversion algorithm is demonstrated using independent data sets. Next the hybrid model for bare-soil surfaces is made fully polarimetric by incorporating the parameters of the co- and cross-polarized phase difference into the model. Experimental data in conjunction with numerical simulations are used to relate the soil moisture content and surface roughness to the phase difference statistics. For this purpose, a novel numerical scattering simulation for inhomogeneous dielectric random surfaces was developed. Finally the scattering problem of short vegetation cover above a rough soil surface was considered. A general scattering model for grass-blades of arbitrary cross section was developed and incorporated in a first order random media model. The vegetation model and the bare-soil model are combined and the accuracy of the combined model is evaluated against experimental observations from a wheat field over the entire growing season. A complete set of ground-truth data and polarimetric backscatter data were collected. Also an inversion algorithm for estimating soil moisture and surface roughness from multi-polarized multi-frequency observations of vegetation-covered ground is developed.

New-generation stents compared with coronary bypass surgery for unprotected left main disease: A word of caution.

PubMed

Benedetto, Umberto; Taggart, David P; Sousa-Uva, Miguel; Biondi-Zoccai, Giuseppe; Di Franco, Antonino; Ohmes, Lucas B; Rahouma, Mohamed; Kamel, Mohamed; Caputo, Massimo; Girardi, Leonard N; Angelini, Gianni D; Gaudino, Mario

2018-05-01

With the advent of bare metal stents and drug-eluting stents, percutaneous coronary intervention has emerged as an alternative to coronary artery bypass grafting surgery for unprotected left main disease. However, whether the evolution of stents technology has translated into better results after percutaneous coronary intervention remains unclear. We aimed to compare coronary artery bypass grafting with stents of different generations for left main disease by performing a Bayesian network meta-analysis of available randomized controlled trials. All randomized controlled trials with at least 1 arm randomized to percutaneous coronary intervention with stents or coronary artery bypass grafting for left main disease were included. Bare metal stents and drug-eluting stents of first- and second-generation were compared with coronary artery bypass grafting. Poisson methods and Bayesian framework were used to compute the head-to-head incidence rate ratio and 95% credible intervals. Primary end points were the composite of death/myocardial infarction/stroke and repeat revascularization. Nine randomized controlled trials were included in the final analysis. Six trials compared percutaneous coronary intervention with coronary artery bypass grafting (n = 4654), and 3 trials compared different types of stents (n = 1360). Follow-up ranged from 6 months to 5 years. Second-generation drug-eluting stents (incidence rate ratio, 1.3; 95% credible interval, 1.1-1.6), but not bare metal stents (incidence rate ratio, 0.63; 95% credible interval, 0.27-1.4), and first-generation drug-eluting stents (incidence rate ratio, 0.85; 95% credible interval, 0.65-1.1) were associated with a significantly increased risk of death/myocardial infarction/stroke when compared with coronary artery bypass grafting. When compared with coronary artery bypass grafting, the highest risk of repeat revascularization was observed for bare metal stents (hazard ratio, 5.1; 95% confidence interval, 2.1-14), whereas first-generation drug-eluting stents (incidence rate ratio, 1.8; 95% confidence interval, 1.4-2.4) and second-generation drug-eluting stents (incidence rate ratio, 1.8; 95% confidence interval, 1.4-2.4) were comparable. The introduction of new-generation drug-eluting stents did not translate into better outcomes for percutaneous coronary intervention when compared with coronary artery bypass grafting. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Elements and rationale for a common approach to assess and report soil disturbance.

Treesearch

Mike Curran; Doug Maynard; Ron Heninger; Tom Terry; Steve Howes; Doug Stone; Tom Niemann; Richard E. Miller

2008-01-01

Soil disturbance from forest practices ranges from barely perceptible to very obvious, and from positive to nil to negative effects on forest productivity and 1 or hydrologic function. Currently, most public and private landholders and various other interested parties have different approaches to describing this soil disturbance. More uniformity is needed to describe,...

Gay Marriage, Same-Sex Parenting, and America's Children

ERIC Educational Resources Information Center

Meezan, William; Rauch, Jonathan

2005-01-01

Same-sex marriage, barely on the political radar a decade ago, is a reality in America. How will it affect the well-being of children? Some observers worry that legalizing same-sex marriage would send the message that same-sex parenting and opposite-sex parenting are interchangeable, when in fact they may lead to different outcomes for children.…

Inferring the origin of populations introduced from a genetically structured native range by approximate Bayesian computation: case study of the invasive ladybird Harmonia axyridis

USDA-ARS?s Scientific Manuscript database

The correct identification of the source population of an invasive species is a prerequisite for defining and testing different hypotheses concerning the environmental and evolutionary factors responsible for biological invasions. The native area of invasive species may be large, barely known and/or...

Sensing water from subsurface drip irrigation laterals: In situ sensors, weighing lysimeters and COSMOS under vegetated and bare conditions

USDA-ARS?s Scientific Manuscript database

Characterization of soil water dynamics in the root zone under subsurface drip irrigated (SDI) is complicated by the three dimensional nature of water fluxes from drip emitters plus the fluxes, if any, of water from precipitation. In addition, soil water sensing systems may differ in their operating...

Implications of climate change for evaporation from bare soils in a Mediterranean environment.

PubMed

Aydin, Mehmet; Yano, Tomohisa; Evrendilek, Fatih; Uygur, Veli

2008-05-01

The purpose of this study was to predict quantitative changes in evaporation from bare soils in the Mediterranean climate region of Turkey in response to the projections of a regional climate model developed in Japan (hereafter RCM). Daily RCM data for the estimation of reference evapotranspiration (ETr) and soil evaporation were obtained for the periods of 1994--2003 and 2070--2079. Potential evaporation (Ep) from bare soils was calculated using the Penman-Monteith equation with a surface resistance of zero. Simulation of actual soil evaporation (Ea) was carried out using Aydin model (Aydin et al., Ecological Modelling 182:91-105, 2005) combined with Aydin and Uygur (2006, A model for estimating soil water potential of bare fields. In Proceedings of the 18th International Soil Meeting (ISM) on Soils Sustaining Life on Earth, Managing Soil and Technology, Sanliurfa, 477-480pp.) model of predicting soil water potential at the top surface layer of a bare soil, after performances of Aydin model (R2 = 94.0%) and Aydin and Uygur model (R2 = 97.6) were tested. The latter model is based on the relations among potential soil evaporation, hydraulic diffusivity, and soil wetness, with some simplified assumptions. Input parameters of the model are simple and easily obtainable such as climatic parameters used to compute the potential soil evaporation, average diffusivity for the drying soil, and volumetric water content at field capacity. The combination of Aydin and Aydin and Uygur models appeared to be useful in estimating water potential of soils and Ea from bare soils, with only a few parameters. Unlike ETr and Ep projected to increase by 92 and 69 mm (equivalent to 8.0 and 7.3% increases) due to the elevated evaporative demand of the atmosphere, respectively, Ea from bare soils is projected to reduce by 50 mm (equivalent to a 16.5% decrease) in response to a decrease in rainfall by 46% in the Mediterranean region of Turkey by the 2070s predicted by RCM, and consequently, to decreased soil wetness in the future.

Highly sensitive detection for proteins using graphene oxide-aptamer based sensors.

PubMed

Gao, Li; Li, Qin; Li, Raoqi; Yan, Lirong; Zhou, Yang; Chen, Keping; Shi, Haixia

2015-07-07

In recent years, the detection of proteins by using bare graphene oxide (GO) to quench the fluorescence of fluorescein-labeled aptamers has been reported. However, the proteins can be adsorbed on the surface of bare GO to prevent the sensitivity from further being improved. In order to solve this problem, polyethylene glycol (PEG)-protected GO was used to prevent the proteins using thrombin as an example from nonspecific binding. The detection limit was improved compared to bare GO under the optimized ratio of GO to PEG concentration. The results show that our method is a promising technique for the detection of proteins.

30 CFR 57.12012 - Bare signal wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Bare signal wires. 57.12012 Section 57.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Electricity Surface...

DETAIL VIEW, SOUTH PORTICO. THE BARE GROUND BENEATH THE PORTICO’S ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW, SOUTH PORTICO. THE BARE GROUND BENEATH THE PORTICO’S CENTER BAY DISCLOSES THE LOCATION OF A REMOVED STAIR. THE ORIGINAL FRAME STAIRCASES UP TO THE PORTICO EXTENDED FROM THE EAST AND WEST SIDES - The Woodlands, 4000 Woodlands Avenue, Philadelphia, Philadelphia County, PA

FREE-WATER DEPTH AS A MANAGEMENT TOOL FOR CONSTRUCTED WETLANDS

EPA Science Inventory

Marsh plants in constructed wetlands have shown the capacity to remove unwanted pollutants from storm water runoff. The plants can be established at the site from bare roots. However, plant growth from bare roots can be restricted by the elevated water depths. Using several wa...

Genetics Home Reference: bare lymphocyte syndrome type II

MedlinePlus

... 6. Citation on PubMed Gobin SJ, Peijnenburg A, van Eggermond M, van Zutphen M, van den Berg R, van den Elsen PJ. The RFX complex is crucial ... D, Szöllosi J, Jenei A. Bare lymphocyte syndrome: an opportunity to discover our immune system. Immunol Lett. ...

High-performance of bare and Ti-doped α-MnO2 nanoparticles in catalyzing the Oxygen Reduction Reaction

NASA Astrophysics Data System (ADS)

Pargoletti, E.; Cappelletti, G.; Minguzzi, A.; Rondinini, S.; Leoni, M.; Marelli, M.; Vertova, A.

2016-09-01

Nanostructured MnO2 has unique electrocatalytic properties towards the Oxygen Reduction Reaction (ORR, the main cathodic reaction in metal-air devices), representing an excellent alternative to the expensive platinum. Herein, we report the hydrothermal synthesis of bare and 5% Ti-doped α-MnO2 nanoparticles using two different oxidizing agents, namely ammonium persulfate for MH_N samples and potassium permanganate for MH_K ones. The physico-chemical characterizations show that oxidant cations induce different structural, morphological and surface properties of the final powders. Hence, correlations between the different α-MnO2 characteristics and their electrocatalytic performances towards the ORR are drawn, highlighting the diverse effect even on the kinetic point of view. The ORR activity in alkaline media is examined by means of Staircase - Linear Sweep Voltammetry (S-LSV), using Gas Diffusion Electrode (GDE) as the air-cathode. The presence of these nanoparticles in the GDEs leads to a significant shift of the ORR onset potential (∼100 mV) towards less cathodic values, underlining the electrocatalytic efficiency of all the nanopowders. Furthermore, high exchange current densities (j0) are determined for GDEs with Ti-doped MnO2, comparable to the well-performing Pd45Pt5Sn50, and making it a promising material for the ORR.

Sero-immunity to poliovirus in children and young women: England 1972-4.

PubMed

Mortimer, P P; Cunningham, P

1975-04-01

A total of 292 children's sera and 706 antenatal sera from different parts of England were tested for the presence of poliovirus neutralizing antibodies. Little vairation was found between different areas and types of community, but a lower porportion of the 5-14 year old children had antibody than younger children and young adult women. The proportion of the young population with antibody, and the current acceptance rates for oral poliovirus vaccine are barely satisfactory.

Erratum: Correction to: Polarisation vision: overcoming challenges of working with a property of light we barely see

NASA Astrophysics Data System (ADS)

Foster, James J.; Temple, Shelby E.; How, Martin J.; Daly, Ilse M.; Sharkey, Camilla R.; Wilby, David; Roberts, Nicholas W.

2018-06-01

In "Polarisation vision: overcoming challenges of working with a property of light we barely see" (Foster et al. 2018) we provide a basic description of how Stokes parameters can be estimated and used to calculate the angle of polarisation (AoP).

Evaluation of interior and exterior latex paints : final report.

DOT National Transportation Integrated Search

1979-10-01

The wood panels that have only one coat of paint over bare wood and one coat of paint over primed wood are continuing to show sighs of deterioration. The wood panels that have two coats of paint over bare wood and two coats of paint over primed wood ...

Grazing intensity and spatial heterogeneity in bare soil in a grazing-resistant grassland

USDA-ARS?s Scientific Manuscript database

Spatial patterns in rangeland vegetation serve as indicators of rangeland condition and are an important component of wildlife habitat. We illustrate the use of very-large-scale aerial photography (VLSA) to quantify spatial patterns in bare soil of the northeastern Colorado shortgrass steppe. Using ...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

30 CFR 56.12012 - Bare signal wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bare signal wires. 56.12012 Section 56.12012 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12012...

A Management Information System for Bare Base Civil Engineering Commanders

DTIC Science & Technology

1988-09-01

initial beddown stage. The purpose of this research was to determine the feasibility of developing a microcomputer based management information system (MIS...the software best suited to synthesize four of the categories into a prototype field MIS. Keyword: Management information system , Bare bases, Civil engineering, Data bases, Information retrieval.

Radar reflectivity of bare and vegetation-covered soil

NASA Technical Reports Server (NTRS)

Ulaby, F. T.; Dobson, M. C.; Bradley, G. A.

1981-01-01

Radar sensitivity to soil moisture content has been investigated experimentally for bare and vegetation-covered soil using detailed spectral measurements obtained by a truck-mounted radar spectrometer in the 1-8 GHz band and by airborne scatterometer observations at 1.6, 4.75, and 13.3 GHz. It is shown that radar can provide quantitative information on the soil moisture content of both bare and vegetation-covered soil. The observed soil moisture is in the form of the soil matric potential or a related quantity such as the percent of field capacity. The depth of the monitored layer varies from 1 cm for very wet soil to about 15 cm for very dry soil.

Bare Quantum Null Energy Condition.

PubMed

Fu, Zicao; Marolf, Donald

2018-02-16

The quantum null energy condition (QNEC) is a conjectured relation between a null version of quantum field theory energy and derivatives of quantum field theory von Neumann entropy. In some cases, divergences cancel between these two terms and the QNEC is intrinsically finite. We study the more general case here where they do not and argue that a QNEC can still hold for bare (unrenormalized) quantities. While the original QNEC applied only to locally stationary null congruences in backgrounds that solve semiclassical theories of quantum gravity, at least in the formal perturbation theory at a small Planck length, the quantum focusing conjecture can be viewed as the special case of our bare QNEC for which the metric is on shell.

Bare Quantum Null Energy Condition

NASA Astrophysics Data System (ADS)

Fu, Zicao; Marolf, Donald

2018-02-01

The quantum null energy condition (QNEC) is a conjectured relation between a null version of quantum field theory energy and derivatives of quantum field theory von Neumann entropy. In some cases, divergences cancel between these two terms and the QNEC is intrinsically finite. We study the more general case here where they do not and argue that a QNEC can still hold for bare (unrenormalized) quantities. While the original QNEC applied only to locally stationary null congruences in backgrounds that solve semiclassical theories of quantum gravity, at least in the formal perturbation theory at a small Planck length, the quantum focusing conjecture can be viewed as the special case of our bare QNEC for which the metric is on shell.

Magnetic moment evolution and spin freezing in doped BaFe2As2

DOE PAGES

Pelliciari, Jonathan; Huang, Yaobo; Ishii, Kenji; ...

2017-08-14

Fe-K β X-ray emission spectroscopy measurements reveal an asymmetric doping dependence of the magnetic moments μ bare in electron- and hole-doped BaFe 2As 2. At low temperature, μ bare is nearly constant in hole-doped samples, whereas it decreases upon electron doping. Increasing temperature substantially enhances μ bare in the hole-doped region, which is naturally explained by the theoretically predicted crossover into a spin-frozen state. Our measurements demonstrate the importance of Hund’s-coupling and electronic correlations, especially for hole-doped BaFe 2As 2, as well as the inadequacy of a fully localized or fully itinerant description of the 122 family of Fe pnictides.

Vegetation Coverage Mapping and Soil Effect Correction in Estimating Vegetation Water Content and Dry Biomass from Satellites

NASA Astrophysics Data System (ADS)

Huang, J.; Chen, D.

