Sample records for early decomposition observation

  1. Asymmetric landscapes of early spinodal decomposition

    Microsoft Academic Search

    Y. Mao; T. C. B. McLeish; P. I. C. Teixeira; D. J. Read

    2001-01-01

    We address the effect of an asymmetric concentration-dependent mobility on the early stages of spinodal decomposition in polymer blends and solutions, and characterise it quantitatively. This is particularly important when one of the components has a slower dynamics than the other, e.g., because it is closer to its glass transition, or is weakly cross-linked. Composition mode coupling is proposed as

  2. Asymmetric landscapes of early spinodal decomposition

    Microsoft Academic Search

    Y. Mao; T. C. B. McLeish; P. I. C. Teixeira; D. J. Read

    2001-01-01

    :   We address the effect of an asymmetric concentration-dependent mobility on the early stages of spinodal decomposition in polymer\\u000a blends and solutions, and characterise it quantitatively. This is particularly important when one of the components has a\\u000a slower dynamics than the other, e.g., because it is closer to its glass transition, or is weakly cross-linked. Composition mode coupling is proposed

  3. Evidence for early morphological decomposition: combining masked priming with magnetoencephalography.

    PubMed

    Lehtonen, Minna; Monahan, Philip J; Poeppel, David

    2011-11-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime-target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner-CLEAN) and opaque (corner-CORN) prime-target pairs, but not for prime-target pairs with only an orthographic relationship (brothel-BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime-target pairs can be used to further understand the neural substrates and the time course of lexical processing. PMID:21557645

  4. Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

    ERIC Educational Resources Information Center

    Lehtonen, Minna; Monahan, Philip J.; Poeppel, David

    2011-01-01

    Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked…

  5. Young Children's Thinking about Decomposition: Early Modeling Entrees to Complex Ideas in Science

    ERIC Educational Resources Information Center

    Ero-Tolliver, Isi; Lucas, Deborah; Schauble, Leona

    2013-01-01

    This study was part of a multi-year project on the development of elementary students' modeling approaches to understanding the life sciences. Twenty-three first grade students conducted a series of coordinated observations and investigations on decomposition, a topic that is rarely addressed in the early grades. The instruction included…

  6. Young Children's Thinking About Decomposition: Early Modeling Entrees to Complex Ideas in Science

    NASA Astrophysics Data System (ADS)

    Ero-Tolliver, Isi; Lucas, Deborah; Schauble, Leona

    2013-01-01

    This study was part of a multi-year project on the development of elementary students' modeling approaches to understanding the life sciences. Twenty-three first grade students conducted a series of coordinated observations and investigations on decomposition, a topic that is rarely addressed in the early grades. The instruction included in-class observations of different types of soil and soil profiling, visits to the school's compost bin, structured observations of decaying organic matter of various kinds, study of organisms that live in the soil, and models of environmental conditions that affect rates of decomposition. Both before and after instruction, students completed a written performance assessment that asked them to reason about the process of decomposition. Additional information was gathered through one-on-one interviews with six focus students who represented variability of performance across the class. During instruction, researchers collected video of classroom activity, student science journal entries, and charts and illustrations produced by the teacher. After instruction, the first-grade students showed a more nuanced understanding of the composition and variability of soils, the role of visible organisms in decomposition, and environmental factors that influence rates of decomposition. Through a variety of representational devices, including drawings, narrative records, and physical models, students came to regard decomposition as a process, rather than simply as an end state that does not require explanation.

  7. Decomposition

    USGS Publications Warehouse

    Middleton, Beth A.

    2014-01-01

    A cornerstone of ecosystem ecology, decomposition was recognized as a fundamental process driving the exchange of energy in ecosystems by early ecologists such as Lindeman 1942 and Odum 1960). In the history of ecology, studies of decomposition were incorporated into the International Biological Program in the 1960s to compare the nature of organic matter breakdown in various ecosystem types. Such studies still have an important role in ecological studies of today. More recent refinements have brought debates on the relative role microbes, invertebrates and environment in the breakdown and release of carbon into the atmosphere, as well as how nutrient cycling, production and other ecosystem processes regulated by decomposition may shift with climate change. Therefore, this bibliography examines the primary literature related to organic matter breakdown, but it also explores topics in which decomposition plays a key supporting role including vegetation composition, latitudinal gradients, altered ecosystems, anthropogenic impacts, carbon storage, and climate change models. Knowledge of these topics is relevant to both the study of ecosystem ecology as well projections of future conditions for human societies.

  8. Decomposition of sensitivity of the symmetry energy observables

    E-print Network

    He-Lei Liu; Gao-Chan Yong; De-Hua Wen

    2014-11-26

    To exactly answer which density region that some frequently used symmetry-energy-sensitive observables probe, for the first time, we make a study of decomposition of the sensitivity of some symmetry-energy-sensitive observables. We find that for the Au+Au reaction at incident beam energies of 200 and 400 MeV/nucleon, frequently used symmetry-energy-sensitive observables mainly probe the density-dependent symmetry energy around 1.25$\\rho_{0}$ (for pionic observables) or 1.5$\\rho_{0}$ (for nucleonic observables). Effects of the symmetry energy from the low-density region is integrally small but observable.

  9. Decomposition of sensitivity of the symmetry energy observables

    E-print Network

    He-Lei Liu; Gao-Chan Yong; De-Hua Wen

    2015-03-31

    To exactly answer which density region that some frequently used symmetry-energy-sensitive observables probe, for the first time, we make a study of decomposition of the sensitivity of some symmetry-energy-sensitive observables. It is found that for the Au+Au reaction at incident beam energies of 200 and 400 MeV/nucleon, frequently used symmetry-energy-sensitive observables mainly probe the density-dependent symmetry energy around 1.25$\\rho_{0}$ (for pionic observables) or 1.5$\\rho_{0}$ (for nucleonic observables). Effects of the symmetry energy in the low-density region is in general small but observable. The fact that the symmetry-energy-sensitive observables are not sensitive to the symmetry energy in the maximal baryon-density region increases the difficulty of studying nuclear symmetry energy at super-density.

  10. Decomposition of surface drifter observations in the Atlantic Ocean Rick Lumpkin

    E-print Network

    Decomposition of surface drifter observations in the Atlantic Ocean Rick Lumpkin Cooperative and techniques. Citation: Lumpkin, R., Decomposition of surface drifter observations in the Atlantic Ocean are usually examined in the framework of a decomposition in which a record y(t) is divided into mean and eddy

  11. Evidence for Early Morphological Decomposition in Visual Word Recognition

    ERIC Educational Resources Information Center

    Solomyak, Olla; Marantz, Alec

    2010-01-01

    We employ a single-trial correlational MEG analysis technique to investigate early processing in the visual recognition of morphologically complex words. Three classes of affixed words were presented in a lexical decision task: free stems (e.g., taxable), bound roots (e.g., tolerable), and unique root words (e.g., vulnerable, the root of which…

  12. Changes in the quality of chromophoric dissolved organic matter leached from senescent leaf litter during the early decomposition.

    PubMed

    Nishimura, Satoshi; Maie, Nagamitsu; Baba, Mitsuhisa; Sudo, Takahiro; Sugiura, Toshihiro; Shima, Eikichi

    2012-01-01

    Chromophoric dissolved organic matter (CDOM) leached from leaf litter is a major source of humus in mineral soil of forest ecosystems. While their functions and refractoriness depend on the physicochemical structure, there is little information on the quality of CDOM, especially for that leached in the very early stages of litter decomposition when a large amount of dissolved organic matter (DOM) is leached. This study aimed to better understand the variations/changes in the composition of CDOM leached from senescent leaf litter from two tree species during the early stage of decomposition. Leaf litter from a conifer tree (Japanese cedar, D. Don) and a deciduous broad-leaved tree (Konara oak, Thunb.) were incubated in columns using simulated rainfall events periodically for a total of 300 d at 20°C. The quality of CDOM was investigated based on the fluorescence properties by using a combination of excitation-emission matrix fluorescence (EEM) and parallel factor analysis (PARAFAC). In addition, the phenolic composition of DOM was investigated at a molecular level by thermally assisted hydrolysis and methylation-gas chromatography-mass spectrometry (THM-GC-MS) in the presence of tetramethylammonium hydroxide (TMAH). The EEM was statistically decomposed into eight fluorescence components (two tannin/peptide-like peaks, one protein-like peak, and five humic-like peaks). A significant contribution of tannin/peptide-like peaks was observed at the beginning of incubation, but these peaks decreased quickly and humic-like peaks increased within 1 mo of incubation. The composition of humic-like peaks was different between tree species and changed over the incubation period. Since tannin-derived phenolic compounds were detected in the DOM collected after 254 d of incubation on THM-GC-MS, it was suggested that tannins partially changed its structure, forming various humic-like peaks during the early decomposition. PMID:22565264

  13. Acousto-spinodal decomposition of compressible polymer solutions: early stage analysis.

    PubMed

    Rasouli, Ghoncheh; Rey, Alejandro D

    2011-05-14

    The structure and dynamics of early stage kinetics of pressure-induced phase separation of compressible polymer solutions via spinodal decomposition is analyzed using a linear Euler-Cahn-Hilliard model and the modified Sanchez Lacombe equation of state. The integrated density wave and Cahn-Hilliard equations combine the kinetic and structural characteristics of spinodal decomposition with density waves arising from pressure-induced couplings. When mass transfer rate is slower that acoustic waves, concentration gradients generate density waves that cycle back into the spinodal decomposition dynamics, resulting in oscillatory demixing. The wave attenuation increases with increasing mass transfer rates eventually leading to nonoscillatory spinodal demixing. The novel aspects of acousto-spinodal decomposition arise from the coexistence of stable oscillatory density dynamics and the unstable monotonic concentration dynamics. Scaling laws for structure and dynamics indicate deviations from incompressible behavior, with a significant slowing down of demixing due to couplings with density waves. Partial structure factors for density and density-concentration reflect the oscillatory nature of acousto-spinodal modes at lower wave vectors, while the single maximum at a constant wave vector reflects the presence of a dominant mode in the linear regime. The computed total structure factor is in qualitative agreement with experimental data for a similar polymer solution. PMID:21568529

  14. Acousto-spinodal decomposition of compressible polymer solutions: Early stage analysis

    NASA Astrophysics Data System (ADS)

    Rasouli, Ghoncheh; Rey, Alejandro D.

    2011-05-01

    The structure and dynamics of early stage kinetics of pressure-induced phase separation of compressible polymer solutions via spinodal decomposition is analyzed using a linear Euler-Cahn-Hilliard model and the modified Sanchez Lacombe equation of state. The integrated density wave and Cahn-Hilliard equations combine the kinetic and structural characteristics of spinodal decomposition with density waves arising from pressure-induced couplings. When mass transfer rate is slower that acoustic waves, concentration gradients generate density waves that cycle back into the spinodal decomposition dynamics, resulting in oscillatory demixing. The wave attenuation increases with increasing mass transfer rates eventually leading to nonoscillatory spinodal demixing. The novel aspects of acousto-spinodal decomposition arise from the coexistence of stable oscillatory density dynamics and the unstable monotonic concentration dynamics. Scaling laws for structure and dynamics indicate deviations from incompressible behavior, with a significant slowing down of demixing due to couplings with density waves. Partial structure factors for density and density-concentration reflect the oscillatory nature of acousto-spinodal modes at lower wave vectors, while the single maximum at a constant wave vector reflects the presence of a dominant mode in the linear regime. The computed total structure factor is in qualitative agreement with experimental data for a similar polymer solution.

  15. Early stage of single and mixed leaf-litter decomposition in semiarid forest pine-oak: the role of rainfall and microsite

    Microsoft Academic Search

    Marlín Pérez-Suárez; J. Tulio Arredondo-Moreno; Elisabeth Huber-Sannwald

    It is well known that inherent characteristics of forest species constitute the main control of litter decomposition. In mixed\\u000a forest, chemical interactions occurring through precipitation turn mechanisms of litter decomposition very uncertain and difficult\\u000a to predict. Early-stage leaf litter decomposition of Quercus potosina and Pinus cembroides and their controls were examined based on Ostrofsky’s decomposition mechanisms. From June 2007 to

  16. Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications

    NASA Astrophysics Data System (ADS)

    Opsahl, Stephen; Benner, Ronald

    1995-12-01

    Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood ( Avicennia germinans), cypress needles and wood ( Taxodium distichum) and smooth cordgrass ( Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39, and 93%, respectively. Analysis of the lignin component of herbaceous tissues using alkaline CuO oxidation was complicated by the presence of a substantial ester-bound phenol component composed primarily of cinnamyl phenols. To overcome this problem, we introduce a new parameter to represent lignin, ?6. ?6 is comprised only of the six syringyl and vanillyl phenols and was found to be much less sensitive to diagenetic variation than the commonly used parameter ?, which includes the cinnamyl phenols. Patterns of change in lignin content were strongly dependent on tissue type, ranging from 77% enrichment in smooth cordgrass to 6% depletion in cypress needles. In contrast, depletion of cutin was extensive (65-99%) in all herbaceous tissues. Despite these differences in the overall reactivity of lignin and cutin, both macromolecules were extensively degraded during the decomposition period. The long-term decomposition series also provided very useful information about the compositional parameters which are derived from the specific oxidation products of both lignin and cutin. The relative lability of ester-bound cinnamyl phenols compromised their use in parameters to distinguish woody from herbaceous plant debris. The dimer to monomer ratios of lignin-derived phenols indicated that most intermonomeric linkages in lignin degraded at similar rates. Acid to aldehyde ratios of vanillyl and syringyl phenols became elevated, particularly during the latter stages of decomposition supporting the use of these parameters as indicators of diagenetic alteration. Given the observation that cutin-derived source indicator parameters were generally more sensitive to diagenetic alteration than those of lignin, we suggest the distributional patterns of cutin-derived acids and their associated positional isomers may be most useful for tissue-specific distinctions complementing the general categorical information obtained from lignin phenol analysis alone.

  17. Early stages of spinodal decomposition in Fe-Cr resolved by in-situ small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Hörnqvist, M.; Thuvander, M.; Steuwer, A.; King, S.; Odqvist, J.; Hedström, P.

    2015-02-01

    In-situ, time-resolved small-angle neutron scattering (SANS) investigations of the early stages of the spinodal decomposition process in Fe-35Cr were performed at 773 and 798 K. The kinetics of the decomposition, both in terms of characteristic distance and peak intensity, followed a power-law behaviour from the start of the heat treatment (a'= 0.10-0.11 and a? = 0.67-0.86). Furthermore, the method allows tracking of the high-Q slope, which is a sensitive measure of the early stages of decomposition. Ex-situ SANS and atom probe tomography were used to verify the results from the in-situ investigations. Finally, the in-situ measurement of the evolution of the characteristic distance at 773 K was compared with the predictions from the Cahn-Hilliard-Cook model, which showed good agreement with the experimental data (a'= 0.12-0.20 depending on the assumed mobility).

  18. Environmental aspects of VOCs evolved in the early stages of human decomposition.

    PubMed

    Statheropoulos, M; Agapiou, A; Spiliopoulou, C; Pallis, G C; Sianos, E

    2007-10-15

    In the present study, the time profile, measured as "accumulation", of volatile organic compounds (VOCs) produced during the early stages of human decomposition was investigated. A human cadaver was placed in a sealed bag at approximately the 4th day after death. Evolved VOCs were monitored for 24 h by sampling at different time intervals. VOCs produced were analyzed by thermal desorption/gas chromatography/mass spectrometry (TD/GC/MS). Over 30 substances were identified in total. These included mainly aliphatic and aromatic hydrocarbons, oxygenated compounds (alcohols, aldehydes, ketones) and organic sulfides. The last were the most prominent class of compounds identified. Eleven compounds were present in all the sampling cycles and constitute a "common core": ethanol, 2-propanone, dimethyl disulfide, methyl benzene, octane, 2-butanone, methyl ethyl disulfide, dimethyl trisulfide and o-, m- and p-xylenes. The last sampling cycle yielded the most abundant compounds in number and quantities. Inorganic gases such as CO2, CO, NH3 and H2S were also determined. The fundamental physicochemical properties of the evolved VOCs were used for evaluating their environmental impacts. It appears that the decay process, which is a dynamic procedure, can provide chemical signals that might be detected and properly evaluated by experts in the fields of forensic sciences, search and rescue units and environmental scientists. PMID:17669473

  19. Early diagenesis of vascular plant tissues: Lignin and cutin decomposition and biogeochemical implications

    Microsoft Academic Search

    Stephen Opsahl; Ronald Benner

    1995-01-01

    Long-term subaqueous decomposition patterns of five different vascular plant tissues including mangrove leaves and wood (Avicennia germinans), cypress needles and wood (Taxodium distichum) and smooth cordgrass (Spartina alternifora) were followed for a period of 4.0 years, representing the longest litter bag decomposition study to date. All tissues decomposed under identical conditions and final mass losses were 97, 68, 86, 39,

  20. An Early Astronomical Observation by John Goodricke

    NASA Astrophysics Data System (ADS)

    French, Linda M.

    2009-12-01

    John Goodricke (1764-1786) is one of the most intriguing and enigmatic figures in the history of astronomy. Deaf from the age of five, his observations of the light variation of Algol brought him acclaim and the Copley Medal of the Royal Society by the age of nineteen. Together with his neighbor, mentor, and distant relative Edward Pigott, he went on to discover and quantify the light variations of other stars, including Delta Cephei. Goodricke's careful accounts of his observations, and their accuracy, remain a model of clear scientific thinking and reporting. His final derived value for the time between eclipse minima for Algol, for example, is within eight seconds of the modern value. Goodricke's astronomical observing career is generally thought to have begun with his return to his family home in York in 1781 at the age of seventeen. His school mathematics notebook and workbook from the Warrington Academy, however, contains a detailed drawing of the sky which suggest that he was already a knowledgable observer by the age of fifteen. This drawing is presented and interpreted.

  1. SOAR remote observing: tactics and early results

    NASA Astrophysics Data System (ADS)

    Cecil, Gerald N.; Crain, J. Adam

    2004-09-01

    Travel from North America to the 4.1m SOAR telescope atop Cerro Pachon exceeds $1000, and takes >16 hours door to door (20+ hours typically). SOAR aims to exploit best seeing, requiring dynamic scheduling that is impossible to accomplish when catering to peripatetic astronomers. According to technical arguments at www.peakoil.org, we are near the peak rate of depleting world petroleum, so can expect travel costs to climb sharply. With the telecom bubble's glut of optical fiber, we can transmit data more efficiently than astronomers and "observe remotely". With data compression, less than half of the 6 Mbps bandwidth shared currently by SOAR and CTIO is enough to enable a high-fidelity observing presence for SOAR partners in North America, Brazil, and Chile. We discuss access from home by cable modem/DSL link.

  2. The Early Years: Observing With Magnifiers

    NSDL National Science Digital Library

    Peggy Ashbrook

    2008-02-01

    Inspire your students to become detailed observers by encouraging the use of magnifiers. Magnification can make us see an object with new understanding. Rachel Carson said, "Some of nature's most exquisite handiwork is on a miniature scale, as anyone knows who has applied a magnifying glass to a snowflake" (Carson 1965). The lesson described here uses interesting objects to give children a reason to learn to use a magnifier.

  3. Collision-free photochemistry of methylazide: Observation of unimolecular decomposition of singlet methylnitrene

    SciTech Connect

    Larson, Christopher; Ji Yuanyuan; Samartzis, Petros; Wodtke, Alec M.; Lee, S.-H.; Lin, Jim Jr-Min; Chaudhuri, Chanchal; Ching, T.-T. [Department of Chemistry and Biochemistry, University of California, Santa Barbara, Santa Barbara, California 93106 (United States); National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Science-Based Industrial Park, Hsinchu 30077, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 106, Taiwan (China)

    2006-10-07

    Methylazide photolysis at 248 nm has been investigated by ionizing photofragments with synchrotron radiation in a photofragmentation translational spectroscopy study. CH{sub 3}N and N{sub 2} were the only observed primary products. The translational energy release suggests a simple bond rupture mechanism forming singlet methylnitrene, {sup 1}CH{sub 3}N, and N{sub 2}. Thus, these experiments reveal the unimolecular decomposition of this highly unstable species. We explain our observations through a mechanism which is initiated by the isomerization of {sup 1}CH{sub 3}N to a highly internally excited methanimine H{sub 2}C=NH isomer, which decomposes by 1,1-H{sub 2} elimination forming HNC+H{sub 2} as well as sequential H-atom loss (N-H followed by C-H bond cleavage), to form HCN. No evidence for dynamics on the triplet manifold of surfaces is found.

  4. Decomposition of the wind and nonwind effects on observed year-to-year air quality variation

    NASA Astrophysics Data System (ADS)

    Li, Ying; Lau, Alexis; Wong, Agnes; Fung, Jimmy

    2014-05-01

    Changes in emissions and wind are often identified as the two dominant factors contributing to year-to-year variations in the concentration of primary pollutants. However, because changes in wind and emissions are intertwined, it has been difficult to quantitatively differentiate their effects on air quality directly from observed data. In particular, if the annual mean concentration of pollutants is higher than the previous year, it is difficult to identify whether the deterioration in air quality is caused by wind blowing from more polluted regions or an increase in contributing emissions. In this paper, based on wind and pollution roses, we propose a method to differentiate the effects of wind and nonwind (e.g., emissions) changes using direct observation. An index (L) is first defined to quantify the validity of the linear decomposition. The method is then validated by idealized experiments, numerical experiments, and a 2 year observation data set from an actual emissions control program. Finally, we demonstrate the proposed method by studying long-term particulate matter (PM10) variations in Hong Kong during 2000-2011. We find that for most of the period, the linear decomposition of the changes in annual PM10 is valid (up to 90% confidence) and is dominated by the change in nonwind effects (e.g., emissions), whereas the average absolute effect from the wind variability is about 20%. Sensitivity analyses also suggest that our method should work in any location as long as the observed wind and pollution data have sufficient duration and resolution to resolve the corresponding wind and pollution roses.

  5. Indium hydroxide to oxide decomposition observed in one nanocrystal during in situ transmission electron microscopy studies

    SciTech Connect

    Miehe, Gerhard; Lauterbach, Stefan; Kleebe, Hans-Joachim [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)] [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany); Gurlo, Aleksander, E-mail: gurlo@materials.tu-darmstadt.de [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)] [Technische Universitaet Darmstadt, Fachbereich Material- und Geowissenschaften, Petersenstr. 23, 64287 Darmstadt (Germany)

    2013-02-15

    The high-resolution transmission electron microscopy (HR-TEM) is used to study, in situ, spatially resolved decomposition in individual nanocrystals of metal hydroxides and oxyhydroxides. This case study reports on the decomposition of indium hydroxide (c-In(OH){sub 3}) to bixbyite-type indium oxide (c-In{sub 2}O{sub 3}). The electron beam is focused onto a single cube-shaped In(OH){sub 3} crystal of {l_brace}100{r_brace} morphology with ca. 35 nm edge length and a sequence of HR-TEM images was recorded during electron beam irradiation. The frame-by-frame analysis of video sequences allows for the in situ, time-resolved observation of the shape and orientation of the transformed crystals, which in turn enables the evaluation of the kinetics of c-In{sub 2}O{sub 3} crystallization. Supplementary material (video of the transformation) related to this article can be found online at (10.1016/j.jssc.2012.09.022). After irradiation the shape of the parent cube-shaped crystal is preserved, however, its linear dimension (edge) is reduced by the factor 1.20. The corresponding spotted selected area electron diffraction (SAED) pattern representing zone [001] of c-In(OH){sub 3} is transformed to a diffuse strongly textured ring-like pattern of c-In{sub 2}O{sub 3} that indicates the transformed cube is no longer a single crystal but is disintegrated into individual c-In{sub 2}O{sub 3} domains with the size of about 5-10 nm. The induction time of approximately 15 s is estimated from the time-resolved Fourier transforms. The volume fraction of the transformed phase (c-In{sub 2}O{sub 3}), calculated from the shrinkage of the parent c-In(OH){sub 3} crystal in the recorded HR-TEM images, is used as a measure of the kinetics of c-In{sub 2}O{sub 3} crystallization within the framework of Avrami-Erofeev formalism. The Avrami exponent of {approx}3 is characteristic for a reaction mechanism with fast nucleation at the beginning of the reaction and subsequent three-dimensional growth of nuclei with a constant growth rate. The structural transformation path in reconstructive decomposition of c-In(OH){sub 3} to c-In{sub 2}O{sub 3} is discussed in terms of (i) the displacement of hydrogen atoms that lead to breaking the hydrogen bond between OH groups of [In(OH){sub 6}] octahedra and finally to their destabilization and (ii) transformation of the vertices-shared indium-oxygen octahedra in c-In(OH){sub 3} to vertices- and edge-shared octahedra in c-In{sub 2}O{sub 3}. - Graphical abstract: Frame-by-frame analysis of video sequences recorded of HR-TEM images reveals that a single cube-shaped In(OH){sub 3} nanocrystal with {l_brace}100{r_brace} morphology decomposes into bixbyite-type In{sub 2}O{sub 3} domains while being imaged. The mechanism of this decomposition is evaluated through the analysis of the structural relationship between initial (c-In(OH){sub 3}) and transformed (c-In{sub 2}O{sub 3}) phases and though the kinetics of the decomposition followed via the time-resolved shrinkage of the initial crystal of indium hydroxide. Highlights: Black-Right-Pointing-Pointer In-situ time-resolved High Resolution Transmission Electron Microscopy. Black-Right-Pointing-Pointer Crystallographic transformation path. Black-Right-Pointing-Pointer Kinetics of the decomposition in one nanocrystal.

  6. Unimolecular Thermal Decomposition of Phenol and d5-Phenol: Direct Observation of Cyclopentadiene Formation via Cyclohexadienone

    SciTech Connect

    Scheer, A. M.; Mukarakate, C.; Robichaud, D. J.; Nimlos, M. R.; Carstensen, H. H.; Barney, E. G.

    2012-01-28

    The pyrolyses of phenol and d{sub 5}-phenol (C{sub 6}H{sub 5}OH and C{sub 6}D{sub 5}OH) have been studied using a high temperature, microtubular ({mu}tubular) SiC reactor. Product detection is via both photon ionization (10.487 eV) time-of-flight mass spectrometry and matrix isolation infrared spectroscopy. Gas exiting the heated reactor (375 K-1575 K) is subject to a free expansion after a residence time in the {mu}tubular reactor of approximately 50-100 {micro}s. The expansion from the reactor into vacuum rapidly cools the gas mixture and allows the detection of radicals and other highly reactive intermediates. We find that the initial decomposition steps at the onset of phenol pyrolysis are enol/keto tautomerization to form cyclohexadienone followed by decarbonylation to produce cyclopentadiene; C{sub 6}H{sub 5}OH {yields} c-C{sub 6}H{sub 6} = O {yields} c-C{sub 5}H{sub 6} + CO. The cyclopentadiene loses a H atom to generate the cyclopentadienyl radical which further decomposes to acetylene and propargyl radical; c-C{sub 5}H{sub 6} {yields} c-C{sub 5}H{sub 5} + H {yields} HC {triple_bond} CH + HCCCH{sub 2}. At higher temperatures, hydrogen loss from the PhO-H group to form phenoxy radical followed by CO ejection to generate the cyclopentadienyl radical likely contributes to the product distribution; C{sub 6}H{sub 5}O-H {yields} C{sub 6}H{sub 5}O + H {yields} c-C{sub 5}H{sub 5} + CO. The direct decarbonylation reaction remains an important channel in the thermal decomposition mechanisms of the dihydroxybenzenes. Both catechol (o-HO-C{sub 6}H{sub 4}-OH) and hydroquinone (p-HO-C{sub 6}H{sub 4}-OH) are shown to undergo decarbonylation at the onset of pyrolysis to form hydroxycyclopentadiene. In the case of catechol, we observe that water loss is also an important decomposition channel at the onset of pyrolysis.

  7. Observational effects of the early episodically dominating dark energy

    NASA Astrophysics Data System (ADS)

    Park, Chan-Gyung; Lee, Jae-heon; Hwang, Jai-chan; Noh, Hyerim

    2014-10-01

    We investigate the observational consequences of the early episodically dominating dark energy on the evolution of cosmological structures. For this aim, we introduce the minimally coupled scalar-field dark energy model with the Albrecht-Skordis potential, which allows a sudden ephemeral domination of a dark energy component during the radiation or early matter era. The conventional cosmological parameters in the presence of such an early dark energy are constrained with WMAP and Planck cosmic microwave background radiation data including other external data sets. It is shown that in the presence of such an early dark energy, the estimated cosmological parameters can deviate substantially from the currently known ? cold dark matter (? CDM )-based parameters, with best-fit values differing by several percent for WMAP and by a percent level for Planck data. For the latter case, only a limited amount of dark energy with episodic nature is allowed since the Planck data strongly favor the ? CDM model. Compared with the conventional dark energy model, the early dark energy dominating near the radiation-matter equality or at the early matter era results in the shorter cosmic age or the presence of tensor-type perturbation, respectively. Our analysis demonstrates that the alternative cosmological parameter estimation is allowed based on the same observations even in Einstein's gravity.

  8. Natural Killer Activity: Early Days, Advances, and Seminal Observations

    PubMed Central

    Ortaldo, John R.; Wiltrout, Robert H.; Reynolds, Craig W.

    2014-01-01

    This manuscript describes the early history of NK cell discovery, with emphasis on the events in the first decade of NK cell studies, 1972–1982. The authors highlight some of the earliest and most important observations that would later prove to be milestones in the study of NK cells and their activity. PMID:24941370

  9. Separation of Earth's magnetic field internal component from observed data by means of Empirical Mode Decomposition

    NASA Astrophysics Data System (ADS)

    Tozzi, Roberta; De Michelis, Paola; Consolini, Giuseppe

    2014-05-01

    The need to separate the magnetic field recorded at the Earth's surface into as many components as the sources are, has led to develop different methods of internal/external magnetic field separation. For this purpose, we have recently tested Empirical Mode Decomposition (EMD) over magnetic data registered by a few European observatories. Here we show an extension of the previous work using EMD to separate the internal component from data observed at a larger number of magnetic observatories from low to high latitudes. With respect to the methods used so far to achieve internal/external separation of Earth's magnetic field, EMD has many advantages as, for instance, to give the opportunity to be applied on data from a single observatory or also to be suitable to be implemented for real time internal/external separation. So, EMD has been applied to monthly means of X, Y and Z components of the geomagnetic field measured at the selected observatories and, after the evaluation of the properties of the EMD single monocomponents, the separation of the Earth's magnetic field internal contribution has been achieved. The internal component derived in this way has then been compared with the internal field provided not only by CM4 model, as in the previous test, but also with that provided by CHAOS4 model and by the more recently developed COV-OBS model. Encouraging results have been obtained.

  10. Decomposition kinetics of maltose in subcritical water.

    PubMed

    Haghighat Khajavi, Shabnam; Kimura, Yukitaka; Oomori, Toshinobu; Matsuno, Ryuichi; Adachi, Shuji

    2004-01-01

    The decomposition process of maltose in subcritical water was studied using a tubular reactor in the temperature range of 180 to 260 degrees C and at 10 MPa. The formation of glucose and 5-hydroxymethyl-2-furaldehyde during the maltose decomposition was also observed. The decomposition rate of maltose was faster at higher temperatures. The rate was approximated by first-order kinetics during the early stage of the decomposition, but was accelerated and deviated from these kinetics at the later stage. The effluent pH decreased as the residence time in the reactor increased and the decrease of pH affected the maltose decomposition rate and glucose formation. Low pH of a feed solution accelerated maltose decomposition. A good correlation was obtained between the pH of the effluent and the rate constant of the first-order kinetics. PMID:14745169

  11. Spectral types for early-type stars observed by Skylab

    NASA Technical Reports Server (NTRS)

    Roman, N. G.

    1978-01-01

    MK spectral types are presented for 246 early-type stars observed with the S-019 ultraviolet stellar astronomy experiment on Skylab. K-line types are also given where applicable, and various peculiar stars are identified. The peculiar stars include five silicon stars, a shell star, a helium-rich star, a silicon-strontium star, a chromium-europium star, and two marginal metallic-line stars.

  12. Direct observation of roaming radicals in the thermal decomposition of acetaldehyde.

    SciTech Connect

    Sivaramakrishnan, R.; Michael, J. V.; Klippenstein, S. J.; Chemical Sciences and Engineering Division

    2010-01-21

    The thermal dissociation of acetaldehyde has been studied with the reflected shock tube technique using H(D)-atom atomic resonance absorption spectrometry detection. The use of an unreversed light source yields extraordinarily sensitive H atom detection. As a result, we are able to measure both the total decomposition rate and the branching to radical versus molecular channels. This branching provides a direct measure of the contribution from the roaming radical mechanism since the contributions from the usual tight transition states are predicted by theory to be negligible. The experimental observations also provide a measure of the rate coefficient for H + CH{sub 3}CHO. Another set of experiments employing C{sub 2}H{sub 5}I as an H-atom source provides additional data for this rate coefficient that extends to lower temperature. An evaluation of the available experimental results for H + CH{sub 3}CHO can be expressed by a three-parameter Arrhenius expression as k = 7.66 x 10{sup -20}T{sup 2.75} exp((-486 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (298-1415 K). Analogous experiments employing C{sub 2}D{sub 5}I as a D-atom source allow for the study of the isotopically substituted reaction. The present experiments are the only direct measure for this reaction rate constant, and the results can be expressed by an Arrhenius expression as k = 5.20 x 10{sup -10} exp((-4430 K)/T) cm{sup 3} molecule{sup -1} s{sup -1} (1151-1354 K). The H/D + CH{sub 3}CHO reactions are also studied with ab initio transition-state theory, and the results are in remarkably good agreement with the current experimental data.

  13. Preliminary observations of the decomposition of crown-of-thorns starfish, Acanthaster planci (L.)

    NASA Astrophysics Data System (ADS)

    Moran, P. J.

    1992-07-01

    The rate of decomposition of 67 crown-of-thorns starfish was monitored over 7 9 days on 2 reefs of the Great Barrier Reef in 7 permanent quadrats in different depths and habitats. The pattern of decomposition was similar in all quadrats irrespective of the site or depth. Many different organisms, including crown-of-thorns starfish, fed on or scavenged the remains. Despite this activity the remains could be recognised as crown-of-thorns starfish for up to 5 days. The reason for the sudden disappearance of starfish at the ends of outbreaks is briefly discussed.

  14. Early decomposition in visual word recognition: Dissociating morphology, form, and meaning

    PubMed Central

    Marslen-Wilson, William D.; Bozic, Mirjana; Randall, Billi

    2008-01-01

    The role of morphological, semantic, and form-based factors in the early stages of visual word recognition was investigated across different SOAs in a masked priming paradigm, focusing on English derivational morphology. In a first set of experiments, stimulus pairs co-varying in morphological decomposability and in semantic and orthographic relatedness were presented at three SOAs (36, 48, and 72 ms). No effects of orthographic relatedness were found at any SOA. Semantic relatedness did not interact with effects of morphological decomposability, which came through strongly at all SOAs, even for pseudo-suffixed pairs such as archer-arch. Derivational morphological effects in masked priming seem to be primarily driven by morphological decomposability at an early stage of visual word recognition, and are independent of semantic factors. A second experiment reversed the order of prime and target (stem-derived rather than derived-stem), and again found that morphological priming did not interact with semantic relatedness. This points to an early segmentation process that is driven by morphological decomposability and not by the structure or content of central lexical representations. PMID:18923643

  15. The cosmic microwave background: observing directly the early universe

    E-print Network

    de Bernardis, Paolo

    2012-01-01

    The Cosmic Microwave Background (CMB) is a relict of the early universe. Its perfect 2.725K blackbody spectrum demonstrates that the universe underwent a hot, ionized early phase; its anisotropy (about 80 \\mu K rms) provides strong evidence for the presence of photon-matter oscillations in the primeval plasma, shaping the initial phase of the formation of structures; its polarization state (about 3 \\mu K rms), and in particular its rotational component (less than 0.1 \\mu K rms) might allow to study the inflation process in the very early universe, and the physics of extremely high energies, impossible to reach with accelerators. The CMB is observed by means of microwave and mm-wave telescopes, and its measurements drove the development of ultra-sensitive bolometric detectors, sophisticated modulators, and advanced cryogenic and space technologies. Here we focus on the new frontiers of CMB research: the precision measurements of its linear polarization state, at large and intermediate angular scales, and the m...

  16. Observations of hydroxyl in early-type galaxies

    NASA Astrophysics Data System (ADS)

    McBride, James; Alatalo, Katherine; Nyland, Kristina

    2015-02-01

    We used Arecibo Observatory and the Green Bank Telescope to observe OH in 12 early-type galaxies with known reservoirs of dense gas. We present three new detections of OH in absorption in the 1667 MHz line. One objective of our survey was to find evidence of molecular outflows, but our sensitivity and the strength of the OH absorption were insufficient to detect outflows. The detected sources have infrared luminosities and dust temperatures among the lowest of any galaxy detected in OH absorption. The ratio LHCN/LCO, a measure of the dense gas fraction in galaxies, is a powerful selector of OH megamasers for galaxies with high infrared luminosity. In early-type galaxies, which have much lower infrared luminosities, LHCN/LCO is also a promising tool for discovering OH, but in absorption rather than in maser emission. In addition to dense molecular gas, a radio continuum source and a favourable line of sight to the observer are likely key factors in detecting OH absorbers.

  17. Acquiring Comprehensive Observations using an Integrated Sensorweb for Early Warning

    NASA Technical Reports Server (NTRS)

    Habib, Shahid; Ambrose, Steve

    2006-01-01

    As an integrated observing strategy, the concept of sensorweb for Earth observations is appealing in many aspects. For instance, by increasing the spatial and temporal coverage of observations from space and other vantage points, one can eventually aid in increasing the accuracy of the atmospheric models which are precursor to hurricane track prediction, volcanic eruption forecast, and trajectory path of transcontinental transport of dust, harmful nuclear and chemical plumes. In reality, there is little analysis'available in terms of benefits, costs and optimized set of sensors needed to make these necessary observations. This is a complex problem that must be carefully studied and balanced over many boundaries such as science, defense, early warning security, and surveillance. Simplistically, the sensorweb concept from the technological point of view alone has a great appeal in the defense, early warning and security applications. In fact, it can be relatively less expensive in per unit cost as opposed to building and deploying it for the scientific use. However, overall observing approach should not be singled out and aligned somewhat . orthogonally to serve a particular need. On the other hand, the sensorweb should be designed and deployed to serve multiple subject areas and customers simultaneously; and can behave as directed measuring systems for both science and operational entities. Sensorweb can be designed to act as expert systems, and/or also provide a dedicated integrated surveillance network. Today, there is no system in the world that is fully integrated in terms of reporting timely multiple hazards warnings, computing the lass of life and property damage estimates, and is also designed to cater to everyone's needs. It is not an easier problem to undertake and more so is not practically solvable. At this time due to some recent events in the world, the scientific community, social scientists, and operational agencies are more cognizant and getting together to address such colossal problems. Increasing our knowledge of the home planet, via amplified set of observations, is certainly a right step in a right direction. Furthermore, this is a pre-requisite in understanding multiple hazard phenomena's. This paper examines various sensorweb options and observing architectures that can be useful specifically in addressing some of these complex issues. The ultimate goal is to serve the society by providing potential natural hazards information to the decision makers in the most expeditious manner so they can prepare themselves to mitigate potential risks to human life, livestock and property.

  18. Observational evidence for AGN feedback in early-type galaxies

    NASA Astrophysics Data System (ADS)

    Schawinski, Kevin; Thomas, Daniel; Sarzi, Marc; Maraston, Claudia; Kaviraj, Sugata; Joo, Seok-Joo; Yi, Sukyoung K.; Silk, Joseph

    2007-12-01

    A major amendment in recent models of hierarchical galaxy formation is the inclusion of so-called active galactic nucleus (AGN) feedback. The energy input from an active central massive black hole is invoked to suppress star formation in early-type galaxies at later epochs. A major problem is that this process is poorly understood, and compelling observational evidence for its mere existence is still missing. In search for signatures of AGN feedback, we have compiled a sample of 16000 early-type galaxies in the redshift range 0.05 < z < 0.1 from the Sloan Digital Sky Survey (SDSS) data base (MOSES: Morphologically Selected Ellipticals in SDSS). Key in our approach is the use of a purely morphological selection criterion through visual inspection which produces a sample that is not biased against recent star formation and nuclear activity. Based on the nebular emission-line characteristics we separate between star formation activity, black hole activity, the composite of the two and quiescence. We find that emission is mostly LINER (low ionization nuclear emission line region) like in high-mass galaxies (? > 200kms-1) and roughly evenly distributed between star formation and AGN at intermediate and low (? < 100kms-1) masses. The objects with emission (~20 per cent) are offset from the red sequence and form a well-defined pattern in the colour-mass diagram. Star-forming early-types inhabit the blue cloud, while early-types with AGN are located considerably closer to and almost on the red sequence. Star formation-AGN composites are found right between these two extremes. We further derive galaxy star formation histories using a novel method that combines multiwavelength photometry from near-ultraviolet (UV) to near-infrared (IR) and stellar absorption indices. We find that in those objects deviating from the red sequence star formation occurred several 100Myr in the past involving 1-10per cent of the total stellar mass. We identify an evolutionary sequence from star formation via nuclear activity to quiescence. This transition process lasts about 1Gyr, and the peak AGN phase occurs roughly half a Gyr after the starburst. The most likely interpretation is that star formation is suppressed by nuclear activity in these objects before they settle on the red sequence. This is empirical evidence for the occurrence of AGN feedback in early-type galaxies at recent epochs.

  19. Subionospheric early VLF perturbations observed at Suva: VLF detection of red sprites in the day?

    Microsoft Academic Search

    Sushil Kumar; Abhikesh Kumar; Craig J. Rodger

    2008-01-01

    First observations of early Very Low Frequency (VLF) perturbations on signals from NWC (19.8 kHz) and NPM (21.4 kHz) monitored at Suva, in the month of November 2006, are presented. The early\\/fast, early\\/slow, early\\/short (RORD), and step-like early VLF perturbations are observed on signals from both the transmitters. The early\\/fast VLF events are found to occur more often in the

  20. [ital COBE] DMR observations of early universe physics

    SciTech Connect

    Smoot, G.F. (Lawrence Berkeley Laboratory, SSL and CfPA University of California, Bldg. 50-351 1 Cyclotron Road, Berkeley, California 94720 (United States))

    1992-02-05

    The [ital COBE] Differential Microwave Radiometer (DMR) instrument has observed that the full microwave sky is remarkably uniform in the millimeter to centimeter wavelength range. However at a small level ([le]10[sup [minus]5]), there is large-scale structure. The natural interpretation of this structure is as the imprint of spatial curvature fluctuations, primarily due to density variations, in the early universe. The results are supportive of gravitational instability theories of structure formation and inflation/quantum cosmology models. The natural energy scale for inflation then is [similar to]10[sup 16] GeV. A failure to find fluctuations within a factor of two of the [ital COBE] DMR level would have contradicted gravitational instability models with a near scale-invariant spectra.

  1. "Learning Stories"--Crossing Borders: Introducing Qualitative Early Childhood Observation Techniques to Early Childhood Practitioners in Saudi Arabia

    ERIC Educational Resources Information Center

    Nyland, Berenice; Alfayez, Shatha

    2012-01-01

    Early childhood education has become a focus of government policy across the world. Part of the present increased interest in early childhood education has been a focus on curriculum frameworks and socio/cultural methods of assessment. Currently, New Zealand has emerged as a world leader in early childhood education, and observation and assessment…

  2. Observational and Numerical Constraints on Early Star Cluster Evolution

    NASA Astrophysics Data System (ADS)

    de Grijs, Richard; Allison, R. J.; Hu, Y.; Deng, L.; Goodwin, S. P.

    2011-01-01

    Exciting recent developments in theory and observations call for renewed scrutiny of the early evolution of star clusters spanning a large range of parameter space. First, using a large ensemble of N-body simulations of moderately sized (N=1000), cool, fractal clusters, we find that cool, clumpy clusters dynamically mass segregate on a short timescale. This implies that the notion of ‘primordial mass segregation’ may be obsolete. The cluster properties also change rapidly on very short timescales: young clusters may undergo core collapse on timescales of < 1 Myr, when a dense core containing massive stars is hardened because of energy losses to a halo of lower-mass stars. In addition, we use high-resolution Hubble Space Telescope imaging observations of the young ( 15-25 Myr-old) star cluster NGC 1818 in the Large Magellanic Cloud to derive an estimate for the binary fraction of F stars (1.3 < m*/M¤ 1.6). Our new study provides the strongest constraints yet on the (close to) initial binary fraction in a low-metallicity environment ([Fe/H] -0.4 dex). We find that our novel artificial-star-test method is sensitive to binaries with mass ratios, q? 0.4. For binaries with F-star primaries and mass ratios q> 0.4, the binary fraction is 0.35. This suggests a total binary fraction for F stars of 0.55 to unity, depending on assumptions about the form of the mass-ratio distribution at low q, which is consistent with the field and lower-density clusters. This suggests that, at least among intermediate-mass stars, metallicity down to [Fe/H] -0.4 dex does not suppress fragmentation and binary formation, and the binarity of these stars is at least as high as at solar metallicity. We therefore strongly argue for inclusion of realistic binary fractions in simulations aimed at following early star cluster evolution.

  3. Early Hinode Observations of a Solar Filament Eruption

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.; Moore, Ronald L.

    2007-01-01

    We use Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT) filtergraph (FG) Stokes-V magnetogram observations to study the early onset of a solar eruption that includes an erupting filament that we observe in TRACE EUV images; this is one of the first filament eruptions seen with Hinode. The filament undergoes a slow rise for at least 30 min prior to its fast eruption and strong soft X-ray flaring, and the new Hinode data elucidate the physical processes occurring during the slow-rise period: During the slow-rise phase, a soft X-ray (SXR) sigmoid forms from apparent reconnection low in the sheared core field traced by the filament, and there is a low-level intensity peak in both EUV and SXRs during the slow rise. The SOT data show that magnetic flux cancellation occurs along the neutral line of the filament in the hours before eruption, and this likely caused the low-lying reconnection that produced the microflaring and the slow rise leading up to the eruption.

  4. Using soil enzymes to explain observed differences in the response of soil decomposition to nitrogen fertilization

    NASA Astrophysics Data System (ADS)

    Stone, M.; Weiss, M.; Goodale, C. L.

    2010-12-01

    Soil microbes produce extracellular enzymes that degrade a variety of carbon-rich polymers contained within soil organic matter (SOM). These enzymes are key regulators of the terrestrial carbon cycle. However, basic information about the kinetics of extracellular enzymes and key environmental variables that regulate their catalytic ability is lacking. This study aims to clarify the mechanisms by which microbial carbon-degrading enzymes drive different responses to nitrogen (N) fertilization in soil decomposition at two sites with long-term N fertilization experiments, the Bear Brook (BB) forest in Maine and Fernow Forest (FF) in West Virginia. We examined a suite of cellulolytic and lignolytic enzymes that break down common SOM constituents. We hypothesized that enzymes derived from the site with a higher mean annual temperature (FF) would be more heat-tolerant, and retain their catalytic efficiency (Km) as temperature rises, relative to enzymes from the colder environment (BB). We further hypothesized that cellulolytic enzyme activity would be unaffected by N, while oxidative enzyme activity would be suppressed in N-fertilized soils. To test these hypotheses and examine the interactive effects of temperature and N, we measured enzyme activity in unfertilized and N-fertilized soils under a range of laboratory temperature manipulations. Preliminary results show a significant decrease in cellulolytic enzyme efficiency with temperature at the colder site (BB), as well as a significant increase in efficiency due to N-fertilization for two cellulolytic enzymes. Oxidative enzyme activity shows a marginally significant reduction due to N-fertilization at BB. These results suggest that soil warming may produce a negative feedback on carbon turnover in certain climates, while N-fertilization may alter the relative decomposition rates of different soil organic matter constituents. FF activity will be analyzed in a similar manner and the two sites will be compared in order to fully assess our hypotheses.

  5. TEMPORAL SIGNATURES OF AIR QUALITY OBSERVATIONS AND MODEL OUTPUTS: DO TIME SERIES DECOMPOSITION METHODS CAPTURE RELEVANT TIME SCALES?

    EPA Science Inventory

    Time series decomposition methods were applied to meteorological and air quality data and their numerical model estimates. Decomposition techniques express a time series as the sum of a small number of independent modes which hypothetically represent identifiable forcings, thereb...

  6. CONSTRAINING PERTURBATIVE EARLY DARK ENERGY WITH CURRENT OBSERVATIONS

    SciTech Connect

    Alam, Ujjaini [ISR-1, ISR Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2010-05-10

    In this work, we study a class of early dark energy (EDE) models, in which, unlike in standard dark energy models, a substantial amount of dark energy exists in the matter-dominated era. We self-consistently include dark energy perturbations, and constrain these models using current observations. We consider EDE models in which the dark energy equation of state is at least w{sub m} {approx_gt} -0.1 at early times, which could lead to an EDE density of up to {Omega}{sub DE}(z{sub CMB})= 0.03{Omega}{sub m}(z{sub CMB}). Our analysis shows that marginalizing over the non-DE parameters such as {Omega}{sub m}, H{sub 0}, andn{sub s} , current CMB observations alone can constrain the scale factor of transition from EDE to late-time dark energy to a{sub t} {approx_gt} 0.44 and width of transition to {Delta}{sub t} {approx_lt} 0.37. The equation of state at present is somewhat weakly constrained to w{sub 0} {approx_lt} -0.6, if we allow H{sub 0} < 60 km s{sup -1} Mpc{sup -1}. Taken together with other observations, such as SNe, Hubble Space Telescope, and Sloan Digital Sky Survey luminous red galaxies, w{sub 0} is constrained much more tightly to w{sub 0} {approx_lt} -0.9, while redshift of transition and width of transition are also tightly constrained to a{sub t} {approx_lt} 0.19 and{Delta}{sub t} {approx_lt} 0.21. The evolution of the equation of state for EDE models is thus tightly constrained to {Lambda}CDM-like behavior at low redshifts. Incorrectly assuming dark energy perturbations to be negligible leads to different constraints on the equation of state parameters-w{sub 0} {approx_lt} -0.8, a{sub t} {approx_lt} 0.33, and{Delta}{sub t} {approx_lt} 0.31, thus highlighting the necessity of self-consistently including dark energy perturbations in the analysis. If we allow the spatial curvature to be a free parameter, then the constraints are relaxed to w{sub 0} {approx_lt} -0.77, a{sub t} {approx_lt} 0.35, and{Delta}{sub t} {approx_lt} 0.35 with -0.014 < {Omega}{sub {kappa}} < 0.031 for CMB + other observations. For perturbed EDE models, the 2{sigma} lower limit on {sigma}{sub 8} ({sigma}{sub 8} {>=} 0.59) is much lower than that in {Lambda}CDM ({sigma}{sub 8} {>=} 0.72), thus raising the interesting possibility of discriminating EDE from {Lambda}CDM using future observations such as halo mass functions or the Sunyaev-Zeldovich power spectrum.

  7. No Differences in Decomposition Rates observed between Bacillus thuringiensis and Non-Bacillus thuringiensis Corn Residue Incubated in the Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent speculation of slower residue decomposition for Bt corn hybrids compared to non-Bt corn hybrids has prompted investigative study. We evaluated the residue decomposition rates of Bt and non-Bt corn hybrids over a period of 22 months under field conditions using the litter bag technique. The ...

  8. The Swift XRT: Observations of Early X-ray Afterglows

    SciTech Connect

    Burrows, David N.; Kennea, J. A.; Nousek, J. A. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Osborne, J. P.; O'Brien, P. T. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Chincarini, G. [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Italy); Universita degli studi di Milano-Bicocca, Piazza delle Scienze 3, 20126 Milan (Italy); Tagliaferri, G. [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, 23807 Merate (Italy); Giommi, P. [ASI Science Data Center, via Galileo Galilei, 00044 Frascati (Italy); Zhang, B. [Department of Physics, University of Nevada, Box 454002, Las Vegas, NV 89154-4002 (United States)

    2006-05-19

    During the first year of operations of the Swift observatory, the X-ray Telescope has made a number of discoveries concerning the nature of X-ray afterglows of both long and short GRBs. We highlight the key findings, which include rapid declines at early times, a standard template of afterglow light curve shapes, common flaring, and the discovery of the first short GRB afterglow.

  9. An Observational Study of the Interactions of Socially Withdrawn/Anxious Early Adolescents and Their Friends

    ERIC Educational Resources Information Center

    Schneider, Barry H.

    2009-01-01

    Background: The friendships of socially withdrawn/anxious children and early adolescents have been found to lack critical rewarding qualities. Observational research may help elucidate the obstacles they face in forming and maintaining high-quality friendships with sociable peers. Method: We observed the interactions of 38 socially withdrawn early

  10. Early development of spasticity following stroke: a prospective, observational trial

    PubMed Central

    Schelosky, Ludwig D.; Scott, Jeffrey; Christe, Walter; Faiss, Jürgen H.; Mueller, Jörg

    2010-01-01

    This study followed a cohort of 103 patients at median 6 days, 6 and 16 weeks after stroke and recorded muscle tone, pain, paresis, Barthel Index and quality of life score (EQ-5D) to identify risk-factors for development of spasticity. 24.5% of stroke victims developed an increase of muscle tone within 2 weeks after stroke. Patients with spasticity had significantly higher incidences of pain and nursing home placement and lower Barthel and EQ-5D scores than patients with normal muscle tone. Early predictive factors for presence of severe spasticity [modified Ashworth scale score (MAS) ?3] at final follow-up were moderate increase in muscle tone at baseline and/or first follow-up (MAS = 2), low Barthel Index at baseline, hemispasticity, involvement of more than two joints at first follow-up, and paresis at any assessment point. The study helps to identify patients at highest risk for permanent and severe spasticity, and advocates for early treatment in this group. PMID:20140444

  11. Exploring A Decomposition Community

    NSDL National Science Digital Library

    LaRae Mikkelson, Ellen Hopkins Elementary, Moorhead, MN

    2012-03-19

    In this classroom lab setting, students will construct Decomposition Columns from two-liter plastic bottles. Students will gather organic material and observe activity in the column. Students will record observations and construction steps in their science notebook.

  12. Early Observations in the Taiwanese-American Occultation Survey

    Microsoft Academic Search

    C. Alcock; F. Bianco; M. Lehner; R. Dave; J. Giammarco; M. Schwamb; K. Cook; S. Marshall; I. de Pater; R. Porrata; J. Rice; J. Lissauer; T. Lee; S. K. King; A. Wang; S. Y. Wang; C. Y. Wen; W. P. Chen; W. Ip; Y. H. Chang; D. Kinoshita; H. C. Lin; S. Mondal; Z. W. Zhang; T. Axelrod; Y. I. Byun

    2005-01-01

    The Taiwanese-American Occultation Survey (TAOS) is a program dedicated to performing a survey of the size and number distribution for small bodies (< 10km) in the Kuiper Belt. These objects are too faint to be detected through traditional means, but can be observed via their occultations of background stars. This technique is challenging due to the low event rate, the

  13. Hubble and Shapley - Two Early Giants of Observational Cosmology

    E-print Network

    Bergh, Sidney van den

    2011-01-01

    Observational cosmology of the first decades of the Twentieth Century was dominated by two giants: Edwin Hubble and Harlow Shapley. Hubble's major contributions were to the study and classification of individual galaxies with large telescopes, whereas Shapley is best remembered for his work on groups and clusters of galaxies using telescopes of more modest aperture.

  14. Interstellar matter in early-type galaxies - Optical observations

    NASA Technical Reports Server (NTRS)

    Kim, Dong-Woo

    1989-01-01

    Results of optical observations of 26 bright elliptical galaxies selected on the basis of IRAS data are discussed. Optical broadband imaging (using B and R filters) and narrow-band imaging (using H-alpha interference filters) have been performed to study dust patches and ionized gas. Long-split spectroscopy has also been made to determine gas kinematics and relative line ratios. The spectroscopic data confirm the presence and distribution of interstellar matter (dust lanes and ionized gas) seen in the direct imaging. Decoupled kinematics of interstellar gas and stars favors an external origin of the interstellar matter. However, for one isolated galaxy, an internal origin is not excluded. The rotation curves determined by optical emission lines are symmetric around the center in most galaxies observed. Galaxy masses and mass-to-light ratios are estimated using the rotation curves of the ionized gas.

  15. EARLY ULTRAVIOLET OBSERVATIONS OF A TYPE IIn SUPERNOVA (2007pk)

    SciTech Connect

    Pritchard, T. A.; Roming, P. W. A. [Department of Astronomy and Astrophysics, Penn State University, 525 Davey Lab, University Park, PA 16802 (United States); Brown, P. J. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East 201, Salt Lake City, UT (United States); Kuin, N. P. M.; Oates, S. R. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Bayless, Amanda J. [Southwest Research Institute, Department of Space Science, 6220 Culebra Rd, San Antonio, TX 78238 (United States); Holland, S. T. [Center for Research and Exploration in Space Science and Technology, NASA/GSFC, Greenbelt, MD 20771 (United States); Immler, S. [Astrophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Milne, P., E-mail: proming@swri.edu [Steward Observatory, 933 North Cherry Avenue, RM N204, Tucson, AZ 85721 (United States)

    2012-05-10

    We present some of the earliest UV observations of a Type IIn supernova (SN)-SN 2007pk, where UV and optical observations using Swift's Ultra-Violet/Optical Telescope began 3 days after discovery or {approx}5 days after shock breakout. The SN observations commence at approximately maximum light in the UV and u-band filters, suggesting that the UV light curve peaks begin very rapidly after the initial explosion, and subsequently exhibit a linear decay of 0.20, 0.21, 0.16 mag day{sup -1} in the UVOT uvw2, uvm2, uvw1 ({lambda}{sub c} = 1928, 2246, 2600 Angstrom-Sign ) filters. Meanwhile the b- and v-band light curves begin approximately seven days before v-band peak and exhibit a shallow rise followed by a subsequent decay. A series of optical/near-IR spectra taken with the Hobby-Eberly Telescope at days 3-26 after discovery show spectra similar to that of the peculiar Type IIn 1998S. The emission from 2007pk falls below detection {approx}20 days after discovery in the UV and 50 days in the optical, showing no sign of the long duration emission seen in other Type IIn SNe. We examine the physical and spectral characteristics of 2007pk and compare its UV light curve and decay rate with other Type II SNe.

  16. Geotechnical Trainspotting: Early Observations From the New Seattle Liquefaction Array

    NASA Astrophysics Data System (ADS)

    Bodin, P.; Yelin, T.; Weaver, C. S.; Steidl, J. H.; Steller, R. A.; Gomberg, J. S.

    2012-12-01

    The Seattle Liquefaction Array (SLA) is a geotechnical monitoring array established by the US Geological Survey earlier this year in industrialized Seattle, Washington. Funding for the array was provided by the Advanced National Seismic System, at the behest of the Pacific Northwest Seismic Network's regional advisory committee. The SLA aims to further the understanding of earthquake-induced liquefaction, particularly the processes associated with repeatedly liquefied soils and the liquefaction of deeply buried deposits. The SLA occupies a site at which shaking-induced liquefaction was observed during earthquakes in 1949, 1965, and 2001. The SLA site is seismically noisy but important as it is similar to sites that host many structures in Seattle. The site is comprised chiefly by loose-to-dense interbedded coastal and river outwash sands. Instrumentation at the site includes four 3-component accelerometers at the surface and at depths of 5.4, 44.9, and 56.4 meters, a surface barometer, and six piezometers at depths of 6.9, 22.9, 28.9, 43.1, 46.9, and 51.9 meters. Emplacement depths were selected to sample a variety of liquefaction susceptibilities. Continuous data from all sensors are sampled at 200 samples per second, and are available from the IRIS DMC archive, with a buffer of data stored on site in the event of telemetry failure. To date, only a handful of earthquakes have produced shaking strong enough at the SLA to be observed within the high levels of background noise. However, the noise itself provides data useful to constrain the low-strain seismic and pressure response of the site. Notably, the array is within a few meters of a set of busy railroad tracks. Passing and parked trains expose the site to a broad bandwidth of deformations, including seismic frequencies, albeit with a source at the surface. Many times each day the site experiences both high levels of shaking, and step changes in the pressure field of a variety of amplitudes that may last from seconds to hours. The pore pressure response varies between sensors and can be used to elucidate the drained and undrained pressure response within the different strata. Spectral ratios of the ground motions from trains amongst the accelerometers confirm that the site is still responding linearly to these ground motions.

  17. Chemical Properties, Decomposition, and Methane Production of Tertiary Relict Plant Litters: Implications for Atmospheric Trace Gas Production in the Early Tertiary

    NASA Astrophysics Data System (ADS)

    Yavitt, J. B.; Bartella, T. M.; Williams, C. J.

    2006-12-01

    Throughout the early Tertiary (ca. 65-38 Ma) Taxodiaceae-dominated (redwood) wetland forests occupied the high latitudes and were circumpolar in their distribution. Many of these forests had high standing biomass with moderate primary productivity. The geographic extent and amount of Tertiary coals and fossil forests throughout Arctic Canada suggests large areas of wetland forests that may have cycled substantial quantities of carbon, particularly methane until they were replaced by cold tolerant Pinus, Picea, and Larix following climatic cooling associated with the Terminal Eocene Event. To test this hypothesis we compared physiochemical properties, decomposition, and trace gas production of litter from extant Metasequoia, Pinus, Picea, and Larix. Initial results from plantation-grown trees indicate Metasequoia litter is a better source of labile organic substrate than pinaceous litter. Metasequoia litter contained the least lignin and highest amounts of water-soluble compounds of the four litter types studied. Analysis of the lignin structure using cupric oxide oxidation indicates that Metasequoia lignin is enriched in 4'-hydroxyacetophenone and 4'- Hydroxy-3'-methoxyacetophenone relative to the pinaceous litter. In a 12-month decomposition study using litterbags, average litter mass loss was greater for Metasequoia litter (62%) compared to the pinaceous species (50%). Moreover, Metasequoia litter incubated under anoxic conditions produced nearly twice as much CO2 (ca. 4.2 umol/g.day) and CH4 (2.1 umol/g.day) as the pinaceous litter (2.4 umol/g.day for CO2; 1.2 umol/g.day for CH4). Our results support the idea of greater decomposability and palatability of Metasequoia litter as compared to Larix, Picea, or Pinus. Provided that the biochemical properties of Metasequoia have remained relatively stable through geologic time, it appears that early Tertiary Metasequoia-dominated wetland forests may have had higher microbial driven trace gas production than the Pinaceae-dominated forests that replaced them in the late Tertiary.

  18. Basin-scale, integrated observations of the early 21st century multiyear drought

    E-print Network

    Tregoning, Paul

    Basin-scale, integrated observations of the early 21st century multiyear drought in southeast] The Murray-Darling Basin in southeast Australia is experiencing one of the most severe droughts observed. This paper provides new basin-scale observations of the multiyear drought, integrated to a degree rarely

  19. Direct observation of low-temperature catalytic decomposition of H3BO3 shell in core/shell Ni/H3BO3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhang, X. F.; Guan, P. F.; Dong, X. L.

    2012-08-01

    Decomposition of H3BO3 to B2O3 in core/shell Ni/H3BO3 nanoparticles was in situ recorded by transmission electron microscope as the irradiation time. The direct observation provides compelling evidence of the synergetic effect of the Ni core and the H3BO3 shell, revealing the catalytic mechanisms of metal nanostructures that induce the decomposition at 124 °C, lower than the bulk counterpart at 300 °C. This phenomenon can be theoretically explained by considering the weakening of B-O bond at the Ni-H3BO3 interface, and has important implications in understanding the lubricant behavior of H3BO3 in frictional wear.

  20. A Validation of the Early Childhood Classroom Observation Measure in Finnish and Estonian Kindergartens

    Microsoft Academic Search

    Marja-Kristiina Lerkkanen; Eve Kikas; Eija Pakarinen; Kaili Trossmann; Anna-Maija Poikkeus; Helena Rasku-Puttonen; Martti Siekkinen; Jari-Erik Nurmi

    2012-01-01

    Research Findings: The aim of the study was to examine the applicability and psychometric properties of the Early Childhood Classroom Observation Measure (ECCOM; D. J. Stipek & P. Byler, 2005) outside the United States. The ECCOM was used to observe 83 kindergarten teachers (49 in Finland and 34 in Estonia) in classroom situations. Self-ratings were obtained of teachers’ teaching practices,

  1. A Validation of the Early Childhood Classroom Observation Measure in Finnish and Estonian Kindergartens

    ERIC Educational Resources Information Center

    Lerkkanen, Marja-Kristiina; Kikas, Eve; Pakarinen, Eija; Trossmann, Kaili; Poikkeus, Anna-Maija; Rasku-Puttonen, Helena; Siekkinen, Martti; Nurmi, Jari-Erik

    2012-01-01

    Research Findings: The aim of the study was to examine the applicability and psychometric properties of the Early Childhood Classroom Observation Measure (ECCOM; D. J. Stipek & P. Byler, 2005) outside the United States. The ECCOM was used to observe 83 kindergarten teachers (49 in Finland and 34 in Estonia) in classroom situations. Self-ratings…

  2. Observations of Glide and Decomposition of a<101> Dislocations at High Temperatures in Ni-Al Single Crystals Deformed along the Hard Orientation

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Daw, M. S.; Noebe, R. D.; Mills, M. J.