2005-12-01

Vegetation water content (VWC) attracts great research interests in hydrology research in recent years. As an important parameter describing the horizontal expansion of vegetation, vegetation coverage is essential to implement soil effect correction for partially vegetated fields to estimate VWC accurately. Ground measurements of corn and soybeans in SMEX02 resulted in an identical expolinear relationship between vegetation coverage and leaf area index (LAI), which is used for vegetation coverage mapping. Results illustrated two parts of LAI growth quantitatively: the horizontal expansion of leaf coverage and the vertical accumulation of leaf layers. It is believed that the former part contributes significantly to LAI growth at initial vegetation growth stage and the latter is more dominant after vegetation coverage reaches a certain level. The Normalized Difference Water Index (NDWI) using short-wave infrared bands is convinced for its late saturation at high LAI values, in contrast to the Normalized Difference Vegetation Index (NDVI). NDWI is then utilized to estimate LAI, via another expolinear relationship, which is evidenced having vegetation species independency in study of corn and soybeans in SMEX02 sites. It is believed that the surface reflectance measured at satellites spectral bands are the mixed results of signals reflected from vegetation and bare soil, especially at partially vegetated fields. A simple linear mixture model utilizing vegetation coverage information is proposed to correct soil effect in such cases. Surface reflectance fractions for -rpure- vegetation are derived from the model. Comparing with ground measurements, empirical models using soil effect corrected vegetation indices to estimate VWC and dry biomass (DB) are generated. The study enhanced the in-depth understanding of the mechanisms how vegetation growth takes effect on satellites spectral reflectance with and without soil effect, which are particularly useful for modeling in hydrology, agriculture, forestry and meteorology etc.

Influence of spring snowpack melting on thunderstorm activity in the Catalan Pyrenees

NASA Astrophysics Data System (ADS)

Pascual, R.; Callado, A.; Terradelles, E.; Téllez, B.

2009-09-01

Catalan Pyrenees, the eastern half of the Pyrenees range, is a very popular area for tourism, hiking and climbing. This sector of the range is 200 km long and, on average, 80 km wide. Its highest peaks reach 3000 m ASL and there are many summits above 2500 m ASL. Two of the main climatic characteristics of the region are the very frequent summer convective storms and the late autumn, winter and spring snow-cover. Both characteristics have normally been studied from different points of view, and weather forecasts in late spring have not normally considered the plausible relationship between them. The snowpack melting from April to June, especially rapid in May, leads to important changes on the surface energy balance since the evolution from snow-covered ground to bare soil or canopy, significantly alters the surface albedo and the turbulent, latent and sensible, heat fluxes. These modifications have a noticeable influence in developing or inhibiting thermally-induced mesoscale circulations such as upslope winds, valley breezes or plane-mountain breezes, and could condition the triggering of convection, showers and storm activity. In order to gain insight into the relationship between the spring snowpack melting and the location of thunderstorm activity, a comparison between seasonal snow-cover and thunderstorm frequency evolution (using lightning network data) for a period of 5 years has been carried out, showing a progressive transition from a non-convective to a convective precipitation regime in areas where the snowpack has melted recently Furthermore, a meso-beta scale non-hydrostatic numerical weather prediction model at a 2.5-km horizontal resolution is used to study the sensitivity of snowpack extension on the thunderstorms development over the complex orography of the Catalan Pyrenees. A spring case with thunderstorm activity restricted to snow-free areas has been selected and accurately simulated. A number of sensitivity runs with different initial snow fields has been performed, so allowing evaluation of the influence of snow-cover on the triggering of convection.

Access in Scotland: Access to Higher Education for People from Less Advantaged Backgrounds in Scotland

ERIC Educational Resources Information Center

Blackburn, Lucy Hunter; Kadar-Satat, Gitit; Riddell, Sheila; Weedon, Elisabet

2016-01-01

Access to universities across the United Kingdom remains a challenge despite improvements in recent years. Those challenges are still more marked in Scotland than in the other nations, as this report shows. This report lays bare the extent of the challenge. Scotland has a different approach to higher education. It no longer charges tuition fees,…

Deriving Meaning through Context: Interpreting Bare Nominals in Second Language Japanese

ERIC Educational Resources Information Center

Gabriele, Alison

2010-01-01

Previous studies on the second language acquisition of telicity have suggested that learners can use morphosyntactic cues to interpret sentences as telic or atelic even in cases where the cues differ in the first language (L1) and second language (L2) (Slabakova, 2001, 2005; Gabriele, 2008; Kaku et al., 2008a, 2008b). The present study extends…

The Upbringing of Children under the Conditions of the Extreme North

ERIC Educational Resources Information Center

Prokhorova, O. G.

2007-01-01

Ethnographic scientists have determined that there are about 300 ethnic communities in Russia. The number of indigenous peoples in the North barely adds up to 200,000, and they make up less than 2 percent of the total population of the Russian North. They have been designated in different ways in official documents, for example "the small…

Temporary placement of a paclitaxel or rapamycin-eluting stent is effective to reduce stenting induced inflammatory reaction and scaring in benign cardia stricture models.

PubMed

Wang, Lin; Zhu, Yue-Qi; Cheng, Ying-Sheng; Cui, Wen-Guo; Chen, Ni-Wei

2014-12-01

To investigate whether temporary placement of a paclitaxel or rapamycin eluting stent is more effective to reduce stenting induced inflammatory reaction and scaring than a bared stent in benign cardia stricture models. Eighty dog models of stricture were randomly divided into a control group (CG, n=20, no stent insertion), a bare stent group (BSG, n=20), a paclitaxel eluting (Pacl-ESG, n=20) and a rapamycin eluting stent group (Rapa-ESG, n=20), with one-week stent retention. Lower-oesophageal-sphincter pressure (LOSP), 5-minute barium height (5-mBH) and cardia diameter were assessed before, immediately after the procedure, and regularly for 6 months. Five dogs in each group were euthanized for histological examination at each follow-up assessment. Stent insertion was well tolerated, with similar migration rates in three groups. At 6 months, LOSP and 5-mBH improved in Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with no difference between Pacl-ESG and Rapa-ESG (p>0.05). Cardia kept more patency in the Pacl-ESG and Rapa-ESG than in BSG (p<0.05). Reduced peak inflammatory reactions and scarring occurred in the Pacl-ESG and Rapa-ESG compared to BSG (p<0.05), with a similar outcome in the Pacl-ESG and Rapa-ESG (p>0.05). Paclitaxel or rapamycin-eluting stents insertion led to better outcomes than bare stents in benign cardia stricture models.

Sci—Fri PM: Topics — 01: A monte carlo model of a miniature low-energy x-ray tube using EGSnrc

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

Watson, P; Seuntjens, J

The INTRABEAM system (Carl Zeiss, Oberkochen, Germany) is a miniature x-ray generator for use in intraoperative radiotherapy and brachytherapy. The device accelerates electrons to up to 50 keV, which are then steered down an evacuated needle probe to strike a thin gold target. For accurate dosimetry of the INTRABEAM system, it is important that the photon spectrum be well understood. Measurements based on air-kerma are heavily impacted by photon spectra, particularly for low photon energies due to the large photoelectric contribution in air mass energy absorption coefficient. While low energy photons have little clinical significance at treatment depths, they maymore » have a large effect on air-kerma measurements. In this work, we have developed an EGSnrc-based monte carlo (MC) model of the Zeiss INTRABEAM system to study the source photon spectra and half-value layers (HVLs) of the bare probe and with various spherical applicators. HVLs were calculated using the analytical attenuation of air-kerma spectra. The calculated bare probe spectrum was compared with simulated and measured results taken from literature. Differences in the L-line energies of gold were found between the spectra predicted by EGSnrc and Geant4. This is due to M and N shell averaging during atomic transitions in EGSnrc. The calculated HVLs of the bare probe and spherical applicators are consistent with literature reported measured values.« less

A new Bayesian recursive technique for parameter estimation

NASA Astrophysics Data System (ADS)

Kaheil, Yasir H.; Gill, M. Kashif; McKee, Mac; Bastidas, Luis

2006-08-01

The performance of any model depends on how well its associated parameters are estimated. In the current application, a localized Bayesian recursive estimation (LOBARE) approach is devised for parameter estimation. The LOBARE methodology is an extension of the Bayesian recursive estimation (BARE) method. It is applied in this paper on two different types of models: an artificial intelligence (AI) model in the form of a support vector machine (SVM) application for forecasting soil moisture and a conceptual rainfall-runoff (CRR) model represented by the Sacramento soil moisture accounting (SAC-SMA) model. Support vector machines, based on statistical learning theory (SLT), represent the modeling task as a quadratic optimization problem and have already been used in various applications in hydrology. They require estimation of three parameters. SAC-SMA is a very well known model that estimates runoff. It has a 13-dimensional parameter space. In the LOBARE approach presented here, Bayesian inference is used in an iterative fashion to estimate the parameter space that will most likely enclose a best parameter set. This is done by narrowing the sampling space through updating the "parent" bounds based on their fitness. These bounds are actually the parameter sets that were selected by BARE runs on subspaces of the initial parameter space. The new approach results in faster convergence toward the optimal parameter set using minimum training/calibration data and fewer sets of parameter values. The efficacy of the localized methodology is also compared with the previously used BARE algorithm.

Trace element storage capacity of sediments in dead Posidonia oceanica mat from a chronically contaminated marine ecosystem.

PubMed

Di Leonardo, Rossella; Mazzola, Antonio; Cundy, Andrew B; Tramati, Cecilia Doriana; Vizzini, Salvatrice

2017-01-01

Posidonia oceanica mat is considered a long-term bioindicator of contamination. Storage and sequestration of trace elements and organic carbon (C org ) were assessed in dead P. oceanica mat and bare sediments from a highly polluted coastal marine area (Augusta Bay, central Mediterranean). Sediment elemental composition and sources of organic matter have been altered since the 1950s. Dead P. oceanica mat displayed a greater ability to bury and store trace elements and C org than nearby bare sediments, acting as a long-term contaminant sink over the past 120 yr. Trace elements, probably associated with the mineral fraction, were stabilized and trapped despite die-off of the overlying P. oceanica meadow. Mat deposits registered historic contamination phases well, confirming their role as natural archives for recording trace element trends in marine coastal environments. This sediment typology is enriched with seagrass-derived refractory organic matter, which acts mainly as a diluent of trace elements. Bare sediments showed evidence of inwash of contaminated sediments via reworking; more rapid and irregular sediment accumulation; and, because of the high proportions of labile organic matter, a greater capacity to store trace elements. Through different processes, both sediment typologies represent a repository for chemicals and may pose a risk to the marine ecosystem as a secondary source of contaminants in the case of sediment dredging or erosion. Environ Toxicol Chem 2017;36:49-58. © 2016 SETAC. © 2016 SETAC.

Time-resolved mapping of water diffusion coefficients in a working soft actuator device.

PubMed

Naji, Leila; Chudek, John A; Baker, Richard T

2008-08-14

Diffusion-weighted imaging was employed to spatially map the distribution of the diffusion coefficient of water, D, in bare, water-soaked, Li(+)-exchanged, cast Nafion and in an ionic polymer-metal composite (IPMC) soft actuator element, prepared from this bare Nafion by impregnation with Pt electrodes. D was evaluated in two orthogonal directions: along one of the long dimensions of the sample (Dx) and through its thickness (Dz). D-maps of the IPMC element were obtained both in the absence of an applied potential and in situ during the application of a 3 V dc potential across the thickness of the sample. In the bare Nafion, D-maps showed uniform values of both Dx and Dz of about 6 x 10 (-10) m(2) s(-1). In the IPMC two effects were observed: (i) D at the electroded surfaces of the IPMC was higher than at the center of the sample; (ii) this difference was much greater in Dz than in Dx . Both effects were explained by the influence of the impregnated Pt electrodes on polymer structure. The D-maps in the electrochemical measurements showed high values of D (up to 8 x 10(-10) m(2) s(-1)) at the cathode and low values (from 1 x 10(-10) m(2) s(-1)) at the anode. This was explained in terms of the effect on the Nafion nanostructure of the forced electro-migration of Li(H2O)x(+) species toward the cathode.

The Influence of Edaphic and Orographic Factors on Algal Diversity in Biological Soil Crusts on Bare Spots in the Polar and Subpolar Urals

NASA Astrophysics Data System (ADS)

Patova, E. N.; Novakovskaya, I. V.; Deneva, S. V.

2018-03-01

The influence of edaphic and orographic factors on the formation of algal diversity in biological soil crusts was studied in mountain tundras of the Polar and Subpolar Urals. Bare spots developed in the soils on different parent materials and overgrown to different extents were investigated. Overall, 221 algal species from six divisions were identified. Among them, eighty-eight taxa were new for the region studied. The Stigonema minutum, S. ocellatum, Nostoc commune, Gloeocapsopsis magma, Scytonema hofmannii, Leptolyngbya foveolarum, Pseudococcomyxa simplex, Sporotetras polydermatica species and species of the Cylindrocystis, Elliptochloris, Fischerella, Leptosira, Leptolyngbya, Myrmecia, Mesotaenium, Phormidium, Schizothrix genera were permanent components of biological soil crusts. The basis of the algal cenoses in soil crusts was composed of cosmopolitan cyanoprokaryotes, multicellular green algae with thickened covers and abundant mucus. The share of nitrogen fixers was high. The physicochemical properties of primary soils forming under the crusts of spots are described. The more important factors affecting the species composition of algae in the crusts are the elevation gradient, temperature, soil moisture, and the contents of Ca, Mg, mobile phosphorus, and total nitrogen.

Growth process and anticancer properties of gold nanorods.

PubMed

Zhang, Junyan; Wang, Mian; Webster, Thomas J

2017-09-01

Gold nanoparticles have been of great interest because of their unique optical properties, facile synthesis and conjugation. Among various shapes of gold nanoparticles, gold nanorods have been widely studied. They can be conjugated with different molecules for biomedical applications, such as tumor imaging and therapy. However, few researchers have studied the antitumor properties of bare gold nanorods. In this study, unfunctionalized gold nanorods were synthesized and tested on breast tumor cells. Results showed that the aspect ratio of gold nanorods could be easily influenced by both reaction time and the amount of silver nitrate in the growth solution. A new growth process is proposed here based on the UV-Vis spectra and TEM images of gold nanorods at different reaction times. More importantly, cell studies showed that within a certain concentration range, the gold nanorods can selectively kill tumor cells while having limited or little influence on healthy mammalian (dermal fibroblast) cells. Thus, this study shows promise for the use of bare gold nanorods for further study alone or in combination with photothermal treatment. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2616-2621, 2017. © 2017 Wiley Periodicals, Inc.

Heavy metal remediation with Ficus microcarpa through transplantation and its environmental risks through field scale experiment.

PubMed

Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Gu, Xiaowen Sophie

2018-02-01

The phytoremediation efficiency of various metals by Ficus microcarpa was evaluated through a real scale experiment in the present study. The root biomass production of the species varied significantly from 3.68 to 5.43 g because of the spatial heterogeneity of different metals. It would take 4-93 years to purify the excess Cd of the experimental site. Mercury was the most inflexible element which can barely be phytoremediated by F. microcarpa. After the species transplanted from the polluted soil to the clean site, Cd and Cu were transferred to the rhizosphere soil to different extent while the bulk soil was barely influenced. Relative to Cd and Cu, significantly fewer amounts of Pb and Hg were released. The highest concentrations of Cd, Cu, Hg and Pb in the clean soil were far below their corresponding safe thresholds for agricultural land after 3 months of the polluted plants were cultivated and metal concentrations of plant leaves were negligible, both indicated the low ecological risk of transplantation. Results from this study suggested a feasible disposal method for metal rich plants after phytoremediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Responses of alpine grassland landscape in the source region of Shule River Basin to topographical factors and frozen ground types].