    2003-01-01

    Ni-44at.% Al and Ni-50at.% single crystals were tested in compression in the hard (001) orientations. The dislocation processes and deformation behavior were studied as a function of temperature, strain and strain rate. A slip transition in NiAl occurs from alpha(111) slip to non-alphaaaaaaaaaaa9111) slip at intermediate temperatures. In Ni-50at.% Al single crystal, only alpha(010) dislocations are observed above the slip transition temperature. In contrast, alpha(101)(101) glide has been observed to control deformation beyond the slip transition temperature in Ni-44at.%Al. alpha(101) dislocations are observed primarily along both (111) directions in the glide plane. High-resolution transmission electron microscopy observations show that the core of the alpha(101) dislocations along these directions is decomposed into two alpha(010) dislocations, separated by a distance of approximately 2nm. The temperature window of stability for these alpha(101) dislocations depends upon the strain rate. At a strain rate of 1.4 x 10(exp -4)/s, lpha(101) dislocations are observed between 800 and 1000K. Complete decomposition of a alpha(101) dislocations into alpha(010) dislocations occurs beyond 1000K, leading to alpha(010) climb as the deformation mode at higher temperature. At lower strain rates, decomposition of a alpha(101) dislocations has been observed to occur along the edge orientation at temperatures below 1000K. Embedded-atom method calculations and experimental results indicate that alpha(101) dislocation have a large Peieris stress at low temperature. Based on the present microstructural observations and a survey of the literature with respect to vacancy content and diffusion in NiAl, a model is proposed for alpha(101)(101) glide in Ni-44at.%Al, and for the observed yield strength versus temperature behavior of Ni-Al alloys at intermediate and high temperatures.

  3. LU Decomposition

    NSDL National Science Digital Library

    Fitchett, Stephanie

    Created by Stephanie Fitchett and David Smith for the Connected Curriculum Project, the purpose of this module is to examine LU decompositions of matrices and to see how an LU decomposition can improve computational efficiency in solving matrix equations. This is part of a larger collection of learning modules hosted by Duke University.

  4. Probing the interstellar medium in early-type galaxies with Infrared Space Oberservatory observations

    NASA Technical Reports Server (NTRS)

    Malhotra, S.; Hollenbach, D.; Helou, D.; Silbermann, N.; Valjavec, E.; Rubin, R.; Dale, D.; Hunter, D.; Lu, N.; Lord, S.; Dinerstein, H.; Thronson, H.

    2000-01-01

    Four IRAS-detected early-type galaxies were observed with the Infrared Space Observatory (ISO). With the exception of the 15 mu m image of NGC 1052, the mid-IR images of NGC 1052, NGC 1155, NGC 5866, and NGC 6958 at 4.5, 7, and 15 mu m show extended emission.

  5. Validity, Reliability, and Utility of the Observation Survey of Early Literacy Achievement

    ERIC Educational Resources Information Center

    Denton, Carolyn A.; Ciancio, Dennis J.; Fletcher, Jack M.

    2006-01-01

    This study evaluated the validity, reliability, and utility of five of the six subtests of Clay's (2002) Observation Survey of Early Literacy Achievement (OS), including Letter Identification, Word Reading, Writing Vocabulary, Hearing and Recording Sounds in Words, and Text Reading. In addition to a review of studies providing assessment of the…

  6. Child Observation and Accountability in Early Childhood Education: Perspectives from Australia and the United States

    Microsoft Academic Search

    J. Amos Hatch; Susan Grieshaber

    2002-01-01

    The changing ways child observation is being used by preschool teachers in the United States and Australia are described in relation to the accountability movement pressuring young children and their teachers in both countries. The costs of the accountability movement in early childhood education are explored, and a call for genuine accountability based on assessment strategies such as traditional child

  7. Early Childhood Teachers' Curriculum Beliefs: Are They Consistent with Observed Classroom Practices?

    ERIC Educational Resources Information Center

    Wen, Xiaoli; Elicker, James G.; McMullen, Mary B.

    2011-01-01

    Research Findings: This study examined the consistency between early childhood teachers' self-reported curriculum beliefs and observations of their actual interactive behaviors with children in classrooms. Also tested was the hypothesized moderation by teacher and classroom characteristics of the association between beliefs and practices. A total…

  8. Early HiRISE Observations of Ring/Mound Landforms in Athabasca Valles, Mars

    NASA Astrophysics Data System (ADS)

    Jaeger, W. L.; Keszthelyi, L. P.; McEwen, A. S.; Dundas, C. M.; Russell, P. S.; HiRISE Team

    2007-03-01

    Small ring/mound landforms (RMLs) pepper the floor of Athabasca Valles, which is a young flood-carved channel system on Mars. Early HiRISE observations of these RMLs show them to be hydrovolcanic constructs similar to terrestrial rootless cones.

  9. Clinical observations of early and late normal tissue injury in patients receiving fast neutron irradiation

    SciTech Connect

    Ornitz, R.D. (George Washington Univ. Medical Center, Washington, DC); Bradley, E.W.; Mossman, K.L.; Fender, F.M.; Schell, M.C.; Rogers, C.C.

    1980-03-01

    This communication describes early and late normal tissue effects in 177 patients treated totally or in part by 15 MeV neutrons from the Naval Research Laboratory Cyclotron in Washington, D.C. between October 1973 and December 1976. Late normal tissue reactions were found to be greater than would be expected from careful observation of the early clinical responses to neutron treatment. Neutron prescriptions must be written based on the late effect tolerance level experience which is being accumulated at several neutron therapy facilities.

  10. Ulysses radio observations of the heliospheric activity in early June 1991

    NASA Technical Reports Server (NTRS)

    Hoang, S.; Lacombe, C.; Mangeney, A.; Poquerusse, M.; Bougeret, J.-L.; Lengyel-Frey, D.; Macdowall, R. J.; Stone, R. G.

    1995-01-01

    The radio receiver of the URAP (Unified Radio and Plasma Wave) experiment on Ulysses has recorded a heliospheric activity particularly intense between late May and early June 1991. Many solar radio emissions of types III and II were observed together with interplanetary (IP) shocks. In the same time, the radio spectrograph ARTEMIS at Nancay (France) observed several intense type II bursts. We investigate the association and/or interaction of these radio emissions, which are remotely observed, with some IP shocks detected in situ, in the context of a Coronal Mass Ejection (CME) induced scenario.

  11. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    NASA Technical Reports Server (NTRS)

    Hinshaw, Gary; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics,of the early universe. Within the framework of inflationary dark matter models observations of the anisotropy on sub-degree angular scales will reveal the signatures of acoustic oscillations of the photon-baryon fluid at a redshift of approx. 1100. The validity of inflationary models will be tested and, if agreement is found, accurate values for most of the key cosmological parameters will result. If disagreement is found, we will need to rethink our basic ideas about the physics of the early universe. I will present an overview of the physical processes at work in forming the anisotropy and discuss what we have already learned from current observations. I will conclude with a brief overview of the recently launched Microwave Anisotropy Probe (MAP) mission which will observe the anisotropy over the full sky with 0.21 degree angular resolution. At the time of this meeting, MAP will have just arrived at the L2 Lagrange point, marking the start of its observing campaign. The MAP hardware is being produced by Goddard in partnership with Princeton University.

  12. Blue Straggler Stars: Early Observations That Failed to Solve the Problem

    NASA Astrophysics Data System (ADS)

    Cannon, Russell D.

    In this chapter, I describe early ideas on blue stragglers, and various observations (some published, some not) that promised but failed to resolve the question of their origin. I review the data and ideas that were circulating from Allan Sandage's original discovery in 1953 of "anomalous blue stars" in the globular cluster M3, up until about 1992, when what seems to have been the only previous meeting devoted to Blue Straggler Stars (BSSs) was held at the Space Telescope Science Institute.

  13. ROSAT PSPC observation of the X-ray faint early-type galaxy NGC5866

    E-print Network

    S. Pellegrini

    1994-07-03

    We present the results of the analysis of the ROSAT PSPC pointed observation of the S0 galaxy NGC5866. Previous Einstein observations had revealed that this galaxy has a low X-ray to optical ratio Lx/Lb. Theoretical models of the X-ra emission of early-type galaxies had suggested that in objects of this kind the emission is not dominated by the presence of a hot diffuse gas, but should originate in stellar sources. We discuss the evidence in favor of this hypothesis following from the results of the analysis of the ROSAT PSPC data. The X-ray spectrum shows properties similar to those of the other two low Lx/Lb early-type galaxies observed by ROSAT so far, including the presence of very soft emission. So, these galaxies can be recognized as a group with homogeneous properties, and a more exhaustive picture of the nature of the X-ray emission across the Lx/Lb plane of early-type galaxies can be outlined. We also discuss the importance of rotation in the X-ray emission of S0 galaxies, and suggest that it could explain why on average S0s are less X-ray luminous than ellipticals.

  14. Decomposition techniques

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

  15. Early GRB Optical and Infrared Afterglow Observations with the 2-m Robotic Liverpool Telescope

    E-print Network

    A. Gomboc; C. G. Mundell; C. Guidorzi; A. Monfardini; C. J. Mottram; R. Priddey; R. J. Smith; S. Pak; I. A. Steele; N. Tanvir; D. Carter; S. N. Fraser; M. F. Bode; A. M. Newsam; M. Hughes

    2005-05-03

    We present the first optical observations of a Gamma Ray Burst (GRB) afterglow using the 2-m robotic Liverpool Telescope (LT), which is owned and operated by Liverpool John Moores University and situated on La Palma. We briefly discuss the capabilities of LT and its suitability for rapid follow-up observations of early optical and infrared GRB light curves. In particular, the combination of aperture, site, instrumentation and rapid response (robotic over-ride mode aided by telescope's rapid slew and fully-opening enclosure) makes the LT ideal for investigating the nature of short bursts, optically-dark bursts, and GRB blast-wave physics in general. We briefly describe the LT's key position in the RoboNet-1.0 network of robotic telescopes. We present the LT observations of GRB041006 and use its gamma-ray properties to predict the time of the break in optical light curve, a prediction consistent with the observations.

  16. Singular Value Decomposition Proper Orthogonal Decomposition

    E-print Network

    Noelle, Sebastian

    Singular Value Decomposition Proper Orthogonal Decomposition Model Order Reduction Techniques SVD;Singular Value Decomposition Proper Orthogonal Decomposition Singular values and vectors Properties Application: Low-Rank Approximation Singular Value Decomposition Satz For each matrix Y RmÃ?n there exists

  17. The Uffo Slewing Mirror Telescope for Early Optical Observation from Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Nam, Jiwoo; Ahmad, S.; Ahn, K.; Barrillon, P.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chang, S.-H.; Chen, C.-R.; Chen, P.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Huang, J.-J.; Jeong, S.; Jung, A.; Kim, J. E.; Kim, S. H.; Kim, Y. W.; Lee, J.; Lim, H.; Lin, C.-Y.; Linder, E. V.; Liu, T.-C.; Lund, N.; Min, K. W.; Na, G. W.; Panayuk, M. I.; Park, I. H.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.; Zhao, M. H.

    2013-01-01

    While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of the UFFO project and present the payload development status, especially for Slewing Mirror Telescope which is the key instrument of the UFFO-pathfinder mission.

  18. The Uffo Slewing Mirror Telescope for Early Optical Observation from Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Nam, Jiwoo; Ahmad, S.; Ahn, K.; Barrillon, P.; Brandt, S.; Budtz-Jørgensen, C.; Castrotirado, A. J.; Chang, S.-H.; Chen, C.-R.; Chen, P.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Huang, J.-J.; Jeong, S.; Jung, A.; Kim, J. E.; Kim, S. H.; Kim, Y. W.; Lee, J.; Lim, H.; Lin, C.-Y.; Linder, E. V.; Liu, T.-C.; Lund, N.; Min, K. W.; Na, G. W.; Panayuk, M. I.; Park, I. H.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.; Zhao, M. H.

    2013-12-01

    While some space born observatories, such as SWIFT and FERMI, have been operating, early observation of optical after grow of GRBs is still remained as an unexplored region. The Ultra-Fast Flash Observatory (UFFO) project is a space observatory for optical follow-ups of GRBs, aiming to explore the first 60 seconds of GRBs optical emission. Using fast moving mirrors to redirect our optical path rather than slewing the entire spacecraft, UFFO is utilized to catch early optical emissions from GRB within 1 sec. We have developed the UFFO Pathfinder Telescope which is going to be on board of the Lomonosov satellite and launched in middle of 2012. We will discuss about scientific potentials of the UFFO project and present the payload development status, especially for Slewing Mirror Telescope which is the key instrument of the UFFO-pathfinder mission.

  19. Constraining the temperature history of the past millennium using early instrumental observations

    NASA Astrophysics Data System (ADS)

    Brohan, P.

    2012-12-01

    The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations - notable differences include large differences in multi-decadal variability between proxy reconstructions, and big uncertainties in the effect of volcanic eruptions. Because the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. By constraining key aspects of the reconstructions and simulations, instrumental observations, inevitably from a limited period, can reduce reconstruction uncertainty throughout the millennium. A considerable quantity of early instrumental observations are preserved in the world's archives. One organisation which systematically made observations and collected the results was the English East-India Company (EEIC), and 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure have been preserved in the British Library. Similar records from voyages of exploration and scientific investigation are preserved in published literature and the records in National Archives. Some of these records have been extracted and digitised, providing hundreds of thousands of new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5C). This provides a powerful out-of-sample validation for the proxy reconstructions --- supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this --- such simulations are unlikely to be accurate in this respect.

  20. Constraining the temperature history of the past millennium using early instrumental observations

    NASA Astrophysics Data System (ADS)

    Brohan, P.; Allan, R.; Freeman, E.; Wheeler, D.; Wilkinson, C.; Williamson, F.

    2012-05-01

    The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations. As the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. One organisation which systematically made observations and collected the results was the English East-India Company (EEIC), and their archives have been preserved in the British Library. Inspection of those archives revealed 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure, and subjective estimates of wind speed and direction, from voyages across the Atlantic and Indian Oceans between 1789 and 1834. Those records have been extracted and digitised, providing 273 000 new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5 °C). This provides a powerful out-of-sample validation for the proxy reconstructions - supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this - such simulations are unlikely to be accurate in this respect.

  1. Constraining the temperature history of the past millennium using early instrumental observations

    NASA Astrophysics Data System (ADS)

    Brohan, P.; Allan, R.; Freeman, E.; Wheeler, D.; Wilkinson, C.; Williamson, F.

    2012-10-01

    The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores, etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations. As the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. One organisation which systematically made observations and collected the results was the English East India Company (EEIC), and their archives have been preserved in the British Library. Inspection of those archives revealed 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure, and subjective estimates of wind speed and direction, from voyages across the Atlantic and Indian Oceans between 1789 and 1834. Those records have been extracted and digitised, providing 273 000 new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5 °C). This provides an out-of-sample validation for the proxy reconstructions - supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this - such simulations are unlikely to be accurate in this respect.

  2. Observation of early photons from gamma-ray bursts with the Lomonosov / UFFO-pathfinder

    NASA Astrophysics Data System (ADS)

    Jeong, S.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Connell, P.; Eyles, C.; Huang, M.-H. A.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Lee, J.; Lim, H.; Liu, T.-C.; Nam, J. W.; Park, H. W.; Park, I. H.; Panasyuk, M. I.; Reglero, V.; Ripa, J.; Rodrigo, J. M.; Svertilov, S.; Vedenkin, N.; Yashin, I.

    2014-12-01

    UFFO-pathfinder is a pioneering space mission to observe the early evolution of Gamma-ray Bursts using a fast slewing strategy. It consists of the Slewing Mirror Telescope, for rapid pointing at UV/optical wavelengths and the UFFO Burst Alert and Trigger Telescope. It has a total weight of ˜ 20 kg and will be launched on-board the Russian Lomonosov satellite at the end of 2015. The instrumental details of UFFO-pathfinder and its performance are discussed briefly here.

  3. Woodland Decomposition.

    ERIC Educational Resources Information Center

    Napier, J.

    1988-01-01

    Outlines the role of the main organisms involved in woodland decomposition and discusses some of the variables affecting the rate of nutrient cycling. Suggests practical work that may be of value to high school students either as standard practice or long-term projects. (CW)

  4. Sector Decomposition

    E-print Network

    Gudrun Heinrich

    2008-05-16

    Sector decomposition is a constructive method to isolate divergences from parameter integrals occurring in perturbative quantum field theory. We explain the general algorithm in detail and review its application to multi-loop Feynman parameter integrals as well as infrared divergent phase-space integrals over real radiation matrix elements.

  5. Experimental observation of critical slowing down as an early warning of population collapse

    NASA Astrophysics Data System (ADS)

    Vorselen, Daan; Dai, Lei; Korolev, Kirill; Gore, Jeff

    2012-02-01

    Near tipping points marking population collapse or other critical transitions in complex systems small changes in conditions can result in drastic shifts in the system state. In theoretical models it is known that early warning signals can be used to predict the approach of these tipping points (bifurcations), but little is known about how these signals can be detected in practice. Here we use the budding yeast Saccharomyces cerevisiae to study these early warning signals in controlled experimental populations. We grow yeast in the sugar sucrose, where cooperative feeding dynamics causes a fold bifurcation; falling below a critical population size results in sudden collapse. We demonstrate the experimental observation of an increase in both the size and timescale of the fluctuations of population density near this fold bifurcation. Furthermore, we test the utility of theoretically predicted warning signals by observing them in two different slowly deteriorating environments. These findings suggest that these generic indicators of critical slowing down can be useful in predicting catastrophic changes in population biology.

  6. Early observations of comet Churyumov-Gerasimenko with the Rosetta MIRO submillimeter instrument

    NASA Astrophysics Data System (ADS)

    Gulkis, S.; Allen, M.; Von Allmen, P.; Beaudin, G.; Biver, N.; Bockelee-Morvan, D.; Choukroun, M.; Crovisier, J.; Encrenaz, P.; Encrenaz, T.; Frerking, M.; Hartogh, P.; Hofstadter, M.; Ip, W.; Janssen, M.; Jarchow, C.; Kamp, L.; Keihm, S.; Lee, S.; Lellouch, E.; Leyrat, C.; Rezac, L.; Schloerb, F.; Spilker, T.

    2014-07-01

    The Rosetta spacecraft is now approaching comet 67P/Churyumov- Gerasimenko, preparing to enter orbit in August 2014 and place a lander on the nucleus in November. The Microwave Instrument on the Rosetta Orbiter (MIRO) is designed to study the coma and immediate sub-surface of the nucleus. It has two broad-band continuum channels (center frequencies near 560 and 190 GHz, or wavelengths near 0.5 and 1.6 mm) which probe the thermal and dielectric properties of the upper ˜ centimeters of the nucleus. It also contains a high spectral resolution (44 kHz) spectrometer working in the submillimeter band to study the abundance, velocity, temperature, and three-dimensional structure of select species in the coma. Those species are H_2O, H_2^{17}O, H_2^{18}O, CO, NH_3, and CH_3OH. Scientific observations with the MIRO instrument were started in early May 2014, when the comet-spacecraft separation distance was 1.8 million kilometers. Initial observations were designed to search for H_2O and CO in the coma and for thermal emission from the nucleus. Early detection of the coma is expected only if gas production rates are relatively high (˜ 1×10^{26} water molecules/second at a heliocentric distance near 4 au). We will present the results of our initial measurements, describe the detailed mapping of the coma and nucleus we plan to do over the coming months.

  7. Observational Manifestations of Early Mixing in b- and O-Type Stars

    NASA Astrophysics Data System (ADS)

    Lyubimkov, L. S.

    The helium and nitrogen en-rich-ment of the atmospheres of early B-type stars during the main sequence (MS) evolutionary phase is re-analysed. It is con-fir-med that the effect depends on both the age t and the stellar mass M. For example, the helium abundance He/H increases by 0.04 (60-70% of initial value) for stars with M=8-13 M_odot and by 0.025 (about 30%) for stars with M=6M_odot. The nitrogen abundance rises by three times for M=14 M_odot and by two times for M=10 M_odot. According to the latest theoretical computations, the observed appearance of CNO-cycled material in surface layers of the stars can be a result of the rotationally induced mixing, in particular, of the turbulent diffusion. Carbon is in deficiency in B stars, but unexpectedly does not show any correlation with the stellar age. However it is shown that the total C+N abundance derived for early B stars conflicts with the theory. Basing on modern data the helium en-rich-ment is first examined in O-type MS stars, as well as in components of binaries. As compared with early B stars, the He abundance for more massive O stars and for components of binaries show a different relation with the relative age t/t_{MS. Namely during the first half of the MS stage the normal value He/H=0.08-0.10 is conserved, whereas in the short time between t/t_{MS approx 0.5 and 0.7 a sharp jump is observed up to He/H=0.2 and more. In particular, such a jump is typical for fast rotating O stars (v,sin,i ge 200 km s^{-1). Therefore the effect of mixing depends on mass M, relative age t/t_{MS, rotational velocity v and duplicity. The mass problem (the discrepancy between M_{ev and M_{sp) is also analysed, because some authors consider it as a possible evidence of early mixing, too. It is shown that the ac-cu-ra-te data for components of binaries lead to the conclusion that the discrepancy is less than 30%. Such a difference can be removed at the expense of the M_{ev lowering, if the displacement of evolutionary tracks owing to the rotationally induced mixing is taken into consideration. Full version of this paper will be published in {it Astrophysics and Space Science.

  8. Observational manifestations of early mixing in B- and O-type stars

    NASA Astrophysics Data System (ADS)

    Lyubimkov, L. S.

    1996-09-01

    The helium and nitrogen enrichment of the atmospheres of early B-type stars during the main sequence (MS) evolutionary phase is re-analysed. It is confirmed that the effect depends on both the aget and the stellar massM. For example, the helium abundanceHe/H increases by 0.04 (60 70% of initial value) for stars withM=8 13M ? and by 0.025 (about 30%) for stars withM=6M ?. The nitrogen abundance rises by three times forM=14M ? and by, two times forM=10M ?. According to the latest theoretical computations, the observed appearance of CNO-cycled material in surface layers of the stars can be a result of the rotationally induced mixing, in particular, of the turbulent diffusion. Carbon is in deficiency in B stars, but unexpectedly does not show any correlation with the stellar age. However it is shown that the total C+N abundance derived for early B stars conflicts with the theory. Basing on modern data the helium enrichment is first examined in O-type MS stars, as well as in components of binaries. As compared with early B stars, the He abundance for more massive O stars and for components of binaries show a different relation with the relative aget/t MS . Namely during short time betweent/t MS ?0.5 and 0.7 a sharp jump is observed up toHe/H=0.2 and more. In particular, such a jump is typical for fast rotating O stars (v sini?200 km s-1),. Therefore the effect of mixing depends on massM, relative aget/t MS , rotational velocityv and duplicity. The mass problem (the discrepancy betweenM ev andM sp ) is also analysed, because some authors consider it as a possible evidence of early mixing, too. It is shown that the accurate data for components of binaries lead to the conclusion that the discrepancy is less than 30%. Such a difference can be removed at the expense of theM ev lowering, if the displacement of evolutionary tracks, owing to the rotationally induced mixing is taken into consideration.

  9. Observations and Modeling of the Early Acceleration Phase of Erupting Filaments Involved in Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Schrijver, Carolus J.; Elmore, Christopher; Kliem, Bernhard; Török, Tibor; Title, Alan M.

    2008-02-01

    We examine the early phases of two near-limb filament destabilizations involved in coronal mass ejections (CMEs) on 2005 June 16 and July 27, using high-resolution, high-cadence observations made with the Transition Region and Coronal Explorer (TRACE), complemented by coronagraphic observations by the Mauna Loa Solar Observatory (MLSO) and the Solar and Heliospheric Observatory (SOHO). The filaments' heights above the solar limb in their rapid-acceleration phases are best characterized by a height dependence h(t)~tm with m near, or slightly above, 3 for both events. Such profiles are incompatible with published results for breakout, MHD-instability, and catastrophe models. We show numerical simulations of the torus instability that approximate this height evolution in case a substantial initial velocity perturbation is applied to the developing instability. We argue that the sensitivity of magnetic instabilities to initial and boundary conditions requires higher fidelity modeling of all proposed mechanisms if observations of rise profiles are to be used to differentiate between them. The observations show no significant delays between the motions of the filament and of overlying loops: the filaments seem to move as part of the overall coronal field until several minutes after the onset of the rapid-acceleration phase.

  10. EARLY PHASE OBSERVATIONS OF EXTREMELY LUMINOUS TYPE Ia SUPERNOVA 2009dc

    SciTech Connect

    Yamanaka, M.; Arai, A.; Chiyonobu, S.; Fukazawa, Y.; Ikejiri, Y.; Itoh, R.; Komatsu, T.; Miyamoto, H. [Department of Physical Science, Hiroshima University, Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 (Japan); Kawabata, K. S. [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kinugasa, K.; Hashimoto, O.; Honda, S. [Gunma Astronomical Observatory, Takayama, Gunma 377-0702 (Japan); Tanaka, M. [Department of Astronomy, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Imada, A.; Kuroda, D. [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Kamogata, Asakuchi-shi, Okayama 719-0232 (Japan); Maeda, K.; Nomoto, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa (Japan); Kamata, Y. [National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Kawai, N. [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Konishi, K., E-mail: myamanaka@hiroshima-u.ac.j [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba, 277-8582 (Japan)

    2009-12-20

    We present early phase observations in optical and near-infrared wavelengths for the extremely luminous Type Ia supernova (SN Ia) 2009dc. The decline rate of the light curve is DELTAm{sub 15}(B) = 0.65 +- 0.03, which is one of the slowest among SNe Ia. The peak V-band absolute magnitude is estimated to be M{sub V} = -19.90 +- 0.15 mag if no host extinction is assumed. It reaches M{sub V} = -20.19 +- 0.19 mag if we assume the host extinction of A{sub V} = 0.29 mag. SN 2009dc belongs to the most luminous class of SNe Ia, like SNe 2003fg and 2006gz. Our JHK{sub s} -band photometry shows that this SN is also one of the most luminous SNe Ia in near-infrared wavelengths. We estimate the ejected {sup 56}Ni mass of 1.2 +- 0.3 M{sub sun} for the no host extinction case (and of 1.6 +- 0.4 M{sub sun} for the host extinction of A{sub V} = 0.29 mag). The C II lambda6580 absorption line remains visible until a week after the maximum brightness, in contrast to its early disappearance in SN 2006gz. The line velocity of Si II lambda6355 is about 8000 km s{sup -1} around the maximum, being considerably slower than that of SN 2006gz. The velocity of the C II line is similar to or slightly less than that of the Si II line around the maximum. The presence of the carbon line suggests that the thick unburned C+O layer remains after the explosion. Spectropolarimetric observations by Tanaka et al. indicate that the explosion is nearly spherical. These observational facts suggest that SN 2009dc is a super-Chandrasekhar mass SN Ia.

  11. Watching Teachers Work: Using Observation Tools to Promote Effective Teaching in the Early Years and Early Grades

    ERIC Educational Resources Information Center

    Guernsey, Lisa; Ochshorn, Susan

    2011-01-01

    This paper paints a picture of the dismal state of early education for many children--especially the disadvantaged--who are rarely given access to the kinds of stimulating, content-rich conversations that provide them with the cognitive and social-emotional skills they need to succeed throughout their years in school. With many states currently…

  12. Interactions of tissue and fertilizer nitrogen on decomposition dynamics of lignin-rich conifer litter

    USGS Publications Warehouse

    Perakis, Steven S.; Matkins, Joselin J.; Hibbs, David E.

    2012-01-01

    High tissue nitrogen (N) accelerates decomposition of high-quality leaf litter in the early phases of mass loss, but the influence of initial tissue N variation on the decomposition of lignin-rich litter is less resolved. Because environmental changes such as atmospheric N deposition and elevated CO2 can alter tissue N levels within species more rapidly than they alter the species composition of ecosystems, it is important to consider how within-species variation in tissue N may shape litter decomposition and associated N dynamics. Douglas-fir (Pseudotsuga menziesii ) is a widespread lignin-rich conifer that dominates forests of high carbon (C) storage across western North America, and displays wide variation in tissue and litter N that reflects landscape variation in soil N. We collected eight unique Douglas-fir litter sources that spanned a two-fold range in initial N concentrations (0.67–1.31%) with a narrow range of lignin (29–35%), and examined relationships between initial litter chemistry, decomposition, and N dynamics in both ambient and N fertilized plots at four sites over 3 yr. High initial litter N slowed decomposition rates in both early (0.67 yr) and late (3 yr) stages in unfertilized plots. Applications of N fertilizer to litters accelerated early-stage decomposition, but slowed late-stage decomposition, and most strongly affected low-N litters, which equalized decomposition rates across litters regardless of initial N concentrations. Decomposition of N-fertilized litters correlated positively with initial litter manganese (Mn) concentrations, with litter Mn variation reflecting faster turnover of canopy foliage in high N sites, producing younger litterfall with high N and low Mn. Although both internal and external N inhibited decomposition at 3 yr, most litters exhibited net N immobilization, with strongest immobilization in low-N litter and in N-fertilized plots. Our observation for lignin-rich litter that high initial N can slow decomposition yet accelerate N release differs from findings where litter quality variation across species promotes coupled C and N release during decomposition. We suggest reevaluation of ecosystem models and projected global change effects to account for a potential decoupling of ecosystem C and N feedbacks through litter decomposition in lignin-rich conifer forests.

  13. Ultra-Fast Flash Observatory for observation of early photons from gamma ray bursts

    NASA Astrophysics Data System (ADS)

    Park, I. H.; Ahmad, S.; Barrillon, P.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Jeong, S.; Jung, A.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Kim, Y. W.; Krasnov, A. S.; Lee, J.; Lim, H.; Linder, E. V.; Liu, T.-C.; Lund, N.; Min, K. W.; Na, G. W.; Nam, J. W.; Panasyuk, M. I.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Suh, J. E.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

    2012-09-01

    We describe the space project of Ultra-Fast Flash Observatory (UFFO) which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast response Slewing Mirror Telescope (SMT) that redirects optical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We describe the science and the mission of the UFFO project, including a next version called UFFO-100. With our program of ultra-fast optical response GRB observatories, we aim to gain a deeper understanding of GRB mechanisms, and potentially open up the z<10 universe to study via GRB as point source emission probes.

  14. Early observational research and registries during the 2009–2010 influenza A pandemic

    PubMed Central

    Fowler, Robert A.; Webb, Steven A. R.; Rowan, Kathy M.; Sprung, Charles L.; Thompson, B. Taylor; Randolph, Adrienne G.; Jouvet, Philippe; Lapinsky, Stephen; Rubinson, Lewis; Rello, Jordi; Cobb, J. Perren; Rice, Todd W.; Uyeki, Tim; Marshall, John C.

    2013-01-01

    As a critical care community, we have an obligation to provide not only clinical care but also the research that guides initial and subsequent clinical responses during a pandemic. There are many challenges to conducting such research. The first is speed of response. However, given the near inevitability of certain events, for example, viral respiratory illness such as the 2009 pandemic, geographically circumscribed natural disasters, or acts of terror, many study and trial designs should be preplanned and modified quickly when specific events occur. Template case report forms should be available for modification and web entry; centralized research ethics boards and funders should have the opportunity to preview and advise on such research beforehand; and national and international research groups should be prepared to work together on common studies and trials for common challenges. We describe the early international critical care research response to the influenza A 2009 (H1N1) pandemic, including specifics of observational study case report form, registry, and clinical trial design, cooperation of international critical care research organizations, and the early results of these collaborations. PMID:20101176

  15. Prelexical Decomposition of Compound and Pseudocompound Words

    E-print Network

    Diener, Un So Park

    2007-12-12

    Previous studies on morphologically complex words suggest early decomposition in the visual word process. In that case, morpheme-like constituents of pseudocompound words (e.g. mushroom) should also be decomposed during ...

  16. Earth Observing System (EOS) Aqua Launch and Early Mission Attitude Support Experiences

    NASA Technical Reports Server (NTRS)

    Tracewell, D.; Glickman, J.; Hashmall, J.; Natanson, G.; Sedlak, J.

    2003-01-01

    The Earth Observing System (EOS) Aqua satellite was successfully launched on May 4,2002. Aqua is the second in the series of EOS satellites. EOS is part of NASA s Earth Science Enterprise Program, whose goals are to advance the scientific understanding of the Earth system. Aqua is a three-axis stabilized, Earth-pointing spacecraft in a nearly circular, sun-synchronous orbit at an altitude of 705 km. The Goddard Space Flight Center (GSFC) Flight Dynamics attitude team supported all phases of the launch and early mission. This paper presents the main results and lessons learned during this period, including: real-time attitude mode transition support, sensor calibration, onboard computer attitude validation, response to spacecraft emergencies, postlaunch attitude analyses, and anomaly resolution. In particular, Flight Dynamics support proved to be invaluable for successful Earth acquisition, fine-point mode transition, and recognition and correction of several anomalies, including support for the resolution of problems observed with the MODIS instrument.

  17. In situ observations of soil minerals and organic matter in the early phases of prescribed fires

    NASA Astrophysics Data System (ADS)

    Kavouras, Ilias G.; Nikolich, George; Etyemezian, Vic; Dubois, David W.; King, James; Shafer, David

    2012-06-01

    We examined the chemical composition of aerosol samples collected during a prescribed fire at a Great Basin Desert site in the context of samples collected from controlled combustion of vegetation clippings from the same site and resuspension of soil samples obtained prior to and after the burn event. We observed a distinct difference in the composition of organic carbon resuspended soil dust after the burn, reflecting changes caused by the heating of the soil. The relative abundances of minerals and organic carbon fractions in aerosols collected during the first period of the burn were identical to those measured in soil dust. For aerosol samples collected for the remaining two periods of the burn event, the profiles of both minerals and organic carbon matched quite well those observed for vegetation combustion. Reconstruction of aerosol samples collected during the burn event showed that vegetation combustion dominated emissions but mineral soil dust may account for about 10% of PM10emissions (reconstructed) during the early stages of the fire. A large fraction of emissions during the first two hours was also unaccounted mainly because of the insufficient conversion of organic carbon to organic mass. The abundance of heavier non-volatile organics in soil dust suggested the presence of humic/fulvic acids that exhibit higher OM-to-OC ratios and thus, account for a proportion of the unaccounted emissions. These findings indicated that soil dust may be released into the air during a fire event, probably due to the enhanced turbulent mixing near the burn front.

  18. Ultra-Fast Flash Observatory for the observation of early photons from gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Park, I. H.; Brandt, S.; Budtz-Jørgensen, C.; Castro-Tirado, A. J.; Chen, P.; Connell, P.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Jeong, S.; Jung, A.; Kim, J. E.; Kim, S.-W.; Lee, J.; Lim, H.; Linder, E. V.; Liu, T.-C.; Min, K. W.; Na, G. W.; Nam, J. W.; Panasyuk, M. I.; Reglero, V.; Ripa, J.; Rodrigo, J. M.; Smoot, G. F.; Svertilov, S.; Vedenkin, N.; Yashin, I.

    2013-02-01

    One of the least documented and understood aspects of gamma-ray bursts (GRBs) is the rise phase of the optical light curve. The Ultra-Fast Flash Observatory (UFFO) is an effort to address this question through extraordinary opportunities presented by a series of space missions including a small spacecraft observatory. The UFFO is equipped with a fast-response Slewing Mirror Telescope (SMT) that uses a rapidly moving mirror or mirror array to redirect the optical beam rather than slewing the entire spacecraft to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with sub-second response, for the first time, opening a completely new frontier in GRBs and transient studies. Its fast response measurements of the optical emission of dozens of GRBs each year will provide unique probes of the burst mechanism and test the prospect of GRBs as a new standard candle, potentially opening up the z > 10 universe. For the first time we employ a motorized slewing stage in SMT that can point to the event within 1 s after the x-ray trigger provided by the UFFO Burst Alert and Trigger Telescope. These two scientific instruments comprise the UFFO-pathfinder payload, which will be placed onboard the Lomonosov satellite and launched in 2013. The UFFO-pathfinder is the first step of our long-term program of space instruments for rapid-response GRB observations. We describe early photon science, our soon-to-be-launched UFFO-pathfinder hardware and mission, and our next planned mission, the UFFO-100.

  19. The Long-Term Daily Central Belgium Temperature (CBT) Series (1767–1998) and Early Instrumental Meteorological Observations in Belgium

    Microsoft Academic Search

    G. R. Demarée; P.-J. Lachaert; T. Verhoeve; E. Thoen

    2002-01-01

    This article presents the problems and results of constructing the Central Belgium Temperature series, a homogeneous multi-site instrumental daily maximum and minimum temperature series which has been made for the time period 1767 to the present. First, an outline of the history of early meteorological observations in Belgium is presented. The long-term daily observations which were subsequently used in the

  20. NIRS0S: Observations of early-type galaxy secular evolution spanning the Sa/S0/disky-E boundaries

    NASA Astrophysics Data System (ADS)

    Laurikainen, Eija; Salo, Heikki; Buta, Ronald; Knapen, Johan

    2015-03-01

    NIRS0S (Near-IR S0 galaxy Survey), is a K-band survey of ~ 200 early-type disk galaxies, mainly S0s, 2-3 mag deeper than the 2Micron All Sky Survey. In depth morphological analysis was done, in which multi-component structural decompositions played an important role. Possible implications to internal dynamical galaxy evolution were discussed. S0s were suggested to be former spirals in which star formation has ceased, forming a parallel sequence with spirals (see Fig. 1). If that evolution is faster among the brighter galaxies, the observed magnitude difference between the barred and non-barred S0s could be understood. Bars are suggested to play a critical role in such evolution. For example, the inner lenses in the bright non-barred S0s can be explained as former barlenses (inner parts of bars), in which the elongated bar component has dissolved. We suggest that the last destructive merger event happened at a fairly large redshift.

  1. Early results on 67P/Churyumov-Gerasimenko observed by Rosetta/OSIRIS

    NASA Astrophysics Data System (ADS)

    Sierks, H.; Tubiana, C.; Snodgrass, C.; Agarwal, J.; Güttler, C.; Oklay, N.; Vincent, J.; Küppers, M.; Barbieri, C.; Lamy, P.; Rickman, H.; Rodrigo, R.; Koschny, D.; Hviid, S.; Mottola, S.; Osiris Team

    2014-07-01

    67P/Churyumov-Gerasimenko (67P) is the target comet of the ESA Rosetta mission. Launched in 2004, the Rosetta spacecraft woke up on the 20th of January 2014. After 36 months of deep space hibernation, Rosetta is now traveling to rendezvous with the comet at 4.1 au from the Sun, and it will follow 67P along its orbit, investigating how the comet changes and evolves while approaching the Sun. The Optical, Spectroscopic, and Infrared Remote Imaging System OSIRIS (Keller et al., 2007) is the scientific imaging system onboard Rosetta. It comprises the Narrow Angle Camera (NAC) with wavelength range 250--1000 nm and the Wide Angle Camera (WAC) with wavelength range 240--720 nm. The NAC (FOV = 2.20×2.22 deg) is a system with high spatial resolution that allows an initial detection of the nucleus, studies its structure and rotation from relatively great distances, investigates the mineralogy of the surface, and studies the dust ejection processes. The WAC has much lower spatial resolution but, accordingly, a much wider field of view (about 11.35×12.11 deg). This allows observations of the 3-dimensional flow field of dust and gas near the nucleus and, in addition, provides a synoptic view of the whole nucleus. In summary, the WAC would provide long-term monitoring of the entire nucleus from close distances, while the NAC studies the details. The two camera units have been designed as a complementary pair, which, on one hand, addresses the study of the nucleus surface, and on the other hand, investigates the dynamics of the sublimation process. After commissioning in March 2014, OSIRIS took first images of comet 67P and its dust environment. Ground-based observations performed in 2007/08 when 67P was in the same orbital arc as it will be in March/April 2014, show that the comet was already active at 4.3 au inbound and that its behavior was repetitive during the last three apparitions (Snodgrass et al. 2013). We therefore expect to detect early comet activity by OSIRIS in March/April 2014. At this time, Rosetta will be at about 4 million kilometers from the comet and 67P will still be unresolved. We present results about the early cometary activity based on OSIRIS images. Orange-filter images (central wavelength 649.2 nm) will be used to determine the dust environment of 67P, since this wavelength range is quite free from gas emission lines. Moreover, a series of lightcurves will be taken to compare with the existing ones and look for possible changes in the rotational period due to its last perihelion passage.

  2. Fast Approximate Convex Decomposition

    E-print Network

    Ghosh, Mukulika

    2012-10-19

    Approximate convex decomposition (ACD) is a technique that partitions an input object into "approximately convex" components. Decomposition into approximately convex pieces is both more efficient to compute than exact convex decomposition and can...

  3. An overview of the Cosmic Background Explorer (COBE) and its observations - New sky maps of the early universe

    NASA Technical Reports Server (NTRS)

    Smoot, George F.

    1992-01-01

    This paper discusses the three instruments aboard NASA's Cosmic Background Explorer (COBE) satellite and presents early results obtained from the first six months of observations. The three instruments (FIRAS, DMR, and DIRBE) have operated well and produced significant new results. The FIRAS measurement of the CMB spectrum supports the standard Big Bang model. The maps made from the DMR instrument measurements show a spatially smooth early universe. The maps of galactic and zodiacal emission produced by the DIRBE instrument are needed to identify the foreground emissions from extragalactic and thus to interpret its and the other COBE results in terms of events in the early universe.

  4. [Psychometry and psychological observations in early treated children with phenylketonuria (PKU) during 12 years (author's transl)].

    PubMed

    Knoll, E; Wehle, E; Thalhammer, O

    1980-11-01

    Among 81 PKU's uncovered until 1978/12/31 63 were 1 to more than 8 years old so at least once up to 4 times psychometrically examined. Although the IQ's at 8 years were still in the normal rang there was a slight but between 6 and 8 years statistically significant (p less than 0.01) decline in IQ. There is no correlation between this decline and the diet introduction age (26--29, average 26,4 days) nor the diet discontinuation age (4 to 8 years) and the predominantly good diet quality. But there were relations to the parental IQ. It seems remarkable that the centers of London and Warschau report declines of the same extent at approximately the same ages in spite of different diet discontinuation ages. The IQ losses in the patients derive almost totally from losses in the verbal part of the tests. Also the slight but statistically significant IQ deficits demonstrated in heterozygotes for PKU (parents) arise almost entirely from the verbal quotient. It is supposed that both observations are phenylalanine blood level independent phenomena. The demonstration of statistically highly significant augmentations of intracellular phenylalanine (and tyrosine) in heterozygotes and homozygotes for PKU may indicate an explanation. Our early treated children with PKU show the same weakness in concentration, perseverance and cognitive abilities (mathematics, orthography, picture coordination) as observed by other centers. These disabilities are largely IQ independent, influence school work adversely but can be improved by psychological promotion. Children with hyperphenylalaninemia do not show the slight decline in IQ nor the specific disabilities. PMID:7194401

  5. Constraint on the early Universe by relic gravitational waves: From pulsar timing observations

    SciTech Connect

    Zhao Wen [Department of Physics, Zhejiang University of Technology, Hangzhou 310014 (China) and Niels Bohr Institute, Copenhagen University, Blegdamsvej 17, Copenhagen DK-2100 (Denmark)

    2011-05-15

    Recent pulsar timing observations by the Parkers Pulsar Timing Array (PPTA) and European Pulsar Timing Array (EPTA) teams obtained the constraint on the relic gravitational waves at the frequency f{sub *}=1/yr, which provides the opportunity to constrain H{sub *}, the Hubble parameter, when these waves crossed the horizon during inflation. In this paper, we investigate this constraint by considering the general scenario for the early Universe: we assume that the effective (average) equation-of-state w before the big bang nucleosynthesis stage is a free parameter. In the standard hot big-bang scenario with w=1/3, we find that the current PPTA result follows a bound H{sub *{<=}}1.15x10{sup -1}m{sub Pl}, and the EPTA result follows H{sub *{<=}}6.92x10{sup -2}m{sub Pl}. We also find that these bounds become much tighter in the nonstandard scenarios with w>1/3. When w=1, the bounds become H{sub *{<=}}5.89x10{sup -3}m{sub Pl} for the current PPTA and H{sub *{<=}}3.39x10{sup -3}m{sub Pl} for the current EPTA. In contrast, in the nonstandard scenario with w=0, the bound becomes H{sub *{<=}}7.76m{sub Pl} for the current PPTA.

  6. Early-time observations of Type Ia supernovae to reveal progenitors

    NASA Astrophysics Data System (ADS)

    Howell, D. Andrew; Sullivan, Mark; Parrent, Jerod; Nugent, Peter; Hook, Isobel; Dilday, Ben; Maguire, Kate; Graham, Melissa

    2012-02-01

    SNe Ia remain nature's best standardized candles, and yet their progenitors have long been a mystery. However, in a series of three studies this year, our group has placed the first serious constraints on the progenitors of two SNe Ia, finding (1) the first hard evidence that the primary is a CO white dwarf star; (2) in one case the white dwarf is accreting from a mass-losing evolved secondary and has become a recurrent nova like RS Oph; (3) in another case a system like RS Oph is ruled out and the companion is probably a main sequence star. Taken together with our earlier work implicating white dwarfs mergers in the super-Chandra systems, we are led to the remarkable conclusion that there are a multiplicity of progenitors for SNe Ia. This may explain our finding that supernovae in different environments correct to different absolute magnitudes, and could have serious implications for cosmology. Our results depend on early-time observations for which the queue-scheduled Gemini is uniquely suited. We will use these data to rapidly trigger high-resolution searches for circumstellar material at Keck and VLT, and the Gemini data will directly probe the unburned progenitor material in the supernovae themselves.

  7. Hubble's Early Release Observations Student Pilot Project: Implementing Formal and Informal Collaborations

    NASA Astrophysics Data System (ADS)

    Eisenhamer, B.; Ryer, H.; McCallister, D.

    2012-08-01

    The Hubble Space Telescope's Early Release Observations (EROs) were revealed to the public on September 9, 2009, and K-12 students and educators in five states across the country were able to join the celebration. To date, students and educators in Maryland, Ohio, New York, California, and Florida have participated in the Hubble Space Telescope's ERO Pilot Project. This is an interdisciplinary project created by the Space Telecope Science Institute's (STScI) Office of Public Outreach in which students use skills from subject areas such as language arts, science, art, and technology to research the four ERO objects and create compositions. In recognition of their participation, the students' compositions are displayed at host institutions in each state (a museum, science center, school, planetarium or library) during a special public event for participating students, their families, and teachers. As part of its evaluation program, STScI's Office of Public Outreach has been conducting an evaluation of the project to determine the viability and potential of conducting large-scale, formal/informal collaborative projects in the future and to share lessons learned. Lessons learned will be applied to a new interdisciplinary project, the James Webb Space Telescope Student Innovation Project.

  8. Reading, Reasoning, and Literacy: Strategies for Early Childhood Education from the Analysis of Classroom Observations

    ERIC Educational Resources Information Center

    McKie, Brooke K.; Manswell Butty, Jo-Anne; Green, Rodney D.

    2012-01-01

    Researchers have posited that children generally learn to read in environments that are trusting, comfortable, and offer small group or one-to-one adult support, all of which are characteristics of a high quality early childhood education program. This evaluation research study examines the Pre-Kindergarten Incentive Program, an early childhood…

  9. Observing the Cosmic Microwave Background Radiation: A Unique Window on the Early Universe

    Microsoft Academic Search

    Gary Hinshaw

    2001-01-01

    The cosmic microwave background radiation is the remnant heat from the Big Bang. It provides us with a unique probe of conditions in the early universe, long before any organized structures had yet formed. The anisotropy in the radiation's brightness yields important clues about primordial structure and additionally provides a wealth of information about the physics of the early universe.

  10. Herschel and JCMT observations of the early-type dwarf galaxy NGC 205

    NASA Astrophysics Data System (ADS)

    De Looze, I.; Baes, M.; Parkin, T. J.; Wilson, C. D.; Bendo, G. J.; Boquien, M.; Boselli, A.; Cooray, A.; Cormier, D.; Fritz, J.; Galliano, F.; Gear, W.; Gentile, G.; Lebouteiller, V.; Madden, S. C.; Roussel, H.; Sauvage, M.; Smith, M. W. L.; Spinoglio, L.; Verstappen, J.; Young, L.

    2012-07-01

    We present Herschel dust continuum, James Clerk Maxwell Telescope CO (3-2) observations and a search for [C II] 158 ?m and [O I] 63 ?m spectral line emission for the brightest early-type dwarf satellite of Andromeda, NGC 205. While direct gas measurements [Mg˜ 1.5 × 106 M?, H I+ CO (1-0)] have proven to be inconsistent with theoretical predictions of the current gas reservoir in NGC 205 (>107 M?), we revise the missing interstellar medium mass problem based on new gas mass estimates (CO (3-2), [C II], [O I]) and indirect measurements of the interstellar medium content through dust continuum emission. Based on Herschel observations, covering a wide wavelength range from 70 to 500 ?m, we are able to probe the entire dust content in NGC 205 (? M? at Td˜ 18-22 K) and rule out the presence of a massive cold dust component (? M?, Td˜ 12 K), which was suggested based on millimetre observations from the inner 18.4 arcsec. Assuming a reasonable gas-to-dust ratio of ˜400, the dust mass in NGC 205 translates into a gas mass Mg˜ 4-7 × 106 M?. The non-detection of [O I] and the low L[C II]-to-LCO(1-0) line intensity ratio (˜1850) imply that the molecular gas phase is well traced by CO molecules in NGC 205. We estimate an atomic gas mass of 1.5 × 104 M? associated with the [C II] emitting photodissociation regions in NGC 205. From the partial CO (3-2) map of the northern region in NGC 205, we derive a molecular gas mass of ? M?. Upon comparison with the molecular gas mass estimated from CO (1-0) observations (? M?), we find most of the H2 gas in NGC 205 to be locked in diffuse regions of low density and/or temperature, characteristic for an interstellar medium with little star formation activity. New total gas mass estimates from Herschel dust continuum (4-7 × 106 M?), Herschel [C II] line spectroscopic mapping (1.5 × 104 M?) and James Clerk Maxwell Telescope CO (3-2) observations (7 × 105 M?), including the H I mass (? M?) and a correction for heavier elements, confirm the deficiency of the interstellar medium (gas+dust) in the inner regions of NGC 205, which is predicted to contain at least >107 M? of gas if we assume a reasonable star formation efficiency of 10 per cent and account for the mass return from planetary nebulae. In an attempt to explain the missing interstellar medium mass problem, we claim that efficient supernova feedback capable of expelling gas from the inner, star-forming regions to the outer regions and/or tidal interactions with M31 stripping the gas component from the galaxy provide the best explanation for the removal of a significant amount of gas and dust from NGC 205.

  11. Titan: Preliminary results on surface properties and photometry from VIMS observations of the early flybys

    USGS Publications Warehouse

    Buratti, B.J.; Sotin, C.; Brown, R.H.; Hicks, M.D.; Clark, R.N.; Mosher, J.A.; McCord, T.B.; Jaumann, R.; Baines, K.H.; Nicholson, P.D.; Momary, T.; Simonelli, D.P.; Sicardy, B.

    2006-01-01

    Cassini observations of the surface of Titan offer unprecedented views of its surface through atmospheric windows in the 1-5 ??m region. Images obtained in windows for which the haze opacity is low can be used to derive quantitative photometric parameters such as albedo and albedo distribution, and physical properties such as roughness and particle characteristics. Images from the early Titan flybys, particularly T0, Ta, and T5 have been analyzed to create albedo maps in the 2.01 and 2.73 ??m windows. We find the average normal reflectance at these two wavelengths to be 0.15??0.02 and 0.035??0.003, respectively. Titan's surface is bifurcated into two albedo regimes, particularly at 2.01 ??m. Analysis of these two regimes to understand the physical character of the surface was accomplished with a macroscopic roughness model. We find that the two types of surface have substantially different roughness, with the low-albedo surface exhibiting mean slope angles of ???18??, and the high-albedo terrain having a much more substantial roughness with a mean slope angle of ???34??. A single-scattering phase function approximated by a one-term Henyey-Greenstein equation was also fit to each unit. Titan's surface is back-scattering (g???0.3-0.4), and does not exhibit substantially different backscattering behavior between the two terrains. Our results suggest that two distinct geophysical domains exist on Titan: a bright region cut by deep drainage channels and a relatively smooth surface. The two terrains are covered by a film or a coating of particles perhaps precipitated from the satellite's haze layer and transported by eolian processes. Our results are preliminary: more accurate values for the surface albedo and physical parameters will be derived as more data is gathered by the Cassini spacecraft and as a more complete radiative transfer model is developed from both Cassini orbiter and Huygens Lander measurements. ?? 2006 Elsevier Ltd. All rights reserved.

  12. EarlyTime Observations of GRBs afterglow with 2m Robotic Telescopes

    E-print Network

    Gomboc, Andreja

    . In the era of rapid and accurate localisation of Gamma Ray Bursts by the Swift satellite, high quality early INTRODUCTION The advent of the Swift satellite [1] has contributed to shed light on the complex variety

  13. Early-Time Observations of GRBs afterglow with 2-m Robotic Telescopes

    SciTech Connect

    Melandri, A.; Mundell, C. G.; Steele, I. A.; Carter, D.; Kobayashi, S.; Bersier, D.; Bode, M. F.; Mottram, C. J.; Smith, R. J. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom); Gomboc, A. [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubiana (Slovenia); Guidorzi, C. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom); Physics Department University of Milano-Bicocca, Piazza delle Scienze 3, 20126 Milano (Italy); Monfardini, A. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead, CH41 1LD (United Kingdom); CNRS-CRTBT, Avenue des Martyrs 25, 38000 Grenoble (France)

    2007-08-21

    In the era of rapid and accurate localisation of Gamma Ray Bursts by the Swift satellite, high quality early time multi-wavelength light curves, obtained by space and ground-based robotic telescopes, have shown that the standard 'smooth temporal power law decays' typical of late-time afterglow emission can be substantially modified at early times by e.g. energy injection from long-lived central engines, and/or interactions between the ejecta and clumps in the surrounding circumburst medium. Well-sampled optical light curves (covering a wide range in time, brightness and redshift) together with early-time polarimetry provide a powerful probe of the physics of GRBs, their ejecta and their environments. Here we summarise the GRB followup programme being conducted on a network of the world's three largest robotic telescopes that aims to obtain early-time multicolour photometric and polarimetric measurements crucial for the understanding of GRB physics.

  14. Conflict Resolution and Children's Behaviour: Observing and Understanding Social and Cooperative Play in Early Years Educational Settings

    ERIC Educational Resources Information Center

    Broadhead, Pat

    2009-01-01

    This paper draws from continuing research into the growth of sociability and cooperation in young children. It began in the mid-1980s and has continued periodically in a range of early years educational settings across the 3-6 age range. The research has underpinned the development of an observational tool. This tool--the Social Play Continuum or…

  15. Simulated NASA Satellite Data Products for the NOAA Integrated Coral Reef Observation Network/Coral Reef Early Warning System

    NASA Technical Reports Server (NTRS)

    Estep, Leland; Spruce, Joseph P.

    2007-01-01

    This RPC (Rapid Prototyping Capability) experiment will demonstrate the use of VIIRS (Visible/Infrared Imager/Radiometer Suite) and LDCM (Landsat Data Continuity Mission) sensor data as significant input to the NOAA (National Oceanic and Atmospheric Administration) ICON/ CREWS (Integrated Coral Reef Observation System/Coral Reef Early Warning System). The project affects the Coastal Management Program Element of the Applied Sciences Program.

  16. Assessment of skeletal changes after post-mortem exposure to fire as an indicator of decomposition stage.

    PubMed

    Keough, N; L'Abbé, E N; Steyn, M; Pretorius, S

    2015-01-01

    Forensic anthropologists are tasked with interpreting the sequence of events from death to the discovery of a body. Burned bone often evokes questions as to the timing of burning events. The purpose of this study was to assess the progression of thermal damage on bones with advancement in decomposition. Twenty-five pigs in various stages of decomposition (fresh, early, advanced, early and late skeletonisation) were exposed to fire for 30 min. The scored heat-related features on bone included colour change (unaltered, charred, calcined), brown and heat borders, heat lines, delineation, greasy bone, joint shielding, predictable and minimal cracking, delamination and heat-induced fractures. Colour changes were scored according to a ranked percentage scale (0-3) and the remaining traits as absent or present (0/1). Kappa statistics was used to evaluate intra- and inter-observer error. Transition analysis was used to formulate probability mass functions [P(X=j|i)] to predict decomposition stage from the scored features of thermal destruction. Nine traits displayed potential to predict decomposition stage from burned remains. An increase in calcined and charred bone occurred synchronously with advancement of decomposition with subsequent decrease in unaltered surfaces. Greasy bone appeared more often in the early/fresh stages (fleshed bone). Heat borders, heat lines, delineation, joint shielding, predictable and minimal cracking are associated with advanced decomposition, when bone remains wet but lacks extensive soft tissue protection. Brown burn/borders, delamination and other heat-induced fractures are associated with early and late skeletonisation, showing that organic composition of bone and percentage of flesh present affect the manner in which it burns. No statistically significant difference was noted among observers for the majority of the traits, indicating that they can be scored reliably. Based on the data analysis, the pattern of heat-induced changes may assist in estimating decomposition stage from unknown, burned remains. PMID:25460103

  17. A Different View on the Checkerboard? Alterations in Early and Late Visually Evoked EEG Potentials in Asperger Observers

    PubMed Central

    Kornmeier, Juergen; Wörner, Rike; Riedel, Andreas; Bach, Michael; Tebartz van Elst, Ludger

    2014-01-01

    Background Asperger Autism is a lifelong psychiatric condition with highly circumscribed interests and routines, problems in social cognition, verbal and nonverbal communication, and also perceptual abnormalities with sensory hypersensitivity. To objectify both lower-level visual and cognitive alterations we looked for differences in visual event-related potentials (EEG) between Asperger observers and matched controls while they observed simple checkerboard stimuli. Methods In a balanced oddball paradigm checkerboards of two checksizes (0.6° and 1.2°) were presented with different frequencies. Participants counted the occurrence times of the rare fine or rare coarse checkerboards in different experimental conditions. We focused on early visual ERP differences as a function of checkerboard size and the classical P3b ERP component as an indicator of cognitive processing. Results We found an early (100–200 ms after stimulus onset) occipital ERP effect of checkerboard size (dominant spatial frequency). This effect was weaker in the Asperger than in the control observers. Further a typical parietal/central oddball-P3b occurred at 500 ms with the rare checkerboards. The P3b showed a right-hemispheric lateralization, which was more prominent in Asperger than in control observers. Discussion The difference in the early occipital ERP effect between the two groups may be a physiological marker of differences in the processing of small visual details in Asperger observers compared to normal controls. The stronger lateralization of the P3b in Asperger observers may indicate a stronger involvement of the right-hemispheric network of bottom-up attention. The lateralization of the P3b signal might be a compensatory consequence of the compromised early checksize effect. Higher-level analytical information processing units may need to compensate for difficulties in low-level signal analysis. PMID:24632708

  18. What's Appropriate about Developmentally Appropriate Practices? Observing Early Childhood Development Center Classroom Environments.

    ERIC Educational Resources Information Center

    Ricard, Richard J.; Brown, Angela; Sanders, Jana

    This chapter is part of a book that recounts the year's work at the Early Childhood Development Center (ECDC) at Texas A & M University-Corpus Christi. Rather than an "elitist" laboratory school for the children of university faculty, the dual-language ECDC is a collaboration between the Corpus Christi Independent School District and the…

  19. Early prenatal ontogeny of central monoamine neurons in the rat: Fluorescence histochemical observations

    Microsoft Academic Search

    Lars Olson; Åke Seiger

    1972-01-01

    The early ontogeny of the monoamine neuron systems in the rat brain has been analysed using Falck-Hillarp fluorescence histochemistry. Serial sagittal sections of embryos with a crown rump length between 7 and 13 mm, approximately corresponding to gestational days 12 to 15 were obtained from mothers treated with a monoamine oxidase inhibitor given in order to increase the monoamine levels

  20. Gestalt experiments and inductive observations Konrad Lorenz's early epistemological writings and the methods of classical ethology

    Microsoft Academic Search

    Ingo Brigandt

    During the 1940s Konrad Lorenz formulated his early epistemological views, focusing on the cognitive mechanisms induction and Gestalt perception. After the war he used this philosophical framework to defend the approach of classical ethology against other approaches to animal behavior. The present paper examines the relationship between Lorenz's ethological methodology and his philosophy of science and knowledge. The main aim

  1. Checklist of Coping Skills: An Early Childhood Special Education Observation Schedule.

    ERIC Educational Resources Information Center

    Becker, Ruth W.

    Presented is a checklist developed by the Austin Early Childhood Special Education Program to help teachers evaluate children's classroom behavior and coping skills. It is explained that results of the checklist should provide information on such factors as possible underlying problems experienced by a student, situations in which a student…

  2. An Observational Study on Early Empiric versus Culture-Directed Antifungal Therapy in Critically Ill with Intra-Abdominal Sepsis

    PubMed Central

    Lee, Winnie; Liew, Yixin; Chlebicki, Maciej Piotr; Ong, Sharon; Lee, Pang; Kwa, Andrea

    2014-01-01

    Objective. To compare early empiric antifungal treatment with culture-directed treatment in critically ill patients with intra-abdominal sepsis. Methods. A prospective observational cohort study was conducted between August 2010 and July 2011, on SICU patients admitted after surgery for gastrointestinal perforation, bowel obstruction or ischemia, malignancy and anastomotic leakages. Patients who received antifungal treatment within two days of sepsis onset were compared to patients who received culture-directed antifungal treatment in terms of mortality rate and clinical improvement. Patients' demographics, comorbidities, severity-of-illness scores, and laboratory results were systematically collected and analysed. Results. Thirty-three patients received early empiric and 19 received culture-directed therapy. Of these, 30 from the early empiric group and 18 from culture-directed group were evaluable and analysed. Both groups had similar baseline characteristics and illness severity. Patients on empiric antifungal use had significantly lower 30-day mortality (P = 0.03) as well as shorter median time to clinical improvement (P = 0.025). Early empiric antifungal therapy was independently associated with survival beyond 30 days (OR 0.131, 95% CI: 0.018 to 0.966; P = 0.046). Conclusion. Early empiric antifungal therapy in surgical patients with intra-abdominal sepsis was associated with reduced mortality and warrants further evaluation in randomised controlled trials. PMID:24959349

  3. Monitoring Classroom Behavior in Early Childhood: Using Group Observation Data to Make Decisions

    Microsoft Academic Search

    Delilah Krasch; Deborah Russell Carter

    2009-01-01

    Monitoring and evaluating classroom behavior in early childhood for the purpose of improving teaching and learning is critical.\\u000a There is a clear link between social behavior and academic learning. Classrooms where students are following expectations,\\u000a engaging academically, and transitioning effectively between activities are classrooms where students spend more time accessing\\u000a instruction. In order to make efficient and effective decisions for

  4. Use of 13C NMR and ftir for elucidation of degradation pathways during natural litter decomposition and composting I. early stage leaf degradation

    USGS Publications Warehouse

    Wershaw, R.L.; Leenheer, J.A.; Kennedy, K.R.; Noyes, T.I.

    1996-01-01

    Oxidative degradation of plant tissue leads to the formation of natural dissolved organic carbon (DOC) and humus. Infrared (IR) and 13C nuclear magnetic resonance (NMR) spectrometry have been used to elucidate the chemical reactions of the early stages of degradation that give rise to DOC derived from litter and compost. The results of this study indicate that oxidation of the lignin components of plant tissue follows the sequence of O-demethylation, and hydroxylation followed by ring-fission, chain-shortening, and oxidative removal of substituents. Oxidative ring-fission leads to the formation of carboxylic acid groups on the cleaved ends of the rings and, in the process, transforms phenolic groups into aliphatic alcoholic groups. The carbohydrate components are broken down into aliphatic hydroxy acids and aliphatic alcohols.

  5. Early retinopathy in the Bernese Mountain Dog in France: preliminary observations.

    PubMed

    Chaudieu, G; Molon-Noblot, S

    2004-01-01

    The objective of the study was to describe a form of early retinopathy in the Bernese Mountain Dog in France. Sixty-two Bernese Mountain Dogs (38 males and 24 females), whose ages ranged from 2 months to 9 years, were examined over a period of 3 years. Visual behavior, pupillary light reflexes, menace responses and ocular fundi were evaluated in all animals. Electroretinography (ERG) was performed on six of the affected dogs after dark adaptation. Fluorescein angiography (FA) was performed on one affected dog. Whenever possible, the pedigrees of the affected dogs were evaluated. A histological examination of the retina was performed on one of the affected dogs. Eight dogs (seven males and one female) were diagnosed with retinopathy with an early onset of clinical signs. (Four dogs were aged between 3 months and 1 year, two dogs were aged 2 and 3.5 years, and one dog was 7 years old.) Night vision was impaired in most of the dogs. Retinopathy was characterized ophthalmoscopically by a bilateral, symmetrical horizontal zone of tapetal hyper-reflectivity adjacent to and above the optic disc, and sometimes by peri-papillary hyper-reflectivity. ERG changes included a reduction in b-wave amplitude varying from one case to another. Fluoroscein angiography demonstrated an ischemic-type alteration with epitheliopathy opposite the hyper-reflective zone. Pedigree examinations suggested a familial predisposition. The histological examination indicated photoreceptor degeneration that was more pronounced in the central tapetal zone. In France, retinopathy in the Bernese Mountain Dog involves an early retinal degeneration that produces specific manifestations of the ocular fundus, night visual impairment or blindness, and has familial transmission. PMID:15091325

  6. Using Videoconferencing Technology to Enhance Classroom Observation Methodology for the Instruction of Preservice Early Childhood Professionals

    ERIC Educational Resources Information Center

    Pickering, Lloyd E.; Walsh, Eamonn Joseph

    2011-01-01

    To learn about and become acclimated to the environment in which they someday plan to work, preservice teachers and pre-professional daycare providers are typically required to conduct onsite observations. Traditionally, these observations require that the pre-professional spend a required number of hours studying the dynamics of the real-world…

  7. Early lidar observations of the June 1991 Pinatubo eruption plume at Mauna Loa Observatory, Hawaii

    Microsoft Academic Search

    Thomas E. Defoor; Elmer Robinson; Steven Ryan

    1992-01-01

    The Pinatubo plume was first observed by lidar on 1 July 1991. During July and August the observable effects from this plume increased in intensity in terms of aerosol optical properties, plume height, and broad-band solar radiation. Preliminary data analysis shows that the plume over Hawaii arrived in three generalized pulses or waves on approximately 3 July, 24 July, and

  8. UIT Observations of Early-Type Galaxies and Analysis of the FUSE Spectrum of a Subdwarf B Star

    NASA Technical Reports Server (NTRS)

    Ohl, Raymond G.; Krebs, Carolyn (Technical Monitor)

    2001-01-01

    This work covers Ultraviolet Imaging Telescope (UIT) observations of early-type galaxies (155 nm) and Far Ultraviolet Spectroscopic Explorer (FUSE) spectra of a Galactic subdwarf B star (sdB). Early UV space astronomy missions revealed that early-type galaxies harbor a population of stars with effective temperatures greater than that of the main sequence turn-off (about 6,000 K) and UV emission that is very sensitive to characteristics of the stellar population. We present UV (155 nm) surface photometry and UV-B color profiles for 8 E and SO galaxies observed by UIT. Some objects have de Vaucouleurs surface brightness profiles, while others have disk-like profiles, but we find no other evidence for the presence of a disk or young, massive stars. There is a wide range of UV-B color gradients, but there is no correlation with metallicity gradients. SdB stars are the leading candidate UV emitters in old, high metallicity stellar populations (e.g., early-type galaxies). We observed the Galactic sdB star PG0749+658 with FUSE and derived abundances with the aim of constraining models of the heavy element distribution in sdB atmospheres. All of the elements measured are depleted with respect to solar, except for Cr and Mn, which are about solar, and Ni, which is enhanced. This work was supported in part by NASA grants NAG5-700 and NAG5-6403 to the University of Virginia and NAS5-32985 to Johns Hopkins University.

  9. Assessing the remote sensing derived Evaporative Stress Index with ground observations of crop condition to advance drought early warning

    NASA Astrophysics Data System (ADS)

    Semmens, K. A.; Anderson, M. C.; Mladenova, I. E.; Hain, C.; Otkin, J.; Guindin, N.

    2013-12-01

    Drought has significant impacts over broad spatial and temporal scales, and information about the timing and extent of such conditions is of critical importance to many end users in the agricultural and water resource management communities. The ability to accurately monitor effects on crops, and provide early warning of developing vegetation stress, will provide valuable information for mitigating negative impacts of drought. This research assesses the potential of the thermal remote sensing based Evaporative Stress Index (ESI) as a relatively early indication of declining crop condition using county level crop condition (CC) and soil moisture (SM) weekly reports from the USDA National Agricultural Statistics Service (NASS) collected by trained observers on the ground in crop growing counties in the contiguous United States (CONUS). Spatial and temporal correlations between these datasets will be explored over a variety of temporal and spatial scales, as well as for different crop types and phenologic stages. Preliminary analysis shows that monthly ESI agrees well with the ground observations, suggesting the ESI as a valuable, spatially continuous dataset for improving drought modeling efforts. In addition, stress-induced changes in ESI are hypothesized to precede declines in crop cover fraction, typically observed using optical vegetation indices such as the Normalized Difference Vegetation Index. Increases in canopy and soil temperatures (detectable via thermal remote sensing) are hypothesized to occur before crop biomass is visibly affected by soil moisture depletion. Spatiotemporal agreement between NASS CC and SM observations, gridded over CONUS, will be assessed in comparison with ESI data fields and other standard drought indictors to identify optimal indices for early detection of degrading crop conditions. Analysis over the time period 2002-2013 will allow the relationships to be assessed in a variety of climatological conditions (i.e. wet and dry years, etc.). This research, by comparing both remote sensing and ground observations, provides a unique and valuable perspective of evapotranspiration and drought estimation with implications for modeling and operational decision making.

  10. Early-infantile galactosialidosis: Clinical, biochemical, and molecular observations in a new patient

    SciTech Connect

    Zammarchi, E.; Donati, M.A.; Morrone, A. [Univ. of Florence (Italy)] [and others] [Univ. of Florence (Italy); and others

    1996-08-23

    Few patients with the early-infantile form of galactosialidosis have been described to date. Presented here is the first Italian case. Fetal hydrops was detected by ultrasound at week 24 of gestation. At birth, the infant presented with hypotonial, massive edema, a flattened coarse facies. telangiectasias, and hepatosplenomegaly, but no dysostosis multiplex. The patient died 72 days postpartum. Excessive sialyloligosaccharides in urine, as well as vacuolation of lymphocytes and eosinophilic granulocytes in peripheral blood, were indicative of a lysosomal storage disease. In the patient`s fibroblasts, both {alpha}-neuraminidase and {beta}-galactosidase activities were severely reduced, and cathepsin A activity was <1% of control levels, confirming the biochemical diagnosis of galactosialidosis. However, in contrast to previously reported early-infantile cases, a normal amount of protective protein/cathepsin A mRNA was detected on Northern blots. This mutant transcript was translated into a precursor protein that was not processed into the mature enzyme and lacked both protective and catalytic activities. 28 refs., 4 figs., 1 tab.

  11. Spinodal Decomposition Mechanism of ?' Precipitation in a Single Crystal Ni-Based Superalloy

    NASA Astrophysics Data System (ADS)

    Tan, X. P.; Mangelinck, D.; Perrin-Pellegrino, C.; Rougier, L.; Gandin, Ch.-A.; Jacot, A.; Ponsen, D.; Jaquet, V.

    2014-10-01

    The precipitation of ?' phase in a commercial single crystal Ni-based superalloy with different cooling rates has been investigated by atom probe tomography. Numerous irregular interconnected ?' precipitates in the size range of ~30 to 50 nm were obtained even utilizing the fastest possible cooling rate. Diffuse ?/?' interface and far from equilibrium composition of ?' phase were observed in the fast-cooled sample, suggesting that ?' precipitation occurs via a spinodal decomposition at the very early stage.

  12. Risk of Trastuzumab-Related Cardiotoxicity in Early Breast Cancer Patients: A Prospective Observational Study

    PubMed Central

    Xue, Jian; Jiang, Zefei; Qi, Fan; Lv, Shuanghong; Zhang, Shaohua; Wang, Tao

    2014-01-01

    Purpose In the present study, we investigated the incidence of cardiotoxicity within 5 years of trastuzumab treatment and evaluated potential risk factors in clinical practice. Methods The study cohort included 415 patients diagnosed with early breast cancer (EBC). Cardiotoxicity incidence was evaluated in patients receiving trastuzumab and those who did not. Multivariate Cox proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals of potential risk factors for trastuzumab-related cardiotoxicity after appropriate adjustments. Results Incidence of cardiotoxicity in patients treated with trastuzumab was significantly higher than that in controls (23.7% vs. 10.8%, p<0.001). This result was adjusted for factors that might increase the risk of cardiotoxicity, such as history of coronary artery diseases or the use of anthracyclines for more than four cycles. Conclusion Our findings indicated that treatment with trastuzumab was strongly associated with cardiotoxicity in EBC patients. PMID:25548585

  13. In Situ Observations of the Early Stages of Localized Corrosion in Type 304 SS Using the Electrochemical Atomic Force Microscope

    SciTech Connect

    Williford, Ralph E.; Windisch, Charles F.; Jones, Russell H.

    2000-08-31

    In situ, time-lapse images of the early stages of pitting in dilute NaCl solutions, and intergranular corrosion in dilute oxalic acid solutions, have been obtained in Type 304 SS (UNS S30400) using an Electrochemical Atomic Force Microscope (ECAFM). A pit was observed to grow from an irregular shape with ledges along the pit walls, to a round pit with an island formation, over a 6-min time span. Grain boundary chromium carbides were exposed, and then partially dissolved, over a 26-min time span. The intergranular corrosion was most prominent along the grain boundary between the carbides, rather than between the carbides and the matrix, leaving the carbides intact via ligaments of matrix material. This study demonstrated the usefulness and complexities in using the ECAFM for studying the early stages in pitting and intergranular corrosion.

  14. Ultra-Fast Flash Observatory (uffo) for Observation of Early Photons from Gamma Ray Bursts

    NASA Astrophysics Data System (ADS)

    Park, I. H.; Ahmad, S.; Barrillon, P.; Brandt, S.; Budtz-Jorgensen, C.; Castro-Tirado, A. J.; Chen, P.; Choi, Y. J.; Connell, P.; Dagoret-Campagne, S.; Eyles, C.; Grossan, B.; Huang, M.-H. A.; Jung, A.; Jeong, S.; Kim, J. E.; Kim, M. B.; Kim, S.-W.; Kim, Y. W.; Krasnov, A. S.; Lee1, J.; Lim, H.; Linder, E. V.; Liu, T.-C.; Lund, N.; Min, K. W.; Na, G. W.; Nam, J. W.; Panasyuk, M. I.; Ripa, J.; Reglero, V.; Rodrigo, J. M.; Smoot, G. F.; Suh, J. E.; Svertilov, S.; Vedenkin, N.; Wang, M.-Z.; Yashin, I.

    2013-12-01

    One of the least documented and understood aspects of gamma-ray bursts (GRB) is the rise phase of the optical light curve. The Ultra-Fast Flash Observatory (UFFO) is an effort to address this question through extraordinary opportunities presented by a series of space missions including a small spacecraft observatory. The UFFO is equipped with a fast-response Slewing Mirror Telescope (SMT) which uses rapidly moving mirror or mirror arrays to redirect the optical beam rather than slewing the entire spacecraft to aim the optical instrument at the GRB position. The UFFO will probe the early optical rise of GRBs with a sub-second response, for the first time, opening a completely new frontier in GRB and transient studies, the only GRB system which can point and measure on these time scales. Its fast response measurements of the optical emission of dozens of GRB each year will provide unique probes of the burst mechanism, shock breakouts in core-collapse supernovae, tidal disruptions around black holes, test Lorentz violation, be the electromagnetic counterpart to neutrino and gravitational wave signatures of the violent universe, and verify the prospect of GRB as a new standard candle potentially opening up the z>10 universe. As a first step, we employ a motorized slewing stage in SMT which can point to the event within 1s after X-ray trigger, in the UFFO-pathfinder payload onboard the Lomonosov satellite to be launched in 2012. The pathfinder was a small and limited, yet remarkably powerful micro-observatory for rapid optical response to bright gamma-ray bursts, the first part of our GRB and rapid-response long-term program. We describe the early photon science, the space mission of UFFO-pathfinder, and our plan for the next step.

  15. Mid-Infrared Observational and Theoretical Studies of Star Formation and Early Solar Systems

    NASA Technical Reports Server (NTRS)

    Jones, Barbara

    1997-01-01

    The first 2 years of this program were used to make mid-IR observations of regions of star formation in the Orion nebula with the UCSD mid-IR camera at the UCSD/University of Minnesota telescope at Mt. Lemmon. These observations attempted to make the first systematic study of an extended region, known to have newly forming stars, and expected to have complex mid-IR emission. We discovered, to our surprise, that most of the thermal emission originated from extended sources rather than from point sources. This interesting observation made the analysis of the data much more complex, since the chop/nod procedures used at these wavelengths produce a differential measurement of the emission in one region compared to that in the adjacent region. Disentangling complex extended emission in such a situation is very difficult. In parallel with this work we were also observing comets in the thermal infrared, the other component of the original proposal. Some spectacular data on the comet Swift-Tuttle was acquired and published. A changing jet structure observed over a 2 week period is described. The rotation period of the comet can be measured at 66 hours. The size of the nucleus can also be estimated (at 30 km) from the observed excess flux from the nucleus. These data have lead to the development of models describing the action of dust particles of differing sizes and composition leaving the nucleus. The spatial distribution of the predicted IR emission has been compared to the observed jet structures, leading to estimates of both particles sizes, relative amounts of silicate vs organic grains, and the amounts of dust emitted in the jets vs isotopic emission.

  16. Time dependence of ethylene decomposition and byproducts formation in a continuous flow dielectric-packed plasma reactor.

    PubMed

    Gandhi, M Sanjeeva; Ananth, Antony; Mok, Young Sun; Song, Jun-Ik; Park, Kyu-Hyun

    2013-04-01

    This work investigated the decomposition of ethylene in a continuous flow dielectric-packed bed plasma reactor filled with various packing materials at atmospheric pressure and room temperature. When compared to the case without any packing material, the reactor filled with packing materials remarkably facilitated the plasma-induced decomposition of ethylene in the order of ?-alumina>silica>zirconia>glass wool (GW). Under identical condition, the increase in the decomposition efficiency (DE) with increasing the specific energy input was more rapid in the plasma reactor filled with the packing materials than in the blank plasma reactor. In the early stage, almost complete decomposition of ethylene was observed with the ?-alumina, but after a certain period of time, the DE decreased with time. Unlike the ?-alumina, the other packing materials examined did not show any significant deterioration in the decomposition over time during 10-h operation. After the regeneration of the used packing materials by using the plasma in the presence of oxygen, the original decomposition performance was nearly recovered. The decrease in the BET surface area due to the formation of polymer deposits was observed in the used ?-alumina and silica; however the surface area was almost regained by the regeneration. While no other byproducts except carbon oxides and N2O were detected with the ?-alumina and silica, methane, acetylene, formaldehyde and N2O were identified in the effluent gas with the zirconia and GW packing materials. PMID:23415991

  17. The Early Development of Object Knowledge: A Study of Infants' Visual Anticipations during Action Observation

    ERIC Educational Resources Information Center

    Hunnius, Sabine; Bekkering, Harold

    2010-01-01

    This study examined the developing object knowledge of infants through their visual anticipation of action targets during action observation. Infants (6, 8, 12, 14, and 16 months) and adults watched short movies of a person using 3 different everyday objects. Participants were presented with objects being brought either to a correct or to an…

  18. Intra- and inter-observer analysis in the morphological assessment of early-stage embryos

    Microsoft Academic Search

    Goedele Paternot; Johanna Devroe; Sophie Debrock; Thomas M D'Hooghe; Carl Spiessens

    2009-01-01

    BACKGROUND: The aim of this study was to determine the intra- and inter-observer variability in the evaluation of embryo quality. Multilevel images of embryos on day 1, day 2 and day 3, were analysed using different morphological parameters. METHODS: Multilevel images of embryos on day 1, day 2 and day 3, were analysed using a standard scoring system. The kappa

  19. Assessing the Observability of Hypernovae and Pair-Instability Supernovae in the Early Universe

    E-print Network

    Wiggins, Brandon K; Whalen, Daniel J; Even, Wesley P; Migenes, Victor; Fryer, Chris L

    2015-01-01

    The era of the universe's first (Population III) stars is essentially unconstrained by observation. Ultra-luminous and massive stars from this time altered the chemistry of the cosmos, provided the radiative scaffolding to support the formation of the first protogalaxies, and facilitated the creation and growth of now-supermassive black holes. Unfortunately, because these stars lie literally at the edge of the observable universe, they will remain beyond the reach of even the next generation of telescopes such as the James Webb Space Telescope and the Thirty-Meter Telescope. In this paper, we provide a primer to supernovae modeling and the first stars to make our discussion accessible to those new to or outside our field. We review recent work of the Los Alamos Supernova Light Curve Project and Brigham Young University to explore the possibility of probing this era through observations of the spectacular deaths of the first stars. We find that many such brilliant supernova explosions will be observable as far...

  20. Basin-scale, integrated observations of the early 21st century multiyear drought in southeast Australia

    NASA Astrophysics Data System (ADS)

    Leblanc, Marc J.; Tregoning, Paul; Ramillien, Guillaume; Tweed, Sarah O.; Fakes, Adam

    2009-04-01

    The Murray-Darling Basin in southeast Australia is experiencing one of the most severe droughts observed recently in the world, driven by several years of rainfall deficits and record high temperatures. This paper provides new basin-scale observations of the multiyear drought, integrated to a degree rarely achieved on such a large scale, to assess the response of water resources and the severity of the drought. A combination of Gravity Recovery and Climate Experiment (GRACE) data with in situ and modeled hydrological data shows the propagation of the water deficit through the hydrological cycle and the rise of different types of drought. Our observations show the rapid drying of soil moisture and surface water storages, which reached near-stationary low levels only ˜2 years after the onset of the drought in 2001, with a loss of ˜80 and ˜12 km3 between January 2001 and January 2003, respectively. The multiyear drought has led to the almost complete drying of surface water resources which account for most of the water used for irrigation and domestic purposes. High correlation between observed groundwater variations and GRACE data substantiates the persistent reduction in groundwater storage, with groundwater levels still declining 6 years after the onset of the drought (groundwater loss of ˜104 km3 between 2001 and 2007). The hydrological drought continues even though the region returned to average annual rainfall during 2007.

  1. Swift/XRT early time observations of SGR 1935+2154

    NASA Astrophysics Data System (ADS)

    D'Avanzo, P.; Campana, S.; Zelati, F. Coti; Palmer, D. M.

    2015-02-01

    We report on Swift/XRT observations of the 2015 Feb 22 outburst of SGR 1935+2154 (D'Avanzo et al., ATel #7123). We have analysed 15.3 ks of XRT data in Photon Counting (PC) mode from 93 s to 100.0 ks after the first BAT trigger reported in D'Avanzo et al.

  2. Childhood Maltreatment and Prospectively Observed Quality of Early Care as Predictors of Antisocial Personality Disorder Features.

    PubMed

    Shi, Zhenyu; Bureau, Jean-Francois; Easterbrooks, M Ann; Zhao, Xudong; Lyons-Ruth, Karlen

    2012-01-01

    Few studies have evaluated the separate contributions of maltreatment and ongoing quality of parent-child interaction to the etiology of antisocial personality features using a prospective longitudinal design. 120 low-income young adults (aged 18-23) were assessed for extent of ASPD features on the Structured Clinical Interview for Diagnosis-Axis II, for presence of maltreatment on the Conflict Tactics Scale, Traumatic Experiences Scale, and Adult Attachment Interview, and for referral in infancy to parent-infant clinical services. Fifty-six of these families had been studied longitudinally since the first year of life. In infancy, attachment disorganization and disrupted mother-infant interaction were assessed; in middle childhood, disorganized-controlling attachment behaviors were reliably rated. In kindergarten and second grade, behavior problems were assessed by teacher report. In cross-sectional analyses, maltreatment was significantly associated with ASPD features but did not account for the independent effect of early referral to parent-infant services on ASPD features. In longitudinal analyses, maternal withdrawal in infancy predicted the extent of ASPD features twenty years later, independently of childhood abuse. In middle childhood, disorganized attachment behavior and maladaptive behavior at school added to prediction of later ASPD features. Antisocial features in young adulthood have precursors in the minute-to-minute process of parent-child interaction beginning in infancy. PMID:22754051

  3. In situ observations of nanoparticle early development kinetics at mineral-water interfaces.

    SciTech Connect

    Jun, Y. S.; Lee, B.; Waychunas, G. A. (X-Ray Science Division); (Washington Univ.); (LBNL)

    2010-10-08

    The early development of nanoparticles at mineral?water interfaces exerts crucial influences on the sequestration and transport of aqueous toxic species originating from both natural and anthropogenic sources. Homogeneous and heterogeneous nucleation often occur simultaneously, making it difficult to sort out whether toxic species are transported as free species, sorbed on nanoparticle surfaces, or trapped between aggregated nanoparticles. Here, using a newly developed X-ray scattering setup, we show how homogeneous nucleation and growth can be quantitatively separated from heterogeneous processes under aqueous conditions in real-time. Under conditions found in acid-mine-drainage (at pH 3.6 and [Fe{sup 3+}] = 10{sup -4} M), heterogeneous nucleation of iron oxide nanoparticles on quartz dominated homogeneous nucleation by a factor of 192 (by particle volume). The smallest heterogeneously formed nanoparticles had radii of 1.7 {+-} 0.5 nm, significantly smaller than the size estimated using classical nucleation theory (CNT). Based on the data, the dominant nucleation and growth mechanisms of iron oxide nanoparticles depending on ionic strength were presented. Our findings have implications for the formation and transport of nanoparticles, and thus toxins, in both environmental and biological systems.

  4. White Noise from Dark Matter: 21 cm Observations of Early Baryon Collapse

    E-print Network

    Kathryn M. Zurek; Craig J. Hogan

    2007-03-26

    In concordance cosmology, dark matter density perturbations generated by inflation lead to nonlinear, virialized minihalos, into which baryons collapse at redshift $z \\sim 20$. We survey here novel baryon evolution produced by a modification of the power spectrum from white noise density perturbations at scales below $k \\sim 10 h {Mpc}^{-1}$ (the smallest scales currently measured with the Lyman-$\\alpha$ forest). Exotic dark matter dynamics, such as would arise from scalar dark matter with a late phase transition (similar to an axion, but with lower mass), create such an amplification of small scale power. The dark matter produced in such a phase transition collapses into minihalos, with a size given by the dark matter mass within the horizon at the phase transition. If the mass of the initial minihalos is larger than $\\sim 10^{-3} M_\\odot$, the modified power spectrum is found to cause widespread baryon collapse earlier than standard $\\Lambda$CDM, leading to earlier gas heating. It also results in higher spin temperature of the baryons in the 21 cm line relative to $\\Lambda$CDM at redshifts $z > 20$ if the mass of the minihalo is larger than $1 M_\\odot$. It is estimated that experiments probing 21 cm radiation at high redshift will contribute a significant constraint on dark matter models of this type for initial minihalos larger than $\\sim 10 M_\\odot$. Early experiments reaching to $z\\approx 15$ will constrain minihalos down to $\\sim 10^3 M_\\odot$.

  5. Integrating observation and statistical forecasts over sub-Saharan Africa to support Famine Early Warning

    USGS Publications Warehouse

    Funk, C.; Verdin, J.P.; Husak, G.

    2007-01-01

    Famine early warning in Africa presents unique challenges and rewards. Hydrologic extremes must be tracked and anticipated over complex and changing climate regimes. The successful anticipation and interpretation of hydrologic shocks can initiate effective government response, saving lives and softening the impacts of droughts and floods. While both monitoring and forecast technologies continue to advance, discontinuities between monitoring and forecast systems inhibit effective decision making. Monitoring systems typically rely on high resolution satellite remote-sensed normalized difference vegetation index (NDVI) and rainfall imagery. Forecast systems provide information on a variety of scales and formats. Non-meteorologists are often unable or unwilling to connect the dots between these disparate sources of information. To mitigate these problem researchers at UCSB's Climate Hazard Group, NASA GIMMS and USGS/EROS are implementing a NASA-funded integrated decision support system that combines the monitoring of precipitation and NDVI with statistical one-to-three month forecasts. We present the monitoring/forecast system, assess its accuracy, and demonstrate its application in food insecure sub-Saharan Africa.

  6. Erbium hydride decomposition kinetics.

    SciTech Connect

    Ferrizz, Robert Matthew

    2006-11-01

    Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

  7. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C454.3

    SciTech Connect

    Abdo, A

    2009-05-07

    This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7-October 6, indicate strong, highly variable {gamma}-ray emission with an average flux of {approx} 3 x 10{sup -6} photons cm{sup -2} s{sup -1}, for energies > 100 MeV. The {gamma}-ray flux is variable, with strong, distinct, symmetrically-shaped flares for which the flux increases by a factor of several on a time scale of about three days. This variability indicates a compact emission region, and the requirement that the source is optically thin to pair-production implies relativistic beaming with Doppler factor {delta} > 8, consistent with the values inferred from VLBI observations of superluminal expansion ({delta} {approx} 25). The observed {gamma}-ray spectrum is not consistent with a simple power-law, but instead steepens strongly above {approx} 2 GeV, and is well described by a broken power-law with photon indices of {approx} 2.3 and {approx} 3.5 below and above the break, respectively. This is the first direct observation of a break in the spectrum of a high luminosity blazar above 100 MeV, and it is likely direct evidence for an intrinsic break in the energy distribution of the radiating particles. Alternatively, the spectral softening above 2GeV could be due to -ray absorption via photonphoton pair production on the soft X-ray photon field of the host AGN, but such an interpretation would require the dissipation region to be located very close ({approx}< 100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

  8. Observing Preschoolers’ Social-Emotional Behavior: Structure, Foundations, and Prediction of Early School Success

    Microsoft Academic Search

    Susanne A. Denham; Hideko Hamada Bassett; Sara K. Thayer; Melissa S. Mincic; Yana S. Sirotkin; Katherine Zinsser

    2012-01-01

    Social-emotional behavior of 352 3- and 4-year-olds attending private childcare and Head Start programs was observed using the Minnesota Preschool Affect Checklist, Revised (MPAC-R). Goals of the investigation included (a) using MPAC-R data to extract a shortened version, MPAC-R\\/S, comparing structure, internal consistency, test–retest reliability, and stability of both versions; and, using the shortened measure, to examine (b) age, gender,

  9. Early Fermi Gamma-ray Space Telescope Observations of the Quasar 3C 454.3

    Microsoft Academic Search

    A. A. Abdo; M. Ackermann; M. Ajello; W. B. Atwood; M. Axelsson; L. Baldini; J. Ballet; G. Barbiellini; D. Bastieri; M. Battelino; B. M. Baughman; K. Bechtol; R. Bellazzini; B. Berenji; R. D. Blandford; E. D. Bloom; E. Bonamente; A. W. Borgland; A. Bouvier; J. Bregeon; A. Brez; M. Brigida; P. Bruel; T. H. Burnett; G. A. Caliandro; R. A. Cameron; P. A. Caraveo; J. M. Casandjian; E. Cavazzuti; C. Cecchi; E. Charles; S. Chaty; A. Chekhtman; C. C. Cheung; J. Chiang; S. Ciprini; R. Claus; J. Cohen-Tanugi; L. R. Cominsky; J. Conrad; L. Costamante; S. Cutini; C. D. Dermer; A. de Angelis; F. de Palma; S. W. Digel; E. do Couto e. Silva; D. Donato; P. S. Drell; R. Dubois; D. Dumora; C. Farnier; C. Favuzzi; W. B. Focke; L. Foschini; M. Frailis; L. Fuhrmann; Y. Fukazawa; S. Funk; P. Fusco; F. Gargano; D. Gasparrini; N. Gehrels; S. Germani; B. Giebels; N. Giglietto; P. Giommi; F. Giordano; T. Glanzman; G. Godfrey; I. A. Grenier; M.-H. Grondin; J. E. Grove; L. Guillemot; S. Guiriec; Y. Hanabata; A. K. Harding; R. C. Hartman; M. Hayashida; E. Hays; R. E. Hughes; G. Jóhannesson; A. S. Johnson; R. P. Johnson; W. N. Johnson; T. Kamae; H. Katagiri; J. Kataoka; N. Kawai; M. Kerr; J. Knödlseder; M. L. Kocian; F. Kuehn; M. Kuss; L. Latronico; S.-H. Lee; M. Lemoine-Goumard; F. Longo; F. Loparco; B. Lott; M. N. Lovellette; P. Lubrano; G. M. Madejski; A. Makeev; E. Massaro; M. N. Mazziotta; J. E. McEnery; S. McGlynn; C. Meurer; P. F. Michelson; W. Mitthumsiri; T. Mizuno; A. A. Moiseev; C. Monte; M. E. Monzani; A. Morselli; I. V. Moskalenko; S. Murgia; P. L. Nolan; J. P. Norris; E. Nuss; T. Ohsugi; N. Omodei; E. Orlando; J. F. Ormes; D. Paneque; J. H. Panetta; D. Parent; V. Pelassa; M. Pepe; M. Pesce-Rollins; F. Piron; T. A. Porter; S. Rainò; R. Rando; M. Razzano; A. Reimer; O. Reimer; T. Reposeur; L. C. Reyes; S. Ritz; L. S. Rochester; A. Y. Rodriguez; F. Rahoui; F. Ryde; H. F.-W. Sadrozinski; R. Sambruna; D. Sanchez; A. Sander; P. M. Saz Parkinson; C. Sgrò; M. S. Shaw; D. A. Smith; P. D. Smith; G. Spandre; P. Spinelli; J.-L. Starck; M. S. Strickman; D. J. Suson; H. Tajima; H. Takahashi; T. Takahashi; T. Tanaka; J. B. Thayer; J. G. Thayer; D. J. Thompson; L. Tibaldo; D. F. Torres; G. Tosti; A. Tramacere; Y. Uchiyama; T. L. Usher; N. Vilchez; M. Villata; V. Vitale; A. P. Waite; B. L. Winer; K. S. Wood; T. Ylinen; J. A. Zensus; M. Ziegler

    2009-01-01

    This is the first report of Fermi Gamma-Ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope, covering 2008 July 7-October 6, indicate strong, highly variable gamma-ray emission with an average flux of ~3 × 10-6 photons cm-2 s-1, for energies >100 MeV. The gamma-ray

  10. Observations of Photospheric Vortical Motions During the Early Stage of Filament Eruption

    NASA Astrophysics Data System (ADS)

    Dhara, Sajal Kumar; Ravindra, B.; Banyal, Ravinder Kumar

    2014-12-01

    Solar filaments/prominences exhibit rotational motion during different phases of their evolution from their formation to eruption. We have observed the rotational/vortical motion in the photosphere near the ends of ten filaments during their initial phase of eruption, at the onset of the fast rise phase. All the filaments were associated with active regions. The photospheric vortical motions we observed lasted for 4 - 20 minutes. In the vicinity of the conjugate ends of the filament the direction of rotation was opposite, except for two cases, where rotational motion was observed at only one end point. The sudden onset of a large photospheric vortex motion could have played a role in destabilizing the filament by transporting axial flux into the activated filament thereby increasing the outward magnetic pressure in it. The outward magnetic pressure may have pushed the filament/flux rope to the height where the torus instability criterion was satisfied, and hence it could have caused the filament instability and eruption.

  11. Early Additional Immune-Modulators for Mycoplasma pneumoniae Pneumonia in Children: An Observation Study

    PubMed Central

    Lee, Sung-Churl; Rhim, Jung-Woo; Shin, Myung-Seok; Kang, Jin-Han

    2014-01-01

    Background Mycoplasma pneumoniae (MP) pneumonia is a self-limiting disease, but some patients complain of progressive pneumonia, despite of appropriate antibiotic treatment. We aimed to introduce the role of immune-modulators (corticosteroid and/or intravenous immunoglobulin, IVIG) treatment for childhood MP pneumonia based on previous our experiences. Materials and Methods A retrospective case series analysis for 183 children with MP pneumonia was performed. MP pneumonia patients were diagnosed by two Immunoglobulin M (IgM) tests: the micro-particle agglutination method (?1:40) and the cold agglutination test (?1:4), and were examined twice at the initial admission and at discharge. Among 183 MP pneumonia patients, 90 patients with persistent fever for over 48 hours after admission or those with severe respiratory symptoms and signs received additional prednisolone (82 patients, 1 mg/kg/day) or intravenous methylprednisolone (8 patients, 5-10 mg/kg/day) with antibiotics. Four patients with aggravated clinical symptoms and chest radiographic findings after corticosteroid treatment received IVIG (1 g/kg/day, 1-2 doses). Results Mean age of 183 patients was 5.5 ± 3.2 years (6 months-15 years), and the male: female ratio was 1.1:1 (96:87). Fifty-seven patients (31%) were seroconverters and 126 seropositive patients showed increased diagnostic IgM antibody titres during admission (over 4 folds). The majority of the patients who received corticosteroids (86/90 cases) showed rapid defervescence within 48 hours with improved clinical symptoms, regardless of the used antibiotics. Also, 4 patients who received additional IVIG improved both clinically and radiographically within 2 days without adverse reaction. Conclusions In the era of macrolide-resistant MP strains, early additional immune-modulator therapy with antibiotics might prevent from the disease progression and reduce the disease morbidity without adverse reaction. PMID:25566403

  12. Earth Observations for Early Detection of Agricultural Drought in Countries at Risk: Contributions of the Famine Early Warning Systems Network (FEWS NET) (Invited)

    NASA Astrophysics Data System (ADS)

    Verdin, J. P.; Rowland, J.; Senay, G. B.; Funk, C. C.; Budde, M. E.; Husak, G. J.; Jayanthi, H.

    2013-12-01

    The Group on Earth Observations' Global Agricultural Monitoring (GEOGLAM) implementation plan emphasizes the information needs of countries at risk of food insecurity emergencies. Countries in this category are often vulnerable to disruption of agricultural production due to drought, while at the same time they lack well developed networks of in-situ observations to support early drought detection. Consequently, it is vital that Earth observations by satellites supplement those available from surface stations. The USGS, in its role as a FEWS NET implementing partner, has recently developed a number of new applications of satellite observations for this purpose. (1) In partnership with the University of California, Santa Barbara, a 30+ year time series of gridded precipitation estimates (CHIRPS) has been developed by blending NOAA GridSat B1 geostationary thermal infrared imagery with station observations using robust geostatistical methods. The core data set consists of pentadal (5-daily) accumulations from 1981-2013 at 0.05 degree spatial resolution between +/- 50 degrees latitude. Validation has been recently completed, and applications for gridded crop water balance calculations and mapping the Standardized Precipitation Index are in development. (2) Actual evapotranspiration (ETa) estimates using MODIS Land Surface Temperature (LST) data at 1-km have been successfully demonstrated using the operational Simplified Surface Energy Balance model with 8-day composites from the LPDAAC. A new, next-day latency implementation using daily LST swath data from the NASA LANCE server is in development for all the crop growing regions of the world. This ETa processing chain follows in the footsteps of (3) the expedited production of MODIS 250-meter NDVI images every five days at USGS EROS, likewise using LANCE daily swath data as input since 2010. Coverage includes Africa, Central Asia, the Middle East, Central America, and the Caribbean. (4) A surface water point monitoring method for pastoralist areas has been successfully demonstrated. It involves mapping small surface water bodies with ASTER and Landsat imagery, delineating their catchment areas with SRTM elevation data, and maintaining a continuous water balance calculation with satellite rainfall and weather model evaporation estimates to track relative fullness of these ephemeral water bodies. Piloted with NASA funds in partnership with Texas A&M University, the technique is now being implemented across the Sahel. (5) To move beyond monitoring and early warning to disaster risk management, loss exceedence probability functions are being derived for crop production shortfalls in FEWS NET countries. Drought hazard indicators, based on both ETa and crop water balance modeling forced by CHIRPS, have been used to develop regional crop drought risk models. In the case of ETa, the drought risk model provides the basis for index insurance in experiments being conducted in Senegal. A program of training events with GEO partners ensures that the data sets and applications are made available to scientists in FEWS NET countries.

  13. Early Chromospheric Response During a Solar Microflare Observed with SOHO's CDS and RHESSI

    NASA Technical Reports Server (NTRS)

    Brosius, Jeffrey W.; Holman, Gordon D.

    2010-01-01

    We observed a solar microflare with RHESSI and SOHO's Coronal Diagnostic Spectrometer (CDS) on 2009 July 5. With CDS we obtained rapid cadence (7 s) stare spectra within a narrow field of view toward the center of AR 11024. The spectra contain emission lines from ions that cover a wide range of temperature, including He I (< 0.025 MK), O V (0.25 MK), Si XII (2 MK), and Fe XIX (8 MK). The start of a precursor burst of He I and O V line emission preceded the steady increase of Fe XIX line emission by about 1 minute, and the emergence of 3-12 keV X-ray emission by about 4 minutes. Thus the onset of the microflare was observed in upper chromospheric (He I) and transition region (O V) line emission before it was detected in high temperature flare plasma emission. Redshifted O V emission during the precursor suggests explosive chromospheric evaporation, but no corresponding blueshifts were found with either Fe XIX (which was very weak) or Si XII. Similarly, in subsequent microflare brightenings the O V and He I intensities increased (between 49 s and almost 2 minutes) before emissions from the hot flare plasma. Although these time differences likely indicate heating by a nonthermal particle beam, the RHESSI spectra provide no additional evidence for such a beam. In intervals lasting up to about 3 minutes during several bursts, the He I and O V emission line profiles showed secondary, highly blueshifted ( approximately 200 km/s) components; during intervals lasting nearly 1 minute the velocities of the primary and secondary components were oppositely directed. Combined with no corresponding blueshifts in either Fe XIX or Si XII, this indicates that explosive chromospheric evaporation occurred predominantly at either comparatively cool temperatures (< 2 MK) or within a hot temperature range to which our observations were not sensitive (e.g., between 2 and 8 MK).

  14. The early Earth Observing System reference handbook: Earth Science and Applications Division missions, 1990-1997

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Prior to the launch of the Earth Observing System (EOS) series, NASA will launch and operate a wide variety of new earth science satellites and instruments, as well as undertake several efforts collecting and using the data from existing and planned satellites from other agencies and nations. These initiatives will augment the knowledge base gained from ongoing Earth Science and Applications Division (ESAD) programs. This volume describes three sets of ESAD activities -- ongoing exploitation of operational satellite data, research missions with upcoming launches between now and the first launch of EOS, and candidate earth probes.

  15. The Early History of Photometric Observations of Asteroids made at the Table Mountain Observatory

    NASA Astrophysics Data System (ADS)

    Young, James W.; Harris, Alan W.

    2009-05-01

    An Ascop S-20 photomultiplier tube mounted in a Mt. Wilson designed dry-ice cold-box assembly was used with a pulse-counting system to measure the colors, magnitudes, rotational rates, and phase coefficients of over 300 different asteroids between 1978 and 1993. During this time period, nearly one third of all known asteroid rotational rates (~150) were obtained from this effective system. All observations were made with manual telescopic pointing, with data written out long-hand utilizing the 0.6 meter telescope at JPL's Table Mountain Facility. Nearly 40 refereed journal (mostly ICARUS) papers were published containing these results, with yet a few more to come.

  16. Unit III-3 -Singular value decomposition 1 Singular value decomposition

    E-print Network

    Birkett, Stephen

    Unit III-3 - Singular value decomposition 1 Unit III-3 Singular value decomposition Unit III-3 - Singular value decomposition 2 Eigenvalue decomposition re-visited · for a square matrix A the eigenvalue decomposition (EVD) can be written AU = DU ..... · ..... but only for some matrices as A = UDU-1 · what about

  17. [CII] At 1 < z < 2: Observing Star Formation in the Early Universe with Zeus (1 and 2)

    NASA Technical Reports Server (NTRS)

    Ferkinhoff, Carl; Hailey-Dunsheath, S.; Nikola, T.; Oberst, T.; Parshley, S.; Stacey, G.; Benford, D.; staguhn, J.

    2010-01-01

    We report the detection of the [CII] 158 micron fine structure line from six submillimeter galaxies with redshifts between 1.12 and 1.73. This more than doubles the total number of [CII] 158 micron detections reported from high redshift sources. These observations were made with the Redshift(z) and Early Universe Spectrometer(ZEUS) at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii between December 2006 and March 2009. ZEUS is a background limited submm echelle grating spectrometer (Hailey-Dunsheath 2009). Currently we are constructing ZEUS-2. This new instrument will utilize the same grating but will feature a two dimensional transition-edge sensed bolometer array with SQUID multiplexing readout system enabling simultaneous background limited observations in the 200, 340,450 and 650 micron telluric windows. ZEUS-2 will allow for long slit imaging spectroscopy in nearby galaxies and a [CII] survey from z 0.25 to 2.5.

  18. A SOLAR CYCLE LOST IN 1793-1800: EARLY SUNSPOT OBSERVATIONS RESOLVE THE OLD MYSTERY

    SciTech Connect

    Usoskin, Ilya G. [Sodankylae Geophysical Observatory (Oulu unit), University of Oulu (Finland); Mursula, Kalevi [Department of Physical Sciences, University of Oulu (Finland); Arlt, Rainer [Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam (Germany); Kovaltsov, Gennady A. [Ioffe Physical-Technical Institute of RAS, 194021 St. Petersburg (Russian Federation)], E-mail: ilya.usoskin@oulu.fi

    2009-08-01

    Because of the lack of reliable sunspot observations, the quality of the sunspot number series is poor in the late 18th century, leading to the abnormally long solar cycle (1784-1799) before the Dalton minimum. Using the newly recovered solar drawings by the 18-19th century observers Staudacher and Hamilton, we construct the solar butterfly diagram, i.e., the latitudinal distribution of sunspots in the 1790s. The sudden, systematic occurrence of sunspots at high solar latitudes in 1793-1796 unambiguously shows that a new cycle started in 1793, which was lost in the traditional Wolf sunspot series. This finally confirms the existence of the lost cycle that has been proposed earlier, thus resolving an old mystery. This Letter brings the attention of the scientific community to the need of revising the sunspot series in the 18th century. The presence of a new short, asymmetric cycle implies changes and constraints to sunspot cycle statistics, solar activity predictions, and solar dynamo theories, as well as for solar-terrestrial relations.

  19. Early observations on an emerging Great Lakes invader Hemimysis anomala in Lake Ontario

    USGS Publications Warehouse

    Walsh, Maureen G.; Lantry, Brian F.; Boscarino, Brent; Bowen, Kelly; Gerlofsma, Jocelyn; Schaner, Ted; Back, Richard; Questel, Jennifer; Smythe, A. Garry; Cap, Roberta; Goehle, Michael; Young, Bryan; Chalupnicki, Marc; Johnson, James H.; McKenna, James E.

    2010-01-01

    Hemimysis anomala, a Ponto-Caspian littoral mysid, is an emerging Great Lakes invader that was discovered in Lakes Michigan and Ontario in 2006. Similar to the native mysid Mysis diluviana, Hemimysis exhibits a diel vertical migration pattern but generally inhabits shallower and warmer waters than M. diluviana. Because basic information on the distribution, habitat use, and biology of Hemimysis in the Great Lakes is scarce, the potential for food web disruption by Hemimysis cannot easily be predicted. Preliminary observations indicate widespread invasion of Hemimysis in Lake Ontario. In this study, we confirm the presence of Hemimysis at sites spanning the northern and southern shores of Lake Ontario and the presence of the individuals during winter months. In one horizontal tow in November 2007, over 26,000 individuals were collected with a length range of 4.4 to 9.0. mm and an average caloric density of 611. cal/g wet weight. The most effective methods for sampling Hemimysis were horizontal tows with either a zooplankton net in the water column or a benthic sled near the lake bottom. Although more quantitative data on the life history and distribution of this species is necessary, our preliminary observations support the prediction that the potential for Hemimysis to impact the nearshore food web in Lake Ontario appears high.

  20. Decomposition Duality Reinhard Diestel

    E-print Network

    Diestel, Reinhard

    NOTE Decomposition Duality Reinhard Diestel The purpose of this note is just to point out a duality a decomposition angle. Let G, H be graphs. Consider a family D = (Gh)hH of induced subgraphs of G indexed by the vertices of H. Let us call D an H-decomposition of G (into the parts Gh) if (D1) every vertex of G lies

  1. Observations of ionospheric electron content near the geomagnetic equator in Nha Trang (SRV) - Early results

    NASA Astrophysics Data System (ADS)

    Jakowski, N.; Jungstand, A.; Binh, T. T.; Khuang, T. X.; Tan, N. D.

    Faraday-rotation observations have been started in Nha Trang in September 1986 using the ETS-II geostationary satellite. The subionospheric point at 11.4 deg N, 110.8 deg E is located close to the geomagnetic equator. The daytime variation occurs as a broad noon-afternoon maximum, sometimes modified by the well known noontime biteout effect. The ionospheric electron content is closely related to changes in the low-level solar activity during the day as well as during night. A seasonal variation could not be derived from the data. During the declining phase, a period of reduced loss has been found around 19-21 LT, indicated by a shoulder in the Faraday records. This phenomenon is assumed to be caused by an eastward-directed electric field.

  2. HST WFC3 Early Release Science: Emission-Line Galaxies from IR Grism Observations

    NASA Technical Reports Server (NTRS)

    Straughn, A. N.; Kuntschner, H.; Kuemmel, M.; Walsh, J. R.; Cohen, S. H.; Gardner, J. P.; Windhorst, R. A.; O'Connell, R. W.; Pirzkal, N.; Meurer, G.; McCarthy, P. J.; Hathi, N. P.; Malhotra, S.; Rhoads, J.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, J. A.; Hall, D. N. B.; Holtzman, J. A.; Kimlbe, R. A.; Trauger, J. T.; Young, E. T.

    2010-01-01

    We present grism spectra of emission line galaxies (ELGs) from 0.6-1.6 microns from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). These new infrared grism data augment previous optical Advanced Camera for Surveys G800L (0.6-0.95 micron) grism data in GOODS South, extending the wavelength coverage well past the G800L red cutoff. The ERS grism field was observed at a depth of 2 orbits per grism, yielding spectra of hundreds of faint objects, a subset of which are presented here. ELGs are studied via the Ha, [O III ], and [OII] emission lines detected in the redshift ranges 0.2 less than or equal to z less than or equal to 1.6, 1.2 less than or equal to z less than or equal to 2.4 and 2.0 less than or equal to z less than or equal to 3.6 respectively in the G102 (0.8-1.1 microns; R approximately 210) and C141 (1.1-1.6 microns; R approximately 130) grisms. The higher spectral resolution afforded by the WFC3 grisms also reveals emission lines not detectable with the G800L grism (e.g., [S II] and [S III] lines). From these relatively shallow observations, line luminosities, star formation rates, and grism spectroscopic redshifts are determined for a total of 25 ELGs to M(sub AB)(F098M) approximately 25 mag. The faintest source in our sample with a strong but unidentified emission line--is MAB(F098M)=26.9 mag. We also detect the expected trend of lower specific star formation rates for the highest mass galaxies in the sample, indicative of downsizing and discovered previously from large surveys. These results demonstrate the remarkable efficiency and capability of the WFC3 NIR grisms for measuring galaxy properties to faint magnitudes.

  3. Newly observed several peroxides from the gas phase ozonolysis of isoprene using a flow tube reactor and the water vapor effect on their formation and decomposition

    NASA Astrophysics Data System (ADS)

    Huang, D.; Chen, Z.; Zhao, Y.

    2012-12-01

    In recent years, one has been paying more and more attention to the formation of hydrogen peroxide and organic peroxides in the oxidation of volatile organic compounds (VOCs) because peroxides play important roles, such as reservoir of OH, HO2 and RO2 radicals, intermediate of Criegee radical chemistry and contributor to secondary organic aerosol. However, to the best of our knowledge, in the reaction of ozone with VOCs, only several small peroxides such as hydrogen peroxide (H2O2), hydroxymethyl hydroperoxide (HMHP), and methyl hydroperoxide (MHP) were separately identified, and their yields varied widely between different studies. Moreover, the information on the formation mechanism of peroxides in the ozonolysis of VOCs was mostly from a speculation rather than experimental evidence. Notably, a static chamber was employed in most of the previous studies, potentially resulting in the decomposition and heterogeneous reaction of peroxides on the chamber walls within an experiment time of tens of minutes to several hours, and possibly missing the details about the generation of peroxides. In the present study, we have used a flow quartz tube reactor to investigate the formation of peroxides in the ozonolysis of isoprene at various relative humidities (RH). A variety of peroxides have been detected on the tens of seconds of time scale using an online high performance liquid chromatography coupled with post-column derivatization using p-hydroxyphenylacetic acid and fluorescence detection. Our experimental results show that in addition to the three peroxides mentioned previously, more four ones, those are peroxyacetic acid (PAA) and three unknown peroxides, have been found. Furthermore, the total yield of the three small peroxides (H2O2, HMHP and MHP) is found to be similar to the result of literature; while for PAA and three unknown peroxides, they highlight a combined molar yield, for example, ~ 40% at 5% RH, much higher than that of the three small peroxides. Opposite to the previous conclusion that the peroxide yield would be positively correlated with RH, the yields of PAA and three unknown peroxides detected in the present study decreased with the RH increase. We tentatively assign these unknown peroxides to be hydroxyl hydroperoxides, which are produced by the reaction of different Criegee radicals with water. We used a box model coupled with the MCM v3.2 mechanism to simulate the reaction processes of the ozone-initiated oxidation of isoprene, adding the reaction between the gaseous water (and water dimer) and Criegee radicals and the decomposition of water-assisted hydroxyl hydroperoxides. We find that this modified mechanism would better explain the variation of peroxides with the RH increase, implying that molecular water and water cluster should be involved in the production and removal of peroxides in the future model.

  4. Passive microwave observations of the Wedell Sea during austral winter and early spring

    NASA Technical Reports Server (NTRS)

    Grenfell, T. C.; Comiso, J. C.; Lange, M. A.; Eicken, H.; Wensnahan, M. R.

    1994-01-01

    The results of multispectral passive microwave observations (6.7 to 90-GHz) are presented from the cruises of the FS Polarstern in the Weddell Sea from July to December 1986. This paper includes primarily the analysis of radiometric observations taken at ice station sites. Averaged emissivity spectra for first-year (FY) ice were relatively constant throughout the experiment and were not statistically different from FY ice signatures in the Arctic. Detailed ice characterization was carried out at each site to compare the microwave signatures of the ice with the physical properties. Absorption optical depths of FY ice were found to be sufficiently high that only the structure in the upper portions of the ice contributed significantly to interstation emissivity variations. The emissivities at 90-GHz, e(90), had the greatest variance. Both e(90) at vertical polarization and GR(sub e)(90, 18.7)(defined as (e(sub V)(90)-e(sub V)(18.7))/e(sub V)(90 + e(sub V)(18.7)) depended on the scattering optical depth which is a function of the snow grain diameter and layer thickness. The variance showed a latitude dependence and is probably due to an increase in the strength of snow metamorphism nearer the northern edge of the ice pack. The contribution of variations of near-surface brine volume to the emissivity was not significant over the range of values encountered at the station sites. Emissivity spectra are presented for a range of thin ice types. Unsupervised principal component analysis produced three significant eigenvectors and showed a separation among four different surface types: open water, thin ice, FY ice, and FY ice with a thick snow cover. A comparison with SMMR satellite data showed that average ice concentrations derived from the ship's ice watch log were consistent with the satellite concentrations. The surface based emissivities for FY ice were also compared with emissivities calculated from scanning multichannel microwave radiometer (SMMR) satellite radiances. Best agreement was found at 6.7 and 10-GHz, while at 18 and 37-GHz, SMMR emissivities were slightly lower than surface based results. For the three lower frequencies agreement was found within a confidence limit of 95% and for 37-GHz within about 90%.

  5. The performance of field scientists undertaking observations of early life fossils while in simulated space suit

    NASA Astrophysics Data System (ADS)

    Willson, D.; Rask, J. C.; George, S. C.; de Leon, P.; Bonaccorsi, R.; Blank, J.; Slocombe, J.; Silburn, K.; Steele, H.; Gargarno, M.; McKay, C. P.

    2014-01-01

    We conducted simulated Apollo Extravehicular Activity's (EVA) at the 3.45 Ga Australian 'Pilbara Dawn of life' (Western Australia) trail with field and non-field scientists using the University of North Dakota's NDX-1 pressurizable space suit to overview the effectiveness of scientist astronauts employing their field observation skills while looking for stromatolite fossil evidence. Off-world scientist astronauts will be faced with space suit limitations in vision, human sense perception, mobility, dexterity, the space suit fit, time limitations, and the psychological fear of death from accidents, causing physical fatigue reducing field science performance. Finding evidence of visible biosignatures for past life such as stromatolite fossils, on Mars, is a very significant discovery. Our preliminary overview trials showed that when in simulated EVAs, 25% stromatolite fossil evidence is missed with more incorrect identifications compared to ground truth surveys but providing quality characterization descriptions becomes less affected by simulated EVA limitations as the science importance of the features increases. Field scientists focused more on capturing high value characterization detail from the rock features whereas non-field scientists focused more on finding many features. We identified technologies and training to improve off-world field science performance. The data collected is also useful for NASA's "EVA performance and crew health" research program requirements but further work will be required to confirm the conclusions.

  6. Estimates for Lorentz Factors of Gamma-Ray Bursts from Early Optical Afterglow Observations

    NASA Astrophysics Data System (ADS)

    Hascoët, Romain; Beloborodov, Andrei M.; Daigne, Frédéric; Mochkovitch, Robert

    2014-02-01

    The peak time of optical afterglow may be used as a proxy to constrain the Lorentz factor ? of the gamma-ray burst (GRB) ejecta. We revisit this method by including bursts with optical observations that started when the afterglow flux was already decaying; these bursts can provide useful lower limits on ?. Combining all analyzed bursts in our sample, we find that the previously reported correlation between ? and the burst luminosity L ? does not hold. However, the data clearly show a lower bound ?min that increases with L ?. We suggest an explanation for this feature: explosions with large jet luminosities and ? < ?min suffer strong adiabatic cooling before their radiation is released at the photosphere; they produce weak bursts, barely detectable with present instruments. To test this explanation, we examine the effect of adiabatic cooling on the GRB location in the L ? - ? plane using a Monte Carlo simulation of the GRB population. Our results predict detectable on-axis "orphan" afterglows. We also derive upper limits on the density of the ambient medium that decelerates the explosion ejecta. We find that the density in many cases is smaller than expected for stellar winds from normal Wolf-Rayet progenitors. The burst progenitors may be peculiar massive stars with weaker winds, or there might exist a mechanism that reduces the stellar wind a few years before the explosion.

  7. Relativistic Particle-in-Cell Simulation Studies of Prompt and Early Afterglows Observed by GLAST

    NASA Technical Reports Server (NTRS)

    Mizuno, Y.; Nishikawa, K.-I.; Hardee, P.; Fishman, G. J.; Preece, R.

    2007-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that acceleration occurs within the downstream jet. Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "'jitter" radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  8. Autonomous Gaussian Decomposition

    NASA Astrophysics Data System (ADS)

    Lindner, Robert R.; Vera-Ciro, Carlos; Murray, Claire E.; Stanimirovi?, Snežana; Babler, Brian; Heiles, Carl; Hennebelle, Patrick; Goss, W. M.; Dickey, John

    2015-04-01

    We present a new algorithm, named Autonomous Gaussian Decomposition (AGD), for automatically decomposing spectra into Gaussian components. AGD uses derivative spectroscopy and machine learning to provide optimized guesses for the number of Gaussian components in the data, and also their locations, widths, and amplitudes. We test AGD and find that it produces results comparable to human-derived solutions on 21 cm absorption spectra from the 21 cm SPectral line Observations of Neutral Gas with the EVLA (21-SPONGE) survey. We use AGD with Monte Carlo methods to derive the H i line completeness as a function of peak optical depth and velocity width for the 21-SPONGE data, and also show that the results of AGD are stable against varying observational noise intensity. The autonomy and computational efficiency of the method over traditional manual Gaussian fits allow for truly unbiased comparisons between observations and simulations, and for the ability to scale up and interpret the very large data volumes from the upcoming Square Kilometer Array and pathfinder telescopes.

  9. Early evolution of a stratospheric volcanic eruption cloud as observed with TOMS and AVHRR

    USGS Publications Warehouse

    Schneider, D.J.; Rose, W.I.; Coke, L.R.; Bluth, G.J.S.; Sprod, I.E.; Krueger, A.J.

    1999-01-01

    This paper is a detailed study of remote sensing data from the total ozone mapping spectrometer (TOMS) and the advanced very high resolution radiometer (AVHRR) satellite detectors, of the 1982 eruption of El Chicho??n, Mexico. The volcanic cloud/atmosphere interactions in the first four days of this eruption were investigated by combining ultraviolet retrievals to estimate the mass of sulfur dioxide in the volcanic cloud [Krueger et al., 1995] with thermal infrared retrievals of the size, optical depth, and mass of fine-grained (1-10 ??m radius) volcanic ash [Wen and Rose, 1994]. Our study provides the first direct evidence of gravitational separation of ash from a stratospheric, gas-rich, plinian eruption column and documents the marked differences in residence times of volcanic ash and sulfur dioxide in volcanic clouds. The eruption column reached as high as 32 km [Carey and Sigurdsson, 1986] and was injected into an atmosphere with a strong wind shear, which allowed for an observation of the separation of sulfur dioxide and volcanic ash. The upper, more sulfur dioxide-rich part of the cloud was transported to the west in the stratosphere, while the fine-grained ash traveled to the south in the troposphere. The mass of sulfur dioxide released was estimated at 7.1 ?? 109 kg with the mass decreasing by approximately 4% 1 day after the peak. The mass of fine-grained volcanic ash detected was estimated at 6.5 ?? 109 kg, amounting to about 0.7% of the estimated mass of the ash which fell out in the mapped ash blanket close to the volcano. Over the following days, 98% of this remaining fine ash was removed from the volcanic cloud, and the effective radius of ash in the volcanic cloud decreased from about 8 ??m to about 4 ??m. Copyright 1999 by the American Geophysical Union.

  10. Early Ultraviolet, Optical and X-Ray Observations of the Type IIP SN 2005cs in M51 with Swift

    E-print Network

    Peter J. Brown; Luc Dessart; Stephen T. Holland; Stefan Immler; Wayne Landsman; Stephane Blondin; Alexander J. Blustin; Alice Breeveld; Gulab C. Dewangan; Neil Gehrels; Robert B. Hutchins; Robert P. Kirshner; Keith O. Mason; Paolo A. Mazzali; Peter Milne; Maryam Modjaz; Peter W. A. Roming

    2006-12-19

    We report early photospheric-phase observations of the Type IIP Supernova (SN) 2005cs obtained by Swift's Ultraviolet-Optical and X-Ray Telescopes. Observations started within two days of discovery and continued regularly for three weeks. During this time the V-band magnitude remained essentially constant, while the UV was initially bright but steadily faded until below the brightness of an underlying UV-bright HII region. This UV decay is similar to SNe II observed by the International Ultraviolet Explorer. UV grism spectra show the P-Cygni absorption of MgII 2798A, indicating a photospheric origin of the UV flux. Based on non-LTE model atmosphere calculations with the CMFGEN code, we associate the rapid evolution of the UV flux with the cooling of the ejecta, the peak of the spectral energy distribution (SED) shifting from ~700A on June 30th to ~1200A on July 5th. Furthermore, the corresponding recombination of the ejecta, e.g., the transition from FeIII to FeII, induces considerable strengthening of metal line-blanketing at and above the photosphere, blocking more effectively this fading UV flux. SN2005cs was not detected in X-rays, and the upper limit to the X-ray luminosity yields a limit to the mass loss rate of the progenitor of about 10^-5 solar masses per year. Overall, Swift presents a unique opportunity to capture the early and fast evolution of Type II SNe in the UV, providing additional constraints on the reddening, the SED shortward of 4000A, and the ionization state and temperature of the photon-decoupling regions.

  11. Lattice Boltzmann study of spinodal decomposition in two dimensions.

    PubMed

    Chin, Jonathan; Coveney, Peter V

    2002-07-01

    A lattice Boltzmann model using the Shan-Chen prescription for a binary immiscible fluid is described, and the macroscopic equations obeyed by the model are derived. The model is used to quantitatively examine spinodal decomposition of a two-dimensional binary fluid. This model allows examination of the early-time period corresponding to interface formation, and shows agreement with analytical solutions of the linearized Cahn-Hilliard equation, despite the fact that the model contains no explicit free-energy functional. This regime has not, to the knowledge of the authors, been previously observed using any lattice Boltzmann method. In agreement with other models, a scaling law with the exponent 2/3 is observed for late-time domain growth. Breakdown of scaling is also observed for certain sets of simulation parameters. PMID:12241477

  12. Spitzer Observations of Passive and Star-Forming Early-Type Galaxies: An Infrared Color-Color Sequence

    NASA Astrophysics Data System (ADS)

    Temi, Pasquale; Brighenti, Fabrizio; Mathews, William G.

    2009-12-01

    We describe the infrared properties of a large sample of early-type galaxies, comparing data from the Spitzer archive with Ks-band emission from the Two Micron All Sky Survey. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-Multiband Imaging Photometer bands (24, 70, and 160 ?m) and the Ks band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate (SFR) of S0 galaxies estimated from the 24 ?m luminosity increases with decreasing K-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. SFRs in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently, with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late-type galaxies. For those early-type galaxies also observed at radio frequencies, we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SFRs.

  13. Observation of early shell-dopant mix in OMEGA direct-drive implosions and comparisons with radiation-hydrodynamic simulations

    SciTech Connect

    Baumgaertel, J. A.; Bradley, P. A.; Hsu, S. C.; Cobble, J. A.; Hakel, P.; Tregillis, I. L.; Krasheninnikova, N. S.; Murphy, T. J.; Schmitt, M. J.; Shah, R. C.; Obrey, K. D.; Batha, S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Johns, H.; Joshi, T.; Mayes, D.; Mancini, R. C.; Nagayama, T. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States)

    2014-05-15

    Temporally, spatially, and spectrally resolved x-ray image data from direct-drive implosions on OMEGA were interpreted with the aid of radiation-hydrodynamic simulations. Neither clean calculations nor those using a turbulent mix model can explain fully the observed migration of shell-dopant material (titanium) into the core. Shell-dopant migration was observed via time-dependent, spatially integrated spectra, and spatially and spectrally resolved x-ray images of capsule implosions and resultant dopant emissions. The titanium emission was centrally peaked in narrowband x-ray images. In post-processed clean simulations, the peak titanium emission forms in a ring in self-emission images as the capsule implodes. Post-processed simulations with mix reproduce trends in time-dependent, spatially integrated spectra, as well having centrally peaked Ti emission in synthetic multiple monochromatic imager. However, mix simulations still do not transport Ti to the core as is observed in the experiment. This suggests that phenomena in addition to the turbulent mix must be responsible for the transport of Ti. Simple diffusion estimates are unable to explain the early Ti mix into the core. Mechanisms suggested for further study are capsule surface roughness, illumination non-uniformity, and shock entrainment.

  14. Insect succession and carrion decomposition in selected forests of Central Europe. Part 1: Pattern and rate of decomposition.

    PubMed

    Matuszewski, Szymon; Bajerlein, Daria; Konwerski, Szymon; Szpila, Krzysztof

    2010-01-30

    Pig carrion decomposition and insect succession were monitored in different seasons and forests of Central Europe. Pattern of decomposition as well as onset, duration and rate of decompositional processes were measured. Pattern of decomposition was the same in almost all cases with putrefaction, active and advanced decay. In the majority of carcasses active decay was driven by larvae of Calliphoridae with a clear seasonal shift in dominant taxa. However, in some spring, alder forest cases active decay was driven by larvae of Necrodes littoralis (Coleoptera: Silphidae). As a rule the mosaic decomposition was observed. In spring a significant delay in onset of all decompositional processes was found. Season significantly affected rate of active decay due to a much higher rate in summer. Decomposition in alder forest proceeded faster than in pine-oak forest and hornbeam-oak forest. Differences between the latter two forests were practically negligible. Implications for forensic entomology are discussed. PMID:19914786

  15. Thermal Decomposition Mechanism of Butyraldehyde

    NASA Astrophysics Data System (ADS)

    Hatten, Courtney D.; Warner, Brian; Wright, Emily; Kaskey, Kevin; McCunn, Laura R.

    2013-06-01

    The thermal decomposition of butyraldehyde, CH_3CH_2CH_2C(O)H, has been studied in a resistively heated SiC tubular reactor. Products of pyrolysis were identified via matrix-isolation FTIR spectroscopy and photoionization mass spectrometry in separate experiments. Carbon monoxide, ethene, acetylene, water and ethylketene were among the products detected. To unravel the mechanism of decomposition, pyrolysis of a partially deuterated sample of butyraldehyde was studied. Also, the concentration of butyraldehyde in the carrier gas was varied in experiments to determine the presence of bimolecular reactions. The results of these experiments can be compared to the dissociation pathways observed in similar aldehydes and are relevant to the processing of biomass, foods, and tobacco.

  16. Thermal Decomposition of Formaldehyde

    NASA Astrophysics Data System (ADS)

    Irdam, Erwin Ayandra

    The role of formaldehyde as a reactive intermediate in combustion is well recognized and this has led to numerous kinetic investigations of its decomposition. There are issues remaining to be resolved in the dissociation which include the construction of an accurate chain mechanism valid over a wide range of conditions and the determination of the branching ratio of the two possible dissociation channels, radical and molecular. This has been achieved with a combination of new shock tube laser-schlieren measurements and theory. The experiments were conducted using a trimer of formaldehyde, 1,3,5-trioxane, which is shown to dissociate exclusively to three molecules of formaldehyde, thus providing a convenient source of pure formaldehyde. The rate of dissociation of 1,3,5-trioxane dissociation is measured here over 900-1270K and extended using unimolecular reaction rate theory. The subsequent dissociation of formaldehyde is observed above 2200K and measured to 3200K. A chain mechanism for the formaldehyde decomposition derived from a combination of theory and laser-schlieren measurements has been constructed. This includes new measurements of the rate constant for the abstraction reaction, CH _2O + H to HCO + H _2. These measured rates are consistent with theoretical rates which show non-Arrhenius behavior at high temperature. The second order rate constant for the bond fission CH_2O + M to HCO + H + M, was extrapolated from the previous direct low temperature (1600-2000K) measurements using unimolecular rate theory. These laser-schlieren measurements are insensitive to the rate of terminating reactions involving formyl radicals and hydrogen atoms. The present kinetic mechanism with improved rate constants has been tested against previous experiments (1600-2600K) using IR emission, ARAS, and CO laser absorption giving quite satisfactory results. The branching ratio of the rate of the faster molecular dissociation, CH_2 O + (M) to CO + H _2 + (M) to that of the bond fission reaction, was estimated to lie around 2 or 3 over 2000 to 3000K. This ratio is consistent with a recent theoretical estimate and most experimental observations.