PubMed

Chen, Jian-Jun; Yi, Shu-Hua; Qin, Yu; Wang, Xiao-Yun

2014-06-01

This paper retrieved the fractional vegetation cover of alpine grassland in the source region of the Shule River Basin based on Chinese environmental satellite (HJ-1A/1B) images and field data, and analyzed the response of the vegetation cover to topographic factors and types of frozen ground. The results showed that the vegetation coverage of this region was low with large spatial heterogeneity and high degree of dispersion. The landscape consisted mainly of non-vegetation surface types, eg. ice, snow, the bare rock gravel land and bare land. Slopes and aspects were the main limiting factors of vegetation distribution. The average vegetation coverage decreased with the increase of slope. The average vegetation coverage was the lowest on the sunny slope, and the highest on the shady slope. There were significant differences of vegetation coverage among different types of frozen ground. The distribution of vegetation coverage presented a reversed "U" curve trend by extremely stable permafrost, stable permafrost, sub-stable permafrost, transition permafrost, unstable permafrost and seasonal frost, and the average vegetation coverage was the highest in the sub-stable permafrost.

Erodibility of and dust emissions from bare soil surfaces in the North American Southwest

USDA-ARS?s Scientific Manuscript database

Native plant communities throughout the Southwestern United States are subject to increased abiotic stress due to climate change. As native grass cover is replaced by shrubs, more bare soil surface is susceptible to erosion by wind. The dust record for the last 20 years indicates that wind erosion...

75 FR 30750 - Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-02

...-AA09 Drawbridge Operation Regulation; Arkansas Waterway, Little Rock, AR AGENCY: Coast Guard, DHS... procedures on the Baring Cross Railroad Drawbridge across the Arkansas Waterway at mile 119.6 at Little Rock....123(b) state that the draw of the Baring Cross Railroad Drawbridge, mile 119.6, at Little Rock, AR is...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

Genericity Distinctions and the Interpretation of Determiners in Second Language Acquisition

ERIC Educational Resources Information Center

Ionin, Tania; Montrul, Silvina; Kim, Ji-Hye; Philippov, Vadim

2011-01-01

English uses three types of generic NPs: bare plurals ("Lions are dangerous"), definite singulars ("The lion is dangerous"), and indefinite singulars ("A lion is dangerous"). These three NP types are not interchangeable: definite singulars and bare plurals can have generic reference at the NP-level, while indefinite singulars are compatible only…

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

49 CFR 192.457 - External corrosion control: Buried or submerged pipelines installed before August 1, 1971.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false External corrosion control: Buried or submerged... SAFETY STANDARDS Requirements for Corrosion Control § 192.457 External corrosion control: Buried or... areas in which active corrosion is found: (1) Bare or ineffectively coated transmission lines. (2) Bare...

More California-poppy in stubble field than in old field

Treesearch

Raymond D. Ratliff; Stanley E. Westfall; Richard W. Robarts

1972-01-01

The density and flowering of California-poppy (Eschscholzia californica var. peninsularis Green), amount of bare ground, and occurrence of other plants were studied in an old field and a stubble field near Madera, California. The stubble field had more poppy plants per unit of area, more plants flowering, and more bare ground than...

Split Personality: Assessing the Potential for Organizational Identity in Reinforcing U.S. Military Jointness

DTIC Science & Technology

2015-07-17

company name’ ( logo ) ‘parent company name’ ( logo ) ‘business unit name’ ‘parent company name’ ( logo ) ‘specialization’ Example Barings Barings...26 in times of war when it seemed apparent that force goals would not be met. Most useful, however, is his recognition of an overall pattern of

Alternatives to preplant soil fumigation for Western forest nurseries.

Treesearch

Diane M. Hildebrand; Jeffrey K. Stone; Robert L. James; Susan J. Frankel

2004-01-01

Field trials at six bare-root forest tree nurseries in the Western United States compared cultural treatments including timing and depth of sowing; bare fallow (with and without periodic tilling); organic amendments including sawdust, composts, and cover crops; mulches including pine needles, sawdust, and rice straw; and fumigation with methyl bromide/chloropicrin or...

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan

PubMed Central

Chen, P.; Tsay, T.T.

2006-01-01

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region. PMID:19259538

Alcohol molecules adsorption on graphane nanosheets - A first-principles investigation

NASA Astrophysics Data System (ADS)

Nagarajan, V.; Chandiramouli, R.

2018-05-01

The geometric structure, electronic and adsorption properties of methanol, ethanol and 1-propanol molecules on hydrogenated graphene (graphane) were investigated using first-principles calculations. The stability of graphane base material is confirmed using formation energy and phonon band structures. The adsorption of alcohol molecules on bare graphane and hydrogen vacant graphane nanosheet is found to be prominent and the selectivity of alcohol molecules can be achieved using bare or hydrogen vacant graphane nanosheet. Moreover, the interaction of alcohol molecules on bare and hydrogen vacant graphane nanosheets is studied using the adsorption energy, energy band gap variation, Bader charge transfer and average energy band gap variation. The adsorption energy ranges from -0.149 to -0.383 eV upon alcohol adsorption. The energy gap varies from 4.71 to 2.62 eV for bare graphane and from 4.02 to 3.60 eV for hydrogen vacant graphane nanosheets upon adsorption of alcohol molecules. The adsorption properties of alcohol molecules provide useful information for the possible application of graphane nanosheet as a base material for the detection of alcohol molecules.

Spectral characteristics and the extent of paleosols of the Palouse formation

NASA Technical Reports Server (NTRS)

Frazier, B. E.; Busacca, A.; Cheng, Y.; Wherry, D.; Hart, J.; Gill, S.

1986-01-01

Spectral relationships were investigated for several bare soil fields which were in summer fallow rotation on the date of the imagery. Printouts of each band were examined and compared to aerial photography. Bands with dissimilar reflectance patterns for known areas were then combined using ratio techniques which were proven useful in other studies (Williams, 1983). Selected ratios were Thematic Mapper (TM) 1/TM4, TM3/TM4, and TM5/TM4. Cluster analyses and Baysian and Fastclass classifier images were produced using the three ratio images. Plots of cluster analysis outputs revealed distinct groupings of reflectance data representing green crops, ripened crops, soil and green plants, and bare soil. Bare soil was represented by a line of clusters on plots of the ratios TM5/TM4 and TM3/TM4. The soil line was investigated further to determine factors involved in the distributin of clusters alone the line. The clusters representing the bare soil line were also studied by plotting the Tm5/TM4, TM1/TM4 dimension. A total of 76 soil samples were gathered and analyzed for organic carbon.

Portable chamber measurements of evapotranspiration at the Amargosa Desert Research Site near Beatty, Nye County, Nevada, 2003-06

USGS Publications Warehouse

Garcia, C. Amanda; Johnson, Michael J.; Andraski, Brian J.; Halford, Keith J.; Mayers, C. Justin

2008-01-01

Portable chamber measurements of evapotranspiration (ET) were made at the U.S. Geological Survey's Amargosa Desert Research Site in southern Nevada to help quantify component- and landscape-scale contributions to ET in an arid environment. Evapotranspiration data were collected approximately every 3 months from 2003 to 2006. Chamber measurements of ET were partitioned into bare-soil evaporation and mixed-species transpiration components. The component-scale ET fluxes from native shrubs typically surpassed those from bare soil by as much as a factor of four. Component-scale ET fluxes were extrapolated to landscape-scale ET using a one-layer, multi-component canopy model. Landscape-scale ET fluxes predominantly were controlled by bare-soil evaporation. Bare soil covered 94 percent of the landscape on average and contributed about 70 percent of the landscape-scale vapor flux. Creosote bush, an evergreen shrub, accounted for about 90 percent of transpiration on average due to its dominance across the landscape (80 percent of the 6 percent shrub cover) and evergreen character.

Changing tidal hydrodynamics during different stages of eco-geomorphological development of a tidal marsh: A numerical modeling study

NASA Astrophysics Data System (ADS)

Stark, J.; Meire, P.; Temmerman, S.

2017-03-01

The eco-geomorphological development of tidal marshes, from initially low-elevated bare tidal flats up to a high-elevated marsh and its typical network of channels and creeks, induces long-term changes in tidal hydrodynamics in a marsh, which will have feedback effects on the marsh development. We use a two-dimensional hydrodynamic model of the Saeftinghe marsh (Netherlands) to study tidal hydrodynamics, and tidal asymmetry in particular, for model scenarios with different input bathymetries and vegetation coverages that represent different stages of eco-geomorphological marsh development, from a low elevation stage with low vegetation coverage to a high and fully vegetated marsh platform. Tidal asymmetry is quantified along a 4 km marsh channel by (1) the difference in peak flood and peak ebb velocities, (2) the ratio between duration of the rising tide and the falling tide and (3) the time-integrated dimensionless bed shear stress during flood and ebb. Although spatial variations in tidal asymmetry are large and the different indicators for tidal asymmetry do not always respond similarly to eco-geomorphological changes, some general trends can be obtained. Flood-dominance prevails during the initial bare stage of a low-lying tidal flat. Vegetation establishment and platform expansion lead to marsh-scale flow concentration to the bare channels, causing an increase in tidal prism in the channels along with a less flood-dominant asymmetry of the horizontal tide. The decrease in flood-dominance continues as the platform grows vertically and the sediment-demand of the platform decreases. However, when the platform elevation gets sufficiently high in the tidal frame and part of the spring-neap cycle is confined to the channels, the discharge in the channels decreases and tidal asymmetry becomes more flood-dominant again, indicating an infilling of the marsh channels. Furthermore, model results suggest that hydro-morphodynamic feedbacks based on tidal prism to channel cross-sectional area relationships keep the marsh channels from filling in completely by enhancing ebb-dominance as long as the tidal volume and flow velocities remain sufficiently high. Overall, this study increases insight into the hydro-morphodynamic interactions between tidal flow and marsh geomorphology during various stages of eco-geomorphological development of marshes and marsh channels in particular.

Electroanalytical detection of pindolol: comparison of unmodified and reduced graphene oxide modified screen-printed graphite electrodes.

PubMed

Cumba, Loanda R; Smith, Jamie P; Brownson, Dale A C; Iniesta, Jesús; Metters, Jonathan P; do Carmo, Devaney R; Banks, Craig E

2015-03-07

Recent work has reported the first electroanalytical detection of pindolol using reduced graphene oxide (RGO) modified glassy carbon electrodes [S. Smarzewska and W. Ciesielski, Anal. Methods, 2014, 6, 5038] where it was reported that the use of RGO provided significant improvements in the electroanalytical signal in comparison to a bare (unmodified) glassy carbon electrode. We demonstrate, for the first time, that the electroanalytical quantification of pindolol is actually possible using bare (unmodified) screen-printed graphite electrodes (SPEs). This paper addresses the electroanalytical determination of pindolol utilising RGO modified SPEs. Surprisingly, it is found that bare (unmodified) SPEs provide superior electrochemical signatures over that of RGO modified SPEs. Consequently the electroanalytical sensing of pindolol is explored at bare unmodified SPEs where a linear range between 0.1 μM-10.0 μM is found to be possible whilst offering a limit of detection (3σ) corresponding to 0.097 μM. This provides a convenient yet analytically sensitive method for sensing pindolol. The optimised electroanalytical protocol using the unmodified SPEs, which requires no pre-treatment (electrode polishing) or electrode modification step (such as with the use of RGO), was then further applied to the determination of pindolol in urine samples. This work demonstrates that the use of RGO modified SPEs have no significant benefits when compared to the bare (unmodified) alternative and that the RGO free electrode surface can provide electro-analytically useful performances.

Analysis of ProSEDS Test of Bare-Tether Collection

NASA Technical Reports Server (NTRS)

Sanmartin, J. R.; Lorenzini, E. C.; Estes, R. D.; Charro, M.; Cosmo, M. L.

2003-01-01

NASA's tether experiment ProSEDS will be placed in orbit on board a Delta-II rocket to test bare-tether electron collection, deorbiting of the rocket second stage, and the system dynamic stability. ProSEDS performance will vary because ambient conditions change along the orbit and tether-circuit bulk elements at the cathodic end follow the step-by-step sequence for the current cycles of operating modes (open-circuit, shunt and resistor modes for primary cycles; shunt and battery modes for secondary cycles). In this work we discuss expected ProSEDS values of the ratio L,/L*, which jointly with cathodic bulk elements determines bias and current tether profiles; L, is tether length, and L* (changing with tether temperature and ionospheric plasma density and magnetic field) is a characteristic length gauging ohmic versus baretether collection impedances. We discuss how to test bare-tether electron collection during primary cycles, using probe measurements of plasma density, measurements of cathodic current in resistor and shunt modes, and an estimate of tether temperature based on ProSEDS orbital position at the particular cycle concerned. We discuss how a temperature misestimate might occasionally affect the test of bare-tether collection, and how introducing the battery mode in some primary cycles, for an additional current measurement, could obviate the need of a temperature estimate. We also show how to test bare-tether collection by estimating orbit-decay rate from measurements of cathodic current for the shunt and battery modes of secondary cycles.

Comparing XPS on bare and capped ZrN films grown by plasma enhanced ALD: Effect of ambient oxidation

NASA Astrophysics Data System (ADS)

Muneshwar, Triratna; Cadien, Ken

2018-03-01

In this article we compare x-ray photoelectron spectroscopy (XPS) measurements on bare- and capped- zirconium nitride (ZrN) films to investigate the effect of ambient sample oxidation on the detected bound O in the form of oxide ZrO2 and/or oxynitride ZrOxNy. ZrN films in both bare- and Al2O3/AlN capped- XPS samples were grown by plasma-enhanced atomic layer deposition (PEALD) technique using tetrakis dimethylamino zirconium (TDMAZr) precursor, forming gas (5% H2, rest N2) inductively coupled plasma (ICP), and as received research grade process gases under identical process conditions. Capped samples were prepared by depositing 1 nm thick PEALD AlN on ZrN, followed by additional deposition of 1 nm thick ALD Al2O3, without venting of ALD reactor. On bare ZrN sample at room temperature, spectroscopic ellipsometry (SE) measurements with increasing ambient exposure times (texp) showed a self-limiting surface oxidation with the oxide thickness (dox) approaching 3.7 ± 0.02 nm for texp > 120 min. In XPS data measured prior to sample sputtering (tsput = 0), ZrO2 and ZrOxNy were detected in bare- samples, whereas only ZrN and Al2O3/AlN from capping layer were detected in capped- samples. For bare-ZrN samples, appearance of ZrO2 and ZrOxNy up to sputter depth (dsput) of 15 nm in depth-profile XPS data is in contradiction with measured dox = 3.7 nm, but explained from sputtering induced atomic inter-diffusion within analyzed sample. Appearance of artifacts in the XPS spectra from moderately sputtered (dsput = 0.2 nm and 0.4 nm) capped-ZrN sample, provides an evidence to ion-bombardment induced modifications within analyzed sample.

Bacterial and Fungal Communities in a Degraded Ombrotrophic Peatland Undergoing Natural and Managed Re-Vegetation

PubMed Central

Elliott, David R.; Caporn, Simon J. M.; Nwaishi, Felix; Nilsson, R. Henrik; Sen, Robin

2015-01-01

The UK hosts 15–19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat oligotrophy, re-vegetation recalcitrance, rhizosphere-microbe-soil interactions, C, N and P cycling, trajectory of restoration, and ecosystem service implications for peatland restoration. PMID:25969988

Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

PubMed

Elliott, David R; Caporn, Simon J M; Nwaishi, Felix; Nilsson, R Henrik; Sen, Robin

2015-01-01

The UK hosts 15-19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat oligotrophy, re-vegetation recalcitrance, rhizosphere-microbe-soil interactions, C, N and P cycling, trajectory of restoration, and ecosystem service implications for peatland restoration.

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

Wheat, C.G.; Mottl, M.J.