  17. CHANDRA OBSERVATIONS OF NGC 4342, AN OPTICALLY FAINT, X-RAY GAS-RICH EARLY-TYPE GALAXY

    SciTech Connect

    Bogdan, Akos; Forman, William R.; Kraft, Ralph P.; Jones, Christine; Randall, Scott W.; Li Zhiyuan; Nulsen, Paul E. J.; Vikhlinin, Alexey [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Blom, Christina [Centre for Astrophysics and Supercomputing, Swinburne University, Hawthorn, VIC 3122 (Australia); Zhang Zhongli; Zhuravleva, Irina; Churazov, Eugene [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-str. 1, 85748 Garching (Germany); Schindler, Sabine, E-mail: abogdan@cfa.harvard.edu [Institut fuer Astrophysik, Leopold-Franzens Universitaet Innsbruck, Technikerstrasse 25, 6020 Innsbruck (Austria)

    2012-08-10

    Chandra x-ray observations of NGC 4342, a low-stellar mass (M{sub K} = -22.79 mag) early-type galaxy, show luminous, diffuse x-ray emission originating from hot gas with temperature of kT {approx} 0.6 keV. The observed 0.5-2 keV band luminosity of the diffuse x-ray emission within the D{sub 25} ellipse is L{sub 0.5-2keV} = 2.7 Multiplication-Sign 10{sup 39} erg s{sup -1}. The hot gas has a significantly broader distribution than the stellar light, and shows strong hydrodynamic disturbances with a sharp surface brightness edge to the northeast and a trailing tail. We identify the edge as a cold front and conclude that the distorted morphology of the hot gas is produced by ram pressure as NGC 4342 moves through external gas. From the thermal pressure ratios inside and outside the cold front, we estimate the velocity of NGC 4342 and find that it moves supersonically (M {approx} 2.6) toward the northeast. Outside the optical extent of the galaxy, we detect {approx}17 bright (L{sub 0.5-8keV} > or approx. 3 x 10{sup 37} erg s{sup -1}) excess x-ray point sources. The excess sources are presumably LMXBs located in metal-poor globular clusters (GCs) in the extended dark matter halo of NGC 4342. Based on the number of excess sources and the average frequency of bright LMXBs in GCs, we estimate that NGC 4342 may host roughly 850-1700 GCs. In good agreement with this, optical observations hint that NGC 4342 may harbor 1200 {+-} 500 GCs. This number corresponds to a GC specific frequency of S{sub N} = 19.9 {+-} 8.3, which is among the largest values observed in full-size galaxies.

  18. The 3-D effects in the long-term solar wind speed rise observed by Voyager 2 in early 1994

    NASA Technical Reports Server (NTRS)

    Pizzo, V. J.; Paularena, K. I.; Richardson, J. D.; Lazarus, A. J.; Belcher, J. W.

    1995-01-01

    In early 1994, Voyager 2 at 42-43 AU near heliolatitude 10 deg S observed over a period of approximately 100 days a remarkable sequence of quasi-recurrent stream fronts, wherein the background (ambient) speed rose steadily from approximately 450 to approximately 550 km/s while the mean period of the streams decreased from the usual 25 days down to approximately 20 days. A qualitative explanation for this effect can be derived from IMP observations, which show that the amplitude of the stream structure at 1 AU increased monotonically in late 1993, concurrent with major secular evolution in the corona. The reduction in period, then, amounts to a doppler shift due to the progressive overtaking of successively faster streams in the sequence. Attempts to model this process quantitatively with 1-D dynamic simulations falter on three accounts: (1) the reduction in period is overestimated, (2) the simulation predicts many more fronts surviving to 43 AU than are observed by Voyager; (3) the density variations are much too large. It is argued that inclusion of the 3-D geometry in the simulation would resolve most all these shortcomings. Using a series of calculations executed with 1-D, 2-D, and 3-D MHD models of hypothetical tilted-dipole flows, we show that: (1) the radial propagation velocities of 3-D fronts are less than those of 1-D or 2-D fronts, owing to the tilt of (and increased shearing across) the interaction surfaces hence the overtaking rate of successive streams is reduced; (2) in a tilted-dipole geometry, the reverse fronts should largely disappear from the equatorial plane by 43 AU, effectively halving the number of fronts to be observed (see companion paper on predominance of forward fronts at Voyager); and (3) the density enhancements would be much smaller than predicted by a 1-D model.

  19. Chandra Observations of NGC 4342, an Optically Faint, X-Ray Gas-rich Early-type Galaxy

    NASA Astrophysics Data System (ADS)

    Bogdán, Ákos; Forman, William R.; Kraft, Ralph P.; Jones, Christine; Blom, Christina; Randall, Scott W.; Zhang, Zhongli; Zhuravleva, Irina; Churazov, Eugene; Li, Zhiyuan; Nulsen, Paul E. J.; Vikhlinin, Alexey; Schindler, Sabine

    2012-08-01

    Chandra x-ray observations of NGC 4342, a low-stellar mass (M K = -22.79 mag) early-type galaxy, show luminous, diffuse x-ray emission originating from hot gas with temperature of kT ~ 0.6 keV. The observed 0.5-2 keV band luminosity of the diffuse x-ray emission within the D 25 ellipse is L 0.5-2 keV = 2.7 × 1039 erg s-1. The hot gas has a significantly broader distribution than the stellar light, and shows strong hydrodynamic disturbances with a sharp surface brightness edge to the northeast and a trailing tail. We identify the edge as a cold front and conclude that the distorted morphology of the hot gas is produced by ram pressure as NGC 4342 moves through external gas. From the thermal pressure ratios inside and outside the cold front, we estimate the velocity of NGC 4342 and find that it moves supersonically (M ~ 2.6) toward the northeast. Outside the optical extent of the galaxy, we detect ~17 bright (L_{0.5{--8\\, keV}} \\gtrsim 3\\times 10^{37} \\ erg \\ s^{-1}) excess x-ray point sources. The excess sources are presumably LMXBs located in metal-poor globular clusters (GCs) in the extended dark matter halo of NGC 4342. Based on the number of excess sources and the average frequency of bright LMXBs in GCs, we estimate that NGC 4342 may host roughly 850-1700 GCs. In good agreement with this, optical observations hint that NGC 4342 may harbor 1200 ± 500 GCs. This number corresponds to a GC specific frequency of S N = 19.9 ± 8.3, which is among the largest values observed in full-size galaxies.

  20. Thermal decomposition of allylbenzene ozonide

    SciTech Connect

    Ewing, J.C.; Church, D.F.; Pryor, W.A. (Louisiana State Univ., Baton Rouge (USA))

    1989-07-19

    Thermal decomposition of allylbenzene ozonide (ABO) at 98{degree}C in the liquid phase yields toluene, bibenzyl, phenylacetaldehyde, formic acid, and (benzyloxy)methyl formate as major products; benzyl chloride is formed when chlorinated solvents are employed. These products, as well as benzyl formate, are formed when ABO is decomposed at 37{degree}C. When the decomposition of ABO is carried out in the presence of 1-butanethiol, the product distribution changes: yields of toluene increase, no bibenzyl is formed, and decreases in yields of (benzyloxy)methyl formate, phenylacetladehyde, and benzyl chloride are observed. The decomposition of 1-octene ozonide (OTO) also was studied for comparison. The activation parameters for both ABO and OTO are similar (28.2 kcal/mol, log A = 13.6 and 26.6 kcal/mol, log A = 12.5, respectively); these data suggest that ozonides decompose by homolysis of the O-O bond, rather than by an alternative synchronous two-bond scission process. When ABO is decomposed at 37{degree}C in the presence of the spin traps 5,5-dimethyl-1-pyrroline N-oxide (DMPO) or 3,3,5,5-tetramethyl-1-pyrroline N-oxide (M{sub 4}PO), ESR signals are observed that are consistent with the trapping of benzyl and other carbon- and oxygen-centered radicals. A mechanism for the thermal decomposition of ABO that involves peroxide bond homolysis and subsequent {beta}-scission is proposed. Thus, Criegee ozonides decompose to give free radicals at quite modest temperatures.

  1. Observing slow EEG activity from same area as spikes in paediatric patients with focal epilepsy by using signal decomposition and dipole

    E-print Network

    Observing slow EEG activity from same area as spikes in paediatric patients with focal epilepsy.vanrumste@esat.kuleuven.ac.be Introduction The background EEG in patients with focal epilepsy often shows abnormalities related of the epileptogenic source. The algorithm has been applied to eight EEGs of paediatric patients with focal epilepsy

  2. Decomposition of blackberry and broomsedge bluestem as influenced by ozone

    SciTech Connect

    Kim, J.S. [Sunchon National Univ. (Korea, Republic of); Chappelka, A.H.; Miller-Goodman, M.S. [Auburn Univ., AL (United States)

    1998-07-01

    Many researchers have reported on individual plant responses to O{sub 3}, but few have investigated the effects of this pollutant on ecosystem function. This investigation examined the influence of O{sub 3} on short-term (Phase 1) litter decomposition of blackberry (Rubus cuneifolus Pursh.) and broomsedge bluestem (Andropogon virginicus L.), two plant species native to early successional forest communities in the southern US. Mixed blackberry/broomsedge litter (1:1) collected from plants exposed to different levels of O{sub 3} for one growing season was placed in open-top chambers and exposed to different O{sub 3} levels of treatments for 24 weeks. Litter also was incubated in microcosms in the laboratory t 25 or 30 C to determine the effects of climate change on O{sub 3}-treated litter. Initial C and N concentrations of the collected foliage did not differ significantly among treatments for either species. Blackberry litter had approximately twice as much N as broomsedge, and when collected from 2X O{sub 3} chambers, had significantly greater permanganate lignin than the other treatments. Initial permanganate lignin concentration of blackberry, over all O{sub 3} treatments, correlated significantly with remaining mass of the litter mixture after 24 wk exposure. Litter decomposed more slowly in the 2X chambers than in the other treatment chambers, regardless of litter source. Elevated O{sub 3}-exposed litter (2X) decomposed the slowest regardless of treatment applied. There were significant temperature and time effects observed with litter decomposition: litter incubated at 30 C decomposed faster than at 25 C. The data suggest O{sub 3} may influence substrate quality and microbial activity, thus reducing the rate of litter decomposition in early successional forest communities.

  3. HF radar observations of Pc 5 field line resonances in the midnight/early morning MLT sector

    SciTech Connect

    Ruohoniemi, J.M.; Greenwald, R.A.; Baker, K.B. (Johns Hopkins Univ., Laurel, MD (United States)); Samson, J.C. (Univ. of Alberta, Edmonton (Canada))

    1991-09-01

    On a number of occasions The Johns Hopkins University/Applied Physics Laboratory HF radar at Goose Bay, Labrador, has observed the effects of field line resonances on the drift velocities of irregularities in the F region of the high-latitude ionosphere. One of the most interesting sets of resonances occurs near midnight MLT and may be associated with shear in the convective flow in the magnetotail. This paper discusses in detail a particularly clear example which shows field line resonance equatorward of a region of shear flow in the early morning sector. The motions were predominantly in the geomagnetic east-west direction, indicating north-south electric fields. As expected of field line resonance pulsations, these oscillations had pronounced peaks in their latitudinal power distribution. The pulsations could occur simultaneously but remained distinct as the latitude of peak response was observed to vary inversely with the frequency of the pulsation. The authors interpret these features in terms of field line resonance theory and discuss the possible sources of the pulsation energy.

  4. BOLOCAM OBSERVATIONS OF TWO UNCONFIRMED GALAXY CLUSTER CANDIDATES FROM THE PLANCK EARLY SUNYAEV-ZEL'DOVICH SAMPLE

    SciTech Connect

    Sayers, J.; Czakon, N. G.; Bridge, C.; Golwala, S. R. [Division of Physics, Math, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Koch, P. M.; Lin, K.-Y.; Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Molnar, S. M., E-mail: jack@caltech.edu [LeCosPA Center, National Taiwan University, Taipei 10617, Taiwan (China)

    2012-04-10

    We present Bolocam observations of two galaxy cluster candidates reported as unconfirmed in the Planck early Sunyaev-Zel'dovich (eSZ) sample, PLCKESZ G115.71+17.52 and PLCKESZ G189.84-37.24. We observed each of these candidates with Bolocam at 140 GHz from the Caltech Submillimeter Observatory in 2011 October. The resulting images have white noise levels of {approx_equal} 30 {mu}K{sub CMB} arcmin in their central regions. We find a significant SZ decrement toward PLCKESZ G115.71. This decrement has a false detection probability of 5.3 Multiplication-Sign 10{sup -5}, and we therefore confirm PLCKESZ G115.71 as a cluster. The maximum SZ decrement toward PLCKESZ G189.84 corresponds to a false detection probability of 0.027, and it therefore remains as an unconfirmed cluster candidate. In order to make our SZ-derived results more robust, we have also analyzed data from the Wide-field Infrared Survey Explorer (WISE) at the location of each cluster candidate. We find an overdensity of WISE sources consistent with other clusters in the eSZ at the location of PLCKESZ G115.71, providing further evidence that it is a cluster. We do not find a significant overdensity of WISE sources at the location of PLCKESZ G189.84.

  5. Northward migration of Helicoverpa armigera (Lepidoptera: Noctuidae) and other moths in early summer observed with radar in northern China.

    PubMed

    Feng, Hong-Qiang; Wu, Kong-Ming; Cheng, Deng-Fa; Guo, Yu-Yuan

    2004-12-01

    The northward migration of Helicoverpa armigera (Hübner) and other moths in early summer was observed with radar in 2001 and 2002 at Langfang, Hebei province, China. Migratory flights typically occurred at heights up to 1.2 km above ground level (AGL), and high density layer concentrations frequently formed at 200-300 m AGL. Adult moths of local populations took off at dusk and ceased flight approximately 0.5 h before sunrise with area density peaking approximately 35 min after dusk. A strong dumb-bell pattern of echoes on the plan position indicator screen, indicating collective orientation of the targets, was evident in 2001, when targets were typically moving toward the northeast and when layering was associated with a temperature inversion and maximum wind speed. By contrast, there was no notable dumb-bell pattern in 2002, when targets were moving toward the northwest. However, orientations calculated from target and wind velocities showed that downwind common orientation also was occurring in 2002 and that the direction varied with the wind direction. The probable sources of the H. armigera observed at Langfang were deduced to be Henan province in 2001 and Shandong province in 2002, and the destination regions were Liaoning and Inner Mongolia. PMID:15666739

  6. Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR

    NASA Astrophysics Data System (ADS)

    Pérot, K.; Urban, J.; Murtagh, D. P.

    2014-08-01

    The middle atmosphere was affected by an exceptionally strong midwinter stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These unusual meteorological conditions led to a breakdown of the polar vortex, followed by the reformation of a strong upper stratospheric vortex associated with particularly efficient descent of air. Measurements by the submillimetre radiometer (SMR), on board the Odin satellite, show that very large amounts of nitric oxide (NO), produced by energetic particle precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus enter the polar stratosphere in early 2013. The mechanism referring to the downward transport of EPP-generated NOx during winter is generally called the EPP indirect effect. SMR observed up to 20 times more NO in the upper stratosphere than the average NO measured at the same latitude, pressure and time during three previous winters where no mixing between mesospheric and stratospheric air was noticeable. This event turned out to be the strongest in the aeronomy-only period of SMR (2007-present). Our study is based on a comparison with the Arctic winter 2008/2009, when a similar situation was observed. This outstanding situation is the result of the combination of a relatively high geomagnetic activity and an unusually high dynamical activity, which makes this case a prime example to study the EPP impacts on the atmospheric composition.

  7. The combination of high sensitivity troponin T and copeptin facilitates early rule-out of ACS: a prospective observational study

    PubMed Central

    2013-01-01

    Background The combination of the new high sensitivity troponin T (hsTnT) assays and copeptin, a biomarker of endogenous stress, has been suggested to have the potential of early rule-out of acute coronary syndrome (ACS). The aim of this study was to examine the ability of this combination to rule out ACS in patients presenting with chest pain and to compare the diagnostic performance to hsTnT alone. Method In this prospective observational study, patients with chest pain admitted for observation were consecutively included. Patients presenting with ST elevation were excluded. Copeptin and hsTnT were analyzed at admission and hsTnT was thereafter determined approximately every 3rd hour as long as clinically indicated. The follow-up period was 60 days. A combined primary endpoint of ACS, non-elective percutanous coronary intervention, non-elective coronary artery bypass surgery and death of all causes was used. Results 478 patients were included. 107 (22%) patients were diagnosed with ACS during hospital stay. 70 (14%) had non-ST-segment elevation myocardial infarction (NSTEMI) and 37 (8%) had unstable angina pectoris (UAP). The combination of hsTnT >14 ng/L or copeptin ?14 pmol/L at admission identified ACS with a higher sensitivity than hsTnT alone: 0.83 (95% confidence interval (CI): 0.74-0.89) versus 0.69 (95% CI: 0.59-0.77), p <0.001. Negative predictive values (NPV) 91% (95% CI: 86-94) versus 89% (95% CI: 84-92). A repeated hsTnT analyzed 3-4 hours after admission resulted in a sensitivity of: 0.77 (95% CI: 0.65-0.86), p =0.031 for comparison with the combination analyzed at admission. Conclusions In patients presenting with chest pain admitted for observation, the combination of hsTnT and copeptin analyzed at admission had a significantly higher sensitivity to diagnose ACS than hsTnT alone. We report a sensitivity of 83% and a NPV of 91% for the combination of hsTnT and copeptin and we conclude that biomarkers alone are not sufficient to rule out ACS. However, the combination of hsTnT and copeptin seems to have a significantly higher sensitivity to identify ACS than a repeated hsTnT test, and thus enables an earlier risk stratification of chest pain patients. This can be time-saving and beneficial for the individual patient by contributing to early decisions on treatment, need of further assessment and level of care. PMID:23777442

  8. Canonical Polyadic Decomposition based on joint eigenvalue decomposition

    E-print Network

    Paris-Sud XI, Université de

    Canonical Polyadic Decomposition based on joint eigenvalue decomposition Xavier Luciania Atlantique, Rennes, F-35000, France Abstract A direct algorithm based on Joint EigenValue Decomposition (JEVD) has been proposed to com- pute the Canonical Polyadic Decomposition (CPD) of multi-way arrays (tensors

  9. A Multistage Position\\/Force Control for Constrained Robotic Systems With Friction: Joint-Space Decomposition, Linearization, and Multiobjective Observer\\/Controller Synthesis Using LMI Formalism

    Microsoft Academic Search

    Karim Khayati; Pascal Bigras; L.-A. Dessaint

    2006-01-01

    A historical review of constrained robot modeling and control strategies is first introduced. Next, a design of a motion\\/force controller for a constrained servo-robot, which is based on a commonly known modeling structure, is proposed. The contact between the end-effector and the environment is subject to frictional features. Accordingly, the control plant is based on the LuGre friction closed-loop observer.

  10. Thermal decomposition of ammonia borane at high pressures

    NASA Astrophysics Data System (ADS)

    Nylén, Johanna; Sato, Toyoto; Soignard, Emmanuel; Yarger, Jeffery L.; Stoyanov, Emil; Häussermann, Ulrich

    2009-09-01

    The effects of high pressure (up to 9 GPa) on the thermal decomposition of ammonia borane, BH3NH3, were studied in situ by Raman spectroscopy in a diamond anvil cell. In contrast with the three-step decomposition at ambient pressure, thermolysis under pressure releases almost the entire hydrogen content of the molecule in two distinct steps. The residual of the first decomposition is polymeric aminoborane, (BH2NH2)x, which is also observed at ambient pressure. The residual after the second decomposition is unique to high pressure. Presumably it corresponds to a precursor to hexagonal BN where macromolecular fragments of planar hexagon layers formed by B and N atoms are terminated by H atoms. Increasing pressure increases the temperature of both decomposition steps. Due to the increased first decomposition temperature it becomes possible to observe a new high pressure, high temperature phase of BH3NH3 which may represent melting.

  11. Gauge- and frame-independent decomposition of nucleon spin

    SciTech Connect

    Wakamatsu, M. [Department of Physics, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2011-01-01

    In a recent paper, we have shown that the way of gauge-invariant decomposition of the nucleon spin is not necessarily unique, but there still exists a preferable decomposition from the observational viewpoint. What was not complete in this argument is a fully satisfactory answer to the following questions. Does the proposed gauge-invariant decomposition, especially the decomposition of the gluon total angular momentum into its spin and orbital parts, correspond to observables which can be extracted from high-energy deep-inelastic-scattering measurements? Is this decomposition not only gauge invariant but also Lorentz frame independent, so that it is legitimately thought to reflect an intrinsic property of the nucleon? We show that we can answer both of these questions affirmatively by making full use of a gauge-invariant decomposition of the covariant angular-momentum tensor of QCD in an arbitrary Lorentz frame.

  12. Early-type Galaxies at Intermediate Redshift Observed with Hubble Space Telescope WFC3: Perspectives on Recent Star Formation

    NASA Astrophysics Data System (ADS)

    Rutkowski, Michael J.; Jeong, Hyunjin; Cohen, Seth H.; Kaviraj, Sugata; Windhorst, Rogier A.; Ryan, Russell E., Jr.; Koekemoer, Anton; Yi, Sukyoung K.; Hathi, Nimish P.; Dopita, Michael A.

    2014-12-01

    We present an analysis of the stellar populations of 102 visually selected early-type galaxies (ETGs) with spectroscopic redshifts (0.35 lsim z lsim 1.5) from observations in the Early Release Science program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). We fit one- and two-component synthetic stellar models to the ETGs UV-optical-near-IR spectral energy distributions and find that a large fraction (~40%) are likely to have experienced a minor (fYC lsim 10% of stellar mass) burst of recent (tYC lsim 1 Gyr) star formation. The measured age and mass fraction of the young stellar populations do not strongly trend with measurements of galaxy morphology. We note that massive (M > 1010.5 M ?) recent star-forming ETGs appear to have larger sizes. Furthermore, high-mass, quiescent ETGs identified with likely companions populate a distinct region in the size-mass parameter space, in comparison with the distribution of massive ETGs with evidence of recent star formation (RSF). We conclude that both mechanisms of quenching star formation in disk-like ETGs and (gas-rich, minor) merger activity contribute to the formation of young stars and the size-mass evolution of intermediate redshift ETGs. The number of ETGs for which we have both HST WFC3 panchromatic (especially UV) imaging and spectroscopically confirmed redshifts is relatively small, therefore, a conclusion about the relative roles of both of these mechanisms remains an open question.

  13. Environmental effects of solar-thermal power systems: ecological observations during early testing of the Barstow 10-MWe pilot STPS

    SciTech Connect

    Turner, F.B. (ed.)

    1982-11-01

    Environmental measurements were continued at Solar One during 1982, while final steps in construction and early testing were carried out. Measurements of sand depths downwind (east) of the heliostat field indicated that some of the sand blown off the field (most of it between September 1979 and March 1980) has been carried farther east, reducing sand depths somewhat in areas just east of the field. Observations of birds between March and June 1982 revealed that (1) the natural avifauna of the field has been altered, although the area is still used for feeding by some icterids (larks, blackbirds) and aerial insectivores (swallows, swifts); (2) of 15 bird casualties ascribable to the presence and/or operation of Solar One, 12 followed collisions with heliostats, three resulted from incineration in heliostat beams; (3) the central receiver tower does not appear to be a source of mortality. Numbers of rodents (particularly kangaroo rats) trapped in areas downwind of the site declined steadily between 1978 and 1982 in areas both clost to the field and as far east as 600 m from the fence. The most likely interpretation of these changes is a reduction in reproductivity and/or early survival caused by four consecutive years (1978, 1979, 1980, 1981) of suboptimal autumn rainfall. Micrometeorological measurements in areas downwind of Solar One showed small effects on air temperatures (<0.5/sup 0/C), wind speeds (<0.4 m/sec), and evaporation rates (<1.5 ml/hr).Effects were detected only in areas 100 to 190 m from the east perimeter fence. Because these differences are so small, relative to natural heterogeneities, the effects of Solar One on rates of evaporation, air temperatures and wind speed will not affect the downwind biological community. The relavance of these findings to construction of a larger solar thermal power plant (e.g., Solar 100) are considered.

  14. Biological characterization and selection criteria of adjuvant chemotherapy for early breast cancer: experience from the Italian observational NEMESI study

    PubMed Central

    2012-01-01

    Background International treatment guidelines recommend administration of adjuvant chemotherapy in early breast cancer based on clinical, prognostic and predictive parameters. Methods An observational study (NEMESI) was conducted in 63 Italian oncology centres in patients with early breast cancer. Age, performance status, concomitant disease, menopausal status, histology, tumor dimension (pT), axillary lymph node status (pN), grading (G), estrogen and progesterone receptor (ER and PgR), proliferative index (ki67 or MIB-1), human epidermal growth factor receptor 2 (HER2) and type of adjuvant treatment were recorded. The primary objective of the study was to define parameters influencing the decision to prescribe adjuvant chemotherapy and the type of chemotherapy. Results Data for 1894 patients were available. 69.0% postmenopausal, 67.0% pT1, 22.3% pTmic/pT1a/pT1b, 61.0% pN0, 48.7% luminal A, 18.1% luminal B, 16.1% HER2 positive, 8.7% triple negative, 8.4% unknown. 57.8% received adjuvant chemotherapy: 38.1% of luminal A, 67.3% luminal B, 88.2% HER2-positive, 97.6% triple negative. Regimens administered: 9.1% CMF-like, 48.8% anthracyclines, 38.4% anthracyclines plus taxanes, 3.7% taxanes alone. Increasing pT/pN and, marginally, HER2-positive were associated with the prescription of anthracyclines plus taxanes. Suboptimal schedules (CMF-like or AC/EC or FEC-75) were prescribed in 37.3% receiving chemotherapy, even in HER2-positive and triple negative disease (36.5% and 34.0%, respectively). Conclusions This study showed an overprescription of adjuvant chemotherapy for early breast cancer, particularly referred to luminal A. pT, pN and, marginally, HER2 were the principal determinants for the choice of chemotherapy type. Suboptimal chemotherapy regimens were adopted in at least one third of HER2-positve and triple negative. PMID:22672524

  15. Identification of old tidal dwarfs near early-type galaxies from deep imaging and H I observations

    NASA Astrophysics Data System (ADS)

    Duc, Pierre-Alain; Paudel, Sanjaya; McDermid, Richard M.; Cuillandre, Jean-Charles; Serra, Paolo; Bournaud, Frédéric; Cappellari, Michele; Emsellem, Eric

    2014-05-01

    It has recently been proposed that the dwarf spheroidal galaxies located in the Local Group discs of satellites (DoSs) may be tidal dwarf galaxies (TDGs) born in a major merger at least 5 Gyr ago. Whether TDGs can live that long is still poorly constrained by observations. As part of deep optical and H I surveys with the Canada-France-Hawaii Telescope (CFHT) MegaCam camera and Westerbork Synthesis Radio Telescope made within the ATLAS3D project, and follow-up spectroscopic observations with the Gemini-North telescope, we have discovered old TDG candidates around several early-type galaxies. At least one of them has an oxygen abundance close to solar, as expected for a tidal origin. This confirmed pre-enriched object is located within the gigantic, but very low surface brightness, tidal tail that emanates from the elliptical galaxy, NGC 5557. An age of 4 Gyr estimated from its SED fitting makes it the oldest securely identified TDG ever found so far. We investigated the structural and gaseous properties of the TDG and of a companion located in the same collisional debris, and thus most likely of tidal origin as well. Despite several Gyr of evolution close to their parent galaxies, they kept a large gas reservoir. Their central surface brightness is low and their effective radius much larger than that of typical dwarf galaxies of the same mass. This possibly provides us with criteria to identify tidal objects which can be more easily checked than the traditional ones requiring deep spectroscopic observations. In view of the above, we discuss the survival time of TDGs and question the tidal origin of the DoSs.

  16. Decomposition with Cheerios

    NSDL National Science Digital Library

    Tracey DeCloedt

    2012-07-06

    The students will use Cheerios as manipulatives for decomposing numbers 5-10. Students will be encouraged to decompose numbers in as many different ways as possible. Students will also record their decompositions as addition problems.

  17. A Multilinear Singular Value Decomposition

    Microsoft Academic Search

    Lieven De Lathauwer; Bart De Moor; Joos Vandewalle

    2000-01-01

    We discuss a multilinear generalization of the singular value decomposition. There is a strong analogy between several properties of the matrix and the higher-order tensor decomposition; uniqueness, link with the matrix eigenvalue decomposition, first-order perturbation effects, etc., are analyzed. We investigate how tensor symmetries affect the decomposition and propose a multilinear generalization of the symmetric eigenvalue decomposition for pair-wise symmetric

  18. HF radar observations of Pc 5 field line resonances in the midnight/early morning MLT sector

    NASA Technical Reports Server (NTRS)

    Ruohoniemi, J. M.; Greenwald, R. A.; Baker, K. B.; Samson, J. C.

    1991-01-01

    The technique of F region sounding by HF coherent radar is applied to the study of field line resonances equatorward of a region of shear flow in the early morning sector. The motions were predominantly in the geomagnetic east-west direction, indicating north-south electric fields. These oscillations had pronounced peaks in their latitudinal power distribution. For the pulsation at 1.95 mHz, a latitudinal phase shift of 180 deg was observed across the peaks in all the look directions of the radar, and a longitudinal wavelength corresponding to an m value of 3 was obtained. For the 2.6-mHz pulsation, the phase shifts across the peaks had a variation with a look direction that indicated a significant longitudinal as well as latitudinal variation; for this activity, an m value of about 16 is estimated. These features are interpreted in terms of the field line resonance theory, and the possible sources of the pulsation energy are discussed.

  19. Ab initio molecular dynamics study on the initial chemical events in nitramines: thermal decomposition of CL-20.

    PubMed

    Isayev, Olexandr; Gorb, Leonid; Qasim, Mo; Leszczynski, Jerzy

    2008-09-01

    CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane or HNIW) is a high-energy nitramine explosive. To improve atomistic understanding of the thermal decomposition of CL-20 gas and solid phases, we performed a series of ab initio molecular dynamics simulations. We found that during unimolecular decomposition, unlike other nitramines (e.g., RDX, HMX), CL-20 has only one distinct initial reaction channelhomolysis of the N-NO2 bond. We did not observe any HONO elimination reaction during unimolecular decomposition, whereas the ring-breaking reaction was followed by NO 2 fission. Therefore, in spite of limited sampling, that provides a mostly qualitative picture, we proposed here a scheme of unimolecular decomposition of CL-20. The averaged product population over all trajectories was estimated at four HCN, two to four NO2, two to four NO, one CO, and one OH molecule per one CL-20 molecule. Our simulations provide a detailed description of the chemical processes in the initial stages of thermal decomposition of condensed CL-20, allowing elucidation of key features of such processes as composition of primary reaction products, reaction timing, and Arrhenius behavior of the system. The primary reactions leading to NO2, NO, N 2O, and N2 occur at very early stages. We also estimated potential activation barriers for the formation of NO2, which essentially determines overall decomposition kinetics and effective rate constants for NO2 and N2. The calculated solid-phase decomposition pathways correlate with available condensed-phase experimental data. PMID:18686996

  20. Early Neurological Outcome of Young Infants Exposed to Selective Serotonin Reuptake Inhibitors during Pregnancy: Results from the Observational SMOK Study

    PubMed Central

    de Vries, Nathalie K. S.; van der Veere, Christine N.; Reijneveld, Sijmen A.; Bos, Arend F.

    2013-01-01

    Background Use of selective serotonin reuptake inhibitors (SSRI) during pregnancy is common while the effect on the infant’s neurological outcome is unknown. Our objective was to determine the effects of prenatal SSRI-exposure on the infants’ neurological functioning, adjusted for maternal mental health. Methods A prospective observational study from May 2007 to April 2010. The study groups comprised 63 SSRI-exposed infants (SSRI group) and 44 non-exposed infants (non-SSRI group). Maternal depression and anxiety were measured using questionnaires. The main outcome measures during the first week after birth and at three to four months were the quality of the infants’ general movements (GMs) according to Prechtl and a detailed motor optimality score. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for abnormal GM quality in the SSRI and non-SSRI groups, and adjusted for maternal depression, anxiety, and other confounders. The study was registered under 53506435 in the ISRCTN. Findings All infants were born around term. During the first week, abnormal GMs occurred more frequently in the SSRI group than in the non-SSRI group (59% versus 33%) and the median MOS was lower (13 versus 18). The OR for abnormal GMs in the SSRI versus the non-SSRI group was 3·0 (95% CI, 1.3 to 6.9) and increased after adjustment for confounders. At three to four months, more SSRI-exposed infants had monotonous movements (48% versus 20%) with lower median MOSs (26 versus 28). The OR for monotonous movements was 3·5 (95% CI, 1.5 to 8.6) and increased after adjusting for confounders. Interpretation Prenatal exposure to SSRI had an adverse effect on early neurological functioning as reflected by GM quality, irrespective of maternal depression and anxiety, and other confounders. Physicians should take this into account in consultation with parents. PMID:23785389

  1. Use of the Earth Observing One (EO-1) Satellite for the Namibia SensorWeb Flood Early Warning Pilot

    NASA Technical Reports Server (NTRS)

    Mandl, Daniel; Frye, Stuart; Cappelaere, Pat; Handy, Matthew; Policelli, Fritz; Katjizeu, McCloud; Van Langenhove, Guido; Aube, Guy; Saulnier, Jean-Francois; Sohlberg, Rob; Silva, Julie; Kussul, Nataliia; Skakun, Sergii; Ungar, Stephen; Grossman, Robert

    2012-01-01

    The Earth Observing One (EO-1) satellite was launched in November 2000 as a one year technology demonstration mission for a variety of space technologies. After the first year, it was used as a pathfinder for the creation of SensorWebs. A SensorWeb is the integration of variety of space, airborne and ground sensors into a loosely coupled collaborative sensor system that automatically provides useful data products. Typically, a SensorWeb is comprised of heterogeneous sensors tied together with a messaging architecture and web services. Disasters are the perfect arena to use SensorWebs. One SensorWeb pilot project that has been active since 2009 is the Namibia Early Flood Warning SensorWeb pilot project. The Pilot Project was established under the auspices of the Namibian Ministry of Agriculture Water and Forestry (MAWF)/Department of Water Affairs, the Committee on Earth Observing Satellites (CEOS)/Working Group on Information Systems and Services (WGISS) and moderated by the United Nations Platform for Space-based Information for Disaster Management and Emergency Response (UN-SPIDER). The effort began by identifying and prototyping technologies which enabled the rapid gathering and dissemination of both space-based and ground sensor data and data products for the purpose of flood disaster management and water-borne disease management. This was followed by an international collaboration to build small portions of the identified system which was prototyped during that past few years during the flood seasons which occurred in the February through May timeframe of 2010 and 2011 with further prototyping to occur in 2012. The SensorWeb system features EO-1 data along with other data sets from such satellites as Radarsat, Terra and Aqua. Finally, the SensorWeb team also began to examine the socioeconomic component to determine the impact of the SensorWeb technology and how best to assist in the infusion of this technology in lesser affluent areas with low levels of basic infrastructure. This paper provides an overview of these efforts, highlighting the EO-1 usage in this SensorWeb.

  2. The generalized triangular decomposition

    NASA Astrophysics Data System (ADS)

    Jiang, Yi; Hager, William W.; Li, Jian

    2008-06-01

    Given a complex matrix mathbf{H} , we consider the decomposition mathbf{H} = mathbf{QRP}^* , where mathbf{R} is upper triangular and mathbf{Q} and mathbf{P} have orthonormal columns. Special instances of this decomposition include the singular value decomposition (SVD) and the Schur decomposition where mathbf{R} is an upper triangular matrix with the eigenvalues of mathbf{H} on the diagonal. We show that any diagonal for mathbf{R} can be achieved that satisfies Weyl's multiplicative majorization conditions: prod_{iD1}^k \\vert r_{i}\\vert le prod_{iD1}^k sigma_i, ; ; 1 le k < K, quad prod_{iD1}^K \\vert r_{i}\\vert = prod_{iD1}^K sigma_i, where K is the rank of mathbf{H} , sigma_i is the i -th largest singular value of mathbf{H} , and r_{i} is the i -th largest (in magnitude) diagonal element of mathbf{R} . Given a vector mathbf{r} which satisfies Weyl's conditions, we call the decomposition mathbf{H} = mathbf{QRP}^* , where mathbf{R} is upper triangular with prescribed diagonal mathbf{r} , the generalized triangular decomposition (GTD). A direct (nonrecursive) algorithm is developed for computing the GTD. This algorithm starts with the SVD and applies a series of permutations and Givens rotations to obtain the GTD. The numerical stability of the GTD update step is established. The GTD can be used to optimize the power utilization of a communication channel, while taking into account quality of service requirements for subchannels. Another application of the GTD is to inverse eigenvalue problems where the goal is to construct matrices with prescribed eigenvalues and singular values.

  3. The early development of joint attention in infants with autistic disorder using home video observations and parental interview.

    PubMed

    Clifford, Sally M; Dissanayake, Cheryl

    2008-05-01

    The aim in the current study was to investigate the early development of joint attention, eye contact and affect during the first 2 years of life, by using retrospective parental interviews and analyses of home videos of infants who were later diagnosed with Autistic Disorder (AD). The 36 children with AD and the 27 matched control children were all aged between 3 and 5 years at recruitment. Reported anomalies in gaze and affect emerged in the children with AD as early as the first 6 months of life, generally becoming more severe just prior to the second birthday. Video data confirmed these anomalies from as early as the first year. Joint attention impairments were found throughout the second year of life. The results suggest that early dyadic behaviours-eye contact and affect-may play a role in the joint attention impairment in AD. PMID:17917803

  4. Optimal domain decomposition strategies

    NASA Technical Reports Server (NTRS)

    Yoon, Yonghyun; Soni, Bharat K.

    1995-01-01

    The primary interest of the authors is in the area of grid generation, in particular, optimal domain decomposition about realistic configurations. A grid generation procedure with optimal blocking strategies has been developed to generate multi-block grids for a circular-to-rectangular transition duct. The focus of this study is the domain decomposition which optimizes solution algorithm/block compatibility based on geometrical complexities as well as the physical characteristics of flow field. The progress realized in this study is summarized in this paper.

  5. Simulation of a Stratospheric Intrusion Using the Lagrangian Particle Transport Model FLEXPART, Combined With Observed Surface Impacts Over the United States in Early May 1999

    Microsoft Academic Search

    S. J. Reid; O. R. Cooper; A. Stohl; A. O. Langford; A. Wimmers

    2003-01-01

    This paper reports observations and a model simulation of an exceptionally-strong tropopause fold in early May 1999 which impacted the surface of Colorado and the south-central United States. The model simulation was performed using a special version of the Lagrangian particle dispersion model FLEXPART, which revealed the evolution of the fold eastward across the United States during the subsequent week.

  6. Observed differences between early childhood programs in the U.S. and Korea: Reflections of “developmentally appropriate practices” in two cultural contexts

    Microsoft Academic Search

    K. Alison Clarke-Stewart; Young Lee; Virginia D. Allhusen; Myoung Soon Kim; David J. McDowell

    2006-01-01

    Ninety children from South Korea and 119 children from the United States were observed in early childhood programs, and differences in classroom environments and teachers' and children's behavior in the two countries were identified. In both countries, there was evidence that preschool education is guided by ideas about “developmentally appropriate practice”. However, in Korea, education was also influenced by Asian

  7. Observed Differences between Early Childhood Programs in the U.S. and Korea: Reflections of "Developmentally Appropriate Practices" in Two Cultural Contexts

    ERIC Educational Resources Information Center

    Clarke-Stewart, K. Alison; Lee, Young; Allhusen, Virginia D.; Kim, Myoung Soon; McDowell, David J.

    2006-01-01

    Ninety children from South Korea and 119 children from the United States were observed in early childhood programs, and differences in classroom environments and teachers' and children's behavior in the two countries were identified. In both countries, there was evidence that preschool education is guided by ideas about "developmentally…

  8. Swedish Religious Education at the End of the 1960s: Classroom Observations, Early Video Ethnography and the National Curriculum of 1962

    ERIC Educational Resources Information Center

    Flensner, K. Kittelmann; Larsson, G.

    2014-01-01

    The aim of this article is to present a unique corpus of film-recorded classroom observations of sixth-grade classes (age 12-13) in the Swedish cities of Gothenburg, Partille and Trollhättan in the late 1960s. The material documents how RE could be taught in Swedish schools in line with the curriculum of Lgr 62 which internationally was an early

  9. The Association between Parent Early Adult Drug Use Disorder and Later Observed Parenting Practices and Child Behavior Problems: Testing Alternate Models

    ERIC Educational Resources Information Center

    Bailey, Jennifer A.; Hill, Karl G.; Guttmannova, Katarina; Oesterle, Sabrina; Hawkins, J. David; Catalano, Richard F.; McMahon, Robert J.

    2013-01-01

    This study tested the association between parent illicit drug use disorder (DUD) in early adulthood and observed parenting practices at ages 27-28 and examined the following 3 theoretically derived models explaining this link: (a) a disrupted parent adult functioning model,(b) a preexisting parent personality factor model, and (c) a disrupted…

  10. High temperature phase decomposition in TixZryAlzN

    NASA Astrophysics Data System (ADS)

    Lind, Hans; Pilemalm, Robert; Rogström, Lina; Tasnadi, Ferenc; Ghafoor, Naureen; Forsén, Rikard; Johnson, Lars J. S.; Johansson-Jöesaar, Mats P.; Odén, Magnus; Abrikosov, Igor A.

    2014-12-01

    Through a combination of theoretical and experimental observations we study the high temperature decomposition behavior of c-(TixZryAlzN) alloys. We show that for most concentrations the high formation energy of (ZrAl)N causes a strong tendency for spinodal decomposition between ZrN and AlN while other decompositions tendencies are suppressed. In addition we observe that entropic effects due to configurational disorder favor a formation of a stable Zr-rich (TiZr)N phase with increasing temperature. Our calculations also predict that at high temperatures a Zr rich (TiZrAl)N disordered phase should become more resistant against the spinodal decomposition despite its high and positive formation energy due to the specific topology of the free energy surface at the relevant concentrations. Our experimental observations confirm this prediction by showing strong tendency towards decomposition in a Zr-poor sample while a Zr-rich alloy shows a greatly reduced decomposition rate, which is mostly attributable to binodal decomposition processes. This result highlights the importance of considering the second derivative of the free energy, in addition to its absolute value in predicting decomposition trends of thermodynamically unstable alloys.

  11. Decomposition, lookup, and recombination: MEG evidence for the Full Decomposition model of complex visual word recognition.

    PubMed

    Fruchter, Joseph; Marantz, Alec

    2015-04-01

    There is much evidence that visual recognition of morphologically complex words (e.g., teacher) proceeds via a decompositional route, first involving recognition of their component morphemes (teach+-er). According to the Full Decomposition model, after the visual decomposition stage, followed by morpheme lookup, there is a final "recombination" stage, in which the decomposed morphemes are combined and the well-formedness of the complex form is evaluated. Here, we use MEG to provide evidence for the temporally-differentiated stages of this model. First, we demonstrate an early effect of derivational family entropy, corresponding to the stem lookup stage; this is followed by a surface frequency effect, corresponding to the later recombination stage. We also demonstrate a late effect of a novel statistical measure, semantic coherence, which quantifies the gradient semantic well-formedness of complex words. Our findings illustrate the usefulness of corpus measures in investigating the component processes within visual word recognition. PMID:25797098

  12. Hydrazine decomposition and other reactions

    NASA Technical Reports Server (NTRS)

    Armstrong, Warren E. (Inventor); La France, Donald S. (Inventor); Voge, Hervey H. (Inventor)

    1978-01-01

    This invention relates to the catalytic decomposition of hydrazine, catalysts useful for this decomposition and other reactions, and to reactions in hydrogen atmospheres generally using carbon-containing catalysts.

  13. ChemTeacher: Decomposition Reactions

    NSDL National Science Digital Library

    2012-07-23

    ChemTeacher compiles background information, videos, articles, demonstrations, worksheets and activities for high school teachers to use in their classrooms. The Decomposition Reactions page includes resources for teaching students about identifying and predicting decomposition reactions.

  14. Clinical assessment of peripheral perfusion to predict postoperative complications after major abdominal surgery early: a prospective observational study in adults

    PubMed Central

    2014-01-01

    Introduction Altered peripheral perfusion is strongly associated with poor outcome in critically ill patients. We wanted to determine whether repeated assessments of peripheral perfusion during the days following surgery could help to early identify patients that are more likely to develop postoperative complications. Methods Haemodynamic measurements and peripheral perfusion parameters were collected one day prior to surgery, directly after surgery (D0) and on the first (D1), second (D2) and third (D3) postoperative days. Peripheral perfusion assessment consisted of capillary refill time (CRT), peripheral perfusion index (PPI) and forearm-to-fingertip skin temperature gradient (Tskin-diff). Generalized linear mixed models were used to predict severe complications within ten days after surgery based on Clavien-Dindo classification. Results We prospectively followed 137 consecutive patients, from among whom 111 were included in the analysis. Severe complications were observed in 19 patients (17.0%). Postoperatively, peripheral perfusion parameters were significantly altered in patients who subsequently developed severe complications compared to those who did not, and these parameters persisted over time. CRT was altered at D0, and PPI and Tskin-diff were altered on D1 and D2, respectively. Among the different peripheral perfusion parameters, the diagnostic accuracy in predicting severe postoperative complications was highest for CRT on D2 (area under the receiver operating characteristic curve = 0.91 (95% confidence interval (CI) = 0.83 to 0.92)) with a sensitivity of 0.79 (95% CI = 0.54 to 0.94) and a specificity of 0.93 (95% CI = 0.86 to 0.97). Generalized mixed-model analysis demonstrated that abnormal peripheral perfusion on D2 and D3 was an independent predictor of severe postoperative complications (D2 odds ratio (OR) = 8.4, 95% CI = 2.7 to 25.9; D2 OR = 6.4, 95% CI = 2.1 to 19.6). Conclusions In a group of patients assessed following major abdominal surgery, peripheral perfusion alterations were associated with the development of severe complications independently of systemic haemodynamics. Further research is needed to confirm these findings and to explore in more detail the effects of peripheral perfusion–targeted resuscitation following major abdominal surgery. PMID:24894892

  15. Brake Lining Decomposition Products

    Microsoft Academic Search

    Jeremiah R. Lynch

    1968-01-01

    A number of investigators have found asbestos bodies in the lungs of urban residents who were not occupationally exposed to asbestos. A relationship between the carinogenic properties of asbestos and the urban excess of lung cancer has been suggested. The decomposition products of brake linings have been described as a possible source of these fibers. Brake testing laboratory methods were

  16. Rainbow decompositions Raphael Yuster

    E-print Network

    Yuster, Raphael

    Rainbow decompositions Raphael Yuster Department of Mathematics University of Haifa Haifa 31905, Israel Abstract A rainbow coloring of a graph is a coloring of the edges with distinct colors. We prove-disjoint rainbow copies of Kk. Our proof uses, as a main ingredient, a double application of the probabilistic

  17. Decomposition of geometric perturbations

    E-print Network

    Roman V. Buniy; Thomas W. Kephart

    2008-11-12

    For an infinitesimal deformation of a Riemannian manifold, we prove that the scalar, vector, and tensor modes in decompositions of perturbations of the metric tensor, the scalar curvature, the Ricci tensor, and the Einstein tensor decouple if and only if the manifold is Einstein. Four-dimensional space-time satisfying the condition of the theorem is homogeneous and isotropic. Cosmological applications are discussed.

  18. Primary Decomposition: Algorithms and Comparisons

    E-print Network

    Pfister, Gerhard

    Primary Decomposition: Algorithms and Comparisons Wolfram Decker 1 Gert­Martin Greuel 2 and Gerhard Kaiserslautern 1 Introduction Primary decomposition of an ideal in a polynomial ring over a field belongs to the decomposition of an affine variety into irreducible components and is, therefore, also an important geometric

  19. Thermal Decomposition of Phenanthrene Oxyradicals

    E-print Network

    Frenklach, Michael

    Thermal Decomposition of Phenanthrene Oxyradicals David E. Edwards, Xiaoqing You, Dmitry Yu examination of oxyradical decomposition focused on the zigzag edge of graphene O + CO O + CO + CO O + CO O 5 average vibrational energy of reactant kT,P= slope kT,P #12;12 Decomposition Rate Results 100 1000 10 4 10

  20. Environmental effects of solar-thermal power systems: ecological observations during early testing of the Barstow 10-MWe pilot STPS

    Microsoft Academic Search

    1982-01-01

    Environmental measurements were continued at Solar One during 1982, while final steps in construction and early testing were carried out. Measurements of sand depths downwind (east) of the heliostat field indicated that some of the sand blown off the field (most of it between September 1979 and March 1980) has been carried farther east, reducing sand depths somewhat in areas

  1. The Early Development of Joint Attention in Infants with Autistic Disorder Using Home Video Observations and Parental Interview

    ERIC Educational Resources Information Center

    Clifford, Sally M; Dissanayake, Cheryl

    2008-01-01

    The aim in the current study was to investigate the early development of joint attention, eye contact and affect during the first 2 years of life, by using retrospective parental interviews and analyses of home videos of infants who were later diagnosed with Autistic Disorder (AD). The 36 children with AD and the 27 matched control children were…

  2. Extension to the North Atlantic oscillation using early instrumental pressure observations from Gibraltar and south-west Iceland

    Microsoft Academic Search

    P. D. Jones; T. Jonsson; D. Wheeler

    1997-01-01

    Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations. In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO). The extended winter half-year record of the NAO enables recent changes in the

  3. Observation of Early Cleavage in Animal Development: A Simple Technique for Obtaining the Eggs of Rhabditis (Nematoda)

    ERIC Educational Resources Information Center

    Hinchliffe, J. R.

    1973-01-01

    Outlines the advantages of using the readily available eggs of the nematode Rhabditis in studying the early cleavage stages of animal development. Discusses the identification and life history of Rhabditis, how to culture and examine the organism, the cleavage stages and cell lineage, and sources of visual aids. (JR)

  4. Narratability and Cluster Decomposition

    E-print Network

    Simon Judes

    2010-02-08

    Recently David Albert presented an argument that relativistic quantum theories are non-narratable. That is, specifying the state on every space-like hypersurface in a given foliation of space-time is not in general sufficient to determine the states on other hypersurfaces, so the history of the universe cannot be told as a narration of states at successive times. We show that the system Albert examined to arrive at this conclusion violates cluster decomposition of the S-matrix, a locality requirement satisfied by relativistic quantum field theories. We formulate the general requirements for a system to display non-narratability, and argue that a large class of systems satisfying them violate the cluster decomposition principle.

  5. A Large Web-Based Observer Reliability Study of Early Ischaemic Signs on Computed Tomography. The Acute Cerebral CT Evaluation of Stroke Study (ACCESS)

    PubMed Central

    Wardlaw, Joanna M.; von Kummer, Rüdiger; Farrall, Andrew J.; Chappell, Francesca M.; Hill, Michael; Perry, David

    2010-01-01

    Background Early signs of ischaemic stroke on computerised tomography (CT) scanning are subtle but CT is the most widely available diagnostic test for stroke. Scoring methods that code for the extent of brain ischaemia may improve stroke diagnosis and quantification of the impact of ischaemia. Methodology and Principal Findings We showed CT scans from patients with acute ischaemic stroke (n?=?32, with different patient characteristics and ischaemia signs) to doctors in stroke-related specialties world-wide over the web. CT scans were shown twice, randomly and blindly. Observers entered their scan readings, including early ischaemic signs by three scoring methods, into the web database. We compared observers' scorings to a reference standard neuroradiologist using area under receiver operator characteristic curve (AUC) analysis, Cronbach's alpha and logistic regression to determine the effect of scales, patient, scan and observer variables on detection of early ischaemic changes. Amongst 258 readers representing 33 nationalities and six specialties, the AUCs comparing readers with the reference standard detection of ischaemic signs were similar for all scales and both occasions. Being a neuroradiologist, slower scan reading, more pronounced ischaemic signs and later time to CT all improved detection of early ischaemic signs and agreement on the rating scales. Scan quality, stroke severity and number of years of training did not affect agreement. Conclusions Large-scale observer reliability studies are possible using web-based tools and inform routine practice. Slower scan reading and use of CT infarct rating scales improve detection of acute ischaemic signs and should be encouraged to improve stroke diagnosis. PMID:21209901

  6. Episodic Accretion at Early Stages of Evolution of Low-Mass Stars and Brown Dwarfs: A Solution for the Observed Luminosity Spread in HR Diagrams?

    Microsoft Academic Search

    I. Baraffe; G. Chabrier; J. Gallardo

    2009-01-01

    We present evolutionary models for young low-mass stars and brown dwarfs taking into account episodic phases of accretion at early stages of the evolution, a scenario supported by recent large surveys of embedded protostars. An evolution including short episodes of vigorous accretion (\\\\dot{M}>= 10^{-4} M_&sun; yr^{-1}) followed by longer quiescent phases (\\\\dot{M}< 10^{-6} M_&sun; yr^{-1}) can explain the observed luminosity

  7. Extension to the North Atlantic oscillation using early instrumental pressure observations from Gibraltar and south-west Iceland

    NASA Astrophysics Data System (ADS)

    Jones, P. D.; Jonsson, T.; Wheeler, D.

    1997-11-01

    Early instrumental pressure measurements from Gibraltar and the Reykjavik area of Iceland have been used to extend to 1821 the homogeneous pressure series at the two locations. In winter the two sites are located close to the centres of action that comprise the North Atlantic Oscillation (NAO). The extended winter half-year record of the NAO enables recent changes in the record to be placed in the context of the period 1823-1996. The period since the early 1970s is the most prolonged positive phase of the oscillation and the late 1980s and early 1990s is the period with the highest values (strongest westerlies). The winter of 1995-1996 marked a dramatic switch in the index, with the change from 1994-1995 being the greatest change recorded from one year to the next since the series began in 1823. (The extended Gibraltar and Reykjavik monthly pressures and the NAO series can be found on the Climatic Research Unit home page, http://www.cru.uea.ac.uk/.).

  8. Multicriteria approximation through decomposition

    SciTech Connect

    Burch, C. [Carnegie Mellon Univ., Pittsburgh, PA (United States). School of Computer Science; Krumke, S. [Univ. of Wuerzburg (Germany). Dept. of Computer Science; Marathe, M. [Los Alamos National Lab., NM (United States); Phillips, C. [Sandia National Labs., Albuquerque, NM (United States). Applied Mathematics Dept.; Sundberg, E. [Rutgers Univ., NJ (United States). Dept. of Computer Science

    1998-06-01

    The authors propose a general technique called solution decomposition to devise approximation algorithms with provable performance guarantees. The technique is applicable to a large class of combinatorial optimization problems that can be formulated as integer linear programs. Two key ingredients of their technique involve finding a decomposition of a fractional solution into a convex combination of feasible integral solutions and devising generic approximation algorithms based on calls to such decompositions as oracles. The technique is closely related to randomized rounding. Their method yields as corollaries unified solutions to a number of well studied problems and it provides the first approximation algorithms with provable guarantees for a number of new problems. The particular results obtained in this paper include the following: (1) the authors demonstrate how the technique can be used to provide more understanding of previous results and new algorithms for classical problems such as Multicriteria Spanning Trees, and Suitcase Packing; (2) they also show how the ideas can be extended to apply to multicriteria optimization problems, in which they wish to minimize a certain objective function subject to one or more budget constraints. As corollaries they obtain first non-trivial multicriteria approximation algorithms for problems including the k-Hurdle and the Network Inhibition problems.

  9. Multicriteria approximation through decomposition

    SciTech Connect

    Burch, C. [Carnegie Mellon Univ., Pittsburgh, PA (United States). School of Computer Sciences]|[Sandia National Labs., Albuquerque, NM (United States); Krumke, S. [Univ. of Wuerzburg (Germany). Dept. of Computer Science; Marathe, M. [Los Alamos National Lab., NM (United States); Phillips, C. [Sandia National Labs., Albuquerque, NM (United States). Applied Mathematics Dept.; Sundberg, E. [Rutgers Univ., NJ (United States). Dept. of Computer Science]|[Sandia National Labs., Albuquerque, NM (United States)

    1997-12-01

    The authors propose a general technique called solution decomposition to devise approximation algorithms with provable performance guarantees. The technique is applicable to a large class of combinatorial optimization problems that can be formulated as integer linear programs. Two key ingredients of the technique involve finding a decomposition of a fractional solution into a convex combination of feasible integral solutions and devising generic approximation algorithms based on calls to such decompositions as oracles. The technique is closely related to randomized rounding. The method yields as corollaries unified solutions to a number of well studied problems and it provides the first approximation algorithms with provable guarantees for a number of new problems. The particular results obtained in this paper include the following: (1) The authors demonstrate how the technique can be used to provide more understanding of previous results and new algorithms for classical problems such as Multicriteria Spanning Trees, and Suitcase Packing. (2) They show how the ideas can be extended to apply to multicriteria optimization problems, in which they wish to minimize a certain objective function subject to one or more budget constraints. As corollaries they obtain first non-trivial multicriteria approximation algorithms for problems including the k-Hurdle and the Network Inhibition problems.

  10. Decomposition in diverse dimensions

    E-print Network

    E. Sharpe

    2014-07-07

    This paper discusses the relationships between gauge theories defined by gauge groups with finite trivially-acting centers, and theories with restrictions on nonperturbative sectors, in two and four dimensions. In two dimensions, these notions seem to coincide. Generalizing old results on orbifolds and abelian gauge theories, we propose a decomposition of two-dimensional nonabelian gauge theories with center-invariant matter into disjoint sums of theories with rotating discrete theta angles; for example, schematically, SU(2) = SO(3)_+ + SO(3)_-. We verify that decomposition directly in pure nonsupersymmetric two-dimensional Yang-Mills as well as in supersymmetric theories. In four dimensions, by contrast, these notions do not coincide. To clarify the relationship, we discuss theories obtained by restricting nonperturbative sectors. These theories violate cluster decomposition, but we illustrate how they may at least in special cases be understood as disjoint sums of well-behaved quantum field theories, and how dyon spectra can be used to distinguish, for example, an SO(3) theory with a restriction on instantons from an SU(2) theory. We also briefly discuss how coupling various analogues of Dijkgraaf-Witten theory, as part of a description of instanton restriction via coupling TQFT's to QFT's, may modify these results.

  11. Litter evenness influences short-term peatland decomposition processes.

    PubMed

    Ward, Susan E; Ostle, Nick J; McNamara, Niall P; Bardgett, Richard D

    2010-10-01

    There is concern that changes in climate and land use could increase rates of decomposition in peatlands, leading to release of stored C to the atmosphere. Rates of decomposition are driven by abiotic factors such as temperature and moisture, but also by biotic factors such as changes in litter quality resulting from vegetation change. While effects of litter species identity and diversity on decomposition processes are well studied, the impact of changes in relative abundance (evenness) of species has received less attention. In this study we investigated effects of changes in short-term peatland plant species evenness on decomposition in mixed litter assemblages, measured as litter weight loss, respired CO(2) and leachate C and N. We found that over the 307-day incubation period, higher levels of species evenness increased rates of decomposition in mixed litters, measured as weight loss and leachate dissolved organic N. We also found that the identity of the dominant species influenced rates of decomposition, measured as weight loss, CO(2) flux and leachate N. Greatest rates of decomposition were when the dwarf shrub Calluna vulgaris dominated litter mixtures, and lowest rates when the bryophyte Pleurozium schreberi dominated. Interactions between evenness and dominant species identity were also detected for litter weight loss and leachate N. In addition, positive non-additive effects of mixing litter were observed for litter weight loss. Our findings highlight the importance of changes in the evenness of plant community composition for short-term decomposition processes in UK peatlands. PMID:20431923

  12. The early stage of formation of self-organized nanocolumns in thin films: Monte Carlo simulations versus atomic-scale observations in Ge-Mn

    SciTech Connect

    Mouton, I.; Talbot, E., E-mail: etienne.talbot@univ-rouen.fr; Pareige, C.; Lardé, R.; Blavette, D. [Groupe de Physique des Matériaux (GPM) UMR 6634, Normandie Université, Université et INSA de Rouen - CNRS, Av. de l'Université, BP 12, 76801 Saint Etienne du Rouvray (France)

    2014-02-07

    Formation kinetics of self-organized nanocolumns during epitaxial growth of a thin film composed of immiscible elements (A,B) has been investigated using Kinetic Monte Carlo simulations. Simulated nanostructures show a good agreement with those observed in Ge-Mn using Atom Probe Tomography and Transmission Electron Microscopy. Self organisation is observed although the rigid lattice simulations used do not account for misfit elastic strain. Simulations reveal that the final nanostructure, in term of number density and diameter of nanocolumns, is controlled by the early stages of growth of the film. The influence of both growth temperature and solute concentration on the nanostructure features is discussed in details.

  13. Early structural anomalies observed by high-resolution imaging in two related cases of autosomal-dominant retinitis pigmentosa.

    PubMed

    Park, Sung Pyo; Lee, Winston; Bae, Eun Jin; Greenstein, Vivianne; Sin, Bum Ho; Chang, Stanley; Tsang, Stephen H

    2014-01-01

    The authors report the use of adaptive-optics scanning laser ophthalmoscopy (AO-SLO) to investigate RHO, D190N autosomal-dominant retinitis pigmentosa in two siblings (11 and 16 years old, respectively). Each patient exhibited distinct hyperautofluorescence patterns in which the outer borders corresponded to inner segment ellipsoid band disruption. Areas within the hyperautofluorescence patterns exhibited normal photoreceptor outer segments and retinal pigment epithelium. However, AO-SLO imaging revealed noticeable spacing irregularities in the cone mosaic. AO-SLO allows researchers to characterize retinal structural abnormalities with precision so that early structural changes in retinitis pigmentosa can be identified and reconciled with genetic findings. PMID:25215869

  14. Early Structural Anomalies Observed by High-Resolution Imaging in Two Related Cases of Autosomal-Dominant Retinitis Pigmentosa

    PubMed Central

    Park, Sung Pyo; Lee, Winston; Bae, Eun Jin; Greenstein, Vivianne; Sin, Bum Ho; Chang, Stanley; Tsang, Stephen H.

    2015-01-01

    The authors report the use of adaptive-optics scanning laser ophthalmoscopy (AO-SLO) to investigate RHO, D190N autosomal-dominant retinitis pigmentosa in two siblings (11 and 16 years old, respectively). Each patient exhibited distinct hyperautofluorescence patterns in which the outer borders corresponded to inner segment ellipsoid band disruption. Areas within the hyperautofluorescence patterns exhibited normal photoreceptor outer segments and retinal pigment epithelium. However, AO-SLO imaging revealed noticeable spacing irregularities in the cone mosaic. AO-SLO allows researchers to characterize retinal structural abnormalities with precision so that early structural changes in retinitis pigmentosa can be identified and reconciled with genetic findings. PMID:25215869

  15. Early X-ray and radio observations of Nova Sco 2015 implicate strong shocks against a red giant wind

    NASA Astrophysics Data System (ADS)

    Nelson, T.; Linford, J.; Chomiuk, L.; Sokoloski, J.; Mukai, K.; Finzell, T.; Weston, J.; Rupen, M.; Mioduszewski, A.

    2015-02-01

    We report the first observations of Nova Sco 2015 (PNV J17032620-3504140) at X-ray, UV and radio wavelengths. The X-ray observations were carried out with the Swift satellite between 2015 February 15.5 and 16.3 UT (roughly 4 days after discovery) and resulted in a total exposure time with the XRT instrument of 4065 s.

  16. Leaf litter traits of invasive species slow down decomposition compared to Spanish natives: a broad phylogenetic comparison.

    PubMed

    Godoy, Oscar; Castro-Díez, Pilar; Van Logtestijn, Richard S P; Cornelissen, Johannes H C; Valladares, Fernando

    2010-03-01

    Leaf traits related to the performance of invasive alien species can influence nutrient cycling through litter decomposition. However, there is no consensus yet about whether there are consistent differences in functional leaf traits between invasive and native species that also manifest themselves through their "after life" effects on litter decomposition. When addressing this question it is important to avoid confounding effects of other plant traits related to early phylogenetic divergences and to understand the mechanism underlying the observed results to predict which invasive species will exert larger effects on nutrient cycling. We compared initial leaf litter traits, and their effect on decomposability as tested in standardized incubations, in 19 invasive-native pairs of co-familial species from Spain. They included 12 woody and seven herbaceous alien species representative of the Spanish invasive flora. The predictive power of leaf litter decomposition rates followed the order: growth form > family > status (invasive vs. native) > leaf type. Within species pairs litter decomposition tended to be slower and more dependent on N and P in invaders than in natives. This difference was likely driven by the higher lignin content of invader leaves. Although our study has the limitation of not representing the natural conditions from each invaded community, it suggests a potential slowing down of the nutrient cycle at ecosystem scale upon invasion. PMID:20155374

  17. Combining field observations and modeling approaches to examine Greenland halibut (Reinhardtius hippoglossoides) early life ecology in the southeastern Bering Sea

    NASA Astrophysics Data System (ADS)

    Duffy-Anderson, J. T.; Blood, D. M.; Cheng, W.; Ciannelli, L.; Matarese, A. C.; Sohn, D.; Vance, T. C.; Vestfals, C.