Warm hydrothermal springs were discovered on Baby Bare, which is an isolated basement outcrop on 3.5 Ma-old crust on the eastern flank of the Juan de Fuca Ridge. The authors have sampled these spring waters from a manned submersible, along with associated sediment pore waters from 48 gravity and piston cores. Systematic variations in the chemical composition of these waters indicate that hydrothermal reactions in basement at moderate temperatures remove Na, K, Li, Rb, Mg, TCO{sub 2}, alkalinity, and phosphate from the circulating seawater and leach Ca, Sr, Si, B, and Mn from the oceanic crust; and that reactions withmore » the turbidite sediment surrounding Baby Bare remove Na, Li, Mg, Ca, Sr, and sulfate from the pore water while producing ammonium and Si and both producing and consuming phosphate, nitrate, alkalinity, Mn, and Fe. K, Rb, and B are relatively unreactive in the sediment column. The composition of altered seawater in basement at Baby Bare is similar to the inferred composition of 58 C formation water from crust nearly twice as old (5.9 Ma) on the southern flank of the Costa Rica Rift. The Baby Bare fluids also exhibit the same directions of net elemental transfer between basalt and seawater as solutions produced in laboratory experiments at a similar temperature, and complement compositional changes form seawater observed in seafloor basalts altered at cool to moderate temperatures. The common parameter among the two ridge flanks and experiments is temperature, suggesting that the residence time of seawater in the two ridge-flank sites is sufficiently long for the solutions to equilibrate with altered basalt. The authors use the Baby Bare spring water to estimate upper limits on the global fluxes of 14 elements at warm ridge-flank sites such as Baby Bare. Maximum calculated fluxes of Mg, Ca, sulfate, B, and K may equal or exceed 25% of the riverine flux, and such sites may represent the missing, high K/Rb sink required for the K budget.« less

Functional connectivity as a possible indicator of desertification in degraded grasslands

NASA Astrophysics Data System (ADS)

Vest, K. R.; Elmore, A. J.; Kaste, J. M.; Okin, G. S.

2011-12-01

Desertification of semi-arid grasslands impacts air quality, climate, biodiversity, and soil fertility. Desertification processes such as wind erosion lead to declining soil resources and sometimes local climate change. Desertification is irreversible; however, identifying when and where ecological changes are irreversible is problematic, requiring observations of a new ecological state, favoring the continued process of wind erosion and continued depletion of soil resources. Scientists hypothesize that an indicator of irreversibility in desertification might be "connected pathways". The connected pathway hypothesis requires that vegetation structure has changed from a grass to a shrub dominated system with increasing number and size of bare soil gaps. These bare soil gaps are functionally connected through the action of wind; therefore, functional connectivity of a landscape is related to the length and size of pathways through vegetation. This study used a combination of field measurements (total horizontal flux (Qtot) and vegetation structure) and landscape modeling to examine the difference in functional connectivity between grassland locations that were either degraded or relatively intact. At our field site, the degradation process was initiated by groundwater pumping, which adversely affects groundwater dependent grasses, providing a useful link to management seeking to limit the effects or extent of desertification. To analyze the functional connectivity of these locations in Owens Valley, we used circuit theory, a novel graph-based approach, which integrates all possible pathways to determine a "resistance distance" between any two points. Circuit theory uses current and resistance to represent movement of wind and the effect of vegetation and soil roughness on wind. Circuit theory was implemented using the open source software package, Circuitscape. To estimate landscape resistance, we performed a supervised classification on 1m aerial photographs. For each landscape class (shrub, grass, and soil), we applied a standardized resistance value which decreased downwind of vegetation. We validated the resistance layer by using Qtot data collected from 13 plots with BSNE catchers (i.e., plots with higher Qtot should be associated with higher connectivity). Next, we developed a focal region grid containing source and ground regions for current at these plots; these regions represent wind directions (N, S, E, W). We ran Circuitscape on data from different locations with similar vegetation structure but differing histories of groundwater withdrawal. From the model output, we found that degraded landscapes have greater connectivity than landscapes that are not degraded. We also found that locations with fewer larger and elongated bare soil gaps had greater connectivity than locations with numerous small bare soil gaps. Our results support the idea that functional connectivity is a possible indicator of desertification and that managing for reduced connectivity might limit the effects and extent of desertification.

The role of surface water redistribution in an area of patterned vegetation in a semi-arid environment, south-west Niger

NASA Astrophysics Data System (ADS)

Bromley, J.; Brouwer, J.; Barker, A. P.; Gaze, S. R.; Valentine, C.

1997-11-01

The surface hydrology of a semi-arid area of patterned vegetation in south-west Niger is described. In this region alternating bands of vegetation and bare ground aligned along the contours of a gently sloping terrain give rise to a phenomenon known as `brousse tigrée' (tiger bush). At the selected study site the vegetation bands are 10-30 m wide, separated by 50-100-m-wide bands of bare ground. Five species of shrub dominate, Guiera senegalensis, Combretum micranthum, C. nigricans, Acacia ataxacantha and A. macrostachya. Herbaceous vegetation is generally limited to the upslope edges of vegetation bands. A comprehensive field programme was undertaken to investigate the hydrology. Topographic, vegetation and surface feature surveys were carried out in conjunction with the measurement of rainfall, surface and subsurface hydraulic conductivity, particle size and soil moisture content. Four types of vegetation class are recognised, each tending to occupy a constant position relative to the others and to the regional slope. In a downslope direction the classes are: bare ground, grassy open bush, closed bush, bare open bush, bare ground etc. The nature of the ground surface is closely linked to the vegetation class. Over the bare, bare open and grassy open classes various types of surface crust are present with each type of crust tending to occupy a constant position on the regional slope relative to the vegetation class and other crust types. Below closed bush crusts are generally absent. The typical downslope sequence from the downslope boundary of a vegetation band is: structural (sieving) crust→erosion crust→(gravel crust)→sedimentation crust→microphytic sedimentation crust→no crust→sieving crust, etc. It is also shown that these crust types are dynamic and evolve from one to the other as hydrological conditions change. Hydraulic conductivities of surface crusts are low, typically falling within the range 10 -6-10 -7 m s -1. The presence of large expanses of crust over bare regions tends to generate run-off, which moves down the regional slope to be intercepted and pond within and just upslope of vegetated areas. Such run-off concentrates rainfall by a factor of up to 3.7 below vegetated areas. This concentration combined with an absence of crust development in closed bush areas promotes rapid infiltration below and just upslope of vegetation bands. In this way the hydrology of the area operates to ensure that the bulk of the rain which falls is directed as quickly as possible to the areas where it is most needed to support the existing vegetation.

Biomimetic hairy surfaces as superhydrophobic highly transmissive films for optical applications (Conference Presentation)

NASA Astrophysics Data System (ADS)

Vuellers, Felix; Gomard, Guillaume; Preinfalk, Jan B.; Klampaftis, Efthymios; Worgull, Matthias; Richards, Bryce S.; Hölscher, Hendrik; Kavalenka, Maryna N.

2017-02-01

Combining high optical transmission, water-repellency and self-cleaning is of great interest for optoelectronic devices operating in outdoor conditions, such as photovoltaics where shading can significantly reduce the power output. The surface of water plant Pistia stratiotes combines these functionalities through a dense layer of transparent microhairs. It renders the surface superhydrophobic without affecting absorption of sunlight necessary for photosynthesis. Inspired by this surface, we fabricated a superhydrophobic flexible thin nanofur film made from optical grade polycarbonate using a scalable combination of hot embossing and hot pulling techniques. During fabrication, heated sandblasted steel plates locally elongate softened polymer, thus covering its surface in microcavities surrounded by high aspect ratio micro- and nanohairs. The superhydrophobic nanofur exhibits contact angles of (166+/-6°), low sliding angles (<6°) and is self-cleaning against various contaminants. The overall transmission of the self-standing nanofur film stands above 85% over the visible range, with 97% of the transmitted light scattered forward. Reflection drops below 4% when coated on a polymeric substrate, which can enhance light extraction in organic light emitting diodes (OLEDs). We report an increase of more than 10% in luminous efficacy for a nanofur coated OLED compared to a bare device. Finally, the nanofur film can be used for enhancing the incoupling of light to solar cells, while additionally providing self-cleaning properties. Optical coupling of the nanofur to a multi-crystalline silicon solar cell results in a 5.8% gain in photocurrent compared to a bare device under normal incidence.

Integrating satellite remote sensing data and field data to predict rangeland structural indicators at the continental scale

NASA Astrophysics Data System (ADS)

Zhang, J.; Okin, G.

2016-12-01

Rangelands provide a variety of important ecosystem goods and services across drylands globally. They are also the most important emitters of dust across the globe. Field data collection based on points does not represent spatially continuous information about surface variables and, given the vast size of the world's rangelands, cannot cover even a small fraction of their area. Remote sensing is potentially a labor- and time-saving method to observe important rangeland vegetation variables at both temporal and spatial scales. Information on vegetation cover, bare gap size, and plant height provide key rangeland vegetation variables in arid and semiarid rangelands, in part because they strongly impact dust emission and determine wildlife habitat characteristics. This study reports on relationships between remote sensing in the reflected solar spectrum and field measures related to these three variables, and shows how these relationships can be extended to produce spatially and temporally continuous datasets coupled with quantitative estimates of error. Field data for this study included over 3,800 Assessment, Inventory, and Monitoring (AIM) measurements on Bureau of Land Management (BLM) lands throughout the western US. Remote sensing data were derived from MODIS nadir BRDF-adjusted reflectance (NBAR) and Landsat 8 OLI surface reflectance. Normalized bare gap size, total foliar cover, herbaceous cover and herbaceous height exhibit the greatest predictability from remote sensing variables with physically-reasonable relationships between remote sensing variables and field measures. Data fields produced using these relationships across the western US exhibit good agreement with independent high-resolution imagery.

Mobility of an elastic glove for extravehicular activity without prebreathing.

PubMed

Tanaka, Kunihiko; Ikeda, Mizuki; Mochizuki, Yosuke; Katafuchi, Tetsuro

2011-09-01

The current U.S. extravehicular activity (EVA) suit is pressurized at 0.29 atm, which is much lower than the pressures of sea level and inside a space station. Higher pressure can reduce the risk of decompression sickness (DCS), but mobility would be sacrificed. We have demonstrated that a glove and sleeve made of elastic material increased mobility when compared with those made of nonelastic material, such as that found in the current suit. We hypothesized that an elastic glove of 0.65 atm that has no risk of DCS also has greater mobility compared with a non-elastic glove of 0.29 atm. The right hands of 10 healthy volunteers were studied in a chamber with their bare hands at normal ambient pressure, after donning a non-elastic glove with a pressure differential of 0.29 atm, and after donning an elastic glove with a pressure differential of 0.29 and 0.65 atm. Range of motion (ROM) of the index finger and surface electromyography (EMG) amplitudes during finger flexion were measured. ROM with gloves was significantly smaller than that of bare hands, but was similar between conditions of gloves regardless of elasticity and pressure differentials. However, EMG amplitudes with the elastic glove of 0.29 and 0.65 atm were significantly smaller than those with the non-elastic glove of 0.29 atm. The results suggest that mobility of the elastic glove of 0.65 atm may be better than that of the non-elastic glove of 0.29 atm, similar to that used in the current EVA suit.

Red-light-induced positive phototropism in Arabidopsis roots

NASA Technical Reports Server (NTRS)

Ruppel, N. J.; Hangarter, R. P.; Kiss, J. Z.

2001-01-01

The interaction between light and gravity is critical in determining the final form of a plant. For example, the competing activities of gravitropism and phototropism can determine the final orientation of a stem or root. The results reported here indicate that, in addition to the previously described blue-light-dependent negative phototropic response in roots, roots of Arahidopsis thaliana (L.) Heynh. display a previously unknown red-light-dependent positive phototropic response. Both phototropic responses in roots are considerably weaker than the graviresponse, which often masks phototropic curvature. However, through the use of mutant strains with impaired gravitropism, we were able to identify a red-light-dependent positive phototropic response in Arabidopsis roots. The red-induced positive phototropic response is considerably weaker than the blue-light response and is barely detectable in plants with a normal gravitropic response.

Red-light-induced positive phototropism in Arabidopsis roots.

PubMed

Ruppel, N J; Hangarter, R P; Kiss, J Z

2001-02-01

The interaction between light and gravity is critical in determining the final form of a plant. For example, the competing activities of gravitropism and phototropism can determine the final orientation of a stem or root. The results reported here indicate that, in addition to the previously described blue-light-dependent negative phototropic response in roots, roots of Arahidopsis thaliana (L.) Heynh. display a previously unknown red-light-dependent positive phototropic response. Both phototropic responses in roots are considerably weaker than the graviresponse, which often masks phototropic curvature. However, through the use of mutant strains with impaired gravitropism, we were able to identify a red-light-dependent positive phototropic response in Arabidopsis roots. The red-induced positive phototropic response is considerably weaker than the blue-light response and is barely detectable in plants with a normal gravitropic response.

Distribution of angiographic measures of restenosis after drug-eluting stent implantation.

PubMed

Byrne, R A; Eberle, S; Kastrati, A; Dibra, A; Ndrepepa, G; Iijima, R; Mehilli, J; Schömig, A

2009-10-01

A bimodal distribution of measures of restenosis has been demonstrated at 6-8 months after bare metal stent implantation. Drug-eluting stent (DES) treatment has attenuated the impact of certain factors (eg, diabetes) on restenosis but its effect on the distribution of indices of restenosis is not known. To perform a detailed analysis of the metrics of restenosis indices after DES implantation. Design, settings, Prospective observational study of patients undergoing DES implantation (Cypher, sirolimus-eluting stent; or Taxus, paclitaxel-eluting stent) at two German centres, with repeat angiography scheduled at 6-8 months after coronary stenting. In-stent late luminal loss (LLL) and in-segment percentage diameter stenosis (%DS) as determined by quantitative coronary angiography at recatheterisation. Paired cineangiograms were available for 2057 patients. Overall mean (SD) LLL was 0.31 (0.50) mm; mean (SD) %DS was 30.3 (15.7)%. Distribution of both LLL and %DS differed significantly from normal (Kolmogorov-Smirnov test; p<0.001 for each). For both parameters a mixed distribution model better described the data (likelihood ratio test with 3df; p<0.001 for each). This consisted of two normally distributed subpopulations with means (SD) of 0.10 (0.25) mm and 0.69 (0.60) mm for LLL, and means (SD) of 22.2 (8.6)% and 40.1 (16.6)% for %DS. The results were consistent across subgroups of DES type, "on-label" versus "off-label" indication, and presence or absence of diabetes. LLL and %DS at follow-up angiography after DES implantation have a complex mixed distribution that may be accurately represented by a bimodal distribution model. The introduction of DES treatment has not resulted in elimination of a variable propensity to restenosis among subpopulations of patients with stented lesions.

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

PubMed Central

2017-01-01

Due to their electrochemical and economical characteristics, pencil graphite electrodes (PGEs) gained in recent years a large applicability to the analysis of various types of inorganic and organic compounds from very different matrices. The electrode material of this type of working electrodes is constituted by the well-known and easy commercially available graphite pencil leads. Thus, PGEs are cheap and user-friendly and can be employed as disposable electrodes avoiding the time-consuming step of solid electrodes surface cleaning between measurements. When compared to other working electrodes PGEs present lower background currents, higher sensitivity, good reproducibility, and an adjustable electroactive surface area, permitting the analysis of low concentrations and small sample volumes without any deposition/preconcentration step. Therefore, this paper presents a detailed overview of the PGEs characteristics, designs and applications of bare, and electrochemically pretreated and chemically modified PGEs along with the corresponding performance characteristics like linear range and detection limit. Techniques used for bare or modified PGEs surface characterization are also reviewed. PMID:28255500

Dressed ion theory of size-asymmetric electrolytes: effective ionic charges and the decay length of screened Coulomb potential and pair correlations.

PubMed

Forsberg, Björn; Ulander, Johan; Kjellander, Roland

2005-02-08

The effects of ionic size asymmetry on long-range electrostatic interactions in electrolyte solutions are investigated within the primitive model. Using the formalism of dressed ion theory we analyze correlation functions from Monte Carlo simulations and the hypernetted chain approximation for size asymmetric 1:1 electrolytes. We obtain decay lengths of the screened Coulomb potential, effective charges of ions, and effective permittivity of the solution. It is found that the variation of these quantities with the degree of size asymmetry depends in a quite intricate manner on the interplay between the electrostatic coupling and excluded volume effects. In most cases the magnitude of the effective charge of the small ion species is larger than that of the large species; the difference increases with increasing size asymmetry. The effective charges of both species are larger (in absolute value) than the bare ionic charge, except for high asymmetry where the effective charge of the large ions can become smaller than the bare charge.

First-principles investigation of armchair boron nitride nanoribbons for sensing PH3 gas molecules

NASA Astrophysics Data System (ADS)

Srivastava, Pankaj; Jaiswal, Neeraj K.; Sharma, Varun

2014-09-01

The present work exhibits density functional theory (DFT) based first-principles calculations to explore the sensing properties of bare armchair boron nitride nanoribbons (ABNNR) for PH3 gas molecules. Edges of the ribbon were considered as the sites of possible adsorption with two different configurations i.e. adsorption at one edge and adsorption at both edges of the ribbon. It is revealed that B atoms of the ribbons are more energetically favorable sites for the adsorption of PH3 molecules as compared with N atoms. The adsorption of PH3 affects the electronic properties of nanoribbons. One edge PH3 adsorbed ribbons are metallic whereas in both edges PH3 adsorption, the band gap is decreased than that of bare ribbon. The changes in electronic properties caused by PH3 adsorption are further supported by the current-voltage (I-V) characteristics of the considered configurations. The results show that ABNNR can serve as a potential candidate for PH3 sensing applications.

Characterisation of bare and tannase-loaded calcium alginate beads by microscopic, thermogravimetric, FTIR and XRD analyses.

PubMed

Larosa, Claudio; Salerno, Marco; de Lima, Juliana Silva; Merijs Meri, Remo; da Silva, Milena Fernandes; de Carvalho, Luiz Bezerra; Converti, Attilio

2018-08-01

Incorporating enzymes into calcium alginate beads is an effective method to immobilise them and to preserve, at the same time, their catalytic activity. Sodium alginate was mixed with Aspergillus ficuum tannase in aqueous solution, and tannase-loaded calcium alginate beads were prepared using a simple droplet-based microfluidic system. Extensive experimental analysis was carried out to characterise the samples. Microscopic imaging revealed morphological differences between the surfaces of bare alginate matrix and tannase-loaded alginate beads. Thermal analysis allowed assessing the hydration contents of alginate and revealed the presence of tannase entrapped in the loaded beads, which was confirmed by vibrational spectroscopy. X-ray diffraction allowed us to conclude that alginate of tannase-loaded beads is not crystalline, which would make them suitable as carriers for possible controlled release. Moreover, they could be used in food applications to improve tea quality or clarify juices. Copyright © 2018 Elsevier B.V. All rights reserved.

Many-body perturbation theory and non-perturbative approaches: screened interaction as the key ingredient

NASA Astrophysics Data System (ADS)

Tarantino, Walter; Mendoza, Bernardo S.; Romaniello, Pina; Berger, J. A.; Reining, Lucia

2018-04-01

Many-body perturbation theory is often formulated in terms of an expansion in the dressed instead of the bare Green’s function, and in the screened instead of the bare Coulomb interaction. However, screening can be calculated on different levels of approximation, and it is important to define what is the most appropriate choice. We explore this question by studying a zero-dimensional model (so called ‘one-point model’) that retains the structure of the full equations. We study both linear and non-linear response approximations to the screening. We find that an expansion in terms of the screening in the random phase approximation is the most promising way for an application in real systems. Moreover, by making use of the nonperturbative features of the Kadanoff-Baym equation for the one-body Green’s function, we obtain an approximate solution in our model that is very promising, although its applicability to real systems has still to be explored.

Surface-dependent chemical equilibrium constants and capacitances for bare and 3-cyanopropyldimethylchlorosilane coated silica nanochannels.

PubMed

Andersen, Mathias Bækbo; Frey, Jared; Pennathur, Sumita; Bruus, Henrik

2011-01-01

We present a combined theoretical and experimental analysis of the solid-liquid interface of fused-silica nanofabricated channels with and without a hydrophilic 3-cyanopropyldimethylchlorosilane (cyanosilane) coating. We develop a model that relaxes the assumption that the surface parameters C(1), C(2), and pK(+) are constant and independent of surface composition. Our theoretical model consists of three parts: (i) a chemical equilibrium model of the bare or coated wall, (ii) a chemical equilibrium model of the buffered bulk electrolyte, and (iii) a self-consistent Gouy-Chapman-Stern triple-layer model of the electrochemical double layer coupling these two equilibrium models. To validate our model, we used both pH-sensitive dye-based capillary filling experiments as well as electro-osmotic current-monitoring measurements. Using our model we predict the dependence of ζ potential, surface charge density, and capillary filling length ratio on ionic strength for different surface compositions, which can be difficult to achieve otherwise. Copyright © 2010 Elsevier Inc. All rights reserved.

The Effects of Foam Thermal Protection System on the Damage Tolerance Characteristics of Composite Sandwich Structures for Launch Vehicles

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Hodge, A. J.; Jackson, J. R.

2011-01-01

For any structure composed of laminated composite materials, impact damage is one of the greatest risks and therefore most widely tested responses. Typically, impact damage testing and analysis assumes that a solid object comes into contact with the bare surface of the laminate (the outer ply). However, most launch vehicle structures will have a thermal protection system (TPS) covering the structure for the majority of its life. Thus, the impact response of the material with the TPS covering is the impact scenario of interest. In this study, laminates representative of the composite interstage structure for the Ares I launch vehicle were impact tested with and without the planned TPS covering, which consists of polyurethane foam. Response variables examined include maximum load of impact, damage size as detected by nondestructive evaluation techniques, and damage morphology and compression after impact strength. Results show that there is little difference between TPS covered and bare specimens, except the residual strength data is higher for TPS covered specimens.

New Convex and Spherical Structures of Bare Boron Clusters

NASA Astrophysics Data System (ADS)

Boustani, Ihsan

1997-10-01

New stable structures of bare boron clusters can easily be obtained and constructed with the help of an "Aufbau Principle" suggested by a systematicab initioHF-SCF and direct CI study. It is concluded that boron cluster formation can be established by elemental units of pentagonal and hexagonal pyramids. New convex and small spherical clusters different from the classical known forms of boron crystal structures are obtained by a combination of both basic units. Convex structures simulate boron surfaces which can be considered as segments of open or closed spheres. Both convex clusters B16and B46have energies close to those of their conjugate quasi-planar clusters, which are relatively stable and can be considered to act as a calibration mark. The closed spherical clusters B12, B22, B32, and B42are less stable than the corresponding conjugated quasi-planar structures. As a consequence, highly stable spherical boron clusters can systematically be predicted when their conjugate quasi-planar clusters are determined and energies are compared.

Chiral Selective Chemistry Induced by Natural Selection of Spin-Polarized Electrons.

PubMed

Rosenberg, Richard A; Mishra, Debabrata; Naaman, Ron

2015-06-15

The search to understand the origin of homochirality in nature has been ongoing since the time of Pasteur. Previous work has shown that DNA can act as a spin filter for low-energy electrons and that spin-polarized secondary electrons produced by X-ray irradiation of a magnetic substrate can induce chiral selective chemistry. In the present work it is demonstrated that secondary electrons from a substrate that are transmitted through a chiral overlayer cause enantiomeric selective chemistry in an adsorbed adlayer. We determine the quantum yields (QYs) for dissociation of (R)- or (S)-epichlorohydrin adsorbed on a chiral self-assembled layer of DNA on gold and on bare gold (for control). The results show that there is a significant difference in the QYs between the two enantiomers when adsorbed on DNA, but none when they are adsorbed on bare Au. We propose that the effect results from natural spin filtering effects cause by the chiral monolayer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer electrolytes based on sulfonated polysulfone for direct methanol fuel cells

NASA Astrophysics Data System (ADS)

Lufrano, F.; Baglio, V.; Staiti, P.; Arico', A. S.; Antonucci, V.

This paper reports the development and characterization of sulfonated polysulfone (SPSf) polymer electrolytes for direct methanol fuel cells. The synthesis of sulfonated polysulfone was performed by a post sulfonation method using trimethyl silyl chlorosulfonate as a mild sulfonating agent. Bare polysulfone membranes were prepared with two different sulfonation levels (60%, SPSf-60 and 70%, SPSf-70), whereas, a composite membrane of SPSf-60 was prepared with 5 wt% silica filler. These membranes were investigated in direct methanol fuel cells (DMFCs) operating at low (30-40 °C) and high temperatures (100-120 °C). DMFC power densities were about 140 mW cm -2 at 100 °C with the bare SPSf-60 membrane and 180 mW cm -2 at 120 °C with the SPSf-60-SiO2 composite membrane. The best performance achieved at ambient temperature using a membrane with high degree of sulfonation (70%, SPSf-70) was 20 mW cm -2 at atmospheric pressure. This makes the polysulfone-based DMFC suitable for application in portable devices.

Wave Propagation and Localization via Quasi-Normal Modes and Transmission Eigenchannels

NASA Astrophysics Data System (ADS)

Wang, Jing; Shi, Zhou; Davy, Matthieu; Genack, Azriel Z.

2013-10-01

Field transmission coefficients for microwave radiation between arrays of points on the incident and output surfaces of random samples are analyzed to yield the underlying quasi-normal modes and transmission eigenchannels of each realization of the sample. The linewidths, central frequencies, and transmitted speckle patterns associated with each of the modes of the medium are found. Modal speckle patterns are found to be strongly correlated leading to destructive interference between modes. This explains distinctive features of transmission spectra and pulsed transmission. An alternate description of wave transport is obtained from the eigenchannels and eigenvalues of the transmission matrix. The maximum transmission eigenvalue, τ1 is near unity for diffusive waves even in turbid samples. For localized waves, τ1 is nearly equal to the dimensionless conductance, which is the sum of all transmission eigenvalues, g = Στn. The spacings between the ensemble averages of successive values of lnτn are constant and equal to the inverse of the bare conductance in accord with predictions by Dorokhov. The effective number of transmission eigenvalues Neff determines the contrast between the peak and background of radiation focused for maximum peak intensity. The connection between the mode and channel approaches is discussed.

Wave Propagation and Localization via Quasi-Normal Modes and Transmission Eigenchannels

NASA Astrophysics Data System (ADS)

Wang, Jing; Shi, Zhou; Davy, Matthieu; Genack, Azriel Z.

Field transmission coefficients for microwave radiation between arrays of points on the incident and output surfaces of random samples are analyzed to yield the underlying quasi-normal modes and transmission eigenchannels of each realization of the sample. The linewidths, central frequencies, and transmitted speckle patterns associated with each of the modes of the medium are found. Modal speckle patterns are found to be strongly correlated leading to destructive interference between modes. This explains distinctive features of transmission spectra and pulsed transmission. An alternate description of wave transport is obtained from the eigenchannels and eigenvalues of the transmission matrix. The maximum transmission eigenvalue, τ1 is near unity for diffusive waves even in turbid samples. For localized waves, τ1 is nearly equal to the dimensionless conductance, which is the sum of all transmission eigenvalues, g = Στn. The spacings between the ensemble averages of successive values of lnτn are constant and equal to the inverse of the bare conductance in accord with predictions by Dorokhov. The effective number of transmission eigenvalues Neff determines the contrast between the peak and background of radiation focused for maximum peak intensity. The connection between the mode and channel approaches is discussed.

Transcutaneous in vivo Raman spectroscopic studies in a mouse model: evaluation of changes in the breast associated with pregnancy and lactation

NASA Astrophysics Data System (ADS)

Bhattacharjee, Tanmoy; Maru, Girish; Ingle, Arvind; Krishna, C. Murali

2013-04-01

Raman spectroscopy (RS) has been extensively explored as an alternative diagnostic tool for breast cancer. This can be attributed to its sensitivity to malignancy-associated biochemical changes. However, biochemical changes due to nonmalignant conditions like benign lesions, inflammatory diseases, aging, menstrual cycle, pregnancy, and lactation may act as confounding factors in diagnosis of breast cancer. Therefore, in this study, the efficacy of RS to classify pregnancy and lactation-associated changes as well as its effect on breast tumor diagnosis was evaluated. Since such studies are difficult in human subjects, a mouse model was used. Spectra were recorded transcutaneously from the breast region of six Swiss bare mice postmating, during pregnancy, and during lactation. Data were analyzed using multivariate statistical tool Principal Component-Linear Discriminant Analysis. Results suggest that RS can differentiate breasts of pregnant/lactating mice from those of normal mice, the classification efficiencies being 100%, 60%, and 88% for normal, pregnant, and lactating mice, respectively. Frank breast tumors could be classified with 97.5% efficiency, suggesting that these physiological changes do not affect the ability of RS to detect breast tumors.

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

NASA Technical Reports Server (NTRS)

Franklin, J.; Duncan, J.

1992-01-01

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

Distribution of body mass index in the forensic victim population: comparison with the general population and relation to manner of death.

PubMed

Godin, Anny; Redpath, Margaret; Guay, Jean-Pierre; Sauvageau, Anny

2010-07-01

Despite a dramatic increase in the worldwide prevalence of overweight and obese people in recent years, the implication of this epidemic on forensic practice has barely been studied. Over a one-year period, all autopsy cases performed on adult victims in the province of Quebec (Canada) were retrospectively reviewed (582 cases). In the forensic population, manner of death differed in relation to BMI: underweight people most commonly died of natural causes, whereas normal weight, overweight and obese individuals most commonly died as the result of an accident. Results also revealed an over-representation of underweight victims and under-representation of overweight victims in the forensic population compared to the population of both Quebec and Canada. The latter is particularly worrisome considering it suggests that overweight corpses are less frequently referred for an autopsy. It is important to emphasize to forensic teams that just because an obese person is more likely to suffer from health problems that can lead to death, does not mean a natural death has occurred. Obese people are equally susceptible to unnatural causes of death and it is crucial to maintain an adequate level of suspicion while investigating the cases of these individuals. Copyright 2010 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Characterization of shrubland ecosystem components as continuous fields in the northwest United States

USGS Publications Warehouse

Xian, George Z.; Homer, Collin G.; Rigge, Matthew B.; Shi, Hua; Meyer, Debbie

2015-01-01

Accurate and consistent estimates of shrubland ecosystem components are crucial to a better understanding of ecosystem conditions in arid and semiarid lands. An innovative approach was developed by integrating multiple sources of information to quantify shrubland components as continuous field products within the National Land Cover Database (NLCD). The approach consists of several procedures including field sample collections, high-resolution mapping of shrubland components using WorldView-2 imagery and regression tree models, Landsat 8 radiometric balancing and phenological mosaicking, medium resolution estimates of shrubland components following different climate zones using Landsat 8 phenological mosaics and regression tree models, and product validation. Fractional covers of nine shrubland components were estimated: annual herbaceous, bare ground, big sagebrush, herbaceous, litter, sagebrush, shrub, sagebrush height, and shrub height. Our study area included the footprint of six Landsat 8 scenes in the northwestern United States. Results show that most components have relatively significant correlations with validation data, have small normalized root mean square errors, and correspond well with expected ecological gradients. While some uncertainties remain with height estimates, the model formulated in this study provides a cross-validated, unbiased, and cost effective approach to quantify shrubland components at a regional scale and advances knowledge of horizontal and vertical variability of these components.

Evidence that Soil Properties and Organic Coating Drive the Phytoavailability of Cerium Oxide Nanoparticles.

PubMed

Layet, Clément; Auffan, Mélanie; Santaella, Catherine; Chevassus-Rosset, Claire; Montes, Mélanie; Ortet, Philippe; Barakat, Mohamed; Collin, Blanche; Legros, Samuel; Bravin, Matthieu N; Angeletti, Bernard; Kieffer, Isabelle; Proux, Olivier; Hazemann, Jean-Louis; Doelsch, Emmanuel

2017-09-05

The ISO-standardized RHIZOtest is used here for the first time to decipher how plant species, soil properties, and physical-chemical properties of the nanoparticles and their transformation regulate the phytoavailability of nanoparticles. Two plants, tomato and fescue, were exposed to two soils with contrasted properties: a sandy soil poor in organic matter and a clay soil rich in organic matter, both contaminated with 1, 15, and 50 mg·kg -1 of dissolved Ce 2 (SO 4 ) 3 , bare and citrate-coated CeO 2 nanoparticles. All the results demonstrate that two antagonistic soil properties controlled Ce uptake. The clay fraction enhanced the retention of the CeO 2 nanoparticles and hence reduced Ce uptake, whereas the organic matter content enhanced Ce uptake. Moreover, in the soil poor in organic matter, the organic citrate coating significantly enhanced the phytoavailability of the cerium by forming smaller aggregates thereby facilitating the transport of nanoparticles to the roots. By getting rid of the dissimilarities between the root systems of the different plants and the normalizing the surfaces exposed to nanoparticles, the RHIZOtest demonstrated that the species of plant did not drive the phytoavailability, and provided evidence for soil-plant transfers at concentrations lower than those usually cited in the literature and closer to predicted environmental concentrations.