    2013-01-01

    Spawning in Greenland halibut (Reinhardtius hippoglossoides) occurs along the continental slope and in submarine canyons in the eastern Bering Sea. It is assumed that these bathymetric features and their associated circulation patterns deliver eggs and larvae to suitable nursery habitats over the continental shelf. However, there have been no directed field studies examining spawning areas or transport of Greenland halibut early life stages in the Bering Sea, nor is it known how large-scale oceanographic forcing modulates specific physical mechanisms of delivery. The present study was undertaken to: better define spawning areas of Greenland halibut, examine development and distribution of larvae, and understand the influence of climate variations on interannual patterns of transport, distribution and abundance. Eggs were found in Bering and Pribilof Canyons and over the adjacent slope in February and early March, confirming that spawning occurs in these regions. Larvae were present over the slope, outer shelf and middle shelf in winter and spring, and settled juveniles were collected over the shelf in September. Oceanographic modeling approaches that simulate larval advection from spawning to nursery habitats indicate that depth-discrete variations in transport pathways from submarine canyons to the adjacent shelf contribute to interannual variability in transport trajectories. Overall, our results highlight specific physical mechanisms of delivery that are modulated by large-scale atmospheric and oceanographic forcing, potentially varying the degree of slope-shelf connectivity for Greenland halibut and other slope-spawning species.

  18. A Fantastic Decomposition: Unsettling the Fury of Having to Wait

    ERIC Educational Resources Information Center

    Holmes, Rachel

    2012-01-01

    This article draws on data from a single element of a larger project, which focused on the issue of "how children develop a reputation as "naughty" in the early years classroom." The author draws attention to the (in)corporeal (re)formation of the line in school, undertaking a decomposition of the topological spaces of research/art/education. She…

  19. Hydraulic redistribution may stimulate decomposition

    Microsoft Academic Search

    Zachary T. Aanderud; James H. Richards

    2009-01-01

    Roots influence root litter decomposition through multiple belowground processes. Hydraulic lift or redistribution (HR) by\\u000a plants is one such process that creates diel drying–rewetting cycles in soil. However, it is unclear if this phenomenon influences\\u000a decomposition. Since decomposition in deserts is constrained by low soil moisture and is stimulated when dry soils are rewetted,\\u000a we hypothesized that diel drying–rewetting, via

  20. Polymerization-induced spinodal decomposition of ethylene glycol?phenolic resin solutions under electric fields.

    PubMed

    Zhang, Gang; Qiao, Guanjun

    2013-10-01

    Temporal evolution of polymerization-induced spinodal decomposition (PISD) under electric fields was investigated numerically in ethylene glycol?phenolic resin solutions with different initial composition. A model composed of the nonlinear Cahn-Hilliard-Cook equation for spinodal decomposition and a rate equation for curing reaction was utilized to describe the PISD phenomenon. As initial composition varied, deformed droplet-like and aligned bi-continuous structures were observed in the presence of an electric field. Moreover, the anisotropic parameter (D), determined from the 2D-FFT power spectrum, was employed to quantitatively characterize the degree of morphology anisotropy. The value of D increased quickly in the early stage and then decreased in the intermediate stage of spinodal decomposition, which was attributed to the resistance of coarsening process to morphology deformation and the decline of electric stress caused by polymerization reaction. The results can also provide a guidance on how to control the morphology of monolithic porous polymer and carbon materials with anisotropic structures. PMID:24116581

  1. Polymerization-induced spinodal decomposition of ethylene glycol/phenolic resin solutions under electric fields

    NASA Astrophysics Data System (ADS)

    Zhang, Gang; Qiao, Guanjun

    2013-10-01

    Temporal evolution of polymerization-induced spinodal decomposition (PISD) under electric fields was investigated numerically in ethylene glycol/phenolic resin solutions with different initial composition. A model composed of the nonlinear Cahn-Hilliard-Cook equation for spinodal decomposition and a rate equation for curing reaction was utilized to describe the PISD phenomenon. As initial composition varied, deformed droplet-like and aligned bi-continuous structures were observed in the presence of an electric field. Moreover, the anisotropic parameter (D), determined from the 2D-FFT power spectrum, was employed to quantitatively characterize the degree of morphology anisotropy. The value of D increased quickly in the early stage and then decreased in the intermediate stage of spinodal decomposition, which was attributed to the resistance of coarsening process to morphology deformation and the decline of electric stress caused by polymerization reaction. The results can also provide a guidance on how to control the morphology of monolithic porous polymer and carbon materials with anisotropic structures.

  2. MAGIC gamma-ray and multifrequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

    E-print Network

    Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; de Almeida, U Barres; Barrio, J A; González, J Becerra; Bednarek, W; Bernardini, E; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Carreto-Fidalgo, D; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Mendez, C Delgado; Doert, M; Domínguez, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Farina, E; Ferenc, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadasch, D; Hayashida, M; Herrera, J; Herrero, A; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Meucci, M; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Nowak, N; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Partini, S; Persic, M; Prada, F; Moroni, P G Prada; Prandini, E; Preziuso, S; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saggion, A; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Sun, S; Suri?, T; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Wagner, R M; Zandanel, F; Zanin, R; Lucarelli, F; Pittori, C; Vercellone, S; Verrecchia, F; Buson, S; D'Ammando, F; Stawarz, L; Giroletti, M; Orienti, M; Mundell, C; Steele, I; Zarpudin, B; Raiteri, C M; Villata, M; Sandrinelli, A; Lähteenäki, A; Tammi, J; Tornikoski, M; Hovatta, T; Readhead, A C S; Max-Moerbeck, W; Richards, J L; Jorstad, S; Marscher, A; Gurwell, M A; Larionov, V M; Blinov, D A; Konstantinova, T S; Kopatskaya, E N; Larionova, L V; Larionova, E G; Morozova, D A; Troitsky, I S; Mokrushina, A A; Pavlova, Yu V; Chen, W P; Lin, H C; Panwar, N; Agudo, I; Casadio, C; Gómez, J L; Molina, S N; Kurtanidze, O M; Nikolashvili, M G; Kurtanidze, S O; Chigladze, R A; Acosta-Pulido, J A; Carnerero, M I; Manilla-Robles, A; Ovcharov, E; Bozhilov, V; Metodieva, I; Aller, M F; Aller, H D; Fuhrmann, L; Angelakis, E; Nestoras, I; Krichbaum, T P; Zensus, J A; Ungerechts, H; Sievers, A; Riquelme, D

    2014-01-01

    Among more than fifty blazars detected in very high energy (VHE, E>100GeV) gamma-rays, only three belong to the subclass of Flat Spectrum Radio Quasars (FSRQs). MAGIC observed FSRQ PKS 1510-089 in February-April 2012 during a high activity state in the high energy (HE, E>100 MeV) gamma-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 sigma. In agreement with the previous VHE observations of the source, we find no statistically significant variability during the MAGIC observations in daily, weekly or monthly time scales. The other two known VHE FSRQs have shown daily scale to sub-hour variability. We study the multifrequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO and VLBA telescopes), X-ray (Swift satellite) and HE gamma-ray frequencies. The gamma-ray SED combining AGILE, Fermi and MAGIC dat...

  3. Decomposition Pathways of Z-Selective Ruthenium Metathesis Catalysts

    PubMed Central

    Herbert, Myles B.; Lan, Yu; Keitz, Benjamin K.; Liu, Peng; Endo, Koji; Day, Michael W.; Houk, K. N.; Grubbs, Robert H.

    2012-01-01

    The decomposition of a Z-selective ruthenium metathesis catalyst and structurally similar analogs has been investigated utilizing X-ray crystallography and density functional theory. Isolated X-ray crystal structures suggest that recently reported C-H activated catalysts undergo decomposition via insertion of the alkylidene moiety into the chelating ruthenium-carbon bond followed by hydride elimination, which is supported by theoretical calculations. The resulting ruthenium hydride intermediates have been implicated in previously observed olefin migration, and thus lead to unwanted byproducts in cross metathesis reactions. Preventing these decomposition modes will be essential in the design of more active and selective Z-selective catalysts. PMID:22500642

  4. Mode decomposition evolution equations.

    PubMed

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2012-03-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be easily used for secondary processing. Various simplifications of the proposed MoDEEs, including a linearized version, and an algebraic version, are discussed for computational convenience. The Fourier pseudospectral method, which is unconditionally stable for linearized the high order MoDEEs, is utilized in our computation. Validation is carried out to mode separation of high frequency adjacent modes. Applications are considered to signal and image denoising, image edge detection, feature extraction, enhancement etc. It is hoped that this work enhances the understanding of high order PDEs and yields robust and useful tools for image and signal analysis. PMID:22408289

  5. Mode decomposition evolution equations

    PubMed Central

    Wang, Yang; Wei, Guo-Wei; Yang, Siyang

    2011-01-01

    Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be easily used for secondary processing. Various simplifications of the proposed MoDEEs, including a linearized version, and an algebraic version, are discussed for computational convenience. The Fourier pseudospectral method, which is unconditionally stable for linearized the high order MoDEEs, is utilized in our computation. Validation is carried out to mode separation of high frequency adjacent modes. Applications are considered to signal and image denoising, image edge detection, feature extraction, enhancement etc. It is hoped that this work enhances the understanding of high order PDEs and yields robust and useful tools for image and signal analysis. PMID:22408289

  6. Hydrogen peroxide catalytic decomposition

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2010-01-01

    Nitric oxide in a gaseous stream is converted to nitrogen dioxide using oxidizing species generated through the use of concentrated hydrogen peroxide fed as a monopropellant into a catalyzed thruster assembly. The hydrogen peroxide is preferably stored at stable concentration levels, i.e., approximately 50%-70% by volume, and may be increased in concentration in a continuous process preceding decomposition in the thruster assembly. The exhaust of the thruster assembly, rich in hydroxyl and/or hydroperoxy radicals, may be fed into a stream containing oxidizable components, such as nitric oxide, to facilitate their oxidation.

  7. Slewing Mirror Telescope optics for the early observation of UV/optical photons from Gamma-Ray Bursts.

    PubMed

    Jeong, S; Nam, J W; Ahn, K B; Park, I H; Kim, S W; Lee, J; Lim, H; Brandt, S; Budtz-Jørgensen, C; Castro-Tirado, A J; Chen, P; Cho, M H; Choi, J N; Grossan, B; Huang, M A; Jung, A; Kim, J E; Kim, M B; Kim, Y W; Linder, E V; Min, K W; Na, G W; Panasyuk, M I; Ripa, J; Reglero, V; Smoot, G F; Suh, J E; Svertilov, S; Vedenkin, N; Yashin, I

    2013-01-28

    We report on design, manufacture, and testing of a Slewing Mirror Telescope (SMT), the first of its kind and a part of Ultra-Fast Flash Observatory-pathfinder (UFFO-p) for space-based prompt measurement of early UV/optical light curves from Gamma-Ray Bursts (GRBs). Using a fast slewing mirror of 150 mm diameter mounted on a 2 axis gimbal stage, SMT can deliver the images of GRB optical counterparts to the intensified CCD detector within 1.5~1.8 s over ± 35 degrees in the slewing field of view. Its Ritchey-Chrétien telescope of 100 mm diameter provides a 17 × 17 arcmin² instantaneous field of view. Technical details of design, construction, the laboratory performance tests in space environments for this unique SMT are described in conjunction with the plan for in-orbit operation onboard the Lomonosov satellite in 2013. PMID:23389206

  8. Early Metacarpal Bone Mineral Density Loss Using Digital X-Ray Radiogrammetry and 3-Tesla Wrist MRI in Established Rheumatoid Arthritis: A Longitudinal One-Year Observational Study

    PubMed Central

    Algulin, Jakob; Mangat, Pamela; Lim, Adrian K. P.; Satchithananda, Keshthra; Hajnal, Joseph V.; Taylor, Peter C.

    2015-01-01

    Objectives. Early change in rheumatoid arthritis (RA) is characterised by periarticular osteopenia. We investigated the relationship of early metacarpal digital X-ray radiogrammetry bone mineral density (DXR-BMD) change rate (RC-BMD, mg/cm2/month) to longitudinal changes in hand and feet radiographic and wrist MRI scores over 1 year. Materials and Methods. 10 RA patients completed the study and had wrist 3T-MRI and hand and feet X-rays at various time points over 1 year. MRI was scored by RAMRIS, X-ray was done by van der Heijde modified Sharp scoring, and RC-BMD was analysed using dxr-online. Results. There was good correlation amongst the two scorers for MRI measures and ICC for erosions: 0.984, BME: 0.943, and synovitis: 0.657. Strong relationships were observed between RC-BMD at 12-week and 1-year change in wrist marrow oedema (BME) (r = 0.78, P = 0.035) but not with erosion, synovitis, or radiographic scores. Conclusion. Early RC-BMD correlates with 1-year wrist BME change, which is a known predictor of future erosion and joint damage. However, in our pilot study, early RC-BMD did not show relationships to MRI erosion or radiographic changes over 1 year. This may reflect a slower kinetic in the appearance of MRI/radiographic erosions, generating the hypothesis that RC-BMD may be a more sensitive and early structural prognostic marker in RA follow-up.

  9. Early metacarpal bone mineral density loss using digital x-ray radiogrammetry and 3-tesla wrist MRI in established rheumatoid arthritis: a longitudinal one-year observational study.

    PubMed

    Rastogi, Anshul; Algulin, Jakob; Mangat, Pamela; Lim, Adrian K P; Satchithananda, Keshthra; Hajnal, Joseph V; Taylor, Peter C

    2015-01-01

    Objectives. Early change in rheumatoid arthritis (RA) is characterised by periarticular osteopenia. We investigated the relationship of early metacarpal digital X-ray radiogrammetry bone mineral density (DXR-BMD) change rate (RC-BMD, mg/cm(2)/month) to longitudinal changes in hand and feet radiographic and wrist MRI scores over 1 year. Materials and Methods. 10 RA patients completed the study and had wrist 3T-MRI and hand and feet X-rays at various time points over 1 year. MRI was scored by RAMRIS, X-ray was done by van der Heijde modified Sharp scoring, and RC-BMD was analysed using dxr-online. Results. There was good correlation amongst the two scorers for MRI measures and ICC for erosions: 0.984, BME: 0.943, and synovitis: 0.657. Strong relationships were observed between RC-BMD at 12-week and 1-year change in wrist marrow oedema (BME) (r = 0.78, P = 0.035) but not with erosion, synovitis, or radiographic scores. Conclusion. Early RC-BMD correlates with 1-year wrist BME change, which is a known predictor of future erosion and joint damage. However, in our pilot study, early RC-BMD did not show relationships to MRI erosion or radiographic changes over 1 year. This may reflect a slower kinetic in the appearance of MRI/radiographic erosions, generating the hypothesis that RC-BMD may be a more sensitive and early structural prognostic marker in RA follow-up. PMID:25785197

  10. The Association between Parent Early Adult Drug Use Disorder and Later Observed Parenting Practices and Child Behavior Problems: Testing Alternate Models

    PubMed Central

    Bailey, Jennifer A.; Hill, Karl G.; Guttmannova, Katarina; Oesterle, Sabrina; Hawkins, J. David; Catalano, Richard F.; McMahon, Robert J.

    2012-01-01

    This study tested the association between parent illicit drug use disorder (DUD) in early adulthood and observed parenting practices at ages 27 – 28 and examined the following three, theoretically-derived models explaining this link: a) a disrupted parent adult functioning model, b) a pre-existing parent personality factor model, c) a disrupted adolescent family process model. Associations between study variables and child externalizing problems also were examined. Longitudinal data linking two generations were drawn from the Seattle Social Development Project (SSDP) and The SSDP Intergenerational Project (TIP), and included 167 parents and their 2- to 8-year-old child. Path modeling revealed that parent DUD in early adulthood predicted later observed low-skilled parenting, which was related to child externalizing problems. The pre-existing parent personality factor model was supported. Parent negative emotionality accounted for the association between parent early adult DUD and later parenting practices. Parent negative emotionality also was related directly to child externalizing behavior. Limited support for the disrupted transition to adulthood model was found. The disrupted adolescent family process model was not supported. Results suggest that problem drug use that occurs early in adulthood may affect later parenting skills, independent of subsequent parent drug use. Findings highlight the importance of parent negative emotionality in influencing their own problem behavior, their interactions with their child, and their child’s problem behavior. Prevention and treatment programs targeting young adult substance use, poor parenting practices, and child behavior problems should address parent personality factors that may contribute to these behaviors. PMID:22799581

  11. Hydrogen iodide decomposition

    DOEpatents

    O'Keefe, Dennis R. (San Diego, CA); Norman, John H. (San Diego, CA)

    1983-01-01

    Liquid hydrogen iodide is decomposed to form hydrogen and iodine in the presence of water using a soluble catalyst. Decomposition is carried out at a temperature between about 350.degree. K. and about 525.degree. K. and at a corresponding pressure between about 25 and about 300 atmospheres in the presence of an aqueous solution which acts as a carrier for the homogeneous catalyst. Various halides of the platinum group metals, particularly Pd, Rh and Pt, are used, particularly the chlorides and iodides which exhibit good solubility. After separation of the H.sub.2, the stream from the decomposer is countercurrently extracted with nearly dry HI to remove I.sub.2. The wet phase contains most of the catalyst and is recycled directly to the decomposition step. The catalyst in the remaining almost dry HI-I.sub.2 phase is then extracted into a wet phase which is also recycled. The catalyst-free HI-I.sub.2 phase is finally distilled to separate the HI and I.sub.2. The HI is recycled to the reactor; the I.sub.2 is returned to a reactor operating in accordance with the Bunsen equation to create more HI.

  12. Early-type stars observed in the ESO UVES Paranal Observatory Project: I -- Interstellar Na I UV, Ti II and Ca II K observations

    E-print Network

    I. Hunter; J. V. Smoker; F. P. Keenan; C. Ledoux; E. Jehin; R. Cabanac; C. Melo; S. Bagnulo

    2006-01-17

    We present an analysis of interstellar Na I (lambda=3302.37\\AA, 3302.98\\AA), Ti II (lambda=3383.76\\AA) and Ca II K (lambda=3933.66\\AA) absorption features for 74 sightlines towards O- and B-type stars in the Galactic disc. The data were obtained from the UVES Paranal Observatory Project, at a spectral resolution of 3.75km/s and with mean signal to noise ratios per pixel of 260, 300 and 430 for the Na I, Ti II and Ca II observations, respectively. Interstellar features were detected in all but one of the Ti II sightlines and all of the Ca II sightlines. The dependence of the column density of these three species with distance, height relative to the Galactic plane, H I column density, reddening and depletion relative to the solar abundance has been investigated. We also examine the accuracy of using the Na I column density as an indicator of that for H I. In general we find similar strong correlations for both Ti and Ca, and weaker correlations for Na. Our results confirm the general belief that Ti and Ca occur in the same regions of the interstellar medium and also that the Ti II/Ca II ratio is constant over all parameters. We hence conclude that the absorption properties of Ti and Ca are essentially constant under the general interstellar medium conditions of the Galactic disc.

  13. Quality in Kindergarten Classrooms: Observational Evidence for the Need to Increase Children's Learning Opportunities in Early Education Classrooms

    Microsoft Academic Search

    Karen M. La Paro; Bridget K. Hamre; Jennifer Locasale-Crouch; Robert C. Pianta; Donna Bryant; Dianne Early; Richard Clifford; Oscar Barbarin; Carollee Howes; Margaret Burchinal

    2009-01-01

    Research Findings: Using observational data gathered in 730 kindergarten classrooms in 6 states, the present study focuses on the quality of children's learning opportunities in kindergarten classrooms. Findings show that overall, children experience moderate to low levels of quality in the areas of classroom organization and instructional support in kindergarten. Results are also presented in comparison to children's experiences in

  14. Quality in Kindergarten Classrooms: Observational Evidence for the Need to Increase Children's Learning Opportunities in Early Education Classrooms

    ERIC Educational Resources Information Center

    La Paro, Karen M.; Hamre, Bridget K.; Locasale-Crouch, Jennifer; Pianta, Robert C.; Bryant, Donna; Early, Dianne; Clifford, Richard; Barbarin, Oscar; Howes, Carollee; Burchinal, Margaret

    2009-01-01

    Research Findings: Using observational data gathered in 730 kindergarten classrooms in 6 states, the present study focuses on the quality of children's learning opportunities in kindergarten classrooms. Findings show that overall, children experience moderate to low levels of quality in the areas of classroom organization and instructional support…

  15. The impact of extended release dopamine agonists on prescribing patterns for therapy of early Parkinson’s disease: an observational study

    PubMed Central

    2013-01-01

    Background Dopamine agonists (DA) are the first-choice drug for treatment of the early stage of Parkinson’s disease (PD) in subjects younger than 70 years. Recently, a number of third generation DA have been marketed, including transdermal patch of rotigotine and extended release oral formulation of ropinirole and pramipexole. We investigated the impact of third generation DA on management of the early stage of PD in an outpatient service for Movement Disorders in Italy. Methods Two 12-month observation periods were selected (January - December, 2007, and January - December, 2011) as representative for prescription of immediate and extended release formulations of DA respectively. Within each period, PD patients were divided into subgroups according to age (<65 years; 65–75 years; >75 years) or functional requirement (high; moderate; low). For each period, the number of subjects receiving monotherapy with DA, monotherapy with levodopa (LD), or combined DA/LD therapy and the relative doses were calculated. The severity of parkinsonian motor symptoms was calculated by means of the Unified Parkinson’s Disease Rating Scale part III (UPDRS-III) score. The frequency and severity of side-effects leading to discontinuation or reduction of DA drugs at each time point were also calculated. Results We found a significant reduction of daily LD dose (both as mono- and combined therapy) between the second and the first observation period. There was also a significant increase of monotherapy with DA and corresponding reduction of monotherapy with LD in patients aged 65–75 years, as well as in PD patients with moderate functional requirements. A significant reduction of frequency of side-effects was measured with extended release DA as compared to immediate release formulations. There were no significant differences of the UPDRS-III scores between the 2 observation periods in any subgroup. Conclusions Our results suggest that extended release DA might optimize therapeutic management of the early stages of PD even in patients older than 70 years of age. PMID:24360350

  16. Initiation and Early Evolution of the Coronal Mass Ejection on 2009 May 13 from Extreme-ultraviolet and White-light Observations

    NASA Astrophysics Data System (ADS)

    Reva, A. A.; Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

    2014-10-01

    We present the results of the observations of a coronal mass ejection (CME) that occurred on 2009 May 13. The most important feature of these observations is that the CME was observed from the very early stage (the solar surface) up to a distance of 15 solar radii (R ?). Below 2 R ?, we used the data from the TESIS extreme-ultraviolet telescopes obtained in the Fe 171 Å and He 304 Å lines, and above 2 R ?, we used the observations of the LASCO C2 and C3 coronagraphs. The CME was formed at a distance of 0.2-0.5R ? from the Sun's surface as a U-shaped structure, which was observed both in the 171 Å images and in the white light. Observations in the He 304 Å line showed that the CME was associated with an erupting prominence, which was not located above—as the standard model predicts—but rather in the lowest part of the U-shaped structure close to the magnetic X point. The prominence location can be explained with the CME breakout model. Estimates showed that CME mass increased with time. The CME trajectory was curved—its heliolatitude decreased with time. The CME started at a latitude of 50° and reached the ecliptic plane at distances of 2.5 R ?. The CME kinematics can be divided into three phases: initial acceleration, main acceleration, and propagation with constant velocity. After the CME, onset GOES registered a sub-A-class flare.

  17. MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE FRACTALS

    E-print Network

    Edgar, Gerald

    MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE that the multifractal decomposition behaves as expected* * for a family of sets K known as digraph recursive is roughly equal to (2")d, the dth power of the * *diameter #12; MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH

  18. Decomposition of Relational Schemata into Components

    E-print Network

    Hegner, Stephen J.

    Decomposition of Relational Schemata into Components Defined by Both Projection and Restriction Version) ABSTRACT A generalized approach to the decomposition of relational schemata is developed in which horizontal and vertical decompositions. The realization of restrictions is enabled through the use

  19. CONTACT HANDLE DECOMPOSITIONS BURAK OZBAGCI

    E-print Network

    Ozbagci, Burak

    CONTACT HANDLE DECOMPOSITIONS BURAK OZBAGCI ABSTRACT. We review Giroux's contact handles and contact handle attachments in dimen- sion three and show that a bypass attachment consists of a pair of contact 1 and 2-handles. As an application we describe explicit contact handle decompositions

  20. Sonochemical acceleration of persulfate decomposition

    Microsoft Academic Search

    Gareth J. Price; Andrew A. Clifton

    1996-01-01

    The decomposition kinetics of potassium persulfate in aqueous solution have been investigated using a radical trapping method. The use of ultrasound was found to markedly accelerate the decomposition so that the sonochemical process at 25°C occurs at the same rate as the purely thermal reaction at 55°C. The effect of ultrasound intensity has also been studied and can be used

  1. Modular decomposition and transitive orientation

    Microsoft Academic Search

    Ross M. Mcconnell; Jeremy P. Spinrad

    1999-01-01

    Abstract A module of an undirected graph is a set X of nodes such for each node x not in X, either every member of X is adjacent to x, or no member of X is adjacent to x. There is a canonical linear-space representation for the modules of a graph, called the modular decomposition. Closely related to modular decomposition

  2. ATOMIC DECOMPOSITION BY BASIS PURSUIT

    Microsoft Academic Search

    SCOTT SHAOBING; Michael A. Saunders

    1998-01-01

    The time-frequency and time-scale communities have recently developed a large number of overcomplete waveform dictionaries | stationary wavelets, wavelet packets, cosine packets, chirplets, and warplets, to name a few. Decomposition into overcomplete systems is not unique, and several methods for decomposition have been proposed, including the method of frames (MOF), Matching pursuit (MP), and, for special dictionaries, the best orthogonal

  3. Thermal plasma decomposition of chlorofluorocarbons

    Microsoft Academic Search

    Hidetoshi Sekiguchi; Takuya Honda; Atsushi Kanzawa

    1993-01-01

    Dichlorodifluoromethane was decomposed by a thermal argon plasma generated by a DC are discharge. The experiments and the kinetic calculations showed that the complete decomposition of the chlorofluorocarbon proceeded with the simultaneous additions of hydrogen and oxygen. Both the expertimental and calculated results confirmed that it is favorable, for the decomposition, not to quench the products but to add an

  4. Direct Sum Decomposition of Groups

    ERIC Educational Resources Information Center

    Thaheem, A. B.

    2005-01-01

    Direct sum decomposition of Abelian groups appears in almost all textbooks on algebra for undergraduate students. This concept plays an important role in group theory. One simple example of this decomposition is obtained by using the kernel and range of a projection map on an Abelian group. The aim in this pedagogical note is to establish a direct…

  5. VLT and NTT Observations of Two EIS Cluster Candidates. Detection of the Early-Type Galaxies Sequence at z~1

    E-print Network

    L. da Costa; M. Scodeggio; L. F. Olsen; M. Nonino; R. Rengelink; R. Bender; M. Franx; H. E. Jorgensen; A. Renzini; P. Rosati

    1999-01-19

    Optical data from the ESO VLT-UT1 Science Verification observations are combined with near-infrared data from SOFI at the NTT to obtain optical-infrared color-magnitude diagrams for the objects in the fields of two EIS cluster candidates. In both cases, evidence is found for a well-defined sequence of red galaxies that appear to be significantly more clustered than the background population. These results suggest that the two systems are real physical associations. The (R-Ks), (I-Ks) and (J-Ks) colors of the red sequences are used, in conjunction with similar data for spectroscopically confirmed clusters, to obtain redshift estimates of z ~ 0.9 and z ~ 1.0 for these two systems. These results make these EIS cluster candidates prime targets for follow-up spectroscopic observations to confirm their reality and to measure more accurately their redshift.

  6. A review of myrmecophily in ant nest beetles (Coleoptera: Carabidae: Paussinae): linking early observations with recent findings

    NASA Astrophysics Data System (ADS)

    Geiselhardt, Stefanie F.; Peschke, Klaus; Nagel, Peter

    2007-11-01

    Myrmecophily provides various examples of how social structures can be overcome to exploit vast and well-protected resources. Ant nest beetles (Paussinae) are particularly well suited for ecological and evolutionary considerations in the context of association with ants because life habits within the subfamily range from free-living and predatory in basal taxa to obligatory myrmecophily in derived Paussini. Adult Paussini are accepted in the ant society, although parasitising the colony by preying on ant brood. Host species mainly belong to the ant families Myrmicinae and Formicinae, but at least several paussine genera are not host-specific. Morphological adaptations, such as special glands and associated tufts of hair (trichomes), characterise Paussini as typical myrmecophiles and lead to two different strategical types of body shape: while certain Paussini rely on the protective type with less exposed extremities, other genera access ant colonies using glandular secretions and trichomes (symphile type). We compare these adaptations with other taxonomic groups of insects by joining contemporary research and early sources and discuss the possibility of an attracting or appeasing effect of the secretion. Species that are ignored by their host ants might use chemical mimicry instead. Furthermore, vibrational signals may contribute to ant-beetle communication, and chemical signals have proven to play a role in host finding. The powerful defense chemistry of paussines as “bombardier beetles” is not used in contact with host ants. We attempt to trace the evolution of myrmecophily in paussines by reviewing important aspects of the association between paussine beetles and ants, i.e. morphological and potential chemical adaptations, life cycle, host specificity, alimentation, parasitism and sound production.

  7. THE SIZE EVOLUTION OF PASSIVE GALAXIES: OBSERVATIONS FROM THE WIDE-FIELD CAMERA 3 EARLY RELEASE SCIENCE PROGRAM

    SciTech Connect

    Ryan, R. E. Jr. [Physics Department, University of California, Davis, CA 95616 (United States); McCarthy, P. J. [Observatories of the Carnegie Institute of Washington, Pasadena, CA 91101 (United States); Cohen, S. H.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Yan, H. [Center for Cosmology and Astroparticle Physics, Ohio State University, Columbus, OH 43210 (United States); Hathi, N. P. [Department of Physics and Astronomy, University of California, Riverside, CA 92521 (United States); Koekemoer, A. M.; Bond, H. E.; Bushouse, H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); O'Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Crockett, R. M. [Department of Physics, University of Oxford, Oxford OX1 3PU (United Kingdom); Disney, M. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia); Frogel, J. A. [Galaxies Unlimited, Lutherville, MD 21093 (United States); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A., E-mail: rryan@physics.ucdavis.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); and others

    2012-04-10

    We present the size evolution of passively evolving galaxies at z {approx} 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z {approx}> 1.5. We identify 30 galaxies in {approx}40 arcmin{sup 2} to H < 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 {mu}m {approx}< {lambda}{sub obs} {approx}< 1.6 {mu}m with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of {approx}0.033(1 + z). We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M{sub *} {approx} 10{sup 11} M{sub Sun }) undergo the strongest evolution from z {approx} 2 to the present. Parameterizing the size evolution as (1 + z){sup -{alpha}}, we find a tentative scaling of {alpha} Almost-Equal-To (- 0.6 {+-} 0.7) + (0.9 {+-} 0.4)log (M{sub *}/10{sup 9} M{sub Sun }), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of high-redshift systems. We discuss the implications of this result for the redshift evolution of the M{sub *}-R{sub e} relation for red galaxies.

  8. The Size Evolution of Passive Galaxies: Observations From the Wide-Field Camera 3 Early Release Science Program

    NASA Technical Reports Server (NTRS)

    Ryan, R. E., Jr.; Mccarthy, P.J.; Cohen, S. H.; Yan, H.; Hathi, N. P.; Koekemoer, A. M.; Rutkowski, M. J.; Mechtley, M. R.; Windhorst, R. A.; O’Connell, R. W.; Balick, B.; Bond, H. E.; Bushouse, H.; Calzetti, D.; Crockett, R. M.; Disney, M.; Dopita, M. A.; Frogel, J. A.; Hall, D., N., B.; Holtzman, J. A.; Kaviraj, S.; Kimble, R. A.; MacKenty, J.; Trauger, J.; Young, E.

    2012-01-01

    We present the size evolution of passively evolving galaxies at z approximately 2 identified in Wide-Field Camera 3 imaging from the Early Release Science program. Our sample was constructed using an analog to the passive BzK galaxy selection criterion, which isolates galaxies with little or no ongoing star formation at z greater than approximately 1.5. We identify 30 galaxies in approximately 40 arcmin(sup 2) to H less than 25 mag. By fitting the 10-band Hubble Space Telescope photometry from 0.22 micrometers less than approximately lambda (sub obs) 1.6 micrometers with stellar population synthesis models, we simultaneously determine photometric redshift, stellar mass, and a bevy of other population parameters. Based on the six galaxies with published spectroscopic redshifts, we estimate a typical redshift uncertainty of approximately 0.033(1+z).We determine effective radii from Sersic profile fits to the H-band image using an empirical point-spread function. By supplementing our data with published samples, we propose a mass-dependent size evolution model for passively evolving galaxies, where the most massive galaxies (M(sub *) approximately 10(sup 11) solar mass) undergo the strongest evolution from z approximately 2 to the present. Parameterizing the size evolution as (1 + z)(sup - alpha), we find a tentative scaling of alpha approximately equals (-0.6 plus or minus 0.7) + (0.9 plus or minus 0.4) log(M(sub *)/10(sup 9 solar mass), where the relatively large uncertainties reflect the poor sampling in stellar mass due to the low numbers of highredshift systems. We discuss the implications of this result for the redshift evolution of the M(sub *)-R(sub e) relation for red galaxies.

  9. The Study of Dusty Star-Forming Galaxies in the Early Universe Through Far-Infrared Observations

    NASA Astrophysics Data System (ADS)

    Calanog, Jae Alyson

    In this thesis I use far-infrared (far-IR) observations performed by the Herschel Space Observatory to study dusty star-forming galaxies, which are believed to be the likely progenitors of massive elliptical galaxies. More specifically, I investigate the far-IR emission of dust-obscured galaxies (DOGs), analyze the near-IR imaging of Herschel-selected lensed galaxies, and investigate the rest-frame UV emission of HFLS3, a z = 6.34 Herschel-selected starburst.

  10. Art of spin decomposition

    E-print Network

    Xiang-Song Chen; Wei-Min Sun; Fan Wang; T. Goldman

    2011-05-31

    We analyze the problem of spin decomposition for an interacting system from a natural perspective of constructing angular momentum eigenstates. We split, from the total angular momentum operator, a proper part which can be separately conserved for a stationary state. This part commutes with the total Hamiltonian and thus specifies the quantum angular momentum. We first show how this can be done in a gauge-dependent way, by seeking a specific gauge in which part of the total angular momentum operator vanishes identically. We then construct a gauge-invariant operator with the desired property. Our analysis clarifies what is the most pertinent choice among the various proposals for decomposing the nucleon spin. A similar analysis is performed for extracting a proper part from the total Hamiltonian to construct energy eigenstates.

  11. Decomposition and insect succession on cadavers inside a vehicle environment.

    PubMed

    Voss, Sasha C; Forbes, Shari L; Dadour, Ian R

    2008-01-01

    This study presents differences in rate of decomposition and insect succession between exposed carcasses on the soil surface and those enclosed within a vehicle following carbon monoxide (CO) poisoning. Nine 45-kg pigs were used as models for human decomposition. Six animals were sacrificed by CO gas, half of which were placed within the driver's side of separate enclosed vehicles and half were placed under scavenger-proof cages on the soil surface. A further three animals were sacrificed by captive headbolt and placed under scavenger proof cages on the soil surface. The pattern of insect succession and rate of decomposition were similar between surface carcasses within trials regardless of the mode of death. Progression through the physical stages of decomposition was 3-4 days faster in the enclosed vehicle due to higher temperatures there compared to external ambient temperatures. Patterns of insect succession also differed between the vehicle and surface treatments. Carcass attendance by representatives of the Calliphoridae was delayed within the vehicle environment by 16-18 h, while oviposition was not observed until 24-28 h following death. In contrast, attendance by Calliphoridae at surface carcasses occurred within 1 h of death, and oviposition occurred within 6-8 h of death. Typical patterns of insect succession on the carcasses were also altered. Carcass attendance by representatives of the Coleoptera occurred during the bloat stage of decomposition at surface carcasses but was delayed until the onset of wet decomposition (as defined by carcass deflation and breakage of the skin) within the vehicle environment. This study provides baseline data outlining the decomposition patterns of a carcass enclosed within a vehicle following CO poisoning in Western Australia. Understanding how variations in decomposition situations impact on the rate of decomposition and patterns of insect succession is essential to obtaining an accurate estimate of minimum post-mortem interval (PMI). PMID:19291466

  12. Hydroxyl radical formation during peroxynitrous acid decomposition

    SciTech Connect

    Coddington, J.W.; Hurst, J.K.; Lymar, S.V.

    1999-03-24

    Yields of O{sub 2} formed during decomposition of peroxynitrous acid (ONOOH) under widely varying medium conditions are compared to predictions based upon the assumption that the reaction involves formation of discrete {sm{underscore}bullet}OH and {sm{underscore}bullet}NO{sub 2} radicals as oxidizing intermediates. The kinetic model used includes all reactions of {sm{underscore}bullet}OH, {sm{underscore}bullet}O{sub 2}{sup {minus}}, and reactive nitrogen species known to be important under the prevailing conditions; because the rate constants for all of these reactions have been independently measured, the calculations contain no adjustable fitting parameters. The model quantitatively accounts for (1) the complex pH dependence of the O{sub 2} yields and (2) the unusual effects of NO{sub 2} {sup {minus}}, which inhibits O{sub 2} formation in neutral, but not alkaline, solutions and also reverses inhibition by organic {sm{underscore}bullet}OH scavengers in alkaline media. Other observations, including quenching of O{sub 2} yields by ferrocyanide and bicarbonate, the pressure dependence of the decomposition rate, and the reported dynamic behavior for O{sub 2} generation in the presence of H{sub 2}O{sub 2}, also appear to be in accord with the suggested mechanism. Overall, the close correspondence between observed and calculated O{sub 2} yields provides strong support for decomposition via homolysis of the ONOOH peroxo bond.

  13. Loss of diversity in wood-inhabiting fungal communities affects decomposition activity in Norway spruce wood

    PubMed Central

    Valentín, Lara; Rajala, Tiina; Peltoniemi, Mikko; Heinonsalo, Jussi; Pennanen, Taina; Mäkipää, Raisa

    2014-01-01

    Hundreds of wood-inhabiting fungal species are now threatened, principally due to a lack of dead wood in intensively managed forests, but the consequences of reduced fungal diversity on ecosystem functioning are not known. Several experiments have shown that primary productivity is negatively affected by a loss of species, but the effects of microbial diversity on decomposition are less studied. We studied the relationship between fungal diversity and the in vitro decomposition rate of slightly, moderately and heavily decayed Picea abies wood with indigenous fungal communities that were diluted to examine the influence of diversity. Respiration rate, wood-degrading hydrolytic enzymes and fungal community structure were assessed during a 16-week incubation. The number of observed OTUs in DGGE was used as a measure of fungal diversity. Respiration rate increased between early- and late-decay stages. Reduced fungal diversity was associated with lower respiration rates during intermediate stages of decay, but no effects were detected at later stages. The activity of hydrolytic enzymes varied among decay stages and fungal dilutions. Our results suggest that functioning of highly diverse communities of the late-decay stage were more resistant to the loss of diversity than less diverse communities of early decomposers. This indicates the accumulation of functional redundancy during the succession of the fungal community in decomposing substrates. PMID:24904544

  14. X-Ray, UV, and Optical Observations of Supernova 2006bp with Swift: Detection of Early X-Ray Emission

    E-print Network

    S. Immler; P. J. Brown; P. Milne; L. Dessart; P. A. Mazzali; W. Landsman; N. Gehrels; R. Petre; D. N. Burrows; J. A. Nousek; R. A. Chevalier; C. L. Williams; M. Koss; C. J. Stockdale; M. T. Kelley; K. W. Weiler; S. T. Holland; E. Pian; P. W. A. Roming; D. Pooley; K. Nomoto; J. Greiner; S. Campana; A. M. Soderberg

    2007-03-29

    We present results on the X-ray and optical/UV emission from the type IIP SN 2006bp and the interaction of the SN shock with its environment, obtained with the X-Ray Telescope (XRT) and UV/Optical Telescope (UVOT) on-board the Swift observatory. SN 2006bp is detected in X-rays at a 4.5 sigma level of significance in the merged XRT data from days 1 to 12 after the explosion. If the X-ray luminosity of (1.8+/-0.4)E39 ergs/s is caused by interaction of the SN shock with circumstellar material (CSM), deposited by a stellar wind from the progenitor's companion star, a mass-loss rate of ~E-05 M_sun/yr is inferred. The mass-loss rate is consistent with the non-detection in the radio with the VLA on days 2, 9, and 11 after the explosion and characteristic of a red supergiant progenitor with a mass around 12-15 M_sun prior to the explosion. In combination with a follow-up XMM-Newton observation obtained on day 21 after the explosion, an X-ray rate of decline with index 1.2+/-0.6 is inferred. Since no other SN has been detected in X-rays prior to the optical peak and since type IIP SNe have an extended 'plateau' phase in the optical, we discuss the scenario that the X-rays might be due to inverse Compton scattering of photospheric optical photons off relativistic electrons produced in circumstellar shocks. However, due to the high required value of the Lorentz factor (~10-100) we conclude that Inverse Compton scattering is an unlikely explanation for the observed X-ray emission. The fast evolution of the optical/ultraviolet spectral energy distribution and the spectral changes observed with Swift reveal the onset of metal line-blanketing and cooling of the expanding photosphere during the first few weeks after the outburst.

  15. Nearby Supernova Factory Observations of SN 2006D: On Sporadic Carbon Signatures in Early Type Ia Supernova Spectra

    E-print Network

    The Nearby Supernova Factory; :; R. C. Thomas; G. Aldering; P. Antilogus; C. Aragon; S. Bailey; C. Baltay; E. Baron; A. Bauer; C. Buton; S. Bongard; Y. Copin; E. Gangler; S. Gilles; R. Kessler; S. Loken; P. Nugent; R. Pain; J. Parrent; E. Pecontal; R. Pereira; S. Perlmutter; D. Rabinowitz; G. Rigaudier; K. Runge; R. Scalzo; G. Smadja; L. Wang; B. A. Weaver

    2006-11-10

    We present four spectra of the Type Ia supernova (SN Ia) 2006D extending from -7 to +13 days with respect to B-band maximum. The spectra include the strongest signature of unburned material at photospheric velocities observed in a SN Ia to date. The earliest spectrum exhibits C II absorption features below 14,000 km/s, including a distinctive C II \\lambda 6580 absorption feature. The carbon signatures dissipate as the SN approaches peak brightness. In addition to discussing implications of photospheric-velocity carbon for white dwarf explosion models, we outline some factors that may influence the frequency of its detection before and around peak brightness. Two effects are explored in this regard, including depopulation of the C II optical levels by non-LTE effects, and line-of-sight effects resulting from a clumpy distribution of unburned material with low volume-filling factor.

  16. Unlocking the Power of Observation: Activities to teach early learners the fundamentals of an important inquiry skill

    NSDL National Science Digital Library

    Dean M. Martin

    2006-09-01

    The dawn of a new school year is the perfect time to reflect on last year's successes while setting even higher expectations for the upcoming year. For several years, many of our new-school-year resolutions have revolved around a common theme: improving the introduction of inquiry skills to young (kindergarten through second grade) learners, particularly students with limited English-language skills. After experiencing many partial successes, we have found that following easy-to-implement workshop activities to be just what we needed to make our resolutions come true. The activities focus on observation and communication. These skills not only help to focus young children's natural curiosity but also build a solid foundation for future scientific learning.

  17. Cassini ISS Observations Of The Early Stages Of The Formation Of Titan's South Polar Hood And Vortex In 2012

    NASA Astrophysics Data System (ADS)

    West, Robert A.; Del Genio, A.; Perry, J.; Ingersoll, A. P.; Turtle, E. P.; Porco, C.; Ovanessian, A.

    2012-10-01

    Northern spring equinox on Titan occurred on August 11, 2009. In March of 2012 the Imaging Science Subsystem (ISS) on the Cassini spacecraft saw the first evidence for the formation of a polar hood in the atmosphere above Titan’s south pole. Views of the limb showed an optical thickening primarily at about 360 km altitude across a few degrees of latitude centered on the pole. Images of Titan in front of Saturn provide a nearly direct measure of the line-of-sight optical depth as a function of latitude and altitude from about 250 km and higher. Two or more distinct layers are seen, both near the pole and at other latitudes. The highest of these, near 360 km altitude, hosts the embryonic polar hood. On June 27, 2012 ISS observed the pole from high latitude. These images show a distinct and unusual cloudy patch, elongated and not centered on the pole and with an elevated perimeter. The morphology and color indicate an unfamiliar (for Titan) composition and dynamical regime. The interior of the feature consists of concentrations of cloud/haze organized on spatial scales of tens of kilometers. Its morphology is reminiscent of the open cellular convection sometimes seen in the atmospheric boundary layer over Earth’s oceans under conditions of large-scale subsidence. Unlike Earth, where such convection is forced by large surface heat fluxes or the onset of drizzle, convection at 360 km on Titan is more likely to be driven from above by radiative cooling. During the 9 hours we observed Titan, this feature completed a little over one rotation around the pole, providing direct evidence for a polar vortex rotating at a rate roughly consistent with angular-momentum-conserving flow for air displaced from the equator. Part of this work was performed by the Jet Propulsion Laboratory, California Institute of Technology.

  18. Satellite observations of terrestrial water storage provide early warning information about drought and fire season severity in the Amazon

    NASA Astrophysics Data System (ADS)

    Chen, Yang; Velicogna, Isabella; Famiglietti, James S.; Randerson, James T.

    2013-06-01

    risk in the Amazon can be predicted several months before the onset of the dry season using sea surface temperatures in the tropical north Atlantic and tropical Pacific. The lead times between ocean state and the period of maximum burning (4-11 months) may enable the development of forecasts with benefits for forest conservation, yet the underlying physical and biological mechanisms responsible for these temporal offsets are not well known. Here, we examined the hypothesis that year-to-year variations in soil water recharge during the wet season modify atmospheric water vapor and fire behavior during the following dry season. We tested this hypothesis by analyzing terrestrial water storage observations from the Gravity Recovery and Climate Experiment (GRACE), active fires from the Moderate Resolution Imaging Spectroradiometer (MODIS), and several other satellite and atmospheric reanalysis datasets during 2002-2011. We found that terrestrial water storage deficits preceded severe fire seasons across the southern Amazon. The most significant relationships between monthly terrestrial water storage and the sum of active fires during the dry season occurred during April-August (p < 0.02), corresponding to 1-5 month lead times before the peak month of burning (September). Analysis of other datasets provided evidence for a cascade of processes during drought events, with lower cumulative precipitation (and higher cumulative evapotranspiration) in the wet season substantially reducing terrestrial water storage, and subsequently, surface and column atmospheric water vapor. Our results suggest that terrestrial water storage observations from GRACE have the potential to improve fire season forecasts for the southern Amazon.

  19. Evidence of laser induced decomposition of triaminotrinitrobenzene from surface enhanced Raman spectroscopy

    Microsoft Academic Search

    F. J. Owens

    2011-01-01

    It is observed that the focused 632 nm laser of the confocal micro-Raman spectrometer decomposes triaminotrinitrobenzene (TATB). The temperature generated in the laser spot determined by measuring the ratio of the intensities of the anti-Stokes to Stokes spectra is too low to cause thermal decomposition. The observed decomposition is suggested to be a result of laser induced electronic excitation. The

  20. Decomposition and arthropod succession in Whitehorse, Yukon Territory, Canada.

    PubMed

    Bygarski, Katherine; LeBlanc, Helene N

    2013-03-01

    Forensic arthropod succession patterns are known to vary between regions. However, the northern habitats of the globe have been largely left unstudied. Three pig carcasses were studied outdoors in Whitehorse, Yukon Territory. Adult and immature insects were collected for identification and comparison. The dominant Diptera and Coleoptera species at all carcasses were Protophormia terraneovae (R-D) (Fam: Calliphoridae) and Thanatophilus lapponicus (Herbst) (Fam: Silphidae), respectively. Rate of decomposition, patterns of Diptera and Coleoptera succession, and species dominance were shown to differ from previous studies in temperate regions, particularly as P. terraenovae showed complete dominance among blowfly species. Rate of decomposition through the first four stages was generally slow, and the last stage of decomposition was not observed at any carcass due to time constraints. It is concluded that biogeoclimatic range has a significant effect on insect presence and rate of decomposition, making it an important factor to consider when calculating a postmortem interval. PMID:23278195

  1. Monte Carlo simulations for spinodal decomposition

    SciTech Connect

    Sander, E. [George Mason Univ., Fairfax, VA (United States). Dept. of Mathematical Sciences] [George Mason Univ., Fairfax, VA (United States). Dept. of Mathematical Sciences; Wanner, T. [Univ. of Maryland, Baltimore, MD (United States). Dept. of Mathematics and Statistics] [Univ. of Maryland, Baltimore, MD (United States). Dept. of Mathematics and Statistics

    1999-06-01

    This paper addresses the phenomenon of spinodal decomposition for the Cahn-Hilliard equation. Namely, the authors are interested in why most solutions to the Cahn-Hilliard equation which start near a homogeneous equilibrium u{sub 0} {equivalent_to} {mu} in the spinodal interval exhibit phase separation with a characteristic wavelength when exiting a ball of radius R in a Hilbert space centered at u{sub 0}. There are two mathematical explanations for spinodal decomposition, due to Grant and to Maier-Paape and Wanner. In this paper, the authors numerically compare these two mathematical approaches. In fact, they are able to synthesize the understanding they gain from the numerics with the approach of Maier-Paape and Wanner, leading to a better understanding of the underlying mechanism for this behavior. With this new approach, they can explain spinodal decomposition for a longer time and larger radius than either of the previous two approaches. A rigorous mathematical explanation is contained in a separate paper. The approach is to use Monte Carlo simulations to examine the dependence of R, the radius to which spinodal decomposition occurs, as a function of the parameter {var_epsilon} of the governing equation. The authors give a description of the dominating regions on the surface of the ball by estimating certain densities of the distributions of the exit points. They observe, and can show rigorously, that the behavior of most solutions originating near the equilibrium is determined completely by the linearization for an unexpectedly long time. They explain the mechanism for this unexpectedly linear behavior, and show that for some exceptional solutions this cannot be observed. They also describe the dynamics of these exceptional solutions.

  2. Observational Evidence Against Mountain-Wave Generation of Ice Nuclei as a Prerequisite for the Formation of Three Solid Nitric Acid Polar Stratospheric Clouds Observed in the Arctic in Early December 1999

    NASA Technical Reports Server (NTRS)

    Pagan, Kathy L.; Tabazadeh, Azadeh; Drdla, Katja; Hervig, Mark E.; Eckermann, Stephen D.; Browell, Edward V.; Legg, Marion J.; Foschi, Patricia G.

    2004-01-01

    A number of recently published papers suggest that mountain-wave activity in the stratosphere, producing ice particles when temperatures drop below the ice frost point, may be the primary source of large NAT particles. In this paper we use measurements from the Advanced Very High Resolution Radiometer (AVHRR) instruments on board the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites to map out regions of ice clouds produced by stratospheric mountain-wave activity inside the Arctic vortex. Lidar observations from three DC-8 flights in early December 1999 show the presence of solid nitric acid (Type Ia or NAT) polar stratospheric clouds (PSCs). By using back trajectories and superimposing the position maps on the AVHRR cloud imagery products, we show that these observed NAT clouds could not have originated at locations of high-amplitude mountain-wave activity. We also show that mountain-wave PSC climatology data and Mountain Wave Forecast Model 2.0 (MWFM-2) raw hemispheric ray and grid box averaged hemispheric wave temperature amplitude hindcast data from the same time period are in agreement with the AVHRR data. Our results show that ice cloud formation in mountain waves cannot explain how at least three large scale NAT clouds were formed in the stratosphere in early December 1999.

  3. The influence of minerals on decomposition of the n-alkyl-?-amino acid norvaline under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    McCollom, Thomas M.

    2013-03-01

    Laboratory experiments were conducted to observe the effect of iron oxide and sulfide minerals on decomposition reactions of norvaline, a representative of a group of alkyl-?-amino acids observed in meteorites and prebiotic synthesis experiments. The primary products observed during heating of aqueous solutions of norvaline at temperatures of 156-186 °C in the presence of minerals included CO2, NH3, butyric acid, and valeric acid. The products indicated that norvaline predominantly decomposed by a combination of pathways that included both decarboxylation followed rapidly by oxidative deamination (norvaline ? butanamide + CO2 ? butyric acid + NH3) and deamination directly to valeric acid (norvaline ? valeric acid + NH3). An experiment performed with alanine under similar conditions showed it decomposed by analogous reactions that produced acetic and propionic acids along with CO2 and NH3. For both amino acids, the presence of minerals accelerated decomposition rates as well as altered the final products of reaction, when compared with decomposition in the absence of mineral substrates. In addition, decomposition of norvaline was found to proceed much faster in the presence of the mineral assemblage hematite-magnetite-pyrite (HMP) than with the assemblage pyrite-pyrrhotite-magnetite (PPM), a trend that has been observed for several other organic compounds. The influence of minerals on decomposition reactions of these amino acids appears to be attributable to a combination of surface catalysis and production of dissolved sulfur compounds. Overall, the results indicate that minerals may exert a substantial influence on amino acid stability in many geologic environments, and emphasize the need to consider the impact of minerals when evaluating the lifetimes and decomposition rates of amino acids in terrestrial and planetary systems. Estimated half-lives for alkyl-?-amino acids based on the experimental results indicate that moderately hot hydrothermal environments (<˜100 °C) would have been the most favorable for accumulation of these amino acids in the early solar system, and that the predominance of alkyl-?-amino acids in some meteorites may only be compatible with temperature remaining below about 60 °C following their formation.

  4. One Dose versus Three Weekly Doses of Benzathine Penicillin G for Patients Co-Infected with HIV and Early Syphilis: A Multicenter, Prospective Observational Study

    PubMed Central

    Yang, Chia-Jui; Lee, Nan-Yao; Chen, Tun-Chieh; Lin, Yu-Hui; Liang, Shiou-Haur; Lu, Po-Liang; Huang, Wen-Chi; Tang, Hung-Jen; Lee, Chen-Hsiang; Lin, Hsi-Hsun; Chen, Yen-Hsu; Ko, Wen-Chien; Hung, Chien-Ching

    2014-01-01

    Background One dose of benzathine penicillin G (BPG) has been recommended for HIV-infected patients with early syphilis (primary, secondary, and early latent syphilis) in the sexually transmitted diseases treatment guidelines, but clinical data to support such a recommendation are limited. Methods We prospectively observed the serological response to 1 or 3 weekly doses of BPG in HIV-infected adults who sought treatment of early syphilis at 8 hospitals around Taiwan. Rapid plasma reagin (RPR) titers were followed every 3–6 months after treatment. The serological response was defined as a 4-fold or greater decline in RPR titers at 12 months of treatment. The missing values were treated by following the last-observed-carried-forward principle. We hypothesized that 1 dose was non-inferior to 3 weekly doses of BPG with the non-inferiority margin for the difference of serological response set to 10%. Results Between 2007 and 2012, 573 patients completed at least 12 months of follow-up: 295 (51.5%) receiving 1 dose of BPG (1-dose group) and 278 (48.5%) 3 doses (3-dose group). Overall, 198 patients (67.1%; 95% confidence interval [CI], 61.4–72.5%) in the 1-dose group achieved serological response at 12 months, as did 208 patients (74.8%; 95% CI, 69.3–79.8%) in the 3-dose group (one-sided 95% CI of the difference, 15.1%). In the multivariate analysis, secondary syphilis (adjusted odds ratio [AOR], 1.90; 95% CI 1.17–3.09), RPR titer ?32 (AOR, 1.93; 95% CI, 1.38–2.69), and 3 doses of BPG (AOR, 1.68; 95% CI, 1.20–2.36) were independently associated with a serological response. The time to the first episode of treatment failure was 1184 (standard deviation [SD], 70.5) and 1436 (SD, 80.0) days for 1- and 3-dose group, respectively. Conclusions Single-dose BPG resulted in a higher serological failure rate and shorter time to treatment failure than 3 weekly doses of BPG in the treatment of early syphilis in HIV-infected patients. PMID:25286091

  5. Epiphyseal fusion assessment based on wavelets decomposition analysis.

    PubMed

    Pietka, E; Huang, H K

    1995-01-01

    Epiphyseal fusion is a finding frequently analysed in hand wrist radiographs. It is tested in the bone age assessment, the gonadal dysgenesis, etc. The computerized fusion analysis is performed on an automatically selected region of interest containing the lower edge of epiphysis and the upper edge of metaphysis. In the analysis a wavelets decomposition approach is employed. The wavelets decomposition components are first subjected to a preliminary test which rejects the overexposed images whose analysis would not give reasonable results. This increases the accuracy of the algorithm and a chance for an unsupervised application. Then, a quantitative measure is found. Its value decreases while the epiphyseal fusion proceeds. The analysis yields an assignment of fusion to one of four stages: no fusion, early stage of fusion, advanced stage of fusion, and fusion completed. The results show that wavelets decomposition components may efficiently be applied to a texture analysis. PMID:8796967

  6. Descent theory for semiorthogonal decompositions

    SciTech Connect

    Elagin, Alexei D

    2012-05-31

    We put forward a method for constructing semiorthogonal decompositions of the derived category of G-equivariant sheaves on a variety X under the assumption that the derived category of sheaves on X admits a semiorthogonal decomposition with components preserved by the action of the group G on X. This method is used to obtain semiorthogonal decompositions of equivariant derived categories for projective bundles and blow-ups with a smooth centre as well as for varieties with a full exceptional collection preserved by the group action. Our main technical tool is descent theory for derived categories. Bibliography: 12 titles.

  7. Perfluoropolyalkylether decomposition on catalytic aluminas

    NASA Technical Reports Server (NTRS)

    Morales, Wilfredo

    1994-01-01

    The decomposition of Fomblin Z25, a commercial perfluoropolyalkylether liquid lubricant, was studied using the Penn State Micro-oxidation Test, and a thermal gravimetric/differential scanning calorimetry unit. The micro-oxidation test was conducted using 440C stainless steel and pure iron metal catalyst specimens, whereas the thermal gravimetric/differential scanning calorimetry tests were conducted using catalytic alumina pellets. Analysis of the thermal data, high pressure liquid chromatography data, and x-ray photoelectron spectroscopy data support evidence that there are two different decomposition mechanisms for Fomblin Z25, and that reductive sites on the catalytic surfaces are responsible for the decomposition of Fomblin Z25.

  8. THE RESOLVED STELLAR POPULATION IN 50 REGIONS OF M83 FROM HST/WFC3 EARLY RELEASE SCIENCE OBSERVATIONS

    SciTech Connect

    Kim, Hwihyun; Cohen, Seth H.; Windhorst, Rogier A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Whitmore, Bradley C.; Mutchler, Max; Bond, Howard E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Chandar, Rupali [Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Saha, Abhijit [National Optical Astronomy Observatories, Tucson, AZ 85726-6732 (United States); Kaleida, Catherine C. [Cerro Tololo Inter-American Observatory, La Serena (Chile); Calzetti, Daniela [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); O'Connell, Robert W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Balick, Bruce [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Carollo, Marcella [Department of Physics, ETH-Zurich, Zurich 8093 (Switzerland); Disney, Michael J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, Michael A. [Mount Stromlo and Siding Spring Observatories, Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Frogel, Jay A. [Galaxies Unlimited, 1 Tremblant Court, Lutherville, MD 21093 (United States); Hall, Donald N. B. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Holtzman, Jon A. [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); Kimble, Randy A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McCarthy, Patrick J., E-mail: hwihyun.kim@asu.edu [Observatories of the Carnegie Institution of Washington, Pasadena, CA 91101-1292 (United States); and others

    2012-07-01

    We present a multi-wavelength photometric study of {approx}15,000 resolved stars in the nearby spiral galaxy M83 (NGC 5236, D = 4.61 Mpc) based on Hubble Space Telescope Wide Field Camera 3 observations using four filters: F336W, F438W, F555W, and F814W. We select 50 regions (an average size of 260 pc by 280 pc) in the spiral arm and inter-arm areas of M83 and determine the age distribution of the luminous stellar populations in each region. This is accomplished by correcting for extinction toward each individual star by comparing its colors with predictions from stellar isochrones. We compare the resulting luminosity-weighted mean ages of the luminous stars in the 50 regions with those determined from several independent methods, including the number ratio of red-to-blue supergiants, morphological appearance of the regions, surface brightness fluctuations, and the ages of clusters in the regions. We find reasonably good agreement between these methods. We also find that young stars are much more likely to be found in concentrated aggregates along spiral arms, while older stars are more dispersed. These results are consistent with the scenario that star formation is associated with the spiral arms, and stars form primarily in star clusters and then disperse on short timescales to form the field population. The locations of Wolf-Rayet stars are found to correlate with the positions of many of the youngest regions, providing additional support for our ability to accurately estimate ages. We address the effects of spatial resolution on the measured colors, magnitudes, and age estimates. While individual stars can occasionally show measurable differences in the colors and magnitudes, the age estimates for entire regions are only slightly affected.

  9. Systemic endotoxin activity correlates with clot formation: an observational study in patients with early systemic inflammation and sepsis

    PubMed Central

    2013-01-01

    Introduction Inflammation and coagulation are closely linked, and both can be triggered by endotoxin. Thrombelastometry and impedance aggregometry are of diagnostic and predictive value in critically ill patients. In this observational study we investigated the correlation of endotoxin activity with thrombelasometric and aggregometric variables in patients with systemic inflammation. Methods Based on a daily screening on a tertiary academic surgical ICU, patients, as soon as they fulfilled two or more criteria for systemic inflammatory response syndrome (SIRS), were included. In whole blood we performed endotoxin activity (EA) assay, thrombelastometry (ROTEM®) and impendance aggregometry (Multiplate®). Results In total, 49 patients were included with a broad spread of EA levels of (median (minimum to maximum)) 0.27 (0.01 to 0.72), allowing expedient correlative analysis. Clot formation time (CFT) (263 s (60 to 1,438 s)) and clotting time (CT) (1,008 s (53 to 1,481 s)) showed a significant negative correlation with EA level (r = -0.38 (P < 0.005) and r = -0.29 (P < 0.05)). Positive correlations were found for alpha-angle (50° (17 to 78°), r = 0.40 (P < 0.005)) and maximum clot firmness (MCF) (55 mm (5/76), r = 0.27 (P < 0.05)). No significant correlations were found between Lysis Index at 60 minutes (LI60) and EA levels. There was no correlation between EA level and aggregometric values, or classical coagulation parameters. Conclusions In patients with systemic inflammation, increasing endotoxin concentrations correlate with increased clot formation. PMID:24025340

  10. Developing a General Understanding of the Decomposition Process: Results From a Network Experiment

    NASA Astrophysics Data System (ADS)

    Harmon, M. E.

    2007-12-01

    Although leaf and fine root litter undergo many changes during the process of decomposition, there is relatively little long-term data to develop a general, global level understanding of this process. The LIDET (Long-term Intersite Decomposition Experiment Team) study, conducted at 27 sites in North and Central America using a wide range of litter types, created a database suitable for this purpose. Analysis of the long-term pattern of mass loss indicated that while a slower, later phase of decomposition occurred in most cases for a substantial fraction (30%) it did not. These results imply that average long-term decomposition rates may be overestimated by up to a factor of 2 if based on short-term (1 year) decomposition losses. The relationship between wooden dowel decomposition and climatic indices indicated limits on the ability to predict decomposition rates for sites more favorable for decomposition, with a maximum coefficient of determination of 70%. Regression analysis of the relationship between climatic and substrate quality indices and decomposition rates indicated controls on decomposition processes changed from the early to late stages, with early-stage processes controlled by climate and initial litter chemistry, but late-stage processes more likely controlled by other factors such as the soil environment. Development of a mechanistic model based on AIC analysis indicates at least 3 litter fractions need to be considered and that a climatic index that combines the effects of temperature and moisture explains the most variation (70%). Analysis of the relationship between nitrogen release and mass loss indicated a global relationship exists that is largely dependent on the initial nitrogen content with 77% of the variation explained by this simple model. Overall the LIDET study indicated that there are general global patterns to long- term decomposition dynamics, however, current models indicate limits to our ability to predict global patterns of this important process.

  11. Decomposition rates and termite assemblage composition in semiarid Africa

    USGS Publications Warehouse

    Schuurman, G.

    2005-01-01

    Outside of the humid tropics, abiotic factors are generally considered the dominant regulators of decomposition, and biotic influences are frequently not considered in predicting decomposition rates. In this study, I examined the effect of termite assemblage composition and abundance on decomposition of wood litter of an indigenous species (Croton megalobotrys) in five terrestrial habitats of the highly seasonal semiarid Okavango Delta region of northern Botswana, to determine whether natural variation in decomposer community composition and abundance influences decomposition rates. 1 conducted the study in two areas, Xudum and Santawani, with the Xudum study preceding the Santawani study. I assessed termite assemblage composition and abundance using a grid of survey baits (rolls of toilet paper) placed on the soil surface and checked 2-4 times/month. I placed a billet (a section of wood litter) next to each survey bait and measured decomposition in a plot by averaging the mass loss of its billets. Decomposition rates varied up to sixfold among plots within the same habitat and locality, despite the fact that these plots experienced the same climate. In addition, billets decomposed significantly faster during the cooler and drier Santawani study, contradicting climate-based predictions. Because termite incidence was generally higher in Santawani plots, termite abundance initially seemed a likely determinant of decomposition in this system. However, no significant effect of termite incidence on billet mass loss rates was observed among the Xudum plots, where decomposition rates remained low even though termite incidence varied considerably. Considering the incidences of fungus-growing termites and non-fungus-growing termites separately resolves this apparent contradiction: in both Santawani and Xudum, only fungus-growing termites play a significant role in decomposition. This result is mirrored in an analysis of the full data set of combined Xudum and Santawani data. The determination that natural variation in the abundance of a single taxonomic group of soil fauna, a termite subfamily, determines almost all observed variation in decomposition rates supports the emerging view that biotic influences may be important in many biomes and that consideration of decomposer community composition and abundance may be critical for accurate prediction of decomposition rates. ?? 2005 by the Ecological Society of America.