Production and assessment of red alder planting stock.

Treesearch

M.A. Radwan; Y. Tanaka; A. Dobkowskl; W. Fangen

1992-01-01

A series of experiments was conducted over 4 years to test and develop methods to produce acceptable red alder planting stock and to assess quality and outplanting performance of resulting stock. Results indicated that red alder planting stock can be produced as containerized seedlings (plugs) or as bare-root nontransplant and transplant trees. In general, bare-root...

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

Doenmez, Halil, E-mail: hdonmez68@yahoo.com; Mavili, Ertugrul, E-mail: ertmavili@yahoo.com; Ikizceli, Tuerkan

Aseptic meningitis related to hydrogel-coated coils is a known complication, but it is extremely rare after platinum bare coil aseptic meningitis. Here we report the development of aseptic meningitis causing brain stem and cerebellar infarct in a patient with a giant aneurysm treated with bare platinum coils. We conclude that aneurysm size is an important factor affecting the occurrence of aseptic meningitis associated with stroke.

Influence of cultural practices on edaphic factors related to root disease in Pinus nursery seedlings

Treesearch

J Juzwik; K. M. Gust; R. R. Allmaras

1999-01-01

Conifer seedlings grown in bare-root nurseries are frequently damaged and destroyed by soil-borne pathogenic fungi that cause root rot. Relationships between nursery cultural practices, soils characteristics, and populations of potential pathogens in the soil were examined in three bare-root tree nurseries in the midwestern USA. Soil-borne populations of ...

Human's Capability to Discriminate Spatial Forces at the Big Toe.

PubMed

Hagengruber, Annette; Höppner, Hannes; Vogel, Jörn

2018-01-01

A key factor for reliable object manipulation is the tactile information provided by the skin of our hands. As this sensory information is so essential in our daily life it should also be provided during teleoperation of robotic devices or in the control of myoelectric prostheses. It is well-known that feeding back the tactile information to the user can lead to a more natural and intuitive control of robotic devices. However, in some applications it is difficult to use the hands as natural feedback channels since they may already be overloaded with other tasks or, e.g., in case of hand prostheses not accessible at all. Many alternatives for tactile feedback to the human hand have already been investigated. In particular, one approach shows that humans can integrate uni-directional (normal) force feedback at the toe into their sensorimotor-control loop. Extending this work, we investigate the human's capability to discriminate spatial forces at the bare front side of their toe. A state-of-the-art haptic feedback device was used to apply forces with three different amplitudes-2 N, 5 N, and 8 N-to subjects' right big toes. During the experiments, different force stimuli were presented, i.e., direction of the applied force was changed, such that tangential components occured. In total the four directions up (distal), down (proximal), left (medial), and right (lateral) were tested. The proportion of the tangential force was varied corresponding to a directional change of 5° to 25° with respect to the normal force. Given these force stimuli, the subjects' task was to identify the direction of the force change. We found the amplitude of the force as well as the proportion of tangential forces to have a significant influence on the success rate. Furthermore, the direction right showed a significantly different successrate from all other directions. The stimuli with a force amplitude of 8 N achieved success rates over 89% in all directions. The results of the user study provide evidence that the subjects were able to discriminate spatial forces at their toe within defined force amplitudes and tangential proportion.

Spectral Remote Sensing of Dust Sources on the U.S. Great Plains from 1930s Panchromatic Aerial Phtography

NASA Astrophysics Data System (ADS)

Bolles, K.; Forman, S. L.

2017-12-01

Understanding the spatiotemporal dynamics of dust sources is essential to accurately quantify the various impacts of dust on the Earth system; however, a persistent deficiency in modeling dust emission is detailed knowledge of surface texture, geomorphology, and location of dust emissive surfaces, which strongly influence the effects of wind erosion. Particle emission is closely linked to both climatic and physical surface factors - interdependent variables that respond to climate nonlinearly and are mitigated by variability in land use or management practice. Recent efforts have focused on development of a preferential dust source (PDS) identification scheme to improve global dust-cycle models, which posits certain surfaces are more likely to emit dust than others, dependent upon associated sediment texture and geomorphological limitations which constrain sediment supply and availability. In this study, we outline an approach to identify and verify the physical properties and distribution of dust emissive surfaces in the U.S. Great Plains from historical aerial imagery in order to establish baseline records of dust sources, associated erodibility, and spatiotemporal variability, prior to the satellite era. We employ a multi-criteria, spatially-explicit model to identify counties that are "representative" of the broader landscape on the Great Plains during the 1930s. Parameters include: percentage of county cultivated and uncultivated per the 1935 Agricultural Census, average soil sand content, mean annual Palmer Drought Severity Index (PDSI), maximum annual temperature and percent difference to the 30-year normal maximum temperature, and annual precipitation and percent difference to the 30-year normal precipitation level. Within these areas we generate random points to select areas for photo reproduction. Selected frames are photogrammetrically scanned at 1200 dpi, radiometrically corrected, mosaicked and georectified to create an IKONOS-equivalent image. Gray-level co-occurrence matrices are calculated in a 3x3 moving window to determine textural properties of the mosaic and delineate bare surfaces of different sedimentological properties. Field stratigraphic assessments and spatially-referenced historical data are integrated within ArcGIS to ground-truth imagery.

Human's Capability to Discriminate Spatial Forces at the Big Toe

PubMed Central

Hagengruber, Annette; Höppner, Hannes; Vogel, Jörn

2018-01-01

A key factor for reliable object manipulation is the tactile information provided by the skin of our hands. As this sensory information is so essential in our daily life it should also be provided during teleoperation of robotic devices or in the control of myoelectric prostheses. It is well-known that feeding back the tactile information to the user can lead to a more natural and intuitive control of robotic devices. However, in some applications it is difficult to use the hands as natural feedback channels since they may already be overloaded with other tasks or, e.g., in case of hand prostheses not accessible at all. Many alternatives for tactile feedback to the human hand have already been investigated. In particular, one approach shows that humans can integrate uni-directional (normal) force feedback at the toe into their sensorimotor-control loop. Extending this work, we investigate the human's capability to discriminate spatial forces at the bare front side of their toe. A state-of-the-art haptic feedback device was used to apply forces with three different amplitudes—2 N, 5 N, and 8 N—to subjects' right big toes. During the experiments, different force stimuli were presented, i.e., direction of the applied force was changed, such that tangential components occured. In total the four directions up (distal), down (proximal), left (medial), and right (lateral) were tested. The proportion of the tangential force was varied corresponding to a directional change of 5° to 25° with respect to the normal force. Given these force stimuli, the subjects' task was to identify the direction of the force change. We found the amplitude of the force as well as the proportion of tangential forces to have a significant influence on the success rate. Furthermore, the direction right showed a significantly different successrate from all other directions. The stimuli with a force amplitude of 8 N achieved success rates over 89% in all directions. The results of the user study provide evidence that the subjects were able to discriminate spatial forces at their toe within defined force amplitudes and tangential proportion. PMID:29692718

Numerical modeling of coupled water flow and heat transport in soil and snow

Treesearch

Thijs J. Kelleners; Jeremy Koonce; Rose Shillito; Jelle Dijkema; Markus Berli; Michael H. Young; John M. Frank; William Massman

2016-01-01

A one-dimensional vertical numerical model for coupled water flow and heat transport in soil and snow was modified to include all three phases of water: vapor, liquid, and ice. The top boundary condition in the model is driven by incoming precipitation and the surface energy balance. The model was applied to three different terrestrial systems: A warm desert bare...

Building Bridges to the World: Utilizing Service Learning during the Senior Year to Develop Participatory Citizenship

ERIC Educational Resources Information Center

Myers, Aimee

2016-01-01

The senior year of high school has the potential to be a bridge between childhood and adulthood, but senior courses are not vastly different than courses offered to freshman who are barely into their teenage years. A service learning component that is embedded throughout the senior year provides students with the space to think critically and then…

Erosion of mountain hiking trail over a seven-year period in Daisetsuzan National Park, central Hokkaido, Japan

Treesearch

Akemi Yoda; Teiji Watanabe

2000-01-01

Erosion of mountain hiking trails was investigated in Daisetsuzan National Park over a seven-year period. The amount and rate of erosion were different in the two typical landscape components. Cross-section diagrams revealed that trail depth became deeper in snowy vegetated areas than in wind-beaten bare ground areas. The existence and timing of runoff from snowmelt...

Ground-Truthing of Airborne LiDAR Using RTK-GPS Surveyed Data in Coastal Louisiana's Wetlands

NASA Astrophysics Data System (ADS)

Lauve, R. M.; Alizad, K.; Hagen, S. C.

2017-12-01

Airborne LiDAR (Light Detection and Ranging) data are used by engineers and scientists to create bare earth digital elevation models (DEM), which are essential to modeling complex coastal, ecological, and hydrological systems. However, acquiring accurate bare earth elevations in coastal wetlands is difficult due to the density of marsh grasses that prevent the sensors reflection off the true ground surface. Previous work by Medeiros et al. [2015] developed a technique to assess LiDAR error and adjust elevations according to marsh vegetation density and index. The aim of this study is the collection of ground truth points and the investigation on the range of potential errors found in existing LiDAR datasets within coastal Louisiana's wetlands. Survey grids were mapped out in an area dominated by Spartina alterniflora and a survey-grade Trimble Real Time Kinematic (RTK) GPS device was employed to measure bare earth ground elevations in the marsh system adjacent to Terrebonne Bay, LA. Elevations were obtained for 20 meter-spaced surveyed grid points and were used to generate a DEM. The comparison between LiDAR derived and surveyed data DEMs yield an average difference of 23 cm with a maximum difference of 68 cm. Considering the local tidal range of 45 cm, these differences can introduce substantial error when the DEM is used for ecological modeling [Alizad et al., 2016]. Results from this study will be further analyzed and implemented in order to adjust LiDAR-derived DEMs closer to their true elevation across Louisiana's coastal wetlands. ReferencesAlizad, K., S. C. Hagen, J. T. Morris, S. C. Medeiros, M. V. Bilskie, and J. F. Weishampel (2016), Coastal wetland response to sea-level rise in a fluvial estuarine system, Earth's Future, 4(11), 483-497, 10.1002/2016EF000385. Medeiros, S., S. Hagen, J. Weishampel, and J. Angelo (2015), Adjusting Lidar-Derived Digital Terrain Models in Coastal Marshes Based on Estimated Aboveground Biomass Density, Remote Sensing, 7(4), 3507-3525, 10.3390/rs70403507.

Tribology and hydrophobicity of a biocompatible GPTMS/PFPE coating on Ti6Al4V surfaces.

PubMed

Panjwani, Bharat; Sinha, Sujeet K

2012-11-01

Tribological properties of perfluoropolyether (PFPE) coated 3-glycidoxypropyltrimethoxy silane (GPTMS) SAMs (self-assembled monolayers) onto Ti6Al4V alloy substrate were studied using ball-on-disk experiments. GPTMS SAMs deposition onto a Ti6Al4V alloy surface was carried out using solution phase method. Ultra-thin layer of PFPE was dip-coated onto SAMs modified specimens. Tribological tests were carried out at 0.2 N normal load and rotational speed of 200 rpm using track radius of 2 mm. Wear track and counterface surface conditions were investigated using optical microscopy. PFPE modified specimens were baked at 150 °C for 1h to investigate the effect of thermal treatment on tribological properties. Surface characterization tests such as contact angle measurement, AFM morphology and X-ray photoelectron spectroscopy were carried out for differently modified specimens. PFPE overcoat meets the requirements of cytotoxicity test using the ISO 10993-5 elution method. PFPE top layer lowered the coefficient of friction and increased wear durability for different specimens (with and without GPTMS intermediate layer). PFPE overcoat onto GPTMS showed significant increase in the wear resistance compared with overcoat onto bare Ti6Al4V specimens. The observed improvement in the tribological properties can be attributed to the change in the interaction of PFPE molecules with the substrate surface due to the GPTMS intermediate layer. Copyright © 2012 Elsevier Ltd. All rights reserved.

Speech outcome in unilateral complete cleft lip and palate patients: a descriptive study.

PubMed

Rullo, R; Di Maggio, D; Addabbo, F; Rullo, F; Festa, V M; Perillo, L

2014-09-01

In this study, resonance and articulation disorders were examined in a group of patients surgically treated for cleft lip and palate, considering family social background, and children's ability of self monitoring their speech output while speaking. Fifty children (32 males and 18 females) mean age 6.5 ± 1.6 years, affected by non-syndromic complete unilateral cleft of the lip and palate underwent the same surgical protocol. The speech level was evaluated using the Accordi's speech assessment protocol that focuses on intelligibility, nasality, nasal air escape, pharyngeal friction, and glottal stop. Pearson product-moment correlation analysis was used to detect significant associations between analysed parameters. A total of 16% (8 children) of the sample had severe to moderate degree of nasality and nasal air escape, presence of pharyngeal friction and glottal stop, which obviously compromise speech intelligibility. Ten children (10%) showed a barely acceptable phonological outcome: nasality and nasal air escape were mild to moderate, but the intelligibility remained poor. Thirty-two children (64%) had normal speech. Statistical analysis revealed a significant correlation between the severity of nasal resonance and nasal air escape (p ≤ 0.05). No statistical significant correlation was found between the final intelligibility and the patient social background, neither between the final intelligibility nor the age of the patients. The differences in speech outcome could be explained with a specific, subjective, and inborn ability, different for each child, in self-monitoring their speech output.

Forest cover change prediction using hybrid methodology of geoinformatics and Markov chain model: A case study on sub-Himalayan town Gangtok, India

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Anirban; Mondal, Arun; Mukherjee, Sandip; Khatua, Dipam; Ghosh, Subhajit; Mitra, Debasish; Ghosh, Tuhin

2014-08-01

In the Himalayan states of India, with increasing population and activities, large areas of forested land are being converted into other land-use features. There is a definite cause and effect relationship between changing practice for development and changes in land use. So, an estimation of land use dynamics and a futuristic trend pattern is essential. A combination of geospatial and statistical techniques were applied to assess the present and future land use/land cover scenario of Gangtok, the subHimalayan capital of Sikkim. Multi-temporal satellite imageries of the Landsat series were used to map the changes in land use of Gangtok from 1990 to 2010. Only three major land use classes (built-up area and bare land, step cultivated area, and forest) were considered as the most dynamic land use practices of Gangtok. The conventional supervised classification, and spectral indices-based thresholding using NDVI (Normalized Difference Vegetation Index) and SAVI (Soil Adjusted Vegetation Index) were applied along with the accuracy assessments. Markov modelling was applied for prediction of land use/land cover change and was validated. SAVI provides the most accurate estimate, i.e., the difference between predicted and actual data is minimal. Finally, a combination of Markov modelling and SAVI was used to predict the probable land-use scenario in Gangtok in 2020 AD, which indicted that more forest areas will be converted for step cultivation by the year 2020.

Influence of different aspect ratios on the structural and electrical properties of GaN thin films grown on nanoscale-patterned sapphire substrates

NASA Astrophysics Data System (ADS)

Lee, Fang-Wei; Ke, Wen-Cheng; Cheng, Chun-Hong; Liao, Bo-Wei; Chen, Wei-Kuo

2016-07-01

This study presents GaN thin films grown on nanoscale-patterned sapphire substrates (NPSSs) with different aspect ratios (ARs) using a homemade metal-organic chemical vapor deposition system. The anodic aluminum oxide (AAO) technique is used to prepare the dry etching mask. The cross-sectional view of the scanning electron microscope image shows that voids exist between the interface of the GaN thin film and the high-AR (i.e. ∼2) NPSS. In contrast, patterns on the low-AR (∼0.7) NPSS are filled full of GaN. The formation of voids on the high-AR NPSS is believed to be due to the enhancement of the lateral growth in the initial growth stage, and the quick-merging GaN thin film blocks the precursors from continuing to supply the bottom of the pattern. The atomic force microscopy images of GaN on bare sapphire show a layer-by-layer surface morphology, which becomes a step-flow surface morphology for GaN on a high-AR NPSS. The edge-type threading dislocation density can be reduced from 7.1 × 108 cm-2 for GaN on bare sapphire to 4.9 × 108 cm-2 for GaN on a high-AR NPSS. In addition, the carrier mobility increases from 85 cm2/Vs for GaN on bare sapphire to 199 cm2/Vs for GaN on a high-AR NPSS. However, the increased screw-type threading dislocation density for GaN on a low-AR NPSS is due to the competition of lateral growth on the flat-top patterns and vertical growth on the bottom of the patterns that causes the material quality of the GaN thin film to degenerate. Thus, the experimental results indicate that the AR of the particular patterning of a NPSS plays a crucial role in achieving GaN thin film with a high crystalline quality.

Self-organized multi-species vegetation patterns: the role of connectivity of environmental niches in natural water harvesting ecosystems

NASA Astrophysics Data System (ADS)

Callegaro, Chiara; Ursino, Nadia

2016-04-01

Self-organizing vegetation patterns are natural water harvesting systems in arid and semi-arid regions of the world and should be imitated when designing man-managed water-harvesting systems for rain-fed crop. Disconnected vegetated and bare zones, functioning as a source-sink system of resources, sustain vegetation growth and reduce water and soil losses. Mechanisms such as soil crusting over bare areas and soil loosening in vegetated areas feed back to the local net facilitation effect and contribute to maintain the patterned landscape structure. Dis-connectivity of run-off production and run-on infiltration sites reduces runoff production at the landscape scale, and increases water retention in the vegetated patches. What is the effect of species adaptation to different resource niches on the landscape structure? A minimal model for two coexisting species and soil moisture balance was formulated, to improve our understanding of the effects of species differentiation on the dynamics of plants and water at single-pattern and landscape scale within a tiger bush type ecosystem. A basic assumption of our model was that soil moisture availability is a proxy for the environmental niche of plant species. Connectivity and dis-connectivity of specific niches of adaptation of two differing plant species was an input parameter of our model, in order to test the effect of coexistence on the ecosystem structure. The ecosystem structure is the model outcome, including: patterns persistence of coexisting species; patterns persistence of one species with exclusion of the other; patterns decline with just one species surviving in a non organized structure; bare landscape with loss of both species. Results suggest that pattern-forming-species communities arise as a result of complementary niche adaptation (niche dis-connecivity), whereas niche superposition (niche connectivity) may lead to impoverishment of environmental resources and loss of vegetation cover and diversity.

Time scale dependence of the center of pressure entropy: What characteristics of the neuromuscular postural control system influence stabilographic entropic half-life?

PubMed

Federolf, Peter; Zandiyeh, Payam; von Tscharner, Vinzenz

2015-12-01

The center of pressure (COP) movement in studies of postural control reveals a highly regular structure (low entropy) over short time periods and a highly irregular structure over large time scales (high entropy). Entropic half-life (EnHL) is a novel measure that quantifies the time over which short-term temporal correlations in a time series deteriorate to an uncorrelated, random structure. The current study suggested and tested three hypotheses about how characteristics of the neuromuscular postural control system may affect stabilometric EnHL: (H1) control system activity hypothesis: EnHL decreases with increased frequency of control system interventions adjusting COP motion; (H2) abundance of states hypothesis: EnHL decreases with increased number of mechanically equivalent states available to the postural system; and (H3) neurologic process hierarchy hypothesis: EnHL increases if postural control functions shift from the spinal level to the motor cortex. Thirty healthy participants performed quiet stance tests for 90 s in 18 different conditions: stance (bipedal, one-legged, and tandem); footwear (bare foot, regular sports shoe, and rocker sole shoes); and simultaneous cognitive task (two-back working memory task, no challenge). A four-way repeated-measures ANOVA revealed significant changes in EnHL for the different stance positions and for different movement directions (medio-lateral, anterior-posterior). These changes support H1 and H2. Significant differences were also found between rocker sole shoes and normal or barefoot standing, which supports H3. This study contributes to the understanding of how and why EnHL is a useful measure to monitor neuromuscular control of balance.

Differential accumulation and pigmenting ability of dietary carotenoids in colorful finches.

PubMed

McGraw, Kevin J; Hill, Geoffrey E; Navara, Kristen J; Parker, Robert S

2004-01-01

Many animals develop bright red, orange, or yellow carotenoid pigmentation that they use to attract mates. Colorful carotenoid pigments are acquired from the diet and are either directly incorporated as integumentary colorants or metabolized into other forms before deposition. Because animals often obtain several different carotenoids from plant and animal food sources, it is possible that these pigments are accumulated at different levels in the body and may play unique roles in shaping the ultimate color expression of individuals. We studied patterns of carotenoid accumulation and integumentary pigmentation in two colorful finch species--the American goldfinch (Carduelis tristis) and the zebra finch (Taeniopygia guttata). Both species acquire two main hydroxycarotenoids, lutein and zeaxanthin, from their seed diet but transform these into a series of metabolites that are used as colorful pigments in the plumage (goldfinches only) and beak (both species). We conducted a series of carotenoid-supplementation experiments to investigate the relative extent to which lutein and zeaxanthin are accumulated in blood and increase carotenoid coloration in feathers and bare parts. First, we supplemented the diets of both species with either lutein or zeaxanthin and measured plasma pigment status, feather carotenoid concentration (goldfinches only), and integumentary color. Zeaxanthin-supplemented males grew more colorful feathers and beaks than lutein-supplemented males, and in goldfinches incorporated a different ratio of carotenoids in feathers (favoring the accumulation of canary xanthophyll B). We also fed goldfinches different concentrations of a standard lutein-zeaxanthin mix and found that at physiologically normal and high concentrations, birds circulated proportionally more zeaxanthin over lutein than occurred in the diet. Collectively, these results demonstrate that zeaxanthin is preferentially accumulated in the body and serves as a more potent substrate for pigmentation than lutein in these finches.

Chromatographic analysis of salicylic compounds in different species of the genus Salix.

PubMed

Pobłocka-Olech, Loretta; van Nederkassel, Anne-Marie; Vander Heyden, Yvan; Krauze-Baranowska, Mirosława; Glód, Daniel; Baczek, Tomasz

2007-11-01

The separation of nine phenol glycosides--salicin, salicortin, 2'-acetylsalicortin, populin, tremulacin, salidroside, triandrin, picein and helicin--by normal phase (NP), reversed phase (RP) HPLC techniques and a coupling of NP and RP monolithic silica columns was studied. Among the above nine compounds only five--salicin, populin, tremulacin, salidroside and triandrin--were resolved in an NP system with a mobile phase comprising hexane/isopropanol/methanol (87:12:1, v/v/v). Optimized separation was performed with two coupled monolithic silica columns of different polarity (bare silica and RP-18). The method was applied to verify the presence of salicylic compounds and other phenolic derivatives in the bark of six species from the genus Salix, namely S. purpurea, S. daphnoides clone 1095, S. alba clone 1100, S. triandra, S. viminalis, and S. herbacea. Gradient elution with a mobile phase composed of acetonitrile and water containing 0.05% of trifluoroacetic acid, with increasing acetonitrile concentration from 3% to 48%, was chosen as optimal. For the selective detection of the salicylic compounds, an evaporative light scattering detector was employed along with a UV detector. The differences in the composition of phenols in the different plant materials were confirmed. Additionally, it must be emphasized that for the first time the presence of 2'-acetylsalicortin was revealed in S. alba clone 1100. Furthermore, an SPE-HPLC method was developed for the rapid analysis of the salicin content, analyzed as free and total fraction, in willow barks. The determined concentrations of total salicin varied from 25.4 mg/g in S. alba clone 1100 to 96.47 mg/g in S. daphnoides clone 1095.

Is saltmarsh restoration success constrained by matching natural environments or altered succession? A test using niche models.

PubMed

Sullivan, Martin J P; Davy, Anthony J; Grant, Alastair; Mossman, Hannah L

2018-05-01

Restored habitats, such as saltmarsh created through managed realignment, sometimes fail to meet targets for biological equivalence with natural reference sites. Understanding why this happens is important in order to improve restoration outcomes.Elevation in the tidal frame and sediment redox potential are major controls on the distribution of saltmarsh plants. We use niche models to characterize 10 species' responses to these, and test whether differences in species occurrence between restored and natural saltmarshes in the UK result from failure to recreate adequate environmental conditions.Six species occurred less frequently in recently restored marshes than natural marshes. Failure of restored marshes to achieve the elevation and redox conditions of natural marshes partially explained the underrepresentation of five of these species, but did not explain patterns of occurrence on older (>50 years) restored marshes.For all species, an effect of marsh age remained after controlling for differences in environmental conditions. This could be due to differences in successional mechanism between restored and natural marshes. In recently restored marshes, high-marsh species occurred lower in the tidal frame and low-marsh species occurred higher in the tidal frame than in natural marshes. This supports the hypothesis that competition is initially weaker in restored marshes, because of the availability of bare sediment across the whole tidal frame. Species that establish outside their normal realized niche, such as Atriplex portulacoides , may inhibit subsequent colonization of other species that occurred less frequently than expected on older restored marshes. Synthesis and applications . Niche models can be used to test whether abiotic differences between restored sites and their natural counterparts are responsible for discrepancies in species occurrence. In saltmarshes, simply replicating environmental conditions will not result in equivalent species occurrence.

The influence of large wood accumulations on riparian seed bank diversity

NASA Astrophysics Data System (ADS)

Osei, N. A.

2012-04-01

Little is known about the structure and complexity of seed bank within the riparian corridor and the how large wood accumulations contribute to riparian seed bank diversity. This study aimed to examine and quantify seed bank assemblage and diversity along the undisturbed riparian corridor of the Highland Water, a second order lowland stream draining the New Forest. Seed bank samples were collected from five riparian corridor microhabitats namely mid-channel bars, floodplains, bare banks, banks adjacent large wood accumulations and within large wood accumulations that differed in their hydrologic connectivity with the river. Descriptive statistics and ordination methods applied to the floristic and sediment data sets indicates that sediment organic matter content, species richness and proportions of functional types distinctly differed among the riparian microhabitats types but there was no difference in viable seed densities. Banks adjacent large wood accumulations were the most floristically diverse and rich in organic matter with mid-channel bars exhibiting the reverse. This was due to the ability of large wood accumulations to buffer varying magnitudes of physical gradients and sort seeds and sediments, therefore altering the character of bare banks. This study not only strengthen the evidence that riparian corridors exhibit elevated spatial sediment and vegetation heterogeneity but also demonstrates the importance of large wood accumulation as habitat modifiers, ecosystem engineers and conservation sink for moisture, organic matter and seeds, resources essential for riparian vegetation conservation, recovery and restoration efforts.

The Influence of Prescribed Fire, Habitat, and Weather on Amblyomma americanum (Ixodida: Ixodidae) in West-Central Illinois, USA.

PubMed

Gilliam, Mary E; Rechkemmer, Will T; McCravy, Kenneth W; Jenkins, Seán E

2018-03-22

The distribution of Amblyomma americanum (L.) is changing and reports of tick-borne disease transmitted by A. americanum are increasing in the USA. We used flagging to collect ticks, surveyed vegetation and collected weather data in 2015 and 2016. A. americanum dominated collections in both years (97%). Ticks did not differ among burn treatments; however, tick abundance differed between years among total, adult, and larval ticks. Habitat variables showed a weak negative correlation to total ticks in respect to: Shannon diversity index, percent bare ground, perennial cover, and coarse woody debris. Nymphal ticks showed a weak negative correlation to percent bare ground and fewer adults were collected in areas with more leaf litter and coarse woody debris. Conversely, we found larvae more often in areas with more total cover, biennials, vines, shrubs, and leaf litter, suggesting habitat is important for this life stage. We compared weather variables to tick presence and found, in 2015, temperature, precipitation, humidity, and sample period influenced tick collection and were life stage specific. In 2016, temperature, precipitation, humidity, wind, and sample period influenced tick collection and were also life stage specific. These results indicate that spring burns in an oak woodland do not reduce ticks; other variables such as habitat and weather are more influential on tick abundance or presence at different life stages.

Bare ground as a crucial habitat feature for a rare terrestrially foraging farmland bird of Central Europe

NASA Astrophysics Data System (ADS)

Tagmann-Ioset, Aline; Schaub, Michael; Reichlin, Thomas S.; Weisshaupt, Nadja; Arlettaz, Raphaël

2012-02-01

Most farmland birds have declined significantly throughout the world due to agricultural intensification. Agri-environmental policies could not halt the decline of ground-foraging insectivorous farmland birds in Europe, indicating a gap in knowledge of species' ecological requirements. This represents a major impediment to the development of efficient, evidence-based agri-environmental measures. Using radio-tracking we studied habitat selection by farmland Hoopoes, a rare terrestrially foraging bird in Central Europe, and assessed habitat preferences of their main prey (Molecrickets), with the aim to identify optimal foraging habitat profiles in order to guide farmland management. Hierarchical logistic regression modelling of habitat descriptors at actual foraging locations vs. random locations within the home ranges of 13 males showed that the availability of bare ground was the principal determinant of foraging activity, with an optimum of 60-70% bare ground at patch scale. This ideal habitat configuration, which facilitates birds' terrestrial hunting, was found primarily in intensively farmed fruit tree plantations which dominated the landscape matrix: this habitat offers extensive strips of bare ground due to systematic removal of ground vegetation along tree rows. In contrast, dense grassland and cropland were avoided. Another important habitat feature was the availability of nongravelly soil, which enabled Hoopoes to probe the earth with their long, curved bill in search of underground invertebrates. The role of Molecrickets, however, appeared secondary to foraging patch selection, suggesting that prey accessibility was per se more important than prey abundance. Creating patches of bare ground within modern farmland where sufficient supplies of suitable invertebrate prey exist will support Hoopoe populations.

Water stress impacts on bacterial carbon monoxide oxidation on recent volcanic deposits.

PubMed

Weber, Carolyn F; King, Gary M

2009-12-01

Water availability oscillates dramatically on young volcanic deposits, and may control the distribution and activity of microbes during early stages of biological succession. Carbon monoxide (CO)-oxidizing bacteria are among the pioneering colonists on volcanic deposits and are subjected to these water stresses. We report here the effects of water potential on CO-oxidizing bacteria in unvegetated (bare) and vegetated (canopy) sites on a 1959 volcanic deposit on Kilauea Volcano (Hawai'i). Time course measurements of water potential showed that average water potentials in the surface layer (0-1 cm) of canopy soil remained between -0.1 and 0 MPa, whereas dramatic diurnal oscillations (for example, between -60 and 0 MPa) occur in bare site surface cinders. During a moderate drying event in situ (-1.7 to 0 MPa), atmospheric CO consumption by intact bare site cores decreased 2.7-fold. For bare and canopy surface samples, maximum potential CO oxidation rates decreased 40 and 60%, respectively, when water potentials were lowered from 0 to -1.5 MPa in the laboratory. These observations indicated that CO oxidation is moderately sensitive to changes in water potential. Additional analyses showed that CO oxidation resumes within a few hours of rehydration, even after desiccation at -150 MPa for 63 days. Samples from both sites exposed to multiple cycles of drying and rewetting (-80 to 0 MPa), lost significant activity after the first cycle, but not after subsequent cycles. Similar responses of CO oxidation in both sites suggested that active CO-oxidizing communities in bare and canopy sites do not express differential adaptations to water stress.

[O3 dry deposition flux observation and soil resistance modeling over a bare soil in Nanjing area in autumn].