  12. Evaluating litter decomposition and soil organic matter dynamics in earth system models: contrasting analysis of long-term litter decomposition and steady-state soil carbon

    NASA Astrophysics Data System (ADS)

    Bonan, G. B.; Wieder, W. R.

    2012-12-01

    Decomposition is a large term in the global carbon budget, but models of the earth system that simulate carbon cycle-climate feedbacks are largely untested with respect to litter decomposition. Here, we demonstrate a protocol to document model performance with respect to both long-term (10 year) litter decomposition and steady-state soil carbon stocks. First, we test the soil organic matter parameterization of the Community Land Model version 4 (CLM4), the terrestrial component of the Community Earth System Model, with data from the Long-term Intersite Decomposition Experiment Team (LIDET). The LIDET dataset is a 10-year study of litter decomposition at multiple sites across North America and Central America. We show results for 10-year litter decomposition simulations compared with LIDET for 9 litter types and 20 sites in tundra, grassland, and boreal, conifer, deciduous, and tropical forest biomes. We show additional simulations with DAYCENT, a version of the CENTURY model, to ask how well an established ecosystem model matches the observations. The results reveal large discrepancy between the laboratory microcosm studies used to parameterize the CLM4 litter decomposition and the LIDET field study. Simulated carbon loss is more rapid than the observations across all sites, despite using the LIDET-provided climatic decomposition index to constrain temperature and moisture effects on decomposition. Nitrogen immobilization is similarly biased high. Closer agreement with the observations requires much lower decomposition rates, obtained with the assumption that nitrogen severely limits decomposition. DAYCENT better replicates the observations, for both carbon mass remaining and nitrogen, without requirement for nitrogen limitation of decomposition. Second, we compare global observationally-based datasets of soil carbon with simulated steady-state soil carbon stocks for both models. The models simulations were forced with observationally-based estimates of annual litterfall and model-derived climatic decomposition index. While comparison with the LIDET 10-year litterbag study reveals sharp contrasts between CLM4 and DAYCENT, simulations of steady-state soil carbon show less difference between models. Both CLM4 and DAYCENT significantly underestimate soil carbon. Sensitivity analyses highlight causes of the low soil carbon bias. The terrestrial biogeochemistry of earth system models must be critically tested with observations, and the consequences of particular model choices must be documented. Long-term litter decomposition experiments such as LIDET provide a real-world process-oriented benchmark to evaluate models and can critically inform model development. Analysis of steady-state soil carbon estimates reveal additional, but here different, inferences about model performance.

  13. Clavulanic acid decomposition is catalyzed by the compound itself and by its decomposition products.

    PubMed

    Brethauer, Simone; Held, Martin; Panke, Sven

    2008-08-01

    The decomposition kinetics of the beta-lactamase inhibitor clavulanic acid (CA) was investigated for CA concentrations between 2.5 and 20 g L(-1), which is assumed to represent a characteristic range for an industrial CA production process. For each initial concentration, first order kinetics plots could be obtained, however the kinetic constant increased from 3.8 x 10(-3) to 8.6 x 10(-3) h(-1) with increasing initial CA concentration, indicating that CA accelerates its own decomposition by general acid-base catalysis. Furthermore, the kinetic constant remained approximately constant during the reaction, suggesting that also the decomposition products of CA had to show similar catalytic activity. This was confirmed experimentally by increased CA decomposition rates when CA degradation products were added to the reaction. A kinetic model is proposed, which is able to reliably predict the observed pseudo first order rate constants. The presented results should be considered in any process where highly concentrated CA solutions are employed, for example, during final downstream processing or in industrial fermentations. PMID:17969123

  14. Seasonal necrophagous insect community assembly during vertebrate carrion decomposition.

    PubMed

    Benbow, M E; Lewis, A J; Tomberlin, J K; Pechal, J L

    2013-03-01

    Necrophagous invertebrates have been documented to be a predominant driver of vertebrate carrion decomposition; however, very little is understood about the assembly of these communities both within and among seasons. The objective of this study was to evaluate the seasonal differences in insect taxa composition, richness, and diversity on carrion over decomposition with the intention that such data will be useful for refining error estimates in forensic entomology. Sus scrofa (L.) carcasses (n = 3-6, depending on season) were placed in a forested habitat near Xenia, OH, during spring, summer, autumn, and winter. Taxon richness varied substantially among seasons but was generally lower (1-2 taxa) during early decomposition and increased (3-8 taxa) through intermediate stages of decomposition. Autumn and winter showed the highest richness during late decomposition. Overall, taxon richness was higher during active decay for all seasons. While invertebrate community composition was generally consistent among seasons, the relative abundance of five taxa significantly differed across seasons, demonstrating different source communities for colonization depending on the time of year. There were significantly distinct necrophagous insect communities for each stage of decomposition, and between summer and autumn and summer and winter, but the communities were similar between autumn and winter. Calliphoridae represented significant indicator taxa for summer and autumn but replaced by Coleoptera during winter. Here we demonstrated substantial variability in necrophagous communities and assembly on carrion over decomposition and among seasons. Recognizing this variation has important consequences for forensic entomology and future efforts to provide error rates for estimates of the postmortem interval using arthropod succession data as evidence during criminal investigations. PMID:23540134

  15. In situ incubations highlight the environmental constraints on soil organic carbon decomposition

    Microsoft Academic Search

    David Risk; Lisa Kellman; Hugo Beltrami; Amanda Diochon

    2008-01-01

    We use root exclusion plots, subsurface gas sampling and in situ diffusivity measurements to quantify in situ soil organic carbon (SOC) decomposition dynamics within separate depth-dependent soil pools (0 and 35 cm). We contrast these measurements with observations of temperature-decomposition potentials, generated from laboratory incubations of the same soils at optimal moisture levels and native temperatures. The decomposition-temperature response was

  16. THERMAL DECOMPOSITION OF URANYL NITRATE HEXAHYDRATE

    Microsoft Academic Search

    Ondrejcin

    1963-01-01

    The thermal decomposition of uranyl nitrate hexahydrate was studied in ; the temperature range of 250to 400 deg C at atmospheric and at <0.1 mm pressure. ; The intermediate and final products of the decomposition were determined. The ; decomposition follows a zero-order reaction until less than half of the uranyl ; nitrate remains. The remaining portion of the decomposition

  17. Decomposition of graphs: some polynomial cases

    E-print Network

    Paris-Sud XI, Université de

    Decomposition of graphs: some polynomial cases Cristina Bazgan Zsolt Tuza Daniel Vanderpooten such a decomposition if it exists. We also give polynomial-time algorithms that always find a decomposition at least 5 such that d(v) a(v) + b(v) - 1 for all v V . Keywords: Graph, decomposition, degree

  18. Catalyst for sodium chlorate decomposition

    NASA Technical Reports Server (NTRS)

    Wydeven, T.

    1972-01-01

    Production of oxygen by rapid decomposition of cobalt oxide and sodium chlorate mixture is discussed. Cobalt oxide serves as catalyst to accelerate reaction. Temperature conditions and chemical processes involved are described.

  19. Algorithm for singular value decomposition

    SciTech Connect

    Ross, D.C.

    1984-01-01

    An iterative algorithm for the singular value decomposition (SVD) of a non-zero m x n matrix M is described and illustrated numerically. Derivations of the algorithm and sufficient conditions for convergence are outlined.

  20. Bridge Decomposition of Restriction Measures

    NASA Astrophysics Data System (ADS)

    Alberts, Tom; Duminil-Copin, Hugo

    2010-08-01

    Motivated by Kesten's bridge decomposition for two-dimensional self-avoiding walks in the upper half plane, we show that the conjectured scaling limit of the half-plane SAW, the SLE(8/3) process, also has an appropriately defined bridge decomposition. This continuum decomposition turns out to entirely be a consequence of the restriction property of SLE(8/3), and as a result can be generalized to the wider class of restriction measures. Specifically we show that the restriction hulls with index less than one can be decomposed into a Poisson Point Process of irreducible bridges in a way that is similar to Itô's excursion decomposition of a Brownian motion according to its zeros.

  1. Bridge Decomposition of Restriction Measures

    E-print Network

    Tom Alberts; Hugo Duminil-Copin

    2010-07-03

    Motivated by Kesten's bridge decomposition for two-dimensional self-avoiding walks in the upper half plane, we show that the conjectured scaling limit of the half-plane SAW, the SLE(8/3) process, also has an appropriately defined bridge decomposition. This continuum decomposition turns out to entirely be a consequence of the restriction property of SLE(8/3), and as a result can be generalized to the wider class of restriction measures. Specifically we show that the restriction hulls with index less than one can be decomposed into a Poisson Point Process of irreducible bridges in a way that is similar to Ito's excursion decomposition of a Brownian motion according to its zeros.

  2. Actual-Waste Tests of Enhanced Chemical Cleaning for Retrieval of SRS HLW Sludge Tank Heels and Decomposition of Oxalic Acid - 12256

    SciTech Connect

    Martino, Christopher J.; King, William D. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Ketusky, Edward T. [Savannah River Remediation, Aiken, SC 29808 (United States)

    2012-07-01

    Savannah River National Laboratory conducted a series of tests on the Enhanced Chemical Cleaning (ECC) process using actual Savannah River Site waste material from Tanks 5F and 12H. Testing involved sludge dissolution with 2 wt% oxalic acid, the decomposition of the oxalates by ozonolysis (with and without the aid of ultraviolet light), the evaporation of water from the product, and tracking the concentrations of key components throughout the process. During ECC actual waste testing, the process was successful in decomposing oxalate to below the target levels without causing substantial physical or chemical changes in the product sludge. During ECC actual waste testing, the introduction of ozone was successful in decomposing oxalate to below the target levels. This testing did not identify physical or chemical changes in the ECC product sludge that would impact downstream processing. The results from these tests confirm observations made by AREVA NP during larger scale testing with waste simulants. This testing, however, had a decreased utilization of ozone, requiring approximately 5 moles of ozone per mole of oxalate decomposed. Decomposition of oxalates in sludge dissolved in 2 wt% OA to levels near 100 ppm oxalate using ECC process conditions required 8 to 12.5 hours without the aid of UV light and 4.5 to 8 hours with the aid of UV light. The pH and ORP were tracked during decomposition testing. Sludge components were tracked during OA decomposition, showing that most components have the highest soluble levels in the initial dissolved sludge and early decomposition samples and exhibit lower soluble levels as OA decomposition progresses. The Deposition Tank storage conditions that included pH adjustment to approximately 1 M free hydroxide tended to bring the soluble concentrations in the ECC product to nearly the same level for each test regardless of storage time, storage temperature, and contact with other tank sludge material. (authors)

  3. Thermal decomposition of allylbenzene ozonide

    Microsoft Academic Search

    James C. Ewing; Daniel F. Church; William A. Pryor

    1989-01-01

    Thermal decomposition of allylbenzene ozonide (ABO) at 98°C in the liquid phase yields toluene, bibenzyl, phenylacetaldehyde, formic acid, and (benzyloxy)methyl formate as major products; benzyl chloride is formed when chlorinated solvents are employed. These products, as well as benzyl formate, are formed when ABO is decomposed at 37°C. When the decomposition of ABO is carried out in the presence of

  4. Orthogonal decomposition of Lorentz transformations

    E-print Network

    Jason Hanson

    2012-11-26

    The canonical decomposition of a Lorentz algebra element into a sum of orthogonal simple (decomposable) Lorentz bivectors is discussed, as well as the decomposition of a proper orthochronous Lorentz transformation into a product of commuting Lorentz transformations, each of which is the exponential of a simple bivector. As an application, we obtain an alternative method of deriving the formulas for the exponential and logarithm for Lorentz transformations.

  5. Atomic Decomposition by Basis Pursuit

    Microsoft Academic Search

    Scott Shaobing Chen; David L. Donoho

    1998-01-01

    The time-frequency and time-scale communities have recently developed a large number of overcomplete waveform dictionaries—stationary wavelets, wavelet packets, cosine packets, chirplets, and warplets, to name a few. Decomposition into overcomplete systems is not unique, and several methods for decomposition have been proposed, including the method of frames (MOF), matching pursuit (MP), and, for special dictionaries, the best orthogonal basis (BOB).

  6. Sector decomposition via computational geometry

    E-print Network

    Toshiaki Kaneko; Takahiro Ueda

    2010-04-30

    A non-iterative method is presented for the factorization step of sector decomposition method, which separates infrared divergent part from loop integration. This method is based on a classification of asymptotic behavior of polynomials. The problem is converted to ones for convex body in Euclidean space. They are solved with algorithms developed in computational geometry. A test implementation shows that this method produces less number of decomposed sectors than usual iterative sector decompositions.

  7. Discovery and preliminary confirmation of novel early detection biomarkers for triple-negative breast cancer using preclinical plasma samples from the Women’s Health Initiative observational study

    PubMed Central

    Li, Christopher I.; Mirus, Justin E.; Zhang, Yuzheng; Ramirez, Arturo B.; Ladd, Jon J.; Prentice, Ross L.; McIntosh, Martin; Hanash, Samir M.; Lampe, Paul D.

    2012-01-01

    Triple-negative breast cancer is a particularly aggressive and lethal breast cancer subtype that is more likely to be interval-detected rather than screen-detected. The purpose of this study is to discover and initially validate novel early detection biomarkers for triple-negative breast cancer using preclinical samples. Plasma samples collected up to 17 months prior to diagnosis from 28 triple-negative cases and 28 matched controls from the Women’s Health Initiative Observational Study were equally divided into a training set and a test set and interrogated using a customized antibody array. Data were available on 889 antibodies, and in the training set statistically significant differences in case vs. control signals were observed for 93 (10.5%) antibodies at p<0.05. Of these 93 candidates, 29 were confirmed in the test set at p<0.05. Areas under the curve for these candidates ranged from 0.58 to 0.79. With specificity set at 98%, sensitivity ranged from 4% to 68% with ?20 candidates having a sensitivity 20% and 6 having a sensitivity ?40%. In an analysis of KEGG gene sets, the pyrimidine metabolism gene set was upregulated in cases compared to controls (p=0.004 in the testing set) and the JAK/Stat signaling pathway gene set was downregulated (p=0.003 in the testing set). Numerous potential early detection biomarkers specific to triple-negative breast cancer in multiple pathways were identified. Further research is required to follow-up on promising candidates in larger sample sizes and to better understand their potential biological importance as our understanding of the etiology of triple-negative breast cancer continues to grow. PMID:22903690

  8. Effects of temperature gradient and elastic strain on spinodal decomposition and microstructure evolution of binary alloys

    NASA Astrophysics Data System (ADS)

    Li, Yongsheng; Pang, Yuxuan; Wu, Xingchao; Liu, Wei

    2014-04-01

    The phase-field model was extended to simulate spinodal decomposition under the temperature gradient and external elastic strain in binary alloys, and the variations of phase decomposition temperature and precipitate morphology were investigated. In the system with a temperature gradient, the phase decomposition happens gradually from low temperature to high temperature. The strain energy induced by the applied strain promotes spinodal decomposition, and the morphology orientation is intensified with the increase of temperature and applied strain. The inhomogeneous microstructure is induced under the temperature gradient and applied strain along the temperature increment. Promoted by the composition inhomogeneity of the early precipitates and applied strain, the transition of the spinodal decomposition to nucleation and growth occurred in the high temperature regions.

  9. Early impact of treatment with tiotropium, long-acting anticholinergic preparation, in patients with COPD – real-life experience from an observational study

    PubMed Central

    Jahnz-Ró?yk, Karina; Szepiel, Pawe?

    2015-01-01

    Background Long-acting inhaled bronchodilators, including anticholinergic tiotropium, are recommended for the maintenance therapy of chronic obstructive pulmonary disease (COPD). It has been shown in a number of studies that treatment with tiotropium alleviates symptoms, improves exercise tolerance, health status, and reduces exacerbations in patients with moderate to very severe stage COPD. Aim The aim of this noninterventional study was to observe the early effects of the maintenance treatment with tiotropium in patients with COPD of different severities, who had been previously treated on a regular basis, or as required, with at least one short-acting bronchodilator, in a real-life setting in Poland. The effect of the treatment was assessed through the collection of COPD Assessment Test (CAT) data. Patients and methods The MATHS clinical study was an observational, noninterventional, open-label, prospective, uncontrolled, single-arm, postmarketing, surveillance, real-life study conducted with the involvement of 236 pulmonology clinics based in Poland. The tiotropium observational period was 3 months. The health and COPD status was measured with the CAT questionnaire. The primary efficacy endpoint was the mean change from the baseline in the total CAT score at the end of the 3-month observational period. Results Patients treated with 18 ?g of tiotropium once daily for 3 months showed a statistically significant result, with a clinically meaningful mean reduction (improvement) of 7.0 points in the total CAT score. The improvement was slightly greater in patients with more severe COPD; the mean change in the total CAT score was 7.6 in the subgroup of patients with more severe COPD and 6.7 points in the subgroup of patients with moderate COPD. Conclusion Results of this real-life study provide further support for the use of tiotropium as a first-line maintenance treatment for patients with COPD of different severities in Poland.

  10. Solving Polynomial Systems via Triangular Decomposition (Spine title: Solving Polynomial Systems via Triangular Decomposition)

    E-print Network

    Moreno Maza, Marc

    Solving Polynomial Systems via Triangular Decomposition (Spine title: Solving Polynomial Systems via Triangular Decomposition) (Thesis format: Monograph) by Changbo Chen Graduate Program in Computer Polynomial Systems via Triangular Decomposition is accepted in partial fulfillment of the requirements

  11. Decomposition of Protein Tryptophan Fluorescence Spectra into Log-Normal Components. I. Decomposition Algorithms

    E-print Network

    Rhode Island, University of

    Decomposition of Protein Tryptophan Fluorescence Spectra into Log-Normal Components. I. Decomposition Algorithms Edward A. Burstein, Sergei M. Abornev, and Yana K. Reshetnyak Institute of Theoretical algorithms of decomposition of composite protein tryptophan fluorescence spectra were developed based

  12. Mon. Not. R. Astron. Soc. (2007) doi:10.1111/j.1365-2966.2007.12487.x Observational evidence for AGN feedback in early-type galaxies

    E-print Network

    Thomas, Daniel

    ­mass diagram. Star-forming early-types inhabit the blue cloud, while early-types with AGN are located: galaxies: active ­ galaxies: elliptical and lenticular, cD ­ galaxies: evolution ­ galaxies: formation. 1

  13. Experimental Schmidt Decomposition and Entanglement Detection

    E-print Network

    Laskowski, Wieslaw; Schwemmer, Christian; Paterek, Tomasz; Weinfurter, Harald

    2011-01-01

    We introduce an experimental procedure for the detection of quantum entanglement of an unknown quantum state with as few measurements as possible. The method requires neither a priori knowledge of the state nor a shared reference frame between the observers. The scheme starts with local measurements, possibly supplemented with suitable filtering, that can be regarded as calibration. Consecutive correlation measurements enable detection of the entanglement of the state. We utilize the fact that the calibration stage essentially establishes the Schmidt decomposition for pure states. Alternatively we develop a decision tree which reveals entanglement within few steps. These methods are illustrated and verified experimentally for various two-qubit entangled states.

  14. BIODIVERSITY AND LITTER DECOMPOSITION IN TERRESTRIAL ECOSYSTEMS

    Microsoft Academic Search

    Stephan Hattenschwiler; Alexei V. Tiunov; Stefan Scheu

    2005-01-01

    ? Abstract We explore empirical and theoretical evidence,for the functional sig- nificance of plant-litter diversity and the extraordinary,high diversity of decomposer organisms,in the process of litter decomposition,and the consequences,for biogeochem- ical cycles. Potential mechanisms,for the frequently observed,litter-diversity effects on mass,loss and nitrogen dynamics,include fungi-driven nutrient transfer among,litter species, inhibition or stimulation of microorganisms by specific litter compounds, and positive feedback,of

  15. Kinetics of the pyrolytic and hydrothermal decomposition of water hyacinth.

    PubMed

    Luo, Guang'en; Strong, P James; Wang, Hailong; Ni, Wuzhong; Shi, Weiyong

    2011-07-01

    The kinetics of water hyacinth decomposition using pyrolysis and hydrothermal treatment was compared. With pyrolysis, initial vaporization occurred at 453 K as determined by thermogravimetric analysis, while initial solubilisation occurred at 433 K with subcritical hydrothermal treatment. The "kinetic triplet" was determined for the ranges of 423-483 K (range I) and 473-553 K (range II) using the Coats-Redfern method for both treatments. The calculated activation energies for ranges I and II were 110 and 116 kJ/mol for conventional pyrolysis and 145 and 90 kJ/mol for hydrothermal treatment. The similar activation energies for the two temperature ranges observed for pyrolysis implied that only hemicellulose decomposition occurred. For hydrothermal treatment, both hemicellulose and cellulose decomposition occurred in temperature range II, in which a notable lower activation energy was observed. This implied hydrothermal treatment was more suitable for conversion lignocellulosic biomass under these conditions. PMID:21558054

  16. Radio-cesium accumulation during decomposition of leaf litter in a deciduous forest after the Fukushima NPP accident.

    NASA Astrophysics Data System (ADS)

    Kaneko, Nobuhiro; Huang, Yao; Nakamori, Taizo; Tanaka, Yoichiro; Nonaka, Masanori

    2013-04-01

    Fukusima NPP accident contaminated vast area in eastern Japan with radio isotopes. Most of the area is covered by natural and plantation forest. The forest floor in deciduous forests, and canopy of evergreen forest were most contaminated by fall out. Radio-cesium is known to stay bioavailable in forest ecosystems for long time, and it is necessary to cut the cycling process to decontaminate the forest ecosystem. Ecological process to recycle radio-Cs in forest ecosystem should be studied to enhance decontamination of radio-Cs. Mushrooms show high concentration of Cs. Although mushroom biomass in a forest ecosystem is small, fungal mycelium in detritus and soil is large, thus fungi contain substantial amount of radio-Cs. It is well known that concentration of some nutrients, such as nitrogen and phosphorus, increase, whereas potassium decreases during the leaf litter decomposition. We observed radio-Cs concentration of leaf litter during decomposition on a forest floor where 134-Cs and 137-Cs of surface soil were 5,700, and 6,800 Bq/kg, respectively. We put 16 g (dry weight) of newly fallen mixed deciduous leaf litter (half of which was oak, Quercus serrata) into 25 cm x 25 cm litter bag (2 mm mesh size) in a deciduous forest about 50 km from Fukushima NPP. Fresh litter 137-Cs concentration was ca. 1,000 Bq/kg in December 2011. During the decomposition process on the forest floor, litter Cs increased exponentially and exceeded 10,000 Bq/kg after 6 months, indicating that Cs and K show contrasting dynamics during early decomposition phase. Increase in fungal biomass in the early stage of litter decomposition was observed. Therefore, this upward movement of Cs from humus and soil layer suggests fungal translocation of nutrients from outside of litter substrate. Retrieving the litter after 6 months can remove 18.0% of 134-Cs. Interaction between fungal species, grazing effect on fungi by fungivorous invertebrates will change the amount of translocation of radio-Cs from soil to decomposing litter.

  17. Gauge-invariant decomposition of nucleon spin

    SciTech Connect

    Wakamatsu, M. [Department of Physics, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2010-06-01

    We investigate the relation between the known decompositions of the nucleon spin into its constituents, thereby clarifying in what respect they are common and in what respect they are different essentially. The decomposition recently proposed by Chen et al. can be thought of as a nontrivial generalization of the gauge-variant Jaffe-Manohar decomposition so as to meet the gauge-invariance requirement of each term of the decomposition. We however point out that there is another gauge-invariant decomposition of the nucleon spin, which is closer to the Ji decomposition, while allowing the decomposition of the gluon total angular momentum into the spin and orbital parts. After clarifying the reason why the gauge-invariant decomposition of the nucleon spin is not unique, we discuss which decomposition is more preferable from an experimental viewpoint.

  18. Nitrogen fixation associated with the leaf litter of Japanese cedar (Cryptomeria Japonica) of various decomposition stages

    Microsoft Academic Search

    Ichio Nioh

    1980-01-01

    Leaf litter and organic layer samples from Japanese cedar (Cryptomeria japonica) forests with varying decomposition stages were tested for nitrogen-fixing (acetylene-reducing) activities. The result obtained with samples from Gifu University Forest in Kuraiyama indicated that nitrogen-fixing activity was found almost exclusively at a certain limited stage of decomposition, possibly a fairly early stage termed F1 fraction. Specific activity for acetylene

  19. Constraining Galaxy Evolution With Bulge-Disk-Bar Decomposition

    E-print Network

    Tim Weinzirl; Shardha Jogee; Fabio D. Barazza

    2008-02-26

    Structural decomposition of galaxies into bulge, disk, and bar components is important to address a number of scientific problems. Measuring bulge, disk, and bar structural parameters will set constraints on the violent and secular processes of galaxy assembly and recurrent bar formation and dissolution models. It can also help to quantify the fraction and properties of bulgeless galaxies (those systems having no bulge or only a relatively insignificant disky-pseudobulges), which defy galaxy formation paradigms requiring almost every disk galaxy to have a classical bulge at its core. We demonstrate a proof of concept and show early results of our ongoing three-component bulge-disk-bar decomposition of NIR images for a sample of three complementary samples spanning different epochs and different environments (field and cluster). In contrast to most early studies, which only attempt two-component bulge-disk decomposition, we fit three components using GALFIT: a bulge, a disk, and a bar. We show that it is important to include the bar component, as this can significantly lower the bulge-to-total luminosity ratio (B/T), in many cases by a factor of two or more, thus effectively changing the Hubble type of a galaxy from early to late.

  20. Moessbauer spectroscopy evidence of a spinodal mechanism for the thermal decomposition of fcc FeCu

    SciTech Connect

    Crespo, P. [IMA, Madrid (Spain)] [IMA, Madrid (Spain); [CENIM-CSIC, Madrid (Spain); Barro, M.J.; Hernando, A. [IMA, Madrid (Spain)] [IMA, Madrid (Spain); Escorial, A.G. [CENIM-CSIC, Madrid (Spain)] [CENIM-CSIC, Madrid (Spain); Menendez, N.; Tornero, J.D. [UAM, Madrid (Spain). Dpto. Quimica-Fisica Aplicada] [UAM, Madrid (Spain). Dpto. Quimica-Fisica Aplicada; Barandiaran, J.M. [Univ. del Pais Vasco, Bilbao (Spain)] [Univ. del Pais Vasco, Bilbao (Spain)

    1998-07-24

    Moessbauer spectroscopy shows the existence of compositional fluctuations, where different Fe environments coexist, during decomposition upon heat treatment of metastable f.c.c. FeCu solid solution. The presence of isolated Fe atoms in the Cu matrix, f.c.c. Fe{sub rich}Cu, f.c.c. FeCu{sub rich} and b.c.c. Fe has been detected in early decomposition stages. At later decomposition stages, low temperature Moessbauer spectroscopy indicates the presence of a broad distribution of Curie temperatures, coexisting with isolated Fe atoms in the Cu matrix, f.c.c. Fe and b.c.c. Fe.

  1. Meshless helmholtz-hodge decomposition.

    PubMed

    Petronetto, Fabiano; Paiva, Afonso; Lage, Marcos; Tavares, Geovan; Lopes, Hélio; Lewiner, Thomas

    2010-01-01

    Vector fields analysis traditionally distinguishes conservative (curl-free) from mass preserving (divergence-free) components. The Helmholtz-Hodge decomposition allows separating any vector field into the sum of three uniquely defined components: curl free, divergence free and harmonic. This decomposition is usually achieved by using mesh-based methods such as finite differences or finite elements. This work presents a new meshless approach to the Helmholtz-Hodge decomposition for the analysis of 2D discrete vector fields. It embeds into the SPH particle-based framework. The proposed method is efficient and can be applied to extract features from a 2D discrete vector field and to multiphase fluid flow simulation to ensure incompressibility. PMID:20075492

  2. Surgical Data and Early Postoperative Outcomes after Minimally Invasive Lumbar Interbody Fusion: Results of a Prospective, Multicenter, Observational Data-Monitored Study

    PubMed Central

    Pereira, Paulo; Buzek, David; Franke, Jörg; Senker, Wolfgang; Kosmala, Arkadiusz; Hubbe, Ulrich; Manson, Neil; Rosenberg, Wout; Assietti, Roberto; Martens, Frederic; Barbanti Brodano, Giovanni; Scheufler, Kai-Michael

    2015-01-01

    Minimally invasive lumbar interbody fusion (MILIF) offers potential for reduced operative morbidity and earlier recovery compared with open procedures for patients with degenerative lumbar disorders (DLD). Firm conclusions about advantages of MILIF over open procedures cannot be made because of limited number of large studies of MILIF in a real-world setting. Clinical effectiveness of MILIF in a large, unselected real-world patient population was assessed in this Prospective, monitored, international, multicenter, observational study. Objective: To observe and document short-term recovery after minimally invasive interbody fusion for DLD. Materials and Methods: In a predefined 4-week analysis from this study, experienced surgeons (?30 MILIF surgeries pre-study) treated patients with DLD by one- or two-level MILIF. The primary study objective was to document patients’ short-term post-interventional recovery (primary objective) including back/leg pain (visual analog scale [VAS]), disability (Oswestry Disability Index [ODI]), health status (EQ-5D) and Patient satisfaction. Results: At 4 weeks, 249 of 252 patients were remaining in the study; the majority received one-level MILIF (83%) and TLIF was the preferred approach (94.8%). For one-level (and two-level) procedures, surgery duration was 128 (182) min, fluoroscopy time 115 (154) sec, and blood-loss 164 (233) mL. Time to first ambulation was 1.3 days and time to study-defined surgery recovery was 3.2 days. Patients reported significantly (P < 0.0001) reduced back pain (VAS: 2.9 vs 6.2), leg pain (VAS: 2.5 vs 5.9), and disability (ODI: 34.5% vs 45.5%), and a significantly (P < 0.0001) improved health status (EQ-5D index: 0.61 vs 0.34; EQ VAS: 65.4 vs 52.9) 4 weeks postoperatively. One adverse event was classified as related to the minimally invasive surgical approach. No deep site infections or deaths were reported. Conclusions: For experienced surgeons, MILIF for DLD demonstrated early benefits (short time to first ambulation, early recovery, high patient satisfaction and improved patient-reported outcomes) and low major perioperative morbidity at 4 weeks postoperatively. PMID:25811615

  3. Thermal decomposition and non-isothermal decomposition kinetics of carbamazepine

    NASA Astrophysics Data System (ADS)

    Qi, Zhen-li; Zhang, Duan-feng; Chen, Fei-xiong; Miao, Jun-yan; Ren, Bao-zeng

    2014-12-01

    The thermal stability and kinetics of isothermal decomposition of carbamazepine were studied under isothermal conditions by thermogravimetry (TGA) and differential scanning calorimetry (DSC) at three heating rates. Particularly, transformation of crystal forms occurs at 153.75°C. The activation energy of this thermal decomposition process was calculated from the analysis of TG curves by Flynn-Wall-Ozawa, Doyle, distributed activation energy model, Šatava-Šesták and Kissinger methods. There were two different stages of thermal decomposition process. For the first stage, E and log A [s-1] were determined to be 42.51 kJ mol-1 and 3.45, respectively. In the second stage, E and log A [s-1] were 47.75 kJ mol-1 and 3.80. The mechanism of thermal decomposition was Avrami-Erofeev (the reaction order, n = 1/3), with integral form G(?) = [-ln(1 - ?)]1/3 (? = ˜0.1-0.8) in the first stage and Avrami-Erofeev (the reaction order, n = 1) with integral form G(?) = -ln(1 - ?) (? = ˜0.9-0.99) in the second stage. Moreover, ? H ?, ? S ?, ? G ? values were 37.84 kJ mol-1, -192.41 J mol-1 K-1, 146.32 kJ mol-1 and 42.68 kJ mol-1, -186.41 J mol-1 K-1, 156.26 kJ mol-1 for the first and second stage, respectively.

  4. Convexity Rule for Shape Decomposition Based on Discrete Contour Evolution

    Microsoft Academic Search

    Longin Jan Latecki; Rolf Lakämper

    1999-01-01

    We concentrate here on decomposition of 2D objects into mean- ingful parts of visual form ,o rvisual parts. It is a simple observation that convex parts of objects determine visual parts. However, the problem is that many significant visual parts are not convex, since a visual part may have concavities. We solve this problem by identify- ing convex parts at

  5. Symmetry of Attractors and the KarhunenLo`eve Decomposition

    E-print Network

    Nicol, Matthew

    Symmetry of Attractors and the Karhunen­Lo`eve Decomposition Michael Dellnitz Department in the time­average of an appropriate observable such as the intensity of transmitted light in the Faraday] have investigated the Faraday surface wave model, looking for indications of pattern on average

  6. A new seismogeodetic approach applied to GPS and accelerometer observations of the 2012 Brawley seismic swarm: Implications for earthquake early warning

    NASA Astrophysics Data System (ADS)

    Geng, Jianghui; Bock, Yehuda; Melgar, Diego; Crowell, Brendan W.; Haase, Jennifer S.

    2013-07-01

    The 26 August 2012 Brawley seismic swarm of hundreds of events ranging from M1.4 to M5.5 in the Salton Trough, California provides a unique data set to investigate a new seismogeodetic approach that combines Global Positioning System (GPS) and accelerometer observations to estimate displacement and velocity waveforms. First in simulated real-time mode, we analyzed 1-5 Hz GPS data collected by 17 stations fully encircling the swarm zone at near-source distances up to about 40 km using precise point positioning with ambiguity resolution (PPP-AR). We used a reference network of North American GPS stations well outside the region of deformation to estimate fractional-cycle biases and satellite clock parameters, which were then combined with ultrarapid orbits from the International GNSS Service to estimate positions during the Brawley seismic swarm. Next, we estimated seismogeodetic displacements and velocities from GPS phase and pseudorange observations and 100-200 Hz accelerations collected at three pairs of GPS and seismic stations in close proximity using a new tightly coupled Kalman filter approach as an extension of the PPP-AR process. We can clearly discern body waves in the velocity waveforms, including P-wave arrivals not detectable with the GPS-only approach for earthquake magnitudes as low as Mw 4.6 and significant static offsets for magnitudes as low as Mw 5.4. Our study shows that GPS networks upgraded with strong motion accelerometers can provide new information for improved understanding of the earthquake rupture process and be of critical value in creating a robust early warning system for any earthquake of societal significance.

  7. Subaru/COMICS Mid-Infrared Observation of the Near-Nucleus Region of Comet 17P/Holmes at the Early Phase of an Outburst

    NASA Astrophysics Data System (ADS)

    Watanabe, Jun-Ichi; Honda, Mitsuhiko; Ishiguro, Masateru; Ootsubo, Takafumi; Sarugaku, Yuki; Kadono, Toshihiko; Sakon, Itsuki; Fuse, Tetsuharu; Takato, Naruhisa; Furusho, Reiko

    2009-08-01

    Mid-infrared 8--25?m imaging and spectroscopic observations of the comet 17P/Holmes in the early phase of its outburst in brightness were performed on 2007 October 25--28UT using the Cooled Mid-Infrared Camera and Spectrometer (COMICS) on the 8.2-m Subaru Telescope. We detected an isolated dust cloud that moved toward the south-west direction from the nucleus. The 11.2?m peak of a crystalline silicate feature onto a broad amorphous silicate feature was also detected both in the central condensation of the nucleus and an isolated dust cloud. The color temperature of the isolated dust cloud was estimated to be ˜200K, which is slightly higher than the black-body temperature. Our analysis of the motion indicates that the isolated cloud moved anti-sunward. We propose several possibilities for the motion of the cloud: fluffy dust particles in the isolated cloud started to depart from the nucleus due to radiation pressure almost as soon as the main outburst occurred, or dust particles moved by some other anti-sunward forces, such as a rocket effect and photophoresis when the surrounding dust coma became optically thin. The origin and the nature of the isolated dust cloud are discussed in this paper.

  8. Graphs States and the necessity of Euler Decomposition

    E-print Network

    Ross Duncan; Simon Perdrix

    2009-02-03

    Coecke and Duncan recently introduced a categorical formalisation of the interaction of complementary quantum observables. In this paper we use their diagrammatic language to study graph states, a computationally interesting class of quantum states. We give a graphical proof of the fixpoint property of graph states. We then introduce a new equation, for the Euler decomposition of the Hadamard gate, and demonstrate that Van den Nest's theorem--locally equivalent graphs represent the same entanglement--is equivalent to this new axiom. Finally we prove that the Euler decomposition equation is not derivable from the existing axioms.

  9. [Characteristics of the biochemical composition of plant litter at different stages of decomposition (according to thermal analysis data)].

    PubMed

    Kosheleva, Iu P; Trofimov, S Ia

    2008-01-01

    The composition of samples of needles, leaves, sheaved cottongrass (Eriophorum vaginatum) tissues, and the L horizon of the forest floor of different degree of decomposition, isolated from the plant litter in southern taiga ecosystems, was studied by thermal analysis. It was established that plant litter decomposition is accompanied by structural changes in celluloses and that the decomposition rates of hemicellulose and structured cellulose vary at different stages of decomposition. The structural specificity and incongruent thermal decomposition of grass lignocellulose were observed in all samples of plant material. The rates at which the content of components of the plant litter decreased depended on the type and stage of decomposition of plant material. The decomposition rate of biochemical components tended to increase in better drained soils. PMID:18491564

  10. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Products 2 2013-01-01 2013-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  11. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Products 2 2011-01-01 2011-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  12. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Products 2 2014-01-01 2014-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  13. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Products 2 2012-01-01 2012-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  14. 9 CFR 381.93 - Decomposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Products 2 2010-01-01 2010-01-01 false Decomposition. 381.93 Section 381.93 Animals and Animal Products...Inspection; Disposition of Carcasses and Parts § 381.93 Decomposition. Carcasses of poultry deleteriously affected by...

  15. Tremolite Decomposition and Water on Venus

    NASA Technical Reports Server (NTRS)

    Johnson, N. M.; Fegley, B., Jr.

    2000-01-01

    We present experimental data showing that the decomposition rate of tremolite, a hydrous mineral, is sufficiently slow that it can survive thermal decomposition on Venus over geologic timescales at current and higher surface temperatures.

  16. Photocatalytic decomposition of cortisone acetate in aqueous solution.

    PubMed

    Romão, Joana Sobral; Hamdy, Mohamed S; Mul, Guido; Baltrusaitis, Jonas

    2015-01-23

    The photocatalytic decomposition of cortisone 21-acetate (CA), a model compound for the commonly used steroid, cortisone, was studied. CA was photocatalytically decomposed in a slurry reactor with the initial rates between 0.11 and 0.46 mg L(-1)min(-1) at 10 mg L(-1) concentration, using the following heterogeneous photocatalysts in decreasing order of their catalytic activity: ZnO>Evonik TiO2 P25>Hombikat TiO2>WO3. Due to the lack of ZnO stability in aqueous solutions, TiO2 P25 was chosen for further experiments. The decomposition reaction was found to be pseudo-first order and the rate constant decreased as a function of increasing initial CA concentration. Changing the initial pH of the CA solution did not affect the reaction rate significantly. The decomposition reaction in the presence of the oxidizing sacrificial agent sodium persulfate showed an observed decomposition rate constant of 0.004 min(-1), lower than that obtained for TiO2 P25 (0.040 min(-1)). The highest photocatalytic degradation rate constant was obtained combining both TiO2 P25 and S2O8(2-) (0.071 min(-1)) showing a synergistic effect. No reactive intermediates were detected using LC-MS showing fast photocatalytic decomposition kinetics of CA. PMID:24953705

  17. Kinetic modeling of Pt-catalyzed glycolaldehyde decomposition to syngas.

    PubMed

    Salciccioli, Michael; Vlachos, Dionisios G

    2012-05-10

    Fundamental knowledge of the elementary reaction mechanisms involved in oxygenate decomposition on transition metal catalysts can facilitate the optimization of future catalyst and reactor systems for biomass upgrade to fuels and chemicals. Pt-catalyzed decomposition of glycolaldehyde, as the smallest oxygenate with alcohol and aldehyde functionality, was studied via a DFT-based microkinetic model. It was found that two decomposition pathways exist. Under conditions of low hydrogen surface coverage, the initial C-H bond breaking reaction to HOCH(2)CO* is prevalent, while under conditions of high hydrogen coverage, the rather unexpected O-H bond forming reaction to HOCH(2)CHOH* is more active (subsequent decomposition is energetically favorable from HOCH(2)CHOH*). Our results indicate the possibility that (de)hydrogenation chemistry is rate-controlling in many small polyoxygenate biomass derivatives, and suitable catalysts are needed. Finally, DFT was used to understand the increased decomposition activity observed on the surface segregated Ni-Pt-Pt bimetallic catalyst. It was found that the initial O-H bond breaking of glycolaldehyde to OCH(2)CHO* has an activation barrier of just 0.21 eV. This barrier is lower than that of any glycolaldehyde consuming reaction on Pt. These computational predictions are in qualitative agreement with experimental results. PMID:22483365

  18. Exsolution by spinodal decomposition in multicomponent mineral solutions

    PubMed Central

    Petrishcheva, E.; Abart, R.

    2012-01-01

    Phase separation in a three-component system that results from the uphill diffusion of chemical components is considered. The binary decomposition model of Cahn and Hilliard is generalized to account for the interdiffusion of several chemical components with considerably different diffusion constants. Thereafter the decomposition dynamics and the phase relations of the final system state are investigated by means of finite-element modeling. Examples from a hypothetical regular solution and from ternary feldspar are addressed. Special attention is given to situations in which different diffusivities affect decomposition dynamics and the final system states. Good qualitative agreement between our modeling and petrographic observations on exsolved feldspar is achieved. Our model explains systematic deviations from equilibrium element partitioning between the two phases exsolving from an initially homogeneous ternary feldspar during slow cooling. PMID:23888123

  19. Exsolution by spinodal decomposition in multicomponent mineral solutions.

    PubMed

    Petrishcheva, E; Abart, R

    2012-09-01

    Phase separation in a three-component system that results from the uphill diffusion of chemical components is considered. The binary decomposition model of Cahn and Hilliard is generalized to account for the interdiffusion of several chemical components with considerably different diffusion constants. Thereafter the decomposition dynamics and the phase relations of the final system state are investigated by means of finite-element modeling. Examples from a hypothetical regular solution and from ternary feldspar are addressed. Special attention is given to situations in which different diffusivities affect decomposition dynamics and the final system states. Good qualitative agreement between our modeling and petrographic observations on exsolved feldspar is achieved. Our model explains systematic deviations from equilibrium element partitioning between the two phases exsolving from an initially homogeneous ternary feldspar during slow cooling. PMID:23888123

  20. Pressure-induced decomposition of indium hydroxide.

    PubMed

    Gurlo, Aleksander; Dzivenko, Dmytro; Andrade, Miria; Riedel, Ralf; Lauterbach, Stefan; Kleebe, Hans-Joachim

    2010-09-15

    A static pressure-induced decomposition of indium hydroxide into metallic indium that takes place at ambient temperature is reported. The lattice parameter of c-In(OH)(3) decreased upon compression from 7.977(2) to approximately 7.45 A at 34 GPa, corresponding to a decrease in specific volume of approximately 18%. Fitting the second-order Birch-Murnaghan equation of state to the obtained compression data gave a bulk modulus of 99 +/- 3 GPa for c-In(OH)(3). The c-In(OH)(3) crystals with a size of approximately 100 nm are comminuted upon compression, as indicated by the grain-size reduction reflected in broadening of the diffraction reflections and the appearance of smaller (approximately 5 nm) incoherently oriented domains in TEM. The rapid decompression of compressed c-In(OH)(3) leads to partial decomposition of indium hydroxide into metallic indium, mainly as a result of localized stress gradients caused by relaxation of the highly disordered indium sublattice in indium hydroxide. This partial decomposition of indium hydroxide into metallic indium is irreversible, as confirmed by angle-dispersive X-ray diffraction, transmission electron microscopy imaging, Raman scattering, and FTIR spectroscopy. Recovered c-In(OH)(3) samples become completely black and nontransparent and show typical features of metals, i.e., a falling absorption in the 100-250 cm(-1) region accompanied by a featureless spectrum in the 250-2500 cm(-1) region in the Raman spectrum and Drude-like absorption of free electrons in the region of 4000-8000 cm(-1) in the FTIR spectrum. These features were not observed in the initial c-In(OH)(3), which is a typical white wide-band-gap semiconductor. PMID:20731389

  1. The ecology of carrion decomposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrion, or the remains of dead animals, is something that most people would like to avoid. It is visually unpleasant, emits foul odors, and may be the source of numerous pathogens. Decomposition of carrion, however, provides a unique opportunity for scientists to investigate how nutrients cycle t...

  2. Cadaver decomposition in terrestrial ecosystems

    NASA Astrophysics Data System (ADS)

    Carter, David O.; Yellowlees, David; Tibbett, Mark

    2007-01-01

    A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.

  3. Cadaver decomposition in terrestrial ecosystems.

    PubMed

    Carter, David O; Yellowlees, David; Tibbett, Mark

    2007-01-01

    A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems. PMID:17091303

  4. Amino Acid Free Energy Decomposition

    Microsoft Academic Search

    Hui Wang; Michael Fairchild; Dennis Livesay; Donald Jacobs

    2009-01-01

    The Distance Constraint Model (DCM) describes protein thermodynamics at a coarse-grained level based on a Free Energy Decomposition (FED) that assigns energy and entropy contributions to specific molecular interactions. Application of constraint theory accounts for non-additivity in conformational entropy so that the total free energy of a system can be reconstituted from all its molecular parts. In prior work, a

  5. AVALANCHES, SANDPILES AND TUTTE DECOMPOSITION

    E-print Network

    Gabrielov, Andrei

    AVALANCHES, SANDPILES AND TUTTE DECOMPOSITION Andrei GABRIELOV Department of Geology, Cornell and avalanche models of failure were introduced recently (Bak et al., 1987, and an avalanche of publications properties of an important class of these models, Abelian sandpiles (Dhar, 1990) and Abelian avalanches

  6. Observations of Seafloor Outcrops in the Oblique Subduction Setting of Adak Canyon: Implications for Understanding the Early History of the Aleutian Island Arc

    NASA Astrophysics Data System (ADS)

    Yogodzinski, G.; Scholl, D.; Jicha, B.; Wyatt, C.; Singer, B.; Kelemen, P.

    2004-12-01

    Submarine canyons in the western Aleutians (west of 177°W) are formed by oblique subduction, which has broken crustal blocks away from the arc massif and rotated them in clockwise sense, resulting in the formation of triangular-shaped summit basins and deep, structurally controlled submarine canyons (Geist et al., Tectonics v7, p327, 1988). A series of dives with the ROV Jason II on July 28-30, 2004 on Adak Canyon has provided the first-ever view of seafloor outcrops in an Aleutian canyon formed by this process. Two dives on the canyon's steep eastern wall revealed extensive exposures of blocky outcrops of volcanic rock at depths of 2900-1500 m. Samples of these units collected by the Jason II are a mixture of dark, pyroxene and plagioclase-phyric lavas and volcaniclastics. Degree of weathering/alteration is highly variable but some samples appear fresh. We anticipate that these rocks are offshore-equivalents of the Finger Bay Volcanics, which represent the earliest phase of Aleutian volcanism exposed on nearby Adak Island (e.g., Coats, 1956, USGS Bull. 1028-C). Exposures of granitic rock in Adak Canyon form low ledges of exfoliating outcrop interspersed with spheroidally weathered, bouldery sub-crop, in the depth range of 1800-1600 meters. Obtaining in-situ samples from these massive and subrounded exposures was not possible with the Jason II, but recovery of large, sub-angular slabs that litter the surface included samples of fresh diorite, fine-grained felsic intrusives and hydrothermally altered volcanic country rock. The stratigraphically highest exposures observed in Adak Canyon are gently dipping, poorly lithified `Middle Series' sedimentary rocks of probable Miocene-Oligocene age. All outcrop surfaces in Adak Canyon are covered with a uniformly dark brown, opaque coating of Mn oxide less than 1mm thick. Well-rounded cobbles and boulders interpreted to be glacial drift are largely free of Mn oxide coatings. Thick pavements of Mn-oxide were not observed. These observations indicate that combined seismic and dredging-geochemical studies will be a successful approach to unraveling the complete magmatic and tectonic history of the Aleutian arc crust, which due to the absence of significant arc-parallel rifting and backarc spreading remains largely intact and available for study. Dating and geochemical analysis of samples recovered on the July '04 Jason II expedition will provide a much-improved view of early Aleutian history.

  7. Balanced 0 1 Matrices Part I: Decomposition

    E-print Network

    Cornuejols, Gerard P.

    Balanced 0 1 Matrices Part I: Decomposition Michele Conforti Gerard Cornuejols y Ajai Kapoor z extends the decomposition of balanced 0 1 matrices obtained by Conforti, Cornuejols and Rao to the class is a multiple of four. This paper extends the decomposition of balanced 0 1 matrices obtained by Conforti

  8. MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE FRACTALS

    E-print Network

    Mauldin, R. Daniel

    MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE FRACTALS G. A. Edgar and R. Daniel Mauldin that the multifractal decomposition behaves as expected for a family of sets K known as digraph recursive fractals OF DIGRAPH RECURSIVE FRACTALS 3 for all x 2 K. Multifractal decomposition will be interesting exactly when

  9. Investigating hydrogel dosimeter decomposition by chemical methods

    NASA Astrophysics Data System (ADS)

    Jordan, Kevin

    2015-01-01

    The chemical oxidative decomposition of leucocrystal violet micelle hydrogel dosimeters was investigated using the reaction of ferrous ions with hydrogen peroxide or sodium bicarbonate with hydrogen peroxide. The second reaction is more effective at dye decomposition in gelatin hydrogels. Additional chemical analysis is required to determine the decomposition products.

  10. From External to Internal System Decompositions

    E-print Network

    Southampton, University of

    From External to Internal System Decompositions A.J. van der Schaft P. Rapisarda Johann external and internal decompositions and symmetries of a linear system. This is applied commonly referred to as the Kalman decomposition), and to the correspondence between external and internal

  11. Periodic decomposition of integer valued Gyula Karolyi

    E-print Network

    Károlyi, Gyula

    Periodic decomposition of integer valued functions Gyula K´arolyi , Tam´as Keleti , G´eza K prove that the existence of a real valued periodic decomposition of a Z Z function implies the existence of an integer valued periodic decomposition with the same periods. This result depends

  12. Decomposition Orders another generalisation of the fundamental

    E-print Network

    Luttik, Bas

    Decomposition Orders another generalisation of the fundamental theorem of arithmetic Bas Luttik a, The Netherlands Abstract We discuss unique decomposition in partial commutative monoids. Inspired by a result from process theory, we propose the notion of decomposition order for partial commutative monoids, and prove

  13. Decomposition Methods 1.0 Introduction

    E-print Network

    McCalley, James D.

    1 Decomposition Methods 1.0 Introduction Consider the XYZ corporation that has 10 departments, each are referred to as decomposition methods. #12;3 2.0 Connection with optimization: problem structure [2] Linear to decomposition methods. Almost all of these structures involve the constraint matrix A bei

  14. DECOMPOSITION OF THREE-DIMENSIONAL MAGNETOTELLURIC DATA

    E-print Network

    Jones, Alan G.

    Chapter 13 DECOMPOSITION OF THREE-DIMENSIONAL MAGNETOTELLURIC DATA Xavier Garcia and Alan G. Jones Geological Survey of Canada. 615 Booth Street. Ottawa, ON, KIA OE9, Canada Abstract: Decomposition is the most widely adopted tensor decomposition approach, and rightly so given its physical basis and its

  15. Flow Decomposition for Ocean Velocity Data Assimilation

    E-print Network

    Chu, Peter C.

    Flow Decomposition for Ocean Velocity Data Assimilation Peter C Chu and Leonid Ivanov Naval and noisy ocean current data using flow decomposition. Part 1: Theory. Journal of Atmospheric and Oceanic, 2003: Analysis of sparse and noisy ocean current data using flow decomposition. Part 2: Application

  16. Decomposition Techniques for Subgraph Stephane Zampelli1

    E-print Network

    Deville, Yves

    Decomposition Techniques for Subgraph Matching St´ephane Zampelli1 , Martin Mann2 , Yves Deville1. In the constraint programming framework, state-of-the-art static and dynamic decomposition techniques are hard structure to achieve decomposition. The underlying idea is to pre- compute a static heuristic on a subset

  17. DECOMPOSITION OF SEPARABLE CONCAVE STRUCTURING FUNCTIONS

    E-print Network

    Smeulders, Arnold

    DECOMPOSITION OF SEPARABLE CONCAVE STRUCTURING FUNCTIONS R. VAN DEN BOOMGAARD, E.A. ENGBERS and A a decomposition scheme for a large class of greyscale structur- ing elements from mathematical morphology. In contrast with many existing decomposition schemes, our method is valid in the continuous domain. Conditions

  18. A closer look at arrested spinodal decomposition in protein solutions

    E-print Network

    Thomas Gibaud; Peter Schurtenberger

    2009-07-24

    Concentrated aqueous solutions of the protein lysozyme undergo a liquid solid transition upon a temperature quench into the unstable spinodal region below a characteristic arrest temperature of Tf=15C. We use video microscopy and ultra-small angle light scattering in order to investigate the arrested structures as a function of initial concentration, quench temperature and rate of the temperature quench. We find that the solid-like samples show all the features of a bicontinuous network that is formed through an arrested spinodal decomposition process. We determine the correlation length Xi and demonstrate that Xi exhibits a temperature dependence that closely follows the critical scaling expected for density fluctuations during the early stages of spinodal decomposition. These findings are in agreement with an arrest scenario based on a state diagram where the arrest or gel line extends far into the unstable region below the spinodal line. Arrest then occurs when during the early stage of spinodal decomposition the volume fraction phi2 of the dense phase intersects the dynamical arrest threshold phi2Glass, upon which phase separation gets pinned into a space-spanning gel network with a characteristic length Xi.

  19. Spectral Decomposition of Broad-Line AGNs and Host Galaxies

    E-print Network

    Daniel E. Vanden Berk; Jiajian Shen; Ching-Wa Yip; Donald P. Schneider; Andrew J. Connolly; Ross E. Burton; Sebastian Jester; Patrick B. Hall; Alex S. Szalay; John Brinkmann

    2005-09-13

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  20. Spectral decomposition of broad-line agns and host galaxies

    SciTech Connect

    Vanden Berk, Daniel E.; Shen, Jiajian; /Penn State U., Astron. Astrophys.; Yip, Ching-Wa; /Pittsburgh U.; Schneider, Donald P.; /Penn State U., Astron. Astrophys.; Connolly,; /Pittsburgh U.; Burton, Ross E.; /Pittsburgh U. /Case Western Reserve U.; Jester, Sebastian; /Fermilab; Hall, Patrick B.; /York U., Canada; Szalay, Alex S.; /Johns Hopkins; Brinkmann, John; /Apache Point Observ.

    2005-09-01

    Using an eigenspectrum decomposition technique, we separate the host galaxy from the broad line active galactic nucleus (AGN) in a set of 4666 spectra from the Sloan Digital Sky Survey (SDSS), from redshifts near zero up to about 0.75. The decomposition technique uses separate sets of galaxy and quasar eigenspectra to efficiently and reliably separate the AGN and host spectroscopic components. The technique accurately reproduces the host galaxy spectrum, its contributing fraction, and its classification. We show how the accuracy of the decomposition depends upon S/N, host galaxy fraction, and the galaxy class. Based on the eigencoefficients, the sample of SDSS broad-line AGN host galaxies spans a wide range of spectral types, but the distribution differs significantly from inactive galaxies. In particular, post-starburst activity appears to be much more common among AGN host galaxies. The luminosities of the hosts are much higher than expected for normal early-type galaxies, and their colors become increasingly bluer than early-type galaxies with increasing host luminosity. Most of the AGNs with detected hosts are emitting at between 1% and 10% of their estimated Eddington luminosities, but the sensitivity of the technique usually does not extend to the Eddington limit. There are mild correlations among the AGN and host galaxy eigencoefficients, possibly indicating a link between recent star formation and the onset of AGN activity. The catalog of spectral reconstruction parameters is available as an electronic table.

  1. Linking early Earth magma ocean crystallization and overturn with observed large low-shear-velocity provinces (LLSVPs) and short-lived radioisotopic measurements in Archean rocks

    NASA Astrophysics Data System (ADS)

    Brown, S. M.; Elkins-Tanton, L. T.; Walker, R. J.

    2013-12-01

    Motivated by the well-characterized discrepancy between measurements of 142Nd in chondrites and those in Earth rocks (e.g.,[1][2]) in addition to recent measurements of Archean rocks with anomalous 142Nd and 182W (e.g.,[3][4][5]), we model the crystallization and overturn of a terrestrial chondritic magma ocean, and track the isotopic reservoirs that may result. Following magma ocean solidification, solid-state overturn occurs because solidification produces a gravitationally unstable configuration where the last cumulates to solidify are densest and also enriched in incompatible elements. As suggested by [1][2], these originally shallow cumulates that, following overturn, would now reside near the core-mantle boundary are tantalizing targets for the hypothesized hidden reservoir(s) of incompatible elements. These last, dense, enriched cumulates may have evolved negative 142Nd and 182W isotopic anomalies, while cumulates that form earlier and deeper in the magma ocean would likely be poor in incompatible elements and have evolved complementary positive isotopic anomalies. Because crystal - liquid partition coefficients of Sm, Nd, Hf, and W in nucleating mantle phases are poorly constrained and vary over orders of magnitude, we use a Monte Carlo approach to cover the parameter space of reported partition coefficients. Although data are limited, Archean rocks appear to show a non-linear trend between age and 142Nd and 182W, suggesting inefficient heterogeneous mixing of some of the early enriched reservoir (EER or late stage cumulates) back into the early depleted reservoir (EDR or deeper cumulates) during or after overturn, also first suggested by [1][2]. To account for this, we model various mixing scenarios using post-overturn mantle stratigraphy. Additionally, because 142Nd and 182W are decay products of short-lived radioisotopes, the timing of magma ocean crystallization is critical to producing a modern day mantle consistent with measured compositions. We therefore iterate through time to determine the statistically most likely time of the last major mantle-melting event. Consistent with [2], we argue that the EER is not hidden but is instead the seismologically observed large low-shear-velocity provinces (LLSVPs), or the D'' region, and the ultra low velocity zones (ULVZs) are dense, iron-rich silicon-poor melts of the LLSVPs. Given this, the isotopic reservoirs produced by our models must mix such that the EER remaining after mixing is the same volume as the LLSVPs, or 2% of the mantle (e.g., [6][7]). Approximately two-thirds our run results are "successful" given known partition coefficients, and so our results suggest that this model is viable: magma ocean fractional solidification can produce mantle reservoirs consistent with isotopic compositions observed in some rocks, and can produce a dense lower mantle layer consistent in longevity and volume to the LLSVPs. [1]Boyet and Carlson,2005,Science,309(5743),576-81.[2]Carlson and Boyet,2008,Phil. Trans. R. Soc. A,366(1883),4077-103. [3]Willbold et al.,2011,Nature,477(7363), 195-8. [4]Touboul et al.,2012,Science,335(6072),1065-9. [5]Rizo et al.,Nature,491(7422),96-100. [6]Burke et al.,2008,EPSL,265(1-2),49-60. [7]Hernlund and Houser,2008,EPSL,265(3-4),423-37.

  2. Stellar Populations of Lyman Break Galaxies at z approx. to 1-3 in the HST/WFC3 Early Release Science Observations

    NASA Technical Reports Server (NTRS)

    Hathi, N. P.; Cohen, S. H.; Ryan, R. E., Jr.; Finkelstein, S. L.; McCarthy, P. J.; Windhorst, R. A.; Yan, H.; Koekemoer, A. M.; Rutkowski, M. J.; OConnell, R. W.; Straughn, A. N.; Balick, B.; Bond, H. E.; Calzetti, D.; Disney, M. J.; Dopita, M. A.; Frogel, Jay A.; Hall, D. N. B.; Holtzman, J. A.; Kimble, R. A.; Paresce, F.; Saha, A.; Silk, J. I.; Tauger, J. T.; Young, E. T.

    2012-01-01

    We analyze the spectral energy distributions (SEDs) of Lyman break galaxies . (LBGs) at z approx = 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST /WFC3 obse,rvations cover about 50 arcmin2 in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z approx = 1-3 are selected using dropout selection criteria similar to high redshift LBGs. The deep multi-band photometry in this field is used to identify best-fit SED models, from which we infer the following results: (1) the photometric redshift estimate of these dropout selected LBGs is accurate to within few percent; (2) the UV spectral slope f3 is redder than at high redshift (z > 3), where LBGs are less dusty; (3) on average, LBGs at .z approx = 1-3 are massive, dustier and more highly star-forming, compared to LBGs at higher redshifts with similar luminosities, though their median values are similar within 1a uncertainties. This could imply that identical dropout selection technique, at all. redshifts, find physically similar galaxies; and (4) the stellar masses of these LBGs are directly proportional to their UV luminosities with a logarithmic slope of approx 0.46, and star-formation rates are proportional to their stellar masses with a logarithmic slope of approx 0.90. These relations hold true - within luminosities probed in this study - for LBGs from z approx = 1.5 to 5. The star-forming galaxies selected using other color-based techniques show similar correlations at z approx = 2, but to avoid any selection biases, and for direct comparison with LBGs at z > 3, a true Lyman break selection at z approx = 2 is essential. The future HST UV surveys,. both wider and deeper, covering a large luminosity range are important to better understand LBG properties, and their evolution.

  3. Nuclei fluorescence microscopic observation on early embryonic development of mitogynogenetic diploid induced by hydrostatic pressure treatment in olive flounder (Paralichthys olivaceus).

    PubMed

    Lin, Zhengmei; Zhu, Xiangping; You, Feng; Wu, Zhihao; Cao, Yuanshui

    2015-05-01

    Sperm genetic material of olive flounder (Paralichthys olivaceus) was inactivated by ultraviolet irradiation. The nuclear phase changes during early embryonic development of diploid, haploid, and mitogynogenetic diploid induced by hydrostatic pressure treatment were observed under fluorescent microscope with 4',6-diamidino-2-phenylindole staining. The parameters of hydrostatic pressure treatment were 600 kg/cm(2) for 6 minutes at prometaphase stage. The data showed that developmental timing sequence of diploid and haploid fertilized eggs was similar. The cell cycle was about 48 minutes, including interphase (about 21 minutes), prophase (about 3 minutes), prometaphase (about 6 minutes), metaphase (about 6 minutes), anaphase (around 9 minutes), and telophase (about 3 minutes). After entering the fertilized egg, ultraviolet-inactivated sperm formed a male pronucleus and became a dense chromatin body in the cytoplasm. Dense chromatin body did not participate in nuclear division and unchanged all the time. For hydrostatic pressure-treated embryos, the first nuclear division and cytokinesis after treatment proceeded normally after about 15 minutes recovery. During the second mitosis, having undergone interphase, prophase, and prometaphase stage, chromosomes began to slowly spread around and scattered in the cell but not entered into metaphase and anaphase. The second nuclear division and cytokinesis was inhibited. The occurrence frequency of developmentally delayed embryos also showed that the second cleavage of about 80% treated eggs was inhibited. The inhibition of the second cleavage resulted to chromosome set doubling. So chromosome set doubling for mitogynogenetic flounder diploid induced by hydrostatic pressure treatment, performed at prometaphase stage, was mainly due to inhibition of the second mitosis rather than the first one. PMID:25726149

  4. Early fluid loading in acute respiratory distress syndrome with septic shock deteriorates lung aeration without impairing arterial oxygenation: a lung ultrasound observational study

    PubMed Central

    2014-01-01

    Introduction The study was designed to assess the impact of fluid loading on lung aeration, oxygenation and hemodynamics in patients with septic shock and acute respiratory distress syndrome (ARDS). Methods During a 1-year period, a prospective observational study was performed in 32 patients with septic shock and ARDS. Cardiorespiratory parameters were measured using Swan Ganz (n?=?29) or PiCCO catheters (n?=?3). Lung aeration and regional pulmonary blood flows were measured using bedside transthoracic ultrasound. Measurements were performed before (T0), at the end of volume expansion (T1) and 40 minutes later (T2), consisting of 1-L of saline over 30 minutes during the first 48 h following onset of septic shock and ARDS. Results Lung ultrasound score increased by 23% at T2, from 13 at baseline to 16 (P?Early fluid loading transitorily improves hemodynamics and oxygenation and worsens lung aeration. Aeration changes can be detected at the bedside by transthoracic lung ultrasound, which may serve as a safeguard against excessive fluid loading. PMID:24887155

  5. SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU

    SciTech Connect

    Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cenko, S. B.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Jha, S. W.; McCully, C. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Anderson, J. P.; De Jaeger, T.; Forster, F. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Benetti, S. [INAF Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Bufano, F., E-mail: mjc@mso.anu.edu.au [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); and others

    2013-06-10

    We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II {lambda}6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II {lambda}6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of {approx}12,000 km s{sup -1} until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v Almost-Equal-To 12,000 km s{sup -1} with narrow line width and long velocity plateau, as well as an HVF beginning at v Almost-Equal-To 31,000 km s{sup -1} two weeks before maximum. SN 2012fr resides on the border between the ''shallow silicon'' and ''core-normal'' subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the ''low velocity gradient'' group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

  6. Study on thermal decomposition characteristics of AIBN.

    PubMed

    Li, Xin-Rui; Wang, Xin-Long; Koseki, Hiroshi

    2008-11-15

    It is found that the results such as observed in the differential scanning calorimeter (DSC), which show the major thermal decomposition (TD) of a self-reactive material, lack the detail to reveal what happens at the initial stage of a reaction. The reaction at this stage is corresponding to the handling condition of storage or transportation, often possibly having the potential to be developed to a runaway reaction. This paper examined and compared the thermal behaviors of AIBN at various working conditions in calorimeters and Dewar vessels. The mechanism that affects the initial reaction and self-heating behavior of the given material was clarified. Near its onset decomposition temperature, physical processes, such as sublimation or melting interfered the initial reaction of AIBN. The mutuality of the physical effect and the chemical reaction made AIBN behave differently under different measuring conditions, and as the result, quasi-autocatalysis or TD possibly occurs in the same sample at the handling temperature range. The heat accumulation storage tests in two Dewar vessels presented completely different self-heating behaviors due to this mechanism and heat transfer capability of the vessels. PMID:18328620

  7. Stability of the Trotter-Suzuki decomposition

    E-print Network

    Ish Dhand; Barry C. Sanders

    2014-07-09

    The Trotter-Suzuki decomposition is an important tool for the simulation and control of physical systems. We provide evidence for the stability of the Trotter-Suzuki decomposition. We model the error in the decomposition and determine sufficiency conditions that guarantee the stability of this decomposition under this model. We relate these sufficiency conditions to precision limitations of computing and control in both classical and quantum cases. Furthermore we show that bounded-error Trotter-Suzuki decomposition can be achieved by a suitable choice of machine precision.

  8. Potential role of gas hydrate decomposition in generating submarine slope failures: Chapter 12

    USGS Publications Warehouse

    Pauli, Charles K.; mUssler, William III; Dillon, William P.

    2003-01-01

    Gas hydrate decomposition is hypothesized to be a factor in generating weakness in continental margin sediments that may help explain some of the observed patterns of continental margin sediment instability. The processes associated with formation and decomposition of gas hydrate can cause the strengthening of sediments in which gas hydrate grow and the weakening of sediments in which gas hydrate decomposes. The weakened sediments may form horizons along which the potential for sediment failure is increased. While a causal relationship between slope failures and gas hydrate decomposition has not been proven, a number of empirical observations support their potential connection.

  9. Climate sensitivity and macronutrient regulation of peat decomposition

    NASA Astrophysics Data System (ADS)

    Marshall, Rachel; Ostle, Nick; McNamara, Niall; Baggs, Elizabeth

    2013-04-01

    Organic soils act as vital global carbon stores maintained in northern latitudes by climate and nutrient limited rates of organic matter decomposition. Peatland decomposition rates are sensitive to climate change, however predicting the magnitude of the microbial respiratory response is complex due to unknown interactions between climate and substrate quality. The nutrient status of peatlands varies widely from mineral rich fens to nutrient poor ombrotrophic bogs, which have the potential to respond differently to climate driven changes in temperature and carbon (C) inputs. In this work we examine the links between peatland macronutrient C, phosphorus (P) and nitrogen (N) stoichiometry, microbial community structure and the microbial response to direct and indirect effects of climate change. Using total soil C:N and C:P ratios to define nutrient gradients in organic soils from Svalbard and Finland we investigated the interaction between the microbial response to temperature and nutrient limitation of decomposition. In organic rich soils from Svalbard we found there was a significant relationship between increasing temperature sensitivity of respiration and decreasing total soil P concentrations. Further investigation of the potential direct link between P limitation of decomposition and increased temperature sensitivity along a minerotrophic-ombroptrophic gradient in Finland was performed using multi-factorial P limitation assays. These showed that despite varying degrees of P limitation across four peatland soils there was no relationship between P limitation and increased temperature sensitivity of soil respiration. Throughout this study we found consistently high temperature sensitivity of decomposition in organic rich soils with Q10 values ranging between 2 to 4.5, indicating potentially higher vulnerability of these C stores to warming than is currently predicted using a globally invariant Q10. Following on from this we examined the interaction between peatland nutrient status and the potential for labile C substrates to stimulate (prime) decomposition of the peat organic matter. Using 13C labelled glucose and hemicellulose compounds we observed significant differences in the amount and rate of microbial substrate use between peats with differing nutrient status. Nutrient addition experiments were used with labelled C substrates to investigate the role of N and P limitation in enhancing or restricting priming effects. This is one of the first studies to use 13C substrates to examine potential priming effects in peat soil and it provides an insight into the importance of priming mechanisms in peat decomposition. This work explicitly links soil microbial responses to temperature and nutrient manipulations with microbial community structure allowing us to observe how microbial communities mediate soil C losses in peat soils. Disentangling the complex interactions between soil microbial community, C and nutrient limitation of decomposition is essential for predicting the vulnerability of different peatland ecosystems to climate driven changes.

  10. Leaf Litter Mixtures Alter Microbial Community Development: Mechanisms for Non-Additive Effects in Litter Decomposition

    PubMed Central

    Chapman, Samantha K.; Newman, Gregory S.; Hart, Stephen C.; Schweitzer, Jennifer A.; Koch, George W.

    2013-01-01

    To what extent microbial community composition can explain variability in ecosystem processes remains an open question in ecology. Microbial decomposer communities can change during litter decomposition due to biotic interactions and shifting substrate availability. Though relative abundance of decomposers may change due to mixing leaf litter, linking these shifts to the non-additive patterns often recorded in mixed species litter decomposition rates has been elusive, and links community composition to ecosystem function. We extracted phospholipid fatty acids (PLFAs) from single species and mixed species leaf litterbags after 10 and 27 months of decomposition in a mixed conifer forest. Total PLFA concentrations were 70% higher on litter mixtures than single litter types after 10 months, but were only 20% higher after 27 months. Similarly, fungal-to-bacterial ratios differed between mixed and single litter types after 10 months of decomposition, but equalized over time. Microbial community composition, as indicated by principal components analyses, differed due to both litter mixing and stage of litter decomposition. PLFA biomarkers a15?0 and cy17?0, which indicate gram-positive and gram-negative bacteria respectively, in particular drove these shifts. Total PLFA correlated significantly with single litter mass loss early in decomposition but not at later stages. We conclude that litter mixing alters microbial community development, which can contribute to synergisms in litter decomposition. These findings advance our understanding of how changing forest biodiversity can alter microbial communities and the ecosystem processes they mediate. PMID:23658639

  11. Leaf litter mixtures alter microbial community development: mechanisms for non-additive effects in litter decomposition.

    PubMed

    Chapman, Samantha K; Newman, Gregory S; Hart, Stephen C; Schweitzer, Jennifer A; Koch, George W

    2013-01-01

    To what extent microbial community composition can explain variability in ecosystem processes remains an open question in ecology. Microbial decomposer communities can change during litter decomposition due to biotic interactions and shifting substrate availability. Though relative abundance of decomposers may change due to mixing leaf litter, linking these shifts to the non-additive patterns often recorded in mixed species litter decomposition rates has been elusive, and links community composition to ecosystem function. We extracted phospholipid fatty acids (PLFAs) from single species and mixed species leaf litterbags after 10 and 27 months of decomposition in a mixed conifer forest. Total PLFA concentrations were 70% higher on litter mixtures than single litter types after 10 months, but were only 20% higher after 27 months. Similarly, fungal-to-bacterial ratios differed between mixed and single litter types after 10 months of decomposition, but equalized over time. Microbial community composition, as indicated by principal components analyses, differed due to both litter mixing and stage of litter decomposition. PLFA biomarkers a15?0 and cy17?0, which indicate gram-positive and gram-negative bacteria respectively, in particular drove these shifts. Total PLFA correlated significantly with single litter mass loss early in decomposition but not at later stages. We conclude that litter mixing alters microbial community development, which can contribute to synergisms in litter decomposition. These findings advance our understanding of how changing forest biodiversity can alter microbial communities and the ecosystem processes they mediate. PMID:23658639

  12. Effects of decomposition on gunshot wound characteristics: under moderate temperatures with insect activity.

    PubMed

    MacAulay, Lauren E; Barr, Darryl G; Strongman, Doug B

    2009-03-01

    Previous studies document characteristics of gunshot wounds shortly after they were inflicted. This study was conducted to determine if the early stages of decomposition obscure or alter the physical surface characteristics of gunshot wounds, thereby affecting the quantity and quality of information retrievable from such evidence. The study was conducted in August and September, 2005 in Nova Scotia, Canada in forested and exposed environments. Recently killed pigs were used as research models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Under these test conditions, the gunshot wounds maintained the characteristics unique to each gunshot range and changes that occurred during decomposition were not critical to the interpretation of the evidence. It was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence until the skin was degraded in the late active or advanced decay stage of decomposition. PMID:19215324

  13. Recent applications of PIXE spectrometry in archaeology part I Observations on the early development of copper metallurgy in the Old World

    Microsoft Academic Search

    S. J. Fleming; C. P. Swann

    1993-01-01

    The early development of copper metallurgy can be characterized by three steps of innovation: i) exploitation of native copper resources for simple tool-making as early as the 7th millennium B.C. in the Near East; ii) the recovery of copper metal from minerals such as malachite, by smelting, during the 5th millennium B.C., both in the Near East and in eastern

  14. Spinodal decomposition and giant magnetoresistance

    NASA Astrophysics Data System (ADS)

    Miranda, M. G. M.; da Rosa, A. T.; Hinrichs, R.; Golla-Schindler, U.; Antunes, A. B.; Martínez, G.; Estévez-Rams, E.; Baibich, M. N.

    2006-10-01

    We explore the relation of nanostructures with the appearance of giant magnetoresistance (GMR) in melt-spun CuCo ribbons. We find by energy-filtered transmission electron microscopy that the ribbons are composed of a periodic distribution of Co within the Cu, as in spinodal decomposition. The lamellar structure should thus be associated with GMR, as only a small percentage of the Co is present in the form of grains. This is counterintuitive, for no clear interfaces are present as required by standard models, and the period of the composition oscillation (43-52 nm) is an order of magnitude larger than the mean free paths for electrons. Upon annealing, a secondary spinodal decomposition appears following the same direction as the original.

  15. Meson Mass Decomposition

    E-print Network

    Yi-Bo Yang; Ying Chen; Terrence Draper; Ming Gong; Keh-Fei Liu; Zhaofeng Liu; Jian-Ping Ma

    2014-11-04

    Hadron masses can be decomposed as a sum of components which are defined through hadronic matrix elements of QCD operators. The components consist of the quark mass term, the quark energy term, the glue energy term and the trace anomaly term. We calculate these components of mesons with lattice QCD for the first time. The calculation is carried out with overlap fermion on $2+1$ flavor domain-wall fermion gauge configurations. We confirm that $\\sim 50\\%$ of the light pion mass comes from the quark mass and $\\sim 10\\%$ comes from the quark energy, whereas, the contributions are found to be the other way around for the $\\rho$ mass. The combined glue components contribute $\\sim 40 - 50\\%$ for both mesons. It is interesting to observe that the quark mass contribution to the mass of the vector meson is almost linear in quark mass over a large quark mass region below the charm quark mass. For heavy mesons, the quark mass term dominates the masses, while the contribution from the glue components is about $400\\sim500$ MeV for the heavy pseudoscalar and vector mesons. The charmonium hyperfine splitting is found to be dominated by the quark energy term which is consistent with the quark potential model.

  16. Null decomposition of conformal algebras

    SciTech Connect

    Mihai, Dana; Sparling, George A. J. [Department of Mathematical Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States); Department of Mathematics, University of Pittsburgh, Pittsburgh, Pennsylvania 15213 (United States)

    2007-05-15

    We analyze the decomposition of the enveloping algebra of the conformal algebra in arbitrary dimension with respect to the mass-squared operator. It emerges that the subalgebra that commutes with the mass-squared operator is generated by its Poincare subalgebra together with a vector operator. The special cases of the conformal algebras of two and three dimensions are described in detail, including the construction of their Casimir operators.

  17. Thermal decomposition of ammonium uranates

    Microsoft Academic Search

    Taichi Sato; Shigeaki Shiota

    1985-01-01

    The thermal decomposition of ammonium uranates precipitated from uranyl nitrate solution on the addition of aqueous ammonium hydroxide and hexamine under various conditions has been studied by means of thermogravimetry, differential thermal analysis, infrared spectroscopy and X-ray diffraction. Although all precipitates show the composition corresponding to UO3 · NH3 · H2O, the precipitates with hexamine give X-ray diffraction patterns designed

  18. Nucleon Momentum Decomposition in QCD

    E-print Network

    Y. M. Cho; Mo-Lin Ge; D. G. Pak; Pengming Zhang

    2011-04-29

    ~Based on the gauge invariant quark canonical momentum we construct two theoretically possible decompositions of nucleon momentum to those of quarks and gluons. We predict that either 6% or 21% of nucleon momentum is carried by gluons, depending on what type of gluons are in nucleons. We clarify the existing confusions on this problem and discuss the physical implications of our result on the proton spin crisis problem.

  19. Phlogopite Decomposition, Water, and Venus

    NASA Technical Reports Server (NTRS)

    Johnson, N. M.; Fegley, B., Jr.

    2005-01-01

    Venus is a hot and dry planet with a surface temperature of 660 to 740 K and 30 parts per million by volume (ppmv) water vapor in its lower atmosphere. In contrast Earth has an average surface temperature of 288 K and 1-4% water vapor in its troposphere. The hot and dry conditions on Venus led many to speculate that hydrous minerals on the surface of Venus would not be there today even though they might have formed in a potentially wetter past. Thermodynamic calculations predict that many hydrous minerals are unstable under current Venusian conditions. Thermodynamics predicts whether a particular mineral is stable or not, but we need experimental data on the decomposition rate of hydrous minerals to determine if they survive on Venus today. Previously, we determined the decomposition rate of the amphibole tremolite, and found that it could exist for billions of years at current surface conditions. Here, we present our initial results on the decomposition of phlogopite mica, another common hydrous mineral on Earth.

  20. Direct and indirect effects of UV-B exposure on litter decomposition: a meta-analysis.

    PubMed

    Song, Xinzhang; Peng, Changhui; Jiang, Hong; Zhu, Qiuan; Wang, Weifeng

    2013-01-01

    Ultraviolet-B (UV-B) exposure in the course of litter decomposition may have a direct effect on decomposition rates via changing states of photodegradation or decomposer constitution in litter while UV-B exposure during growth periods may alter chemical compositions and physical properties of plants. Consequently, these changes will indirectly affect subsequent litter decomposition processes in soil. Although studies are available on both the positive and negative effects (including no observable effects) of UV-B exposure on litter decomposition, a comprehensive analysis leading to an adequate understanding remains unresolved. Using data from 93 studies across six biomes, this introductory meta-analysis found that elevated UV-B directly increased litter decomposition rates by 7% and indirectly by 12% while attenuated UV-B directly decreased litter decomposition rates by 23% and indirectly increased litter decomposition rates by 7%. However, neither positive nor negative effects were statistically significant. Woody plant litter decomposition seemed more sensitive to UV-B than herbaceous plant litter except under conditions of indirect effects of elevated UV-B. Furthermore, levels of UV-B intensity significantly affected litter decomposition response to UV-B (P<0.05). UV-B effects on litter decomposition were to a large degree compounded by climatic factors (e.g., MAP and MAT) (P<0.05) and litter chemistry (e.g., lignin content) (P<0.01). Results suggest these factors likely have a bearing on masking the important role of UV-B on litter decomposition. No significant differences in UV-B effects on litter decomposition were found between study types (field experiment vs. laboratory incubation), litter forms (leaf vs. needle), and decay duration. Indirect effects of elevated UV-B on litter decomposition significantly increased with decay duration (P<0.001). Additionally, relatively small changes in UV-B exposure intensity (30%) had significant direct effects on litter decomposition (P<0.05). The intent of this meta-analysis was to improve our understanding of the overall effects of UV-B on litter decomposition. PMID:23818993

  1. Seasonal variation of carcass decomposition and gravesoil chemistry in a cold (Dfa) climate.

    PubMed

    Meyer, Jessica; Anderson, Brianna; Carter, David O

    2013-09-01

    It is well known that temperature significantly affects corpse decomposition. Yet relatively few taphonomy studies investigate the effects of seasonality on decomposition. Here, we propose the use of the Köppen-Geiger climate classification system and describe the decomposition of swine (Sus scrofa domesticus) carcasses during the summer and winter near Lincoln, Nebraska, USA. Decomposition was scored, and gravesoil chemistry (total carbon, total nitrogen, ninhydrin-reactive nitrogen, ammonium, nitrate, and soil pH) was assessed. Gross carcass decomposition in summer was three to seven times greater than in winter. Initial significant changes in gravesoil chemistry occurred following approximately 320 accumulated degree days, regardless of season. Furthermore, significant (p < 0.05) correlations were observed between ammonium and pH (positive correlation) and between nitrate and pH (negative correlation). We hope that future decomposition studies employ the Köppen-Geiger climate classification system to understand the seasonality of corpse decomposition, to validate taphonomic methods, and to facilitate cross-climate comparisons of carcass decomposition. PMID:23822087

  2. STELLAR POPULATIONS OF LYMAN BREAK GALAXIES AT z {approx_equal} 1-3 IN THE HST/WFC3 EARLY RELEASE SCIENCE OBSERVATIONS

    SciTech Connect

    Hathi, N. P.; McCarthy, P. J. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Cohen, S. H.; Windhorst, R. A.; Rutkowski, M. J. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Ryan, R. E. Jr.; Koekemoer, A. M.; Bond, H. E. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Finkelstein, S. L. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Yan, H. [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); O'Connell, R. W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Straughn, A. N.; Kimble, R. A. [NASA-Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); Calzetti, D. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States); Disney, M. J. [School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA (United Kingdom); Dopita, M. A. [Research School of Astronomy and Astrophysics, Australian National University, Weston Creek, ACT 2611 (Australia); Frogel, Jay A. [Astronomy Department, King Abdulaziz University, P.O. Box 80203, Jeddah (Saudi Arabia); Hall, D. N. B. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Holtzman, J. A., E-mail: nhathi@obs.carnegiescience.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States); and others

    2013-03-10

    We analyze the spectral energy distributions (SEDs) of Lyman break galaxies (LBGs) at z {approx_equal} 1-3 selected using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) UVIS channel filters. These HST/WFC3 observations cover about 50 arcmin{sup 2} in the GOODS-South field as a part of the WFC3 Early Release Science program. These LBGs at z {approx_equal} 1-3 are selected using dropout selection criteria similar to high-redshift LBGs. The deep multi-band photometry in this field is used to identify best-fit SED models, from which we infer the following results: (1) the photometric redshift estimate of these dropout-selected LBGs is accurate to within few percent; (2) the UV spectral slope {beta} is redder than at high redshift (z > 3), where LBGs are less dusty; (3) on average, LBGs at z {approx_equal} 1-3 are massive, dustier, and more highly star forming, compared to LBGs at higher redshifts with similar luminosities (0.1L* {approx}< L {approx}< 2.5L*), though their median values are similar within 1{sigma} uncertainties. This could imply that identical dropout selection technique, at all redshifts, finds physically similar galaxies; and (4) the stellar masses of these LBGs are directly proportional to their UV luminosities with a logarithmic slope of {approx}0.46, and star formation rates are proportional to their stellar masses with a logarithmic slope of {approx}0.90. These relations hold true-within luminosities probed in this study-for LBGs from z {approx_equal} 1.5 to 5. The star-forming galaxies selected using other color-based techniques show similar correlations at z {approx_equal} 2, but to avoid any selection biases, and for direct comparison with LBGs at z > 3, a true Lyman break selection at z {approx_equal} 2 is essential. The future HST UV surveys, both wider and deeper, covering a large luminosity range are important to better understand LBG properties and their evolution.

  3. Decomposition-Based Decision Making for Aerospace Vehicle Design

    NASA Technical Reports Server (NTRS)

    Borer, Nicholas K.; Mavris, DImitri N.

    2005-01-01

    Most practical engineering systems design problems have multiple and conflicting objectives. Furthermore, the satisfactory attainment level for each objective ( requirement ) is likely uncertain early in the design process. Systems with long design cycle times will exhibit more of this uncertainty throughout the design process. This is further complicated if the system is expected to perform for a relatively long period of time, as now it will need to grow as new requirements are identified and new technologies are introduced. These points identify a need for a systems design technique that enables decision making amongst multiple objectives in the presence of uncertainty. Traditional design techniques deal with a single objective or a small number of objectives that are often aggregates of the overarching goals sought through the generation of a new system. Other requirements, although uncertain, are viewed as static constraints to this single or multiple objective optimization problem. With either of these formulations, enabling tradeoffs between the requirements, objectives, or combinations thereof is a slow, serial process that becomes increasingly complex as more criteria are added. This research proposal outlines a technique that attempts to address these and other idiosyncrasies associated with modern aerospace systems design. The proposed formulation first recasts systems design into a multiple criteria decision making problem. The now multiple objectives are decomposed to discover the critical characteristics of the objective space. Tradeoffs between the objectives are considered amongst these critical characteristics by comparison to a probabilistic ideal tradeoff solution. The proposed formulation represents a radical departure from traditional methods. A pitfall of this technique is in the validation of the solution: in a multi-objective sense, how can a decision maker justify a choice between non-dominated alternatives? A series of examples help the reader to observe how this technique can be applied to aerospace systems design and compare the results of this so-called Decomposition-Based Decision Making to more traditional design approaches.

  4. Spinodal decomposition of austenite in long-term-aged duplex stainless steel

    SciTech Connect

    Chung, H.M.

    1989-02-01

    Spinodal decomposition of austenite phase in the cast duplex stainless steels CF-8 and -8M grades has been observed after long- term thermal aging at 400 and 350/degree/C for 30,000 h (3.4 yr). At 320/degree/C, the reaction was observed only at the limited region near the austenite grain boundaries. Ni segregation and ''worm-holes'' corresponding to the spatial microchemical fluctuations have been confirmed. The decomposition was observed only for heats containing relatively high overall Ni content (9.6--12.0 wt %) but not in low-Ni (8.0--9.4 wt %) heats. In some specimens showing a relatively advanced stage of decomposition, localized regions of austenite with a Vickers hardness of 340--430 were observed. However, the effect of austenite decomposition on the overall material toughness appears secondary for aging up to 3--5 yr in comparison with the effect of the faster spinodal decomposition in ferrite phase. The observation of the thermally driven spinodal decomposition of the austenite phase in cast duplex stainless steels validates the proposition that a miscibility gap occurs in Fe-Ni and ancillary systems. 16 refs., 7 figs., 1 tab.

  5. FUEL DECOMPOSITION AND FLAME REACTIONS IN CONVERSION OF FUEL NITROGEN TO NOX

    EPA Science Inventory

    The report describes an experimental and analytical research program conducted to provide information on the chemical phenomena involved in the conversion of air and fuel nitrogen to NOx. Under Task 1, Fuel Decomposition, early (preflame) reactions of fuel nitrogen species were i...

  6. Conductimetric determination of decomposition of silicate melts

    NASA Technical Reports Server (NTRS)

    Kroeger, C.; Lieck, K.

    1986-01-01

    A description of a procedure is given to detect decomposition of silicate systems in the liquid state by conductivity measurements. Onset of decomposition can be determined from the temperature curves of resistances measured on two pairs of electrodes, one above the other. Degree of decomposition can be estimated from temperature and concentration dependency of conductivity of phase boundaries. This procedure was tested with systems PbO-B2O3 and PbO-B2O3-SiO2.

  7. Cross decomposition for mixed integer programming

    Microsoft Academic Search

    Tony J. Van Roy

    1983-01-01

    Many methods for solving mixed integer programming problems are based either on primal or on dual decomposition, which yield,\\u000a respectively, a Benders decomposition algorithm and an implicit enumeration algorithm with bounds computed via Lagrangean\\u000a relaxation. These methods exploit either the primal or the dual structure of the problem. We propose a new approach, cross\\u000a decomposition, which allows exploiting simultaneously both

  8. Consistent gauge invariant nucleon spin decomposition

    E-print Network

    D. G. Pak; P. M. Zhang

    2012-04-23

    We consider a non-uniqueness problem of gauge invariant nucleon spin decomposition. A gauge invariant decomposition with a generalized Coulomb constraint for the physical gluon has been constructed. The decomposition scheme is consistent with the concept of helicity in non-Abelian gauge theory. We provide an explicit representation for the gauge invariant Abelian projection which implies further separation of gluon into binding and valence parts.

  9. Upregulation of Cytokines Is Detected in the Placentas of Cattle Infected with Neospora caninum and Is More Marked Early in Gestation When Fetal Death Is Observed

    Microsoft Academic Search

    Anne Rosbottom; E. Helen Gibney; Catherine S. Guy; Anja Kipar; Robert F. Smith; Pete Kaiser; Alexander J. Trees; Diana J. L. Williams

    2008-01-01

    Received 8 November 2006\\/Returned for modification 30 December 2006\\/Accepted 12 February 2008 The protozoan parasite Neospora caninum causes fetal death after experimental infection of pregnant cattle in early gestation, but the fetus survives a similar infection in late gestation. An increase in Th1-type cytokines in the placenta in response to the presence of the parasite has been implicated as a

  10. Nitrogen Addition Significantly Affects Forest Litter Decomposition under High Levels of Ambient Nitrogen Deposition

    PubMed Central

    Chen, Gang; Peng, Yong; Xiao, Yin-long; Hu, Ting-xing; Zhang, Jian; Li, Xian-wei; Liu, Li; Tang, Yi

    2014-01-01

    Background Forest litter decomposition is a major component of the global carbon (C) budget, and is greatly affected by the atmospheric nitrogen (N) deposition observed globally. However, the effects of N addition on forest litter decomposition, in ecosystems receiving increasingly higher levels of ambient N deposition, are poorly understood. Methodology/Principal Findings We conducted a two-year field experiment in five forests along the western edge of the Sichuan Basin in China, where atmospheric N deposition was up to 82–114 kg N ha–1 in the study sites. Four levels of N treatments were applied: (1) control (no N added), (2) low-N (50 kg N ha–1 year–1), (3) medium-N (150 kg N ha–1 year–1), and (4) high-N (300 kg N ha–1 year–1), N additions ranging from 40% to 370% of ambient N deposition. The decomposition processes of ten types of forest litters were then studied. Nitrogen additions significantly decreased the decomposition rates of six types of forest litters. N additions decreased forest litter decomposition, and the mass of residual litter was closely correlated to residual lignin during the decomposition process over the study period. The inhibitory effect of N addition on litter decomposition can be primarily explained by the inhibition of lignin decomposition by exogenous inorganic N. The overall decomposition rate of ten investigated substrates exhibited a significant negative linear relationship with initial tissue C/N and lignin/N, and significant positive relationships with initial tissue K and N concentrations; these relationships exhibited linear and logarithmic curves, respectively. Conclusions/Significance This study suggests that the expected progressive increases in N deposition may have a potential important impact on forest litter decomposition in the study area in the presence of high levels of ambient N deposition. PMID:24551152

  11. A SCALABLE DECOMPOSITION FOR LARGE NETWORKS

    E-print Network

    Chen, Yiling

    GRAPHLETS: A SCALABLE DECOMPOSITION FOR LARGE NETWORKS Hossein Azari Soufiani, Edoardo M. Airoldi of a weighted network. Artificial Intelligence and Statistics (AISTAT), 2012. Azari & Airoldi. 23 #12;

  12. Thermodynamic anomaly in magnesium hydroxide decomposition

    SciTech Connect

    Reis, T.A.

    1983-08-01

    The Origin of the discrepancy in the equilibrium water vapor pressure measurements for the reaction Mg(OH)/sub 2/(s) = MgO(s) + H/sub 2/O(g) when determined by Knudsen effusion and static manometry at the same temperature was investigated. For this reaction undergoing continuous thermal decomposition in Knudsen cells, Kay and Gregory observed that by extrapolating the steady-state apparent equilibrium vapor pressure measurements to zero-orifice, the vapor pressure was approx. 10/sup -4/ of that previously established by Giauque and Archibald as the true thermodynamic equilibrium vapor pressure using statistical mechanical entropy calculations for the entropy of water vapor. This large difference in vapor pressures suggests the possibility of the formation in a Knudsen cell of a higher energy MgO that is thermodynamically metastable by about 48 kJ / mole. It has been shown here that experimental results are qualitatively independent of the type of Mg(OH)/sub 2/ used as a starting material, which confirms the inferences of Kay and Gregory. Thus, most forms of Mg(OH)/sub 2/ are considered to be the stable thermodynamic equilibrium form. X-ray diffraction results show that during the course of the reaction only the equilibrium NaCl-type MgO is formed, and no different phases result from samples prepared in Knudsen cells. Surface area data indicate that the MgO molar surface area remains constant throughout the course of the reaction at low decomposition temperatures, and no significant annealing occurs at less than 400/sup 0/C. Scanning electron microscope photographs show no change in particle size or particle surface morphology. Solution calorimetric measurements indicate no inherent hgher energy content in the MgO from the solid produced in Knudsen cells. The Knudsen cell vapor pressure discrepancy may reflect the formation of a transient metastable MgO or Mg(OH)/sub 2/-MgO solid solution during continuous thermal decomposition in Knudsen cells.

  13. QR-decomposition The QR-decomposition of an n k matrix A, k n, is

    E-print Network

    Sleijpen, Gerard

    QR-decomposition The QR-decomposition of an n � k matrix A, k n, is an n � n unitary matrix Q and an n � k upper triangular matrix R for which A = QR In Matlab [Q,R]=qr(A); Note. The QR-decomposition is unique up to a change of signs of the columns of Q: A = (QD)( ¯DR) with |D| = I #12;QR-decomposition

  14. Decomposition of the sulfates of copper, iron (II), iron (III), nickel, and zinc: XPS, SEM, DRIFTS, XRD, and TGA study

    Microsoft Academic Search

    Ranjani V Siriwardane; James A Poston Jr; Edward P Fisher; Ming-Shing Shen; Angela L Miltz

    1999-01-01

    The bulk and surface characteristics during decomposition of the transition metal sulfates of copper, iron (II), iron (III), nickel, and zinc are investigated utilizing various spectroscopic techniques. An oxidized form of sulfur was detected on the surface during decomposition of all metal sulfate samples, except zinc sulfate. Surface characteristics were not necessarily representative of the bulk characteristics. Oxy-sulfate was observed

  15. NEW SIMULTANEOUS GENERALIZED SCHUR DECOMPOSITION METHODS FOR THE COMPUTATION OF THE CANONICAL POLYADIC DECOMPOSITION

    E-print Network

    NEW SIMULTANEOUS GENERALIZED SCHUR DECOMPOSITION METHODS FOR THE COMPUTATION OF THE CANONICAL POLYADIC DECOMPOSITION Mikael Sørensen and Lieven De Lathauwer K.U.Leuven - E.E. Dept. (ESAT) - SCD) decomposition have been proposed. The original SGSD method re- quires that all three matrix factors of the CP

  16. Spinodal decomposition for the cahn-hilliard equation

    Microsoft Academic Search

    Christopher P. Grant

    1993-01-01

    The Cahn-Hilliard equation is a fourth-order parabolic partial differential equation that is one of the leading models for the study of phase separation in isothermal, isotropic, binary mixtures, such as molten alloys. When a spatially homogeneous alloy is rapidly quenched in a physical experiment, a fine-grained decomposition into two distinct phases is frequently observed; this phenomenon is known as spinodal

  17. The Role of Endophytic Fungal Individuals and Communities in the Decomposition of Pinus massoniana Needle Litter

    PubMed Central

    Yuan, Zhilin; Chen, Lianqing

    2014-01-01

    The role of fungal endophytes (FEs) as “pioneer” decomposers has recently been recognized; however, the extent to which FEs contribute to litter loss is less well understood. The genetic and enzymatic bases of FE-mediated decomposition have also rarely been addressed. The effects of populations and individuals (with an emphasis on two dominant Lophodermium taxa) of FEs on needle-litter decomposition were assessed for Pinus massoniana, a ubiquitous pine in southern China. Data from in vivo (microcosm) experiments indicated that the percentage of litter-mass loss triggered by FEs was linearly correlated with incubation time and approached 60% after seven months. In vitro decomposition tests also confirmed that endophytic Lophodermium isolates caused 14–22% mass loss within two months. Qualitative analysis of exoenzymes (cellulase and laccase, important for lignocellulose degradation) revealed that almost all of the Lophodermium isolates showed moderate or strong positive reactions. Furthermore, partial sequences of ?-glucosidase (glycoside hydrolase family 3, GH3), laccase, and cellobiohydrolase (GH7) genes were amplified from Lophodermium isolates as “functional markers” to evaluate their potential for lignocellulolytic activity. Three different genes were detected, suggesting a flexible and delicate decomposition system rich in FEs. Our work highlights the possibility that the saprophytism and endophytism of FEs may be prerequisites to initiating rapid decomposition and thus may be key in Fes’ contribution to litter decomposition, at least in the early stage. Potential indicators of the presence of core fungal decomposers are also briefly discussed. PMID:25157631

  18. Study of phase decomposition and coarsening of ?? precipitates in Ni-12 at.% Ti alloy

    SciTech Connect

    Garay-Reyes, C.G., E-mail: garay_820123@hotmail.com [Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia, Sierra leona 550, Col. Lomas 2 sección, 78210 S.L.P. (Mexico); Hernández-Santiago, F. [Instituto Politécnico Nacional, ESIME-AZC, Av. de las Granjas 682, col. Sta. Catarina, 02550 D.F. (Mexico); Cayetano-Castro, N. [Instituto Potosino de Investigación Científica y Tecnológica, División de Materiales Avanzados, camino a la Presa San José 2055, Col Lomas 4 sección, 78216 S.L.P. (Mexico); López-Hirata, V.M. [Instituto Politécnico Nacional, ESIQIE-DIM, 118-556, D.F. (Mexico); García-Rocha, J. [Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia, Sierra leona 550, Col. Lomas 2 sección, 78210 S.L.P. (Mexico); Hernández-Rivera, J.L. [Centro de Investigación de Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes 120, 31109 Chihuahua (Mexico); Dorantes-Rosales, H.J. [Instituto Politécnico Nacional, ESIQIE-DIM, 118-556, D.F. (Mexico); Cruz-Rivera, J.J. [Universidad Autónoma de San Luis Potosí, Instituto de Metalurgia, Sierra leona 550, Col. Lomas 2 sección, 78210 S.L.P. (Mexico)

    2013-09-15

    The early stages of phase decomposition, morphological evolution of precipitates, coarsening kinetics of ?? precipitates and micro-hardness in Ni-12 at.% Ti alloy are studied by transmission electron microscopy (TEM) and Vickers hardness tests (VHN). Disk-shaped specimens are solution treated at 1473 K (1200 °C) and aged at 823, 923 and 1023 K (550, 650 and 750 °C) during several periods of time. TEM results show that a conditional spinodal of order occurs at the beginning of the phase decomposition and exhibit the following decomposition sequence and morphological evolution of precipitates: ?{sub sss} ? ?? irregular–cuboidal + ?{sub s} ? ?? cuboidal–parallelepiped + ? ? ? plates + ?. In general during the coarsening of ?? precipitates, the experimental coarsening kinetics do not fit well to the LSW or TIDC (n = 2.281) theoretical models, however the activation energies determined using the TIDC and LSW theories (262.846 and 283.6075 kJ mol{sup ?1}, respectively) are consistent with previously reported values. The highest hardness obtained at 823, 923 and 1023 K (550, 650 and 750 °C) is associated with the presence of ?? precipitates. - Highlights: • It was studied the conditional spinodal during early stages of phase decomposition. • It was obtained decomposition sequence and morphological evolution of precipitates. • It was experimentally evaluated the coarsening kinetics of ?? precipitates. • The maximum hardness is associated with the ?? precipitates.

  19. Sequence of Tissue Responses in the Early Stages of Experimental Allergic Encephalomyelitis (EAE): Immunohistochemical, Light Microscopic, and Ultrastructural Observations in the Spinal Cord

    NASA Technical Reports Server (NTRS)

    DAmelio, Fernando E.; Smith, Marion E.; Eng, Lawrence F.

    1990-01-01

    Experimental allergic encephalomyelitis (EAE) was induced in adult Lewis rats with purified guinea pig CNS myelin and Freund's adjuvant. As soon as the very earliest clinical signs appeared the animals were perfused with fixatives and the spinal cord analyzed by electron microscopy, silver methods, and immunocytochemistry. Our findings suggest that in the early stages of EAE a sequence of events can be traced, although these events frequently overlap. The earliest morphological change appears to be astrocytic edema in both the cell body and processes. Increased amounts of glycogen particles and dispersion of glial filaments are prominent. These changes seem to occur just prior to the time when inflammatory cells begin to penetrate the capillary walls. Invasion of the neuropil mainly by macrophages and lymphocytes closely follows. Both macrophages and microglia seem to participate in phagocytosis of oligodendrocytes and myelin. Demyelination, however, is not a prominent feature at this early stage.

  20. Arlequin based PGD domain decomposition

    NASA Astrophysics Data System (ADS)

    Nazeer, S. Mohamed; Bordeu, Felipe; Leygue, Adrien; Chinesta, Francisco

    2014-11-01

    Problems defined in fully or partially separable domains can be solved by considering a space separated representation of the unknown fields. Thus three-dimensional problems can be solved from the solution of some one-dimensional problems in the case of fully separated representations involving the three space coordinates or as a sequence of 2D and 1D problems in the case of partially separated representations (plates, shells or extruded geometries). When the domains become more complex, sometimes they can be simplified by using appropriate mappings. When it is not possible or such a transformation becomes too complex, the use of domain decomposition could facilitate the use of separated representations. However, domain coupling in the context of space separated representations have never been analyzed. In this paper we propose a domain decomposition strategy based on the use of space separated representations and the Arlequin coupling strategy. First we consider separated representations of the physical space that will be then extended to address parametric solutions.

  1. Cumulative funnel plots for the early detection of interoperator variation: retrospective database analysis of observed versus predicted results of percutaneous coronary intervention

    Microsoft Academic Search

    Babu Kunadian; Joel Dunning; Anthony P Roberts; Robert Morley; Darragh Twomey; James A Hall; Andrew G C Sutton; Robert A Wright; Douglas F Muir; Mark A de Belder

    2008-01-01

    Objective To use funnel plots and cumulative funnel plots to compare in-hospital outcome data for operators undertaking percutaneous coronary interventions with predicted results derived from a validated risk score to allow for early detection of variation in performance.Design Analysis of prospectively collected data.Setting Tertiary centre NHS hospital in the north east of England.Participants Five cardiologists carrying out percutaneous coronary interventions

  2. Thermal decomposition kinetics of PBAN-binder and composite solid rocket propellants

    Microsoft Academic Search

    Thorsten Sell; Sergey Vyazovkin; Charles A. Wight

    1999-01-01

    Thermogravimetric analysis at heating rates between 0.5 and 10°C min?1 has been used to study the decomposition kinetics of the PBAN binder and three propellants based on ammonium perchlorate (AP) with PBAN, HTPB, or BAMO-AMMO binders. Thermal runaway was observed for the PBAN and HTPB propellants at heating rates faster than 4.5 and 3°C min?1, respectively. The multistep decomposition kinetics

  3. Evaluating litter decomposition in earth system models with long-term litterbag experiments: an example using the Community Land Model version 4 (CLM4).

    PubMed

    Bonan, Gordon B; Hartman, Melannie D; Parton, William J; Wieder, William R

    2013-03-01

    Decomposition is a large term in the global carbon budget, but models of the earth system that simulate carbon cycle-climate feedbacks are largely untested with respect to litter decomposition. We tested the litter decomposition parameterization of the community land model version 4 (CLM4), the terrestrial component of the community earth system model, with data from the long-term intersite decomposition experiment team (LIDET). The LIDET dataset is a 10-year study of litter decomposition at multiple sites across North America and Central America. We performed 10-year litter decomposition simulations comparable with LIDET for 9 litter types and 20 sites in tundra, grassland, and boreal, conifer, deciduous, and tropical forest biomes using the LIDET-provided climatic decomposition index to constrain temperature and moisture effects on decomposition. We performed additional simulations with DAYCENT, a version of the CENTURY model, to ask how well an established ecosystem model matches the observations. The results show large discrepancy between the laboratory microcosm studies used to parameterize the CLM4 litter decomposition and the LIDET field study. Simulated carbon loss is more rapid than the observations across all sites, and nitrogen immobilization is biased high. Closer agreement with the observations requires much lower decomposition rates, obtained with the assumption that soil mineral nitrogen severely limits decomposition. DAYCENT better replicates the observations, for both carbon mass remaining and nitrogen, independent of nitrogen limitation. CLM4 has low soil carbon in global earth system simulations. These results suggest that this bias arises, in part, from too rapid litter decomposition. More broadly, the terrestrial biogeochemistry of earth system models must be critically tested with observations, and the consequences of particular model choices must be documented. Long-term litter decomposition experiments such as LIDET provide a real-world process-oriented benchmark to evaluate models. PMID:23504851

  4. DECOMPOSITION IN CONIC OPTIMIZATION WITH PARTIALLY SEPARABLE STRUCTURE

    E-print Network

    Vandenberghe, Lieven

    DECOMPOSITION IN CONIC OPTIMIZATION WITH PARTIALLY SEPARABLE STRUCTURE YIFAN SUN, MARTIN S. ANDERSEN, AND LIEVEN VANDENBERGHE Abstract. Decomposition techniques for linear programming are difficult with a chordal sparsity pattern. Here partial separability derives from the clique decomposition theorems

  5. Innovative Methodology Decomposition of Surface EMG Signals

    E-print Network

    De Luca, Carlo J.

    Innovative Methodology Decomposition of Surface EMG Signals Carlo J. De Luca,1,3 Alexander Adam,1, Robert Wotiz, L. Donald Gilmore, and S. Hamid Nawab. Decomposition of surface EMG signals. J Neurophysiol for decomposing surface electromyographic (sEMG) signals into the constituent motor unit (MU) action potential

  6. The Geography of Organic Decomposition Rates

    Microsoft Academic Search

    Vernon Meentemeyer

    1984-01-01

    Decomposition of organic matter is a critical link in the cycling of nutrients through vegetated ecosystems. The primary controls of decay rates are climatic energy and moisture and the chemical-physical nature of the organic matter. A model was developed which uses these controls to predict the geography of decomposition rates for Canada and the United States. Annual actual evapotranspiration (AE)

  7. SPECIAL ISSUE ON TENSOR DECOMPOSITIONS AND APPLICATIONS

    E-print Network

    SPECIAL ISSUE ON TENSOR DECOMPOSITIONS AND APPLICATIONS This issue of SIAM Journal on Matrix in Luminy, France from August 29 to September 2, 2005. The issue was announced through both the SIMAX decompositions. The papers present new algo- rithms, basic algebraic results including the introduction of new

  8. Litter decomposition, climate and liter quality

    Microsoft Academic Search

    Pierre Bottner; Björn Berg

    1995-01-01

    Litter decomposition is controlled by three main factors: climate, litter quality and the nature and abundance of the decomposing organisms. Climate is the dominant factor in areas subjected to unfavourable weather conditions, whereas litter quality largely prevails as the regulator under favourable conditions. Litter quality remains important until the late decomposition stages through its effects on humus formation. Interest in

  9. Digraph decompositions and monotonicity in digraph searching

    E-print Network

    Stephan Kreutzer; Sebastian Ordyniak

    We consider Cops and Robber games on digraphs and their corresponding decompositions. In particular we show non-monotonicity of two important variants of these games, namely the variants underlying DAG- and Kelly-decompositions. Furthermore we explore the limits of the algorithmic applicability of

  10. MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE FRACTALS

    E-print Network

    Edgar, Gerald

    MULTIFRACTAL DECOMPOSITIONS OF DIGRAPH RECURSIVE FRACTALS G. A. Edgar and R. Daniel Mauldin that the multifractal decomposition behaves as expected for a family of sets K known as digraph recursive fractals OF DIGRAPH RECURSIVE FRACTALS 3 of the ball. This might mean that 0 ! lim sup ''#0 ¯ \\Gamma B '' (x) \\Delta

  11. Sampling Stoichiometry: The Decomposition of Hydrogen Peroxide.

    ERIC Educational Resources Information Center

    Clift, Philip A.

    1992-01-01

    Describes a demonstration of the decomposition of hydrogen peroxide to provide an interesting, quantitative illustration of the stoichiometric relationship between the decomposition of hydrogen peroxide and the formation of oxygen gas. This 10-minute demonstration uses ordinary hydrogen peroxide and yeast that can be purchased in a supermarket.…

  12. Modular polynomial arithmetic in partial fraction decomposition

    NASA Technical Reports Server (NTRS)

    Abdali, S. K.; Caviness, B. F.; Pridor, A.

    1977-01-01

    Algorithms for general partial fraction decomposition are obtained by using modular polynomial arithmetic. An algorithm is presented to compute inverses modulo a power of a polynomial in terms of inverses modulo that polynomial. This algorithm is used to make an improvement in the Kung-Tong partial fraction decomposition algorithm.

  13. Numerical Simulations of Aqueous Ozone Decomposition

    Microsoft Academic Search

    K. Chelkowska; D. Grasso; I. Fábián; G. Gordon

    1992-01-01

    The decomposition of ozone in basic aqueous solutions was simulated on the basis of two previously reported detailed mechanisms. According to the calculations, the mechanism given by Tomiyasu, Fukutomi and Gordon is an appropriate model for the ozone decomposition, both in the presence and the absence of hydrogen peroxide and\\/or carbonate ion in basic solution. On the basis of this

  14. A Theoretical Framework for Chimera Domain Decomposition

    E-print Network

    Keeling, Stephen L.

    A Theoretical Framework for Chimera Domain Decomposition S. L. Keeling Sverdrup Technology, Inc. Steger, UC Davis, May 2-4, 1997. 1 Introduction. The Chimera scheme is a domain decomposition method- ometry is divided into simply shaped regions. Unlike other approaches [5], the Chimera method simplifies

  15. Thermal decomposition of potassium dioxodiaquaperoxyoxalatouranate(VI)

    Microsoft Academic Search

    B. B. V Sailaja; Tesfahun Kebede; M. S Prasada Rao

    2003-01-01

    Potassium dioxodiaquaperoxyoxalatouranate(VI) was obtained by reaction of uranyl nitrate with oxalic acid and then hydrogen peroxide in the presence of potassium ion. The complex was subjected to chemical analysis. The thermal decomposition behavior of the complex was studied using TG, DTA and DTG techniques. The solid complex salt and the intermediate product of its thermal decomposition were characterized using IR

  16. Review on Thermal Decomposition of Ammonium Nitrate

    Microsoft Academic Search

    Shalini Chaturvedi; Pragnesh N. Dave

    2013-01-01

    In this review data from the literature on thermal decomposition of ammonium nitrate (AN) and the effect of additives to their thermal decomposition are summarized. The effect of additives like oxides, cations, inorganic acids, organic compounds, phase-stablized CuO, etc., is discussed. The effect of an additive mainly occurs at the exothermic peak of pure AN in a temperature range of

  17. Modeling Northern Peatland Decomposition and Peat

    E-print Network

    Moore, Tim

    Modeling Northern Peatland Decomposition and Peat Accumulation Steve Frolking,1 * Nigel T. Roulet,2´al, Quebec, H3C 3J7, Canada ABSTRACT To test the hypothesis that long-term peat accumula- tion is related to contemporary carbon flux dynamics, we present the Peat Decomposition Model (PDM), a new model of long-term peat

  18. Domain decomposition methods via boundary integral equations

    Microsoft Academic Search

    G. C. Hsiao; O. Steinbach; W. L. Wendland

    2000-01-01

    Domain decomposition methods are designed to deal with coupled or transmission problems for partial differential equations. Since the original boundary value problem is replaced by local problems in substructures, domain decomposition methods are well suited for both parallelization and coupling of different discretization schemes. In general, the coupled problem is reduced to the Schur complement equation on the skeleton of

  19. IRREDUCIBLE ORTHOGONAL DECOMPOSITIONS IN LIE ALGEBRAS

    Microsoft Academic Search

    Fam Khyu Tep

    1991-01-01

    The weakened Winnie-the-Pooh problem on irreducible orthogonal decompositions (IOD's) of a simple finite-dimensional complex Lie algebra (i.e., orthogonal decompositions of whose automorphism group acts on absolutely irreducibly is solved). It is proved that Lie algebras of types ( a prime number, ), , and , have no IOD's. All IOD's of Lie algebras of types ( is a prime number),

  20. Irreducible Orthogonal Decompositions in Lie Algebras

    NASA Astrophysics Data System (ADS)

    Khyu T'ep, Fam

    1991-02-01

    The weakened Winnie-the-Pooh problem on irreducible orthogonal decompositions (IOD's) of a simple finite-dimensional complex Lie algebra \\mathscr{L} (i.e., orthogonal decompositions of \\mathscr{L} whose automorphism group acts on \\mathscr{L} absolutely irreducibly is solved). It is proved that Lie algebras of types A_{p-2} ( p a prime number, p\

  1. Irreducible Orthogonal Decompositions in Lie Algebras

    Microsoft Academic Search

    Fam Khyu T'ep

    1991-01-01

    The weakened Winnie-the-Pooh problem on irreducible orthogonal decompositions (IOD's) of a simple finite-dimensional complex Lie algebra \\\\mathscr{L} (i.e., orthogonal decompositions of \\\\mathscr{L} whose automorphism group acts on \\\\mathscr{L} absolutely irreducibly is solved). It is proved that Lie algebras of types A_{p-2} ( p a prime number, p\\\

  2. Chinese Orthographic Decomposition and Logographic Structure

    ERIC Educational Resources Information Center

    Cheng, Chao-Ming; Lin, Shan-Yuan

    2013-01-01

    "Chinese orthographic decomposition" refers to a sense of uncertainty about the writing of a well-learned Chinese character following a prolonged inspection of the character. This study investigated the decomposition phenomenon in a test situation in which Chinese characters were repeatedly presented in a word context and assessed…

  3. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Products 2 2011-01-01 2011-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  4. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Products 2 2013-01-01 2013-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  5. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Products 2 2014-01-01 2014-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  6. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Products 2 2012-01-01 2012-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  7. English and Turkish Pupils' Understanding of Decomposition

    ERIC Educational Resources Information Center

    Cetin, Gulcan

    2007-01-01

    This study aimed to describe seventh grade English and Turkish students' levels of understanding of decomposition. Data were analyzed descriptively from the students' written responses to four diagnostic questions about decomposition. Results revealed that the English students had considerably higher sound understanding and lower no understanding…

  8. 9 CFR 354.131 - Decomposition.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Products 2 2010-01-01 2010-01-01 false Decomposition. 354.131 Section 354.131 Animals and Animal Products...Disposition of Diseased Rabbit Carcasses and Parts § 354.131 Decomposition. Carcasses of rabbits deleteriously affected by...

  9. Minimum near-convex shape decomposition.

    PubMed

    Ren, Zhou; Yuan, Junsong; Liu, Wenyu

    2013-10-01

    Shape decomposition is a fundamental problem for part-based shape representation. We propose the minimum near-convex decomposition (MNCD) to decompose arbitrary shapes into minimum number of "near-convex" parts. The near-convex shape decomposition is formulated as a discrete optimization problem by minimizing the number of nonintersecting cuts. Two perception rules are imposed as constraints into our objective function to improve the visual naturalness of the decomposition. With the degree of near-convexity a user-specified parameter, our decomposition is robust to local distortions and shape deformation. The optimization can be efficiently solved via binary integer linear programming. Both theoretical analysis and experiment results show that our approach outperforms the state-of-the-art results without introducing redundant parts and thus leads to robust shape representation. PMID:23969396

  10. Multilinear operators for higher-order decompositions.

    SciTech Connect

    Kolda, Tamara Gibson

    2006-04-01

    We propose two new multilinear operators for expressing the matrix compositions that are needed in the Tucker and PARAFAC (CANDECOMP) decompositions. The first operator, which we call the Tucker operator, is shorthand for performing an n-mode matrix multiplication for every mode of a given tensor and can be employed to concisely express the Tucker decomposition. The second operator, which we call the Kruskal operator, is shorthand for the sum of the outer-products of the columns of N matrices and allows a divorce from a matricized representation and a very concise expression of the PARAFAC decomposition. We explore the properties of the Tucker and Kruskal operators independently of the related decompositions. Additionally, we provide a review of the matrix and tensor operations that are frequently used in the context of tensor decompositions.

  11. How spinodal decomposition influences observables at FAIR energies

    NASA Astrophysics Data System (ADS)

    Herold, Christoph; Nahrgang, Marlene; Mishustin, Igor; Bleicher, Marcus

    2014-04-01

    The FAIR facility will make the region of high net-baryon densities experimentally accessible, where a first-order phase transition is conjectured. We investigate the dynamics of chiral symmetry breaking and the onset of confinement during a heavy-ion collision at large baryochemical potentials within a nonequilibrium chiral fluid dynamics model including effects of dissipation and noise. The order parameters are explicitly propagated and coupled to a fluid dynamically expanding medium of quarks. We demonstrate that the coupled system is strongly influenced by the nonequilibrium dynamics, leading only to a weak growth of the correlation length near the critical point. At the first-order phase transition, spinodal instabilities create domains in the order parameters and large spatial fluctuations in the baryon density within single events. As a consequence we find a clear enhancement of higher flow harmonics in coordinate space at the first-order phase transition in comparison with transitions through the crossover or critical point.

  12. Polar decomposition for attitude determination from vector observations

    NASA Astrophysics Data System (ADS)

    Bar-Itzhack, Itzhack Y.

    1992-08-01

    This study focuses on the problem of weighted least squares fitting of a 3D Euclidean-coordinate transformation matrix to a set of unit vectors measured in the reference and transformed coordinates. A closed-form analytic solution to the problem is rederived. The fact that the solution is the nearest orthogonal matrix to some matrix defined on the measured vectors and their weights is shown.

  13. Management intensity alters decomposition via biological pathways

    USGS Publications Warehouse

    Wickings, Kyle; Grandy, A. Stuart; Reed, Sasha; Cleveland, Cory

    2011-01-01

    Current conceptual models predict that changes in plant litter chemistry during decomposition are primarily regulated by both initial litter chemistry and the stage-or extent-of mass loss. Far less is known about how variations in decomposer community structure (e.g., resulting from different ecosystem management types) could influence litter chemistry during decomposition. Given the recent agricultural intensification occurring globally and the importance of litter chemistry in regulating soil organic matter storage, our objectives were to determine the potential effects of agricultural management on plant litter chemistry and decomposition rates, and to investigate possible links between ecosystem management, litter chemistry and decomposition, and decomposer community composition and activity. We measured decomposition rates, changes in litter chemistry, extracellular enzyme activity, microarthropod communities, and bacterial versus fungal relative abundance in replicated conventional-till, no-till, and old field agricultural sites for both corn and grass litter. After one growing season, litter decomposition under conventional-till was 20% greater than in old field communities. However, decomposition rates in no-till were not significantly different from those in old field or conventional-till sites. After decomposition, grass residue in both conventional- and no-till systems was enriched in total polysaccharides relative to initial litter, while grass litter decomposed in old fields was enriched in nitrogen-bearing compounds and lipids. These differences corresponded with differences in decomposer communities, which also exhibited strong responses to both litter and management type. Overall, our results indicate that agricultural intensification can increase litter decomposition rates, alter decomposer communities, and influence litter chemistry in ways that could have important and long-term effects on soil organic matter dynamics. We suggest that future efforts to more accurately predict soil carbon dynamics under different management regimes may need to explicitly consider how changes in litter chemistry during decomposition are influenced by the specific metabolic capabilities of the extant decomposer communities.

  14. Dynamical density functional theory and its application to spinodal decomposition.

    PubMed

    Archer, A J; Evans, R

    2004-09-01

    We present an alternative derivation of the dynamical density functional theory for the one-body density profile of a classical fluid developed by Marconi and Tarazona [J. Chem. Phys. 110, 8032 (1999)]. Our derivation elucidates further some of the physical assumptions inherent in the theory and shows that it is not restricted to fluids composed of particles interacting solely via pair potentials; rather it applies to general, multibody interactions. The starting point for our derivation is the Smoluchowski equation and the theory is therefore one for Brownian particles and as such is applicable to colloidal fluids. In the second part of this paper we use the dynamical density functional theory to derive a theory for spinodal decomposition that is applicable at both early and intermediate times. For early stages of spinodal decomposition our nonlinear theory is equivalent to the (generalized) linear Cahn-Hilliard theory, but for later times it incorporates coupling between different Fourier components of the density fluctuations (modes) and therefore goes beyond Cahn-Hilliard theory. We describe the results of calculations for a model (Yukawa) fluid which show that the coupling leads to the growth of a second maximum in the density fluctuations, at a wave number larger than that of the main peak. PMID:15332972

  15. Tracking the consequences of morpho-orthographic decomposition using ERPs.

    PubMed

    Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J

    2013-09-01

    We examined the effects of morpho-orthographic decomposition on complex word processing using a combination of masked priming and ERP recordings. The process of morpho-orthographic decomposition was primed by the prior presentation of complex non-words (formed by the combination a legal stem and legal affix, e.g. huntity, cornity, scanity) as prime stimuli. Targets were semantically transparent complex words (e.g., hunter), semantically opaque pseudocomplex words (e.g., corner), and simplex words (e.g., scandal) that contained the same stem as primes or a different stem (e.g., huntity-hunter vs. farmity-hunter). We found a large early (150-200 ms) priming effect for transparent complex words only, followed by widely distributed priming effects between 200 and 300 ms and more spatially focused N400 priming effects for all types of target. Furthermore, in the 150-200 ms time-window, the ERP waveforms generated by pseudocomplex words patterned with those of complex words, both of which generated less negative-going waveforms compared with simplex words. In the N400 time-window, on the other hand, complex words differed from both pseudocomplex and simplex words. The results provide further support for early morpho-orthographic segmentation processes that operate independently of semantic transparency, and suggest that the output of these processes only affects the subsequent processing of truly complex words. PMID:23872217

  16. Tracking the Consequences of Morpho-Orthographic Decomposition Using ERPs

    PubMed Central

    Morris, Joanna; Grainger, Jonathan; Holcomb, Phillip J.

    2013-01-01

    We examined the effects of morpho-orthographic decomposition on complex word processing using a combination of masked priming and ERP recordings. The process of morpho-orthographic decomposition was primed by the prior presentation of complex non-words (formed by the combination a legal stem and legal affix, e.g. huntity, cornity, scanity) as prime stimuli. Targets were semantically transparent complex words (e.g. hunter), semantically opaque pseudocomplex words (e.g. corner), and simplex words (e.g. scandal) that contained the same stem as primes or a different stem (e.g., huntity-hunter vs. farmity-hunter). We found a large early (150–200 ms) priming effect for transparent complex words only, followed by widely distributed priming effects between 200 and 300 ms and more spatially focused N400 priming effects for all types of target. Furthermore, in the 150–200 ms time-window, the ERP waveforms generated by pseudocomplex words patterned with those of complex words, both of which generated less negative-going waveforms compared with simplex words. In the N400 time-window, on the other hand, complex words differed from both pseudocomplex and simplex words. The results provide further support for early morpho-orthographic segmentation processes that operate independently of semantic transparency, and suggest that the output of these processes only affects the subsequent processing of truly complex words. PMID:23872217

  17. Decomposition and CO2 Evolution from Standing Litter of the Emergent Macrophyte Erianthus giganteus.

    PubMed

    Kuehn; Gessner; Wetzel; Suberkropp

    1999-07-01

    > Abstract Decomposition of standing litter of the emergent macrophyte Erianthus giganteus (plumegrass) was quantified in a small freshwater wetland in Alabama, USA. Living green shoots of E. giganteus were tagged and periodically retrieved for determination of leaf and culm mass loss, litter-associated fungal biomass (ergosterol), and nitrogen and phosphorus concentrations. Laboratory studies were also conducted to examine the effects of plant litter moisture content and temperature on rates of CO2 evolution from plant litter. Culm and leaf material lost 25 and 32% AFDM, respectively, during plant senescence and early litter decay. Fungal biomass, as determined by ergosterol concentrations, increased significantly in both leaf and culm litter during decomposition, with maximum biomass accounting for 3.7 and 6.7% of the total detrital weight in culm and leaf litter, respectively. Spatial differences in fungal biomass were observed along the culm axis, with upper regions of the culm accumulating significantly greater amounts of fungal mass than basal regions (p < 0.01, ANOVA). Rates of CO2 evolution from both leaf and culm litter increased rapidly after wetting (0 to 76 µg CO2-C g-1 AFDM h-1 within 5 min). In addition, rates of CO2 evolution from water saturated culms increased exponentially as the temperature was increased from 10 to 30 degrees C. These results provide evidence that considerable microbial colonization and mineralization of standing emergent macrophyte litter can occur before collapse of senescent shoot material to the water and sediment surface.http://link.springer-ny.com/link/service/journals/00248/bibs/38n1p50.html PMID:10384009

  18. Amino Acid Free Energy Decomposition

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Fairchild, Michael; Livesay, Dennis; Jacobs, Donald

    2009-03-01

    The Distance Constraint Model (DCM) describes protein thermodynamics at a coarse-grained level based on a Free Energy Decomposition (FED) that assigns energy and entropy contributions to specific molecular interactions. Application of constraint theory accounts for non-additivity in conformational entropy so that the total free energy of a system can be reconstituted from all its molecular parts. In prior work, a minimal DCM utilized a simple FED involving temperature-independent parameters indiscriminately applied to all residues. Here, we describe a residue-specific FED that depends on local conformational states. The FED of an amino acid is constructed by weighting the energy spectrums associated with local energy minimums in configuration space by absolute entropies estimated using a quasi-harmonic approximation. Interesting temperature-dependent behavior is found. Support is from NIH R01 GM073082 and a CRI postdoctoral Duke research fellowship for H. Wang.

  19. Catalytic Decomposition of Organophosphorus Compounds

    NASA Astrophysics Data System (ADS)

    Michalkova, A.; Leszczynski, J.

    Organophosphorus compounds have several applications (agricultural, industrial, and military). Nevertheless, assessments of the hazards from these applications quite often do not take into account chemical processes during their interactions with environment. The management of contaminants requires considerable knowledge and understanding of contaminant behavior. Unique properties of clay minerals and metal oxides, such as high adsorption and catalytic ability, have resulted in their applications as natural adsorbents and catalysts in the development of cleanup technologies. Knowledge of molecular structure, transformation mechanisms, and the spectrum of potential intermediates/products of the contaminant decomposition is helpful for developing remediation processes. An understanding of the physical characteristics of the adsorption sites of selected soil ingredients, the physical and chemical characteristics of the contaminant, details of sorption of contaminants on soil and in water solution, and also their distribution within the environment is of particular interest. Application of computational chemistry (CC) can provide deeper insight into the aforementioned characteristics of organophosphorus compounds.

  20. Wavefront reconstruction by modal decomposition.

    PubMed

    Schulze, Christian; Naidoo, Darryl; Flamm, Daniel; Schmidt, Oliver A; Forbes, Andrew; Duparré, Michael

    2012-08-27

    We propose a new method to determine the wavefront of a laser beam based on modal decomposition by computer-generated holograms. The hologram is encoded with a transmission function suitable for measuring the amplitudes and phases of the modes in real-time. This yields the complete information about the optical field, from which the Poynting vector and the wavefront are deduced. Two different wavefront reconstruction options are outlined: reconstruction from the phase for scalar beams, and reconstruction from the Poynting vector for inhomogeneously polarized beams. Results are compared to Shack-Hartmann measurements that serve as a reference and are shown to reproduce the wavefront and phase with very high fidelity. PMID:23037024

  1. Fibrinogen Level Deteriorates before Other Routine Coagulation Parameters and Massive Transfusion in the Early Phase of Severe Trauma: A Retrospective Observational Study.