PubMed

Huang, Ji Qing; Zheng, You Fei; Xu, Jing Xin; Zhao, Hui; Yuan, Yue; Chu, Zhong Fang

2016-10-01

In this study, the concentration of O 3 and its deposition flux over a bare soil in Nanjing in autumn were observed by using an eddy covariance system with rapid ozone analyzer. We analyzed the correlation of ozone concentration, deposition flux, and meteorological conditions in order to explore the characteristics of the variations in ozone deposition flux and deposition velocity. We also compared flux and velocity by using modeled soil resistance with observations. The results showed that the diurnal variation of ozone concentration exhibited a single peak distribution, and it increased due to radiation enhancement from September 25th to October 28th, 2015. Ozone deposition flux over a bare soil in autumn was mainly affected by its concentration, with diurnal average values varying from -31.4 to -156.8 ng·s -1 ·m -2 (the negative sign indicated that the deposition direction was toward the ground). As a result of non-vegetation over a bare soil, the ozone deposition flux was significantly influenced by environmental factors. Diurnal average of deposition velocities varied in the range of 0.09-0.30 cm·s -1 . The turbulence exchange played a major role in the atmosphere transportation of ozone, and underlying surface condition was particularly important to O 3 dry deposition over the bare soil. Soil resistance (R s ) increased exponentially with air relative humidity (RH), and the equation was R s =89.981e 0.0246 RH . The parameterized ozone deposition velocities and fluxes were in good agreement with the measured values.

Regional prediction of soil organic carbon content over temperate croplands using visible near-infrared airborne hyperspectral imagery and synchronous field spectra

NASA Astrophysics Data System (ADS)

Vaudour, E.; Gilliot, J. M.; Bel, L.; Lefevre, J.; Chehdi, K.

2016-07-01

This study aimed at identifying the potential of Vis-NIR airborne hyperspectral AISA-Eagle data for predicting the topsoil organic carbon (SOC) content of bare cultivated soils over a large peri-urban area (221 km2) with both contrasted soils and SOC contents, located in the western region of Paris, France. Soil types comprised haplic luvisols, calcaric cambisols and colluvic cambisols. Airborne AISA-Eagle data (400-1000 nm, 126 bands) with 1 m-resolution were acquired on 17 April 2013 over 13 tracks. Tracks were atmospherically corrected then mosaicked at a 2 m-resolution using a set of 24 synchronous field spectra of bare soils, black and white targets and impervious surfaces. The land use identification system layer (RPG) of 2012 was used to mask non-agricultural areas, then calculation and thresholding of NDVI from an atmospherically corrected SPOT image acquired the same day enabled to map agricultural fields with bare soil. A total of 101 sites sampled either in 2013 or in the 3 previous years and in 2015 were identified as bare by means of this map. Predictions were made from the mosaic AISA spectra which were related to topsoil SOC contents by means of partial least squares regression (PLSR). Regression robustness was evaluated through a series of 1000 bootstrap data sets of calibration-validation samples, considering 74 sites outside cloud shadows only, and different sampling strategies for selecting calibration samples. Validation root-mean-square errors (RMSE) were comprised between 3.73 and 4.49 g Kg-1 and were ∼4 g Kg-1 in median. The most performing models in terms of coefficient of determination (R2) and Residual Prediction Deviation (RPD) values were the calibration models derived either from Kennard-Stone or conditioned Latin Hypercube sampling on smoothed spectra. The most generalizable model leading to lowest RMSE value of 3.73 g Kg-1 at the regional scale and 1.44 g Kg-1 at the within-field scale and low bias was the cross-validated leave-one-out PLSR model constructed with the 28 near-synchronous samples and raw spectra.

Cost-effectiveness of drug-eluting stents in patients at high or low risk of major cardiac events in the Basel Stent KostenEffektivitäts Trial (BASKET): an 18-month analysis.

PubMed

Brunner-La Rocca, Hans Peter; Kaiser, Christoph; Bernheim, Alain; Zellweger, Michael J; Jeger, Raban; Buser, Peter T; Osswald, Stefan; Pfisterer, Matthias

2007-11-03

Our aim was to determine whether drug-eluting stents are good value for money in long-term, everyday practice. We did an 18-month cost-effectiveness analysis of the Basel Stent KostenEffektivitäts Trial (BASKET), which randomised 826 patients 2:1 to drug-eluting stents (n=545) or to bare-metal stents (281). We used non-parametric bootstrap techniques to determine incremental cost-effectiveness ratios (ICERs) of drug-eluting versus bare-metal stents, to compare low-risk (> or =3.0 mm stents in native vessels; n=558, 68%) and high-risk patients (<3.0 mm stents/bypass graft stenting; n=268, 32%), and to do sensitivity analyses by altering costs and event rates in the whole study sample and in predefined subgroups. Quality-adjusted life-years (QALYs) were assessed by EQ-5D questionnaire (available in 703/826 patients). Overall costs were higher for patients with drug-eluting stents than in those with bare-metal stents (11,808 euros [SD 400] per patient with drug-eluting stents and 10,450 euros [592] per patient with bare-metal stents, mean difference 1358 euros [717], p<0.0001), due to higher stent costs. We calculated an ICER of 64,732 euros to prevent one major adverse cardiac event, and of 40,467 euros per QALY gained. Stent costs, number of events, and QALYs affected ICERs most, but unrealistic alterations would have been required to achieve acceptable cost-effectiveness. In low-risk patients, the probability of drug-eluting stents achieving an arbitrary ICER of 10,000 euros or less to prevent one major adverse cardiac event was 0.016; by contrast, it was 0.874 in high-risk patients. If used in all patients, drug-eluting stents are not good value for money, even if prices were substantially reduced. Drug-eluting stents are cost effective in patients needing small vessel or bypass graft stenting, but not in those who require large native vessel stenting.

A 5 Year Study of Carbon Fluxes from a Restored English Blanket Bog

NASA Astrophysics Data System (ADS)

Worrall, F.; Dixon, S.; Evans, M.

2014-12-01

This study aimed to measure the effects of ecological restoration on blanket peat water table depths, DOC concentrations and CO2 fluxes. In April 2003 the Bleaklow Plateau, an extensive area of deep blanket peat in the Peak District National Park, northern England, was devegetated by a wildfire. As a result the area was selected for large scale restoration. In this study we considered a 5-year study of four restored sites in comparison to both an unrestored, bare peat control and to vegetated control that did not require restoration. Results suggested that sites with revegetation alongside slope stabilisation had the highest rates of photosynthesis and were the largest net (daylight hours) sinks of CO2. Bare sites were the largest net sources of CO2 and had the deepest water table depths. Sites with gully wall stabilisation were between 5-8 times more likely to be net CO2 sinks than the bare sites. Revegetation without gully flow blocking using plastic dams did not have a large effect on water table depths in and around the gullies investigated whereas a blocked gully had water table depths comparable to a naturally revegetating gully. A ten centimetre lowering in water table depth decreased the probability of observing a net CO2 sink, on a given site, by up to 30%. With respect to DOC the study showed that the average soil porewater DOC concentration on the restored sites rose significantly over the 5 year study representing a 34% increase relative to the vegetated control and an 11% increase relative to the unrestored, bare control. Soil pore water concentrations were not significantly different from surface runoff DOC concentrations and therefore restoration as conducted by this study would have contributed to water quality deterioration in the catchment. The most important conclusion of this research was that restoration interventions were apparently effective at increasing the likelihood of net CO2 sink behaviour and raising water tables on degraded, climatically marginal blanket bog. However, had water table restoration been conducted alongside revegetation then a significant decline in DOC concentrations could have also been realised.

Stent-Protected Carotid Angioplasty Using a Membrane Stent: A Comparative Cadaver Study

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

Mueller-Huelsbeck, Stefan, E-mail: muehue@rad.uni-kiel.de; Guehne, Albrecht; Tsokos, Michael

2006-08-15

Purpose. To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. Methods. Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three testmore » groups: (I) MembraX, n 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 {mu}m effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. Results. Absolute numbers of particles (median; >100 {mu}m) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p 0.011) and the largest number (p = 0.054) of particles. Conclusions. On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.« less

Introducing the Notion of Bare and Effective Mass via Newton's Second Law of Motion

ERIC Educational Resources Information Center

Pinto, Marcus Benghi

2007-01-01

The concepts of bare and effective mass are widely used within modern physics. Their meaning is discussed in advanced undergraduate and graduate courses such as solid state physics, nuclear physics and quantum field theory. Here I discuss how these concepts may be introduced together with the discussion of Newton's second law of motion. The…

Composite materials flown on the Long Duration Exposure Facility

NASA Technical Reports Server (NTRS)

George, Pete E.; Dursch, Harry W.; Pippin, H. Gary

1995-01-01

Organic composite test specimens were flown on several LDEF experiments. Both bare and coated composites were flown. Atomic oxygen eroded bare composite material, with the resins being recessed at a greater rate than the fibers. Selected coating techniques protected the composite substrate in each case. Tensile and optical properties are reported for numerous specimens. Fiberglass and metal matrix composites were also flown.

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

Clements, Abraham Anthony

EPOXY is a LLVM base compiler that applies security protections to bare-metal programs on ARM Cortex-M series micro-controllers. This includes privilege overlaying, wherein operations requiring privileged execution are identified and only these operations execute in privileged mode. It also applies code integrity, control-flow hijacking defenses, stack protections, and fine-grained randomization schemes. All of its protections work within the constraints of bare-metal systems.

30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trolley Wires and Trolley Feeder Wires § 75.1003...

30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Trolley Wires and Trolley Feeder Wires § 75.1003...

16 CFR 1632.31 - Mattresses/mattress pads-labeling, recordkeeping, guaranties and “one of a kind” exemption.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the Standard. (3) Photograph (color or black and white) of the bare surface of each mattress or... (color or black and white) of the bare surface of each mattress or mattress pad tested in accordance with... shall manufacture for sale, import, distribute, or otherwise market or handle any mattress or mattress...

16 CFR 1632.31 - Mattresses/mattress pads-labeling, recordkeeping, guaranties and “one of a kind” exemption.

Code of Federal Regulations, 2011 CFR

2011-01-01

... the Standard. (3) Photograph (color or black and white) of the bare surface of each mattress or... (color or black and white) of the bare surface of each mattress or mattress pad tested in accordance with... shall manufacture for sale, import, distribute, or otherwise market or handle any mattress or mattress...

16 CFR 1632.31 - Mattresses/mattress pads-labeling, recordkeeping, guaranties and “one of a kind” exemption.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the Standard. (3) Photograph (color or black and white) of the bare surface of each mattress or... (color or black and white) of the bare surface of each mattress or mattress pad tested in accordance with... shall manufacture for sale, import, distribute, or otherwise market or handle any mattress or mattress...

16 CFR § 1632.31 - Mattresses/mattress pads-labeling, recordkeeping, guaranties and “one of a kind” exemption.

Code of Federal Regulations, 2013 CFR

2013-01-01

... carried out in accordance with the Standard. (3) Photograph (color or black and white) of the bare surface...) Photograph (color or black and white) of the bare surface of each mattress or mattress pad tested in... Flammable Fabrics Act shall manufacture for sale, import, distribute, or otherwise market or handle any...

16 CFR 1632.31 - Mattresses/mattress pads-labeling, recordkeeping, guaranties and “one of a kind” exemption.

Code of Federal Regulations, 2010 CFR

2010-01-01

... the Standard. (3) Photograph (color or black and white) of the bare surface of each mattress or... (color or black and white) of the bare surface of each mattress or mattress pad tested in accordance with... shall manufacture for sale, import, distribute, or otherwise market or handle any mattress or mattress...

Stock Type Affects Performance of Shortleaf Pine Planted in the Ouachita Mountains Through 10 Years

Treesearch

James P. Barnett; John C. Brissette

2004-01-01

Shortleaf pine (Pinus echinata Mill.) seeds collected from several half-sib families were grown as both bare-root and container stock and outplanted on two sites in the Ouachita Mountains of Arkansas. When outplanted, the bare-root seedlings had greater mean height and root-collar diameter than the container seedlings. However, the container...

Linear and nonlinear optical studies of bare and copper doped TiO2 nanoparticles via sol gel technique

NASA Astrophysics Data System (ADS)

Rajamannan, B.; Mugundan, S.; Viruthagiri, G.; Praveen, P.; Shanmugam, N.

2014-01-01

In general, the nanoparticles of TiO2 may exist in the phases of anatase, rutile and brookite. In the present work, we used titanium terta iso propoxide and 2-propanol as a common starting material to prepare the precursors of bare and copper doped nanosized TiO2. Then the synthesized products were calcinated at 500 °C and after calcination the pure TiO2 nanoparticles in anatase phase were harvested. The crystallite sizes of bare and copper doped TiO2 nanoparticles were calculated from X-ray diffraction analysis. The existence of functional groups of the samples was identified by Fourier transform infrared spectroscopy. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the copper doped TiO2 nanoparticles were studied by scanning electron microscope fitted with energy dispersive X-ray spectrometer arrangement. The nonlinear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP).

The use of the Podotrack in forensic podiatry for collection and analysis of bare footprints using the Reel method of measurement.

PubMed

Burrow, J Gordon

2016-05-01

This small-scale study examined the role that bare footprint collection and measurement processes have on the Reel method of measurement in forensic podiatry and its use in the Criminal Justice System. Previous research indicated that the Reel method was a valid and reliable measurement system for bare footprint analysis but various collection systems have been used to collect footprint data and both manual and digital measurement processes were utilized in forensic podiatry and other disciplines. This study contributes to the debate about collecting bare footprints; the techniques employed to quantify various Reel measurements and considered whether there was asymmetry between feet and footprints of the same person. An inductive, quantitative paradigm used the Podotrack gathering procedure for footprint collection and the subsequent dynamic footprints subjected to Adobe Photoshop techniques of calculating the Reel linear variables. Statistical analyses using paired-sample t tests were conducted to test hypotheses and compare data sets. Standard error of mean (SEM) showed variation between feet and the findings provide support for the Reel study and measurement method. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

Electric generator

DOEpatents

Foster, Jr., John S.; Wilson, James R.; McDonald, Jr., Charles A.

1983-01-01

1. In an electrical energy generator, the combination comprising a first elongated annular electrical current conductor having at least one bare surface extending longitudinally and facing radially inwards therein, a second elongated annular electrical current conductor disposed coaxially within said first conductor and having an outer bare surface area extending longitudinally and facing said bare surface of said first conductor, the contiguous coaxial areas of said first and second conductors defining an inductive element, means for applying an electrical current to at least one of said conductors for generating a magnetic field encompassing said inductive element, and explosive charge means disposed concentrically with respect to said conductors including at least the area of said inductive element, said explosive charge means including means disposed to initiate an explosive wave front in said explosive advancing longitudinally along said inductive element, said wave front being effective to progressively deform at least one of said conductors to bring said bare surfaces thereof into electrically conductive contact to progressively reduce the inductance of the inductive element defined by said conductors and transferring explosive energy to said magnetic field effective to generate an electrical potential between undeformed portions of said conductors ahead of said explosive wave front.

Linear and nonlinear optical studies of bare and copper doped TiO2 nanoparticles via sol gel technique.

PubMed

Rajamannan, B; Mugundan, S; Viruthagiri, G; Praveen, P; Shanmugam, N

2014-01-24

In general, the nanoparticles of TiO2 may exist in the phases of anatase, rutile and brookite. In the present work, we used titanium terta iso propoxide and 2-propanol as a common starting material to prepare the precursors of bare and copper doped nanosized TiO2. Then the synthesized products were calcinated at 500°C and after calcination the pure TiO2 nanoparticles in anatase phase were harvested. The crystallite sizes of bare and copper doped TiO2 nanoparticles were calculated from X-ray diffraction analysis. The existence of functional groups of the samples was identified by Fourier transform infrared spectroscopy. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the copper doped TiO2 nanoparticles were studied by scanning electron microscope fitted with energy dispersive X-ray spectrometer arrangement. The nonlinear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP). Copyright © 2013 Elsevier B.V. All rights reserved.