    PubMed

    Hayakawa, Mineji; Gando, Satoshi; Ono, Yuichi; Wada, Takeshi; Yanagida, Yuichiro; Sawamura, Atsushi

    2015-02-01

    In trauma, hemostatic functions should be maintained appropriately to prevent massive bleeding. This study elucidated the time-dependent changes in platelet count and coagulation variables, and the effects of disseminated intravascular coagulation (DIC) on these changes during the early phase of trauma. Trauma patients with an injury severity score ?16 were enrolled. The critical levels of platelet count and coagulation variables were defined according to recent trauma guidelines. Massive transfusion was defined as >10 units red cell concentrate. The time from arrival at the emergency department to reaching the critical levels and meeting the criteria for massive transfusion were evaluated. Eighty trauma patients were enrolled; 35 were diagnosed with DIC on arrival. Among all patients, fibrinogen levels reached the critical level earliest among routine coagulation parameters; other routine coagulation parameters deteriorated after the patients met the criteria for massive transfusion. Routine coagulation parameters reached their critical levels earlier in DIC patients than patients without DIC. Massive transfusion was performed more frequently in DIC patients, who met the criteria earlier. During the early phase of trauma, fibrinogen levels deteriorate earlier than other routine coagulation parameters, especially in DIC patients. PMID:25590522

  2. Warming and Nitrogen Addition Increase Litter Decomposition in a Temperate Meadow Ecosystem

    PubMed Central

    Gong, Shiwei; Guo, Rui; Zhang, Tao; Guo, Jixun

    2015-01-01

    Background Litter decomposition greatly influences soil structure, nutrient content and carbon sequestration, but how litter decomposition is affected by climate change is still not well understood. Methodology/Principal Findings A field experiment with increased temperature and nitrogen (N) addition was established in April 2007 to examine the effects of experimental warming, N addition and their interaction on litter decomposition in a temperate meadow steppe in northeastern China. Warming, N addition and warming plus N addition reduced the residual mass of L. chinensis litter by 3.78%, 7.51% and 4.53%, respectively, in 2008 and 2009, and by 4.73%, 24.08% and 16.1%, respectively, in 2010. Warming, N addition and warming plus N addition had no effect on the decomposition of P. communis litter in 2008 or 2009, but reduced the residual litter mass by 5.58%, 15.53% and 5.17%, respectively, in 2010. Warming and N addition reduced the cellulose percentage of L. chinensis and P. communis, specifically in 2010. The lignin percentage of L. chinensis and P. communis was reduced by warming but increased by N addition. The C, N and P contents of L. chinensis and P. communis litter increased with time. Warming and N addition reduced the C content and C:N ratios of L. chinensisand P. communis litter, but increased the N and P contents. Significant interactive effects of warming and N addition on litter decomposition were observed (P<0.01). Conclusion/Significance The litter decomposition rate was highly correlated with soil temperature, soil water content and litter quality. Warming and N addition significantly impacted the litter decomposition rate in the Songnen meadow ecosystem, and the effects of warming and N addition on litter decomposition were also influenced by the quality of litter. These results highlight how climate change could alter grassland ecosystem carbon, nitrogen and phosphorus contents in soil by influencing litter decomposition. PMID:25774776

  3. Moisture can be the dominant environmental parameter governing cadaver decomposition in soil.

    PubMed

    Carter, David O; Yellowlees, David; Tibbett, Mark

    2010-07-15

    Forensic taphonomy involves the use of decomposition to estimate postmortem interval (PMI) or locate clandestine graves. Yet, cadaver decomposition remains poorly understood, particularly following burial in soil. Presently, we do not know how most edaphic and environmental parameters, including soil moisture, influence the breakdown of cadavers following burial and alter the processes that are used to estimate PMI and locate clandestine graves. To address this, we buried juvenile rat (Rattus rattus) cadavers (approximately 18 g wet weight) in three contrasting soils from tropical savanna ecosystems located in Pallarenda (sand), Wambiana (medium clay), or Yabulu (loamy sand), Queensland, Australia. These soils were sieved (2mm), weighed (500 g dry weight), calibrated to a matric potential of -0.01 megapascals (MPa), -0.05 MPa, or -0.3 MPa (wettest to driest) and incubated at 22 degrees C. Measurements of cadaver decomposition included cadaver mass loss, carbon dioxide-carbon (CO(2)-C) evolution, microbial biomass carbon (MBC), protease activity, phosphodiesterase activity, ninhydrin-reactive nitrogen (NRN) and soil pH. Cadaver burial resulted in a significant increase in CO(2)-C evolution, MBC, enzyme activities, NRN and soil pH. Cadaver decomposition in loamy sand and sandy soil was greater at lower matric potentials (wetter soil). However, optimal matric potential for cadaver decomposition in medium clay was exceeded, which resulted in a slower rate of cadaver decomposition in the wettest soil. Slower cadaver decomposition was also observed at high matric potential (-0.3 MPa). Furthermore, wet sandy soil was associated with greater cadaver decomposition than wet fine-textured soil. We conclude that gravesoil moisture content can modify the relationship between temperature and cadaver decomposition and that soil microorganisms can play a significant role in cadaver breakdown. We also conclude that soil NRN is a more reliable indicator of gravesoil than soil pH. PMID:20400249

  4. Pacing Early Mars fluvial activity at Aeolis Dorsa: Implications for Mars 1 Science Laboratory observations at Gale Crater and Aeolis Mons 2

    E-print Network

    Kite, Edwin

    for Mars 1 Science Laboratory observations at Gale Crater and Aeolis Mons 2 3 sedimentary 8 sequences include many buried craters. In combination craters can constrain sedimentation rates. Using the 10 frequency of crater

  5. Symptoms during the Menopausal Transition and Early Postmenopause and their Relation to Endocrine Levels over Time: Observations from the Seattle Midlife Women's Health Study

    E-print Network

    Percival, Don

    Levels over Time: Observations from the Seattle Midlife Women's Health Study Nancy Fugate Woods, RN, Ph in sexual desire1 . In the post Women's Health Initiative era, clinicians and researchers search for new

  6. Ocean Models and Proper Orthogonal Decomposition

    NASA Astrophysics Data System (ADS)

    Salas-de-Leon, D. A.

    2007-05-01

    The increasing computational developments and the better understanding of mathematical and physical systems resulted in an increasing number of ocean models. Long time ago, modelers were like a secret organization and recognize each other by using secret codes and languages that only a select group of people was able to recognize and understand. The access to computational systems was reduced, on one hand equipment and the using time of computers were expensive and restricted, and on the other hand, they required an advance computational languages that not everybody wanted to learn. Now a days most college freshman own a personal computer (PC or laptop), and/or have access to more sophisticated computational systems than those available for research in the early 80's. The resource availability resulted in a mayor access to all kind models. Today computer speed and time and the algorithms does not seem to be a problem, even though some models take days to run in small computational systems. Almost every oceanographic institution has their own model, what is more, in the same institution from one office to the next there are different models for the same phenomena, developed by different research member, the results does not differ substantially since the equations are the same, and the solving algorithms are similar. The algorithms and the grids, constructed with algorithms, can be found in text books and/or over the internet. Every year more sophisticated models are constructed. The Proper Orthogonal Decomposition is a technique that allows the reduction of the number of variables to solve keeping the model properties, for which it can be a very useful tool in diminishing the processes that have to be solved using "small" computational systems, making sophisticated models available for a greater community.

  7. Regarding the Potential Impact of Double Star Observations on Conceptions of the Universe of Stars in the Early 17TH Century

    E-print Network

    Graney, Christopher M

    2008-01-01

    Galileo Galilei believed that stars were distant suns whose sizes measured via his telescope were a direct indication of distance -- fainter stars (appearing smaller in the telescope) being farther away than brighter ones. Galileo argued in his Dialogue that telescopic observation of a chance alignment of a faint (distant) and bright (closer) star would reveal annual parallax, if such double stars were found. This would provide support both for Galileo's ideas concerning the nature of stars and for the motion of the Earth. However, Galileo actually made observations of such double stars, well before publication of the Dialogue. We show that the results of these observations, and the likely results of observations of any double star that was a viable subject for Galileo's telescope, would undermine Galileo's ideas, not support them. We argue that such observations would lead either to the more correct idea that stars were sun-like bodies of varying sizes which could be physically grouped, or to the less correc...

  8. Domain decomposition algorithms and computational fluid dynamics

    NASA Technical Reports Server (NTRS)

    Chan, Tony F.

    1988-01-01

    Some of the new domain decomposition algorithms are applied to two model problems in computational fluid dynamics: the two-dimensional convection-diffusion problem and the incompressible driven cavity flow problem. First, a brief introduction to the various approaches of domain decomposition is given, and a survey of domain decomposition preconditioners for the operator on the interface separating the subdomains is then presented. For the convection-diffusion problem, the effect of the convection term and its discretization on the performance of some of the preconditioners is discussed. For the driven cavity problem, the effectiveness of a class of boundary probe preconditioners is examined.

  9. Stability of the Trotter-Suzuki decomposition

    NASA Astrophysics Data System (ADS)

    Dhand, Ish; Sanders, Barry C.

    2014-07-01

    The Trotter-Suzuki decomposition (TSD) is an important tool for the simulation and control of physical systems. We provide evidence for the stability of the TSD. We model the error in the decomposition and determine sufficiency conditions that guarantee the stability of this decomposition under this model. We relate these sufficiency conditions to precision limitations of computing and control in both classical and quantum cases. Furthermore we show that bounded-error TSD can be achieved by a suitable choice of machine precision.

  10. On a Decomposition Model for Optical Flow

    NASA Astrophysics Data System (ADS)

    Abhau, Jochen; Belhachmi, Zakaria; Scherzer, Otmar

    In this paper we present a variational method for determining cartoon and texture components of the optical flow of a noisy image sequence. The method is realized by reformulating the optical flow problem first as a variational denoising problem for multi-channel data and then by applying decomposition methods. Thanks to the general formulation, several norms can be used for the decomposition. We study a decomposition for the optical flow into bounded variation and oscillating component in greater detail. Numerical examples demonstrate the capabilities of the proposed approach.

  11. Nitrous Oxide Decomposition over Fe-ZSM-5 in the Presence of Nitric Oxide: A Comprehensive DFT Study

    E-print Network

    Bell, Alexis T.

    processes used to produce nitric and adipic acid. Since N2O is the third most important greenhouse gas decomposition. Since these authors did not observe NO inhibition at a feed molar ratio of NO/N2O ) 10

  12. [Early Intervention.

    ERIC Educational Resources Information Center

    Pawl, Jeree, Ed.

    1992-01-01

    This newsletter focuses on the theme of early intervention which infants and young children with special needs in nine brief articles: "Early Intervention: A Matter of Context" (Samuel J. Meisels); "Early Intervention Research: Asking and Answering Meaningful Questions" (Jack P. Shonkoff); "From Case Management to Service Coordination: Families,…

  13. Model and Observational Analysis of the Northeast U.S. Regional Climate and Its Relationship to the PNA and NAO Patterns during Early Winter

    E-print Network

    Wisconsin at Madison, University of

    (Leathers and Palecki 1992). The PNA index reflects the mean pat- tern of the polar jet stream across North, in final form 13 February 2006) ABSTRACT The relationship between the large-scale circulation and regional, precipitation, and atmospheric circulation compare well with observations, despite a cold, dry bias. Ten

  14. MAGIC gamma-ray and multi-frequency observations of flat spectrum radio quasar PKS 1510-089 in early 2012

    NASA Astrophysics Data System (ADS)

    Aleksi?, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Godinovi?, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Hayashida, M.; Herrera, J.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Sun, S.; Suri?, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzi?, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Uellenbeck, M.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.; MAGIC Collaboration; Lucarelli, F.; Pittori, C.; Vercellone, S.; Verrecchia, F.; AGILE Collaboration; Buson, S.; D'Ammando, F.; Stawarz, L.; Giroletti, M.; Orienti, M.; Fermi-LAT Collaboration; Mundell, C.; Steele, I.; Zarpudin, B.; Raiteri, C. M.; Villata, M.; Sandrinelli, A.; Lähteenmäki, A.; Tammi, J.; Tornikoski, M.; Hovatta, T.; Readhead, A. C. S.; Max-Moerbeck, W.; Richards, J. L.; Jorstad, S.; Marscher, A.; Gurwell, M. A.; Larionov, V. M.; Blinov, D. A.; Konstantinova, T. S.; Kopatskaya, E. N.; Larionova, L. V.; Larionova, E. G.; Morozova, D. A.; Troitsky, I. S.; Mokrushina, A. A.; Pavlova, Yu. V.; Chen, W. P.; Lin, H. C.; Panwar, N.; Agudo, I.; Casadio, C.; Gómez, J. L.; Molina, S. N.; Kurtanidze, O. M.; Nikolashvili, M. G.; Kurtanidze, S. O.; Chigladze, R. A.; Acosta-Pulido, J. A.; Carnerero, M. I.; Manilla-Robles, A.; Ovcharov, E.; Bozhilov, V.; Metodieva, I.; Aller, M. F.; Aller, H. D.; Fuhrman, L.; Angelakis, E.; Nestoras, I.; Krichbaum, T. P.; Zensus, J. A.; Ungerechts, H.; Sievers, A.

    2014-09-01

    Aims: Amongst more than fifty blazars detected in very high energy (VHE, E> 100 GeV) ? rays, only three belong to the subclass of flat spectrum radio quasars (FSRQs). The detection of FSRQs in the VHE range is challenging, mainly because of their soft spectra in the GeV-TeV regime. MAGIC observed PKS 1510-089 (z = 0.36) starting 2012 February 3 until April 3 during a high activity state in the high energy (HE, E> 100 MeV) ?-ray band observed by AGILE and Fermi. MAGIC observations result in the detection of a source with significance of 6.0 standard deviations (?). We study the multi-frequency behaviour of the source at the epoch of MAGIC observation, collecting quasi-simultaneous data at radio and optical (GASP-WEBT and F-Gamma collaborations, REM, Steward, Perkins, Liverpool, OVRO, and VLBA telescopes), X-ray (Swift satellite), and HE ?-ray frequencies. Methods: We study the VHE ?-ray emission, together with the multi-frequency light curves, 43 GHz radio maps, and spectral energy distribution (SED) of the source. The quasi-simultaneous multi-frequency SED from the millimetre radio band to VHE ? rays is modelled with a one-zone inverse Compton model. We study two different origins of the seed photons for the inverse Compton scattering, namely the infrared torus and a slow sheath surrounding the jet around the Very Long Baseline Array (VLBA) core. Results: We find that the VHE ?-ray emission detected from PKS 1510-089 in 2012 February-April agrees with the previous VHE observations of the source from 2009 March-April. We find no statistically significant variability during the MAGIC observations on daily, weekly, or monthly time scales, while the other two known VHE FSRQs (3C 279 and PKS 1222+216) have shown daily scale to sub-hour variability. The ?-ray SED combining AGILE, Fermi and MAGIC data joins smoothly and shows no hint of a break. The multi-frequency light curves suggest a common origin for the millimetre radio and HE ?-ray emission, and the HE ?-ray flaring starts when the new component is ejected from the 43 GHz VLBA core and the studied SED models fit the data well. However, the fast HE ?-ray variability requires that within the modelled large emitting region, more compact regions must exist. We suggest that these observed signatures would be most naturally explained by a turbulent plasma flowing at a relativistic speed down the jet and crossing a standing conical shock.

  15. Experimental Shock Decomposition of Siderite to Magnetite

    NASA Technical Reports Server (NTRS)

    Bell, M. S.; Golden, D. C.; Zolensky, M. E.

    2005-01-01

    The debate about fossil life on Mars includes the origin of magnetites of specific sizes and habits in the siderite-rich portions of the carbonate spheres in ALH 84001 [1,2]. Specifically [2] were able to demonstrate that inorganic synthesis of these compositionally zoned spheres from aqueous solutions of variable ion-concentrations is possible. They further demonstrated the formation of magnetite from siderite upon heating at 550 C under a Mars-like CO2-rich atmosphere according to 3FeCO3 = Fe3O4 + 2CO2 + CO [3] and they postulated that the carbonates in ALH 84001 were heated to these temperatures by some shock event. The average shock pressure for ALH 84001, substantially based on the refractive index of diaplectic feldspar glasses [3,4,5] is some 35-40 GPa and associated temperatures are some 300-400 C [4]. However, some of the feldspar is melted [5], requiring local deviations from this average as high as 45-50 GPa. Indeed, [5] observes the carbonates in ALH 84001 to be melted locally, requiring pressures in excess of 60 GPa and temperatures > 600 C. Combining these shock studies with the above inorganic synthesis of zoned carbonates it seems possible to produce the ALH 84001 magnetites by the shock-induced decomposition of siderite.

  16. Comparison of the Decomposition VOC Profile during Winter and Summer in a Moist, Mid-Latitude (Cfb) Climate

    PubMed Central

    Forbes, Shari L.; Perrault, Katelynn A.; Stefanuto, Pierre-Hugues; Nizio, Katie D.; Focant, Jean-François

    2014-01-01

    The investigation of volatile organic compounds (VOCs) associated with decomposition is an emerging field in forensic taphonomy due to their importance in locating human remains using biological detectors such as insects and canines. A consistent decomposition VOC profile has not yet been elucidated due to the intrinsic impact of the environment on the decomposition process in different climatic zones. The study of decomposition VOCs has typically occurred during the warmer months to enable chemical profiling of all decomposition stages. The present study investigated the decomposition VOC profile in air during both warmer and cooler months in a moist, mid-latitude (Cfb) climate as decomposition occurs year-round in this environment. Pig carcasses (Sus scrofa domesticus L.) were placed on a soil surface to decompose naturally and their VOC profile was monitored during the winter and summer months. Corresponding control sites were also monitored to determine the natural VOC profile of the surrounding soil and vegetation. VOC samples were collected onto sorbent tubes and analyzed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC-TOFMS). The summer months were characterized by higher temperatures and solar radiation, greater rainfall accumulation, and comparable humidity when compared to the winter months. The rate of decomposition was faster and the number and abundance of VOCs was proportionally higher in summer. However, a similar trend was observed in winter and summer demonstrating a rapid increase in VOC abundance during active decay with a second increase in abundance occurring later in the decomposition process. Sulfur-containing compounds, alcohols and ketones represented the most abundant classes of compounds in both seasons, although almost all 10 compound classes identified contributed to discriminating the stages of decomposition throughout both seasons. The advantages of GC×GC-TOFMS were demonstrated for detecting and identifying trace levels of VOCs, particularly ethers, which are rarely reported as decomposition VOCs. PMID:25412504

  17. Laparoscopic versus Open Liver Resection: Differences in Intraoperative and Early Postoperative Outcome among Cirrhotic Patients with Hepatocellular Carcinoma—A Retrospective Observational Study

    PubMed Central

    Siniscalchi, Antonio; Tarozzi, Giulia; Cipolat, Lucia; Pinna, Antonio D.; Faenza, Stefano

    2014-01-01

    Introduction. Laparoscopic liver resection is considered risky in cirrhotic patients, even if minor surgical trauma of laparoscopy could be useful to prevent deterioration of a compromised liver function. This study aimed to identify the differences in terms of perioperative complications and early outcome in cirrhotic patients undergoing minor hepatic resection for hepatocellular carcinoma with open or laparoscopic technique. Methods. In this retrospective study, 156 cirrhotic patients undergoing liver resection for hepatocellular carcinoma were divided into two groups according to type of surgical approach: laparoscopy (LS group: 23 patients) or laparotomy (LT group: 133 patients). Perioperative data, mortality, and length of hospital stay were recorded. Results. Groups were matched for type of resection, median number of nodules, and median diameter of largest lesions. Groups were also homogeneous for preoperative liver and renal function tests. Intraoperative haemoglobin decrease and transfusions of red blood cells and fresh frozen plasma were significantly lower in LS group. MELD score lasted stable after laparoscopic resection, while it increased in laparotomic group. Postoperative liver and renal failure and mortality were all lower in LS group. Conclusions. Lower morbidity and mortality, maintenance of liver function, and shorter hospital stay suggest the safety and benefit of laparoscopic approach. PMID:25548432

  18. Some Tools for Event Frequency Decomposition and Heterogeneous Transfer Line Analysis

    E-print Network

    Gershwin, Stanley B.

    that hierarchy. Qualitative observations as well as empirical evaluation of the method is done. The second class that hierarchy. Qualitative observations as well as empirical evaluation of the method is done. The second classSome Tools for Event Frequency Decomposition and Heterogeneous Transfer Line Analysis by Augusto

  19. Decomposition numbers of nite general groups Bhama Srinivasan

    E-print Network

    Srinivasan, Bhama

    Decomposition numbers of #12;nite general groups Bhama Srinivasan University of Illinois at Chicago St.Louis, October 2013 Bhama Srinivasan (University of Illinois at Chicago) Decomposition numbers St at Chicago) Decomposition numbers St.Louis, October 2013 2 / 19 #12;The `-Decomposition Matrix D of Gn

  20. Thermal Decomposition of Benzyl Radical via Multiple Active Pathways

    NASA Astrophysics Data System (ADS)

    Buckingham, Grant; Robichaud, David; Ormond, Thomas; Nimlos, Mark R.; Daily, John W.; Ellison, Barney

    2014-06-01

    The thermal decomposition of benzyl radical (C6H5CH2) has been investigated using a combination infrared absorption spectroscopy in a neon matrix and 118.2 (10.487 eV) photoionization mass spectrometry. Both techniques are coupled with a heated tubular reactor to allow temperature control over the decomposition to indicate relative barrier heights of fragmentation pathways. Three possible chemical mechanisms have been considered. 1) Ring expansion to cycloheptatrienyl radical (C7H7) with subsequent breakdown to HCCH and C5H5, 2) isomerization to the substituted five-membered ring fulvenallene (C5H4=C=CH2), which is of interest to kinetic theorists and finally 3) hydrogen shift to form methyl-substituted phenyl radical, which can then form ortho-benzyne, diacetylene and other fragments. Benzyl radical is generated from two precursors, C6H5CH2CH3 and C6H5CH2Br, and both lead to the appearance of HCCH and C5H5. At slightly hotter temperatures peaks are observed at m/z 90, presumed to be C5H4=C=CH2, and 89, potentially the substituted propargyl C5H4=C=CH. Additionally, decomposition of isotopically substituted parent molecules C6H5CD2CD3 and C6D5CH2CH3 indicates C7H7 as an intermediate due to H/D ratios in fragment molecules.

  1. Unimolecular decomposition of methyltrichlorosilane: RRKM calculations

    SciTech Connect

    Osterheld, T.H.; Allendorf, M.D.; Melius, C.F.

    1993-06-01

    Based on reaction thermochemistry and estimates of Arrhenius A-factors, it is expected that Si-C bond cleavage, C-H bond cleavage, and HCl elimination will be the primary channels for the unimolecular decomposition of methyltrichlorosilane. Using RRKM theory, we calculated rate constants for these three reactions. The calculations support the conclusion that these three reactions are the major decomposition pathways. Rate constants for each reaction were calculated in the high-pressure limit (800--1500 K) and in the falloff regime (1300--1500 K) for bath gases of both helium and hydrogen. These calculations thus provide branching fractions as well as decomposition rates. We also calculated bimolecular rate constants for the overall decomposition in the low-pressure limit. Interesting and surprising kinetic behavior of this system and the individual reactions is discussed. The reactivity of this chlorinated organosilane is compared to that of other organosilanes.

  2. The Eigen-Decomposition: Eigenvalues and Eigenvectors

    E-print Network

    Abdi, Hervé

    called its spectrum. 1 In: Neil Salkind (Ed.) (2007). Encyclopedia of Measurement and Statistics-Decomposition and u2 = -1 1 with eigenvalue 2 = -1 (5) We can verify (as illustrated in Figure 1) that only the length

  3. Polynomial decomposition algorithms in signal processing

    E-print Network

    Su, Guolong, S.M. Massachusetts Institute of Technology

    2013-01-01

    Polynomial decomposition has attracted considerable attention in computational mathematics. In general, the field identifies polynomials f(x) and g(x) such that their composition f(g(x)) equals or approximates a given ...

  4. Science Shorts: Gourd-ous Decomposition

    NSDL National Science Digital Library

    Amy Rubenstein

    2009-09-01

    While pumpkins are an iconic symbol in the classroom that represent fall, harvest time, and Halloween, they are also an ideal subject for teaching elementary students the fundamentals of scientific inquiry and plant decomposition. In a second-grade classr

  5. Interactive simulation of fire, burn and decomposition

    E-print Network

    Melek, Zeki

    2009-05-15

    This work presents an approach to effectively integrate into one unified modular fire simulation framework the major processes related to fire, namely: a burning process, chemical combustion, heat distribution, decomposition and deformation...

  6. Phase Field Method: Spinodal Decomposition Computer Laboratory

    NSDL National Science Digital Library

    García, R. Edwin

    2008-08-25

    In this lab, spinodal decomposition is numerically implemented in FiPy. A simple example python script (spinodal.py) summarizes the concepts. This lab is intended to complement the "Phase Field Method: An Introduction" lecture

  7. Photometric Decomposition of Barred Galaxies

    E-print Network

    A. S. Reese; T. B. Williams; J. A. Sellwood; Eric I. Barnes; Brian A. Powell

    2007-02-27

    We present a non-parametric method for decomposition of the light of disk galaxies into disk, bulge and bar components. We have developed and tested the method on a sample of 68 disk galaxies for which we have acquired I-band photometry. The separation of disk and bar light relies on the single assumption that the bar is a straight feature with a different ellipticity and position angle from that of the projected disk. We here present the basic method, but recognise that it can be significantly refined. We identify bars in only 47% of the more nearly face-on galaxies in our sample. The fraction of light in the bar has a broad range from 1.3% to 40% of the total galaxy light. If low-luminosity galaxies have more dominant halos, and if halos contribute to bar stability, the luminosity functions of barred and unbarred galaxies should differ markedly; while our sample is small, we find only a slight difference of low significance.

  8. Decomposition of methanethiol on Ni(111): a TPD and SSIMS study

    NASA Astrophysics Data System (ADS)

    Castro, M. E.; White, J. M.

    1991-11-01

    The adsorption and decomposition of methanethiol on Ni(111) is studied using temperature-programmed desorption (TPD), static secondary ion mass spectroscopy (SSIMS) and Auger electron spectroscopy (AES). CH 3SH adsorption is mostly molecular at 100 K. Thermal decomposition occurs below 150 K by S-H bond cleavage to form H (a) and CH 3S (a). For low thiol coverages, complete decomposition to desorbing hydrogen and residual sulfur and carbon is observed. At higher coverages, desorption of CH 4, C 2H 6 and H 2 is observed in TPD. 0.25 ML of preadsorbed sulfur inhibits thiol desulfurization and dehydrogenation. A simple mechanism that accounts for the observed results is discussed.

  9. Kinetic modeling of Pt catalyzed and computation-driven catalyst discovery for ethylene glycol decomposition

    SciTech Connect

    Salciccioli, Michael [Univ. of Delaware, Newark, DE (United States); Vlachos, D. G. [Univ. of Delaware, Newark, DE (United States)

    2011-10-07

    Knowledge of the underlying mechanisms controlling oxygenate catalytic decomposition to synthesis gas can lead to the design of better catalysts and reactors, enabling the utilization of biomass feedstock for fuels and chemicals. This work studies the decomposition of ethylene glycol, as a simple surrogate to biomass-derived polyols, through the analysis of two catalytic kinetic models. First, a density functional theory (DFT) and statistical mechanical parametrized model of 81 reversible, elementary-like reactions is used to predict and understand ethylene glycol decomposition on Pt. Reaction path analysis indicates that while the majority of decomposition occurs through initial O–H bond breaking, initial C–H bond breaking is active at temperatures around 500 K. Further, sensitivity analysis shows that early dehydrogenation reactions (specifically HOCH?CH?O* ? HOCH?CHO* + H*) are kinetically important reactions, rather than C–C bond breaking. We show that steady state reactor conditions open up new reaction pathways not seen in surface science (temperature programmed desorption) experiments. The second model, parametrized based on semiempirical linear scaling and linear free energy relationships, consists of 250 reversible, elementary-like reactions and maps the dependence of ethylene glycol decomposition rate and selectivity to various products versus atomic binding energy descriptors. The results show that an optimal catalyst that maximizes the H? production rate should have binding energies of 58, 116, and 145 kcal/mol for atomic hydrogen, oxygen, and carbon, respectively. These models can be used to guide future experimental efforts in developing catalysts for polyol reforming.

  10. Blockwise Uniform Channel Decomposition for MIMO Systems

    Microsoft Academic Search

    Kyoung-jae Lee; Bertrand M. Hochwald; Inkyu Lee

    2007-01-01

    In this paper, we investigate spatial multiplexing schemes for closed-loop multiple-input multiple-output (MIMO) systems. The performance of the singular value decomposition (SVD) scheme is limited by the smallest singular value. When all the subchannels are utilized, uniform channel decomposition (UCD) was recently proposed to obtain a performance gain by making subchannels have equal gains. The UCD requires a successive interference

  11. MODEL REDUCTION USING PROPER ORTHOGONAL DECOMPOSITION

    Microsoft Academic Search

    S. VOLKWEIN

    In this lecture notes an introduction to model reduction utilizing proper orthogonal decomposition (POD) is given. The close connection be- tween POD and singular value decomposition (SVD) of rectangular matrices is emphasized. As an application POD is used to derive a reduced-order model for non-linear initial value problems. The strategy is extended to linear-quadratic optimal control problems governed by ordinary

  12. Nucleon spin decomposition and differential geometry

    NASA Astrophysics Data System (ADS)

    François, J.; Lazzarini, S.; Masson, T.

    2015-02-01

    In the past few years, the so-called Chen et al. approach of the nucleon spin decomposition has been widely discussed and elaborated on. In this article we propose a genuine differential geometric understanding of this approach. We mainly highlight its relation to the "dressing field method" we advocated in Fournel et al. [Int. J. Geom. Methods Mod. Phys. 11, 1450016 (2014)]. The gauge invariance of the Chen et al. decomposition is discussed.

  13. Domain decomposition for the SPN solver MINOS

    SciTech Connect

    Jamelot, Erell; Baudron, Anne-Marie; Lautard, Jean-Jacques [CEA Saclay, DEN DANS DM2S SERMA LLPR, Commissariat Energie Atom et Energies Alternat, F-91191 Gif Sur Yvette, (France)

    2012-07-01

    In this article we present a domain decomposition method for the mixed SPN equations, discretized with Raviart-Thomas-Nedelec finite elements. This domain decomposition is based on the iterative Schwarz algorithm with Robin interface conditions to handle communications. After having described this method, we give details on how to optimize the convergence. Finally, we give some numerical results computed in a realistic 3D domain. The computations are done with the MINOS solver of the APOLLO3 (R) code. (authors)

  14. Moisture drives surface decomposition in thawing tundra

    NASA Astrophysics Data System (ADS)

    Hicks Pries, Caitlin E.; Schuur, E. A. G.; Vogel, Jason G.; Natali, Susan M.

    2013-07-01

    Permafrost thaw can affect decomposition rates by changing environmental conditions and litter quality. As permafrost thaws, soils warm and thermokarst (ground subsidence) features form, causing some areas to become wetter while other areas become drier. We used a common substrate to measure how permafrost thaw affects decomposition rates in the surface soil in a natural permafrost thaw gradient and a warming experiment in Healy, Alaska. Permafrost thaw also changes plant community composition. We decomposed 12 plant litters in a common garden to test how changing plant litter inputs would affect decomposition. We combined species' tissue-specific decomposition rates with species and tissue-level estimates of aboveground net primary productivity to calculate community-weighted decomposition constants at both the thaw gradient and warming experiment. Moisture, specifically growing season precipitation and water table depth, was the most significant driver of decomposition. At the gradient, an increase in growing season precipitation from 200 to 300 mm increased mass loss of the common substrate by 100%. At the warming experiment, a decrease in the depth to the water table from 30 to 15 cm increased mass loss by 100%. At the gradient, community-weighted decomposition was 21% faster in extensive than in minimal thaw, but was similar when moss production was included. Overall, the effect of climate change and permafrost thaw on surface soil decomposition are driven more by precipitation and soil environment than by changes to plant communities. Increasing soil moisture is thereby another mechanism by which permafrost thaw can become a positive feedback to climate change.

  15. Temperature programmed decomposition of uranyl nitrate hexahydrate

    Microsoft Academic Search

    S. Dash; M. Kamruddin; Santanu Bera; P. K. Ajikumar; A. K. Tyagi; S. V. Narasimhan; Baldev Raj

    1999-01-01

    Temperature programmed decomposition (TPD) of uranyl nitrate hexahydrate has been studied using evolved gas analysis mass spectrometry (EGA-MS) in the temperature range 300–1400 K. Thermogravimetric (TGA) investigations were performed in the temperature range 300–1100 K. An attempt has been made to resolve the complexity of decomposition behaviour through suitable comparison of TGA and EGA-MS data. Kinetic control regimes for various

  16. Interactive simulation of fire, burn and decomposition

    E-print Network

    Melek, Zeki

    2008-10-10

    INTERACTIVE SIMULATION OF FIRE, BURN AND DECOMPOSITION A Dissertation by ZEKI MELEK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2007... Major Subject: Computer Science INTERACTIVE SIMULATION OF FIRE, BURN AND DECOMPOSITION A Dissertation by ZEKI MELEK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR...

  17. High temperature decomposition of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2005-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  18. A method for exponential operator decomposition

    E-print Network

    Seckin Sefi; Peter van Loock

    2011-10-18

    Exponential operator decompositions are an important tool in many fields of physics, for example, in quantum control, quantum computation, or condensed matter physics. In this work, we present a method for obtaining such decompositions, which is efficient in terms of the required number of operators. Compared to existing schemes, our more direct approach is general, in the sense that it can be applied to various kinds of operators including nested commutation operators, and it is systematic.

  19. High Temperature Decomposition of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2004-01-01

    Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydropemxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

  20. Multilevel domain decomposition for electronic structure calculations

    Microsoft Academic Search

    M.. Barrault; E.. Cances; W. W.. Hager; C.. Le Bris

    2007-01-01

    We introduce a new multilevel domain decomposition method (MDD) for electronic structure calculations within semi-empirical and density functional theory (DFT) frameworks. This method iterates between local fine solvers and global coarse solvers, in the spirit of domain decomposition methods. Using this approach, calculations have been successfully performed on several linear polymer chains containing up to 40,000 atoms and 200,000 atomic

  1. Decomposition of fluorophosphoryl diazide: a joint experimental and theoretical study.

    PubMed

    Li, Dingqing; Li, Hongmin; Zhu, Bifeng; Zeng, Xiaoqing; Willner, Helge; Beckers, Helmut; Neuhaus, Patrik; Grote, Dirk; Sander, Wolfram

    2015-02-18

    The photolytic and thermal decomposition of fluorophosphoryl diazide, FP(O)(N3)2, was studied using matrix isolation spectroscopy. Upon ArF laser photolysis (? = 193 nm), FPO and a new geminal azido nitrene FP(O)(N3)N were identified using matrix IR spectroscopy. The nitrene shows a triplet ground state with the zero-field parameters |D/hc| = 1.566 cm(-1) and |E/hc| = 0.005 cm(-1). Further decomposition of the nitrene into FPO was observed under an irradiation of ? > 335 nm. In contrast, no nitrene but only FPO was identified after flash vacuum pyrolysis of the diazide. To reveal the decomposition mechanism, quantum chemical calculations on the potential energy surface (PES) of the diazide using DFT methods were performed. On the singlet PES four conformers of the nitrene were predicted. The two conformers (syn and anti) showing intramolecular NnitreneN?,azide interactions are much lower in energy (ca. 40 kJ mol(-1), B3LYP/6-311+G(3df)) than the other two exhibiting NnitreneO interactions. syn/anti refers to the relative orientation of the P[double bond, length as m-dash]O bond and the N3 group. The interconversion of these species and the decomposition into FPO via a novel three-membered ring diazo intermediate cyclo-FP(O)N2 were computationally explored. The calculated low dissociation barrier of 45 kJ mol(-1) (B3LYP/6-311+G(3df)) of this cyclic intermediate rationalizes why it could not be detected in our experiments. PMID:25656843

  2. THE SCHMIDT-KENNICUTT LAW OF MATCHED-AGE STAR-FORMING REGIONS; Pa{alpha} OBSERVATIONS OF THE EARLY-PHASE INTERACTING GALAXY TAFFY I

    SciTech Connect

    Komugi, S. [Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago 763-0355 (Chile); Tateuchi, K.; Motohara, K.; Kato, N.; Konishi, M.; Koshida, S.; Morokuma, T.; Takahashi, H.; Tanabe, T.; Yoshii, Y. [Institute of Astronomy, University of Tokyo, Osawa 2-21-1, Mitaka, Tokyo 181-0015 (Japan); Takagi, T. [Institute of Space and Astronautical Science, JAXA, 3-31-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Iono, D.; Kaneko, H.; Ueda, J. [Nobeyama Radio Observatory, National Astronomical Observatory, 462-2 Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Saitoh, T. R., E-mail: skomugi@alma.cl [Interactive Research Center of Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro 152-0033 (Japan)

    2012-10-01

    In order to test a recent hypothesis that the dispersion in the Schmidt-Kennicutt law arises from variations in the evolutionary stage of star-forming molecular clouds, we compared molecular gas and recent star formation in an early-phase merger galaxy pair, Taffy I (UGC 12915/UGC 12914, VV 254) which went through a direct collision 20 Myr ago and whose star-forming regions are expected to have similar ages. Narrowband Pa{alpha} image is obtained using the ANIR near-infrared camera on the mini-TAO 1 m telescope. The image enables us to derive accurate star formation rates within the galaxy directly. The total star formation rate, 22.2 M{sub Sun} yr{sup -1}, was found to be much higher than previous estimates. Ages of individual star-forming blobs estimated from equivalent widths indicate that most star-forming regions are {approx}7 Myr old, except for a giant H II region at the bridge which is much younger. Comparison between star formation rates and molecular gas masses for the regions with the same age exhibits a surprisingly tight correlation, a slope of unity, and star formation efficiencies comparable to those of starburst galaxies. These results suggest that Taffy I has just evolved into a starburst system after the collision, and the star-forming sites are at a similar stage in their evolution from natal molecular clouds except for the bridge region. The tight Schmidt-Kennicutt law supports the scenario that dispersion in the star formation law is in large part due to differences in evolutionary stage of star-forming regions.

  3. Observational Studies and a Statistical Early Warning of Surface Ozone Pollution in Tangshan, the Largest Heavy Industry City of North China

    PubMed Central

    Li, Pei; Xin, Jinyuan; Bai, Xiaoping; Wang, Yuesi; Wang, Shigong; Liu, Shixi; Feng, Xiaoxin

    2013-01-01

    Continuous measurements of surface ozone (O3) and nitrogen oxides (NOX) at an urban site (39°37?N, 118°09?E) in Tangshan, the largest heavy industry city of North China during summertime from 2008 to 2011 are presented. The pollution of O3 was serious in the city. The daily maximum 1 h means (O3_1-hr max) reached 157 ± 55, 161 ± 54, 120 ± 50, and 178 ± 75 ?g/m3 corresponding to an excess over the standard rates of 21%, 27%, 10%, and 40% in 2008–2011, respectively. The total oxidant level (OX = O3 + NO2) was high, with seasonal average concentrations up to 100 ?g/m3 in summer. The level of OX at a given location was made up of NOX-independent and NOX-dependent contributions. The independent part can be considered as a regional contribution and was about 100 ?g/m3 in Tangshan. Statistical early warning analysis revealed that the O3 levels would exceed the standard rate by 50% on the day following a day when the daily average ozone concentration (O3_mean) exceeded 87 ?g/m3 and the daily maximum temperature (T_max) exceeded 29 °C. The exceed-standard rate would reach 80% when O3_mean and T_max exceeded 113 ?g/m3 and 31 °C. Similarly, the exceed-standard rate would reach 100% when O3_mean and T_max exceeded 127 ?g/m3 and 33 °C, respectively. PMID:23485953

  4. Relationship between skin barrier function in early neonates and diaper dermatitis during the first month of life: a prospective observational study.

    PubMed

    Yonezawa, Kaori; Haruna, Megumi; Shiraishi, Mie; Matsuzaki, Masayo; Sanada, Hiromi

    2014-01-01

    Diaper dermatitis, a common skin problem in newborn infants, is characterized by poor functioning of the skin barrier. This study aimed to elucidate the relationship between skin barrier function in 4-day-old infants and the occurrence of diaper dermatitis during the first month of life. We recruited healthy Japanese infants born at 35 weeks of gestation or more. We measured indicators of skin barrier function, namely skin pH and transepidermal water loss, in 4-day-old infants on four places on the body. Individual characteristics were recorded from the infants' medical charts. The presence of diaper dermatitis was judged using the diaper rash and erythema scoring scale, which was based on daily recording of the infants' skin condition by their parents. The parents also filled out a questionnaire 1 month after birth regarding stool frequency and certain external factors. The association between diaper dermatitis and skin barrier function was assessed using multiple logistic regression analysis. The analysis included 88 infants. The incidence of diaper dermatitis was 25.0%. After adjusting for stool frequency for 1 month we noted that high pH on the inner arm skin in 4-day-old infants increased the risk of diaper dermatitis during the first month of life (adjusted odds ratio 3.35 [95% confidence interval = 1.12, 10.04]). Early neonatal skin pH may predict the risk of diaper dermatitis during the first month of life. Our results may be useful in devising strategies to prevent diaper dermatitis. PMID:25209731

  5. CUR matrix decompositions for improved data analysis

    PubMed Central

    Mahoney, Michael W.; Drineas, Petros

    2009-01-01

    Principal components analysis and, more generally, the Singular Value Decomposition are fundamental data analysis tools that express a data matrix in terms of a sequence of orthogonal or uncorrelated vectors of decreasing importance. Unfortunately, being linear combinations of up to all the data points, these vectors are notoriously difficult to interpret in terms of the data and processes generating the data. In this article, we develop CUR matrix decompositions for improved data analysis. CUR decompositions are low-rank matrix decompositions that are explicitly expressed in terms of a small number of actual columns and/or actual rows of the data matrix. Because they are constructed from actual data elements, CUR decompositions are interpretable by practitioners of the field from which the data are drawn (to the extent that the original data are). We present an algorithm that preferentially chooses columns and rows that exhibit high “statistical leverage” and, thus, in a very precise statistical sense, exert a disproportionately large “influence” on the best low-rank fit of the data matrix. By selecting columns and rows in this manner, we obtain improved relative-error and constant-factor approximation guarantees in worst-case analysis, as opposed to the much coarser additive-error guarantees of prior work. In addition, since the construction involves computing quantities with a natural and widely studied statistical interpretation, we can leverage ideas from diagnostic regression analysis to employ these matrix decompositions for exploratory data analysis. PMID:19139392

  6. Tensor decomposition and vibrational coupled cluster theory.

    PubMed

    Godtliebsen, Ian H; Thomsen, Bo; Christiansen, Ove

    2013-08-15

    The use of tensor decomposition in the calculation of anharmonic vibrational wave functions is discussed. The correlation amplitudes of vibrational coupled cluster (VCC) and vibrational configuration interaction (VCI) theories are considered as tensors and decomposed. A pilot code is implemented allowing a numerical study of the performance of the canonical decomposition/parallel factors (CP) for three and higher mode couplings in computations on water, formaldehyde, and 1,2,5-thiadiazole. The results show that there is a significant perspective in applying tensor decomposition in the context of anharmonic vibrational wave functions, with the CP tensor decomposition providing compression of data and a computational convenient representation. The calculations also illustrate how the multiplicative separability of the VCC ansatz with respect to noninteracting degrees of freedom goes well together with a tensor decomposition approach. Tensor decomposition opens for adjusting the computational effort spent on a particular mode-coupling according to the significance of that particular coupling, which is guaranteed to decrease to zero in the case of VCC in the limit of noninteracting subsystems. PMID:23662994

  7. Understanding litter decomposition in semiarid ecosystems: linking leaf traits, UV exposure and rainfall variability

    PubMed Central

    Gaxiola, Aurora; Armesto, Juan J.

    2015-01-01

    Differences in litter quality, microbial activity or abiotic conditions cannot fully account for the variability in decomposition rates observed in semiarid ecosystems. Here we tested the role of variation in litter quality, water supply, and UV radiation as drivers of litter decomposition in arid lands. And show that carry-over effects of litter photodegradation during dry periods can regulate decomposition during subsequent wet periods. We present data from a two-phase experiment, where we first exposed litter from a drought-deciduous and an evergreen shrub to natural UV levels during five, rainless summer months and, subsequently, in the laboratory, we assessed the carry-over effects of photodegradation on biomass loss under different irrigation treatments representing the observed range of local rainfall variation among years (15–240 mm). Photodegradation of litter in the field produced average carbon losses of 12%, but deciduous Proustia pungens lost >25%, while evergreen Porlieria chilensis less than 5%. Natural exposure to UV significantly reduced carbon-to-nitrogen and lignin:N ratios in Proustia litter but not in Porlieria. During the subsequent wet phase, remaining litter biomass was lower in Proustia than in Porlieria. Indeed UV exposure increased litter decomposition of Proustia under low and medium rainfall treatments, whereas no carry-over effects were detected under high rainfall treatment. Consequently, for deciduous Proustia carry-over effects of UV exposure were negligible under high irrigation. Litter decomposition of the evergreen Porlieria depended solely on levels of rainfall that promote microbial decomposers. Our two-phase experiment revealed that both the carry-over effects of photodegradation and litter quality, modulated by inter-annual variability in rainfall, can explain the marked differences in decomposition rates and the frequent decoupling between rainfall and litter decomposition observed in semiarid ecosystems. PMID:25852705

  8. Sensitivity of soil organic matter decomposition to simultaneous changes in temperature and moisture

    NASA Astrophysics Data System (ADS)

    Sierra, Carlos; Trumbore, Susan; Davidson, Eric; Vicca, Sara; Janssens, Ivan

    2014-05-01

    Soil organic matter decomposition depends on multiple factors that are being altered simultaneously as a result of global environmental change. For this reason it is important to study the overall sensitivity of soil organic matter decomposition with respect to multiple and interacting drivers. Here we present an analysis of the potential response of decomposition rates to simultaneous changes in temperature and moisture. To address this problem, we first present a theoretical framework to study the sensitivity of soil organic matter decomposition when multiple driving factors change simultaneously. We then apply this framework to models and data at different levels of abstraction: 1) to a mechanistic model that addresses the limitation of enzyme activity by simultaneous effects of temperature and soil water content, the latter controlling substrate supply and oxygen concentration for microbial activity; 2) to different mathematical functions used to represent temperature and moisture effects on decomposition in biogeochemical models. To contrast model predictions at these two levels of organization, we compiled different datasets of observed responses in field and laboratory studies. Then we applied our conceptual framework to: 3) observations of soil respiration at the ecosystem level; 4) laboratory experiments looking at the response of heterotrophic respiration to independent changes in moisture and temperature; and 5) ecosystem-level experiments manipulating soil temperature and water content simultaneously. The combined theoretical and empirical evidence reviewed suggests: first, large uncertainties still remain regarding the combined controls of temperature and moisture on decomposition rates, particularly at high temperatures and the extremes of the soil moisture range; second, the highest sensitivities of decomposition rates are likely in systems where temperature and moisture are high such as tropical peatlands, and at temperatures near the freezing point of water such as in soils under freeze-thaw cycles. These regions also exhibit the largest differences in projected changes in decomposition rates among different models. Third, the lowest sensitivity of decomposition rates to changes in temperature and moisture is expected in soils with temperatures well below the freezing point. Uncertainty in models can be reduced if some of the functions representing the effects of temperature and moisture on decomposition can be discredited based on empirical observations or experiments.

  9. Alum treatment of poultry litter: decomposition and nitrogen dynamics.

    PubMed

    Gilmour, J T; Koehler, M A; Cabrera, M L; Szajdak, L; Moore, P A

    2004-01-01

    While the poultry industry is a major economic benefit to several areas in the USA, land application of poultry litter to recycle nutrients can lead to impaired surface and ground water quality. Amending poultry litter with alum [Al3(SO4)2 x 14H2O] has received considerable attention as a method of economically reducing ammonia volatilization in the poultry house and soluble phosphorus in runoff waters. The objective of this study was to characterize the effect of alum on broiler litter decomposition and N dynamics under laboratory conditions. Litter that had been amended with alum in the poultry house after each of the first four of five flock cycles (Experiment I) and litter that had been amended with alum after removal from a poultry house after the third flock cycle (Experiment II) were compared with unamended litter in separate studies. The litters in Experiment I were surface-applied to simulate application to grasslands, while the litters in Experiment II were incorporated to simulate application to conventionally tilled crops. The only statistically significant differences in decomposition due to alum occurred early in Experiment II and the differences were small. The only statistically significant differences in net N mineralization, soil inorganic N, and soil NH4+-N in either experiment was found in Experiment I after 70 d of incubation where soil inorganic N was significantly greater for the alum treatment. Thus, alum had little effect on decomposition or N dynamics. Results of many of the studies on litter not amended with alum should be applicable to litters amended with alum to reduce P availability. PMID:14964397

  10. Mid-Cretaceous charred fossil flowers reveal direct observation of arthropod feeding strategies

    PubMed Central

    Hartkopf-Fröder, Christoph; Rust, Jes; Wappler, Torsten; Friis, Else Marie; Viehofen, Agnes

    2012-01-01

    Although plant–arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role in decomposition. PMID:21900310

  11. The Nonexistence ofa (K6-e)-Decomposition

    E-print Network

    Hartke, Stephen

    The Nonexistence ofa (K6-e)-Decomposition ofthe Complete Graph K29 S. G. Hartke,1 P. R. J. ¨Osterg a (K6 -e)- decomposition of K29. This is the first example of a non-complete graph G for which a G-decomposition; complete graph; graph decomposition; isomorph rejection 1. INTRODUCTION Let G and K be graphs. A G-decomposition

  12. To what extent does the Health Professions Admission Test-Ireland predict performance in early undergraduate tests of communication and clinical skills? – An observational cohort study

    PubMed Central

    2013-01-01

    Background Internationally, tests of general mental ability are used in the selection of medical students. Examples include the Medical College Admission Test, Undergraduate Medicine and Health Sciences Admission Test and the UK Clinical Aptitude Test. The most widely used measure of their efficacy is predictive validity. A new tool, the Health Professions Admission Test- Ireland (HPAT-Ireland), was introduced in 2009. Traditionally, selection to Irish undergraduate medical schools relied on academic achievement. Since 2009, Irish and EU applicants are selected on a combination of their secondary school academic record (measured predominately by the Leaving Certificate Examination) and HPAT-Ireland score. This is the first study to report on the predictive validity of the HPAT-Ireland for early undergraduate assessments of communication and clinical skills. Method Students enrolled at two Irish medical schools in 2009 were followed up for two years. Data collected were gender, HPAT-Ireland total and subsection scores; Leaving Certificate Examination plus HPAT-Ireland combined score, Year 1 Objective Structured Clinical Examination (OSCE) scores (Total score, communication and clinical subtest scores), Year 1 Multiple Choice Questions and Year 2 OSCE and subset scores. We report descriptive statistics, Pearson correlation coefficients and Multiple linear regression models. Results Data were available for 312 students. In Year 1 none of the selection criteria were significantly related to student OSCE performance. The Leaving Certificate Examination and Leaving Certificate plus HPAT-Ireland combined scores correlated with MCQ marks. In Year 2 a series of significant correlations emerged between the HPAT-Ireland and subsections thereof with OSCE Communication Z-scores; OSCE Clinical Z-scores; and Total OSCE Z-scores. However on multiple regression only the relationship between Total OSCE Score and the Total HPAT-Ireland score remained significant; albeit the predictive power was modest. Conclusion We found that none of our selection criteria strongly predict clinical and communication skills. The HPAT- Ireland appears to measures ability in domains different to those assessed by the Leaving Certificate Examination. While some significant associations did emerge in Year 2 between HPAT Ireland and total OSCE scores further evaluation is required to establish if this pattern continues during the senior years of the medical course. PMID:23663266

  13. Individual migration of mesentodermal cells in the early embryo of the squid Loligo vulgaris: in vivo recordings combined with observations with TEM and SEM.

    PubMed

    Segmüller, M; Marthy, H J

    1989-06-01

    In the translucent preorganogenetic embryo of the squid Loligo vulgaris a population of single cells between the ectodermal layer and the yolk syncytium can be studied continuously in vivo during migration to the vegetal hemisphere of the egg. The results from 2 different preparations are reported: 1. An intact embryo served to view locomotive cell behavior through the translucent ectoderm with undisturbed cell-substrate interactions. 2. In an embryo a patch of ectoderm was microsurgically removed thereby exposing migrating cells to direct observation and experimental manipulation. In vivo time lapse microcinematographic recordings for 22 h (in 1.) and 10 h (in 2.) revealed the following: cell migration is neither directional nor dependent on the presence of the ectodermal layer (in 2.). Although the migrating cells primarily use the syncytial surface as a substrate for locomotion, under natural conditions they also adhere to the basal ectodermal surface as revealed by TEM and SEM. Migration rates were 18.3 +/- 12.6 mu/h in 1. Locally directed cell migration was observed in a group of cells in 1. which were involved in a process of aggregation, the latter being probably related to precocious formation of organ primordia. A preliminary note has appeared previously (Segmüller and Marthy, 1984). PMID:2641349

  14. Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters and ROSAT Observations of Bright, Early-Type Galaxies

    NASA Technical Reports Server (NTRS)

    White, Raymond E., III

    1994-01-01

    Preliminary results on the elliptical galaxy NGC 1407 were published in the proceedings of the first ROSAT symposium. NGC 1407 is embedded in diffuse X-ray-emitting gas which is extensive enough that it is likely to be related to the surrounding group of galaxies, rather than just NGC 1407. Spectral data for NGC 1407 (AO2) and IC 1459 (AO3) are also included in a complete sample of elliptical galaxies I compiled in collaboration with David Davis. This allowed us to construct the first complete X-ray sample of optically-selected elliptical galaxies. The complete sample allows us to apply Malmquist bias corrections to the observed correlation between X-ray and optical luminosities. I continue to work on the implications of this first complete X-ray sample of elliptical galaxies. Paul Eskridge Dave Davis and I also analyzed three long ROSAT PSPC observations of the small (but not dwarf) elliptical galaxy M32. We found the X-ray spectra and variability to be consistent with either a Low Mass X-Ray Binary (LMXRB) or a putative 'micro"-AGN.

  15. A preliminary fMRI study of a novel self-paced written fluency task: observation of left-hemispheric activation, and increased frontal activation in late vs. early task phases

    PubMed Central

    Golestanirad, Laleh; Das, Sunit; Schweizer, Tom A.; Graham, Simon J.

    2015-01-01

    Neuropsychological tests of verbal fluency are very widely used to characterize impaired cognitive function. For clinical neuroscience studies and potential medical applications, measuring the brain activity that underlies such tests with functional magnetic resonance imaging (fMRI) is of significant interest—but a challenging proposition because overt speech can cause signal artifacts, which tend to worsen as the duration of speech tasks becomes longer. In a novel approach, we present the group brain activity of 12 subjects who performed a self-paced written version of phonemic fluency using fMRI-compatible tablet technology that recorded responses and provided task-related feedback on a projection screen display, over long-duration task blocks (60 s). As predicted, we observed robust activation in the left anterior inferior and medial frontal gyri, consistent with previously reported results of verbal fluency tasks which established the role of these areas in strategic word retrieval. In addition, the number of words produced in the late phase (last 30 s) of written phonemic fluency was significantly less (p < 0.05) than the number produced in the early phase (first 30 s). Activation during the late phase vs. the early phase was also assessed from the first 20 s and last 20 s of task performance, which eliminated the possibility that the sluggish hemodynamic response from the early phase would affect the activation estimates of the late phase. The last 20 s produced greater activation maps covering extended areas in bilateral precuneus, cuneus, middle temporal gyrus, insula, middle frontal gyrus and cingulate gyrus. Among these areas, greater activation was observed in the bilateral middle frontal gyrus (Brodmann area BA 9) and cingulate gyrus (BA 24, 32) likely as part of the initiation, maintenance, and shifting of attentional resources. Consistent with previous pertinent fMRI literature involving overt and covert verbal responses, these findings highlight the promise and practicality of fMRI of written phonemic fluency. PMID:25805984

  16. Signal Decomposition for Nonstationary Processes

    NASA Astrophysics Data System (ADS)

    Xie, Min

    1995-01-01

    The main purpose of this dissertation is to explore and develop better signal modeling (decomposition) methods for nonstationary and/or nonlinear dynamic processes. Localization is the main focus. The characteristics of a nonstationary or nonlinear signal are decomposed onto a set of basis functions, either in the phase space spanned by time-frequency coordinates as Gabor proposed, or in the phase space spanned by a set of derivatives of different degree as defined in physics. To deal with time-varying signals, a Multiresolution Parametric Spectral Estimator (MPSE) is proposed together with its theory, techniques and applications. The resolution study provides the characteristics of windowed Fourier transforms, wavelet transforms, fixed resolution parametric spectral estimators, and the newly developed MPSE. Both the theoretical and the experimental results show that, of the above techniques, MPSE is the best in resolution. Furthermore, with proper a priori knowledge, MPSE can yield better resolution than the lower bound defined by the Heisenberg uncertainty principle. The application examples demonstrate the great potential of the MPSE method for tracking and analyzing time-varying processes. To deal with the time-varying characteristics caused by linearization of nonlinear processes, the Radial Basis Function Network (RBFN) is proposed for modeling nonlinear processes from a 'local' to a 'global' level. An equal distance sample rule is proposed for constructing the RBFN. Experiments indicate that the RBFN is a promising method for modeling deterministic chaos as well as stochastic processes, be it linear or nonlinear. The 'local' to 'global' approach of the RBFN also provides great potential for structure adaptation and knowledge accumulation.

  17. The participation of the ADMIRARI radiometer to the GPM/GV CHUVA Brazilian campaign, tropical precipitating warm clouds observations and early results

    NASA Astrophysics Data System (ADS)

    Saavedra, Pablo; Battaglia, Alessandro; Simmer, Clemens

    2010-05-01

    With the launch of the Global Precipitation Mission core satellite expected for 2013, NASA is planning and pursuing an intense ground validation program with campaigns all over the world (Brazil 2010, Finland 2010, Oklahoma 2011, Canada winter campaign 2011-2012) focused on physical validation of microwave-based rainfall algorithms. The ADvanced MIcrowave RAdiometer for Rain Identification (ADMIRARI) exploits its multi-frequency (10.7-21.0-36.5 GHz) polarimetric (H and V channel) capabilities to partition simultaneously rain and cloud water, thereby addressing an open key issue for improving precipitation estimates. This potentiality has already been extensively demonstrated during the field campaigns COPS over Southern Germany and EUCAARI in the Netherlands. During CHUVA (Cloud processes of tHe main precipitation systems in Brazil: A contribUtion to cloud resolVing modeling and to the GlobAl Precipitation Measurement ) ADMIRARI measures together with numerous ancillary instruments co-located at Alcântara observatory in Northern Brazil (e.g. microwave radiometer profiler, polarimetric X-band radar, disdrometers, micro rain radar, lidar, etc.). These measurements are intended to study warm rain convective systems and to create and validate a 3-D cloud processes database for such precipitation regimes. The operational ADMIRARI retrievals will contribute to the GPM effort in the following areas: 1) Identification of the microphysical cloud properties at the onset of precipitation in warm rain processes; 2) Improved understanding of bright band effects in radiative transfer models for microwave radiometry; 3) Characterization of the microphysical and electromagnetic/radiative properties of ice and mixed-phase precipitating clouds; 4) Partitioning of total liquid water content into cloud and precipitation (rain or snow) water equivalents for different climatological regimes including the validation of cloud resolving and weather forecast models to this respect. Until now, climatological rain/cloud partitioning statistics represent the major outcome of ADMIRARI measurements and will be presented for different climatological regimes. Moreover, ADMIRARI measurements from the CHUVA campaign and preliminary results regarding the observed cloud/rain partition will be shown, and a first assessment on the retrieval performance for an atmospheric regime not yet observed by ADMIRARI. We hope that these first results will lead to feedback from the GPM international community in order to improve and re-arrange the observational strategies in future GPM/GV field campaign where ADMIRARI is scheduled to take part.

  18. An observational study of bimatoprost 0.01% in patients on prior intraocular pressure-lowering therapy: the Canadian Lumigan® RC Early Analysis Review (CLEAR) trial

    PubMed Central

    Crichton, Andrew C; Nixon, Donald R; Simonyi, Susan; Bhogal, Meetu; Sigouin, Christopher S; Discepola, Marino J; Hutnik, Cindy ML; Baptiste, Darryl C; Yan, David B

    2014-01-01

    Purpose To evaluate the ocular hyperemia and intraocular pressure (IOP)-lowering efficacy of bimatoprost 0.01% in subjects with elevated IOP due to primary open-angle glaucoma (POAG) or ocular hypertension (OHT) in a real-world clinical setting. Subjects and methods This open-label, 12-week, observational study was conducted at 67 centers in Canada. Subjects with elevated IOP due to POAG or OHT instilled bimatoprost 0.01% as monotherapy once daily. Ocular hyperemia was graded by the investigator at baseline, week 6, and week 12 using a standardized photographic 5-point grading scale. Change in IOP from baseline was also evaluated at these time points. This analysis includes the subgroup of 268 subjects who had been previously treated with latanoprost 0.005%, bimatoprost 0.03%, travoprost 0.004%, and travoprost 0.004% with SofZia™ or nonselective beta-adrenergic receptor blockers prior to the study. Results After 12 weeks of treatment with 0.01% bimatoprost, ocular hyperemia was graded as none-to-mild hyperemia (grades 0, +0.5, or +1) for 94.1% of subjects and as moderate-to-severe hyperemia (grades +2 or +3) for 5.9%. No statistically significant shifts in ocular hyperemia ratings were observed at week 12 for any of the prior IOP-lowering therapies except bimatoprost 0.03%, in which 20.8% of subjects experienced an improvement. The mean percentage change from baseline IOP at week 12 following the switch to bimatoprost 0.01% monotherapy ranged from ?2.3%±17.3% to ?26.3%±12.4%. Furthermore, the decreased mean percentage change from baseline IOP was statistically significant across all prior IOP-lowering medications, except for bimatoprost 0.03% at the 6- and 12-week visits and travoprost 0.004% at the 6-week visit. Conclusion This observational study demonstrates that bimatoprost 0.01% was well tolerated among POAG and OHT subjects who switched from prior IOP-lowering medication. Furthermore, a switch in ocular hypertensive treatment to bimatoprost 0.01% was associated with an additional 10%–15% reduction in IOP. PMID:24920879

  19. Decomposition of diazomeldrum's acid: a threshold photoelectron spectroscopy study.

    PubMed

    Lang, Melanie; Holzmeier, Fabian; Fischer, Ingo; Hemberger, Patrick

    2014-11-26

    Derivatives of meldrum's acid are known precursors for a number of reactive intermediates. Therefore, we investigate diazomeldrum's acid (DMA) and its pyrolysis products by photoionization using vacuum ultraviolet (VUV) synchrotron radiation. The threshold photoelectron spectrum of DMA yields an ionization energy (IE) of 9.68 eV. Several channels for dissociative photoionization are observed. The first one is associated with loss of CH3, leading to a daughter ion with m/z = 155. Its appearance energy AE0K was determined to be 10.65 eV by fitting the experimental data using statistical theory. A second parallel channel leads to m/z = 69, corresponding to N2CHCO, with an AE0K of 10.72 eV. Several other channels open up at higher energy, among them the formation of acetone cation, a channel expected to be the result of a Wolff-rearrangement (WR) in the cation. When diazomeldrum's acid is heated in a pyrolysis reactor, three thermal decomposition pathways are observed. The major one is well-known and yields acetone, N2 and CO as consequence of the WR. However, two further channels were identified: The formation of 2-diazoethenone, NNCCO, together with acetone and CO2 as the second channel and E-formylketene (OCCHCHCO), propyne, N2 and O2 as a third one. 2-Diazoethenone and E-formylketene were identified based on their threshold photoelectron spectra and accurate ionization energies could be determined. Ionization energies for several isomers of both molecules were also computed. One of the key findings of this study is that acetone is observed upon decomposition of DMA in the neutral as well as in the ion and both point to a Wolff rearrangement to occur. However, the ion is subject to other decomposition channels favored at lower internal energies. PMID:25369422

  20. Decomposition of forest products buried in landfills

    SciTech Connect

    Wang, Xiaoming, E-mail: xwang25@ncsu.edu [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Padgett, Jennifer M. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States); Powell, John S. [Department of Chemical and Biomolecular Engineering, Campus Box 7905, North Carolina State University, Raleigh, NC 27695-7905 (United States); Barlaz, Morton A. [Department of Civil, Construction, and Environmental Engineering, Campus Box 7908, North Carolina State University, Raleigh, NC 27695-7908 (United States)

    2013-11-15

    Highlights: • This study tracked chemical changes of wood and paper in landfills. • A decomposition index was developed to quantify carbohydrate biodegradation. • Newsprint biodegradation as measured here is greater than previous reports. • The field results correlate well with previous laboratory measurements. - Abstract: The objective of this study was to investigate the decomposition of selected wood and paper products in landfills. The decomposition of these products under anaerobic landfill conditions results in the generation of biogenic carbon dioxide and methane, while the un-decomposed portion represents a biogenic carbon sink. Information on the decomposition of these municipal waste components is used to estimate national methane emissions inventories, for attribution of carbon storage credits, and to assess the life-cycle greenhouse gas impacts of wood and paper products. Hardwood (HW), softwood (SW), plywood (PW), oriented strand board (OSB), particleboard (PB), medium-density fiberboard (MDF), newsprint (NP), corrugated container (CC) and copy paper (CP) were buried in landfills operated with leachate recirculation, and were excavated after approximately 1.5 and 2.5 yr. Samples were analyzed for cellulose (C), hemicellulose (H), lignin (L), volatile solids (VS), and organic carbon (OC). A holocellulose decomposition index (HOD) and carbon storage factor (CSF) were calculated to evaluate the extent of solids decomposition and carbon storage. Samples of OSB made from HW exhibited cellulose plus hemicellulose (C + H) loss of up to 38%, while loss for the other wood types was 0–10% in most samples. The C + H loss was up to 81%, 95% and 96% for NP, CP and CC, respectively. The CSFs for wood and paper samples ranged from 0.34 to 0.47 and 0.02 to 0.27 g OC g{sup ?1} dry material, respectively. These results, in general, correlated well with an earlier laboratory-scale study, though NP and CC decomposition measured in this study were higher than previously reported.